JP2005077547A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the availability of light from lowering when images formed on a plurality of respective liquid crystal panels are displayed so as to be made visible at positions mutually different in depth in a display device. <P>SOLUTION: Optical paths of respective light rays, emitted from respective pictures R1, R2 formed on the liquid crystal panels 11A, 11B by receiving light of lighting from light irradiating parts 31A, 31B and propagated through optical paths with mutually different optical path lengths without passing through the liquid crystal panels 11A, 11B, are made to coincide with each other by being let through an optical path synthesizing part 21 which is a polarizing beam splitter so as to make the respective pictures R1, R2 be visible at the positions with the mutually different depths by being let through the optical path synthesizing part 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device, and more particularly, to a display device that displays a plurality of images so that they can be seen at different depths.

2. Description of the Related Art Conventionally, there are known display devices that display images formed on a plurality of liquid crystal panels so that they can be seen at different positions in the depth direction. For example, one of three liquid crystal panels stacked in one direction at a predetermined interval is made translucent, and the remaining two are made transparent, and projected onto the translucent one. There has been proposed a display device that displays images of three types corresponding to each of the three liquid crystal panels by sequentially changing the liquid crystal panels that are projected by a projector and making the translucent liquid crystal (see Patent Document 1). . In this display device, since the optical path lengths from the observer to each liquid crystal panel are different from each other, the observer can easily identify each image projected on each liquid crystal panel superimposed in one direction by a difference in distance. it can.
JP-A-5-307185

  By the way, in the above display device, a plurality of liquid crystal panels are stacked in one direction, and an image projected on a translucent liquid crystal panel through a transparent liquid crystal panel is observed or made transparent. It is configured to project an image on a semi-transparent liquid crystal panel through the liquid crystal panel, and the light emitted from the projector is composed of two translucent liquid crystal panels and one translucent liquid crystal panel. It is transmitted to the observer through the liquid crystal panel.

  However, since the transmittance when the liquid crystal panel is made transparent is generally 10% or less, the intensity of light emitted from the projector is 1/1000 (10% × 10% × 10%) before being transmitted to the observer. Attenuating below, the display device has a problem of low light utilization efficiency.

  The present invention has been made in view of the above circumstances, and suppresses a decrease in light use efficiency when displaying images formed on each of a plurality of liquid crystal panels so that the images are viewed at different depths. An object of the present invention is to provide a display device that can be used.

  The display device of the present invention includes a plurality of liquid crystal panels that display images, and optical paths that are emitted from images formed on each of the plurality of liquid crystal panels and that have different optical path lengths without passing through any of the liquid crystal panels. And an optical path synthesis unit that matches the optical paths of the incident lights, and displays each image formed on each liquid crystal panel so that the images can be seen at different depths through the optical path synthesis unit. To do.

  The optical path combining unit is preferably a polarization beam splitter.

  When the display device emits light from an image formed on the liquid crystal panel by projecting the image onto the liquid crystal panel, the light carrying the image projected onto the liquid crystal panel It is preferable that the liquid crystal panel be configured not to pass through.

  When an image is projected onto the liquid crystal panel, it is desirable that the liquid crystal panel be in a state where it can function as a screen for projecting an image, that is, in an opaque state with little shading.

  Further, matching the optical paths of the respective lights is not limited to the case where the optical paths of the respective lights are completely matched, that is, not only when the center positions of the images formed on each of the plurality of liquid crystal panels seem to be completely overlapped, It means that the optical paths are matched so that at least a part of each image appears to overlap each other.

  The display device of the present invention includes a plurality of liquid crystal panels that display images, and optical paths that are emitted from images formed on the plurality of liquid crystal panels and have different optical path lengths without passing through any of the liquid crystal panels. Since the optical path synthesis unit that matches the optical path of each light that has been propagated and incident, each image formed on each liquid crystal panel is displayed through the optical path synthesis unit so that they can be seen at different depths. Each image can be observed based on the light propagated without passing through any liquid crystal panel emitted from the image formed on each liquid crystal panel. By using a beam splitter or the like having a high rate and reflectivity, the attenuation rate of the amount of light passing through the optical path combining unit is always greater than the attenuation rate of the amount of light passing through the liquid crystal panel. It is possible Kusuru can be suppressed as compared with the prior art, a reduction in the utilization efficiency of light when displaying the image formed on each liquid crystal panel.

