WO2009081674A1 - Display apparatus - Google Patents

Abstract

Disclosed is a display apparatus wherein light emitted from a light source arranged on the side of one focal point (f1) enters from an incoming surface (25) of an elliptical mirror (17), reflects on an elliptical reflection surface (27), passes through a transmissive liquid crystal display panel (5) and is collected to a focal point (f) on the side of the other focal point (f2). Thus, a view angle can be limited only in the direction to the other focal point (f). Furthermore, the light source is arranged on the side of the elliptical mirror (17) so as to collect light from the one focal point (f1) of the ellipse to the side of the other focal point (f2). Thus, the depth of the apparatus is reduced, and the size of the apparatus is reduced.

Description

Display device

The present invention relates to a display device that displays an image, and more particularly to a technique for limiting a viewing angle so that an image can be observed only at a specific position.

Conventionally, as this type of apparatus, the following can be cited (for example, see Patent Document 1).
This apparatus includes a liquid crystal display panel, a diffusion plate, a Fresnel lens having a focal length that forms an image at a predetermined distance from the liquid crystal display panel, and a light source. These are arranged linearly in the housing of the display device. With such a configuration, only an observer at a predetermined position can see the image, and the viewing angle can be limited.
Japanese Patent No. 2620516 (FIG. 18)

However, the conventional example having such a configuration has the following problems.
That is, in the conventional apparatus, since it is necessary to arrange each member linearly, there is a problem that the depth of the apparatus becomes long and the size cannot be reduced.

The present invention has been made in view of such circumstances, and the viewing angle can be limited by using a light guide having a reflecting surface formed of a part of an elliptical arc. An object of the present invention is to provide a display device that can shorten the depth of the device and is advantageous for downsizing.

Another object of the present invention is to reduce the viewing angle by devising the way of capturing light, and to reduce the depth of the apparatus, which is advantageous for downsizing, but uneven brightness. Another object of the present invention is to provide an image display device that can suppress the width of the device even when the field of view of a two-dimensional image is widened.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 is configured by a transmissive liquid crystal display panel for displaying an image, a plate-like appearance, and one end surface being a part of an elliptical arc when viewed from the surface direction. Formed on the end surface of the main body corresponding to one focal side of the ellipse, and formed on the other end surface of the main body when viewed from the surface direction. And formed on the end surface of the main body, and a part of the circular arc of the ellipse when viewed from the surface direction. A light guide having a reflecting surface and a light source disposed on one focal side of the ellipse are provided.

According to the first aspect of the present invention, the light emitted from the light source arranged on one focal side is incident from the incident surface of the light guide, reflected by the elliptical reflecting surface, and emitted from the emitting surface. Then, the light passes through the transmissive liquid crystal display panel and is condensed at the other focal position. Therefore, the viewing angle can be limited only to the other focal direction. In addition, in order to condense light from one focal point of the ellipse to the other focal point, a light source may be arranged on the side of the light guide, so that the depth of the device can be shortened and the size can be reduced. Can be planned.

The invention described in claim 2 is a transmissive liquid crystal display panel for displaying an image, and has a plate-like appearance shape, and one end surface is constituted by a part of an elliptical arc when viewed from the surface direction. Formed on the end surface of the main body corresponding to one focal side of the ellipse, and formed on the other end surface of the main body when viewed from the surface direction. And formed on the end surface of the main body, and a part of the circular arc of the ellipse when viewed from the surface direction. A light guide having a reflective surface;
A reflection unit comprising a plurality of the light guides, the light guide having the incident surface directed to one side, and the light guide having the incident surface directed to the other side, and being laminated with the surfaces facing each other, A pair comprising a first light source disposed in the vicinity of the incident surface of the light guide directed toward the side and a second light source disposed in the vicinity of the incident surface of the light guide directed toward the other side. And a light source.

According to invention of Claim 2, the light radiated | emitted from the 1st light source and 2nd light source which are arrange | positioned at one focus side injects from the entrance plane of each light guide of a reflection unit, and is elliptical. The light is reflected from the reflecting surface and emitted from the emitting surface, is transmitted through the transmissive liquid crystal display panel, and is condensed on the other different focal points. Therefore, the viewing angle can be limited to only two directions. In addition, in order to condense light from one focal point of the ellipse to the other focal point, a light source may be arranged on the side of the light guide, so that the depth of the device can be shortened and the size can be reduced. Can be planned.

Further, in the present invention, image output means for alternately outputting different first images and second images to the transmissive liquid crystal display panel, and the image output means from the first image to the second image, Alternatively, when sequentially switching from the second image to the first image, the first light source is output when the first image is output, and the first light source is output when the second image is output. And a light source control means for turning on the second light source. As the image output means alternately outputs the first image and the second image, the light source control means turns on the first light source and the second light source alternately so that one liquid crystal display panel is provided. Can be observed at different positions, the first image and the second image can be observed. Therefore, a so-called “dual view” display device can be realized.

Further, in the present invention, image output means for alternately outputting a right eye image and a left eye image to the transmissive liquid crystal display panel, and the image output means changes from a right eye image to a left eye image, or When sequentially switching from the left-eye image to the right-eye image, the first light source is output when the right-eye image is output, and the second light source is output when the left-eye image is output. And a light source control means for turning on the light source. As the image output means alternately outputs the image for the right eye and the image for the left eye, the light source control means switches the first light source and the second light source and turns them on so that the image for the right eye is turned on. And a stereoscopic image based on the parallax of the left-eye image can be observed.

In the present invention, it is preferable that the light-reflecting surface of the light guide has a layer of a light-reflecting material that reflects light on the outer surface of the main body (Claim 5).

Further, in the present invention, a black coating is applied to a surface of the main body excluding the exit surface and the incident surface so as to overlap with a white coating, and a black paint is applied to an end surface side excluding the exit surface and the entrance surface. (Claim 6). Light-transmitting resin can efficiently transmit light from the light source, incident light can be reflected by the light-reflecting material on the reflecting surface, and incident light can be efficiently reflected by white paint and black paint. Can be guided to the exit surface. In addition, since the reflective material on the reflective surface is protected by the light-transmitting resin, deterioration with time of the reflective material (such as clouding of the reflective surface) can be suppressed. Further, it is more cost effective than providing a reflective layer on the entire surface.

In the present invention, it is preferable that an air layer is formed between the main bodies when the main bodies are laminated (claim 7). When the light guides are stacked, an air layer can be formed therebetween. Since light has a characteristic of traveling through a medium having a high refractive index, it is possible to prevent light from leaking from each light guide to an adjacent light guide, and coating of the laminated surface can be omitted.

Further, in the present invention, the main body is formed such that one end surface close to the incident surface along the major axis of the ellipse is formed as a sub-reflection surface, and light incident from the incident surface passes through the sub-reflection surface and the reflection surface. It is preferable that the light is emitted outward from the other focal side. In a stereoscopic image display device that collects light at the position of the observer's eye, the image usually becomes invisible when the observer's eye deviates from the focusing position, but the sub-reflecting surface and the reflecting surface move outside the focal position. Since the three-dimensional image cannot be seen, it can be seen as a two-dimensional image by only the right-eye image or the left-eye image. Therefore, it is possible to know the outline of the image stereoscopically viewed by the observer even around the observer viewing stereoscopically.

In the present invention, it is preferable that the incident surface has a thickness greater than that of the reflecting surface. By increasing the thickness of the incident surface, light from the light source can be efficiently incident.

According to a tenth aspect of the present invention, in a display device for displaying an image, a transmissive liquid crystal display panel for displaying an image and a plate-like appearance shape are formed, and one end surface is elliptical when viewed from the surface direction. The main body is formed of a part of the arc and is formed of a member that transmits light, and is separated from one focal point of the ellipse and the major axis of the ellipse, and is formed on the main body along the major axis of the ellipse. An incident surface on which light is incident, an intermediate reflecting surface that is disposed at a position surrounding one focal point of the ellipse when viewed from the surface direction, and reflects light incident from the incident surface, and an ellipse of the main body Are formed on the other end surface of the main body and reflected by the elliptical reflecting surface. A light guide having an emission surface for emitting the light, and the light guide And it is characterized in that it comprises a light source disposed in the intermediate reflecting surface side.

According to the tenth aspect of the present invention, the light emitted from the light source disposed on one focal side enters from the incident surface of the light guide and is reflected by the elliptical reflecting surface via the intermediate reflecting surface. The light is emitted from the emission surface, passes through the transmissive liquid crystal display panel, and is condensed on the other focal side of the ellipse. Therefore, the viewing angle can be limited to the other focal direction. In addition, the incident surface of the main body is formed apart from one focal point of the ellipse and the major axis of the ellipse, and light from the light source is incident through the intermediate reflecting surface, so one of the ellipses out of the light from the light source The amount of light passing through the focal point can be increased. Therefore, it is possible to suppress the luminance unevenness of the transmissive liquid crystal display panel viewed from the viewpoint corresponding to the other focus. Furthermore, since the incident surface of the main body is formed along the long axis of the ellipse, even if the light source is lengthened to widen the field of view of the two-dimensional image, the light source does not become long in the width direction. Therefore, it can suppress that the width | variety of an apparatus spreads.

Note that “along the long axis” as used herein includes parallelism, but does not need to be parallel and does not leave a distance.

