阅读说明：本技术 平视显示器、平视显示器用显示装置以及移动体 (Head-up display, head-up display device, and moving object ) 是由 草深薰 于 2019-01-30 设计创作，主要内容包括：平视显示器具备第1面板、第2面板和光学系统。第1面板具有沿着给利用者的两眼带来视差的视差方向以第1间距排列的多个第1子像素。第2面板具有沿着视差方向以第2间距排列的多个第2子像素。第2面板沿着第1面板设置。第2面板基于第1面板的显示图像来生成给利用者的两眼带来视差的视差图像。光学系统将视差图像放大并成像在利用者的两眼。第1间距和第2间距彼此相等。(A head-up display includes a 1 st panel, a 2 nd panel, and an optical system. The 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a parallax direction giving parallax to both eyes of a user. The 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the parallax direction. The 2 nd panel is disposed along the 1 st panel. The 2 nd panel generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel. The optical system enlarges and images the parallax image to both eyes of the user. The 1 st pitch and the 2 nd pitch are equal to each other.)

1. A head-up display includes a 1 st panel, a 2 nd panel, and an optical system,

the 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a parallax direction giving parallax to both eyes of a user,

the 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the parallax direction, is provided along the 1 st panel, generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel,

the optical system enlarges and images the parallax image on both eyes of the user,

the 1 st pitch and the 2 nd pitch are equal to each other.

2. Head-up display according to claim 1,

the optical system magnifies the 1 st panel and the 2 nd panel at different magnifications, respectively.

3. Head-up display according to claim 1 or 2,

the 1 st panel displays the right-eye image and the left-eye image arranged at the 3 rd pitch along the parallax direction through the 1 st sub-pixel,

the 2 nd panel forms a light transmitting area and a light blocking area arranged at the 3 rd pitch along the parallax direction by the 2 nd sub-pixel,

the 3 rd pitch is calculated based on a distance between the 1 st panel and the 2 nd panel, a focal length of the optical system, and an interocular distance between both eyes of the user.

4. Head-up display according to claim 3,

when a distance between the 1 st panel and the 2 nd panel is represented by g, a focal length of the optical system is represented by f, an interocular distance between both eyes of the user is represented by E, and 1/2 of the 3 rd pitch is represented by R, the following equation holds,

[ mathematical formula 1]

5. Head-up display according to claim 3,

the 3 rd pitch is further calculated based on a distance between both eyes of the user and the optical system.

6. Head-up display according to any one of claims 3 to 5,

the 3 rd pitch is a natural number multiple of the 1 st pitch and the 2 nd pitch.

7. A moving body having a head-up display mounted thereon, the head-up display including a 1 st panel, a 2 nd panel and an optical system,

the 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a parallax direction giving parallax to both eyes of a user,

the 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the parallax direction, is provided along the 1 st panel, generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel,

the optical system enlarges and images the parallax image on both eyes of the user,

the 1 st pitch and the 2 nd pitch are equal to each other.

8. A display device for a head-up display is characterized by having a 1 st panel and a 2 nd panel,

the 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a 1 st direction,

the 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the 1 st direction, is provided along the 1 st panel, generates a parallax image for providing parallax to both eyes of a user arranged along the 1 st direction based on a display image of the 1 st panel,

the 1 st pitch and the 2 nd pitch are equal to each other.

9. The display device for head-up display according to claim 8,

the 2 nd panel is free of color filters.

Technical Field

The present disclosure relates to a Head-Up Display (Head-Up Display), a Display device for a Head-Up Display, and a moving body.

Background

Conventionally, a display device is known which provides stereoscopic vision by projecting a parallax image to both eyes of a user by providing a light barrier (barrier) which defines the direction of image light (for example, patent document 1).

Disclosure of Invention

A head-up display according to an embodiment of the present disclosure includes a 1 st panel, a 2 nd panel, and an optical system. The 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a parallax direction giving parallax to both eyes of a user. The 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the parallax direction. The 2 nd panel is disposed along the 1 st panel. The 2 nd panel generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel. The optical system enlarges the parallax image and forms an image on both eyes of the user. The 1 st pitch and the 2 nd pitch are equal to each other.

A moving body-mounted head-up display according to an embodiment of the present disclosure includes a 1 st panel, a 2 nd panel, and an optical system. The 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a parallax direction giving parallax to both eyes of a user. The 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the parallax direction. The 2 nd panel is disposed along the 1 st panel. The 2 nd panel generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel. The optical system enlarges the parallax image and forms an image on both eyes of the user. The 1 st pitch and the 2 nd pitch are equal to each other.

A head-up display device according to an embodiment of the present disclosure includes a 1 st panel and a 2 nd panel. The 1 st panel has a plurality of 1 st sub-pixels arranged at a 1 st pitch along a 1 st direction. The 2 nd panel has a plurality of 2 nd sub-pixels arranged at a 2 nd pitch along the 1 st direction. The 2 nd panel is disposed along the 1 st panel. The 2 nd panel generates a parallax image which is arranged along the 1 st direction and gives parallax to both eyes of a user, based on the display image of the 1 st panel. The 1 st pitch and the 2 nd pitch are equal to each other.

Drawings

Fig. 1 is a diagram showing a configuration example of a head-up display according to an embodiment.

Fig. 2 is a diagram showing a configuration example of a pixel of the display device.

Fig. 3 is a diagram showing a structural example of the light barrier.