  If the optical path combining unit is a polarization beam splitter, the light transmitted through the liquid crystal panel and the light reflected by the liquid crystal panel become polarized light, so that the polarization of the light emitted from the image formed on each liquid crystal panel. Each image formed on each liquid crystal panel by combining the direction and the polarization direction of the light in the optical path combining unit so that the decrease in the amount of light emitted through the optical path combining unit in the same direction is reduced. It is possible to further suppress a decrease in the light use efficiency when displaying.

  In addition, when the display device emits light from an image formed on the liquid crystal panel by projecting the image onto each liquid crystal panel, the light carrying the image projected on the liquid crystal panel If the liquid crystal panel is configured so as not to pass through the liquid crystal panel, it is possible to prevent the light amount of the light projected onto the liquid crystal panel from being attenuated, and to use light when displaying the image formed on each liquid crystal panel. A decrease in efficiency can be suppressed.

  Embodiments of the present invention will be described below. FIG. 1 is a plan view showing a schematic configuration in Example 1 of a display device according to a first embodiment of the present invention, FIG. 2 is a perspective view showing the structure of a liquid crystal panel, and FIG. 3 forms an image on each liquid crystal panel. FIG. 4 is a plan view showing a schematic configuration of the display device according to the second embodiment, and FIG. 5 is a plan view showing a schematic configuration of the display device according to the third embodiment.

  The display device 101 according to the first embodiment of the first embodiment of the present invention emits a plurality of liquid crystal panels 11A and 11B that display images and images formed on the liquid crystal panels 11A and 11B, respectively. An optical path combining unit 21 that is a polarization beam splitter that propagates optical paths having different optical path lengths without passing through the liquid crystal panel and matches the optical paths of the lights incident from different directions is provided.

  The display device 101 further inputs light irradiation units 31A and 31B for illuminating the liquid crystal panels 11A and 11B and image signals for forming images on the liquid crystal panels 11A and 11B to the liquid crystal panels 11A and 11B. And a controller 41 that controls the timing of illumination by the light irradiation units 31A and 31B.

  The optical path combining unit 21 is a polarization beam splitter configured by bonding two triangular prisms 21G and 21J via a polarizing film, and the bonding surface is a polarization surface 21H. This polarization plane 21H reflects S-component light whose electric field vector direction is perpendicular to the paper surface (B direction in the figure), and the electric field vector direction is parallel to the paper surface (arrow A direction in the figure). The light of P component which is is transmitted.

  The P-polarized light carrying the image information indicating this image, which is emitted from the image formed on the liquid crystal panel 11A upon receiving the illumination of the light irradiation unit 31A, propagates in the direction of the arrow Y in the figure and passes through the optical path synthesis unit 21. Is incident from the surface u1 of the triangular prism 21G, passes through the polarization plane 21H, and exits from the surface u2 of the triangular prism 21J in the direction of the arrow Y in the figure.

  On the other hand, the S-polarized light carrying image information indicating this image, which is emitted from the image formed on the liquid crystal panel 11B under the illumination of the light irradiation unit 31B, propagates in the direction of the arrow X in the figure to synthesize the optical path. The light enters from the surface u3 of the triangular prism 21J of the unit 21 and is reflected by the polarization surface 21H, and is emitted from the surface u2 of the triangular prism 21J in the direction of the arrow Y in the drawing.

  As shown in FIG. 2, the liquid crystal panels 11A and 11B are known ones in which a liquid crystal 19 is sandwiched between two polarizing plates 18A and 18B whose polarization directions are orthogonal to each other, and are transmitted or reflected through the liquid crystal panel. The obtained light becomes polarized light.

  In the display device 101 configured as described above, when the liquid crystal panels 11A and 11B are observed through the surface u2 from the viewpoint position E1 on the surface u2 side of the optical path combining unit 21, the image R1 displayed on the liquid crystal panel 11A is the liquid crystal panel 11B. From the image R2 displayed on the screen, it can be seen in front by a distance K11, and each image can be seen at a position having a different depth. That is, the optical path length from the viewpoint position E1 when observing the liquid crystal panel 11A to the liquid crystal panel 11A is the optical path length from the viewpoint position E1 when observing the liquid crystal panel 11B to the position F1 in the optical path toward the liquid crystal panel 11B. If equal, the distance K11 is an optical path length in the optical path L11 from the position F1 to the liquid crystal panel 11B.