According to an eleventh aspect of the present invention, there is provided a display device for displaying an image, a transmissive liquid crystal display panel for displaying an image, and a rear side of the transmissive liquid crystal display panel as viewed from the display surface. And an elliptical reflecting surface that is configured by a part of an elliptical arc in plan view and reflects light from one focal point of the ellipse to the other focal side of the ellipse, and the transmissive liquid crystal display A light source disposed on the side of the panel and spaced apart from one focal point of the ellipse and the major axis of the ellipse, and disposed along the major axis of the ellipse; the light source and the elliptical reflecting surface; And an intermediate reflecting surface disposed at a position surrounding one focal point of the ellipse and reflecting light from the light source to the ellipsoidal reflecting surface. .

According to the eleventh aspect of the invention, the light emitted from the light source disposed on one focal side is reflected from the elliptical reflecting surface through the intermediate reflecting surface, and is transmitted through the transmissive liquid crystal display panel. To focus on the other focal side of the ellipse. Therefore, the viewing angle can be limited to the other focal direction. In addition, since the light source is disposed apart from one focus of the ellipse and the major axis of the ellipse, and the light from the light source is incident through the intermediate reflection surface, one focus of the ellipse out of the light from the light source The amount of light passing through can be increased. Therefore, it is possible to suppress the luminance unevenness of the transmissive liquid crystal display panel viewed from the viewpoint corresponding to the other focus. Furthermore, since the light source is disposed along the long axis of the ellipse, the light source does not become longer in the width direction even if the light source is lengthened to widen the field of view of the two-dimensional image. Therefore, it can suppress that the width | variety of an apparatus spreads.

Note that “along the long axis” as used herein includes parallelism, but does not need to be parallel and does not leave a distance. Therefore, it includes a state in which it is inclined with respect to the long axis.

According to a twelfth aspect of the present invention, in a display device for displaying an image, a transmissive liquid crystal display panel for displaying an image and a plate-like external shape are formed, and one end surface is elliptical when viewed from the surface direction. The main body is made up of a part of the arc and is made of a light transmitting member, and is separated from one focal point of the ellipse and extends downward along the vertical direction from the major axis side of the ellipse. The incident surface is formed and disposed at a position off the one focal point of the ellipse when viewed from the surface direction, and is incident from the incident surface on the surface opposite to the one focal point of the ellipse. A light guide comprising: an intermediate reflection surface that reflects the reflected light; and an elliptical reflection surface that forms part of an arc of the main body and reflects light from the intermediate reflection surface toward the other focal side of the ellipse And a light source disposed on the intermediate reflection surface side of the light guide. And it is characterized in Rukoto.

According to the invention described in claim 12, the light emitted from the light source disposed on one focal side is incident from the incident surface of the light guide, and is reflected by the elliptical reflecting surface through the intermediate reflecting surface. The light is emitted from the emission surface, passes through the transmissive liquid crystal display panel, and is condensed on the other focal side of the ellipse. Therefore, the viewing angle can be limited to the other focal direction. In addition, the incident surface of the main body is formed away from one focal point of the ellipse, and the light from the light source enters through the intermediate reflection surface, so the amount of light passing through one focal point of the ellipse among the light from the light source Can be increased. Therefore, it is possible to suppress the luminance unevenness of the transmissive liquid crystal display panel viewed from the viewpoint corresponding to the other focus. Furthermore, since the incident surface of the main body is formed to extend downward along the vertical direction from the major axis side of the ellipse, even if the light source is lengthened to widen the field of view of the two-dimensional image, the light source remains in the width direction. It will not be long. Therefore, it can suppress that the width | variety of an apparatus spreads. Further, the intermediate reflecting surface is disposed at a position deviated from one focal point of the ellipse when viewed from the surface direction, and is configured to reflect light incident from the incident surface on a surface opposite to the one focal point of the ellipse. Therefore, the light source can be arranged close to one apparent focal point. Therefore, the width of the device can be narrowed, and the size can be further reduced.

According to a thirteenth aspect of the present invention, in a display device for displaying an image, a transmissive liquid crystal display panel for displaying an image, and a rear side of the transmissive liquid crystal display panel as viewed from the display surface. And an elliptical reflecting surface that is configured by a part of an elliptical arc in plan view and reflects light from one focal point of the ellipse to the other focal side of the ellipse, and the transmissive liquid crystal display A light source disposed on the side of the panel and spaced from one focal point of the ellipse and extending downward along the vertical direction from the long axis side of the ellipse; Located between the ellipsoidal reflecting surface and disposed at a position deviating from one focal point of the ellipse, the light from the light source is reflected by the ellipsoidal reflecting surface on the surface opposite to the one focal point of the ellipse. An intermediate reflective surface that That.

According to the thirteenth aspect of the present invention, the light emitted from the light source disposed on one focal side is reflected from the elliptical reflecting surface through the intermediate reflecting surface and is transmitted through the transmissive liquid crystal display panel. To focus on the other focal side of the ellipse. Therefore, the viewing angle can be limited to the other focal direction. In addition, since the light source is disposed away from one focal point of the ellipse and the light from the light source enters through the intermediate reflection surface, the amount of light passing through one focal point of the ellipse among the light from the light source is increased. be able to. Therefore, it is possible to suppress the luminance unevenness of the transmissive liquid crystal display panel viewed from the viewpoint corresponding to the other focus. Furthermore, since the light source is arranged extending downward along the vertical direction from the long axis side of the ellipse, the light source does not become longer in the width direction even if the light source is lengthened to widen the field of view of the two-dimensional image. . Therefore, it can suppress that the width | variety of an apparatus spreads. Further, the intermediate reflecting surface is disposed at a position deviated from one focal point of the ellipse when viewed from the surface direction, and is configured to reflect light incident from the incident surface on a surface opposite to the one focal point of the ellipse. Therefore, the light source can be arranged close to one apparent focal point. Therefore, the width of the device can be narrowed, and the size can be further reduced.

In the present invention, it is preferable that the intermediate reflection surface includes a parabolic reflection surface using a part of a parabola (claim 14). Light from the light source incident in parallel to the parabolic reflecting surface can be collected so as to pass through one focal point. Alternatively, the light from the light source incident in parallel to the parabolic reflecting surface can be apparently collected at one apparent focal point.

In the present invention, it is preferable that the elliptical reflecting surface reflects light only in the other focal direction of the ellipse. An image display apparatus with a very limited viewing angle can be obtained.

In the present invention, the light guide is a reflection formed by laminating a plurality of light guides having an incident surface directed to one side and a light guide having the incident surface directed to the other side. The light source is configured as a unit, and the light source includes a first light source disposed on the light guide whose incident surface is directed to one side, and a first light source disposed on the light guide whose incident surface is directed to the other side. An image output unit configured as a pair of light sources including two light sources and alternately outputting different first and second images to the transmissive liquid crystal display panel; and When sequentially switching from the first image to the second image, or from the second image to the first image, if the first image is output, the first light source is switched to the second image. A light source control means for turning on the second light source when it is output. (Claim 16). The light emitted from the first light source and the second light source arranged on one focal side enters from the entrance surface of each light guide of the reflection unit, is reflected by the elliptical reflection surface, and exits from the exit surface. Then, the light is transmitted through the transmissive liquid crystal display panel and condensed on the other different focal points. Therefore, the viewing angle can be limited to two directions. Further, in synchronization with the image output means alternately outputting the first image and the second image, the light source control means alternately turns on the first light source and the second light source, thereby When the transmissive liquid crystal display panel is observed at different positions, the first image and the second image can be observed. Therefore, a so-called “dual view” image display apparatus can be realized.

Further, in the present invention, the reflection unit is formed by laminating a plurality of the elliptical reflection surfaces, and is configured such that one focal point of the adjacent elliptical reflection surfaces is directed to the opposite side on one side and the other side. The light source includes a first light source disposed on an intermediate reflecting surface of an elliptic reflecting surface in which one focus of the ellipse is directed to one side, and one focus of the ellipse is directed to the other side. And a second light source disposed on the intermediate reflection surface of the elliptical reflection surface, and the transmissive liquid crystal display panel alternately displays different first images and second images. The image output means for outputting and the first image is output when the image output means sequentially switches from the first image to the second image or from the second image to the first image. When the second image is output to the first light source Preferably comprises a light source control means for lighting the second light source (claim 17). Light emitted from the first light source and the second light source arranged on one focal side is incident on the intermediate reflection surface of the reflection unit, reflected by the intermediate reflection surface, reflected by the elliptical reflection surface, and transmitted. Is transmitted through a liquid crystal display panel of a type and condensed on the other different focal points. Therefore, the viewing angle can be limited to two directions. Further, in synchronization with the image output means alternately outputting the first image and the second image, the light source control means alternately turns on the first light source and the second light source, thereby When the transmissive liquid crystal display panel is observed at different positions, the first image and the second image can be observed.

In the present invention, it is preferable that the first image and the second image are a left-eye image and a right-eye image having parallax with each other (claim 18). A stereoscopic image can be displayed by alternately outputting a left-eye image and a right-eye image.

In the present invention, it is preferable that the first image and the second image are different two-dimensional images. Different images can be observed depending on the viewing direction, and a so-called “dual view” image display apparatus can be realized.

