JP2012118185A - Display and display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display in which utilization efficiency of light emitted from a light source may be improved.SOLUTION: A display 2C comprises an optical path changing panel 12ca and a diffraction grating panel 13c. The optical path changing panel 12ca includes prisms 20 corresponding to respective color light beams for displaying one display pixel, is disposed between a light source 11c and the diffraction grating panel 13c, and changes proceeding directions of the respective color light beams (light L1) emitted from the light source 11c by the prisms 20, so that the respective light beams (light L2) may obliquely enter diffraction grating faces F3 of respective diffraction gratings 30. The respective prisms 20 provided correspondingly to the respective color light beams for displaying one display pixel are formed to have optical characteristics different from one another so that the respective color light beams may enter the diffraction grating faces F3 at the same incident angle.

Description

  The present invention includes an optical path changing unit that changes a traveling direction of light from a light source, and a light diffracting unit that diffracts light from the optical path changing unit in a predetermined direction. The present invention relates to a display that displays a plurality of images so as to be visible, and a display device that includes the display.

  Japanese Patent Application Laid-Open No. 9-304738 discloses a stereoscopic image display device as a display device including this type of display. This stereoscopic image display device includes a display device composed of a CRT or the like (hereinafter referred to as “CRT” in order to clarify the distinction from the “stereoscopic image display device”), a projection lens, and a diffraction grating (a plurality of gratings). A plate body in which diffraction grating patterns are respectively formed in a cell: hereinafter referred to as a “diffraction grating panel” in order to clarify the distinction from the diffraction grating of each grating cell unit) . In this stereoscopic image display apparatus, for each of a plurality of parallax areas defined corresponding to the viewpoint position of the observer, an image of the object (each parallax image) is displayed so that a parallax image corresponding to the parallax area is visually recognized. The composition which is visually recognized as a stereoscopic image (stereoscopic image) is displayed by displaying a combined image).

  In this case, the CRT functions as a light source that emits light for each display pixel in each parallax image. In addition, the projection lens guides each light emitted from the CRT (light corresponding to each display pixel constituting the stereoscopic image) to a predetermined grating cell of the diffraction grating panel (preliminarily specified). It functions as a light guide component (each incident on a lattice cell). Furthermore, the diffraction grating panel has a diffraction grating pattern with a different diffraction grating pattern so that each light guided by the projection lens can be diffracted and emitted toward a predetermined parallax region. Is formed.

  When displaying a stereoscopic image by the stereoscopic image display device, first, an image (composite image) of an object to be viewed as a stereoscopic image is generated. Specifically, first, an object is photographed and parallax images for each parallax region (for example, four parallax images for four parallax regions on the left outer side, the left inner side, the right inner side, and the right outer side) are obtained. Generate it. Next, the parallax images are synthesized by the image synthesis device to generate a synthesized image. At this time, the pixels of the left outer parallax image, the pixels of the left inner parallax image, the pixels of the right inner parallax image, and the pixels of the right outer parallax image are cycled in a predetermined arrangement pattern. The above-described composite image is generated by performing image processing so that the images are arranged in a line. Thereby, the preprocessing for displaying a stereoscopic image is completed.

  Next, the generated composite image is displayed on the CRT. At this time, each light emitted from the CRT is guided to a predetermined grating cell of the diffraction grating panel by the projection lens. In addition, each light incident on the diffraction grating panel (grating cell) is diffracted by the diffraction grating (grating pattern) for each grating cell and emitted toward a predetermined parallax region. Thereby, different parallax images are visually recognized for each parallax region. In this case, in a state where the left eye and the right eye of the observer are located in different parallax regions, the parallax image viewed by the left eye and the parallax image viewed by the right eye differ depending on the position of the parallax region. Therefore, the displayed image is visually recognized as a stereoscopic image. Further, when the observer moves to another parallax area, different parallax images are sequentially viewed according to the position of the parallax area, and thus the displayed image is viewed as a stereoscopic image by motion parallax.

JP-A-9-304738 (page 3-4, Fig. 1-2)

  However, the conventional stereoscopic image display device has the following problems. That is, the conventional stereoscopic image display apparatus employs a configuration in which each light emitted from the CRT is guided by a projection lens and is incident on a desired grating cell (diffraction grating) of the diffraction grating panel. In addition, the diffraction grating panel in the conventional stereoscopic image display device has a diffraction grating formed by different diffraction grating patterns formed of parallel straight line groups for each grating cell defined on the panel surface. Therefore, in a diffraction grating panel in a conventional stereoscopic image display device, a diffraction grating pattern (consisting of a straight line group) for each grating cell is selected according to the position of the parallax region where the diffracted light is to be emitted (direction in which the light is to be diffracted). All diffraction grating patterns are formed in the same plane parallel to the panel surface, although the angles of the diffraction grating) in the panel surface (inclination of the straight line group in the panel surface) are different.

  In this case, as shown in FIG. 44, in the conventional stereoscopic image display device 1x (in the following description, elements related to the conventional stereoscopic image display device are described by adding “x” at the end of the reference numerals). The light L2x guided by the projection lens is perpendicularly incident on the grating cell (diffraction grating) defined at the center of the diffraction grating panel 13x. In such a state, 0th-order diffracted light L3ax, 1st-order diffracted light L3bx, and −1st-order diffracted light L3cx are emitted from the diffraction grating panel 13x as diffracted light of the light L2x. At this time, in a state where the light L2x is perpendicularly incident on the grating cell (diffraction grating), the light amount of the first-order diffracted light L3bx and the light amount of the −1st-order diffracted light L3cx are the same ( The intensity of the first-order diffracted light L3bx and the intensity of the −1st-order diffracted light L3cx are approximately the same).

  Therefore, in the conventional stereoscopic image display device 1x, no matter which of the above-described configurations using the first-order diffracted light L3bx and the −1st-order diffracted light L3cx is used for displaying a stereoscopic image, the center portion of the diffraction grating panel 13x is used. Is more than half of the light L2x guided by the projection lens (the sum of the first-order diffracted light L3bx and the -1st-order diffracted light L3cx that is not used for displaying a stereoscopic image and the 0th-order diffracted light L3ax). This does not contribute to the display of a stereoscopic image, and there is a problem that the utilization efficiency of light emitted from a CRT (light source) is deteriorated.

  The present invention has been made in view of such problems, and a main object of the present invention is to provide a display and a display device that can improve the utilization efficiency of light from a light source.

  In order to achieve the above object, a display device according to the present invention includes a light path changing unit and a light diffraction unit, and is configured to display one display pixel with a plurality of types of colored light having different wavelengths. In addition, a plurality of images can be displayed so that different images can be viewed from different viewpoint positions that face the display and are different in the left-right direction of the display. A diffraction grating is formed for each pixel, and the light from the optical path changing unit is diffracted in a predetermined direction for each diffraction grating, and the optical path changing unit is configured to display the one display pixel. An optical path changing element is provided corresponding to each color light and is disposed between the light source and the light diffracting unit, and the traveling direction of each color light emitted from the light source is changed by the optical path changing element. Before Each color light is obliquely incident on the diffraction grating surface of each diffraction grating, and each optical path changing element provided corresponding to each color light for displaying the one display pixel is provided for each color light. The optical characteristics are different from each other so that the incident angles with respect to the diffraction grating surface are equal to each other.

  The above-mentioned “light source” does not simply mean a light emitter, but means an optical element for emitting light toward the optical path changing unit. Therefore, for example, the light emitted from the light emitter is directly incident on the optical path changing unit without arranging other optical components (light modulation element, polarizing panel, etc.) between the light emitter and the optical path changing unit. In the configuration in which the traveling direction is changed, the light emitter itself corresponds to a “light source”. In a configuration in which the light emitted from the light emitter is transmitted through various optical components such as a light modulation element and a polarizing panel and then incident on the optical path changing unit to change the traveling direction thereof, the light emitter and the optical component are compatible with each other. It corresponds to “light source”.

  In the display device according to the present invention, the optical path changing unit is configured such that the optical path changing element is a prism.

  Furthermore, in the display device according to the present invention, the optical path changing unit is formed such that at least one of the shape and material of each prism corresponding to each color light for displaying the one display pixel is different from each other. ing.

  In the display device according to the present invention, the optical path changing unit is configured by an element in which the optical path changing element changes a traveling direction of light by an electro-optic effect.

  Further, in the display device according to the present invention, the optical path changing unit has a length along the light traveling direction of each element corresponding to each color light for displaying the one display pixel. It is formed so as to be different for each element.

  In the display device according to the present invention, the optical path changing unit and the light diffracting unit are formed so that either the −1st order diffracted light or the + 1st order diffracted light does not exit from the light diffracting unit. In this case, the state that “one of the −1st order diffracted light and the + 1st order diffracted light does not exit from the light diffracting portion” means that either one of the −1st order diffracted light or the + 1st order diffracted light is from the light diffracting portion to the front side of the display Is not emitted ”.

  Moreover, the display apparatus which concerns on this invention is provided with the display in any one of said, the said light source, and the control part which controls lighting of the said light source and displays the said image on the said display.

  Further, the display device according to the present invention includes a display having the optical path changing unit, the optical path changing element being configured by an element that changes a traveling direction of light by an electro-optic effect, the light source, and lighting of the light source. A control unit that controls and changes the traveling direction of the light by applying a voltage to each of the elements of the optical path changing unit, and displays the image on the display unit. Different voltages are applied to the elements corresponding to the respective color lights for displaying one display pixel.

  According to the display device of the present invention, an optical path changing unit provided with an optical path changing element corresponding to each color light for displaying one display pixel is disposed between the light source and the light diffracting unit. -1st order diffracted light emitted from the light diffracting section (by changing the traveling direction of each color light emitted from the light beam by the optical path changing element and causing each color light to enter obliquely to the diffraction grating surface of each diffraction grating ( Alternatively, the light amount of the first-order diffracted light) is sufficiently reduced (the intensity of the −1st-order diffracted light (or the first-order diffracted light) is sufficiently reduced), or the −1st-order diffracted light (or 1 The emission of the first-order diffracted light (or the first-order diffracted light) can be sufficiently increased (the intensity of the first-order diffracted light (or the first-order diffracted light) can be sufficiently increased). Thereby, according to this display, the utilization efficiency of the light from a light source can fully be improved. Further, according to this display, each optical path changing element provided corresponding to each color light for displaying one display pixel is set so that the incident angles with respect to the diffraction grating surface for each color light are equal to each other. By forming the optical characteristics different from each other, the influence of the wavelength dependence of the optical characteristics of the optical path changing element is eliminated, and each color light is incident on the diffraction grating surface at the same incident angle. A single color image of a color image to be viewed at another viewpoint position overlaps a single color image forming a color image to be viewed at one of the viewpoint positions that are different in the left-right direction. Can be visually recognized as a clear color image.

  Moreover, according to the display device according to the present invention, since the optical path changing element of the optical path changing unit is configured by a prism, the optical path changing unit can be easily manufactured using a resin material, glass, or the like. Cost can be reduced sufficiently.

  Furthermore, according to the display device according to the present invention, by forming the optical path changing unit so that at least one of the shape and material of each prism corresponding to each color light for displaying one display pixel is different from each other, Since the incident angle with respect to the diffraction grating surface for each color light can be easily made to be the same angle, a clear color image can be visually recognized without causing an increase in manufacturing cost.

  In the display device according to the present invention, the optical path changing element of the optical path changing unit is configured by an element that changes the traveling direction of light by the electro-optic effect. In this case, by forming the optical path changing unit such that the length along the light traveling direction of each element corresponding to each color light for displaying one display pixel is different for each optical path changing element, Even in the case of adopting a configuration in which a voltage of the same voltage value is applied between a pair of electrodes in the element, the incident angle with respect to the diffraction grating surface for each color light can be made the same angle, so the control of each element is complicated. Therefore, a clear color image can be visually recognized without incurring a situation. Further, by applying different voltages to the elements corresponding to the respective color lights for displaying one display pixel, the light applied from the light source can be changed only by changing the voltage applied between the pair of electrodes. Since the direction can be changed to an arbitrary direction, the optical path changing unit can be easily designed and manufactured. As a result, the manufacturing cost of the display can be sufficiently reduced.

  Further, according to the display device of the present invention, the light path changing unit and the light diffracting unit are formed so that either the −1st order diffracted light or the + 1st order diffracted light is not emitted from the light diffracting unit, so that the light is emitted from the light diffracting unit. Due to the presence of the -1st order diffracted light (or 1st order diffracted light), a clear image can be displayed without causing a so-called ghost image to be displayed.

  In addition, according to the display device according to the present invention, it is configured by including any one of the above-described indicators, a light source, and a control unit that controls lighting of the light source and displays an image on the indicator. The use efficiency of the light from the color image can be sufficiently improved, color blurring occurs in the displayed color image, or the single color image of the color image that should be viewed at other viewpoint positions overlaps and is viewed. It can be avoided and visually recognized as a clear color image.

  In addition, according to the display device of the present invention, the optical path changing element includes a display having an optical path changing unit composed of an element that changes the traveling direction of light by an electro-optic effect, a light source, and lighting of the light source is controlled. And a control unit that applies a voltage to each element of the optical path changing unit to change the traveling direction of the light and display an image on the display, and each color for the control unit to display one display pixel Since it is configured to apply different voltages to the elements corresponding to the light, the traveling direction of the light from the light source is changed to an arbitrary direction only by changing the voltage applied between the pair of electrodes. As a result, the optical path changing unit can be easily designed and manufactured. As a result, the manufacturing cost of the display device can be sufficiently reduced.

