JP3515544B2 - Reflector and reflective liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector and a reflective liquid crystal display device, and more particularly, to a reflector having a reflection characteristic that allows reflected light to appear brighter than other viewing angles when viewed from a specific viewing angle. The present invention relates to a reflective liquid crystal display device using a reflector.

[0002]

2. Description of the Related Art Liquid crystal display devices are roughly classified into a transmission type and a reflection type. Among them, the reflection type liquid crystal display device depends on external light for illumination or is visually recognized by using a front light, and is a portable computer, a computer, a digital clock, a communication device, a game machine, a measuring instrument, an electronic bulletin board. It is often used as a display unit for electronic devices such as. As shown in FIG. 8, an example of the reflective liquid crystal display device includes a light-transmissive display-side substrate 20 and a light-reflective reflective-side substrate 1 with a liquid crystal layer 30 interposed therebetween.
0 and 0 are arranged opposite to each other. The outer surface of the display-side substrate 20 serves as a display surface, and the reflective layer 12 is formed on the reflective-side substrate 10. In this reflection type liquid crystal display device, external light incident from the display surface passes through the display side substrate 20 and the liquid crystal layer 30 and is reflected by the reflection layer 12 of the reflection side substrate 10, and the reflected light passes through the liquid crystal layer 30 again. Then, the image is visually recognized by emitting from the display surface. In FIG. 8, the reflection side substrate 10 is the glass substrate 1 in order from the lower layer.
1, reflection layer 12, intervening layer 13, color filter layer 14,
The display-side substrate 20 in which the flattening layer 15, the transparent electrode 16 made of an ITO (Indium Tin Oxide) film or a NES film, and the alignment layer 17 are laminated, and which is arranged to face the display surface side with the liquid crystal layer 30 interposed therebetween is An alignment layer 21, an insulating layer 22, a transparent electrode 23 made of an ITO film or a NES film, a glass substrate 24, and an optical modulation layer (polarizing plate, retardation plate, etc.) 25 are laminated in this order from the liquid crystal layer 30 side. Has become.

In the exemplified liquid crystal display device, the color filter layer 14 of the reflection side substrate 10 is formed by sequentially arranging stripe-shaped R (red), G (green) and B (blue) colored films in parallel. The stripe-shaped transparent electrodes 16 are arranged in parallel corresponding to the respective colored films. In the display-side substrate 20, the transparent electrodes 23 are arranged in parallel so as to be orthogonal to the transparent electrodes 16 of the reflection-side substrate, and the display-side transparent electrode 23 and the reflection-side transparent electrode 16 intersect with each other.
The part of 0 forms the pixel corresponding to each color. Also,
In this liquid crystal display device, a front light is arranged further outside the display side substrate 20 as necessary (not shown). In this case, the light of the front light is also the same as the outside light, and the display side substrate 20 is the same. Also, the light passes through the liquid crystal layer 30 and is reflected by the reflection layer 12 of the reflection side substrate 10, and the reflected light again passes through the liquid crystal layer 30 and is emitted from the display surface.

The reflection layer 12 of the reflection side substrate 10 can be roughly classified into a smooth reflection type and a diffuse reflection type. In the smooth reflection type shown in FIG. 9A, the reflection surface of the reflection layer 12 (a) is finished to be smooth, and the incident angle (absolute value) and the emission angle (absolute value) of light sandwiching the normal line perpendicular to the display surface are Is the same as the absolute value. Therefore, when observing the display surface, the brightness of the display surface becomes uneven due to the positional relationship between the light source and the viewpoint, and there is a problem that the visibility of the light source and the face of the observer is reflected. In order to solve this problem, the diffuse reflection type
As shown in FIGS. 9B and 10, the reflective layer 12
A large number of fine irregularities (recesses 3 in FIG. 10) are formed on the reflecting surface of FIG.
1) are irregularly formed adjacent to each other. Therefore, in the diffuse reflection type, the external light incident at a constant angle is reflected by the reflection layer 1
2 (b) diffusely reflects on the surface and diffuses the reflected light, the brightness does not change much even if the viewpoint is moved, and there is little reflection.
A so-called wide viewing angle reflective liquid crystal display device can be obtained.

