JP2009163033A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereoscopic image display device where, by laminatingly arranging reflecting members to a direction orthogonal to a direction at which a pair of light sources are arranged, while improving the brightness and darkness uniformity in the right-left direction of an image, there is no need for reducing crosstalks, and further, use efficiency of light is satisfactory. <P>SOLUTION: In an image display device, light radiated from light sources 15, 16 is reflected by an elliptic mirror 17 of reflection unit 19 and transmitted through a light transmitting liquid crystal display panel 5, to form an image for right eye and an image for left eye on focal points. Since the reflecting unit 19 is constituted by laminating surfaces of the blades 18 of the elliptic mirror 17 in the vertical direction, the brightness and darkness uniformity in the right-left direction of the image is improved. Since there is no need to have the light diffuse in the right-left directions, crosstalks are not reduced. Furthermore, since the reflecting unit 19 only reflects the light from the light sources 15, 16 by the reflecting surface of the elliptic mirror 17, use efficiency of light is improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image display device for displaying a stereoscopic image and two types of images.

Conventionally, as this type of apparatus, the following can be cited (for example, see Patent Document 1).
This device alternately displays a right-eye image and a left-eye image with parallax on a liquid crystal display panel in a time-division manner, and a pair of right-eye and left-eye images in synchronization with the image switching display. The light source blinks alternately. Specifically, when a right-eye image is displayed on the liquid crystal display panel, the right-eye light source is turned on and the left-eye light source is turned off. The light emitted from the light source for the right eye is condensed by the Fresnel lens to become parallel light and directed to the right eye of the observer. On the other hand, when the image for the left eye is displayed on the liquid crystal display panel, the light source for the right eye is turned off and the light source for the left eye is turned on. The light emitted from the light source for the left eye is condensed by the Fresnel lens to become parallel light and directed to the left eye of the observer. In this way, the right-eye image and the left-eye image are separated and enter the observer's right eye and left eye, so that the observer can view a stereoscopic image by three-dimensional perception based on so-called binocular parallax. Can see.

  In the above conventional example, since a long distance is required between the liquid crystal display panel and the light source, there is a problem that the depth of the device becomes long. Therefore, there is a configuration (first device) in which a light source is arranged on the liquid crystal display panel side, a Fresnel mirror is arranged on the back side of the liquid crystal display panel, and the light from the light source is reflected to the liquid crystal display panel side using this Fresnel mirror. It has been proposed (see, for example, Patent Document 2). According to this configuration, the depth of the apparatus can be shortened by irradiating light from the light source from the liquid crystal display panel side and reflecting the light to the liquid crystal display panel side by the Fresnel mirror.

Moreover, the following is mentioned as this kind of apparatus (for example, refer patent document 3).
This device (second device) is provided with two light guide plates (first light guide plate and second light guide plate) stacked on the back side of the liquid crystal display panel, and left on the end face of the light guide plate on the opposite side. Eye light sources and right eye light sources (first light source, second light source) are provided. The light emitted from the first light source is guided in the surface direction by the first light guide plate and irradiated to the back surface of the liquid crystal display panel, and the light emitted from the second light source is guided in the surface direction by the second light guide plate. 1 The light is transmitted through the light guide plate and irradiated to the back surface of the liquid crystal display panel.

JP-A-8-262370 (paragraph numbers “0025” to “0026”, FIG. 3) Japanese Unexamined Patent Publication No. 2000-147669 (FIGS. 1 to 3) Japanese Patent No. 3908241 (FIGS. 3, 15, and 16)

However, the conventional example having such a configuration has the following problems.
That is, the first apparatus reflects the light from the right eye light source and the left eye light source in the right eye direction and the left eye direction, respectively, so that the Fresnel mirror includes the right eye light source and the left eye light source. It is configured by alternately combining strip-shaped mirrors each having a vertically long reflecting surface on the side. Therefore, the liquid crystal display panel has a problem that light and darkness occurs in a vertical stripe shape due to the structure of the Fresnel mirror, and the light and dark uniformity in the horizontal direction of the image is poor.

  In order to solve the above problem, it is conceivable to dispose a diffusion member that diffuses light in the left-right direction. However, in this case, crosstalk (a phenomenon in which the image for the right eye enters the left eye and the image for the left eye enters the right eye) deteriorates, and the stereoscopic effect of the stereoscopic image significantly deteriorates. Different problems arise.