In the present invention, it is preferable that the intermediate reflecting surface is configured such that a focal point of the parabola coincides with one focal point of the ellipse. Light incident on the parabolic reflecting surface can be collected at one focal point of the ellipse. Alternatively, the light incident on the parabolic reflection surface can be apparently collected at one focal point of the ellipse.

In the present invention, it is preferable that the intermediate reflection surface is configured such that a portion corresponding to the crosstalk range is linearly configured, and that portion is configured as a reflection surface or an absorption surface. Light incident on the crosstalk range is reflected from the ellipsoidal reflecting surface in a direction deviating from the other focal point. Therefore, when displaying a two-dimensional image, the reflecting surface may be used. On the other hand, when a stereoscopic image is displayed, the stereoscopic image becomes unclear due to light incident on the crosstalk range. Therefore, the stereoscopic image can be made clear by using an absorbing surface.

According to the display device according to the present invention, the light emitted from the light source arranged on one focal side is incident from the incident surface of the light guide, reflected by the elliptical reflecting surface, and emitted from the emitting surface, The light passes through the transmissive liquid crystal display panel and is condensed at the other focal position. Therefore, the viewing angle can be limited only to the other focal direction. In addition, in order to condense light from one focal point of the ellipse to the other focal point, a light source may be arranged on the side of the light guide, so that the depth of the device can be shortened and the size can be reduced. Can be planned.

1 is a cross-sectional view illustrating a schematic configuration of a stereoscopic display device according to Embodiment 1. FIG. It is a schematic diagram explaining the ellipse which comprises an ellipse mirror. It is a figure which shows the partial cross section of an elliptical mirror, (a) is a front view of an elliptical mirror, (b) is a side view. It is an external appearance perspective view of an elliptical mirror. It is the external appearance perspective view of a reflection unit, (a) is the figure seen from the output surface side, (b) is the figure seen from the opposite side. It is a front view of a reflection unit. (A)-(e) is a schematic block diagram which shows the various structures of an incident part. It is a schematic block diagram which shows the modification of an elliptical mirror. It is a block diagram which shows schematic structure of a three-dimensional display apparatus. (A)-(d) is a schematic diagram which shows the example of control of a light source. (A)-(d) is a schematic diagram which shows the other example of control of a light source. It is a schematic diagram with which it uses for description that the viewing angle is restrict | limited. It is a perspective view which shows the modification of an elliptical mirror. It is a schematic diagram explaining the concept of the display apparatus of a dual view. 6 is a cross-sectional view illustrating a schematic configuration of a stereoscopic image display device according to Embodiment 2. FIG. It is a schematic diagram explaining the ellipse which comprises an ellipse mirror. It is a figure which shows the partial cross section of an elliptical mirror, (a) is a front view of an elliptical mirror, (b) is a side view of an elliptical mirror. It is an external appearance perspective view of an elliptical mirror. It is a front view of a reflection unit. It is a partial enlarged view of a blade showing an intermediate reflecting surface. It is a partial enlarged view of a blade showing an intermediate reflecting surface according to a first modification. It is a partial enlarged view of a blade showing an intermediate reflecting surface according to a second modification. It is a schematic diagram with which it uses for description that the viewing angle is restrict | limited. It is a schematic diagram explaining the concept of the image display apparatus of a dual view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Housing 5 ... Liquid crystal display panel 11 ... Diffusing member 15 ... Light source for right eye 16 ... Light source for left eye 17 ... Elliptical mirror 18, 20 ... Blade 19 ... Reflection unit 21 ... Ellipse 24, 24A, 24B ... Projection Unit 26 ... Incident unit 27 ... Outgoing surface 29 ... Acrylic resin 31 ... Aluminum film 36 ... Reflecting surface 53, 53A, 53B ... Intermediate reflecting surface 63 ... Control unit 65 ... Image signal output unit 67 ... Light source control unit

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a transverse cross-sectional view illustrating a schematic configuration of a stereoscopic display device according to the first embodiment, and FIG. 2 is a schematic diagram illustrating an ellipse constituting an elliptic mirror. 3A and 3B are diagrams showing a partial cross section of the elliptical mirror. FIG. 3A is a front view of the elliptical mirror, FIG. 3B is a side view, and FIG. 4 is an external perspective view of the elliptical mirror. FIG. 5 is an external perspective view of the reflection unit, (a) is a view seen from the exit surface side, (b) is a view seen from the opposite side, and FIG. 6 is a front view of the reflection unit. It is.

The stereoscopic image display device according to the present embodiment (the display device in the present invention) includes a housing 3 having a U-shaped cross section. A transmissive liquid crystal display panel 5 is attached to the front surface 4 of the housing 3 via a support portion 7 including a front bezel. A diffusion member 11 is attached to the back side of the support portion 7 corresponding to both ends of the liquid crystal display panel 5 via a support frame 9. The diffusing member 11 has a function of diffusing light in the vertical direction (paper surface direction). A light source 15 for the right eye is attached to one back side of the support frame 9 (left side when viewed from the front surface 4) via a heat dissipation mechanism 13, and the other back side of the support frame 9 (viewed from the front surface 4). A light source 16 for the left eye is attached to the right back) via a heat dissipation mechanism 14. The light sources 15 and 16 (corresponding to the first light source and the second light source in the present invention) have a rod-like appearance, and are arranged so that the longitudinal direction is positioned in the paper surface direction in FIG.

On the back side of the pair of light sources 15 and 16, a reflection unit 19 configured by alternately stacking elliptical mirrors 17 having the same shape is disposed (see FIGS. 1 and 5). The elliptical mirror 17 has a thin plate-like appearance, and one end surface thereof constitutes a part of an elliptical arc when viewed from the surface direction (paper surface direction). Since the elliptical mirror 17 has the same configuration except for the left eye and the right eye, only the right eye is taken as an example and will be described with reference to FIG.

The above-described elliptic mirror 17 corresponds to the light guide in the present invention.

The elliptical mirror 17 is provided with a blade 18 (corresponding to the main body in the present invention) whose outer shape is a blade shape. The blade 18 is constituted by a part of an arc of an ellipse 21. The angle formed by the surface 23 along the major axis a of the elliptical mirror 17 and the incident surface 25 along the minor axis b is located at the position of one focal point f1. That is, an incident portion 26 including a surface 23 and an incident surface 25 is provided on one focal point f1 side. In other words, the blade 18 of the elliptical mirror 17 is configured on the inner peripheral side of the arc on the one focal point f1 side. In addition, an emission surface 27 is provided on the other end surface that is linear when viewed from the surface direction (paper surface direction). The arc portion 28 having a band shape when viewed from the end face side of the elliptical mirror 17 is formed so that the light emitted from the emission surface 27 is condensed on the other focal point f2 side. However, due to the configuration of the elliptical mirror 17 described later, the light emitted from the emission surface 27 is collected at a focal point f closer to the center c side of the ellipse 21 than the other focal point f2. The position of the focal point f corresponds to the position of the observer's right eye ER. When the elliptical mirror 17 is reversed left and right, the position of the focal point f corresponds to the position of the left eye EL of the observer. The distance between the right eye ER and the left eye EL, that is, the distance between the focal point f and the focal point (f) is about 64 mm on average and about 80 mm at the maximum.

As described above, since the blade 18 of the elliptical mirror 17 is configured on the inner peripheral side of the arc on the one focal point f1, the reflection unit 19 having practical strength can be obtained simply by superimposing the surfaces of the blades 18. Can be configured. Note that the following configuration is preferable so that light leakage between the blades 18 can be suppressed.

The blade 18 of the elliptical mirror 17 is made of a light-transmitting resin that transmits light from the light sources 15 and 16, for example, acrylic resin, and has a thickness of about several millimeters (for example, 2 mm). In the arc portion 28 of the elliptical mirror 17, a light reflecting material, for example, an aluminum film 31 is deposited on the outer surface of the acrylic resin 29. On top of this, a black paint 35 is applied to the white paint 33. In other words, the end surface of the circular arc portion 28 is covered with the aluminum film 31, the white coating 33, and the black coating 35, and the innermost surface forms the reflecting surface 36. In addition, an end surface on the side close to the incident surface 25 side of the elliptical mirror 17 along the major axis b of the ellipse 21 is formed as a sub-reflecting portion 37. Similar to the arc portion 28, the sub-reflecting portion 37 is subjected to triple coating composed of an aluminum film 31, a white coating 33, and a black coating 35. The aluminum film 31 of the sub reflective portion 37 constitutes a sub reflective surface 39. The tip part 41 and the surface 23 corresponding to the opposite side of the incident part 26 are not covered with the aluminum film 31 and the white coating 33 and do not constitute the reflecting surface 36. The entrance surface 25 and the exit surface 27 of the entrance portion 26 are not painted at all, but the both surfaces of the acrylic resin 29 are simply coated with the black paint 35 on the white paint 33.

In addition to vapor-depositing the above-described aluminum film, the arc portion 28 may be formed with a light-reflective material, and a film may be formed by attaching a metal foil. May be. Further, as the light reflecting material, in addition to the above-described aluminum, a film made of, for example, a silver alloy may be formed. Furthermore, on both surfaces of the acrylic resin 29, a coating made of the above-described light reflecting material may be formed not only on the white coating 33 but on the innermost surface in addition to the white coating 33.

