Image display device, stereoscopic image display device and stereoscopic image display system

The present invention relates to an image display device, a stereoscopic image display device for displaying a stereoscopic image using a calculated interference fringe (computer hologram), and a stereoscopic image display system.

Conventionally, there is known an image display device that displays an image formed in the light modulation element by applying a voltage to the light modulation element. For example, such an image display device includes a liquid crystal display (LCD) and the like.

Here, the light modulation element is an element having an electro-optical effect. The electro-optical effect is a phenomenon caused by applying an electric field to a substance, and specifically, a phenomenon in which the refractive index of the substance changes according to the strength of the electric field applied to the substance.

An image display device using a conventional light modulation element will be described with reference to FIGS. 23 and 24. 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. 23 (a), 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 thin 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 electrode 23 in the X-axis direction and the electrode 24 in the Y-axis direction is displayed by an image display device having a simple matrix type electrode structure, as shown in FIG. 23 (b). The pixel electrodes 23a correspond to each pixel constituting the image.

On the other hand, as shown in FIG. 24A, in an image display device having an active matrix type 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. Is provided with an electrode 24.

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 type electrode structure. Therefore, a transistor that can independently control ON / OFF is prepared for each pixel electrode 23a. Further, the electrode 24 is grounded.

In an image display device having a conventional simple matrix type and active matrix type electrode structure, the voltage value applied to the pixel electrode 23a is controlled based on the shading value of each pixel constituting the image to be recorded on the light modulation element 25. It is configured to do.<nplcit num="1"><text>Supervised by Fukumi, "New Optical Materials Handbook", pp. 60-67, Realize, published in 2000</text></nplcit><nplcit num="2"><text>Okuyama, "Electronic Devices Using Ferroelectric Thin Films", Institute of Electrical Engineers of Japan E, vol.121, No.10, pp. 537-541, 2001</text></nplcit>

<p> However, in the conventional image display device having the electrode structure of the simple matrix method and the active matrix method, the voltage value applied only in units of each pixel electrode 23a can be changed, so that the inside of the rectangular region (pixel) shown in FIG. 25 There is a problem that the shading values are 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.</p><p> That is, in such a conventional image display device, since there is a limit to the miniaturization of the pixel electrode 23a, there is a problem that the quantization error of the image to be displayed becomes large and the image cannot be displayed with sufficient accuracy. It was.</p><p> Therefore, the present invention has been made in view of the above points, and is an image display device, a stereoscopic image display device, and a stereoscopic image display device, which can eliminate the limitation of image display accuracy due to the size and shape of the pixel electrodes as much as possible. An object of the present invention is to provide an image display system.</p>