Regarding the material of the diffuse reflection type reflection layer 12 (b), the shape and distribution of the unevenness, the method of forming the unevenness, etc.,
Various proposals have been made from the viewpoint of reflection characteristics and productivity. As a method of forming the unevenness, for example, the surface of a plate-shaped resin base material made of a photosensitive resin layer or the like is irradiated with light through a pattern mask, and a large number of adjacent fine spherical recesses 31 are formed by a developing process. A method of vapor-depositing or plating aluminum or silver on the surface where the recess is formed to make it a mirror surface, or a punch with a hemispherical tip is pushed into the surface of a smooth base material such as an aluminum plate or silver plate. A method of forming a large number of fine spherical concave portions 31 ... Which are adjacent to each other is known. The shape of the recesses 31 ...
The depth is a spherical surface distributed within a range of 0.1 μm to 3 μm, and the mutual distance is set so that the pitch (distance between centers) between adjacent concave portions varies within a range of 5 μm to 50 μm. .

[0006]

As for electronic equipment such as a desktop computer and a portable computer, an example of a desktop computer is shown in FIG. 11A and an example of a portable computer is shown in FIG.
As shown in (b), an observer often observes the display surface of the liquid crystal display device obliquely from below when actually viewing the display surface. That is, the observer's viewpoint Ob is inclined below the display surface by the angle θ with respect to the normal line X perpendicular to the display surface.

On the other hand, in the reflection type liquid crystal display device, illumination is often dependent on external light, and the external light is an optical modulation layer 25 such as a polarizing plate, two transparent electrodes 16 and 23, and a liquid crystal layer 30. , The color filter layer 14 and other layers are reciprocally attenuated, and in the diffuse reflection type, the incident light is diffused in a wide range by the reflection layer 12 (b). The screen is generally quite dark. Therefore, if there is little outside light, the visibility is significantly reduced. In particular, in the conventional reflection type liquid crystal display device, the shape and arrangement of the concave portion are designed so as to eliminate the fluctuation of the brightness depending on the viewing angle as much as possible, so that the observation is performed from a specific viewing angle range obliquely below the normal line X. However, there is a problem that sufficient brightness cannot be obtained. Also, when using a front light, there is a problem of attenuation and diffusion as in the case of outside light. Therefore, it is necessary to secure sufficient brightness in a specific visual range without increasing power consumption for lighting. Was difficult.

Therefore, there has been a demand for a reflection type liquid crystal display device in which glare can be suppressed in a wide viewing angle range and the display screen can be particularly brightly observed in a specific viewing angle range. The present invention has been made to solve the above problems, and therefore an object of the present invention is to have a light diffusing property for suppressing glare in a wide viewing angle range, and yet to make the image look particularly bright in a specific viewing angle range. Another object of the present invention is to provide a transparent reflector and a reflective liquid crystal display device using this reflector.

[0009]

According to the present invention, in order to solve the above-mentioned problems, a plurality of recesses having light reflectivity are formed on the surface of a base material, and the inner surface of each recess is a curved surface.
Is has the following specific longitudinal section, each of the recess passes through the deepest point of the recess, the specified longitudinal section, the shape of its inner surface, a first curve which leads to the deepest point from a peripheral portion of the recess, This first
A second curve which is continuous from the curve and extends from the deepest point of the recess to the other peripheral portion, and the average absolute value of the inclination angle of the first curve with respect to the substrate surface is the second curve with respect to the substrate surface. It is made larger than the average value of the absolute value of the tilt angle, and the basis of the first curve is
The maximum absolute value of the tilt angle with respect to the material surface is 4 ° to 35
And the depth of the plurality of recesses is 0.1 μm .
irregularly formed within the range of m to 3 μm, and
The second curve in each recess is the side closer to the observer and the lower side
The first curve is set to the upper side on the side away from the observer, and
Place the substrate diagonally to the horizontal plane so that it can be observed
To provide a reflector. In this reflector, a plurality of concave portions having light reflectivity are formed on the surface of the base material, and since these concave portions are formed of curved surfaces (concave surfaces), a wide bright display range is secured and reflection is suppressed. Has light diffusivity. In addition, the inner surface shape of these recesses is composed of a first curve and a second curve with the deepest point as a boundary in a specific vertical section, and the average value of the absolute values of the inclination angles of the first curve with respect to the substrate surface is The curve is formed so as to be larger than the average value of the absolute values of the inclination angles of the second curve with respect to the substrate surface. That is, the slope of the first curve is relatively steep, the slope of the second curve is relatively gentle, and the second curve is
It is longer than the first curve. Therefore, the light reflected by the surface around the second curve becomes larger than the light reflected by the surface around the first curve. That is, the light is reflected so that the light flux density in the regular reflection direction with respect to the surface around the second curve becomes high. Therefore, if the direction of the first curve of each recess is aligned with a specific direction (single or multiple specific directions), it is possible to increase the reflection intensity of the reflector as a whole in the specific direction.

