JP7360908B2 - 3D image display device and 3D image display method - Google Patents

Description

The present invention relates to a stereoscopic image display device and a stereoscopic image display method that display color stereoscopic images.

The integral method, which is one of the spatial image reproduction methods that forms a three-dimensional image in space, displays a group of elemental images on a display, which is a two-dimensional array of many small images called elemental images. A three-dimensional image is reproduced through the optical element array by arranging an optical element array in which optical elements such as lenses are arranged in a two-dimensional manner so as to face each element image on the front surface. As a display device for the elemental image group, a direct-view type display such as a liquid crystal display or an organic EL display is applied. In a display, pixels that are arranged two-dimensionally to display element images are further provided with sub-pixels of each color of red (R), green (G), and blue (B), so that full-color display is possible. 3D images can be displayed.

In integral playback, the pixels on the display are divided into sub-pixels of each color within the plane, in other words, the pixels of each color of R, G, and B are arranged repeatedly, and a lens array (optical There is a problem in that color moiré occurs in color stereoscopic images due to resampling using an element array. In order to solve this problem, the present inventors created a color 3D image with reduced color moiré by using two or more displays and combining the color 3D images reproduced on each display. (Non-patent Documents 1 and 2). Specifically, two displays each have sub-pixels of three colors R, G, and B arranged in stripes, and lens arrays are placed facing each other with a 1/2 pixel offset, and the two images formed from the displayed images are Three-dimensional images are combined using a half mirror (beam splitter). In the synthesized stereoscopic image, color moiré is reduced by overlapping the moire of each color of the two stereoscopic images with a shift. Furthermore, if the lens arrays are shifted by 1/3 of the pixel on each of the three displays to face each other and three 3D images are synthesized, color moiré will theoretically be completely eliminated (if the subpixel has an aperture ratio of 100%). It will be resolved in

Hisayuki Sasaki, Naoto Okaichi, Hayato Watanabe, Masahiro Kawakita, Tomoyuki Mishina, “Color moire reduction technology for direct-view integral 3D display”, IEICE technical research report, vol. 116, no. 464, IE2016-105, p. 223-226, February 2017 Hisayuki Sasaki, Naoto Okaichi, Hayato Watanabe, Masanori Kano, Masahiro Kawakita, Tomoyuki Mishina, “Color moiré reduction technology for direct-view integral 3D display”, Technical Report of the Institute of Image Information and Television Engineers, vol. 41, no. 26, ME2017- 83, p. 1-4, August 2017

The display methods described in Non-Patent Documents 1 and 2 use two or more displays, lens arrays facing each display, and a half mirror, and further modify the structure of the display device in order to arrange the displays in accordance with the half mirrors. has become complex and large, and there is room for improvement. On the other hand, when a projection type display device without a sub-pixel structure is used, color moiré does not occur. However, in the projection type, since projection distortion occurs, electrical correction means are often required, which causes the problem of reduced resolution. is difficult.

Further, in order to increase parallax information, it is preferable to have a large number of pixels forming an elemental image, but as the elemental image becomes larger and the lens pitch of the lens array becomes larger, the upper limit of resolution decreases. Therefore, a display that displays a group of elemental images is required to have finer pixels, but there is a limit because each pixel is further composed of three or more subpixels.

The present invention has been made in view of the above-mentioned problems, and provides a 3D image display device and 3D image that do not become large in size and are capable of reproducing color 3D images with high resolution and suppressed color moiré using an integral method. The objective is to provide a display method.

A stereoscopic image display device according to the present invention includes an image display means for displaying a two-dimensional array of pixels formed by arranging two or more sub-pixels displayed in a single color, and a display side of the image display means. and a lens array in which a plurality of lenses are arranged two-dimensionally to display a color stereoscopic image. The three- dimensional image display device includes an optical path shifting means between the image displaying means and the lens array, which shifts and transmits light incident from the image displaying means in a stepwise manner , and the optical path shifting means includes: The light output position on the output surface is shifted in the arrangement direction of the sub-pixels in the pixel by a distance equal to the length of the sub-pixels. Alternatively, in the stereoscopic image display device, the pixel includes M (M≧2) or more of the sub-pixels arranged in one direction, and the optical path shifting means moves the pixel in the one direction on the exit surface. It is characterized in that it is displaced by a distance of (1/M) of the length of.

Another stereoscopic image display device according to the present invention includes an image display means for displaying a two-dimensional array of pixels formed by arranging two or more sub-pixels that are displayed in a single color, and a parallel light beam applied to the image display means. It displays a color three-dimensional image by comprising a light source for irradiation and a lens array in which a plurality of lenses are two-dimensionally arranged and provided between the light source and the image display means. The three- dimensional image display device includes an optical path shifting means between the lens array and the image displaying means for displacing incident light stepwise and transmitting it toward the image displaying means , and the optical path shifting means includes: The light output position on the output surface is shifted in the arrangement direction of the sub-pixels in the pixel by a distance equal to the length of the sub-pixels. Alternatively, in the stereoscopic image display device, the pixel includes M (M≧2) or more of the sub-pixels arranged in one direction, and the optical path shifting means moves the pixel in the one direction on the exit surface. It is characterized in that it is displaced by a distance of (1/M) of the length of.

With such a configuration, in the stereoscopic image display device, the elemental images displayed on the image display means are time-divisionally shifted by a fraction of a pixel and incident on the lens array by the optical path shift means. , it is possible to reduce color moiré by forming a color three-dimensional image that overlaps into one. Furthermore, since each pixel of the image display means displays 1.5 or more of the pixels constituting the reproduced stereoscopic image, a color stereoscopic image with a resolution higher than that of the image display means can be obtained.

The stereoscopic image display method according to the present invention includes two-dimensionally arranging pixels in the X direction and the Y direction, which are formed by arranging N sub-pixels (N≧2) in the X direction, each of which is displayed in a single color. A method for displaying a color 3D image using an image display means for displaying images, and a lens array in which a plurality of lenses are two-dimensionally arranged, the color 3D image being constructed by two-dimensionally arranging a plurality of pieces of pixel information. Each of the pixel information of the image information includes sub-pixel information of the color displayed by the sub-pixel of the image display means. In this stereoscopic image display method, the image display means selects and displays the sub-pixel information of the color corresponding to the sub-pixel, one piece of the pixel information of the image information, for each of the sub-pixels. The display step is performed N times, and the i-th image display step (1≦i≦N) displays j-th pixel information in the X direction in the image information, and (j+i−1) in the X direction in the image display means. In the i-th image display step, an optical path shifting means provided between the image display means and the lens array moves the incident light along the length of the pixel in the X direction. (a is an integer constant).

Another stereoscopic image display method according to the present invention is to arrange pixels formed by arranging N sub-pixels (N≧2), each of which is displayed in a single color, in a two-dimensional array in the X direction and the Y direction. A method for displaying a color 3D image using an image display means and a lens array in which a plurality of lenses are two-dimensionally arranged, the color 3D image being constructed by arranging a plurality of pixel information two-dimensionally. Each of the pixel information of the image information has sub-pixel information of a color displayed by the sub-pixel of the image display means. In this stereoscopic image display method, each pixel is divided in the X direction into M subpixel groups each consisting of one subpixel or two or more consecutive subpixels (2≦M≦N ), the image display means selects and displays the subpixel information of the color corresponding to the subpixel of the subpixel group, one piece of the pixel information of the image information for each subpixel group. The image display step is performed M times, and in the i-th image display step (1≦i≦M), the j-th pixel information is displayed in the X direction in the image information, and (j+i− 1) The optical path shifting means provided between the image display means and the lens array directs the incident light to the pixels in the X direction in the i-th image display step. (a is an integer constant).

Through this procedure, sub-pixel information of some colors is sequentially thinned out and displayed from each of the two-dimensionally arranged pixel information in a time-sharing manner, and the displayed image is shifted by the optical path shifting means to be incident on the lens array. , it is possible to reproduce a color three-dimensional image in which color moiré is reduced by apparently overlapping one another.

According to the stereoscopic image display device of the present invention, a color stereoscopic image with high resolution and suppressed color moiré can be reproduced in an integral manner without increasing the size. According to the stereoscopic image display method according to the present invention, a color stereoscopic image with high resolution and suppressed color moiré can be reproduced in an integral manner without increasing the resolution of the display device.

FIG. 1 is a schematic diagram illustrating the structure of a stereoscopic image display device according to the present invention. FIG. 2 is a schematic diagram illustrating an arrangement of sub-pixels of three colors in a pixel of an image display device used in a stereoscopic image display device according to the present invention. FIG. 2 is a schematic diagram illustrating an arrangement of sub-pixels of three colors in a pixel of an image display device used in a stereoscopic image display device according to the present invention. FIG. 1 is a partial cross-sectional view in the XZ plane of the stereoscopic image display device according to the first embodiment of the present invention. FIG. 2 is an exploded view of the optical path shifting means of the stereoscopic image display device according to the first embodiment of the present invention, and is a schematic diagram illustrating the structure and operation. FIG. 2 is an exploded view of the optical path shifting means of the stereoscopic image display device according to the first embodiment of the present invention, and is a schematic diagram illustrating the structure and operation. FIG. 2 is an exploded view of the optical path shifting means of the stereoscopic image display device according to the first embodiment of the present invention, and is a schematic diagram illustrating the structure and operation. FIG. 2 is a partial cross-sectional view in the XZ plane illustrating the structure of the stereoscopic image display device according to the first embodiment of the present invention, which includes a diffuser plate. 1 is a time chart illustrating a stereoscopic image display method according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a first image display step of the stereoscopic image display method according to the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a second image display step of the stereoscopic image display method according to the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a third image display step of the stereoscopic image display method according to the first embodiment of the present invention. FIG. 2 is a partially enlarged view conceptually explaining the configuration of pixels in a stereoscopic image reproduced by the stereoscopic image display method according to the first embodiment of the present invention. FIG. 2 is a partially enlarged view illustrating the configuration of an image displayed in an image display step of the stereoscopic image display method according to the first embodiment of the present invention. FIG. 3 is a schematic diagram illustrating the arrangement of sub-pixels of four colors in a pixel of an image display device used in a stereoscopic image display device according to the present invention. FIG. 7 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a stereoscopic image display method according to a modification of the first embodiment of the present invention. It is an exploded view of the optical path shift means of the stereoscopic image display apparatus based on the modification of 1st Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is an exploded view of the optical path shift means of the stereoscopic image display apparatus based on the modification of 1st Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is an exploded view of the optical path shift means of the stereoscopic image display apparatus based on the modification of 1st Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. FIG. 3 is a partial cross-sectional view in the XZ plane of a stereoscopic image display device according to a modification of the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view in the XZ plane of a stereoscopic image display device according to a modification of the first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an arrangement of sub-pixels of three colors in a pixel of an image display device used in a stereoscopic image display device according to the present invention. It is an exploded view of the optical path shift means of the stereoscopic image display device based on 2nd Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is an exploded view of the optical path shift means of the stereoscopic image display device based on 2nd Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is an exploded view of the optical path shift means of the stereoscopic image display device based on 2nd Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is an exploded view of the optical path shift means of the stereoscopic image display device based on 2nd Embodiment of this invention, and is a schematic diagram explaining a structure and operation|movement. It is a time chart explaining the stereoscopic image display method based on 2nd Embodiment of this invention. FIG. 7 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating the first image display step of the stereoscopic image display method according to the second embodiment of the present invention. FIG. 3 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a second image display step of the stereoscopic image display method according to the second embodiment of the present invention. It is a partial sectional view in the XZ plane of a stereoscopic image display apparatus, and is a schematic diagram explaining the 3rd image display process of the 3D image display method based on 2nd Embodiment of this invention. It is a partial sectional view in the XZ plane of a stereoscopic image display apparatus, and is a schematic diagram explaining the 4th image display process of the stereoscopic image display method based on 2nd Embodiment of this invention. FIG. 7 is a partially enlarged view conceptually illustrating the configuration of pixels in a stereoscopic image reproduced by a stereoscopic image display method according to a second embodiment of the present invention. FIG. 7 is a partially enlarged view illustrating the configuration of an image displayed in an image display step of a stereoscopic image display method according to a second embodiment of the present invention. FIG. 7 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a first image display step of the stereoscopic image display method according to the third embodiment of the present invention. FIG. 7 is a partial cross-sectional view of the stereoscopic image display device in the XZ plane, and is a schematic diagram illustrating a second image display step of the stereoscopic image display method according to the third embodiment of the present invention. FIG. 7 is a partially enlarged view conceptually explaining the configuration of pixels in a stereoscopic image reproduced by a stereoscopic image display method according to a third embodiment of the present invention. FIG. 7 is a partially enlarged view illustrating the configuration of an image displayed in an image display step of a stereoscopic image display method according to a third embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an arrangement of sub-pixels of three colors in a pixel of an image display device used in a stereoscopic image display device according to the present invention.

Embodiments for implementing the stereoscopic image display device and the stereoscopic image display method according to the present invention will be described with reference to the drawings. The size, positional relationship, etc. of the stereoscopic image display device and its elements shown in the drawings may be exaggerated for clarity of explanation, and the shape may be simplified.