It is a block diagram which shows the structure of the display apparatuses 1 and 1A (display 2, 2A). It is a top view for demonstrating the relationship between the indicator 2,2A (2C, 2AC) of the display apparatus 1,1A (1C, 1AC), and the light L4 emitted in the case of an image display. It is sectional drawing for demonstrating the arrangement | positioning relationship of the light source 11 (11c), the optical path change panel 12 (12ca, 12cb), the diffraction grating panel 13 (13c), and the diffusion plate 14 in the indicator 2 (2C). It is sectional drawing for demonstrating the arrangement | positioning relationship of the light source 11 (11c), the optical path change panel 12A (12Aca, 12Acb), the diffraction grating panel 13 (13c), and the diffusion plate 14 in the indicator 2A (2AC). 2 is a front view of a light source 11. FIG. 3 is a front view of an optical path changing panel 12. FIG. It is sectional drawing which looked at the light source 11 (11c), the optical path change panel 12 (12ca, 12cb), and the diffraction grating panel 13 (13c) from the side. It is a front view of optical path change panel 12A. It is sectional drawing which looked at the light source 11 (11c), the optical path change panel 12A (12Aca, 12Acb), and the diffraction grating panel 13 (13c) from the side. 3 is a front view of a diffraction grating panel 13. FIG. It is the perspective view which looked at the diffraction grating panel 13 from diagonally upward. It is sectional drawing which looked at the diffraction grating panel 13 (13c) and the diffusion plate 14 from the side. It is sectional drawing of the diffraction grating panel 13a which concerns on other embodiment. It is sectional drawing of the diffraction grating panel 13b which concerns on other embodiment. It is explanatory drawing for demonstrating the relationship between the light L2 from the optical path change panel 12,12A (12ca, 12cb, 12Aca, 12Acb), and the 0th-order diffracted light L3a and the 1st-order diffracted light L3b by the diffraction grating panel 13 (13c). . 6 is an explanatory diagram for explaining a relationship between a normal line L14 of the panel surface F4 of the diffusion plate 14 and an incident direction of the light L2 with respect to the diffraction grating surface F3 of the diffraction grating panel 13. FIG. The relationship between the normal line L14 of the panel surface F4 of the diffusion plate 14 and the incident direction of the light L2 with respect to the diffraction grating surface F3 of the diffraction grating panel 13, and the relationship between the normal line L14 and the emission direction of the light L3 from the diffraction grating surface F3. FIG. 17 is a diagram illustrating the diffraction grating surface F3, the panel surface F4, the lights L2, L3, and the like as viewed in the direction of the arrow M in FIG. The relationship between the normal line L14 of the panel surface F4 of the diffusion plate 14 and the incident direction of the light L2 with respect to the diffraction grating surface F3 of the diffraction grating panel 13, and the relationship between the normal line L14 and the emission direction of the light L3 from the diffraction grating surface F3. FIG. 17 is another explanatory diagram for explaining the diffraction grating surface F3, the panel surface F4, the lights L2, L3, and the like in the direction of the arrow N in FIG. It is explanatory drawing for demonstrating the relationship between the normal line L14 of the panel surface F4 in the diffuser plate 14, and the normal line L13 of the diffraction grating surface F3 in the diffraction grating panel 13, Comprising: The diffraction grating surface F3, the panel surface F4, and the method It is the figure which looked at the lines L13 and L14 in the direction of the arrow M in FIG. It is another explanatory drawing for demonstrating the relationship between the normal line L14 of the panel surface F4 in the diffusion plate 14, and the normal line L13 of the diffraction grating surface F3 in the diffraction grating panel 13, Comprising: It is the diffraction grating surface F3 and the panel surface F4. It is the figure which looked at normal line L13 and L14 in the direction of the arrow N in FIG. FIG. 6 is an explanatory diagram for explaining a grating line of each diffraction grating 30 in the diffraction grating panel 13. It is explanatory drawing for demonstrating the relationship between the normal line L13 of the diffraction grating surface F3 in the diffraction grating panel 13, and the incident direction of the light L2 with respect to the diffraction grating surface F3. The relationship between the normal L13 of the diffraction grating surface F3 in the diffraction grating panel 13 and the incident direction of the light L2 with respect to the diffraction grating surface F3, and the relationship between the normal L13 and the emission direction of the light L3 from the diffraction grating surface F3 will be described. It is explanatory drawing for, Comprising: It is the figure which looked at diffraction grating surface F3, panel surface F4, light L2, L3, etc. in the direction of arrow M in FIG. The relationship between the normal L13 of the diffraction grating surface F3 in the diffraction grating panel 13 and the incident direction of the light L2 with respect to the diffraction grating surface F3, and the relationship between the normal L13 and the emission direction of the light L3 from the diffraction grating surface F3 will be described. FIG. 24 is another explanatory diagram for viewing the diffraction grating surface F3, the panel surface F4, the lights L2, L3, and the like in the direction of the arrow N in FIG. 4 is an explanatory diagram for explaining a relationship between a normal line L13 of the diffraction grating surface F3 in the diffraction grating panel 13 and an extending direction (solid line La) of each convex portion 31, and a formation pitch of each convex portion 31. FIG. FIG. 11 is another explanatory diagram for explaining the relationship between the normal line L13 of the diffraction grating surface F3 and the extending direction (solid line La) of each convex portion 31 in the diffraction grating panel 13, and the diffraction grating surface F3 and each convex portion. It is the figure which looked at the continuous line La which shows the extending direction of 31 in the direction of the arrow N shown in FIG. It is explanatory drawing for demonstrating the relationship between the normal line L13 of the diffraction grating surface F3 in the diffraction grating panel 13, and the output direction of the light L3 from the diffraction grating surface F3. It is explanatory drawing for demonstrating the relationship between the normal line L14 of the panel surface F4 in the diffusion plate 14, and the output direction of the light L3 from the diffraction grating surface F3. It is a block diagram which shows the structure of display apparatus 1Ca, 1Cb, 1ACa, 1ACb (display 2Ca, 2Cb, 2ACa, 2ACb). It is a front view of the light source 11c. It is a front view of optical path change panel 12ca, 12cb. It is a front view of optical path change panel 12Aca and 12Acb. It is sectional drawing which looked at optical path change panel 12Acb and diffraction grating panel 13c from the side. It is a front view of the diffraction grating panel 13c. It is explanatory drawing for demonstrating the indicator 2Ca of the display apparatus 1Ca. It is explanatory drawing for demonstrating the indicator 2Cb of the display apparatus 1Cb. It is explanatory drawing for demonstrating the indicator 2ACa of display apparatus 1ACa. It is explanatory drawing for demonstrating the indicator 2ACb of display apparatus 1ACb. It is a front view of the diffraction grating panel 13d which concerns on other embodiment. It is the front view which expanded one of each diffraction grating 30 in the diffraction grating panel 13d. It is sectional drawing of the diffraction grating panels 13e and 13h which concern on other embodiment. It is sectional drawing of the diffraction grating panels 13f and 13i which concern on other embodiment. It is sectional drawing of the diffraction grating panels 13g and 13j which concern on other embodiment. It is explanatory drawing for demonstrating the relationship between the light L2x with respect to the diffraction grating panel 13x in the conventional stereoscopic image display apparatus 1x, 0th order diffracted light L3ax, 1st order diffracted light L3bx, and -1st order diffracted light L3cx.

  Embodiments of a display and a display device according to the present invention will be described below with reference to the accompanying drawings.

  First, the basic configuration of the “display device” and “display device” and the principle of image display will be described with reference to the accompanying drawings. Note that the “display” and “display device” according to the present invention are configured so that a color image can be viewed, but in order to facilitate understanding of these basic configurations and display principles, Hereinafter, a “display” and a “display device” configured so that a monochromatic image can be visually recognized will be described as an example.

  The display devices 1 and 1A shown in FIGS. 1 and 2 are 3D display devices configured to be capable of displaying stereoscopic images based on parallax (“configured to be able to display a plurality of images so that different images can be viewed from each viewpoint position”. The display device 1 includes a display device 2 and a control unit 3, and the display device 1A includes a display device 2A and a control unit 3. In order to facilitate understanding of the basic configurations and display principles of the “display device” and “display device”, 81 different types of parallax regions for each viewpoint position in the left and right 81 directions will be described below. In a single-color image of “horizontal × vertical = 1920 × 1080 pixels”, a configuration for visually recognizing 81 pixels (display pixels) corresponding to each other (one display pixel group in a single-color image group including 81 types of single-color images) A configuration for displaying) will be described.

  As shown in FIG. 3, the display 2 has a light source 11 and an optical path changing panel from the back side (left side in the figure) toward the front side (side on which the person viewing the image is present: right side in the figure). 12, the diffraction grating panel 13 and the diffusion plate 14 are arranged in this order. On the other hand, as shown in FIG. 4, the display 2 </ b> A has a light source 11, an optical path from the back side (left side in the figure) toward the front side (side on which the person viewing the image is present: right side in the figure). The change panel 12A, the diffraction grating panel 13, and the diffusion plate 14 are arranged in this order.

  As an example, the light source 11 is formed in a flat plate shape as a whole by arranging a plurality of light emitting portions (LEDs, etc.) on the surface of a flat substrate corresponding to each display pixel of a stereoscopic image to be displayed. Yes. In this case, in the light source 11, a portion for displaying one display pixel group (a group of 81 display pixels corresponding to each other) in the single-color image group, as shown in FIG. X × vertical = 9 × 9 = 81 places ”light emitting portions 10A1 to 10I9 (hereinafter also referred to as“ light emitting portions 10 ”when not distinguished). That is, in the light sources 11 in the displays 2 and 2A, one light emitting unit 10 is provided for each display pixel constituting one single-color image. As shown in FIGS. 3 and 4, the light source 11 is perpendicular to the panel surface F1 (a surface parallel to the substrate surface of the substrate) and parallel to each other, as shown in FIGS. A simple light L1 is emitted for each of the light emitting portions 10. Further, as shown in FIGS. 2 and 2, in the display units 2 and 2A, as an example, the panel surface F1 includes the panel surfaces F2 and F2A of the optical path changing panels 12 and 12A, which will be described later, and the diffraction grating panel 13. The light source 11 is arranged so as to be parallel to each diffraction grating surface F3 and the panel surface F4 of the diffusion plate.

  The optical path changing panel 12 of the display device 2 corresponds to an “optical path changing unit”, and a “prism” that is an example of an “optical path changing element” is provided corresponding to each display pixel of a stereoscopic image to be displayed. As shown in FIG. 2, it is formed in a flat plate shape as a whole and is disposed between the light source 11 and the diffraction grating panel 13. In this case, as shown in FIG. 6, the optical path changing panel 12 is arranged with prisms 20A1 to 20I9 (hereinafter also referred to as “prisms 20” when not distinguished) of “horizontal × vertical = 9 × 9 = 81 places”. Is provided. In other words, the optical path changing panel 12 in the display device 2 is provided with one prism 20 for each display pixel constituting one single-color image. In the present specification, “one optical path changing element” means “one light emitting element” among optical elements (optical elements that refract incident light) configured to change the optical path of incident light. It means a part defined corresponding to “part”.

  In this case, in the optical path changing panel 12 of this example, there is no physical boundary between the nine prisms 20 arranged in the horizontal direction, and these nine prisms 20 are integrally formed continuously as one prism. ing. Hereinafter, a prism in which a plurality of prisms 20 are integrally formed continuously is also referred to as a “prism 200”. That is, the optical path changing panel 12 is formed such that nine prisms 200-1 to 200-9 that are long in the horizontal direction are arranged in the vertical direction (vertical direction). In this case, in the case of adopting the configuration that “the optical path changing element is configured by a prism”, the number of “optical path changing elements” that are integrally formed continuously is “9 arranged in the horizontal direction”. Without limitation, one prism 20 can be formed independently for each “optical path changing element”, or a plurality of “optical path changing elements” arranged in the vertical direction can be formed by one prism 200. A plurality of “optical path changing elements” arranged in the horizontal direction and a plurality of “optical path changing elements” arranged in the vertical direction can be configured by one prism 200.

  Further, as shown in FIG. 7, in this display device 2, the surface (panel surface F <b> 2) facing the light source 11 in the optical path changing panel 12 is formed (arranged) in parallel with the panel surface F <b> 1 of the light source 11. Each of the prisms 20 (200) is formed on the surface of the optical path changing panel 12 facing the diffraction grating panel 13 so as to form a slope that gradually protrudes toward the diffraction grating panel 13 toward the lower side ( The light L1 is configured (disposed) perpendicularly to the surface (panel surface F2) facing the light source 11 in each prism 20 (200)). In this example, a configuration is adopted in which an inclined surface is formed on the front surface of the optical path changing panel 12 (the side on which an image viewer is present) to function as a “prism”. It is also possible to adopt a configuration in which an inclined surface is formed on the side facing the light source 11 to function as a “prism” (not shown). This optical path changing panel 12 changes the traveling direction of the light L1 emitted from each light emitting part 10 of the light source 11 to the vertical direction (vertical direction) of the display 2 by each prism 20, and the diffraction grating panel 13 described later. The light L2 is obliquely incident on each of the diffraction grating surfaces F3.

  On the other hand, the optical path changing panel 12A of the display 2A corresponds to an “optical path changing unit”, and corresponds to each display pixel of a stereoscopic image to be displayed, which is another example of an “optical path changing element”. An element that changes the traveling direction of light by the EO effect: hereinafter, also referred to as an “EO effect element” is provided, and as shown in FIG. 2, the light source 11 and the diffraction grating are formed as a whole as shown in FIG. Arranged between the panels 13. In this case, as shown in FIG. 8, the optical path changing panel 12A has “horizontal × vertical = 9 × 9 = 81 locations” EO effect elements 20AA1 to 20AI9 (hereinafter also referred to as “EO effect element 20A” when not distinguished). ) Are provided side by side. That is, in the optical path changing panel 12A in the display 2A, one EO effect element 20A is provided for each display pixel constituting one single-color image.

  In the optical path changing panel 12A of this example, there is no physical boundary between the nine EO effect elements 20A arranged in the horizontal direction, and these nine EO effect elements 20A are integrated as one EO effect element. It is formed continuously. Hereinafter, an EO effect element in which a plurality of EO effect elements 20A are integrally and continuously formed is also referred to as an “EO effect element 200A”. In other words, in the optical path changing panel 12A, nine EO effect elements 200A-1 to 200A-9 that are long in the horizontal direction are arranged in the vertical direction (vertical direction). In this case, in the case of adopting the configuration that “the optical path changing element is configured by an element that changes the traveling direction of light by the electro-optic effect”, the number of “optical path changing elements” that are integrally formed continuously Is not limited to “9 arranged in the horizontal direction”, and one EO effect element 20A can be formed independently for each “optical path changing element”, or a plurality of “optical path changing elements arranged in the vertical direction” can be used. Can be configured by one EO effect element 200A, or a plurality of “optical path changing elements” arranged in the horizontal direction and a plurality of “optical path changing elements” arranged in the vertical direction are configured by one EO effect element 200A. You can also

As shown in FIGS. 4 and 9, in this indicator 2A, both the surface facing the light source 11 and the surface facing the diffraction grating panel 13 (panel surface F2A) in the optical path changing panel 12A are the panel surface of the light source 11. It is formed in parallel with F1. In this case, in the optical path changing panel 12A, each EO effect element 20A (200A) includes a KTN crystal 21 (a crystal of potassium tantalate niobate (KTa _1-x Nb _x O ₃ )) and the KTN crystal. The electrode 22a (anode) disposed on the upper surface of the electrode 21 and the electrode 22b (cathode) disposed on the lower surface of the KTN crystal body 21 and the thickness of the KTN crystal body 21 (the length in FIG. 9). Each EO effect element 20A is formed so that T) and length (length L in FIG. 9) are equal to each other. In this example, as an example, the KTN crystal 21 having the composition in which “x” is “0.35” is adopted as the KTN crystal 21.

