Virtual image display device, moving body, method for driving virtual image display device, and program

Abstract

A virtual image display device includes a backlight, a display panel, an optical system, and a backlight control unit. The backlight has a plurality of light-emitting parts and a light-emitting surface capable of emitting light from the plurality of light-emitting parts. The display panel has a display surface that displays an image by light emitted from the light-emitting surface. The optical system enlarges the image of the display surface and the image of the light-emitting surface at different magnifications so as to form a virtual image in the field of view of a user. The backlight control unit performs local dimming control by switching the plurality of light-emitting units to either a light-emitting state or a non-light-emitting state on the basis of an image displayed on the display panel. The size of the light-emitting surface is smaller than that of the display surface.

Description

Technical Field

[0001] The present disclosure relates to a virtual image display device, a moving object, a driving method of the virtual image display device, and a program. Background Art

[0002] Conventionally, for example, a virtual image display device described in Patent Document 1 is known.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-112667 Summary of the invention

[0006] A virtual image display device according to one embodiment of the present disclosure comprises: a backlight, a display panel, an optical system, and a backlight control unit. The backlight comprises: a plurality of light-emitting units and a light-emitting surface capable of emitting light from the plurality of light-emitting units. The display panel comprises a display surface for displaying an image by light emitted from the light-emitting surface. The optical system magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision. The backlight control unit switches the plurality of light-emitting units to either a light-emitting state or a non-light-emitting state according to the image displayed on the display panel, and performs local dimming control. The size of the light-emitting surface is configured to be smaller than the size of the display surface.

[0007] Another embodiment of the present disclosure relates to a virtual image display device comprising: a backlight, a display panel, an optical system, and a backlight control unit. The backlight has: a plurality of light-emitting units and a light-emitting surface capable of emitting light from the plurality of light-emitting units. The display panel has a display surface that displays an image by light emitted from the light-emitting surface. The optical system magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are imaged as virtual images in the user's field of view. The backlight control unit selects an area within the light-emitting surface, that is, an area where the image of the area is imaged as a virtual image of the same size as the image of the display surface in the user's field of view. The backlight control unit switches a portion of the light-emitting units among the plurality of light-emitting units corresponding to the selected area to either a light-emitting state or a non-light-emitting state, and performs local dimming control according to the image displayed on the display surface.

[0008] A mobile body according to an embodiment of the present disclosure includes: the above-mentioned virtual image display device and a windshield. The optical system includes a first reflecting portion and a second reflecting portion. The first reflecting portion reflects the image of the display surface and the image of the light-emitting surface toward the second reflecting portion. The second reflecting portion reflects the image of the display surface and the image of the light-emitting surface reflected by the first reflecting portion toward the field of vision of the user. The windshield reflects the image light reflected by the first reflecting portion toward the eyes of the user.

[0009] Another embodiment of the present disclosure relates to a virtual image display device comprising: a backlight, a display panel, an optical system, and a backlight control unit. The backlight has a plurality of light-emitting units and a light-emitting surface capable of emitting light from the plurality of light-emitting units. The display panel has a display surface that displays an image by light emitted from the light-emitting surface. The optical system magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of view. The backlight control unit deforms a first image displayed on the display panel according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image, and based on the second image, switches the plurality of light-emitting units to either a light-emitting state or a non-light-emitting state to perform local dimming control.

[0010] Another embodiment of the present disclosure relates to a virtual image display device comprising: a backlight, a display panel, an optical system, and a backlight control unit. The backlight has a plurality of light-emitting units and a light-emitting surface capable of emitting light from the plurality of light-emitting units. The display panel has a display surface that displays an image by light emitted from the light-emitting surface. The optical system magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of view. The backlight control unit deforms a first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system, generates a second image displayed on the display panel, and switches the plurality of light-emitting units to either a light-emitting state or a non-light-emitting state based on the first image, and performs local dimming control.

[0011] In the driving method of the virtual image display device disclosed in the present invention, the virtual image display device comprises: a backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; a display panel having a display surface for displaying an image by means of light emitted from the light-emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form a virtual image in the user's field of view. The driving method of the virtual image display device comprises: deforming a first image displayed on the display panel according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image; and switching the plurality of light-emitting portions to either a light-emitting state or a non-light-emitting state based on the second image to perform local dimming control.

[0012] In the driving method of the virtual image display device disclosed in the present invention, the virtual image display device comprises: a backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; a display panel having a display surface for displaying an image by means of light emitted from the light-emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form a virtual image in the user's field of view. The driving method of the virtual image display device comprises: deforming a first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image displayed on the display panel; and switching the plurality of light-emitting portions to either a light-emitting state or a non-light-emitting state based on the first image to perform local dimming control.

[0013] The program disclosed in the present invention is a program executed by a virtual image display device, wherein the virtual image display device comprises: a backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; a display panel having a display surface for displaying images by means of light emitted from the light-emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form a virtual image in the user's field of view, wherein the program is used to: deform a first image displayed on the display panel according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image, and based on the second image, switch the plurality of light-emitting portions to either a light-emitting state or a non-light-emitting state to perform local dimming control.

[0014] The program disclosed in the present invention is a program executed by a virtual image display device, wherein the virtual image display device comprises: a backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; a display panel having a display surface for displaying an image by means of light emitted from the light-emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form a virtual image in the user's field of view, wherein the program is used to: deform a first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image displayed on the display panel, and based on the first image, switch the plurality of light-emitting portions to either a light-emitting state or a non-light-emitting state to perform local dimming control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The objects, features and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0016] Figure 1 It is a diagram showing the structure of a virtual image display device according to one embodiment of the present disclosure.

[0017] Figure 2 The diagram shows an example of visual representation of virtual images of the backlight image and the display panel image when a user views the backlight image and the display panel image via an optical system.

[0018] Figure 3A Yes means Figure 1 A front view of a backlight of a virtual image display device.

[0019] Figure 3B Yes means Figure 1 A front view of a display panel of a virtual image display device.

[0020] Figure 4 This is a diagram showing an example of a virtual image on a display surface whose visibility is reduced due to parallax between virtual images.

[0021] Figure 5 Yes means Figure 1 A diagram showing an example of a virtual image on a display surface visually recognized by a user of a virtual image display device.

[0022] Figure 6 It is a diagram showing the structure of a virtual image display device according to another embodiment of the present disclosure.

[0023] Fig. 7A Yes means Figure 6 A front view of a backlight of a virtual image display device.

[0024] Figure 7B Yes means Figure 6 A front view of a display panel of a virtual image display device.

[0025] Figure 8 This is a diagram showing an example of a virtual image on a display surface whose visibility is reduced due to parallax between virtual images.

[0026] Fig. 9 Yes means Figure 6 A diagram showing an example of a virtual image on a display surface visually recognized by a user of a virtual image display device.

[0027] Fig.10 It is a diagram showing the structure of a virtual image display device according to another embodiment of the present disclosure.

[0028] Fig.11 Yes means Fig.10 A diagram showing an example of a virtual image on a display surface visually recognized by a user of a virtual image display device.

[0029] Fig.12 It is a diagram showing a structure of a moving object according to one embodiment of the present disclosure.

[0030] Fig.13 This is a flowchart for explaining a method for driving a virtual image display device according to an embodiment of the present disclosure.

[0031] Fig.14 This is a diagram showing an example of the first image.

[0032] Fig.15 This is a diagram showing an example of the second image.

[0033] Fig.16 is a diagram showing a plurality of local dimming areas.

[0034] Fig.17 This is a graph showing an example of a grayscale value histogram.

[0035] Fig.18 is a graph showing another example of a grayscale value histogram.

[0036] Fig.19 The diagram shows a light emitting portion set to a light emitting state and a light emitting portion set to a non-light emitting state.

[0037] Fig. 20 This is a diagram for explaining detection of the peripheral light emitting portion.

[0038] Fig.21 This is a diagram for explaining detection of the peripheral light emitting portion.

[0039] Fig. 22 A diagram showing a virtual image visually recognized by a user.

[0040] Fig.23 This is a diagram showing an example of the second image.

[0041] Fig.24 The diagram shows a light emitting portion set to a light emitting state and a light emitting portion set to a non-light emitting state.

[0042] Fig.25 A diagram showing a virtual image visually recognized by a user.

[0043] Fig.26 This is a diagram showing an example of the second image.

[0044] Fig. 27 The diagram shows a light emitting portion set to a light emitting state and a light emitting portion set to a non-light emitting state.

[0045] Fig.28 A diagram showing a virtual image visually recognized by the user DETAILED DESCRIPTION

[0046] In the past, various virtual image display devices have been proposed that allow a user to visually recognize a virtual image by causing a reflective portion to reflect image light emitted from a display. In the case where a display is configured to include a backlight and a liquid crystal panel, by performing local dimming control on the backlight, it is possible to suppress the power consumption of the display and allow the user to visually recognize a virtual image with improved contrast. However, in such a virtual image display device, in principle, a parallax is generated between the virtual image of the liquid crystal panel (referred to as a display virtual image) and the virtual image of the backlight (referred to as a light source virtual image), and therefore the visual recognizability of the display virtual image visually recognized by the user should be reduced. For example, Patent Document 1 discloses the following virtual image display device: In order to reduce the reduction in the visual recognizability of the display virtual image, the user's line of sight is estimated, and based on the estimated line of sight, multiple light sources of the backlight are partially illuminated.