[Stereoscopic image display device]
The stereoscopic image display device 100 according to the embodiment of the present invention is a device that forms a color stereoscopic image in space using an integral method. As shown in FIG. 1, the stereoscopic image display device 100 includes an image display device (image display means) 10 whose display surface is an XY plane, and a display surface of the image display device 10 in which element lenses 3 are two-dimensionally arranged in the XY plane. A lens array 30 facing the side (+Z direction) and a wobbling element (optical path shifting means) 2 disposed between the image display device 10 and the lens array 30, A full-color stereoscopic image vI is formed. Each element will be explained in detail below.

[First embodiment]
(Image display device)
The image display device 10 is a display device for inputting a group of elemental images in which a large number of elemental images are two-dimensionally arranged into a lens array 30, and includes color display elements 1 arranged two-dimensionally in the XY plane. As shown in FIGS. 2A and 2B, the color display element 1 is further divided into three equal parts in the X direction, including a display element (subpixel) 1R that displays red and a display element (subpixel) 1G that displays green. , and a display element (sub-pixel) 1B that displays blue color. Note that although the aspect ratio of the color display element 1 is shown as 1 (p _pX =p _pY ) in FIGS. 2A and 2B, it is not particularly specified. In the image display device 10, the color display elements 1 may be arranged so that the display elements 1R, 1G, and 1B are aligned in the same color along the Y direction (stripe arrangement) as shown in FIG. As shown in 2B, the display elements 1R (1G, 1B) may be arranged while being shifted in the X direction by one display element 1R (1G, 1B) (p _pX /3) in the Y direction (mosaic arrangement).

In the stereoscopic image display device 100, the light emitted by the image display device 10 is preferably parallel light. For this purpose, the image display device 10 is, for example, a color liquid crystal display, and as shown in FIG. A planar light source (backlight) 4 that emits _P is provided. The light source 4 uniformly irradiates the back surface of the liquid crystal module 10m with parallel light L _P in the +Z direction. In order to suppress the increase in size, the light source 4 includes, for example, a light emitting element such as a light emitting diode (LED), a light guide plate that propagates the light emitted by the light emitting element, and a back surface, similar to the backlight of a general liquid crystal display. A collimator lens for collimating light and a holographic optical element are further provided on the liquid crystal module 10m side of the light guide plate. The image display device 10 (liquid crystal module 10m) has pixel electrodes provided in each of the display elements 1R, 1G, and 1B on the display surface, and red, green, and blue color filters arranged as opening areas (light emission areas). By equipping it with a light source, it emits light of each color. Furthermore, the light emitted by the image display device 10 becomes light with a polarized component in the Y direction due to the polarizing plate provided in the liquid crystal module 10m. Further, in the present embodiment, it is preferable that the image display device 10 has a response speed of 5.56 ms or less (180 Hz or more). The image display device 10 receives a signal for displaying the element image group from a display control means (not shown).

(lens array)
The lens array 30 is an optical element array that spatially samples the elemental images. The lens array 30 includes element lenses 3 arranged two-dimensionally on a plane parallel to the display surface of the image display device 10 (XY plane). The arrangement of the element lenses 3 in the lens array 30 can be, for example, a square lattice arrangement along the X direction and the Y direction (see FIG. 1) or a triangular lattice shape (barrel shape). The element lenses 3 are convex lenses and are arranged at a pitch of about 1 mm to several mm. The number of element lenses 3 of the lens array 30 corresponds to the number of pixels of the stereoscopic image vI. In the lens array 30, one element lens 3 is arranged corresponding to one of the element images, in other words, the elements in the image displayed on the image display device 10 are arranged such that the element image directly faces the element lens 3. Image dimensions and alignment are set. Specifically, as shown in FIG. 3, one element lens 3 directly faces a group of display elements 1R, 1G, and 1B of the image display device 10 that display one element image eI. The larger the number of display elements 1R, 1G, and 1B that display one element image eI, the more parallax information can be obtained. However, if the pitch of the element lenses 3 in the lens array 30 is large, the upper limit of resolution will be lowered.

Furthermore, the shorter the focal length f of the element lens 3 is with respect to the diameter Φ, that is, the smaller the F value, the wider the viewing angle Ψ of the stereoscopic image vI can be, as expressed by the following formula (1). In FIG. 3, it is assumed that a light ray that is emitted from the image display device 10 and enters one of the element lenses 3 is represented by a straight line with an arrow, and that the wobbling element 2 causes the light to travel straight. The stereoscopic image display device 100 preferably has a viewing angle Ψ of 30° or more, although it depends on the application. The image display device 10 and the lens array 30 are designed so that the necessary viewing angle Ψ, resolution, etc. can be obtained. In the stereoscopic image display device 100, the image display device 10 emits parallel light, so that the element lens 3 is placed at a point of focal length f from the main surface of the element lens 3 of the lens array 30 (the intersection of the light rays in FIG. 3). A bright spot appears every time.

(wobbling element)
The wobbling element 2 is provided between the image display device 10 and the lens array 30 and allows the image displayed by the image display device 10 to pass through and enter the lens array 30 . The wobbling element 2 optionally shifts (displaces) the light stepwise in a plane (XY plane) perpendicular to the optical axis (Z direction) and transmits the light without changing the direction of the optical axis. Specifically, the wobbling element 2 is arranged at a distance of 0 in the arrangement direction of the display elements 1R, 1G, and 1B in the color display element 1 of the image display device 10, and at intervals of 1/M of the length of the color display element 1 in this direction. (M is a natural number of 2 or more) including (no displacement). In this embodiment, the wobbling element 2 is capable of displacing light in the X direction, and displaces the light in three steps of +p _pX /3, 0, -p _pX /3 on the incident surface of the lens array 30 (M=3). . For example, as shown in FIGS. 3 and 4A to 4C, the wobbling element 2 includes, in order from the image display device 10 side, a first polarization control element 21, a first birefringence element 23, a second polarization control element 22, and a second birefringent element 24 are stacked in the Z direction.

The first polarization control element 21 and the second polarization control element 22 rotate the polarization direction by 90 degrees in a plane (XY plane) perpendicular to the optical axis (Z direction) by external electrical means, or It is a selective optical rotator that transmits light without rotation. The polarization control elements 21 and 22 are, for example, liquid crystal elements in which a liquid crystal such as a ferroelectric liquid crystal (FLC) is sealed between transparent electrode films formed on transparent substrates such as two glass plates. As shown in FIG. 4C, power supplies V1 and V2 are connected. In this embodiment, the polarization control elements 21 and 22 change the polarization in the Y direction to the polarization in the X direction and the polarization in the X direction to polarization in the Y direction by applying a voltage, and transmit the light. When the voltage application is stopped, the light is transmitted as is (without changing the direction of polarization).

The first birefringent element 23 and the second birefringent element 24 are each birefringent elements. A birefringent element is an optical element whose refractive index changes depending on the direction of polarization of transmitted light. A birefringent element causes incident light with a predetermined polarization direction to travel straight (ordinary ray). On the other hand, the birefringent element refracts light whose polarization direction is perpendicular to the ordinary ray at the incident surface and the exit surface, and as a result, the light is shifted in the polarization direction, and the incident direction to the birefringent element ( (abnormal ray) is emitted in a direction parallel to the optical axis). Examples of materials having such optical properties include crystals such as calcite (CaCO ₃ ), yttrium vanadate (YVO ₄ ) crystal, and quartz. The traveling direction of the extraordinary ray within the birefringent element is inclined toward the optical axis of the birefringent element. Therefore, the birefringent element is arranged with its optical axis inclined toward the polarization direction of the extraordinary ray with respect to the optical axis.

The displacement distance g of light by the birefringent element made of the crystal material is proportional to the thickness (length in the optical axis direction) t, as expressed by the following equation (2). The displacement distance g/t of light per length in the optical axis direction is the difference between the refractive index n ₀ for the ordinary ray and the refractive index n _e for the extraordinary ray |ne _- n ₀ | is the refractive index n ₀ , n _e It is longer as it is larger than , and becomes longest when the optical axis angle θ (0°<θ<90°) of the birefringent element with respect to the optical axis is around 45°. Note that in a material where n ₀ > _ne (negative crystal), the displacement distance g of light is negative, and the traveling direction of the extraordinary ray is reversed. The optical axis angles θ1, θ2 and thickness of the birefringent elements 23, 24 are designed according to the refractive indices n ₀ , _ne of the selected materials so that the displacement distances g1, g2 of the light become desired values. .

In this embodiment, the polarization direction of the extraordinary ray is set to the X direction so that the extraordinary ray is displaced in the -X direction by the first birefringence element 23 and in the +X direction by the second birefringence element 24, respectively. Further, the birefringent elements 23 and 24 are designed and arranged so that the displacement distances g1 and g2 of light by the birefringent elements 23 and 24 are g1=g2=p _pX /3. Therefore, the first birefringent element 23 and the second birefringent element 24 both use the Y-direction polarized light _L It is arranged so that it is inclined in the direction. In FIGS. 4A to 4C, the optical axis directions of the birefringent elements 23 and 24 are represented by broken lines. The first birefringent element 23 and the second birefringent element 24 are, for example, formed of the same material and have the same thickness, and are arranged with the directions of the optical axes reversed such that θ1=θ2. Further, the image display device 10 emits light with the same polarization direction as the ordinary ray or extraordinary ray of the first birefringent element 23 on the side of the image display device 10, and here, the polarized light L in the same Y direction as the ordinary ray. Designed to emit _Y. With such a configuration, the wobbling element 2 displaces light in three stages of +p _pX /3, 0, -p _pX /3 in the X direction, as described below with reference to FIGS. 4A to 4C. let In FIGS. 4A to 4C, double-headed arrows are attached to the lights L _Y and L _X to indicate the polarization direction, and the power supplies V1 and V2 are shown when they are ON.

As shown in FIG. 4A, when no voltage is applied to either the first polarization control element 21 or the second polarization control element 22 (V1: OFF, V2: OFF), the birefringence elements 23 and 24 are always Since the light L _Y is incident, the light travels straight through and is not displaced. In order to displace the light by +p _pX /3 in the X direction, a voltage is applied only to the second polarization control element 22 (V1: OFF, V2: ON), as shown in FIG. 4B. At this time, since the light L _Y is incident on the first birefringent element 23, it goes straight and is transmitted, and is then modulated by the second polarization control element 22 into polarized light L _X in the X direction, so the second birefringent element 24 is refracted in the +X direction and transmitted, and is displaced by a distance g2 (=p _pX /3). In order to displace the light by -p _pX /3 in the X direction, voltage is applied to both the first polarization control element 21 and the second polarization control element 22 (V1: ON, V2: ON). At this _time , the light _L Since the light L _Y is remodulated by the polarization control element 22 to be an ordinary ray, it passes straight through the second birefringence element 24 and is transmitted. In this way, the wobbling element 2 is configured to displace the light in both directions (+ and -) with a displacement of 0, thereby suppressing the maximum value (absolute value) of the necessary displacement amount and allowing the lens array 30 to Errors in the position of incident light are less likely to occur. Note that when a voltage is applied only to the first polarization control element 21 (V1: ON, V2: OFF), the light L _X is refracted and transmitted by each of the birefringent elements 23 and 24 (see modification example below). ).

The stereoscopic image display device 100 may include a diffusion plate 5 between the wobbling element 2 and the lens array 30, as shown in FIG. The diffuser plate 5 diffuses and transmits the incident parallel light at a predetermined light distribution angle. When the diffuser plate 5 is provided, it is preferable that the lens array 30 is arranged at a focal distance f of the element lens 3 from the diffuser plate 5 . In addition, in FIG. 5, a light ray that is emitted from one point on the display surface of the image display device 10 and enters the lens array 30 is represented by a straight line with an arrow, and it is assumed that the wobbling element 2 causes the light to travel straight. do. When the stereoscopic image display device 100 is provided with the diffuser plate 5, the resolution of the elemental images tends to decrease. can be imaged. In order for the image display device 10 to emit perfectly parallel light, the light source 4 needs to include a collimator lens that is larger than the lens array 30, for example. Therefore, by including the diffuser plate 5, the stereoscopic image display device 100 can suppress increase in size. The diffuser plate 5 can be one provided in a general backlight or the like, and is composed of, for example, a lens array in which micron-sized lenses are randomly arranged. Alternatively, the diffusion plate 5 may be a holographic screen that uniformly diffuses the light incident on the rear surface in all directions (hemisphere) on the display side or in a desired three-dimensional shape and angle. In this case, it is preferable that its shape and angle match the shape of a cone or the like read out by the element lenses 3 of the lens array 30. According to such a diffuser plate 5, the light utilization efficiency is increased, and the occurrence of crosstalk and side lobes is suppressed.

(Stereoscopic image display method)
A method of displaying a stereoscopic image vI according to the first embodiment by the stereoscopic image display device 100 will be described with reference to FIGS. 6 to 9. In the stereoscopic image display method according to the present embodiment, as shown in FIG. 6, during one frame (16.7 ms (≒ 1/60 s)) period _T Image display steps S12, S22, and S32 are performed three times in which three images P1, P2, and P3 are switched and displayed on the display screen. The image display steps S12, S22, and S32 refer to periods during which light of each color is emitted from the selected display elements 1R, 1G, and 1B, that is, the light source 4 of the image display device 10 is emitting light ( Backlight power supply V _BL :ON) period. Further, the three-dimensional image display method according to the present embodiment includes data selection steps S11, S21, and S31 in which data constituting images P1, P2, and P3 are selected and the signals are written into the pixel electrodes of the display elements 1R, 1G, and 1B. I do.