  In this case, the KTN crystal 21 is an oxide having a perovskite crystal structure, and has an “electro-optic effect (EO effect)” in which the refractive index changes when a voltage is applied between the end faces. It is known that Therefore, in the optical path changing panel 12A, as described later, the control unit 3 applies a predetermined voltage between the electrodes 22a and 22b of the EO effect elements 20A in the optical path changing panel 12A to thereby obtain the EO effects. The KTN crystal body 21 of the element 20A is caused to function in the same manner as each prism 20 in the optical path changing panel 12, and the traveling direction of the light L1 emitted from the light source 11 is displayed by each EO effect element 20A (KTN crystal body 21). The light L2 can be incident obliquely on the diffraction grating surface F3 of each diffraction grating 30 of the diffraction grating panel 13 by changing to the vertical direction (vertical direction) of 2A.

  The diffraction grating panel 13 is an example of a “light diffracting unit”, and diffracts the light L2 emitted from the light source 11 and whose optical path is changed by the optical path changing panels 12 and 12A as shown in FIGS. Light L3 is emitted. In this case, in the diffraction grating panel 13, the portion for displaying one display pixel group of the monochromatic image group corresponds to the display pixel of the stereoscopic image to be displayed as shown in FIG. 10. , “Horizontal × vertical = 9 × 9 = 81” diffraction gratings 30A1 to 30I9 (hereinafter also referred to as “diffraction grating 30” when not distinguished) are formed (one diffraction grating is formed for each display pixel). Example of configured)).

  In the present specification, “one diffraction grating” means a portion defined corresponding to “one light emitting portion” among optical elements configured to be able to diffract incident light. In this case, in the diffraction grating panel 13 in the display 2, one diffraction grating 30 is defined corresponding to one light emitting unit 10 in the light source 11, and each of the display pixels constituting one single color image. One diffraction grating 30 is defined for each of the two. In FIG. 10, the grating lines of each diffraction grating 30 are shown at a pitch wider than the actual grating formation pitch. This diffraction grating panel 13 changes the optical path as shown in FIG. 11 by making the peristaltic rotation angle, which will be described later, different for each diffraction grating 30 (which is one of 81 types of peristaltic rotation angles). The light L2 from the panels 12 and 12A is diffracted in 81 directions defined in advance for each diffraction grating 30, and the light L3 is emitted. In FIG. 11, the emission direction of the diffracted light L3 is shown by arrows.

  In this case, as shown in FIGS. 3 and 4, as an example, the diffraction grating panel 13 includes each of the diffraction gratings 30 defined on the surface facing the optical path changing panels 12 and 12 </ b> A (that is, the back surface of the diffraction grating panel 13). An uneven pattern (lattice pattern) is formed in which a plurality of parallel protrusions 31 in a straight line in plan view and a plurality of parallel recesses 32 in a straight line in plan view are formed at a predetermined formation pitch for each formation region, The concave / convex pattern functions as the diffraction grating 30 to diffract the light L2 from the optical path changing panels 12 and 12A in a predetermined direction. In addition, in this example, although the structure which makes the uneven | corrugated pattern formed in the back surface of the diffraction grating panel 13 function as the diffraction grating 30 is employ | adopted, the front side of the diffraction grating panel 13 (side where the person who visually recognizes an image exists) It is also possible to adopt a configuration in which a concavo-convex pattern is formed on the substrate to function as a diffraction grating (not shown). Further, as shown in FIGS. 7 and 9, in the indicators 2 and 2A, the diffraction grating panel 13 is arranged so as to be separated from the optical path changing panels 12 and 12A by a distance G.

  In the present specification, a surface (in FIGS. 3 and 4) including each center line in the width direction (vertical direction in FIGS. 3 and 4) of the protruding end surface of each projection 31 constituting the diffraction grating 30 in the diffraction grating panel 13 is used. A surface including each center 31o is defined as a diffraction grating surface F3 which is an example of a “diffraction grating surface”. Further, even when the cross-sectional shape of the convex portion 31 is different from that of the diffraction grating panel 13 as in the diffraction grating panel 13a shown in FIG. 13 or the diffraction grating panel 13b shown in FIG. A surface including each center line in the width direction on the protruding end surface of each convex portion 31 (a surface including each center 31o in the figure) is defined as a diffraction grating surface F3 as an example of a “diffraction grating surface”. Furthermore, in the following description, the center line or a line segment parallel to the center line (a line indicated by a solid line Lb in FIG. 21 and the like) is also referred to as a lattice line.

  In this case, as shown in FIG. 7, an optical path in which each prism 20 is configured by forming a slope in a direction gradually projecting toward the diffraction grating panel 13 toward the lower side on the surface facing the diffraction grating panel 13. In the display device 2 including the change panel 12, the light L1 from the light source 11 is refracted downward and is incident on the diffraction grating panel 13 (the diffraction grating surface F3 of each diffraction grating 30) as light L2. In addition, as shown in FIG. 9, in the display 2A including the optical path changing panel 12A having each EO effect element 20A configured to use the electrode 22a as an anode and the electrode 22b as a cathode, the light from the light source 11 is used. L1 is refracted downward and is incident on the diffraction grating panel 13 (the diffraction grating surface F3 of each diffraction grating 30) as light L2.

  Therefore, in the indicators 2 and 2A, the incident position of the light L2 emitted from the optical path changing panels 12 and 12A with respect to the diffraction grating panel 13 is lower than the incident position of the light L1 with respect to the optical path changing panels 12 and 12A by a distance D. Misaligned to the side. For this reason, in this indicator 2, 2A, each light emitting part 10 of the light source 11, each prism 20 of the optical path changing panel 12, and each EO effect element 20A of the optical path changing panel 12A, each of the diffraction grating panel 13 A configuration is adopted in which the diffraction grating 30 is arranged so as to be displaced downward by a distance D. Although different from this example, when the optical path changing panels 12 and 12A and the diffraction grating panel 13 are arranged so that the distance G is “0” or “approximately 0”, the distance D is It can be “0” or “nearly 0”.

  The diffusing plate (an example of a “light diffusing portion” as a “light transmissive panel”) 14 is constituted by a lenticular lens formed as a flat plate with a resin material having light transmittance as an example. As shown in FIG. 12, the diffusion plate 14 has, as an example, a plurality of convex lenses positioned per diffraction grating 30 in the diffraction grating panel 13 (in this example, per diffraction grating 30). A plurality of convex lenses that are long in the lateral direction are formed on the front side (side on which the person who views the image is present) so that three convex lenses are positioned. Thereby, in this diffusing plate 14, the light L3 diffracted by the diffraction grating panel 13 (emitted from the diffraction grating panel 13) is transmitted through the diffusing plate 14 and diffused in the vertical direction (vertical direction) by each convex lens. And emitted as light L4. In addition, in FIG. 12, illustration of the uneven | corrugated pattern in the diffraction grating panel 13 is abbreviate | omitted.

  In this case, in this specification, the surface of the diffusion plate 14 that faces the diffraction grating panel 13 (that is, the back surface of the diffusion plate 14) is defined as a panel surface F4 ("light transmission panel surface"). The “diffusing plate” may be formed by forming a concave lens instead of the convex lens (not shown). In addition, a plurality of convex lenses or a plurality of concave lenses can be formed on the back side (the side of the surface facing the diffraction grating panel 13) (not shown). When a configuration in which a convex lens or a concave lens is formed on the back side is adopted, the front surface of the diffuser plate is defined as a panel surface (“light transmission panel surface”). Further, instead of the “diffusion plate”, a “light transmissive panel” other than the “diffusion plate” (for example, a “protection plate” for preventing the diffraction grating panel 13 or the like from being scratched or adhering to dust, or non-glare treatment may be used. In a display device having an applied “decorative board”), any one of the back surface and the front surface of these plates is a panel surface (“light transmission panel surface”).

  In the display units 2 and 2A, as will be described later, the normal lines of the panel surfaces F2 and F2A of the optical path changing panels 12 and 12A, the normal lines of the diffraction grating surfaces F3 of the diffraction grating panel 13, and the panel surface of the diffusion plate 14 The light L1 is emitted from each light emitting portion 10 of the light source 11 in a direction parallel to the normal line of F4 (the normal line of the light transmissive panel surface in the light transmissive panel). In the indicators 2 and 2A, the light L1 emitted from the light source 11 is refracted in the vertical direction (downward in this example) by the prisms 20 of the optical path changing panel 12 and the EO effect elements 20A of the optical path changing panel 12A. Then, the light L2 is emitted from the optical path changing panels 12 and 12A as light L2, and is incident obliquely on the diffraction grating surface F3 of the diffraction grating 30, as shown in FIG. Furthermore, in this example, as shown in FIG. 15, the optical path changing panels 12 and 12A and the diffraction grating panel 13 are configured so that one of the first-order diffracted light L3b and the −1st-order diffracted light L3c does not exit from the diffraction grating panel 13. Has been.

  On the other hand, the control unit 3 outputs the control signal S to the light source 11 in accordance with the image data of the stereoscopic image to be displayed on the display devices 2 and 2A, thereby causing each light emitting unit 10 in the light source 11 to display the stereoscopic image. Are turned on according to the brightness of each display pixel. Further, the control unit 3 of the display device 1A changes the traveling direction of the light L1 from the light source 11 by applying a predetermined voltage between the electrodes 22a and 22b of the EO effect elements 20A in the optical path changing panel 12A. Execute control to The actual display device 1 includes an image processing unit that processes image data and image signals output from an external device, and the control unit 3 displays based on the data and signals processed by the image processing unit. Although the stereoscopic image is displayed on the display 2, in order to facilitate understanding of the “display” and the “display device”, descriptions and illustrations regarding components other than the display 2 and the control unit 3 are omitted. The “control unit” that executes both the control of the light source 11 and the application of voltage between the electrodes 22a and 22b in each EO effect element 20A (200A) is the same as in the display device 1A. It is also possible to adopt a configuration in which the “control unit” executes, or a configuration in which the independent “control unit” performs control of the light source 11 and application of voltage between the electrodes 22a and 22b. You can also

  In the display devices 1 and 1A (displays 2 and 2A), the light L2 emitted from the light source 11 and refracted by the optical path changing panels 12 and 12A is diffracted by the diffraction gratings 30 and distributed in the left and right 81 directions. The light L3 distributed in the left and right direction by each diffraction grating 30 is diffused in the vertical direction (vertical direction) by the diffuser plate 14, thereby expanding the viewing area in the vertical direction (vertical direction) for each parallax area in the left and right 81 directions. A configuration (a configuration in which different parallax images are viewed in the left-right direction and displayed so that the same parallax image is viewed in the vertical direction) is employed. Specifically, when the stereoscopic image is displayed by the display devices 1 and 1A, the control unit 3 outputs the control signal S to the light source 11 of the display device 2 to display each light emitting unit 10. It is lit at a brightness corresponding to the brightness of each display pixel of the stereoscopic image.

  At this time, as shown in FIGS. 3 and 4, each light emitted from each light emitting portion 10 of the light source 11 in a direction parallel to the normal line of the diffraction grating surface F <b> 3 of each diffraction grating 30 in the diffraction grating panel 13. L1 is refracted downward when passing through each prism 20 of the optical path changing panel 12 and each EO effect element 20A of the optical path changing panel 12A. As a result, the light L2 is directed to the diffraction grating surface F3 of the diffraction grating panel 13. Incident at an angle. Further, the light L2 incident on the diffraction grating panel 13 (diffraction grating surface F3) is diffracted by each diffraction grating 30 and emitted as light L3 (diffracted light). At this time, in the display devices 1 and 1A, the inclination of the grating lines, the formation pitch of the convex portions 31, and the like are defined according to the direction in which each diffraction grating 30 in the diffraction grating panel 13 should emit each light L3. Has been formed. As a result, as shown in FIG. 11, the light L3 from each diffraction grating 30 is emitted from the diffraction grating panel 13 so as to spread radially in the left and right 81 directions at predetermined intervals.

  Further, in the indicators 2 and 2A, as described above, the light L1 from the light source 11 is refracted by the prisms 20 in the optical path changing panel 12 and the EO effect elements 20A in the optical path changing panel 12A. Are obliquely incident on the diffraction grating surface F3 of each diffraction grating 30 of the diffraction grating panel 13, and the optical characteristics (material and shape (prism angle)) of the optical path changing panel 12 and the optical path changing panel 12A. The optical characteristics (material and shape), the value of the voltage applied between the electrodes 22a and 22b, and the positional relationship between the optical path changing panels 12 and 12A and the diffraction grating panel 13 are defined. Therefore, in the indicators 2 and 2A, when the light L2 from the optical path changing panels 12 and 12A is diffracted by the diffraction grating 30 of the diffraction grating panel 13, the first-order diffracted light L3b (or −1st-order diffracted light L3c) Strength is strong enough. For this reason, the utilization efficiency of the light L1 from the light source 11 is sufficiently improved, and the first-order diffracted light L3b (or −1st-order diffracted light L3c) having a sufficiently large amount of light is used as light for visually recognizing a stereoscopic image. As a result, the display pixel corresponding to the first-order diffracted light L3b (or −1st-order diffracted light L3c) is viewed sufficiently brightly.

  On the other hand, the 1st-order diffracted light L3b (or -1st-order diffracted light L3c) and 0th-order diffracted light L3a (hereinafter collectively referred to as “light L3”) emitted from the displays 2 and 2A are shown in FIGS. 12 and 12 are diffused in the vertical direction by the lenticular lens constituting the diffusion plate 14 and directed to the front of the display units 2 and 2A (display devices 1 and 1A) as shown in FIGS. And emitted as light L4. As described above, the display units 2 and 2A are configured such that one of the first-order diffracted light L3b and the −1st-order diffracted light L3c is not emitted from the diffraction grating panel 13. Therefore, as shown in FIG. 15, in this example, only the first-order diffracted light L3b (or -1st-order diffracted light L3c) and a small amount of 0th-order diffracted light L3a are incident on the diffusion plate 14. At this time, each light L4 is diffracted by each diffraction grating 30 of the diffraction grating panel 13 so that the light L1 from the light source 11 is radially spread in the left and right 81 directions at predetermined intervals, and from the diffraction grating panel 13. Light L3 is emitted as light diffused in the vertical direction by the diffusion plate 14, respectively. Thereby, for each position in the left and right 81 directions in front of the display devices 1 and 1A, an image corresponding to each viewpoint position (an image having each light L4 as a display pixel) within a predetermined height range in the vertical direction. Visible.

  Therefore, in a state where the left eye and the right eye of the person viewing the image are located in different parallax regions (viewpoint positions), the parallax image viewed by the left eye and the parallax image viewed by the right eye are Since they differ depending on the position, the displayed image is recognized as a stereoscopic image (recognized as a stereoscopic image by binocular parallax). In addition, each person viewing the image visually recognizes the image displayed on the display device 1 (display 2), and each parallax region (each viewpoint position) in the directions (left and right directions) of arrows A1 and A2 shown in FIG. The images displayed on the display device 1 (display device 2) are recognized as stereoscopic images by motion parallax.

