Light source unit and image display device

Abstract

Provided is a light source unit. The present invention is provided with: a first display device; a second display device; a first polarizer that sets light emitted from the first display device as first polarized light having a first polarized light direction; and a second polarizer that sets light emitted from the second display device as second polarized light having a second polarized light direction. A reflective polarizer that transmits the first polarized light and reflects the second polarized light; a first reflective member; a first wavelength plate disposed between the reflective polarizer and the first reflective member; a second reflective member; a first optical path length of light emitted from the first display device from the first display device to the first reflection member is longer than a second optical path length of light emitted from the second display device from the second display device to the second reflection member, and a curvature of the first concave surface is larger than a curvature of the second concave surface.

Description

Technical Field

[0001] Embodiments of the present invention relate to a light source unit and an image display device. Background Art

[0002] Patent document 1 discloses a display device that uses two displays to display two virtual images in a recognizable manner. In the display device disclosed in Patent document 1, the path of light constituting one virtual image and the path of light constituting another virtual image are optically very different, so the visual effects of the two virtual images are inconsistent, and there is a problem of reduced display quality as a whole.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: (Japan) Patent No. 6809441 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] An object of embodiments of the present invention is to provide a light source unit and an image display device capable of improving the quality of a virtual image.

[0008] Technical solutions for solving technical problems

[0009] An embodiment of the present invention provides a light source unit, which includes: a first display device capable of displaying a first image; a second display device capable of displaying a second image; a first polarizer that sets the light emitted from the first display device to a first polarized light having a first polarization direction; a second polarizer that sets the light emitted from the second display device to a second polarized light having a second polarization direction different from the first polarization direction; a reflective polarizer that transmits the first polarized light and reflects the second polarized light; a first reflecting member; a first wave plate that is disposed between the reflective polarizer and the first reflecting member; a second reflecting member; and a second wave plate that is disposed between the reflective polarizer and the second reflecting member. The first reflecting member has a first concave surface, and the first concave surface is used to reflect the first polarized light transmitted through the reflective polarizer toward the reflective polarizer, and a first image corresponding to the first image is projected onto a projection unit, thereby making an image that can be recognized by a viewer appear to be displayed on the opposite side of the projection unit from the viewer. The second reflecting member has a second concave surface, and the second polarized light reflected by the reflective polarizer is reflected toward the reflective polarizer by the second concave surface, and a second image corresponding to the second image is projected onto the projection unit, thereby making the image recognizable by the identifier appear to be displayed on the opposite side of the projection unit from the identifier. A first optical path length of light emitted from the first display device from the first display device to the first reflecting member is longer than a second optical path length of light emitted from the second display device from the second display device to the second reflecting member, and a curvature of the first concave surface is greater than a curvature of the second concave surface. Alternatively, the first optical path length is shorter than the second optical path length, and a curvature of the first concave surface is smaller than a curvature of the second concave surface.

[0010] An embodiment of the present invention provides an image display device including the light source unit and a reflection unit separated from the light source unit and reflecting light emitted from the light source unit. The first image and the second image are formed between the light source unit and the reflection unit.

[0011] Effects of the Invention

[0012] According to the embodiments of the present invention, it is possible to realize a light source unit and an image display device capable of improving the quality of a virtual image. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an end view showing the image display device according to the first embodiment.

[0014] Figure 2 This is an end view showing the light source unit according to the first embodiment.

[0015] Figure 3This is an end view showing the display device of the image display device according to the first embodiment.

[0016] Figure 4 It is a schematic diagram showing the scene observed by the recognizer in the driver's seat.

[0017] Figure 5A It is a schematic diagram showing the principle of the light source unit according to the first embodiment.

[0018] Figure 5B It is a schematic diagram showing the principle of the light source unit of the reference example.

[0019] Fig. 6A It is a graph showing the light distribution pattern of light emitted from one light emitting area in Examples 1 and 11, Reference Example, and LCD.

[0020] Figure 6B It is a graph showing the uniformity of brightness of the third image in Examples 1 to 12 and the reference example.

[0021] Figure 7 It is an end view showing a light source unit according to a second embodiment.

[0022] Figure 8 This is a cross-sectional view showing an enlarged portion of the first display device according to the second embodiment.

[0023] Fig. 9 It is an end view showing a light source unit according to a third embodiment.

[0024] Fig.10 It is a perspective view showing a wire grid polarizing plate according to a fourth embodiment. DETAILED DESCRIPTION

[0025] <First embodiment>

[0026] First, the first embodiment will be described.

[0027] Figure 1 This is an end view showing the image display device according to this embodiment.

[0028] Figure 2 It is an end view showing the light source unit according to the present embodiment.

[0029] like Figure 1 and Figure 2 As shown, the image display device 10 of this embodiment is mounted on, for example, a car 1000 to form a HUD (Head Up Display). The car 1000 includes a vehicle 13 and the image display device 10 fixed to the vehicle 13. The identifier 14 is a passenger of the car 1000, for example, a driver.

[0030] The image display device 10 includes a light source unit 11 and a reflection unit 12. The light source unit 11 includes a first display device 110A, a second display device 110B, a first polarizing plate 111A, a second polarizing plate 111B, a reflective polarizing plate 117, a first reflecting member 113A, a second reflecting member 113B, a first wave plate 114A, a second wave plate 114B, and a third wave plate 115.

[0031] The first display device 110A can display a first image. The second display device 110B can display a second image. As described later, the first image and the second image are virtual images recognized by the recognizer 14 on the opposite side of the front windshield 13a of the vehicle 13. The first image and the second image are, for example, character strings and / or graphics.

[0032] The first polarizer 111A sets the light emitted from the first display device 110A to the first polarized light having the first polarized light direction. The first polarized light is, for example, P polarized light. The second polarized light is, for example, S polarized light. The second polarized light direction is different from the first polarized light direction, for example, orthogonal. The reflective polarizer 117 transmits the first polarized light (for example, P polarized light) and reflects the second polarized light (for example, S polarized light). Here, "P polarized light" refers to light whose vibration direction of the electric field is roughly parallel to the YZ plane. In addition, "S polarized light" refers to light whose vibration direction of the electric field is roughly perpendicular to the YZ plane containing the incident light and the reflected light.

[0033] The first reflecting member 113A has a first concave surface 113aA. The first reflecting member 113A reflects the first polarized light transmitted through the reflective polarizer 117 toward the reflective polarizer 117 by means of the first concave surface 113aA, and projects the first image IM1 corresponding to the first image onto the projection unit. Thus, the image (third image IM3) that can be recognized by the identifier 14 appears to be displayed on the opposite side of the projection unit from the identifier 14. In the present embodiment, the projection unit is, for example, the front windshield 13a of the vehicle 13. However, the projection unit may also be a combiner.

[0034] The second reflecting member 113B has a second concave surface 113aB. The second reflecting member 113B reflects the second polarized light reflected by the reflective polarizer 117 toward the reflective polarizer 117 by the second concave surface 113aB, and projects the second image IM2 corresponding to the second image onto the projection unit. Thus, the image (fourth image IM4) that can be recognized by the identifier 14 appears to be displayed on the opposite side of the projection unit from the identifier 14.

[0035] The first wave plate 114A is disposed between the reflective polarizer 117 and the first reflective member 113A. The second wave plate 114B is disposed between the reflective polarizer 117 and the second reflective member 113B. The third wave plate 115 transmits light reflected by the first reflective member 113A and reflected by the reflective polarizer 117, and light reflected by the second reflective member 113B and transmitted through the reflective polarizer 117.

[0036] The first image IM1 and the second image IM2 are real images and intermediate images. The third image IM3 is a virtual image larger than the first image IM1. The fourth image IM4 is a virtual image larger than the second image IM2. The first image, the first image IM1, and the third image IM3 are in a substantially similar relationship. The second image, the second image IM2, and the fourth image IM4 are in a substantially similar relationship.