[0047] Conventional virtual image display devices have room for improvement in reducing the parallax between the displayed virtual image and the light source virtual image throughout the entire displayed virtual image.

[0048] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The drawings used in the following description are schematic drawings. The dimensional ratios and the like in the drawings do not necessarily correspond to the actual dimensional ratios.

[0049] like Figure 1 As shown, a virtual image display device 1 according to an embodiment of the present disclosure includes a display unit 2, an optical system 3, and a backlight control unit 4. The virtual image display device 1 enables a user 5 to visually recognize a virtual image. The virtual image display device 1 is also called a head-up display. A head-up display is also called a HUD (Head Up Display). The virtual image display device 1 can be mounted on a moving body such as a vehicle, a ship, or an airplane. When the virtual image display device 1 is mounted on a moving body, the user 5 can be a driver, an operator, or a fellow passenger of the moving body.

[0050] The display unit 2 displays an image projected toward the visual field of the user 5. The display unit 2 may be formed of a transmissive display device. For example, the transmissive display device may be a liquid crystal device such as an LCD (Liquid Crystal Display) including a backlight 6 and a display panel (liquid crystal panel) 7. The backlight 6 and the display panel 7 are arranged in this order from the side away from the user 5 along the optical path of image light of the image displayed to the user 5.

[0051] The backlight 6 may be a direct-type backlight. The direct-type backlight 6 includes a plurality of light-emitting units 61 and a light-emitting surface 6a capable of emitting light from the plurality of light-emitting units 61. The backlight 6 may include a substrate 62 and a diffuser 63. The substrate 62 may have a main surface 62a opposite to the display panel 7, and the plurality of light-emitting units 61 may be arranged two-dimensionally on the main surface 62a. The diffuser 63 may be located in front of the substrate 62 ( Figure 1 The backlight 6 can irradiate the display panel 7 with the light emitting surface 6a. The light emitting surface 6a can be the surface of the diffuser 63 on the display panel 7 side, or the main surface 62a of the base 62.

[0052] Each of the plurality of light emitting units 61 is configured to include at least one light source. The light source may be, for example, a point light source such as a light emitting diode (LED). The LED includes a mini LED and a micro LED.

[0053] The display panel 7 has a display surface 7 a. The display surface 7 a is a surface that performs display based on an image display signal, and can emit an image toward the optical system 3 using light emitted from a light emitting surface 6 a of the backlight 6 .

[0054] The display panel 7 may be a well-known liquid crystal panel. As well-known liquid crystal panels, for example, there may be IPS (In-Plane Switching) type, FFS (Fringe Field Switching) type, VA (Vertical Alignment) type, ECB (Electrically Controlled Birefringence) type, and the like liquid crystal panels. The display panel 7 may include a plurality of liquid crystal display elements, two glass substrates configured to sandwich a plurality of liquid crystal display elements, and a color filter. The display panel 7 is not limited to a liquid crystal panel, and may also be a MEMS (Micro Electro Mechanical Systems) shutter type display panel. In the following description, the display panel 7 is set as a liquid crystal panel.

[0055] The backlight control unit (hereinafter also referred to as the control unit) 4 controls the backlight 6. The control unit 4 switches the plurality of light emitting units 61 to either a light emitting state or a non-light emitting state. The control unit 4 can control the light emitting brightness of the light emitting unit 61 set to the light emitting state based on the image data of the image displayed on the display surface 7a. The control unit 4 can control the light emitting brightness of the light emitting unit 61 set to the light emitting state based on the background brightness of the field of view of the user 5.

[0056] The control unit 4 controls not only the backlight 6 but also the components of the virtual image display device 1. The components controlled by the control unit 4 may include a display panel 7, a signal generator that generates an image signal of an image displayed on the display panel 7, and the like. In addition, the control unit 4 may be configured to perform image processing such as enlarging, reducing, and brightness analysis on the image to be displayed on the display panel 7 in order to perform local dimming control. The control unit 4 is configured as a processor, for example. The control unit 4 may include one or more processors. The processor may include a general-purpose processor that reads a specific program to perform a specific function, and a dedicated processor dedicated to a specific process. The dedicated processor may include an IC (ASIC: Application Specific Integrated Circuit: Application Specific Integrated Circuit) for a specific purpose. The processor may include a programmable logic device (PLD: Programmable Logic Device: Programmable Logic Device). The PLD may include an FPGA (Field-Programmable Gate Array: Field Programmable Gate Array). The control unit 4 may be any one of an SoC (System-on-a-Chip) and a SiP (System In a Package) in which one or more processors cooperate. The control unit 4 may include a storage unit, and various information or programs for operating each component of the virtual image display device 1 are stored in the storage unit. The storage unit may be composed of, for example, a semiconductor memory, etc. The storage unit may function as a working memory of the control unit 4 .

[0057] The optical system 3 is located in the optical path of the image light emitted from the display unit 2 and reaching the eye of the user 5. The optical system 3 projects the image light emitted from the display unit 2 to the eye of the user 5, and forms a virtual image on the eye of the user 5. The optical system 3 can enlarge or reduce the image displayed on the display unit 2, so that it is formed on the eye of the user 5. The optical system 3 includes a first optical member (also referred to as a first reflection unit) 3a and a second optical member (also referred to as a second reflection unit) 3b. The first reflection unit 3a reflects the image of the light emitting surface 6a and the image of the display surface 7a toward the second reflection unit 3b. The second reflection unit 3b reflects the image of the light emitting surface 6a and the image of the display surface 7a reflected by the first reflection unit 3a toward the eye of the user 5. The number of optical members constituting the optical system 3 is not limited to 2, and may be 3 or more, or 4 or more. The optical member may include a reflection member, and the reflection member includes a convex or concave mirror. The optical member may include a reflection member, and the reflection member includes a free-form surface mirror. The optical member may include a refractive member, and the refractive member includes a convex lens or a concave lens. Convex lenses include biconvex lenses, plano-convex lenses, and convex meniscus lenses. Concave lenses include biconcave lenses, plano-concave lenses, and concave meniscus lenses. Optical components are not limited to reflective components or refractive components, and may also include various other optical components.

[0058] The virtual image 10Q of the image of the light emitting surface 6a and the virtual image 20Q of the image of the display surface 7a are located forward of the second optical component 3b located closest to the user 5 ( Figure 1 The image of the light emitting surface 6a refers to the image of the light emitting surface 6a when viewed from the front side of the display unit 2 ( Figure 1 The image of the light-emitting surface 6a observed through the display panel 7 when the display unit 2 is observed along the optical path of the image light) in the left side of the image. The image of the display surface 7a refers to the image of the display surface 7a observed when the display unit 2 is observed along the optical path of the image light from the front side of the display unit 2. The image of the display surface 7a can also be said to be an image displayed on the display surface 7a. Hereinafter, the image of the light-emitting surface 6a is also referred to as the light-emitting surface 6a. The image of the display surface 7a is also referred to as the display surface 7a. In addition, the virtual image 10Q is also referred to as the light-emitting surface virtual image, and the virtual image 20Q is also referred to as the display surface virtual image. The size of the display surface 7a is the size corresponding to the maximum display area of ​​the display panel 7, and is the size of the effective display area that can be displayed. In addition, the size of the light-emitting surface 6a is the size of the maximum lit area that can be irradiated with the light of the light source corresponding to the effective display area of ​​the display panel 7.

[0059] The virtual image 10Q and the virtual image 20Q are formed in the eyes of the user 5. The user 5 can visually recognize the virtual image 10Q and the virtual image 20Q. Figure 2 , explaining the visual representation of the virtual image 10Q and the virtual image 20Q from the user 5.

[0060] The backlight 6, the display panel 7 and the optical system 3 are arranged along the Z axis. Whether the optical system 3 includes only one optical component such as a lens or a reflector or includes multiple components, they are all regarded as a surface. Assume that the optical system 3 is located in a plane passing through point O and orthogonal to the Z axis. Assume that the center of the optical system 3 is point O. Assume that the optical axis of the optical system 3 is along the Z axis. The optical system 3 is represented as a line segment on the Y axis. For convenience, the line segment representing the optical system 3 extends only upward from the Z axis, but can also extend downward. The optical system 3 can be symmetrical around the Z axis. The focus of the optical system 3 is located at point F set away from f in the negative direction of the Z axis from point O and point F' set away from f in the positive direction of the Z axis from point O. f represents the focal length of the optical system 3. Assume that the light that radially travels toward the optical system 3 from point F is refracted when passing through the optical system 3, and travels in a direction parallel to the Z axis in an area located in the positive direction of the Z axis than the optical system 3. That is, the optical system 3 makes the light that radially extends from point F become parallel light rays.

[0061] Assume that the light emitting surface 6a is located along a plane perpendicular to the Z axis, away from the optical system 3 in the negative direction of the Z axis (where a<f). The light emitting surface 6a is represented by a line segment having a length d along the Y axis.