  Next, from the diffraction grating surface F3 of the diffraction grating panel 13 and the panel surface F4 of the diffusing plate 14 (normal line of the light transmission panel surface in the light transmission panel) and the optical path changing panels 12 and 12A in the display units 2 and 2A. The relationship between the light L2 and the light L3 diffracted by the diffraction grating panel 13 will be specifically described with reference to FIGS. The display 2 and 2A configured with the diffusion plate 14 will be described as an example. In the display configured with a “light transmissive panel” other than the “diffusion plate (light diffusing unit)”. The “light transmissive panel” and “light transmissive panel surface” in the display device correspond to “diffuser plate 14” and “panel surface F4” in the following description.

In the above displays 2 and 2A, X at an angle formed by the normal line L14 of the panel surface F4 of the diffusion plate 14 and the incident direction of the light L2 incident on the diffraction grating surface F3 of each diffraction grating 30 of the diffraction grating panel 13. Component (a component corresponding to the left-right direction of the diffuser plate 14 and an angle in a state in which the incident direction of the light L2 intersects the panel surface F4 obliquely to the right when viewed from the surface on the light incident side) Is defined as “αX (see FIGS. 16 and 17)”, and the angle in which the incident direction of the light L2 intersects the panel surface F4 obliquely leftward is defined as “αX” (see FIGS. 16 and 17).
Y component (longitudinal direction in the diffusing plate 14 (the longitudinal direction in the diffusing plate 14)) between the normal L14 of the panel surface F4 in the diffusing plate 14 and the incident direction of the light L2 incident on the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13 The angle of the state in which the incident direction of the light L2 intersects diagonally downward with respect to the panel surface F4 when viewed from the surface on the side on which the light L2 is incident. The angle at which the incident direction of L2 intersects obliquely upward with respect to the panel surface F4 is defined as “αY (see FIGS. 16 and 18)”.
X component at the inclination angle of the normal line L13 of the diffraction grating surface F3 with respect to the normal line L14 of the panel surface F4 (a component corresponding to the horizontal direction of the diffuser plate 14 when viewed from the surface on the light incident side) The angle when the normal line L13 of the diffraction grating surface F3 intersects diagonally leftward with respect to the panel surface F4 is positive, and the normal line L13 of the diffraction grating surface F3 intersects diagonally rightward with respect to the panel surface F4. The angle that makes the angle minus) is “γX (see FIG. 19)”,
The Y component (the component corresponding to the vertical direction (vertical direction) of the diffusing plate 14 and the light L2 incident surface) at the inclination angle of the normal line L13 of the diffraction grating surface F3 with respect to the normal line L14 of the panel surface F4 When viewed, the angle of the state in which the normal line L13 of the diffraction grating surface F3 intersects diagonally upward with respect to the panel surface F4 is positive, and the normal line L13 of the diffraction grating surface F3 is diagonally downward with respect to the panel surface F4. The angle where the angle of the intersecting state is minus) is “γY (see FIG. 20)”,
The perist rotation angle (the line indicated by the solid line Lb in FIG. 21) of each grating in the diffraction grating surface F3 of the diffraction grating 30 in the diffraction grating plane F3 is horizontal when viewed from the surface on the light incident side. (A state parallel to the line indicated by the solid line Lc in FIG. 21) is 0 degree, the rotation angle at which the lattice line of each lattice is lowered to the left is positive, and the rotation angle at which the lattice line of each lattice is downward is negative. Angle) is “ε (see FIG. 21)”,
The x component (the extension direction of the grating line of each grating in the diffraction grating 30 (the perist rotation angle is 0 degree) between the normal line L13 of the diffraction grating surface F3 and the incident direction of the light L2 incident on the diffraction grating surface F3. In the diffraction grating surface F3 on which the diffraction grating 30 is formed, the light L2 is a component corresponding to the left and right direction) and viewed from the surface on which the light L2 is incident. The angle in the state of entering obliquely rightward (direction in the case of the diffraction grating 30 with a perist rotation angle of 0 degree) is positive, and the light L2 is obliquely leftward with respect to the diffraction grating surface F3 (a diffraction grating with a perist rotation angle of 0 degree). “Αx (see FIGS. 22 and 23)”, which is an angle in which the incident angle in the direction of 30) is negative, and the normal line L13 of the diffraction grating surface F3 and the diffraction grating surface F3. With the incident direction of the light L2 The y component at the angle (the direction perpendicular to the grating line of each grating in the diffraction grating 30 in the diffraction grating surface F3 (on the diffraction grating surface F3 on which the diffraction grating 30 having a perist rotation angle of 0 degrees is formed, The light L2 is obliquely downward with respect to the diffraction grating surface F3 (when the diffraction grating 30 has a perist rotation angle of 0 degree), as viewed from the surface on the light incident side. The angle of the incident state in the direction) is positive, and the angle of the state in which the light L2 is incident obliquely upward with respect to the diffraction grating plane F3 (the direction in the case of the diffraction grating 30 having a perist rotation angle of 0 degrees) is negative. “Αy (see FIGS. 22 and 24)”, which is an angle, is expressed by the following two expressions.

αx = tan-1 (tan (αX + γX) · cosε) + tan-1 (tan (αY + γY) · sin (−ε))
αy = tan−1 (tan (αX + γX) · sinε) + tan−1 (tan (αY + γY) · cosε)

Further, the wavelength of the light L1 is “λ”, the grating interval of the diffraction grating 30 (grating formation pitch in the diffraction grating 30: in this example, the formation pitch of the convex portions 31) is “d (see FIG. 25)”,
The y component (diffraction grating plane F3 with respect to the grating line of each grating in the diffraction grating 30) in the inclination angle of the extending direction of each protrusion 31 (the direction indicated by the solid line La in FIG. 25) with respect to the normal L13 of the diffraction grating surface F3. When viewed from the surface on the side on which the light L2 is incident, the component corresponding to the direction orthogonal to the inside (the vertical direction in the diffraction grating surface F3 on which the diffraction grating 30 with a perist rotation angle of 0 degrees is formed). In addition, the angle of the state in which the extending direction of the convex portion 31 intersects obliquely upward with respect to the diffraction grating surface F3 is a plus, and the state in which the extending direction of the convex portion 31 intersects obliquely downward with respect to the diffraction grating surface F3 When the angle of () is negative (see FIG. 25, 26),
The x component at the angle formed by the normal line L13 of the diffraction grating surface F3 and the emission direction of the light L3 emitted from the diffraction grating surface F3 (the extension direction of the grating lines of each grating in the diffraction grating 30 (the perist rotation angle is 0 degree) The diffraction grating surface F3 on which the diffraction grating 30 is formed is a component corresponding to the left and right direction, and obliquely leftward from the diffraction grating surface F3 when viewed from the surface on which the light L2 is incident (perist rotation) The angle in the state in which the light L3 is emitted in the direction of the diffraction grating 30 with an angle of 0 degrees is a plus, and is diagonally rightward from the diffraction grating surface F3 (the direction in the case of the diffraction grating 30 with a perist rotation angle of 0 degrees). “Βx (see FIGS. 27 and 23)”, which is a negative angle of the state in which the light L3 is emitted, and the normal line L13 of the diffraction grating surface F3 and the light L3 emitted from the diffraction grating surface F3. With direction The y component in degrees (the direction perpendicular to the grating line of each grating in the diffraction grating 30 in the diffraction grating surface F3 (in the diffraction grating surface F3 on which the diffraction grating 30 having a perist rotation angle of 0 degrees is formed, the vertical direction) ), And when viewed from the surface on which the light L2 is incident, the light L3 is obliquely upward from the diffraction grating surface F3 (the direction in the case of the diffraction grating 30 having a perist rotation angle of 0 degrees). The angle in which the light is emitted is positive, and the angle in which the light L3 is emitted obliquely downward from the diffraction grating surface F3 (the direction in the case of the diffraction grating 30 having a perist rotation angle of 0 degrees) is negative. “βy (see FIGS. 27 and 24)” is expressed by the following two equations.

βx = −αx
βy = sin−1 {(nλ−d · sin αy) / d}

  As is apparent from the above two equations, “βx”, which is an x component in the angle formed by the normal line L13 of the diffraction grating surface F3 and the emission direction of the light L3 emitted from the diffraction grating surface F3, “Βy”, which is the y component at the angle formed by the normal line L13 of the surface F3 and the emission direction of the light L3 emitted from the diffraction grating surface F3, is the extending direction of each convex portion 31 with respect to the normal line L13 of the diffraction grating surface F3. It does not depend on “δy”, which is the y component in the inclination angle.

  Further, the X component (the component corresponding to the left-right direction of the diffusion plate 14) in the angle formed by the normal L14 of the panel surface F4 and the emission direction of the light L3 emitted from the diffraction grating surface F3, the light L3 being the diffusion plate 14, the angle of the state in which the emission direction of the light L3 intersects obliquely leftward with respect to the diffusion plate 14 is positive, and the emission direction of the light L3 is oblique with respect to the diffusion plate 14. “ΒX (see FIGS. 28 and 17)” which is a negative angle), and the normal line L14 of the panel surface F4 and the emission direction of the light L3 emitted from the diffraction grating surface F3 Y component (a component corresponding to the vertical direction (vertical direction) of the diffuser plate 14), and the emission direction of the light L 3 is diffused when viewed from the surface on the side where the light L 3 is incident on the diffuser plate 14. Diagonally above plate 14 “ΒY (see FIGS. 28 and 18)” is an angle in which the angle of the crossing state is positive and the emission direction of the light L3 is obliquely downward with respect to the diffusing plate 14. Are expressed by the following two equations.

βX = tan-1 (tanβx · cosε) + tan-1 (tanβy · sinε) + γX
βY = tan−1 (tan βx · sin (−ε)) + tan−1 (tan βy · cosε) + γY

  Therefore, when designing the indicators 2 and 2A, the light L2 refracted by the optical path changing panels 12 and 12A based on the above six formulas so that the above-mentioned “βX” and “βY” have desired angles. “ΑX”, “αY”, “ε”, “d”, “γX”, and “γY” may be appropriately adjusted in accordance with “λ” of the light L2 incident on the diffraction grating panel 13. In this case, as the absolute value of αy becomes larger than 0 °, the −1st-order diffracted light L3c (or the 1st-order diffracted light L3b) decreases. Further, the first-order diffracted light L3b (or the −1st-order diffracted light L3c) increases as the −1st-order diffracted light L3c (or the first-order diffracted light L3b) decreases.

  16 to 18, 22 to 24, 27, and 28, in order to facilitate understanding of “X component”, “Y component”, “x component”, “y component” and the like in each of the above explanation items. The relationship between the incident direction of the light L2 with respect to the diffraction grating surface F3 and the emission direction of the light L3 from the diffraction grating surface F3 and the incident direction of the light L3 with respect to the panel surface F4 is the actual light in the display 2 (2A). It is shown in a state different from the course of. 16 to 18, 22 to 24, 27, and 28, as an example, “Pelist rotation angle ε ≠ 0 °” and “inclination angle of normal line L13 of diffraction grating surface F3 with respect to normal line L14 of panel surface F4” Is 0 ° (γX = 0 °, γY = 0 °) ”.

  Next, the “display” and “display device” according to the present invention will be specifically described with reference to the accompanying drawings.

  In addition, in order to clarify the relationship with the above-described display devices 2 and 2A (display devices 1 and 1A) exemplified in the description of the basic configurations and display principles of the “display device” and “display device”, The “display (display device)” having the “optical path changing unit” configured by “prism” is referred to as the display 2Ca, 2Cb (display devices 1Ca, 1Cb), and the “optical path” configured by the “EO effect element”. The “displays (display devices)” having the “change unit” are referred to as the display devices 2ACa and 2ACb (display devices 1ACa and 1ACb). When the display devices 1Ca and 1Cb are not distinguished from each other, the display device 1C is referred to. When the display devices 1ACa and 1ACb are not distinguished from each other, the display device 1AC is referred to. , 2ACb is referred to as a display 2AC. In this case, as will be described in detail later, the display devices 2Ca and 2Cb have different “prisms” for refracting each color light, and the display devices 2ACa and 2ACb have “EO effect elements for refracting each color light”. "And the control method thereof are different.

  Further, the light source 11, the optical path changing panels 12, 12A, and the diffraction grating panel 13 in the color image display displays 2C and 2AC are the light source 11 and the optical path changing panel 12 in the single color image display displays 2 and 2A. 12A and the diffraction grating panel 13 are referred to as a light source 11c, optical path changing panels 12ca, 12cb, 12Aca, 12Acb and a diffraction grating panel 13c. Further, components common between the display 2 (display device 1) and the display 2C (display device 1C), and between the display 2A (display device 1A) and the display 2AC (display device 1AC). About the common component, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  When a color image is displayed by this type of display device, a plurality of color lights (for example, R = Red = red, G = Green = green, B = Blue = blue 3 are used for each display pixel constituting the color image. The color of each display pixel is visually recognized as an arbitrary color by synthesizing the color light of the color (hereinafter also simply referred to as “R, G, B”). In this case, when R, G, and B color lights for displaying one display pixel are incident on the same prism or the same EO effect element in the same direction, the wavelength dependence of the photorefractive phenomenon. Due to the characteristics, the emission angles from the prisms and EO effect elements for each color light having different wavelengths λ (the emission angle θo shown in FIGS. 7 and 9) are different. In addition, when R, G, and B light beams for displaying one display pixel are incident on the diffraction grating surface of the same diffraction grating in the same direction, due to the wavelength dependence of the diffraction phenomenon. In this state, the diffraction angles of the respective color lights having different wavelengths λ are different (that is, the emission angles of the diffracted light from the diffraction grating surface are different).

  For this reason, as a result of emitting the first-order diffracted light (or -1st-order diffracted light) of each color of R, G, B to be visually recognized as one display pixel in different directions, it is constituted by such a display image. When the image is viewed, there is a risk that the color blur is visible. In addition, at a position far from the display device, only one color of the first-order diffracted light (or -1st-order diffracted light) of each of R, G, and B colors that should be viewed as one display pixel can be viewed. In such a state, although a color image is displayed, there is a risk of being visually recognized as a red single color image, a green single color image, or a blue single color image.

