JP7347829B2 - optical element - Google Patents

Description

The present invention relates to optical elements.

Patent Document 1 describes a polymer-dispersed liquid crystal structure in the form of a film. The polymer-dispersed liquid crystal structure includes a polymer and a plurality of droplets. Multiple droplets are dispersed within the polymer.

The polymer-dispersed liquid crystal structure exhibits strong light scattering properties in the zero electric field/OFF state. A certain ray L1 enters the film perpendicular to the film surface, but is refracted at the boundary between domains in the droplet. The light ray L1 exits the membrane at a large angle to the normal. Another ray L2 is incident at about 30° from the surface normal, but is effectively internally reflected and exits from the same surface from which it entered. Yet another ray L3 enters the membrane at an acute angle and is scattered to exit at several widely different angles.

Specifically, in a zero electric field/OFF state, cholesteric liquid crystal molecules contained in a droplet are oriented in a helical structure. Regions with a helical structure whose helical axes are parallel to each other and have the same refractive index are called domains. A droplet has many domains. At the boundary of each domain, the refractive indexes of adjacent domains do not match, and the greater the degree of mismatch in the refractive indexes resulting from the mutual deviation of the helical axes and the birefringence of the liquid crystal, the more strongly light is refracted. The helical axes of the multiple helical structures within the droplet are not parallel. Therefore, each helical structure belongs to a different domain in the droplet. Maximize zero field/OFF state opacity by maximizing the number of domains and domain separation stabilized within the droplet.

On the other hand, the polymer-dispersed liquid crystal structure exhibits a property of becoming clear/transparent to visible light wavelengths in an ON state with an electric field of appropriate strength (50 V). When viewed in a direction approximately perpendicular to the substrate surface, some light rays L4 are transmitted, so the display has little blur or a transparency close to that of glass. As the viewing angle increases relative to the normal, the amount of blur increases slightly based on the drop volume and the level of liquid crystal birefringence.

Specifically, when an electric field of appropriate strength (50 V) is turned on, the cholesteric liquid crystal contained in the droplet unwinds its spiral, the domains disappear, and the liquid crystal molecules are aligned parallel to the electric field. Therefore, in each droplet, the liquid crystals have a homeotropic orientation and are highly ordered. As a result, transparency becomes high.

Special Publication No. 2010-531468

However, in the polymer-dispersed liquid crystal structure described in Patent Document 1, the optical properties of the polymer-dispersed liquid crystal structure are controlled by uncoiling the cholesteric liquid crystal using a strong electric field. Therefore, relatively large driving voltages (stimulation) are required to control the optical properties of polymer-dispersed liquid crystal structures.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical element whose optical characteristics can be controlled by a relatively small stimulus from the outside.

According to one aspect of the present invention, an optical element includes a first substrate, a second substrate, a liquid crystal layer, and a liquid crystal structure. A liquid crystal layer is disposed between the first substrate and the second substrate and includes a first liquid crystal. A liquid crystal structure is disposed within the liquid crystal layer and includes a second liquid crystal. The liquid crystal layer has a first region facing the first substrate and a second region facing the second substrate. The liquid crystal structure has a first surface region that determines the orientation of the second liquid crystal, and a second surface region that faces the first surface region. At least one of the first condition and the second condition is satisfied. The first condition is that when no external stimulation is applied to the liquid crystal layer, the orientation of liquid crystal molecules in the first region is different from the orientation of liquid crystal molecules in the second region. The second condition is that when the stimulus is not applied to the liquid crystal layer, the orientation of liquid crystal molecules in the first surface region is different from the orientation of liquid crystal molecules in the second surface region. In response to a change in the orientation of the first liquid crystal based on the stimulus to the liquid crystal layer, the liquid crystal structure changes its posture while maintaining the orientation of the second liquid crystal. The liquid crystal structure reflects light depending on the orientation, or absorbs light depending on the orientation.

In the optical element of the present invention, when the stimulus is not applied to the liquid crystal layer, alignment deformation of the first liquid crystal of the liquid crystal layer causes torsional deformation between the first substrate and the second substrate. It is preferable that it is shown.

In the optical element of the present invention, when the stimulus is not applied to the liquid crystal layer, alignment deformation of the first liquid crystal in the liquid crystal layer spreads and bends between the first substrate and the second substrate. Preferably, it shows deformation.

In the optical element of the present invention, when the stimulus is not applied to the liquid crystal layer, the orientation of the first liquid crystal of the liquid crystal layer is vertical with pretilt between the first substrate and the second substrate. Preferably, it exhibits a twisted orientation.

In the optical element of the present invention, it is preferable that when the stimulus is not applied to the liquid crystal layer, the liquid crystal structure assumes a first posture depending on the orientation of the first liquid crystal. When the stimulus is applied to the liquid crystal layer, it is preferable that the liquid crystal structure assumes a second attitude different from the first attitude according to a change in orientation of the first liquid crystal. When the liquid crystal structure takes one of the first attitude and the second attitude, it is preferable that the liquid crystal structure reflects light. When the liquid crystal structure takes the other of the first attitude and the second attitude, it is preferable that the liquid crystal structure transmits the light.

In the optical element of the present invention, it is preferable that the liquid crystal structure changes its posture according to the magnitude of the stimulus applied to the liquid crystal layer, and changes the direction of light reflection according to the change in the posture. .

In the optical element of the present invention, it is preferable that the second liquid crystal of the liquid crystal structure has a plurality of helical structures each having selective reflection properties. Preferably, each of the plurality of helical structures includes a plurality of liquid crystal molecules. Preferably, in each of the plurality of helical structures, the plurality of liquid crystal molecules are spirally rotated. It is preferable that the helical axes of the plurality of helical structures are aligned in a certain direction.

In the optical element of the present invention, it is preferable that when the stimulus is not applied to the liquid crystal layer, the liquid crystal structure assumes a first posture depending on the orientation of the first liquid crystal. When the stimulus is applied to the liquid crystal layer, it is preferable that the liquid crystal structure assumes a second attitude different from the first attitude according to a change in orientation of the first liquid crystal. When the liquid crystal structure takes one of the first attitude and the second attitude, it is preferable that the liquid crystal structure absorbs light. When the liquid crystal structure takes the other of the first attitude and the second attitude, it is preferable that the liquid crystal structure transmits the light.

In the optical element of the present invention, it is preferable that the liquid crystal structure changes its posture in accordance with the magnitude of the stimulus applied to the liquid crystal layer, and changes the light absorption rate in accordance with the change in the posture. .

In the optical element of the present invention, the liquid crystal structure preferably contains a dichroic dye. Preferably, the second liquid crystal of the liquid crystal structure exhibits planar alignment and uniaxial alignment.

Preferably, the optical element of the present invention further includes an electrode pattern. It is preferable that the electrode pattern individually applies the driving voltage as the stimulus to a plurality of locations on the liquid crystal layer. It is preferable that the liquid crystal structure changes its posture by rotating around a first axis and/or a second axis in response to application of the driving voltage to the liquid crystal layer by the electrode pattern.

In the optical element of the present invention, it is preferable that the plurality of liquid crystal molecules in the first region have different orientations. Preferably, the orientations of the plurality of liquid crystal molecules in the second region are different. When the stimulus is applied to the liquid crystal layer, a plurality of It is preferable that the postures of the liquid crystal structures change individually.

According to the present invention, it is possible to provide an optical element whose optical characteristics can be controlled by a relatively small stimulus from the outside.

1 is a schematic cross-sectional view showing an optical system according to an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view showing an optical element according to an embodiment of the present invention. (a) is a diagram showing a first condition of an optical element according to an embodiment of the present invention. (b) is a diagram showing the second condition of the optical element according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a state of the optical element according to Embodiment 1 of the present invention when no driving voltage is applied to the optical element. FIG. 3 is a schematic cross-sectional view showing the state of the optical element when a driving voltage having a first voltage value is applied to the optical element according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing the state of the optical element according to Embodiment 1 when a driving voltage having a second voltage value is applied to the optical element. (a) is a schematic cross-sectional view showing a state of an optical element according to a comparative example when no driving voltage is applied to the optical element. (b) is a schematic cross-sectional view showing another state of the optical element according to the comparative example when no driving voltage is applied to the optical element. (a) is a schematic cross-sectional view showing a state of an optical element according to a comparative example when a driving voltage having a first voltage value is applied to the optical element. (b) is a diagram showing another state of the optical element when a driving voltage having the first voltage value is applied to the optical element according to the comparative example. FIG. 7 is a schematic cross-sectional view showing a state of the optical element according to Embodiment 2 of the present invention when no driving voltage is applied to the optical element. 7 is a schematic cross-sectional view showing the state of the optical element when a driving voltage is applied to the optical element according to Embodiment 2. FIG. FIG. 7 is a schematic cross-sectional view showing a state of an optical element according to Embodiment 3 of the present invention when no driving voltage is applied to the optical element. 7 is a schematic cross-sectional view showing the state of the optical element when a driving voltage is applied to the optical element according to Embodiment 3. FIG. FIG. 7 is a schematic cross-sectional view showing a liquid crystal structure of an optical element according to Embodiment 4 of the present invention. FIG. 7 is a perspective view showing an optical element according to Embodiment 5 of the present invention. FIG. 7 is a plan view showing an optical system according to Embodiment 5. FIG. 7 is a plan view showing an optical system according to a modification of the fifth embodiment. FIG. 7 is a perspective view showing an optical element according to Embodiment 6 of the present invention. FIG. 7 is a plan view showing an optical system according to a sixth embodiment. FIG. 7 is a plan view showing an optical system according to a modification of the sixth embodiment. 5 is a graph showing the relationship between the driving voltage of the optical element and the rotation angle of the liquid crystal structure according to an example of the present invention. 3 is a graph showing the relationship between the light transmittance and drive voltage of the optical element according to the present example. (a) is a graph showing the reflected light intensity of an optical element according to a comparative example. (b) is a graph showing the reflected light intensity of the optical element according to the present example.

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are given the same reference numerals and the description will not be repeated. Further, in order to facilitate understanding of the invention, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other may be illustrated in the drawings. The X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. However, the description in the drawings does not limit the usage conditions of the optical element of the present invention.

First, an optical system 300 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view showing an optical system 300 according to this embodiment. As shown in FIG. 1, the optical system 300 includes an optical element 100 and a stimulation section 200. Optical element 100 includes a first substrate 1 , a second substrate 2 , a liquid crystal layer 3 , and a plurality of liquid crystal structures 5 . Note that the optical element 100 may include a single liquid crystal structure 5.

The first substrate 1 and the second substrate 2 are arranged substantially parallel to each other. Each of the first substrate 1 and the second substrate 2 includes an alignment film (not shown) and is transparent. "Transparent" may also be translucent.

The liquid crystal layer 3 includes a liquid crystal (hereinafter referred to as "first liquid crystal FL"). The first liquid crystal FL includes a plurality of liquid crystal molecules. The liquid crystal layer 3 transmits light. The liquid crystal layer 3 is arranged between the first substrate 1 and the second substrate 2.

Each of the plurality of liquid crystal structures 5 includes a liquid crystal (hereinafter referred to as "second liquid crystal SL"). The second liquid crystal SL includes a plurality of liquid crystal molecules. Each of the plurality of liquid crystal structures 5 reflects light depending on the attitude of the liquid crystal structure 5. Alternatively, each of the plurality of liquid crystal structures 5 absorbs light depending on the attitude of the liquid crystal structure 5. Further, each of the plurality of liquid crystal structures 5 transmits light depending on the attitude of the liquid crystal structure 5.

A plurality of liquid crystal structures 5 are arranged in the liquid crystal layer 3. Specifically, the plurality of liquid crystal structures 5 are arranged along the first substrate 1 in the liquid crystal layer 3. A plurality of liquid crystal structures 5 are floating in the liquid crystal layer 3. The liquid crystal structure 5 is subjected to an elastic driving force such that it is placed in the center of the liquid crystal layer 3 in the vertical direction Dv in order to minimize the alignment deformation of the liquid crystal layer 3. Therefore, the position of the liquid crystal structure 5 in the vertical direction Dv in the liquid crystal layer 3 is determined by the balance between the elastic driving force and gravity. Therefore, the density of the liquid crystal structure 5 has a value such that the liquid crystal structure 5 does not settle on the surface of the second substrate 2 due to gravity. For example, the density of the liquid crystal structure 5 is smaller than the density of the liquid crystal layer 3. However, as long as the elastic driving force and gravity are balanced and the liquid crystal structure 5 floats in the liquid crystal layer 3, the density of the liquid crystal structure 5 may be greater than the density of the liquid crystal layer 3. The vertical direction Dv indicates a direction substantially perpendicular to the first substrate 1. In the first embodiment, the plurality of liquid crystal structures 5 are arranged at intervals.

Note that the plurality of liquid crystal structures 5 may be arranged along the first substrate 1 in the liquid crystal layer 3 while being in contact with each other or overlapping each other. In this case, the plurality of liquid crystal structures 5 arranged along the first substrate 1 can also be regarded as "one liquid crystal structure".

Further, the plurality of liquid crystal structures 5 may be arranged in the liquid crystal layer 3 along the vertical direction Dv. In this case, the plurality of liquid crystal structures 5 arranged along the vertical direction Dv can also be regarded as "one liquid crystal structure".

When considering a plurality of liquid crystal structures 5 arranged along the vertical direction Dv as "one liquid crystal structure", the first surface area B1 under the second condition (FIG. 3(b)) described later is in the vertical direction Dv. The first surface region B1 of the liquid crystal structure 5 closest to the first substrate 1 among the plurality of liquid crystal structures 5 arranged along the is shown. Further, the second surface region B2 under the second condition indicates the second surface region B2 of the liquid crystal structure 5 closest to the second substrate 2 among the plurality of liquid crystal structures 5 arranged along the vertical direction Dv. .

Note that the plurality of liquid crystal structures 5 arranged along the vertical direction Dv may be a plurality of liquid crystal structures 5 stacked along the vertical direction Dv, or may be arranged in series along the vertical direction Dv. A plurality of liquid crystal structures 5 may be formed.

Further, the plurality of liquid crystal structures 5 may be arranged in the liquid crystal layer 3 along the first substrate 1 while being in contact with each other or overlapping each other, and may be arranged along the vertical direction Dv. In this case, the plurality of liquid crystal structures 5 arranged along the first substrate 1 and along the vertical direction Dv can also be regarded as "one liquid crystal structure".

The stimulation section 200 applies stimulation to the liquid crystal layer 3 . Therefore, stimulation is applied to the liquid crystal layer 3 from outside the optical element 100. In response to stimulation on the liquid crystal layer 3, the orientation of the first liquid crystal FL changes. Therefore, in response to a change in the orientation of the first liquid crystal FL based on stimulation to the liquid crystal layer 3, each of the plurality of liquid crystal structures 5 changes its posture while maintaining the orientation of the second liquid crystal SL. As a result, the optical characteristics of optical element 100 change. Optical properties are properties that reflect light, absorb light, or change the phase of light.

As described above with reference to FIG. 1, according to this embodiment, instead of changing the orientation of the second liquid crystal SL itself inside the liquid crystal structure 5, By changing the orientation of the liquid crystal FL, the orientation of the liquid crystal structure 5 is changed. Therefore, compared to the case where the orientation of the liquid crystal itself is changed inside the liquid crystal structure, in the optical element 100 according to this embodiment, the optical characteristics can be controlled by a relatively small stimulus from the outside.

The stimulus is, for example, an electrical stimulus (eg, voltage), a mechanical stimulus (eg, stress), or a chemical stimulus (eg, a chemical reaction).

