Head-up display

Abstract

To provide a head-up display that can increase the degree of freedom in image arrangement in which the distance from an observer's viewpoint to a virtual image is different.SOLUTION: An HUD 100 makes an observer view an image, as a virtual image, reflected on a light-transmitting member FG, which transmits or reflects incident light, while overlapping the image with an actual image having transmitted the light-transmitting member FG. The HUD includes a display device 1 to display images, and an enlarging optical system 2 that enlarges the image displayed in the display device 1 and projects the image to the light-transmitting member FG. The display device 1 includes a backlight 30, a first image display panel 10 to which direct light from the backlight 30 is incident, and a second image display panel 20 which is disposed with a gap from the first image display panel 10 and to which transmission light of the first image display panel 10 is incident. The first image display panel 10 includes a first polarization plate 12 provided between the first image display panel and the backlight 30. The second image display panel 20 includes a second polarization plate 22 provided between the second image display panel and the enlarging optical system 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a head-up display. [Background technology]

[0002] 2. Description of the Related Art There is known a head up display (HUD) that projects an image onto a light-transmitting member such as glass and allows an observer to visually recognize the image reflected by the light-transmitting member as a virtual image (see, for example, Patent Document 1).

[0003] In a HUD, the spatial position of a virtual image visually recognized by an observer is determined by the relative positions of the display panel, the reflecting member, and the observer's viewpoint. Specifically, the greater the distance between the display panel and the reflecting member, the greater the distance from the observer's viewpoint to the virtual image, and the closer the distance between the display panel and the reflecting member, the closer the distance from the observer's viewpoint to the virtual image. In Patent Document 1, a plurality of display panels are arranged above and below at a distance from each other, and different contents are displayed on each display panel, thereby making the distance from the observer's viewpoint to the virtual image of each content different. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-168230 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above conventional technology, the display areas of the display panels are arranged so as not to overlap in the viewer's line of sight, which may prevent the viewer from freely arranging images, which are different in distance from the viewer's viewpoint to the virtual image, from the viewer's viewpoint.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a head-up display that can increase the degree of freedom in image arrangement in which the distance from the observer's viewpoint to the virtual image varies. [Means for solving the problem]