  In this case, in the “display (display device)” configured to diffuse “each color light from the light diffracting portion” in the vertical direction by the “light diffusing portion” such as the diffusion plate 14, the light is emitted from the “light diffracting portion”. Even if the emission angle of each color light is somewhat different in the vertical direction (up and down direction), there is almost no influence on the visual recognition of the display image, but the emission angle of each color light emitted from the “light diffraction part” is the horizontal direction ( If they are different in the left-right direction), the above-described problems may occur. For this reason, when displaying a color image, it is necessary to configure the display so that each color light constituting each display pixel is emitted in substantially the same direction in the left-right direction. In addition, when displaying a color image on a “display (display device)” that does not include a “light diffusing unit”, each color light constituting each display pixel is substantially the same in both the horizontal and vertical directions. It is necessary to configure so that the light is emitted in the direction.

  On the other hand, in the display device 1C (display 2C) shown in FIG. 29, the shape and material of each prism 20 constituting the optical path changing panels 12ca and 12cb are refracted (the traveling direction should be changed) according to the wavelength of the colored light. Thus, the above-mentioned problems relating to the wavelength dependence of the photorefractive phenomenon are overcome. In addition, the display device 1AC (display 2AC) shown in FIG. 29 should refract the shape of each EO effect element 20A constituting the optical path changing panels 12Aca and 12Acb and the voltage value of the voltage applied to the electrodes 22a and 22b ( The above-mentioned problems relating to the wavelength dependence of the photorefractive phenomenon are overcome by making them different from each other in accordance with the wavelength of the colored light (the traveling direction should be changed). Furthermore, the display devices 1C and 1AC (display units 2C and 2AC) are configured to make the pitches of the protrusions 31 for each diffraction grating 30 in the diffraction grating panel 13c different from each other according to the wavelength of the color light to be diffracted. The problem concerning the wavelength dependency of the diffraction phenomenon is overcome.

  Note that, in the display devices 2C and 2AC in the actual display devices 1C and 1AC, as an example, the parallax areas for the respective viewpoint positions in the left and right 81 directions on the front side of the display devices 1C and 1AC are different from each other depending on the direction. 81 types of “horizontal × vertical = 1920 × 1080 pixels” RGB color images can be viewed, but it is easy to understand the configurations of the display devices 1C and 1AC and the display devices 2C and 2AC. Therefore, a configuration for visually recognizing one display pixel in the RGB color image for each parallax region for each viewpoint position in the left and right 81 directions will be described.

  Specifically, as shown in FIG. 29, the display 2Ca has a light source from the back side (the left side in the figure) toward the front side (the side where the person viewing the image is present: the right side in the figure). 11c, an optical path changing panel 12ca, a diffraction grating panel 13c, and a diffusing plate 14 are arranged in this order, and the display 2Cb includes a light source 11c, an optical path changing panel 12cb, a diffraction grating from the back side to the front side. The panel 13c and the diffusion plate 14 are arranged in this order. Further, the display 2ACa has a light source 11c, an optical path changing panel 12Aca, and a diffraction grating panel from the back side (left side in the figure) toward the front side (side where a person who views the image is present: right side in the figure). 13c and the diffuser plate 14 are arranged in this order, and the display 2ACb includes the light source 11c, the optical path changing panel 12Acb, the diffraction grating panel 13c, and the diffuser plate 14 in this order from the back side to the front side. Arranged and configured.

  As an example, as illustrated in FIG. 30, the light source 11 c includes a light emitting unit 10 that emits light L1R (red color light) (light emitting units 10A1R to 10I9R: red subpixels: The light emitting unit 10 </ b> R ”), and the light emitting unit 10 that emits the light L <b> 1 </ b> G (green color light) (light emitting units 10 </ b> A <b> 1 </ b> A <b> 1 to 10 </ b> I9G: green subpixels). ), And a light emitting unit 10 that emits light L1B (blue color light) (light emitting units 10A1B to 10I9B: blue sub-pixels: hereinafter referred to as “light emitting unit 10B” when these are not distinguished) Provided side by side in the vertical direction (vertical direction), one light emitting unit 10R, one light emitting unit 10G, and one light emitting unit 10B are used to display a color image. One display pixel formed (hereinafter, "color display pixels" and also referred to) is configured to emit respective colors light for viewing the. That is, in the light source 11c, one light emitting unit 10 (light emitting units 10R, 10G, and 10B) is provided for each sub-pixel of each color constituting one display pixel constituting one color image. Either) is provided.

  In FIG. 31 and FIGS. 31 to 38 to be referred to later, an element related to red (R) is denoted by “R”, and an element associated with green (G) is denoted by “G”. In addition, elements related to blue (B) are indicated with a symbol “B”. In the following description, when it is necessary to distinguish between red (R), green (G), and blue (B), “R”, “G”, and “B” are added to the end of the reference numerals. . In the light source 11c, the light emitting portions 10R, 10G, and 10B that emit light of each color for visually recognizing one display pixel are arranged so as to be adjacent in the vertical direction (vertical direction). The positions of the prisms 20 for the lights L1R, L1G, and L1B in 12ca and 12cb, the positions of the EO effect elements 20A for the light L1R, L1G, and L1B in the optical path changing panels 12Aca and 12Acb, and the lights L1R in the diffraction grating panel 13c. , L1G, and L1B are arranged so that the positions of the diffraction gratings 30 match the positions of the light emitting portions 10R, 10G, and 10B, thereby emitting light of each color for visually recognizing one display pixel. 10R, 10G, and 10B can be arranged at arbitrary positions (not shown).

  As illustrated in FIG. 31, the optical path changing panels 12ca and 12cb change the traveling direction of the light L1R emitted from each light emitting unit 10R in the light source 11c (refract the light L1R) as light L2R, as an example. The emitting prism 20 (prisms 20A1R to 20I9R: hereinafter, also referred to as “prism 20R” when these are not distinguished), the traveling direction of the light L1G emitted from each light emitting unit 10G is changed (the light L1G is refracted). ) Prism 20 emitted as light L2G (prisms 20A1G to 20I9G: hereinafter, also referred to as “prism 20G” when not distinguished from each other), and the traveling direction of the light L1B emitted from each light emitting unit 10B is changed (light Prism 20 that refracts L1B and emits it as light L2B (prisms 20A1B to 20I9B: Below, when they are not distinguished from each other, they are also referred to as “prisms 20B”) arranged in the vertical direction (vertical direction) in this order, and one color display is provided by one prism 20R, one prism 20G, and one prism 20B. It is configured to change the traveling direction of each color light for visually recognizing a pixel (example of a configuration in which one prism as an optical path changing element is formed for each color light for displaying one display pixel. ). That is, in the optical path changing panels 12ca and 12cb, for example, one for each of the subpixels of each color (9 × 9 × 3 = 243 subpixels) constituting each display pixel constituting one color image. A prism 20 is provided.

  In this case, as shown in FIG. 31, in the optical path changing panels 12ca and 12cb, there is no physical boundary between the nine prisms 20R arranged in the horizontal direction, and the nine prisms 20R are like one prism. In addition to being formed integrally and continuously, there is no physical boundary between the nine prisms 20G arranged in the horizontal direction, and these nine prisms 20G are integrally formed continuously as one prism. In addition, there is no physical boundary between the nine prisms 20B arranged in the horizontal direction, and the nine prisms 20B are integrally formed continuously as one prism. That is, in the optical path changing panels 12ca and 12cb, nine prisms 200-1R to 200-9R that are long in the horizontal direction, nine prisms 200-1G to 200-9G that are long in the horizontal direction, and nine prisms 200 that are long in the horizontal direction. -1B to 200-9B are arranged in the vertical direction (vertical direction).

  Further, in the optical path changing panel 12ca, in order to overcome the above-described problems relating to the wavelength dependence of the photorefractive phenomenon, the refractive index for the light L1R is 1.514 and the refractive index for the light L1G is taken as an example. Each of the prisms 20R, 20G, and 20B is formed using an optical material having a refractive index of 1.523 and a refractive index of 1.53 for the light L1B, and the shape of the prism 20R (prism angle) and the shape of the prism 20G ( The angle of the prism) and the shape of the prism 20B (prism angle) are different from each other. Specifically, the optical path changing panel 12ca changes the traveling direction of the light L1G when the apex angle θp (see FIG. 7) of the prism 20R that changes the traveling direction of the light L1R is 30.4 °. The prisms 20R, 20G, and 20P are arranged such that the apex angle θp of the prism of the prism 20G is 30.2 ° and the apex angle θp of the prism of the prism 20B that changes the traveling direction of the light L1B is 30.0 °. 20B is formed of a resin material having optical transparency. Thereby, in this optical path changing panel 12ca, the emission angle θo of the light L2R from the prism 20R, the emission angle θo of the light L2G from the prism 20G, and the emission angle θo of the light L2B from the prism 20B are all 19.6. The emission angles of the light L2R, L2G, and L2B from the optical path changing panel 12ca are equal to each other. In this case, since the emission angle θo is equal to the aforementioned “αY”, the “αY” of the light L2R, L2G, and L2B is equal to each other (that is, the light L2R to the diffraction gratings 30 in the diffraction grating panel 13c, The incident angles of L2G and L2B are equal to each other)

  On the other hand, in the optical path changing panel 12cb, the optical material forming each prism 20R and the optical material forming each prism 20G are used in order to overcome the above-described problems relating to the wavelength dependence of the photorefractive phenomenon. In the state where the optical materials forming the prisms 20B are different from each other so that the refractive indexes with respect to the wavelengths of the respective color lights are equal to each other, the shapes (prism angles) of the prisms 20R, 20G, and 20B are mutually different. They are formed to be equal (for example, the apex angle of each prism is 34.1 °). Specifically, the optical path changing panel 12cb is, as an example, a copolymer obtained by polymerizing 2,2,2-trifluoroethyl methacrylate and methyl methacrylate (methyl methacrylate) in a ratio of 68 mol%: 32 mol% (hereinafter, referred to as “the following”). Each of the prisms 20R, 20G, and 20B is formed of any one of “resin A”) and a resin material in which polymethyl methacrylate (hereinafter also referred to as “resin B”) and resin A are blended.

  More specifically, the prism 20R that changes the traveling direction of the light L1R is formed of a resin material in which the ratio of the resin A and the resin B is 44 wt%: 56 wt%, and the prism that changes the traveling direction of the light L1G. 20G is formed of a resin material in which the ratio of the resin A and the resin B is 75 wt%: 25 wt%, and the prism 20R that changes the traveling direction of the light L1B is formed of the resin A alone. Accordingly, in this optical path changing panel 12cb, the refractive index of the prism 20R with respect to the light L1R, the refractive index of the prism 20G with respect to the light L1G, and the refractive index of the prism 20B with respect to the light L1B are all 1.444, and the prism 20R. The output angle θo of the light L2R from the prism 20G, the output angle θo of the light L2G from the prism 20G, and the output angle θo of the light L2B from the prism 20B are all 20.0 °, and the optical path of the light L2R, L2G, L2B is changed. The emission angles from the panel 12cb are equal to each other. In this case, since the emission angle θo is equal to the aforementioned “αY”, the “αY” of the light L2R, L2G, and L2B is equal to each other (that is, the light L2R to the diffraction gratings 30 in the diffraction grating panel 13c, The incident angles of L2G and L2B are equal to each other). In both of the optical path changing panels 12ca and 12cb, the prisms 20 provided corresponding to the same color light are formed to have the same shape (the same prism angle) using the same optical material. .

  On the other hand, as shown in FIG. 32, the optical path changing panels 12Aca and 12Acb change the traveling direction of the light L1R emitted from each light emitting unit 10R in the light source 11c (by refracting the light L1R), for example. The EO effect element 20A emitted as L2R (EO effect elements 20AA1R to 20AI9R: hereinafter referred to as “EO effect element 20AR” when not distinguished from each other) is used to change the traveling direction of the light L1G emitted from each light emitting unit 10G. EO effect element 20A that emits light L2G (refracted light L1G) (EO effect elements 20AA1G to 20AI9G: hereinafter, also referred to as “EO effect element 20AG” when they are not distinguished from each other), and from each light emitting part 10B The traveling direction of the emitted light L1B is changed (refracted light L1B) and emitted as light L2B. EO effect elements 20A (EO effect elements 20AA1B to 20AI9B: hereinafter referred to as “EO effect elements 20AB” when they are not distinguished from each other) are arranged in this order in the vertical direction (vertical direction), and one EO effect element 20AR, one EO effect element 20AG, and one EO effect element 20AB are configured to change the traveling direction of each color light for making one color display pixel visible (one display pixel is displayed). Example of a configuration in which one EO effect element as an optical path changing element is formed for each color light). That is, in the optical path changing panels 12Aca and 12Acb, as an example, one for each of the subpixels (9 × 9 × 3 = 243 subpixels) of each color constituting each display pixel constituting one color image. An EO effect element 20A is provided.

  In this case, as shown in FIG. 32, in the optical path changing panels 12Aca and 12Acb, there is no physical boundary between the nine EO effect elements 20AR arranged in the horizontal direction, and the nine EO effect elements 20AR are one. The EO effect elements 20AG are integrally formed continuously like the EO effect elements, and there is no physical boundary between the nine EO effect elements 20AG arranged in the lateral direction, and the nine EO effect elements 20AG constitute one EO. There are no physical boundaries between the nine EO effect elements 20AB that are integrally formed continuously like the effect elements and are arranged in the lateral direction, and these nine EO effect elements 20AB constitute one EO effect. It is integrally formed continuously like an element. That is, in the optical path changing panels 12Aca and 12Acb, nine EO effect elements 200A-1R to 200A-9R that are long in the horizontal direction, nine EO effect elements 200A-1G to 200A-9G that are long in the horizontal direction, and long in the horizontal direction. Nine EO effect elements 200A-1B to 200A-9B are formed so as to be arranged in the vertical direction (vertical direction).

  In this case, the KTN crystal body 21 constituting each EO effect element 20A has the wavelength dependence of the photorefractive phenomenon in the same manner as the prism 20 described above in a state where no voltage is applied between the electrodes 22a and 22b. Yes. Specifically, each of the EO effect elements 20A of the optical path changing panels 12Aca and 12Acb has a refractive index “2.226” with respect to the light L1R of “wavelength λ = 633 nm” in a state where no voltage is applied between the electrodes 22a and 22b. The refractive index for the light L1G having the wavelength λ = 532 nm is “2.283” and the refractive index for the light L1B having the wavelength λ = 472 nm is “2.292”. Therefore, in the optical path changing panel 12Aca, the voltages applied between the electrodes 22a and 22b of each EO effect element 20AR, each EO effect element 20AG, and each EO effect element 20AB are made different from each other, so that the wavelength of the above-described photorefractive phenomenon. A configuration that overcomes the problem of dependency is adopted.

