WO2014125793A1 - Image display device and lighting device - Google Patents

Abstract

In order to enhance uniformity of backlight in an image display device that is capable of providing naked eye stereoscopic display so as to display high-quality images, an image display device (100) includes: an illumination section (110) in which a plurality of cells are arranged on a flat surface; and a spatial light modulation panel (104) that modulates light emitted from the illumination section based on a first image signal and a second image signal. Each cell includes a first light source, a second light source, and a lens that collimates light from each light source into substantially parallel light. The cells are configured so that the first light source and the second light source of each cell are arranged substantially symmetrically with respect to the center axis of the cell, and that light emitted from a cell located at the center of the illumination section and light emitted from a cell located in a periphery of the illumination section, are emitted from the illumination section in different directions, respectively.

Description

Image display device and lighting device

The present disclosure relates to an image display device and an illumination device including a plurality of light sources and a lens that collimates light from each light source.

Patent Document 1 discloses an image display device in which a viewer can stereoscopically display a display image with the naked eye without using dedicated glasses.

This image display device collimates a plurality of light sources corresponding to the left and right eyes and the light from each light source, and emits the light toward a presumed viewing position (hereinafter also referred to as “viewing assumed position”). It has a plurality of lenses and a liquid crystal panel that displays an image using light emitted from each lens as a backlight. Then, light emission / non-light emission of each light source is switched between when a left-eye image is displayed on the liquid crystal panel and when a right-eye image is displayed. Thus, for the viewer who views the display image from the assumed viewing position, the image for the left eye can be seen only by the left eye, and the image for the right eye can be seen only by the right eye. The displayed image can be stereoscopically viewed with the naked eye.

In this image display device, the lenses have the same optical characteristics. Therefore, by changing the arrangement position of the light source with respect to the optical axis of the lens for each lens, the direction of the light emitted from each lens is adjusted, and the light is emitted from each lens toward the assumed viewing position. Yes. However, as a result, a lens in which light from the light source enters relatively uniformly and a lens in which the light from the light source enters non-uniformly are generated.

For example, in a lens arranged near the center of the image display surface, it is not necessary to largely deflect the emitted light, so the light source is arranged at a position relatively close to the optical axis of the lens. Therefore, the light emitted from the light source enters the lens with a relatively uniform intensity.

On the other hand, in the lens arranged around the image display surface, the emitted light needs to be deflected relatively large, so the light source must be arranged at a position relatively distant from the optical axis of the lens. As a result, the distance from the light source to the lens is biased, and there is a difference in the intensity of light incident on the lens between the region where the distance from the light source to the lens is relatively close and the region where the distance is relatively far.

It is desirable that the light used for the backlight of the liquid crystal panel be as uniform as possible. However, if the light intensity is non-uniform on the entrance surface of the lens, the intensity of the emitted light will also be non-uniform, and the uniformity of the backlight will be impaired and the quality of the display image will be reduced to the viewer. There is a risk of being recognized.

Patent Document 2 discloses a display device including a liquid crystal panel and a cylindrical lens. In the display device having such a structure, the backlight is blocked by a wiring part (non-transmission part) provided between the pixels of the liquid crystal panel, and the area is recognized as a black belt-like shadow by the viewer. There is.

The display device disclosed in Patent Document 2 has a diffusion mask for reducing the occurrence of shadows. Since the light transmitted through the liquid crystal panel is diffused by the diffusion mask, it is possible to prevent the light from diffusing even in the region where the backlight is blocked by the wiring portion, and to generate a black belt-like shadow.

However, even if such a diffusion mask is used, it is difficult to realize a uniform backlight by reducing the unevenness of the intensity of the emitted light described above.

Japanese National Publication No. 4-504786 Japanese Patent Laid-Open No. 6-33030

The present disclosure prevents a difference in the intensity of light incident on the lens regardless of the position of the lens, realizes a highly uniform backlight, and is effective in obtaining a high-quality display image. An apparatus and a lighting device are provided.

An image display device according to the present disclosure includes a first light source that emits light for displaying a first image, a second light source that emits light for displaying a second image, a first light source, and a second light source. An illumination unit having a plurality of cells arranged in a plane, and a second image corresponding to the first image signal and the second image. A spatial light modulation panel that modulates light emitted from the illumination unit based on the image signal. The first light source and the second light source are arranged substantially symmetrically with respect to the central axis of the cell, and the light emitted from the cell arranged at the center of the illumination unit and the cell arranged around the illumination unit The emitted light is configured to have a different emission direction when emitted from the illumination unit.

FIG. 1 is an external view of the image display apparatus according to the first embodiment. FIG. 2A is a diagram schematically illustrating an example of an assumed viewing position of the image display apparatus in the first embodiment. 2B is a diagram schematically illustrating another example of assumed viewing positions of the image display apparatus according to Embodiment 1. FIG. FIG. 3 is an exploded perspective view schematically showing the configuration of the illumination unit of the image display device according to the first embodiment. FIG. 4 is an exploded perspective view schematically showing one of the cells constituting the illumination unit in the first embodiment. FIG. 5 is a partially enlarged view of the light source unit according to Embodiment 1 as viewed from the front. FIG. 6 is a cross-sectional view of the image display apparatus in the first embodiment. FIG. 7A is a cross-sectional view schematically showing the arrangement position of the light source and the emission direction of the emitted light of the cell arranged near the center of the illumination unit in the first embodiment. FIG. 7B is a cross-sectional view schematically showing the arrangement position of the light sources and the emission direction of the emitted light of the cells arranged around the illumination unit in the first embodiment. FIG. 8A is a diagram schematically showing the intensity of incident light on the lens entrance surface of a cell arranged in the vicinity of the center of the illumination unit in the first embodiment. FIG. 8B is a diagram schematically showing the intensity of incident light on the lens entrance surface of the cell arranged around the illumination unit in the first embodiment. FIG. 9A is a diagram schematically illustrating the lens array in the first embodiment. FIG. 9B is a diagram schematically illustrating an example of the shape of each lens constituting the lens array in the first embodiment. FIG. 10 is an exploded perspective view schematically showing the configuration of the illumination unit in the second embodiment. FIG. 11 is a cross-sectional view of the image display apparatus according to the second embodiment. FIG. 12A is a cross-sectional view schematically showing an arrangement position of a light source and an emission direction of emitted light of a cell arranged near the center of an illumination unit in the second embodiment. FIG. 12B is a cross-sectional view schematically showing the arrangement position of the light sources and the emission direction of the emitted light of the cells arranged around the illumination unit in the second embodiment. FIG. 13A is a diagram schematically illustrating a deflection lens in the second embodiment. FIG. 13B is a diagram schematically showing an example of the shape of a lens constituting the deflection lens in the second embodiment. FIG. 14A is a schematic view of a configuration example of a lens array according to another embodiment viewed from the front. FIG. 14B is a schematic view of another configuration example of a lens array according to another embodiment viewed from the front. FIG. 15 is an exploded perspective view schematically showing a configuration including a diffusing plate in another embodiment. FIG. 16 is an exploded perspective view schematically showing an example of the shape of a cell in another embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
The first embodiment will be described below with reference to FIGS.