Images P1, P2, and P3 are each made up of a regular two-dimensional array of red pixels pR, green pixels pG, and blue pixels pB, and the arrays are arranged on the display elements 1R, 1G, and 1B in the image display device 10. (see FIG. 2A). In addition, in the drawings, pixels pR, pG, pB, and a pixel pY in a modified example described later are each given different hatching (pixel pG is white (no hatching)), and furthermore, "R", "G", It is represented by the letters "B" and "Y". Note that FIGS. 7A to 7C are cross-sections of the display elements 1R, 1G, and 1B in the first row (Y=1) of the image display device 10. Further, in FIGS. 7A to 7C, for the sake of brevity, it is shown that one elemental image is displayed by a total of six display elements 1R, 1G, and 1B in the X direction. First, the image display steps S12, S22, and S32 will be explained.

When the image display device 10 displays the image P2 in a state where the wobbling element 2 does not displace the light (V1: OFF, V2: OFF, see FIG. 4A), as shown in FIG. 7B, the lens array 30 causes the An image vI2 is formed with each region (reference region) facing each of the element lenses 3 in the Z direction as an element image eI2. On the other hand, when the image display device 10 displays the image P1 in a state where the wobbling element 2 displaces the light in the +X direction (V1: OFF, V2: ON, see FIG. 4B), the lens The array 30 forms an image vI1 in which each area in the image P1 that is shifted by -p _pX /3 in the X direction from the reference area (the boundary is represented by a dashed line) is an element image eI1. Further, when the image display device 10 displays the image P3 in a state in which the wobbling element 2 displaces the light in the -X direction (V1: ON, V2: ON, see FIG. 4C), the lens array 30 As a result, an image vI3 is formed with each area in the image P3 shifted by +p _pX /3 in the X direction from the reference area (the boundary is represented by a dashed line) as an element image eI3. Here, a first image display step S12 for displaying the image P1, a second image display step S22 for displaying the image P2, and a third image display step S32 for displaying the image P3 are performed in this order. The images P1, P2, and P3 alternately displayed in these steps are shifted by +p _pX /3, 0, and -p _pX /3 in the X direction by the wobbling element 2, respectively, and the images vI1, vI2, and vI3 are displayed by the lens array 30. image is formed. Further, as shown in FIG. 6, the switching of the three combinations of ON/OFF of the power supplies V1 and V2 of the wobbling element 2 is synchronized with the ON/OFF switching of the backlight power supply V _BL , and at least the backlight power supply V BL is switched ON/OFF. _BL : During the ON period (image display steps S12, S22, S32), the above combinations are executed.

The three images vI1, vI2, vI3 are each reproduced in a two-dimensionally arranged group of element images eI1, eI2, eI3 as images P1, P2, P3 by the image display device 10 in a short time within one frame. Since they are switched and displayed, they appear to overlap into one and are combined into a three-dimensional image vI. Here, when images vI1, vI2, and vI3 are microscopically observed, as shown in FIG. 8, each image is composed of pixels pR, pG, and pB arranged two-dimensionally like images P1, P2, and P3. However, the image vI1 is reconstructed by arranging the pixels pR (pG, pB) taken out for each element image eI1 from the image P1 by the element lens 3 of the lens array 30 in the same square lattice shape as the element lens 3. It is a statue. Similarly, the image vI2 is an image obtained by reconstructing the pixels pR (pG, pB) extracted from the image P2 for each element image eI2, and the image vI3 for each element image eI3 from the image P3. The images P1, P2, P3 displayed on the image display device 10 in which the display elements 1R, 1G, 1B of different colors are repeatedly arranged in this way are resampled by the lens array 30, and the images vI1, vI2, vI3 are , each result in an image with color moiré.

However, in the stereoscopic image vI, the pixels pR, pG, and pB extracted from the images P1, P2, and P3 of the images vI1, vI2, and vI3 using the same element lens 3 overlap in the same area. More specifically, pixels pR, pG, and pB having the same coordinates in the element images eI1, eI2, and eI3 overlap each other. The element images eI1, eI2, and eI3 are shifted from each other in the X direction by 1/3 of the pixel length p _pX , that is, by the length of one pixel pR (pG, pB), by the wobbling element 2. Therefore, from FIGS. 7A to 7C, in the stereoscopic image vI, the pixel pG of the image vI2 and the pixel pB of the image vI3 are extracted in the area of the image vI1 from which the pixel pR of the elemental image eI1 shown in FIG. 7A is extracted. overlap. Similarly, the pixel pB of the image vI2 and the pixel pR of the image vI3 overlap the pixel pG of the image vI1, and the pixel pR of the image vI2 and the pixel pG of the image vI3 overlap the pixel pB of the image vI1.

As a result, the three-dimensional image vI is mixed and reduced because the moiré of each color of the images vI1, vI2, and vI3 overlap with each other with a shift of 1/3 of the pixel length p _pX . This is described in Non-Patent Document 2, and combines three 3D images formed from images displayed on each of three displays by shifting the lens array by 1/3 of the pixel length p _pX and facing each other. (moiré modulation degree m(c ₃ ) in FIG. 2 of Non-Patent Document 2). Therefore, in theory (when the display elements 1R, 1G, and 1B have an aperture ratio of 100%), color moiré is completely eliminated in the stereoscopic image vI.

In addition, since the three-color pixels pR, pG, and pB overlap in the same area, the three-dimensional image vI has an area corresponding to one display element 1R (1G, 1B) (the area surrounded by a thick line in FIG. 8). ) can be displayed in color. Note that the pixels pR, pG, and pB of the images vI1, vI2, and vI3 are arranged in a square lattice as described above, but the display element 1R (1G, 1B) has an aspect ratio of 3 and is long in the Y direction. Therefore, three consecutive pixels pR (pG, pB) in the Y direction are displayed on the same display element 1R (1G, 1B). From this, in the image display device 10, generally, the R, G, and B colors of the same pixel are displayed simultaneously on the display elements 1R, 1G, and 1B arranged in one color display element 1. Data (brightness information) can be divided and displayed one by one into images P1, P2, and P3, as shown in FIG. As a result, each of the display elements 1R, 1G, and 1B, which are sub-pixels, is treated as one pixel, and the resolution is tripled in the X direction. Therefore, in this embodiment, the upper left corner of the display surface of the image display device 10 is set as the origin (indicated by a black circle in FIG. 9), and the coordinates of the display element 1R in the first column and first row are (X=1, Y= 1), the coordinates of the display element 1G to the right of the display element 1G will be explained as (X=2, Y=1).

(image data)
Here, the image data constituting the stereoscopic image vI will be explained. The image data (image information) D constituting the stereoscopic image vI displayed in one frame is a two-dimensional array of a large number of pixel data (pixel information) d in the x direction and the y direction, as shown in equation (3) below. It will be done. Furthermore, one pixel data d is composed of red pixel data (sub-pixel information) dR, green pixel data (sub-pixel information) dG, and blue pixel data (sub-pixel information), as shown in equation (4) below. ) dB consists of three monochromatic pixel data (hereinafter referred to as sub-pixel data). The sub-pixel data dR, dG, and dB refer to the minimum unit of information displayed by one of the corresponding colors of the display elements 1R, 1G, and 1B of the image display device 10, and depending on the display method of the image display device 10, (100%) and dark (0%) (1 bit), or further includes one or more intermediate tones (2 bits or more). As shown in equations (3) and (4) below, the pixel data d and the subpixel data dR, dG, dB are represented by appropriately adding the address (xy coordinates) in the image data D with subscripts.

Note that in the drawings, images P1, P2, and P3 are represented by adding coordinates of pixel data d along with colors (R, G, B) within the respective contours of pixels pR, pG, and pB. This also applies to the modified examples described later and the second embodiment and subsequent embodiments. In addition, in FIGS. 7A, 7B, and 7C, images P1, P2, and P3 are pixels pR, pG, and pB displayed on display elements 1R, 1G, and 1B in the first row (Y=1) of the image display device 10, respectively. However, in this embodiment, all y-coordinates k are common. Furthermore, in this specification, the X direction is the horizontal (H) direction and the Y direction is the vertical (V) direction, and the x direction and the y direction in the image data D are respectively assigned to the X direction and the Y direction. However, the X and Y directions can also be interchanged.

Images P1, P2, and P3 can each be composed of part of the image data D. To this end, before the first image display step S12 for displaying the image P1, a first data selection step S11 for extracting data constituting the image P1 from the image data D is performed. Similarly, before the second image display step S22 of displaying the image P2, a second data selection step S21 of extracting data constituting the image P2 from the image data D is performed, and a third image display step S32 of displaying the image P3. Before this, a third data selection step S31 is performed to extract data constituting the image P3 from the image data D. Note that the order of execution of the steps is not limited to the order of steps S11, S12, S21, S22, S31, and S32, and, for example, the second image display step S22 may be performed before the first image display step S12. Further, in the data selection steps S11, S21, and S31, only the selection from the image data D of the data constituting the images P1, P2, and P3 is performed before the first image display step S12, and the display elements 1R, 1G, 1B Writing of signals to the pixel electrodes may be performed before each of the image display steps S12, S22, and S32.

The data selection steps S11, S21, and S31 will be explained in detail. As described above, in this embodiment, the pixel data d is displayed on the display element 1R (1G, 1B) on a one-to-one basis. In the first data selection step S11, each pixel data d _jk is displayed on the display element 1R (1G, 1B) of the image display device 10 at the same coordinates. Since the image display device 10 is arranged in the X direction with display elements 1R, 1G, 1B, 1R, 1G, 1B, etc. in order from the first column (X=1), the pixel data d _jk is d _1k R, d _2k G, d _3k B, d _4k R, d _5k G, d _6k B, . . . are selected by repeating sub-pixel data dR, dG, dB one by one in order from x=1.

As described above, in the stereoscopic image vI, the pixel pR of the image P1 and the pixel pG of the image P2, the pixel pG of the image P1 and the pixel pB of the image P2, and the pixel pB of the image P1 and the pixel pR of the image P2 overlap, respectively. Therefore, in the second data selection step S21, since the pixel data d _1k of x=1 is displayed on the display element 1G of X=2, sub-pixel data d _1k G is selected, and the pixel data d _2k of x=2 is selected. is displayed using the display element 1R with X=3. In this way, the second data selection step S21 shifts the display elements 1R (1G, 1B) one by one in the X direction with respect to the previous first data selection step S11. For this purpose, d _1k G, d _2k B, d _3k R, d _4k G, d _5k B, d _6k R, . . . are selected. Note that in the second data selection step S21, the display element 1R with X=1 is unselected (not displayed in the second image display step S22).

As described above, in the stereoscopic image vI, the pixel pG of the image P2 and the pixel pB of the image P3, the pixel pB of the image P2 and the pixel pR of the image P3, and the pixel pR of the image P2 and the pixel pG of the image P3 overlap, respectively. Therefore, in the third data selection step S31, for the pixel data d _1k of x=1, sub-pixel data d _1k B is selected for display on the display element 1B of X=3, and the pixel data d 1k of x=2 is selected. _2k is displayed on the display element 1R of the color display element 1 in the second column where X=4. In this way, the third data selection step S31 shifts the display elements 1R (1G, 1B) one by one in the X direction with respect to the previous second data selection step S21. For this purpose, d _1k B, d _2k R, d _3k G, d _4k B, d _5k R, d _6k G, . . . are selected. Note that in the third data selection step S31, the display elements 1R and 1G with X=1 to 2 are unselected (not displayed in the third image display step S32).

In this way, images P1, P2, and P3 can be displayed on the image display device 10 by selecting an appropriate one of the sub-pixel data dR, dG, and dB from each of all the pixel data d of the image data D. can. Note that when the image display device 10 includes the color display elements 1 arranged in a mosaic arrangement as shown in FIG. 2B, the sub-pixel data dR, dG, and dB are selected according to the y-coordinate as well. For example, in the first data selection step S11, for the pixel data d _j1 to be displayed on the first row (Y=1), since X=1 is the display element 1R, d ₁₁ R, d ₂₁ G , d ₃₁ B, d ₄₁ R, ... are selected. On the other hand, regarding the pixel data d _j2 to be displayed on the second row, since X=1 is the display element 1B, d ₁₂ B, d ₂₂ R, d ₃₂ G, d ₄₂ B, . . . are selected.

The stereoscopic image display method according to this embodiment can display pixel data d on the color display element 1 on a one-to-one basis when high definition is not required. That is, as image P1, sub-pixel data d _1k R, d _1k G, d _1k B, d _2k R, d _2k G, d _2k B, d _3k R, ... are sequentially generated from the first column (X=1). Select and display. In this case, the image P1 may be displayed three times while being displaced by p _pX /3 in the X direction, but the sub-pixel data d _jk R, d of the pixel data d _jk at the same address in the stereoscopic image vI It is preferable to configure and display the images P2 and P3 so that the pixels pR, pG, and pB formed by _jk G and d _jk B overlap each other. Specifically, the image P2 is d _1k G, d _1k B, d _1k R, d _2k G, d _2k B, d _2k R, d _3k G, ..., and the image P3 is d _1k B, d _1k R , d _1k G, d _2k B, d _2k R, d _2k G, d _3k B, ..., in images P1, P2, P3, the order of dR, dG, dB for each pixel data d is changed and selected and displayed. do.

