JP7332764B2 - Image display module - Google Patents

Description

The present disclosure relates to image display modules.

2. Description of the Related Art Conventionally, there is known a configuration for correcting distortion of an optical system in an image display device that provides stereoscopic vision (for example, see Patent Document 1, etc.).

JP 2019-15823 A

There is a need to further improve the image quality of stereoscopic viewing provided to users.

An object of the present disclosure is to provide an image display module capable of improving stereoscopic image quality provided to a user.

An image display module according to an embodiment of the present disclosure includes a display section, a barrier section, and a concave mirror. The display unit displays a planar image and a parallax image projected through an optical system to the first and second eyes of the user. The barrier section provides parallax to the first eye and the second eye by defining the traveling direction of the image light of the parallax image. The concave mirror constitutes at least part of the optical system. The distortion of the barrier portion projected through the optical system is smaller than the distortion of the display portion projected through the optical system.

An image display module according to an embodiment of the present disclosure includes a display section, a barrier section, and a concave mirror. The display unit displays a planar image and a parallax image projected through an optical system to the first and second eyes of the user. The barrier section provides parallax to the first eye and the second eye by defining the traveling direction of the image light of the parallax image. The concave mirror constitutes at least part of the optical system. The magnification of the barrier section by the optical system is greater than the magnification of the display section by the optical system.

According to the image display module according to an embodiment of the present disclosure, stereoscopic image quality provided to the user can be improved.

1 is a diagram illustrating an example of a schematic configuration of a mobile object according to an embodiment of the present disclosure; FIG. 2 is a diagram showing a schematic configuration of the three-dimensional projection apparatus of FIG. 1; FIG. FIG. 3 is a plan view showing a configuration example of a display surface; FIG. 4 is a plan view showing a configuration example of a barrier; FIG. 3 is a schematic diagram showing the relationship between a user's eyes, a display section, and a barrier section; It is a figure which shows an example of the distortion of the virtual image projected via the optical system. It is a graph which shows an example of the relationship between the distance from a concave mirror, and magnification.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the diagrams used in the following description are schematic. The dimensional ratios and the like on the drawings do not necessarily match the actual ones.

As shown in FIG. 1 , a mobile object 10 according to an embodiment of the present disclosure includes a three-dimensional projection system 100 and an optical member 15. As shown in FIG. Three-dimensional projection system 100 includes a three-dimensional projection device 12 . It can be said that the mobile body 10 is equipped with the three-dimensional projection system 100 and the three-dimensional projection device 12 .

The position of the three-dimensional projection device 12 is arbitrary inside and outside the moving body 10 . For example, the 3D projection device 12 may be located within the dashboard of the vehicle 10 . The three-dimensional projection device 12 emits image light toward the optical member 15 .

The optical member 15 reflects image light emitted from the three-dimensional projection device 12 . The image light reflected by the optical member 15 reaches the eyebox 16 . The eye box 16 is a real space area where the eye 5 of the user 13 is assumed to exist, for example, considering the physique, posture, change in posture, etc. of the user 13 . The shape of the eyebox 16 is arbitrary. Eyebox 16 may include two-dimensional or three-dimensional regions. A solid-line arrow shown in FIG. 1 indicates a path along which at least part of the image light emitted from the three-dimensional projection device 12 reaches the eyebox 16 . The path traveled by the image light is also referred to as the optical path. When the eye 5 of the user 13 is positioned within the eyebox 16 , the user 13 can visually recognize the virtual image 14 with image light reaching the eyebox 16 . The virtual image 14 is positioned on a line indicated by a dashed line extending forward from the path from the optical member 15 to the eye 5 . The three-dimensional projection device 12 can function as a head-up display by making the user 13 visually recognize the virtual image 14 . Optical member 15 may include a windshield, combiner, or the like. In this embodiment, the optical member 15 is assumed to be a windshield. In FIG. 1, the direction in which the eyes 5 of the user 13 are aligned corresponds to the x-axis direction. The vertical direction corresponds to the y-axis direction. A direction orthogonal to the x-axis direction and the y-axis direction corresponds to the z-axis direction.