[0007] A head-up display according to one aspect of the present disclosure is a head-up display that allows an observer to visually recognize an image reflected by a translucent member that transmits and reflects incident light as a virtual image by superimposing the image on a real image that has passed through the translucent member, the head-up display comprising: a display device that displays an image; and a magnifying optical system that magnifies the image displayed on the display device and projects it onto the translucent member, the display device being disposed with a backlight, a first image display panel into which direct light from the backlight is incident, and a gap provided between the first image display panel and the first image display panel, and the transmitted light from the first image display panel is incident on the first image display panel. and a second image display panel, the first image display panel including a first polarizing plate provided between the first image display panel and the backlight, the second image display panel including a second polarizing plate provided between the second image display panel and the magnifying optical system, the first polarizing plate transmitting light polarized in a first direction and blocking light polarized in a direction different from the first direction, the second polarizing plate transmitting light polarized in a second direction different from the first direction and blocking light polarized in a direction different from the second direction, and no polarizing plate is provided between the first image display panel and the second image display panel. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a head-up display according to a first embodiment. [Figure 2A] FIG. 2A is a schematic diagram showing the basic configuration of a HUD. [Figure 2B] FIG. 2B is a schematic diagram illustrating an equivalent configuration of the HUD shown in FIG. 2A. [Diagram 3] FIG. 3 is a diagram showing the relationship between the panel-lens distance a and the virtual distance VID between the viewpoint and the virtual image. [Figure 4]FIG. 4 is a schematic diagram showing an equivalent configuration of the HUD according to the first embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing a detailed configuration of the display device according to the first embodiment. [Figure 6A] FIG. 6A is a diagram showing a first example of a display mode of the HUD according to the first embodiment. [Figure 6B] FIG. 6B is a diagram showing a first object viewed on a virtual image of the first image in the display mode shown in FIG. 6A. [Figure 6C] FIG. 6C is a diagram showing a second object viewed on a virtual image of the second image in the display mode shown in FIG. 6A. [Figure 6D] 6D is a cross-sectional view of the display device according to embodiment 1 taken along line AA shown in FIG. 6A. [Figure 7A] FIG. 7A is a diagram showing a second example of a display mode of the HUD according to the first embodiment. [Figure 7B] FIG. 7B is a diagram showing a first object viewed on a virtual image of the first image in the display mode shown in FIG. 7A. [Figure 7C] FIG. 7C is a diagram showing a second object viewed on a virtual image of the second image in the display mode shown in FIG. 7A. [Figure 7D] 7D is a cross-sectional view of the display device according to embodiment 1 taken along line AA shown in FIG. 7A. [Figure 8] FIG. 8 is a schematic diagram showing a schematic configuration of a HUD according to the second embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a detailed configuration of the display device according to the second embodiment. [Figure 10A] FIG. 10A is a diagram showing an example of a display aspect of a HUD according to the second embodiment. [Figure 10B] FIG. 10B is a diagram showing a first object viewed on a virtual image of the first image in the display mode shown in FIG. 10A. [Figure 10C] FIG. 10C is a diagram showing a second object viewed on a virtual image of the second image in the display mode shown in FIG. 10A. [Figure 10D]FIG. 10D is a cross-sectional view of the display device according to the second embodiment taken along the line AA shown in FIG. 8A. [Figure 11] FIG. 11 is a schematic diagram showing the path of sunlight incident on the HUD according to the second embodiment. [Figure 12] FIG. 12 is a schematic diagram showing the path of sunlight incident on the HUD according to the third embodiment. [Figure 13] FIG. 13 is a schematic diagram showing a schematic configuration of a HUD according to the third embodiment. [Figure 14] FIG. 14 is a schematic diagram showing an incident path of sunlight in a HUD according to a modified example of the third embodiment. [Figure 15] FIG. 15 is a schematic diagram showing a schematic configuration of a HUD according to a modified example of the third embodiment. [Figure 16A] FIG. 16A is a schematic diagram showing a first example of a detailed configuration of the display device according to the fourth embodiment. [Figure 16B] FIG. 16B is a schematic diagram showing a second example of a detailed configuration of the display device according to the fourth embodiment. [Figure 16C] FIG. 16C is a schematic diagram showing a third example of a detailed configuration of the display device according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The form (embodiment) for carrying out the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited by the contents described in the following embodiment. In addition, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the components described below can be appropriately combined. In addition, the disclosure is merely an example, and those that a person skilled in the art can easily imagine appropriate modifications while maintaining the gist of the disclosure are naturally included in the scope of the present disclosure. In addition, in order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment, but they are merely examples and do not limit the interpretation of the present disclosure. In addition, in this specification and each figure, elements similar to those described above with respect to the previously mentioned figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0010] (Embodiment 1) 1 is a schematic diagram showing a schematic configuration of a head-up display according to embodiment 1. A head-up display (HUD, hereinafter also simply referred to as "HUD") 100 includes a display device 1 that displays an image, and a magnifying optical system 2 that magnifies the image displayed on the display device 1 and projects it onto a light-transmitting member FG.

[0011] The light-transmitting member FG is a member having light-transmitting properties, such as glass or resin. Examples of the light-transmitting member FG include a windshield or a combiner of a vehicle. The light-transmitting member FG may be any member that transmits and reflects incident light, and is not limited to a windshield or a combiner of a vehicle.

[0012] A lens is an example of the magnifying optical system 2. However, the present invention is not limited to this, and one magnifying optical system 2 may be configured with a plurality of optical members such as a plane mirror or a concave mirror.

[0013] The display device 1 according to the first embodiment includes, as main components, a first image display panel 10 for displaying a first image, a second image display panel 20 for displaying a second image, and a backlight 30.

[0014] The backlight 30 irradiates planar light (light L) toward the first image display panel 10. As shown by the solid arrow in FIG. 1, the light L emitted from the backlight 30 passes through the first image display panel 10, the second image display panel 20, and the magnifying optical system 2 in that order, and is reflected by the light-transmitting member FG to reach the viewpoint of the observer OB. The image output region of the first image display panel 10 and the image output region of the second image display panel 20 overlap in the optical axis direction of the magnifying optical system. As a result, the virtual image VIR of the first image reflected by the light-transmitting member FG and the virtual image VIF of the second image are visually recognized by the observer OB in a state where they overlap in the line of sight direction shown by the dashed arrow in FIG. 1.

[0015] In the following description, the virtual distance from the viewpoint of the observer OB to the virtual image VIR of the first image and the virtual image VIF of the second image reflected by the light-transmitting member FG is also simply referred to as the “virtual distance.” Also, the virtual positions of the virtual image VIR of the first image and the virtual image VIF of the second image reflected by the light-transmitting member FG are also simply referred to as the “virtual position.”