In the present invention, it is preferable that the plurality of recesses are formed so that the directions of their respective specific longitudinal sections are the same, and that the respective first curves are oriented in a single direction. As a result, the reflectance of the entire reflector in the direction of being reflected by the surface around the second curve is increased. That is, it is possible to provide a reflection characteristic in which reflected light traveling in a specific direction is appropriately concentrated.

In the present invention, it is desirable that the first curve and the second curve have an inclination angle of zero with respect to the surface of the substrate at a position where they are in contact with each other. When the inclination angle of the first curve is negative and the inclination angle of the second curve is positive, the inclination angle of the first curve gradually approaches zero from the negative value side, and the inclination angle of the second curve is positive. It is more preferable that the inclination angles of the first curve and the second curve both become zero at the positions where the values gradually approach zero from the value side of and the two come into contact with each other. As a result, the entire inner surface of the recess can be formed gently, so that it is possible to prevent the amount of reflection in the regular reflection direction from decreasing.

The maximum absolute value of the inclination angle of the first curve with respect to the surface of the substrate can be changed within the range of 2 ° to 90 °. In particular, it is preferable that the angle is in the range of 4 ° to 35 °. The selection of the maximum value is preferably changed according to the angle at which the viewer looks at the display surface of the liquid crystal display device, but the range is preferably 2 ° to 80 °. 8
When the angle exceeds 0 °, the reflection angle on the side surface becomes excessively large, and a part of the reflected light exceeds the frame of the pixel of the reflective liquid crystal display device to darken the field of view. If the maximum inclination angle is less than 2 °, the effect of biasing the field distribution of the amount of reflected light may be insufficient, and the desired brightness may not be obtained at the specific viewing angle. When applied to general electronic equipment such as a desktop computer or a portable computer, the maximum value is within the range of 4 ° to 35 ° in consideration of the normal viewing angle of the observer with respect to the display surface of the liquid crystal display device. Is more preferable. A plurality of the substrate surface
The concave part has a tip shape with each concave part shape converted into a convex surface.
Punched on the base material surface.
You can

The depth of the plurality of recesses is 0.1 μm to 3 μm.
It is preferably irregularly formed within the range of μm. When the depth of the recess is less than 0.1 μm, the light scattering effect is insufficient. If it exceeds 3 μm, the thickness of the base material for realizing this depth becomes too large, which is inconvenient in terms of manufacturing and products. When the depths of the plurality of recesses are irregularly formed, it is possible to prevent the occurrence of a moire pattern due to the interference of light, which is likely to occur when the depths of the recesses are regularly formed, and to prevent a specific viewing angle. The peak concentration of the amount of reflected light at is relaxed, and the change in the amount of reflected light within the field of view becomes gentle.

The plurality of recesses are preferably arranged irregularly adjacent to each other. If the recesses are separated from each other, a flat surface is formed between the recesses, and thus planar reflection increases, and a sufficient diffused reflection effect cannot be obtained in a limited pixel area. Therefore, the recesses are formed adjacent to each other. Preferably. Further, since the moire pattern is generated when the concave portions are regularly arranged, it is preferable to arrange the concave portions irregularly. Further, the present invention makes the shape of the concave portion a convex surface.
The punch with the converted tip shape is stamped on the base material and stamped.
Predetermine the base material by irregularly changing the stroke and stamp interval
The depth of the recess is 0.1 μm by stamping the entire area .
And irregularly formed within the range of 3 μm to 3 μm.
The number of recesses is irregularly arranged adjacent to each other.
It may be a sign.