[0062] Assume that the display surface 7a is located at a position c (where c<a) away from the surface where the light emitting surface 6a is located in the positive direction of the Z axis and along a plane orthogonal to the Z axis. The display surface 7a is represented by a line segment having a length e along the Y axis.

[0063] Straight lines connecting point F and both ends of the line segment representing the light emitting surface 6a intersect the line segment representing the optical system 3 at points O and S. That is, when viewed from the positive direction side of the Z axis through the optical system 3, the line segment corresponding to the light emitting surface 6a is enlarged to line segment OS.

[0064] The straight line connecting point O and the end point of the line segment representing the light-emitting surface 6a opposite to the end point on the Z axis intersects with the straight line passing through point S and parallel to the Z axis at point S'. The perpendicular line drawn from point S' to the Z axis intersects with the Z axis at point S". The line segment S'S" represents the virtual image 10Q of the light-emitting surface 6a. The distance between point O and point S" is represented by h, and h is represented by h = a×f / (fa). That is, when the user 5 observes the light-emitting surface 6a via the optical system 3, the virtual image 10Q is located at a position h away from point O in the negative direction of the Z axis. The length D of the line segment S'S" is equal to the length of the line segment OS. The length D of the line segment S'S" is represented by the following formula (1).

[0065] D=f×d / (fa) ···(1)

[0066] Straight lines connecting point F and both ends of the line segment representing the display surface 7a intersect the line segment representing the optical system 3 at points O and T. That is, when viewed from the positive direction of the Z axis through the optical system 3, the line segment corresponding to the display surface 7a is enlarged to the line segment OT.

[0067] The straight line connecting point O and the end point of the line segment representing the display surface 7a opposite to the end point on the Z axis intersects with the straight line passing through point T and parallel to the Z axis at point T'. The perpendicular line drawn from point T' to the Z axis intersects with the Z axis at point T". Line segment T'T" represents the virtual image 20Q of the display surface 7a. The distance between point O and point T" is represented by b, and b is represented by b = (ac) × f / (f-a+c). That is, when the user 5 observes the display surface 7a via the optical system 3, the virtual image 20Q is located at a position away from b in the negative direction of the Z axis from point O. The length of line segment T'T" is equal to the length of line segment OT. The length E of line segment T'T" is represented by the following formula (2).

[0068] E=f×e / (f-a+c)···(2)

[0069] According to equations (1) and (2), the magnification of the light emitting surface 6a (i.e., the magnification of the virtual image 10Q relative to the light emitting surface 6a) α and the magnification of the display surface 7a (i.e., the magnification of the virtual image 20Q relative to the display surface 7a) β are expressed by the following equations (3) and (4), respectively.

[0070] α=f / (fa)···(3)

[0071] β=f / (f-a+c)···(4)

[0072] If the length d of the light emitting surface 6a is equal to the length e of the display surface 7a, it can be seen from equations (3) and (4) that the magnification α of the light emitting surface 6a is different from the magnification β of the display surface 7a, so the size of the virtual image 10Q is different from the size of the virtual image 20Q. According to equations (1) and (2), when the length d of the light emitting surface 6a is d=e×(fa) / (f-a+c), the length D of the virtual image 10Q along the Y axis can be equal to the length E of the virtual image 20Q along the Y axis.

[0073] The light emitting surface 6a and the display surface 7a are enlarged not only in the Y-axis direction but also in the X-axis direction. The magnification of the light emitting surface 6a in the X-axis direction may be different from the magnification α of the light emitting surface 6a in the Y-axis direction. The magnification of the display surface 7a in the X-axis direction may be different from the magnification β of the display surface 7a in the Y-axis direction.

[0074] Next, refer to Figure 3A , 3B , an example of local dimming control performed by the control unit 4 is described. Figure 3A Indicates the front side of the display unit 2 ( Figure 1 (left side in the figure) A front view of the backlight 6 when the display unit 2 is observed along the optical path of the image light. Figure 3B The front view of the display panel 7 when the display unit 2 is observed from the front side of the display unit 2 along the optical path of the image light is shown. The light-emitting surface 6a and the display surface 7a may have a rectangular shape. The size (length of the long side and the short side) of the light-emitting surface 6a is smaller than that of the display surface 7a. The shape of the light-emitting surface 6a may be similar to or different from that of the display surface 7a. When the magnification α of the virtual image 10Q relative to the light-emitting surface 6a and the magnification β of the virtual image 20Q relative to the display surface 7a are different in the X-axis direction and the Y-axis direction, the shape of the light-emitting surface 6a and the shape of the display surface 7a may be different. In addition, local dimming control is a method of dividing the area of ​​the backlight 6 overlapping the display surface 7a into a plurality of blocks and controlling the brightness of the plurality of blocks independently for each block. For example, when a specific block of the display surface 7a is displayed darkly, the brightness of the corresponding block of the corresponding backlight can be reduced to make the image display darker. In this way, by performing local dimming control, the display performance of the virtual image display device can be improved and the contrast can be improved.

[0075] like Figure 3A As shown, the plurality of light emitting units 61 of the backlight 6 can be arranged in a grid shape. The grids arranged in the grid shape are equivalent to the above-mentioned blocks. The light emitting units 61 can be arranged at a given interval in the X-axis direction and the Y-axis direction. The X-axis direction is also called the horizontal direction or the first direction. The Y-axis direction is also called the vertical direction or the second direction. Figure 3B As shown, the display panel 7 has a plurality of pixels 71. The pixel 71 may include a plurality of sub-pixels. For example, the pixel 71 may include three sub-pixels for displaying each color of red, green and blue. The number of sub-pixels included in the pixel 71 is not limited to three, and may be two, or may be four or more. The plurality of pixels 71 may be arranged in a lattice. Assume that the lattice axes representing the arrangement of the pixels 71 are the X-axis and the Y-axis. The pixels 71 may be arranged at given intervals in the X-axis direction and the Y-axis direction, respectively. The light-emitting portion 61 and the pixels 71 may be arranged at the same intervals in the X-axis direction and the Y-axis direction, respectively, or may be arranged at different intervals.

[0076] The image G displayed on the display surface 7a is visually recognized by the user 5 as a virtual image superimposed on the scenery outside the mobile body. The image G may be, for example, text or graphics indicating the state (speed, posture, etc.) of the mobile body and navigation information (lane guidance, navigation guidance, vehicle spacing warning, pedestrian detection, etc.). Only a part of the display surface 7a is set as the display part of the image G. The transmittance of the liquid crystal display element of the pixel (also called display pixel) 71a corresponding to the display part is set to a given value, and the image is displayed by the light emitted from the light-emitting surface 6a. That is, the light emitted from the light-emitting surface 6a and modulated by the liquid crystal display element is emitted from the display pixel 71a corresponding to the display part as image light. The part of the display surface 7a different from the display part is set as the background part, and substantially nothing is displayed in the background part. The transmittance of the liquid crystal display element of the pixel (also called non-display pixel) 71b corresponding to the background part is set to 0% or a value close to 0% so that the light emitted from the light-emitting surface 6a is not transmitted.

[0077] In the local dimming control, among the plurality of light-emitting sections 61 of the backlight 6, the light-emitting section 61 corresponding to the display pixel 71a is set to a light-emitting state, and the light-emitting section 61 corresponding to the non-display pixel 71b is set to a non-light-emitting state. If, in the case where the light-emitting surface 6a and the display surface 7a are magnified by the same multiple so that the optical system 3 forms the virtual image 10Q and the virtual image 20Q at the same position, by setting the light-emitting section 61 overlapping with the display pixel 71a in the front view to a light-emitting state and setting the light-emitting section 61 not overlapping with the display pixel 71a in the front view to a non-light-emitting state, the user 5 can visually recognize the display surface virtual image with reduced visual recognition. However, as described above, the optical system 3 magnifies the light-emitting surface 6a and the display surface 7a at different magnifications to form the virtual image 10Q and the virtual image 20Q at different positions. Therefore, when the light-emitting portion 61 that overlaps with the display pixel 71a when viewed from the front is set to a light-emitting state, and the light-emitting portion 61 that does not overlap with the display pixel 71a when viewed from the front is set to a non-light-emitting state, in the field of view of the user 5, parallax (hereinafter also referred to as inter-virtual image parallax) is generated between the virtual image 10Q of the light-emitting surface 6a and the virtual image 20Q of the display surface 7a, and the visual recognizability of the virtual image 20Q is reduced.