[0016] In this disclosure, the "optical axis of the magnifying optical system" does not refer to the individual optical axes of each optical element when the magnifying optical system 2 is composed of multiple optical elements, but rather to the optical axis that passes through a single magnifying optical system 2 composed of multiple optical elements and enters the second image display panel 20.

[0017] In the schematic configuration of the HUD 100 according to the first embodiment shown in Fig. 1, the first image display panel 10 and the second image display panel 20 are disposed approximately parallel to a plane (XY plane) perpendicular to the optical axis of the magnifying optical system 2. As a result, a virtual image VIR of the first image and a virtual image VIF of the second image viewed by the observer OB are viewed by the observer OB on a virtual plane (VX-VY plane) approximately parallel to the line of sight of the observer OB indicated by the dashed arrow in Fig. 1.

[0018] In the schematic configuration of the HUD 100 according to the first embodiment shown in FIG. 1, the first image display panel 10 is disposed farther from the magnifying optical system 2 than the second image display panel 20 in the Z direction perpendicular to the optical axis of the magnifying optical system 2, in other words, the XY plane perpendicular to the optical axis of the magnifying optical system 2. As a result, the virtual image VIR of the first image displayed on the first image display panel 10 is viewed by the observer OB at a virtual position farther from the virtual image VIF of the second image displayed on the second image display panel 20 in the VZ direction perpendicular to the VX-VY plane. In other words, the virtual distance from the viewpoint of the observer OB to the virtual image VIR of the first image is farther than the virtual distance from the viewpoint of the observer OB to the virtual image VIF of the second image. In addition, the virtual image VIR of the first image displayed on the first image display panel 10 is viewed by the observer OB while overlapping with the virtual image VIF of the second image displayed on the second image display panel 20. In such a virtual image optical system, if the first image displayed on the first image display panel 10 and the second image displayed on the second image display panel 20 are images of the same size and shape, the virtual image VIR of the first image viewed by the observer OB will be larger than the virtual image VIF of the second image.

[0019] The relative positional relationship between the virtual images VIR and VIF visually recognized by the observer OB in the HUD 100 according to the first embodiment will be described below.

[0020] Figure 2A is a schematic diagram showing the basic configuration of a HUD, and Figure 2B is a schematic diagram showing an equivalent configuration of the HUD shown in Figure 2A.

[0021] An eye box EB shown in Fig. 2A indicates a range in which an observer OB can view a virtual image VI. As shown in Fig. 2B, when the lens O and image display panel D of the HUD shown in Fig. 2A are arranged in the line of sight of the observer OB, a distance a (mm) between the image display panel D and the center line of the lens O, a virtual distance b (mm) between the virtual image VI and the center line of the lens O, and a focal length f (mm) of the lens O have the relationship shown in the following formula (1). The distance a between the image display panel D and the center line of the lens O is set to be less than the focal length f of the lens O (f>a).

[0022]

number

[0023] The virtual distance VID (mm) from the viewpoint of observer OB to virtual image VI is expressed by the following formula (2) using the distance e from the center line of lens O to the viewpoint of observer OB. Fig. 3 is a diagram showing the relationship between the distance a between the panel and the lens and the virtual distance VID between the viewpoint and the virtual image.

[0024]

number

[0025] 3, the longer the distance a from the image display panel D to the center line of the lens O, the farther the virtual distance VID from the viewpoint of the observer OB to the virtual image VI becomes. Also, the closer the distance a from the image display panel D to the center line of the lens O becomes to the focal length f, the greater the change in the virtual distance VID from the viewpoint of the observer OB to the virtual image VI with respect to the change in the distance a becomes.

[0026] Fig. 4 is a schematic diagram showing an equivalent configuration of the HUD according to the first embodiment. As described above, in the schematic configuration of the HUD 100 according to the first embodiment shown in Fig. 1, the first image display panel 10 is disposed farther from the magnifying optical system 2 than the second image display panel 20 in the direction (Z direction) perpendicular to the optical axis of the magnifying optical system 2, in other words, the XY plane perpendicular to the optical axis of the magnifying optical system 2. Specifically, in the equivalent configuration of the HUD 100 according to the first embodiment shown in Fig. 4, the distance a1 from the first image display panel 10 to the center line of the lens O (the magnifying optical system 2) is greater than the distance a2 from the second image display panel 20 to the center line of the lens O (the magnifying optical system 2) (a1>a2).