[1-1. Constitution]
FIG. 1 is an external view of an image display device 100 according to the first embodiment. In the following description, as shown in FIG. 1, for the sake of convenience, the horizontal direction of the image display device 100 is the X-axis direction, the vertical direction is the Y-axis direction, and the front direction (from the center of the image display device 100 for image display). The direction in which the light is emitted is defined as the Z-axis direction. However, the present disclosure is not limited to this setting.

The image display device 100 can alternately display the first image and the second image. For example, the left-eye image constituting the stereoscopic image is set as the first image, the right-eye image is set as the second image, and the images are alternately displayed at a cycle of 120 Hz. Although details will be described later, when the viewer looks at the image display surface of the image display apparatus 100 from a presumed viewing position (assumed viewing position), the image for the left eye can be seen only by the left eye, and the image for the right eye Is visible only with the right eye. Thus, the viewer can stereoscopically display the display image with the naked eye without using glasses for stereoscopic viewing. An example of the assumed viewing position is as follows.

FIG. 2A is a diagram schematically showing an example of an assumed viewing position of the image display apparatus 100 in the first embodiment. 2B is a diagram schematically illustrating another example of assumed viewing positions of the image display apparatus 100 according to Embodiment 1. FIG.

For example, if the image display device 100 is 50 inches in size, L1 is about 2 m as shown in FIG. 2A. That is, a position that is about 2 m away from the center of the image display surface of the image display device 100 in the Z-axis direction is set as an assumed viewing position.

Further, if the image display device 100 is 20 inches in size that can be held by the viewer, L2 is set to about 40 cm as shown in FIG. 2B. That is, a position that is about 40 cm away from the center of the image display surface of the image display apparatus 100 in the Z-axis direction is set as an assumed viewing position.

In the image display device 100, the light emission direction and the like are about the average interval between eyes (for example, about 10 cm) and the front-rear direction (Z-axis direction) with respect to the assumed viewing position in the left-right direction (X-axis direction). ), The range of about one head (for example, about 30 cm) is set so that autostereoscopic viewing is possible.

Note that the size and expected viewing position of the image display device 100 described above are merely examples in the embodiment, and the present embodiment is not limited to these. Further, the first image and the second image are not limited to images for stereoscopic viewing, and may be images independent from each other.

FIG. 3 is an exploded perspective view schematically showing the configuration of the illumination unit 110 of the image display apparatus 100 according to the first embodiment. FIG. 3 shows an enlarged part of the illumination unit 110. FIG. 4 is an exploded perspective view showing, in an enlarged manner, one of the cells 111 constituting the illumination unit 110 in the first embodiment.

The image display apparatus 100 includes an illumination unit 110, a panel 104 that is a spatial light modulator (SLM), a control circuit for the illumination unit 110 and the panel 104, and a power supply circuit (not shown) inside the casing.

The illumination unit 110 includes a light source unit 101, a light shielding unit 102, and a lens array 103, and is configured by arranging a plurality of cells 111 having these members as components in a planar shape.

The light source unit 101 has a plurality of light sources on a plane parallel to the image display surface. Specifically, the light source unit 101 pairs the first light source 101a that emits light for displaying the first image and the second light source 101b that emits light for displaying the second image, They are arranged in a matrix in the X-axis direction and the Y-axis direction. That is, as shown in FIG. 3, each light source includes a line connecting the first light sources 101a and the second light source so that a line connecting the pair of first light sources 101a and second light sources 101b is parallel to the X axis. The lines connecting the 101b are arranged so as to be parallel to the Y axis.

In the illumination unit 110, each cell 111 has a pair of a first light source 101a and a second light source 101b. In the illumination unit 110 of FIG. 3, the boundary of each cell 111 is indicated by a broken line for convenience.

The light source unit 101 can be realized, for example, by mounting light sources such as LEDs in a matrix on a flat substrate.

Note that each of the pair of the first light source 101a and the second light source 101b may be a single point light source as shown in FIG. 3, for example, but each may be composed of a plurality of light sources. Or you may comprise so that it may become substantially a pair of 1st light source 101a and 2nd light source 101b by optically isolate | separating the light which one light source emits.

The light shielding unit 102 is provided on the front surface (Z-axis positive direction) of the light source unit 101, and is formed by combining a plurality of light shielding walls in a lattice shape. The region surrounded by the light shielding wall has a rectangular cylindrical shape opened in the Z-axis direction. In the illumination unit 110, the region surrounded by the light shielding wall forms one cell 111. The light shielding wall is formed for the purpose of preventing light emitted from the first light source 101a and the second light source 101b from leaking into the adjacent cell 111. Thus, each cell 111 has a light shielding wall that shields light from the adjacent cell 111.

The light shielding wall may be formed of any material such as a metal such as aluminum or resin, but the light emitted from the first light source 101a and the second light source 101b is reflected by the wall surface on the surface of the light shielding wall. In order to prevent the light from entering the lens array 103, a black paint having a low reflectance is applied.

