JP4673045B2 - Image display device, stereoscopic image display device, and stereoscopic image display system - Google Patents

Description

  The present invention relates to an image display device, a stereoscopic image display device that displays a stereoscopic image using calculated interference fringes (computer hologram), and a stereoscopic image display system.

  2. Description of the Related Art Conventionally, an image display device that displays an image formed in a light modulation element by applying a voltage to the light modulation element is known. For example, a liquid crystal display (LCD) etc. are mentioned as this image display apparatus.

  Here, the light modulation element is an element having an electro-optic effect. The electro-optic effect is a phenomenon that occurs when an electric field is applied to a substance. Specifically, the electro-optic effect is a phenomenon in which the refractive index of the substance changes according to the electric field strength applied to the substance.

  With reference to FIGS. 23 and 24, a conventional image display device using a light modulation element will be described. As an image display device using a conventional light modulation element, an image display device having a simple matrix type electrode structure shown in FIG. 23 and an image display device having an active matrix type electrode structure shown in FIG. 24 are known. .

  As shown in FIG. 23A, in the image display device having a simple matrix type electrode structure, the electrode 23 in the X-axis direction is provided on the upper surface of the thinned light modulation element 25, and the thinned film is formed. An electrode 24 in the Y-axis direction is provided on the lower surface of the light modulation element 25.

  Here, each of the intersections of the X-axis direction electrode 23 and the Y-axis direction electrode 24 is displayed by an image display device having a simple matrix type electrode structure as shown in FIG. It becomes the pixel electrode 23a corresponding to each pixel which comprises an image.

  On the other hand, as shown in FIG. 24A, in the image display device having an active matrix electrode structure, a plurality of electrodes 23 are provided on the upper surface of the light modulation element 25, and the lower surface of the light modulation element 25 is provided. An electrode 24 is provided on the substrate.

  Here, as shown in FIG. 24B, the electrode 23 has a plurality of pixel electrodes 23a corresponding to each pixel constituting an image displayed by an image display device having an active matrix electrode structure. In addition, for each pixel electrode 23a, a configuration is prepared in which a transistor that can be independently controlled ON / OFF is prepared. The electrode 24 is grounded.

In a conventional image display device having an electrode structure of a simple matrix system and an active matrix system, a voltage value applied to the pixel electrode 23a is controlled based on a gray value or the like of each pixel constituting an image to be recorded on the light modulation element 25. Is configured to do.
Supervised by Fukumi, “New Handbook of Optical Materials”, pp. 60-67, Realize, 2000 Okuyama, “Electronic devices using ferroelectric thin films”, Electron Theory E, vol. 121, No. 10, pp. 537-541, 2001

  However, in the conventional image display device having a simple matrix type and active matrix type electrode structure, the voltage value to be applied can only be changed in units of each pixel electrode 23a, and therefore, within the rectangular region (pixel) shown in FIG. In this case, the gray value becomes the same, and the accuracy of the image that can be displayed by the conventional image display device is limited by the size and shape of the pixel electrode 23a.

  That is, in such a conventional image display device, since there is a limit to miniaturization of the pixel electrode 23a, a quantization error of an image to be displayed increases, and there is a problem that the image cannot be displayed with sufficient accuracy. It was.

  Therefore, the present invention has been made in view of the above points, and an image display device, a three-dimensional image display device, and a three-dimensional image display device that can eliminate as much as possible the limitation of image display accuracy due to the size and shape of the pixel electrode. An object is to provide an image display system.

  According to a first aspect of the present invention, there is provided a light modulation element having an electro-optic effect in which a refractive index changes according to an electric field strength, and a relative surface between the light modulation element and the light modulation element. A plurality of control points whose physical positional relationship is changeable, a pre-change electric field displacement surface formed by a voltage applied to the plurality of control points before the change of the positional relationship, and after the change of the positional relationship An electric field configured to combine an after-change electric field displacement surface formed by voltages applied to the plurality of control points to form an electric field displacement surface having a predetermined image pattern in the light modulation element. The gist of the present invention is an image display device including a control unit.

  A second feature of the present invention is a stereoscopic image display device that displays a stereoscopic image using calculated interference fringes, and a light modulation element having an electro-optic effect in which a refractive index changes according to electric field strength; A plurality of control points provided on the surface of the light modulation element and capable of changing a relative positional relationship with the light modulation element, and applied to the plurality of control points before the change of the positional relationship Combining the pre-change electric field displacement surface formed by the applied voltage and the post-change electric field displacement surface formed by the voltage applied to the plurality of control points after the change of the positional relationship, The gist of the present invention is to include an electric field control unit configured to form an electric field displacement surface having an image pattern equivalent to the image pattern in the light modulation element.

  In the second aspect of the present invention, the electric field control unit maintains a state in which the refractive index of the light modulation element is changed by applying a voltage to the plurality of control points before the positional relationship is changed. A voltage may be applied to the plurality of control points after the positional relationship is changed.

  In the second aspect of the present invention, the image pattern is configured by either the phase information of the interference fringes or the amplitude information of the interference fringes, or by both the phase information of the interference fringes and the amplitude information of the interference fringes. May be.

  In the second feature of the present invention, the control point may be an intersection of a vertical wiring electrode wired in the vertical direction and a horizontal wiring electrode wired in the horizontal direction on the surface of the light modulation element. Good.

  In the second aspect of the present invention, the electric field control unit stores an image pattern of the interference fringes and a voltage value applied to each of the plurality of control points in association with each other, and calculates the calculated interference fringes. The voltage value associated with the image pattern may be configured to be applied to each of the plurality of control points.

  In the second aspect of the present invention, the plurality of control points may be electrodes that are movably provided on the surface of the light modulation element.

  In the second aspect of the present invention, the light modulation element may be configured to be movable with respect to the plurality of control points.

  In the second feature of the present invention, the plurality of control points may be protrusion-shaped portions of electrodes provided on the surface of the light modulation element.