Specifically, “the refractive index of the KTN crystal 21 in a state where no voltage is applied” is set to “n ₀ ”, and “the dielectric constant of vacuum” is set to “ε ₀ = 8.88541882 × 10 −12 F / m”, “Relative permittivity” is set to “ε _r (30000 in this example)”, “voltage applied between the electrodes 22a and 22b” is set to “V”, and “direction parallel to the electrodes 22a and 22b in the KTN crystal 21” Is “L (for example, 1000 μm for each EO effect element 20A of the optical path changing panel 12Aca)” and “the length between the electrodes 22a and 22b in the KTN crystal body 21” is “T (for example, 33 μm), the light emission angle θo of the light from each EO effect element 20A can be calculated by the expression “−0.153n ₀ ³ ε ₀ ² ε _r ² V ² L / T ³ ”. . Therefore, the optical path changing panel 12Aca should be applied between the electrodes 22a and 22b for each of the EO effect elements 20AR, 20AG, and 20AB based on the above formula in order to match the emission angles θo of the lights L2R, L2G, and L2B. The voltage has been calculated.

  More specifically, in the optical path changing panel 12Aca, 10.28 V is applied to the electrodes 22a and 22b of the EO effect element 20AR that changes the traveling direction of the light L1R, and the EO effect element that changes the traveling direction of the light L1G. A configuration is adopted in which 9.90 V is applied to the 20AG electrodes 22a and 22b, and 9.84 V is applied to the electrodes 22a and 22b of the EO effect element 20AB that changes the traveling direction of the light L1B. Thereby, in the optical path changing panel 12Aca, the emission angle θo of the light L2R from the EO effect element 20AR, the emission angle θo of the light L2G from the EO effect element 20AG, and the emission angle θo of the light L2B from the EO effect element 20AB are In all cases, the angle is 20.1 °, and the emission angles of the light L2R, L2G, and L2B from the optical path changing panel 12Aca are equal to each other. In this case, since the emission angle θo is equal to the aforementioned “αY”, the “αY” of the light L2R, L2G, and L2B is equal to each other (that is, the light L2R to the diffraction gratings 30 in the diffraction grating panel 13c, The incident angles of L2G and L2B are equal to each other).

  On the other hand, in the optical path changing panel 12Acb, the electrodes 22a of the EO effect elements 20AR, the EO effect elements 20AG, and the EO effect elements 20AB are provided in order to overcome the problems related to the wavelength dependency of the photorefractive phenomenon. , 22b are defined to be equal to each other (for example, 10.00V as an example), along the light traveling direction of each EO effect element 20AR, each EO effect element 20AG, and each EO effect element 20AB. 33 (each length L shown in FIG. 33: length in the direction parallel to the electrodes 22a and 22b in the KTN crystal body 21: between the incident surface of the light L1 and the output surface of the light L2 in the KTN crystal body 21) The distances are different from each other.

  Specifically, as shown in FIG. 33, in the optical path changing panel 12Acb, the length L of the EO effect element 20AR that changes the traveling direction of the light L1R is 1053.5 μm, and the EO effect that changes the traveling direction of the light L1G. Each EO effect element 20A is formed such that the length L of the element 20AG is 976.6 μm and the length L of the EO effect element 20AB that changes the traveling direction of the light L1B is 965.1 μm. Thereby, in this optical path changing panel 12Acb, the emission angle θo of the light L2R from the EO effect element 20AR, the emission angle θo of the light L2G from the EO effect element 20AG, and the emission angle θo of the light L2B from the EO effect element 20AB are These are all 20.0 °, and the emission angles of the light L2R, L2G, and L2B from the optical path changing panel 12Acb are equal to each other. In this case, since the emission angle θo is equal to the aforementioned “αY”, the “αY” of the light L2R, L2G, and L2B is equal to each other (that is, the light L2R to the diffraction gratings 30 in the diffraction grating panel 13c, The incident angles of L2G and L2B are equal to each other). In each of the optical path changing panels 12Aca and 12Acb, the EO effect elements 20A provided corresponding to the same color light are made of the same shape (the length L along the light traveling direction is the same) using the same optical material. And the length T between the electrodes 22a and 22b is the same), and the same voltage value is applied to the electrodes 22a and 22b.

  In this case, as an example, the optical path changing panel 12Acb is formed so that the end surfaces on the diffraction grating panel 13c side of the EO effect elements 20AR, 20AG, and 20AB are positioned on the same plane (panel surface F2A). Therefore, the optical path changing panel 12Acb has a flat surface (panel surface F2A) on the diffraction grating panel 13c side, and a surface on the light source 11c side is uneven according to the length L of each EO effect element 20AR, 20AG, 20AB. It has become a state. Although different from this example, by forming the end faces on the light source 11c side in the EO effect elements 20AR, 20AG, and 20AB on the same plane, one surface on the light source 11c side is flat, and It can also be formed so that one surface of the diffraction grating panel 13c side is uneven according to the length L of each EO effect element 20AR, 20AG, 20AB (not shown).

  The diffraction grating panel 13c diffracts the light L2G, as shown in FIG. 34, for diffracting the light L2R (diffraction gratings 30A1R to 30I9R: hereinafter referred to as “diffraction grating 30R” when they are not distinguished). Diffraction grating 30 (diffractive gratings 30A1G to 30I9G: hereinafter, also referred to as “diffraction grating 30G” when not distinguished from each other), and diffraction grating 30 for diffracting the light L2B (diffraction gratings 30A1B to 30I9B: hereinafter, these Are also arranged in the vertical direction (vertical direction) in this order, and one color grating 30R, one diffraction grating 30G and one diffraction grating 30B provide one color. Each color light for visually recognizing a display pixel is configured to be diffracted (one display pixel Examples of configurations in which one diffraction grating is formed for each color light to display).

  As described above, in this specification, “one diffraction grating” is defined corresponding to “one light emitting portion” among optical elements configured to be able to diffract incident light. Means the site. Therefore, in this diffraction grating panel 13c, one diffraction grating 30 (diffraction gratings 30R, 30G, 30B) corresponding to one light emitting part 10 (any of the light emitting parts 10R, 10G, 10B) in the light source 11c. 1) for each sub-pixel of each color constituting one of the display pixels constituting one color image (any one of the diffraction gratings 30R, 30G, 30B). Is stipulated.

  Further, in the displays 2C and 2AC of this example, in order to emit each color light for visually recognizing one color display pixel from the diffusion plate 14 in the same direction in the left-right direction, the diffraction grating with respect to the panel surface F4 of the diffusion plate 14 In a state where the slopes of the surface F3 are equal to each other (in this example, each diffraction grating surface F3 is parallel to the panel surface F4), each color light (light L2) for displaying one color display pixel is emitted. For each of the diffraction gratings 30R, 30G, and 30B diffracting, the light L2 having a longer wavelength λ is diffracted than the grating formation pitch d (the formation pitch d of the protrusions 31) in the diffraction grating 30 that diffracts the light L2 having a shorter wavelength λ The diffraction grating panel 13c is formed so that the grating formation pitch d (the formation pitch d of the convex portions 31) in the diffraction grating 30 is larger.

  Specifically, with respect to the grating formation pitch d (projection 31 formation pitch d), the diffraction grating 30G that diffracts the light L2G having a longer wavelength λ than the light L2B is larger than the diffraction grating 30B, and The diffraction gratings 30R, 30G, and 30B are formed so that the diffraction grating 30R that diffracts the light L2R having a longer wavelength λ than the light L2G is larger than the diffraction grating 30G. More specifically, in the diffraction grating panel 13c, the grating in the diffraction grating 30R that diffracts the light L2R having the “wavelength λ = 633 nm” has the “forming pitch d = 633 nm” and the light L2G having the “wavelength λ = 532 nm”. The grating in the diffraction grating 30G that diffracts is “formation pitch d = 532 nm”, and the grating in the diffraction grating 30B that diffracts the light L2B of “wavelength λ = 472 nm” is “formation pitch d = 472 nm” ( Example of “configuration in which the pitch of the grating in the grating is equal to the wavelength λ of the light to be diffracted”). By adopting such a configuration, the diffraction grating panel 13c can be easily designed.

  In this case, as shown in FIG. 7, on the surface facing the diffraction grating panel 13c, an inclined surface is formed so as to gradually protrude toward the diffraction grating panel 13c toward the lower side, and each prism 20 is configured. In the display device 2C having the change panels 12ca and 12cb, the light L1 (lights L1R, L1G, and L1B) from the light source 11c is refracted downward to form the light L2 (lights L2R, L2G, and L2B) as a diffraction grating panel 13c (diffraction). The light is incident on the diffraction grating surfaces F3) of the gratings 30R, 30G, and 30B. Therefore, in this display 2C, the incident position of the light L2 emitted from the optical path changing panels 12ca and 12cb on the diffraction grating panel 13c is the incident position of the light L1 on the optical path changing panels 12ca and 12cb, and the optical path changing panels 12ca and 12cb. The position is shifted downward by a distance D from the emission position of the light L2 from the light source. For this reason, in this indicator 2C, each light emission of the light source 11c according to the refractive index characteristic of each prism 20 in the optical path changing panels 12ca and 12cb and the separation distance G of the optical path changing panels 12ca and 12cb from the diffraction grating panel 13c. A configuration is employed in which each diffraction grating 30 of the diffraction grating panel 13c is displaced downward by a distance D with respect to the section 10 and each prism 20 of the optical path changing panels 12ca and 12cb.

  Specifically, in the display device 2C, for example, when the size of one subpixel is 33 μm in the vertical direction and 100 μm in the horizontal direction, the size of each prism 20 in the optical path changing panels 12ca and 12cb is vertical. The width (length T in FIG. 7) is 33 μm, the horizontal width is 100 μm, and the size of each prism 200 is vertical width: 33 μm and horizontal width: 891 μm.

  In this case, the prism angle (angle θp in FIG. 7) of each prism 20R, 20G, 20B in the optical path changing panel 12ca is 30.4 °, 30.2 °, 30.0 °, respectively. The protrusion lengths (length H in FIG. 7) of the prisms 20R, 20G, and 20B in the panel 12ca are 19.7 μm, 19.8 μm, and 19.9 μm, respectively. In the optical path changing panel 12ca, the emission angle θo of the light L2R from the prism 20R, the emission angle θo of the light L2G from the prism 20G, and the emission angle θo of the light L2B from the prism 20B are all 19.6 °. It has become. Here, the distance in the direction parallel to the normal line of the diffraction grating surface F3 between the tip of each prism 20R, 20G, 20B in the optical path changing panel 12ca and the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13c. When the optical path changing panel 12ca and the diffraction grating panel 13c are arranged so that G becomes 10.0 μm, 10.1 μm, and 10.2 μm, respectively, the light L2R, L2G, and L2B from the prisms 20R, 20G, and 20B The distances from the longitudinal center of the emission position (position P12 in FIG. 7) to the diffraction grating surface F3 of the diffraction grating 30 in the diffraction grating panel 13c are (H / 2 + G) are 19.8 μm, 20.0 μm, and 20. 1 μm.

  In such an optical path changing panel 12ca, the light L2R is moved from the position P12 of the prism 20R to the position P13 of the diffraction grating surface F3 in the diffraction grating 30 (vertical center at the incident position of the light L2 on the diffraction grating panel 13: see FIG. 7). Amount of descent along the diffraction grating surface F3 before reaching (the amount of deviation between the emission position P12 and the incident position P13 of the light L2R: distance D shown in FIG. 7), and the light L2G reaches the incident position P13 from the emission position P12. The amount (distance D) that descends along the diffraction grating surface F3 by the time before and the amount (distance D) that descends along the diffraction grating surface F3 until the light L2B reaches the incident position P13 from the emission position P12 These are 7.1 μm, 7.1 μm, and 7.2 μm, respectively. Accordingly, in the display device 2Ca, the diffraction gratings 30R, 30G, and 30B that diffract the lights L2R, L2G, and L2B with respect to the prisms 20R, 20G, and 20B in the optical path changing panel 12ca have distances D = 7.1 μm and 7.1 μm, respectively. The diffraction gratings 30R, 30G, and 30B are formed so as to be positioned lower by 7.2 μm. In this case, since the difference in distance D from each diffraction grating 30R, 30G, 30B to each prism 20R, 20G, 20B is sufficiently small with respect to the size of the display pixel (in this example, 0.1 μm), this distance It is also possible to align D with the same distance (for example, distance D = 7.1 μm) in each diffraction grating 30R, 30G, and 30B.

  Similarly, in the optical path changing panel 12cb, the direction parallel to the normal line of the diffraction grating surface F3 between the tip of each prism 20R, 20G, 20B and the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13c. When the optical path changing panel 12cb and the diffraction grating panel 13c are arranged so that the distance G becomes 10.0 μm, the emission positions of the lights L2R, L2G, L2B from the prisms 20R, 20G, 20B (in FIG. 7) The distance (H / 2 + G) from the position P12) to the diffraction grating surface F3 of the diffraction grating 30 in the diffraction grating panel 13c is 27.1 μm. In such an optical path changing panel 12ca, the diffraction grating surface from the position P12 of the prisms 20R, 20G, 20B to the position P13 (see FIG. 7) of the diffraction grating surface F3 in the diffraction grating 30 is reached by the light L2R, L2G, L2B. The amount of descending along F3 (the amount of deviation between the emission position P12 and the incident position P13 of the light L2R, L2G, L2B: distance D shown in FIG. 7) is 9.8 μm. Therefore, in the display device 2Cb, the diffraction gratings 30R, 30G, and 30B that diffract the light beams L2R, L2G, and L2B are positioned below the prisms 20R, 20G, and 20B in the optical path changing panel 12cb by a distance D = 9.8 μm, respectively. Thus, the diffraction gratings 30R, 30G, and 30B are formed.

  Although different from the present example, when the optical path changing panels 12ca, 12cb and the diffraction grating panel 13c are arranged so that the above-described distance G is “0” or “almost 0”, the above-mentioned distance D is set as follows. It can be “0” or “nearly 0”.

  On the other hand, in the indicator 2AC that changes the traveling direction of the light L1R, L1G, and L1B from the light source 11c by the optical path changing panels 12Aca and 12Acb, the light from each EO effect element 20A in a state where a voltage is applied between the electrodes 22a and 22b. The emission angles θo of L2R, L2G, and L2B are different from the emission angles θo of the lights L2R, L2G, and L2B from the prisms 20 of the optical path changing panels 12ca and 12cb described above. For this reason, the shift amounts of the diffraction gratings 30R, 30G, 30B are different from the shift amounts of the diffraction gratings 30R, 30G, 30B in the diffraction grating panel 13c of the display 2C.