  In addition, although the second device can reduce crosstalk, when the first light source and the second light source have the same luminous intensity, the second light source passes through the first light guide plate, so that the second light source The irradiated image becomes dark. For this reason, although it is necessary to make the luminous intensity of the 2nd light source stronger than the 1st light source, the utilization efficiency of the light of the 2nd light source is still bad. Further, since the first light guide plate needs to transmit the light of the second light source irradiated from the second light guide plate, it is not possible to take measures for preventing light leakage on the back side. For this reason, the light from the first light guide plate leaks not only to the liquid crystal display panel side but also to the second light guide plate side, so that there is a problem that the light use efficiency of the first light source is poor.

  The present invention has been made in view of such circumstances, and by arranging a reflective member in a direction orthogonal to the direction in which the pair of light sources are arranged, the brightness uniformity in the left-right direction of the image is achieved. An object of the present invention is to provide an image display device that does not reduce crosstalk and has good light utilization efficiency.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention described in claim 1 includes a transmissive liquid crystal display panel for displaying an image, and a first light source and a second light source for irradiating the transmissive liquid crystal display panel from the back side. A pair of light sources provided, and a function of emitting light from the first light source and the second light source in different first and second directions, respectively, and emitting light in the first direction A first light guide and a second light guide that emits light in a second direction, and the light output surfaces of the first light guide and the second light guide are of the transmission type A reflection unit that is directed to the liquid crystal display panel and is configured by alternately stacking the first light guide and the second light guide in a direction perpendicular to a line connecting the pair of light sources; The first light source and the second light source, and the first light guide and the second light guide are laminated. A plurality of light emitting sources, an image output means for alternately outputting the first image and the second image to the transmissive liquid crystal display panel, and the image output means from the first image. Light source control means for controlling lighting of the pair of light sources in accordance with each image when sequentially switching to the second image or from the second image to the first image. It is what.

  [Operation / Effect] According to the first aspect of the present invention, light emitted from the first light source of the pair of light sources is emitted in the first direction by the first light guide, and is transmissive. The first image is condensed in the first direction through the liquid crystal display panel. The light emitted from the second light source of the pair of light sources is emitted in the second direction by the second light guide, passes through the transmissive liquid crystal display panel, and the second image is the second. It is condensed in the direction of. Since the reflection unit is configured by laminating the first light guide and the second light guide alternately in a direction perpendicular to a line connecting the pair of light sources, the brightness uniformity in the horizontal direction of the image is improved. Can be improved. Therefore, since it is not necessary to diffuse light in the left-right direction, the crosstalk in which the first image and the second image are mixed is not deteriorated. In addition, since the reflection unit guides light from the light source to the back surface of the liquid crystal display panel using the first and second light guides, there is almost no member that attenuates light, and the light use efficiency can be improved. .

  Note that when the first image and the second image are alternately displayed on the transmissive liquid crystal display panel, 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. . In that case, since both images enter the observer at the same time, the images cannot be normally observed. Therefore, the light source control means turns on (scans) the light emission source on the side corresponding to the image output from the image output means according to the display position of the image. Thereby, even if both images (the first image and the second image) are simultaneously displayed on the liquid crystal display panel, the images can be normally observed. Further, since it is not necessary to turn off all the light emitting sources during a period in which both images are displayed and the image cannot be normally observed, the luminance of the image does not decrease.

  According to a second aspect of the present invention, there is provided a transmissive liquid crystal display panel for displaying an image, and a first light source and a second light source for irradiating the transmissive liquid crystal display panel from the back side. A pair of light sources provided and a function of condensing the light from the first light source and the second light source to a first focal point and a second focal point at different positions, respectively, in the vicinity of the first light source And a first elliptical mirror in a band shape formed as a part of an elliptical arc whose focal point is the vicinity of the first focal point, and an ellipse having a focal point in the vicinity of the second light source and in the vicinity of the second focal point A second elliptical mirror in a band shape formed as a part of a circular arc of the first elliptical mirror, and the reflective surface of the first elliptical mirror and the reflective surface of the second elliptical mirror are on the transmissive liquid crystal display panel side. Directed to alternate between the first elliptical mirror and the second elliptical mirror. A reflection unit configured by stacking in a direction orthogonal to a line connecting the pair of light sources, the first light source and the second light source, and the first elliptic mirror and the second elliptic mirror A plurality of light emitting sources arranged in a direction in which the first and second images are stacked, image output means for alternately outputting a first image and a second image to the transmissive liquid crystal display panel, and the image output means When sequentially switching from the first image to the second image, or from the second image to the first image, light source control means for controlling the lighting of the pair of light sources according to each image, It is characterized by having.