[0027] A virtual distance VID1 from the viewpoint of the observer OB to the virtual image VIR of the first image displayed on the first image display panel 10 corresponds to a distance a1 from the first image display panel 10 to the center line of the lens O (magnifying optical system 2). A virtual distance VID2 from the viewpoint of the observer OB to the virtual image VIF of the second image displayed on the second image display panel 20 corresponds to a distance a2 from the second image display panel 20 to the center line of the lens O (magnifying optical system 2). Therefore, in the equivalent configuration of the HUD 100 according to the first embodiment shown in FIG. 4, the virtual distance VID1 from the viewpoint of the observer OB to the virtual image VIR of the first image displayed on the first image display panel 10 is larger than the virtual distance VID2 from the viewpoint of the observer OB to the virtual image VIF of the second image displayed on the second image display panel 20 (VID1>VID2).

[0028] As a result, the virtual image VIR of the first image displayed on the first image display panel 10 is viewed at a virtual position farther away from the observer OB than the virtual image VIF of the second image displayed on the second image display panel 20.

[0029] In the present disclosure, the image output region of the first image display panel 10 and the image output region of the second image display panel 20 overlap in the optical axis direction of the magnifying optical system 2 as described above, and the virtual image VIR of the first image and the virtual image VIF of the second image reflected by the light-transmitting member FG are viewed in a state of overlapping in the line of sight direction of the observer OB. In such an embodiment, the display device 1 according to the present disclosure is capable of arranging the first object on the virtual image VIR of the first image and the second object on the virtual image VIF of the second image at arbitrary positions in the region where the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight direction of the observer OB. Hereinafter, a detailed configuration of the display device 1 that enables the above-mentioned display embodiment will be described.

[0030] FIG. 5 is a schematic diagram showing a detailed configuration of the display device according to the first embodiment.

[0031] The first image display panel 10 receives direct light from the backlight 30 .

[0032] The second image display panel 20 is disposed with a gap S provided between it and the first image display panel 10. The second image display panel 20 receives transmitted light from the first image display panel 10.

[0033] In the display device 1 according to the first embodiment, the first image display panel 10 includes a first liquid crystal panel 11 and a first polarizing plate 12. The first polarizing plate 12 is provided on the surface of the first liquid crystal panel 11 facing the backlight 30.

[0034] Moreover, in the display device 1 according to the first embodiment, the second image display panel 20 includes a second liquid crystal panel 21 and a second polarizing plate 22. The second polarizing plate 22 is provided on the surface of the second liquid crystal panel 21 on the magnifying optical system 2 side.

[0035] The first liquid crystal panel 11 and the second liquid crystal panel 21 are transmissive liquid crystal display panels, and have a plurality of pixels driven by, for example, an active matrix system. The plurality of pixels are two-dimensionally arranged along the plate surfaces of the first liquid crystal panel 11 and the second liquid crystal panel 21. In an image output region (not shown) in which the plurality of pixels are arranged, the plurality of pixels are individually controlled to form a light transmission pattern corresponding to the virtual image VIR of the first image and the virtual image VIF of the second image. As a result, when the incident light passes through the image output region of the first liquid crystal panel 11, the amount of light is adjusted according to the gradation value of the pixel provided at the position corresponding to the first object OBJ1 on the virtual image VIR of the first image, and the light is emitted as transmitted light. Also, when the incident light passes through the image output region of the second liquid crystal panel 21, the amount of light is adjusted according to the gradation value of the pixel provided at the position corresponding to the second object OBJ2 on the virtual image VIF of the second image, and the light is emitted as transmitted light.

[0036] The first polarizing plate 12 and the second polarizing plate 22 are arranged in a state in which their transmission axes are perpendicular to each other with respect to the incident light (crossed Nicols). In the display device 1 according to the present disclosure, no polarizing plate is provided between the first image display panel 10 and the second image display panel 20.

[0037] The first polarizing plate 12 is an optical member that transmits light polarized in a first direction and blocks light polarized in a direction different from the first direction. Specifically, the first polarizing plate 12 is a linear polarizing plate having a transmission axis in, for example, the Y direction.

[0038] The second polarizing plate 22 is an optical member that transmits light polarized in a second direction different from the first direction and blocks light polarized in a direction different from the second direction. Specifically, the second polarizing plate 22 is a linear polarizing plate having a transmission axis in, for example, the X direction.