  In the second feature of the present invention, the relationship between the electric field strength and the change in the refractive index may be nonlinear in the light modulation element.

  In the second aspect of the present invention, the plurality of control points may include a plurality of microelectrodes, and the electric field control unit may be configured to control a voltage value applied to each of the microelectrodes. Good.

  In the second aspect of the present invention, the electric field control unit may be configured to individually control an application time for applying a voltage to the control point before and after the change of the positional relationship.

  In the second aspect of the present invention, the electric field control unit may be configured to individually control an application time for applying a voltage to the control point for each control point.

  A third feature of the present invention is a stereoscopic image display system that includes a stereoscopic image display device and a server device and displays a stereoscopic image, and the server device generates interference generated from object light and reference light. Interference fringe calculation unit for calculating fringes, image pattern of interference fringes, change information regarding change of relative positional relationship between a plurality of control points and light modulation elements of the stereoscopic image display device, and the positional relationship A storage unit that associates and stores a pre-change voltage value applied to each of the plurality of control points before the change and a post-change voltage value applied to each of the plurality of control points after the change of the positional relationship; A transmission unit configured to transmit the change information associated with the calculated image pattern of the interference fringes, the pre-change voltage value, and the post-change voltage value to the stereoscopic image display device; A light modulation element having an electro-optic effect in which a refractive index changes according to electric field strength, a plurality of control points provided on the surface of the light modulation element, and the pre-change voltage value received from the server device The changed voltage value received from the server device after changing the relative positional relationship between the plurality of control points and the light modulation element based on the change information. And an electric field control unit configured to form an electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes in the light modulation element. Is the gist.

  As described above, according to the present invention, it is possible to provide an image display device, a stereoscopic image display device, and a stereoscopic image display system that can eliminate as much as possible the limitation of image display accuracy due to the size and shape of pixel electrodes. can do.

(Configuration of stereoscopic image display system according to the first embodiment of the present invention)
FIG. 1 is a diagram illustrating an overall configuration of a stereoscopic image display system according to a first embodiment of the present invention. The stereoscopic image display system according to the present embodiment is a stereoscopic image display system that displays a stereoscopic image using calculated interference fringes (computer hologram).

  In the present embodiment, the “image” is a concept including both a still image and a moving image (video or video).

  As illustrated in FIG. 1, the stereoscopic image display system according to the present embodiment includes an interference fringe calculation device 1, a stereoscopic image display device 2, and a reference light irradiation device 3.

  The interference fringe calculation apparatus 1 is configured by a computer, and interference generated from object light and reference light generated by reflection of laser light irradiated on a three-dimensional object (for example, cubic 3D data). It is configured to calculate fringes. Here, as shown in FIGS. 2A and 2B, for example, the interference fringes are grayscale images in which a change in luminance corresponds to light amplitude information and a striped pattern corresponds to light phase information. It is.

  The stereoscopic image display device 2 includes a light modulation element 25 having an electro-optic effect in which the refractive index changes according to the electric field strength, and the light modulation element 25 corresponds to the interference fringe calculated by the interference fringe calculation device 1. An image pattern equivalent to the image pattern of the interference fringes is formed in the light modulation element 25 by changing the applied electric field strength.

  As shown in FIG. 1, the stereoscopic image display device 2 includes a hologram recording element 21, an electric field control unit 22, and an electrode moving unit 27.

  As shown in FIG. 3A, the hologram recording element 21 includes a light modulation element 25 having an electro-optic effect in which the refractive index changes according to the electric field strength, and a plurality of light modulation elements 25 provided on the surface of the light modulation element 25. And a control point 26.

  Specifically, the hologram recording element 21 has a configuration in which the light modulation element 25 is sandwiched between the fine upper surface electrode 23 and the lower surface electrode 24.

  In the present embodiment, the horizontal wiring electrode wired in the X-axis direction (lateral direction) on the upper surface of the light modulation element 25 and the vertical wiring wired in the Y-axis direction (vertical direction) on the lower surface of the light modulation element 25. Let the intersection with the electrode be a “control point 26”, which is a point for controlling the voltage value applied by the electric field controller 22.

  The present invention is not limited to such a control point 26, but can be applied to a case where another form of control point 26 is used according to the configuration of the upper surface electrode 23 and the lower surface electrode 24.

  In this embodiment, a material such as PLZT, SBT, or SBN, which is a ferroelectric material that can easily realize refractive index modulation by electric field control using polarization inversion, is used as the light modulation element 25.

  An example of the relationship between the applied voltage (potential difference) and the refractive index in a specific region of the light modulation element 25 used in this embodiment is shown in FIG. As shown in FIG. 3, the light modulation element 25 used in the present embodiment has a characteristic that the refractive index of the specific region increases as the voltage applied in the specific region increases.

  Each of the plurality of control points 26 is configured such that the relative positional relationship with the light modulation element 25 can be changed. In the present embodiment, the control point 26 provided on the surface of the light modulation element 25 is configured to be movable by the electrode moving unit 27.

  Specifically, as shown in FIG. 4, the upper surface electrode 23 and the lower surface electrode 24 can be freely moved in the X-axis direction and the Y-axis direction by an electrode moving unit 27 configured by a piezoelectric element, a damper, or the like. It is configured.

  The electric field control unit 22 applies an electric field applied to the control point 26 on the surface of the light modulation element 25 based on the information (interference fringe image pattern) for displaying the interference fringes transmitted by the image signal from the interference fringe calculation device 1. By changing the intensity (voltage value), the refractive index inside the light modulation element 25 is changed, and the interference fringes are formed in the light modulation element 25.

  In other words, the electric field control unit 22 controls the voltage values applied to the plurality of upper surface electrodes 23 and the plurality of lower surface electrodes 24, and converts the electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes to the light modulation element. 25 to be formed within.

