WO2019059071A1

WO2019059071A1 - Three-dimensional display device and moving body

Info

Publication number: WO2019059071A1
Application number: PCT/JP2018/033856
Authority: WO
Inventors: 秀也高橋; 濱岸　五郎; 薫草深
Original assignee: 公立大学法人大阪市立大学; 京セラ株式会社
Priority date: 2017-09-25
Filing date: 2018-09-12
Publication date: 2019-03-28
Also published as: JP2019060989A

Abstract

This three-dimensional display device comprises a display panel and an optical element. The display panel has a display surface having a shape that is at least a part of the shape of a cylindrical plane around the center axis. Left sub-pixel groups and right sub-pixel groups are arrayed in a grid pattern along the direction of the center axis and the circumferential direction around the center axis in the display surface. The left sub-pixel groups and the right sub-pixel groups are alternately arrayed in the circumferential direction. Each left sub-pixel group has sub pixels for displaying an image for a left eye. Each right sub-pixel group has sub pixels for displaying an image for a right eye. The optical element includes: a plurality of light-reduction regions which are arranged along the display surface 51 and in which image light from the display surface is reduced or blocked; and a plurality of light-transmissive regions through each of which the image light is transmitted at a higher transmittance than that of each light-reduction region. The plurality of light-reduction regions and the plurality of light-transmissive regions are alternately arrayed along the circumferential direction so as to be adjacent to each other. The light-reduction regions and the light-transmissive regions are alternately arrayed at approximately the same interval in the circumferential direction. This interval is defined on the basis of: the radius R of curvature of an arc formed by a cross section, of the display surface, that is taken along a plane orthogonal to the direction of the center axis; an image pitch that is the interval at which the left sub-pixel groups and the right sub-pixel groups are arranged; and the gap between the display surface and the optical element.

Description

Three-dimensional display device and moving body

Cross-reference to related applications

This application claims the priority of Japanese Patent Application No. 2017-184198 filed on Sep. 25, 2017, and the entire disclosure of the prior application is incorporated herein by reference.

The present disclosure relates to a three-dimensional display device and a movable body.

Conventionally, a three-dimensional display device using a parallax barrier that defines the direction of image light that performs three-dimensional display without using glasses is known. In Patent Document 1, a filter (parallax barrier) is used to cause a part of the image light emitted from the flat display panel to reach the right eye, and another part of the image light emitted from the display panel A three-dimensional display has been described which causes the left eye to reach.

Japanese Patent Laid-Open No. 7-287196

The three-dimensional display device of the present disclosure includes a display panel and an optical element. The display panel comprises a display surface having the shape of at least a portion of a cylindrical surface around a central axis. The left sub-pixel group and the right sub-pixel group are arranged in a lattice along the circumferential direction around the central axis in the display surface and the central axis direction. The left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction. The left sub-pixel group has sub-pixels for displaying a left-eye image. The right sub-pixel group includes sub-pixels that display a right-eye image. The optical element is disposed along the display surface, and a plurality of light reduction regions for reducing or blocking image light from the display surface, and a plurality of light components transmitting the image light with a higher transmittance than the light reduction region. And a translucent region of The plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction. The circumferential intervals at which the light reduction regions and the light transmission regions are alternately arranged are substantially equal. The interval is a radius of curvature of an arc formed by a cross section of a plane orthogonal to the central axis direction of the display plane, an image pitch which is an arrangement interval of the left sub-pixel group and the right sub-pixel group, and the display plane and the It is defined based on the gap between the optical element.

The three-dimensional display device of the present disclosure includes a display panel and an optical element. The display panel comprises a display surface having the shape of at least a portion of a cylindrical surface around a central axis. The left sub-pixel group and the right sub-pixel group are arranged in a lattice along the circumferential direction around the central axis in the display surface and the central axis direction. The left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction. The left sub-pixel group has sub-pixels for displaying a left-eye image. The right sub-pixel group includes sub-pixels that display a right-eye image. The optical element is disposed along the display surface, and a plurality of light reduction regions for reducing or blocking image light from the display surface, and a plurality of light components transmitting the image light with a higher transmittance than the light reduction region. And a translucent region of The plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction. The first ratio and the second ratio are substantially equal. The first ratio corresponds to the light reduction area corresponding to the first area with respect to an interval in which the left sub-pixel group and the right sub-pixel group are arranged in the circumferential direction in the first area on the display surface. It is a ratio of intervals arranged in the circumferential direction. The second ratio corresponds to the two areas with respect to an interval at which the left sub-pixel group and the right sub-pixel group are arranged in the circumferential direction in a second area different from the first area on the display surface. A light reduction area is a ratio of intervals arranged in the circumferential direction. The ratio is defined based on a radius of curvature of an arc formed by a cross section of a surface orthogonal to the central axis direction of the display surface, and a gap between the display surface and the optical element. It is determined based on the curvature.

The mobile unit of the present disclosure includes a three-dimensional display. The three-dimensional display device includes a display panel and an optical element. The display panel comprises a display surface having the shape of at least a portion of a cylindrical surface around a central axis. The display panel comprises a display surface having the shape of at least a portion of a cylindrical surface around a central axis. The left sub-pixel group and the right sub-pixel group are arranged in a lattice along the circumferential direction around the central axis in the display surface and the central axis direction. The left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction. The left sub-pixel group has sub-pixels for displaying a left-eye image. The right sub-pixel group includes sub-pixels that display a right-eye image. The optical element is disposed along the display surface, and a plurality of light reduction regions for reducing or blocking image light from the display surface, and a plurality of light components transmitting the image light with a higher transmittance than the light reduction region. And a translucent region of The plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction. The circumferential intervals at which the light reduction regions and the light transmission regions are alternately arranged are substantially equal. The interval is a radius of curvature of an arc formed by a cross section of a plane orthogonal to the central axis direction of the display plane, an image pitch which is an arrangement interval of the left sub-pixel group and the right sub-pixel group, and the display plane and the It is defined based on the gap between the optical element.