  Here, since the display device 101 is disposed in the air and the refractive index of air is approximately 1, the optical path length of the optical path L11 = the distance K11.

  When the display device 101 displays an image, the controller 41 displays an image signal for forming an image on each of the liquid crystal panels 11A and 11B and illumination of the liquid crystal panels 11A and 11B by the light irradiation units 31A and 31B as shown in FIG. Control is performed according to the timing chart shown in FIG.

  As shown in the timing chart of FIG. 3, in the first time zone T1, the image R1 is formed on the liquid crystal panel 11A, and the liquid crystal panel 11A is illuminated by the light irradiation unit 31A, and the image formed on the liquid crystal panel 11A. R1 is displayed. At this time, no image is formed on the liquid crystal panel 11B, and the light irradiation unit 31B does not illuminate the liquid crystal panel 11B.

  In the next time zone T2, the image R2 is formed on the liquid crystal panel 11B, and the liquid crystal panel 11B is illuminated by the light irradiation unit 31B, and the image R2 formed on the liquid crystal panel 11B is displayed. At this time, no image is formed on the liquid crystal panel 11A, and the light irradiation unit 31A does not illuminate the liquid crystal panel 11A.

  In the next time period T3, the image R1 is formed on the liquid crystal panel 11A, and the liquid crystal panel 11A is illuminated by the light irradiation unit 31A, and the image R1 formed on the liquid crystal panel 11A is displayed. At this time, no image is formed on the liquid crystal panel 11B, and the light irradiation unit 31B does not illuminate the liquid crystal panel 11B.

  As described above, in the display device 101, the image R1 and the image R2 are superimposed on the same region in the field of view of the observer through the optical path synthesis unit 21, and are displayed at different distances from the observer at different timings. As a result, the image R1 and the image R2 can be displayed without reducing the display space of each image and without hiding and interfering with other images. In addition, the observer can easily identify each image based on a difference in distance.

  In addition, as shown in Example 2 of FIG. 4, while changing the direction of liquid crystal panel 11B and light irradiation part 31B so that it may become the same direction as liquid crystal panel 11A and light irradiation part 31A, liquid crystal panel 11B and optical path composition part A total reflection mirror 51 composed of a triangular prism is disposed in the optical path between the light and the light 21, and the light propagating from the image formed on the liquid crystal panel 11 </ b> B and propagating in the direction of arrow Y in the figure is totally reflected by the total reflection mirror 51. It is also possible to make the light incident on the surface u3 of the optical path combining unit 21 after being reflected by the surface 51H.

  In this case, from the observation, the image R1 displayed on the liquid crystal panel 11A can be seen in front of the image R2 displayed on the liquid crystal panel 11B by a distance K12. That is, the distance K12 is the sum of the optical path length in the optical path L12 from the position F1 to the total reflection surface 51H and the optical path length in the optical path L13 from the total reflection surface 51H to the liquid crystal panel 11B.

  Further, as shown in the third embodiment of FIG. 5, a polarizing beam splitter 61 configured by bonding two triangular prisms 61G and 61J through a polarizing film is disposed instead of the total reflection mirror 51. It may be. Here, the polarization plane 61H, which is the bonding surface, reflects S-component light whose electric field vector direction is perpendicular to the paper surface (direction B in the figure), and the electric field vector direction is parallel to the paper surface. The light of P component which is a direction (direction of arrow A in the figure) is transmitted. As a result, the S-polarized light emitted from the image formed on the liquid crystal panel 11B propagates in the direction of the arrow Y in the figure, passes through the surface v1 of the triangular prism 61G, and is reflected by the polarizing surface 61H. After passing through the surface v2, the light enters the surface u3 of the optical path combining unit 21.

  In this case, from the observation, the image R1 displayed on the liquid crystal panel 11A can be seen in front of the image R2 displayed on the liquid crystal panel 11B by a distance K13. That is, the distance K13 is the sum of the optical path length in the optical path L14 from the position F1 to the polarization plane 61H and the optical path length in the optical path L15 from the polarization plane 61H to the liquid crystal panel 11B.