In the present embodiment, the light source unit 101 is fixed in close contact with one opening of the light shielding unit 102, and the lens array 103 is fixed in close contact with the other opening. Therefore, for example, the light shielding wall of the light shielding unit 102 can play a role of separating the light source unit 101 and the lens array 103 by the focal length of the lens 113 included in the lens array 103. In such a configuration, it is desirable that the light shielding portion 102 be formed of a material having sufficient strength to play this role.

If the light source unit 101 and the lens array 103 are separated from each other by a necessary distance in a stable state without depending on the light shielding unit 102, for example, by fixing to the housing of the image display device 100, the light shielding unit 102 is provided. May be formed of a relatively low strength material. Further, as long as the light from the adjacent cells 111 can be shielded, the light source unit 101, the light shielding unit 102, and the lens array 103 need not be in close contact with each other.

The lens array 103 is an aggregate of a plurality of lenses 113 having different optical characteristics, and is formed by arranging a plurality of lenses 113 in a matrix in the X-axis direction and the Y-axis direction in parallel with the image display surface. Yes. One lens 113 corresponds to one cell 111, and the lens 113 collimates and emits light emitted from the first light source 101a and the second light source 101b into substantially parallel light. The emission direction of the light emitted from each lens 113, that is, the emission direction of the light emitted from each cell 111 is a viewing position (viewing assumed position) assumed in advance. Specifically, for example, the light emission of the first light source 101a is emitted from the assumed viewing position toward the left eye of the viewer viewing the display image, and the light emission of the second light source 101b is directed to the right eye of the viewer. Emitted. For this reason, the lenses constituting the lens array 103 have different deflection angles of the emitted light, and the lens 113 arranged in the peripheral portion is more effective in emitting light than the lens 113 arranged in the central portion of the lens array 103. Large deflection angle.

Thus, in the present embodiment, the plurality of lenses 113 constituting the lens array 103 and arranged in each cell 111 are element lenses having different deflection angles. In the lens array 103 in FIG. 3, the boundary of each cell 111 is indicated by a broken line for convenience.

The panel 104 uses the light emitted from the illumination unit 110 as a backlight, and modulates the light emitted from the illumination unit 110 based on the first image signal corresponding to the first image and the second image signal corresponding to the second image. The first image and the second image are alternately displayed on the image display surface of the panel 104. The panel 104 can be configured using, for example, a generally known liquid crystal display panel.

The illumination unit 110 emits the first light source 101 a and emits the second light source 101 b when the first image is displayed on the panel 104, and turns off when the second image is displayed on the panel 104. The two light sources 101b emit light and the first light source 101a is turned off.

As shown in FIG. 4, one cell 111 is set as a region optically shielded by other neighboring cells 111 by a light shielding wall, and includes a pair of first light source 101 a and second light source 101 b, 1 Two lenses 113 are provided. In the present embodiment, one cell 111 is formed in a square shape having a side of about 20 mm. However, the cell 111 is not limited to this size and has the shape shown in FIG. It is not limited.

In the light source unit 101, each of the pair of the first light source 101a and the second light source 101b is disposed at a position that is substantially symmetric (substantially symmetric) in the X-axis direction with respect to the central axis of each cell 111. Yes.

Note that the central axis is a straight line parallel to the Z axis passing through a point where the distance from each vertex in the region of the cell 111 is substantially equal. Alternatively, it may be a straight line parallel to the Z axis passing through a point where lines connecting diagonals in the region of the cell 111 intersect. Alternatively, it may be a straight line parallel to the Z axis passing through the center of gravity of the area of the cell 111.

Note that FIG. 4 shows a cell 111 disposed near the center of the illumination unit 110 as an example. Although not shown, the other cell 111 has substantially the same structure as the cell 111 shown in FIG. 4 except that the optical characteristics regarding the deflection angle of the lens 113 are different (for example, the shape of the lens 113 is different). Have.

FIG. 5 is a partially enlarged view of the light source unit 101 according to the first embodiment when viewed from the front (Z-axis direction). In FIG. 5, the boundary of the cell 111 is represented by a solid line, and the intersection of the broken lines represents the central axis of the cell 111. However, these lines are merely shown for convenience, and these lines are not actually written on the light source unit 101.

As described above, the pair of the first light source 101a and the second light source 101b are disposed at positions that are substantially symmetrical with respect to the central axis of the cell 111 in the X-axis direction. Thereby, in any of the cells 111 in the illumination unit 110, a difference in light intensity on the incident surface of the lens 113 (difference in intensity between light having the highest intensity and light having the lowest intensity on the incident surface of one lens 113). Is within a predetermined range.

It is desirable to set the arrangement positions of the first light source 101a and the second light source 101b so that the difference in intensity is 5% or less, more preferably 1% or less.

In order to reduce the difference in intensity, the first light source 101a and the second light source 101b may be arranged as close to the central axis of the cell 111 as possible. However, the first light source 101a and the second light source 101b In the meantime, it is desirable that the light emitted from the lens 113 be separated so as to reach the right eye and the left eye of the viewer who views the display image from the expected viewing position.

Further, as shown in FIG. 5, the arrangement positions (arrangement positions in the cells 111) of the pair of the first light source 101 a and the second light source 101 b are in any cell regardless of the arrangement position of the cells 111 in the illumination unit 110. 111 is substantially the same. Therefore, the generation position of light incident on the lens 113 is substantially the same in any cell 111, and no difference (substantial difference) occurs in the incident state of light on the incident surface of the lens 113 in any lens 113. .

Thereby, substantially uniform light is emitted from any cell 111 in the present embodiment. Therefore, in the image display device 100, light with substantially uniform intensity emitted from the illumination unit 110 can be used as the backlight of the panel 104.

FIG. 6 is a cross-sectional view of the image display device 100 according to the first embodiment. FIG. 6 is a cross-sectional view taken along line AA shown in FIG. FIG. 6 also shows viewers who view the display image from the assumed viewing position.

As described above, in the illumination unit 110, the generation position of light incident on the lens 113 (the position in the region of the cell 111) is substantially the same in any cell 111. However, light has to be emitted from each cell 111 toward a presumed viewing position (viewing expected position). The assumed viewing position is a position that is separated from the center of the image display surface of the image display device 100 by a predetermined distance in the Z-axis direction, and therefore has a relatively small deflection angle from the cell 111 disposed in the center of the image display surface. It is necessary to emit light at a relatively large deflection angle from the cells 111 arranged in the peripheral portion.