The mobile unit of the present disclosure includes a three-dimensional display. The three-dimensional display device includes a display panel and an optical element. The display panel comprises a display surface having the shape of at least a portion of a cylindrical surface around a central axis. The left sub-pixel group and the right sub-pixel group are arranged in a lattice along the circumferential direction around the central axis in the display surface and the central axis direction. The left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction. The left sub-pixel group has sub-pixels for displaying a left-eye image. The right sub-pixel group includes sub-pixels that display a right-eye image. The optical element is disposed along the display surface, and a plurality of light reduction regions for reducing or blocking image light from the display surface, and a plurality of light components transmitting the image light with a higher transmittance than the light reduction region. And a translucent region of The plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction. The first ratio and the second ratio are substantially equal. The first ratio corresponds to the light reduction area corresponding to the first area with respect to an interval in which the left sub-pixel group and the right sub-pixel group are arranged in the circumferential direction in the first area on the display surface. It is a ratio of intervals arranged in the circumferential direction. The second ratio corresponds to the two areas with respect to an interval at which the left sub-pixel group and the right sub-pixel group are arranged in the circumferential direction in a second area different from the first area on the display surface. A ratio of intervals at which the light reduction regions are arranged in the circumferential direction is a second ratio. The ratio is defined based on a radius of curvature of an arc formed by a cross section of a surface orthogonal to the central axis direction of the display surface, and a gap between the display surface and the optical element. It is determined based on the curvature.

FIG. 1 is a view showing an example in which the three-dimensional display device of the first embodiment is viewed from a second direction. FIG. 2 is a plan view of the display panel shown in FIG. FIG. 3 is a plan developed view of the optical element shown in FIG. FIG. 4 is a schematic view for explaining the relationship between the interocular distance, the gap, the barrier pitch, the image pitch, and the radius of curvature of the arc in the three-dimensional display device shown in FIG. FIG. 5 is a plan view of the three-dimensional display shown in FIG. 1 viewed from the optical element side. FIG. 6 is a diagram showing an example in which the eye of the user visually recognizes the vicinity of the end portion of the display panel. FIG. 7 is a schematic view for explaining the visible region when the barrier pitch deviates from the ideal value. FIG. 8A is a schematic view for explaining the visible region when the user's eye is at the reference position. FIG. 8B is a schematic diagram for explaining the visible region when the user's eye is displaced by less than 2E / n from the reference position. FIG. 8C is a schematic diagram for explaining the visible region when the user's eye is displaced by 2E / n from the reference position. FIG. 9 is a schematic view for explaining the visible region when the user's eye is displaced in the third direction from the interocular center. FIG. 10 is a diagram showing an example in which the three-dimensional display device of the second embodiment is viewed from the second direction. FIG. 11 is a schematic diagram for explaining the relationship between the interocular distance, the gap, the barrier pitch, the image pitch, and the radius of curvature of the arc in the three-dimensional display device shown in FIG. FIG. 12 is a view of another example of the three-dimensional display device of the first embodiment as viewed from the optical element side. FIG. 13 is a view of another example of the three-dimensional display device of the first embodiment as viewed from the optical element side. FIG. 14 is a schematic configuration diagram of a three-dimensional display device when the optical element of the three-dimensional display device of the first embodiment is a lenticular lens. FIG. 15 is a view showing an example of a movable body on which the three-dimensional display shown in FIGS. 1 and 10 is mounted. FIG. 1 is a schematic view of a planar three-dimensional display according to the prior art.

In a three-dimensional display device having a flat display panel like the above-mentioned prior art, the arrangement of each component is defined in order to allow image light from a desired image to reach each of the left eye and right eye. ing. Specifically, relationships such as the distance from the user's eye to the parallax barrier, the distance from the parallax barrier to the display panel, the arrangement interval of the parallax barrier, and the like are defined.

Specifically, as shown in FIG. 16, in the conventional three-dimensional display device 103, the gap g between the parallax barrier 106 and the display panel 105 and the distance d between the user's eye and the parallax barrier 106. Is defined by the relationship of d: Bp = (d + g): k. Here, Bp is the arrangement interval of the parallax barrier 106 (barrier pitch), k is the arrangement interval on the display panel 105 of the right eye image that the right eye should recognize and the left eye image that the left eye should recognize ). The above-described relationship can be established in any region on the flat display panel 105. By appropriately designing the barrier pitch Bp, the image pitch k, and the gap g according to the distance d according to the application of the three-dimensional display device 103, the occurrence of crosstalk can be suppressed in an arbitrary region on the display panel 105. Cross talk is caused by the left eye reaching the right eye image and / or the right eye reaching the left eye image.

However, in a three-dimensional display device having a curved display panel, when the user refers to each region on the display panel, the relationship between the gap g, the distance d, the barrier pitch Bp, and the image pitch k as described above. Will not hold. For this reason, it is necessary to change the barrier pitch Bp in accordance with the position facing the display panel so as not to generate crosstalk. However, in consideration of the position of the user's eyes and the orientation of the face, changing the barrier pitch Bp depending on the position requires complicated design and is not easy.

The present disclosure provides a three-dimensional display and a movable body in which an image displayed by a three-dimensional display having a curved display panel can be appropriately viewed.

Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. Each drawing in the present disclosure is schematic. The dimensional ratios and the like in the drawings do not necessarily match the actual ones.

As shown in FIG. 1, the three-dimensional display device 3 of the first embodiment is configured to include an irradiator 4, a display panel 5, and a parallax barrier 6 as an optical element.

The irradiator 4 planarly illuminates the display panel 5. The irradiator 4 may be configured to include a light source, a light guide plate, a diffusion plate, a diffusion sheet, and the like. The irradiator 4 emits irradiation light by a light source, and makes the irradiation light uniform in the surface direction of the display panel 5 by a light guide plate, a diffusion plate, a diffusion sheet or the like. Then, the irradiator 4 emits the homogenized light toward the display panel 5.

The display surface 51 of the display panel 5 is a surface that forms a part of a cylindrical surface around a virtual central axis. The display surface 51 is disposed inside the cylindrical surface. The direction perpendicular to the central axis and along the cylindrical surface forming the display surface 51 is called the circumferential direction. Circumferential direction, when the eye between the centers O _E of the user is at the center axis, the user is parallax direction when observing the display surface 51 of the front. Circumferential direction of the center O _P of the display surface 51 is the first direction. The first direction is shown as the x-axis direction in FIG. The direction along the central axis is called the central axis direction. The central axial direction is a second direction. The second direction is shown as the y-axis direction in FIG. In the display surface 51, a cross section of a surface orthogonal to the second direction forms an arc. In the following description, a direction orthogonal to the first direction and the second direction is referred to as a third direction. The third direction is shown as the z-axis direction in FIG.