  [Operation / Effect] According to the invention described in claim 2, the light emitted from the first light source of the pair of light sources is reflected by the ellipsoidal reflecting surface of the first ellipsoidal mirror, thereby transmitting the transmissive liquid crystal. The first image is focused on the first focus through the display panel. The light emitted from the second light source of the pair of light sources is reflected by the reflecting surface of the second elliptical mirror, passes through the transmissive liquid crystal display panel, and forms a second image at the second focus. Focused. The reflection unit is configured by laminating the first ellipsoidal mirror and the second ellipsoidal mirror in the direction perpendicular to the line connecting the pair of light sources, so that the brightness uniformity in the left-right direction of the image Can be improved. Therefore, since it is not necessary to diffuse light in the left-right direction, the crosstalk in which the first image and the second image are mixed is not deteriorated. In addition, the reflection unit reflects light from the light source by the reflection surfaces of the first and second elliptical mirrors and guides it to the back surface of the liquid crystal display panel. Can be.

  Note that when the first image and the second image are alternately displayed on the transmissive liquid crystal display panel, 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. . In that case, since both images enter the observer at the same time, the images cannot be normally observed. Therefore, the light source control means turns on (scans) the light emission source on the side corresponding to the image output from the image output means according to the display position of the image. Thereby, even if both images (the first image and the second image) are simultaneously displayed on the liquid crystal display panel, the images can be normally observed. Further, since it is not necessary to turn off all the light emitting sources during a period in which both images are displayed and the image cannot be normally observed, the luminance of the image does not decrease.

  In the present invention, it is preferable that a diffusion member for diffusing light from the reflection unit in the stacking direction is provided between the reflection unit and the transmissive liquid crystal display panel side. ). Although the light is diffused by the diffusing member, the diffusion direction is the stacking direction of the elliptical mirror or the light guide, so that the vertical uniformity of the image by the elliptical mirror or the light guide can be improved without reducing the crosstalk. Can be improved.

  Further, in the present invention, the plurality of light emitting sources includes a plurality of the blocks, each of which includes a unit including at least two adjacent light emitting sources, and the light source control means turns on each block. It is preferable to control (claim 4). Since lighting control may be performed in units of blocks, the load on the light source control means can be reduced.

  In the present invention, it is preferable that the image output means insert a black belt at a boundary between the first image and the second image. The boundary between the first image and the second image is an image that is unclear due to the memory effect of the liquid crystal element, such as a state where the image is not fixed, for example, a transition state from the previous image to the next image is displayed. It becomes. Therefore, by displaying a black belt at the boundary, it is possible to suppress the influence of the indeterminate image and display the stereoscopic image clearly.

  In the present invention, the light source control means may delay each response time from when the image output control means outputs an image until a time when the image is actually displayed on the transmissive liquid crystal display panel. It is preferable to turn on the light emission source of the block. Even if the light emitting source is turned on before the response time, an uncertain image, for example, a transition state from the previous image is displayed on the liquid crystal display panel, resulting in a blurred image. Therefore, by turning on the light emitting source with a delay of the response time of the liquid crystal display panel from the output time of the image, until the image is determined at the boundary between the first image and the second image in an indeterminate state. Since the light source is turned off, a clear image can be displayed.

  In the present invention, it is preferable that the light source control means turns off the light source corresponding to the boundary between the first image and the second image. The boundary between the first image and the second image is an image that is unclear due to the memory effect of the liquid crystal element, such as a state where the image is not fixed, for example, a transition state from the previous image to the next image is displayed. It becomes. Therefore, by turning off the light source corresponding to the boundary, it is possible to suppress the influence of the indeterminate image and display the stereoscopic image clearly.