[0037] The first wavelength plate 114A, the second wavelength plate 114B, and the third wavelength plate 115 are, for example, ¼λ plates. However, the first wavelength plate 114A, the second wavelength plate 114B, and the third wavelength plate 115 do not necessarily need to be ¼λ plates. In addition, the third wavelength plate 115 may not be provided.

[0038] exist Figure 2 In the example shown, a first optical path length LPA of light emitted from the first display device 110A from the first display device 110A to the first reflecting component 113A is longer than a second optical path length LPB of light emitted from the second display device 110B from the second display device 110B to the second reflecting component 113B, and a curvature RA of the first concave surface 113aA is greater than a curvature RB of the second concave surface 113aB, that is, LPA>LPB, and RA>RB.

[0039] In another example, the first optical path length LPA is shorter than the second optical path length LPB, and the curvature RA of the first concave surface 113aA is smaller than the curvature RB of the second concave surface 113aB. That is, LPA<LPB and RA<RB may be satisfied.

[0040] The reflection unit 12 is separated from the light source unit 11, and reflects the light emitted from the light source unit 11. The first image IM1 and the second image IM2 are formed between the light source unit 11 and the reflection unit 12.

[0041] The front windshield 13a reflects the light reaching from the reflection unit 12 on its inner surface, and makes the light enter the eye movement range 14a of the identifier 14. Thus, the identifier 14 can identify the third image IM3 and the fourth image IM4. It should be noted that the "eye movement range" refers to the range in the space in front of the eyes of the identifier where the virtual image can be identified.

[0042] Next, the positional relationship between the components of the image display device 10 will be described.

[0043] In order to facilitate the understanding of the description below, an XYZ orthogonal coordinate system is used. In the present embodiment, the front-to-back direction of the vehicle 13 is set as the "X direction", the left-to-right direction of the vehicle 13 is set as the "Y direction", and the up-down direction of the vehicle 13 is set as the "Z direction". The XY plane is a horizontal plane of the vehicle 13. The direction of the arrow in the X direction (front) is called the "+X direction", and its opposite direction (rear) is also called the "-X direction". In addition, the direction of the arrow in the Y direction (left) is called the "+Y direction", and its opposite direction (right) is also called the "-Y direction". In addition, the direction of the arrow in the Z direction (upward) is called the "+Z direction", and its opposite direction (downward) is also called the "-Z direction".

[0044] like Figure 1 As shown, in this embodiment, the light source unit 11 is provided on the top 13b of the vehicle 13. The light source unit 11 is, for example, arranged on the inner side of a wall 13s1 exposed in the vehicle in the top 13b. The wall 13s1 is provided with a through hole 13h1 through which the light emitted from the light source unit 11 can pass. The light emitted from the light source unit 11 passes through the through hole 13h1 and is irradiated to the space between the identifier 14 and the front windshield 13a. The light source unit 11 may also be mounted on the top surface of the vehicle 13.

[0045] A transparent or translucent cover or a cover colored black, i.e., a cover with a small haze value, may be provided over the through hole 13h1. By providing a cover, it is possible to prevent dust and the like from adhering to the optical unit. In addition, it is possible to prevent the light source unit 11 from being recognized from the through hole 13h1, and the design properties can be improved. The haze value is preferably less than 50%, and more preferably less than 20%. By providing a cover with such a haze value, the above-mentioned effect can be obtained while suppressing a significant reduction in the brightness of the light emitted from the light source unit 11 and image disturbance.

[0046] like Figure 2 As shown, in the light source unit 11, the first display device 110A and the second display device 110B are arranged with the image display surface facing the +X direction. The first display device 110A and the second display device 110B are arranged along the Z direction, and the first display device 110A is arranged on the +Z direction side (upper side) than the second display device 110B. However, this is not limited to this, and the second display device 110B may also be arranged on the +Z direction side (upper side) than the first display device 110A. In addition, the first display device 110A and the second display device 110B may also be arranged along the Y direction.

[0047] The first polarizing plate 111A is disposed on the +X direction side (front side) of the first display device 110A. Thus, light emitted from the first display device 110A (light forming the first image) is incident on the first polarizing plate 111A. The second polarizing plate 111B is disposed on the +X direction side (front side) of the second display device 110B. Thus, light emitted from the second display device 110B (light forming the second image) is incident on the second polarizing plate 111B.

[0048] The reflective polarizer 117 is arranged on the +X direction side of the first polarizer 111A and the second polarizer 111B. The reflective polarizer 117 is inclined relative to the Z direction in a manner that the more it moves toward the +Z direction, the more it moves toward the +X direction. The reflective polarizer 117 has a first surface 117a and a second surface 117b on the opposite side of the first surface 117a. The first surface 117a faces the direction between the +Z direction and the -X direction, and is opposite to the first polarizer 111A and the second polarizer 111B. The second surface 117b faces the direction between the -Z direction and the +X direction.

[0049] The first wave plate 114A is arranged on the +X direction side of the reflective polarizer 117, and is opposite to the second surface 117b of the reflective polarizer 117. The first reflective component 113A is arranged on the +X direction side of the first wave plate 114A, and the first concave surface 113aA of the first reflective component 113A faces the -X direction side. Thus, the first concave surface 113aA faces the first wave plate 114A. As a result, the first display device 110A, the first polarizer 111A, the reflective polarizer 117, the first wave plate 114A, and the first reflective component 113A are arranged in sequence on the same straight line along the +X direction.

[0050] When viewed from the reflective polarizer 117, the second wave plate 114B is arranged along the direction between the -X direction and the +Z direction, and is opposite to the first surface 117a of the reflective polarizer 117. The second reflective component 113B is arranged on the direction side between the -X direction and the +Z direction of the second wave plate 114B, and the second concave surface 113aB of the second reflective component 113B faces the direction side between the +X direction and the -Z direction. Thus, the second concave surface 113aB faces the second wave plate 114B. As a result, the second display device 110B, the second polarizer 111B, and the reflective polarizer 117 are arranged in sequence on the same straight line along the +X direction, and the reflective polarizer 117, the second wave plate 114B, and the second reflective component 113B are arranged in sequence on the same straight line along the direction between the -X direction and the +Z direction.

[0051] The third wave plate 115 is disposed in a direction between the +X direction and the −Z direction as viewed from the reflective polarizer 117, and is opposed to the second surface 117b of the reflective polarizer 117. Light reaching the third wave plate 115 from the reflective polarizer 117 and transmitting through the third wave plate 115 is emitted in a direction between the +X direction and the −Z direction.

[0052] In this way, the first display device 110A and the first polarizing plate 111A, the second display device 110B and the second polarizing plate 111B, the second wave plate 114B and the second reflecting member 113B are arranged on the first surface 117a side of the reflective polarizing plate 117. However, the first display device 110A and the first polarizing plate 111A are arranged at a position that does not hinder the optical path between the second display device 110B and the reflective polarizing plate 117, and the optical path between the reflective polarizing plate 117 and the second reflecting member 113B. The second display device 110B and the second polarizing plate 111B are arranged at a position that does not hinder the optical path between the first display device 110A and the reflective polarizing plate 117, and the optical path between the reflective polarizing plate 117 and the second reflecting member 113B. The second wave plate 114B and the second reflecting member 113B are arranged at a position that does not hinder the optical path between the first display device 110A and the reflective polarizing plate 117, and the optical path between the second display device 110B and the reflective polarizing plate 117.