The display panel 5 is arranged to be irradiated to the irradiator 4 from the side opposite to the center of the arc.

As shown in FIG. 2, in the display surface 51, a direction corresponding to the circumferential direction is taken as a first in-plane direction (u-axis direction). A direction corresponding to the central axial direction is taken as a second in-plane direction (v-axis direction). As described above, since the display surface 51 has no curvature in the central axial direction, the central axial direction may correspond to the second direction. In FIG. 2, for convenience of explanation, the display panel 5 is shown in a plane constituted by a sheet of paper, but in fact the display panel 5 has a curved surface in which the face to the user side is recessed and the xz plane The cross section according to is curved to form an arc.

The display surface 51 includes a plurality of divided areas arranged in a lattice along the circumferential direction and the central axis direction. One subpixel corresponds to each of the divided regions. The plurality of sub-pixels are arranged in a matrix along the circumferential direction and the central axis direction. The shapes of the plurality of sub-pixels are substantially equal to one another. Specifically, circumferential lengths of the plurality of sub-pixels are substantially equal. The lengths in the central axis direction of the plurality of sub-pixels are substantially equal.

Each subpixel corresponds to one of R (Red), G (Green), and B (Blue). The three sub-pixels of R, G and B can constitute one pixel as a set. One pixel is sometimes referred to as one pixel. On the display surface 51, a plurality of pixels are arranged in a matrix along the circumferential direction and the central axis direction. The display panel 5 is not limited to the transmissive liquid crystal panel, and may be a self-luminous display panel such as an organic EL. When the display panel 5 is a self-luminous display panel, the irradiator 4 is unnecessary.

On the display surface 51, the sub-pixel group Pg continuously arranged in n rows in the circumferential direction is arranged. In the example shown in FIG. 2, n = 12. However, n is not limited to 12 and may be any even number. Sub-pixel group Pg is repeatedly arranged adjacent to each other in the circumferential direction. Sub-pixel group Pg is repeatedly arranged adjacent to a position shifted by one sub-pixel in the circumferential direction in the central axis direction.

Sub-pixel group Pg includes left sub-pixel group Pgl and right sub-pixel group Pgr. The left sub-pixel group Pgl and the right sub-pixel group Pgr are alternately and repeatedly arranged adjacent to each other in the circumferential direction.

The left sub-pixel group Pgl includes sub-pixels of predetermined rows and columns. Specifically, the left sub-pixel group Pgl is arranged continuously (n / 2) × b (n rows) in the central axis direction and n / 2 (n / 2 columns) in the circumferential direction. b) A plurality (hereinafter referred to as (n / 2) × b = m) of sub-pixels P1 to Pm. The right sub-pixel group Pgr includes sub-pixels of predetermined rows and columns similar to the left sub-pixel group Pgl. Specifically, in the right sub-pixel group Pgr, m sub-pixels P (b rows (b rows) in the central axis direction, n / 2 (n / 2 m + 1) to P (2 × m) are included.

In the example shown in FIG. 2, b = 1. Therefore, on the display surface 51, a left sub-pixel group Pgl including six sub-pixels P1 to P6 arranged one by one in the central axis direction and six in the circumferential direction is arranged. On the display surface 51, a right sub-pixel including six sub-pixels P7 to P12 continuously arranged one by one in the central axis direction and six each in the circumferential direction adjacent to the left sub-pixel group Pgl in the circumferential direction Pixel group Pgr is arranged.

The left eye image is displayed on the sub-pixels P1 to P6 included in the left sub-pixel group Pgl. The right eye image is displayed on the sub-pixels P7 to P12 included in the right sub-pixel group Pgr. Although the example shown in FIG. 2 is described as b = 1, b may be any integer of 1 or more.

The arrangement interval of the left sub-pixel group Pgl is an image pitch k. The image pitch k is the sum of the circumferential length of the left sub-pixel group Pgl and the circumferential length of the right sub-pixel group Pgr. Since the left sub-pixel group Pgl and the right sub-pixel group Pgr are alternately arranged in the circumferential direction, the image pitch k is also the arrangement interval of the left sub-pixel group Pgl and the right sub-pixel group Pgr. As shown in FIG. 2, when the circumferential length of one sub-pixel is Hp, it can be expressed as k = n × Hp = 12 × Hp.

As shown in FIG. 1, the parallax barrier 6 is formed by a curved surface along the display surface 51. The parallax barrier 6 is disposed on the center side of the circular arc with respect to the display surface 51. The parallax barrier 6 is disposed apart from the display surface 51 by a gap g.

As shown in FIG. 3, the parallax barrier 6 has a plurality of light reduction regions 61. The plurality of light reduction regions 61 define a plurality of light transmission regions 62 that define light beam directions that are propagation directions of image light emitted from the sub-pixels. Specifically, a region between two light reduction regions 61 adjacent to each other is defined as a light transmission region 62. That is, the light transmitting regions 62 and the light reducing regions 61 are repeatedly and alternately arranged in the direction along the circumferential direction of the display surface 51. In the example shown in FIG. 3, the parallax barrier 6 sets the light beam direction, which is the propagation direction of the image light emitted from the sub-pixel, for each of the plurality of light transmitting regions 62, which are a plurality of strip regions extending in a predetermined direction in the plane. Specify. The predetermined direction is a direction forming a predetermined angle which is not 0 degrees with the vertical direction. By defining the image light emitted from the sub-pixels by the parallax barrier 6, an area on the display surface 51 where the eye of the user can view is determined. The light reduction region 61 can reduce or shield a portion of the image light emitted from the sub-pixel displaying the left eye image toward the user's right eye. The dimming area 61 can dim a portion of the image light emitted from the sub-pixel displaying the right-eye image toward the user's left eye.

The plurality of light transmitting areas 62 transmit image light with a higher transmittance than the light reducing area 61. The light transmitting region 62 may transmit light with a transmittance of a first predetermined value or more. The first predetermined value may be, for example, 100%, or a value close to 100%. The light reduction region 61 may block light with a transmittance equal to or less than a second predetermined value. The second predetermined value may be, for example, 0% or a value close to 0%. The light reduction area 61 may be composed of the film or plate member. The film may be composed of a resin. The film may be composed of other materials. The plate-like member may be made of resin, metal or the like. The plate-like member may be made of other materials. The light reduction area 61 is not limited to a film or a plate-like member, and may be composed of other kinds of members. The base of the light reduction area 61 may have the property of reducing or blocking light. The base of the light reduction area 61 may contain an additive having a property of reducing or blocking light.