Therefore, in the present embodiment, as shown in FIG. 6, the deflection angle of the emitted light is larger in the lens 113 disposed in the peripheral portion than in the lens 113 disposed in the central portion of the lens array 103. In other words, the lens array 103 is configured using the lenses 113 having different optical characteristics regarding the deflection angle of the emitted light so that the light is emitted from the lens 113 at a deflection angle corresponding to the arrangement position of the cell 111.

As described above, in the present embodiment, the light emitted from the cell 111 arranged in the center of the illumination unit 110 and the light emitted from the cell 111 arranged around the illumination unit 110 are emitted from the illumination unit 110. The illuminating unit 110 is configured so that the emission direction when the light is emitted is different.

FIG. 6 shows, as an example, a state in which the light emitted from the second light source 101b is deflected by the lens array 103 and emitted from the image display device 100 and reaches the right eye of the viewer at the assumed viewing position. Although not shown, the light emitted from the first light source 101a is deflected by the lens array 103 and emitted from the image display device 100, and reaches the viewer's left eye at the assumed viewing position.

FIG. 7A is a cross-sectional view schematically showing the arrangement position of the light source and the emission direction of the emitted light of the cell 111 (referred to as “cell 111A”) arranged in the vicinity of the center of the illumination unit 110 in the first embodiment. FIG. 7B is a cross-sectional view schematically showing the arrangement position of the light source and the emission direction of the emitted light of the cell 111 (referred to as “cell 111B”) arranged around the illumination unit 110 in the first exemplary embodiment. FIG. 7A shows an enlarged view of the region 105 indicated by a broken line in FIG. 6, and FIG. 7B shows an enlarged view of the region 106.

7A and 7B, the center axis of the cell 111 is indicated by a one-dot chain line, and as an example, the optical path of light emitted from the second light source 101b is indicated by a broken line. In FIG. 7A, the lens 113 is referred to as “lens 113A”, and in FIG. 7B, the lens 113 is referred to as “lens 113B”.

In the cell 111A disposed near the center of the illumination unit 110, as shown in FIG. 7A, the light emitted from the second light source 101b is collimated by the lens 113A, and the collimated parallel light is based on the optical characteristics of the lens 113A. The light is emitted with a relatively small deflection angle and proceeds toward the assumed viewing position. Although not shown, the same applies to the light emitted from the first light source 101a.

In the cell 111B arranged around the illumination unit 110, as shown in FIG. 7B, the light emitted from the second light source 101b is collimated by the lens 113B, and the collimated parallel light is relative based on the optical characteristics of the lens 113B. The light is emitted with a large deflection angle and travels toward the assumed viewing position. Although not shown, the same applies to the light emitted from the first light source 101a.

As for the other cells 111, the description with reference to the drawings is omitted, but the light emitted from the first light source 101a and the second light source 101b is collimated by the lens 113, and the collimated light after collimation is the same as described above. The light is emitted at a deflection angle based on the optical characteristics of the lens 113 and travels toward the assumed viewing position.

FIG. 8A is a diagram schematically showing the intensity of incident light on the incident surface of the lens 113A of the cell 111A arranged in the vicinity of the center of the illumination unit 110 in the first embodiment. FIG. 8B is a diagram schematically showing the intensity of incident light on the incident surface of the lens 113B of the cell 111B arranged around the illumination unit 110 in the first embodiment. 8A and 8B show the light intensity on the lens incident surface when the second light source 101b emits light. 8A and 8B, the vertical axis represents the position on the lens incident surface, and the horizontal axis represents the light intensity on the lens incident surface.

For example, when the second light source 101b emits light, the incident light to the lens 113 is a position where the distance from the second light source 101b to the entrance surface of the lens 113 is the closest (position x0 for the lens 113A, position for the lens 113B). x3) is the strongest, and is the weakest at the farthest position (position x2 for the lens 113A and position x5 for the lens 113B).

However, since the second light source 101b is disposed in the vicinity of the central axis, the difference between the incident light having the highest intensity and the incident light having the lowest intensity is shown in FIGS. 8A and 8B. In either case, it is suppressed to a predetermined range. As described above, this predetermined range is within 5%, preferably within 1%.

The difference in the intensity of the incident light is, for example, a numerical value expressed as a percentage by dividing the difference between the intensity of the incident light having the highest intensity and the intensity of the incident light having the lowest intensity by the intensity of the incident light having the highest intensity. However, the present embodiment is not limited to this, and the intensity difference may be calculated by another method.

The explanation of the other cells 111 is omitted, but is the same as described above.

Further, although description when the first light source 101a emits light is also omitted, the first light source 101a is arranged symmetrically with the second light source 101b in the X-axis direction with respect to the central axis in any cell 111. Therefore, it is the same as described above except that a difference occurs between the position where the intensity of the incident light is the strongest and the position where the intensity is the weakest.

Thereby, in this embodiment, the light emitted from any cell 111 becomes substantially uniform light with the difference in intensity kept within a predetermined range. Therefore, the emitted light from the illumination unit 110 becomes substantially uniform light, and the quality of the display image can be improved by using this light as the backlight of the panel 104.

Next, an example of the shape of the lens 113 constituting the lens array 103 will be described.

FIG. 9A is a diagram schematically showing the lens array 103 in the first embodiment. FIG. 9B is a diagram schematically illustrating an example of the shape of each lens 113 constituting the lens array 103 in the first embodiment. FIG. 9B shows a front view, a side view, and a top view of the convex lens 114.

Each lens 113 constituting the lens array 103 may be any lens as long as it satisfies the above-described optical characteristics, but here, as an example, the objective is based on a commonly used convex lens. An example in which each lens 113 is configured so as to obtain the following optical characteristics will be described.

FIG. 9B is only shown for explaining an example of the shape of each lens 113 formed based on the target optical characteristics, and shows that each lens 113 is formed by cutting out from the convex lens 114. is not. The lens array 103 may be manufactured by an appropriate method such as a molding method.