<p> The first feature of the present invention is a relative between a light modulation element having an electro-optical effect in which the refractive index changes according to the electric field strength and the light modulation element provided on the surface of the light modulation element. A plurality of control points whose positional relationship can be changed, an electric field displacement surface before change formed by a voltage applied to the plurality of control points before the change of the positional relationship, and a surface after the change of the positional relationship. An electric field configured to combine an modified 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 is that it is an image display device including a control unit.</p><p> The second feature of the present invention is a stereoscopic image display device that displays a stereoscopic image using calculated interference fringes, and an optical modulation element having an electro-optical effect in which the refractive index changes according to the electric field strength. It is applied to a plurality of control points provided on the surface of the optical modulation element and whose relative positional relationship with the optical modulation element can be changed, and the plurality of control points before the change of the positional relationship. The pre-change electric field displacement surface formed by the voltage to be generated and the post-change electric field displacement surface formed by the voltage applied to the plurality of control points after the change in the positional relationship are combined to form the interference fringes. It is a gist 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 optical modulation element.</p><p> In the second feature of the present invention, the electric field control unit keeps the 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 change of the positional relationship. The voltage may be applied to the plurality of control points after the positional relationship is changed.</p><p> In the second feature of the present invention, the image pattern is composed of either the phase information of the interference fringes or the amplitude information of the interference fringes, or both the phase information of the interference fringes and the amplitude information of the interference fringes. It may have been.</p><p> In the second feature of the present invention, even if the control point is an intersection of a vertically wired vertical wiring electrode and a horizontally wired horizontal wiring electrode on the surface of the light modulation element. Good.</p><p> In the second feature of the present invention, the electric field control unit stores the image pattern of the interference fringe and the voltage value applied to each of the plurality of control points in association with each other, and calculates the interference fringe of the interference fringe. The voltage value associated with the image pattern may be configured to be applied to each of the plurality of control points.</p><p> In the second feature of the present invention, the plurality of control points may be electrodes movably provided on the surface of the light modulation element.</p><p> In the second feature of the present invention, the light modulation element may be configured to be movable with respect to the plurality of control points.</p><p> In the second feature of the present invention, the plurality of control points may be protrusion-shaped portions of the electrodes provided on the surface of the light modulation element.</p><p> In the second feature of the present invention, the relationship between the electric field strength and the change in the refractive index in the light modulation element may be non-linear.</p><p> In the second feature of the present invention, even if the plurality of control points have a plurality of microelectrodes and the electric field control unit controls the voltage value applied to each of the microelectrodes. Good.</p><p> In the second feature of the present invention, the electric field control unit may be configured to individually control the application time for applying a voltage to the control point before and after the change in the positional relationship.</p><p> In the second feature of the present invention, the electric field control unit may be configured to individually control the application time for applying a voltage to the control points for each control point.</p><p> A third feature of the present invention is a stereoscopic image display system including a stereoscopic image display device and a server device for displaying a stereoscopic image, and the server device is an interference generated from an object light and a reference light. The interference fringe calculation unit that calculates the fringes, the image pattern of the interference fringes, the change information regarding the change in the relative positional relationship between the plurality of control points and the optical modulation element of the stereoscopic image display device, and the positional relationship. A storage unit that stores the unchanged voltage value applied to each of the plurality of control points before the change and the changed voltage value applied to each of the plurality of control points after the change of the positional relationship. It includes a transmission unit that transmits the change information associated with the calculated image pattern of the interference fringes, the voltage value before the change, and the voltage value after the change to the stereoscopic image display device, and displays the stereoscopic image. The apparatus includes an optical modulation element having an electro-optical effect in which the refractive index changes according to the electric field strength, a plurality of control points provided on the surface of the optical modulation element, and the unchanged voltage value received from the server apparatus. Is applied to the plurality of control points to change the relative positional relationship between the plurality of control points and the optical modulation element based on the change information, and then the changed voltage value received from the server device. Is provided to the plurality of control points to provide 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 optical modulation element. Is the gist.</p>

<p> As described above, according to the present invention, an image display device, a stereoscopic image display device, and a stereoscopic image display system capable of eliminating the limitation of image display accuracy due to the size and shape of pixel electrodes as much as possible are provided. can do.</p>

(Structure of stereoscopic image display system according to the first embodiment of the present invention) FIG. 1 is a diagram showing an overall configuration of a stereoscopic image display system according to the 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 shown 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 device 1 is composed of a computer, and is an interference generated from an object light generated by reflecting a laser beam irradiating a three-dimensional object (for example, 3D data of a cube) and a reference light. It is configured to calculate fringes. Here, the interference fringes are, for example, as shown in FIGS. 2A and 2B, a shading image in which the change in brightness corresponds to the amplitude information of light and the pattern of the fringe pattern corresponds to the phase information of light. Is.

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

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 an optical modulation element 25 having an electro-optical 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. It includes 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 electrodes 23 and the lower surface electrodes 24.

In the present embodiment, the horizontal wiring electrode wired in the X-axis direction (horizontal direction) on the upper surface of the optical modulation element 25 and the vertical wiring wired in the Y-axis direction (vertical direction) on the lower surface of the optical modulation element 25. The intersection with the electrode is referred to as a "control point 26" which is a point for controlling the voltage value applied by the electric field control unit 22.

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

Further, in the present embodiment, as the light modulation element 25, materials such as PLZT, SBT, and SBN, which are ferroelectric materials that can easily realize refractive index modulation by electric field control using polarization inversion, are used.

