JP7536693B2 - Three-dimensional display device, head-up display and mobile body - Google Patents

Description

The present disclosure relates to a three-dimensional display device, a head-up display, and a moving object.

Conventionally, in order to perform 3D display without using glasses, there is known a 3D display device equipped with an optical element that causes a part of the light emitted from the display panel to reach the right eye and another part of the light emitted from the display panel to reach the left eye (see, for example, Patent Document 1).

JP 2001-166259 A

In a three-dimensional display device such as the one described above, it is necessary to allow the user to properly view the three-dimensional image.

A three-dimensional display device according to an embodiment of the present disclosure includes a display panel, a barrier unit, a detection unit, and a control unit. The display panel is configured to display a parallax image including a first image and a second image having parallax with respect to the first image. The barrier unit is configured to provide parallax to the first eye and the second eye of a user by defining the traveling direction of image light of the parallax image. The detection unit is configured to capture an image of the face of the user viewing the parallax image. The control unit generates a first reference image by synthesizing the first image and the second image, which are different from each other, based on a predetermined index that defines the arrangement of the first image and the second image to be displayed on the display panel, and displays the first reference image on the display panel. The control unit adjusts the index based on an image of the user's face captured by the detection unit onto which the first reference image is projected.

A head-up display according to an embodiment of the present disclosure includes a display panel, a barrier unit, an optical member, a detection unit, and a control unit. The display panel is configured to display a parallax image including a first image and a second image having parallax with respect to the first image. The barrier unit is configured to provide parallax to the first eye and the second eye of a user by defining the traveling direction of image light of the parallax image. The optical member is configured to allow the user to view the image light emitted from the display panel as a virtual image. The detection unit is configured to capture an image of the face of the user viewing the parallax image. The control unit generates a first reference image by synthesizing the first image and the second image, which are different from each other, based on a predetermined index that defines the arrangement of the first image and the second image to be displayed on the display panel, and displays the first reference image on the display panel. The control unit adjusts the index based on an image of the user's face captured by the detection unit onto which the first reference image is projected.

A moving body according to an embodiment of the present disclosure includes a head-up display. The head-up display includes a display panel, a barrier unit, an optical member, a detection unit, and a control unit. The display panel is configured to display a parallax image including a first image and a second image having parallax with respect to the first image. The barrier unit is configured to provide parallax to the first eye and the second eye of a user by defining the traveling direction of image light of the parallax image. The optical member is configured to allow the user to view the image light emitted from the display panel as a virtual image. The detection unit is configured to capture an image of the face of the user viewing the parallax image. The control unit generates a first reference image by synthesizing the first image and the second image, which are different from each other, based on a predetermined index that defines the arrangement of the first image and the second image to be displayed on the display panel, and displays the first reference image on the display panel. The control unit adjusts the index based on an image of the user's face captured by the detection unit onto which the first reference image is projected.

The three-dimensional display device, head-up display, and moving object according to an embodiment of the present disclosure allow a user to properly view a three-dimensional image.

1 is a diagram showing an example of a three-dimensional display device according to an embodiment of the present disclosure as viewed from above and below; 2 is a diagram showing an example of a display panel of the three-dimensional display device shown in FIG. 1 as viewed from the depth direction. FIG. 2 is a diagram showing an example of a barrier section of the three-dimensional display device shown in FIG. 1 as viewed from the depth direction. FIG. 2 is a diagram for explaining a left visible area in a display panel of the three-dimensional display device shown in FIG. 1 . 2 is a diagram for explaining a right visible area in a display panel of the three-dimensional display device shown in FIG. 1 . 11 is a diagram for explaining information for identifying the position of the left eye and the position of the right eye. FIG. 13 is a diagram showing an example of an image table indicating the correspondence between the positions of the left and right eyes and the images to be displayed on each sub-pixel when the interocular distance is a standard distance. FIG. FIG. 13 is a diagram showing an example of a reference image used to adjust an index. 11 is a diagram showing an example of an image of a user onto which a reference image is projected, the image being captured by a detection unit; FIG. FIG. 11 is a diagram for explaining origin correction. 11 is a flowchart illustrating an example of a process for adjusting an index. 2 is a diagram for explaining a binocular visible area in the three-dimensional display system shown in FIG. 1 . FIG. 11 is a diagram showing an example of an image of a user onto which a reference image is projected, the image being captured by a detection unit; FIG. 11A and 11B are diagrams for explaining a correction process for the interocular distance; FIG. 1 is a diagram illustrating a head-up display according to an embodiment of the present disclosure. FIG. 1 is a diagram illustrating a moving body according to an embodiment of the present disclosure.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the drawings used in the following description are schematic. The dimensional ratios and other details in the drawings do not necessarily correspond to the actual ones.

Figure 1 is a diagram showing an example of a three-dimensional display device according to an embodiment of the present disclosure, viewed from above and below. The three-dimensional display device 1 according to this embodiment includes a display panel 5, a barrier unit 6, a detection unit 2, and a control unit 7.

The detection unit 2 is configured to capture an image of the user's face. The detection unit 2 is configured to capture an image of the user's face viewing the three-dimensional image displayed by the three-dimensional display device 1. The detection unit 2 may detect the positions of the user's left eye 15L and right eye 15R and output the position to the control unit 7. The detection unit 2 may include, for example, a camera. The detection unit 2 may capture an image of the user's face using the camera. The detection unit 2 may detect the positions of the left eye 15L and right eye 15R from an image of the user's face captured by the camera. The detection unit 2 may detect the positions of the left eye 15L and right eye 15R as coordinates in three-dimensional space from an image captured by one camera. The detection unit 2 may detect the positions of the left eye 15L and right eye 15R as coordinates in three-dimensional space from images captured by two or more cameras. The detection unit 2 may detect a three-dimensional image projected onto the user's face from an image captured by the camera. The left eye 15L is also referred to as the first eye. The right eye 15R is also referred to as the second eye. When there is no distinction between the left eye 15L and the right eye 15R, the left eye 15L and the right eye 15R are collectively referred to as eye 15.

The detection unit 2 may include a visible light camera or an infrared camera. The detection unit 2 may include both a visible light camera and an infrared camera. The detection unit 2 may have the functions of both a visible light camera and an infrared camera. The detection unit 2 may include, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image sensor.

The detection unit 2 may not include a camera, but may be connected to a camera external to the device. The detection unit 2 may include an input terminal that inputs a signal from a camera external to the device. The camera external to the device may be directly connected to the input terminal. The camera external to the device may be indirectly connected to the input terminal via a shared network. The detection unit 2 that does not include a camera may include an input terminal to which the camera inputs a video signal. The detection unit 2 that does not include a camera may detect the positions of the left eye and right eye from the video signal input to the input terminal.

The detection unit 2 may include, for example, a sensor. The sensor may be an ultrasonic sensor or an optical sensor. The detection unit 2 may detect the position of the user's head using the sensor, and detect the positions of the left eye 15L and the right eye 15R based on the position of the head. The detection unit 2 may detect the positions of the left eye 15L and the right eye 15R as coordinate values in three-dimensional space using one or more sensors.

The three-dimensional display device 1 may not include a detection unit 2. If the three-dimensional display device 1 does not include a detection unit 2, the three-dimensional display device 1 may include an input terminal for inputting a signal from a detection device external to the device. The detection device external to the device may be connected to the input terminal. The detection device external to the device may use an electrical signal and an optical signal as a transmission signal to the input terminal. The detection device external to the device may be indirectly connected to the input terminal via a shared communication network. The three-dimensional display device 1 may be configured to receive position coordinates indicating the positions of the left eye and right eye obtained from a detection device external to the device.