Fig. 4 is a view showing an observation mode of the display device and the light barrier in a case where the parallax image is projected to both eyes of the user without passing through the optical system.

Fig. 5 is a diagram showing an example of an observation mode of a virtual image of each of the light barrier and the display device in a case where a user observes the light barrier and the display device through the optical system.

Fig. 6 is a diagram showing an observation mode of a virtual image in a case where a parallax image is projected to both eyes of a user via an optical system.

Fig. 7 is a diagram showing an example of the arrangement of the sub-pixels of the light barrier.

Fig. 8 is a diagram showing an example of the structure of the sub-pixel.

Detailed Description

A display device providing stereoscopic vision to a user may include, for example, an optical barrier as an active optical barrier realized by a liquid crystal panel or the like. In this case, the black matrix provided around the pixels of the liquid crystal panel functioning as the light barrier reduces the transmittance of light in the light barrier. The light transmittance of the light barrier is improved.

As shown in fig. 1, a head-up display 1 according to one embodiment includes a display device 10, a light barrier 20, and an optical system 30. The head-Up display 1 is also referred to as hud (head Up display). The head-up display 1 displays an image on the display device 10 and shields a part of image light from the light barrier 20, thereby projecting different images to the left eye 5L of the user and the right eye 5R of the user. That is, the head-up display 1 can project parallax images to both eyes of the user. The parallax image may be an image including images projected to the left eye 5L and the right eye 5R of the user. The user can stereoscopically observe the image by observing the parallax image with the left eye 5L and the right eye 5R. The display device 10 and the light barrier 20 can be combined into 2, and 1 HUD display device 100 is configured.

The display device 10 displays a left-eye image projected to the left eye 5L of the user and displays a right-eye image projected to the right eye 5R of the user. The Display device 10 may be a Liquid Crystal device such as an LCD (Liquid Crystal Display). The display device 10 may be a self-light emitting device such as an organic EL (Electro-Luminescence) inorganic EL.

The light barrier 20 is positioned between the left and right eyes 5L and 5R of the user and the display device 10. The light barrier 20 is located along the display device 10. The light barrier 20 causes the right-eye image displayed on the display device 10 to be projected to the right eye 5R of the user and not to be projected to the left eye 5L of the user. The light barrier 20 causes the left-eye image displayed on the display device 10 to be projected to the left eye 5L of the user and not to be projected to the right eye 5R of the user.

The optical system 30 is positioned on an optical path 32 of the image light that is emitted from the display device 10 and the light barrier 20 and reaches the left eye 5L and the right eye 5R of the user. The optical system 30 forms an image of image light related to the parallax image and projects the parallax image to both eyes of the user. That is, the optical system 30 images the parallax image on both eyes of the user. The optical system 30 may enlarge or reduce the parallax image to form an image on both eyes of the user. The optical system 30 includes an optical member 30a, an optical member 30b, and an optical member 30 c. The number of optical members constituting the optical system 30 is not limited to 3, and may be 2 or less, or 4 or more. The optical member may comprise a reflective member comprising a convex or concave mirror. The optical member may comprise a refractive member comprising a convex lens or a concave lens. The convex lens includes a biconvex lens, a plano-convex lens, and a convex meniscus lens. The concave lens includes a biconcave lens, a plano-concave lens, a concave meniscus lens. The optical member is not limited to the reflective member or the refractive member, and may include various other optical members.

The virtual image 10Q of the display device 10 and the virtual image 20Q of the light barrier 20 are located: the optical member 30c disposed closest to the user is located forward of the two-dot chain line extending straight to the rear side. The virtual images 10Q and 20Q are formed as parallax images by both eyes of the user. That is, the user can visually recognize the virtual images 10Q and 20Q as parallax images. Thereby providing stereoscopic vision to the user.

As shown in fig. 2, the display device 10 has a plurality of sub-pixels 11. The sub-pixels 11 may be arranged in a lattice. In the present embodiment, the lattice axes representing the arrangement of the sub-pixels 11 are assumed to be the X axis and the Y axis. The sub-pixels 11 may be arranged at a given pitch in the X-axis direction and the Y-axis direction, respectively. The pitch in the X-axis direction and the pitch in the Y-axis direction are represented as Hp and Vp, respectively. Hereinafter, Vp is assumed to be larger than Hp.

The direction giving parallax to both eyes of the user is also referred to as a parallax direction. The parallax direction corresponds to a direction in which the left eye 5L and the right eye 5R of the user are arranged. In the present embodiment, it is assumed that the X-axis direction corresponds to the parallax direction. The X-axis direction is also referred to as the horizontal direction or 1 st direction. The Y-axis direction is also referred to as the vertical direction or 2 nd direction.

The sub-pixel 11 may constitute a pixel 12. The pixel 12 may comprise 3 sub-pixels 11 enclosed by dashed lines. The pixel 12 may include, for example, a sub-pixel 11 for displaying each color of RGB. The number of the sub-pixels 11 included in the pixel 12 is not limited to 3, and may be 2, or 4 or more. In the case where the display device 10 is an LCD, an organic EL, or an inorganic EL, each pixel may correspond to the sub-pixel 11 or the pixel 12. In the present embodiment, the pixel 12 is assumed to include the sub-pixels 11 arranged in the horizontal direction. In other words, in the present embodiment, the horizontal direction is a direction in which the plurality of sub-pixels 11 constituting the pixel 12 are arranged.