[0039] In the configuration of the display device 1 according to the above-mentioned embodiment 1, the gradation value at a position on the virtual image seen from the viewpoint of the observer OB is expressed by the following formula (3) using the gradation value R at the corresponding position in the image output region of the first liquid crystal panel 11 and the gradation value F at the corresponding position in the image output region of the second liquid crystal panel 21. In the following formula (3), the gradation value R and the gradation value F are normalized with a maximum value of 1. Note that the initial alignment and rotation direction of the liquid crystal molecules of the first liquid crystal panel 11 and the second liquid crystal panel 21 are determined so as to satisfy the following formula (3).

[0040] A = R + F - 2 × R × F (3)

[0041] For example, when the gradation value R at a position corresponding to the first object OBJ1 on the virtual image VIR of the first image is 0.8 (R=0.8) and the gradation value F is 0 (F=0), the gradation value A of the first object OBJ1 viewed by the observer OB is 0.8 (A=0.8).

[0042] Also, for example, when the gradation value R at a position corresponding to the second object OBJ2 on the virtual image VIF of the second image is 0 (R=0) and the gradation value F is 0.5 (F=0.4), the gradation value A of the second object OBJ2 viewed by the observer OB is 0.4 (A=0.4).

[0043] Furthermore, for example, in a display mode (described later) in which a first object OBJ1 on a virtual image VIR of a first image and a second object OBJ2 on a virtual image VIF of a second image overlap in the line of sight of an observer OB to form one composite object COMP_OBJ, when the gradation value R at the position corresponding to the composite object COMP_OBJ is 0.8 (R=0.8) and the gradation value F is 0.4 (F=0.4), the gradation value A of the composite object COMP_OBJ viewed by the observer OB is 0.56 (A=0.56).

[0044] When the composite object COMP_OBJ is viewed by the observer OB, the first object OBJ1 on the virtual image VIR of the first image is smaller than the second object OBJ2 on the virtual image VIF of the second image. Also, if the viewpoint of the observer OB shifts, the first object OBJ1 on the virtual image VIR of the first image and the second object OBJ2 on the virtual image VIF of the second image are viewed out of alignment, which may give the observer OB a visually uncomfortable feeling.

[0045] In the configuration of the present disclosure which allows an observer to view a virtual image VIR of the first image and a virtual image VIF of the second image, the area in which the first object OBJ1 and the second object OBJ2 are misaligned and viewed by the observer OB is limited to the area EB2-EB1 where the eyebox EB1 in which the virtual image VIR of the first image is viewable and the eyebox EB2 in which the virtual image VIF of the second image is viewable do not overlap (see Figure 4).

[0046] A specific example of the display mode of the HUD 100 according to the first embodiment will be described below.

[0047] Fig. 6A is a diagram showing a first example of a display mode of the HUD according to embodiment 1. Fig. 6B is a diagram showing a first object viewed on a virtual image of a first image in the display mode shown in Fig. 6A. Fig. 6C is a diagram showing a second object viewed on a virtual image of a second image in the display mode shown in Fig. 6A. Fig. 6D is a cross-sectional view of the display device according to embodiment 1 taken along line AA shown in Fig. 6A.

[0048] In the display mode shown in FIG. 6A, in the area where the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight of the observer OB, the first object OBJ1 is positioned relatively higher, and the second object OBJ2 is positioned relatively lower.

[0049] Fig. 7A is a diagram showing a second example of a display mode of the HUD according to embodiment 1. Fig. 7B is a diagram showing a first object viewed on a virtual image of a first image in the display mode shown in Fig. 7A. Fig. 7C is a diagram showing a second object viewed on a virtual image of a second image in the display mode shown in Fig. 7A. Fig. 7D is a cross-sectional view of the display device according to embodiment 1 taken along line AA shown in Fig. 7A.

[0050] In the display mode shown in Fig. 7A, a first object OBJ1 on the virtual image VIR of the first image and a second object OBJ2 on the virtual image VIF of the second image overlap in the line of sight of the observer OB to form one composite object COMP_OBJ. Also, in the VY direction of the area where the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight of the observer OB from the viewpoint of the observer OB, as the gradation value of the first object OBJ1 increases, the gradation value of the second object OBJ2 decreases. As a result, in the area where the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight of the observer OB from the viewpoint of the observer OB, the observer OB visually recognizes a composite object COMP_OBJ that appears to be inclined from the bottom to the top, from the front to the back.

[0051] In this way, the HUD 100 of embodiment 1 can freely position a first object on the virtual image VIR of the first image and a second object on the virtual image VIF of the second image in an area visible to the observer OB with the virtual image VIR of the first image and the virtual image VIF of the second image overlapping in the line of sight of the observer OB.