The parallax barrier 6 may be configured of a liquid crystal shutter. The liquid crystal shutter can control the light transmittance in accordance with the applied voltage. The liquid crystal shutter may be composed of a plurality of pixels, and may control the transmittance of light in each pixel. The liquid crystal shutter can form an area with high light transmittance or an area with low light transmittance in an arbitrary shape. When the parallax barrier 6 is formed of a liquid crystal shutter, the light transmitting region 62 may be a region having a transmittance equal to or more than a first predetermined value. When the parallax barrier 6 is configured by a liquid crystal shutter, the light reduction region 61 may be a region having a transmittance equal to or less than a second predetermined value.

The arrangement interval of the light reduction region 61 in the circumferential direction is a barrier pitch Bp. The barrier pitch Bp is the sum of the width in the direction corresponding to the circumferential direction of the light reduction region 61 and the width in the direction corresponding to the circumferential direction of the light transmission region 62. Since the light reduction regions 61 and the light transmission regions 62 are alternately arranged in the direction corresponding to the circumferential direction, the barrier pitch Bp is also the arrangement interval of the light reduction regions 61 and the light transmission regions 62.

The circumferential widths of the plurality of light reduction regions 61 are substantially equal to one another. The circumferential widths of the plurality of translucent regions 62 are substantially equal to one another. Therefore, the widths of the barrier pitches Bp are equal to one another in any region of the parallax barrier 6.

Subsequently, the relationship between the display panel 5 and the parallax barrier 6 will be described. The display panel 5 can be viewed by the user through the parallax barrier 6 from the concave side of the curved surface. The display panel 5 and the parallax barrier 6, as shown in FIG. 1, toward the face on the display position of the three-dimensional image which the user observes the eye between the centers O _E of the user is located in the center of the arc In the state, the user is designed to view an optimal three-dimensional image. Mekan center O _E is the midpoint between the left eye and the right eye of the user. In the following, the center of the arc is sometimes referred to as a reference position O _S. The circumferential direction between the direction connecting the centers of the user's eyes and the position of the image observed by the user of the display panel 5 is parallel.

<Definition of barrier pitch>
In a state where Mekan center O _E is positioned at the reference position O _S, the distance to the display surface 51 from Mekan center O _E is the radius of curvature R of the arc formed by the display panel 5. For this reason, the display panel 5 and the parallax barrier 6 are designed such that the total of the suitable viewing distance d and the gap g becomes the radius of curvature R of the arc, as shown in the equation (1). Proper viewing distance d, such as cross-talk is minimized, and the center in the direction corresponding to the circumferential direction of the parallax barrier 6, the distance between the Mekan center O _E.
R = d + g formula (1)

The barrier pitch Bp is defined based on the radius of curvature R, the image pitch k, and the gap g. Specifically, as shown in FIG. 4, when the interocular distance of the user is E, the barrier pitch Bp uses the gap g and the suitable viewing distance d to set the following equation (2) and the equation (2) It is defined that 3) holds.
E: d = k / 2: g equation (2)
d: Bp = (d + g): k equation (3)

Therefore, the barrier pitch Bp is defined such that the following equation (4) holds.
Bp = (d / (d + g)) × k = ((R−g) / R) × k Formula (4)

That is, the interval at which the parallax barriers 6 are arranged in the circumferential direction is defined to be ((R−g) / R) × k.

In other words, the barrier pitch Bp is defined such that the ratio of the barrier pitch Bp to the image pitch k is ((R−g) / R).

By thus configuring the three-dimensional display device 3, the image light from the sub-pixel displaying the target eye image transmitted through the light transmitting area 62 of the parallax barrier 6 reaches the target eye of the user. The target eye image is an image to be visually recognized by the target eye. The non-target eye image is an image to be visually recognized by an eye other than the target eye. Specifically, when the target eye is the right eye, the target eye image is the right eye image, and the non-target eye image is the left eye image. When the target eye is a left eye, the target eye image is a left eye image, and the non-target eye image is a right eye image.

FIG. 5 shows an example of the parallax barrier 6 and the display surface 51 visually recognized by the right eye of the user. The right visible area 51R (an area without hatching of the display surface 51 shown in FIG. 5) visible to the user's right eye includes at least a part of the right sub-pixel group Pgr, and the left sub-pixel group Pgl is not included. By displaying the right-eye image in the sub-pixels constituting the right sub-pixel group Pgr, the right eye of the user can view only the right-eye image. Similarly, the left visible region 51L visible to the left eye of the user includes at least a part of the left sub-pixel group Pgl and does not include the right sub-pixel group Pgr. The left eye of the user can view only the left eye image. The parallax between the left eye image and the right eye image allows the user to view a three-dimensional image.

<Relationship of Multiple Barrier Pitches Bp in Different Areas>
In FIG. 1, an example is shown in which the user visually recognizes the vicinity of the center in the circumferential direction of the display surface 51. As described above with reference to FIG. 1 and the like, when the barrier pitch Bp near the center is defined such that the relationships shown in Equations (2) and (3) hold, the user appropriately selects the center vicinity. Three-dimensional images can be viewed. Hereinafter, the barrier pitch Bp corresponding to the vicinity of the center is particularly referred to as “Bp1”.

Next, the barrier pitch Bp corresponding to the vicinity of the end in the circumferential direction of the display surface 51 will be described. Hereinafter, the barrier pitch Bp corresponding to the vicinity of the end is particularly referred to as “Bp2”. Since the interocular center O _E is at the reference position O _S , as shown in FIG. 6, the distance from the interocular center O _E to the vicinity of the end of the display surface 51 is the curvature of the arc as in the distance to the central vicinity. It is radius R. If the barrier pitch Bp2 in the vicinity of the end is defined such that the relationships shown in Equations (2) and (3) hold similarly to the barrier pitch Bp1, the user turns the face to the vicinity of the end , 3D images in the vicinity of the end can be appropriately viewed. As shown in equation (3), the barrier pitch Bp is represented by the image pitch k, the radius of curvature R, and the gap g. The image pitch k, the radius of curvature R, and the gap g are the same in the region corresponding to the vicinity of the center of the display surface 51 and in the region corresponding to the vicinity of the end. Therefore, the barrier pitch Bp2 and the barrier pitch Bp1 are substantially equal.