For example, the stimulation applying unit 200 applies electrical stimulation to the liquid crystal layer 3 (for example, applying a voltage). The liquid crystal layer 3 responds to electrical stimulation, and the orientation of the first liquid crystal FL changes. For example, the stimulus applying unit 200 applies a mechanical stimulus to the liquid crystal layer 3 (for example, applying stress). The liquid crystal layer 3 responds to mechanical stimulation, and the orientation of the first liquid crystal FL changes. For example, the stimulus applying unit 200 applies a chemical stimulus to the liquid crystal layer 3 (for example, induces a chemical reaction). The liquid crystal layer 3 responds to chemical stimulation, and the orientation of the first liquid crystal FL changes.

In this embodiment, "stimulation" is "voltage (hereinafter referred to as "driving voltage")." Therefore, the stimulation applying section 200 is a power source. Then, the stimulation applying section 200 applies a driving voltage to the liquid crystal layer 3 as an electrical stimulation. That is, the stimulation applying section 200 applies a driving voltage between the first substrate 1 and the second substrate 2.

The driving voltage is an alternating current voltage having a predetermined frequency. In response to the application of a driving voltage to the liquid crystal layer 3, each of the plurality of liquid crystal structures 5 changes its posture according to the change in the orientation of the first liquid crystal FL while maintaining the orientation of the second liquid crystal SL. As a result, the optical characteristics of optical element 100 change.

When the "stimulus" is a "driving voltage", the optical element 100 further includes a first electrode 51 and a second electrode 52. The first electrode 51 is formed on the first substrate 1 . The first electrode 51 is, for example, a planar electrode. The second electrode 52 is formed on the second substrate 2. The second electrode 52 is, for example, a planar electrode. Each of the first electrode 51 and the second electrode 52 is formed of a transparent electrode material in this embodiment. The transparent electrode material is, for example, ITO (Indium Tin Oxide). "Transparent" may be colorless and transparent, colored and transparent, or translucent. The stimulation section 200 then applies a driving voltage to the liquid crystal layer 3 between the first substrate 1 and the second substrate 2 via the first electrode 51 and the second electrode 52.

FIG. 2 is a schematic cross-sectional view showing the optical element 100. In addition, in FIG. 2, one liquid crystal structure 5 is illustrated in order to simplify the drawing. As shown in FIG. 2, the liquid crystal layer 3 includes a first area A1 and a second area A2. The first region A1 faces the first substrate 1 and is adjacent to the first substrate 1. The first region A1 is substantially parallel to the first substrate 1. The second region A2 faces the second substrate 2 and is adjacent to the second substrate 2. The second region A2 is approximately parallel to the second substrate 2. The first area A1 and the second area A2 face each other with the liquid crystal structure 5 in between and are substantially parallel to each other.

The first area A1 and the second area A2 determine the orientation of the first liquid crystal FL. That is, the orientation of the first liquid crystal FL is determined by the orientation of each of the plurality of liquid crystal molecules in the first region A1 and the orientation of each of the plurality of liquid crystal molecules in the second region A2.

The liquid crystal structure 5 has a first surface region B1 and a second surface region B2. The first surface region B1 and the second surface region B2 are opposed to each other. The first surface region B1 and the second surface region B2 determine the orientation of the second liquid crystal SL. That is, the orientation of the second liquid crystal SL is determined by the orientation of each of the plurality of liquid crystal molecules in the first surface region B1 and the orientation of each of the plurality of liquid crystal molecules in the second surface region B2.

In the example of FIG. 2, the posture vector PV of the liquid crystal structure 5 is substantially perpendicular to the first substrate 1. The posture vector PV is a vector indicating the orientation of the liquid crystal structure 5. The posture vector PV is substantially perpendicular to the first surface region B1 and points toward the outside of the liquid crystal structure 5.

Next, conditions for the optical element 100 according to this embodiment will be explained with reference to FIGS. 3(a) and 3(b). FIG. 3A is a diagram showing the first condition of the optical element 100. Note that in FIG. 3A, the liquid crystal structure 5 is omitted to simplify the drawing. FIG. 3(b) is a diagram showing the second condition of the optical element 100. Note that in FIG. 3(b), only the liquid crystal structure 5 is shown in order to simplify the drawing.

As shown in FIGS. 3A and 3B, the optical element 100 satisfies at least one of the first condition and the second condition. That is, in the optical element 100, only the first condition is satisfied, only the second condition is satisfied, or both the first condition and the second condition are satisfied.

Hereinafter, each liquid crystal molecule constituting the first liquid crystal FL of the liquid crystal layer 3 may be referred to as a "liquid crystal molecule LC1". In particular, the liquid crystal molecules LC1 present in the first region A1 may be referred to as "liquid crystal molecules LCA." The liquid crystal molecules LC1 present in the second region A2 may be referred to as "liquid crystal molecules LCB."

Furthermore, each liquid crystal molecule that constitutes the second liquid crystal SL of the liquid crystal structure 5 may be referred to as a "liquid crystal molecule LC2." In particular, the liquid crystal molecules LC2 present in the first surface region B1 may be referred to as "liquid crystal molecules LCC." The liquid crystal molecules LC2 present in the second surface region B2 may be referred to as "liquid crystal molecules LCD".

As shown in FIG. 3(a), the first condition is that when no stimulus is applied to the liquid crystal layer 3, the alignment of liquid crystal molecules LCA in the first area A1 and the alignment of liquid crystal molecules LCB in the second area A2 This is different. In this embodiment, "when no stimulus is applied to the liquid crystal layer 3" corresponds to "when no driving voltage is applied to the liquid crystal layer 3". Furthermore, "when a stimulus is applied to the liquid crystal layer 3" corresponds to "when a driving voltage is applied to the liquid crystal layer 3".

Specifically, the first condition is such that when no stimulus is applied to the liquid crystal layer 3, the orientation of liquid crystal molecules LCA orthogonally projected onto the XY plane and the orientation of liquid crystal molecules LCB orthogonally projected onto the XY plane are the same. That's different.

Alternatively, the first condition is that when no stimulus is applied to the liquid crystal layer 3, the orientation of the liquid crystal molecules LCA orthogonally projected onto the ZX plane is different from the orientation of the liquid crystal molecules LCB orthogonally projected onto the ZX plane. be.

Alternatively, the first condition is that when no stimulus is applied to the liquid crystal layer 3, the orientation of the liquid crystal molecules LCA orthogonally projected onto the XY plane is different from the orientation of the liquid crystal molecules LCB orthogonally projected onto the XY plane, and The orientation of the liquid crystal molecules LCA orthogonally projected onto the ZX plane is different from the orientation of the liquid crystal molecules LCB orthogonally projected onto the ZX plane.

Note that the XY plane indicates a plane substantially parallel to the first substrate 1. The ZX plane indicates a plane substantially perpendicular to the first substrate 1.

As shown in FIG. 3(b), the second condition is that when no stimulus is applied to the liquid crystal layer 3, the alignment of liquid crystal molecules LCC in the first surface area B1 and the alignment of liquid crystal molecules LCD in the second surface area B2 The difference is that the orientation of

Specifically, the second condition is such that when no stimulus is applied to the liquid crystal layer 3, the orientation of the liquid crystal molecules LCC orthogonally projected onto the XY plane and the orientation of the liquid crystal molecules LCD orthogonally projected onto the XY plane are the same. That's different.

Alternatively, the second condition is that when no stimulus is applied to the liquid crystal layer 3, the orientation of the liquid crystal molecules LCC orthogonally projected onto the ZX plane is different from the orientation of the liquid crystal molecules LCD orthogonally projected onto the ZX plane. be.

Alternatively, the second condition is that when no stimulus is applied to the liquid crystal layer 3, the orientation of the liquid crystal molecules LCC orthogonally projected onto the XY plane is different from the orientation of the liquid crystal molecules LCD orthogonally projected onto the XY plane, and The orientation of the liquid crystal molecules LCC orthogonally projected onto the ZX plane is different from the orientation of the liquid crystal molecules LCD orthogonally projected onto the ZX plane.

When the optical element 100 satisfies the first condition, the plurality of liquid crystal molecules LC1 existing between the first region A1 and the second region A2 of the liquid crystal layer 3 are aligned in the same manner as the liquid crystal molecules LCA in the first region A1. The alignment is linearly deformed depending on the alignment of the liquid crystal molecules LCB in the second region A2. Further, when the optical element 100 satisfies the second condition, the orientation of the liquid crystal molecules LCC in the first surface region B1 is different from the orientation of the liquid crystal molecules LCD in the second surface region B2.

Therefore, when the optical element 100 satisfies at least one of the first condition and the second condition, even when no stimulus is applied to the liquid crystal layer 3, the first area A1 and the first surface area B1 are The orientation of the plurality of liquid crystal molecules LC1 in the vertical direction Dv is different between the liquid crystal molecules and/or between the second region A2 and the second surface region B2. Therefore, alignment deformation is induced in the liquid crystal molecules LC1 around the liquid crystal structure 5. Then, the liquid crystal structure 5 is adjusted so that the alignment deformation of the liquid crystal molecules LC1 around the liquid crystal structure 5 is minimized, that is, so that the elastic energy of the first liquid crystal FL around the liquid crystal structure 5 is minimized. Posture is determined uniquely. That is, in the initial state where no stimulus is applied to the liquid crystal layer 3, the posture of the liquid crystal structure 5 is uniquely determined.

Therefore, when the stimulation is applied to the liquid crystal layer 3 to change the posture of the liquid crystal structure 5 and then the stimulation to the liquid crystal layer 3 is removed, the elastic restoring force due to the alignment deformation of the first liquid crystal FL is applied to the liquid crystal structure 5. Acting on the body 5, the posture of the liquid crystal structure 5 returns to the posture before applying the stimulus to the liquid crystal layer 3.

Further, since the optical element 100 satisfies at least one of the first condition and the second condition, when the liquid crystal layer 3 is stimulated, the liquid crystal molecules LC1 around the liquid crystal structure 5 Further orientation deformation is induced. Therefore, even when a stimulus is applied to the liquid crystal layer 3, the posture of the liquid crystal structure 5 is uniquely determined.

As a result, if the same stimulus is applied to the liquid crystal layer 3 again after the stimulus applied to the liquid crystal layer 3 is canceled and the attitude of the liquid crystal structure 5 is changed, the attitude of the liquid crystal structure 5 changes depending on the stimulus applied to the liquid crystal layer 3. Return to the posture before canceling the grant.

As described above, in this embodiment, the posture of the liquid crystal structure 5 can be reversibly controlled between when no stimulus is applied to the liquid crystal layer 3 and when the stimulus is applied. In other words, the posture vector PV of the liquid crystal structure 5 can be reversibly controlled. Therefore, the reproducibility of the optical characteristics of the optical element 100 can be improved.

Furthermore, when the liquid crystal layer 3 is stimulated, the elastic energy of the first liquid crystal FL around the liquid crystal structure 5 is greater than when the liquid crystal layer 3 is not stimulated. Therefore, when the stimulus to the liquid crystal layer 3 is removed, the elastic restoring force caused by the alignment deformation of the first liquid crystal FL causes the liquid crystal structure to 5's posture is changed. As a result, the response speed of the liquid crystal structure 5 can be improved.

Note that if the optical element 100 does not satisfy the first condition, the orientation of the liquid crystal molecules LCA in the first region A1 and the orientation of the liquid crystal molecules LCB in the second region A2 are aligned. Therefore, the orientation of the plurality of liquid crystal molecules LC1 existing between the first region A1 and the second region A2 is uniform in the region where the liquid crystal structure 5 is not present. For example, the orientation of the plurality of liquid crystal molecules LC1 is aligned in one direction.

Further, when the optical element 100 does not satisfy the second condition, the orientation of the liquid crystal molecules LCC in the first surface region B1 and the orientation of the liquid crystal molecules LCD in the second surface region B2 are aligned. Therefore, the orientation of the plurality of liquid crystal molecules LC2 existing between the first surface region B1 and the second surface region B2 is uniform. For example, a plurality of liquid crystal molecules LC2 are aligned in one direction. Alternatively, for example, if the plurality of liquid crystal molecules LC2 have a spiral shape, the plurality of liquid crystal molecules LC2 are oriented so as to be an integral multiple of one period or a half period of the spiral.

Note that when the optical element 100 satisfies the second condition, the plurality of liquid crystal molecules LC2 existing between the first surface area B1 and the second surface area B2 of the liquid crystal structure 5 are The alignment is deformed depending on the alignment of the liquid crystal molecules LCC and the alignment of the liquid crystal molecules LCD in the second surface region B2.

Next, optical systems 300 according to embodiments 1 to 4 of the present invention will be described with reference to FIGS. 3(a) to 13. In Embodiments 1 to 4, "driving voltage" applied to the liquid crystal layer 3 will be described as an example of "stimulus" applied to the liquid crystal layer 3. Therefore, in the description of Embodiments 1 to 4, "when no driving voltage is applied to the liquid crystal layer 3" can be read as "when no stimulus is applied to the liquid crystal layer 3". Furthermore, “when a driving voltage is applied to the liquid crystal layer 3” can be read as “when a stimulus is applied to the liquid crystal layer 3”.

(Embodiment 1)
The optical element 100 of the optical system 300 according to Embodiment 1 of the present invention will be described with reference to FIG. 3(a) and FIGS. 4 to 8(b). In the first embodiment, the first liquid crystal FLA of the liquid crystal layer 3 is a twisted nematic liquid crystal, and the second liquid crystal SLA of the liquid crystal structure 5 is a cholesteric liquid crystal. This embodiment is mainly different from the present embodiment described with reference to . Hereinafter, the differences between the first embodiment and the present embodiment will be mainly explained.

First, with reference to FIG. 4, the optical element 100 when no driving voltage is applied to the liquid crystal layer 3 in the optical system 300 according to the first embodiment will be described. FIG. 4 is a schematic cross-sectional view showing the optical element 100 according to the first embodiment. In FIG. 4, no driving voltage is applied to the liquid crystal layer 3 of the optical element 100. In addition, in FIG. 4, one liquid crystal structure 5 is illustrated in order to simplify the drawing.

As shown in FIG. 4, the liquid crystal layer 3 includes a first liquid crystal FLA. The first liquid crystal FLA includes a plurality of liquid crystal molecules LC1. As shown in FIGS. 3A and 4, the optical element 100 according to the first embodiment satisfies the first condition. That is, in the first embodiment, the orientation of liquid crystal molecules LCA orthogonally projected onto the XY plane is different from the orientation of liquid crystal molecules LCB orthogonally projected onto the XY plane. Specifically, when no driving voltage is applied to the liquid crystal layer 3, the alignment deformation of the first liquid crystal FLA shows twisting deformation between the first substrate 1 and the second substrate 2. In other words, the first liquid crystal FLA has a twisted orientation. Therefore, according to the first embodiment, it is easy to make the optical element 100 satisfy the first condition. Further, the first liquid crystal FLA has planar alignment.

In particular, in the first embodiment, the first liquid crystal FLA is a twisted nematic liquid crystal. Twisted nematic liquid crystals have positive dielectric anisotropy. Therefore, when a driving voltage is applied, the orientation of the first liquid crystal FLA changes so that the liquid crystal molecules LC1 move from a lying state to an upright state.

In the example of FIG. 4, in the first region A1 of the liquid crystal layer 3, the directors of the liquid crystal molecules LCA are inclined by "+45 degrees" with respect to the X axis in a plane parallel to the XY plane. On the other hand, in the second region A2 of the liquid crystal layer 3, the directors of the liquid crystal molecules LCB are inclined by "-45 degrees" with respect to the X axis in a plane parallel to the XY plane. Therefore, the optical element 100 satisfies the first condition. Note that the twist angle of the first liquid crystal FL is not limited to 90 degrees, but can take any value.