9A and 9B, as a representative example of the lens 113 constituting the lens array 103, the center (shown as position E in FIG. 9A) and the periphery (shown as positions AD and FI in FIG. 9A). The lens 113 arrange | positioned is shown.

The convex lens 114 is a lens whose focal distance is set to be equal to the separation distance between the light source unit 101 and the lens array 103 in the image display device 100.

The lens 113 disposed at the center (position E) of the lens array 103 has a relatively small deflection angle as described above. Accordingly, as shown in FIG. 9B, the lens 113 has a shape obtained by cutting out the vicinity of the center of the convex lens 114, which is a region having a relatively small deflection angle.

The lens 113 arranged around the lens array 103 (positions A to D, F to I) has a relatively large deflection angle as described above. Therefore, as shown in FIG. 9B, these lenses 113 can obtain a deflection angle and a deflection direction corresponding to the arrangement position of the lens 113 in the peripheral region of the convex lens 114, which is a region having a relatively large deflection angle. It has a cut shape.

The description of the other lens 113 is omitted, but it is formed so as to obtain a deflection angle and a deflection direction according to the arrangement position of the lens 113, as described above.

[1-2. Operation]
The operation of the image display device 100 configured as described above will be described below.

The image display device 100 receives, for example, an image signal for the right eye and an image signal for the left eye that constitute an image for stereoscopic viewing alternately (for example, at a cycle of 120 Hz). In the present embodiment, for example, a left-eye image is a first image, and a right-eye image is a second image.

When the panel 104 is controlled by an image signal for the left eye, in each cell 111 constituting the illumination unit 110, the first light source 101a emits light and the second light source 101b is turned off. The light emitted from the first light source 101a is collimated by the lens 113 and is emitted at a deflection angle corresponding to the arrangement position of the lens 113. That is, the light emission of the first light source 101a collimated with parallel light is emitted from each cell 111 toward the assumed viewing position.

The light emitted from each cell 111 passes through the panel 104 and enters only the left eye of the viewer at the assumed viewing position.

Since the light that enters the viewer's left eye is modulated on the panel 104 based on the image signal for the left eye, the image for the left eye based on this image signal is visible to the viewer's left eye.

When the panel 104 is controlled by the image signal for the right eye, in each cell 111 constituting the illumination unit 110, the second light source 101b emits light and the first light source 101a is turned off. The light emitted from the second light source 101b is collimated by the lens 113 and is emitted at a deflection angle corresponding to the arrangement position of the lens 113. That is, the light emitted from the second light source 101b collimated to the parallel light is emitted from each cell 111 toward the assumed viewing position.

As shown in FIG. 6, the light emitted from each cell 111 passes through the panel 104 and enters only the right eye of the viewer at the assumed viewing position.

Since the light that enters the viewer's right eye is modulated on the panel 104 based on the right eye image signal, the viewer's right eye can see the right eye image based on the image signal.

As described above, when the left-eye image is displayed to the viewer who views the stereoscopic image displayed on the image display device 100 from the assumed viewing position, the left-eye light source (first Since the light emitted from the light source 101a enters only the left eye, the image for the left eye can be seen only by the left eye. Conversely, when the right-eye image is displayed, the light emitted from the right-eye light source (second light source 101b) enters only the right eye, so that the right-eye image can be viewed only with the right eye. it can. Thus, the viewer can stereoscopically view the stereoscopic image displayed on the image display device 100 with the naked eye.

[1-3. Effect]
As described above, in the illumination unit 110 of the image display apparatus 100 according to the present embodiment, the arrangement position (cell) of the pair of the first light source 101a and the second light source 101b in any cell 111 regardless of the arrangement position of the cell 111. The arrangement position in 111) is substantially the same. The difference in light intensity at the entrance surface of each lens 113 is suppressed within a predetermined range (5%, preferably 1%).

Each lens 113 constituting the lens array 103 for collimating incident light has different optical characteristics regarding the deflection angle depending on the arrangement position of the lens 113, and its emission direction is a presumed viewing position (viewing expected position). is there.

Therefore, each cell 111 constituting the illumination unit 110 emits parallel light having substantially uniform intensity toward the right or left eye of the viewer at the assumed viewing position.

In this way, the image display device 100 uses the parallel light with substantially uniform intensity emitted from the illumination unit 110 as the backlight, and the first image (for example, the image for the left eye) and the second image (for example, the right eye). Are displayed on the panel 104 alternately. Accordingly, a viewer who views the image display apparatus 100 from the assumed viewing position can display an image with a high-quality backlight with improved intensity uniformity, and the image for the left eye is the image for the right eye only with the left eye. Can be seen only with the right eye. That is, the viewer can stereoscopically view a high-quality stereoscopic image with the naked eye without using dedicated glasses or the like.

(Embodiment 2)
Hereinafter, the second embodiment will be described with reference to FIGS.

[2-1. Constitution]
The image display device 500 according to the second embodiment has substantially the same appearance, configuration, and function as the image display device 100 shown in the first embodiment, and operates substantially the same, and thus detailed description thereof is omitted. . Also, the viewing position (viewing position assumed in advance) when the viewer views the display image is the same as in the first embodiment. However, the illumination unit 510 included in the image display device 500 has a configuration different from that of the illumination unit 110 described in the first embodiment. Hereinafter, this difference will be described.

FIG. 10 is an exploded perspective view schematically showing the configuration of the illumination unit 510 in the second embodiment. FIG. 10 shows an enlarged part of the illumination unit 510.

In the following, components having substantially the same operations, functions, and configurations as those shown in the first embodiment are given the same reference numerals as those shown in the first embodiment, and description thereof is omitted. .

The illumination unit 510 includes a light source unit 101, a light shielding unit 102, and a lens array 503, and is configured by arranging a plurality of cells 511 (not shown) having these components as planar elements. However, unlike the illumination unit 110 of the first embodiment, the illumination unit 510 includes a deflecting lens 507 that is a deflecting optical element at the subsequent stage of the lens array 503 (between the lens array 503 and the panel 104).