The present invention also provides a reflective liquid crystal display device equipped with any one of the above reflectors. In particular, the reflector is formed such that the specific longitudinal sections of each of the plurality of recesses are the same, and each first curve is oriented in a single direction, and the reflector is formed in each recess. It is preferable that the first curve is provided so as to be located above the second curve as seen by the observer. in this way,
If the first curves of all the concave portions are provided so as to be located above the second curve as seen from the observer, normally, the external light or the like that is incident mainly from above will be received more than the foot direction of the observer. It can be shifted in the direction normal to the surface of the substrate. In addition, the amount of reflected light is increased as a whole from the viewpoint of the observer, since the external light or the like mainly incident from above efficiently enters the surface around the second curve. Therefore, the amount of light reflected in the direction of the line of sight of the observer increases, and a reflective liquid crystal display device having a bright screen from a practical viewpoint is realized.

The present invention is also characterized in that the integral value of reflectance in the reflection angle range smaller than the regular reflection angle with respect to the substrate surface and the integral value of reflectance in the reflection angle range larger than the regular reflection angle are different. To provide a reflector. According to the present invention, when the normal viewing angle of the observer deviates from the direction of specular reflection, the reflector can reflect light mainly in the direction of the normal viewing angle.

The present invention also provides a reflector in which the integral value of reflectance in the reflection angle range smaller than the regular reflection angle with respect to the substrate surface and the integral value of reflectance in the reflection angle range larger than the regular reflection angle are different. The reflector is provided such that the reflection angle range in which the integral value of the reflectance of the reflector becomes large is higher than the angle of regular reflection with respect to the surface of the base material as seen from an observer. A reflective liquid crystal display device is provided. According to the present invention, it is possible to shift outside light or the like, which is normally incident mainly from above, in the normal direction to the surface of the base material rather than in the foot direction of the observer. Therefore, when used as a display device of a mobile phone or a notebook computer, for example, the amount of light reflected in the direction of the line of sight of the observer increases, and a reflective liquid crystal display device having a bright screen from a practical viewpoint is realized.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be specifically described with reference to the drawings, but the following embodiments do not limit the present invention in any way. FIG. 1 is a diagram showing a reflector of this embodiment. As shown in FIG. 1, the reflector 1 of the present embodiment has a large number of light-reflecting concave portions 3a on a surface S (reference surface) of a flat plate-shaped substrate 2 made of, for example, aluminum.
.. (generally referred to as recesses 3) are irregularly adjacent to each other.

As shown in the perspective view of FIG. 2 and the sectional view of FIG. 3, these recesses 3 have an inner surface shape in a specific vertical section X of the recess 3 from the peripheral portion S1 of the recess to the deepest point D. And a second curve B which is continuous with the first curve A and extends from the deepest point D of the recess to the other peripheral portion S2. Both of these curves have an inclination angle of zero with respect to the substrate surface S at the deepest point D and are connected to each other. The inclination angle of the first curve A with respect to the substrate surface S is steeper than the inclination angle of the second curve D, and the deepest point D is at a position deviated from the center O of the recess 3 in the x direction. That is, the average value of the absolute values of the inclination angles of the first curve A with respect to the substrate surface S is
It is larger than the average value of the absolute values of the inclination angle of the second curve B with respect to the substrate surface S. The average value of the absolute values of the inclination angles of the first curve A with respect to the substrate surface S in the recesses 3a, 3b, 3c, ... Randomly varies in the range of 1 to 89 °. Further, the average value of the absolute values of the inclination angles of the second curve B in the recesses 3a, 3b, 3c, ...
Randomly scattered in the range of 5 to 88 °. Since the inclination angles of both curves are changing gently,
The maximum inclination angle δmax (absolute value) of the curve A is larger than the maximum inclination angle (absolute value) δb of the second curve. Further, the inclination angle of the deepest point D where the first curve A and the second curve B are in contact with the substrate surface is zero, and the inclination angle is a negative value and the inclination angle is a positive value. The second curve B which is
And are continuous in a gentle manner. In the reflector of the present embodiment, the maximum inclination angles δmax of the recesses 3a, 3b, 3c, ... Randomly vary within the range of 2 to 90 °. However, many recesses have irregularities in the maximum inclination angle δmax within the range of 4 ° to 35 °.

The concave portion 3 has a single minimum point D (a point on the curved surface where the inclination angle is zero) D.
Then, the distance between the minimum point D and the surface S of the base material forms the depth d of the concave portion 3, and the depth d is the concave portions 3a, 3b,
3c, ... Randomly varies within the range of 0.1 μm to 3 μm.