Note that the first liquid crystal FLA has a pretilt. Therefore, the liquid crystal molecules LCA in the first area A1 have a tilt angle with respect to the first substrate 1, and the liquid crystal molecules LCB in the second area A2 have a tilt angle with respect to the second substrate 2.

In the first embodiment, the liquid crystal structure 5 has a substantially disk shape. For example, the diameter of the liquid crystal structure 5 is on the order of nanometers or micrometers. However, the shape of the liquid crystal structure 5 is not limited to a disk shape, and can take any shape. For example, the maximum length of the liquid crystal structure 5 is on the order of nanometers or micrometers.

When no driving voltage is applied to the liquid crystal layer 3, the first surface region B1 is substantially parallel to the first substrate 1, and the second surface region B2 is substantially parallel to the second substrate 2. Further, the first surface region B1 faces the first substrate 1, and the second surface region B2 faces the second substrate 2. Further, when no driving voltage is applied to the liquid crystal layer 3, the first surface region B1 is the region of the liquid crystal structure 5 that is closest to the first substrate 1, and the second surface region B2 is the region of the liquid crystal structure 5 that is closest to the first substrate 1. 5, this is the region closest to the second substrate 2.

The liquid crystal structure 5 includes a second liquid crystal SLA. The second liquid crystal SL has a plurality of spiral structures 7. Each of the plurality of helical structures 7 has selective reflectivity. Selective reflectivity means that light having a wavelength in a band corresponding to the structure and optical properties of the helical structure 7 and having a polarization state that matches the direction of rotation of the helix of the helical structure 7 is reflected. , the property of transmitting light having a polarization state opposite to the direction of spiral rotation of the helical structure 7. Therefore, according to the first embodiment, the liquid crystal structure 5 can function as a light reflector. As a result, by controlling the drive voltage and changing the attitude of the liquid crystal structure 5, it is possible to switch between reflection and transmission of light or to continuously deflect light.

Each of the plurality of helical structures 7 includes a plurality of liquid crystal molecules LC2. In each of the plurality of helical structures 7, the plurality of liquid crystal molecules LC2 are spirally swirled. The helical axes AX1 of the plurality of helical structures 7 are aligned in a certain direction. In the first embodiment, the second liquid crystal SLA is a cholesteric liquid crystal. Posture vector PV is approximately parallel to helical axis AX1. Note that in the first embodiment, the helical axis AX1 is substantially perpendicular to the first surface region B1 and the second surface region B2.

In addition, although the example of FIG. 4 shows the helical structure 7 with a half period, the period of the helical structure 7 is not limited to a half period, and may be one period. Further, the spiral structure 7 may have a length twice or more of a half period by repeating a structure for half a period, or may have a length twice or more of one period by repeating a structure for one period. It may have a

Here, if the optical element 100 satisfies the second condition, for example, the helical structure 7 has a portion that is less than half a period or a portion that is less than one period.

Note that, as shown in FIGS. 3(b) and 4, in the first embodiment, the optical element 100 does not satisfy the second condition. In the example of FIG. 4, in the first surface region B1 of the liquid crystal structure 5, the directors of the liquid crystal molecules LCC are substantially parallel to the X axis in a plane parallel to the XY plane. In addition, in the second surface region B2 of the liquid crystal structure 5, the directors of the liquid crystal molecules LCD are substantially parallel to the X axis in a plane parallel to the XY plane. Therefore, the optical element 100 does not satisfy the second condition.

As shown in FIG. 4, when no driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the first posture according to the orientation of the first liquid crystal FLA. That is, the first attitude indicates the attitude of the liquid crystal structure 5 when no driving voltage is applied to the liquid crystal layer 3. In the first embodiment, when the liquid crystal structure 5 takes the first attitude, the attitude vector PV of the liquid crystal structure 5 is approximately parallel to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is approximately It is zero degrees. The rotation angle θ indicates the inclination angle of the posture vector PV with respect to the vertical direction Dv.

The liquid crystal structure 5 has a reflective surface RF. On the reflective surface RF, a plurality of liquid crystal molecules LC2 are aligned in the same direction. The reflective surface RF reflects light. The reflective surface RF of the liquid crystal structure 5 in the first attitude is substantially parallel to the parallel direction Dp. The parallel direction Dp indicates a direction substantially parallel to the first substrate 1. In the first embodiment, the parallel direction Dp is parallel to the X axis. Further, the posture vector PV is approximately perpendicular to the reflective surface RF.

For example, the light L1 is incident on the liquid crystal structure 5 in the first attitude. Light L1 has linear polarization. Therefore, of the light L1, the liquid crystal structure 5 reflects the light L2 (for example, right-handed circularly polarized light) having a polarization state that matches the spiral rotation direction (for example, clockwise) of the helical structure 7 by the reflecting surface RF. On the other hand, the liquid crystal structure 5 transmits the light L3 (for example, left-handed circularly polarized light) having a polarization state opposite to the direction of spiral rotation (for example, clockwise) of the helical structure 7. In the example of FIG. 4, the liquid crystal structure 5 reflects the light L2 substantially parallel to the vertical direction Dv.

Next, the intermediate posture of the liquid crystal structure 5 will be explained with reference to FIG. FIG. 5 is a schematic cross-sectional view showing the optical element 100. In FIG. 5, a driving voltage having a first voltage value V1 is applied to the liquid crystal layer 3 of the optical element 100 by the stimulation applying section 200. Therefore, the orientation of the first liquid crystal FLA changes from the initial orientation. That is, the first liquid crystal FLA undergoes further alignment deformation from the initial alignment deformation. The initial orientation indicates the orientation of the first liquid crystal FLA when no driving voltage is applied to the liquid crystal layer 3. The initial alignment deformation indicates the alignment deformation of the first liquid crystal FLA along the vertical direction Dv when no driving voltage is applied to the liquid crystal layer 3. Note that the first voltage value V1 is represented by the effective value or maximum value of the drive voltage.

When a driving voltage having the first voltage value V1 is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes an intermediate posture according to a change in the orientation of the first liquid crystal FLA. In other words, the intermediate posture indicates the posture of the liquid crystal structure 5 when the driving voltage having the first voltage value V1 is applied to the liquid crystal layer 3. The intermediate posture is different from the first posture. Specifically, the liquid crystal structure 5 assumes an intermediate posture in response to further alignment deformation from the initial alignment deformation of the first liquid crystal FLA.

In the first embodiment, when the liquid crystal structure 5 is in the intermediate posture, the posture vector PV of the liquid crystal structure 5 is inclined with respect to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is an acute angle. be. In the example of FIG. 5, the liquid crystal structure 5 is rotated counterclockwise by the rotation angle θ from the first attitude to the intermediate attitude. As the liquid crystal structure 5 changes from the first attitude to the intermediate attitude, the reflective surface RF is inclined by the rotation angle θ with respect to the parallel direction Dp.

As a result, the liquid crystal structure 5 reflects the light L2 by the reflective surface RF in a direction according to the rotation angle θ. That is, the liquid crystal structure 5 reflects the light L2 by the reflecting surface RF in a direction corresponding to the orientation of the posture vector PV. Therefore, the direction in which the light L2 is reflected by the liquid crystal structure 5 when the liquid crystal structure 5 takes the intermediate attitude is different from the direction in which the light L2 is reflected by the liquid crystal structure 5 when the liquid crystal structure 5 takes the first attitude. That is, in the first embodiment, light can be deflected by controlling the attitude of the liquid crystal structure 5. Note that the liquid crystal structure 5 transmits the light L3.

Next, the second attitude of the liquid crystal structure 5 will be explained with reference to FIG. FIG. 6 is a schematic cross-sectional view showing the optical element 100. In FIG. 6, a driving voltage having a second voltage value V2 is applied to the liquid crystal layer 3 of the optical element 100 by the stimulation applying section 200. The second voltage value V2 is greater than the first voltage value V1 (FIG. 4).

Therefore, the orientation of the first liquid crystal FLA further changes from the orientation when the driving voltage having the first voltage value V1 is applied. That is, the first liquid crystal FLA undergoes further alignment deformation from the alignment deformation upon application of the drive voltage having the first voltage value V1. Note that the second voltage value V2 is represented by the effective value or maximum value of the AC voltage.

When a driving voltage having a second voltage value V2 is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the second attitude according to the change in the orientation of the first liquid crystal FLA. That is, the second attitude indicates the attitude of the liquid crystal structure 5 when the driving voltage having the second voltage value V2 is applied to the liquid crystal layer 3. Specifically, the liquid crystal structure 5 assumes the second attitude in response to further alignment deformation from the alignment deformation of the first liquid crystal FLA when the driving voltage having the first voltage value V1 is applied. The second attitude is different from each of the first attitude and the intermediate attitude. Note that the intermediate posture (FIG. 5) of the liquid crystal structure 5 indicates a posture between the first posture and the second posture.

In the first embodiment, when the liquid crystal structure 5 takes the second attitude, the attitude vector PV of the liquid crystal structure 5 is approximately perpendicular to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is approximately It is 90 degrees. In the example of FIG. 6, the liquid crystal structure 5 is rotated counterclockwise by the rotation angle θ from the first attitude to the intermediate attitude and then to the second attitude. As the liquid crystal structure 5 changes from the first attitude to the second attitude, the reflective surface RF becomes approximately parallel to the vertical direction Dv.

As a result, the liquid crystal structure 5 transmits the light L1. That is, the liquid crystal structure 5 transmits the light L2 and the light L3. The light L2 is one circularly polarized light component (for example, right-handed circularly polarized light) included in the linearly polarized light L1. Light L3 is the other circularly polarized light component (for example, left circularly polarized light) included in light L1.

As described above with reference to FIGS. 4 and 6, according to the first embodiment, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, the liquid crystal layer 3 The attitude of the structure 5 can be switched between the first attitude and the second attitude. Therefore, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, a state in which the optical element 100 reflects the light L2 and a state in which the optical element 100 transmits the light L2 can be changed. You can easily switch between

That is, by switching between "not applying" and "applying" stimulation to the liquid crystal layer 3, a state in which the optical element 100 reflects the light L2 and a state in which the optical element 100 transmits the light L2 can be achieved. can be easily switched.

Further, as described with reference to FIGS. 4 to 6, according to the first embodiment, by controlling the voltage value of the driving voltage for the liquid crystal layer 3, the posture of the liquid crystal structure 5 is adjusted according to the voltage value. Can be changed continuously. Therefore, by controlling the voltage value of the drive voltage, the direction of reflection of the light L2 can be changed continuously.

That is, the liquid crystal structure 5 changes its posture according to the magnitude of the stimulus applied to the liquid crystal layer 3, and changes the direction of light reflection according to the change in posture. That is, by controlling the magnitude of the stimulus to the liquid crystal layer 3, the attitude of the liquid crystal structure 5 can be continuously changed according to the magnitude of the stimulus. Therefore, by controlling the magnitude of the stimulus, the direction of reflection of the light L2 can be continuously changed.

Furthermore, in the first embodiment, the optical element 100 satisfies the first condition. Therefore, as shown in FIG. 4, even when no driving voltage is applied to the liquid crystal layer 3, the distance between the first area A1 and the first surface area B1, and between the second area A2 and the second surface area B2 is The orientations of the plurality of liquid crystal molecules LC1 in the vertical direction Dv are different between the two. Therefore, alignment deformation is induced in the liquid crystal molecules LC1 around the liquid crystal structure 5. Then, the posture of the liquid crystal structure 5 is uniquely determined so that the alignment deformation of the liquid crystal molecules LC1 around the liquid crystal structure 5 is minimized. That is, in the initial state where no driving voltage is applied to the liquid crystal layer 3, the attitude of the liquid crystal structure 5 is uniquely determined.

Therefore, when the driving voltage is applied to the liquid crystal layer 3 to change the orientation of the liquid crystal structure 5 and then the application of the driving voltage to the liquid crystal layer 3 is canceled, the elastic restoring force due to the alignment deformation of the first liquid crystal FL is reduced. Acting on the liquid crystal structure 5, the attitude of the liquid crystal structure 5 returns to the attitude before applying the driving voltage to the liquid crystal layer 3.

Further, as shown in FIG. 6, since the optical element 100 satisfies the first condition, when the driving voltage is applied to the liquid crystal layer 3, the liquid crystal molecules LC1 around the liquid crystal structure 5 are further affected. An orientation deformation is induced. Therefore, even when a driving voltage is applied to the liquid crystal layer 3, the posture of the liquid crystal structure 5 is uniquely determined.

As a result, when the same driving voltage is applied to the liquid crystal layer 3 again after the application of the driving voltage to the liquid crystal layer 3 is canceled and the attitude of the liquid crystal structure 5 is changed, the attitude of the liquid crystal structure 5 relative to the liquid crystal layer 3 changes. Returns to the posture before the application of the drive voltage is released.

As described above, in the first embodiment, the posture of the liquid crystal structure 5 can be reversibly controlled between when the driving voltage is not applied to the liquid crystal layer 3 and when it is applied. In other words, the posture vector PV of the liquid crystal structure 5 can be reversibly controlled. Therefore, the reproducibility of the reflection characteristics of the optical element 100 can be improved.

Furthermore, when a driving voltage is applied to the liquid crystal layer 3, the elastic energy of the first liquid crystal FL around the liquid crystal structure 5 is greater than when no driving voltage is applied to the liquid crystal layer 3. Therefore, when the application of the driving voltage to the liquid crystal layer 3 is released, the elastic restoring force caused by the alignment deformation of the first liquid crystal FL causes the elastic energy of the liquid crystal molecules LC1 around the liquid crystal structure 5 to be minimized. The attitude of the liquid crystal structure 5 is changed from the second attitude to the first attitude. As a result, the response speed of the liquid crystal structure 5 can be improved.

Note that the second liquid crystal SLA of the liquid crystal structure 5 is not limited to cholesteric liquid crystal as long as it reflects light. The second liquid crystal SLA may be a chiral liquid crystal other than a cholesteric liquid crystal. Chiral liquid crystals other than cholesteric liquid crystals are, for example, chiral smectic C phase, twisted grain boundary phase, or cholesteric blue phase. Further, the cholesteric liquid crystal may be, for example, in a helicoidal cholesteric phase.

Next, an example of a method for manufacturing the liquid crystal structure 5 will be described. In step S1, a glass substrate SB1 and a chrome mask substrate SB2 are prepared. The chrome mask substrate SB2 is a substrate in which a chrome mask is formed on one of a pair of main surfaces of a glass substrate. The chrome mask has multiple micropores arranged in it. The diameter of the micropores is, for example, several micrometers.

In step S2, a polymer film PL1 is formed on one of the pair of main surfaces of the glass substrate SB1, and a polymer film PL2 is formed on the chrome mask side of the chrome mask substrate SB2. In the polymer film PL1 and the polymer film PL2, liquid crystals can be aligned by rubbing, and they can be easily peeled off using a solvent (for example, water). The solvent does not attack the liquid crystal structure 5.

For example, ICP (Intrinsically Conducting Polymers) is spin coated on one main surface of the glass substrate SB1 and the chrome mask side of the chrome mask substrate SB2 to form a polymer film PL1 and a polymer film PL2. ICP is, for example, PEDOT/PSS. PEDOT/PSS is a composite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonic acid (PSS).

In step S3, the glass substrate SB1 on which the polymer film PL1 is formed and the chrome mask substrate SB2 on which the polymer film PL2 is formed are heated at a predetermined temperature (e.g., 80° C.) for a predetermined time (e.g., 1 minute). .

In step S4, a rubbing process is performed on the polymer film PL1 of the glass substrate SB1 and the polymer film PL2 of the chrome mask substrate SB2.