[0078] Figure 4 2 is a diagram showing an example of a virtual image 20Q whose visibility is reduced due to parallax between virtual images. Figure 4 In FIG. 1 , for the convenience of illustration, the case where the image G is a black and white checkered pattern is shown. Figure 4 In FIG. 1 , not only the virtual image 20Q of the display surface 7a but also the virtual image 10Q of the light emitting surface 6a is shown. Figure 4 In the virtual image 20Q shown, the white portion 20w is the virtual image of the display pixel 71a, and the black portion 20b is the virtual image of the non-display pixel 71b. Figure 4 In the virtual image 10Q shown, the white portion 10w is a virtual image of the light emitting unit 61 set to the light emitting state, and the gray portion 10g is a virtual image of the light emitting unit 61 set to the non-light emitting state. Figure 4 As shown in FIG. 1 , when parallax between virtual images occurs, sometimes the virtual image of the display pixel 71a overlaps with the virtual image of the light emitting unit 61 set to a non-light emitting state, or the virtual image of the non-display pixel 71b overlaps with the virtual image of the light emitting unit 61 set to a light emitting state, resulting in reduced visibility of the virtual image 20Q. Figure 4 It can be seen that the parallax between virtual images is different throughout the entire virtual image 20Q, and is small in the central part of the virtual image 20Q and large in the peripheral part of the virtual image 20Q. In addition, the parallax between virtual images is different in the horizontal direction ( Figure 4 ) and vertically ( Figure 4 By estimating the sight line of the user 5, the parallax between virtual images near the center of the estimated sight line can be reduced. However, considering the processing burden of the virtual image display device, it is difficult to reduce the parallax between virtual images throughout the entire virtual image 20Q.

[0079] The virtual image display device 1 of the present embodiment is a structure in which the size of the light emitting surface 6a is smaller than the size of the display surface 7a. Based on the magnification α of the light emitting surface 6a and the magnification β of the display surface 7a, the size of the light emitting surface 6a is set to be smaller than the size of the display surface 7a so that the virtual image 10Q and the virtual image 20Q have the same size. The control unit 4 switches the plurality of light emitting units 61 to either a light emitting state or a non-light emitting state based on the image data of the image G displayed on the display surface 7a, the magnification α of the light emitting surface 6a, and the magnification β of the display surface 7a. The control unit 4 may, for example, Figure 3A The light emitting surface 6a is shown enlarged to Figure 3B When the display surface 7a shown is consistent, the light emitting portion 61a overlapping with the display pixel 71a in the front view is set to the light emitting state, and the light emitting portion 61b not overlapping with the display pixel 71a in the front view is set to the non-light emitting state. Thus, the virtual image display device 1 can make the size of the virtual image 10Q of the light emitting surface 6a and the size of the virtual image 20Q of the display surface 7a substantially equal. Figure 5 1 is a diagram showing an example of a virtual image 10Q and a virtual image 20Q visually recognized by a user 5 of the virtual image display device 1 . Figure 5 and Figure 4 Similarly, the case where the image G is a black and white checkered pattern is shown. Figure 5 The reference numerals in Figure 4 The same reference numerals are used in the drawings. Figure 5 It can be seen that the virtual image display device 1 can reduce the parallax between virtual images over the entire virtual image 20Q, and as a result, can allow the user 5 to visually recognize the virtual image 20Q with less reduction in visibility.

[0080] For example, the control unit 4 may set the light emitting unit 61 corresponding to a portion of the virtual image 10Q that overlaps with the virtual image of the display pixel 71a to a light emitting state, and set the light emitting unit 61 corresponding to a portion of the virtual image 10Q that does not overlap with the virtual image of the display pixel 71a to a non-light emitting state. In this case, the parallax between virtual images can be effectively reduced over the entire virtual image 20Q, and as a result, the user 5 can visually recognize the virtual image 20Q with a further reduced reduction in visibility.

[0081] Next, a virtual image display device according to another embodiment of the present disclosure is described. A virtual image display device 1A of this embodiment differs from the virtual image display device 1 of the above embodiment in that the display unit 2 and the control unit 4 are configured differently, and the other configurations are the same, so detailed descriptions of the same configurations are omitted.

[0082] like Figure 6 , Fig. 7A , Figure 7B As shown, the virtual image display device 1A of this embodiment has a structure in which the size of the light emitting surface 6a is substantially equal to the size of the display surface 7a. The light emitting surface 6a may be the same size as the display surface 7a, or may be larger than the display surface 7a.

[0083] The control unit 4 selects an area (also referred to as a light-emitting area) 6aa within the light-emitting surface 6a. The control unit 4 selects the light-emitting area 6aa so that the size of the virtual image 10Q' of the light-emitting area 6aa formed in the field of view of the user 5 is substantially the same as the size of the virtual image 20Q of the display surface 7a. The control unit 4 selects a portion of the light-emitting units 61c corresponding to the light-emitting area 6aa among the plurality of light-emitting units 61 of the backlight 6, and performs local dimming control to switch the selected light-emitting units 61c to either a light-emitting state or a non-light-emitting state. The light-emitting unit 61c may be a light-emitting unit 61 included in the light-emitting area 6aa. The control unit 4 always sets the light-emitting unit 61d that does not correspond to the light-emitting area 6aa to a non-light-emitting state regardless of the image G displayed on the display surface 7a. The light-emitting unit 61d may be a light-emitting unit 61 that is not included in the light-emitting area 6aa. The virtual image display device 1A can reduce the parallax between virtual images throughout the entire virtual image 20Q, and as a result, the user 5 can visually recognize the virtual image 20Q with reduced visibility. The light emitting area 6aa has a size corresponding to the effective display area of ​​the display surface 7a. In other words, even when the images of the four corners of the display surface 7a are displayed, the light emitting area 6aa can irradiate the images of the four corners with light.

[0084] Figure 8 1 is a diagram showing an example of a virtual image 20Q whose visibility is reduced due to parallax between virtual images. Figure 8 Shown in Fig. 7A , 7BIn the backlight 6 and display panel 7 shown, if the light-emitting portion 61 overlapping with the display pixel 71a when viewed in the main view is set to a light-emitting state, and the light-emitting portion 61 not overlapping with the display pixel 71a when viewed in the main view is set to a non-light-emitting state, an example of a virtual image 20Q visually recognized by the user 5. Figure 8 and Figure 4 Similarly, the case where the image G is a black and white checkered pattern is shown. Figure 8 Reference numerals 20w, 20b and Figure 4 The reference numerals 20w and 20b are the same. Figure 8 FIG. 2 shows a captured image obtained by capturing a virtual image 20Q using an imaging device disposed in the eye box 8. The eye box 8 is a region in the actual space where the eye of the user 5 is assumed to exist. Figure 8 It can be seen that in the peripheral part of the virtual image 20Q (for example Figure 8 (A portion in the figure), the virtual image of the display pixel 71a overlaps with the virtual image of the light-emitting portion 61 which is set to a non-light-emitting state, and the visual recognizability of the virtual image 20Q is reduced. Fig. 9 1A is a diagram showing an example of a virtual image 20Q visually recognized by the user 5 of the virtual image display device 1A. Fig. 9 and Figure 8 Similarly, the case where the image G is a black and white checkered pattern is shown. Fig. 9 Reference numerals 20w, 20b and Figure 4 The reference numerals 20w and 20b are the same. Fig. 9 It can be seen that the virtual image display device 1A can reduce the parallax between virtual images over the entire virtual image 20Q, and as a result, can allow the user 5 to visually recognize the virtual image 20Q with less degradation in visibility. Fig. 9 The deformation of the virtual image 20Q shown can be reduced by changing the design of the optical system 3 or deforming the image G displayed on the display surface 7 a.

[0085] The light-emitting area 6aa can be selected as follows. The magnification α of the light-emitting surface 6a is α1 in the horizontal direction and α2 in the vertical direction, and the magnification β of the display surface 7a is β1 in the horizontal direction and β2 in the vertical direction. In this case, the area where the display surface 7a is reduced by β1 / α1 times in the horizontal direction and by β2 / α2 times in the vertical direction can be selected as the light-emitting area 6aa. The light-emitting area 6aa can be selected so that the center (center of the image) in the main view is roughly consistent with the center of the light-emitting surface 6a.

[0086] The magnifications α1, α2, β1, and β2 can be determined, for example, by simulation based on the shape, refractive index, and arrangement position of the optical components constituting the optical system 3 when the virtual image display device 1A is manufactured or installed. The magnifications α1, α2, β1, and β2 can be determined by the camera images of the virtual image 10Q and the virtual image 20Q captured by the camera device disposed in the eye box (the area in the actual space where the eye of the user 5 is assumed to exist) when the virtual image display device 1A is manufactured or installed. However, the virtual image 10Q is Fig. 7A In the backlight 6 shown in the figure, a virtual image is formed when the light emitting portion 61 overlapping with the display pixel 71a in the front view is set to the light emitting state, and the light emitting portion 61 not overlapping with the display pixel 71a in the front view is set to the non-light emitting state. Figure 8 As shown in FIG. 1 , the magnification ratio β1 / α1 may be a ratio H2 / H1 of the horizontal length H2 of a given portion of the virtual image 20Q to the horizontal length H1 of a given portion of the virtual image 10Q. The given portion of the virtual image 10Q and the given portion of the virtual image 20Q may be portions having the same length on the display surface 7a. The magnification β2 / α2 may be determined based on the captured images of the virtual image 10Q and the virtual image 20Q in the same manner as the magnification β1 / α1.