Since the light source unit 101 and the light shielding unit 102 are substantially the same as the light source unit 101 and the light shielding unit 102 shown in the first embodiment, description thereof is omitted. The structure of the cell 511 is substantially the same as that of the cell 111 described in Embodiment 1.

Similarly to the lens array 103 of the first embodiment, the lens array 503 is formed by arranging a plurality of lenses 513 in a matrix in the X-axis direction and the Y-axis direction in parallel with the image display surface. The lens 513 collimates the light emitted from the first light source 101a and the second light source 101b into substantially parallel light and emits the light as in the lens 113 constituting the lens array 103. However, unlike the lens 113, the lens 513 has the same (substantially equal) optical characteristics regarding the deflection angle. Since each cell 511 includes this lens 513, the light emitted from each cell 511 is in the same direction (practically the same). The emission direction is, for example, a direction (front direction) parallel to the Z axis.

In each cell 511, it is desirable to set the arrangement position of each lens 513 so that the optical axis of the lens 513 overlaps the center axis of the cell 511.

The deflection lens 507 receives the light emitted from each lens 513, that is, the light emitted from each cell 511, deflects the light to a presumed viewing position (viewing assumed position), and emits the light. The outgoing direction of the outgoing light from the deflection lens 507 is the direction of the assumed viewing position. Specifically, for example, the light emission of the first light source 101a is emitted toward the left eye of the viewer at the assumed viewing position, and the light emission of the second light source 101b is emitted toward the right eye of the viewer. That is, the deflection lens 507 has the same function as the lens array 103 shown in Embodiment 1 in that incident light is deflected and emitted toward the assumed viewing position.

Therefore, the light emitted from the illumination unit 510 is substantially equal to the light emitted from the illumination unit 110 described in Embodiment 1, and travels toward the right or left eye of the viewer at the assumed viewing position. To do.

Note that, in the light source unit 101 and the lens array 503 in FIG. 10, the boundaries of the cells 511 are indicated by broken lines for convenience.

In the present embodiment, one cell 511 is formed in a square shape having a side of about 20 mm, as in the first embodiment, but the cell 511 is not limited to this size. There is no limitation to the shape shown in FIG.

FIG. 11 is a cross-sectional view of the image display device 500 according to the second embodiment. FIG. 11 is a cross-sectional view similar to FIG.

As described above, in the illumination unit 510, the emission directions of the light emitted from the lens 513 are the same (substantially equal). However, since the illumination unit 510 includes the deflection lens 507 at the subsequent stage of the lens array 503, the light deflected by the deflection lens 507 is emitted from the illumination unit 510 and travels toward the assumed viewing position.

FIG. 11 shows a state in which the light emitted from the second light source 101b is deflected by the deflecting lens 507 and reaches the right eye of the viewer at the assumed viewing position. It is deflected by the deflecting lens 507 and reaches the viewer's left eye at the assumed viewing position.

FIG. 12A is a cross-sectional view schematically showing the arrangement position of the light source and the emission direction of the emitted light of the cell 511 (referred to as “cell 511A”) arranged near the center of the illumination unit 510 in the second embodiment. FIG. 12B is a cross-sectional view schematically showing the arrangement position of the light source and the emission direction of the emitted light in cell 511 (referred to as “cell 511B”) arranged around illumination unit 510 in the second embodiment. 12A shows an enlarged view of the region 505 indicated by a broken line in FIG. 11, and FIG. 12B shows an enlarged view of the region 506.

As shown in FIGS. 12A and 12B, in the illumination unit 510, the cell 511A disposed near the center and the cell 511B disposed near the center are the same as each other (substantially the optical characteristics related to the deflection angle of the lens 513). The same) structure. Although not shown, the same applies to the other cells 511.

Therefore, parallel light is emitted from any cell 511 constituting the illumination unit 510 in the same direction (for example, a direction parallel to the X axis).

Then, the parallel light emitted from each cell 511 is deflected by the deflection lens 507 at a deflection angle based on the arrangement position of each cell 511 and is emitted toward the assumed viewing position.

For example, as shown in FIG. 12A, parallel light emitted from the cell 511A arranged in the vicinity of the center is incident near the center of the deflection lens 507. Therefore, the parallel light is relatively based on the optical characteristics of the deflection lens 507 in that region. The light is emitted from the deflecting lens 507 with a small deflection angle and proceeds toward the assumed viewing position.

As shown in FIG. 12B, the parallel light emitted from the cell 511 </ b> B arranged in the periphery enters the vicinity of the periphery of the deflection lens 507. Is emitted from the deflection lens 507 and proceeds toward the assumed viewing position.

In each cell 511, the intensity of the incident light on the incident surface of the lens 513 is substantially the same as that shown in FIGS. 8A and 8B, and a predetermined range (within 5%, preferably 1% or less). Therefore, the light emitted from any cell 511 is substantially uniform light with the intensity difference kept within a predetermined range.

Next, a configuration example of the deflection lens 507 will be described.

FIG. 13A is a diagram schematically showing the deflection lens 507 in the second embodiment. FIG. 13B is a diagram schematically illustrating an example of the shape of a lens constituting the deflection lens 507 in the second embodiment. FIG. 13B shows a front view, a side view, and a top view of the convex lens 514.

The deflecting lens 507 may be any lens that satisfies the above-described optical characteristics, but here, as an example, the objective optical characteristics are obtained based on a commonly used convex lens. An example in which the deflection lens 507 is configured will be described.

Note that FIG. 13B is only shown for explaining an example of the shape of the deflection lens 507 formed based on the target optical characteristics, and shows that the deflection lens 507 is formed by cutting out from the convex lens 514. is not. The deflection lens 507 may be manufactured by an appropriate method such as a molding method.

The convex lens 514 is a lens in which the focal length is set to be equal to the separation distance from the deflection lens 507 to the position set as the assumed viewing position.

The deflection lens 507 has a shape in which the convex lens 514 set in this way is cut out based on the size of the deflection lens 507 so that the optical axis of the convex lens 514 is at the center of the deflection lens 507 as shown in FIG. 13B. Have

The lens array 503 may be formed by arranging, for example, a plurality of lenses having the same shape as the lens 113 shown at the position E in FIGS. 9A and 9B.