In step S5, a sandwich cell is formed with the glass substrate SB1 and the chrome mask substrate SB2 so that the polymer film PL1 and the polymer film PL2 after the rubbing treatment face each other, and the sandwich cell is filled with photopolymerizable liquid crystal.

In step S6, the sandwich cell filled with the photopolymerizable liquid crystal is vertically irradiated with ultraviolet light from the chrome mask substrate SB2 side. Therefore, ultraviolet light is applied to the photopolymerizable liquid crystal through the plurality of micropores in the chrome mask. As a result, only the portion of the photopolymerizable liquid crystal that is irradiated with ultraviolet light is polymerized, and a plurality of liquid crystal structures 5 are formed.

In step S7, the glass substrate SB1 and the chrome mask substrate SB2 are peeled off from the photopolymerizable liquid crystal. Then, the photopolymerizable liquid crystal is soaked in water, unpolymerized liquid crystal is removed by centrifugation, and the water is evaporated to dry it. As a result, a plurality of liquid crystal structures 5 are taken out. A plurality of liquid crystal structures 5 are mixed with a first liquid crystal FLA as a host.

Next, an optical element 500 according to a comparative example will be described with reference to FIGS. 7(a) to 8(b). FIG. 7A is a schematic cross-sectional view showing an optical element 500 according to a comparative example. FIG. 7(b) is a schematic cross-sectional view showing another state of the optical element 500 according to the comparative example.

As shown in FIGS. 7A and 7B, the optical element 500 includes a first substrate 81, a second substrate 82, a liquid crystal layer 83, a liquid crystal structure 85, a first electrode 61, and a second electrode 62. The liquid crystal layer 83 includes liquid crystal (hereinafter referred to as "first liquid crystal FC"). The first liquid crystal FC includes a plurality of liquid crystal molecules LC10. The liquid crystal structure 85 includes a liquid crystal (hereinafter referred to as "second liquid crystal SC"). The second liquid crystal SC includes a plurality of liquid crystal molecules LC20. The first electrode 61 and the second electrode 62 are planar electrodes and are made of a transparent electrode material. The transparent electrode material is, for example, ITO.

In FIGS. 7A and 7B, no drive voltage is applied to the liquid crystal layer 83. The optical element 500 according to the comparative example does not satisfy the first condition and the second condition.

Specifically, in the comparative example, in the liquid crystal layer 83, the orientation of liquid crystal molecules LCA orthogonally projected onto the XY plane and the orientation of liquid crystal molecules LCB orthogonally projected onto the XY plane are aligned. Therefore, optical element 500 does not satisfy the first condition. Specifically, when no driving voltage is applied to the liquid crystal layer 3, the first liquid crystal FC of the liquid crystal layer 83 has a planar alignment and a uniaxial alignment. Uniaxial alignment is an alignment in which a plurality of liquid crystal molecules are aligned in one direction. Specifically, the first liquid crystal FC is a nematic liquid crystal without twist.

The configuration of the liquid crystal structure 85 is similar to the configuration of the liquid crystal structure 5 according to the first embodiment. Therefore, optical element 500 does not satisfy the second condition. The second liquid crystal SC is a cholesteric liquid crystal. If the second condition is not satisfied and the alignment of the liquid crystal molecules LCC in the first surface area B1 and the alignment of the liquid crystal molecules LCD in the second surface area B2 are aligned, the alignment of the first surface area B1 and the alignment of the second surface area The posture of the liquid crystal structure 85 is determined so that the orientation of B2 is aligned with the orientation direction of the first liquid crystal FC of the liquid crystal layer 83. However, even if the liquid crystal structure 85 rotates around the alignment axis AX2, alignment deformation of the first liquid crystal FC is not induced, so that no elastic restoring force acts on the liquid crystal structure 85.

Therefore, the liquid crystal structure 85 is rotatable around the alignment axis AX2. As a result, when no driving voltage is applied to the liquid crystal layer 83, the posture of the liquid crystal structure 85 is difficult to stabilize. The alignment axis AX2 indicates an axis substantially parallel to the alignment direction of the first liquid crystal FC of the liquid crystal layer 83.

FIG. 8A is a schematic cross-sectional view showing an optical element 500 according to a comparative example. FIG. 8(b) is a schematic cross-sectional view showing another state of the optical element 500 according to the comparative example. In FIGS. 8A and 8B, a driving voltage having a first voltage value V1 is applied to the liquid crystal layer 83.

As shown in FIGS. 8(a) and 8(b), when a driving voltage having a first voltage value V1 is applied to the liquid crystal layer 83, the liquid crystal structure 85 changes the orientation of the first liquid crystal FC. Adapt your attitude to change. In this case, even if the liquid crystal structure 85 rotates around the alignment axis AX2, alignment deformation of the first liquid crystal FC is not induced, so that no elastic restoring force acts on the liquid crystal structure 85. Therefore, the liquid crystal structure 85 is rotatable around the alignment axis AX2. As a result, even when a driving voltage is applied to the liquid crystal layer 83, the posture of the liquid crystal structure 85 is difficult to stabilize.

As described above with reference to FIGS. 7(a) to 8(b), in the optical element 500 according to the comparative example, the liquid crystal structure 85's posture is difficult to stabilize. In other words, the orientation of the posture vector PV of the liquid crystal structure 85 is difficult to stabilize. Therefore, in the optical element 500 according to the comparative example, it is difficult to reversibly control the liquid crystal structure 85.

In contrast, as described with reference to FIGS. 4 to 6, according to the first embodiment, the liquid crystal structure 85 can be reversibly controlled.

(Embodiment 2)
An optical system 300 according to Embodiment 2 of the present invention will be described with reference to FIGS. 3(a), 9, and 10. Embodiment 2 differs from Embodiment 1 mainly in that the first liquid crystal FLB of liquid crystal layer 3 according to Embodiment 2 has a hybrid alignment. Hereinafter, the differences between the second embodiment and the first embodiment will be mainly explained.

First, with reference to FIG. 9, the optical element 100 of the optical system 300 according to the second embodiment will be described. FIG. 9 is a schematic cross-sectional view showing the optical element 100 according to the second embodiment. In FIG. 9, no driving voltage is applied to the liquid crystal layer 3 of the optical element 100.

As shown in FIG. 9, the liquid crystal layer 3 includes a first liquid crystal FLB. The first liquid crystal FLB includes a plurality of liquid crystal molecules LC3. As shown in FIGS. 3A and 9, the optical element 100 according to the second embodiment satisfies the first condition. That is, in the first embodiment, the orientation of liquid crystal molecules LCA orthogonally projected onto the ZX plane is different from the orientation of liquid crystal molecules LCB orthogonally projected onto the ZX plane.

Specifically, when no driving voltage is applied to the liquid crystal layer 3, the alignment deformation of the first liquid crystal FLB exhibits spreading/curving deformation between the first substrate 1 and the second substrate 2. In other words, the first liquid crystal FLB has a hybrid orientation. Therefore, according to the second embodiment, it is easy to make the optical element 100 satisfy the first condition. In particular, in the second embodiment, the first liquid crystal FLB is a nematic liquid crystal having a hybrid orientation.

In the example of FIG. 9, in the first region A1 of the liquid crystal layer 3, the liquid crystal molecules LCA have a pretilt, and the tilt angle of the liquid crystal molecules LCA is approximately 1 degree with respect to the first substrate 1, for example. Further, in the second region A2 of the liquid crystal layer 3, the liquid crystal molecules LCB have a pretilt, and the tilt angle of the liquid crystal molecules LCB is, for example, approximately 89 degrees. That is, the tilt angle of the liquid crystal molecules LCA in the first area A1 is different from the tilt angle of the liquid crystal molecules LCB in the second area A2. Note that, as long as the tilt angle of the liquid crystal molecules LCA and the tilt angle of the liquid crystal molecules LCB are different, the tilt angle is not limited to 1 degree and 89 degrees, and can take any value.

As shown in FIG. 9, when no driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the first attitude according to the orientation of the first liquid crystal FLB. That is, the first attitude indicates the attitude of the liquid crystal structure 5 when no driving voltage is applied to the liquid crystal layer 3. In the second embodiment, when the liquid crystal structure 5 takes the first attitude, the attitude vector PV of the liquid crystal structure 5 is inclined with respect to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is an acute angle. It is.

Therefore, the liquid crystal structure 5 reflects the light L2 by the reflective surface RF in the direction according to the rotation angle θ. That is, the liquid crystal structure 5 reflects the light L2 by the reflecting surface RF in a direction corresponding to the orientation of the posture vector PV. Note that the liquid crystal structure 5 transmits the light L3.

Note that in the second embodiment, the first liquid crystal FLB of the liquid crystal layer 3 has a hybrid alignment, so the optical element 100 satisfies the first condition. Therefore, the orientation of the liquid crystal molecules LCC in the first surface region B1 and the orientation of the liquid crystal molecules LCD in the second surface region B2 of the liquid crystal structure 5 may be arbitrary.

Next, the second attitude of the liquid crystal structure 5 will be explained with reference to FIG. FIG. 10 is a schematic cross-sectional view showing the optical element 100. In FIG. 10, a driving voltage having a third voltage value V3 is applied to the liquid crystal layer 3 of the optical element 100 by the stimulation applying section 200. Note that the third voltage value V3 is represented by the effective value or maximum value of the AC voltage.

As shown in FIG. 10, when a driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the second attitude according to the change in the orientation of the first liquid crystal FLB. That is, the second attitude indicates the attitude of the liquid crystal structure 5 when the driving voltage is applied to the liquid crystal layer 3. The second attitude is different from the first attitude. Specifically, the liquid crystal structure 5 assumes the second attitude in response to further alignment deformation from the initial alignment deformation of the first liquid crystal FLB.

In the second embodiment, when the liquid crystal structure 5 takes the second attitude, the attitude vector PV of the liquid crystal structure 5 is approximately parallel to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is approximately It is zero degrees. Therefore, of the light L1, the liquid crystal structure 5 reflects the light L2 (for example, right-handed circularly polarized light) having a polarization state that matches the spiral rotation direction (for example, clockwise) of the helical structure 7 by the reflecting surface RF. On the other hand, the liquid crystal structure 5 transmits the light L3 (for example, left-handed circularly polarized light) having a polarization state opposite to the direction of spiral rotation (for example, clockwise) of the helical structure 7. In the example of FIG. 10, the liquid crystal structure 5 reflects the light L2 substantially parallel to the vertical direction Dv.

As described above with reference to FIGS. 9 and 10, according to the second embodiment, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, the liquid crystal layer 3 The attitude of the structure 5 can be switched between the first attitude and the second attitude. Therefore, by switching between "not applying" and "applying" the drive voltage to the liquid crystal layer 3, the direction of reflection of the light L2 can be easily switched.

Further, according to the second embodiment, similarly to the first embodiment, by controlling the voltage value of the driving voltage for the liquid crystal layer 3, the attitude of the liquid crystal structure 5 can be continuously changed according to the voltage value. Therefore, by controlling the voltage value of the drive voltage, the direction of reflection of the light L2 can be changed continuously.

Furthermore, according to the second embodiment, the posture of the liquid crystal structure 5 is reversible between when no driving voltage is applied to the liquid crystal layer 3 and when the driving voltage is applied to the liquid crystal layer 3 based on the same principle as in the first embodiment. control is possible. In other words, the posture vector PV of the liquid crystal structure 5 can be reversibly controlled. Furthermore, in the second embodiment, the response speed of the liquid crystal structure 5 can be improved based on the same principle as in the first embodiment.

(Embodiment 3)
An optical system 300 according to Embodiment 3 of the present invention will be described with reference to FIGS. 3(a), 11, and 12. Embodiment 3 differs from Embodiment 1 mainly in that the first liquid crystal FLC of liquid crystal layer 3 according to Embodiment 3 has a vertical twisted orientation with pretilt. Hereinafter, the differences between the third embodiment and the first embodiment will be mainly explained.

First, with reference to FIG. 11, the optical element 100 of the optical system 300 according to the third embodiment will be described. FIG. 11 is a schematic cross-sectional view showing an optical element 100 according to the third embodiment. In FIG. 13, no driving voltage is applied to the liquid crystal layer 3 of the optical element 100.

As shown in FIG. 11, the liquid crystal layer 3 includes a first liquid crystal FLC. The first liquid crystal FLC includes a plurality of liquid crystal molecules LC4. As shown in FIGS. 3A and 11, the optical element 100 according to the third embodiment satisfies the first condition. That is, in the first embodiment, the orientation of liquid crystal molecules LCA orthogonally projected onto the XY plane is different from the orientation of liquid crystal molecules LCB orthogonally projected onto the XY plane. Specifically, when no driving voltage is applied to the liquid crystal layer 3, the orientation of the first liquid crystal FLC exhibits a vertical twisted orientation with pretilt between the first substrate 1 and the second substrate 2. . Therefore, according to the third embodiment, it is easy to make the optical element 100 satisfy the first condition.

In particular, in embodiment 3, the first liquid crystal FLC is a nematic liquid crystal with a vertically twisted orientation with pretilt. Nematic liquid crystals with pretilted vertical twist orientation have negative dielectric anisotropy. Therefore, when a driving voltage is applied, the orientation of the first liquid crystal FLC changes such that the liquid crystal molecules LC4 move from the upright state to the lying state. Further, in the vertical twisted orientation with pretilt, each of the tilt angles of the liquid crystal molecules LCA with respect to the first substrate 1 and the tilt angles of the liquid crystal molecules LCB with respect to the second substrate 2 is, for example, larger than 45 degrees and smaller than 90 degrees.

In the example of FIG. 11, in the first region A1 of the liquid crystal layer 3, the directors of the liquid crystal molecules LCA are inclined by "+45 degrees" with respect to the X axis in a plane parallel to the XY plane. On the other hand, in the second region A2 of the liquid crystal layer 3, the directors of the liquid crystal molecules LCB are inclined by "-45 degrees" with respect to the X axis in a plane parallel to the XY plane. Therefore, the optical element 100 satisfies the first condition.

Further, the tilt angle of the liquid crystal molecules LCA in the first region A1 with respect to the first substrate 1 is, for example, 85 degrees, and the tilt angle of the liquid crystal molecules LCB in the second region A2 with respect to the second substrate 2 is, for example, 85 degrees. be. However, the tilt angle is not limited to 85 degrees and can take any value.

As shown in FIG. 11, when no driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the first attitude according to the orientation of the first liquid crystal FLC. That is, the first attitude indicates the attitude of the liquid crystal structure 5 when no driving voltage is applied to the liquid crystal layer 3. In the third embodiment, when the liquid crystal structure 5 takes the first attitude, the attitude vector PV of the liquid crystal structure 5 is approximately perpendicular to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is approximately It is 90 degrees. Therefore, the reflective surface RF becomes approximately parallel to the vertical direction Dv. As a result, the liquid crystal structure 5 transmits the light L1. That is, the liquid crystal structure 5 transmits the light L2 and the light L3.

In Embodiment 3, each of the first surface region B1 and the second surface region B2 is a liquid crystal molecule LCA having a pretilt or a liquid crystal of the liquid crystal structure 5 when a driving voltage is not applied to the liquid crystal layer 3. The region along the orientation direction of the molecule LCB is shown. The first surface region B1 and the second surface region B2 face each other.

Next, the second attitude of the liquid crystal structure 5 will be described with reference to FIG. 12. FIG. 12 is a schematic cross-sectional view showing the optical element 100. In FIG. 12, a driving voltage having a fourth voltage value V4 is applied to the liquid crystal layer 3 of the optical element 100 by the stimulation applying section 200. Note that the fourth voltage value V4 is represented by the effective value or maximum value of the AC voltage.