  In the first embodiment, the polarization beam splitter is used as the optical path combining unit. However, the present invention is not limited to this, and the polarization beam splitter may be changed to a simple beam splitter. In this case, the amount of light emitted from each liquid crystal panel and passing through the beam splitter is attenuated to ½.

  A display device according to the second embodiment of the present invention will be described below. FIG. 6 is a plan view showing a schematic configuration of the display device according to the second embodiment.

  The display device 102 is formed into a plurality of liquid crystal panels 12A, 12B,... For displaying images (hereinafter, the liquid crystal panels 12A, 12B,... Are collectively referred to as the liquid crystal panel 12) and the liquid crystal panels 12A, 12B,. , Which are emitted from the images Ra, Rb,... (Hereinafter, the images Ra, Rb,... Are collectively referred to as an image R) and propagate through the optical paths having different optical path lengths without passing through any of the liquid crystal panels. .. (Hereinafter, the optical path combining units 22A, 22B, 22C,... Are collectively referred to as the optical path combining unit 22).

  Each of the optical path combining units 22 emits each light carrying image information indicating each of the images R emitted from the liquid crystal panels 12B, 12C... Onto a common optical path KK passing through each of the optical path combining units 22.

  The display device 102 further includes light irradiators 32A, 32B,... For illuminating the liquid crystal panels 12 (hereinafter, the light irradiators 32A, 32B,... Are collectively referred to as the light irradiators 32) and the optical path KK. Reflecting mirrors M1, M2, M3, and M4 that change the direction, and image signals for forming images on the respective liquid crystal panels 12 are input to the respective liquid crystal panels 12, and the light irradiation units 32 of the respective liquid crystal panels 12 And a controller 42 for controlling the timing of illumination.

  Each optical path combining unit 22 is a beam splitter formed by bonding two triangular prisms (the optical path combining unit 22A is a triangular prism 22Ag, 22Aj, the optical path combining unit 22B is a triangular prism 22Bg, 22Bj, and so on). The bonding surface is a light branching surface 22Ah, 22Bh,... For branching light in two directions (hereinafter, the light branching surfaces 22Ah, 22Bh,... Are collectively referred to as a light branching surface 22h). Hereinafter, the triangular prism 22Ag, the triangular prism 22Bg,... Are collectively referred to as a triangular prism 22G. Further, the triangular prism 22Aj, the triangular prism 22Bj,... Are collectively referred to as a triangular prism 22J.

  Since the light splitting surface 22h of each optical path combining unit 22 is not a polarization plane, the light incident on the surface g1 of the triangular prism 22G from the Y direction in the figure is 1 / of the light quantity regardless of the direction of the electric field vector. 2 is reflected and emitted from the surface g2 on the triangular prism 22G side, and ½ of the light quantity of the light is transmitted and emitted from the surface j2 of the triangular prism 22J. It should be noted that the same symbols are used for the surfaces g1, g2, j1, and j2 when the optical path combining units 22 face the same direction.

  Therefore, the light carrying the image information indicating the image R emitted from the image R formed on each liquid crystal panel 12 upon receiving the illumination of each light irradiation unit 32 propagates in the direction of the arrow Y in the figure and passes through each optical path. Incident light from the surface g1 of the triangular prism 22g of the synthesizer 22 and half the amount of light incident from this surface g1 is transmitted through the light branching surface 22h and from the surface j2 of the triangular prism 22j in the direction of arrow Y in the figure. The amount of light that is ½ of the amount of light incident from the surface g1 is reflected by the light branching surface 22h and emitted from the surface g2 of the triangular prism 22g in the direction of the arrow X in the figure.

  Here, in the optical path synthesis units 22B, 22C... Other than the optical path synthesis unit 22A, the light emitted from the surface g2 of the triangular prism 22G in the direction of the arrow X in the figure propagates through the optical path KK and is adjacent to each other. The light enters the surface j1 of the triangular prism 22J of the optical path combining unit 22.

  Therefore, the light emitted from each image formed on each liquid crystal panel 12 is incident from the surface g1 of each optical path combining unit 22 and transmitted through the light branching surface 22h or reflected by the light branching surface 22h. Each light heads to the viewpoint position E2 facing the surface j2 side of the optical path combining unit 22A while the light amount is attenuated to ½ at each light branch surface 22h.