[0087] Even when the specification of the optical system 3 (e.g., the magnification β of the display surface 7a) is changed, the virtual image display device 1A does not need to change the design of the backlight 6 in order to reduce the parallax between virtual images. According to the virtual image display device 1A, for example, based on the camera image of the virtual images 10Q and 20Q, the light-emitting area 6aa is selected, the light-emitting unit 61c included in the light-emitting area 6aa is selected, and the light-emitting unit 61c is respectively subjected to local dimming control, so that the user 5 can visually recognize the virtual image 20Q with reduced visual recognition. In addition, according to the virtual image display device 1A, the size of the virtual image 20Q can be changed only by changing the specification of the optical system 3. Therefore, the virtual image display device 1A can be applied to a variety of moving objects without changing the design of the display unit 2.

[0088] like Fig.10 As shown, the virtual image display device 1A may have a structure in which the display surface 7a is inclined relative to the light emitting surface 6a. Fig.11 As shown, it is possible to reduce the decrease in visibility and allow the user 5 to visually recognize the virtual image 20Q having a sense of depth. Fig.11 The case where the image G is a black and white checkered pattern is shown. Fig.11 Reference numerals 20w, 20b and Figure 4 In the figure, the reference numerals 20w and 20b are the same. When the display surface 7a is inclined relative to the light-emitting surface 6a, the magnification β of the display surface 7a can be adjusted in the vertical direction ( Fig.11The light-emitting area 6aa can be selected, for example, as follows. Based on the camera images of the virtual image 10Q of the light-emitting surface 6a and the virtual image 20Q of the display surface 7a captured by the camera device disposed in the eye box 8, the magnifications α1, α2, β2 and the magnification β1 that changes in the vertical direction are calculated. Based on the calculated magnifications α1, α2, β1, β2, the display surface 7a is reduced to β1 / α1 times in the horizontal direction and to β2 / α2 times in the vertical direction, so that the light-emitting area 6aa can be selected.

[0089] like Fig.12 As shown, the virtual image display device 1, 1A can be mounted on the mobile body 100. When the virtual image display device 1, 1A is mounted on the mobile body 100, a part of the structure of the virtual image display device 1, 1A can also be used as other devices or components of the mobile body 100. For example, the windshield 12 of the mobile body 100 can also be used as a part of the structure of the virtual image display device 1, 1A. Figure 1 The second reflection portion 3b shown may be replaced by the windshield 12 of the mobile body 100. The virtual image display device 1, 1A may be located arbitrarily inside or outside the mobile body 100. For example, the virtual image display device 1, 1A may be located inside the dashboard of the mobile body 100.

[0090] The virtual image display device 1, 1A may further include a detection device 11 for detecting the position of the eyes of the user 5. The detection device 11 is configured to detect the position of the eyes of the user 5. The detection device 11 is configured to output information related to the detected position of the eyes to the control unit 4. Information related to the detected position of the eyes is also referred to as eye position information. The control unit 4 may be configured to control the light emission and non-light emission of each of the plurality of light emitting units 61 based on the position of the eyes of the user 5 detected by the detection device 11. When the virtual image display device 1, 1A is mounted on the mobile body 100, the position of the detection device 11 is arbitrary inside and outside the mobile body 100. For example, the detection device 11 may be located in the dashboard of the mobile body 100. The detection device 11 may output information related to the position of the eyes of the user 5 to the control unit 4, for example, via wired, wireless, and CAN (Controller Area Network).

[0091] The detection device 11 may be configured to include a camera. The camera may include, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The camera may be configured to be able to capture the face of the user 5. The camera range of the camera includes an eye box. The eye box is, for example, an area in the actual space where the eyes of the user 5 are assumed to exist, taking into account the physique, posture, and changes in posture of the user 5. The user 5 may include, for example, a driver of the mobile body 100. The detection device 11 may be configured to detect the position of the eyes of the user 5 in the actual space based on the camera image generated by the camera.

[0092] The detection device 11 may include, for example, a sensor. The sensor may be an ultrasonic sensor or a light sensor. The detection device 11 may be configured to detect the position of the head of the user 5 through the sensor, and detect the position of the eyes of the user 5 based on the position of the head. The detection device 11 may be configured to detect the position of the eyes of the user 5 as coordinates in a three-dimensional space through two or more sensors.

[0093] The display unit 2 can be configured to include an optical element for enabling the user 5 to visually recognize a stereoscopic image. The optical element can be located between the backlight 6 and the display panel 7 along the optical path of the image light reaching the eyes of the user 5. The optical element can be located between the display panel 7 and the optical system 3 along the optical path of the image light reaching the eyes of the user 5. The display panel 7 can be configured to display a left-eye image and a right-eye image having a parallax with respect to the left-eye image on a display surface 7a. The optical element can be configured to separate the image light emitted from the display surface 7a into a left-eye image light representing the left-eye image and a right-eye image light representing the right-eye image. Thus, the virtual image display device 1, 1A enables the user 5 to visually recognize a stereoscopic image with reduced visual recognition. The optical element can be composed of a parallax barrier or a cylindrical lens. The parallax barrier can be configured to include a liquid crystal panel.

[0094] Hereinafter, a driving method of a virtual image display device according to an embodiment of the present disclosure will be described. The driving method of this embodiment relates to local dimming control of the backlight 6 . Fig.13 is a flowchart illustrating a method for driving a virtual image display device according to an embodiment of the present disclosure. Figures 14 to 28 1A and 1B are diagrams and charts for explaining the driving method of the present embodiment. Figure 6 , Fig.10 ) is described below. In addition, the image displayed on the display surface 7a is basically a black and white checkered pattern, but for easy understanding, Fig.16 , Fig. 20 , Fig.21 In the example, an image different from the black and white checkered pattern is displayed on the display surface 7a.

[0095] (first example)

[0096] First, a first example of the driving method of this embodiment will be described. Fig.13 The flowchart is executed by the control unit 4. Fig.13 When the flowchart ends, the control unit 4 returns to [S1] and repeatedly executes [S1] to [S8].

[0097] In [S1], the control unit 4 may obtain dynamic image data of a dynamic image displayed on the display surface 7a from the outside. The dynamic image may be, for example, a dynamic image of 30 to 120 fps (frames per second). The control unit 4 may generate the following based on the obtained dynamic image data: Fig.14 An image of each frame is shown (also referred to as the first image G1 ).

[0098] In [S2], the control unit 4 generates a second image G2 by deforming the first image G1 based on the magnification of the image on the display surface 7a (also referred to as the first magnification M1) and the magnification of the image on the light-emitting surface 6a (also referred to as the second magnification M2). In this example, the control unit 4 deforms the first image G1 in the horizontal direction ( Fig.14 ) and vertically ( Fig.14 The first image G1 is enlarged in the up and down directions (in the vertical direction) to generate Fig.15 The second image G2 is shown. The predetermined magnification is a value obtained by dividing the second magnification M2 by the first magnification M1, and is a value greater than 1 in the virtual image display device 1A.

[0099] In [S3], if Fig.16 As shown, the control unit 4 divides the first image G1 into a plurality of local dimming areas 72. The number of local dimming areas 72 may be the same as or different from the number of light-emitting units 61. The plurality of local dimming areas 72 may be rectangular areas including a given number of pixels. The plurality of local dimming areas 72 are substantially illuminated by the light-emitting units 61 corresponding to the local dimming areas 72. The plurality of local dimming areas 72 are substantially illuminated by the light-emitting units 61 located directly below the local dimming areas 72.

[0100] In [S4], the control unit 4 generates a grayscale histogram for each local dimming area 72. Fig.17 , Fig.18As shown, the grayscale histogram is a histogram with the vertical axis set to the number of pixels and the horizontal axis set to the grayscale value. The grayscale value is calculated for each of the multiple pixels in each local dimming area 72 according to the hue components R, G, and B of the pixel. The grayscale value can be, for example, a value obtained by overlapping the hue components R, G, and B of each pixel. In other words, when cr, cg, and cb are set to given coefficients, the grayscale value can be represented by c×R+cg×G+cb×B. The coefficients cr, cg, and cb can satisfy cr+cg+cb=1. Fig.17 , Fig.18 Indicates a grayscale histogram when grayscale values ​​are represented by integers ranging from 0 to 255.

[0101] like Fig.17 As shown, the control unit 4 determines that the local dimming area 72 where the number of pixels having grayscale values ​​below the threshold TH is N% or more of the total number of pixels (the total number of pixels in the local dimming area) is the background area 72a. Fig.18 As shown, the control unit 4 determines that the local dimming area in which the number of pixels having a grayscale value below the threshold value TH is less than N% of the total number of pixels is the display area 72b. When the threshold value TH is represented by an integer in the range of 0 to 255, it can be, for example, an integer in the range of 0 to 68. N can be, for example, a number in the range of 50 to 90.