The elliptical mirror 17 is configured as described above, and can efficiently transmit the light of the light sources 15 and 16 by the light-transmitting acrylic resin, and the incident light is reflected by the light reflecting material of the reflecting surface 36. In addition, the light incident by the white paint 33 and the black paint 35 can be efficiently guided to the emission surface 27. In addition, since the aluminum film 31 on the reflective surface 36 is protected by the acrylic resin 29, it is possible to suppress deterioration over time such that the reflectance is lowered due to the aluminum film 31 being clouded or corroded.

As described above, the light emitted from one focus f1 side of the ellipse 21 is collected at the focus f instead of the other focus f2 of the ellipse 21 because the elliptic mirror 17 is made of the acrylic resin 29. Therefore, the light is refracted at the emission surface 27.

Further, in the stereoscopic image display device, the image usually becomes invisible when the observer's eyes deviate from the condensing position. However, the image is emitted outward from the focal position f by the sub-reflecting surface 39 and the reflecting surface 36. Therefore, although the stereoscopic image cannot be seen, it can be seen as a two-dimensional image only by the right eye image or the left eye image. Therefore, it is possible to know the outline of the image stereoscopically viewed by the observer even around the observer viewing stereoscopically.

As shown in FIGS. 1 and 5, the reflection unit 19 has the elliptical mirror 17 with the emission surface 27 facing the transmission-type liquid crystal display panel 5 and the incident portions 26 facing the opposite sides. It is configured by laminating surfaces in a direction orthogonal to a line connecting the pair of light sources 15 and 16 (paper surface direction in FIG. 1, vertical direction in FIG. 5) and in the longitudinal direction of the pair of light sources 15 and 16. . At this time, since the emission surface 27 is laminated so as to constitute one plane, the diffusion plate 11 can be easily disposed.

In the stereoscopic image display apparatus configured as described above, the light emitted from the light source 15 for the right eye corresponding to one focal side f1 is incident from the incident portion 26 of the elliptical mirror 17 of the reflection unit 19 and is reflected on the reflection surface 36. And the right-eye image is formed at the focal point f corresponding to the other focal position f2 through the transmissive liquid crystal display panel 5. Further, the light emitted from the light source 16 for the left eye is symmetrical to the right eye, and the other focal side f2 by the elliptical mirror 17 having the same shape with the incident portion 26 directed to the opposite side. An image for the left eye is formed at a position corresponding to this. Since the reflection unit 19 is configured by laminating surfaces in the vertical direction when viewed from the front of the stereoscopic image display device, it is possible to improve brightness uniformity in the horizontal direction of the image. Therefore, since it is not necessary to diffuse light in the left-right direction, crosstalk is not deteriorated.

In addition, although the light is diffused in the vertical direction by the diffusing member 11, the diffusion direction is the stacking direction of the elliptical mirrors 17, so that the vertical and vertical brightness uniformity of the image by the elliptical mirrors 17 is reduced without deteriorating the crosstalk. Can be improved.

In addition, it is preferable to comprise the incident part 26 mentioned above as follows. Reference is now made to FIG. 7A to 7E are schematic configuration diagrams showing various configurations of the incident portion. As a premise here, it is assumed that the light source 15 (16) is composed of a plurality of light emitting diodes 43. In addition, according to the following structure, the utilization efficiency of the light of the light emitting diode 43 can be improved.

(1) FIG. 7A A diffusion member 45 that diffuses light in the stacking direction of the elliptical mirror 17 is provided between the incident surface 25 of the elliptical mirror 17 and the light source 15 (16). As a result, even if the light emitting diode 43 is misaligned, the light can be reliably incident on the incident surface 25.

(2) FIG. 7B: The thickness of the incident surface 25 is set to about twice the thickness of the reflecting surface 36 of the elliptical mirror 17. For example, as shown in FIG. 7B, the inclined surface 46 is formed so that the thickness increases toward the incident surface 25 side. If the angle of the inclined surface 46 is formed so that the incident light is totally reflected, a reflector for the inclined surface 46 can be eliminated.

(3) FIG. 7 (c) A reflector 47 is arranged at a position between the elliptical mirrors 17 and coincident with the incident surface 25. Thereby, the light irradiated between the elliptical mirrors 17 is reflected to the light emitting diode 43 side, and is reflected by the diffusing member 45 so that the light can be directed to the incident surface 25.

(4) FIG. 7 (d) The elliptical mirror 17 and the light emitting diode 43 are arranged in a one-to-one correspondence. In this case, the diffusing member 45 can be omitted, and the configuration can be simplified.

(5) FIG. 7 (e) This is a modification of (3) described above, in which the reflector 47 is arranged closer to the arc portion 28 than the incident surface 25. In this case, the outer peripheral surface of the elliptical mirror 17 on the incident surface 25 side is not painted, and the acrylic resin 29 is left exposed. Thereby, the light emitted between the elliptical mirrors 17 by the reflecting plate 47 can be reflected by the reflecting plate 47 and incident on the acrylic resin 29. Further, as shown by a dotted line, the reflecting plate 47 may be inclined.

The present invention is not limited to the above embodiment, and can be modified as follows.

(1) In the above-described embodiment, the white coating 33 and the black coating 35 are applied to the surface of the elliptical mirror 17 excluding the exit surface 27 and the incident portion 26. You may comprise so that the surfaces of the elliptical mirror 17 may not contact | adhere in a state. If comprised in this way, the white coating 33 and the black coating 35 can be abbreviate | omitted, and the cost of the elliptical mirror 17 can be reduced. In addition, since the acrylic resin 29 has a higher refractive index than the acrylic resin 29 and the minute space (air), the leakage of light to the adjacent elliptical mirror 17 can be suppressed.

Further, instead of the minute projections, a sheet for preventing light leakage may be sandwiched between the elliptical mirrors 17 and laminated.

(2) In the above-described embodiment, the diffusing member 11 is provided to diffuse the light in the stacking direction of the elliptical mirror 17, but the diffusing member can be obtained by devising the exit surface 27 of the elliptical mirror 17. 11 can be omitted to simplify the structure and reduce the cost.

For example, an etching process for roughening the surface may be performed so that light is diffused on the emission surface 27, or a concave lens with a concave surface may be formed.

(3) Instead of the elliptical mirror 17 described above, an elliptical mirror 17A shown in FIG. FIG. 8 is a schematic configuration diagram showing a modification of the elliptical mirror.

In this elliptical mirror 17A, the reflecting surface 36 is formed of a part of an elliptical arc similar to the elliptical mirror 17 described above, but the blade 50 of the elliptical mirror 17A exists on the outer peripheral side of the arc from one focal point f1. . That is, the light travels in the air and is reflected by the reflecting surface 36. Even if the reflection unit 19A is configured by stacking the elliptical mirrors 17A having such a structure, the same effect as the configuration by the reflection unit 19 described above can be obtained. However, a blocking member 51 for preventing light leakage between adjacent elliptical mirrors 17A needs to be arranged between the elliptical mirrors 17A.

<Example of lighting control>
Next, a case where the light sources 15A and 16A are employed in the stereoscopic image display apparatus having the above-described configuration will be described with reference to FIG. FIG. 9 is a block diagram illustrating a schematic configuration of the stereoscopic display device.

In this configuration, each of the light sources 15A and 16A includes a plurality of light emitting diodes 61. The elliptical mirror 17 constituting the reflection unit 19 </ b> A preferably has a thickness that matches the pitch of the display lines of the liquid crystal display panel 5. Each light emitting diode 61 is disposed for each elliptical mirror 17 and is controlled to be lit independently.

The control unit 63 receives the video signal VD and outputs the right-eye image and the left-eye image to the liquid crystal display panel 5 alternately, and the image signal output unit 65 outputs the right-eye image and the left-eye image. When sequentially switching to the eye image, the light source control unit 67 turns on only the light emitting diodes 61 of the light sources 15A and 16A on the side corresponding to the image according to the display position of the image according to the vertical synchronization signal VS. And.

The image signal output unit 65 corresponds to the image output unit in the present invention, and the light source control unit 67 corresponds to the light source control unit in the present invention.

When the image signal output unit 65 outputs the image for the right eye and the image for the left eye to the liquid crystal display panel 5, the light source control unit 67 emits the light emitting diodes of the light source 15A for the right eye and the light source 16A for the left eye. Turn on 61. Specifically, the control is performed as shown in FIG. FIGS. 10A to 10D are schematic diagrams showing examples of light source control.

As shown in FIG. 10A, in the state where only the image for the left eye is displayed on the liquid crystal display panel 5, all the light emitting diodes 61 of the light source 16A for the left eye are turned on. Next, the image is switched to the right-eye image. As shown in FIGS. 10B and 10C, at the first stage, the upper part of the liquid crystal display panel 5 is simply rewritten to the right-eye image. . In this state, only the light emitting diode 61 corresponding to the display position of the left-eye image is emitted from the left-eye light source 16A on the side corresponding to the left-eye image, and the right side on the side corresponding to the right-eye image is displayed. Only the light emitting diode 61 corresponding to the display position of the right-eye image in the eye light source 15A is caused to emit light. In this way, as shown in FIG. 10D, a plurality of right-eye light sources 15A and left-eye light sources 16A are formed until the image on the liquid crystal display panel 5 is only the right-eye image. The lighting of the light emitting diode 61 is controlled independently.