An example of the relationship between the applied voltage (potential difference) and the refractive index in the specific region of the light modulation element 25 used in the present embodiment is shown in FIG. 3 (b). 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.

Further, each of the plurality of control points 26 is configured so 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 portion 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 the electrode moving portion 27 composed of a piezo element, a damper, or the like. It is configured.

The electric field control unit 22 applies an electric field to the control point 26 on the surface of the light modulation element 25 based on information for displaying the interference fringes transmitted by the image signal from the interference fringe calculation device 1 (interference fringe image pattern). 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.

That is, 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 the light modulation element on the electric field displacement surface having an image pattern equivalent to the above-mentioned image pattern of the interference fringes. It is configured to form within 25.

In the present embodiment, the above-mentioned image pattern of the interference fringes is composed of the phase information of the interference fringes, the amplitude information of the interference fringes, or a combination of the phase information of the interference fringes and the amplitude information.

Specifically, the electric field control unit 22 is a pre-change electric field displacement formed by a voltage applied to each control point 26 before the change in the relative positional relationship between each control point 26 and the light modulation element 25. The surface and the modified electric field displacement surface formed by the voltage applied to each changed control point in the relative positional relationship between each control point 26 and the light modulation element 25 are combined. , 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.

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

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

In the present 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 the electric field displacement surfaces of 2 or 3. The electric field displacement surface having an image pattern equivalent to the image pattern of the interference fringes is formed in the optical modulation element 25, but the present invention is not limited to this case, and the electric field control unit is not limited to this case. 22 moves the control point 26 (that is, the upper surface electrode 23 or the lower surface electrode 24) an arbitrary number of times to synthesize an arbitrary number of electric field displacement surfaces, thereby forming an image pattern equivalent to the image pattern of the interference fringes. It is also applicable when the electric field displacement surface having the above is formed in the optical modulation element 25.

Specifically, as shown in FIG. 5, the electric field control unit 22 according to the present embodiment includes an image signal reception unit 22a, a storage unit 22b, a determination unit 22c, a voltage application unit 22d, and a movement control unit 22e. And are equipped.

The image signal receiving unit 22a receives information (an image pattern of the interference fringes) 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 contains the image pattern of the interference fringes, change information regarding the change in the relative positional relationship between the plurality of control points 26 and the light modulation element 25, and the plurality of control points 26 before the change in the positional relationship. The voltage value before the change applied to each of the above and the voltage value after the change applied to each of the plurality of control points 26 after the change of the positional relationship is stored in association with each other.

In the present embodiment, the storage unit 22b has the image pattern of the interference fringes, the movement information (change information) regarding the movement of the plurality of control points 26, and the pre-movement voltage value applied to each of the plurality of control points 26 before the movement. It is configured to associate and store (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.

For example, it is assumed that the storage unit 22b stores the image patterns of the three types of interference fringes shown in FIGS. 6A to 6C. Hereinafter, the image pattern shown in FIG. 6 (a) is referred to as "image pattern (a)", the image pattern shown in FIG. 6 (b) is referred to as "image pattern (b)", and the image pattern shown in FIG. 6 (c) is referred to as "image pattern (b)". Let it be "image pattern (c)".

In such a case, as shown in FIG. 6D, for example, the storage unit 22b sets the image pattern, the movement information, the pre-movement voltage value, the post-movement voltage value, and the applied time. Remember the table to associate.

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, but the present invention is not limited to this case and is not limited to two or more. It is also applicable when formed by potential differences at any number of control points.

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

Further, the "pre-movement voltage value" 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). It shows the voltage value to be used. Such a voltage value shall be expressed by (voltage value applied to control point 26a, voltage value applied to control point 26b, voltage value applied to control point 26c, voltage value applied to control point 26d).

Similarly, the post-movement voltage value is the four control points 26a to 26d that surround the region corresponding to the image pattern after moving the four control points 26a to 26d (ie, the top electrode 23 or the bottom electrode 24). It shows the voltage value applied to. Such a voltage value shall be expressed by (voltage value applied to control point 26a, voltage value applied to control point 26b, voltage value applied to control point 26c, voltage value applied to control point 26d).