  According to the image display device of the present invention, the reflection unit is configured by laminating the first light guide and the second light guide alternately in a direction perpendicular to the line connecting the pair of light sources. Therefore, it is possible to improve the brightness uniformity in the left-right direction of the image. Therefore, since it is not necessary to diffuse light in the left-right direction, the crosstalk in which the first image and the second image are mixed is not deteriorated. In addition, since the reflection unit guides light from the light source to the back surface of the liquid crystal display panel using the first and second light guides, there is almost no member that attenuates light, and the light use efficiency can be improved. . Further, since the light source control means turns on the light emitting source on the side corresponding to the image output from the image output means according to the display position of the image, both images (the first image and the second image) are liquid crystal. An image can be normally observed even in a state where the images are simultaneously displayed on the display panel. Further, since it is not necessary to turn off all the light emitting sources during a period in which both images are displayed and the image cannot be normally observed, the luminance of the image does not decrease.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a stereoscopic display device according to an 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 apparatus according to the present embodiment (the image display apparatus according to 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 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 laminating 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 elliptical mirror 17 corresponds to the first elliptical mirror and the second elliptical mirror in the present invention. The light source 15 corresponds to the first light source in the present invention, and the light source 16 corresponds to the second light source in the present invention.

  The elliptical mirror 17 is provided with a blade 18 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. As shown in FIG. 2, the reflection unit 19 configured in this way has a function of condensing the light from the light source 15 and the light source 16 to the first focal point f2 and the second focal point (f2) at different positions. Have.

  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 condensed 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. The image for the left eye is condensed 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.

  Furthermore, since the reflection unit 19 reflects the light from the light sources 15 and 16 by the reflection surface 36 of the elliptical mirror 17 and guides it to the back surface of the liquid crystal display panel 5, there is almost no member that attenuates the light, and the light use efficiency is improved. Can be good.

  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 in 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. 7C A reflector 47 is disposed between the elliptical mirrors 17 at a position that coincides 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 reflecting plate 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 fine protrusions, a sheet for preventing light leakage may be sandwiched between the elliptical mirrors 17 and stacked.

  (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. 8 may be adopted. FIG. 8 is a schematic configuration diagram showing a modification of the elliptical mirror.

  In this elliptical mirror 17A, the reflection 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 light emitting diode 61 corresponds to the light source in the present invention.

  The control unit 63 receives the video signal VD and outputs an image signal output unit 65 that alternately outputs a video signal corresponding to the right-eye image and the left-eye image to the liquid crystal display panel 5. When the video signals of the image for the eye and the image for the left eye are sequentially switched, the light sources 15A and 16A on the side corresponding to the image (the image for the right eye or the image for the left eye) correspond to the vertical synchronization signal VS. And a light source control unit 67 that turns on the diode 61 in accordance with the image display position.

  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. Further, the image for the right eye corresponds to the first image in the present invention, and the image for the left eye corresponds to the second image in the present invention.

  When the image signal output unit 65 outputs the image signals corresponding to the right-eye image and the left-eye image to the liquid crystal display panel 5, the light source control unit 67 outputs the right-eye light source 15A and the left-eye light source 16A. The respective light emitting diodes 61 are turned on. Specifically, the control is performed as shown in FIG. FIGS. 10A to 10D are schematic diagrams illustrating 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 unit including two or more adjacent light emitting diodes 61 is a block, and the lighting control is divided into four blocks consisting of blocks BL1 to BL4. You just have to do it. As a result, it is possible to perform lighting control relatively easily by reducing the load on the light source control unit 67 while performing stereoscopic viewing normally.

  Another control example in the case of the above configuration will be described with reference to FIG. FIGS. 11A to 11D are schematic diagrams illustrating 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 the control of each of 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.

  In the above example, the black band BS is inserted into the image. However, this may be omitted and control may be performed so that only the light source corresponding to the position corresponding to the black band BS is turned off. Even if it does in this way, there exists an effect similar to black belt BS insertion mentioned above.

  Here, a suitable lighting control example in the case where the light emitting diode 61 is made into blocks to form blocks BL1 to BL4 will be described with reference to FIG. FIG. 12A is a schematic diagram showing the correspondence between the area and the block of the liquid crystal display panel, and FIG. 12B is a time chart showing the lighting timing of the image signal and the light emitting diode.