  Specifically, in the display device 2ACa, as described above, the electrodes L2R, L2G, and L2B from the EO effect elements 20AR, 20AG, and 20AB have an output angle θo of 20.1 °. A configuration in which a voltage is applied between 22a and 22b is employed. Therefore, in the display 2ACa, the diffraction between the end face (panel surface F2) on the diffraction grating panel 13c side of each EO effect element 20AR, 20AG, 20AB and the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13c. When the optical path changing panel 12Aca and the diffraction grating panel 13c are arranged so that the distance G in the direction parallel to the normal line of the grating plane F3 is 10.0 μm, they are incident on the EO effect elements 20AR, 20AG, and 20AB. The amount of light L1R, L1G, L1B refracted by each EO effect element 20AR, 20AG, 20AB and descending along the diffraction grating surface F3 before reaching the diffraction grating surface F3 in the diffraction grating 30, that is, the optical path change The incident position (the position shown in FIG. 9) where the light L1 is incident on each EO effect element 20A of the panel 12Aca. P12A) and the amount of deviation (the distance shown in FIG. 9) between the incident position (position P13 shown in FIG. 9) where the light L1 is refracted by each EO effect element 20A, is emitted as light L2, and enters the diffraction grating 30 D) is 144.1 μm in all cases. Therefore, in the display device 2ACa, the diffraction gratings 30R, 30G, and 30B that diffract the lights L2R, L2G, and L2B are lower than the EO effect elements 20AR, 20AG, and 20AB in the optical path changing panel 12Aca by a distance D = 144.1 μm, respectively. The diffraction gratings 30R, 30G, and 30B are formed so as to be positioned at the positions.

  Further, in the display 2ACb, as described above, the EO effect element 20AR is set so that the emission angles θo of the lights L2R, L2G, and L2B from the EO effect elements 20AR, 20AG, and 20AB are all 20.0 °. , 20AG, 20AB are formed. Therefore, in the display 2ACb, the diffraction between the end face (panel surface F2) on the diffraction grating panel 13c side of each EO effect element 20AR, 20AG, 20AB and the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13c. When the optical path changing panel 12Acb and the diffraction grating panel 13c are arranged so that the distance G in the direction parallel to the normal line of the grating plane F3 is 10.0 μm, they are incident on the EO effect elements 20AR, 20AG, 20AB. The amount of light L1R, L1G, L1B refracted by each EO effect element 20AR, 20AG, 20AB and descending along the diffraction grating surface F3 before reaching the diffraction grating surface F3 in the diffraction grating 30, that is, the optical path change The incident position (the position shown in FIG. 9) where the light L1 is incident on each EO effect element 20A of the panel 12Aca. P12A) and the amount of deviation (the distance shown in FIG. 9) between the incident position (position P13 shown in FIG. 9) where the light L1 is refracted by each EO effect element 20A, is emitted as light L2, and enters the diffraction grating 30 D) is 143.6 μm in all cases. Accordingly, in the display device 2ACb, the diffraction gratings 30R, 30G, and 30B that diffract the lights L2R, L2G, and L2B are lower than the EO effect elements 20AR, 20AG, and 20AB in the optical path changing panel 12Acb by a distance D = 143.6 μm, respectively. The diffraction gratings 30R, 30G, and 30B are formed so as to be positioned at the positions.

  In the display devices 1C and 1AC (display units 2C and 2AC), each diffraction grating emits light L2 emitted from the light source 11c and whose traveling direction is changed (refracted) by the optical path changing panels 12ca, 12cb, 12Aca, and 12Acb. 30 diffracted by 30 and distributed in the left and right 81 directions, and the light L3 distributed in the left and right direction by each diffraction grating 30 is diffused in the vertical direction (up and down direction) by the diffusion plate 14, so that each parallax region in the left and right 81 directions In the vertical direction (up and down direction) (a configuration in which different parallax images are viewed in the left and right direction and the same parallax image is displayed in the vertical direction) is adopted. ing.

  Specifically, when the stereoscopic image is displayed by the display devices 1C and 1AC, the control unit 3 controls the light source 11c so that each light emitting unit 10 displays each display pixel of the stereoscopic image to be displayed. Turn on the light according to the brightness. At this time, in the display device 2ACa of the display device 1ACa, in parallel with the control of the light source 11c, the control unit 3 is arranged between the electrodes 22a, 22b in the EO effect elements 20AR, 20AG, 20AB of the optical path changing panel 12Aca. Voltages of 10.28V, 9.90V and 9.84V are applied, respectively. Further, in the display device 2ACb of the display device 1ACb, the control unit 3 is arranged between the electrodes 22a, 22b of the EO effect elements 20AR, 20AG, 20AB of the optical path changing panel 12Aca in parallel with the control of the light source 11c. Apply a voltage of .00V.

  On the other hand, as shown in FIGS. 3 and 7, in the display device 1 </ b> C (display device 2 </ b> C), each light emitting portion 10 of the light source 11 c is parallel to the normal line of the diffraction grating surface F <b> 3 of each diffraction grating 30 in the diffraction grating panel 13 c. When each light L1 emitted in the direction passes through each prism 20 of the optical path changing panels 12ca and 12cb, its traveling direction is changed (refracted). As a result, the light L2 is incident obliquely on the diffraction grating surface F3 of the diffraction grating panel 13c. Similarly, as shown in FIGS. 4, 9, and 33, in the display device 1AC (display unit 2AC), parallel to the normal line of the diffraction grating surface F3 of each diffraction grating 30 in the diffraction grating panel 13c from each light emitting unit 10. When each light L1 emitted in any direction passes through each EO effect element 20A (KTN crystal body 21) of the optical path changing panels 12Aca and 12Acb, its traveling direction is changed (refracted). As a result, the light L2 is incident obliquely on the diffraction grating surface F3 of the diffraction grating panel 13c.

  Accordingly, in the same manner as the display units 2 and 2A (display units 1 and 1A) exemplified in the explanation of the basic configuration and display principle of the “display unit” and “display unit” according to the present invention, the optical path changing panel is used. When the lights L2R, L2G, and L2B from 12ca, 12cb, 12Aca, and 12Acb are diffracted by the diffraction gratings 30 of the diffraction grating panel 13c, the intensity of the first-order diffracted light L3b (or −1st-order diffracted light L3c) is sufficiently high. Become stronger. For this reason, the utilization efficiency of the light L1R, L1G, and L1B from the light source 11c is sufficiently improved, and the first-order diffracted light L3b (or the −1st-order diffracted light L3c) having a sufficiently large amount of light is viewed in a stereoscopic image. As a result, the display pixel corresponding to the first-order diffracted light L3b (or -1st-order diffracted light L3c) is viewed sufficiently brightly.

  More specific examples are shown in FIG. 35 for the display 2Ca, FIG. 36 for the display 2Cb, FIG. 37 for the display 2ACa, and FIG. 38 for the display 2ACb. The various parameters in the display devices 1C and 1AC (display units 2C and 2AC) are as shown in FIGS. 35 to 38 show various parameters related to only five of the 81 color display pixels A1 to I9, that is, the color display pixels A1, C3, E5, G7, and I9.

  As shown in FIGS. 35 to 38, in the display devices 1C and 1AC (display units 2C and 2AC), light L2R, L2G, and L2B for visually recognizing one of the 81 color display pixels A1 to I9 is obtained. Regarding the diffraction gratings 30R, 30G, and 30B to be diffracted, the slopes (γX and γY) of the diffraction grating surface F3 with respect to the panel surface F4 are equal to each other, and the wavelength of the light L2 to be diffracted is short. The diffraction grating panel 13c is formed and arranged so that the formation pitch d of the projections 31 in the diffraction grating 30 in which the wavelength λ of the light L2 to be diffracted is longer than the formation pitch d. More specifically, the formation pitch of each diffraction grating is equal to the wavelength λ of the light to be diffracted. Further, the peristaltic rotation angles ε are formed equal to each other with respect to the diffraction gratings 30R, 30G, and 30B that diffract light L2R, L2G, and L2B for visually recognizing one display pixel. Therefore, the incident angles (αx, αy) of the lights L2R, L2G, L2B for making one display pixel incident on the diffraction grating surfaces F3 of the diffraction gratings 30R, 30G, 30B are equal to each other.

  Therefore, in the display devices 1C and 1AC (display units 2C and 2AC), as shown in FIGS. 35 to 38, the light is emitted from the diffraction grating panel 13c (each diffraction grating surface F3) in order to make one color display pixel visible. The horizontal components (βX described above) of the indicators 2C and 2AC at the emission angle of the light L3 (lights L3R, L3G, and L3B: see FIG. 29) are equal to each other, and the indicators 2C and 2AC at the emission angle of the light L3 are equal to each other. Are equal to each other in the vertical direction (βY described above). Thus, in the display devices 1C and 1AC (display devices 2C and 2AC), the light L3R, L3G, and L3B are diffused in the vertical direction by the diffusion plate 14, and the light L4R, L4G, and L4B are displayed as the display devices 1C and 1AC. The light is emitted in the same direction in both the left-right direction and the up-down direction toward the front of the (display units 2C, 2AC).

  As shown in FIGS. 35 to 38, in the diffraction grating panel 13c in the display devices 1C and 1AC (display units 2C and 2AC), “| (−λ−d · sin αy) / d | ≧ 1” is satisfied. The condition is met. In the diffraction grating panel 13c that satisfies such conditions, the −1st order diffracted light L3c does not exit from the diffraction grating panel 13c, and thus the −1st order diffracted light L3c is emitted from the diffraction grating panel 13c (incident on the diffusion plate 14). Thus, a situation where the stereoscopic image (color image) image is blurred is avoided. Further, in order not to emit the first-order diffracted light L3b from the diffraction grating panel 13c, the first-order diffracted light L3b may be configured to satisfy the condition “| (λ−d · sin αy) / d | ≧ 1”. By configuring so as to satisfy such conditions, there is a situation in which the stereoscopic image (color image) image is blurred due to emission of the first-order diffracted light L3b from the diffraction grating panel 13c (incident on the diffusion plate 14). It is avoided to occur.

  In this case, in the display devices 1C and 1AC (display units 2C and 2AC), the light L2 from the optical path changing panels 12ca, 12cb, 12Aca, and 12Acb is diffracted by the diffraction gratings 30R, 30G, and 30B in the diffraction grating panel 13c. Thus, the light L3 is emitted from the diffraction grating panel 13c toward each parallax region in the left-right direction (the image can be visually recognized from each parallax region in the left-right direction), and this light L3 is diffused in the vertical direction by the diffusion plate Thus, a configuration is adopted in which the viewing area in the vertical direction for each parallax area is expanded (the image can be viewed in a predetermined viewing area in the vertical direction). In other words, in the above display devices 1C and 1AC (display units 2C and 2AC), the “left and right direction” in which the light L3 is not diffused by the diffusion plate 14 is different for each diffraction grating 30R, 30G, and 30B in the diffraction grating panel 13c. A configuration is adopted in which the light L3 is emitted in an arbitrary direction in the left-right direction by appropriately defining the perist rotation angle ε within a range including ε = 0 °.

  In the display device 1C (display device 2C) having such a configuration, the optical path changing panel 12c having the prism 20 is disposed between the light source 11c and the diffraction grating panel 13c, whereby each of the L1R and L1G from the light source 11c is provided. By changing the traveling direction of L1B to the vertical direction of the display 2C (the direction in which the diffusion plate 14 diffuses light) by each prism 20, and αY ≠ 0 °, αy ≠ 0 °. Further, in the display device 1AC (display 2AC) having such a configuration, the optical path changing panel 12Ac having the EO effect element 20A is disposed between the light source 11c and the diffraction grating panel 13c. By changing the advancing direction of each L1R, L1G, and L1B to the vertical direction of the display 2AC (direction in which the diffusion plate 14 diffuses light) by each EO effect element 20A and αY ≠ 0 °, αy ≠ 0 ° It is said.

  Thereby, in the diffraction grating panel 13c for expanding the range in which the image can be visually recognized in the left-right direction, the diffraction gratings 30R and 30G having various perist rotation angles ε with a small absolute value of the perist rotation angle ε = 0 ° and the perist rotation angle ε. , 30B, the -1st order diffracted light L3c (or 1st order diffracted light L3b) is sufficiently reduced in each of the diffraction gratings 30R, 30G, 30B, and the emission direction of the light L3 from the diffraction grating panel 13c is changed in the horizontal direction. It is possible to expand sufficiently.

  As described above, according to the above-described displays 2C and 2AC, an optical path changing element (in this example, the prism 20 or the EO effect element 20A) is provided corresponding to each color light for displaying one display pixel. Optical path changing panels 12ca, 12cb, 12Aca, 12Acb are disposed between the light source 11c and the diffraction grating panel 13c, and the traveling directions of the respective color lights (lights L1R, L1G, L1B in this example) emitted from the light source 11c Are changed by the optical path changing element, and light of each color (light L2R, L2G, L2B in this example) is obliquely incident on the diffraction grating surface F3 of each diffraction grating 30 to be emitted from the diffraction grating panel 13c. The amount of the −1st order diffracted light L3c (or the 1st order diffracted light L3b) is sufficiently reduced (−1st order diffracted light L3c (or 1st order diffracted light). 3b) is sufficiently reduced), or the emission of the −1st order diffracted light L3c (or 1st order diffracted light L3b) from the diffraction grating panel 13c is eliminated, and the 1st order diffracted light L3b (or −1st order diffracted light is used). L3c) can be sufficiently increased (the intensity of the first-order diffracted light L3b (or -1st-order diffracted light L3c) can be sufficiently increased). Thereby, according to this indicator 2C and 2AC, the utilization efficiency of the light L1R, L1G, and L1B from the light source 11c can fully be improved.

  Further, according to the indicators 2C and 2AC, each optical path changing element (in this example, the prisms 20R, 20G, and 20B or the EO effect) provided corresponding to each color light for displaying one display pixel. The elements 20AR, 20AG, 20AB) are formed with their optical characteristics different from each other so that the incident angles with respect to the diffraction grating surface F3 for each color light are equal to each other. The influence of wavelength dependence is eliminated, and each light L2R, L2G, L2B is incident on the diffraction grating surface F3 at the same incident angle. The single color image of the color image to be viewed at another viewpoint position overlaps with the single color image constituting the color image to be viewed in one of the images. And avoid a situation can be visually recognized as clear color image.

  Further, according to the indicator 2C, the “optical path changing element” of the “optical path changing part” is configured by the prism 20, so that the “optical path changing part” can be easily manufactured using a resin material, glass, or the like. Therefore, the manufacturing cost of the display device 2C can be sufficiently reduced.

  Furthermore, according to the display 2C, at least one of the shape and material of each prism 20 corresponding to each color light for displaying one display pixel (in the display 2Ca, the shape of each prism 20, the display 2Cb Then, by forming the optical path changing panels 12ca and 12cb so that the materials of the respective prisms 20 are different from each other, the incident angle with respect to the diffraction grating surface F3 of each of the lights L2R, L2G, and L2B can be reliably and easily set to the same angle. Therefore, a clear color image can be visually recognized without causing an increase in manufacturing cost.