[0053] In addition, the first wave plate 114A, the first reflecting member 113A, and the third wave plate 115 are arranged on the second surface 117b side of the reflective polarizer 117. However, the first wave plate 114A and the first reflecting member 113A are arranged at positions that do not hinder the optical path between the reflective polarizer 117 and the third wave plate 115. The third wave plate 115 is arranged at a position that does not hinder the optical path between the reflective polarizer 117 and the first reflecting member 113A.

[0054] like Figure 1As shown, in the present embodiment, the reflection unit 12 is provided in the instrument panel portion 13c of the vehicle 13. The reflection unit 12 is, for example, arranged on the inner side of the wall 13s2 exposed in the vehicle in the instrument panel portion 13c. A through hole 13h2 is provided on the wall 13s2 through which the light emitted from the light source unit 11 can pass. As with the through hole 13h1, a transparent or translucent cover or a cover colored in black, i.e., a cover with a small haze value, may also be provided in the through hole 13h2. In the present embodiment, the reflection unit 12 includes a reflector 131 having a concave reflector surface 131a. The reflector 131 is arranged to be opposite to the front windshield 13a. The reflector 131 may also be composed of a main body component composed of glass or resin material and a reflective film such as a metal film or a dielectric multilayer film provided on the surface of the main body component to form the reflector surface 131a. In addition, the entirety of the reflector 131 may also be composed of a metal material. In one example, the reflective mirror surface 131a is a biconical surface, but the reflective mirror surface may be a part of a spherical surface or a free-form surface.

[0055] Next, the structures of the first display device 110A and the second display device 110B in the light source unit 11 will be described in detail.

[0056] The first display device 110A is a first LED display having a plurality of LED elements. The second display device 110B is a second LED display having a plurality of LED elements. Hereinafter, the first display device 110A and the second display device 110B are also collectively referred to as "display device 110". That is, the following description of "display device 110" applies to both the first display device 110A and the second display device 110B. However, one of the first display device 110A and the second display device 110B may have a structure different from the following description.

[0057] Figure 3 This is an end view of the display device showing the image display device according to the present embodiment.

[0058] In the display device 110, Figure 3 As shown, a plurality of LED elements 112 are arranged in a matrix. One or more LED elements 112 correspond to each pixel of the display device 110 .

[0059] In the display device 110, each LED element 112 is mounted face-down on the substrate 111. However, each LED element may be mounted face-up on the substrate. Each LED element 112 includes a semiconductor stack 112a, an anode electrode 112b, and a cathode electrode 112c.

[0060] The semiconductor stack 112a includes a p-type semiconductor layer 112p1, an active layer 112p2 disposed on the p-type semiconductor layer 112p1, and an n-type semiconductor layer 112p3 disposed on the active layer 112p2. X Al Y Ga 1－X－Y A gallium nitride compound semiconductor represented by N (0≤X, 0≤Y, X+Y<1). In the present embodiment, the light emitted by the LED element 112 is visible light.

[0061] The anode electrode 112b is electrically connected to the p-type semiconductor layer 112p1. The anode electrode 112b is electrically connected to the wiring 118b. The cathode electrode 112c is electrically connected to the n-type semiconductor layer 112p3. The cathode electrode 112c is electrically connected to another wiring 118a. Each electrode 112b and 112c can be made of, for example, a metal material.

[0062] In this embodiment, a plurality of recesses 112t are provided on the light emitting surface 112s of each LED element 112. In this specification, the "light emitting surface of the LED element" refers to a surface of the surface of the LED element from which light incident on the imaging optical system 120 is mainly emitted. In this embodiment, in the n-type semiconductor layer 112p3, the surface located on the opposite side to the surface facing the active layer 112p2 corresponds to the light emitting surface 112s.

[0063] Hereinafter, the optical axis of the light emitted from each pixel 110p will be referred to as the "optical axis C". The optical axis C is, for example, a straight line connecting point a1 and point a2, where point a1 is the point with the highest brightness in the range illuminated by the light from one pixel 110p in a first plane P1 that is parallel to the YZ plane in which the multiple pixels 110p are arranged and located on the light emission side of the display device 110, and point a2 is the point with the highest brightness in the range illuminated by the light from the pixel 110p in a second plane P2 that is parallel to the YZ plane and separated from the first plane P1. When there are multiple points with the highest brightness, for example, the center point of these points may also be set as the point with the highest brightness. It should be noted that from a production point of view, it is preferred that the optical axis C is parallel to the X-axis.

[0064] By providing a plurality of recesses 112t on the light emitting surface 112s of each LED element 112, light emitted from each LED element 112, that is, light emitted from each pixel 110p, is as follows: Figure 3 Here, “the light emitted from each pixel has a substantially Lambertian light distribution” means that the light intensity in the direction of the angle θ relative to the optical axis C of each pixel can be set to a value greater than 0, and the cosine of the light intensity on the optical axis C is nHere, n is preferably less than 11, and more preferably 1. It should be noted that there are multiple planes including the optical axis C of the light emitted from one pixel 110p, but the light distribution pattern of the light emitted from the pixel 110p in each plane is a roughly Lambertian light distribution, and the value of n is also roughly equal.

[0065] The values ​​of n are preferably equal to each other for the first display device 110A and the second display device 110B, but they may not necessarily be equal. That is, the light emitted from the first display device 110A has a luminous intensity in a direction at an angle θ relative to the optical axis C of the light emitted from the first display device 110A, which is equal to the cosine of the luminous intensity on the optical axis C. n1 In addition, the light emitted from the second display device 110B has a luminous intensity in a direction that forms an angle θ with respect to the optical axis C of the light emitted from the second display device 110B, which is equal to cosine of the luminous intensity on the optical axis C. n2 The light distribution pattern is approximated by θ times. Furthermore, n1 and n2 are each a value greater than 0, preferably 11 or less, and more preferably 1. In addition, n1 and n2 are preferably equal.

[0066] The first reflecting member 113A is substantially telecentric on the first image IM1 side. In addition, the second reflecting member 113B is substantially telecentric on the second image IM2 side. Here, “the first reflecting member 113A is substantially telecentric on the first image IM1 side” means that a plurality of principal light rays LA emitted from different positions in the first display device 110A and reaching the first image IM1 via the first reflecting member 113A are substantially parallel to each other in front of and behind the first image IM1. The different positions are, for example, different pixels 110p of the first display device 110A. “A plurality of principal light rays LA are substantially parallel to each other” means that they are substantially parallel within a practical range that allows errors caused by manufacturing accuracy and assembly accuracy of the components of the light source unit 11. In the case of “a plurality of principal light rays L are substantially parallel to each other”, for example, the angle formed by the principal light rays LA is less than 10 degrees. The same is true for “the second reflecting member 113B is substantially telecentric on the second image IM2 side”. It should be noted that one of the first reflecting member 113A and the second reflecting member 113B may not be substantially telecentric.

[0067] When the first reflecting member 113A has a substantially telecentric property on the first image IM1 side, the plurality of principal rays LA intersect each other before entering the first reflecting member 113A. Figure 2In order to simplify the figure, the intersection is not shown. Hereinafter, the point where multiple main light rays LA intersect each other is referred to as "focus F". Therefore, whether the first reflective component 113A has a substantially telecentric property on the first image IM1 side can be confirmed by, for example, utilizing the reverse travel of light and by the following method. First, a light source such as a laser light source that can emit parallel light is arranged near the position where the first image IM1 is formed. The light emitted from the light source is irradiated to the reflective polarizer 117. The light emitted from the light source and passing through the reflective polarizer 117 is incident on the first reflective component 113A. Moreover, in the case where the point where the light emitted from the first reflective component 113A converges before reaching the display device 110A, that is, the focus F, exists, it can be determined that the first reflective component 113A has a substantially telecentric property on the first image IM1 side. The same is true for the case where the second reflective component 113B has a substantially telecentric property on the second image IM2 side.

[0068] Next, the operation of the image display device 10 according to this embodiment will be described.