Further, the "application time" indicates an application time for applying a voltage to the control point. For example, in the table shown in FIG. 6 (d), the unit of application time is assumed to be "ms".

That is, in the table shown in FIG. 6 (d), the control points 26a to 26d ( That is, it is shown that the image pattern (a) can be generated without moving the upper surface electrode 23 or the lower surface electrode 24).

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

Further, in the table shown in FIG. 6 (d), as shown in FIGS. 8 (a) to 8 (c), no voltage is applied to each of the four control points 26a to 26d (voltage value before movement). Is "0V"), and the four control points 26a to 26d are moved from the control points 26a to 26d (that is, the upper surface electrode 23 or the lower surface electrode 24) by "1 (unit distance)" in the Y-axis direction. A "post-movement voltage value" of "20V" is applied to each of the above for a period of "20ms", and the top electrode 23 or the bottom electrode 24 (that is, the control point 26) is further set to "1 (unit distance) in the X-axis direction. The image pattern (c) can be generated by applying the "post-movement voltage value" of "20V" to each of the four control points 26a to 26d for a period of "50ms" while moving only ")". Show that you can.

The table shown in FIG. 6D is an example, and the storage unit 22b can be any record as long as it is a record that associates the movement information of the control point 26, the voltage value before movement and the voltage value after movement, and the image pattern. It may be configured to store a table containing records of the format.

The determination unit 22c determines the movement information of the control points 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 most resembles the image pattern of the interference fringes received by the image signal reception unit 22a from the table (see FIG. 6 (d)) stored in the storage unit 22b. Select "Image pattern", and based on the movement information of the control point 26, the pre-movement voltage value, and the post-movement voltage value associated with the selected "image pattern", the movement information of the control point 26 and each control. It is configured to determine the pre-movement voltage value and the post-movement voltage value applied to the point 26.

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

Further, the determination unit 22c may be configured to individually control the application time for applying the 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 pre-movement voltage value to be applied to each control point 26 determined by the determination unit 22c, and is determined by the determination unit 22c. A predetermined voltage is applied to the upper surface electrode 23 and the lower surface electrode 24 after movement based on the determined voltage value after movement applied to each control point 26.

Specifically, the voltage application unit 22d applies a voltage (voltage of the 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). 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 It may be configured to apply a voltage (voltage of the voltage value after movement) to 26.

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. Is what you do.

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

As described above, when the reference light B is irradiated toward the light modulation element 25 in a state where the interference fringes are recorded on the light modulation element 25, the object light is caused by the interference fringes recorded on the light modulation element 25. A occurs. As a result, the same object light A as the light coming from the three-dimensional object used for the calculation of the interference fringes by the interference fringe calculation device 1 enters the observer's eyes, so that the observer can see 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, but the present invention is not limited to this, and the stereoscopic image display device 2 interferes. It 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) The operation of the stereoscopic image display system according to the first embodiment of the present invention will be described with reference to FIG.

In step S101, the electric field control unit 22 of the stereoscopic image display device 2 receives an image signal including information (image pattern of the interference fringes) for displaying the interference fringes calculated by the interference fringe calculation device 1.

In step S102, the electric field control unit 22 analyzes the image pattern of the 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 displays the movement information of the control points 26 associated with the selected image pattern, the pre-movement voltage value (electric field strength or potential difference) of each control point 26, and the voltage value (electric field strength or potential difference) of each control point 26 in the table in the storage unit 26. The voltage value (electric field strength or potential difference) after movement and the application time of each voltage value are extracted.

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

Further, the electric field control unit 22 determines the pre-movement voltage value and the 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 S104, the electric field control unit 22 determines the 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 of the determined control points 26. By applying a voltage, the refractive index in the light modulation element 25 is changed, and 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 or not all the movements determined in step S103 have been completed. If it is determined that it has not been completed, this operation proceeds to step S106, and if it is determined that it has been completed, this 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 moving method determined in step S103.