The detection unit 2 may have a function of detecting the position of the user's eye 15. The detection unit 2 does not need to have a function of detecting the position of the eye 15. The three-dimensional display device 1 may be configured so that the control unit 7 detects the position of the eye 15, or may have a position acquisition unit 3 that detects the position of the eye 15 and outputs it to the control unit 7.

The display panel 5 displays a parallax image including a left eye image (first image) and a right eye image (second image) having parallax with respect to the left eye image. The left eye image is an image projected onto the user's first eye 15L, and the right eye image is an image projected onto the user's second eye 15R. The parallax image is also called a mixed image. The barrier unit 6 is an optical element that determines the traveling direction of the image light emitted from the display panel 5. The barrier unit 6 is also called a parallax barrier. The control unit 7 synthesizes the first image and the second image to generate a parallax image. The control unit 7 may synthesize the first image and the second image based on at least one of the position of the first eye 15L and the position of the second eye 15R detected by the detection unit 2.

The control unit 7 causes the generated parallax image to be displayed on the display panel 5. The display panel 5 may have multiple display areas within an active area. Each of the multiple display areas may correspond to one of multiple reference indexes. The reference index is also simply referred to as an index. The control unit 7 synthesizes the parallax image to be displayed in each of the multiple display areas based on the reference index of the display area.

The display panel 5 may be a transmissive display panel or a self-luminous display panel. A transmissive display panel may be, for example, a liquid crystal display panel. A self-luminous display panel may be, for example, a display panel including self-luminous elements such as light emitting diode (LED) elements, organic electroluminescence (OEL) elements, organic light emitting diode (OLED) elements, and semiconductor laser (LD) elements. In this embodiment, a liquid crystal display panel is used as the display panel 5.

When the display panel 5 is a transmissive display panel, the three-dimensional display device 1 includes an illuminator 4. The illuminator 4 can irradiate light onto the display panel 5 in a planar manner. The illuminator 4 can include a light source, a light guide plate, a diffusion plate, a diffusion sheet, etc. The illuminator 4 can emit irradiation light from the light source, and can homogenize the irradiation light in the planar direction of the display panel 5 by the light guide plate, the diffusion plate, the diffusion sheet, etc. The illuminator 4 can emit the homogenized light towards the display panel 5.

The irradiator 4 includes a visible light source that emits visible light. The visible light source may be, for example, an LED element, a cold cathode fluorescent lamp, a halogen lamp, or a xenon lamp. The irradiator 4 may include an infrared light source that emits infrared light. The infrared light source may be, for example, an infrared LED element. The three-dimensional display device 1 may be configured to drive the visible light source and the infrared light source separately. When the three-dimensional display device 1 drives the visible light source and the infrared light source, the three-dimensional image displayed by the three-dimensional display device 1 includes a visible light component and an infrared light component. When the three-dimensional display device 1 drives only the infrared light source, the three-dimensional image displayed by the three-dimensional display device 1 includes only the infrared light component. When the detection unit 2 includes an infrared camera or has the function of an infrared camera, the detection unit 2 can detect the infrared light component of the three-dimensional image projected on the user's face.

The irradiator 4 may be configured to include a plurality of infrared LED elements. The plurality of infrared LED elements may be distributed throughout the irradiator 4, or may be biased toward a portion of the irradiator 4. The irradiator 4 may be configured such that a visible light source is disposed in the center of its light emission surface, and a plurality of infrared LED elements are disposed to surround the visible light source.

The display panel 5 has a plurality of partitioned regions on an active area 51 formed in a planar shape, as shown in FIG. 2, for example. The active area 51 displays a parallax image. The parallax image includes a first image and a second image having parallax with respect to the first image. The partitioned regions are regions partitioned in a first direction and a second direction perpendicular to the first direction by a lattice-shaped black matrix 52. The direction perpendicular to the first direction and the second direction is called a third direction. The first direction may be called a horizontal direction. The second direction may be called a vertical direction. The third direction may be called a depth direction. The first direction, the second direction, and the third direction are not limited to these. In the drawings, the first direction is represented as the x-axis direction, the second direction is represented as the y-axis direction, and the third direction is represented as the z-axis direction.

Each partitioned region corresponds to one subpixel. Thus, the active area 51 comprises a number of subpixels arranged in a grid pattern along the horizontal and vertical directions.

Each subpixel corresponds to one of the colors red (R), green (G), or blue (B), and a set of three subpixels, R, G, and B, can form one pixel. One pixel can be called one picture element. The horizontal direction is, for example, the direction in which the multiple subpixels that form one pixel are lined up. The vertical direction is, for example, the direction in which subpixels of the same color are lined up.

As described above, the subpixels arranged in the active area 51 constitute a subpixel group Pg. The subpixel group Pg is arranged repeatedly in the horizontal direction. In the vertical direction, the subpixel group Pg is arranged repeatedly adjacent to each other at positions shifted by one subpixel in the horizontal direction. The subpixel group Pg includes subpixels in a predetermined row and column. Specifically, the subpixel group Pg includes (2×n×b) subpixels P1 to Pk (k=2×n×b) arranged continuously in a vertical direction of b (b rows) and a horizontal direction of 2×n (n columns). In the example shown in FIG. 2, n=6 and b=1. The subpixel group Pg is arranged in the active area 51, including 12 subpixels P1 to P12 arranged continuously in a vertical direction of 12 and a horizontal direction of 12. In the example shown in FIG. 2, some of the subpixel groups Pg are labeled.

The subpixel group Pg is the smallest unit for which the control unit 7 exercises control to display an image. Subpixels P1 to Pk (k = 2 x n x b) having the same identification information in all subpixel groups Pg are controlled simultaneously by the control unit 7. For example, when switching the image displayed in subpixel P1 from a left-eye image to a right-eye image, the control unit 7 can simultaneously switch the image displayed in subpixel P1 in all subpixel groups Pg from a left-eye image to a right-eye image.

(Parallax Barrier)
1, the barrier section 6 is formed by a plane along the active area 51. The barrier section 6 may be disposed at a predetermined distance (gap) g from the active area 51. The barrier section 6 may be located on the opposite side of the display panel 5 to the illuminator 4. The barrier section 6 may be located on the illuminator 4 side of the display panel 5.

The barrier section 6 may be configured to be movable in the traveling direction of the image light emitted from the display panel 5. In other words, the barrier section 6 may be configured to be movable in the third direction shown in FIG. 1. The three-dimensional display device 1 may include a drive section 11 that drives the barrier section 6 in the third direction. The drive section 11 may be controlled by the control section 7. The drive section 11 may drive the barrier section 6 in the third direction by a motor or a piezoelectric element, etc. The drive section 11 may drive the barrier section 6 in the positive direction of the third direction, or may drive the barrier section 6 in the negative direction of the third direction.

As shown in FIG. 3, the barrier section 6 defines the light direction, which is the propagation direction of the image light emitted from the subpixels, for each of the light-transmitting regions 62, which are multiple strip-shaped regions extending in a predetermined direction in the plane. The predetermined direction is a direction that forms a predetermined angle other than 0 degrees with the vertical direction. As shown in FIG. 1, the barrier section 6 defines the image light emitted from the subpixels arranged in the active area 51, thereby determining the area on the active area 51 that is visible to the user's eye 15. Hereinafter, the area in the active area 51 that emits the image light that propagates to the position of the user's eye 15 is referred to as the visible area 51a. The area in the active area 51 that emits the image light that propagates to the position of the user's left eye 15L is referred to as the left visible area 51aL (first visible area). The area in the active area 51 that emits the image light that propagates to the position of the user's right eye 15R is referred to as the right visible area 51aR (second visible area).