  In this example, the display area of the liquid crystal display panel 5 is divided into four areas, which are areas r1 to r4 in order from the top. These regions r1 to r4 include a plurality of pixel lines in the liquid crystal display panel 5. The blocks BL1 to BL4 correspond to the areas r1 to r4. Further, the symbol rt in FIG. 12B represents the response time. This response time rt is the time required from when the video signal is given to the liquid crystal display panel 5 until the image based on the video signal is actually displayed. Since the response time rt is unique to the liquid crystal display panel 5, it may be measured in advance and stored so that the light source controller 67 can refer to it. The symbol ht is a screen hold period corresponding to a period from the displayed image until the video signal of the next image is output, and the screen rewriting period is a time during which the video signal is given.

  The image signal output unit 65 outputs a video signal of an image for the right eye between time t2 and time t6. Among these, the time point t2 to t3 corresponds to the video signal in the region r1, the time point t3 to t4 corresponds to the video signal in the region r2, the time point t4 to t5 corresponds to the video signal in the region r3, and the time point t5 to t6 corresponds to the video signal in the region r4. On the other hand, the light source controller 67 turns on the block BL1 that illuminates the region r1 with a delay of the response time rt from the time point t3 when the video signal for the region r1 is output. This lighting state is turned off by the time point r7 when the video signal of the region r1 of the image for the left eye is given. The block BL2 that illuminates the region r2 is turned on with a delay of the response time rt from the time t4 when the video signal for the region r2 is output, and the block BL3 that illuminates the region r3 is the time t5 when the video signal for the region r3 is output. The block BL4 that illuminates the region r4 is turned on with a delay of the response time rt from the time t6 when the video signal for the region r4N is output.

  Since the liquid crystal element of the liquid crystal display panel 5 generally has a response time rt as described above, even if the liquid crystal display panel 5 is turned on before the response time rt, an uncertain image, for example, the front time is displayed. Only the transition state from the image is displayed and the image becomes unclear. Therefore, a clear stereoscopic image can be displayed by performing the lighting control in consideration of the response time rt as described above. In other words, since the light source is turned off at the boundary between the left-eye image and the right-eye image that are in an indeterminate state, a clear stereoscopic image can be displayed. .

  The stereoscopic image display device has been described above as an example, but the present invention can also be applied to the following image display device.

(Dual view display)
Reference is now made to FIG. FIG. 13 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 areas VR1 and VR2 (hatched areas in FIG. 13) excluding the invisible area IVR1 in FIG. 13 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. 13, 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. 13, 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. .

  Further, it is needless to say that this dual view display device can achieve the same effect by controlling the light sources 15 and 16 as in the above <Lighting Control Example>.

  In the above-described embodiment, the reflection unit 19 is configured by the elliptical mirror 17, but the following light guide may be employed instead of the elliptical mirror 17.

(Light guide body 1)
Reference is now made to FIG. In addition, FIG. 14 is a figure which shows the modification of a reflection unit.

  The reflection unit 19B includes a plurality of light guides 71. The light guide 71 has a thin plate-like appearance, and includes reflective surfaces 73 to 75 each having an upward inclined surface in order from the light source 15 side. Each of the reflection surfaces 73 to 75 is configured to be different from the light source 15 side, and guides light from the light source 15 to the light output surface 77 side.

  The reflection unit 19 </ b> B is configured by laminating surfaces with such light guides 71 facing opposite sides. Therefore, the light guide 71 that emits the light on the light source 15 side in the first direction (indicated by a two-dot chain line) corresponds to the first light guide in the present invention, and the light on the light source 16 side in the second direction. The light guide 71 that emits light (indicated by a dotted line) corresponds to the second light guide in the present invention.

(Light guide body 2)
Reference is now made to FIG. FIG. 15 is a diagram showing a modification of the reflection unit.

  The reflection unit 19C includes a plurality of light guides 81. The light guide 81 has a thin plate-like appearance and includes recesses 83 to 85 in order from the light source 15 side. Each recessed part 83-85 is comprised so that the depth may become deep as it leaves | separates from the light source 15 side. As for each recessed part 83-85, the surface at the side of the light source 15 functions as the reflective surfaces 86-88, respectively. Each reflective surface 86-88 guides the light from the light source 15 to the light exit surface 89 side.

  The reflection unit 19 </ b> C is configured by laminating surfaces with such a light guide 81 facing opposite sides. Therefore, the light guide 81 that emits the light on the light source 15 side in the first direction (indicated by a two-dot chain line) corresponds to the first light guide in the present invention, and the light on the light source 16 side in the second direction. The light guide 81 that emits light (indicated by a dotted line) corresponds to the second light guide in the present invention.