[0069] Figure 4 It is a schematic diagram showing the scene viewed from the viewer in the driver's seat.

[0070] like Figure 2 As shown, the first display device 110A displays a first image. The light emitted from the first display device 110A passes through the first polarizer 111A, thereby becoming a first polarized light (e.g., P polarized light) having a first polarization direction. When the first polarized light reaches the first surface 117a of the reflective polarizer 117, the reflective polarizer 117 transmits the first polarized light.

[0071] Then, the first polarized light transmitted through the reflective polarizer 117 passes through the first wave plate 114A to become circularly polarized light, is reflected and condensed by the first concave surface 113aA of the first reflective member 113A, passes through the first wave plate 114A again to become second polarized light (for example, S polarized light), and returns to the second surface 117b of the reflective polarizer 117. The second polarized light is reflected on the second surface 117b of the reflective polarizer 117, passes through the third wave plate 115, and becomes circularly polarized light LA, which is emitted from the light source unit 11 in an obliquely downward direction, that is, in a direction between the +X direction and the −Z direction.

[0072] On the other hand, the second display device 110B displays a second image. The light emitted from the second display device 110B passes through the second polarizer 111B, thereby becoming a second polarized light (e.g., S polarized light) having a second polarization direction. When the second polarized light reaches the first surface 117a of the reflective polarizer 117, the first surface 117a of the reflective polarizer 117 reflects the second polarized light.

[0073] Furthermore, the second polarized light reflected by the reflective polarizer 117 passes through the second wave plate 114B to become circularly polarized light, is reflected and condensed by the second concave surface 113aB of the second reflective member 113B, passes through the second wave plate 114B again to become first polarized light (for example, P polarized light), and returns to the first surface 117a of the reflective polarizer 117. When the first polarized light reaches the first surface 117a of the reflective polarizer 117, it passes through the reflective polarizer 117 and reaches the third wave plate 115. The first polarized light passes through the third wave plate 115 to become circularly polarized light LB, and is emitted from the light source unit 11 in an obliquely downward direction, that is, in a direction between the +X direction and the -Z direction.

[0074] In this way, Figure 1 As shown, light LA ​​having information of a first image and light LB having information of a second image are emitted from the light source unit 11. The light LA ​​and the light LB form a first image IM1 and a second image IM2 between the light source unit 11 and the reflection unit 12, respectively.

[0075] After the light LA ​​and the light LB form the first image IM1 and the second image IM2, they reach the reflecting unit 12. The light LA ​​and the light LB pass through the through hole 13h2 provided in the wall 13s2 of the instrument panel portion 13c, are reflected and focused by the reflecting mirror surface 131a of the reflecting mirror 131, pass through the through hole 13h2 again and head toward the front windshield 13a. Then, they are reflected toward the -X direction (backward) by the inner surface of the front windshield 13a, and enter the eye movement range 14a of the recognizer 14.

[0076] Therefore, if Figure 4 As shown, the recognizer 14 recognizes the third image IM3 by the light LA ​​incident on the eye movement range 14a, and recognizes the fourth image IM4 by the light LB incident on the eye movement range 14a. The third image IM3 is a virtual image based on the first image, and the fourth image IM4 is a virtual image based on the second image. In this embodiment, the fourth image IM4 is displayed above the third image IM3.

[0077] Moreover, the distance DA to the third image IM3 recognized by the identifier 14 can be mainly controlled by the curvature RA of the first concave surface 113aA of the first reflecting member 113A. Similarly, the distance DB to the fourth image IM4 recognized by the identifier 14 can be mainly controlled by the curvature RB of the second concave surface 113aB of the second reflecting member 113B. The larger the curvature RA or RB, the closer the third image IM3 or the fourth image IM4 appears. Therefore, by making the curvature RA and the curvature RB different, the distance DA to the third image IM3 and the distance DB to the fourth image IM4 recognized by the identifier 14 can be made different. As a result, the identifier 14 can recognize the virtual image three-dimensionally.

[0078] In this embodiment, for example, by making the curvature RA greater than the curvature RB and making the distance DA shorter than the distance DB, the identifier 14 can see the third image IM3 as being closer than the fourth image IM4. For example, the third image IM3 is recognized at a position 5 m in front of the identifier 14, and the fourth image IM4 is recognized at a position 10 m in front of the identifier 14. In one example, Figure 4 As shown, the third image IM3 can display information indicating the driving state of the automobile 1000, such as speed, and the fourth image IM4 can also display navigation information, such as the direction of the turn.

[0079] The values ​​of the curvature RA and the curvature RB depend on the design conditions of the image display device 10, and are generally about 5 mm to 1000 mm. In addition, the curvature RA and the curvature RB have a positive correlation with the first optical path length LPA from the first display device 110A to the first reflecting component 113A and the second optical path length LPB from the second display device 110B to the second reflecting component 113B. The greater the curvature, the longer the optical path length is required. That is, RA>RB, and LPA>LPB, or RA<RB, and LPA<LPB. It should be noted that RA=RB, and LPA=LPB may also be used. In this case, DA=DB, and no three-dimensional effect is obtained.

[0080] In one example, when the distance DA and the distance DB are set to 3m~10m, the size of the eye movement range 14a is set to 150mm in the horizontal direction (X direction) and 60mm in the vertical direction (Z direction), the FOV (field of view) is set to 1.46 degrees in the horizontal direction (X direction) and 0.365 degrees in the vertical direction (Z direction), and the size of the display device 110 is set to 2.2mm×8.8mm, the curvature RA and the curvature RB become 100mm~200mm, and the first optical path length LPA and the second optical path length LPB become 80mm~90mm.

[0081] Next, the effects of this embodiment will be described.

[0082] In this embodiment, the light source unit 11 includes two display devices (a first display device 110A and a second display device 110B), and by independently setting the curvature RA of the first concave surface 113aA of the first reflecting member 113A and the curvature RB of the second concave surface 113aB of the second reflecting member 113B, the distance DA to the third image IM3 and the distance DB to the fourth image IM4 can be independently set. Thus, a three-dimensional virtual image can be formed.

[0083] In addition, in the present embodiment, the light emitted from the first display device 110A is emitted from the light source unit 11 via the first polarizer 111A, the reflective polarizer 117, the first wave plate 114A, the first reflective member 113A, the first wave plate 114A, the reflective polarizer 117, and the third wave plate 115. On the other hand, the light emitted from the second display device 110B is emitted from the light source unit 11 via the second polarizer 111B, the reflective polarizer 117, the second wave plate 114B, the second reflective member 113B, the second wave plate 114B, the reflective polarizer 117, and the third wave plate 115. In this way, the light emitted from the first display device 110A and forming the third image IM3 and the light emitted from the second display device 110B and forming the fourth image IM4 pass through the same number and the same type of optical elements. Therefore, the quality of the third image IM3 and the fourth image IM4 can be made consistent, and the third image IM3 and the fourth image IM4 are less mismatched from the viewer 14. As a result, a virtual image of good quality can be displayed as a whole.

[0084] In addition, since the light source unit 11 of the present embodiment has the third wave plate 115, the light LA ​​and the light LB emitted from the light source unit 11 can be circularly polarized. As a result, the difference in reflectivity when the light LA ​​and the light LB are reflected on the front windshield 13a is reduced, and the brightness of the third image IM3 and the fourth image IM4 becomes uniform. As a result, the quality of the virtual image is also improved.

[0085] In addition, in the present embodiment, since the first reflecting member 113A and / or the second reflecting member 113B have a substantially telecentric property on the first image IM1 side and / or the second image IM2 side, a compact and high-quality image can be displayed. This effect will be described in detail below.

[0086] Figure 5A It is a schematic diagram showing the principle of the light source unit of this embodiment.