A “moving object” in the present disclosure may include, for example, a vehicle, a ship, an aircraft, and the like. Vehicles may include, for example, automobiles, industrial vehicles, railroad vehicles, utility vehicles, fixed-wing aircraft that travel on runways, and the like. Motor vehicles may include, for example, cars, trucks, buses, motorcycles, trolleybuses, and the like. Industrial vehicles may include, for example, industrial vehicles for agriculture and construction, and the like. Industrial vehicles may include, for example, forklifts, golf carts, and the like. Industrial vehicles for agriculture may include, for example, tractors, tillers, transplanters, binders, combines, lawn mowers, and the like. Industrial vehicles for construction may include, for example, bulldozers, scrapers, excavators, mobile cranes, tippers, road rollers, and the like. Vehicles may include those that are powered by humans. Vehicle classification is not limited to the above example. For example, automobiles may include road-drivable industrial vehicles. Multiple classifications may contain the same vehicle. Vessels may include, for example, marine jets, boats, tankers, and the like. Aircraft may include, for example, fixed-wing aircraft, rotary-wing aircraft, and the like.

The three-dimensional projection system 100 may further include a detection device 11 for detecting the position of the eye 5 of the user 13. FIG. The detection device 11 detects the position of the eye 5 of the user 13 and outputs the detected position of the eye 5 to the three-dimensional projection device 12 . The three-dimensional projection device 12 may control the image to be projected based on the position of the eye 5 of the user 13 detected by the detection device 11 . The position of the detection device 11 is arbitrary inside and outside the moving body 10 . For example, detection device 11 may be located in the dashboard of mobile 10 . The detection device 11 may output information indicating the position of the eye 5 to the three-dimensional projection device 12 via, for example, a cable, wireless, CAN (Controller Area Network), or the like.

The detection device 11 may include an imaging device. The imaging device may include, for example, a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging device can image the face of the user 13 . The imaging range of the imaging device includes the eyebox 16 . The user 13 may include, for example, the driver of the mobile object 10 . The detection device 11 may detect the positions of both eyes of the user 13 in real space based on the captured image generated by the imaging device.

The detection device 11 may be connected to an imaging device without including an imaging device. The detection device 11 may include an input terminal for receiving signals from the imaging device. In this case, the imaging device may be directly connected to the input terminal. The detection device 11 may be indirectly connected to the input terminals through a shared network. The detection device 11 may detect the position of the eye 5 of the user 13 from the video signal input to the input terminal.

Detection device 11 may include, for example, a sensor. The sensor may be an ultrasonic sensor, an optical sensor, or the like. The detection device 11 may detect the position of the head of the user 13 using a sensor, and detect the position of the eyes 5 of the user 13 based on the position of the head. The detection device 11 may detect the position of the eye 5 of the user 13 as coordinates in a three-dimensional space using two or more sensors.

As shown in FIG. 2 , the 3D projection device 12 includes a 3D display device 17 and an optical element 18 . The three-dimensional projection device 12 is also called an image display module. The three-dimensional display device 17 includes a backlight 19 , a display section 20 having a display surface 20 a , a barrier section 21 and a control section 24 . The three-dimensional display device 17 may further include a communication section 22 . The three-dimensional display device 17 may further include a storage section 23 .

The optical element 18 may include a first mirror 18a and a second mirror 18b. At least one of the first mirror 18a and the second mirror 18b may have optical power. In this embodiment, the first mirror 18a is assumed to be a concave mirror having optical power. It is assumed that the second mirror 18b is a plane mirror. The optical element 18 may function as an enlarging optical system for enlarging the image displayed on the three-dimensional display device 17 . 2 indicates that at least part of the image light emitted from the three-dimensional display device 17 is reflected by the first mirror 18a and the second mirror 18b and emitted to the outside of the three-dimensional projection device 12. indicates the route to be taken. The image light emitted to the outside of the three-dimensional projection device 12 reaches the optical member 15 , is reflected by the optical member 15 , and reaches the eye 5 of the user 13 . As a result, the user 13 can visually recognize the image displayed on the three-dimensional display device 17 .

The optical element 18 and the optical member 15 allow the image light emitted from the three-dimensional display device 17 to reach the eye 5 of the user 13 . The optical element 18 and the optical member 15 may constitute an optical system 30 . In other words, optical system 30 includes optical element 18 and optical member 15 . The optical system 30 causes the image light emitted from the three-dimensional display device 17 to reach the eye 5 of the user 13 along the optical path indicated by the dashed line. The optical system 30 may control the traveling direction of the image light so that the image visually recognized by the user 13 is enlarged or reduced. The optical system 30 may control the traveling direction of the image light so as to deform the shape of the image visually recognized by the user 13 based on a predetermined matrix.