By repeating the operations of steps S103 and S104, it is formed by the pre-movement electric field displacement surface formed by the voltage applied to the plurality of control points 26 before the movement and the voltage applied to the plurality of control points 26 after the movement. The post-movement electric field displacement surface is combined, and 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.

(Action / Effect of Stereoscopic Image Display System According to First Embodiment of the Present Invention) According to the stereoscopic image display system according to the first embodiment of the present invention, interference is utilized by utilizing the property of the optical modulation element 25 that the refractive index changed by the applied voltage value (electric field strength) can be held for a certain period of time. Since an electric field displacement surface having an image pattern equivalent to the fringed image pattern is formed in the optical modulation element 25, an analog image pattern can be displayed, and the image display accuracy is limited by the size and shape of the pixel electrodes. It can be excluded to display an image with sufficient accuracy.

(Three-dimensional image display system according to the second embodiment of the present invention) A stereoscopic image display system according to a 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 the light modulation element moving portion 27a instead of the electrode moving portion 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 so that the relative positional relationship between 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 the light modulation element moving unit 27a composed of a piezo element, a damper, or the like. Has been done.

In the present embodiment, the electric field control unit 22 has 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 optical modulation element 25 moves, and photomodulation. By synthesizing the post-movement electric field displacement surface (changed electric field displacement surface) formed by the voltages applied to the plurality of control points 26 after the element 25 moves, an image pattern equivalent to the image pattern of the interference fringes can be obtained. The electric field displacement surface to be provided is configured to be formed in the optical 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 represented by (distance in the X-axis direction, distance in the Y-axis direction).

Further, the pre-movement voltage value indicates a voltage value applied to the four control points 26a to 26d surrounding the region corresponding to the image pattern before moving the light modulation element 25. Such a voltage value shall be expressed by (voltage value applied to control point 26a, voltage value applied to control point 26b, voltage value applied to control point 26c, voltage value applied to control point 26d).

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

(Three-dimensional 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. 12 (a) and 12 (b).

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

FIG. 12 (a) is a side view of the cross section of the hologram recording element 21 according to the present embodiment, and FIG. 12 (b) is a view of the hologram recording element 21 according to the present embodiment as viewed from above. Is.

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

Therefore, since a large amount of electric charge is accumulated at the tip of the protrusion-shaped portion of the lower surface electrode 24, 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 portions of the bottom electrode 24 are 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 protrusion-shaped portion of the lower surface electrode 24 is composed of a transistor or the like that can actively control the applied voltage.

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

(Three-dimensional image display system according to the fourth embodiment of the present invention) A stereoscopic image display system according to a fourth embodiment of the present invention will be described with reference to FIGS. 13 to 16. Hereinafter, the difference between the stereoscopic image display system according to the present embodiment and the stereoscopic image display system according to the first to third embodiments described above will be mainly described.

As shown 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 will be described in which the stereoscopic image display device 2 is configured by a mobile communication terminal capable of communicating with the server device 100 via the packet communication network 5.

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

The interference fringe calculation unit 1a calculates the interference fringes (computer hologram) generated from the object light and the reference light.

The storage unit 1b has an image pattern of interference fringes, movement information (change information) regarding the movement of the plurality of control points 26 (or the light modulation element 25), and movement applied to each of the plurality of control points 26 before the movement. It is configured to associate and store the pre-voltage value (pre-change voltage value) and the post-move voltage value (changed voltage value) applied to each of the plurality of control points 26 after movement. In such a case, for example, the storage unit 1b is configured to store the table shown in FIG. 6 (d).

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 image pattern of the interference fringes 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 reflector 33. There is.

The communication unit 31 requests the server device 100 to transmit the movement information, the pre-movement voltage value, and the post-movement voltage value corresponding to the image pattern of the interference fringes, and sends the received information to the electric field control unit 22. It is configured to send.