In this embodiment, the recesses 3a, 3b,
All the specific vertical cross sections X in 3c, ... Are in the same direction. Further, each first curve A is formed so as to be oriented in a single direction. That is, any of the recesses is formed so that the x direction shown in FIGS. 2 and 3 is the same.

In the reflector 1 of this embodiment, since the respective first curves A are formed so as to be oriented in a single direction, the reflection characteristics thereof are as shown in FIG. Is deviated from the direction of regular reflection with respect to. That is, as shown in FIG. 4, the reflected light K with respect to the incident light J from diagonally above in the x direction has a bright display range in the direction H shifted with respect to the base material surface S rather than the direction K _{0 of} regular reflection. It has been shifted.

As a result, as the total reflection characteristic in the specific vertical section X, the reflectance in the direction of being reflected by the surface around the second curve B is increased. Therefore,
It is possible to have a reflection characteristic in which reflected light is moderately concentrated in a specific direction. That is, FIG. 5 shows that the display surface of the reflection device 1 of the present embodiment is irradiated with external light at an incident angle of 30 ° and the light reception angle is the direction of regular reflection with respect to the display surface (base material surface).
It shows the relationship between the light receiving angle (θ °) and the brightness (reflectance) when shaken from the vertical position (0 °) to 60 ° around 0 °. FIG. 5 also shows, as a comparative example, the relationship between the light receiving angle and the reflectance of a reflection type liquid crystal display device using a conventionally used reflector having a spherical recess. As is apparent from FIG. 5, the light receiving angle of the comparative example is about 15 ° to about 45 °.
While the reflectance is almost uniform in the range up to °, the reflection device 1 of the present embodiment has a reflectance in a reflection angle range smaller than 30 °, which is the angle of regular reflection with respect to the substrate surface S. The integral value is larger than the integral value of the reflectance in the reflection angle range larger than the regular reflection angle. That is, sufficient brightness can be achieved in a visual field at an angle of about 20 °.

The method of manufacturing the reflector 1 is not particularly limited, but it can be manufactured, for example, as follows. First, a punch (perforation tool) having a tip shape in which the shape of the recess is converted to a convex surface is produced, the tip of the punch is made to face an aluminum base material, and the orientation direction relative to the aluminum base material of the punch is made constant. While keeping the same, the embossing stroke is irregularly changed, and the embossing interval is irregularly changed, and the entire surface of a predetermined region of the aluminum base material is engraved. The engraving stroke is adjusted so that the depth of the recess is within a predetermined range. The embossing interval is adjusted so that moire patterns do not occur.

FIG. 6 is a sectional view showing the layer structure of a reflective liquid crystal display device 100 incorporating the reflective device 1 of this embodiment. In FIG. 6, the reflection type liquid crystal display device 100 is
A light-transmissive display-side substrate 20 and a light-reflective reflective-side substrate 10 are arranged to face each other with the liquid crystal layer 30 interposed therebetween. The outer surface of the display side substrate 20 is a display surface, and the reflector 1 is incorporated in the reflection side substrate 10.

The reflection side substrate 10 comprises, in order from the bottom, a glass substrate 11, a reflector 1, a transparent intervening layer 13, a color filter layer 14, a transparent flattening layer 15, and an ITO (Indium Tin Oxid).
e) The display-side substrate 20 in which the transparent electrode 16 formed of a film or a NES film and the alignment layer 17 are laminated, and the display-side substrate 20 opposed to the display surface side with the liquid crystal layer 30 interposed therebetween is aligned in order from the liquid crystal layer 30 side. A layer 21, an insulating layer 22, a transparent electrode 23 made of an ITO film or a NES film, a glass substrate 24, and an optical modulation layer (polarizing plate, retardation plate, etc.) 25 are laminated. Further, the transparent electrode 16 and the transparent electrode 23 sandwiching the liquid crystal layer 30 are formed in stripes orthogonal to each other, and constitute a simple matrix type liquid crystal device in which the intersection area is a pixel.

In this reflective liquid crystal display device 100,
The reflector 1 has a first curve A of each of the recesses 3a, 3b, 3c, ....
Is mounted so as to be on the x direction side of the second curve B having a gentle slope. Characters and the like are displayed with the x direction as the upper side.