As shown in FIG. 12, when a driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5 assumes the second attitude according to the change in the orientation of the first liquid crystal FLC. That is, the second attitude indicates the attitude of the liquid crystal structure 5 when the driving voltage is applied to the liquid crystal layer 3. The second attitude is different from the first attitude. Specifically, the liquid crystal structure 5 assumes the second attitude in response to further alignment deformation from the initial alignment deformation of the first liquid crystal FLC.

In the third embodiment, when the liquid crystal structure 5 takes the second attitude, the attitude vector PV of the liquid crystal structure 5 is approximately parallel to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5 is approximately It is zero degrees. Therefore, of the light L1, the liquid crystal structure 5 reflects the light L2 (for example, right-handed circularly polarized light) having a polarization state that matches the spiral rotation direction (for example, clockwise) of the helical structure 7 by the reflecting surface RF. On the other hand, the liquid crystal structure 5 transmits the light L3 (for example, left-handed circularly polarized light) having a polarization state opposite to the direction of spiral rotation (for example, clockwise) of the helical structure 7. In the example of FIG. 12, the liquid crystal structure 5 reflects the light L2 substantially parallel to the vertical direction Dv.

As described above with reference to FIGS. 11 and 12, according to the third embodiment, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, the liquid crystal layer 3 The attitude of the structure 5 can be switched between the first attitude and the second attitude. Therefore, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, a state in which the optical element 100 transmits the light L2 and a state in which the optical element 100 reflects the light L2 You can easily switch between

Further, according to the third embodiment, similarly to the first embodiment, by controlling the voltage value of the driving voltage for the liquid crystal layer 3, the attitude of the liquid crystal structure 5 can be continuously changed according to the voltage value. Therefore, by controlling the voltage value of the drive voltage, the direction of reflection of the light L2 can be changed continuously.

Further, according to the third embodiment, based on the same principle as the first embodiment, the posture of the liquid crystal structure 5 is reversible between when no driving voltage is applied to the liquid crystal layer 3 and when it is applied. control is possible. In other words, the posture vector PV of the liquid crystal structure 5 can be reversibly controlled. Furthermore, in the third embodiment, the response speed of the liquid crystal structure 5 can be improved based on the same principle as in the first embodiment.

Here, as described with reference to FIG. 4, FIG. 6, FIG. 11, and FIG. When taking one posture, the liquid crystal structure 5 reflects the light L2. When the liquid crystal structure 5 takes the other of the first attitude and the second attitude, the liquid crystal structure 5 transmits the light L2.

(Embodiment 4)
An optical system 300 according to Embodiment 4 of the present invention will be described with reference to FIGS. 3(b) to 6 and 13. Embodiment 4 differs from Embodiment 1 mainly in that a dichroic dye 21 is added to the liquid crystal structure 5A according to Embodiment 4. Hereinafter, the differences between the fourth embodiment and the first embodiment will be mainly explained.

FIG. 13 is a schematic cross-sectional view showing a liquid crystal structure 5A of the optical element 100 according to the fourth embodiment. As shown in FIGS. 4 and 13, the optical element 100 according to the fourth embodiment includes a liquid crystal structure 5A instead of the liquid crystal structure 5 of the optical element 100 according to the first embodiment. The shape of the liquid crystal structure 5A is similar to the shape of the liquid crystal structure 5.

As shown in FIG. 13, the liquid crystal structure 5A includes a liquid crystal SLB (hereinafter referred to as "second liquid crystal SLB") and a dichroic dye 21. The alignment of the second liquid crystal SLB is a planar alignment and a uniaxial alignment. In the fourth embodiment, the second liquid crystal SLB is a nematic liquid crystal. The second liquid crystal SLB includes a plurality of liquid crystal molecules LC5.

The dichroic dye 21 refers to a dye in which the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction of the molecule. Specifically, the dichroic dye 21 includes a plurality of dichroic dye molecules 21a. The absorbance in the long axis direction of the dichroic dye molecule 21a is different from the absorbance in the short axis direction of the dichroic dye molecule 21a. In the fourth embodiment, the absorbance of the dichroic dye molecule 21a in the long axis direction is greater than the absorbance of the dichroic dye molecule 21a in the short axis direction. The dichroic dye 21 is, for example, DCM or BTBP. DCM is [2-[2-[4-(Dimethylamino)phenyl]ethenyl]-6-methyl-4H-pyran-4-ylidene]propanedinitrile. BTBP is N,N'-bis(2,5-di-tert-butylphenyl)-3,4,9,10-perylene dicarboimide. However, the type of dichroic dye 21 is not particularly limited. For example, dichroic dye 21 is produced by Aleksandr V. It may be a dichroic dye described in "Dichroic Dyes for Liquid Crystal Displays" by M. Ivashchenko (CRC Press, 1994).

The dichroic dye 21 is aligned along the alignment direction AL of the second liquid crystal SLB. Specifically, a plurality of dichroic dye molecules 21a are added between a plurality of liquid crystal molecules LC5. As a result, the plurality of dichroic dye molecules 21a are arranged along the alignment direction AL of the plurality of liquid crystal molecules LC5. In the fourth embodiment, the long axis of each of the plurality of dichroic dye molecules 21a is substantially parallel to the alignment direction AL of the second liquid crystal SLB.

As shown in FIGS. 4 and 13, when no driving voltage is applied to the liquid crystal layer 3, the liquid crystal structure 5A assumes the first posture according to the orientation of the first liquid crystal FLA. When the liquid crystal structure 5A is in the first attitude, the attitude vector PV of the liquid crystal structure 5A is approximately parallel to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5A is approximately zero degrees. Therefore, the long axis of the dichroic dye molecule 21a is approximately perpendicular to the vertical direction Dv. As a result, when the light L1 substantially parallel to the vertical direction Dv enters the liquid crystal structure 5A, the dichroic dye 21 absorbs the light L1.

On the other hand, as shown in FIGS. 6 and 13, when the driving voltage having the second voltage value V2 is applied to the liquid crystal layer 3, the liquid crystal structure 5A changes according to the change in the orientation of the first liquid crystal FLA. Take the second position. When the liquid crystal structure 5A is in the second attitude, the attitude vector PV of the liquid crystal structure 5A is approximately perpendicular to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5A is approximately 90 degrees. Therefore, the long axis of the dichroic dye molecule 21a is approximately parallel to the vertical direction Dv. As a result, when the light L1 substantially parallel to the vertical direction Dv enters the liquid crystal structure 5A, the dichroic dye 21 transmits the light L1.

Note that, as shown in FIGS. 5 and 13, when a driving voltage having the first voltage value V1 is applied to the liquid crystal layer 3, the liquid crystal structure 5A changes according to the change in the orientation of the first liquid crystal FLA. Take an intermediate position. When the liquid crystal structure 5A has an intermediate posture, the posture vector PV of the liquid crystal structure 5A is inclined with respect to the vertical direction Dv, and the rotation angle θ of the liquid crystal structure 5A is an acute angle. Therefore, the long axis of the dichroic dye molecule 21a is inclined with respect to the parallel direction Dp. As a result, when light L1 substantially parallel to the vertical direction Dv enters the liquid crystal structure 5A, the dichroic dye 21 absorbs the light L1 at an absorption rate corresponding to the inclination of the long axis of the dichroic dye molecule 21a. . The greater the inclination of the long axis of the dichroic dye molecule 21a with respect to the parallel direction Dp, the lower the light absorption rate by the dichroic dye molecule 21a.

As described above with reference to FIGS. 4, 6, and 13, according to the fourth embodiment, the driving voltage is switched between "not applying" and "applying" to the liquid crystal layer 3. By doing so, the attitude of the liquid crystal structure 5A can be switched between the first attitude and the second attitude. Therefore, by switching between "not applying" and "applying" the driving voltage to the liquid crystal layer 3, a state in which the optical element 100 absorbs the light L1 and a state in which the optical element 100 transmits the light L1 can be changed. You can easily switch between

That is, by switching between "not applying" and "applying" stimulation to the liquid crystal layer 3, a state in which the optical element 100 absorbs the light L1 and a state in which the optical element 100 transmits the light L1 can be created. can be easily switched.

Further, as described with reference to FIGS. 4 to 6 and FIG. 13, according to the fourth embodiment, by controlling the voltage value of the driving voltage for the liquid crystal layer 3, the posture of the liquid crystal structure 5 can be adjusted to the voltage value. It can be changed continuously according to the Therefore, by controlling the voltage value of the drive voltage, the absorption rate of the light L1 can be changed continuously.

That is, the liquid crystal structure 5 changes its posture depending on the magnitude of the stimulus applied to the liquid crystal layer 3, and changes its light absorption rate in accordance with the change in posture. That is, by controlling the magnitude of the stimulus to the liquid crystal layer 3, the attitude of the liquid crystal structure 5 can be continuously changed according to the magnitude of the stimulus. Therefore, by controlling the magnitude of the stimulus, the absorption rate of the light L1 can be continuously changed.

Further, according to the fourth embodiment, similarly to the first embodiment, the posture of the liquid crystal structure 5A can be reversibly controlled, and the response speed of the liquid crystal structure 5A can be improved.

Note that, as a modification of the second embodiment, the optical element 100 according to the second embodiment described with reference to FIGS. 9 and 10 includes the liquid crystal structure 5A according to the fourth embodiment instead of the liquid crystal structure 5. You can leave it there. In this case, the absorption rate of the light L1 of the liquid crystal structure 5A in the first attitude is smaller than the light absorption rate of the liquid crystal structure 5A in the second attitude.

Further, the optical element 100 according to the third embodiment described with reference to FIGS. 11 and 12 includes the liquid crystal structure 5A according to the fourth embodiment in place of the liquid crystal structure 5 as a modification of the third embodiment. You can leave it there. In this case, the liquid crystal structure 5A in the first attitude transmits light, and the liquid crystal structure 5A in the second attitude absorbs light.

In the modified example of the second embodiment and the modified example of the third embodiment, the light absorption rate can be easily controlled. Furthermore, the liquid crystal structure 5A can be manufactured in the same manner as the method for manufacturing the liquid crystal structure 5 according to the first embodiment.

Here, in the fourth embodiment described with reference to FIGS. 4, 6, and 13, or the modified example of the third embodiment described with reference to FIGS. 11 to 13, the liquid crystal structure 5A is When taking one of the postures and the second posture, the liquid crystal structure 5A absorbs the light L1. When the liquid crystal structure 5A takes the other of the first attitude and the second attitude, the liquid crystal structure 5A transmits the light L1.

(Embodiment 5)
An optical system 300A according to Embodiment 5 of the present invention will be described with reference to FIGS. 14 and 15. The fifth embodiment is different from the present embodiment described with reference to FIGS. 1 to 3(b) in that the optical element 100A of the optical system 300A according to the fifth embodiment controls the attitude of the liquid crystal structure 5 around two axes. It differs mainly in form. Hereinafter, the differences between the fifth embodiment and the present embodiment will be mainly described.

FIG. 14 is a perspective view showing an optical element 100A according to the fifth embodiment. As shown in FIG. 14, the optical element 100A includes an electrode pattern EL1 instead of the first electrode 51 and second electrode 52 shown in FIG. In FIG. 14, the electrode pattern EL1 is indicated by dot hatching. The electrode pattern EL1 individually applies driving voltages as stimulation to multiple locations on the liquid crystal layer 3. Then, in response to application of a driving voltage to the liquid crystal layer 3 by the electrode pattern EL1, the liquid crystal structure 5 changes its posture by rotating around the first axis AS1 and/or the second axis AS2. Therefore, according to the fifth embodiment, when the optical element 100A including the liquid crystal structure 5 that reflects light functions as a light deflection element, the direction of light deflection depending on the attitude of the liquid crystal structure 5 (that is, the output direction of the reflected light) This improves the degree of freedom in controlling direction).

Specifically, the electrode pattern EL1 includes a plurality of first electrodes 51A and a plurality of second electrodes 52A. In FIG. 14, the first electrode 51A and the second electrode 52A are indicated by dot hatching. In the example of FIG. 14, the number of the plurality of first electrodes 51A is not particularly limited as long as it is two or more. Moreover, in the example of FIG. 14, the number of the plurality of second electrodes 52A is not particularly limited as long as it is two or more. In the fifth embodiment, the first electrode 51A and the second electrode 52A are formed of a transparent electrode material. The transparent electrode material is, for example, ITO.

The plurality of first electrodes 51A are formed on the first substrate 1. In the fifth embodiment, the plurality of first electrodes 51A are formed on the main surface of the pair of main surfaces of the first substrate 1 on the side where the liquid crystal structure 5 is located. The plurality of first electrodes 51A are spaced apart from each other and extend along the first direction D1.

A plurality of second electrodes 52A are formed on the second substrate 2. In the fifth embodiment, the plurality of second electrodes 52A are formed on the main surface of the pair of main surfaces of the second substrate 2 on the side where the liquid crystal structure 5 is located. The plurality of second electrodes 52A are spaced apart from each other and extend along the second direction D2. The second direction D2 intersects the first direction D1. In the fifth embodiment, the second direction D2 is substantially orthogonal to the first direction D1. The first direction D1 and the second direction D2 are substantially orthogonal to the vertical direction Dv.

The plurality of second electrodes 52A intersect with the plurality of first electrodes 51A. In the fifth embodiment, the plurality of second electrodes 52A are substantially orthogonal to the plurality of first electrodes 51A while being spaced apart from each other in the vertical direction Dv.

The liquid crystal structure 5 is disposed astride the first electrodes 51A adjacent to each other while being spaced apart from the first electrodes 51A in the vertical direction Dv. Therefore, a part of the liquid crystal structure 5 faces one of the first electrodes 511 of the mutually adjacent first electrodes 51A in the vertical direction Dv. Furthermore, another part of the liquid crystal structure 5 faces the other first electrode 512 in the vertical direction Dv.

The liquid crystal structure 5 is disposed astride the second electrodes 52A adjacent to each other while being spaced apart from the second electrodes 52A in the vertical direction Dv. Therefore, a part of the liquid crystal structure 5 faces one of the second electrodes 521 of the mutually adjacent second electrodes 52A in the vertical direction Dv. Furthermore, another part of the liquid crystal structure 5 faces the other second electrode 522 in the vertical direction Dv.

FIG. 15 is a plan view showing an optical system 300A according to the fifth embodiment. As shown in FIG. 15, the optical system 300A includes a stimulation section 200A instead of the stimulation section 200 in FIG. The stimulation section 200A includes a first drive section 71 and a second drive section 72. In the fifth embodiment, a simple matrix method is adopted as the driving method for the liquid crystal layer 3.

The first drive section 71 selectively drives the plurality of first electrodes 51A. That is, the first drive section 71 selectively supplies the first drive signal to the plurality of first electrodes 51A. For example, the first driving unit 71 performs line sequential scanning to sequentially drive the first electrodes 51A one by one. That is, the first drive unit 71 performs line sequential scanning and sequentially supplies the first drive signal to the plurality of first electrodes 51A one by one. For example, the first drive unit 71 may drive two or more first electrodes 51A at the same time. That is, the first drive section 71 may supply the first drive signal to two or more first electrodes 51A simultaneously. The first drive unit 71 is, for example, a driver circuit that generates a first drive signal.

The second drive unit 72 selectively drives the plurality of second electrodes 52A. That is, the second drive section 72 selectively supplies the second drive signal to the plurality of second electrodes 52A. For example, the second drive unit 72 drives one or more second electrodes 52A in response to driving each of the plurality of first electrodes 51A. That is, the second drive unit 72 supplies the second drive signal to one or more second electrodes 52A in accordance with the drive of each of the plurality of first electrodes 51A. The second drive unit 72 is, for example, a driver circuit that generates a second drive signal.