[0102] The threshold TH may be determined based on the background brightness of the user 5's field of view (i.e., the foreground brightness of the moving object 100). In other words, the threshold TH may be determined based on the surrounding environment of the moving object 100. The surrounding environment may be the time of day, the weather around the moving object 100, the road conditions, etc. For example, when the surrounding environment is nighttime and the background brightness of the user 5 is 5 (cd / m 2 ) in order for the user 5 to visually recognize a clear virtual image (white virtual image), the image (white image) displayed on the display surface 7a needs to have a brightness of 350 (cd / m 2 ) display brightness, at this time, the background contrast is 71. When the background brightness is set to a (cd / m 2 ), set the display brightness to b (cd / m 2 ), the background contrast is represented by (a+b) / a, and if the background contrast becomes 1.0, it is difficult for the user 5 to visually recognize the virtual image (white). Therefore, the grayscale value TH is the value converted from the display brightness b when the background contrast becomes 1.0 in consideration of the γ correction (γ=2.2). MAX When the threshold TH is set to 0~TH MAX As shown in Table 1, when the surrounding environment is nighttime and the background brightness of the user 5 is 5 (cd / m 2), the threshold TH can be set to a value in the range of 0 to 9. In addition, when the surrounding environment is dusk and the background brightness of the user 5 is 50 (cd / m 2 ), the threshold TH can be set to a value in the range of 0 to 17. When the surrounding environment is a snow wall or direct light, and the background brightness of user 5 is 11,000 (cd / m 2 ), the threshold TH can be set to a value in the range of 0 to 68.

[0103] [Table 1]

[0104]

[0105] like Fig.19 As shown, the control unit 4 sets the light emitting unit 61 included in at least a part of the display area to the light emitting unit 61 in the light emitting state when the first image G1 is viewed from the front (i.e., when the first image G1 and the light emitting surface 6a are overlapped in the emission direction of the light from the backlight 6). ON , the light-emitting portion 61 completely included in the background area is set to the light-emitting portion 61 in a non-light-emitting state OFF .

[0106] In [S5], the control unit 4 obtains the background brightness of the field of view of the user 5, and sets the light emitting unit 61 based on the obtained background brightness. ON The higher the background brightness, the higher the control unit 4 will light up the light emitting unit 61. ON The luminous brightness (i.e., the luminous brightness supplied to the luminous portion 61 ON Thus, the user 5 can visually recognize a clear virtual image 20Q.

[0107] The virtual image display device 1A may include a luminance meter that measures the background brightness of the field of view of the user 5 and outputs the background brightness to the control unit 4. When the moving body 100 includes a luminance meter that measures its foreground brightness, the control unit 4 may obtain the foreground brightness from the luminance meter of the moving body 100 and use the obtained foreground brightness as the background brightness of the field of view of the user 5.

[0108] In addition to the background brightness, the control unit 4 may also set the light emitting unit 61 based on the surrounding environment of the mobile object 100. ON For example, as shown in Table 2, when the surrounding environment is an asphalt road at night and the background brightness is 5 (cd / m 2 ) in order to allow the user to visually recognize a clear virtual image (white virtual image), the light emission brightness of the backlight 6 can be set to 54,000 (cd / m 2 ), the brightness of the image (white image) displayed on the display surface 7a is set to 350 (cd / m 2 ). Therefore, the control unit 4 may be provided with a light emitting unit 61ON The luminous brightness of the backlight 6 is 54,000 (cd / m 2 In addition, as shown in Table 2, when the surrounding environment is a snowy trail at night and the background brightness of user 5 is 50 (cd / m 2 ) in the case of ON The luminous brightness of the backlight 6 is 140,000 (cd / m 2 ), and set the brightness of the image (white image) displayed on the display surface 7a to 900 (cd / m 2 ). Other background brightness and surrounding environment are also shown in Table 2. The control unit 4 may have a database, which stores the light emitting brightness to be set for the backlight 6 according to the background brightness and the surrounding environment. The control unit 4 may read the light emitting brightness to be set for the backlight 6 from the database according to the background brightness and the surrounding environment, and set the light emitting unit 61 based on the read light emitting brightness. ON The luminous brightness.

[0109] [Table 2]

[0110]

[0111] In [S6], the control unit 4 determines whether each light emitting unit 61 OFF (Reference Fig. 20 ) whether it is with the light emitting unit 61 ON Adjacent light emitting section 61 OFF .like Fig.21 As shown, the control unit 4 may determine that the light source 61 is not ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF The light emitting unit 61 is kept in a non-light emitting state. OFF , and will be judged as being in accordance with the light emitting unit 61 ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF The light emitting unit 61 is set to a light emitting state OFF (Also referred to as peripheral light emitting unit 61 PERI ). In [S8] described later, the control unit 4 causes the peripheral light emitting unit 61 PERI The peripheral light emitting unit 61 is detected PERI The peripheral light emitting unit 61 PERIThe peripheral light emitting unit 61 can reduce the possibility of blurring (not being clear) the outline of the text, graphics, etc. displayed in the display area 72b. In addition, when the position of the eye of the user 5 moves in the eye box 8, the brightness reduction of the virtual image 20Q visually recognized by the user 5 can be reduced, so that the user 5 can visually recognize a clear virtual image 20Q. PERI The luminous brightness of the light emitting portion 61 can be ON The same luminous brightness as the luminous brightness of the luminous portion 61 may also be ON The luminous brightness is about 20% to 80%, about 30% to 70% or about 40% to 60%.

[0112] In [ S7 ], the control unit 4 generates image data by adding a backlight control code indicating the content of control on each light emitting unit 61 to the image data of the second image G2 .

[0113] In [S8], the control unit 4 controls the display panel 7 to display the second image G2 on the display surface 7a based on the image data with the backlight control code, and the backlight 6 to light the light emitting unit 61 based on the image data with the backlight control code. ON and the peripheral light emitting unit 61 PERI Therefore, Fig. 22 As shown, the user 5 can visually recognize the virtual image 20Q with improved contrast.

[0114] In the above description, an example of performing the processing [S3] to [S6] based on the first image G1 and the arrangement of the light-emitting portions 61 in the light-emitting surface 6a is described, but the processing [S3] to [S6] can also be performed based on the second image G2 and the arrangement of the light-emitting portions 61 in the light-emitting surface 6a enlarged by the second magnification M2.

[0115] (Second example)

[0116] Next, a second example of the driving method of this embodiment will be described. Hereinafter, detailed descriptions of the same processes as those in the first example will be omitted.

[0117] In [S1], the control unit 4 can obtain dynamic image data of a dynamic image displayed on the display surface 7a from the outside. The control unit 4 can generate the following based on the obtained dynamic image data: Fig.14 The first image G1 of each frame is shown.

[0118] In [S2], the control unit 4 generates a second image G2 by deforming the first image G1 based on the first magnification ratio M1 and the second magnification ratio M2. In this example, the control unit 4 reduces the first image G1 in the horizontal direction and the vertical direction at a given reduction ratio to generate the second image G2. Fig.23 The second image G2 is shown. The predetermined reduction ratio is a value obtained by dividing the first magnification ratio M1 by the second magnification ratio M2, and is a value smaller than 1 in the virtual image display device 1A.

[0119] In [S3], if Fig.16 As shown, the control unit 4 divides the second image G2 into a plurality of local dimming areas 72 .

[0120] In [S4], the control unit 4 creates a grayscale histogram for each local dimming area 72, and determines the local dimming area 72 whose number of pixels with a grayscale value below the threshold value TH is more than N% of the total number of pixels as a background area 72a, and determines the local dimming area 72 whose number of pixels with a grayscale value below the threshold value TH is less than N% of the total number of pixels as a display area 72b.

[0121] like Fig.24 As shown, the control unit 4 determines that at least a part of the light emitting unit 61 included in the display area 72b is the light emitting unit 61 set to the light emitting state when the display area 72b is in the front view. ON , the light-emitting portion 61 completely included in the background area is determined as the light-emitting portion 61 set to the non-light-emitting state OFF .

[0122] In [S5], the control unit 4 obtains the background brightness in the field of view of the user 5, and sets the light emitting unit 61 based on the obtained background brightness. ON The luminous brightness.

[0123] In [S6], the control unit 4 controls each light emitting unit 61 OFF , determine whether it is with the light emitting unit 61 ON Adjacent light emitting section 61 OFF The control unit 4 may determine that the light source 61 is not ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF The light emitting unit 61 is kept in a non-light emitting state. OFF and can be judged as being related to the light emitting unit 61 ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF Set as peripheral light emitting unit 61 PERI .

[0124] In [ S7 ], the control unit 4 generates image data by adding a backlight control code indicating the content of control on each light emitting unit 61 to the image data of the first image G1 .

[0125] In [S8], the control unit 4 controls the display panel 7 to display the first image G1 on the display surface 7a based on the image data with the backlight control code, and the backlight 6 to control the light emitting unit 61 based on the image data with the backlight control code. ON and the peripheral light emitting unit 61 PERI Therefore, Fig.25 As shown, the user 5 can visually recognize the virtual image 20Q with improved contrast.

[0126] (Third example)

[0127] Next, a third example of the driving method of this embodiment is described. Hereinafter, detailed descriptions of the same processes as those of the first and second examples are omitted. According to the driving method of this example, even when the display surface 7a is tilted relative to the light-emitting surface 6a (see Fig.10 ), and the user 5 can also visually recognize the virtual image 20Q with improved contrast and a sense of depth. The tilt angle θ of the display surface 7a of the virtual image display device 1A relative to the light emitting surface 6a can be, for example, 10° to 45°. The tilt angle θ is the angle between the normal line of the display surface 7a and the normal line of the light emitting surface 6a.