In the present embodiment, it is assumed that the sub-pixels 11 constituting the pixel 12 are arranged in the lateral direction as viewed by a user. In this case, the X-axis direction and the Y-axis direction correspond to the horizontal direction and the vertical direction, respectively. The ratio of the vertical and horizontal lengths of the sub-pixel 11 as viewed by a user is also referred to as the aspect ratio of the sub-pixel 11. In this case, the aspect ratio is Vp/Hp. Vp/Hp is hereinafter characterized as x. In this case, x is greater than 1.

The arrangement of the sub-pixels 11 can be divided by a display boundary 15 shown in a stepped shape of a thick line. The display device 10 may determine the location and shape of the display boundary 15. The display boundary 15 is not limited to the shape shown in fig. 2, and may have another shape. The arrangement of the sub-pixels 11 is divided into a 1 st region 11L and a 2 nd region 11R by a display boundary 15. The display device 10 may cause the 1 st region 11L to display a left-eye image and the 2 nd region 11R to display a right-eye image. The display boundary 15 may include a 1 st display boundary indicating a range of the 1 st region 11L and a 2 nd display boundary indicating a range of the 2 nd region 11R. This enables characterization of the sub-pixels 11 that are not included in either of the 1 st region 11L and the 2 nd region 11R.

As shown in fig. 3, the light barrier 20 includes a light-transmitting area 21 and a light-blocking area 22. The light transmission region 21 transmits light incident to the light barrier 20. The light-transmitting region 21 can transmit light at a transmittance of 1 st predetermined value or more. The 1 st given value may be, for example, 100% or a value close to 100%. The light blocking area 22 blocks light incident to the light barrier 20. The light-shielding region 22 can transmit light at a transmittance of 2 nd predetermined value or less. The 2 nd given value may be 0% or a value close to 0%, for example.

The light-transmitting regions 21 and the light-blocking regions 22 are alternately arranged in the X-axis direction. The boundary of the light-transmitting area 21 and the light-shielding area 22 is along a direction inclined at a given angle represented by θ with respect to the Y-axis direction. The line indicating the end of the light-transmitting region 21 is also referred to as an end line of the light-transmitting region 21. The given angle θ is also referred to as the light barrier tilt angle. θ may be an angle greater than 0 degrees and less than 90 degrees.

The light barrier 20 may be constituted by a liquid crystal shutter. The liquid crystal shutter can control the transmittance of light based on an applied voltage. The liquid crystal shutter may be constituted by a plurality of pixels, and controls the transmittance of light in each pixel. The liquid crystal shutter can form a region having a high light transmittance or a region having a low light transmittance into an arbitrary shape. In the case where the light barrier 20 is constituted by a liquid crystal shutter, the light transmitting region 21 may have a transmittance of 1 st or more given value. In the case where the light barrier 20 is constituted by a liquid crystal shutter, the light-shielding region 22 may have a transmittance of 2 nd given value or less.

The light-transmitting region 21 transmits the left-eye image so that the left-eye image displayed on the display device 10 is projected to the left eye 5L of the user, and transmits the right-eye image so that the right-eye image is projected to the right eye 5R of the user. The light-shielding region 22 shields the left-eye image so that the left-eye image displayed on the display device 10 is not projected to the right eye 5R of the user, and shields the right-eye image so that the right-eye image is not projected to the left eye 5L of the user. That is, the light barrier 20 projects the right-eye image displayed on the display device 10 to the right eye 5R of the user and does not project the right-eye image to the left eye 5L of the user. The light barrier 20 causes the left-eye image displayed on the display device 10 to be projected to the left eye 5L of the user and not to be projected to the right eye 5R of the user. The light barrier 20 may be disposed spaced apart from the display device 10 by a given distance.

The configuration of the light barrier 20 may be different between a case where the parallax image is projected to both eyes of the user via the optical system 30 and a case where the parallax image is projected to both eyes of the user without via the optical system 30. The following describes an observation mode of the display device 10 and the light barrier 20 in a case where a parallax image is projected to both eyes of a user without passing through the optical system 30, with reference to fig. 4.

Assume that the user's left and right eyes 5L, 5R are disposed a distance characterized by P away from the light barrier 20. The interval at which the light-transmitting areas 21 and the light-shielding areas 22 are alternately arranged in the X-axis direction is also referred to as an optical barrier interval, and is denoted by j. The distance between the left eye 5L and the right eye 5R, also called the interocular distance, is characterized as E. The distance from the light barrier 20 to the display device 10, also referred to as the gap, is characterized by g. The distances from the left and right eyes 5L and 5R of the user to the display device 10 are denoted by a.

The display device 10 includes a left-eye visible region 13L that is visible from the left eye 5L of the user via the light-transmitting region 21, and a left-eye light-shielding region 14L that is not visible from the left eye 5L of the user due to the light-shielding region 22. The left-eye visible regions 13L and the left-eye light-shielding regions 14L are alternately arranged in the X-axis direction. The position of the boundary between the left-eye visible region 13L and the left-eye light-shielding region 14L is determined by the position of the end line of the light-transmitting region 21, the distance (P) from the light barrier 20 to both eyes of the user, and the gap (g).

The display device 10 includes a right-eye visible region 13R that is visible from the right eye 5R of the user through the light-transmitting region 21, and a right-eye light-blocking region 14R that is not visible from the right eye 5R of the user due to the light-blocking region 22. The right-eye visible regions 13R and the right-eye light-shielding regions 14R are alternately arranged in the X-axis direction. The position of the boundary between the right-eye visible region 13R and the right-eye light blocking region 14R is determined by the position of the end line of the light transmitting region 21, the distance (P) from the light barrier 20 to both eyes of the user, and the gap (g).