The optical element 18 is not limited to the illustrated configuration. The mirror may be a concave mirror, a convex mirror, or a plane mirror. When the mirror is a concave mirror or a convex mirror, its shape may include at least a portion of a spherical shape or at least a portion of an aspheric shape. The number of elements constituting the optical element 18 is not limited to two, and may be one or three or more. The optical element 18 is not limited to mirrors and may include lenses. The lens may be a concave lens or a convex lens. The shape of the lens may at least partially include a spherical shape, or at least partially include an aspherical shape.

The backlight 19 is located farther than the display section 20 and the barrier section 21 when viewed from the user 13 . The backlight 19 emits light toward the barrier section 21 and the display section 20 . At least part of the light emitted by the backlight 19 travels along the optical path indicated by the dashed line and reaches the eye 5 of the user 13 . The backlight 19 may include light emitting elements such as LEDs (Light Emission Diodes) or organic ELs or inorganic ELs. The backlight 19 may be configured to be able to control the emission intensity and its distribution.

Display unit 20 includes a display panel. The display unit 20 may be, for example, a liquid crystal device such as an LCD (Liquid Crystal Display). In this embodiment, the display unit 20 is assumed to include a transmissive liquid crystal display panel. The display unit 20 is not limited to this example, and may include various display panels.

The display unit 20 has a plurality of pixels, controls the transmittance of light incident from the backlight 19 in each pixel, and emits the light as image light reaching the eye 5 of the user 13 . The user 13 visually recognizes an image formed by image light emitted from each pixel of the display unit 20 .

The barrier section 21 defines the traveling direction of incident light. When the barrier section 21 is positioned closer to the backlight 19 than the display section 20 , the light emitted from the backlight 19 enters the barrier section 21 and then enters the display section 20 . In this case, the barrier section 21 blocks or attenuates part of the light emitted from the backlight 19 and transmits the other part toward the display section 20 . The display section 20 emits the incident light traveling in the direction defined by the barrier section 21 as image light traveling in the same direction. When the display section 20 is positioned closer to the backlight 19 than the barrier section 21 , the light emitted from the backlight 19 enters the display section 20 and further enters the barrier section 21 . In this case, the barrier section 21 blocks or attenuates part of the image light emitted from the display section 20 and transmits the other part toward the eye 5 of the user 13 .

Regardless of which of the display unit 20 and the barrier unit 21 is positioned closer to the user 13, the barrier unit 21 can control the traveling direction of the image light. The barrier unit 21 allows part of the image light emitted from the display unit 20 to reach either the left eye 5L or the right eye 5R (see FIG. 5) of the user 13, and utilizes the other part of the image light. The light reaches the other of the left eye 5L and the right eye 5R of the person 13. That is, the barrier section 21 divides the traveling direction of at least part of the image light into the left eye 5L and the right eye 5R of the user 13 . The left eye 5L and right eye 5R are also called the first eye and the second eye, respectively. In this embodiment, the barrier section 21 is positioned between the backlight 19 and the display section 20 . That is, the light emitted from the backlight 19 first enters the barrier section 21 and then enters the display section 20 .

By defining the traveling direction of the image light by the barrier section 21, different image light can reach the left eye 5L and the right eye 5R of the user 13, respectively. As a result, the user 13 can visually recognize different images with the left eye 5L and the right eye 5R.

As shown in FIG. 3, the display unit 20 has a first display area 201 and a second display area 202 on the display surface 20a. The first display area 201 includes a left-eye viewing area 201L viewed with the left eye 5L of the user 13 and a right-eye viewing area 201R viewed with the right eye 5R of the user 13 . The display unit 20 displays a parallax image including a left-eye image viewed by the left eye 5L of the user 13 and a right-eye image viewed by the right eye 5R of the user 13 . The parallax image is an image projected on each of the left eye 5L and the right eye 5R of the user 13, and is an image that gives parallax to both eyes of the user 13. FIG. The display unit 20 displays a left-eye image in the left-eye visual recognition area 201L and displays a right-eye image in the right-eye visual confirmation area 201R. That is, the display unit 20 displays parallax images in the left-eye visual recognition area 201L and the right-eye visual recognition area 201R. It is assumed that the left-eye visual recognition area 201L and the right-eye visual recognition area 201R are arranged in the u-axis direction representing the parallax direction. The left-eye visible region 201L and the right-eye visible region 201R may extend along the v-axis direction orthogonal to the parallax direction, or may extend in a direction inclined at a predetermined angle with respect to the v-axis direction. . That is, the left-eye visual recognition area 201L and the right-eye visual recognition area 201R may be alternately arranged along a predetermined direction including the component in the parallax direction. The pitch at which the left-eye visual recognition area 201L and the right-eye visual recognition area 201R are alternately arranged is also referred to as a parallax image pitch. The left-eye visual recognition area 201L and the right-eye visual recognition area 201R may be positioned with a gap therebetween, or may be adjacent to each other. The display unit 20 displays a planar image on the second display area 202 . It is assumed that the planar image is an image that does not give parallax to the eyes 5 of the user 13 and is not viewed stereoscopically.