As shown in FIG. 3, the barrier section 6 has a plurality of light-shielding regions 61 that block image light. The plurality of light-shielding regions 61 define light-transmitting regions 62 between adjacent light-shielding regions 61. The light-transmitting regions 62 have a higher light transmittance than the light-shielding regions 61. In other words, the light-shielding regions 61 have a lower light transmittance than the light-transmitting regions 62.

The light-transmitting region 62 is a portion that transmits light incident on the barrier unit 6. The light-transmitting region 62 may transmit light with a transmittance equal to or greater than a first predetermined value. The first predetermined value may be, for example, approximately 100% or less. The first predetermined value may be 100% or less as long as the image light emitted from the active area 51 is well visible, and may be, for example, 80% or 50%. The light-shielding region 61 is a portion that blocks light incident on the barrier unit 6 and hardly transmits it. In other words, the light-shielding region 61 blocks the image displayed in the active area 51 of the display panel 5 from reaching the user's eyes. The light-shielding 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, approximately 0% or more than 0%. The second predetermined value may be a value close to 0%, such as 0.5%, 1%, or 3%. The first predetermined value can be several times, for example, 10 times or more, larger than the second predetermined value.

The light-transmitting regions 62 and light-shielding regions 61 extend in a predetermined direction along the active area 51 and are repeatedly arranged alternately in a direction perpendicular to the predetermined direction. The light-transmitting regions 62 determine the light direction of the image light emitted from the subpixels.

As shown in FIG. 1, the barrier pitch Bp, which is the horizontal spacing between the light-transmitting regions 62, and the gap g between the active area 51 and the barrier section 6 are determined so that the following formulas (1) and (2) hold, using the optimal viewing distance d and the standard distance E0.

E0:d=(n×Hp):g…(1)

d:Bp=(d+g):(2×n×Hp)…(2)

The optimal viewing distance d is the distance between each of the user's right and left eyes and the barrier section 6 such that the horizontal length of the visible area 51a is n subpixels. The direction of the line passing through the right and left eyes (interocular direction) is the horizontal direction. The standard distance E0 is the standard interocular distance E of the user. The standard distance E0 may be, for example, 61.1 mm to 64.4 mm, a value calculated through research by the National Institute of Advanced Industrial Science and Technology. Hp is the horizontal length of a subpixel as shown in FIG. 2.

The barrier section 6 may be composed of a film or plate-like member having a transmittance less than a second predetermined value. In this case, the light-shielding area 61 is composed of the film or plate-like member. The light-transmitting area 62 is composed of an opening provided in the film or plate-like member. The film may be composed of a resin or other material. The plate-like member may be composed of a resin, metal, or the like, or may be composed of other materials. The barrier section 6 is not limited to a film or plate-like member, and may be composed of other types of members. The barrier section 6 may have a base material that has light-shielding properties, or the base material may contain an additive that has light-shielding properties.

The barrier section 6 may be composed of a liquid crystal shutter. The liquid crystal shutter may control the light transmittance according to the applied voltage. The liquid crystal shutter may be composed of multiple pixels and may control the light transmittance of each pixel. The liquid crystal shutter may form areas of high light transmittance or low light transmittance in any shape. When the barrier section 6 is composed of a liquid crystal shutter, the light-transmitting area 62 may be an area having a transmittance equal to or greater than a first predetermined value. When the barrier section 6 is composed of a liquid crystal shutter, the light-shielding area 61 may be an area having a transmittance equal to or less than a second predetermined value.

By being configured as described above, the barrier section 6 can transmit image light emitted from some of the subpixels in the active area 51 through the light-transmitting region 62 and propagate to the right eye of the user. The barrier section 6 can transmit image light emitted from other subpixels through the light-transmitting region 62 and propagate to the left eye of the user.

(Parallax image)
The image viewed by the user will be described in detail with reference to Fig. 4 and Fig. 5. The left visible region 51aL shown in Fig. 4 is a region on the active area 51 that is viewed by the left eye 15L of the user as a result of the image light having passed through the light-transmitting region 62 of the barrier section 6 reaching the left eye 15L of the user, as described above. The left invisible region 51bL is a region that cannot be viewed by the left eye 15L of the user as the image light is blocked by the light-shielding region 61 of the barrier section 6. The left visible region 51aL includes half of the subpixel P1, all of the subpixels P2 to P6, and half of the subpixel P7.

The right visible region 51aR shown in FIG. 5 is a region on the active area 51 that is visible to the user's right eye 15R as a result of image light from some of the other subpixels that has passed through the light-transmitting region 62 of the barrier section 6 reaching the user's right eye 15R. The right invisible region 51bR is a region that cannot be seen by the user's right eye 15R as the image light is blocked by the light-shielding region 61 of the barrier section 6. The right visible region 51aR includes half of subpixel P7, all of subpixels P8 to P12, and half of subpixel P1.

When a left eye image is displayed on the subpixels P1 to P6 and a right eye image is displayed on the subpixels P7 to P12, the left eye 15L and the right eye 15R view the left eye image and the right eye image, respectively. The left eye image and the right eye image are parallax images having mutual parallax. Specifically, the left eye 15L views half of the left eye image displayed on the subpixel P1, the entire left eye image displayed on the subpixels P2 to P6, and half of the right eye image displayed on the subpixel P7. The right eye 15R views half of the right eye image displayed on the subpixel P7, the entire right eye image displayed on the subpixels P8 to P12, and half of the left eye image displayed on the subpixel P1. In FIG. 4 and FIG. 5, the subpixels that display the left eye image are marked with the symbol "L", and the subpixels that display the right eye image are marked with the symbol "R".

In this state, the area of the left eye image viewed by the user's left eye 15L is maximum, and the area of the right eye image is minimum. The area of the right eye image viewed by the user's right eye 15R is maximum, and the area of the left eye image is minimum. Therefore, the user views a three-dimensional image with the crosstalk minimized.

In the three-dimensional display device 1 configured as described above, when the left eye image and the right eye image having a parallax are displayed on the subpixels included in the left visible region 51aL and the right visible region 51aR, respectively, a user with a standard interocular distance E of E0 can properly view the three-dimensional image. In the above configuration, the left eye image is displayed on the subpixels half of which are viewed by the left eye 15L, and the right eye image is displayed on the subpixels half of which are viewed by the right eye 15R. Not limited to this, the subpixels that display the left eye image and the right eye image may be appropriately determined based on the left visible region 51aL and the right visible region 51aR so as to minimize crosstalk, depending on the design of the active area 51, the barrier section 6, etc. For example, depending on the aperture ratio of the barrier section 6, the left eye image may be displayed on the subpixels half of which are viewed by the left eye 15L, and the right eye image may be displayed on the subpixels half of which are viewed by the right eye 15R.

(Configuration of the control unit)
The control unit 7 is connected to each component of the three-dimensional display device 1 and can control each component. The components controlled by the control unit 7 may include the detection unit 2, the display panel 5, and the drive unit 11. The three-dimensional display device 1 may include a control unit that controls the detection unit 2 in addition to the control unit 7 that controls the display panel 5 and the drive unit 11. The control unit 7 is configured as, for example, a processor. The control unit 7 may include one or more processors. The processor may include a general-purpose processor that reads a specific program and executes a specific function, and a dedicated processor specialized for a specific process. The dedicated processor may include an application specific integrated circuit (ASIC). The processor may include, for example, a programmable logic device (PLD). The programmable logic device may include a field-programmable gate array (FPGA). The control unit 7 may be either a system-on-a-chip (SoC) in which one or more processors work together, or a system in a package (SiP). The control unit 7 includes a memory 8, and may store various information or programs for operating each component of the three-dimensional display device 1 in the memory 8. The memory 8 may be configured, for example, by a semiconductor memory. The memory 8 may function as a work memory for the control unit 7. The memory 8 may be configured, for example, by any storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The memory 8 may store a first table, which will be described later.