When the left-eye image and the right-eye image are alternately displayed on the liquid crystal display panel 5, there is a state in which images of both the preceding and following fields are displayed due to the memory effect of the liquid crystal element (FIG. 10 ( b), (c)). In this case, since both images are incident on the observer at the same time, stereoscopic viewing cannot be performed normally. Therefore, the light source control unit 67 turns on only the light emitting diode 61 corresponding to the image among the plurality of light emitting diodes 61 constituting the pair of light sources 15A and 16A according to the display position of the image. Go (scan). As a result, the left-eye image is incident on the left eye and the right-eye image is incident on the right eye, so that even if both images are simultaneously displayed on the liquid crystal display panel 5, a stereoscopic view can be normally performed. Further, since it is not necessary to turn off one light source during a period in which both images are displayed and cannot be normally stereoscopically viewed, the luminance of the image does not decrease.

In the above description, each light emitting diode 61 is arranged for each elliptical mirror 17, but one light emitting diode 61 may be provided for every several elliptical mirrors 17. In this case, since the number of the light emitting diodes 61 can be reduced, the cost can be suppressed.

In the case of the above configuration, as shown in FIG. 10, for example, the lighting control may be performed by dividing into four blocks including blocks BL1 to BL4. As a result, it is possible to perform lighting control relatively easily while performing stereoscopic viewing normally.

Another example of control in the case of the above configuration will be described with reference to FIG. FIGS. 11A to 11D are schematic diagrams showing other control examples of the light source.

In this example, a black belt BS is displayed at the boundary (adjacent region) between the left-eye image and the right-eye image. Specifically, when the above-described image signal output unit 65 outputs the right-eye image and the left-eye image to the liquid crystal display panel 5, the video signal related to the black band BS is inserted and output between the images. To do. In this case, since both the right-eye and left- eye light sources 15A and 16A may be lit in the black belt BS, lighting control can be facilitated. Therefore, it is suitable for controlling the blocks BL1 to BL4 of the light emitting diode 61 described above.

In addition, the boundary between the left-eye image and the right-eye image is unclear due to the memory effect of the liquid crystal element, such as when the state of the image is not fixed, for example, the transition state from the previous image to the next image is displayed. It becomes a correct image. Therefore, by displaying the black belt BS at this boundary, it is possible to suppress the influence of the indeterminate image and display the stereoscopic image clearly.

<Viewing angle restriction>
The embodiment described above is an example of a display device related to a stereoscopic image, but an example of viewing angle restriction is shown below.

Here, refer to FIG. FIG. 12 is a schematic diagram for explaining that the viewing angle is limited.

This device is configured using only one elliptical mirror 17. However, the sub-reflection surface 39 of the sub-reflection part 37 is not necessary. In this case, the light emitted from the emission surface 27 of the elliptical mirror 17 is collected at the focal point f. Therefore, a visible region VR1 (hatched region in FIG. 12) and an invisible region IVR1 are generated. Therefore, an image can be observed at the position L1 corresponding to the visible region VR1, whereas an image cannot be observed at the position L2 corresponding to the invisible region IVR1. That is, by using only one of the elliptical mirrors 17, it is possible to limit to the focal point f direction.

In addition, when the sub-reflection surface 37 is provided, the visible region VR1 also expands to the invisible region IVR1 side (position L2 side in FIG. 12) (a fan-shaped region including the visible region VR1). Even in this case, the viewing angle can be limited only to the observer's right eye ER side in FIG.

Further, even if both elliptical mirrors 17 are provided, the positions of the observer's right eye ER and left eye EL in FIG. A visible trapezoidal area formed by connecting the panel 5 and the inverted trapezoidal area in which the trapezoidal area is arranged symmetrically by a line connecting the right eye ER and the left eye EL is the visible area VR1. This is a region in which the visible region VR1 in FIG. 12 is also arranged at the focal point f near the left eye EL in FIG.

When it is sufficient to simply limit the viewing angle with the above-described configuration, it is not necessary to output images alternately as in the above-described stereoscopic display device, and it is not necessary to perform lighting control of the light source, and the light source is always turned on. You can let it go.

According to the above-described apparatus, the light emitted from the light source arranged on the one side of the focal point f1 is incident from the incident surface 25 of the elliptical mirror 17, reflected by the elliptical reflective surface 36, and emitted from the output surface 27. The light passes through the transmissive liquid crystal display panel 5 and is focused on the focal point f on the other focal point f2. Therefore, the viewing angle can be limited only to the other focus f direction. Further, in order to condense the light from one focal point f1 of the ellipse toward the other focal point f2, the light sources 15 and 16 may be arranged on the side of the elliptical mirror 17, so that the depth of the apparatus can be shortened. And can be reduced in size.

(Blade deformation)
Reference is now made to FIG. FIG. 13 is a perspective view showing a modification of the elliptical mirror.
In the embodiment described above, the elliptical mirror 17 has a thin plate shape. However, when the stereoscopic display is not performed, the elliptical mirror 17 may have a thick plate shape.

That is, in the case of a display device that does not need to perform stereoscopic display and only needs to limit the viewing angle, it is not necessary to stack the elliptical mirrors 17, and thus the elliptical mirror 17 </ b> A configured by a single thick blade 18 </ b> A. It is good. However, as shown in FIG. 12, when the visual field only needs to be the visible region VR1 in the direction of the focus f, it is not necessary to provide the sub-reflecting surface 39 in the sub-reflecting portion 37.

(Dual view display)
Reference is now made to FIG. FIG. 14 is a schematic diagram illustrating the concept of a dual view display device.

By adopting the elliptical mirror 17 and the reflection unit 19 in which the distance between the focal point f and the focal point (f) is wider than the average distance between both eyes of the person, an apparatus capable of viewing different images depending on the viewing direction. It can be. Such a thing is called a dual view. For example, a navigation image can be displayed on the driver's seat side and a television image can be displayed on the passenger's seat side by deploying in the center console of an automobile. Specifically, an area where the two-dimensional image obtained by the sub-reflecting unit 39 of the elliptical mirror 17 can be observed may be used. That is, the visible regions VR1 and VR2 in FIG. 14 are used. Note that, by setting the focal points f and (f) to the above-described interval, it is possible to minimize the region where both images are observed in an overlapping manner. Further, by configuring the elliptical mirror 17 so that the focal point f is positioned outside the dotted line DL in FIG. 14, it is possible to eliminate an area where both images can be observed as viewed from the front of the apparatus. Although not shown in FIG. 14, the other focal points f <b> 2 and (f <b> 2) are located outside the ellipse 21.

In terms of control, instead of the right-eye image and the left-eye image in the above-described stereoscopic image display device, the first image (for example, navigation image) and the second image (for example, television image) are image signals. What is necessary is just to make it alternately output from the output part 65 (FIG. 9), and to light the light sources 15 and 16 according to each alternately.

In order to increase the amount of light in the visible regions VR1 and VR2, it is preferable to use not only the light sources 15 and 16 but also the sub-reflecting surface 39 as an incident surface, and a light source similar to the light sources 15 and 16 is added here. .

In the first embodiment described above, as shown in FIG. 2, the incident surface 25 of the elliptical mirror 17 is opposed to the reflecting surface formed of a part of the elliptical arc, with one focal point f1 of the elliptical as an end point. It is comprised by the inclined surface which leaves | separates from a long axis as it goes to the circular arc side from one focus f1. The light source 15 is attached to a plane whose end point is one of the focal points f1.

However, the apparatus according to the first embodiment increases the screen brightness of the liquid crystal display panel 5 as viewed from the viewpoint corresponding to the other focal point f2 because the amount of light emitted from the light source 15 passes through one focal point f1 is small. Is difficult. Further, in the apparatus of the first embodiment, since the luminance distribution of the liquid surface display panel 5 depends on the light distribution (angular intensity distribution) of the light source, there is a problem that large luminance unevenness occurs in the liquid crystal display panel 5. Furthermore, in order to widen the field of view of the two-dimensional image while keeping the light source 15 flat, it is necessary to lengthen the light source 15 toward the ellipse arc, which increases the width of the apparatus.

Therefore, an embodiment that solves the problem of the apparatus of the first embodiment will be described below. In the second embodiment, by devising how to capture light, the viewing angle can be limited, and the depth of the apparatus can be shortened, which is advantageous for downsizing, but also suppresses uneven brightness. It is possible to suppress the width of the apparatus even when the field of view of the two-dimensional image is widened.

Embodiment 2 of the present invention will be described below with reference to the drawings.
FIG. 15 is a cross-sectional view illustrating a schematic configuration of the stereoscopic image display apparatus according to the second embodiment, and FIG. 16 is a schematic diagram illustrating an ellipse constituting an elliptic mirror. 17 is a diagram showing a partial cross section of the elliptical mirror, where (a) is a front view of the elliptical mirror, (b) is a side view of the elliptical mirror, and FIG. 18 is an external perspective view of the elliptical mirror. FIG. 19 is a front view of the reflection unit.