As shown in FIG. 4 , the barrier section 21 has a first barrier region 211 and a second barrier region 212 . When the barrier section 21 is positioned nearer than the display section 20 when viewed from the user 13 , the barrier section 21 controls the transmittance of the image light emitted from the display section 20 . The first barrier area 211 corresponds to the first display area 201 and controls the transmittance of the image light related to the parallax image emitted from the first display area 201 . The first barrier region 211 has an opening region 21b and a light blocking surface 21a. The opening region 21 b transmits light entering the barrier section 21 from the display section 20 . The opening region 21b may transmit light with a transmittance equal to or greater than the first predetermined value. The first predetermined value may be, for example, 100% or a value close to 100%. The light shielding surface 21 a blocks light entering the barrier section 21 from the display section 20 . The light shielding surface 21a may transmit light with a transmittance equal to or lower than the second predetermined value. The second predetermined value may be, for example, 0% or a value close to 0%. The first predetermined value is greater than the second predetermined value.

The opening regions 21b and the light shielding surfaces 21a are arranged alternately in the u-axis direction representing the parallax direction. The boundary between the opening region 21b and the light shielding surface 21a may be along the v-axis direction orthogonal to the parallax direction as illustrated in FIG. good too. In other words, the opening regions 21b and the light shielding surfaces 21a may be alternately arranged along a predetermined direction including the component in the parallax direction.

The shapes of the opening area 21b and the light shielding surface 21a may be determined based on the shapes of the left eye visible area 201L and the right eye visible area 201R. Conversely, the shapes of the left-eye visible region 201L and the right-eye visible region 201R may be determined based on the shapes of the opening region 21b and the light shielding surface 21a.

The second barrier area 212 corresponds to the second display area 202 and controls the transmittance of image light relating to a planar image emitted from the second display area 202 .

In this embodiment, the barrier section 21 is located farther than the display section 20 when viewed from the user 13 . The barrier section 21 controls the transmittance of light incident from the backlight 19 toward the display section 20 . The opening region 21 b transmits light incident from the backlight 19 toward the display section 20 . The light blocking surface 21 a blocks light entering the display section 20 from the backlight 19 . By doing so, the traveling direction of the light incident on the first display area 201 is limited to a predetermined direction. As a result, part of the image light can be controlled by the barrier section 21 to reach the left eye 5L of the user 13 . Another part of the image light can be controlled by the barrier section 21 to reach the right eye 5R of the user 13 .

The barrier section 21 may be composed of a liquid crystal shutter. The liquid crystal shutter can control the transmittance of light based on the applied voltage. The liquid crystal shutter may be composed of a plurality of pixels and control the light transmittance of each pixel. The liquid crystal shutter can form a region with high light transmittance or a region with low light transmittance in any shape. When the barrier section 21 is composed of a liquid crystal shutter, the opening region 21b may have a transmittance equal to or higher than the first predetermined value. When the barrier section 21 is composed of a liquid crystal shutter, the light shielding surface 21a may have a transmittance equal to or lower than the second predetermined value. The first predetermined value may be set to a value higher than the second predetermined value. In one example, the ratio of the second predetermined value to the first predetermined value may be set to 1/100. The ratio of the second predetermined value to the first predetermined value may be set to 1/1000 in another example. The barrier section 21 configured such that the shape of the opening region 21b and the light shielding surface 21a can be changed is also called an active barrier.

The control section 24 controls the display section 20 . If the barrier section 21 is an active barrier, the control section 24 may control the barrier section 21 . The control section 24 may control the backlight 19 . The control unit 24 may acquire information about the position of the eye 5 of the user 13 from the detection device 11 and control the display unit 20, the barrier unit 21, or the backlight 19 based on the information. The control unit 24 is configured, for example, as a processor. Control unit 24 may include one or more processors. The processor may include a general-purpose processor that loads a specific program to execute a specific function, and a dedicated processor that specializes in specific processing. A dedicated processor may include an Application Specific Integrated Circuit (ASIC). The processor may include a programmable logic device (PLD). The PLD may include an FPGA (Field-Programmable Gate Array). The control unit 24 may be either SoC (System-on-a-Chip) or SiP (System In a Package) in which one or more processors cooperate.