In the fifth embodiment, the "stimulation" by the stimulation applying section 200A is "the first drive signal and the second drive signal." "The first drive signal and the second drive signal" are examples of "drive voltage." Note that FIGS. 14 and 15 show the state of the liquid crystal structure 5 when the first drive signal and the second drive signal are not supplied to the plurality of first electrodes 51A and the plurality of second electrodes 52A. . That is, FIGS. 14 and 15 show the state of the liquid crystal structure 5 when no stimulus is applied to the liquid crystal layer 3 from the outside.

Each of the plurality of liquid crystal structures 5 corresponds to four mutually adjacent intersection positions Qa, Qb, Qc, and Qd among the plurality of intersection positions of the plurality of first electrodes 51A and the plurality of second electrodes 52A, respectively. It has four portions Ua, Ub, Uc, and Ud located at the same point. In FIG. 15, portions Ua, Ub, Uc, and Ud are shown with broken lines for easy understanding, but in reality, the broken lines do not exist.

As shown in FIG. 14, the first liquid crystal FLa of the first liquid crystals FL constituting the liquid crystal layer 3 is located corresponding to the portion Ua of the liquid crystal structure 5. The first liquid crystal FLa includes a plurality of liquid crystal molecules LC1a. The first liquid crystal FLb of the first liquid crystal FL is located corresponding to the portion Ub of the liquid crystal structure 5. The first liquid crystal FLb includes a plurality of liquid crystal molecules LC1b. A first liquid crystal FLc of the first liquid crystals FL is located corresponding to a portion Uc of the liquid crystal structure 5. The first liquid crystal FLc includes a plurality of liquid crystal molecules LC1c. A first liquid crystal FLd of the first liquid crystals FL is located corresponding to a portion Ud of the liquid crystal structure 5. The first liquid crystal FLd includes a plurality of liquid crystal molecules LC1d.

Therefore, as shown in FIGS. 14 and 15, according to the fifth embodiment, the first drive signal is selectively supplied to the plurality of first electrodes 51A, and the first drive signal is selectively supplied to the plurality of second electrodes 52A. By supplying the second drive signal to the liquid crystal structure 5, the first liquid crystal FLa corresponding to the portion Ua, the first liquid crystal FLb corresponding to the portion Ub, the first liquid crystal FLc corresponding to the portion Uc, and the portion Ud are By individually driving the first liquid crystals FLd corresponding to , the alignment of the liquid crystal molecules LC1a, the alignment of the liquid crystal molecules LC1b, the alignment of the liquid crystal molecules LC1c, and the alignment of the liquid crystal molecules LC1d can be individually controlled.

As a result, the forces acting on the portions Ua to Ud of the liquid crystal structure 5 from the first liquid crystals FLa to FLd can be individually controlled for each of the portions Ua to Ud. Therefore, by rotating the liquid crystal structure 5 around the first axis AS1 and/or the second axis AS2, the attitude of the liquid crystal structure 5 can be changed around the first axis AS1 and/or the second axis AS2.

When the optical element 100A including the liquid crystal structure 5 that reflects light functions as a light deflection element, the attitude of the liquid crystal structure 5 can be changed around the first axis AS1 and/or the second axis AS2. The degree of freedom in controlling the direction of polarization of light (that is, the direction of emission of reflected light) is improved.

Here, the first axis AS1 is approximately parallel to the first electrode 51A and the first direction D1. The second axis AS2 is substantially parallel to the second electrode 52A and the second direction D2. The first axis AS1 intersects the second axis AS2. In the fifth embodiment, the first axis AS1 is substantially orthogonal to the second axis AS2. Note that, in FIG. 14, some liquid crystal molecules LC1 out of a large number of liquid crystal molecules LC1 are illustrated for the sake of simplification of the drawing.

In particular, in the fifth embodiment, as shown in FIG. 15, the portion Ua of the liquid crystal structure 5 is located at the intersection position Qa. The intersection position Qa indicates a position where the first electrode 511 and the second electrode 521 intersect three-dimensionally. Therefore, the portion Ua is located between the first electrode 511 and the second electrode 521 at the intersection position Qa. Portion Ub of liquid crystal structure 5 is located at intersection position Qb. The intersection position Qb indicates a position where the first electrode 511 and the second electrode 522 intersect three-dimensionally. Therefore, the portion Ub is located between the first electrode 511 and the second electrode 522 at the intersection position Qb.

Portion Uc of liquid crystal structure 5 is located at intersection position Qc. The intersection position Qc indicates a position where the first electrode 512 and the second electrode 522 intersect three-dimensionally. Therefore, the portion Uc is located between the first electrode 512 and the second electrode 522 at the intersection position Qc. Portion Ud of liquid crystal structure 5 is located at intersection position Qd. The intersection position Qd indicates a position where the first electrode 512 and the second electrode 521 intersect three-dimensionally. Therefore, the portion Ud is located between the first electrode 512 and the second electrode 521 at the intersection position Qd.

(Modification of Embodiment 5)
An optical system 300B according to a modification of the fifth embodiment of the present invention will be described with reference to FIGS. 14 and 16. The modified example differs from the fifth embodiment described with reference to FIGS. 14 and 15 in that the driving method of the liquid crystal layer 3 by the optical element 100B of the optical system 300B according to the modified example of the fifth embodiment is an active matrix method. Mainly different. Hereinafter, the differences between the modified example and the fifth embodiment will be mainly explained. Note that for common parts between the modified example and the fifth embodiment, FIG. 14 is appropriately referred to in the description of the modified example.

FIG. 16 is a plan view showing an optical system 300B according to a modification of the fifth embodiment. As shown in FIG. 16, the optical element 100B of the optical system 300B includes an electrode pattern EL2 instead of the electrode pattern EL1 shown in FIG. Similarly to the electrode pattern EL1 of the fifth embodiment, the electrode pattern EL2 individually applies driving voltages as stimulation to multiple locations on the liquid crystal layer 3 (FIG. 14). Then, in response to application of a driving voltage to the liquid crystal layer 3 by the electrode pattern EL2, the liquid crystal structure 5 changes its posture by rotating around the first axis AS1 and/or the second axis AS2.

Specifically, the electrode pattern EL2 includes a plurality of first electrodes 51B, a plurality of second electrodes 52B, and a common electrode CM. In the example of FIG. 16, the number of the plurality of first electrodes 51B is not particularly limited as long as it is two or more. Moreover, in the example of FIG. 16, the number of the plurality of second electrodes 52B is not particularly limited as long as it is two or more.

The plurality of first electrodes 51B and the plurality of second electrodes 52B are formed on the second substrate 2 (FIG. 14). In the modified example, the plurality of first electrodes 51B and the plurality of second electrodes 52B are formed on the main surface of the pair of main surfaces of the second substrate 2 on the side where the liquid crystal structure 5 is located. The plurality of first electrodes 51A are spaced apart from each other and extend along the first direction D1. The plurality of second electrodes 52B are spaced apart from each other and extend along the second direction D2.

In the second substrate 2 (FIG. 14), the plurality of second electrodes 52B intersect with the plurality of first electrodes 51B. In the modified example, in the second substrate 2, the plurality of second electrodes 52B are substantially orthogonal to the plurality of first electrodes 51B while being separated from each other.

Further, the optical element 100B further includes a plurality of thin film transistors T (TFTs) and a plurality of pixel electrodes P. It is preferable that the optical element 100B further includes a plurality of capacitors CP. The plurality of thin film transistors T are arranged corresponding to the plurality of intersection positions of the plurality of first electrodes 51B and the plurality of second electrodes 52B, respectively. The plurality of pixel electrodes P are arranged corresponding to the plurality of thin film transistors T, respectively. In a modified example, the pixel electrode P is formed of a transparent electrode material. The transparent electrode material is, for example, ITO. The plurality of capacitors CP are arranged corresponding to the plurality of pixel electrodes P, respectively.

The gate electrode of the thin film transistor T is connected to the corresponding first electrode 51B, the source electrode of the thin film transistor T is connected to the corresponding second electrode 52B, and the drain electrode of the thin film transistor T is connected to the corresponding pixel electrode P. . A corresponding capacitor CP is connected to the pixel electrode P. Capacitor CP holds charge. The thin film transistor T, pixel electrode P, and capacitor CP are formed on the second substrate 2 (FIG. 14) similarly to the first electrode 51B and the second electrode 52B.

The common electrode CM is a planar electrode and is formed on the first substrate 1 (FIG. 14). The common electrode CM faces a plurality of pixel electrodes P formed on the second substrate 2 via the liquid crystal layer 3 (FIG. 14). A common signal is supplied to the common electrode CM. In a modified example, the common electrode CM is formed of a transparent electrode material. The transparent electrode material is, for example, ITO.

The first drive section 71 selectively drives the plurality of first electrodes 51B. That is, the first drive unit 71 selectively supplies the first drive signal to the plurality of first electrodes 51B, and turns on the thin film transistor T to which the first drive signal is supplied. For example, the first drive unit 71 performs line sequential scanning and sequentially supplies the first drive signal to the plurality of first electrodes 51B one by one. For example, the first drive section 71 may simultaneously supply the first drive signal to two or more first electrodes 51B.

The second drive section 72 selectively drives the plurality of second electrodes 52B. That is, the second drive section 72 selectively supplies the second drive signal to the plurality of second electrodes 52B. For example, the second drive unit 72 supplies the second drive signal to one or more second electrodes 52B in accordance with the drive of each of the plurality of first electrodes 51B. As a result, the second drive signal is supplied to the pixel electrode P connected to the thin film transistor T that is turned on. That is, a voltage is applied to the pixel electrode P. The voltage applied to the pixel electrode P is a driving voltage that drives the first liquid crystal FL located between the pixel electrode P and the common electrode CM. The capacitor CP is an auxiliary capacitor that holds charge based on the voltage applied to the pixel electrode P.

In the modified example, the "stimulation" by the stimulation applying unit 200A is "the first drive signal and the second drive signal". "The first drive signal and the second drive signal" are examples of "drive voltage." Note that FIG. 16 shows the state of the liquid crystal structure 5 when the first drive signal and the second drive signal are not supplied to the plurality of first electrodes 51B and the plurality of second electrodes 52B. In other words, FIG. 16 shows the state of the liquid crystal structure 5 when no stimulus is applied to the liquid crystal layer 3 from the outside.

Each of the plurality of liquid crystal structures 5 corresponds to four mutually adjacent intersection positions Qa, Qb, Qc, and Qd among the plurality of intersection positions of the plurality of first electrodes 51B and the plurality of second electrodes 52B, respectively. It has four portions Ua, Ub, Uc, and Ud located at the same point. In FIG. 16, portions Ua, Ub, Uc, and Ud are shown with broken lines for easy understanding, but in reality, the broken lines do not exist.

As shown in FIG. 16, according to the modification, the first drive signal is selectively supplied to the plurality of first electrodes 51B, and the second drive signal is selectively supplied to the plurality of second electrodes 52B. By supplying the drive signal, the first liquid crystal FLa (FIG. 14) corresponding to the portion Ua of the liquid crystal structure 5, the first liquid crystal FLb (FIG. 14) corresponding to the portion Ub, and the first liquid crystal FLc (corresponding to the portion Uc) 14) and the first liquid crystal FLd (FIG. 14) corresponding to the portion Ud are individually driven to align the liquid crystal molecules LC1a, the liquid crystal molecules LC1b, the liquid crystal molecules LC1c, and the liquid crystal molecules LC1d. The orientation of each can be individually controlled.

As a result, the forces acting on the portions Ua to Ud of the liquid crystal structure 5 from the first liquid crystals FLa to FLd can be individually controlled for each of the portions Ua to Ud. Therefore, by rotating the liquid crystal structure 5 around the first axis AS1 and/or the second axis AS2 (FIG. 14), the attitude of the liquid crystal structure 5 can be adjusted around the first axis AS1 and/or the second axis AS2. Can be changed.

When the optical element 100B including the liquid crystal structure 5 that reflects light functions as a light deflection element, the attitude of the liquid crystal structure 5 can be changed around the first axis AS1 and/or the second axis AS2. The degree of freedom in controlling the direction of polarization of light (that is, the direction of emission of reflected light) is improved.

In particular, in the modified example, as shown in FIG. 16, the portion Ua of the liquid crystal structure 5 faces the pixel electrode Pa in the vertical direction Dv (FIG. 14). The pixel electrode Pa is close to the intersection position Qa, corresponding to the intersection position Qa. The intersection position Qa indicates a position where the first electrode 511 and the second electrode 521 intersect three-dimensionally. Portion Ua is located between pixel electrode Pa and common electrode CM.

The portion Ub of the liquid crystal structure 5 faces the pixel electrode Pb in the vertical direction Dv (FIG. 14). The pixel electrode Pb is close to the intersection position Qb in correspondence with the intersection position Qb. The intersection position Qb indicates a position where the first electrode 512 and the second electrode 521 intersect three-dimensionally. Portion Ub is located between pixel electrode Pb and common electrode CM.

The portion Uc of the liquid crystal structure 5 faces the pixel electrode Pc in the vertical direction Dv (FIG. 14). The pixel electrode Pc is close to the intersection position Qc, corresponding to the intersection position Qc. The intersection position Qc indicates a position where the first electrode 512 and the second electrode 522 intersect three-dimensionally. Portion Uc is located between pixel electrode Pc and common electrode CM.

The portion Ud of the liquid crystal structure 5 faces the pixel electrode Pd in the vertical direction Dv (FIG. 14). The pixel electrode Pd is close to the intersection position Qd, corresponding to the intersection position Qd. The intersection position Qd indicates a position where the first electrode 511 and the second electrode 522 intersect three-dimensionally. Portion Ud is located between pixel electrode Pd and common electrode CM.

The liquid crystal structure 5 is arranged astride the four pixel electrodes Pa, Pb, Pc, and Pd while being spaced apart in the vertical direction Dv (FIG. 14) from the four pixel electrodes Pa, Pb, Pc, and Pd that are adjacent to each other. has been done.

Here, in the fifth embodiment and the modified example shown in FIGS. 15 and 16, the first driving section 71 selectively drives the plurality of first electrodes 51A so that the plurality of liquid crystal structures 5 take substantially the same posture. In addition to supplying the first drive signal, the second drive section 72 selectively supplies the second drive signal to the plurality of second electrodes 52A. Therefore, the emission directions (light deflection directions) of the light reflected by the plurality of liquid crystal structures 5 are substantially the same. Note that the first drive section 71 selectively supplies the first drive signal to the plurality of first electrodes 51A, and the second drive section 72 supplies the first drive signal to the plurality of first electrodes 51A so that the plurality of liquid crystal structures 5 take different postures. The second drive signal may be selectively supplied to the two electrodes 52A.

In addition, in the fifth embodiment and the modified example, as shown in FIG. (corresponding to the liquid crystal molecules LCA in FIG. 3(a)) are aligned. Further, the alignment of a plurality of liquid crystal molecules LCB (corresponding to liquid crystal molecules LCB in FIG. 3(a)) in a second region A2 (corresponding to the second region A2 in FIG. 2) adjacent to the second substrate 2 in the liquid crystal layer 3 are complete.

Note that in the fifth embodiment and the modified example, at least one of the first condition and the second condition is satisfied, similarly to the present embodiment described with reference to FIGS. 1 to 3(b). . In the example of FIG. 14, the first condition is not satisfied, but the second condition is satisfied. Further, in FIG. 14, in order to facilitate understanding, the first region A1 and the second region A2 are shown by a two-dot chain line, but the two-dot chain line does not actually exist. Further, in order to make the drawing easier to read, in FIG. 16, the liquid crystal structure 5 and the common electrode CM are shown by two-dot chain lines.