(Index adjustment)
6, the horizontal positions of the right eye 15R and the left eye 15L are each identified by information 0 to 11. When the interocular distance E is the standard distance E0, the information identifying the position of the right eye 15R is assigned in the same manner as the information identifying the position of the left eye 15L.

As shown in FIG. 7, the first table stores the positions of the left eye 15L and the right eye 15R when the interocular distance E is the standard distance E0, and the left subpixels and right subpixels that are included in the left visible area 51aL and the right visible area 51aR at a predetermined rate or more. In the example shown in FIG. 7, information 0 to 11 for identifying the position of the eye 15 is shown in the column direction, and information P1 to P12 for identifying the subpixels is shown in the row direction. The information for identifying the position of the eye 15 is called an index or a reference index. The first table indicates whether each subpixel is a left subpixel or a right subpixel when the eye 15 is at each position. In FIG. 7, "left" is shown for the left subpixel, and "right" is shown for the right subpixel. As described with reference to FIG. 6, when the interocular distance E is the standard distance E0, if the left eye 15L is at the position indicated by "0", the right eye 15R is at the position indicated by "0". In this case, in the example shown in FIG. 7, subpixels P1 to P6 are left subpixels, and subpixels P7 to P12 are right subpixels. When the left eye 15L is at the position indicated by "1", the right eye 15R is at the position indicated by "1". In this case, subpixels P2 to P7 are left subpixels, and P1 and P8 to P12 are right subpixels. The control unit 7 selects one of the indexes 0 to 11. The control unit 7 specifies the order of the left eye image and right eye image to be displayed on the display surface of the display panel 5 based on the information P1 to P12 that identifies the subpixels corresponding to the selected index.

The control unit 7 synthesizes the first image and the second image based on the position of the left eye 15L or the position of the right eye 15R detected by the detection unit 2 or the position acquisition unit 3, and the index stored in the first table, to generate a parallax image. The control unit 7 may adjust the order of the first image and the second image displayed on the display surface of the display panel 5 based on the position of the left eye 15L or the position of the right eye 15R, and the index. This allows a user whose interocular distance E is the standard distance E0 to properly view a three-dimensional image.

The position of the user's eye 15 can move in a first direction (horizontal direction). When the control unit 7 fixes the index to one of indexes 0 to 11 stored in the first table and generates a parallax image based on the fixed index, crosstalk may occur in the three-dimensional image viewed by the user.

The three-dimensional display device 1 of this embodiment is configured so that the control unit 7 adjusts the index. When adjusting the index, the control unit 7 generates a parallax image for index adjustment and displays the generated parallax image for index adjustment on the display panel. The parallax image for index adjustment is also called a reference image.

The reference image is an image obtained by combining a first image and a second image that are different from each other. The first image and the second image that constitute the reference image may be monochromatic images that are different from each other in color. One of the first image and the second image that constitute the reference image (the first image) may be a black image, and the other (the second image) may be a white image. In this case, the reference image is a striped image in which white areas and black areas are alternately arranged periodically, as shown in FIG. 8. The reference image may be a visible light image or an infrared light image. The visible light image may be a black and white striped image or a color striped image. The infrared light image may be a striped image obtained by combining a first image and a second image that have different wavelengths of image light.

The control unit 7 synthesizes the first and second images, which are different from each other, based on a predetermined index to generate a reference image. The predetermined index may be any one of indexes 0 to 11 stored in the first table. The reference image may be an image synthesized on the assumption that the right eye 15R is in the position indicated by "0" in the first table, or may be an image synthesized on the assumption that both the left eye 15L and the right eye 15R are in the position indicated by "0" in the first table. The reference image generated based on the predetermined index is also called the first reference image 14. The control unit 7 displays the generated first reference image 14 on the display panel 5. FIG. 8 shows an example of the reference image displayed on the display panel 5 viewed from the depth direction. The first reference image 14 displayed on the display panel 5 is transmitted to the left eye 15L and right eye 15R of the user via the barrier unit 6 and optical elements, etc. The first reference image 14 is projected onto the user's face.

The control unit 7 controls the detection unit 2 to capture an image of the user's face onto which the first reference image 14 is projected. FIG. 9 is a diagram showing an example of an image captured by the detection unit 2. Hereinafter, the image captured by the detection unit 2 is also referred to as the first detection image 12. FIG. 9 shows an example of the first detection image 12 when the first reference image 14 shown in FIG. 8 is used. As shown in FIG. 9, the first detection image 12 includes the user's left eye 15L and right eye 15R and the first reference image 14 projected onto the user's face. The first reference image 14 projected onto the user's face may form a striped pattern in the first detection image 12, for example, as shown in FIG. 9. The striped pattern is also referred to as a shading pattern.

Below, the adjustment of the index performed by the three-dimensional display device 1 based on the first detection image 12 will be described. The detection unit 2 detects at least one of the positions of the left eye 15L and the right eye 15R, and the position of the shading pattern. In the following, it is assumed that the detection unit 2 detects the position of the right eye 15R. The position of the shading pattern may be the luminance value distribution of the shading pattern. The shading pattern includes a high luminance area 12a and a low luminance area 12b. The high luminance area 12a is a band-shaped area with a brighter brightness in the shading pattern, and the low luminance area 12b is a band-shaped area with a darker brightness in the shading pattern.

When the first reference image 14 is generated based on an appropriate index according to the position of the user's eye 15, the high-luminance area 12a and the right eye 15R overlap in the first detection image 12. If the high-luminance area 12a and the right eye 15R do not overlap, this means that the index used to generate the first reference image 14 is not an appropriate index according to the actual position of the user's eye 15.

The control unit 7 adjusts the index based on the first detected image 12. In the following, it is assumed that the index used to generate the first reference image 14 was "0".

The control unit 7 detects the amount of deviation Dd between the position of the right eye 15R and the position of the high brightness region 12a in the first direction (horizontal direction) as the amount of deviation of the index. The position of the high brightness region 12a may be the position in the high brightness region 12a where the brightness value is the highest in the first direction. For example, if the amount of deviation Dd between the position of the right eye 15R and the position of the high brightness region 12a in the first direction is three subpixels, the amount of deviation of the index is "+3", and the control unit 7 changes the index from "0" to "3". If the amount of deviation Dd between the position of the right eye 15R and the position of the high brightness region 12a in the first direction is six subpixels, the amount of change in the index is "+6", and the control unit 7 changes the index from "0" to "6". In this way, the control unit 7 can adjust the index based on the image of the user's face onto which the first reference image 14 is projected.

With the three-dimensional display device 1, the index is adjusted based on the image of the user's face onto which the first reference image 14 is projected, so adjustments can be made without relying on the subjective judgment of the user. Therefore, the three-dimensional display device 1 allows the user to properly view the three-dimensional image.

The three-dimensional display device 1 does not require the user to make a decision when adjusting the index. Therefore, the three-dimensional display device 1 makes it possible to repeat the adjustment of the index multiple times without bothering the user, thereby improving the accuracy of the index adjustment.

The control unit 7 may adjust the index based on the amount of deviation between the position of the left eye 15L and the position of the low-luminance area 12b in the first direction. This makes it possible to adjust the index based on the image of the user's face onto which the first reference image 14 is projected, even if it is difficult to distinguish the high-luminance area 12a in the shading pattern due to the influence of external light, etc.

When the control unit 7 determines that it is difficult to distinguish the high-luminance area 12a in the shading pattern, the control unit 7 may generate a reference image by combining the left eye image, which is a white image, and the right eye image, which is a black image. The reference image by combining the left eye image, which is a white image, and the right eye image, which is a black image, is also called an inverted reference image. The control unit 7 may adjust the index based on the image of the face of the user viewing the inverted reference image, which is captured by the detection unit 2. The control unit 7 may adjust the index based on the amount of deviation between the position of the right eye 15R and the position of the low-luminance area of the shading pattern included in the inverted reference image projected onto the user's face. In this way, even if it is difficult to distinguish the high-luminance area 12a of the shading pattern due to the influence of light coming from outside, the index can be adjusted based on the image of the user's face onto which the inverted reference image is projected.