The communication unit 22 may include an interface capable of communicating with an external device. External devices may include, for example, the detection device 11 . The communication unit 22 may acquire information from the detection device 11 and output it to the control unit 24 . A "communication interface" in this disclosure may include, for example, a physical connector and a radio. The physical connectors may include an electrical connector compatible with electrical signal transmission, an optical connector compatible with optical signal transmission, and an electromagnetic connector compatible with electromagnetic wave transmission. The electrical connector may include a connector complying with IEC60603, a connector complying with the USB standard, or a connector compatible with RCA terminals. The electrical connector may include a connector compatible with the S terminal specified in EIAJ CP-121aA or a connector compatible with the D terminal specified in EIAJ RC-5237. The electrical connector may include a connector conforming to the HDMI (registered trademark) standard, or a connector compatible with a coaxial cable including a BNC (British Naval Connector or Baby-series N Connector, etc.). Optical connectors may include various connectors conforming to IEC 61754. The wireless communicator may include wireless communicators conforming to standards including Bluetooth® and IEEE8021a. A radio includes at least one antenna.

The storage unit 23 may store various information, programs for operating each component of the three-dimensional display device 17, and the like. The storage unit 23 may be composed of, for example, a semiconductor memory. The storage unit 23 may function as a work memory for the control unit 24 . Storage unit 23 may be included in control unit 24 .

As shown in FIG. 5 , light emitted from the backlight 19 passes through the barrier section 21 and the display section 20 and reaches the eye 5 of the user 13 . A path through which light emitted from the backlight 19 reaches the eye 5 is indicated by a dashed line. Light passing through the opening region 21 b of the barrier section 21 and reaching the right eye 5</b>R passes through the right eye viewing region 201</b>R of the display section 20 . That is, the right eye 5R can visually recognize the right eye visual recognition area 201R with the light transmitted through the opening area 21b. Light that passes through the opening region 21 b of the barrier section 21 and reaches the left eye 5</b>L passes through the left eye visible region 201</b>L of the display section 20 . That is, the left eye 5L can visually recognize the left eye visual recognition area 201L with the light transmitted through the opening area 21b.

The display unit 20 displays a right-eye image and a left-eye image in the right-eye visual recognition area 201R and the left-eye visual recognition area 201L, respectively. As a result, the barrier section 21 allows the image light relating to the left eye image to reach the left eye 5L, and allows the image light relating to the right eye image to reach the right eye 5R. That is, the aperture region 21b is configured to allow the image light relating to the left eye image to reach the left eye 5L of the user 13 and the image light relating to the right eye image to reach the right eye 5R of the user 13 . By doing so, the three-dimensional display device 17 can project parallax images to both eyes of the user 13 . The user 13 can stereoscopically view the images by viewing the parallax images with the left eye 5L and the right eye 5R. The direction that gives parallax to both eyes of the user 13 is also called a parallax direction. The parallax direction corresponds to the direction in which the left eye 5L and the right eye 5R of the user 13 are aligned.

When the user 13 is stereoscopically viewing, the image light related to the right eye image is incident on the left eye 5L, and the image light related to the left eye image is incident on the right eye 5R. can lose stereoscopic vision. A phenomenon in which image light relating to a right-eye image enters the left eye 5L and image light relating to a left-eye image enters the right eye 5R is also called crosstalk. Crosstalk deteriorates the stereoscopic image quality provided to the user 13 . The barrier section 21 prevents the image light related to the left eye image from reaching the right eye 5R and prevents the image light related to the right eye image from reaching the left eye 5L. That is, the light shielding surface 21a is configured to prevent the image light related to the left eye image from reaching the right eye 5R of the user 13 and prevent the image light related to the right eye image from reaching the left eye 5L of the user 13. . By doing so, the user 13 can view only the left-eye image with the left eye 5L and view only the right-eye image with the right eye 5R. As a result, crosstalk is less likely to occur.