[0087] Figure 5B It is a schematic diagram showing the principle of the light source unit of the reference example.

[0088] exist Figure 5A In FIG. 1 , the light distribution pattern of light emitted from two pixels 110 p among the plurality of pixels 110 p of the display device 110 of the present embodiment is indicated by a dotted line. Figure 5B In FIG. 1 , the light distribution pattern of light emitted from two pixels 2110p among the plurality of pixels 2110p of the display device 2110 of the reference example is indicated by a dotted line. Figure 5A and Figure 5B In the figure, the imaging optical systems 120 and 2120 are simplified.

[0089] like Figure 5BAs shown, in the light source unit 2011 of the reference example, the display device 2110 is a liquid crystal display device (Liquid Crystal Display: LCD) including a plurality of pixels 2110p. Figure 5B As shown by the dotted line in the middle, the light emitted from each pixel 2110p is mainly distributed in the normal direction of the light emitting surface 2110s. In addition, there are multiple planes including the optical axis of the light emitted from a pixel 2110p. In the display device 2110 as an LCD, the light distribution pattern of the light emitted from a pixel 2110p is different in each plane. Moreover, in one plane among the multiple planes, the light emitted from each pixel 2110p has a luminous intensity in the direction at an angle θ relative to the optical axis, which is cosine of the luminous intensity on the optical axis. 20 The light distribution pattern is approximately theta times.

[0090] In such a display device 2110, even for light emitted from the same position of the display device 2110, the luminosity and chromaticity vary depending on the angle at which the viewer observes. Therefore, assuming that the first reflecting component 113A and / or the second reflecting component 113B (hereinafter collectively referred to as the "reflecting component") takes in light emitted from each pixel 2110p in a direction other than the normal direction, even if the brightness of the light emitted from all pixels 2110p is made uniform, uneven brightness or chromaticity occurs in the first image IM1 and / or the second image (hereinafter collectively referred to as the "first image, etc."). That is, the quality of the first image, etc. is reduced. Therefore, in order to prevent the quality of the first image, etc. from being reduced, it is necessary to take in light emitted from each pixel 2110p of the display device 2110 from the normal direction. As a result, the reflecting component is enlarged.

[0091] In contrast, in the light source unit 11 of the present embodiment, the reflective component has a substantially telecentric property on one side of the first image, etc., and the light emitted from the display device 110 has a substantially Lambertian distribution. Therefore, it is possible to improve the quality of the first image, etc. while miniaturizing the light source unit 11. Specifically, the display device 110 is an LED display having a plurality of LED elements 112, and the light emitted from each LED element 112 has a substantially Lambertian distribution. Therefore, the luminance and chromaticity of the light emitted from each pixel 110p of the display device 110 have a lower dependence on the angle than the luminance and chromaticity of the light emitted from each pixel 2110p of the display device 2110 in the reference example. In particular, the closer to the strict Lambertian distribution, that is, the approximate formula of the light distribution pattern, i.e., cos n The closer n of θ is to 1, the more uniform the luminance and chromaticity of light emitted from each pixel 110p of the display device 110 are regardless of the angle. Figure 5A As shown, even if the reflecting member takes in light from a direction other than the normal direction, it is possible to suppress unevenness in brightness and chromaticity of the first image, etc., thereby improving the quality of the first image, etc.

[0092] In addition, in the present embodiment, the first image etc. is formed between the light source unit 11 and the reflection unit 12. In this case, light emitted from a certain point of the display device 110 is focused at the position where the first image etc. is formed. On the other hand, in the case where the first image etc. is not formed between the light source unit 11 and the reflection unit 12, the optical path of light emitted from a certain point of the display device 110 gradually expands from the light source unit 11 toward the reflection unit 12. Therefore, in the present embodiment, the range of the light emitted from a certain point of the display device 110 in the third wave plate 115 can be reduced compared to the case where the first image etc. is not formed. Therefore, the third wave plate 115 can be miniaturized.

[0093] Furthermore, since the light source unit 11 of the present embodiment is small, when the light source unit 11 is mounted on the vehicle 13 and used as a head-up display, the light source unit 11 can be easily arranged in a limited space in the vehicle 13 .

[0094] <Example>

[0095] Next, light source units according to the embodiment and reference examples are described.

[0096] Fig. 6A It is a graph showing the light distribution pattern of light emitted from one light emitting area in Examples 1 and 11, Reference Example, and LCD.

[0097] Figure 6B It is a graph showing the uniformity of brightness of the third image in Examples 1 to 12 and the reference example.

[0098] The image display devices of Examples 1 to 12 and the reference example include a light source unit and a reflection unit, and the light source unit is set on the simulation software in a manner that includes a plurality of light-emitting regions arranged in a matrix and an imaging optical system including a first polarizer 111A, a reflective polarizer 117, a first reflection member 113A, a first wavelength plate 114A, and a third wavelength plate 115. Each light-emitting region corresponds to each pixel 110p of the display device 110 of the above-described embodiment.

[0099] exist Fig. 6A In the figure, the horizontal axis is the angle of the light-emitting area relative to the optical axis, and the vertical axis is the luminance normalized by dividing the luminance at the angle by the luminance on the optical axis, indicating a relative value when the maximum value is set to 1. Fig. 6A As shown, the light emitted from each light emitting area is set on the simulation software to have a light distribution pattern in which the light intensity in the direction forming an angle θ with respect to the optical axis is expressed as cosθ times the light intensity on the optical axis. That is, in Example 1, the light emitted from each light emitting area has a strict Lambertian light distribution.

[0100] In Examples 2 to 12, the light emitted from each light emitting region has a luminous intensity in a direction that makes an angle θ with respect to the optical axis and a cosine of the luminous intensity on the optical axis. n The form of the light distribution pattern expressed by θ times is set on the simulation software. It should be noted that in Example 2, n=2, and n is set to be gradually increased from Example 2 to Example 12.

[0101] In addition, the light distribution pattern of light emitted from the pixels of the LCD in one plane is investigated and found to be Fig. 6A As described above, it can be seen that the light distribution pattern can be adjusted to the light intensity in the direction forming an angle θ with respect to the optical axis by cosine of the light intensity on the optical axis. 20 Therefore, in the reference example, the luminous intensity in the direction having an angle θ with respect to the optical axis of each light emitting region is calculated by cosine of the luminous intensity on the optical axis. 20 The method of expressing the light distribution pattern in θ-fold is set on the simulation software.

[0102] The optical functions of the imaging optical system in Examples 1 to 12 and the reference example, namely, the first polarizing plate 111A, the reflective polarizing plate 117 , the first reflecting member 113A, the first wave plate 114A, and the third wave plate 115 are all set to have telecentricity on the first image side.

[0103] Next, for each of Examples 1 to 12 and the reference example, the brightness distribution of the third image formed when the brightness of the entire light-emitting area is constant was simulated. At this time, the third image was set to a rectangle with a long side of 111.2 mm and a short side of 27.8 mm. In addition, at this time, the plane forming the third image was divided into square areas with a side of 1 mm, and the brightness value of each area was simulated.

[0104] In addition, the brightness uniformity of the third image at this time was evaluated. Here, "brightness uniformity" is a value expressing the ratio of the minimum brightness value to the maximum brightness value in the third image in percentage. The results are shown in Figure 6B It should be noted that Figure 6B In the figure, the horizontal axis represents the embodiments and the reference example, and the vertical axis represents the uniformity of brightness.

[0105] like Figure 6B As shown, it can be seen that the larger n is, the lower the uniformity of brightness is. This is because the larger n is, the lower the brightness is at the position far from the center in the third image. In particular, it can be seen that in Example 11, that is, when n=11, the uniformity of brightness is 30%. Because it is easy for the viewer to distinguish the third image and the area where the third image is not formed, it is also considered that the uniformity of brightness of the third image only needs to be 30% or more.