(Embodiment 6)
An optical system 300C according to Embodiment 6 of the present invention will be described with reference to FIGS. 17 and 18. The optical element 100C of the optical system 300C according to the sixth embodiment controls the orientation of the liquid crystal structure 5 at each position by controlling the orientation of the liquid crystal molecules LCA and LCB in the first area A1 and the second area A2. , Embodiment 6 is mainly different from Embodiment 5 described with reference to FIGS. 14 and 15. Hereinafter, the differences between the sixth embodiment and the fifth embodiment will be mainly explained.

FIG. 17 is a perspective view showing an optical element 100C according to the sixth embodiment. As shown in FIG. 17, the optical element 100C includes a plurality of liquid crystal structures 5 spaced apart from each other. In the example of FIG. 17, the positions of the plurality of liquid crystal structures 5 in the vertical direction Dv are approximately the same. In the example of FIG. 17, the number of first electrodes 51A and the number of second electrodes 52A are not particularly limited as long as the number of any one of the first electrodes 51A and the second electrodes 52A is 2 or more. .

The orientations of the plurality of liquid crystal molecules LCA in the first region A1 (corresponding to the first region A1 in FIG. 2) of the liquid crystal layer 3 are different. Furthermore, the orientations of the plurality of liquid crystal molecules LCB in the second region A2 (corresponding to the second region A2 in FIG. 2) of the liquid crystal layer 3 are different. Then, when a stimulus (driving voltage in the sixth embodiment) is applied to the liquid crystal layer 3 by the stimulus applying unit 200A (see FIG. 18 described later), the difference in orientation of the plurality of liquid crystal molecules LCA in the first region A1 and the The postures of the plurality of liquid crystal structures 5 change individually depending on the difference in orientation of the plurality of liquid crystal molecules LCA in the two areas A2. Therefore, according to the sixth embodiment, the attitude of the liquid crystal structure 5 can be controlled for each liquid crystal structure 5 at each position in the liquid crystal layer 3.

Specifically, the first region A1 of the liquid crystal layer 3 has a plurality of first portions J1. That is, the first area A1 is divided into a plurality of first portions J1. The second region A2 of the liquid crystal layer 3 has a plurality of second portions J2. A liquid crystal structure 5 is located between the first portion J1 and the second portion J2. That is, the second area A2 is divided into a plurality of second portions J2.

In addition, in FIG. 17, in order to facilitate understanding, the first region A1 and the second region A2 are shown by two-dot chain lines, but in reality, the two-dot chain lines do not exist. Further, in order to facilitate understanding, the boundaries between the adjacent first portions J1 are shown by two-dot chain lines, but in reality, no two-dot chain lines exist. Similarly, although the boundaries of the second portions J2 adjacent to each other are shown by two-dot chain lines, the two-dot chain lines do not actually exist.

Regarding the first portion J1, the liquid crystal structure 5, and the second portion J2 that are lined up along the vertical direction Dv, at least one of the first condition and the second condition is satisfied. That is, regarding the first portion J1, the second portion J2 opposite to the first portion J1, and the liquid crystal structure 5 located between the first portion J1 and the second portion J2, the first condition and the second condition are satisfied. At least one of the following conditions is satisfied.

The first condition is the same as the first condition described with reference to FIG. 3(a). However, in the sixth embodiment, the first condition is ``When no stimulus is applied to the liquid crystal layer 3, in the first portion J1 and the second portion J2 facing each other, the liquid crystal molecules LCA in the first portion J1 are The orientation is different from the orientation of the liquid crystal molecules LCB in the second portion J2. "When no stimulation is applied to the liquid crystal layer 3" means "when no driving voltage is applied to the liquid crystal layer 3", "when the first driving signal is applied to the plurality of first electrodes 51A and the plurality of second electrodes 52A", This corresponds to "when the second drive signal is not supplied" or "when the plurality of first electrodes 51A and the plurality of second electrodes 52A are not driven".

The second condition is the same as the second condition described with reference to FIG. 3(b). Note that in the example of FIG. 17, the first condition is not satisfied, but the second condition is satisfied.

The orientation of the liquid crystal molecules LCA is different between the first portions J1 and the first portions J1 that are adjacent to each other among the plurality of first portions J1. In the example of FIG. 17, the orientation of the liquid crystal molecules LCA is different in the first portion J1a, the first portion J1b, the first portion J1c, and the first portion J1d that are adjacent to each other. Further, within the first portion J1a, the orientation of the liquid crystal molecules LCA is uniform. Similarly, within the first portion J1b, the orientation of the liquid crystal molecules LCA is uniform, within the first portion J1c, the orientation of the liquid crystal molecules LCA is uniform, and within the first portion J1d, the orientation of the liquid crystal molecules LCA is uniform. The orientation of is the same. However, the orientation of the liquid crystal molecules LCA may gradually change between the first portions J1 and the first portions J1 that are adjacent to each other. In this case, the boundaries between the first portions J1 and the first portions J1 that are adjacent to each other may not be clear.

In addition, the orientation of the liquid crystal molecules LCB is different between the second portions J2 and the second portions J2 that are adjacent to each other among the plurality of second portions J2. In the example of FIG. 17, the orientation of the liquid crystal molecules LCB is different in the second portion J2a, the second portion J2b, the second portion J2c, and the second portion J2d that are adjacent to each other. Furthermore, within the second portion J2a, the orientation of the liquid crystal molecules LCB is uniform. Similarly, within the second portion J2b, the orientation of the liquid crystal molecules LCB is uniform, within the second portion J2c, the orientation of the liquid crystal molecules LCB is uniform, and within the second portion J2d, the orientation of the liquid crystal molecules LCB is uniform. The orientation of is the same. However, the orientation of the liquid crystal molecules LCB may gradually change between the second portions J2 and J2 that are adjacent to each other. In this case, the boundary between the second portions J2 and the second portions J2 that are adjacent to each other may not be clear.

Therefore, according to the sixth embodiment, when a driving voltage is applied to the liquid crystal layer 3, each of the plurality of liquid crystal structures 5 is aligned oppositely to the orientation of the liquid crystal molecules LCA in the opposing first portion J1. It takes a posture according to the orientation of the liquid crystal molecules LCB in the second portion J2. As a result, the plurality of liquid crystal structures 5 can reflect light in different directions, for example, depending on the orientation of the liquid crystal molecules LCA in the first portion J1 and the orientation of the liquid crystal molecules LCB in the second portion J2. That is, the attitude of the liquid crystal structure 5 can be controlled for each liquid crystal structure 5 at each position in the liquid crystal layer 3 .

FIG. 18 is a plan view showing an optical system 300C according to the sixth embodiment. As shown in FIG. 18, the plurality of liquid crystal structures 5 are respectively arranged corresponding to the plurality of intersection positions of the plurality of first electrodes 51A and the plurality of second electrodes 52A. In the example of FIG. 18, the plurality of liquid crystal structures 5a, 5b, 5c, and 5d are arranged at four intersecting positions Qa adjacent to each other among the plurality of intersecting positions of the plurality of first electrodes 51A and the plurality of second electrodes 52A. , Qb, Qc, and Qd, respectively.

As shown in FIG. 17, the first liquid crystal FLa of the first liquid crystals FL constituting the liquid crystal layer 3 is located corresponding to the liquid crystal structure 5a. The first liquid crystal FLa includes a plurality of liquid crystal molecules LC1a. The first liquid crystal FLb of the first liquid crystals FL is located corresponding to the liquid crystal structure 5b. The first liquid crystal FLb includes a plurality of liquid crystal molecules LC1b. A first liquid crystal FLc of the first liquid crystals FL is located corresponding to the liquid crystal structure 5c. The first liquid crystal FLc includes a plurality of liquid crystal molecules LC1c. A first liquid crystal FLd of the first liquid crystals FL is located corresponding to the liquid crystal structure 5d. The first liquid crystal FLd includes a plurality of liquid crystal molecules LC1d.

Therefore, as shown in FIGS. 17 and 18, according to the sixth embodiment, the first drive signal is selectively supplied to the plurality of first electrodes 51A, and the first drive signal is selectively supplied to the plurality of second electrodes 52A. The first liquid crystal FLa between the first portion J1a and the second portion J2a, the first liquid crystal FLb between the first portion J1b and the second portion J2b, and the first The first liquid crystal FLc between the portion J1c and the second portion J2c and the first liquid crystal FLd between the first portion J1d and the second portion J2d are individually driven to adjust the alignment of the liquid crystal molecules LC1a and the liquid crystal. The orientation of the molecule LC1b, the orientation of the liquid crystal molecule LC1c, and the orientation of the liquid crystal molecule LC1d can be individually controlled.

As a result, the forces acting on the liquid crystal structures 5a to 5d from the first liquid crystals FLa to FLd can be individually controlled for each of the liquid crystal structures 5a to 5d. Therefore, by rotating the liquid crystal structures 5a to 5d individually, the postures of the liquid crystal structures 5a to 5d can be changed individually. If the postures of the liquid crystal structures 5a to 5d can be changed individually, the direction of light reflection by the liquid crystal structures 5a to 5d can be controlled for each of the liquid crystal structures 5a to 5d.

In particular, in the sixth embodiment, as shown in FIG. 18, the liquid crystal structure 5a is located at the intersection position Qa. Therefore, the first portion J1a and the second portion J2a shown in FIG. 17 are also located at the intersection position Qa. The liquid crystal structure 5b is located at the intersection position Qb. Therefore, the first portion J1b and the second portion J2b shown in FIG. 17 are also located at the intersection position Qb. The liquid crystal structure 5c is located at the intersection position Qc. Therefore, the first portion J1c and the second portion J2c shown in FIG. 17 are also located at the intersection position Qc. The liquid crystal structure 5d is located at the intersection position Qd. Therefore, the first portion J1d and the second portion J2d shown in FIG. 17 are also located at the intersection position Qd.

Note that FIGS. 17 and 18 show the state of the liquid crystal structure 5 when the first drive signal and the second drive signal are not supplied to the plurality of first electrodes 51A and the plurality of second electrodes 52A. . That is, FIGS. 17 and 18 show the state of the liquid crystal structure 5 when no stimulus is applied to the liquid crystal layer 3 from the outside. Note that in FIG. 17, some liquid crystal molecules LC1 out of a large number of liquid crystal molecules LC1 are illustrated for the sake of simplification of the drawing. Furthermore, the method for forming the plurality of first portions J1 of the first region A1 and the plurality of second portions J2 of the second region A2 of the liquid crystal layer 3 is as follows: As a method for patterning the liquid crystal molecules LCB of the second portion J2, for example, a photo-alignment method, a nanoimprint method, or a μ-rubbing method can be used.

(Modification of Embodiment 6)
An optical system 300D according to a modification of the sixth embodiment of the present invention will be described with reference to FIGS. 17 and 19. The modified example is different from the sixth embodiment described with reference to FIGS. 17 and 18 in that the driving method of the liquid crystal layer 3 by the optical element 100D of the optical system 300D according to the modified example of the sixth embodiment is an active matrix method. Mainly different. Hereinafter, the differences between the modified example of the sixth embodiment and the sixth embodiment will be mainly explained. Further, the configuration for implementing the active matrix method in the modified example of the sixth embodiment is similar to the configuration for implementing the active matrix method in the modified example of the fifth embodiment described with reference to FIG. Therefore, a description of the active matrix method will be omitted as appropriate. For common parts between the modification and the sixth embodiment, FIG. 17 will be referred to as appropriate in the description of the modification.

FIG. 19 is a plan view showing an optical system 300D according to a modification of the sixth embodiment. As shown in FIG. 19, the optical element 100D of the optical system 300D includes an electrode pattern EL2 instead of the electrode pattern EL1 shown in FIG. The orientations of the plurality of liquid crystal molecules LCA in the first region A1 (FIG. 17) of the liquid crystal layer 3 are different. Further, the orientations of the plurality of liquid crystal molecules LCB in the second region A2 (FIG. 17) of the liquid crystal layer 3 are different. Then, when the stimulation (driving voltage in the modified example) is applied to the liquid crystal layer 3 by the stimulation applying section 200A, the difference in orientation of the plurality of liquid crystal molecules LCA in the first region A1 and the difference in the orientation of the plurality of liquid crystal molecules LCA in the second region A2 are detected. The postures of the plurality of liquid crystal structures 5 change individually depending on the difference in orientation of the liquid crystal molecules LCA.

Specifically, the plurality of liquid crystal structures 5 are respectively arranged corresponding to the plurality of intersection positions of the plurality of first electrodes 51B and the plurality of second electrodes 52B. In the example of FIG. 19, the plurality of liquid crystal structures 5a, 5b, 5c, and 5d are arranged at four intersecting positions Qa adjacent to each other among the plurality of intersecting positions of the plurality of first electrodes 51B and the plurality of second electrodes 52B. , Qb, Qc, and Qd, respectively.

According to the modification, by selectively supplying the first drive signal to the plurality of first electrodes 51B and selectively supplying the second drive signal to the plurality of second electrodes 52B, , the first liquid crystal FLa between the first part J1a and the second part J2a shown in FIG. 17, the first liquid crystal FLb between the first part J1b and the second part J2b shown in FIG. The first liquid crystal FLc between the first part J1c and the second part J2c and the first liquid crystal FLd between the first part J1d and the second part J2d shown in FIG. The orientation of LC1a, the orientation of liquid crystal molecules LC1b, the orientation of liquid crystal molecules LC1c, and the orientation of liquid crystal molecules LC1d can be individually controlled.

As a result, the forces acting on the liquid crystal structures 5a to 5d from the first liquid crystals FLa to FLd can be individually controlled for each of the liquid crystal structures 5a to 5d. Therefore, by rotating the liquid crystal structures 5a to 5d individually, the postures of the liquid crystal structures 5a to 5d can be changed individually. If the postures of the liquid crystal structures 5a to 5d can be changed individually, the direction of light reflection by the liquid crystal structures 5a to 5d can be controlled for each of the liquid crystal structures 5a to 5d.

In particular, in the modified example, as shown in FIG. 19, the liquid crystal structure 5a faces the pixel electrode Pa in the vertical direction Dv (FIG. 17). Therefore, the first portion J1a, the second portion J2a, the liquid crystal structure 5a shown in FIG. 17, and the pixel electrode Pa shown in FIG. 19 are arranged along the vertical direction Dv.

The liquid crystal structure 5b faces the pixel electrode Pb in the vertical direction Dv (FIG. 17). Therefore, the first portion J1b, the second portion J2b, the liquid crystal structure 5b shown in FIG. 17, and the pixel electrode Pb shown in FIG. 19 are arranged along the vertical direction Dv.

The liquid crystal structure 5c faces the pixel electrode Pc in the vertical direction Dv (FIG. 17). Therefore, the first portion J1c, the second portion J2c, the liquid crystal structure 5c shown in FIG. 17, and the pixel electrode Pc shown in FIG. 19 are arranged along the vertical direction Dv.

The liquid crystal structure 5d faces the pixel electrode Pd in the vertical direction Dv (FIG. 17). Therefore, the first portion J1d, the second portion J2d, the liquid crystal structure 5d shown in FIG. 17, and the pixel electrode Pd shown in FIG. 19 are arranged along the vertical direction Dv.

In addition, in FIG. 19, the liquid crystal structure 5 and the common electrode CM are shown by two-dot chain lines in order to make the drawing easier to see.