At least part of the image light emitted from the display surface 20 a of the display section 20 passes through the opening region 21 b of the barrier section 21 and reaches the optical member 15 via the optical element 18 . The image light is reflected by the optical member 15 and reaches the eye 5 of the user 13 . Thereby, the eye 5 of the user 13 can visually recognize the first virtual image 14a located on the negative direction side of the z-axis with respect to the optical member 15 . The first virtual image 14a corresponds to the image displayed on the display surface 20a. The opening region 21b of the barrier section 21 and the light shielding surface 21a form a second virtual image 14b in front of the optical member 15 and on the optical member 15 side of the first virtual image 14a. As shown in FIG. 5, the user 13 visually recognizes the image as if the display unit 20 were present at the position of the first virtual image 14a and the barrier unit 21 was present at the position of the second virtual image 14b. I can.

Image light associated with an image displayed on the display surface 20 a is emitted from the three-dimensional display device 17 in a direction defined by the barrier section 21 . The optical element 18 reflects or refracts the image light and emits it toward the optical member 15 . The optical member 15 reflects the image light and causes it to travel toward the eye 5 of the user 13 . The user 13 visually recognizes the parallax image as a virtual image 14 by the image light entering the eye 5 of the user 13 . The user 13 can view the virtual image 14 stereoscopically. An image corresponding to the parallax image among the virtual images 14 is also called a parallax virtual image. The parallax virtual image can also be said to be a parallax image projected via the optical system 30 . An image corresponding to a plane image among the virtual images 14 is also called a plane virtual image. A planar virtual image can also be said to be a planar image projected via the optical system 30 .

A parallax virtual image visually recognized by the user 13 is projected onto the eye 5 of the user 13 via the optical system 30 . The optical system 30 may be required to project an image input by incident image light while enlarging or reducing it while maintaining a similarity relationship. However, the optical system 30 may not maintain a similarity relationship between the input image and the projected image. That is, distortion may occur between the parallax image before entering the optical system 30 and the parallax image (parallax virtual image) projected through the optical system 30 . For example, as shown in FIG. 6, the image displayed on the rectangular display surface 20a is projected onto the eye 5 of the user 13 via the optical system 30, so that the more it goes in the positive direction of the v-axis, the more The virtual image 14 may be distorted to expand in the u-axis direction. The shape of the display surface 20a is represented by solid lines. The shape of the virtual image 14 is represented by dashed lines. The virtual image 14 includes a parallax virtual image and a plane virtual image. When the distortion of the parallax virtual image is large, crosstalk tends to occur. On the other hand, planar virtual image distortion is irrelevant to crosstalk. The user 13 is more likely to recognize the occurrence of crosstalk than the distortion of the virtual image 14 . That is, the distortion of the parallax virtual image is more likely to reduce the quality of the stereoscopic vision provided to the user 13 than the distortion of the planar virtual image.

It is difficult to completely eliminate the distortion of the optical system 30 . However, changing the distortion distribution of the optical system 30 is easier than eliminating the distortion. Therefore, in the three-dimensional projection device 12 according to this embodiment, the optical A system 30 is designed. That is, the optical system 30 may distribute the range in which the image light of the plane image passes through the range in which the distortion is equal to or greater than the predetermined value, and distribute the range in which the image light of the parallax image passes through the range in which the distortion is less than the predetermined value. . For example, the optical system 30 may be designed to reduce distortion in the area corresponding to the first display area 201 and increase distortion in the area corresponding to the second display area 202 . By doing so, even if the optical system 30 is distorted, the stereoscopic image quality provided to the user 13 can be improved.

The parallax images include right eye images and left eye images that are alternately arranged along the parallax direction. The display unit 20 displays a right-eye image in the right-eye visual recognition area 201R and displays a left-eye image in the left-eye visual confirmation area 201L on the display surface 20a. When the parallax image (parallax virtual image) projected via the optical system 30 is distorted in the parallax direction, the right eye image enters the left eye visual recognition area 201L or the left eye image enters the right eye visual recognition area 201R in the parallax virtual image. more likely to occur. That is, distortion in the parallax direction tends to cause crosstalk.

The distortion of the optical system 30 is expressed by combining a distortion component along the parallax direction and a distortion component along a direction crossing the parallax direction. Controlling the direction of distortion in optical system 30 is easier than eliminating distortion. Therefore, the optical system 30 may be designed such that, of the distortion of the optical system 30, the distortion component along the parallax direction is smaller than the distortion component along the direction crossing the parallax direction. By doing so, even if the optical system 30 is distorted, the stereoscopic image quality provided to the user 13 can be improved.