The stereoscopic image display apparatus according to the present embodiment (“image display apparatus” in the present invention) includes a housing 3 having a U-shaped cross section. A transmissive liquid crystal display panel 5 is attached to the front surface 4 of the housing 3 via a support portion 7 including a front bezel. Hereinafter, the transmissive liquid crystal display panel 5 is appropriately referred to as a liquid crystal display panel 5. A diffusion member 11 is attached to the back side of the support portion 7 corresponding to both ends of the liquid crystal display panel 5 via a support frame 9. The diffusing member 11 has a function of diffusing light in the vertical direction (paper surface direction). A light source 15 for the right eye is attached to one back side of the support frame 9 (left side back when viewed from the front surface 4), and the other back side (right side back when viewed from the front surface 4) of the support frame 9 is A light source 16 for the left eye is attached. The light sources 15 and 16 (corresponding to the first light source and the second light source in the present invention) have, for example, a rod-like appearance and are attached so that the longitudinal direction is positioned in the paper surface direction in FIG.

On the back side of the pair of light sources 15 and 16, a reflection unit 19 configured by laminating the elliptical mirrors 17 having the same shape in different directions is arranged (see FIGS. 15 and 19). . The elliptical mirror 17 has a thin plate-like appearance, and one end surface thereof constitutes a part of an elliptical arc when viewed from the surface direction (paper surface direction). Since the elliptical mirror 17 is the same for the left eye and the right eye only in different directions, the configuration of the elliptical mirror 17 for the right eye will be described as an example with reference to FIG.

The light sources 15 and 16 described above correspond to the “first light source” and the “second light source” in the present invention, and the elliptic mirror 17 described above corresponds to the “light guide” in the present invention.

The elliptical mirror 17 includes a blade 20 (corresponding to a “main body” in the present invention) whose outer shape is a blade shape. The blade 20 is constituted by a part of an arc having an ellipse 21 as viewed from the surface direction. On one focal point f1 side of the blade 20, there is provided an incident surface 22 that is separated from the one focal point f1 and the major axis a and is formed along the lower major axis a of the ellipse 21. The incident surface 22 is formed over a parabolic projection 24 that is on the upper right side of the blade 20. The term “along” here includes parallel but does not need to be parallel, and does not attach to the long axis a on the lower side of the ellipse 21 and keeps a distance. In other words, the blade 20 is configured on the inner peripheral side of the arc of the ellipse 21 on the one focal point f1 side. An emission surface 27 is formed on the other end surface that is linear when viewed from the surface direction (paper surface direction) of the blade 20. The circular arc portion 28 having a narrow band shape when viewed from the end surface side of the elliptical mirror 17 is formed so that the light emitted from the emission surface 27 is condensed on the other focal point f2 side. Although not shown, actually, the light emitted from the emission surface 27 is more elliptical than the other focal point f2 due to the configuration of the elliptic mirror 17 described later (refraction when emitted from the acrylic resin 29). The light is condensed at a position close to the center c side. However, here, in order to facilitate understanding of the explanation, it is assumed that the other focal point f2 corresponds to the position of the right eye ER of the observer. If the left and right sides of the elliptical mirror 17 are reversed, the other focal point f2 corresponds to the position of the left eye EL of the observer. The distance between the right eye ER and the left eye EL, that is, the distance between the focal point f2 and the focal point (f2) is about 64 mm on average and about 80 mm at the maximum.

An intermediate reflecting surface 53 is formed in the blade 20 at a position surrounding one focal point f1 when viewed from the surface direction. The intermediate reflecting surface 53 reflects the light from the light source 15 for the right eye that has entered from the incident surface 22 toward the arc portion 28 (more precisely, a reflecting surface 36 described later). Details of the intermediate reflecting surface 53 will be described later.

As described above, since the blade 20 of the elliptical mirror 17 is configured on the inner peripheral side of the arc on the one focal point f1, the reflection unit 19 having a practical strength can be obtained by simply overlapping the surfaces of the blades 20. Can be configured. In order to prevent light leakage between the blades 20, the elliptical mirror 17 is preferably configured as follows.

The blade 20 of the elliptical mirror 17 is made of a light-transmitting resin that transmits light from the light sources 15 and 16, specifically, an acrylic resin, for example, and has a thickness of about several millimeters (for example, 2 mm). The arc portion 25 and the intermediate reflecting surface 53 of the elliptical mirror 17 are formed by depositing a light reflecting material, for example, an aluminum film 31 on the outer surface of the acrylic resin 29. On top of this, a black paint 35 is applied to the white paint 33. In other words, the end surface of the acrylic resin 29 in the circular arc portion 28 is covered in that order by the aluminum film 31, the white coating 33, and the black coating 35, and the innermost side surface is the reflecting surface 36 (“elliptical reflecting surface in the present invention”). Is equivalent). The entrance surface 22 and the exit surface 27 are not painted at all on the end surfaces, but the both surfaces of the acrylic resin 29 are coated with the white coating 33 and the black coating 35.

In addition to vapor-depositing the aluminum film 31 described above, a film may be formed on the arc portion 28 by applying a light reflecting material, and further, a film is formed by attaching a metal foil. You may do it. Further, as the light reflecting material, in addition to the above-described aluminum, a film made of, for example, a silver alloy may be formed. Furthermore, on both surfaces of the acrylic resin 29, a coating made of the above-described light reflecting material may be formed not only on the white coating 33 but on the innermost surface in addition to the white coating 33.

The elliptical mirror 17 is configured as described above, and can efficiently transmit the light from the light sources 15 and 16 by the light-transmitting acrylic resin 29. The incident light is reflected by the light reflecting material of the reflecting surface 36. In addition to being able to reflect, the white paint 33 and the black paint 35 can efficiently guide the incident light to the emission surface 27. Further, since the aluminum film 31 on the reflective surface 36 is protected from the external atmosphere by the acrylic resin 29, the aluminum film 31 is protected from deterioration with time such that the reflectance is lowered by the clouding or corrosion of the aluminum film 31. Can be suppressed.

In the stereoscopic image display device, the image is usually invisible when the observer's eyes deviate from the condensing position. However, by extending the light source 15 along the incident surface 22 as shown by the dotted line in FIG. The light is emitted outward (leftward in FIG. 16) from the focal position f2 (a two-dot chain line with an arrow in FIG. 16). Therefore, although a stereoscopic image cannot be observed, it can be observed as a two-dimensional image using only the right-eye image or the left-eye image. Therefore, it is possible to know the outline of the image stereoscopically viewed by the observer even from around the stereoscopic observer.

As shown in FIGS. 15 and 19, the reflection unit 19 directs the exit surface 27 of the elliptical mirror 17 to the back surface of the transmissive liquid crystal display panel 5 and directs the entrance surface 22 to opposite sides (left and right). In a staggered state, the surfaces are stacked in a direction perpendicular to the line connecting the pair of light sources 15 and 16 (the paper surface direction in FIG. 15 and the vertical direction in FIG. 19) and in the longitudinal direction of the pair of light sources 15 and 16. Configured. At this time, since the emission surface 27 is laminated so as to constitute one plane, the diffusion plate 11 can be easily disposed.

Here, the intermediate reflecting surface 53 will be described with reference to FIG. FIG. 20 is a partially enlarged view of the blade showing the intermediate reflecting surface.

The intermediate reflecting surface 53 has a horizontal parabolic shape, and the horizontal central axis PC is located slightly above the emission surface 27. An intermediate reflecting surface 53 is formed so that the parabola has the focal point coincident with one focal point f 1 of the ellipse 21. In order to make the screen luminance distribution uniform in the liquid crystal display panel 5 as viewed from the other focal point f2 of the ellipse 21, the following configuration is preferable.

Here, as shown in FIG. 16, the intersection of the straight line passing through the right end of the liquid crystal display panel 5 from the other focal point f2 of the ellipse 21 and the arc portion 28 is denoted by p, and the left end of the liquid crystal display panel 5 from the other focal point f2. The intersection of the straight line passing through and the arc portion 28 is denoted by q. The intersection point with the light source 15 when a straight line is drawn from the intersection point p to one focus f1 is denoted by R1, and the intersection point with the light source 15 when a straight line is drawn from the intersection point q to one focus f1 is denoted by R2. In this case, the intersection R1 is preferably on the uppermost part of the light source 15 or on the parabola. The light that passes through one focal point f1 and illuminates the entire surface of the liquid crystal display panel 5 is light that is parallel to the central axis PC of the parabola, and the screen luminance distribution and each surface point of the light source 15 can be associated one-to-one. it can. For this reason, when the light source 15 is a uniform light source over the entire surface of the liquid crystal display panel 5, the intensities of the light beams passing through one focal point f1 are all equal, and a uniform luminance distribution can be obtained. Even if the light source 15 is not uniform on the entire surface, if the angular intensity ratio distribution is uniform, the luminance adjustment at each point on the screen is made uniform by adjusting the luminous flux at each point of the light source 15. If the light source 15 is provided with a light emitting diode, and the light source 15 is provided with a light emitting diode, the brightness of the screen is compared by adjusting the driving current of each light emitting diode and adjusting the pitch of the light emitting diode. Can be easily achieved.