[0052] In addition, in a display mode in which a first object OBJ1 on the virtual image VIR of the first image and a second object OBJ2 on the virtual image VIF of the second image overlap in the line of sight of the observer OB to form one composite object COMP_OBJ, in at least one direction of the area in which the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight of the observer OB, the gradation value of the first object OBJ1 is controlled to increase as the gradation value of the second object OBJ2 decreases, thereby allowing the observer OB to view the composite object COMP_OBJ as if it is tilted in one direction.

[0053] (Embodiment 2) Fig. 8 is a schematic diagram showing a schematic configuration of a HUD according to embodiment 2. Fig. 9 is a schematic diagram showing a detailed configuration of a display device according to embodiment 2. Note that configurations and operations different from those of embodiment 1 will be described here, and overlapping descriptions may be omitted.

[0054] In the display device 1a of the HUD 100a according to the second embodiment, the first image display panel 10 is disposed in a tilted state with respect to the second image display panel 20. The second image display panel 20 is disposed approximately parallel to an XY plane perpendicular to the optical axis of the magnifying optical system 2. The tilt angle of the first image display panel 10 with respect to the second image display panel 20 (the XY plane perpendicular to the optical axis of the magnifying optical system 2) is set to, for example, about 40 degrees. As a result, the virtual image VIR of the first image displayed on the first image display panel 10 is visually recognized by the observer OB in a tilted state with respect to the virtual image VIF of the second image displayed on the second image display panel 20.

[0055] More specifically, in the schematic configuration of the HUD 100a according to the second embodiment shown in FIG. 8, the virtual image VIR of the first image is viewed from the viewpoint of the observer OB, tilted from bottom to top, from the front to the back.

[0056] A specific example of the display mode of the HUD 100a according to the second embodiment will be described below.

[0057] Fig. 10A is a diagram showing an example of a display mode of a HUD according to embodiment 2. Fig. 10B is a diagram showing a first object visually recognized on a virtual image of a first image in the display mode shown in Fig. 10A. Fig. 10C is a diagram showing a second object visually recognized on a virtual image of a second image in the display mode shown in Fig. 10A. Fig. 10D is a cross-sectional view of the display device according to embodiment 2 taken along line AA shown in Fig. 8A.

[0058] 10A, in a region where the virtual image VIR of the first image and the virtual image VIF of the second image overlap in the line of sight of the observer OB, the first objects OBJ1_1, OBJ1_2, and OBJ1_3 are visually recognized relatively at the top, and the second object OBJ2 is visually recognized relatively at the bottom. Also, the first objects OBJ1_1, OBJ1_2, and OBJ1_3 visually recognized on the virtual image VIF of the second image are visually recognized as if they are arranged from the front to the back in the order of the first object OBJ1_3, the first object OBJ1_2, and the first object OBJ1_3.

[0059] To achieve this display mode, the first image display panel 10a is positioned at an angle with respect to the XY plane that is approximately parallel to the second image display panel 20 so that the gap S between the first image display panel 10a and the second image display panel 20 is large at the upper end in the Y direction and small at the lower end in the Y direction (see Figure 10D).

[0060] In this way, the HUD 100a of embodiment 2 can cause the virtual image VIR of the first image to be viewed at an angle relative to the virtual image VIF of the second image in an area viewed by the observer OB with the virtual image VIR of the first image and the virtual image VIF of the second image overlapping in the line of sight of the observer OB.

[0061] Furthermore, by tilting the first image display panel 10 relative to the XY plane that is approximately parallel to the second image display panel 20 so that the gap S between the first image display panel 10 and the second image display panel 20 is large at the upper end in the Y direction and small at the lower end in the Y direction, a virtual image VIR of the first image can be viewed from the viewpoint of the observer OB, tilted from bottom to top, from the front to the back.

[0062] (Embodiment 3) Fig. 11 is a schematic diagram showing an incident path of sunlight in a HUD in which the second image display panel is disposed approximately parallel to the XY plane. The XY plane shown in Fig. 11 is a plane perpendicular to the optical axis of the magnifying optical system 2. Fig. 11 illustrates a HUD according to embodiment 2 as an example of an aspect in which the second image display panel is disposed approximately parallel to the XY plane, and the incident path of sunlight is indicated by a dashed arrow.