  In the present embodiment, the above-described interference fringe image pattern is configured by interference fringe phase information, interference fringe amplitude information, or a combination of interference fringe phase information and amplitude information.

  Specifically, the electric field control unit 22 changes the electric field displacement before change formed by the voltage applied to each control point 26 before changing the relative positional relationship between each control point 26 and the light modulation element 25. And the changed electric field displacement surface formed by the voltage applied to each control point after the change of the positional relationship of the relative positional relationship between each control point 26 and the light modulation element 25. The electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes is formed in the light modulation element 25.

  In the present embodiment, the electric field control unit 22 includes a pre-movement electric field displacement surface (pre-change electric field displacement surface) formed by voltages applied to the plurality of control points 26 before movement, and a plurality of control points 26 after movement. An electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes is formed in the light modulation element 25 by synthesizing the post-movement electric field displacement surface (post-change electric field displacement surface) formed by the voltage applied to It is configured to form.

  That is, the electric field control unit 22 according to the present embodiment uses the property of the light modulation element 25 that can maintain the refractive index changed by the applied voltage value (electric field strength) for a certain time, An electric field displacement surface having an equivalent image pattern is formed in the light modulation element 25.

  In this embodiment, the electric field control unit 22 moves the control point 26 (that is, the upper surface electrode 23 or the lower surface electrode 24) only once or twice to synthesize two or three electric field displacement surfaces. Thus, the electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes is formed in the light modulation element 25. However, the present invention is not limited to this case, and the electric field control unit 22, the control point 26 (that is, the upper surface electrode 23 or the lower surface electrode 24) is moved an arbitrary number of times to synthesize an arbitrary number of electric field displacement surfaces, whereby an image pattern equivalent to an image pattern of interference fringes is obtained. The present invention can also be applied to a case where an electric field displacement surface having s is formed in the light modulation element 25.

  Specifically, as shown in FIG. 5, the electric field control unit 22 according to the present embodiment includes an image signal receiving unit 22a, a storage unit 22b, a determining unit 22c, a voltage applying unit 22d, and a movement control unit 22e. It is equipped with.

  The image signal receiving unit 22a receives information (interference fringe image pattern) for displaying the interference fringes transmitted by the image signal from the interference fringe calculation device 1 via a wired line or a wireless line.

  The storage unit 22b includes an interference fringe image pattern, change information regarding a change in relative positional relationship between the plurality of control points 26 and the light modulation element 25, and a plurality of control points 26 before the change in the positional relationship. Are stored in association with the pre-change voltage value applied to each of the control points 26 and the post-change voltage value applied to each of the plurality of control points 26 after the positional relationship is changed.

  In the present embodiment, the storage unit 22b includes an interference fringe image pattern, movement information (change information) regarding movement of the plurality of control points 26, and a pre-movement voltage value applied to each of the plurality of control points 26 before movement. The voltage value before change and the voltage value after movement (voltage value after change) applied to each of the plurality of control points 26 after movement are stored in association with each other.

  For example, it is assumed that the storage unit 22b stores image patterns of three types of interference fringes illustrated in FIGS. Hereinafter, the image pattern illustrated in FIG. 6A is referred to as “image pattern (a)”, the image pattern illustrated in FIG. 6B is referred to as “image pattern (b)”, and the image pattern illustrated in FIG. This is “image pattern (c)”.

  In such a case, for example, as shown in FIG. 6D, the storage unit 22b stores the “image pattern”, “movement information”, “voltage value before movement”, “voltage value after movement”, and “application time”. Store the associated table.

  Here, the “image pattern” indicates an image pattern of the electric field displacement surface formed by the potential difference at the four control points # 1 to # 4.

  In the present embodiment, the electric field displacement surface is configured to be formed by the potential difference at the four control points # 1 to # 4. However, the present invention is not limited to such a case, and two or more The present invention can also be applied to a case where it is formed by a potential difference at an arbitrary number of control points.

  The “movement information” indicates a direction in which the control point 26 (that is, the upper surface electrode 23 or the lower surface electrode 24) moves by a vector expressed by (distance in the X-axis direction, distance in the Y-axis direction). is there.

  Further, the “voltage value before movement” is applied to the four control points 26a to 26d surrounding the region corresponding to the image pattern before moving the four control points 26 (that is, the upper surface electrode 23 or the lower surface electrode 24). The voltage value to be displayed is shown. Such a voltage value is expressed by (a voltage value applied to the control point 26a, a voltage value applied to the control point 26b, a voltage value applied to the control point 26c, and a voltage value applied to the control point 26d).

  Similarly, the “post-movement voltage value” is the four control points 26a to 26d surrounding the area corresponding to the image pattern after the four control points 26a to 26d (that is, the upper surface electrode 23 or the lower surface electrode 24) are moved. The voltage value applied to is shown. Such a voltage value is expressed by (a voltage value applied to the control point 26a, a voltage value applied to the control point 26b, a voltage value applied to the control point 26c, and a voltage value applied to the control point 26d).

  The “application time” indicates the application time for applying a voltage to the control point. For example, in the table shown in FIG. 6D, the unit of the application time is “ms”.

  That is, in the table shown in FIG. 6D, the “pre-movement voltage value” of “20 V” is applied to each of the four control points 26 a to 26 d for a period of “10 ms”, whereby the control points 26 a to 26 d ( That is, the image pattern (a) can be generated without moving the upper surface electrode 23 or the lower surface electrode 24).

  In addition, as shown in FIGS. 7A to 7C, the table shown in FIG. 6D includes a “pre-movement voltage” of “20 V” for each of the four control points 26 a to 26 d for a period of “100 ms”. After applying “value”, the control points 26a to 26d (that is, the upper surface electrode 23 or the lower surface electrode 24) are moved by “1 (unit distance)” in the X-axis direction and “1 (unit distance)” in the Y-axis direction. In the state, it is shown that the image pattern (b) can be generated by applying the “post-movement voltage value” of “20 V” to each of the four control points 26 a to 26 d for a period of “100 ms”.