In the image display device 10 of the stereoscopic image display device 100 according to the present embodiment, the display elements 1R, 1G, and 1B of the color display element 1 do not have to have the same shape. For example, the green display element 1G is different from the other display element 1R. , 1B may be larger in the X direction. In the stereoscopic image display method according to the present embodiment, the wobbling element 2 divides the images P1, P2, and P3 into three stages in steps of 1/3 of the pixel length p _pX , regardless of the dimensions of the display elements 1R, 1G, and 1B. shift. In the stereoscopic image vI, even if the pixels pR, pG, and pB do not completely match and overlap, the pixels pR, pG, and pB are sufficiently fine, so that the colors appear to be mixed appropriately, and color moiré is prevented. A suppressive effect can be obtained.

In the stereoscopic image display device 100, the wobbling element 2 includes only two of either the first birefringence element 23 or the second birefringence element 24, and has an angle of 0, -p _pX /3, -2p _pX /3 in the X direction. , or +2Xp _pX /3, +p _pX /3,0. In order to displace the distance by 2p _pX /3, a voltage is applied only to the first polarization control element 21, and the two birefringent elements 23, 23 (24, 24) shift the extraordinary ray in the same direction by p _pX /3. Displace.

(Modified example)
The stereoscopic image display method according to this embodiment can be applied not only to an image display device in which color display elements of three colors are arranged. Hereinafter, as a modification of the first embodiment, a three-dimensional image display device including an image display device in which color display elements of four colors are arranged will be described with reference to FIGS. 10 and 11. Elements that are the same as those in the first embodiment (see FIGS. 1 to 9) are designated by the same reference numerals, and explanations thereof will be omitted. As shown in FIG. 11, a stereoscopic image display device 100A according to this modification includes an image display device 10A, a lens array 30, and a wobbling element 2A disposed between the image display device 10A and the lens array 30. Be prepared. The stereoscopic image display device 100A may further include a diffusion plate 5 (see FIG. 5) between the wobbling element 2A and the lens array 30.

As shown in FIG. 10, the image display device 10A includes color display elements 1A arranged two-dimensionally in the XY plane, and the color display element 1A is further divided into four equal parts in the , 1B, and a display element 1Y that displays yellow. In the image display device 10A, the color display elements 1A may be arranged (stripe arrangement) so that the display elements 1R, 1G, 1B, and 1Y are aligned in the same color along the Y direction, as shown in FIG. The display elements 1R, 1G, 1B, and 1Y may be arranged while being shifted in the X direction by one (p _pX /4) or two display elements (p _pX /2) in the Y direction (see FIG. 2B). Furthermore, the display elements 1R, 1G, 1B, and 1Y may not have the same shape, and for example, the display elements 1G, 1Y may be smaller in the X direction than the display elements 1R, 1B. Note that the display element 1Y may display white (W), for example. The image display device 10A has the same configuration as the image display device 10 of the first embodiment except for the color display element 1A. However, in this modification, it is preferable that the image display device 10A has a response speed of 4.17 ms or less (240 Hz or more).

The wobbling element 2A is configured to displace the light in four steps in the X direction in increments of p _pX /4 (M=4), including a displacement of 0. For this purpose, the wobbling element 2A includes a first polarization control element 21, a first birefringence element 23, a second polarization control element 22, and a second birefringence element 24 stacked in the Z direction. The polarization control elements 21 and 22 and the birefringence elements 23 and 24 are as described in the first embodiment. However, in the wobbling element 2A, the birefringent elements 23 and 24 are designed such that the displacement distances g1 and g2 are g1=p _pX /2 and g2=p _pX /4, respectively. Therefore, the first birefringence element 23 displaces the extraordinary ray by p _pX /2 in the -X direction, and the second birefringence element 24 displaces the extraordinary ray by p _pX /4 in the +X direction. With such a configuration, the wobbling element 2A can displace light by +p _pX /4, 0, -p _pX /4, -2p _pX /4 in the X direction. Specifically, similar to the wobbling element 2 shown in FIG. 4A, when no voltage is applied to the polarization control elements 21 and 22 (V1: OFF, V2: OFF), the light L _Y is transmitted to both the birefringence elements 23 and 24. The displacement is 0 because it passes straight through. When voltage is applied only to the second polarization control element 22 (V1: OFF, V2: ON), the light _L Since it is transmitted and refracted (see FIG. 4B), it is displaced by +p _pX /4. On the other hand, when voltage is applied only to the first polarization control element 21 (V1: ON, V2: OFF), the light _L Since it is refracted and transmitted as a light beam, it is displaced by -p _pX /2+p _pX /4=-p _pX /4. Further, when voltage is applied to the polarization control elements 21 and 22 (V1: ON, V2: ON), the light _L Since the light L _Y travels straight and is transmitted (see FIG. 4C), it is displaced by -2p _pX /4.

(Stereoscopic image display method)
A method of displaying a stereoscopic image vI by the stereoscopic image display device 100A according to a modification of the first embodiment will be described with reference to FIG. 11. FIG. 11 shows a cross section of display elements 1R, 1G, 1B, and 1Y in the first row (Y=1) of the image display device 10A. Further, in FIG. 11, for the sake of brevity, it is shown that one elemental image is displayed by a total of six display elements 1R, 1G, 1B, and 1Y in the X direction. The stereoscopic image display method according to this modification includes four image display steps S12, in which the image display device 10A switches and displays four images P1A, P2A, P3A, and P4A on the display screen in one frame period T _F ; Perform S22, S32, and S42. Further, the stereoscopic image display method according to this modification includes a data selection step of selecting data constituting images P1A, P2A, P3A, and P4A, respectively, and writing the signals to pixel electrodes of display elements 1R, 1G, 1B, and 1Y. Perform S11, S21, S31, and S41. Note that each of the images P1A, P2A, P3A, and P4A is made up of a regular two-dimensional array of red pixels pR, green pixels pG, blue pixels pB, and yellow pixels pY, and the arrays are arranged in a regular two-dimensional manner depending on the image display device. This corresponds to the arrangement of display elements 1R, 1G, 1B, and 1Y in 10A (see FIG. 10).

(image data)
Here, image data constituting the stereoscopic image vI according to the stereoscopic image display method of this modification will be explained. As explained in the first embodiment, the image data (image information) D constituting the stereoscopic image vI displayed in one frame is obtained by dividing a large number of pixel data d in the x direction and the y direction as shown in the following formula (3). It becomes a two-dimensional array. Furthermore, in this modification, one pixel data d is composed of red pixel data dR, green pixel data dG, blue pixel data dB, and yellow pixel data dY, as shown in equation (5) below. Consists of four subpixel data. The sub-pixel data dR, dG, dB, and dY refer to the minimum unit of information displayed in one of the corresponding colors of the display elements 1R, 1G, 1B, and 1Y of the image display device 10A. Note that the yellow sub-pixel data d _jk Y is obtained, for example, by calculation from the sub-pixel data d _jk R, d _jk G, and d _jk B of the same pixel data d _jk .

In the first image display step S12, the image display device 10A displays the image P1A while the wobbling element 2A displaces the light by +p _pX /4 in the X direction (V1: OFF, V2: ON), as shown in FIG. Then, an image vI1A is formed by the lens array 30, with each region of the image P1A shifted by −p _pX /4 in the X direction from the reference region as an element image eI1. In the second image display step S22, the image display device 10A displays the image P2A while the wobbling element 2A does not displace the light (V1: OFF, V2: OFF), and the lens array 30 displays the element lens 3 in the image P2A. An image vI2A is formed with each area (reference area) directly facing each of these in the Z direction as an element image eI2. In the third image display step S32, the image display device 10A displays the image P3A while the wobbling element 2A displaces the light by −p _pX /4 in the X direction (V1: ON, V2: OFF), and the lens array 30 , an image vI3A is formed with each region in the image P3A shifted by +p _pX /4 in the X direction from the reference region as an element image eI3. In the fourth image display step S42, the image display device 10A displays the image P4A while the wobbling element 2A displaces the light by -2p _pX /4 in the X direction (V1: ON, V2: ON), and the lens array 30 , image vI4A is formed with each region in image P4A shifted by +2p _pX /4 in the X direction from the reference region as elemental image eI4. As a result, the four images vI1A, vI2A, vI3A, and vI4A formed alternately are combined into a three-dimensional image vI.

In the synthesized stereoscopic image vI, images vI1A, vI2A, vI3A, and vI4A are shifted by 1/4 of the pixel length p _pX in the X direction, that is, shifted by 1 pixel pR (pG, pB, pY). They overlap. Therefore, color moiré is suppressed in the stereoscopic image vI as in the first embodiment. Furthermore, in the stereoscopic image vI, pixels of four colors, pixel pR of image vI1A, pixel pG of image vI2A, pixel pB of image vI3A, and pixel pY of image vI4A, overlap in the same area. Similarly, the other pixels pR, pG, pB, and pY of the images vI1A, vI2A, vI3A, and vI4A overlap each other in four colors. These four overlapping pixels pR, pG, pB, and pY are displayed by display elements 1R, 1G, 1B, and 1Y arranged in one color display element 1A, as in the first embodiment. It is. Therefore, by setting each of the display elements 1R, 1G, 1B, and 1Y as one pixel, the resolution can be increased four times in the X direction. For this purpose, data selection steps S11, S21, S31, and S41 are performed as follows.

In the first data selection step S11, similarly to the first embodiment, each pixel data d _jk is displayed on the display elements 1R (1G, 1B, 1Y) at the same coordinates of the image display device 10A. In this modification, the image display device 10A has display elements 1R, 1G, 1B, 1Y, 1R, 1G, 1B, etc. arranged in the X direction in order from the first column, so the pixel data d _jk is d _1k R, d _2k G, d _3k B, d _4k Y, d _5k R, d _6k G, ... are selected by repeating sub-pixel data dR, dG, dB, dY one by one in order from x = 1. . Note that in this modification, all y-coordinates k are the same, similar to the first embodiment.

In the second data selection step S21, as described in the first embodiment, the display elements 1R (1G, 1B, 1Y) are shifted one by one in the X direction with respect to the previous first data selection step S11. For this purpose, d _1k G, d _2k B, d _3k Y, d _4k R, d _5k G, . . . are selected. Similarly, in the third data selection step S31, d _1k B, d _2k Y, d _3k R, d _4k G, d _5k B, ... are selected, and in the fourth data selection step S41, d _1k Y, d _2k R, Select d _3k G, d _4k B, d _5k Y, etc. Note that in the second data selection step S21, the display element 1R with X=1 is unselected (not displayed in the second image display step S22), and in the third data selection step S31, the display element 1R with X=1 to 2 is , 1G are unselected (not displayed in the third image display step S32), and in the fourth data selection step S41, the display elements 1R, 1G, 1B of (hidden).

In the image display device 10A, the color display element 1A includes a second display element 1G that displays green color in place of the display element 1Y, and display elements 1R, 1G, 1B, and 1G are arranged in order in the X direction. It may also be a color configuration. In this case, the same subpixel data d _jk G is displayed once each on the two display elements 1G and 1G in two of the data selection steps S11, S21, S31, and S41 (as described in the second embodiment below). reference). Furthermore, the color display elements 1A may be arranged in a pentile arrangement in which the display elements 1R and 1G are alternately arranged in the Y direction, with the display elements 1R and 1G being arranged while being shifted in the X direction by p _pX /2.

The wobbling elements 2 and 2A are not limited to a combination of a polarization control element (optical rotator) and a birefringence element, and may have any configuration as long as they can stepwise displace light to a predetermined position. For example, a polarization diffraction grating that diffracts light depending on the direction of polarization may be applied to the birefringence element. As a type of polarization diffraction grating, the liquid crystal molecules are oriented by regularly changing direction by an alignment film formed on a transparent substrate such as a glass plate that sandwiches the liquid crystal, and has periodicity in one direction on the film surface. A liquid crystal polarization grating (LCPG) configured as shown in FIG. Such a liquid crystal polarization diffraction grating diffracts the incident light at an angle φ (0°<φ<90°) in the one direction (periodic direction), and generates circularly polarized light in opposite directions in the + and - directions. is emitted. Further, the liquid crystal polarization diffraction grating diffracts and transmits, for example, right-handed circularly polarized light (RCP) incident thereon at an angle +φ, and left-handed circularly polarized light (LCP) incident thereon at an angle −φ. Note that the liquid crystal polarization diffraction grating causes a phase difference in the transmitted light, so that the light is diffracted and circularly polarized in the opposite direction. In the polarization diffraction grating, when the grating period is expressed as Λ, the angle (diffraction angle) φ is expressed by the following equation (6). Note that λ indicates the wavelength of light. The optical axis of the light diffracted and transmitted through the polarization diffraction grating is tilted +φ or −φ. direction). That is, according to the polarization diffraction grating, two elements laminated in the optical axis direction constitute one birefringent element. The displacement distance g of light by the birefringent element composed of such two polarization diffraction gratings is proportional to the distance l between the two polarization diffraction gratings, as expressed in the following equation (7). Furthermore, the displacement distance g of light is expressed by the following equation (8) from equations (6) and (7).