FIG. 7 is an explanatory diagram showing a usage state of the liquid crystal display device 100. Note that, in FIG. 7, for convenience of description, only the first curve A and the second curve B of the reflective liquid crystal display device 100 are illustrated, and the other constituent members are omitted. Such a reflective liquid crystal display device 100 has x
It is installed in a mobile phone, laptop computer, etc. with the direction facing up. In this case, the reflective liquid crystal display device 100 is usually installed or held obliquely with respect to the horizontal plane with the x direction obliquely upward as shown in FIG. 7. That is, the first curve A in each recess is provided so as to be located above the second curve B when viewed from the observer when in use. Then, the observer sees the reflective liquid crystal display device 1
It is usual to look at 00 from diagonally above the horizontal. In this case, the reflected light K of the external light (incident light J) mainly incident from above is mainly reflected by the surface around the second curve B, and therefore, as described with reference to FIG. Is less likely to be reflected, and is reflected in a direction higher than the direction K _{0 of} regular reflection. For this reason,
Since the normal observation range of the observer and the bright display range coincide with each other, a bright display device can be practically realized.

In the reflective liquid crystal display device of the embodiment shown in FIG. 6, the reflector 1 is formed as a layer different from the transparent electrode 16, but the transparent electrode 16 itself is formed by the reflector 1 and the transparent electrode is formed. If 16 is formed at the position of the reflector 1 in FIG. 6, the transparent electrode can also serve as the reflector, and the layer structure of the reflective liquid crystal display device can be simplified.

If the reflector is formed of a semi-transmissive / semi-reflective base material such as a half mirror and an illumination plate is arranged on the back surface of the liquid crystal panel, it becomes a reflection type when the external light is bright and the external light is When the lighting plate is turned on when it becomes dark, a transflective liquid crystal display device that can be used as a transmissive type is obtained. This transflective liquid crystal display device is also included in the present invention.

Further, if a front light is provided on the display surface side of the display side substrate 20, only the outside light is used when the outside light is bright, and the front light is turned on when the outside light becomes dark. A light type liquid crystal display device can be obtained. This front light type liquid crystal display device is also included in the present invention.

The liquid crystal driving method of the present invention is not particularly limited, and in addition to the simple matrix type, it can be similarly applied to an active matrix type using a thin film transistor or a thin film diode, or a segment type. . All of these liquid crystal display devices are included in the present invention.

[0033]

EFFECTS OF THE INVENTION The reflector of the present invention is formed with a plurality of concave portions having light reflectivity, and each of the concave portions has the following specific longitudinal section that passes through the deepest point of the concave portion. The longitudinal cross section has a shape in which the inner surface is continuous with the first curve extending from one peripheral portion of the recess to the deepest point,
A second curve extending from the deepest point of the recess to the other peripheral portion, and the average of the absolute values of the inclination angles of the first curve with respect to the base material surface is the absolute value of the inclination angle of the second curve with respect to the base material surface. It is formed to be larger than the average value, and the basis of the first curve is
The maximum absolute value of the tilt angle with respect to the material surface is 4 ° to 35
And the depth of the plurality of recesses is 0.1 μm .
irregularly formed within the range of m to 3 μm, and
The second curve in each recess is the side closer to the observer and the lower side
The first curve is set to the upper side on the side away from the observer, and
Place the substrate diagonally to the horizontal plane so that it can be observed
Therefore, it is possible to diffuse the incident light and suppress the reflection in a wide viewing angle range, and to increase the reflected light amount in the normal viewing angle range of the observer. Well
In addition, the plurality of concave portions on the surface of the base material change each concave shape into a convex surface.
Engraving of punch with modified tip shape on substrate surface
If it is formed by
Depth 0. Irregularly formed within the 1μm~3μm
It is possible to realize a different structure, and the specific vertical section of each of the plurality of recesses
Orientation is equal and each first curve is oriented in a single direction
Can be implemented in a manner that is irregular to each other
It is possible to realize a configuration of a plurality of concave portions arranged adjacent to each other. The reflection-type liquid crystal display device of the present invention equipped with the reflector of the present invention suppresses glare in a wide viewing angle range, and is a reflection with improved visibility that looks particularly bright when the display surface is observed from a specific viewing angle. Type liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a perspective view showing a portion of a reflector of an embodiment.

FIG. 2 is a perspective view showing one recess of the embodiment.

FIG. 3 is a sectional view of a specific vertical section of the recess.