[2-2. Operation]
The operation of the image display device 500 configured as described above is the same as the image display shown in Embodiment 1 except that the configuration of the illumination unit 510 included in the image display device 500 is different from that of the illumination unit 110 shown in Embodiment 1. Since it is substantially the same as the apparatus 100, description is abbreviate | omitted.

[2-3. Effect]
In the image display apparatus 500 configured as described above, as in the first embodiment, regardless of the position of the cell 511, the position of the pair of the first light source 101a and the second light source 101b ( The arrangement position in the cell 511) is substantially the same. Therefore, the difference in light intensity at the incident surface of each lens 513 is suppressed within a predetermined range (5%, preferably 1%), and the intensity is substantially uniform from each cell 511 constituting the illumination unit 510. Parallel light is emitted.

However, unlike the first embodiment, the parallel light is emitted in substantially the same direction, and the emitted light is deflected by the deflection lens 507 disposed at the subsequent stage of the lens array 503 and emitted toward the assumed viewing position. The

As described above, the illumination unit 510 described in Embodiment 2 is different in configuration from the illumination unit 110 described in Embodiment 1, but its operation and intended effect (ie, emitted light) are different. To increase the uniformity) is substantially the same.

Therefore, the image display device 500 in the second embodiment has no substantial difference in operation as compared with the image display device 100 shown in the first embodiment, and the main effect obtained, that is, the viewer is The effect that a high-quality display image by a highly uniform backlight can be stereoscopically viewed with the naked eye without using dedicated glasses or the like is substantially the same.

However, since the lens array 503 in the present embodiment is configured by the lenses 513 having the same optical characteristics regarding the deflection angle, the lens array 503 is more manufactured than the lens array 103 including the lenses 113 having different optical characteristics regarding the deflection angle. The difficulty level can be reduced.

(Other embodiments)
As described above, Embodiments 1 and 2 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, and the like are performed. Moreover, it is also possible to combine each component demonstrated in the said Embodiment 1, 2 and it can be set as a new embodiment.

Therefore, other embodiments will be exemplified below.

In Embodiments 1 and 2, as an example of the lens array, an example in which each lens constituting the lens array is configured by a single lens has been described. However, the lens array is not limited to this. Any object may be used as long as the desired optical characteristics can be obtained.

FIG. 14A is a schematic view of a configuration example of a lens array according to another embodiment viewed from the front (Z-axis direction). FIG. 14B is a schematic view of another configuration example of the lens array according to another embodiment viewed from the front (Z-axis direction). In FIGS. 14A and 14B, the cell boundary is represented by a solid line, and the intersection of the broken lines represents the central axis of the cell. However, these lines are shown for convenience only, and these lines are not actually marked on the lens array.

For example, as shown in FIG. 14A, the lens array 103 shown in Embodiment 1 may be replaced with a lens array 123 configured with a Fresnel lens whose optical characteristics regarding the deflection angle are substantially equal to the lens array 103. Similarly, as shown in FIG. 14B, the lens array 503 shown in the second embodiment may be replaced with a lens array 523 configured with a Fresnel lens whose optical characteristics regarding the deflection angle are substantially equal to the lens array 503. .

In FIGS. 14A and 14B, the deflection direction of the emitted light is represented by the arrangement position of the ring with respect to the center axis of the cell indicated by the intersection of the broken lines.

Although not shown, the deflection lens 507 shown in the second embodiment can also be replaced with a Fresnel lens whose optical characteristics regarding the deflection angle are substantially equal to those of the deflection lens 507.

As described above, when the lens arrays 103 and 503 and the deflection lens 507 are replaced with Fresnel lenses having functions equivalent to those, the thickness of the image display device is reduced as compared with the configuration examples described in the first and second embodiments. It can be made thinner.

In particular, replacing the deflection lens 507 with a Fresnel lens having an equivalent function is effective in increasing the screen size of the image display device 500.

Although not shown, the lens arrays 103 and 503 and the deflection lens 507 may be configured by a combined lens or may be configured by a diffractive lens.

Also, the deflection lens 507 may be configured by an assembly of a plurality of lenses having different optical characteristics regarding the deflection angle, like the lens array 103 shown in the first embodiment.

Alternatively, the deflection lens 507 is replaced with a deflection plate that is made of glass having a thickness inclined so as to obtain a target deflection angle and that has substantially the same optical characteristics as the deflection lens 507. May be used.

However, in any case, the optical characteristics related to the deflection angle of each lens array or deflection lens are set so that parallel light is emitted from the illumination unit toward the assumed viewing position. In the first and second embodiments, the assumed viewing position is a position separated from the center of the panel 104 by a predetermined distance in the Z-axis direction. However, the assumed viewing position is not limited to this position.

Further, the image display devices 100 and 500 may include a diffusion plate. FIG. 15 is an exploded perspective view schematically showing a configuration including a diffusion plate 124 according to another embodiment. FIG. 15 shows an example of another embodiment of the image display device 100.

As shown in FIG. 15, for example, the image display device 100 may have a configuration in which a diffusion plate 124 is interposed between the illumination unit 110 and the panel 104. Although not shown, a similar diffusing plate 124 may be inserted between the illumination unit 510 and the panel 104 in the image display device 500 shown in Embodiment 2.

The diffusion plate 124 diffuses the light emitted from the illumination unit 110 or the illumination unit 510 and enters the panel 104. By providing the diffusion plate 124, the light emitted from the illumination unit 110 or the illumination unit 510 can be made more uniform and used for the backlight of the panel 104.

The diffusion plate 124 has a direction in which diffusion in a direction perpendicular to the arrangement direction of the first light source 101a and the second light source 101b (Y-axis direction) is parallel to the arrangement direction of the first light source 101a and the second light source 101b ( It is desirable to be configured to be larger than diffusion in the (X-axis direction). This is due to the following reason.