[0128] In [S1], the control unit 4 can obtain dynamic image data of a dynamic image displayed on the display surface 7a from the outside. The control unit 4 can generate the following based on the obtained dynamic image data: Fig.14 The first image G1 of each frame is shown.

[0129] In [S2], the control unit 4 generates a second image G2 (see FIG. 1 ) obtained by deforming the first image G1 based on the first magnification M1 and the second magnification M2. Fig.26 ). In this example, the control unit 4 reduces the first image G1 in the vertical direction based on the first magnification M1 and the second magnification M2. The control unit 4 may also reduce the first image G in the vertical direction by (cosθ) times based on the inclination angle θ of the display surface 7a relative to the light-emitting surface 6a. Furthermore, the control unit 4 deforms the first image G1 in the horizontal direction at a given ratio based on the first magnification M1 and the second magnification M2. The given ratio can be changed in the vertical direction of the first image G1. The given ratio is a value obtained by dividing the magnification of the display surface 7a in the horizontal direction by the magnification of the light-emitting surface 6a in the horizontal direction for each region g1, g2, g3 when the first image G1 is virtually divided into a plurality of regions g1, g2, g3 whose positions are different from each other in the vertical direction. In addition, the number of the plurality of regions g1, g2, g3 (the number of divisions of the first image G1) is arbitrary, and for example, it may be the same as the number of pixel rows of the first image G1.

[0130] In [S3], if Fig.16 As shown, the control unit 4 divides the second image G2 into a plurality of local dimming areas 72 .

[0131] In [S4], the control unit 4 creates a grayscale histogram for each local dimming area 72, and determines the local dimming area 72 whose number of pixels with a grayscale value below the threshold value TH is more than N% of the total number of pixels as a background area 72a, and determines the local dimming area 72 whose number of pixels with a grayscale value below the threshold value TH is less than N% of the total number of pixels as a display area 72b.

[0132] like Fig. 27 As shown, the control unit 4 sets at least a portion of the light emitting unit 61 included in the display area 72b to the light emitting state when the display area 72b is viewed from the front. ON , the light emitting portion 61 completely included in the background area 72a is set to the light emitting portion 61 in a non-light emitting state OFF .

[0133] In [S5], the control unit 4 obtains the background brightness in the field of view of the user 5, and sets the light emitting unit 61 based on the obtained background brightness. ON The luminous brightness.

[0134] In [S6], the control unit 4 controls each light emitting unit 61 OFF , determine whether it is with the light emitting unit 61 ON Adjacent light emitting section 61 OFF The control unit 4 may determine that the light source 61 is not ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF The light emitting unit 61 is kept in a non-light emitting state. OFF and can be judged as being related to the light emitting unit 61 ON Adjacent light emitting section 61 OFF The light emitting portion 61 OFF Set as peripheral light emitting unit 61 PERI .

[0135] In [ S7 ], the control unit 4 generates image data by adding a backlight control code indicating the content of control on each light emitting unit 61 to the image data of the first image G1 .

[0136] In [S8], the control unit 4 controls the display panel 7 to display the first image G1 on the display surface 7a based on the image data with the backlight control code, and the backlight 6 to control the light emitting unit 61 based on the image data with the backlight control code. ON and the peripheral light emitting unit 61 PERI Therefore, Fig.28As shown, the user 5 can visually recognize the virtual image 20Q with improved contrast and a sense of depth.

[0137] The control unit 4 of the virtual image display device 1A may be configured to execute each process in the driving method of the virtual image display device disclosed in the present invention. In addition, a program for causing a computer to execute each process in the driving method of the virtual image display device disclosed in the present invention may also be provided. The program may be stored in a non-temporary computer-readable medium. The computer-readable medium may be, for example, a magnetic storage medium, an optical storage medium, a magneto-optical storage medium, a semiconductor storage medium, etc.

[0138] The "mobile body" in the present disclosure includes vehicles, ships, and aircraft. The "vehicle" in the present disclosure includes automobiles and industrial vehicles, but is not limited to this, and may also include railway vehicles and life vehicles, and fixed-wing aircraft running on runways. Automobiles include passenger cars, trucks, buses, two-wheeled vehicles, and trolley buses, but are not limited to this, and may also include other vehicles running on the road. Industrial vehicles include industrial vehicles for agriculture and construction. Industrial vehicles include but are not limited to forklifts and golf carts. Industrial vehicles for agriculture include tractors, tillers, transplanters, balers, combine harvesters, and mowers, but are not limited to this. Industrial vehicles for construction include bulldozers, graders, forklifts, cranes, dump trucks, and load rollers, but are not limited to this. Vehicles include vehicles driven by manpower. In addition, the classification of vehicles is not limited to the above. For example, automobiles can include industrial vehicles that can travel on roads, and multiple classifications can include the same vehicle. The ships in the present disclosure include ship jets, ships, and tankers. The aircraft in the present disclosure includes fixed-wing aircraft and rotary-wing aircraft.

[0139] According to the present disclosure, the parallax between the display virtual image and the light source virtual image can be reduced over the entire display virtual image, and the reduction in visibility of the display virtual image can be reduced.

[0140] The structure involved in the present disclosure is not limited to the above-described embodiments, and various modifications or changes can be made. For example, the functions included in each structural part can be rearranged so as not to be logically contradictory, and multiple structural parts can be combined into one or divided.

[0141] In the present disclosure, the records such as "first" and "second" are identifiers for distinguishing the structure. The structures distinguished by the records such as "first" and "second" in the present disclosure can replace the numbers in the structures. For example, the first reflecting part can exchange the "first" and "second" as identifiers with the second reflecting part. The exchange of identifiers is carried out simultaneously. The structures are also distinguished after the exchange of identifiers. The identifiers can be deleted. The structures from which the identifiers are deleted are distinguished by figure marks. The records based solely on the identifiers such as "first" and "second" in the present disclosure cannot be used to interpret the order of the structures or the basis for the existence of identifiers with smaller numbers.

[0142] In the present disclosure, the X-axis, Y-axis, and Z-axis are provided for convenience of description and can be replaced with each other. The structures involved in the present disclosure are described using an orthogonal coordinate system consisting of the X-axis, Y-axis, and Z-axis. The positional relationship of the structures involved in the present disclosure is not limited to an orthogonal relationship.

[0143] The virtual image display device, the moving object, the driving method of the virtual image display device, and the program of the present disclosure can be implemented by the following configurations (1) to (19).

[0144] (1) A virtual image display device comprising:

[0145] A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions;

[0146] A display panel having a display surface for displaying an image by light emitted from the light emitting surface;

[0147] an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form virtual images in the user's field of vision; and

[0148] The backlight control unit switches the plurality of light emitting units to either a light emitting state or a non-light emitting state according to an image displayed on the display panel to perform local dimming control.

[0149] The light emitting surface is configured to have a smaller size than the display surface.

[0150] (2) A virtual image display device comprising:

[0151] A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions;

[0152] A display panel having a display surface for displaying an image by light emitted from the light emitting surface;

[0153] an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form virtual images in the user's field of vision; and

[0154] Backlight control unit,

[0155] The backlight control unit selects an area within the light emitting surface, that is, an area where an image of the area is formed as a virtual image of the same size as an image on the display surface in the field of vision of the user,

[0156] The backlight control unit performs local dimming control by switching a portion of the light emitting units corresponding to the selected area among the plurality of light emitting units to either a light emitting state or a non-light emitting state according to an image displayed on the display surface.

[0157] (3) The virtual image display device according to the above configuration (1) or (2),

[0158] The optical system has a plurality of reflecting parts.

[0159] A first reflecting portion among the plurality of reflecting portions reflects the image of the display surface and the image of the light emitting surface toward a second reflecting portion as another reflecting portion,

[0160] The second reflecting unit reflects the image on the display surface and the image on the light emitting surface toward the field of vision of the user.

[0161] (4) The virtual image display device according to any one of the above configurations (1) to (3),

[0162] The display surface is arranged to be inclined with respect to the light emitting surface.

[0163] (5) A mobile object comprising:

[0164] The virtual image display device according to the above structure (3); and

[0165] The windshield reflects the image light reflected by the first reflecting portion toward the eyes of the user.

[0166] (6) A virtual image display device comprising:

[0167] A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions;

[0168] A display panel having a display surface for displaying an image by light emitted from the light emitting surface;

[0169] an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form virtual images in the user's field of vision; and

[0170] The backlight control unit deforms the first image displayed on the display panel according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image, and switches the multiple light-emitting units to either a light-emitting state or a non-light-emitting state based on the second image to perform local dimming control.

[0171] (7) A virtual image display device comprising:

[0172] A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions;

[0173] A display panel having a display surface for displaying an image by light emitted from the light emitting surface;

[0174] an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so as to form virtual images in the user's field of vision; and

[0175] The backlight control unit deforms the first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image displayed on the display panel, and switches the multiple light-emitting units to either a light-emitting state or a non-light-emitting state based on the first image to perform local dimming control.