Similarly, when the barrier pitch Bp corresponding to an arbitrary area of the display surface 51 is defined such that the relationships shown in the equation (2) and the equation (3) hold similarly to the barrier pitch Bp1, the user can A three-dimensional image of an arbitrary area can be appropriately viewed. Thus, the barrier pitch Bp can be defined substantially equally so that the relationship shown in the equation (3) holds in any region.

<Ratio of barrier pitch to image pitch>
As described above, in the display surface 51, the numbers of circumferential sub-pixels included in each sub-pixel group Pg are equal. The shapes of the plurality of sub-pixels are equal. For this reason, as shown in FIGS. 2 and 5, the plurality of image pitches k are substantially equal to one another. For example, the image pitch k1 near the center (first area) on the display surface 51 and the image pitch k2 near the end (second area) are substantially equal.

Therefore, the first ratio Bp1 / k1 near the center (first region) on the display surface 51 and the second ratio Bp2 / k2 near the end (second region) on the display surface 51 are substantially equal. The first ratio Bp1 / k1 is a ratio of the barrier pitch Bp1 corresponding to the vicinity of the center to the image pitch k1 near the center on the display surface 51. The image pitch k1 is an interval at which the left sub-pixel group Pgl and the right sub-pixel group Pgr are arranged in the circumferential direction. The barrier pitch Bp1 is an interval at which the light reduction regions 61 are arranged in the circumferential direction. The second ratio Bp2 / k2 is a ratio of the barrier pitch Bp2 corresponding to the vicinity of the end to the image pitch k2 near the end (second region) on the display surface 51. The image pitch k2 is an interval at which the left sub-pixel group Pgl and the right sub-pixel group Pgr are arranged in the circumferential direction. The barrier pitch Bp2 is an interval at which the light reduction regions 61 are arranged in the circumferential direction.

<Permissible range of barrier pitch>
In the above, it has been described that the barrier pitch Bp is a value satisfying the formula (3) (hereinafter referred to as “ideal value Bp0”). However, the barrier pitch Bp is not limited to Bp0, and may deviate from the ideal value Bp0 within a predetermined range. In FIG. 7, a parallax barrier 6A having a barrier pitch Bp1 slightly different from the ideal barrier pitch Bp0 is shown by a broken line, together with the parallax barrier 6 having the ideal barrier pitch Bp0. For convenience, in FIG. 7, the parallax barrier 6A is described at a position radially shifted with respect to the parallax barrier 6, but the parallax barrier 6A has the same radial position with respect to the parallax barrier 6 is there. When the light reduction region 61A and the light transmission region 62A of the parallax barrier 6A are arranged in the circumferential direction, as shown in FIG. 7, for example, in the region (1), each of the light reduction region 61A and the light transmission region 62A The deviation from the light reduction area 61 and the light transmission area 62 is slight. However, as the distance from the region (1) in the circumferential direction (see, for example, regions (2) to (5)), the shift of the light reducing region 61 and the light transmitting region 62 of the light reducing region 61A and the light transmitting region 62A of 6A, respectively Will grow.

Therefore, the more the user's target eye moves away from the area (1), the more the image light from the sub-pixel displaying the non-target image can be viewed. Specifically, as the user moves away from the area (1), less image light from the sub-pixel displaying the left-eye image reaches the user's left eye, and image light from the sub-pixel displaying the right-eye image Can reach a lot. The farther from the region (1), the less the image light from the sub-pixel displaying the right-eye image reaches the right eye of the user, and the more the image light from the sub-pixel displaying the left-eye image reaches. For this reason, as the distance from the region (1) increases, the crosstalk generated in the user's eyes increases.

In order to suppress such crosstalk, the maximum value of the displacement of the light reduction region 61A and the light transmission region 62A from the light reduction region 61 and the light transmission region 62 is less than the circumferential length Hp of the sub-pixel The barrier pitch Bp may be defined to have a width corresponding to. The width corresponding to the circumferential length Hp of one sub-pixel is the width of the light transmitting region 62 that transmits the image light from the image displayed in one sub-pixel, and the radius of curvature R, gap g, one sub-pixel May be defined in accordance with the circumferential length Hp of In this example, the barrier pitch Bp is defined so that the target eye of the user does not visually recognize the non-target eye image longer than Hp in the circumferential direction, but the present invention is not limited thereto. In accordance with the performance required of the three-dimensional display device 3, for example, the barrier pitch Bp may be defined such that the user's target eye does not visually recognize non-target eye images longer than 0.5 × Hp in the circumferential direction. . However, as described above, as the barrier pitch Bp is closer to the ideal value Bp0, crosstalk generated in the user's eyes is reduced.

<Switching of images on display surface>
Subsequently, switching of an image on the display surface 51 in accordance with displacement of the user's eye in the first direction will be described with reference to FIGS. 8A, 8B, and 8C. In the example shown in FIGS. 8A, 8B and 8C, the image pitch is n = 8. However, the image pitch n may be any even number. The circumferential widths of the light reduction region 61 and the light transmission region 62 of the parallax barrier 6 are equal (barrier aperture ratio is 50%).

As shown in Figure 8A, when the eye between the centers O _E of the user is at the reference position O _S, the left visible 51AL, it contains the most left sub-pixel groups Pgl for displaying the left-eye image, the right eye The right sub-pixel group Pgr for displaying an image is the least included. In this state, crosstalk generated in the user's eyes is most reduced.

As shown in FIG. 8B, when the user's interocular center O _E is at a position displaced by a distance 2E / n in the first direction from the reference position O _S , a left image is displayed in the left visible region 51aL. (N / 2-1) The entire sub-pixel of the column is included. The left visible region 51aL includes less than half of one row of subpixels displaying the right image. Similarly, the right viewable area 51aR includes the entire (n / 2-1) row of sub-pixels displaying the right image. The right visible region 51aR includes less than half of one row of subpixels displaying the right image. For this reason, crosstalk occurs in the image visually recognized by the user's eye.