The arrangement direction (X-axis direction) of the first light source 101a and the second light source 101b is the viewer's parallax direction. Therefore, the diffusion of light in the X-axis direction is undesirable because it obstructs the viewer's autostereoscopic vision. On the other hand, since the Y-axis direction is not the viewer's parallax direction, even if light is diffused in this direction, it is unlikely that the viewer is obstructed by stereoscopic vision. From the above, it is desirable that the diffusion plate 124 is configured so that the diffusion in the Y-axis direction is larger than the diffusion in the X-axis direction.

In the first and second embodiments, the example in which the cell has a square shape has been described. However, the cell may have another shape.

FIG. 16 is an exploded perspective view schematically showing an example of the shape of a cell in another embodiment.

As another embodiment, for example, as shown in FIG. 16, the illumination part may be configured by forming a light shielding wall so that the shape of the cell when viewed from the Z-axis direction is a hexagon. However, in order to reduce the light emitted from the first light source 101a and the second light source 101b by being reflected by the light-shielding wall inside the cell, the six light sources on the extension of the line connecting the first light source 101a and the second light source 101b. It is desirable to form the light shielding wall so that the corners of the square are arranged.

Further, even if the cell shape when viewed from the Z-axis direction is a quadrangle, the light shielding wall is arranged so that the quadrangle apex is arranged on the extension of the line connecting the first light source 101a and the second light source 101b. By forming, it can reduce that the light emission of the 1st light source 101a and the 2nd light source 101b is reflected and light-emitted by the light-shielding wall.

In the first embodiment, the left-eye image constituting the stereoscopic image is the first image, the right-eye image is the second image, and the light emission of the first light source 101a is displayed from the assumed viewing position. The example in which the light is emitted toward the left eye of the viewer who views the image and the light emission of the second light source 101b is emitted toward the right eye of the viewer has been described. However, the right-eye image is the first image, the left-eye image is the second image, the first light source 101a emits light toward the viewer's right eye, and the second light source 101b emits light. You may comprise so that it may radiate | emit toward the left eye. Moreover, the period which displays a 1st image and a 2nd image alternately may be numerical values other than 120 Hz, and the structure which alternates irregularly may be sufficient. In addition, the first image and the second image may not be the first image and the second image, but the first image and the second image may be independent from each other. It may be an image. Further, the first image and the second image may be either a still image or a moving image.

In addition, the arrangement positions of the first light source 101a and the second light source 101b may be reversed from the arrangement positions shown in FIGS. 3 to 5. When the second image is displayed on the panel 104, the first light source 101a emits light. The second light source 101b may be turned off, and when the first image is displayed on the panel 104, the second light source 101b may emit light and the first light source 101a may be turned off.

In the above description, the spatial angle distribution of the emitted light of each of the first light source 101a and the second light source 101b is assumed to be isotropic for easy understanding, but the present disclosure The spatial angle distribution of the emitted light of each of the first light source 101a and the second light source 101b is not limited to be isotropic. For example, the spatial angle distribution of the emitted light that reduces the difference in the intensity of the incident light of the lens 113 due to a slight shift between the first light source 101a and the second light source 101b with respect to the central axis in FIG. By providing the second light source 101b, the uniformity of light intensity as a backlight can be further improved.

It should be noted that the specific numerical values shown in the first and second embodiments are merely examples in the embodiment, and the present disclosure is not limited to these numerical values. It is desirable to set each numerical value to an optimal value according to the specifications of the image display apparatus.

The present disclosure is applicable to an image display device that alternately displays a first image and a second image. Specifically, the present disclosure can be applied to a liquid crystal television or the like that can stereoscopically view a stereoscopic image displayed on the image display surface with the naked eye.

DESCRIPTION OF SYMBOLS 100,500 Image display apparatus 101,131 Light source part 101a 1st light source 101b 2nd light source 102,132 Light-shielding part 103,123,133,503,523 Lens array 104 Panel 105,106,505,506 Area | region 110,510 Illumination part 111, 111A, 111B, 511, 511A, 511B Cell 113, 113A, 113B, 513, 513A, 513B Lens 114, 514 Convex lens 124 Diffusion plate 507 Deflection lens

Claims (7)

1. An image display device that alternately displays a first image and a second image,
   A first light source that emits light for displaying the first image, a second light source that emits light for displaying the second image, and substantially the light from the first light source and the second light source. A illuminating unit in which a plurality of cells having a collimating lens for collimated light are arranged in a plane,
   A spatial light modulation panel that modulates light emitted from the illumination unit based on a first image signal corresponding to the first image and a second image signal corresponding to the second image;
   With
   The first light source and the second light source are disposed substantially symmetrically with respect to the central axis of the cell,
   The light emitted from the cell arranged in the center of the illumination unit and the light emitted from the cell arranged around the illumination unit are configured so that the emission directions when emitted from the illumination unit are different. ,
   Image display device.
2. The emission direction is a direction from each cell to a viewing position of the image display device assumed in advance.
   The image display device according to claim 1.
3. The lenses arranged in each cell are element lenses having different deflection angles.
   The image display device according to claim 1.
4. The illumination unit is further provided with a deflecting optical element that is arranged at a rear stage of the lens arranged in each cell and deflects the emission direction of the light emitted from each cell.
   The image display device according to claim 1.
5. A diffusion plate that is inserted between the illumination unit and the spatial light modulation panel and diffuses the light emitted from the illumination unit;
   The diffusion plate is configured such that diffusion in the direction perpendicular to the arrangement direction of the first light source and the second light source of the cell is larger than diffusion in a direction parallel to the arrangement direction.
   The image display device according to claim 1.
6. Each of the cells has a light shielding wall that shields light from an adjacent cell.
   The image display device according to claim 1.
7. An illumination device used in an image display device that alternately displays a first image and a second image,
   A first light source that emits light for displaying the first image, a second light source that emits light for displaying the second image, and substantially the light from the first light source and the second light source. And a lighting unit in which a plurality of cells having a lens collimating parallel light are arranged in a plane,
   The first light source and the second light source are disposed substantially symmetrically with respect to the central axis of the cell,
   The light emitted from the cell arranged in the center of the illumination unit and the light emitted from the cell arranged around the illumination unit are configured so that the emission directions when emitted from the illumination unit are different. ,
   Lighting device.

Images