When the intermediate reflecting surface 53 is designed under the above-described conditions, the intersection R1 is the uppermost part for displaying a three-dimensional image in the light source 15, and the light source 15 is extended below the intersection R1 by a necessary amount. If the point extended below this is R3, this point R3 must be above the intersection R2. When the point R3 is above the intersection R2, the necessary light quantity can be secured by setting the range of the light source 15 for displaying a three-dimensional image from the intersection R1 to the intersection R2. When the point R3 is below the intersection point R2, it is necessary to move the light source 15 further outward (right side in FIG. 20) and set the intersection point R1 above. By doing so, the full width of the stereoscopic image display device is widened. Therefore, if the full width of the stereoscopic image display device is within an allowable range, it is preferable to design by the above-described method.

In FIG. 20, the crosstalk limit line LC is indicated by a dotted line on the left side of one focal point f1. The crosstalk limit line LC indicates a light beam that comes to the center of the observer's face (the center of the right eye and the left eye). For example, when collecting light rays in the right eye of the observer, if there is light traveling from the liquid crystal display panel 5 side that exceeds the crosstalk limit line LC toward the elliptical mirror 17 without passing through one focus f1, the elliptical mirror The light beam reflected by 17 is directed to the left side of the center of the observer's face. That is, of the light that is not parallel to the parabola central axis PC, if there is light that is reflected on the liquid crystal display panel 5 side from the crosstalk limit line LC and is directed to the elliptical mirror 17, crosstalk occurs and the stereoscopic image becomes unclear. Cause. Therefore, the intersection PE between the crosstalk limit line LC and the central axis PC of the parabola constituting the intermediate reflection surface 53 is set as the end of the parabola of the intermediate reflection surface 53, so that all the rays are not crosstalked. It can be used for imaging.

Further, in the intermediate reflecting surface 53, a range (crosstalk range) from the intersection point CP to the crosstalk limit line LC in the parabola of one focal point f1, the intersection q, and the intermediate reflecting surface 53 is formed as a linear surface LS. Then, the light ray incident here enters the reflecting surface 36 on the left side of the intersection point q. Therefore, this light beam is directed further to the right side (the observer's right arm side) than the observer's right eye ER of the stereoscopic image display device at the stereoscopic viewing distance. As a result, it is possible to effectively use light rays for displaying a two-dimensional image, and the use efficiency of the light source 15 can be expected to be improved. In addition, what is necessary is just to comprise the surface LS with the absorption surface which absorbs light, when the object for two-dimensional images is not required.

In the stereoscopic image display apparatus configured as described above, the light emitted from the light source 15 for the right eye disposed on the one focus f1 side is incident from the incident surface 22 of the blade 20, and the intermediate reflecting surface. The light is reflected by the elliptical reflection surface 36 through 53 and emitted from the emission surface 27, passes through the transmissive liquid crystal display panel 5, and is condensed on the other focal side f <b> 2 of the ellipse 21. Therefore, the viewing angle can be limited to the other focus f2 direction. Further, the incident surface 22 of the blade 20 is formed apart from one focal point f1 of the ellipse 21 and the long axis a of the ellipse 21, and light from the light source 15 for the right eye is incident through the intermediate reflecting surface 53. Therefore, the amount of light passing through one focal point f1 of the ellipse 21 among the light from the light source 15 for the right eye can be increased. Therefore, the luminance unevenness of the transmissive liquid crystal display panel 5 viewed from the viewpoint corresponding to the other focal point f2 can be suppressed. Further, since the incident surface 22 of the blade 20 is formed along the long axis a of the ellipse 21, even if the right-eye light source 15 is lengthened to widen the field of view of the two-dimensional image, the right-eye light source 15 does not become longer in the width direction of the apparatus. Therefore, it can suppress that the width | variety of an apparatus spreads.

Further, although the light is diffused in the vertical direction by the diffusion plate 11, the diffusion direction is the stacking direction of the elliptical mirrors 17, so that the vertical and vertical brightness uniformity of the image by the elliptical mirror 17 is reduced without deteriorating the crosstalk. Can be improved.

In the above-described embodiment, the configuration in which the blade 20 includes the incident surface 22, the output surface 27, the intermediate reflecting surface 53, and the reflecting surface 36 has been described as an example. However, the blade 20 does not exist. Even if the configuration includes only the elliptical reflection surface 36 and the parabolic intermediate reflection surface 53, the same effect as the above configuration can be obtained.

It should be noted that the focal point of the parabola that constitutes the intermediate reflecting surface 53 and one focal point f1 of the elliptical mirror 17 do not have to coincide with each other, and the same effect as described above can be obtained even if there is a slight deviation.

<First Modification of Intermediate Reflecting Surface>
Next, a modified example of the intermediate reflecting surface will be described with reference to FIG. FIG. 21 is a partially enlarged view of the blade showing the intermediate reflecting surface according to the first modification.

The intermediate reflecting surface 53A formed on the protrusion 24A is common to the above-described intermediate reflecting surface 53 in a parabolic shape, but the shape is different. Specifically, when the total width is outside the allowable range in the first design method described above, the right eye light source 15 is brought closer to the one focus f1 side within the allowable range, and the necessary light amount from the intersection R1. A point where the light source 15 for the right eye is extended upward by an amount corresponding to the top of the light source 15 for the three-dimensional image is obtained, and a parabola passing through the top is obtained. When the parabola is obtained, the intersection R2 is obtained, and the lower intersection (intersection R1 in this example) of the intersection R1 and the intersection R2 becomes the lowermost end of the light source 15 for the three-dimensional image. If the light source 15 is extended below here, the field of view for a two-dimensional image can be expanded. At this time, the light beam for the three-dimensional image is once reflected on the parabola and directed toward the reflecting surface 36, and directly toward the reflecting surface 36. Since the light rays directly directed to the reflecting surface 36 have different emission angles from the light source 15, the luminance is reduced near the position corresponding to the boundary between the parabola and the light source 15. For this reason, it is preferable to configure by the first design method as much as possible.

Note that, also in the first modification, the crosstalk can be reduced by setting the portion corresponding to the crosstalk range in the intermediate reflecting surface 53A as the linear surface LS.

<Second Modification of Intermediate Reflecting Surface>
Next, another modification of the intermediate reflection surface will be described with reference to FIG. FIG. 22 is a partially enlarged view of the blade showing the intermediate reflecting surface according to the second modification.

The intermediate reflecting surfaces 53 and 53A formed on the two protrusions 24 and 24A described above are disposed at positions where the parabolas both surround one focal point f1, but in this modification, the intermediate reflecting surfaces 53 and 53A deviate from one focal point f1. This is different in that the intermediate reflection surface 53B of the protrusion 24B is formed at the position. Specifically, the upper end surface of the projecting portion 24B is formed in a parabolic shape to form an intermediate reflecting surface 53B. The focal point and one focal point f1 are matched. Then, the light from the light source 15 is reflected on the reflecting surface 36 by the intermediate reflecting surface 53B on the side opposite to the one focal point f1.

Since one focal point f1 is an apparent focal point from the intermediate reflecting surface 53B and the reflecting surface 36, the light source 15 can be disposed closer to the liquid crystal display panel 5 side. Therefore, the width of the device can be narrowed, and the size can be further reduced.

Even in the first and second modified examples described above, the blade 20 does not exist, and simply includes an elliptical reflecting surface 36 and parabolic intermediate reflecting surfaces 27A and 27B. Also has the same effect as the above configuration.

Note that the modifications (1) to (3) in the first embodiment described above can also be applied to the second embodiment.

<Example of lighting control>
The lighting control of the light sources 15 and 16 may be performed in the same manner as in the first embodiment.

<Viewing angle restriction>
Although the above-described embodiment is an example of an image display device for a stereoscopic image, an example of viewing angle restriction will be described below.

Here, refer to FIG. FIG. 23 is a schematic diagram for explaining that the viewing angle is limited.

This device is configured using only one elliptical mirror 17. In this case, the light emitted from the emission surface 27 of the elliptical mirror 17 is collected at the focal point f2. Therefore, a visible region VR1 (hatched region in FIG. 23) and an invisible region IVR1 are generated. Therefore, an image can be observed at the position L1 corresponding to the visible region VR1. An image cannot be observed at a position L2 corresponding to the invisible region IVR1. That is, by using only one elliptical mirror 17, the observable region can be limited only to the focus f2 direction.

In the above-described configuration, when it is only necessary to limit the viewing angle, it is not necessary to alternately display images as in the above-described stereoscopic image display device, and it is not necessary to control lighting of the light source.

(Blade modification)
When the viewing angle is simply limited, it is not necessary to form the reflection unit 19 by stacking a plurality of thin blades 20 as described above, and there is one thickness as in the first embodiment. You may comprise the reflection unit 19 with a braid | blade (refer FIG. 13).

<Dual view display>
Reference is now made to FIG. FIG. 24 is a schematic diagram illustrating the concept of a dual view image display device.

By adopting the elliptical mirror 17 and the reflection unit 19 in which the distance between the focal point f and the focal point (f) is wider than the average distance between both eyes of the person, an apparatus capable of viewing different images depending on the viewing direction. Can be realized. Such a device is called a dual view display device. For example, a navigation image can be displayed on the driver's seat side and a television image can be displayed on the passenger's seat side by deploying in the center console of an automobile. Specifically, the light sources 15 and 16 of the elliptical mirror 17 may be elongated along the incident surface 22 and an area where a two-dimensional image can be observed may be used. That is, the visible regions VR1 and VR2 in FIG. 24 are used. Note that, by setting the focal points f and (f) to the above-described interval, it is possible to minimize the region where both images are observed in an overlapping manner.