  Further, the table shown in FIG. 6D is a state in which no voltage is applied to each of the four control points 26a to 26d ("voltage value before movement"), as shown in FIGS. 8A to 8C. In the state in which the control points 26a to 26d (that is, the upper surface electrode 23 or the lower surface electrode 24) are moved by “1 (unit distance)” in the Y-axis direction from the “0V” state). Is applied with a “voltage value after movement” of “20 V” for a period of “20 ms”, and the upper electrode 23 or the lower electrode 24 (that is, the control point 26) is further set to “1 (unit distance) in the X-axis direction. ) ”Is applied to each of the four control points 26a to 26d by applying a“ post-movement voltage value ”of“ 20V ”for a period of“ 50 ms ”to generate the image pattern (c). Can Indicating that.

  Note that the table shown in FIG. 6D is an example, and the storage unit 22b is an arbitrary record as long as it is a record that associates the movement information of the control point 26, the pre-movement voltage value and the post-movement voltage value, and the image pattern. It may be configured to store a table including records of the format.

  The determination unit 22c determines the movement information of the control point 26 (that is, the upper surface electrode 23 or the lower surface electrode 24) and the pre-movement voltage value and the post-movement voltage value applied to each control point 26.

  Specifically, the determination unit 22c is most similar to the image pattern of the interference fringes received by the image signal reception unit 22a from the table (see FIG. 6D) stored in the storage unit 22b. "Image pattern" is selected, and the movement information of the control point 26 and each control based on the movement information, the pre-movement voltage value, and the post-movement voltage value of the control point 26 associated with the selected "image pattern". The voltage value before movement and the voltage value after movement applied to the point 26 are determined.

  Further, the determination unit 22c determines the application time for applying the voltage to each control point 26 based on the table shown in FIG. 6D before and after the movement (relative between the light modulation element 25 and each control point). It may be configured to be individually controlled before and after the positional relationship is changed.

  The determination unit 22 c may be configured to individually control the application time for applying a voltage to each control point 26 for each control point 26.

  The voltage application unit 22d applies a predetermined voltage to the upper surface electrode 23 and the lower surface electrode 24 before movement based on the voltage value before movement to be applied to each control point 26 determined by the determination unit 22c. Based on the determined post-movement voltage value applied to each control point 26, a predetermined voltage is applied to the upper electrode 23 and the lower electrode 24 after movement.

  Specifically, the voltage application unit 22d applies a voltage (voltage having a voltage value before movement) to each control point 26 before movement (before changing the relative positional relationship between the light modulation element 25 and each control point). A plurality of control points after moving (after changing the relative positional relationship between the light modulation element 25 and each control point) while maintaining the state in which the refractive index of the light modulation element 25 is changed by applying 26 may be configured to apply a voltage (voltage having a voltage value after movement).

  The movement control unit 22e instructs the electrode movement unit 27 to move the upper surface electrode 23, the lower surface electrode 24, or both electrodes 23, 24 based on the movement information of the control point 26 determined by the determination unit 22c. To do.

  The reference light irradiation device 3 is configured to irradiate the reference light B toward the light modulation element 25, and here, the reference light B is a reference used for calculation of interference fringes by the interference fringe calculation device 1. It has the same wavelength and the same incident angle as light.

  As described above, when the light modulation element 25 is irradiated with the reference light B in a state where interference fringes are recorded on the light modulation element 25, object light is generated by the interference fringes recorded on the light modulation element 25. A is generated. As a result, when the same object light A as the light coming from the object having the three-dimensional shape used for the calculation of the interference fringes by the interference fringe calculating apparatus 1 enters the observer's eyes, the observer has the above-mentioned three-dimensional object. Can be observed three-dimensionally.

  In the above-described embodiment, the interference fringe calculation device 1 and the stereoscopic image display device 2 are provided as separate devices. However, the present invention is not limited to this, and the stereoscopic image display device 2 interferes. The present invention can also be applied to a configuration having the function of the fringe calculation device 1.

(Operation of the stereoscopic image display system according to the first embodiment of the present invention)
With reference to FIG. 9, the operation of the stereoscopic image display system according to the first embodiment of the present invention will be described.

  In step S <b> 101, the electric field control unit 22 of the stereoscopic image display device 2 receives an image signal including information (interference fringe image pattern) for displaying the interference fringes calculated by the interference fringe calculation device 1.

  In step S102, the electric field control unit 22 analyzes an image pattern of interference fringes included in the received image signal. Specifically, the electric field control unit 22 selects an image pattern most similar to the image pattern of the interference fringes included in the received image signal from the table in the storage unit 26.

  In step S103, the electric field control unit 22 in the table in the storage unit 26, the movement information of the control point 26 associated with the selected image pattern, the pre-movement voltage value (electric field strength or potential difference) of each control point 26, and After the movement, the voltage value (electric field strength or potential difference) and the application time of each voltage value are extracted.

  As a result, the electric field control unit 22 determines how to move the upper surface electrode 23, the lower surface electrode 24, or both electrodes 23, 24 based on the extracted information (ie, to which position the control point 26 is moved, and the control point). How many times to move 26).

  Further, the electric field control unit 22 determines the pre-movement voltage value and post-movement voltage value to be applied to each control point 26 and the application time of each voltage value based on the extracted information.

  In step S <b> 104, the electric field control unit 22 determines a predetermined application time for the upper surface electrode 23 and the lower surface electrode 24 based on the pre-movement voltage value (or the post-movement voltage value) applied to each determined control point 26. By applying a voltage, the refractive index in the light modulation element 25 is changed. As a result, a pre-movement electric field displacement surface or a post-movement electric field displacement surface is formed in the light modulation element 25.