The display device 10 may form the left-eye visible region 13L by causing the sub-pixels 11 located in the 1 st region 11L (refer to fig. 2) to display the left-eye image. The display device 10 may form the right-eye visible region 13R by causing the sub-pixels 11 located in the 2 nd region 11R (refer to fig. 2) to display the right-eye image. When the 1 st region 11L and the 2 nd region 11R correspond to the left-eye visible region 13L and the right-eye visible region 13R, respectively, the display boundary 15 represents a boundary between the left-eye visible region 13L and the right-eye visible region 13R. That is, the display device 10 can determine the position of the display boundary 15 based on the position of the end line of the light-transmitting region 21, the distance (P) from the light barrier 20 to both eyes of the user, and the gap (g).

In the case where the left-eye visible region 13L and the right-eye visible region 13R are overlapped at least partially in the X-axis direction, crosstalk may occur in which a part of the left-eye image is projected to the right eye 5R or a part of the right-eye image is projected to the left eye 5L. The crosstalk deteriorates the image quality of the parallax image projected to the user.

In the case where the left-eye visible regions 13L and the right-eye visible regions 13R are alternately arranged in the X-axis direction without being repeated with each other, the left eye 5L can visually recognize only the left-eye image, and the right eye 5R can visually recognize only the right-eye image. In this case, crosstalk can be reduced. The distance (P) from the optical barrier 20 to both eyes of the user when the left eye image and the right eye image are visually recognized by the left eye 5L and the right eye 5R, respectively, can be said to be an appropriate observation distance. The suitable viewing Distance is also referred to as OVD (optimal viewing Distance).

The left-eye visible region 13L and the right-eye visible region 13R are also called a monocular point (dot) group, respectively. The pitch of the monocular point groups arranged in the X-axis direction is also referred to as a monocular point group pitch and is denoted by R. The configuration in which the left-eye visible region 13L and the right-eye visible region 13R are combined is also referred to as a left-right dot group. The pitch of the left and right dot groups arranged in the X-axis direction is also referred to as a left and right dot group pitch. When P is an appropriate observation distance, the left-right dot group pitch is 2 times the monocular dot group pitch, and is represented as 2R.

In the configuration example shown in fig. 4, P is an appropriate observation distance, and the monocular point groups are arranged in the X-axis direction without overlapping each other. In this case, the relationships expressed by the following equations (1) and (2) are established based on the geometric positional relationship between the eyes of the user, the light barrier 20, and the display device 10. Geometrically positional relationships encompass similar relationships.

[ mathematical formula 1]

Based on the formula (1) and the formula (2), R can be eliminated. That is, P that is suitable for the observation distance can be determined based on the optical barrier pitch (j), the gap (g), and the inter-eye distance (E).

When the user visually recognizes the display device 10 and the light barrier 20 through the optical system 30, the user can visually recognize the virtual images of the display device 10 and the light barrier 20, respectively. The following describes an observation mode of the virtual image 10Q of the display device 10 and the virtual image 20Q of the light barrier 20 of the user with reference to a configuration example shown in fig. 5.

The display device 10, the light barrier 20 and the optical system 30 are arranged along the Z-axis. The optical system 30 includes only 1 optical member such as a lens or a mirror, or a plurality of optical members, and is regarded as a surface. The optical system 30 is assumed to be located in a plane orthogonal to the Z-axis passing through the point O. The center of the optical system 30 is assumed to be the point O. The optical axis of the optical system 30 is assumed to be along the Z-axis. The optical system 30 is characterized by a line segment on the X-axis. The line segment representing the optical system 30 extends only leftward from the Z axis for convenience, but may also extend rightward. The optical system 30 may be symmetrical about the Z-axis. The focal point of the optical system 30 is located: a point F located at a position away from the point O by F in the negative direction of the Z axis, and a point F' located at a position away from the point O by F in the positive direction of the Z axis. f characterizes the focal length of the optical system 30. It is assumed that light traveling from the point F radially toward the optical system 30 is refracted when passing through the optical system 30, and travels in a direction parallel to the Z axis in a region located in the positive direction of the Z axis with respect to the optical system 30. That is, the optical system 30 converts the light radially spread from the point F into parallel rays.

The display device 10 is assumed to be disposed along a plane orthogonal to the Z axis, which is separated from the optical system 30, which is regarded as a plane orthogonal to the Z axis, in the negative direction of the Z axis by a. The display device 10 is characterized by a line segment having a length corresponding to the left-right dot group pitch (2R).

The light barrier 20 is assumed to be provided along a plane orthogonal to the Z axis, which is apart from the plane on which the display device 10 is located in the positive direction of the Z axis by g. The light barrier 20 is characterized by a line segment having a length corresponding to the light barrier pitch (j).

A straight line connecting the point F and both ends of the line segment representing the display device 10, respectively, intersects the line segment representing the optical system 30 at the point O and the point S. That is, a line segment corresponding to the left-right dot group pitch of the display device 10 is enlarged as a line segment OS when viewed from the positive Z-axis direction side through the optical system 30.