In terms of control, instead of the right-eye image and the left-eye image in the above-described stereoscopic image display device, the first image (for example, navigation image) and the second image (for example, television image) are image signals. What is necessary is just to make it alternately output from the output part 65 (FIG. 9), and to light the light sources 15 and 16 according to each alternately.

As described above, the present invention is suitable for a display device such as a monitor for displaying an image.

Claims (21)

1. A transmissive liquid crystal display panel for displaying images;
   A main body having a plate-like appearance shape, one end surface of which is formed by a part of an elliptical arc when viewed from the surface direction, and a member transmitting light, and an end surface of the main body corresponding to one focal side of the ellipse The light incident surface is formed on the other end surface of the main body when viewed from the surface direction, and the light incident on the main body from the incident surface is emitted to the other focal side of the ellipse. A light guide including a surface and a reflecting surface formed on a part of the elliptical arc when viewed from the surface direction, and an end surface of the main body;
   A light source disposed on one focal side of the ellipse;
   A display device comprising:
2. A transmissive liquid crystal display panel for displaying images;
   A main body having a plate-like appearance shape, one end surface of which is formed by a part of an elliptical arc when viewed from the surface direction, and a member transmitting light, and an end surface of the main body corresponding to one focal side of the ellipse The light incident surface is formed on the other end surface of the main body when viewed from the surface direction, and the light incident on the main body from the incident surface is emitted to the other focal side of the ellipse. A light guide including a surface and a reflecting surface formed on a part of the elliptical arc when viewed from the surface direction, and an end surface of the main body;
   A plurality of the light guides, a reflection unit configured by laminating a light guide having an incident surface directed to one side and a light guide having the incident surface directed to the other side;
   A first light source disposed in the vicinity of the incident surface of the light guide directed to one side, and a second light source disposed in the vicinity of the incident surface of the light guide directed to the other side. A pair of light sources;
   A display device comprising:
3. The display device according to claim 2,
   Image output means for alternately outputting different first images and second images to the transmissive liquid crystal display panel;
   When the first image is output when the image output means sequentially switches from the first image to the second image or from the second image to the first image, the first light source is output. A light source control means for turning on the second light source when the second image is output;
   A display device comprising:
4. The display device according to claim 2,
   Image output means for alternately outputting right-eye images and left-eye images to the transmissive liquid crystal display panel;
   When the image output means sequentially switches from the right-eye image to the left-eye image or from the left-eye image to the right-eye image, when the right-eye image is output, the first light source A light source control means for turning on the second light source when an image for the left eye is output;
   A display device comprising:
5. The display device according to any one of claims 1 to 4,
   The display device according to claim 1, wherein a light reflecting material that reflects light forms a layer on a peripheral surface that is outside the main body.
6. The display device according to any one of claims 1 to 4,
   Of the main body, a black coating is applied to the surface side excluding the exit surface and the entrance surface, overlaid with white paint, and a black paint is applied to the end surface side excluding the exit surface and the entrance surface. Display device.
7. The display device according to any one of claims 1 to 6,
   A display device, wherein an air layer is formed between the main bodies when the main bodies are laminated.
8. The display device according to any one of claims 1 to 7,
   In the main body, one end surface close to the incident surface along the major axis of the ellipse is formed as a sub-reflection surface, and light incident from the incident surface is transmitted from the other focal side through the sub-reflection surface and the reflection surface. The display device is also configured to emit light toward the outside.
9. The display device according to any one of claims 1 to 8,
   The display device according to claim 1, wherein a thickness of the incident surface is greater than a thickness of the reflective surface.
10. In a display device for displaying an image,
    A transmissive liquid crystal display panel for displaying images;
    A body having a plate-like appearance, one end surface of which is formed by a part of an elliptical arc when viewed from the surface direction, a light transmitting member, one focal point of the ellipse, and the major axis of the ellipse The incident surface formed on the main body along the major axis of the ellipse and disposed at a position surrounding one focal point of the ellipse when viewed from the surface direction. An intermediate reflecting surface that reflects light incident from the main body, and an elliptical reflecting surface that forms part of an elliptical arc of the main body and reflects light from the intermediate reflecting surface to the other focal side of the ellipse; A light guide including an emission surface that is formed on the other end surface of the main body and emits light reflected by the elliptical reflection surface;
    A light source disposed on the intermediate reflecting surface side of the light guide;
    A display device comprising:
11. In a display device for displaying an image,
    A transmissive liquid crystal display panel for displaying images;
    It is disposed behind the transmissive liquid crystal display panel as viewed from the display surface, and is constituted by a part of an elliptical arc in plan view, and transmits light from one focal point of the elliptical to the other focal point of the elliptical shape. An elliptical reflecting surface that reflects toward the side;
    A light source disposed on the side of the transmissive liquid crystal display panel, spaced apart from one focal point of the ellipse and the major axis of the ellipse, and disposed along the major axis of the ellipse;
    An intermediate reflection surface located between the light source and the elliptical reflection surface, disposed at a position surrounding one focal point of the ellipse, and reflecting light from the light source to the elliptical reflection surface;
    A display device comprising:
12. In a display device for displaying an image,
    A transmissive liquid crystal display panel for displaying images;
    Presenting a plate-like appearance shape, one end surface when viewed from the surface direction is constituted by a part of an elliptical arc, and is separated from a main body constituted by a light transmitting member, and one focal point of the ellipse, and Formed by extending downward along the vertical direction from the long axis side of the ellipse, disposed on the incident surface on which light is incident, and at a position deviated from one focal point of the ellipse when viewed from the surface direction, An intermediate reflection surface that reflects light incident from the incident surface on a surface opposite to one focal point of the ellipse and a part of an arc of the main body, and the light from the intermediate reflection surface is converted to the other of the ellipse A light guide with an elliptical reflecting surface that reflects toward the focal side of the
    A light source disposed on the intermediate reflecting surface side of the light guide;
    A display device comprising:
13. In a display device for displaying an image,
    A transmissive liquid crystal display panel for displaying images;
    It is disposed behind the transmissive liquid crystal display panel as viewed from the display surface, and is constituted by a part of an elliptical arc in plan view, and transmits light from one focal point of the elliptical to the other focal point of the elliptical shape. An elliptical reflecting surface that reflects toward the side;
    A light source disposed on the side of the transmissive liquid crystal display panel and spaced from one focal point of the ellipse and extending downward along the vertical direction from the long axis side of the ellipse When,
    Located between the light source and the ellipsoidal reflecting surface, disposed at a position deviated from one focus of the ellipse, the light from the light source on the surface opposite to the one focus of the ellipse An intermediate reflective surface that reflects off the reflective surface;
    A display device comprising:
14. The display device according to any one of claims 10 to 13,
    The display device, wherein the intermediate reflecting surface includes a parabolic reflecting surface using a part of a parabola.
15. The display device according to any one of claims 10 to 14,
    The display device characterized in that the elliptical reflecting surface reflects light only in the other focal direction of the ellipse.
16. The display device according to claim 10 or 13,
    The light guide is configured as a reflection unit formed by laminating a plurality of light guides having an incident surface directed to one side and a light guide having the incident surface directed to the other side,
    The light source includes a first light source disposed on a light guide having an incident surface directed toward one side, and a second light source disposed on the light guide having an incident surface directed toward the other side. Configured as a pair of light sources,
    Image output means for alternately outputting different first images and second images to the transmissive liquid crystal display panel;
    When the first image is output when the image output means sequentially switches from the first image to the second image or from the second image to the first image, the first light source is output. A light source control means for turning on the second light source when the second image is output;
    A display device comprising:
17. The display device according to claim 11 or 13,
    A plurality of the elliptical reflection surfaces, and a reflection unit configured such that one focal point of the adjacent elliptical reflection surfaces is directed to the opposite side on one side and the other side;
    The light source includes a first light source disposed on an intermediate reflecting surface of an elliptical reflecting surface in which one focal point of the ellipse is directed to one side, and an elliptical reflection in which one focal point of the ellipse is directed to the other side. Configured as a pair of light sources including a second light source disposed on the intermediate reflection surface of the surface,
    Image output means for alternately outputting different first images and second images to the transmissive liquid crystal display panel;
    When the first image is output when the image output means sequentially switches from the first image to the second image or from the second image to the first image, the first light source is output. A light source control means for turning on the second light source when the second image is output;
    A display device comprising:
18. The display device according to claim 16 or 17,
    The display device, wherein the first image and the second image are a left-eye image and a right-eye image having parallax with each other.
19. The display device according to claim 16 or 17,
    The display device, wherein the first image and the second image are two-dimensional images different from each other.
20. The display device according to claim 14, wherein
    The display device according to claim 1, wherein the intermediate reflecting surface is configured such that a focal point of the parabola coincides with one focal point of the ellipse.
21. The display device according to claim 20,
    The intermediate reflection surface is configured such that a portion corresponding to a crosstalk range is configured linearly, and the portion is configured as a reflection surface or an absorption surface.

Images