The three-dimensional display device 1 may be configured to adjust the index at night. This reduces the risk that the position of the user's eye 15 or the first reference image 14 projected onto the user's face may be difficult to detect due to the influence of light coming from outside. Nighttime may be, for example, the period from sunset to sunrise. Nighttime may be an environment with low ambient brightness, regardless of the time of day.

The three-dimensional display device 1 may be configured to readjust the index after adjusting the index as described above. When the control unit 7 readjusts the index, the control unit 7 synthesizes the first image and the second image, which are different from each other, based on the adjusted index to generate a second reference image. The control unit 7 causes the display panel 5 to display the second reference image. The second reference image displayed on the display panel 5 is transmitted to the left eye 15L and the right eye 15R of the user via the barrier unit 6 and the optical element, etc. The second reference image is projected onto the user's face. The control unit 7 controls the detection unit 2 to capture an image of the user's face onto which the second reference image is projected. The image of the user's face onto which the second reference image is projected, captured by the detection unit 2, is similar to the first detection image 12 shown in FIG. 9, but the position of the user's eye 15 and the position of the shading pattern may be different from the first detection image 12 shown in FIG. 9. The process performed by the three-dimensional display device 1 to readjust the index is similar to the process performed to adjust the index, so a detailed description will be omitted.

The three-dimensional display device 1 can improve the accuracy of index adjustment by readjusting the index. Therefore, the three-dimensional display device 1 can allow the user to properly view the three-dimensional image. According to the three-dimensional display device 1, it is possible to repeat the adjustment of the index multiple times, thereby improving the accuracy of the index adjustment.

The three-dimensional display device 1 may display the reference image only when the index is being adjusted. When the index is not being adjusted, the three-dimensional display device 1 may display various information about a moving object such as a vehicle, ship, or aircraft equipped with the three-dimensional display device 1. The three-dimensional display device 1 may display the reference image between frames of successive images showing various information, and cause the detection unit 2 to capture an image of the user's face onto which the reference image is projected. This allows the three-dimensional display device 1 to repeatedly adjust the index while displaying various information about the moving object. As a result, the three-dimensional display device 1 can always use an appropriate index according to the position of the user's eye 15, allowing the user to properly view the three-dimensional image.

In the three-dimensional display device 1, the detection unit 2 detects at least one of the positions of the left eye 15L and the right eye 15R and the position of the shading pattern, but the detection unit 2 does not need to detect at least one of the positions of the left eye 15L and the right eye 15R and the position of the shading pattern. In this case, the three-dimensional display device 1 may be configured such that the position acquisition unit 3 detects at least one of the positions of the left eye 15L and the right eye 15R and the position of the shading pattern.

The display panel 5 may have multiple display areas with different indexes within the active area 51. The control unit 7 may adjust the index of a display area located in the center of the active area 51 as described above, and adjust the indexes of other display areas in synchronization with the index of the display area.

The three-dimensional display device 1 may be configured to correct the first detected image 12 and adjust the index based on the corrected first detected image 12. The correction of the first detected image 12 may be performed based on the reflectance of the user's face. The correction of the first detected image 12 and the adjustment of the index using the corrected first detected image 12 will be described below.

The control unit 7 causes the display panel 5 to display a test image before the first reference image 14 is displayed on the display panel 5. The test image may be a monochromatic image. The monochromatic image may be a white image. The test image may be generated, for example, by combining a white first image and a white second image. The control unit 7 may cause the display panel 5 to display the test image before generating the first reference image 14, or may cause the display panel 5 to display the test image after generating the first reference image 14.

The control unit 7 causes the detection unit 2 to capture an image of the user's face on which the test image is projected. The detection unit 2 measures the reflectance of the user's face based on the captured reflectance measurement image (hereinafter also simply referred to as the measurement image). The reflectance of the user's face can be measured for each pixel of the measurement image based on the luminance value of the test image displayed on the display panel 5 and the luminance value of each pixel of the measurement image. The detection unit 2 detects at least one of the positions of the left eye 15L and the right eye 15R based on the measurement image. In the following, it is assumed that the detection unit 2 detects the position of the right eye 15R.

After the detection unit 2 detects the reflectance of the user's face and the position of the right eye 15R, the control unit 7 causes the display panel 5 to display the first reference image 14. The control unit 7 causes the detection unit 2 to capture an image of the user's face onto which the first reference image 14 is projected, and obtains the first detection image 12. The control unit 7 corrects the first detection image 12 by dividing the luminance value of each pixel in the first detection image 12 by the reflectance of that pixel measured from the measurement image.

The corrected first detected image 12 is an image in which the influence of the reflectance of the user's face is reduced. The corrected first detected image 12 may be an image that does not substantially include the user's face and includes only the shading pattern. The detection unit 2 detects the position of the high luminance area 12a of the shading pattern based on the corrected first detected image 12. Since the corrected second detected image 13 is an image in which the influence of the reflectance of the user's face is reduced, the position of the high luminance area 12a can be detected with high accuracy by detecting the position of the high luminance area 12a from the corrected second detected image 13.

To adjust the index, it is necessary to determine how many subpixels the shift amount Dd between the position of the right eye 15R and the position of the high-luminance area 12a in the first direction (x-axis direction) corresponds to. Since the positions of the right eye 15R and the high-luminance area 12a are expressed in coordinates based on the origin of the camera provided in the detection unit 2, in order to make the above determination, it is first necessary to convert the coordinates of the right eye 15R and the coordinates of the high-luminance area 12a into coordinates based on the origin of the display panel 5. This coordinate conversion is also called origin correction. Figure 10 is a diagram for explaining origin correction. The origin O5 of the display panel 5 is located in the high-luminance area 12a. The origin O2 of the camera is located at the position shown in Figure 10. The control unit 7 converts the coordinates of the right eye 15R and the coordinates of the high-luminance area 12a based on the origin O2 (collectively referred to as "x") into coordinates x + xd - xe based on the origin O5. Here, xd is the distance between the right eye 15R and the high-luminance region 12a in the x-axis direction, and xe is the x-coordinate of the right eye 15R with respect to the origin O2. The control unit 7 uses the above-mentioned origin correction to determine how many subpixels the shift amount Dd corresponds to, and adjusts the index based on this determination.

The three-dimensional display device 1 configured as described above detects the position of the right eye 15R from the measurement image and detects the position of the high-luminance area 12a from the corrected first detection image 12, so that the positions of the right eye 15R and the high-luminance area 12a can be detected with high accuracy. As a result, the index can be adjusted with high accuracy.

The control unit 7 may detect the position of the left eye 15L based on the measurement image. The control unit 7 may adjust the index based on the amount of deviation in the first direction between the position of the left eye 15L detected from the measurement image and the position of the low-brightness area 12b detected from the corrected first detection image 12.

The control unit 7 may display an inverted reference image on the display panel 5 instead of the first reference image 14. The control unit 7 may cause the detection unit 2 to capture an image of the user's face onto which the inverted reference image is projected, to obtain a detection image. The control unit 7 may correct the detection image using the reflectance of the user's face, and detect the position of the right eye and the position of the low-luminance area based on the corrected detection image. The control unit 7 may adjust the index based on the amount of deviation between the position of the right eye and the position of the low-luminance area in the first direction. This makes it possible to adjust the index based on the image of the user's face onto which the inverted reference image is projected, even if it is difficult to distinguish high-luminance areas in the shading pattern due to the influence of light coming from outside, etc.