A straight line connecting the point O and an opposite end point to the end point on the Z axis of the line segment characterizing the display device 10 intersects a straight line passing through the point S and parallel to the Z axis at a point S'. The perpendicular drawn from point S' to the Z axis intersects the Z axis at point S ". The line segment S' S "represents the virtual image 10Q of the display device 10. The distance between point O and point S "is characterized as h. That is, when the user observes the display device 10 via the optical system 30, the virtual image 10Q is located away from the point O in the negative direction of the Z axis by h. The length of the line segment S' S "is equal to the length of the line segment OS, and corresponds to the left-right dot group pitch in the virtual image 10Q. The left and right dot group spacing in virtual image 10Q is characterized as 2Q. The left and right dot group pitches in the virtual image 10Q are enlarged with respect to the left and right dot group pitches in the display device 10.

A straight line connecting both ends of the point F and the line segment characterizing the light barrier 20, respectively, intersects the line segment characterizing the optical system 30 at the point O and the point T. That is, a line segment corresponding to the optical barrier pitch is enlarged to a line segment OT when viewed from the positive direction side of the Z axis via the optical system 30.

A straight line connecting the point O and an opposite end point to the end point on the Z axis of the line segment characterizing the light barrier 20 intersects the straight line passing through the point T and parallel to the Z axis at a point T'. The perpendicular drawn from point T' to the Z axis intersects the Z axis at point T ". The line segment T' T "characterizes the virtual image 20Q of the light barrier 20. The distance between point O and point T "is characterized as b. That is, when the user observes the light barrier 20 via the optical system 30, the virtual image 20Q is located at a position away from the point O in the negative direction of the Z axis by b. The length of the line segment T' T "is equal to the length of the line segment OT, corresponding to the light barrier spacing in the virtual image 20Q. The light barrier spacing in virtual image 20Q is characterized as k. The light barrier pitch in the virtual image 20Q is enlarged with respect to the light barrier pitch in the light barrier 20.

The virtual image 10Q of the display device 10 and the virtual image 20Q of the light barrier 20 are formed as parallax images in both eyes of the user. The following describes how a user views the virtual images 10Q and 20Q when the user projects a parallax image via the optical system 30, with reference to a configuration example shown in fig. 6.

The distance between the optical system 30 and the left and right eyes 5L and 5R of the user is characterized by P. The user visually recognizes the virtual image 10Q of the display device 10 and the virtual image 20Q of the light barrier 20 via the optical system 30. The light barrier spacing in virtual image 20Q is characterized as k. The monocular point group pitch and the left-right point group pitch in the virtual image 10Q are represented as Q and 2Q, respectively. The distance between virtual image 10Q and virtual image 20Q is characterized as m. The distance between optical system 30 and virtual image 10Q is characterized as h. The distance between the optical system 30 and the virtual image 20Q is characterized as b.

The configuration example shown in fig. 6 assumes that the monocular point groups in the virtual image 10Q of the display device 10 are arranged in the X-axis direction without overlapping each other. In this case, the relationships expressed by the following equations (3) and (4) are established based on the geometric positional relationship between the user's eyes, the virtual image 20Q, and the virtual image 10Q. Geometrically positional relationships encompass similar relationships.

[ mathematical formula 2]

In fig. 5, a triangle having both ends of a line segment representing the light barrier 20 and a point F as vertices and a triangle having points O, T, and F as vertices are in a similar relationship to each other. The relationship of the light barrier pitch (j) in the light barrier 20 and the light barrier pitch (k) in the virtual image 20Q is characterized by the following equation (5) based on a similar relationship.

[ mathematical formula 3]

In fig. 5, a triangle having both ends of a line segment representing the display device 10 and a point F as vertexes and a triangle having the point O, the point S, and the point F as vertexes are in a similar relationship with each other. The relationship between the left-right dot group pitch (2R) in the display device 10 and the left-right dot group pitch (2Q) in the virtual image 10Q is represented by the following equation (6) based on a similar relationship.

[ mathematical formula 4]

The light barrier interval (j) is represented by the following formula (7) based on the formulas (4), (5) and (6).

[ math figure 5]

The distance (P + b) from both eyes of the user to the virtual image 20Q of the optical barrier 20 is characterized by the following formula (8) based on the formula (3) and the formula (6).

[ mathematical formula 6]

The distance (m) between the virtual images 20Q and 10Q is characterized by the following formula (9) based on fig. 5.

[ math figure 7]

As shown in the following equations (10) and (11), the magnification ratio of the virtual image 10Q with respect to the display device 10 and the magnification ratio of the virtual image 20Q with respect to the light barrier 20 are defined as a and B, respectively.

[ mathematical formula 8]

The light barrier interval (j) is characterized by the following formula (12) based on the formulas (7) to (11).

[ mathematical formula 9]

Expression (12) representing the relationship between the optical barrier pitch (j) and the left-right dot group pitch (2R) is a condition for arranging the monocular dot groups in the virtual image 10Q in the X-axis direction without overlapping each other. When equation (12) is satisfied, crosstalk in the parallax image formed by the virtual images 10Q and 20Q of both eyes of the user can be reduced.

When the equation (12) is satisfied, the condition for equalizing the light barrier pitch (j) and the left-right dot group pitch (2R) is represented by the following equation (13).

[ mathematical formula 10]

The formula (13) is modified to the formula (14) and the formula (15) based on the definitions of a and B.

[ mathematical formula 11]

The light barrier pitch (j) and the left-right dot group pitch (2R) may be equal to each other when the formula (14) or the formula (15) is satisfied. That is, when a condition for arranging monocular point groups in the X axis direction without overlapping each other is satisfied, j — 2R is satisfied in the case of further expression (14) or expression (15).