Furthermore, when a voltage is applied to the liquid crystal polarization diffraction grating, all the liquid crystal molecules become oriented in the same direction, eliminating periodic alignment, and transmitting light without diffracting it, that is, allowing it to travel straight. For this purpose, the liquid crystal polarization diffraction grating is manufactured by forming a transparent electrode film on each of two transparent substrates like the polarization control elements 21 and 22 of the wobbling element 2, and forming an alignment film on the transparent electrode film. It is formed by sealing liquid crystal in between. A birefringent element in which two such liquid crystal polarization diffraction gratings are laminated can displace light in three stages including a distance of 0 (no displacement) in the periodic direction. Therefore, as shown in FIGS. 12A to 12C, the wobbling element 2D including a liquid crystal polarization diffraction grating as a birefringent element includes, in order from the image display device 10 side (light incident side), the wavelength plate 27, the first polarization control element 21 and a birefringent element 25 are stacked in the Z direction. The wavelength plate 27 is a 1/4 wavelength plate or a 3/4 wavelength plate, and modulates the Y-direction linearly polarized light L _Y emitted by the image display device 10 into right-handed circularly polarized light L _R and transmits the modulated light. The first polarization control element 21 has the same configuration as the first polarization control element 21 of the wobbling element 2 (see FIGS. 4A to 4C), and here, the right-handed circularly polarized light L _R that passes through the wavelength plate 27 and enters is , the right-handed circularly polarized light L _R remains, or is modulated into the left-handed circularly polarized light L _L and transmitted. The birefringent element 25 is composed of two liquid crystal polarization diffraction gratings each having periodicity in the X direction, and is designed so that the displacement distance g1 is g1=p _pX /3. Further, the two liquid crystal polarization diffraction gratings of the birefringent element 25 are connected to the power supply V3 in parallel here so that voltages are applied to them at the same time.

As shown in FIG. 12A, when no voltage is applied to either the first polarization control element 21 or the birefringence element 25 (V1: OFF, V3: OFF), the first polarization control element 21 receives linearly polarized light. The right-handed circularly polarized light L _R modulated by L _Y passing through the wavelength plate 27 is incident, passes through the first polarization control element 21 as it is, and enters the birefringence element 25 . The right-handed circularly polarized light L _R is diffracted at an angle +φ in the periodic direction, that is, the X direction, by the liquid crystal polarization grating at the first stage (light incident side) of the birefringent element 25, and becomes the left-handed circularly polarized light L _L. The left-handed circularly polarized light L _L enters the second-stage liquid crystal polarization grating at an incident angle +φ in the X direction, and is diffracted by this liquid crystal polarization grating at an angle −φ in the X direction, so that the optical axis is It returns to the direction and becomes right-handed circularly polarized light L _R again. On the other hand, as shown in FIG. 12B, when a voltage is applied to the first polarization control element 21 (V1: ON, V3: OFF), the left-handed circularly polarized light L modulated by the first polarization control element 21 _L enters the birefringent element 25. The left-handed circularly polarized light L _L is diffracted in the X direction at an angle -φ by the first-stage liquid crystal polarization grating of the birefringent element 25, and becomes right-handed circularly polarized light L _R. Then, the right-handed circularly polarized light L _R is diffracted in the X direction at an angle +φ by the second-stage liquid crystal polarization diffraction grating, so that the optical axis returns to the Z direction, and becomes the left-handed circularly polarized light L _L. In this way, the birefringent element 25 displaces the right-handed circularly polarized light L _R in the +X direction and the left-handed circularly polarized light L _L in the -X direction by an equal distance (g1=p _pX /3). On the other hand, in order not to displace the light in the birefringent element 25, as shown in FIG. 12C, a voltage is applied to the two liquid crystal polarization gratings of the birefringent element 25 (V1: OFF, V3: ON). As a result, the birefringent element 25 allows the right-handed circularly polarized light L _R to travel straight and pass through. Note that a voltage may also be applied to the first polarization control element 21 (V1: ON, V3: ON). With such a configuration, the wobbling element 2D displaces the light in the X direction in three steps of +p _pX /3, 0, -p _pX /3, like the wobbling element 2, by switching the power supplies V1 and V3. .

Note that the arrangement of the wavelength plate 27 and the first polarization control element 21 may be exchanged. Further, the wobbling element 2D does not include the wavelength plate 27, and the first polarization control element 21 converts the linearly polarized light L _Y in the Y direction emitted by the image display device 10 into the right circularly polarized light L _R and the left circularly polarized light L _L. It may be configured to be modulated in two ways and transmitted. To this end, the first polarization control element 21 applies the voltage from the power source V1 while switching the magnitude of the voltage in two levels so that Δnd (retardation)=λ/4, 3/4λ. Note that when the wobbling element 2D does not displace the light, the linearly polarized light L _Y may be made to enter the birefringent element 25 as it is (V1: OFF, V3: ON).

In polarization diffraction gratings, the shorter the grating period Λ, the larger the diffraction angle φ, so the distance l between two polarization gratings may be shorter than the displacement distance g of light, that is, the thickness of the birefringent element 25 ( Z-direction length) can be made smaller. On the other hand, the displacement distance g of light also depends on the wavelength λ, and its dependence increases as the diffraction angle φ increases. Therefore, according to the wobbling element 2D, the red pixel pR emitted from the display element 1R has a larger shift length (displacement amount) than the green pixel pG emitted from the display element 1G, and is emitted from the display element 1B. The resulting blue pixel pB is small. Specifically, in order to make the difference in the amount of displacement for each color by the wobbling element 2D sufficiently small, the shift due to this difference is caused by the area ( It is preferable to design the polarization diffraction grating constituting the birefringent element 25 so that it fits within the non-aperture).

The wobbling element includes two birefringent elements each composed of a polarization diffraction grating, thereby displacing light in four steps in one direction, similar to the wobbling element 2A of the stereoscopic image display device 100A (see FIG. 11). Can be done. As shown in FIG. 14, such a wobbling element 2E includes, in order from the light incident side, a wavelength plate 27, a first polarization control element 21, a first birefringence element 25A, a second polarization control element 22, and a second polarization control element 22. Birefringent elements 26 are stacked in the Z direction. The first birefringence element 25A and the second birefringence element 26 are each formed by laminating two polarization diffraction gratings having periodicity in the X direction, similarly to the birefringence element 25 (see FIGS. 12A and 12B). No power supply is connected, and therefore no electrode film is required. Further, the birefringent elements 25A and 26 are designed so that the respective light displacement distances g1 and g2 are g1=p _pX /4 and g2=p _pX /8. Polarization control elements 21 and 22 are connected to power supplies V1 and V2, respectively, similarly to wobbling element 2 (see FIGS. 4A to 4C).

In the wobbling element 2E, when no voltage is applied to the polarization control elements 21 and 22 (V1: OFF, V2: OFF), the right circularly polarized light L _R is +p _pX /4 in the X direction at the first birefringence element 25A. The second birefringent element 26 further displaces +p _pX /8 in the X direction, resulting in a total displacement of +3 _{p pX} /8. When a voltage is applied only to the second polarization control element 22 (V1: OFF, V2: ON), the right-handed circularly polarized light L _R displaced by +p _pX /4 in the X direction by the first birefringence element 25A is It is modulated into left-handed circularly polarized light L _L by the polarization control element 22 and enters the second birefringence element 26, where it is displaced by -p _pX /8, resulting in a total displacement of +p _pX /8. When voltage is applied only to the first polarization control element 21 (V1: ON, V2: OFF), the left circularly polarized light L _L modulated by the first polarization control element 21 is - p _pX /4 and -p _pX /8 in the second birefringent element 26, respectively, displaced in the X direction, so the total displacement is -3 p _pX /8. When voltage is applied to the polarization control elements 21 and 22 (V1: ON, V2: ON), the left circularly polarized light L _L displaced by -p _pX /4 by the first birefringence element 25A is transferred to the second polarization control element 22. It is modulated into right-handed circularly polarized light L _R by , and is displaced by +p _pX /8 in the second birefringent element 26, resulting in a total displacement of -p _pX /8. In this way, the wobbling element 2E displaces the light by +3p _pX /8, +p _pX /8, -p _pX /8, -3p _pX /8 in the X direction by switching ON/OFF of the power supplies V1 and V2. , similarly to the wobbling element 2A, the light can be displaced in four steps in the X direction in steps of p _pX /4. Note that since the wobbling element 2E does not have a state in which the light is not displaced (goes straight), in the stereoscopic image display device 100A including the wobbling element 2E, the lens array is arranged so that the element lens 3 directly faces the displaced element image. Place 30.

In a stereoscopic image display device, the light emitted by the image display device is not limited to parallel light. Therefore, a general color liquid crystal display or an organic EL display that is equipped with a backlight that emits light without collimating it can be used as the image display device. As shown in FIG. 13, the stereoscopic image display device 100D according to the present modification is a color liquid crystal display in which the image display device 10D is equipped with a planar light source (backlight) 4A on the back surface that emits diffused light L _D. . The liquid crystal module 10m of the image display device 10D has the same structure as the embodiment described above. Alternatively, the image display device 10D is an organic EL display, and in order to directly emit light of each color from the display elements 1R, 1G, and 1B, and further emit light with a polarized component in the Y direction, the display surface side A filter (polarizing plate) is installed to select the polarized components of the light. Furthermore, the stereoscopic image display device 100D includes a wobbling element 2D (see FIGS. 12A to 12C). According to the stereoscopic image display device 100D according to this modification, it is easy to reduce the thickness and weight, and the response speed can be increased by applying an organic EL display. In addition, in FIG. 13, a light ray that is emitted from one point on the display surface of the image display device 10D and enters the lens array 30 is represented by a straight line with an arrow, and it is assumed that the wobbling element 2D causes the light to travel straight. do.

In the stereoscopic image display device 100D, the lens array 30 is arranged so that the focal point of the element lens 3 is closer to the display surface of the image display device 10D, that is, the lens array 30 is arranged so that the focal point of the element lens 3 is closer to the display surface of the image display device 10D. It is preferable that the distance to the main surface of f is closer to the focal length f, and ideally they match. Therefore, it is preferable that the focal length f of the element lens 3 is greater than or equal to the thickness (length in the Z direction) of the wobbling element 2D. On the other hand, in order to shorten the focal length f of the element lens 3 and widen the viewing angle Ψ of the stereoscopic image vI, the wobbling element 2D is designed to have a smaller thickness than the first polarization control element 21 and the birefringence element 25. It is preferred that the thickness of each is not too large. In addition, in the stereoscopic image display device 100D, the optical axis of the light incident on the wobbling element 2D is not uniform (only in the Z direction), and the smaller the F value of the element lens 3 (shorter the focal length f), the more the incident angle The range becomes wider. Therefore, it is preferable that the stereoscopic image display device 100D includes a wobbling element 2D to which a polarization diffraction grating is applied, which is relatively unaffected by the incident angle and can increase the displacement distance of light regardless of the thickness.

When the image display device 10D is an organic EL display or the like and irradiates light (natural light) containing a plurality of polarized components, the stereoscopic image display device 100D places the polarizing plate on the light output side of the wobbling element 2D, not on the light incidence side. At the same time, the arrangement of the wobbling element 2D is changed, and the birefringence element 25, the first polarization control element 21, the wavelength plate 27, and the polarizing plate are arranged in order from the image display device 10D side (light incident side). Good too. When no voltage is applied to the birefringent element 25 (V3: OFF), when natural light enters the birefringent element 25, right circularly polarized light L _R displaced in the +X direction and right circularly polarized light L R displaced in the -X direction are generated from the birefringence element 25. The displaced left-handed circularly polarized light L _L is emitted. The circularly polarized lights L _R and L _L are modulated into linearly polarized lights L _X and L _Y by the wave plate 27, and only one of them, for example, the linearly polarized light L _X in the X direction, is transmitted through the polarizing plate. Then, depending on whether or not a voltage is applied to the first polarization control element 21 (ON/OFF of V1), light displaced in either the +X direction or the -X direction is extracted from the polarizing plate.

The stereoscopic image display device 100D can also include a wobbling element 2 (see FIGS. 3 and 4A to 4C) in which a crystal material is applied to a birefringent element. In order to make the thickness of the wobbling element 2 equal to or less than the focal length f of the element lens 3, the birefringent elements 23 and 24 have a refractive index such that the displacement distance g/t of light per length in the optical axis direction becomes large. It is preferable to select a material in which the difference |n _e −n ₀ | is larger than the refractive index n ₀ , n _e , and to design the optical axis angles θ1 and θ2 with respect to the Z direction to be around 45° (formula ( (See 2). Further, when the image display device 10D is an organic EL display, the polarizing plate is disposed on the light output side of the wobbling element 2 instead of the light incidence side, and in the wobbling element 2, as in the above embodiment including the wobbling element 2D. The arrangement of the first polarization control element 21 and the first birefringence element 23, and the arrangement of the second polarization control element 22 and the second birefringence element 24 may be exchanged. That is, the first birefringence element 23, the first polarization control element 21, the second birefringence element 24, the second polarization control element 22, and the polarizing plate are arranged in order from the image display device 10D side (light incidence side). do. When natural light enters the first birefringent element 23, linearly polarized light L _Y in the Y direction that is not displaced and linearly polarized light L _X in the X direction that is displaced in the -X direction are emitted from the first birefringent element 23. .