Assume that the optical system 30 is represented by a single concave mirror. In this case, the magnification of the virtual image 14 visible to the user 13 by projecting the object to be projected with the concave mirror changes according to the distance between the object to be projected and the concave mirror, as shown in FIG. In FIG. 7, the horizontal axis represents the distance between the object to be projected and the concave mirror. The vertical axis represents the magnification of the virtual image 14 . Let f be the focal length of the concave mirror. When the distance between the object to be projected and the concave mirror is 0, that is, when the object to be projected is located on the concave mirror, the magnification of the virtual image 14 is 1 (1:1). When the distance between the object to be projected and the concave mirror is f, that is, when the object to be projected is positioned on the focal point of the concave mirror, the magnification of the virtual image 14 diverges to infinity. As the distance between the object to be projected and the concave mirror approaches f, the magnification of the virtual image 14 increases, and the rate of change in the magnification of the virtual image 14 with respect to the change in distance also increases.

In the present embodiment, the barrier section 21 is positioned farther from the display surface 20 a with respect to the optical system 30 . In other words, the distance between the barrier section 21 and the optical system 30 is longer than the distance between the display surface 20a and the optical system 30 . Assume that the distance between the display surface 20a and the optical system 30 is represented by D1. Let D2 be the distance between the barrier section 21 and the optical system 30 . That is, D2>D2 is established. Let A1 and A2 be the magnifications when the distances between the object to be projected and the concave mirror are D1 and D2, respectively. According to the graph of FIG. 7, A2>A1 holds. That is, the magnification of the second virtual image 14b corresponding to the barrier section 21 is greater than the magnification of the first virtual image 14a corresponding to the display surface 20a. When the area of the barrier section 21 and the area of the display surface 20a are the same, the area of the second virtual image 14b is larger than the area of the first virtual image 14a. Thereby, the second virtual image 14b can cover the first virtual image 14a. That is, in the parallax virtual image visually recognized by the user 13, the barrier section 21 can cover the image displayed on the display surface 20a. If the barrier section 21 cannot cover a part of the image displayed on the display surface 20a, the uncovered part causes crosstalk. By covering the image displayed on the display surface 20a with the barrier section 21, crosstalk is less likely to occur. As a result, the stereoscopic image quality provided to the user 13 can be improved.

Assuming that the optical system 30 is represented by a single concave mirror, the distortion of the virtual image 14 projected through the optical system 30 from the three-dimensional display device 17, which is the object to be projected, is calculated from the object to be projected to the optical system. Depends on the distance up to 30. For example, the distortion of the virtual image 14 of the projection object located at the first distance is different from the distortion of the virtual image 14 of the projection object located at the second distance. The optical system 30 can be designed to minimize the distortion of the virtual image 14 of the projection object positioned at a predetermined distance.

The display surface 20a and the barrier section 21 are positioned across a predetermined gap represented by g in FIG. That is, the distance from the display surface 20a to the optical system 30 and the distance from the barrier section 21 to the optical system 30 are different. In this case, the distortion of the first virtual image 14a corresponding to the display surface 20a and the distortion of the second virtual image 14b corresponding to the barrier section 21 are different. The distortion of the second virtual image 14b deforms the right eye visual recognition area 201R and the left eye visual recognition area 201L on the first virtual image 14a. The deformation of the right eye viewing area 201R and the left eye viewing area 201L increases the possibility that the right eye image will enter the left eye viewing area 201L or the left eye image will enter the right eye viewing area 201R. On the other hand, the distortion of the first virtual image 14 a can be corrected by distorting the image displayed on the display unit 20 based on a matrix obtained by inversely transforming the matrix representing the distortion of the optical system 30 . That is, the distortion of the second virtual image 14b is more likely to cause crosstalk than the distortion of the first virtual image 14a. Therefore, the optical system 30 may be designed such that the distortion of the barrier section 21 is smaller than the distortion of the display surface 20a. The position of the three-dimensional display device 17 with respect to the optical system 30 may be determined such that the distortion of the barrier section 21 is smaller than the distortion of the display surface 20a. In other words, the barrier section 21 may be arranged at a position where the distortion of the optical system 30 is minimized. By doing so, even if the optical system 30 is distorted, the stereoscopic image quality provided to the user 13 can be improved.

The configuration according to the present disclosure is not limited to the embodiments described above, and many modifications and changes are possible. For example, the functions included in each component can be rearranged so as not to be logically inconsistent, and multiple components can be combined into one or divided.