  Further, in the above-described indicator 2AC, the “optical path changing element” of the “optical path changing unit” is configured by the EO effect element 20A. In this case, the optical path is such that the length L along the light traveling direction of each EO effect element 20A corresponding to each color light for displaying one display pixel is different for each EO effect element 20AR, 20AG, 20AB. Even when the configuration in which the voltage of the same voltage value is applied between the electrodes 22a and 22b in each of the EO effect elements 20AR, 20AG, and 20AB by forming the change panel 12Acb, each of the light L2R, L2G, and L2B is used. Since the incident angles with respect to the diffraction grating surface F3 can be set to the same angle, a clear color image can be visually recognized without causing a complicated control of each EO effect element 20A. Further, by applying different voltages to the EO effect elements 20AR, 20AG, 20AB corresponding to each color light for displaying one display pixel, the voltage applied between the pair of electrodes 22a, 22b is changed. Therefore, the traveling direction of the light L1R, L1G, and L1B from the light source 11c can be changed to an arbitrary direction. Therefore, the optical path changing panel 12Aca can be easily designed and manufactured. As a result, the optical path changing panel 12Aca The manufacturing cost can be sufficiently reduced.

  Further, according to the indicators 2C and 2AC, one of the −1st order diffracted light L3c and the 1st order diffracted light L3b (in this example, the −1st order diffracted light L3c) is prevented from being emitted from the diffraction grating panel 13c. , 12cb, 12Aca, 12Acb and the diffraction grating panel 13c, the so-called ghost image is not displayed due to the presence of the −1st order diffracted light L3c emitted from the diffraction grating panel 13c. A clear image can be displayed.

  Moreover, according to this display apparatus 1Ca, 1Cb, 1ACb, the control part 3 which controls lighting of the indicator 2Ca, 2Cb, 2ACb, the light source 11c, and the light source 11c, and displays an image on the indicator 2Ca, 2Cb, 2ACb. The use efficiency of the light L1R, L1G, and L1B from the light source 11c can be sufficiently improved, and color blurring occurs in the displayed color image, or it is visually recognized at other viewpoint positions. It is possible to avoid a situation in which single-color images of the color image to be overlapped and be visually recognized, and to make the color image visible as a clear color image.

  Further, according to the display device 1ACa, lighting of the display 2ACa, the light source 11c, and the light source 11c is controlled, and a voltage is applied to each EO effect element 20A of the optical path changing panel 12Aca to change the traveling direction of light. And a control unit 3 that displays an image on the display 2ACa, and the control unit 3 is different from each other for the EO effect elements 20AR, 20AG, and 20AB corresponding to each color light for displaying one display pixel. Since the voltage is applied, the traveling direction of the light L1R, L1G, and L1B from the light source 11c can be changed to an arbitrary direction only by changing the voltage applied between the pair of electrodes 22a and 22b. As a result, the optical path changing panel 12Aca can be easily designed and manufactured. As a result, the manufacturing cost of the display device 1ACa can be sufficiently reduced. .

  The configurations of the “display device” and the “display device” are not limited to the configurations of the display devices 2C and 2AC and the display devices 1C and 1AC. For example, a concavo-convex pattern (grating pattern) in which a plurality of projections 31 parallel to each other in a straight line in plan view and a plurality of recesses 32 in a straight line in plan view are formed at a predetermined formation pitch functions as the diffraction grating 30. Although the example provided with the diffraction grating panel 13c configured to be described has been described, the “diffraction grating” is not limited to this, and as an example, the diffraction grating panel 13d shown in FIGS. A concave / convex pattern (grating pattern) composed of a plurality of convex portions having a curved shape in plan view and a plurality of concave portions having a curved shape in plan view that do not intersect with each other is formed to function as a “diffraction grating” A configuration can be employed. In both figures, as an example, the center of the convex portion in the width direction is shown by a solid line (curve).

  In this case, as described above, in this specification, “one diffraction grating” is defined corresponding to “one light emitting portion” among optical elements configured to be able to diffract incident light. It means the part which was done. Therefore, in a diffraction grating panel in which convex portions having a curved shape in plan view and concave portions having a curved shape in plan view are formed as a grating pattern, one light emitting portion in the light source (the light emitting portions 10R, 10G, and 10B in the light source 11c described above). Element corresponding to one of them: In other words, an optical element that emits light corresponding to one of the sub-pixels corresponding to each color light in one of the display pixels constituting one monochrome image. ) Is defined corresponding to one diffraction grating 30a (a rectangular region divided by rough broken lines in both figures).

  In addition, in the diffraction grating 30a in which a convex portion having a curved shape in plan view and a concave portion having a curved shape in plan view are formed as a grating pattern, as shown in FIG. 40, as an example, the convex portion as the grating is one end portion of the diffraction grating 30a. For example, a solid line Lc connecting the intersection point P1 intersecting with the left end portion in the figure and the intersection point P2 where the convex portion intersects with the other end portion of the diffraction grating 30a (in this example, the right end portion in the figure) is represented by a grid line. And Also in the diffraction grating panel 13d having such a configuration, the diffraction grating panel 13c described above is defined for each diffraction grating 30a by defining the formation pitch d of each convex portion, the perist rotation angle (rotation angle of the grating line), and the like. Similarly, the light L2R, L2G, and L2B from the optical path changing panels 12ca, 12cb, 12Aca, and 12Acb can be diffracted and emitted in an arbitrary direction.

  Further, for example, a concavo-convex pattern in which a plurality of convex portions 31 and a plurality of concave portions 32 are formed at a predetermined formation pitch is formed for each formation region of each diffraction grating 30, and this concavo-convex pattern functions as the diffraction grating 30. Display units 2C, 2AC and display devices 1C, 1AC having a diffraction grating panel 13c configured to diffract light L2R, L2G, L2B from the optical path changing panels 12ca, 12cb, 12Aca, 12Acb in a predetermined direction. Although described as an example, the light L2R, L2G, L2B from the optical path changing panels 12ca, 12cb, 12Aca, 12Acb is obtained by any of the diffraction grating panels 13e-13g shown in FIGS. Can be configured to diffract in a predetermined direction.

  In this case, the diffraction grating panels 13e to 13g include a plurality of convex portions 31a and a plurality of concave portions (slits) 32a instead of the grating pattern (concave / convex pattern) including the convex portions 31 and the concave portions 32 in the diffraction grating panel 13c described above. And the grating pattern functions as a diffraction grating 30b to diffract light L2R, L2G, and L2B from the optical path changing panels 12ca, 12cb, 12Aca, and 12Acb in a predetermined direction. Has been. Note that, in the diffraction grating panels 13e to 13g, the same elements as those of the diffraction grating panel 13c described above are denoted by the same reference numerals and redundant description is omitted.

  In this case, as shown in FIGS. 41 and 42, in the diffraction grating 30b of the diffraction grating panels 13e and 13f, the extending direction of the convex portion 31a (the direction of the solid line La in the figure) is relative to the diffraction grating surface F3. The direction intersects perpendicularly (direction parallel to the normal line of the diffraction grating surface F3: δy = 0 °). Therefore, the diffraction grating 30b of the diffraction grating panels 13e and 13g functions in the same manner as the diffraction grating 30 of the diffraction grating panel 13c with δy = 0 °. On the other hand, as shown in FIG. 43, in the diffraction grating 30b of the diffraction grating panel 13g, the extending direction of the convex portion 31a (the direction of the solid line La in FIG. 43) obliquely intersects the diffraction grating surface F3. (Orientation non-parallel to the normal line of the diffraction grating surface F3: δy ≠ 0 °). Therefore, the diffraction grating 30b of the diffraction grating panel 13g functions in the same manner as the diffraction grating of the diffraction grating panel (for example, the diffraction grating panel 13 shown in FIG. 25) with δy ≠ 0 °.

  Further, the light L2 (L2R, L2G, L2B) from the optical path changing panel 12 (12c) is diffracted in a predetermined direction by any of the diffraction grating panels 13h to 13j shown in FIGS. You can also. In this case, the diffraction grating panels 13h to 13j are replaced with a plurality of high refractive index materials formed of a high refractive index material in place of the grating pattern (concave / convex pattern) including the convex portions 31 and the concave portions 32 in the diffraction grating panel 13 (13c) described above. A grating pattern composed of a refractive index portion 35 and a plurality of low refractive index portions 36 formed of a low refractive index material is formed, and this grating pattern functions as a diffraction grating 30c, from the optical path changing panel 12 (12c). The light L2 (L2R, L2G, L2B) is diffracted in a predetermined direction. In this case, in the present specification, the high refractive index portions 35 in the diffraction gratings 30c of the diffraction grating panels 13h to 13j are the same components as the convex portions 31 of the diffraction grating 30 and the convex portions 31a of the diffraction grating 30b described above. To do. That is, the “extending direction of the convex portion” in the diffraction grating 30c of the diffraction grating panels 13h to 13j means the extending direction of the high refractive index portion 35 (the direction of the solid line La in each drawing). Even when such a configuration is adopted, it functions as an “optical diffraction section” similar to the diffraction grating panels 13 (13c), 13a, 13b, and 13e to 13f described above.

  Furthermore, the display devices 2C and 2AC configured integrally with the light source 11c have been described as examples, but the configuration of the “display device” is not limited to this. For example, even in a display device (not shown) configured to change the traveling direction of light emitted from a “light source” as an external device and enter a diffraction grating panel (diffraction grating surface) by using an “optical path changing unit”. By configuring the “optical path changing unit” and “light refracting unit” in the display device in the same manner as the optical path changing panels 12ca, 12cb, 12Aca, 12Acb, the diffraction grating panel 13c, and the like in the display units 2C and 2AC, The same effects as those of the display devices 2C and 2AC can be obtained.

  In addition, the usage form for displaying the “stereoscopic image by parallax” has been described as an example, but the “image” displayed by the “display device” and the “display device” is not limited to this. For example, it is possible to adopt a usage form in which a plurality of types of two-dimensional images (for example, news program images, educational program images, and animation program images) are displayed on the “display” as “different images”. it can. In such a usage mode, as an example, the “news program image” is visually recognized from the left side toward the “display”, and the “education program image” is viewed from the front toward the “display”. By making “an image of an animation program” visible from the right side toward the “display”, three viewers can visually recognize different images from one “display device”.

  Further, the display devices 2C and 2AC (display devices 1C and 1AC) configured to be able to display RGB color images have been described as examples, but “display devices” can display various color images other than RGB color images. Also, a “display device” can be configured. In the case of adopting such a configuration, the above-described d and ε may be appropriately adjusted for each display pixel for each color light constituting the color image. In addition, the light source 11c provided with the LED as the light emitting portion has been described as an example. However, the “light source” is not limited to this, and the organic EL, CRT, liquid crystal display, plasma display, and surface conduction electron emission are not limited thereto. Various light emitting devices such as an element display (SED) can be provided. In this case, when the above-described various light emitting devices are used for a display device for displaying a color image, the light emitting device uses a sub-color of each color in one of the display pixels constituting one color image. An optical element for emitting light corresponding to one of the pixels corresponds to a “light emitting portion”.

  Further, the display devices 2C and 2AC configured by including the diffusion plate 14 have been described as an example. However, instead of the diffusion plate 14 (or in addition to the diffusion plate 14), scratches such as an “optical diffraction portion” are present. In addition, a “display device” can be configured by arranging a “protective plate” for preventing adhesion of dust and a “decorative plate” subjected to non-glare treatment. In this case, when a light transmission panel that diffuses light from the diffraction grating panel such as the diffusion plate 14 in the vertical direction (vertical direction) is not used, the number of diffraction gratings in the diffraction grating panel is increased as appropriate, and only in the left-right direction. Alternatively, it is possible to adopt a configuration in which different parallax images are displayed at each of the vertical viewpoint positions (vertical parallax regions).

1, 1Ca, 1Cb, 1A, 1ACa, 1ACb Display device 2, 2Ca, 2Cb, 2A, 2ACa, 2ACb Display device 3 Control unit 10, 10R, 10G, 10B Light emitting unit 11, 11c Light source 12, 12ca, 12cb, 12A , 12Aca, 12Acb Optical path changing panel 13, 13a-13j Diffraction grating panel 14 Diffuser plate 20, 20R, 20G, 20B, 200, 200-1 to 200-9 Prism 20A, 20AR, 20AG, 20AB, 200A, 200A-1 200A-9 EO effect element 21 KTN crystal 22a, 22b Electrode 30, 30R, 30G, 30B, 30a-30c Diffraction grating F1, F2, F2A, F4 Panel surface F3 Diffraction grating surface L Length L1, L1R, L1G, L1B , L2, L2R, L2G, L2B, L3, L3R, L G, L3B, L4, L4R, L4G, L4B light L3a 0-order diffracted light L3b 1-order diffracted light L3c -1-order diffracted light

Claims (8)

An indicator having an optical path changing unit and an optical diffraction unit,
A single display pixel can be displayed with multiple types of colored light with different wavelengths, and different images can be viewed from different viewpoint positions facing the display and different in the left-right direction of the display Is configured to display multiple images,
The light diffracting unit diffracts the light from the optical path changing unit for each of the display pixels, a diffraction grating is formed for each display pixel,
The optical path changing unit is provided with an optical path changing element corresponding to each color light for displaying the one display pixel, is disposed between the light source and the light diffracting unit, and is emitted from the light source. The traveling direction of each of the colored lights is changed by the optical path changing element, and the colored lights are incident obliquely on the diffraction grating surface of each diffraction grating,
Each optical path changing element provided corresponding to each color light for displaying the one display pixel has an optical characteristic such that incident angles with respect to the diffraction grating surface for each color light are equal to each other. Indicators that are different from each other.   The display device according to claim 1, wherein the optical path changing unit includes a prism as the optical path changing element.   The display according to claim 2, wherein the optical path changing unit is formed so that at least one of the shape and material of each prism corresponding to each color light for displaying the one display pixel is different from each other.   The display device according to claim 1, wherein the optical path changing unit is configured by an element in which the optical path changing element changes a traveling direction of light by an electro-optic effect.   The optical path changing unit is formed such that the length along the light traveling direction of each element corresponding to each color light for displaying the one display pixel is different for each optical path changing element. The display according to claim 4.   6. The display according to claim 1, wherein the optical path changing unit and the light diffracting unit are formed so that any one of the −1st order diffracted light and the + 1st order diffracted light is not emitted from the light diffracting unit.   A display device comprising: the display according to claim 1; the light source; and a control unit that controls lighting of the light source and causes the display to display the image. 5. The display according to claim 4, the light source, and lighting of the light source are controlled, and a voltage is applied to each element of the optical path changing unit to change the traveling direction of the light. A control unit for displaying the image,
The said control part is a display apparatus which applies a mutually different voltage with respect to the said element corresponding to each said color light for displaying the said one display pixel.

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