When the parallax image is projected to both eyes of the user without passing through the optical system 30 (see fig. 4), the condition for arranging the monocular point groups in the X-axis direction without overlapping each other includes the condition represented by the formula (2). When g > 0 in the formula (2), j ≠ 2R is a necessary condition for arranging monocular dot groups in the X-axis direction so as not to overlap each other. On the other hand, when the parallax image is enlarged and projected to both eyes of the user via the optical system 30 and the formula (14) or the formula (15) is satisfied, the point j ≠ 2R is not a necessary condition for arranging the monocular dot groups in the X-axis direction so as not to overlap each other. In other words, only when the parallax image is projected to both eyes of the user via the optical system 30, the monocular point groups can be arranged in the X-axis direction without overlapping each other even when j is 2R.

When the optical system 30 enlarges and projects the parallax image to the user, the virtual images 10Q and 20Q correspond to a product of enlarging the display device 10 and the light barrier 20. In other words, it can be said that the optical system 30 enlarges the optical barrier interval (j) and the left-right dot group interval (2R) at different magnifications, and the left-right dot group interval (2Q) in the virtual image 10Q and the optical barrier interval (k) in the virtual image 20Q are made different.

The light barrier 20 may be a liquid crystal panel. As shown in fig. 7, the light barrier 20 may have sub-pixels 23. The sub-pixels 23 may be arranged in a lattice. It is assumed that lattice axes characterizing the arrangement of the sub-pixels 23 are an X axis and a Y axis. The sub-pixels 23 may be arranged at a given pitch in the X-axis direction and the Y-axis direction, respectively. The light barrier 20 may have a sub-pixel 23 corresponding to the light transmission region 21 and a sub-pixel 23 corresponding to the light blocking region 22. The sub-pixels 23 corresponding to the light transmitting regions 21 are controlled to a state where the liquid crystal shutters are opened. The sub-pixels 23 corresponding to the light-shielding regions 22 are controlled to a state where the liquid crystal shutters are closed. The region in which the sub-pixels 23 corresponding to the light transmission region 21 are arranged and the region in which the sub-pixels 23 corresponding to the light blocking region 22 are arranged may be divided by the control boundary 25. The light barrier 20 includes a shutter panel capable of transition between a light transmitting state and a light shielding state in each minute region. The shutter panel includes a liquid crystal panel and a MEMS (Micro Electro mechanical system) panel using a MEMS shutter. The shutter panel is also referred to as a 2 nd panel.

As shown in fig. 8, the sub-pixel 23 may have a shutter portion 23A and a black matrix 23B. The shutter portion 23A transmits light when controlled to be in an open state, and blocks light when controlled to be in a closed state. In the case where the shutter section 23A is in the opened state, the sub-pixel 23 may have a transmittance of 1 st predetermined value or more. In the case where the shutter portion 23A is in the closed state, the sub-pixel 23 may have a transmittance of 2 nd predetermined value or less.

The black matrix 23B is provided around the sub-pixels 23 to divide the sub-pixels 23. The black matrix 23B blocks light regardless of the state of the shutter portion 23A. The horizontal length and the vertical length of the sub-pixel 23 are respectively represented by H1 and V1. The black matrix 23B has a width represented by W. The lateral length and the longitudinal length of the shutter portion 23A are respectively represented by (H1-Wx 2) and (V1-Wx 2). Even when the size of the sub-pixel 23 is changed, the width (W) of the black matrix 23B may not be changed. When H1 or V1 is increased without changing W, the ratio of the area occupied by the black matrix 23B to the area of the entire sub-pixel 23 increases. By increasing H1 or V1, the transmittance of light of the sub-pixel 23 when the shutter portion 23A is controlled to be in the open state is increased.

The display device 10 may be a liquid crystal panel. The liquid crystal panel as the display device 10 is also referred to as a 1 st panel. The sub-pixel 11 of the 1 st panel is also referred to as the 1 st sub-pixel. The 1 st sub-pixels are arranged at a 1 st pitch along the parallax direction. The display device 10 includes a shutter type display panel capable of transitioning between a light transmitting state and a light shielding state in each minute region. The shutter type display panel includes a MEMS display panel using a MEMS shutter, in addition to a liquid crystal panel. The shutter type display panel is also referred to as a 1 st panel.

The liquid crystal panel as the light barrier 20 is also referred to as a 2 nd panel. The sub-pixel 23 of the 2 nd panel is also referred to as a 2 nd sub-pixel. The 2 nd sub-pixels are arranged at a 2 nd pitch in the parallax direction. The 2 nd sub-pixel can be controlled to be in an open state by the shutter portion 23A to form the light-transmitting region 21. The 2 nd sub-pixel can be controlled to be in a closed state by the shutter portion 23A to form the light-shielding region 22.

In the case where the 2 nd sub-pixel forms the light-transmitting region 21, the larger the 2 nd sub-pixel is, the lower the proportion of the area occupied by the black matrix 23B in the area of the entire 2 nd sub-pixel is. As a result, the larger the 2 nd sub-pixel is, the greater the transmittance of light in the light-transmitting region 21 formed by the 2 nd sub-pixel may be.

In one embodiment, the 1 st panel displays a display image including a left-eye image and a right-eye image. The 2 nd panel projects the left-eye image and the right-eye image to the left eye 5L and the right eye 5R of the user through the light-transmitting region 21 and the light-blocking region 22, respectively. That is, the 2 nd panel generates a parallax image that gives parallax to both eyes of the user based on the display image of the 1 st panel. The optical system 30 enlarges and images the parallax image to both eyes of the user.