[0063] Sunlight incident on a display device (e.g., display device 1a according to embodiment 2) from the optical axis direction of the magnifying optical system 2 is reflected by the surface of the second image display panel 20 (more specifically, the surface of the second polarizing plate 22). In a HUD (e.g., HUD 100a according to embodiment 2) in which the second image display panel 20 is disposed approximately parallel to the XY plane perpendicular to the optical axis of the magnifying optical system 2, the sunlight reflected by the surface of the second image display panel 20 (the surface of the second polarizing plate 22) may be reflected by the light-transmitting member FG along the optical axis of the magnifying optical system 2 and enter the eyes of the observer OB.

[0064] Fig. 12 is a schematic diagram showing an incident path of sunlight in a HUD according to embodiment 3. Fig. 13 is a schematic diagram showing a schematic configuration of a HUD according to embodiment 3. Note that configurations and operations different from those of embodiments 1 and 2 will be described here, and overlapping descriptions may be omitted.

[0065] In the display device 1b of the HUD 100b according to the third embodiment, the second image display panel 20 is disposed in a tilted state with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2. The tilt angle of the second image display panel 20 with respect to the XY plane may be smaller than the tilt angle of the first image display panel 10 with respect to the XY plane. Specifically, for example, when the tilt angle of the first image display panel 10 with respect to the XY plane is, for example, about 40 degrees, the tilt angle of the second image display panel 20 with respect to the XY plane is, for example, about 20 degrees. As a result, the sunlight incident from the optical axis direction of the magnifying optical system 2 is reflected by the surface of the second image display panel 20 (the surface of the second polarizing plate 22) in a direction deviated from the optical axis of the magnifying optical system 2. As a result, it is possible to prevent the sunlight reflected by the surface of the second image display panel 20 (the surface of the second polarizing plate 22) from entering the eyes of the observer OB.

[0066] (Modification) Fig. 14 is a schematic diagram showing an incident path of sunlight in a HUD according to a modified example of embodiment 3. Fig. 15 is a schematic diagram showing a schematic configuration of a HUD according to a modified example of embodiment 3.

[0067] The tilt direction of the second image display panel 20 is not limited to the aspects shown in Figures 12 and 13, and may be, for example, the aspect of a HUD 100c according to a modified example of the third embodiment shown in Figures 14 and 15. Specifically, the tilt direction of the second image display panel 20 with respect to the XY plane may be, for example, a direction rotated by 180 on the XY plane with respect to the tilt direction of the first image display panel 10 with respect to the XY plane. The present disclosure is not limited by the tilt direction of the second image display panel 20.

[0068] (Embodiment 4) In a HUD in which the first image display panel 10 is arranged at an angle with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2 (for example, HUD 100a according to embodiment 2), if the backlight 30 is arranged approximately parallel to the XY plane perpendicular to the optical axis of the magnifying optical system 2, the light incident on the first image display panel 10 may be reduced, resulting in a decrease in contrast and brightness.

[0069] Fig. 16A is a schematic diagram showing a first example of a detailed configuration of a display device according to embodiment 4. Fig. 16B is a schematic diagram showing a second example of a detailed configuration of a display device according to embodiment 4. Fig. 16C is a schematic diagram showing a third example of a detailed configuration of a display device according to embodiment 4.

[0070] In the display devices 1d, 1e, and 1f according to the fourth embodiment shown in Figs. 16A, 16B, and 16C, the first image display panel 10a further includes a prism sheet 13 in addition to the first liquid crystal panel 11 and the first polarizing plate 12. In the display devices 1d, 1e, and 1f according to the fourth embodiment shown in Figs. 16A, 16B, and 16C, the backlight 30 is disposed in a state inclined with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2. The inclination of the backlight 30 with respect to the XY plane is, for example, within a range of about 20 degrees to 40 degrees. More preferably, the backlight 30 is disposed so as to be substantially parallel to the first image display panel 10a.

[0071] In the first example shown in FIG. 16A, the second image display panel 20 is disposed approximately parallel to the XY plane perpendicular to the optical axis of the magnifying optical system 2, as in the display device 1a according to the second embodiment. In the second example shown in FIG. 16B, the second image display panel 20 is disposed in a tilted state with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2, as in the display device 1b according to the third embodiment. In the third example shown in FIG. 16C, the second image display panel 20 is disposed in a tilted state with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2, as in the display device 1c according to the modified example of the third embodiment. In the display devices 1d, 1e, and 1f according to the fourth embodiment, the second image display panel 20 may be disposed approximately parallel to the XY plane perpendicular to the optical axis of the magnifying optical system 2, as shown in FIG. 16A, or may be disposed in a tilted state with respect to the XY plane perpendicular to the optical axis of the magnifying optical system 2, as shown in FIGS. 16B and 16C.