  In step S105, the electric field control unit 22 determines whether all the movements determined in step S103 have been completed. If it is determined that the operation has not been completed, the operation proceeds to step S106. If it is determined that the operation has been completed, the operation ends.

  In step S106, the electric field control unit 22 moves the upper surface electrode 23, the lower surface electrode 24, or both electrodes 23, 24 based on the movement method determined in step S103.

  By repeating the operations of steps S103 and S104, the electric field displacement plane before movement formed by the voltage applied to the plurality of control points 26 before movement and the voltage applied to the plurality of control points 26 after movement are formed. As a result, an electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes is formed in the light modulation element 25.

(Operation and effect of the stereoscopic image display system according to the first embodiment of the present invention)
According to the three-dimensional image display system according to the first embodiment of the present invention, interference is achieved by utilizing the property of the light modulation element 25 that can maintain a refractive index changed by an applied voltage value (electric field strength) for a certain period of time. Since an electric field displacement surface having an image pattern equivalent to the fringe image pattern is formed in the light modulation element 25, an analog image pattern can be displayed, and the display accuracy of the image is limited by the size and shape of the pixel electrode. The image with sufficient accuracy can be displayed.

(Stereoscopic image display system according to the second embodiment of the present invention)
A stereoscopic image display system according to the second embodiment of the present invention will be described with reference to FIGS. 10 and 11.

  As shown in FIG. 10, the stereoscopic image display system according to the present embodiment includes a light modulation element moving unit 27a instead of the electrode moving unit 27, and the stereoscopic image according to the first embodiment described above. It has the same configuration as the display system.

  In the present embodiment, the light modulation element 25 is configured such that the relative positional relationship with each of the plurality of control points 26 can be changed. In the present embodiment, the light modulation element 25 is configured to be movable by the light modulation element moving unit 27a.

  Specifically, as shown in FIG. 11, the light modulation element 25 is configured to be freely movable in the X-axis direction and the Y-axis direction by a light modulation element moving unit 27 a configured by a piezoelectric element, a damper, or the like. Has been.

  In the present embodiment, the electric field control unit 22 includes a pre-movement electric field displacement surface (pre-change electric field displacement surface) formed by voltages applied to a plurality of control points 26 before the light modulation element 25 moves, and an optical modulation. By synthesizing a post-movement electric field displacement surface (post-change electric field displacement surface) formed by voltages applied to a plurality of control points 26 after the element 25 moves, an image pattern equivalent to the image pattern of the interference fringes is obtained. The electric field displacement surface is formed in the light modulation element 25.

  That is, in the present embodiment, the “movement information” indicates the direction in which the light modulation element 25 moves by a vector expressed by (distance in the X-axis direction, distance in the Y-axis direction).

  The “voltage value before movement” indicates voltage values applied to the four control points 26 a to 26 d surrounding the area corresponding to the image pattern before moving the light modulation element 25. Such a voltage value is expressed by (a voltage value applied to the control point 26a, a voltage value applied to the control point 26b, a voltage value applied to the control point 26c, and a voltage value applied to the control point 26d).

  Similarly, the “post-movement voltage value” indicates a voltage value applied to the four control points 26a to 26d surrounding the area corresponding to the image pattern after the light modulation element 25 is moved. Such a voltage value is expressed by (a voltage value applied to the control point 26a, a voltage value applied to the control point 26b, a voltage value applied to the control point 26c, and a voltage value applied to the control point 26d).

  Further, the movement control unit 22e instructs the light modulation element moving unit 27a to move the light modulation element 25 based on the movement information of the light modulation element 25 determined by the determination unit 22c. .

(Stereoscopic image display system according to the third embodiment of the present invention)
A stereoscopic image display system according to a third embodiment of the present invention will be described with reference to FIGS.

  The three-dimensional image display system according to the present embodiment is a three-dimensional image display system according to the first and second embodiments described above, except that the plurality of control points 26 are protrusion-shaped portions in electrodes provided on the light modulation element 25. It has the same configuration as the image display system.

  FIG. 12A is a diagram of a cross section of the hologram recording element 21 according to the present embodiment as viewed from the lateral direction, and FIG. 12B is a diagram of the hologram recording element 21 according to the present embodiment as viewed from above. It is.

  As shown in FIG. 12A, in the hologram recording element 21 according to this embodiment, the lower surface electrode 24 has a protruding shape. In such a case, the protrusion-shaped portion of the lower surface electrode 24 corresponds to a control point 26 that controls the voltage value applied by the electric field control unit 22.

  Accordingly, a large amount of electric charge is accumulated at the tip of the protruding portion of the lower surface electrode 24, so that a large potential difference can be generated between the upper surface electrode 23 and the lower surface electrode 24. Further, by using the lower surface electrode 24 according to the present embodiment, the interval between the control points 26 can be narrowed, and the hologram recording element 21 can be downsized.

  As shown in FIG. 12B, in the hologram recording element 21 according to the present embodiment, the protrusion-shaped portion of the lower surface electrode 24 is configured to be uniformly distributed on the surface of the light modulation element 25.

  Further, in the hologram recording element 21 according to the present embodiment, the protruding portion of the lower surface electrode 24 is configured by a transistor or the like that can actively control the applied voltage.

  Therefore, the electric field control unit 22 according to the present embodiment changes the protrusion-shaped portion to which a predetermined voltage is applied on the lower surface electrode 24 as needed, so that the upper surface is similar to the stereoscopic image display system according to the second embodiment described above. An image pattern equivalent to a highly accurate image pattern of interference fringes can be formed in the light modulation element 25 by synthesizing a plurality of electric field displacement surfaces without moving the electrode 23 or the lower surface electrode 24.

(3D image display system according to the fourth embodiment of the present invention)
A stereoscopic image display system according to the fourth embodiment of the present invention will be described with reference to FIGS. 13 to 16. Hereinafter, differences between the stereoscopic image display system according to the present embodiment and the stereoscopic image display systems according to the first to third embodiments described above will be mainly described.