The method of displaying the stereoscopic image vI by the stereoscopic image display device 100D is the same as the method of displaying the stereoscopic image vI by the stereoscopic image display device 100 described above (see FIGS. 6 to 9). Note that when the image display device 10D is an organic EL display, the image display steps S12, S22, and S32 are periods in which the display elements 1R, 1G, and 1B are injected with current and emit light.

The image display device 10D of the stereoscopic image display device 100D may have four color display elements 1A (see FIGS. 10 and 11) arranged similarly to the image display device 10A. Such a stereoscopic image display device 100D includes a wobbling element 2E (see FIG. 14) or a wobbling element 2A that displaces light in four steps in the X direction.

In a stereoscopic image display device, when the display element emits light by being irradiated with light from a light source, such as a liquid crystal display, a lens array can be placed on the back side of the image display device, and the light source The parallel light irradiated by the lens is transmitted directly to the lens array. As shown in FIG. 14, a stereoscopic image display device 100E according to this modification includes a lens array 30 between the light source 4 of the image display device 10 in the embodiment and the liquid crystal module 10m (image display device 10E). , and further includes a wobbling element 2E on the light output side. The stereoscopic image display device 100E further includes a filter (polarizing plate) 6 between the light source 4 and the wobbling element 2E, which selects the polarized component of the light emitted by the light source 4, and the filter (polarizing plate) 6 is provided between the wobbling element 2E and the image display device 10E. A wavelength plate 7 is provided in between. In FIG. 14, the polarizing plate 6 is arranged on the light output side of the lens array 30, but it may be arranged between the light source 4 and the lens array 30. The stereoscopic image display device 100E forms a stereoscopic image vI in a space on the +Z direction side of the image display device 10E. In the stereoscopic image display device 100E, it is preferable that the distance from the main surface of the element lens 3 of the lens array 30 to the display surface of the image display device 10E be closer to twice the focal length f of the element lens 3 (2f), which is ideal. They match. Therefore, it is preferable that the wobbling element 2E is designed such that the total thickness of the wobbling element 2E and the wavelength plate 7 is 2f or less. Further, the image display device 10E has the same structure as the liquid crystal module 10m of the image display device 10A, and has color display elements 1A of four colors arranged (see FIGS. 10 and 11). In FIG. 14, it is assumed that a light beam that passes through one of the element lenses 3 and enters the image display device 10E is represented by a straight line with an arrow, and that the wobbling element 2E causes the light to travel straight.

In the stereoscopic image display device 100E, similarly to the stereoscopic image display device 100D according to the modification (see FIG. 13), the optical axis of the incident light is not uniform (only in the Z direction), so the influence of the incident angle is It is preferable to include a wobbling element 2E to which a relatively small polarization diffraction grating is applied. Further, the stereoscopic image display device 100E is configured such that light having a polarized component in the direction of the transmission axis (for example, the X direction) of a polarizing plate provided on the light incident side enters the image display device 10E at a constant amount configured. Since the light emitted by the wobbling element 2E is of two types: right-handed circularly polarized light L _R and left-handed circularly polarized light L _L , the stereoscopic image display device 100E performs wobbling to make the light incident on the image display device 10E linearly polarized light. A wavelength plate 7 is provided between the element 2E and the image display device 10E. The wavelength plate 7 is a 1/4 wavelength plate or a 3/4 wavelength plate, and modulates, for example, right-handed circularly polarized light L _R into 45° linearly polarized light and left-handed circularly polarized light L _L into 135° linearly polarized light, respectively. . When these linearly polarized lights pass through the polarizing plate of the image display device 10E, they become linearly polarized lights _LX in the X direction (0°) with a constant amount of light.

The stereoscopic image display device 100E includes a polarization control element having the same configuration as the polarization control elements 21 and 22 such as the wobbling element 2 between the wobbling element 2E and the image display device 10E, and by applying a voltage, a right circular It may be configured to modulate each of the polarized light L _R and the left-handed circularly polarized light L _L into linearly polarized light L _X in the X direction. Further, the stereoscopic image display device 100E can also include a wobbling element 2A instead of the wobbling element 2E. Since the wobbling element 2E emits two types of light, linearly polarized light L _X and L _Y , such a stereoscopic image display device 100E includes the polarization control element described above between the wobbling element 2A and the image display device 10E. so that the linearly polarized light L _X in the X direction always enters the image display device 10E.

The method of displaying the stereoscopic image vI by the stereoscopic image display device 100E is the same as the method of displaying the stereoscopic image vI by the stereoscopic image display device 100A described above (see FIG. 11). Further, the image display device 10E of the stereoscopic image display device 100E may have color display elements 1 of three colors arranged (see FIG. 2A) similarly to the image display device 10. Such a stereoscopic image display device 100E includes a wobbling element 2D (see FIGS. 12A to 12C) that displaces light in three steps in the X direction.

As described above, according to the stereoscopic image display device and the stereoscopic image display method according to the first embodiment and its modification, the color moiré reduction effect can be obtained using one color display, and the existing color display can be used. It can be reused, and it can be made even more precise.

[Second embodiment]
In the stereoscopic image display device according to the first embodiment and its modification, the color display element of the image display device has a structure in which display elements of each color are arranged only in one direction in the arrangement, but the display elements are arranged in a two-dimensional arrangement. A color display element can be applied. A stereoscopic image display device and a stereoscopic image display method according to a second embodiment will be described below. Elements that are the same as those in the first embodiment (see FIGS. 1 to 11) are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 18A, the stereoscopic image display device 100B according to the present embodiment includes an image display device 10B, a lens array 30, and a wobbling element 2B arranged between the image display device 10B and the lens array 30. Be prepared.

(Image display device)
As shown in FIG. 15, the image display device 10B includes color display elements 1D arranged two-dimensionally on the XY plane, and the color display elements 1D are further divided into four 2×2 display elements for displaying red. (sub-pixel) 1R, display elements (sub-pixels) 1G _a and 1G _b that display green, and display element (sub-pixel) 1B that displays blue. That is, the color display element 1D displays three colors, but since _it has two green display elements 1G _a and 1G _b on the diagonal line, the color display element _1D displays three colors. This is a Bayer array. Therefore, in the image display device 10B, the display elements 1R and 1G _a are arranged alternately in the X direction in the odd-numbered rows, and the display elements 1B and 1G _b are arranged alternately in the X-direction in the even-numbered rows. are arranged in In addition, in the image display device 10B, the display elements 1R and 1G _b are arranged alternately in the Y direction in the odd-numbered columns, and the display elements 1B and 1G _a are arranged alternately in the Y-direction in the even-numbered columns. are arranged in The image display device 10B has the same configuration as the image display device 10 of the first embodiment except for the color display element 1D. However, in this embodiment, the image display device 10B preferably has a response speed of 4.17 ms or less (240 Hz or more), similarly to the image display device 10A of the modification of the first embodiment.

Note that the following embodiments can be applied to the configurations of stereoscopic image display devices 100D and 100E (see FIGS. 13 and 14) according to modified examples of the first embodiment, unless otherwise specified. That is, the image display devices 10D and 10E can have a configuration in which each color display element 1 is replaced with a color display element 1D.

(wobbling element)
The wobbling element 2B is configured to displace light independently of each other in the X direction and the Y direction in two stages of 1/2 the length of the color display element 1D, including a displacement of 0, for a total of four stages. . For this purpose, the wobbling element 2B has a first polarization control element 21, a first birefringence element 23, a second polarization control element 22, and a second birefringence element 24A stacked in the Z direction, as shown in FIGS. 16A to 16D. and prepare. As explained in the first embodiment, the first birefringence element 23 transmits the polarized light L _Y in the Y direction as an ordinary ray, so as to displace the extraordinary ray in the −X direction. _X is refracted and transmitted as an extraordinary ray, and g1=p _pX /2. On the other hand, the second birefringence element 24A transmits the polarized light L X in the X direction as an ordinary ray and refracts the polarized light L _Y in the Y direction as an extraordinary ray so _as to displace the extraordinary ray in the −Y direction. Then, g2=p _pY /2. Therefore, as shown in FIGS. 16A to 16D, the first birefringent element 23 is arranged so that the optical axis is inclined in the X direction with respect to the optical axis (Z direction), as in the first embodiment, The second birefringent element 24A is arranged so that its optical axis is inclined in the Y direction. Further, similarly to the first embodiment, the image display device 10B is designed to emit polarized light L _Y in the same Y direction as the ordinary ray of the first birefringent element 23. In FIGS. 16A to 16D, double-headed arrows are attached to the lights L _Y and L _X to indicate the polarization direction. With such a configuration, the wobbling element 2B has (0,0), (-p _pX /2,0), (0,-p _pY /2), (-p _pX /2, -p _pY /2) can displace the light.

As shown in FIG. 16A, when no voltage is applied to the polarization control elements 21 and 22 (V1: OFF, V2: OFF), polarized light L _Y in the Y direction is incident on the birefringence elements 23 and 24. In the first birefringence element 23, it passes straight as an ordinary ray, and in the second birefringence element 24A, since it is an extraordinary ray, it is refracted in the -Y direction and transmitted, and becomes (0, -p _pY /2). Displace. On the other hand, as shown in FIG. 16B, when voltage is applied only to the second polarization control element 22 (V1: OFF, V2: ON), the polarized light L _Y in the Y direction travels straight to the first birefringence element 23. Then, the second polarization control element 22 modulates the light into polarized light L _X in the X direction, so the second birefringence element 24A also passes straight and is transmitted, with a displacement of 0 (0, 0). Further, as shown in FIG. 16C, when a voltage is applied only to the first polarization control element 21 (V1: ON, V2: OFF), the light _L The light is refracted in the -X direction through the birefringent element 23 and transmitted, and then passes straight through the second birefringent element 24A, so that it is displaced to (-p _pX /2,0). Then, as shown in FIG. 16D, when voltage is applied to the polarization control elements 21 and 22 (V1: ON, V2: ON), the light _L The light L _Y that is refracted and transmitted through the element 23 in the -X direction and then remodulated by the second polarization control element 22 is refracted and transmitted in the -Y direction through the second birefringent element 24A, so that (-p _pX /2, - p _pY /2).

(Stereoscopic image display method)
A method of displaying a stereoscopic image vI by the stereoscopic image display device 100B according to the second embodiment will be described with reference to FIGS. 17 to 20. In the stereoscopic image display method according to the present embodiment, as shown in FIG. 17, the image display device 10B switches and displays four images P1B, P2B, P3B, and P4B on the display screen in one frame period T _F. The image display steps S12A, S22A, S32A, and S42A are performed, and the data selection steps S11A, S21A, S31A, and S41A are further performed. Images P1B, P2B, P3B, and P4B are each made up of a regular two-dimensional arrangement of red pixels pR, green pixels pG, and blue pixels pB, and the arrangement is similar to that of display elements 1R and 1G in image display device 10B. This corresponds to the arrays _a , _1Gb , and 1B (see FIG. 15). Note that FIGS. 18A to 18D are shown as cross sections at the display elements 1G _b and 1B in the second row (Y=2) of the image display device 10B. Pixels pG and pB displayed by display elements 1G _b and 1B in the row are shown. Further, in FIGS. 18A to 18D, for the sake of simplicity, it is shown that one elemental image is displayed by a total of six display elements 1G _b and 1B or display elements 1R and 1G _a in the X direction.

Note that image data D constituting a stereoscopic image vI according to the stereoscopic image display method of this embodiment is expressed by the following equations (3) and (4) similarly to the first embodiment.

In the first image display step S12A, the image display device 10B displays the image P1B while the wobbling element 2B does not displace the light (V1: OFF, V2: ON, see FIG. 16B), and as shown in FIG. 18A, the lens The array 30 forms an image vI1B with each area (reference area) directly facing each of the element lenses 3 in the Z direction in the image P1B as an element image eI1. In the second image display step S22A, the image display device 10B displays the image P2B while the wobbling element 2B displaces the light by −p _pX /2 in the X direction (V1: ON, V2: OFF, see FIG. 16C), As shown in FIG. 18B, the lens array 30 forms an image vI2B using each region of the image P2B that is shifted by +p _pX /2 in the X direction from the reference region (the boundary is represented by a dashed line) as an element image eI2. . In the third image display step S32A, the image is displayed while the wobbling element 2B displaces the light by -p _pX /2 in the X direction and by -p _pY /2 in the Y direction (V1: ON, V2: ON, see FIG. 16D). The device 10B displays the image P3B, and as shown in FIG. 18C, the lens array 30 converts each region of the image P3B shifted by +p _pX /2 in the X direction and +p _pY /2 in the Y direction from the reference region into an element image. An image vI3B is formed as eI3. In the fourth image display step S42A, the image display device 10B displays the image P4B while the wobbling element 2B displaces the light by −p _pY /2 in the Y direction (V1: OFF, V2: OFF, see FIG. 16A), As shown in FIG. 18D, the lens array 30 forms an image vI4B with each region of the image P4B shifted by +p _pY /2 in the Y direction from the reference region as an element image eI4. As a result, the four images vI1B, vI2B, vI3B, and vI4B formed alternately are combined into the three-dimensional image vI. In addition, in FIGS. 18C and 18D, the illustrated portions of the lens array 30 include the display elements 1R and 1G a of the third row (Y=3) of the image display device 10B on the back side of the page of the images P3B and P4B _. The pixels pR and pG indicated by are incident.