  Even the reflection units 19B and 19C as described above can achieve the same effects as the reflection units 19 and 19A using the elliptical mirror 17. Further, since the light guides 71 and 81 can be made narrower and lighter than the elliptical mirror 17, the image display device can be reduced in size and weight. Needless to say, the image display device including these reflection units 19B and 19C can achieve the same effect by controlling the light sources 15 and 16 as in the above <lighting control example>. .

It is a cross-sectional view which shows schematic structure of the three-dimensional display apparatus which concerns on an Example. 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. (A) is a schematic diagram which shows the correspondence of the area | region and block of a liquid crystal display panel, (b) is a time chart showing the lighting timing of an image signal and a light emitting diode. It is a schematic diagram explaining the concept of the display apparatus of a dual view. It is a figure which shows the modification of a reflection unit. It is a figure which shows the modification of a reflection unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Case 5 ... Liquid crystal display panel 11 ... Diffusing member 15 ... Light source for right eye 16 ... Light source for left eye 17 ... Ellipse mirror 19 ... Reflection unit 21 ... Ellipse 26 ... Incident part 27 ... Outgoing surface 29 ... Acrylic resin 31 ... Aluminum film 36 ... Reflecting surface 63 ... Control unit 65 ... Image signal output unit 67 ... Light source control unit

Claims (7)

A transmissive liquid crystal display panel for displaying images;
A pair of light sources including a first light source and a second light source for irradiating the transmissive liquid crystal display panel from the back side;
A first light guide having a function of emitting light from the first light source and the second light source in different first directions and second directions, respectively, and emitting light in the first direction; And a second light guide that emits light in a second direction, and the light output surfaces of the first light guide and the second light guide are directed to the transmissive liquid crystal display panel side. A reflection unit configured by alternately stacking the first light guide and the second light guide in a direction orthogonal to a line connecting the pair of light sources;
A plurality of light sources constituting the first light source and the second light source and arranged in a direction in which the first light guide and the second light guide are laminated;
Image output means for alternately outputting the first image and the second image to the transmissive liquid crystal display panel;
When the image output unit sequentially switches from the first image to the second image, or from the second image to the first image, the light source control for controlling lighting of the pair of light sources according to each image Means,
An image display device comprising: A transmissive liquid crystal display panel for displaying images;
A pair of light sources including a first light source and a second light source for irradiating the transmissive liquid crystal display panel from the back side;
The first light source and the second light source have a function of condensing the light from the first focus and the second focus at different positions, respectively, in the vicinity of the first light source and in the vicinity of the first focus The first elliptical mirror in the shape of a band formed as a part of an elliptical arc having a focal point and a part of an elliptical arc having a focus in the vicinity of the second light source and the vicinity of the second focal point. A second elliptical mirror in the form of a band, and the reflective surface of the first elliptical mirror and the reflective surface of the second elliptical mirror are directed to the transmissive liquid crystal display panel side, A reflection unit configured by stacking the mirror and the second elliptical mirror in a staggered state in a direction perpendicular to a line connecting the pair of light sources;
A plurality of light sources constituting the first light source and the second light source and disposed in a direction in which the first elliptical mirror and the second elliptical mirror are laminated;
Image output means for alternately outputting the first image and the second image to the transmissive liquid crystal display panel;
When the image output unit sequentially switches from the first image to the second image, or from the second image to the first image, the light source control for controlling lighting of the pair of light sources according to each image Means,
An image display device comprising: The image display device according to claim 1 or 2,
An image display device comprising a diffusion member for diffusing light from the reflection unit in the stacking direction between the reflection unit and the transmissive liquid crystal display panel side. In the image display device according to any one of claims 1 to 3,
The plurality of light emitting sources includes a plurality of blocks, each of which includes a unit including at least two adjacent light emitting sources.
The light source control means controls lighting for each block. The image display device according to any one of claims 1 to 4,
The image display device, wherein the image output means inserts a black belt at a boundary between the first image and the second image. The image display device according to claim 4,
The light source control means turns on the light emission sources of the respective blocks after a response time from when the image output control means outputs an image until the image is actually displayed on the transmissive liquid crystal display panel. An image display device characterized in that In the image display device according to any one of claims 1 to 3,
The image display device, wherein the light source control means turns off a light source corresponding to a boundary between the first image and the second image.

Images