  As illustrated in FIG. 13, the stereoscopic image display system according to the present embodiment includes a server device 100 and a stereoscopic image display device 2. In the present embodiment, an example in which the stereoscopic image display device 2 is configured by a mobile communication terminal that can communicate with the server device 100 via the packet communication network 5 will be described.

  As shown in FIG. 14, the server apparatus 100 includes an interference fringe calculation unit 1a, a storage unit 1b, and a transmission unit 1c.

  The interference fringe calculator 1a calculates an interference fringe (computer hologram) generated from the object light and the reference light.

  The storage unit 1b applies an image pattern of interference fringes, movement information (change information) regarding movement of the plurality of control points 26 (or the light modulation elements 25), and movement applied to each of the plurality of control points 26 before movement. The previous voltage value (pre-change voltage value) and the post-movement voltage value (post-change voltage value) applied to each of the plurality of control points 26 after movement are associated and stored. In such a case, for example, the storage unit 1b is configured to store the table shown in FIG.

  The transmission unit 1c is configured to transmit the movement information, the pre-movement voltage value, and the post-movement voltage value associated with the calculated interference fringe image pattern to the stereoscopic image display device 2.

  As shown in FIG. 15, the stereoscopic image display device 2 includes a communication unit 31, a hologram recording element 21, an electric field control unit 22, an electrode moving unit 27, a light source 32, and a light reflection plate 33. Yes.

  The communication unit 31 requests the server apparatus 100 to transmit the movement information corresponding to the interference fringe image pattern, the pre-movement voltage value, and the post-movement voltage value, and sends the received information to the electric field control unit 22. Configured to send.

  Further, the electric field control unit 22 is based on the movement information, the pre-movement voltage value, and the post-movement voltage value of the control point 26 corresponding to the pixel pattern of the interference fringe received from the server device via the communication unit 31. Similar to the electric field control unit 22 of the stereoscopic image display device 2 according to the first embodiment, the upper surface electrode 23, the lower surface electrode 24 or the electrodes 23, 24 are moved and moved with respect to each control point 26 at a predetermined timing. By applying a pre-voltage value and a post-movement voltage value, an electric field displacement surface is formed in the light modulation element 25 of the hologram recording element 21, and interference fringes composed of a plurality of electric field displacement surfaces are recorded. ing.

  The configuration of the hologram recording element 21 is the same as the configuration of the hologram recording element 21 according to the first to third embodiments described above. Here, the upper surface electrode 23 is configured by a transparent electrode.

  The light reflection plate 33 generates the reference light B by reflecting the light from the light source 32. Here, the reference light B has the same wavelength and the same incident angle as the reference light used for calculation of interference fringes by the interference fringe calculation unit 1a of the server apparatus 100. The light source 32 may be a backlight used in a liquid crystal display of a mobile communication terminal, or may be a light source provided separately from such a backlight.

  In addition, as shown in FIG. 16, the stereoscopic image display device 2 includes a communication unit 31, a hologram recording element 21, an electric field control unit 22, a light modulation element moving unit 27 a, a light source 32, and a light reflection plate 33. It has.

  In such a case, the electric field control unit 22 is based on the movement information, the pre-movement voltage value, and the post-movement voltage value of the light modulation element 25 corresponding to the pixel pattern of the interference fringe received from the server device via the communication unit 31. Similar to the electric field control unit 22 of the stereoscopic image display device 2 according to the second embodiment described above, the light modulation element 25 is moved, and the voltage value before movement and the value after movement are moved with respect to each control point 26 at a predetermined timing. By applying a voltage value, an electric field displacement surface is formed in the light modulation element 25 of the hologram recording element 21 to record interference fringes composed of a plurality of electric field displacement surfaces.

  Next, an example of the operation of the stereoscopic image display system according to the present embodiment will be described with reference to FIG.

  In step S1001, the interference fringe calculation unit 1a of the server device 100 calculates an interference fringe (computer hologram) generated from the object light and the reference light.

  In step S1002, the transmission unit 1c of the server apparatus 100 refers to the storage unit 1b and extracts the movement information, the pre-movement voltage value, and the post-movement voltage value associated with each image pattern of the computer generated hologram.

  In step S1003, the transmission unit 1c of the server apparatus 100 extracts the extracted movement information (electrode movement information or light modulation element movement information), the voltage value before movement, the voltage value after movement, and the application time of each voltage value (field strength information). Is transmitted to the stereoscopic image display device 2 via the packet communication network 5.

  In step S1004, the electric field control unit 22 of the stereoscopic image display device 2 instructs the electrode moving unit 27 to move the control point 26 based on the image information received from the server device via the communication unit 31. At the same time, a predetermined voltage (a voltage value before movement or a voltage value after movement) is applied to the upper surface electrode 23 and the lower surface electrode 24 at a predetermined timing for a predetermined application time. In addition, an electric field displacement surface is formed, and interference fringes composed of a plurality of electric field displacement surfaces are recorded.

  Alternatively, in step S1004, the electric field control unit 22 of the stereoscopic image display device 2 moves the light modulation element 25 with respect to the light modulation element moving unit 27a based on the image information received from the server device via the communication unit 31. And applying a predetermined voltage (a voltage value before movement or a voltage value after movement) to the upper surface electrode 23 and the lower surface electrode 24 at a predetermined timing for a predetermined application time. An electric field displacement surface is formed in the light modulation element 25, and interference fringes composed of a plurality of electric field displacement surfaces are recorded.

  In step S <b> 1005, the light source 32 irradiates the interference fringes formed in the light modulation element 25 of the hologram recording element 21 with the reference light B through the light reflection plate 33, thereby displaying a stereoscopic image.

(3D image display system according to the fifth embodiment of the present invention)
A stereoscopic image display system according to the fifth embodiment of the present invention will be described with reference to FIGS. 18 and 19. Hereinafter, differences between the stereoscopic image display system according to the present embodiment and the stereoscopic image display systems according to the above-described first to fourth embodiments will be mainly described.