[0072] In the display devices 1d, 1e, and 1f according to the fourth embodiment of the above aspect, the prism sheet 13 refracts the light transmitted through the first image display panel so as to be substantially parallel to the optical axis of the magnifying optical system 2. This makes it possible to suppress a decrease in the light incident on the first image display panel 10, thereby improving the contrast and brightness.

[0073] Although the preferred embodiment of the present disclosure has been described above, the present disclosure is not limited to such an embodiment. The contents disclosed in the embodiment are merely examples, and various modifications are possible within the scope of the present disclosure. For example, appropriate modifications made within the scope of the present disclosure naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0074] 1,1a,1b,1c,1d,1e,1f Display device 2. Magnification optical system 10, 10a First image display panel 11 First LCD panel 12 First polarizing plate 13 Prism sheet 20 Second image display panel 21 Second LCD panel 22 Second polarizing plate 30 Backlight 100,100a,100b,100c HUD (Head Up Display) COMP_OBJ Composite Object EB, EB1, EB2 Eye Box FG Translucent material L light O Lens OB Observer OBJ1,OBJ1_1,OBJ1_2,OBJ1_3 First object OBJ2 Second object S gap VI Virtual Image VIF Virtual image (second image) VIR Virtual image (first image)

Claims

1. A head-up display in which an image reflected by a translucent member that transmits and reflects incident light is superimposed on a real image transmitted through the translucent member, and the image reflected by the translucent member is visually recognized by an observer as a virtual image, A display device for displaying an image; a magnifying optical system that magnifies an image displayed on the display device and projects the magnified image onto the light-transmitting member; Equipped with The display device includes: Backlight and a first image display panel on which direct light from the backlight is incident; a second image display panel disposed with a gap between it and the first image display panel, and into which transmitted light of the first image display panel is incident; Equipped with The first image display panel includes: A first polarizing plate is provided between the backlight and the first polarizing plate, The second image display panel includes: a second polarizing plate provided between the magnifying optical system and the second polarizing plate; the first polarizing plate transmits light polarized in a first direction and blocks light polarized in a direction different from the first direction; the second polarizing plate transmits light polarized in a second direction different from the first direction and blocks light polarized in a direction different from the second direction; No other polarizing plate is provided between the first image display panel and the second image display panel. Head-up display.

2. an image output region of the first image display panel and an image output region of the second image display panel overlap with each other in a direction of an optical axis of the magnifying optical system; The head-up display according to claim 1 .

3. a virtual distance from a viewpoint of an observer to a virtual image of a first image displayed on the first image display panel is greater than a virtual distance from a viewpoint of an observer to a virtual image of a second image displayed on the second image display panel; The head-up display according to claim 2 .

4. A virtual image of the first image and a virtual image of the second image overlap in a line of sight of an observer. The head-up display according to claim 3.

5. a first object on the virtual image of the first image and a second object on the virtual image of the second image overlap in a line of sight of an observer to form one composite object; The head-up display according to claim 4.

6. In at least one direction of a region in which the virtual image of the first image and the virtual image of the second image overlap in a line of sight of an observer, as the gradation value of the first object increases, the gradation value of the second object decreases. The head-up display according to claim 5 .

7. The first image display panel is disposed at an angle with respect to the second image display panel. The head-up display according to claim 4.

8. The virtual image of the first image is tilted with respect to the virtual image of the second image. The head-up display according to claim 7.

9. A virtual distance from a viewpoint of the observer to an object disposed relatively at an upper part on the virtual image of the first image is longer than a virtual distance from a viewpoint of the observer to an object disposed relatively at a lower part on the virtual image of the first image. The head-up display according to claim 8.

10. the second image display panel is disposed inclined with respect to a plane perpendicular to the optical axis of the magnifying optical system; A head-up display according to any one of claims 4 to 9.

11. The backlight is disposed at an angle with respect to a plane perpendicular to the optical axis of the magnifying optical system. The head-up display according to claim 10.

12. The backlight is disposed substantially parallel to the first image display panel. The head-up display of claim 11.

13. a prism sheet provided between the first image display panel and the second image display panel, the prism sheet refracts the light transmitted through the first image display panel so as to be substantially parallel to the optical axis of the magnifying optical system. The head-up display of claim 12.

Images