As shown in FIG. 8C, when the user's interocular center O _E moves from the reference position O _S by a distance 2E / n in the first direction, the left visible area 51a L is moved to the left of the (n / 2-1) row. It includes all of the sub-pixels that display an image, and sub-pixels that display less than half of one column of the left image. In addition, the left visible region 51aL includes half or more of one row of subpixels displaying the right-eye image. Similarly, the right visible region 51aR includes all the subpixels that display the right image in (n / 2-1) rows and the subpixels that display the right image in less than half of one row. In addition, the right visible region 51aR includes half or more of one row of subpixels displaying the left eye image. Therefore, larger crosstalk occurs than in the case shown in FIG. 8B. In order to reduce the occurrence of crosstalk, the image is switched such that the sub-pixel displaying the right-eye image having a half or more included in the left visible region 51aL displays the left-eye image. Similarly, the image is switched such that the sub-pixel displaying the left-eye image for which the right visible region 51aR includes half or more is displayed the right-eye image.

As described above, by switching the image according to the displacement of the user's eye in the first direction, it is possible to prevent the target eye from visually recognizing the non-target eye image of half or more of one sub-pixel in the circumferential direction. Therefore, the occurrence of crosstalk in which the target eye visually recognizes a non-target eye image having a width of 0.5 × Hp or more in the circumferential direction can be suppressed.

<Aperture ratio of parallax barrier>
The aperture ratio of the parallax barrier 6 may be 50% or less. That is, the circumferential width of the light reduction area 61 may be 50% or more of the barrier pitch Bp. If the circumferential width of the light reduction area 61 is less than 50%, there are sub-pixels that emit image light that reaches both the right eye and the left eye of the user. In this case, when the right eye image is displayed on the sub pixel, the left eye visually recognizes the right eye image, and when the left eye image is displayed, the right eye visually recognizes the left eye image. That is, even if the sub-pixel displays either the left-eye image or the right-eye image, it becomes difficult to prevent the occurrence of crosstalk. Therefore, by setting the aperture ratio of the parallax barrier 6 to 50% or less, crosstalk generated in the user's eyes can be reduced.

<Range of eye box>
Subsequently, the range of the eye box EB in the three-dimensional display device 3 in which the barrier pitch Bp is defined as described above will be described. The eye box EB is a range of eye positions where the two eyes of the user can appropriately view a three-dimensional image.

As shown in FIG. 9, when the interocular center O _E is at the reference position O _S (see O _{E 0 in} FIG. 9), the left sub-pixel group Pgl is displayed in the left visible region 51 L viewed by the left eye on the display surface 51 Is included. The right sub-pixel group Pgr is included in the right visible region 51R that is viewed by the right eye on the display surface 51. That is, the eye box EB includes the center of an arc in a cross section by a plane orthogonal to the central axis direction of the display surface 51.

As shown in FIG. 9, when the distance from the display surface 51 to the interocular center O _E becomes longer than the curvature radius R of the arc (see O _{E1 in} FIG. 9), the left visible area 51L ′ changes from the left visible area 51L. Do. The left visible area 51L ′ includes a part of the right sub-pixel group Pgr. The right visible region 51R 'changes from the right visible region 51R. The right visible region 51R ′ includes a part of the left sub-pixel group Pgl. For this reason, the target eye visually recognizes a part of the non-target eye image, and crosstalk occurs.

As shown in FIG. 9, when the distance from the display surface 51 to the interocular center O _E becomes shorter than the radius of curvature R of the arc (see O _{E2 in} FIG. 9), the left visible area 51L ′ ′ changes from the left visible area 51L The left visible area 51L ′ ′ includes a part of the right sub-pixel group Pgr. The right visible region 51R 'changes from the right visible region 51R. The right visible region 51R ′ ′ includes a part of the left sub-pixel group Pgl. Therefore, the target eye visually recognizes a part of the non-target eye image, and crosstalk occurs.

As shown in FIG. 9, the change from the left visible area 51L to the left visible area 51L ′ ′ when the interocular center O _E changes to a predetermined distance to O _E2 is the same as the interocular center O _E to O _E1. Therefore, the right sub-pixel group Pgr included in the left visible area 51L ′ ′ is a right sub-pixel included in the left visible area 51L ′. Greater than group Pgr. Similarly, the left sub-pixel groups Pgl included in the right visible region 51R "is greater than the left sub-pixel groups Pgl included in the right visible region 51R '. Therefore, the distance from the display surface 51 to Mekan center O _E as compared with a case longer than the arc of curvature radius R, when the distance from the display surface 51 to Mekan center O _E is shorter than the radius of curvature R of the arc, crosstalk is likely to occur in the eyes of the user. Thus as shown in FIG. 1, the dimension from the reference position O _S eyeboxes EB to the end of the display surface 51 side may be shorter than the dimension of the end portion opposite to the display surface 51 from the reference position O _S in other words., the center in the z-axis direction of the eye box EB may be located on the opposite side of the display surface 51 with respect to the reference position O _S.

The position in the central axis direction of the eye box EB may be arbitrary. For example, the position of the eye box EB in the central axis direction may be within the range of the width of the display surface 51 in the direction along the central axis direction. The position of the eye box EB in the second direction may be outside the range of the width of the display surface 51 in the direction along the central axis direction.

As described above, in the first embodiment, the barrier pitch Bp is substantially equal in any region of the parallax barrier 6 and is defined based on the radius of curvature R of the arc, the image pitch k, and the gap g. In other words, the ratio of the barrier pitch Bp to the image pitch k is substantially equal in any region, and is defined based on the radius of curvature R of the arc and the gap g. Thus, if Mekan center O _E is positioned at the reference position O _S, the user can visually recognize the appropriate 3-dimensional image in an arbitrary area of the display surface 51. In addition, even if the user changes the orientation of the face to look at images at different positions on the display surface 51, there is no change in parameters such as the interocular distance E, the image pitch k, the barrier pitch Bp, and the gap g. Therefore, the appropriate viewing distance is maintained at the curvature radius R of the arc, and it is possible to visually recognize a good three-dimensional image in which crosstalk is suppressed.

Subsequently, the three-dimensional display device 7 according to the second embodiment will be described in detail with reference to the drawings.

As shown in FIG. 10, the three-dimensional display device 7 according to the second embodiment includes an irradiator 4, a display panel 5, and a parallax barrier 6 as an optical element. In the second embodiment, only configurations different from the first embodiment will be described. About the composition which omits explanation in a 2nd embodiment, it is the same as that of a 1st embodiment.