  As shown in FIG. 18A, the hologram recording element 21 according to this embodiment includes an optical modulation element 25 having an electro-optic effect in which the refractive index changes according to the electric field strength, and a surface of the optical modulation element 25. And a plurality of control points 26 provided.

  Specifically, in the hologram recording element 21, a plurality of upper surface electrodes 23 are provided on the upper surface of the light modulation element 25, and a lower surface electrode 24 is provided on the lower surface of the light modulation element 25. Here, the lower surface electrode 24 is grounded.

  In the present embodiment, each of the plurality of upper surface electrodes 23 provided on the upper surface of the light modulation element 25 is defined as a “control point 26” that is a point for controlling the voltage value applied by the electric field control unit 22.

  Further, the voltage value applied to each of the upper surface electrodes 23 is independently controlled by the electric field control unit 22.

  Note that the upper surface electrode 23 in the present embodiment does not correspond to each pixel constituting an image to be displayed, unlike the upper surface electrode 23 in the image display device having an active matrix electrode structure according to the related art.

  In the present embodiment, as shown in FIG. 18B, in the light modulation element 25, the relationship between the applied electric field strength (potential difference) and the refractive index change is non-linear. That is, the light modulation element 25 according to the present embodiment has a characteristic that the refractive index rapidly changes as the applied electric field strength increases.

  FIG. 19A shows an example of using a light modulation element in which the relationship between the applied electric field strength (potential difference) and the change in refractive index is linear, and FIG. 19B shows the applied electric field. An example in which the light modulation element according to this embodiment in which the relationship between the intensity (potential difference) and the change in the refractive index is nonlinear is used.

  19A and 19B, “C” indicates the state of the hologram recording element 21 (refractive index change pattern) viewed from the B direction in FIG. 18A, and “D” indicates FIG. A cross-sectional view of the hologram recording element 21 as viewed from the A direction of (a) is shown.

  As can be seen from FIGS. 19A and 19B, even when the same potential difference (for example, 20 V) is applied between the upper surface electrode 23 and the lower surface electrode 24, the hologram recording shown in FIG. The element 21 and the hologram recording element 21 shown in FIG. 19B have different refractive index changes inside the light modulation element 25 (see the refractive index change curve in “D”), and from the B direction in FIG. The change pattern of the refractive index when viewed is also different.

  Specifically, the refractive index change pattern in the hologram recording element 21 shown in FIG. 19B is smaller than the refractive index change pattern in the hologram recording element 21 shown in FIG.

  That is, according to the present embodiment, when a predetermined potential difference is applied between the upper surface electrode 23 and the lower surface electrode 24, the relationship between the applied electric field strength (potential difference) and the change in refractive index is linear. Since a refractive index change pattern smaller than the refractive index change pattern in the hologram recording element 21 using a modulation element can be generated, a finer interference fringe image pattern can be generated.

(A stereoscopic image display system according to a sixth embodiment of the present invention)
A stereoscopic image display system according to the sixth embodiment of the present invention will be described with reference to FIGS. 20 to 22. Hereinafter, differences between the stereoscopic image display system according to the present embodiment and the stereoscopic image display systems according to the first to fifth embodiments described above will be mainly described.

  The configuration of the hologram recording element 21 according to this embodiment is the same as the configuration of the hologram recording element 21 in the fifth embodiment described above (see FIG. 18A).

  In the present embodiment, as shown in FIG. 20A, the control point 26 is configured to have a plurality of microelectrodes 26a. In the example of FIG. 20 (a), the microelectrode 26a has a circular shape, but the present invention is not limited to this, and can be applied to the case where the control point 26 has a microelectrode 26a having an arbitrary shape. It is.

  The electric field control unit 22 is configured to control the voltage value applied to each of the microelectrodes 26a.

  Specifically, as shown in FIG. 20B, the electric field control unit 22 is connected to each of the microelectrodes 26a by a connection unit 26b such as a cable, and the voltage value applied to each of the microelectrodes 26a is determined. It can be controlled independently.

  Further, as shown in FIG. 21, the upper surface electrode 23 (or the lower surface electrode 24) provided with the control point 26 is in a predetermined direction (upper surface electrode moving direction or the same as in the case of the second embodiment described above). It may be configured to be movable in the lower electrode movement direction).

  FIG. 22 shows patterns (a) to (c) of the microelectrode 26a to which a voltage is applied when a voltage is applied to a part of the microelectrode 26a constituting the control point 26. In FIG. 22, it is assumed that a voltage is applied to the minute voltage 26a represented by a white circle, and no voltage is applied to the minute voltage 26a represented by a black circle.

  When the pattern of the microelectrode 26a to which the voltage is applied is “pattern (a)”, the equipotential surface formed in the light modulation element 25 is “pattern (a)”, and the microelectrode 26a to which the voltage is applied. Is the “pattern (b)”, the equipotential surface formed inside the light modulation element 25 is “pattern (b)”, and the pattern of the microelectrode 26a to which the voltage is applied is “pattern (c)”. In this case, the equipotential surface formed inside the light modulation element 25 is “pattern (c)”.

  As described above, according to the present embodiment, the electric field control unit 22 can generate a plurality of equipotential surface patterns by changing the pattern of the microelectrodes 26a to which the voltage is applied. An image pattern of interference fringes can be generated.