In this embodiment, the 2 nd sub-pixel can be made large by making the light barrier pitch (j) and the left-right dot pitch (2R) equal. As a result, the transmittance of light of the 2 nd panel can be improved.

As illustrated in fig. 4, a case where the parallax image is projected to both eyes of the user without passing through the optical system 30 for enlarging the parallax image is assumed as a comparative example. In the comparative example, when P is the suitable observation distance, the relationship represented by the above expression (2) is established. Based on the formula (2), the relationship of j < 2R is established because P and g are positive numbers. That is, when the parallax image is projected to both eyes of the user without passing through the optical system 30, the light barrier pitch is smaller than the left-right dot group pitch, which is a necessary condition for arranging the monocular dot groups in the X axis direction without overlapping each other.

On the other hand, in the head-up display 1 according to the present embodiment, when the relationship expressed by the expression (14) or the expression (15) is satisfied, a relationship of j being 2R is satisfied. That is, when the parallax image is projected to both eyes of the user without passing through the optical system 30, the point that the optical barrier pitch is equal to the left-right dot group pitch is a necessary condition for arranging the monocular dot groups in the X axis direction without overlapping each other.

The left and right dot groups are formed of a set of 1 st sub-pixels. In this case, the left-right dot group pitch is a natural number multiple of the 1 st pitch. The light-transmitting area 21 and the light-shielding area 22 of the light barrier 20 are formed by a set of 2 nd sub-pixels. In this case, the light barrier pitch is a natural number multiple of the 2 nd pitch.

In the comparative example, the light barrier pitch is smaller than the left and right dot group pitch. Based on the fact that the left-right dot group pitch and the light barrier pitch are natural numbers times of the 1 st pitch and the 2 nd pitch, respectively, the 2 nd pitch is generally smaller than the 1 st pitch. That is, the 2 nd sub-pixel is smaller than the 1 st sub-pixel. In this case, it can be said that the 1 st panel and the 2 nd panel having mutually different pitches have different pixel structures.

On the other hand, in the present embodiment, when the light barrier pitch is equal to the left-right dot group pitch, the size of the 2 nd sub-pixel is equal to the size of the 1 st sub-pixel. In this case, the 1 st panel and the 2 nd panel have a pixel structure common to each other. The 1 st panel may have a color filter for expressing each of rgb (red Green blue) colors in a display image. On the other hand, the 2 nd panel may not have a color filter. The 2 nd panel has no color filter, so that the transmittance of the 2 nd panel can be improved. In the case where the 1 st panel and the 2 nd panel have a pixel structure common to each other, members other than the color filter can be commonly used in the 1 st panel and the 2 nd panel. That is, since the 1 st panel and the 2 nd panel have a common pixel structure, the cost of the members can be reduced as compared with the comparative example.

In the comparative example and the present embodiment, it is assumed that the size of the 1 st sub-pixel is common. Under this assumption, the 2 nd sub-pixel of the present embodiment is larger than the 2 nd sub-pixel of the comparative example based on the comparison of the size of the 1 st sub-pixel and the size of the 2 nd sub-pixel. When the light-transmitting region 21 is formed in the 2 nd sub-pixel, the transmittance of light in the 2 nd sub-pixel of the present embodiment is higher than that in the 2 nd sub-pixel of the comparative example. That is, in the present embodiment, the transmittance of light in the light barrier 20 can be increased by making the size of the 2 nd sub-pixel equal to the size of the 1 st sub-pixel. As a result, the luminance of the parallax image projected to both eyes of the user can be increased.

The head-up display 1 controls the left-right dot group pitch and the light barrier pitch at the 1 st panel and the 2 nd panel, respectively. If the 1 st pitch and the 2 nd pitch are different, it is difficult to determine m1 and m2 so that m1 times the 1 st pitch and m2 times the 2 nd pitch are equal, and ml times the 1 st pitch and m2 times the 2 nd pitch are equal to j and 2R, respectively. On the other hand, when the 1 st pitch and the 2 nd pitch are equal, it is easy to make n times of the 1 st pitch and n times of the 2 nd pitch equal. In this case, n times of the 1 st pitch and n times of the 2 nd pitch can be easily made equal to j and 2R. That is, when the 1 st pitch and the 2 nd pitch are equal, the light barrier pitch (j) and the left-right dot group pitch (2R) can be easily made equal. m1, m2, and n are natural numbers.

When the optical barrier pitch and the left and right dot group pitch are equal, the monocular dot groups can be arranged in the X-axis direction without overlapping each other by projecting the parallax image to both eyes of the user via the optical system 30. As a result, crosstalk in the parallax image can be reduced.

When the left-right dot group pitch (2R) is equal to the optical barrier pitch (j), both the pitch (R) of 1/2, which is the left-right dot group pitch, and the pitch (1/2), which is the optical barrier pitch (j), are also referred to as the 3 rd pitch. The above expression (14) represents that the 3 rd pitch is calculated based on the gap (g), the focal length (f) of the optical system 30, and the inter-ocular distance (E) of both eyes of the user. For example, when the inter-eye distances of the users are different, the head-up display 1 can determine the 3 rd pitch in accordance with the inter-eye distances of the users, and project the parallax image.