Further, the electric field control unit 22 described above is based on the movement information of the control point 26 corresponding to the pixel pattern of the interference fringes received from the server device via the communication unit 31, the pre-movement voltage value, and the post-movement voltage value. First implementation Similar to the electric field control unit 22 of the stereoscopic image display device 2 according to the portable device, the upper surface electrode 23, the lower surface electrode 24, or the electrodes 23, 24 are moved and moved to each control point 26 at a predetermined timing. By applying the pre-voltage value and the post-movement voltage value, an electric field displacement surface is formed in the optical 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 composed of a transparent electrode.

The light reflector 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 the calculation of the interference fringes by the interference fringe calculation unit 1a of the server device 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 the backlight.

Further, 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 27a, a light source 32, and a light reflector 33. Is equipped with.

In such a case, the electric field control unit 22 is based on the movement information of the light modulation element 25 corresponding to the pixel pattern of the interference fringes received from the server device via the communication unit 31, the pre-movement voltage value, and the post-movement voltage value. Similar to the electric field control unit 22 of the stereoscopic image display device 2 according to the second implementation described above, the light modulation element 25 is moved, and the voltage value before movement and the voltage 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, and interference fringes composed of a plurality of electric field displacement surfaces are recorded.

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 the interference fringes (computer hologram) generated from the object light and the reference light.

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

In step S1003, the transmission unit 1c of the server device 100 extracts the movement information (electrode movement information or optical modulation element movement information), the voltage value before movement, the voltage value after movement, and the application time of each voltage value (electric field strength information). The image information including and 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, by applying a predetermined voltage (voltage before movement or voltage after movement) to the upper surface electrode 23 and the lower surface electrode 24 at a predetermined timing for a predetermined application time, the inside of the optical modulation element 25 of the hologram recording element 21 An electric field displacement surface is formed in the above, 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 optical modulation element 25 with respect to the optical modulation element moving unit 27a based on the image information received from the server device via the communication unit 31. By applying a predetermined voltage (voltage before movement or voltage after movement) to the upper surface electrode 23 and the lower surface electrode 24 for a predetermined application time at a predetermined timing, the hologram recording element 21 An electric field displacement surface is formed in the optical modulation element 25, and interference fringes composed of a plurality of electric field displacement surfaces are recorded.

In step S1005, the light source 32 displays a stereoscopic image by irradiating the interference fringes formed in the light modulation element 25 of the hologram recording element 21 with the reference light B via the light reflector 33.

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

As shown in FIG. 18A, the hologram recording element 21 according to the present embodiment has an electro-optical effect in which the refractive index changes according to the electric field strength, and the light-modulating element 25 on the surface thereof. It includes a plurality of provided control points 26.

Specifically, the hologram recording element 21 is provided with a plurality of upper surface electrodes 23 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, it is assumed that the bottom 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 referred to as a control point 26 which 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 top electrode 23 in the present embodiment does not correspond to each pixel constituting the image to be displayed, unlike the top electrode 23 in the image display device having the electrode structure of the active matrix type according to the prior art.

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

FIG. 19 (a) 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 the refractive index is linear, and FIG. 19 (b) shows the applied electric field. An example of using the light modulation element according to the present embodiment in which the relationship between the intensity (potential difference) and the change in the refractive index is non-linear is shown.

In FIGS. 19 (a) and 19 (b), C indicates the state of the hologram recording element 21 (change pattern of refractive index) seen from the direction B of FIG. 18 (a), and D is FIG. The cross-sectional view of the hologram recording element 21 seen from the direction A of (a) is shown.

As can be seen from FIGS. 19 (a) and 19 (b), 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. 19 (a) is shown. The change in the refractive index inside the light modulation element 25 differs between the element 21 and the hologram recording element 21 shown in FIG. 19 (b) (see the refractive index change curve in D), from the direction B in FIG. 18 (a). The change pattern of the refractive index when viewed is also different.

Specifically, the change pattern of the refractive index in the hologram recording element 21 shown in FIG. 19 (b) is smaller than the change pattern of the refractive index in the hologram recording element 21 shown in FIG. 19 (a).

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 the refractive index is linear. Since it is possible to generate a change pattern of the refractive index smaller than the change pattern of the refractive index in the hologram recording element 21 using the modulation element, it is possible to generate an image pattern of finer interference fringes.