1 is an overall configuration diagram of a stereoscopic image display system according to a first embodiment of the present invention. It is a figure which shows an example of the computer generated hologram recorded on the light modulation element in the three-dimensional image display system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on the 1st Embodiment of this invention. It is a functional block diagram of the electric field control part in the three-dimensional image display system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the control method by the electric field control part in the three-dimensional image display system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the control method by the electric field control part in the three-dimensional image display system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the control method by the electric field control part in the three-dimensional image display system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the stereo image display system which concerns on the 1st Embodiment of this invention. It is a whole block diagram of the three-dimensional image display system which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the hologram recording element in the three-dimensional image display system which concerns on the 3rd Embodiment of this invention. It is a whole block diagram of the three-dimensional image display system which concerns on the 4th Embodiment of this invention. It is a functional block diagram of the server apparatus in the three-dimensional image display system which concerns on the 4th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 4th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 4th Embodiment of this invention. It is a flowchart which shows operation | movement of the stereo image display system which concerns on the 4th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 5th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 5th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 6th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 6th Embodiment of this invention. It is a figure for demonstrating the stereo image display apparatus in the stereo image display system which concerns on the 6th Embodiment of this invention. It is a figure for demonstrating the image display apparatus which has the electrode structure of the conventional simple matrix system. It is a figure for demonstrating the image display apparatus which has the electrode structure of the conventional active matrix system. It is a figure for demonstrating the problem of the conventional image display apparatus.

Explanation of symbols

A ... Object light B ... Reference light 1 ... Interference fringe calculation device 2 ... Stereoscopic image display device 21 ... Hologram recording element 22 ... Electric field control unit 22a ... Image signal receiving unit 22b ... Storage unit 22c ... Determination unit 22d ... Voltage application unit 22e ... movement control unit 23 ... upper surface electrode 24 ... lower surface electrode 25 ... light modulation element 26 ... control point 27 ... electrode movement unit 31 ... communication unit 32 ... light source 33 ... light reflector 3 ... reference light irradiation device 5 ... packet communication network 100 ... Server equipment

Claims (14)

A light modulation element having an electro-optic effect in which the refractive index changes according to the electric field intensity;
A plurality of control points provided on the surface of the light modulation element, the relative positional relationship between the light modulation elements being changeable,
The electric field displacement surface before change formed by the voltage applied to the plurality of control points before the change of the positional relationship, and the change formed by the voltage applied to the plurality of control points after the change of the positional relationship. An image display apparatus comprising: an electric field control unit configured to synthesize a rear electric field displacement surface to form an electric field displacement surface having a predetermined image pattern in the light modulation element. A stereoscopic image display device that displays a stereoscopic image using the calculated interference fringes,
A light modulation element having an electro-optic effect in which the refractive index changes according to the electric field intensity;
A plurality of control points provided on the surface of the light modulation element, the relative positional relationship between the light modulation elements being changeable,
The electric field displacement surface before change formed by the voltage applied to the plurality of control points before the change of the positional relationship, and the change formed by the voltage applied to the plurality of control points after the change of the positional relationship. And an electric field control unit configured to form an electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes in the light modulation element by combining the rear electric field displacement surface. A featured stereoscopic image display device.   The electric field control unit applies the voltage to the plurality of control points before the change of the positional relationship and maintains the state in which the refractive index of the light modulation element is changed, and the plurality of the changed positional relationship The three-dimensional image display device according to claim 2, wherein a voltage is applied to the control point.   The image pattern is configured by either phase information of the interference fringes or amplitude information of the interference fringes, or both of phase information of the interference fringes and amplitude information of the interference fringes. 3. The stereoscopic image display device according to 2.   3. The control point according to claim 2, wherein the control point is an intersection of a vertical wiring electrode wired in a vertical direction on a surface of the light modulation element and a horizontal wiring electrode wired in a horizontal direction. Stereoscopic image display device.   The electric field control unit stores an image pattern of the interference fringes and a voltage value to be applied to each of the plurality of control points in association with each other, and the voltage associated with the calculated image pattern of the interference fringes The stereoscopic image display apparatus according to claim 2, wherein a value is applied to each of the plurality of control points.   The three-dimensional image display device according to claim 2, wherein the plurality of control points are electrodes movably provided on a surface of the light modulation element.   The stereoscopic image display apparatus according to claim 2, wherein the light modulation element is configured to be movable with respect to the plurality of control points.   The stereoscopic image display device according to claim 2, wherein the plurality of control points are protrusion-shaped portions of electrodes provided on a surface of the light modulation element.   The stereoscopic image display apparatus according to claim 2, wherein a relationship between the electric field intensity and the change in the refractive index is nonlinear in the light modulation element. The plurality of control points have a plurality of microelectrodes,
The stereoscopic image display apparatus according to claim 2, wherein the electric field control unit controls a voltage value applied to each of the microelectrodes.   The stereoscopic image display according to claim 2, wherein the electric field control unit is configured to individually control an application time for applying a voltage to the control point before and after the change of the positional relationship. apparatus.   The stereoscopic image display apparatus according to claim 2, wherein the electric field control unit is configured to individually control an application time for applying a voltage to the control point for each control point. A stereoscopic image display system that includes a stereoscopic image display device and a server device and displays a stereoscopic image,
The server device
An interference fringe calculation unit for calculating interference fringes generated from the object light and the reference light;
An interference fringe image pattern, a plurality of control points and change information regarding a change in relative positional relationship between the light modulation elements of the stereoscopic image display device, and a plurality of control points before the change in the positional relationship. A storage unit that associates and stores a pre-change voltage value applied to each and a post-change voltage value applied to each of the plurality of control points after the positional relationship is changed;
A transmitter that transmits the change information, the pre-change voltage value, and the post-change voltage value associated with the calculated image pattern of the interference fringes to the stereoscopic image display device;
The stereoscopic image display device includes:
A light modulation element having an electro-optic effect in which the refractive index changes according to the electric field intensity;
A plurality of control points provided on the surface of the light modulation element;
The electric field displacement surface before change formed by the voltage applied to the plurality of control points before the change of the positional relationship, and the change formed by the voltage applied to the plurality of control points after the change of the positional relationship. And an electric field control unit configured to form an electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes in the light modulation element by combining the rear electric field displacement surface. A featured stereoscopic image display system.