The figures describing the configuration according to the present disclosure are schematic. The dimensional ratios and the like on the drawings do not necessarily match the actual ones.

Descriptions such as “first” and “second” in the present disclosure are identifiers for distinguishing the configurations. Configurations that are differentiated in descriptions such as "first" and "second" in this disclosure may interchange the numbers in that configuration. For example, the first eye can exchange identifiers "first" and "second" with the second eye. The exchange of identifiers is done simultaneously. The configurations are still distinct after the exchange of identifiers. Identifiers may be deleted. Configurations from which identifiers have been deleted are distinguished by codes. The description of identifiers such as “first” and “second” in this disclosure should not be used as a basis for interpreting the order of the configuration or the existence of lower numbered identifiers.

In the present disclosure, the X-axis, Y-axis, and Z-axis are provided for convenience of explanation and may be interchanged with each other. Configurations according to the present disclosure have been described using a Cartesian coordinate system formed by X, Y, and Z axes. The positional relationship of each configuration according to the present disclosure is not limited to an orthogonal relationship.

The present disclosure can be implemented in the following configurations (1) to (6).
(1) a display unit that displays a planar image and a parallax image projected via an optical system to the first and second eyes of the user;
a barrier section that provides parallax to the first eye and the second eye by defining a traveling direction of image light of the parallax image;
A concave mirror that constitutes at least part of the optical system,
The image display module, wherein distortion of the parallax image projected via the optical system is smaller than distortion of the planar image projected via the optical system.

(2) Distortion of the parallax image projected through the optical system includes a component in a parallax direction that imparts parallax to the first eye and the second eye, and a component in a direction that intersects the parallax direction. ,
The image display module according to configuration (1), wherein the component in the parallax direction is smaller than the component in the direction crossing the parallax direction.

(3) a display unit that displays a planar image and a parallax image projected via an optical system to the first and second eyes of the user;
a barrier section that provides parallax to the first eye and the second eye by defining a traveling direction of image light of the parallax image;
An image display module equipped with a concave mirror that constitutes at least part of the optical system,
including a windshield forming part of the optical system;
The moving object, wherein distortion of the parallax image projected via the optical system is smaller than distortion of the planar image projected via the optical system.

(4) configuring at least part of an optical system that projects a planar image and a parallax image to the first and second eyes of a user;
A concave mirror, wherein distortion of the parallax image projected via the optical system is smaller than distortion of the planar image projected via the optical system.

(5) a display unit that displays parallax images projected via an optical system to the first and second eyes of the user;
a barrier section that provides parallax to the first eye and the second eye by defining a traveling direction of image light of the parallax image;
A concave mirror that constitutes at least part of the optical system,
The image display module, wherein distortion of the barrier section projected through the optical system is smaller than distortion of the display section projected through the optical system.

(6) a display unit that displays parallax images projected via an optical system to the first and second eyes of the user;
a barrier section that provides parallax to the first eye and the second eye by defining a traveling direction of image light of the parallax image;
A concave mirror that constitutes at least part of the optical system,
The image display module, wherein the magnification of the barrier section by the optical system is larger than the magnification of the display section by the optical system.

5 eyes (5L: left eye, 5R: right eye)
10 moving body 12 three-dimensional projection device (image display module)
13 user 14 virtual image (14a: first virtual image, 14b: second virtual image)
15 optical member 16 eyebox 17 three-dimensional display device 18 optical element (18a: first mirror, 18b: second mirror)
19 backlight 20 display unit (20a: display surface)
201 first display area 201L left eye visible area 201R right eye visible area 202 second display area 21 barrier part (21a: light shielding surface, 21b: opening area)
211 first barrier region 212 second barrier region 22 communication unit 23 storage unit 24 control unit 30 optical system 100 three-dimensional projection system

Claims (2)

a display unit that displays parallax images projected via an optical system to the first and second eyes of the user;
a barrier section that provides parallax to the first eye and the second eye by defining a traveling direction of image light of the parallax image;
A concave mirror that constitutes at least part of the optical system,
distortion of the barrier portion projected through the optical system is smaller than distortion of the display portion projected through the optical system;
The image display module , wherein the magnification of the barrier section by the optical system is larger than the magnification of the display section by the optical system . 2. The image display module according to claim 1, wherein said optical system is configured such that a distortion component along a parallax direction is smaller than a distortion component along a direction crossing said parallax direction.