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

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

In this 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 it can be applied even when the control point 26 has a microelectrode 26a having an arbitrary shape. Is.

Further, 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 part 26b such as a cable, and the voltage value applied to each of the microelectrodes 26a is set. 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 has a predetermined direction (upper surface electrode moving direction or the upper surface electrode moving direction) as in the case of the second embodiment described above. It may be configured to be movable in the lower surface electrode moving direction).

FIG. 22 shows patterns (a) to (c) of the microelectrodes 26a to which the voltage is applied when the voltage is applied to a part of the microelectrodes 26a constituting the control point 26. In FIG. 22, it is assumed that the voltage is applied to the minute voltage 26a represented by the white circle and the voltage is not applied to the minute voltage 26a represented by the black circle.

When the pattern of the microelectrode 26a to which the voltage is applied is the "pattern (a)", the equipotential surface formed inside the photomodulator 25 becomes the "pattern (a)", and the microelectrode 26a to which the voltage is applied becomes the "pattern (a)". When the pattern of is "Pattern (b)", the equipotential surface formed inside the optical modulation element 25 becomes "Pattern (b)", and the pattern of the microelectrode 26a to which the voltage is applied is "Pattern (c)". In the case of, the equipotential surface formed inside the optical modulation element 25 becomes a 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 microelectrode 26a to which the voltage is applied, and thus more accurately. An image pattern of interference fringes can be generated.

<figref num="1">It is an overall block diagram of the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="2">It is a figure which shows an example of the computer hologram recorded in the light modulation element in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="3">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="4">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="5">It is a functional block diagram of the electric field control part in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="6">It is a figure for demonstrating the control method by the electric field control part in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="7">It is a figure for demonstrating the control method by the electric field control part in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="8">It is a figure for demonstrating the control method by the electric field control part in the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="9">It is a flowchart which shows the operation of the stereoscopic image display system which concerns on 1st Embodiment of this invention.</figref><figref num="10">It is an overall block diagram of the stereoscopic image display system which concerns on 2nd Embodiment of this invention.</figref><figref num="11">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 2nd Embodiment of this invention.</figref><figref num="12">It is a figure for demonstrating the hologram recording element in the stereoscopic image display system which concerns on 3rd Embodiment of this invention.</figref><figref num="13">It is an overall block diagram of the stereoscopic image display system which concerns on 4th Embodiment of this invention.</figref><figref num="14">It is a functional block diagram of the server apparatus in the stereoscopic image display system which concerns on 4th Embodiment of this invention.</figref><figref num="15">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 4th Embodiment of this invention.</figref><figref num="16">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 4th Embodiment of this invention.</figref><figref num="17">It is a flowchart which shows the operation of the stereoscopic image display system which concerns on 4th Embodiment of this invention.</figref><figref num="18">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 5th Embodiment of this invention.</figref><figref num="19">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 5th Embodiment of this invention.</figref><figref num="20">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 6th Embodiment of this invention.</figref><figref num="21">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 6th Embodiment of this invention.</figref><figref num="22">It is a figure for demonstrating the stereoscopic image display apparatus in the stereoscopic image display system which concerns on 6th Embodiment of this invention.</figref><figref num="23">It is a figure for demonstrating the image display apparatus which has the electrode structure of the conventional simple matrix system.</figref><figref num="24">It is a figure for demonstrating the image display apparatus which has the electrode structure of the conventional active matrix type.</figref><figref num="25">It is a figure for demonstrating the problem of the conventional image display apparatus.</figref>

Code description

A ... Object light B ... Reference light 1 ... Interference fringe calculation device 2 ... 3D image display device 21 ... Hologram recording element 22 ... Electric field control unit 22a ... Image signal receiver 22b ... Memory 22c ... Decision Department 22d ... Voltage application part 22e ... Movement control unit 23 ... Top electrode 24 ... Bottom electrode 25 ... Light modulation element 26 ... Control point 27 ... Electrode moving part 31 ... Communication Department 32 ... light source 33 ... Light reflector 3 ... Reference light irradiation device 5 ... Packet communication network 100 ... server device