The expression (15) above represents the gap (g) calculated based on the focal length (f) of the optical system 30, the inter-ocular distance (E) of both eyes of the user, and the pitch (R) of 1/2 of the left and right dot group pitches. For example, when the head-up display 1 is manufactured, a spacer or the like space adjusting member may be interposed between the 1 st panel and the 2 nd panel. The gap (g) can be determined according to the thickness of the spacer. That is, the thickness of the spacer may be determined based on the focal length (f) of the optical system 30, the inter-eye distance (E) between both eyes of the user, and the pitch (R) of 1/2 between the left and right dot groups.

The above-described expression (14) or (15) is satisfied when the optical system 30 ideally functions and parallel rays are formed in a positive region of the Z axis shown in fig. 5. In this case, by satisfying equation (14) or equation (15) regardless of the distance (P) from the optical system 30 to both eyes of the user, stereoscopic vision can be provided even in a configuration in which the light barrier pitch and the left-right dot group pitch are equal.

On the other hand, in the region of fig. 5 located in the positive Z-axis direction with respect to the optical system 30, the optical system 30 may not form parallel rays. In this case, the condition for providing stereoscopic vision with a configuration in which the light barrier pitch and the left-right dot group pitch are equal is based not only on each parameter included in equation (14) or equation (15), but also on the distance (P) from the optical system 30 to both eyes of the user. In this case, for example, the 3 rd pitch is calculated based on not only the gap (g), the focal length (f), and the inter-eye distance (E), but also the distance (P) from the optical system 30 to both eyes of the user.

The 3 rd pitch may be a natural number multiple of the 1 st pitch and the 2 nd pitch. The display device 10 and the light barrier 20 can determine the number of pixels of the monocular group or the number of pixels of the light transmission region 21 based on the value of R calculated by equation (14).

The head-up display 1 according to the present embodiment can be mounted on a mobile body. When the head-up display 1 is mounted on a mobile body, the user of the head-up display 1 may be a driver, an operator, or a fellow passenger of the mobile body. When the head-up display 1 is mounted on a mobile body, a part of the structure of the head-up display 1 can be used in combination with other devices and components provided in the mobile body. For example, the windshield of the moving body can be used as a part of the structure of the head-up display 1. For example, the optical member 30c shown in fig. 1 may be replaced with a windshield of a mobile body.

In the case where the display device 10 includes a shutter type display panel, the display device 10 may include a light source device. The head-up display 1 enables the light barrier 20 to be located between the shutter display panel and the light source device.

The "mobile body" in the present disclosure includes a vehicle, a ship, and an aircraft. The "vehicle" in the present disclosure includes an automobile and an industrial vehicle, but is not limited thereto, and may include a railway vehicle, a living vehicle, and a fixed-wing aircraft running on a runway. The automobile includes a passenger car, a truck, a bus, a two-wheeled vehicle, a trolley bus, and the like, but is not limited thereto, and may include other vehicles that run on a road. Industrial vehicles include agricultural and construction oriented industrial vehicles. Industrial vehicles include, but are not limited to, forklifts and golf carts. Industrial vehicles for agriculture include, but are not limited to, tractors, tillers, transplanters, harvesters, combine harvesters, and mowers. Industrial vehicles for construction include, but are not limited to, bulldozers, scrapers, forklifts, lift trucks, dump trucks, and road rollers. The vehicle includes a vehicle driven by human power. In addition, the classification of the vehicle is not limited to the above. For example, an industrial vehicle that can travel on a road may be included in an automobile, and the same vehicle may be included in a plurality of categories. For vessels in this disclosure, marine jets, boats, tankers are included. For aircraft in this disclosure, fixed wing aircraft, rotorcraft are included.

The configuration according to the present disclosure is not limited to the above-described embodiments, and many modifications and changes can be made. For example, the functions and the like included in the respective components can be logically rearranged, and a plurality of components and the like can be combined into 1 or divided.

The drawings illustrating the structure according to the present disclosure are schematic. The size ratio and the like on the drawing do not necessarily coincide with reality.

In the present disclosure, the terms "1 st" and "2 nd" are identifiers for distinguishing the structures. In the present disclosure, the structures distinguished by the description of "1 st" and "2 nd" can be exchanged with the numbers in the structures. For example, the 1 st panel can exchange "1 st" and "2 nd" as identifiers with the 2 nd panel. The exchange of identifiers takes place simultaneously. After the exchange of identifiers, the structure is also distinguished. The identifier may also be deleted. The structure from which the identifier is deleted is distinguished by a reference numeral. The order of the structure should not be interpreted or the identifier having a small number should be interpreted based on only the description of the identifier such as "1 st" and "2 nd" in the present disclosure.

In the present disclosure, the X-axis, Y-axis, and Z-axis are provided for convenience of description and may be replaced with each other. The configuration according to the present disclosure is explained using an orthogonal coordinate system composed of an X axis, a Y axis, and a Z axis. The positional relationship of the respective structures according to the present disclosure is not limited to the orthogonal relationship.

Description of reference numerals

1 head-up display

5L left eye

5R Right eye

10 display device

Virtual image of 10Q display device

11 sub-pixel

11L region 1

11R 2 nd region

12 pixels

13L left eye visible region

Region visible to the right eye of 13R

14L left eye shading area

14R Right eye photophobic region

15 display boundaries

20 light barrier

Virtual image of 20Q light barrier

21 light transmitting area

22 light-shielding area

23 sub-pixel

23A shutter unit

23B black matrix

25 control boundary

30 optical system

30a, 30b, 30c optical member

32 light path