<Rules of parallax barrier>
The parallax barrier 6 is disposed on the opposite side of the reference position O _S with respect to the display panel 5. The parallax barrier 6 is disposed on the display panel 5 side with respect to the irradiator 4. In the second embodiment, in a state where the eye between the centers O _E of the user is positioned at the reference position O _S, the user is designed to recognize the optimum three-dimensional image. For this reason, as shown in the equation (5), the display panel 5 and the parallax barrier 6 are designed such that the difference between the appropriate viewing distance d and the gap g becomes the curvature radius R of the arc.
R = dg formula (5)

In this case, the barrier pitch Bp is defined using the gap g, the suitable viewing distance d, and the interocular distance E so that the following equations (6) and (7) are satisfied as shown in FIG.
E: d = k / 2: g equation (6)
d: Bp = (d-g): k equation (7)

Therefore, the barrier pitch Bp is defined such that the following equation (8) holds.
Bp = (d / (d−g)) × k = ((R + g) / R) × k Formula (8)

That is, the interval at which the parallax barriers 6 are arranged in the circumferential direction is defined to be ((R + g) / R) × k.

Furthermore, in other words, the barrier pitch Bp is defined such that the ratio of the barrier pitch Bp to the image pitch k is ((R + g) / R).

In the first embodiment, when the display panel 5 is a self-luminous type, the irradiator 4 is unnecessary. However, the display panel 5 of the second embodiment is not a self-luminous display panel. The irradiator 4 is not necessary.

As described above, in the second embodiment, as in the first embodiment, the barrier pitch Bp is substantially equal in any region of the parallax barrier 6, and the barrier pitch Bp is the curvature radius R of the arc, the image pitch It is defined based on k and gap g. In other words, the ratio of the barrier pitch Bp to the image pitch k is substantially equal in any region, and the ratio is defined based on the radius of curvature R of the arc and the gap g. This allows the user to view an appropriate three-dimensional image in an arbitrary area of the display surface 51.

Although the embodiments described above have been described as representative examples, it will be obvious to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications or changes are possible without departing from the scope of the claims. For example, it is possible to combine a plurality of building blocks described in the embodiment and the example into one, or to divide one building block.

In the above embodiment, as shown in FIG. 5, the light reduction region 61 is a plurality of strip regions extending in a predetermined direction in the plane, but the present invention is not limited to this. As shown in FIG. 12, the light reduction region 61 is a set of rectangular regions repeatedly arranged adjacent to a position shifted by a length corresponding to one sub-pixel in the circumferential direction in the central axis direction. You may The parallax barrier 6 having such a light reduction region 61 can be configured by a liquid crystal shutter. Although n = 12 in the example shown in FIG. 12, n may be 8 as in the first embodiment. n may be any even number.

In the above embodiment, as shown in FIG. 2, the sub-pixel group Pg is repeatedly arranged adjacent to a position shifted by one sub-pixel in the circumferential direction in the central axis direction, but this limitation is not. For example, as shown in FIG. 13, on the display surface 51, left sub-pixel groups Pgl composed of n / 2 rows of sub-pixels continuously in the circumferential direction may be repeatedly arranged without shifting in the central axis direction. . On the display surface 51, the right sub-pixel group Pgr composed of n / 2-row sub-pixels continuously in the circumferential direction may be repeatedly arranged without being shifted in the central axis direction. In the example shown in FIG. 13, the sub-pixel displaying the left image is given the symbol L. The sub-pixel that displays the right image is labeled R. In the example shown in FIG. 13, n = 8, but n may be any even number. In this case, the parallax barrier 6 defines the light beam direction, which is the propagation direction of the image light emitted from the sub-pixel, for each of the plurality of light transmitting regions 62 which are strip regions extending in the central axis direction.

In the above embodiment, the optical element is the parallax barrier 6, but the present invention is not limited to this. For example, as shown in FIG. 14, the optical element provided in the three-dimensional display device 3 may be a lenticular lens 8. In this case, the lenticular lens 8 is configured by arranging the cylindrical lenses 81 in a plane along the display surface 51. Like the parallax barrier 6, the lenticular lens 8 propagates the image light emitted from a part of the sub-pixels of the display surface 51 to the position of the user's left eye and emits it from the other part of the sub-pixels The image light is propagated to the position of the user's right eye.

In the above-described embodiment, the three-dimensional display devices 3 and 7 may be mounted on the mobile unit 100 as shown in FIG. The "mobile" in the present disclosure includes vehicles, ships, and aircraft. The "vehicle" in the present disclosure includes, but is not limited to, a car and an industrial vehicle, and may include a railway vehicle and a living vehicle, and a fixed wing aircraft traveling on a runway. Automobiles include but are not limited to passenger cars, trucks, buses, two-wheeled vehicles, trolley buses, etc., and may include other vehicles traveling on the road. Industrial vehicles include industrial vehicles for agriculture and construction. Industrial vehicles include, but are not limited to, forklifts and golf carts. Industrial vehicles for agriculture include, but are not limited to, tractors, cultivators, transplanters, binders, combine harvesters, and lawn mowers. Industrial vehicles for construction include, but are not limited to, bulldozers, scrapers, excavators, cranes, dump trucks, and road rollers. Vehicles include those that travel by human power. The classification of vehicles is not limited to the above. For example, a car may include an industrial vehicle capable of traveling on a road, and a plurality of classifications may include the same vehicle. The vessels in the present disclosure include marine jets, boats, and tankers. The aircraft in the present disclosure includes fixed wing aircraft and rotary wing aircraft.