[0106] Therefore, it can be seen that when the imaging optical system is configured to have a substantially telecentric property, in order to suppress the uneven brightness of the first image and the third image, it is preferred that the light emitted from the display device has a substantially Lambertian light distribution. Specifically, it can be seen that the approximate formula of the light distribution pattern, i.e., cos n The value n of θ is preferably 11 or less, and more preferably 1. It should be noted that, as described above, the uniformity of the brightness of the third image IM3 decreases as n deviates from 1, but a predetermined brightness distribution can be set in advance for the display brightness of the display device 110 to compensate for such brightness non-uniformity. For example, in a case where the brightness of the light emitted from each pixel 110p of the display device 110 is easily lower at the outer edge portion of the second image IM2 than at the center portion via the imaging optical system, the display device 110 can also be controlled so that the output of the LED element 112 of the pixel 110p on the outer edge side of the display device 110 is greater than the output of the LED element 112 of the pixel 110p on the center side.

[0107] <Second embodiment>

[0108] Next, a second embodiment will be described.

[0109] Figure 7 It is an end view showing the light source unit according to the present embodiment.

[0110] Figure 8 This is a cross-sectional view showing an enlarged portion of the first display device according to the present embodiment.

[0111] like Figure 7 As shown, the light source unit 21 of this embodiment is different from the light source unit 11 of the first embodiment in that a first display device 710A is provided to replace the first display device 110A and the first polarizer 111A, and a second display device 710B is provided to replace the second display device 110B and the second polarizer 111B.

[0112] like Figure 8 As shown, in the first display device 710A of this embodiment, the light emitting surface of the LED element 712 is substantially flat, and it also has a protective layer 714, a wavelength conversion component 715, a light scattering component 716, and a first polarizer 740, which is different from the first display device 110A of the first embodiment. The first polarizer 740 is arranged on the LED element 712 for the light emitted from the LED element 112 to enter. The other structures of the display device 710A are the same as those of the first display device 110A of the first embodiment.

[0113] Similarly, in the second display device 710B, the light emitting surface of the LED element 712 is substantially flat, and it also has a protective layer 714, a wavelength conversion component 715, a light scattering component 716, and a second polarizer. The other structures of the second display device 710B are the same as those of the second display device 110B of the first embodiment. In the following description, the first display device 710A is described, but the second display device 710B is also the same.

[0114] In the first display device 710A, a protective layer 714 covers a plurality of LED elements 712 arranged in a matrix. The protective layer 714 can be made of a light-transmitting material such as a polymer material having a sulfur (S)-containing substituent or a phosphorus (P)-containing atom group, or a high-refractive-index nanocomposite material having inorganic nanoparticles of high refractive index introduced into a polymer matrix such as polyimide.

[0115] The wavelength conversion component 715 is disposed on the protective layer 714. The wavelength conversion component 715 includes one or more wavelength conversion materials such as general phosphor materials, perovskite phosphor materials, or quantum dots (Quantum Dot: QD). The light emitted from each LED element 712 is incident on the wavelength conversion component 715. The wavelength conversion material contained in the wavelength conversion component 715 emits light of a peak wavelength different from the peak wavelength of light emission of each LED element 712 by allowing the light emitted from each LED element 712 to be incident. The light emitted by the wavelength conversion component 715 has a substantially Lambertian light distribution.

[0116] The light scattering component 716 includes, for example, a resin component having light transmittance and light scattering particles or pores disposed in the resin component. As the resin component, for example, polycarbonate can be cited. As the light scattering particles, for example, materials having a refractive index difference with the resin component such as titanium oxide can be cited. It should be noted that the light scattering component 716 can also obtain a light scattering effect by roughening its surface and providing concavoconvexity.

[0117] As the first polarizer 740, for example, a multilayer thin film laminated polarizer formed by laminating thin film layers with different polarization characteristics can be used. The first polarizer 740 is arranged on the light scattering component 716. Therefore, the light emitted from the LED element 712 and the wavelength conversion component 715 is incident on the first polarizer 740. The first polarizer 740 transmits the first polarized light 710p in the light emitted from the wavelength conversion component 715, and reflects the second polarized light 710s toward the wavelength conversion component 715. The vibration direction of the electric field of the second polarized light 710s is approximately orthogonal to the vibration direction of the electric field of the first polarized light 710p. In the present embodiment, the first polarized light 710p is P polarized light, and the second polarized light 710s is S polarized light.

[0118] Specifically, if Figure 8As shown, the light emitted from the LED element 712 is irradiated on the wavelength conversion component 715. As a result, the wavelength conversion component 715 is excited to emit light having a peak wavelength longer than the peak wavelength of the light emitted from the LED element 712. In the present embodiment, the light emitted from the wavelength conversion component 715 includes light emitted from the LED element 712 and not subjected to wavelength conversion by the wavelength conversion component 715 and light emitted from the LED element 712 and subjected to wavelength conversion by the wavelength conversion component 715. Hereinafter, among the light emitted from the wavelength conversion component 715, the light emitted from the LED element 712 and not subjected to wavelength conversion by the wavelength conversion component 715 is also referred to as "short wavelength light", and the light emitted from the LED element 712 and subjected to wavelength conversion by the wavelength conversion component 715 is also referred to as "long wavelength light". However, most of the light emitted from the LED element 712 may also be absorbed by the wavelength conversion component 715.

[0119] Most of the first polarized light 710p contained in these short-wavelength light and long-wavelength light is transmitted through the first polarizer 740 and emitted from the first display device 710A. In addition, most of the second polarized light 710s contained in these short-wavelength light and long-wavelength light is reflected by the first polarizer 740. A part of the second polarized light 710s reflected by the first polarizer 740 is scattered and reflected in the components of the first display device 710A such as the light scattering component 716 and the wavelength conversion component 715. Through scattered reflection, a part of the second polarized light 710s is converted into the first polarized light 710p. A part of the first polarized light 710p converted from the second polarized light 710s is transmitted through the first polarizer 740 and emitted from the first display device 710A. Therefore, it is possible to increase the proportion of the first polarized light 710p contained in the light emitted from the first display device 710A, and at the same time increase the brightness of the first image IM1. By increasing the brightness of the first image IM1, the brightness of the third image IM3 is also increased. As a result, the recognizer 14 can easily recognize the third image IM3.

[0120] In addition, a portion of the short-wavelength light contained in the second polarized light 710s may also be incident on the wavelength conversion component 715 after being reflected by the first polarizer 740. In this case, it is expected that the wavelength conversion component 715 absorbs the short-wavelength light of the second polarized light 710s and re-radiates the long-wavelength light. These scattered reflected light and radiated light have a roughly Lambertian light distribution. In addition, the first polarizer 740 itself may also scatter and reflect the second polarized light 710s. In this case, by scattering and reflection, a portion of the second polarized light 710s is also converted into the first polarized light 710p.

[0121] Similarly, in the second display device 710B, the ratio of the second polarized light 710s contained in the light emitted from the second display device 710B can be increased, and the brightness of the second image IM2 can be increased. By increasing the brightness of the second image IM2, the brightness of the fourth image IM4 is also increased. As a result, the viewer 14 can easily recognize the fourth image IM4.

[0122] In the present embodiment, one first polarizer 740 covers all pixels of the first display device 710A. However, the first display device 710A may also include a plurality of first polarizers 740, each of which is disposed on each pixel. In addition, the structure of the first display device is not limited to the above. For example, by using the scattering reflection effect of light possessed by the wavelength conversion component, the first display device may also be configured as a structure in which a light scattering component is not provided. In addition, by using the scattering reflection effect of the light scattering component, the first display device may also be configured as a structure in which a wavelength conversion component is not provided. In addition, as in the first embodiment, by using the scattering reflection effect of light realized by a plurality of concave portions or a plurality of convex portions provided on the light emitting surface of the LED element, the first display device support may also be provided with a structure in which any one of the wavelength conversion component and the light scattering component is provided. The same is true for the second display device.