[0176] (8) A method for driving a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; a display panel having a display surface for displaying an image using light emitted from the light emitting surface; and an optical system for magnifying an image on the display surface and an image on the light emitting surface at different magnifications so that the images are formed as virtual images in a user's field of vision,

[0177] The driving method of the virtual image display device comprises:

[0178] deforming a first image displayed on the display panel according to magnifications of the image of the display surface and the image of the light-emitting surface by the optical system to generate a second image; and

[0179] Based on the second image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

[0180] (9) A method for driving a virtual image display device according to the above configuration (8),

[0181] The local dimming control includes:

[0182] dividing the second image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and

[0183] Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

[0184] (10) A method for driving a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; a display panel having a display surface for displaying an image using light emitted from the light emitting surface; and an optical system for magnifying an image on the display surface and an image on the light emitting surface at different magnifications so that the images are formed as virtual images in a user's field of vision,

[0185] The driving method of the virtual image display device comprises:

[0186] deforming the first image according to the magnification of the image of the display surface and the image of the light emitting surface by the optical system to generate a second image displayed on the display panel; and

[0187] Based on the first image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

[0188] (11) A method for driving a virtual image display device according to the above configuration (10),

[0189] The local dimming control includes:

[0190] dividing the first image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and

[0191] Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

[0192] (12) A method for driving a virtual image display device according to any one of the above configurations (8) to (11),

[0193] The local dimming control includes setting the light emission brightness of the light emitting portion set to a light emitting state based on the background brightness of the user's field of view.

[0194] (13) A method for driving a virtual image display device according to any one of the above configurations (8) to (12),

[0195] The local dimming control includes switching, among the light emitting portions set in the non-light emitting state, a light emitting portion adjacent to the light emitting portion set in the light emitting state to a light emitting state.

[0196] (14) A program executed by a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting portions and a light emitting surface capable of emitting light from the plurality of light emitting portions; a display panel having a display surface for displaying an image using light emitted from the light emitting surface; and an optical system for magnifying an image on the display surface and an image on the light emitting surface at different magnifications so that the images are formed as virtual images in a user's field of vision,

[0197] The procedure is used to:

[0198] The first image displayed on the display panel is deformed according to the magnification of the image of the display surface and the image of the light emitting surface by the optical system to generate a second image.

[0199] Based on the second image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

[0200] (15) The program according to the above structure (14),

[0201] The local dimming control includes:

[0202] dividing the second image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and

[0203] Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

[0204] (16) A program executed by a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; a display panel having a display surface for displaying an image using light emitted from the light emitting surface; and an optical system for magnifying an image on the display surface and an image on the light emitting surface at different magnifications so that the images are formed as virtual images in a user's field of vision,

[0205] The procedure is used to:

[0206] deforming the first image according to the magnification of the image of the display surface and the image of the light emitting surface by the optical system to generate a second image displayed on the display panel,

[0207] Based on the first image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

[0208] (17) The program according to the above structure (16),

[0209] The local dimming control includes:

[0210] dividing the first image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and

[0211] Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

[0212] (18) A program according to any one of the above configurations (14) to (17),

[0213] The local dimming control includes:

[0214] The light emission brightness of the light emitting portion set to the light emitting state is agreed upon based on the background brightness of the user's field of view.

[0215] (19) A program according to any one of the above configurations (14) to (18),

[0216] The local dimming control includes:

[0217] Among the light emitting portions set to the non-light emitting state, the light emitting portions adjacent to the light emitting portion set to the light emitting state are switched to the light emitting state.

[0218] -Explanation of symbols-

[0219] 1.1A Virtual image display device

[0220] 2 Display

[0221] 3 Optical system

[0222] 3a First optical member (first reflecting portion)

[0223] 3b Second optical member (second reflecting portion)

[0224] 4 Backlight control unit (control unit)

[0225] 5 Users

[0226] 6 Backlight

[0227] 6a Luminous surface

[0228] 6aa area (luminous area)

[0229] 61, 61a, 61b, 61c, 61d, 61 ON、 61 OFF、 61 PERI Light-emitting part

[0230] 62 Matrix

[0231] 62a Main side

[0232] 63 Diffuser Plate

[0233] 7 Display Panel

[0234] 7a Display surface

[0235] 71 pixels

[0236] 71a Pixel (display pixel)

[0237] 71b pixels (non-display pixels)

[0238] 72 local dimming zones

[0239] 72a Background area

[0240] 72b Display area

[0241] 8 Eye Box

[0242] 10Q, 10Q', 20Q virtual image

[0243] 10g Gray part

[0244] 10w white part

[0245] 20b Black part

[0246] 20w white part

[0247] 11. Detection device

[0248] 12 Windshield

[0249] 100 moving objects.

Claims

1. A virtual image display device, comprising: A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; An optical system that magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision; as well as The backlight control unit switches the plurality of light emitting units to either a light emitting state or a non-light emitting state according to the image displayed on the display panel to perform local dimming control. The light emitting surface is configured to have a smaller size than the display surface.

2. A virtual image display device, comprising: A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; An optical system that magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision; as well as Backlight control unit, The backlight control unit selects an area within the light emitting surface, that is, an area where an image of the area is formed as a virtual image of the same size as an image on the display surface in the field of vision of the user, The backlight control unit performs local dimming control by switching a portion of the light emitting units corresponding to the selected area among the plurality of light emitting units to either a light emitting state or a non-light emitting state according to an image displayed on the display surface.

3. The virtual image display device according to claim 1 or 2, wherein: The optical system has a plurality of reflecting parts. A first reflecting portion among the plurality of reflecting portions reflects the image of the display surface and the image of the light emitting surface toward a second reflecting portion as another reflecting portion, The second reflecting unit reflects the image on the display surface and the image on the light emitting surface toward the field of vision of the user.

4. The virtual image display device according to claim 2 or 3, wherein: The display surface is arranged to be inclined with respect to the light emitting surface.

5. A mobile object, comprising: The virtual image display device according to claim 3; and The windshield reflects the image light reflected by the first reflecting portion toward the eyes of the user.

6. A virtual image display device, comprising: A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; An optical system that magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision; as well as The backlight control unit deforms the first image displayed on the display panel according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image, and switches the multiple light-emitting units to either a light-emitting state or a non-light-emitting state based on the second image to perform local dimming control.

7. A virtual image display device, comprising: A backlight having a plurality of light-emitting portions and a light-emitting surface capable of emitting light from the plurality of light-emitting portions; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; An optical system that magnifies the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision; as well as The backlight control unit deforms the first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image displayed on the display panel, and switches the multiple light-emitting units to either a light-emitting state or a non-light-emitting state based on the first image to perform local dimming control.

8. A method for driving a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision, The driving method of the virtual image display device comprises: deforming a first image displayed on the display panel according to magnifications of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image; as well as Based on the second image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

9. The driving method of the virtual image display device according to claim 8, wherein: The local dimming control comprises: dividing the second image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

10. A method for driving a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision, The driving method of the virtual image display device comprises: deforming the first image according to the magnification of the image of the display surface and the image of the light-emitting surface based on the optical system to generate a second image displayed on the display panel; as well as Based on the first image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

11. The driving method of the virtual image display device according to claim 10, wherein: The local dimming control comprises: dividing the first image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

12. The driving method of a virtual image display device according to any one of claims 8 to 11, wherein: The performing of the local dimming control includes setting the light emission brightness of the light emitting portion set to the light emission state based on the background brightness of the user's field of view.

13. The driving method of a virtual image display device according to any one of claims 8 to 12, wherein: The performing of the local dimming control includes: switching a light emitting portion adjacent to the light emitting portion set to the light emitting state among the light emitting portions set to the non-light emitting state to the light emitting state.

14. A program executed by a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision, The procedure is used to: The first image displayed on the display panel is deformed according to the magnification of the image of the display surface and the image of the light emitting surface by the optical system to generate a second image. Based on the second image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

15. The program according to claim 14, wherein: The local dimming control comprises: dividing the second image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

16. A program executed by a virtual image display device, the virtual image display device comprising: a backlight having a plurality of light emitting units and a light emitting surface capable of emitting light from the plurality of light emitting units; A display panel having a display surface for displaying an image by light emitted from the light emitting surface; and an optical system for magnifying the image of the display surface and the image of the light-emitting surface at different magnifications so that they are formed as virtual images in the user's field of vision, The procedure is used to: deforming the first image according to the magnification of the image of the display surface and the image of the light emitting surface by the optical system to generate a second image displayed on the display panel, Based on the first image, the plurality of light emitting units are switched to either a light emitting state or a non-light emitting state to perform local dimming control.

17. The program according to claim 16, wherein: The local dimming control comprises: dividing the first image into a plurality of local dimming areas, and generating a grayscale histogram of each of the local dimming areas; and Based on the grayscale histogram, the plurality of light-emitting portions are respectively set to either a light-emitting state or a non-light-emitting state.

18. The program according to any one of claims 14 to 17, wherein: The local dimming control comprises: The light emission brightness of the light emitting portion set to the light emitting state is set based on the background brightness of the user's field of view.

19. The program according to any one of claims 14 to 18, wherein: The local dimming control comprises: Among the light emitting portions set to the non-light emitting state, the light emitting portions adjacent to the light emitting portion set to the light emitting state are switched to the light emitting state.

Images