When the control unit 7 displays a test image on the display panel 5 before generating the first reference image 14, the control unit 7 may change the color or brightness of at least one of the first image and the second image based on the reflectance of the user's face. This makes it possible to accurately detect the position and shading pattern of the eye 15.

FIG. 11 is a flowchart for explaining an example of a process for adjusting an index. When the control unit 7 starts this flowchart, in step S1, the control unit 7 displays a test image on the display panel 5 and causes the detection unit 2 to capture an image of the user's face onto which the test image is projected (measurement image). In step S2, the control unit 7 detects the position of the right eye 15R based on the measurement image. In step S3, the control unit 7 measures the reflectance of the user's face based on the measurement image. In step S4, the control unit 7 displays the first reference image 14 on the display panel 5 and causes the detection unit 2 to capture an image of the user's face onto which the first reference image 14 is projected (first detection image 12). In step S5, the control unit 7 corrects the first detection image 12 using the reflectance of the user's face to obtain the corrected first detection image 12. In step S6, the control unit 7 detects the position of the high brightness area 12a based on the corrected first detection image 12. In step S7, the control unit 7 performs origin correction based on the position of the right eye 15R detected in step S2 and the position of the high luminance area 12a detected in step S6. In step S8, the control unit 7 adjusts the index based on the deviation amount Dd based on the origin O5 of the display panel 5, and ends this flowchart.

When readjusting the index, the three-dimensional display device 1 may correct the image of the user's face captured by the detection unit 2 onto which the second reference image is projected, using the reflectance of the user's face, and readjust the index based on the corrected image.

(Interocular distance correction)
When the interocular distance E1 of the user is different from the standard distance E0, for example, as shown in FIG. 12, there may be a binocular visible area 51aLR in which a part of the left visible area 51aL overlaps a part of the right visible area 51aR. Therefore, there may be a subpixel that is a left subpixel (first subpixel) that is determined to display a left eye image based on the left visible area 51aL, and a right subpixel (second subpixel) that is determined to display a right eye image based on the right visible area 51aR. The left subpixel is, for example, a subpixel that is included in the left visible area 51aL by a predetermined proportion (e.g., half) or more. The right subpixel is, for example, a subpixel that is included in the right visible area 51aR by a predetermined proportion or more.

When a right-eye image is displayed on a subpixel that is a left subpixel and a right pixel, the right-eye image viewed by the left eye 15L increases. When a left-eye image is displayed on a subpixel that is a left subpixel and a right pixel, the left-eye image viewed by the right eye 15R increases. Therefore, whether a left-eye image or a right-eye image is displayed on the overlapping subpixels, crosstalk may increase. The control unit 7 may correct the interocular distance to reduce crosstalk that occurs when a user with an interocular distance E1 different from the standard distance E0 views a three-dimensional image displayed by the three-dimensional display device 1 configured based on the standard distance E0.

When correcting interocular distance, the control unit 7 generates a parallax image for interocular distance correction and displays the generated parallax image on the display panel. The parallax image for interocular distance correction may be a first reference image 14 synthesized based on a predetermined index, or a second reference image synthesized based on an adjusted index. The parallax image for interocular distance correction may be an image different from the first reference image and the second reference image. In the following, the parallax image for interocular distance correction is assumed to be the first reference image 14.

The control unit 7 causes the display panel 5 to display the first reference image 14. The first reference image 14 displayed on the display panel 5 is transmitted to the user's left eye 15L and right eye 15R via the barrier unit 6 and optical elements, etc. The first reference image 14 is projected onto the user's face.

The control unit 7 controls the detection unit 2 to capture an image of the user's face onto which the first reference image 14 is projected. FIG. 13 is a diagram showing an example of an image captured by the detection unit 2. The image captured by the detection unit 2 is also referred to as the second detection image 13. As shown in FIG. 13, the second detection image 13 includes the user's left eye 15L and right eye 15R and the first reference image 14 projected onto the user's face. The first reference image 14 projected onto the user's face may form a striped pattern in the second detection image 13, for example, as shown in FIG. 13. The striped pattern is also referred to as a shading pattern.

The following describes the correction of interocular distance that the three-dimensional display device 1 performs based on the second detection image 13. The detection unit 2 detects the positions of the left eye 15L and the right eye 15R, and the position of the shading pattern. The position of the shading pattern may be the luminance value distribution of the shading pattern. The shading pattern includes a high luminance area 13a and a low luminance area 13b. The high luminance area 13a is a band-shaped area with a brighter brightness in the shading pattern, and the low luminance area 13b is a band-shaped area with a darker brightness in the shading pattern.

The three-dimensional display device 1 without interocular distance correction is configured based on the standard distance E0. Therefore, when the interocular distance E1 of the user is the standard distance E0, the distance between the high-luminance area 13a and the low-luminance area 13b in the first direction (horizontal direction) is equal to the distance between the left eye 15L and the right eye 15R in the horizontal direction. In other words, when the interocular distance E1 of the user is the standard distance E0, the horizontal distance between adjacent high-luminance areas 13a is twice the distance between the first eye 15L and the second eye 15R in the horizontal direction. The horizontal distance between adjacent high-luminance areas 13a is also referred to as the horizontal distance Dh. The horizontal distance between the first eye 15L and the second eye 15R is also referred to as the horizontal distance De. The horizontal distance Dh can be calculated based on the position of the high-luminance area 12a. The horizontal distance De can be calculated based on the position of the left eye 15L and the position of the right eye 15R. If the horizontal distance Dh is greater than twice the horizontal distance De, it can be determined that the user's interocular distance E1 is smaller than the standard distance E0. If the horizontal distance Dh is less than twice the horizontal distance De, it can be determined that the user's interocular distance E1 is greater than the standard distance E0.

The control unit 7 controls the drive unit 11 based on the horizontal distance Dh and the horizontal distance De to move the barrier unit 6 in the third direction. When the control unit 7 determines that the interocular distance E1 of the user is greater than the standard distance E0, it moves the barrier unit 6 along the third direction, for example as shown in FIG. 14, to reduce the distance between the barrier unit 6 and the active area 51. This allows the image light emitted from the subpixels included in the left visible region 51aL to be propagated to the left eye of a user whose interocular distance E1 is greater than the standard distance E0, and the image light emitted from the subpixels included in the right visible region 51aR to be propagated to the right eye of a user whose interocular distance E1 is greater than the standard distance E0.

When the control unit 7 determines that the interocular distance E1 of the user is shorter than the standard distance E0, it moves the barrier unit 6 along the third direction to increase the distance between the barrier unit 6 and the active area 51. This allows the image light emitted from the subpixels included in the left visible region 51aL to be propagated to the left eye 15L of a user whose interocular distance E1 is shorter than the standard distance, and the image light emitted from the subpixels included in the right visible region 51aR to be propagated to the right eye 15R of a user whose interocular distance E1 is shorter than the standard distance E0.

According to the three-dimensional display device 1, the correction of the interocular distance is performed based on the image of the user's face onto which the first reference image is projected, so that the correction can be performed without the subjective judgment of the user. Therefore, the three-dimensional display device 1 can allow the user to properly view the three-dimensional image.

The memory 8 may store a table for correcting the interocular distance that specifies the relationship between the ratio between the horizontal distance Dh and the horizontal distance De and the amount of movement of the barrier unit 6 in the third direction. The control unit 7 may control the drive unit 11 using the table for correcting the interocular distance stored in the memory 8.

The three-dimensional display device 1 does not require the user to make a decision when correcting the interocular distance. Therefore, the three-dimensional display device 1 makes it possible to repeat the correction of the interocular distance multiple times without bothering the user, thereby improving the accuracy of the interocular distance correction.