[0123] Next, the effects of this embodiment will be described.

[0124] In the present embodiment, the light source unit 21 can be further miniaturized by incorporating the first polarizing plate 740 into the first display device 710A and incorporating the second polarizing plate into the second display device 710B.

[0125] In addition, the light emitted from the first polarizer 740 also has a roughly Lambertian light distribution. Therefore, in this embodiment, it is also possible to provide a light source unit 21 that is small and can form a high-quality first image, etc. It should be noted that because the plurality of LED elements 712 are discretely mounted on the substrate 111, the first image, etc. sometimes produces a granular feel. The wavelength conversion component 715 has the effect of alleviating the granular feel. Moreover, the light scattering component 716 can further enhance the effect of alleviating the granular feel. The structure, operation and effect of this embodiment other than the above are the same as those of the first embodiment.

[0126] <Third Embodiment>

[0127] Next, a third embodiment will be described.

[0128] Fig. 9 It is an end view showing the light source unit according to the present embodiment.

[0129] like Fig. 9As shown, the light source unit 31 of this embodiment has the same structure as the light source unit 11 of the first embodiment, but is different in that a first light shielding member 116A and a second light shielding member 116B are further provided.

[0130] The first light shielding member 116A is disposed on the optical path from the first display device 110A to the first reflective member 113A. The first light shielding member 116A is provided with an opening 116aA through which a portion of the light from the first display device 110A to the first reflective member 113A passes. The first light shielding member 116A shields another portion of the light from the first display device 110A to the first reflective member 113A. For example, the first light shielding member 116A is disposed between the first polarizer 111A and the reflective polarizer 117.

[0131] The second light shielding member 116B is disposed on the optical path from the second display device 110B to the second reflective member 113B. The second light shielding member 116B is provided with an opening 116aB through which a portion of the light from the second display device 110B to the second reflective member 113B passes. The second light shielding member 116B shields another portion of the light from the second display device 110B to the second reflective member 113B. For example, the second light shielding member 116B is disposed between the second polarizer 111B and the reflective polarizer 117.

[0132] According to this embodiment, by providing the first light shielding member 116A and the second light shielding member 116B, the generation of stray light can be suppressed, and the quality of the virtual image can be further improved. The structure, operation and effects of this embodiment other than the above are the same as those of the first embodiment.

[0133] <Fourth embodiment>

[0134] Next, a fourth embodiment will be described.

[0135] Fig.10 It is a perspective view showing a wire grid polarizing plate according to this embodiment.

[0136] In the present embodiment, a wire grid polarizing plate 121 is provided as each of the first polarizing plate and the second polarizing plate.

[0137] like Fig.10 As shown, in the wire grid polarizer 121, a plurality of metal wires 121b are arranged in parallel with each other at equal intervals on a transparent resin film 121a. Thus, the wire grid polarizer 121 transmits the first polarized light in the light emitted from the LED element and reflects the second polarized light to return it to the LED element. Alternatively, the second polarized light in the light emitted from the LED element is transmitted and the first polarized light is reflected to return it to the LED element. The structure, operation and effect of this embodiment other than the above are the same as those of the first embodiment.

[0138] The above-mentioned embodiments and their variations are examples of specific implementations of the present invention, and the present invention is not limited to these embodiments. For example, in the above-mentioned embodiments, embodiments in which some components or processes are added, deleted or changed are also included in the present invention. In addition, the above-mentioned embodiments can be implemented in combination with each other.

[0139] The embodiments include the following aspects.

[0140] (Note 1)

[0141] A light source unit, comprising:

[0142] a first display device capable of displaying a first image;

[0143] a second display device capable of displaying a second image;

[0144] a first polarizer configured to set the light emitted from the first display device as first polarized light having a first polarization direction;

[0145] a second polarizer configured to set the light emitted from the second display device as second polarized light having a second polarized light direction different from the first polarized light direction;

[0146] a reflective polarizer that transmits the first polarized light and reflects the second polarized light;

[0147] a first reflecting member having a first concave surface, for reflecting the first polarized light transmitted through the reflective polarizer toward the reflective polarizer by the first concave surface, and projecting a first image corresponding to the first image onto a projection unit, thereby making the image recognizable to the viewer appear to be displayed on the opposite side of the projection unit from the viewer;

[0148] A first wavelength plate disposed between the reflective polarizer and the first reflective component;

[0149] a second reflecting member having a second concave surface, for reflecting the second polarized light reflected by the reflective polarizer toward the reflective polarizer by the second concave surface, and projecting a second image corresponding to the second image onto the projection unit, thereby making the image recognizable by the recognizer appear to be displayed on the opposite side of the projection unit from the recognizer;

[0150] a second wavelength plate disposed between the reflective polarizer and the second reflective member,

[0151] A first optical path length of light emitted from the first display device from the first display device to the first reflecting component is longer than a second optical path length of light emitted from the second display device from the second display device to the second reflecting component, and a curvature of the first concave surface is greater than a curvature of the second concave surface, or, the first optical path length is shorter than the second optical path length, and a curvature of the first concave surface is smaller than a curvature of the second concave surface.

[0152] (Note 2)

[0153] The light source unit according to Supplementary Note 1, wherein:

[0154] A third wave plate is further provided, the third wave plate transmitting the light reflected by the first reflecting member and reflected by the reflective polarizer, and the light reflected by the second reflecting member and transmitted through the reflective polarizer.

[0155] (Note 3)

[0156] The light source unit according to Supplementary Note 2, wherein:

[0157] The first wavelength plate, the second wavelength plate, and the third wavelength plate are 1 / 4λ plates.

[0158] (Note 4)

[0159] The light source unit according to any one of appendices 1 to 3, wherein:

[0160] The first reflecting component and / or the second reflecting component has a substantially telecentric property on the first image side and / or the second image side,

[0161] The light emitted from the first display device and / or the light emitted from the second display device has a substantially Lambertian light distribution.

[0162] (Note 5)

[0163] The light source unit according to Supplement 4, wherein:

[0164] The light emitted from the first display device has a luminance in a direction at an angle θ relative to the optical axis of the light emitted from the first display device, which is equal to cosine of the luminance on the optical axis. n1 The light distribution pattern is similar to θ times.

[0165] The light emitted from the second display device has a luminance in a direction at an angle θ relative to the optical axis of the light emitted from the second display device, which is proportional to the cosine of the luminance on the optical axis. n2 The light distribution pattern is similar to θ times.

[0166] The n1 and the n2 are respectively values ​​greater than 0.

[0167] (Note 6)

[0168] The light source unit according to Supplementary Note 5, wherein:

[0169] The n1 and the n2 are respectively less than 11.

[0170] (Note 7)

[0171] The light source unit according to any one of appendices 1 to 6, wherein:

[0172] The first display device is a first LED display having a plurality of LED elements,

[0173] The second display device is a second LED display having a plurality of LED elements.

[0174] (Note 8)

[0175] The light source unit according to Supplementary Note 7, wherein:

[0176] The light emitted from the LED element has a substantially Lambertian light distribution.

[0177] (Note 9)

[0178] The light source unit according to Appendix 7 or 8, wherein:

[0179] The first display device further includes a first wavelength conversion member, which is arranged on the LED element and for light emitted from the LED element to enter.

[0180] The second display device further includes a second wavelength conversion member that is disposed on the LED element and into which light emitted from the LED element is incident.