Moreover, FIG. 19 shows the state of the liquid crystal structure 5 when the first drive signal and the second drive signal are not supplied to the plurality of first electrodes 51B and the plurality of second electrodes 52B. That is, FIG. 19 shows the state of the liquid crystal structure 5 when no stimulus is applied to the liquid crystal layer 3 from the outside. Further, in the example of FIG. 19, if the number of any one of the first electrodes 51B and the second electrodes 52B is 2 or more, the number of the first electrodes 51B and the number of the second electrodes 52B are particularly Not limited.

Here, in Embodiment 5 (including modified examples) and Embodiment 6 (including modified examples) described with reference to FIGS. 14 to 19, the liquid crystal layer 3 of Embodiment 1 to Embodiment 4 is employed. The liquid crystal structure 5 of Embodiment 1 to Embodiment 3 can be adopted, and the liquid crystal structure 5A of Embodiment 4 can be adopted. Further, in Embodiment 5 (including modified examples) and Embodiment 6 (including modified examples), the configuration for realizing the driving method (simple matrix method, active matrix method) of the liquid crystal layer 3 is an example, and Not particularly limited.

Next, the present invention will be specifically explained based on Examples, but the present invention is not limited by the following Examples.

In an example of the present invention, the optical element 100 according to Embodiment 1 described with reference to FIG. 4 was manufactured. To prepare the liquid crystal structure 5, 93.2 wt% of a photopolymerizable liquid crystal (Merck, RMM141C), 4.0 wt% of a chiral agent (Merck, CD-X), and a photopolymerization initiator (Tokyo Kasei Kogyo, 2- A sample containing 2.8 wt% of Benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone) was used. The sample was sealed in a sandwich cell coated with a horizontal alignment agent (JSR, AL1254) and subjected to anti-parallel rubbing. The liquid crystal structure 5 was produced by a two-photon excitation direct laser writing method using a titanium sapphire laser with a wavelength of 800 nm, a pulse width of 100 fs, and a repetition frequency of 80 MHz at room temperature where the sample exhibits a cholesteric phase. Specifically, after focusing on the center of the cell depth through an oil immersion objective lens (63x, NA = 1.4), the laser irradiation intensity was 4.5MW/cm ² and the irradiation time was 9μs/μm. A circular region with a diameter of 15 μm was raster scanned to produce a liquid crystal structure 5 having a substantially disk shape and a thickness of 3 μm.

Further, the cell was disassembled, and the liquid crystal structure 5 was mixed with nematic liquid crystal (Merck, 5CB), and the mixture was sealed in a 90° TN (Twisted Nematic) cell with a cell thickness of 15 μm. As a result, an optical element 100 was manufactured.

Then, on a temperature control stage set at 27°C, the response of the liquid crystal structure 5 when a rectangular wave AC voltage with a frequency of 10 kHz was applied to the liquid crystal layer 3 of the optical element 100 was observed under a polarizing microscope with an objective lens (×100 , NA=0.90).

On the other hand, as a comparative example, the optical element 500 described with reference to FIG. 7(a) was manufactured. The method for manufacturing optical element 500 was similar to the method for manufacturing optical element 100. However, in the optical element 500, the nematic liquid crystal did not have twisted orientation.

First, linearly polarized light was incident on the optical element 100 according to this example. The incident light was approximately perpendicular to the first substrate 1. The rotation direction of the cholesteric liquid crystal of the liquid crystal structure 5 was clockwise. Then, while applying a driving voltage from 0 V to 4 V to the liquid crystal layer 3, the reflected light from the optical element 100 was observed using a reflective polarizing microscope from a direction substantially perpendicular to the first substrate 1. By observing the reflected light, it was confirmed that when no driving voltage was applied to the liquid crystal layer 3, the liquid crystal structure 5 remained stationary in a state substantially parallel to the first substrate 1 and the second substrate 2. .

Furthermore, the rotation angle θ of the liquid crystal structure 5 was calculated by analyzing the observation results of reflected light at each drive voltage. Specifically, as the driving voltage gradually increases, the rotation angle θ of the liquid crystal structure 5 gradually increases, and the deflection of the reflected light increases. In addition, the reflected light is observed from a direction substantially perpendicular to the first substrate 1. As a result, the observed shape of the reflected light changes from circular to elliptical. Therefore, the rotation angle θ of the liquid crystal structure 5 was calculated based on the ellipticity of the observed shape of the reflected light.

FIG. 20 is a graph showing the relationship between the driving voltage of the optical element 100 and the rotation angle θ of the liquid crystal structure 5 according to this example. In FIG. 20, the horizontal axis shows the drive voltage (volts), and the vertical axis shows the rotation angle θ (degrees). The black squares show measured values, and the curves show theoretical values. As shown in FIG. 20, the rotation angle θ of the liquid crystal structure 5 increased as the driving voltage increased. Further, when the drive voltage was changed from the state in which the drive voltage was applied to the liquid crystal layer 3 to 0V, the rotation angle θ of the liquid crystal structure 5 became approximately zero degrees. Therefore, it was confirmed that the attitude of the liquid crystal structure 5 could be reversibly controlled.

Note that in the optical element 100, the diameter of the liquid crystal structure 5 is equivalent to the cell thickness, and if the thickness of the liquid crystal structure 5 is considered to be 3 μm, the maximum rotation angle is approximately 60 degrees. Therefore, in FIG. 20, the rotation angle θ of the liquid crystal structure 5 does not reach 90 degrees. However, as will be clear from the explanation of FIG. 21, which will be described later, the rotation angle θ of the liquid crystal structure 5 changes from about zero degrees to about 90 degrees. Note that there is a detection limit for reflected light of the reflective polarizing microscope, and based on the numerical aperture of the objective lens and total reflection in the liquid crystal layer 3, the detection limit was approximately 20 degrees.

Next, the spectrum of the transmitted light from the optical element 100 was measured, and the transmittance of light having a wavelength of 532 nm among the incident light was calculated. The transmitted light was measured from a direction substantially perpendicular to the second substrate 2. The measurement spot diameter of the transmitted light was 10 μm.

FIG. 21 is a graph showing the relationship between the light transmittance at a wavelength of 532 nm and the driving voltage of the optical element 100 according to this example. In FIG. 21, the horizontal axis shows the driving voltage (volt), and the vertical axis shows the light transmittance (%). As shown in FIG. 21, the light transmittance increased as the driving voltage increased. In other words, the light reflectance decreased as the driving voltage increased. In other words, the rotation angle θ of the liquid crystal structure 5 increased as the driving voltage increased.

Specifically, at a driving voltage of 0V to about 0.6V, the light transmittance was about 50%. The fact that the light transmittance is approximately 50% indicates that out of the linearly polarized incident light, only left-handed circularly polarized light in the direction opposite to the rotation direction of the cholesteric liquid crystal of the liquid crystal structure 5 was detected as transmitted light. Ta. In other words, the light transmittance of about 50% indicates that right-handed circularly polarized light in the same direction as the rotation direction of the cholesteric liquid crystal was reflected without being transmitted. In other words, it was estimated that about 100% of the right-handed circularly polarized light was reflected, and the rotation angle θ of the liquid crystal structure 5 was about zero degrees.

Further, at a driving voltage of 1.0 V or more, the light transmittance was about 90%. Therefore, it was confirmed that most of the incident light with a wavelength of 532 nm was transmitted. In other words, it was confirmed that not only the left-handed circularly polarized light in the direction opposite to the rotating direction of the cholesteric liquid crystal of the liquid crystal structure 5 but also most of the right-handed circularly polarized light in the same direction as the rotating direction of the cholesteric liquid crystal was transmitted. In other words, since most of the right-handed circularly polarized light of the incident light with a wavelength of 532 nm is transmitted, the rotation angle θ of the liquid crystal structure 5 is sufficiently large, and the reflection wavelength band of the liquid crystal structure 5 is outside of 532 nm. I was able to estimate that.

Next, the intensity of the reflected light from the optical element 100 according to the present example and the intensity of the reflected light from the optical element 500 according to the comparative example were measured. Specifically, a bandpass filter with a wavelength of 532 nm (half width of 10 nm) was inserted into the optical path of the reflected light, and the reflected light with a spot diameter of 200 μm was measured using a photomultiplier tube. The reflected light was measured when a driving voltage of 4V was applied to the liquid crystal layer 3 and the liquid crystal layer 83 and when it was not applied.

FIG. 22(a) is a graph showing the reflected light intensity of the optical element 500 according to the comparative example. FIG. 22(b) is a graph showing the reflected light intensity of the optical element 100 according to this example. In FIGS. 22(a) and 22(b), the horizontal axis indicates time (seconds), the left vertical axis indicates the intensity of reflected light (arbitrary unit), and the right vertical axis indicates drive voltage (volts).

As shown in FIG. 22(a), from a state in which a drive voltage of 4V was applied to the optical element 500 according to the comparative example, the drive voltage was switched to 0V at zero seconds. The intensity of the reflected light did not stabilize even after 12 seconds passed from zero seconds. In other words, in the comparative example, it was confirmed that the intensity of reflected light was difficult to stabilize. The reason why the intensity of the reflected light is difficult to stabilize is that, as explained with reference to FIGS. 7(a) to 8(b), in the comparative example, the liquid crystal structure 85 is rotatable around the alignment axis AX2. , it was shown that the attitude of the liquid crystal structure 85 is not uniquely determined.

As shown in FIG. 22(b), from a state in which a drive voltage of 4V was applied to the optical element 100 according to this example, the drive voltage was switched to 0V at zero seconds. The intensity of the reflected light stabilized after about 2 seconds from zero seconds. In other words, in this example, it was confirmed that the intensity of reflected light was easily stabilized. As explained with reference to FIGS. 4 and 6, the fact that the intensity of the reflected light is easily stabilized means that the posture of the liquid crystal structure 5 is uniquely determined in this example.

Comparing FIGS. 22(a) and 22(b), it was confirmed that the response time of the optical element 100 according to the present example was faster than the response time of the optical element 500 according to the comparative example. Specifically, although there is a time lag due to the detection limit of the objective lens (approximately 20 degrees), the optical element 500 according to the comparative example starts responding in about 2 seconds, and the optical element 100 according to the present example starts responding in about 2 seconds. It started responding in about 1 second.

The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof. Further, the plurality of components disclosed in the above embodiments can be modified as appropriate. For example, some of the components shown in one embodiment may be added to the components of another embodiment, or some of the components shown in one embodiment may be configured. Elements may be deleted from the embodiment.

In addition, the drawings mainly schematically show each component in order to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown in the drawings are Actual results may differ due to circumstances. Further, the configuration of each component shown in the above embodiment is an example, and is not particularly limited, and it goes without saying that various changes can be made without substantially departing from the effects of the present invention. .

The present invention provides an optical element and has industrial applicability.

1 First substrate 2 Second substrate 3 Liquid crystal layer 5, 5A Liquid crystal structure 21 Dichroic dye A1 First region A2 Second region B1 First surface region B2 Second surface region FL, FLA, FLB, FLC First liquid crystal SL, SLA, SLB 2nd liquid crystal EL1, EL2 Electrode pattern

Claims (12)

a first substrate;
a second substrate;
a liquid crystal layer disposed between the first substrate and the second substrate and containing a first liquid crystal;
a liquid crystal structure disposed in the liquid crystal layer and including a second liquid crystal;
The liquid crystal layer has a first region facing the first substrate and a second region facing the second substrate,
The liquid crystal structure has a first surface region that determines the orientation of the second liquid crystal, and a second surface region opposite to the first surface region,
At least one of the first condition and the second condition is satisfied,
The first condition is that when no external stimulation is applied to the liquid crystal layer, the orientation of liquid crystal molecules in the first region and the orientation of liquid crystal molecules in the second region are different,
The second condition is that when the stimulus is not applied to the liquid crystal layer, the orientation of liquid crystal molecules in the first surface region is different from the orientation of liquid crystal molecules in the second surface region,
In response to a change in the orientation of the first liquid crystal based on the stimulus to the liquid crystal layer, the liquid crystal structure changes its posture while maintaining the orientation of the second liquid crystal,
The liquid crystal structure reflects light depending on the orientation or absorbs light depending on the orientation,
The optical element, wherein the attitude is indicated by an attitude vector, the attitude vector being substantially perpendicular to the first surface area and pointing outward from the liquid crystal structure. Claim 1, wherein when the stimulus is not applied to the liquid crystal layer, alignment deformation of the first liquid crystal in the liquid crystal layer indicates torsional deformation between the first substrate and the second substrate. The optical element described in . Claim: When the stimulus is not applied to the liquid crystal layer, alignment deformation of the first liquid crystal in the liquid crystal layer exhibits spreading/curving deformation between the first substrate and the second substrate. Item 1. The optical element according to item 1. 5. An alignment of the first liquid crystal of the liquid crystal layer when the stimulus is not applied to the liquid crystal layer exhibits a vertical twisted alignment with pretilt between the first substrate and the second substrate. 1. The optical element according to 1. When the stimulus is not applied to the liquid crystal layer, the liquid crystal structure assumes a first posture according to the orientation of the first liquid crystal,
When the stimulus is applied to the liquid crystal layer, the liquid crystal structure takes a second attitude different from the first attitude according to a change in the orientation of the first liquid crystal,
When the liquid crystal structure takes one of the first attitude and the second attitude, the liquid crystal structure reflects light;
5 . The liquid crystal structure according to claim 1 , wherein when the liquid crystal structure takes the other of the first attitude and the second attitude, the liquid crystal structure transmits the light. optical element. 5. The liquid crystal structure according to claim 1, wherein the liquid crystal structure changes its posture according to the magnitude of the stimulus applied to the liquid crystal layer, and changes the direction of light reflection according to the change in the posture. The optical element according to item 1. The second liquid crystal of the liquid crystal structure has a plurality of helical structures each having selective reflection properties,
Each of the plurality of helical structures includes a plurality of liquid crystal molecules,
In each of the plurality of helical structures, the plurality of liquid crystal molecules are spirally rotated,
The optical element according to any one of claims 1 to 6, wherein the helical axes of the plurality of helical structures are aligned in a certain direction. When the stimulus is not applied to the liquid crystal layer, the liquid crystal structure assumes a first posture according to the orientation of the first liquid crystal,
When the stimulus is applied to the liquid crystal layer, the liquid crystal structure takes a second attitude different from the first attitude according to a change in the orientation of the first liquid crystal,
When the liquid crystal structure takes one of the first attitude and the second attitude, the liquid crystal structure absorbs light,
5 . The liquid crystal structure according to claim 1 , wherein when the liquid crystal structure takes the other of the first attitude and the second attitude, the liquid crystal structure transmits the light. optical element. 5. The liquid crystal structure according to claim 1, wherein the liquid crystal structure changes its posture according to the magnitude of the stimulus applied to the liquid crystal layer, and changes the light absorption rate according to the change in the posture. The optical element according to item 1. The liquid crystal structure includes a dichroic dye,
Claim 1, Claim 2, Claim 3, Claim 4, Claim 8, or Claim 9, wherein the orientation of the second liquid crystal of the liquid crystal structure is a planar orientation and a uniaxial orientation. The optical element described. further comprising an electrode pattern that individually applies the driving voltage as the stimulus to a plurality of locations on the liquid crystal layer,
11. The liquid crystal structure according to claim 1, wherein the liquid crystal structure changes its attitude by rotating around a first axis and/or a second axis in response to application of the driving voltage to the liquid crystal layer by the electrode pattern. The optical element according to any one of the items. The orientations of the plurality of liquid crystal molecules in the first region are different,
The orientation of the plurality of liquid crystal molecules in the second region is different,
When the stimulus is applied to the liquid crystal layer, a plurality of The optical element according to any one of claims 1 to 10, wherein the postures of the liquid crystal structures change individually.

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