FIG. 4 is an explanatory diagram of a reflection characteristic of the reflector of the embodiment.

FIG. 5 is a graph showing the relationship between the light receiving angle and the reflectance.

FIG. 6 is a cross-sectional view showing the layer structure of the reflective liquid crystal display device of the embodiment.

FIG. 7 is an explanatory diagram of a usage state of the reflective liquid crystal display device of the embodiment.

FIG. 8 is a cross-sectional view showing an example of a general reflective liquid crystal display device.

FIG. 9A is a sectional view showing a reflection-side substrate of a smooth reflection type liquid crystal display device, and FIG.

FIG. 10 is a perspective view showing a portion of a conventional reflector.

FIG. 11A is a perspective view showing a viewing angle when visually observing a desktop computer and FIG. 11B is a perspective view when visually observing a portable computer.

[Explanation of symbols]

1: Reflector 2: Base material 3 3a, 3b, 3c: concave portions 10: Reflection side substrate A: First curve B: Second curve X: Specific longitudinal section

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Kano No. 1-7 Otsuka-cho, Yukiya, Ota-ku, Tokyo Alps Electric Co., Ltd. (56) Reference JP-A-11-52367 (JP, A) JP-A 11-52110 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 5/10 G02B 5/08 G02F 1/1335 520

Claims (11)

(57) [Claims] 1. A plurality of recesses having light reflectivity are formed on the surface of a base material, and the inner surface of each recess is a curved surface.
Is has the following specific longitudinal section, each of the recess passes through the deepest point of the recess, the specified longitudinal section, the shape of its inner surface, a first curve which leads to the deepest point from a peripheral portion of the recess, This first
A second curve which is continuous from the curve and extends from the deepest point of the recess to the other peripheral portion, and the average absolute value of the inclination angle of the first curve with respect to the substrate surface is the second curve with respect to the substrate surface. The maximum absolute value of the inclination angle of the first curve with respect to the substrate surface is set to be larger than the average of the absolute values of the inclination angle.
The value is set in the range of 4 ° to 35 °, and
The depth is irregularly formed within the range of 0.1 μm to 3 μm .
And observe the second curve in each recess
The side closer to the observer and the side away from the observer on the lower side of the first curve
And place the substrate diagonally to the horizontal
A reflector characterized by being observed . 2. The plurality of recesses are formed such that the directions of their respective specific longitudinal sections are the same, and each of the first curves is oriented in a single direction. The described reflector. 3. The reflector according to claim 1, wherein the first curve and the second curve have an inclination angle of zero with respect to the surface of the base material at a position in contact with each other. 4. A plurality of recesses on the surface of the base material each have a recessed shape.
On the surface of the base material of the punch with the tip shape
The reflector according to any one of claims 1 to 3, wherein the reflector is formed by stamping . 5. The first curve and the second curve are in contact with each other
Position is the deepest point of the recess, and the deepest point is the center of the recess.
4. The position shifts according to claim 3,
Reflector. 6. The method according to claim 1, wherein the plurality of concave portions are arranged irregularly adjacent to each other.
The reflector according to any one of 1. 7. A tip shape in which the shape of the recess is converted to a convex surface.
Punch a punch with a shape on the base material,
Engraves the entire surface of a specified area of the base material by irregularly changing the interval.
The depth of the recess is in the range of 0.1 μm to 3 μm .
Are irregularly formed within the plurality of
Claims characterized by being arranged irregularly adjacent to each other
The reflector according to any one of claims 1 to 6. 8. A reflection type liquid crystal display device, wherein the reflector according to claim 1 is mounted. 9. The reflector is formed such that the specific longitudinal sections of each of the plurality of recesses have the same direction, and each first curve is oriented in a single direction. 9. The reflection type liquid crystal display device according to claim 8, wherein the first curve in the concave portion is provided so as to be located above the second curve when seen by an observer. 10. A reflection characterized in that an integral value of reflectance in a reflection angle range smaller than an angle of specular reflection with respect to a surface of a base material and an integral value of reflectance in a reflection angle range larger than an angle of specular reflection are different. body. 11. The reflector according to claim 10 is provided, and the reflection angle range of the reflector in which the integrated value of the reflectance becomes large is specular reflection with respect to the surface of the base material as seen by an observer. The reflective liquid crystal display device is provided so as to be above the angle of.