[0181] (Note 10)

[0182] The light source unit according to any one of appendices 1 to 9, further comprising:

[0183] A first light shielding member is disposed on a light path from the first display device toward the first reflecting member, has an opening for passing a portion of the light from the first display device toward the first reflecting member, and shields another portion of the light from the first display device toward the first reflecting member;

[0184] The second light shielding member is arranged on the optical path from the second display device to the second reflecting member, has an opening for allowing a part of the light from the second display device to the second reflecting member to pass, and shields another part of the light from the second display device to the second reflecting member.

[0185] (Note 11)

[0186] An image display device comprising:

[0187] The light source unit according to any one of supplementary notes 1 to 10;

[0188] a reflection unit, which is separated from the light source unit and reflects the light emitted from the light source unit,

[0189] The first image and the second image are formed between the light source unit and the reflection unit.

[0190] (Note 12)

[0191] A car comprising:

[0192] vehicle;

[0193] The image display device described in Supplementary Note 11 is fixed to the vehicle.

[0194] Industrial Applicability

[0195] The present invention can be used, for example, in a head-up display.

[0196] Description of Reference Numerals

[0197] 10: Image display device

[0198] 11: Light source unit

[0199] 12: Reflection unit

[0200] 13: Vehicles

[0201] 13a: Front windshield

[0202] 13b: Top

[0203] 13c: Instrument panel

[0204] 13h1, 13h2: Through hole

[0205] 13s1, 13s2: wall

[0206] 14: Identifier

[0207] 14a: Eye Movement Range

[0208] 21: Light source unit

[0209] 31: Light source unit

[0210] 110: Display device

[0211] 110A: First display device

[0212] 110B: Second display device

[0213] 110p: Pixel

[0214] 111: Substrate

[0215] 111A: First polarizer

[0216] 111B: Second polarizer

[0217] 112: LED components

[0218] 112a: Semiconductor stack

[0219] 112b: Anode electrode

[0220] 112c: cathode electrode

[0221] 112p1: p-type semiconductor layer

[0222] 112p2: Active layer

[0223] 112p3: n-type semiconductor layer

[0224] 112s: light exit surface

[0225] 112t: concave part

[0226] 113A: First reflecting component

[0227] 113aA: First concave surface

[0228] 113B: Second reflecting member

[0229] 113aB: Second concave surface

[0230] 114A: First Wavelength Plate

[0231] 114B: Second wavelength plate

[0232] 115: Third wavelength plate

[0233] 116A: First light shielding member

[0234] 116aA: Opening

[0235] 116B: Second light shielding member

[0236] 116aB: Opening

[0237] 117: Reflective polarizer

[0238] 117a: Side 1

[0239] 117b: Side 2

[0240] 118a, 118b: Wiring

[0241] 120, 2120: Imaging optical system

[0242] 121: Wire grid polarizer

[0243] 121a: Resin film

[0244] 121b: Metal wire

[0245] 131: Reflector

[0246] 131a: Reflective mirror

[0247] 710A: First display device

[0248] 710B: Second display device

[0249] 712: LED components

[0250] 714: Protective layer

[0251] 715: Wavelength conversion components

[0252] 716: Light scattering components

[0253] 740: First polarizer

[0254] 1000: Cars

[0255] 2011: Light source unit

[0256] 2110: Display device

[0257] 2110p: Pixel

[0258] 2110s: light exit surface

[0259] C: Optical axis

[0260] DA, DB: distance

[0261] IM1: First Image

[0262] IM2: Second Image

[0263] IM3: Third Image

[0264] IM4: The Fourth Image

[0265] LA: light

[0266] LB: Light

[0267] LPA: First optical path length

[0268] LPB: Second optical path length

[0269] RA: Curvature

[0270] RB: Curvature

[0271] a1: point

[0272] a2: point

[0273] θ: Angle

Claims

1. A light source unit, characterized in that: have: a first display device capable of displaying a first image; a second display device capable of displaying a second image; a first polarizer configured to set the light emitted from the first display device as first polarized light having a first polarization direction; a second polarizer configured to set the light emitted from the second display device as second polarized light having a second polarized light direction different from the first polarized light direction; a reflective polarizer that transmits the first polarized light and reflects the second polarized light; a first reflecting member having a first concave surface, for reflecting the first polarized light transmitted through the reflective polarizer toward the reflective polarizer by the first concave surface, and projecting a first image corresponding to the first image onto a projection unit, thereby making the image recognizable to the viewer appear to be displayed on the opposite side of the projection unit from the viewer; A first wavelength plate disposed between the reflective polarizer and the first reflective component; a second reflecting member having a second concave surface, for reflecting the second polarized light reflected by the reflective polarizer toward the reflective polarizer by the second concave surface, and projecting a second image corresponding to the second image onto the projection unit, thereby making the image recognizable by the recognizer appear to be displayed on the opposite side of the projection unit from the recognizer; a second wavelength plate disposed between the reflective polarizer and the second reflective member, A first optical path length of light emitted from the first display device from the first display device to the first reflecting component is longer than a second optical path length of light emitted from the second display device from the second display device to the second reflecting component, and a curvature of the first concave surface is greater than a curvature of the second concave surface, or, the first optical path length is shorter than the second optical path length, and a curvature of the first concave surface is smaller than a curvature of the second concave surface.

2. The light source unit according to claim 1, wherein: A third wave plate is further provided, the third wave plate transmitting the light reflected by the first reflecting member and reflected by the reflective polarizer, and the light reflected by the second reflecting member and transmitted through the reflective polarizer.

3. The light source unit according to claim 2, wherein: The first wavelength plate, the second wavelength plate, and the third wavelength plate are 1 / 4λ plates.

4. The light source unit according to any one of claims 1 to 3, wherein: The first reflecting component and / or the second reflecting component has a substantially telecentric property on the first image side and / or the second image side, The light emitted from the first display device and / or the light emitted from the second display device has a substantially Lambertian light distribution.

5. The light source unit according to claim 4, wherein: The light emitted from the first display device has a luminance in a direction at an angle θ relative to the optical axis of the light emitted from the first display device, which is equal to cosine of the luminance on the optical axis. n1 The light distribution pattern is similar to θ times. The light emitted from the second display device has a luminance in a direction at an angle θ relative to the optical axis of the light emitted from the second display device, which is equal to cosine of the luminance on the optical axis. n2 The light distribution pattern is similar to θ times. The n1 and the n2 are respectively values ​​greater than 0.

6. The light source unit according to claim 5, wherein: The n1 and the n2 are respectively less than 11.

7. The light source unit according to any one of claims 1 to 6, wherein: The first display device is a first LED display having a plurality of LED elements, The second display device is a second LED display having a plurality of LED elements.

8. The light source unit according to claim 7, wherein: The light emitted from the LED element has a substantially Lambertian light distribution.

9. The light source unit according to claim 7 or 8, wherein: The first display device further includes a first wavelength conversion member, which is arranged on the LED element and for light emitted from the LED element to enter. The second display device further includes a second wavelength conversion member that is disposed on the LED element and into which light emitted from the LED element is incident.

10. The light source unit according to any one of claims 1 to 9, wherein: Also available: A first light shielding member is disposed on a light path from the first display device toward the first reflecting member, has an opening for passing a portion of the light from the first display device toward the first reflecting member, and shields another portion of the light from the first display device toward the first reflecting member; The second light shielding member is arranged on the optical path from the second display device to the second reflecting member, has an opening for allowing a part of the light from the second display device to the second reflecting member to pass, and shields another part of the light from the second display device to the second reflecting member.

11. An image display device, characterized in that: have: The light source unit according to any one of claims 1 to 10; a reflection unit, which is separated from the light source unit and reflects the light emitted from the light source unit, The first image and the second image are formed between the light source unit and the reflection unit.

12. A car, characterized in that: have: vehicle; The image display device according to claim 11 is fixed to the vehicle.

Images