  That is, the light carrying the image information indicating the image Ra formed on the liquid crystal panel 12A is incident from the surface g1 of the optical path combining unit 22A, passes through the light branching surface 22Ah, and is directed from the surface j2 to the arrow Y direction in the drawing. Are ejected toward the viewpoint position E2. On the other hand, the light that is reflected by the light branching surfaces 22Bh, 22Ch,... Of the optical path combining units 22B, 22C,... Arranged on the optical path KK toward the surface j1 of the optical path combining unit 22A and propagates on the optical path KK toward the optical path combining unit 22A. Passes through the optical path combining units 22B and 22C, finally enters the surface j1 of the optical path combining unit 22A, is reflected by the light branching surface 22Ah, is emitted from the surface j2 in the direction of the arrow Y in the figure, and travels toward the viewpoint position E2. .

  In the display device 102 configured as described above, when each liquid crystal panel 12 is observed from the viewpoint position E2 through the surface j2, for example, the image Ra displayed on the liquid crystal panel 12A is a distance Ka from the image Rb displayed on the liquid crystal panel 12B. It looks in front. Here, the distance Ka is the difference between the optical path length from the viewpoint position E2 to the liquid crystal panel 12A and the optical path length from the viewpoint position E2 to the liquid crystal panel 12B, and the optical path La from the optical branch surface 22Ah to the optical branch surface 22Bh. Is the optical path length at.

  Further, for the same reason as described above, the image displayed on the liquid crystal panel 12B appears in front of the image displayed on the liquid crystal panel 12C by the optical path length in the optical path Lb from the light branching surface 22Bh to the light branching surface 22Ch. Similarly, for example, the image Rh displayed on the liquid crystal panel 12H is seen in front of the image Ri displayed on the liquid crystal panel 12I by the optical path length in the optical path Lh in the figure, and the image Ri displayed on the liquid crystal panel 12I is It is visible in front of each image Rj displayed on the liquid crystal panel 12J by the length of the optical path in the middle optical path Li.

  When displaying an image on the display device 102, the controller 42 causes each image signal for forming an image on each liquid crystal panel 12 and a signal for illuminating each liquid crystal panel 12 by each light irradiation unit 32. Are controlled so that the images Ra, Rb,... Are displayed at different timings as in the first embodiment. As a result, the image Ra, the image Rb, the image Rc,... Can be displayed without obstructing and hiding the display of other images, and the observer can view the images on the liquid crystal panels with a difference in distance. Can be easily identified.

  In the first and second embodiments, each liquid crystal panel has a function of forming an image, and the light irradiation unit illuminates the image formed on the liquid crystal panel. Not limited to this case, each liquid crystal panel may be in a translucent screen state, and the light irradiation unit may project an image onto the translucent screen made of the liquid crystal panel. The same effect as in the second embodiment can be obtained. For example, in FIG. 1, the liquid crystal panels 11A and 11B are in a translucent screen state, and the light irradiation unit 31A'31B 'is a projection that projects an image onto the liquid crystal panels 11A and 11B in the translucent screen state. The display device 101 'can also be configured as a machine.

The top view which shows schematic structure in Example 1 of the display apparatus by the 1st Embodiment of this invention Perspective view showing structure of liquid crystal panel Timing chart showing the timing to display each image The top view which shows schematic structure of the display apparatus of Example 2. The top view which shows schematic structure of the display apparatus of Example 3. The top view which shows schematic structure of the display apparatus of 2nd Embodiment

Explanation of symbols

11A, 11B Liquid crystal panel 21 Optical path synthesis unit 31A, 31B Light irradiation unit 41 Controller 101 Display device

Claims (3)

A plurality of liquid crystal panels that display images, and images that are emitted from images formed on the plurality of liquid crystal panels and propagate through light paths having different optical path lengths without passing through any of the liquid crystal panels. An optical path synthesis unit that matches the optical path of light,
A display device, wherein each image formed on each liquid crystal panel is displayed through the optical path combining unit so as to be seen at different depths. The display device according to claim 1, wherein the optical path combining unit is a polarization beam splitter. When the display device emits light from an image formed on the liquid crystal panel by projecting the image on the liquid crystal panel, the light carrying the image projected on the liquid crystal panel 3. The display device according to claim 1, wherein the display device is configured not to pass through the liquid crystal panel.

Images