3, 7 Three-dimensional display device 4 Irradiator 5 Display panel 6 Parallax barrier 8 Lenticular lens 51 Display surface 51a Right viewable area 51b Left viewable area 61 Dimming area 62 Translucent area 81 Cylindrical lens 100 Moving body

Claims

A display panel comprising a display surface having a shape of at least a part of a cylindrical surface around a central axis, in a lattice shape along the circumferential direction around the central axis and the central axis in the display surface. A display panel in which left sub-pixel groups having sub-pixels representing left-eye images and right sub-pixel groups having sub-pixels representing right-eye images are alternately arranged in the circumferential direction;
A plurality of light reduction regions disposed along the display surface and reducing or blocking image light from the display surface; and a plurality of light transmission regions transmitting the image light with a higher transmittance than the light reduction region An optical element including: the plurality of light reduction regions and the plurality of light transmission regions arranged alternately adjacent to each other along the circumferential direction;
Equipped with
Spacings in the circumferential direction in which the light reduction areas and the light transmission areas are alternately arranged are substantially equal, and the spacing is a curvature radius of a circular arc formed by a plane orthogonal to the central axis direction of the display surface; A three-dimensional display defined based on an image pitch which is an arrangement interval of a left sub-pixel group and the right sub-pixel group, and a gap between the display surface and the optical element.
The three-dimensional display device according to claim 1, wherein an eye box which is a range of the position of the user's eyes includes the center of the circular arc in a cross section by a plane orthogonal to the central axis direction of the display surface.
The three-dimensional display according to claim 2, wherein a center of the eyebox in a radial direction orthogonal to the circumferential direction and the central axial direction is on the opposite side of the display panel with respect to the center of the arc.
The optical element is disposed on the center side of the arc with respect to the display surface along the display surface,
Assuming that the radius of curvature is R, the gap is g, and the image pitch is k, an arrangement interval of the light reduction region in the circumferential direction is approximately ((R−g) / R) × k. The three-dimensional display device according to any one of to 3.
The optical element is disposed on the display surface opposite to the center of the arc with respect to the display surface.
The arrangement interval of the light reduction region in the circumferential direction is approximately ((R + g) / R) × k, where R is the radius of curvature, g is the gap, and k is the image pitch. The three-dimensional display device according to any one of the above.
The three-dimensional display device according to any one of claims 1 to 5, wherein the circumferential widths of the plurality of light reduction regions are substantially equal.
A display panel comprising a display surface having a shape of at least a part of a cylindrical surface around a central axis, in a lattice shape along the circumferential direction around the central axis and the central axis in the display surface. A display panel in which left subpixels arranged to display a left eye image and right subpixels arranged to display a right eye image are alternately arranged in the circumferential direction;
An optical system comprising: a plurality of light reduction regions disposed along the display surface to reduce or block image light from the display surface; and a plurality of light transmission regions transmitting the image light more than the light reduction region An optical element in which the plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction;
Equipped with
The light reduction area and the light transmission area corresponding to the first area with respect to an interval in which the left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction in the first area on the display surface The ratio of the intervals alternately arranged in the circumferential direction is taken as a first ratio, and the left sub-pixel group and the right sub-pixel group alternate in the circumferential direction in a second area different from the first area on the display surface Assuming that a ratio of intervals at which the light reduction regions corresponding to the two regions are alternately arrayed in the circumferential direction with respect to an arrayed interval is a second ratio, the first ratio and the second ratio are approximately equal. The display panel is defined based on a radius of curvature of an arc formed by a cross section of a surface orthogonal to the central axis direction of the display surface, and a gap between the display surface and the optical element. 3D determined based on curvature of Display devices.
The three-dimensional display device according to claim 7, wherein an eye box which is a range of a position of the user's eyes includes the center of the circular arc in a cross section by a plane orthogonal to the central axis direction of the display surface.
The center of the eye box, which is a range of the position of the user's eyes, in the third direction orthogonal to the circumferential direction and the central axis direction is on the opposite side of the display panel with respect to the center of the arc. The three-dimensional display device according to 8.
The optical element is disposed at the center side of the arc along the display surface,
The three-dimensional display according to any one of claims 7 to 9, wherein the ratio is approximately (Rg) / R, where R is the radius of curvature and g is the gap.
The optical element is disposed on the display surface opposite to the center of the arc.
The three-dimensional display device according to any one of claims 7 to 9, wherein the ratio is approximately (R + g) / R, where R is the radius of curvature and g is the gap.
A display panel comprising a display surface having a shape of at least a part of a cylindrical surface around a central axis, in a lattice shape along the circumferential direction around the central axis and the central axis in the display surface. A display panel in which a left sub-pixel group having sub-pixels for displaying a left-eye image and a right sub-pixel group having sub-pixels for displaying a right-eye image are alternately arranged in the circumferential direction; And a plurality of light reduction regions for reducing or blocking image light from the display surface, and a plurality of light transmission regions for transmitting the image light with a higher transmittance than the light reduction region. An element, comprising: an optical element in which the plurality of light reduction regions and the plurality of light transmission regions are alternately arranged adjacent to each other along the circumferential direction, the light reduction region and the light transmission Areas are arranged alternately Intervals in the circumferential direction are approximately equal, and the intervals are the radius of curvature of the arc of the cross section of the display surface by the plane orthogonal to the central axis direction, the arrangement interval of the left sub-pixel group and the right sub-pixel group A mobile comprising a three-dimensional display defined based on an image pitch and a gap between the display surface and the optical element.
A display panel comprising a display surface having a shape of at least a part of a cylindrical surface around a central axis, in a lattice shape along the circumferential direction around the central axis and the central axis in the display surface. A display panel in which left sub-pixel groups for displaying left-eye images and right sub-pixel groups for displaying right-eye images are alternately arranged in the circumferential direction, and arranged along the display surface; An optical element comprising: a plurality of light reduction regions for reducing or blocking image light from a surface; and a plurality of light transmission regions for transmitting the image light more than the light reduction region, wherein the plurality of light reduction regions And the plurality of light transmitting regions include optical elements alternately arranged adjacent to each other along the circumferential direction, and the left sub-pixel group and the right sub-pixel in the first region on the display surface Groups are arranged alternately in the circumferential direction The ratio of the light reduction area corresponding to the first area to the light separation area and the space in which the light transmission areas are alternately arranged in the circumferential direction is a first ratio, which is different from the first area on the display surface With respect to an interval in which the left sub-pixel group and the right sub-pixel group are alternately arranged in the circumferential direction in the second area, the interval in which the light reduction areas corresponding to the two areas are alternately arrayed in the circumferential direction Assuming that the ratio is a second ratio, the first ratio and the second ratio are substantially equal, and the ratio is a radius of curvature of an arc formed by a cross section of a surface orthogonal to the central axis direction of the display surface; A mobile body comprising: a three-dimensional display device which is determined based on a curvature of the display panel defined based on a gap between the display surface and the optical element.