As shown in FIG. 19, in this stereoscopic image vI, images vI1B, vI2B and images vI3B, vI4B overlap each other with a shift of 1/2 of the pixel length p _pX in the X direction. Furthermore, the images vI1B, vI4B and the images vI2B, vI3B overlap each other with a shift of 1/2 of the pixel length p _pY in the Y direction. Therefore, the stereoscopic image vI is equivalent to the case where two images are synthesized using two displays described in Non-patent Document 2 (moiré modulation degree m(c ₂ ) in FIG. 2 of Non-patent Document 2). It can be said that the effect of reducing color moire can be obtained. Furthermore, in the stereoscopic image vI, the images vI1B, vI2B, vI3B, and vI4B overlap each other with a shift of one pixel pR (pG, pB). That is, the pixels of four layers of three colors, pixel pR of image vI1B, pixel pG of image vI2B, pixel pB of image vI3B, and pixel pG of image vI4B, overlap in the same area. The other pixels pR, pG, and pB of images P1B, P2B, P3B, and P4B similarly overlap each other in four layers (pixel pG has two layers). Therefore, color display is possible in the area of one display element 1R (1G _a , 1G _b , 1B) (the area framed by a thick line in Fig. 19), and the height is doubled in each of the X and Y directions. It can be refined. For this purpose, the following data selection steps S11A, S21A, S31A, and S41A are performed to select subpixel data dR, dG, and dB of pixel data d into image P1B as shown in FIG. , P2B, P3B, and P4B.

In this embodiment, similarly to the first embodiment, display elements 1R (1G _a , 1G _b , 1B) and pixel data d are displayed on a one-to-one basis. In the first data selection step S11A, each pixel data d _jk is displayed on the display element 1R (1G _a , 1G _b , 1B) at the same coordinates of the image display device 10B. In the first row (Y=1), the image display device 10B has display elements 1R, 1G _a , 1R, 1G _a , 1R, . . . arranged in order in the X direction from the first column (X=1). Therefore, the pixel data d _j1 is obtained by alternately selecting sub-pixel data dR, dG one by one in order from x=1, such as d ₁₁ R, d ₂₁ G, d ₃₁ R, d ₄₁ G, d ₅₁ R,... Ru. In the second row (Y=2), the display elements 1G _b , 1B, 1G _b , 1B, 1G _b , ... are arranged in the X direction in order from X=1, so the pixel data d _j2 is ₁₂ G, d ₂₂ B, d ₃₂ G, d ₄₂ B, . . . , the sub-pixel data dG and dB are alternately selected one by one in order from x=1. In this way, for the pixel data d of y=1, 3, 5,... displayed on the odd-numbered rows of the image display device 10B, the sub-pixel data dR of x=1, 2, 3, 4,... , dG, dR, dG, . . . are selected alternately. Then, regarding the pixel data d of y=2, 4, 6, ... displayed on the even-numbered rows, the sub-pixel data dG, dB, dG, dB, Select alternately.

In the second data selection step S21A, one display element 1R (1G _a ) or one display element 1G _b (1B) is shifted in the X direction with respect to the first first data selection step S11A. Therefore, for pixel data d of y=1, 3, 5,..., sub-pixel data dG, dR, dG, dR,... and for pixel data d of y=2, 4, 6,..., sub-pixel data dG, dR, dG, dR,... Data dB, dG, dB, dG, . . . and x=1, 2, 3, 4, . . . are alternately selected in the order of x=1, 2, 3, 4, . Note that in the second data selection step S21A, the display elements 1R and _1Gb with X=1 are unselected (not displayed in the second image display step S22A).

In the third data selection step S31A, one display element 1R (1G _a , 1G _b , 1B) is shifted in each of the X direction and the Y direction with respect to the first first data selection step S11A. In other words, the display elements 1R (1G _b ) or the display elements 1G _a (1B) are shifted one by one in the Y direction with respect to the previous second data selection step S21A. Therefore, the pixel data d _j1 of y=1 is displayed on the display elements 1B, 1G _b , 1B, 1G _b , . . . from X=2 in the second row (Y=2) of the image display device 10B. , d ₁₁ B, d ₂₁ G, d ₃₁ B, d ₄₁ G, . On the other hand, the pixel data d _j2 of y=2 is displayed on the display elements 1G _a , 1R, 1G _a , 1R, . . . from X=2 on the third row (Y=3) of the image display device 10B. , d ₁₂ G, d ₂₂ R, d ₃₃ G, d ₄₂ R, . In this way, since the pixel data d of y=1, 3, 5,... is displayed on the even numbered rows of the image display device 10B, the sub-pixel data d of y=1, 3, 5,... Pixel data dB, dG, dB, dG, . . . are alternately selected one by one. Since the pixel data d of y=2, 4, 6, ... are displayed on odd-numbered rows, the sub-pixel data dG, dR, dG of x=1, 2, 3, 4, ... are displayed in the order of , dR, . . . are selected one by one alternately. Note that in the third data selection step S31A, the display elements 1R, 1G _b with X=1 and the display elements 1R, 1G _a with Y=1 are unselected (not displayed in the third image display step S32A).

In the fourth data selection step S41A, the display elements 1R (1G _a , 1G _b , 1B) are shifted one by one in the Y direction with respect to the first first data selection step S11A. In other words, the display elements 1R (1G _a ) or the display elements 1G _b (1B) are shifted one by one in the X direction with respect to the previous third data selection step S31A. Therefore, for pixel data d of y=1, 3, 5,..., sub-pixel data dG, dB, dG, dB,... and for pixel data d of y=2, 4, 6,..., sub-pixel data dG, dB, dG, dB,... Data dR, dG, dR, dG, . . . and x=1, 2, 3, 4, . . . are alternately selected in the order of x=1, 2, 3, 4, . Note that in the fourth data selection step S41A, the display elements 1R and 1G _a of Y=1 are unselected (not displayed in the fourth image display step S42A).

The wobbling element that displaces light in each of the two directions can also be configured with a polarization diffraction grating, as in the modification of the first embodiment. Such a wobbling element 2E moves the wavelength plate 27, the first polarization control element 21, the first birefringence element 25A, the second polarization control element 22, and the second birefringence element 26 in the Z direction in order from the light incident side. (See FIG. 14). The first birefringent element 25A is formed by stacking two liquid crystal polarization diffraction gratings having periodicity in the X direction, as in the modification of the first embodiment, and the displacement distance g1 of light is determined by g1=p _pX /4. Designed to. On the other hand, in this embodiment, the second birefringent element 26 is formed by stacking two liquid crystal polarization diffraction gratings having periodicity in the Y direction, and is designed so that the light displacement distance g2 is g2=p _pY /4. Ru. With such a configuration, the wobbling element 2E has (-p _pX /4, -p _pY /4), (p _pX /4, -p _pY /4), (-p _pX /4, p _pY /4) , (p _pX /4, p _pY /4). That is, like the wobbling element 2B, the wobbling element 2E can displace the light in two steps, in steps of p _pX /2 in the X direction and in steps p _pY /2 in the Y direction.

(Modified example)
The stereoscopic image display method according to the present embodiment can also be applied to an image display device 10 (see FIG. 2B) that includes a mosaic arrangement of color display elements 1 having three display elements 1R, 1G, and 1B. In this modification, images P1, P2, and P3 (see FIGS. 7A, 7B, and 7C) are displayed in three image display steps S12A, S22A, and S42A. In the image display step S12, the image P1 is displayed without any displacement of light by the wobbling element 2B. In the image display step S22A, the image P2 is displayed while the wobbling element 2B displaces the light by one display element 1R (1G, 1B) (p _pX /3) in the -X direction. In the image display step S42A, the image P3 is displayed while the wobbling element 2B displaces the light in the -Y direction by one display element 1R (1G, 1B), that is, by a pixel length p _pY . According to such a stereoscopic image display method, the resolution can be increased by 1.5 times in the X direction and twice in the Y direction.

As described above, according to the stereoscopic image display device and the stereoscopic image display method according to the second embodiment and its modified examples, similarly to the first embodiment, the color moiré reduction effect can be achieved using one existing color display. can be obtained with high definition.

[Third embodiment]
In the three-dimensional image display methods according to the first embodiment and the second embodiment, the image display device switches the display of images three or four times in one frame period, so the image display device is required to have high-speed responsiveness. . A stereoscopic image display device and a stereoscopic image display method according to a third embodiment will be described below. Elements that are the same as those in the first and second embodiments (see FIGS. 1 to 20) are denoted by the same reference numerals, and explanations thereof will be omitted. As shown in FIG. 21A, a stereoscopic image display device 100C according to the present embodiment includes an image display device 10, a lens array 30, and a wobbling element 2C disposed between the image display device 10 and the lens array 30. Be prepared.

The image display device 10 has the same configuration as described in the first embodiment (see FIG. 2A). However, in this embodiment, the image display device 10 only needs to have a response speed of 8.33 ms or less (120 Hz or more).

The wobbling element 2C is configured to displace the light in two steps in the X direction in steps of p _pX /2, including a displacement of 0. For this purpose, the wobbling element 2C includes a first polarization control element 21 and a first birefringence element 23 stacked in the Z direction. Like the wobbling element 2A of the modification of the first embodiment, the first birefringence element 23 transmits the polarized light L _Y in the Y direction as an ordinary ray and refracts the polarized light L _X in the X direction as an extraordinary ray. The light is transmitted through the lens, and is displaced by p _pX /2 in the -X direction. With such a configuration, the wobbling element 2C can displace light in two steps of 0 and -p _pX /2 in the X direction. Further, as in the first and second embodiments, a wobbling element 2D (see FIGS. 12A and 12B) formed of a polarization diffraction grating may be applied. In this embodiment, instead of the birefringent element 25, a first birefringent element 25A to which no power source is connected is provided, and the light is displaced in two steps of +p _pX /4 and -p _pX /4 in the X direction.

(Stereoscopic image display method)
A method of displaying a stereoscopic image vI according to the third embodiment by the stereoscopic image display device 100C will be described with reference to FIGS. 21A, 21B, 22, and 23. In the stereoscopic image display method according to the present embodiment, the image display device 10 performs two image display steps S12A and S22A in which the two images P1C and P2C are switched and displayed on the display screen in one frame period T _F. Furthermore, the stereoscopic image display method according to the present embodiment performs data selection steps S11B and S21B in which data constituting images P1C and P2C are selected, respectively, and the signals are written into the pixel electrodes of display elements 1R, 1G, and 1B. Images P1C and P2C are each made up of a regular two-dimensional array of red pixels pR, green pixels pG, and blue pixels pB, and the array is the same as the array of display elements 1R, 1G, and 1B in the image display device 10. (see FIG. 2A). Note that FIGS. 21A and 21B are cross sections of the display elements 1R, 1G, and 1B in the first row (Y=1) of the image display device 10. Furthermore, in FIGS. 21A and 21B, for the sake of brevity, it is shown that one elemental image is displayed by a total of six display elements 1R, 1G, and 1B in the X direction.

In the first image display step S12A, the image display device 10 displays the image P1C in a state where the wobbling element 2C does not displace the light (V1: OFF), and as shown in FIG. An image vI1C is formed with each region (reference region) directly facing each of the element lenses 3 in the Z direction as an element image eI1. In the second image display step S22A, the image display device 10 displays the image P2C while the wobbling element 2C displaces the light by −p _pX /2 in the X direction (V1: ON), and as shown in FIG. The array 30 forms an image vI2C in which each area in the image P2C that is shifted by +p _pX /2 in the X direction from the reference area (the boundary is represented by a dashed line) is an element image eI2. As a result, the two images vI1C and vI2C formed alternately are combined into a three-dimensional image vI.

As shown in FIG. 22, in this stereoscopic image vI, images vI1C and vI2C overlap in the X direction with a shift of 1/2 of the sum of pixels pR, pG, and pB (pixel length p _pX ). Therefore, similarly to the second embodiment, when two images are synthesized using the two displays described in Non-Patent Document 2 for the stereoscopic image vI (moiré modulation degree in FIG. 2 of Non-Patent Document 2), The same color moiré reduction effect as m(c ₂ )) can be obtained.

Further, as described above, in the stereoscopic image vI, the images vI1C and vI2C overlap with each other with a shift of 1/2 of the total of the pixels pR, pG, and pB, that is, 1.5 pixels pR (pG, pB). Specifically, for example, since the pixel pB of the image P2C overlaps between the adjacent pixels pR and pG of the image P1C, the pixel pR of the image vI1C and the pixel pB of the image vI2C, the pixel pG of the image vI1C and the pixel pB of the image vI2C, Each overlaps with 1/2 area. Similarly, pixel pR of image vI1C and pixel pG of image vI2C, pixel pB of image vI1C and pixel pG of image vI2C, pixel pG of image vI1C and pixel pR of image vI2C, pixel pB of image vI1C and pixel pR of image vI2C , each overlaps with an area of 1/2. In this way, in the stereoscopic image vI, the pixels pR, pG, and pB, two of which are adjacent to each other, overlap with each other by half the area of the remaining color, but the pixels pR, pG, and pB are not sufficiently fine. Therefore, the three colors appear to be mixed together.