The three-dimensional display device 1 may be configured to correct the second detected image 13 and correct the interocular distance based on the corrected second detected image 13. The correction of the second detected image 13 may be performed based on the reflectance of the user's face. The correction of the second detected image 13 and the correction of the interocular distance using the corrected second detected image 13 will be described below.

The control unit 7 causes the display panel 5 to display a test image before the first reference image 14 is displayed on the display panel 5. The test image may be a monochromatic image. The monochromatic image may be a white image. The test image may be generated, for example, by combining a white first image and a white second image. The control unit 7 may cause the display panel 5 to display the test image before generating the first reference image 14, or may cause the display panel 5 to display the test image after generating the first reference image 14.

The control unit 7 captures an image of the user's face on which the test image is projected on the detection unit 2, and obtains a measurement image. The control unit 7 measures the reflectance of the user's face based on the measurement image, and detects the positions of the left eye 15L and the right eye 15R. The reflectance of the user's face can be measured for each pixel of the measurement image based on the luminance value of the test image displayed on the display panel 5 and the luminance value of each pixel of the measurement image. The control unit 7 may store the reflectance measured when adjusting the index in the memory 8, and use the reflectance read from the memory 8, or may measure the reflectance again when correcting the interocular distance. The control unit 7 calculates the horizontal distance De based on the positions of the left eye 15L and the right eye 15R.

The control unit 7 causes the display panel 5 to display the first reference image 14. The control unit 7 causes the detection unit 2 to capture the user's face on which the first reference image 14 is projected, and obtains the second detection image 13. The control unit 7 corrects the second detection image 13 by dividing the luminance value of each pixel in the second detection image 13 by the reflectance of the pixel measured from the measurement image. The control unit 7 detects the position of the high luminance area 12a based on the corrected second detection image 13, and calculates the horizontal distance Dh based on the position of the high luminance area 12a. The subsequent processing is similar to the case of correcting the interocular distance using the uncorrected second detection image 13, so detailed explanations are omitted. The corrected second detection image 13 has a reduced effect of the reflectance of the user's face, making it easier to detect the shading pattern. Therefore, by using the corrected second detection image 13, it is possible to accurately correct the interocular distance.

When the control unit 7 determines that it is difficult to distinguish the low-luminance areas 13b in the shading pattern, the control unit 7 may set the distance between adjacent high-luminance areas 13a in the horizontal direction as the horizontal distance Dh. This allows the interocular distance to be corrected based on the image of the user's face onto which the first reference image is projected, even if it is difficult to distinguish the low-luminance areas 13b in the shading pattern due to the influence of light coming from outside, etc.

When the control unit 7 determines that it is difficult to distinguish the low-luminance area 13b in the shading pattern, the control unit 7 may generate a reference image by combining the left eye image, which is a white image, and the right eye image, which is a black image. The reference image by combining the left eye image, which is a white image, and the right eye image, which is a black image, is also called an inverted reference image. The control unit 7 may correct the interocular distance based on the image of the face of the user viewing the inverted reference image, which is captured by the detection unit 2. The control unit 7 may correct the interocular distance based on the distance between adjacent high-luminance areas in the horizontal direction and the horizontal distance De. In this way, even if it is difficult to distinguish the low-luminance area 13b in the shading pattern due to the influence of light coming from outside, the interocular distance can be corrected based on the image of the face of the user onto which the inverted reference image is projected.

The three-dimensional display device 1 may be configured to correct the interocular distance at night. This reduces the risk that the position of the user's eye 15 or the first reference image 14 projected onto the user's face may become difficult to detect due to the influence of light coming from outside. Nighttime may be, for example, the period from sunset to sunrise. Nighttime may be an environment with low ambient brightness, regardless of the time of day.

The three-dimensional display device 1 may be configured to recorrect the interocular distance after correcting the interocular distance as described above. When recorrecting the interocular distance, the control unit 7 synthesizes a first image and a second image that are different from each other to generate a parallax image for recorrecting the interocular distance. The control unit 7 causes the display panel to display the generated parallax image. The parallax image for recorrecting the interocular distance may be a first reference image, may be a second reference image, or may be an image different from the first reference image and the second reference image. In the following, the parallax image for recorrecting the interocular distance is assumed to be the second reference image.

The second reference image displayed on the display panel 5 is transmitted to the left and right eyes of the user via the barrier unit 6 and optical elements, etc. The second reference image is projected onto the user's face. The control unit 7 controls the detection unit 2 to capture an image of the user's face onto which the second reference image is projected. The image of the user's face onto which the second reference image is projected, captured by the detection unit 2, is similar to the second detection image 13 shown in FIG. 13, but the position of the user's eye 15 and the position of the shading pattern may be different from the second detection image 13 shown in FIG. 13. The process performed by the three-dimensional display device 1 to recorrect the interocular distance is similar to the above-mentioned process performed to correct the interocular distance, and therefore a detailed description will be omitted.

The three-dimensional display device 1 recorrects the interocular distance, thereby improving the accuracy of the interocular distance correction. Therefore, the three-dimensional display device 1 allows the user to properly view a three-dimensional image. The three-dimensional display device 1 makes it possible to repeat the correction of the interocular distance multiple times, thereby improving the accuracy of the interocular distance correction.

The three-dimensional display device 1 may display the reference image only when the interocular distance is being corrected. When the interocular distance is not being corrected, the three-dimensional display device 1 may display various information about a moving object such as a vehicle, ship, or aircraft equipped with the three-dimensional display device 1. The three-dimensional display device 1 may display the reference image between frames of successive images showing various information, and cause the detection unit 2 to capture the face of the user onto which the reference image is projected. This allows the three-dimensional display device 1 to repeatedly correct the interocular distance while displaying various information about the moving object. As a result, the three-dimensional display device 1 can always display a three-dimensional image according to the interocular distance of the user, allowing the user to properly view the three-dimensional image.

In the three-dimensional display device 1, the detection unit 2 detects the position of the eye 15 and the position of the shading pattern, but the detection unit 2 does not have to detect the position of the eye 15 and the position of the shading pattern. In this case, the three-dimensional display device 1 may be configured so that the control unit 7 detects the position of the eye 15 and the position of the shading pattern, and the position acquisition unit 3 detects the position of the eye 15 and the position of the shading pattern and outputs them to the control unit 7.

When the three-dimensional display device 1 recorrects the interocular distance, it may correct the image of the user's face captured by the detection unit 2 onto which the second reference image is projected, using the reflectance of the user's face, and recorrect the interocular distance based on the corrected image.

As shown in FIG. 15, the three-dimensional display device 1 can be mounted on a head-up display 100. The head-up display 100 is also called a HUD (Head Up Display) 100. The HUD 100 includes the three-dimensional display device 1, an optical member 110, and a projection member 120 having a projection surface 130.

The HUD 100 allows the image light emitted from the three-dimensional display device 1 to reach the projection target 120 via the optical element 110. The HUD 100 allows the image light reflected by the projection target 120 to reach the first and second eyes of the user. In other words, the HUD 100 allows the image light to travel from the three-dimensional display device 1 to the first and second eyes of the user along an optical path 140 indicated by a dashed line in FIG. 15. The user can visually recognize the image light that arrives along the optical path 140 as a virtual image 150.

The HUD 100 adjusts the index of the three-dimensional display device 1 based on the image of the user's face onto which the first reference image is projected, and therefore can perform adjustments that eliminate the subjective judgment of the user. Therefore, the HUD 100 allows the user to properly view the three-dimensional image. The HUD 100 does not require the user's judgment when adjusting the index. Therefore, the HUD 100 makes it possible to repeat the adjustment of the index multiple times without causing the user any inconvenience, and the accuracy of the index adjustment can be improved.

As shown in FIG. 16, a HUD 100 including a three-dimensional display device 1 may be mounted on a moving body 10 such as a vehicle, ship, or aircraft. Part of the configuration of the HUD 100 may be shared with other devices or parts of the moving body 10. For example, the moving body 10 may share the windshield as the projection target member 120. When part of the configuration is shared with other devices or parts of the moving body 10, the other configuration may be called a HUD module or a three-dimensional display component. The HUD 100 may be mounted on the moving body 10.

The mobile body 10 can adjust the index of the three-dimensional display device 1 based on the image of the user's face onto which the first reference image is projected, and therefore can perform adjustments that eliminate the subjective judgment of the user. Therefore, the mobile body 10 can allow the user to properly view the three-dimensional image. The mobile body 10 does not require the user's judgment when adjusting the index. Therefore, the mobile body 10 makes it possible to repeat the adjustment of the index multiple times without causing the user any inconvenience, and the accuracy of the index adjustment can be improved.

In this disclosure, "vehicles" include, but are not limited to, automobiles and industrial vehicles, and may include railroad vehicles, lifestyle vehicles, and fixed-wing aircraft that run on runways. Automobiles include, but are not limited to, passenger cars, trucks, buses, motorcycles, and trolley buses, and may include other vehicles that run on roads. 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, combines, and lawnmowers. Industrial vehicles for construction include, but are not limited to, bulldozers, scrapers, excavators, cranes, dump trucks, and road rollers. Vehicles include those that run by human power. Note that the classification of vehicles is not limited to the above. For example, automobiles may include industrial vehicles that can run on roads, and the same vehicle may be included in multiple classifications. Marine vessels in this disclosure include marine jets, boats, and tankers. Aircraft in this disclosure include fixed-wing aircraft and rotorcraft.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the spirit of the present disclosure. It goes without saying that all or part of the components of each of the above-described embodiments can be combined as appropriate and consistent.

In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. Configurations distinguished by descriptions such as "first" and "second" in this disclosure may have their numbers exchanged. For example, the first eye may exchange identifiers "first" and "second" with the second eye. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the exchange of identifiers. Identifiers may be deleted. Configurations from which identifiers have been deleted are distinguished by symbols. Descriptions of identifiers such as "first" and "second" in this disclosure alone should not be used to interpret the order of the configurations or to justify the existence of identifiers with smaller numbers.

In this disclosure, the x-axis, y-axis, and z-axis are provided for convenience of explanation and may be interchanged. The configurations according to this disclosure have been described using an orthogonal coordinate system consisting of the x-axis, y-axis, and z-axis. The positional relationship of each configuration according to this disclosure is not limited to an orthogonal relationship.

REFERENCE SIGNS LIST 1 3D display device 2 Detection unit 3 Position acquisition unit 4 Illuminator 5 Display panel 51 Active area 51a Visible area 51aL Left visible area 51aR Right visible area 51bL Left invisible area 51bR Right invisible area 51aLR Binocular visible area 6 Barrier unit 61 Light-shielding area 62 Light-transmitting area 7 Control unit 8 Memory 10 Moving body 11 Driving unit 12 First detected image 13 Second detected image 12a, 13a High-luminance area 12b, 13b Low-luminance area 14 Reference image (first reference image)
15 Eye 15L Left Eye 15R Right Eye 100 Head-up Display (HUD)
110 Optical member 120 Projected member 130 Projected surface 140 Optical path 150 Virtual image

Claims (14)

a display panel configured to display a parallax image including a first image and a second image having parallax with respect to the first image;
a barrier unit configured to provide parallax to a first eye and a second eye of a user by regulating a traveling direction of image light of the parallax image;
A detection unit configured to capture an image of a face of the user viewing the parallax image;
A control unit,
The control unit is
generating a first reference image by combining the first image and the second image, which are different from each other, based on a predetermined index that defines an arrangement of the first image and the second image to be displayed on the display panel;
displaying the first reference image on the display panel;
a three-dimensional display device that calculates an amount of deviation between the index and an appropriate index corresponding to the position of the user's eyes based on an image of the user's face captured by the detection unit onto which the first reference image is projected, and adjusts the index based on the amount of deviation. The three-dimensional display device according to claim 1 ,
The control unit adjusts a position of the barrier unit in the traveling direction of the image light based on an image of the user's face onto which the first reference image is projected. 3. The three-dimensional display device according to claim 1,
the first image and the second image are monochromatic images different from each other,
The control unit calculates the amount of deviation and adjusts the index based on at least one of the position of the user's first eye and the position of the second eye obtained from the image of the user's face captured by the detection unit and the shading pattern of the first reference image projected onto the user's face. The three-dimensional display device according to claim 3,
The control unit adjusts the position of the barrier unit in the direction of travel of the image light based on the position of the first eye and the position of the second eye of the user obtained from the image of the user's face captured by the detection unit and the shading pattern of the first reference image projected onto the user's face. The three-dimensional display device according to any one of claims 1 to 4,
The control unit is
generating a second reference image by combining the first image and the second image, which are different from each other, based on the adjusted index;
displaying the second reference image on the display panel;
A three-dimensional display device that readjusts the index based on an image of the user's face captured by the detection unit onto which the second reference image is projected. The three-dimensional display device according to claim 5 ,
The control unit readjusts a position of the barrier unit in the traveling direction of the image light based on an image of the user's face onto which the second reference image is projected. The three-dimensional display device according to any one of claims 1 to 6,
The control unit causes the display panel to display a monochromatic test image before causing the display panel to display the first reference image. The three-dimensional display device according to claim 7,
The test image is a white monochromatic image. 9. The three-dimensional display device according to claim 7 or 8,
The control unit causes the detection unit to capture an image of the user's face onto which the test image is projected. The three-dimensional display device according to claim 9,
The control unit measures the reflectance of the user's face based on an image of the user's face captured by the detection unit onto which the test image is projected. The three-dimensional display device according to claim 10,
The control unit corrects an image of the user's face, captured by the detection unit, onto which the first reference image is projected, based on the reflectance. The three-dimensional display device according to claim 11,
The control unit calculates the amount of deviation based on the corrected image of the user's face, and adjusts the index. a display panel configured to display a parallax image including a first image and a second image having parallax with respect to the first image;
a barrier unit configured to provide parallax to a first eye and a second eye of a user by regulating a traveling direction of image light of the parallax image;
an optical member configured to allow the user to visually recognize the image light emitted from the display panel as a virtual image;
A detection unit configured to capture an image of a face of the user viewing the parallax image;
A control unit,
The control unit is
generating a first reference image by combining the first image and the second image, which are different from each other, based on an index that specifies an order of the first image and the second image to be displayed on the display panel;
Displaying the first reference image on the display panel;
A head-up display that calculates the amount of deviation between the index and an appropriate index corresponding to the position of the user's eyes based on an image of the user's face captured by the detection unit onto which the first reference image is projected, and adjusts the index based on the amount of deviation . a display panel configured to display a parallax image including a first image and a second image having parallax with respect to the first image;
a barrier unit configured to provide parallax to a first eye and a second eye of a user by regulating a traveling direction of image light of the parallax image;
an optical member configured to allow the user to visually recognize the image light emitted from the display panel as a virtual image;
A detection unit configured to capture an image of a face of the user viewing the parallax image;
A control unit,
The control unit is
generating a first reference image by combining the first image and the second image, which are different from each other, based on an index that specifies an order of the first image and the second image to be displayed on the display panel;
displaying the first reference image on the display panel;
A mobile body equipped with a head-up display that calculates an amount of deviation between the index and an appropriate index corresponding to the position of the user's eyes based on an image of the user's face captured by the detection unit onto which the first reference image is projected, and adjusts the index based on the amount of deviation .