From this, color display is possible with two adjacent pixels pB, pR of image P1C and pixel pG of image P2C, and with pixel pG of image P1C and two adjacent pixels pB, pR of image P2C. . In other words, color display is possible in an area equivalent to 1.5 display elements 1R (1G, 1B) (the area enclosed by a thick line in FIG. 22), and the resolution is doubled in the X direction. I can do it. Although there is no particular limitation on the classification of pixels pR, pG, and pB into groups of one and two, here, one pixel pG, which is displayed with relatively high brightness on display element 1G, is considered to be one group, and the other Regarding pixels pR and pB, two adjacent pixels pB and pR in the same image P1C (P2C) are considered as one set. For this purpose, the following data selection steps S11B and S21B are performed to display each sub-pixel data dR, dG, and dB of the pixel data d in an image P1C and an image P2C as shown in FIG. 23. Note that the image data D constituting the stereoscopic image vI according to the stereoscopic image display method of this embodiment has the same configuration as described in the first embodiment (see formulas (3) and (4)).

The data selection steps S11B and S21B will be explained in detail. In this embodiment, the color display elements 1 of the image display device 10 are arranged in the order in which the display elements 1G, 1B, and 1R are arranged. One display element 1G that displays the pixel pG is referred to as a display element group 11, and two adjacent display elements 1B and 1R are referred to as a display element group 12. Further, the display element 1R in the first row of the image display device 10 is made non-selected and non-displayed, and the display element 1G on the right side is set to X=1. Furthermore, in this embodiment, all y-coordinates k are the same, similar to the first embodiment.

In the first data selection step S11B, in order to display the pixel data d _1k of x=1 on the display element 1G, which is the display element group 11 of the first column, that is, the display element of X=1, the sub-pixel data d _{1k is} Select G. Regarding the pixel data _d2k of x=2, in order to simultaneously display it on the display element group 12 of the second column, that is, the display element 1B of X=2 and the display element 1R of X=3, the sub-pixel data d2k is Select _2k B, d _2k R. Further, regarding the pixel data d _3k of x=3, sub-pixel data d _3k G is selected in order to display it on the display element group 11 in the third column, that is, the display element 1G of X=4. In this way, one sub-pixel data dG is selected so that the pixel data d is displayed on the display element 1G for x=1, 3, 5, . On the other hand, for x=2, 4, 6, . . . , two sub-pixel data dB and dR are selected so as to be displayed on two adjacent display elements 1B and 1R.

In the second data selection step S21B, in order to simultaneously display the pixel data d _1k of x=1 on the display element group 12 of the second column, that is, the display elements 1B and 1R of X=2, 3, Select _1k B, d _1k R. Regarding the pixel data d _2k of x=2, sub-pixel data d _2k G is selected for display on the display element group 11 in the third column, that is, the display element 1G of X=4. In this way, two sub-pixel data dR and dB are selected so that pixel data d is displayed on two adjacent display elements 1B and 1R for x=1, 3, 5, . . . For pixels 2, 4, 6, . . . , one sub-pixel data dG is selected so as to be displayed on the display element 1G. Note that in the second data selection step S21B, the display element 1G with X=1 is unselected (not displayed in the second image display step S22A).

In this way, the display elements 1G, 1R, and 1B are divided into two display element groups 11 and 12, and from each of all the pixel data d of the image data D, the corresponding sub-pixel data dR, Images P1C and P2C can be displayed on the image display device 10 by regularly selecting and displaying one or two of dG and dB.

(Modified example)
As shown in FIG. 24, the stereoscopic image display method according to this embodiment can also use an image display device 10C including a color display element 1C in which three display elements 1R, 1G, and 1B are arranged in a delta arrangement. The image display device 10C repeatedly arranges display elements 1R, 1G, and 1B in the X direction, and shifts the display elements 1R (1G, 1B) by 1.5 (3p _pX /4) in the X direction in the even-numbered rows. are arranged. Therefore, similarly to the embodiment described above, the images P1C and P2C can be displayed by displacing the light in the X direction with the wobbling element 2B. Alternatively, the light may be displaced by one display element 1R (1G, 1B) (p _pY /2) in the Y direction. Note that, similarly to the above embodiment, when the display element 1G is used as the display element group 11, and the two adjacent display elements 1B and 1R are used as the display element group 12, the first column of the odd-numbered row of the image display device 10C The eye display element 1R is not selected and is not displayed.

The stereoscopic image display method according to this embodiment can be applied not only to the image display device 10 in which color display elements 1 having three display elements 1G, 1B, and 1R are arranged. For example, for an image display device 10A in which color display elements 1A of four colors are arranged as shown in FIG. 1Y are a display element group 11 and a display element group 12, respectively. In this case as well, the image display steps S12A and S22A are performed twice, similarly to the embodiment described above. Then, in data selection steps S11B and S21B, two sub-pixel data dR and dG or two sub-pixel data dB and dY are selected from each of the pixel data d. Alternatively, the color display element 1A is divided into three parts, one display element 1R and one display element 1G are used as two display element groups, and two adjacent display elements 1B and 1Y are used as one display element group. It may also be an element group. In this case, as in the first embodiment, the image display steps S12, S22, and S32 are performed three times while the wobbling element 2 displaces the light in three steps in the X direction in steps of p _pX /3.

Further, as shown in FIG. 15, for an image display device 10B including a color display element 1D in which display elements 1R, 1G _a , 1G _b , and 1B are arranged in a 2×2 arrangement, two color display elements 1D are arranged in the X direction. The display elements 1R, 1G _b and the display elements 1G _a , 1B adjacent to each other in the Y direction can be divided into a display element group 11 and a display element group 12, respectively. Alternatively, the color display element 1D is divided into two in the Y direction, and the two display elements 1R, 1G _a and the display elements 1G _b , 1B adjacent to each other in the X direction are divided into the display element group 11 and the display element group 12, respectively. You can also use it as In this case, the image display steps S12A and S42A are performed twice while displacing the light in two steps in steps of p _pY /2 in the Y direction.

As described above, according to the three-dimensional image display device and the three-dimensional image display method according to the third embodiment and its modifications, color moiré is achieved by using one existing color display, similar to the first and second embodiments. A reduction effect can be obtained, and higher definition can be achieved. Furthermore, the response speed of the image display device that displays the elemental image group may be slower than in the first and second embodiments.

Although the embodiments for carrying out the stereoscopic image display device and the stereoscopic image display method according to the present invention have been described above, the present invention is not limited to these embodiments, and the scope of the present invention is not limited to these embodiments. Various changes are possible.

The stereoscopic image display device and stereoscopic image display method according to the present invention can be applied to a wide range of industries such as broadcasting, remote control, and entertainment.

100, 100A, 100B, 100C, 100D, 100E Stereoscopic image display device 10, 10A, 10B, 10C, 10D, 10E Image display device (image display means)
1, 1A, 1C, 1D Color display element (pixel)
1R display element (subpixel)
1G display element (subpixel)
1B Display element (subpixel)
1Y display element (subpixel)
1G _a display element (subpixel)
_1Gb display element (subpixel)
11 Display element group (sub-pixel group)
12 Display element group (sub-pixel group)
2, 2A, 2B, 2C, 2D, 2E Wobbling element (optical path shifting means)
21 first polarization control element 22 second polarization control element 23 first birefringence element 24, 24A second birefringence element 25 birefringence element 25A first birefringence element 26 second birefringence element 30 lens array 3 element lens 4, 4A Light source D Image data (image information)
d Pixel data (pixel information)
dR Subpixel data (subpixel information)
dG Subpixel data (subpixel information)
dB Sub-pixel data (sub-pixel information)
dY Subpixel data (subpixel information)
vI Stereo image S11, S11A, S11B First data selection process S21, S21A, S21B Second data selection process S31, S31A Third data selection process S41, S41A Fourth data selection process S12, S12A First image display process S22, S22A Second image display step S32, S32A Third image display step S42, S42A Fourth image display step

Claims (11)

An image display means that displays a two-dimensional array of pixels formed by arranging two or more sub-pixels that are displayed in a single color, and a lens that is a two-dimensional array of a plurality of lenses provided on the display side of the image display means. A stereoscopic image display device that displays a color stereoscopic image, comprising:
Optical path shifting means for transmitting light incident from the side of the image display means by shifting the light emitting position stepwise by a distance equal to the length of the sub-pixels in the arrangement direction of the sub-pixels in the pixel on the light-emitting surface. A three-dimensional image display device comprising: between the image display means and the lens array. The stereoscopic image display device according to claim 1, wherein the image display means is configured to emit parallel light. an image display means for displaying a two-dimensional array of pixels formed by arranging two or more sub-pixels displayed in a single color; a light source for irradiating the image display means with parallel light; and the light source and the image display means. A 3D image display device that displays a color 3D image and includes a lens array in which a plurality of lenses are two-dimensionally arranged between the lenses,
Optical path shifting means for transmitting the incident light toward the image display means by displacing the incident light in stages on the output surface by a distance equal to the length of the subpixels in the arrangement direction of the subpixels in the pixel; A three-dimensional image display device comprising: between the lens array and the image display means. The pixel includes the sub-pixels arranged in a two-dimensional manner,
The stereoscopic image display device according to any one of claims 1 to 3, wherein the optical path shift means displaces the output position in two different directions on the output surface. An image display means that displays a two-dimensional array of pixels formed by arranging two or more sub-pixels that are displayed in a single color, and a lens that is a two-dimensional array of a plurality of lenses provided on the display side of the image display means. A stereoscopic image display device that displays a color stereoscopic image, comprising:
The pixel includes M (M≧2) or more of the sub-pixels arranged in one direction,
An optical path shifting means for transmitting light incident from the side of the image display means by displacing the light incident from the side of the image display means stepwise in the one direction by a distance of (1/M) of the length of the pixel on the exit surface; A stereoscopic image display device, characterized in that it is provided between a display means and the lens array . 6. The stereoscopic image display device according to claim 5, wherein the image display means is configured to emit parallel light. an image display means for displaying a two-dimensional array of pixels formed by arranging two or more sub-pixels displayed in a single color; a light source for irradiating the image display means with parallel light; and the light source and the image display means. A 3D image display device that displays a color 3D image and includes a lens array in which a plurality of lenses are two-dimensionally arranged between the lenses,
The pixel includes M (M≧2) or more of the sub-pixels arranged in one direction,
The lens includes an optical path shifting means for displacing the incident light stepwise in the one direction by a distance of (1/M) of the length of the pixel on the exit surface and transmitting it to the image display means side. A stereoscopic image display device, characterized in that it is provided between an array and the image display means. The optical path shifting means includes a polarization control element that transmits light while switching between an optically rotating state and a non-optically rotating state, and a polarization control element that allows the light that has passed through the polarization control element to travel straight or to be refracted and transmitted depending on the direction of the polarized light. 8. A birefringent element, which is arranged in the order from the light incident side, and the light is displaced by being refracted and transmitted through the polarization control element. The stereoscopic image display device described above. The stereoscopic image display device according to any one of claims 1 to 8 , wherein the optical path shifting means periodically switches between displacement and non-displacement of the light, with one frame displayed by the image display means as one period. . an image display means for displaying pixels formed by arranging N sub-pixels (N≧2) in the X direction, each of which is displayed in a single color, in a two-dimensional arrangement in the X direction and the Y direction; A 3D image display method for displaying a color 3D image using a lens array in which lenses are arranged in a two-dimensional manner,
Each of the pixel information of the image information that constitutes the color stereoscopic image by two-dimensionally arranging a plurality of pixel information has sub-pixel information of the color displayed by the sub-pixel of the image display means,
The image display means performs an image display step of selecting and displaying the subpixel information of the image information one by one for each subpixel, and selecting and displaying the subpixel information of the color corresponding to the subpixel, N times,
The i-th image display step (1≦i≦N) displays the j-th pixel information in the X direction in the image information with the (j+i-1)th sub-pixel in the X direction in the image display means. death,
In the i-th image display step, an optical path shift means provided between the image display means and the lens array shifts the incident light in the X direction to the length of the pixel ((ai)/N ) (a is an integer constant). An image display means that displays pixels formed by arranging N sub-pixels (N≧2), each of which is displayed in a single color, in a two-dimensional array in the X direction and the Y direction, and a plurality of lenses. A stereoscopic image display method for displaying a color stereoscopic image using a dimensionally arranged lens array,
Each of the pixel information of the image information that constitutes the color stereoscopic image by two-dimensionally arranging a plurality of pixel information has sub-pixel information of the color displayed by the sub-pixel of the image display means,
Each of the pixels is divided in the X direction into M subpixel groups each consisting of one subpixel or two or more consecutive subpixels (2≦M≦N),
An image in which the image display means selects and displays the sub-pixel information of the color corresponding to the sub-pixel of the sub-pixel group, one piece of the pixel information of the image information for each sub-pixel group. Perform the display process M times,
The i-th image displaying step (1≦i≦M) displays the j-th pixel information in the X direction in the image information and the (j+i-1)th sub-pixel group in the X direction in the image display means. display,
In the i-th image display step, an optical path shift means provided between the image display means and the lens array shifts the incident light in the X direction to the length of the pixel ((ai)/M ) (a is an integer constant).

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