Head-up display device

Abstract

A head-up display device (10) comprises a single image forming unit (20) for emitting each of a first light (L1) and a second light (L2), and an optical path adjustment part (40) which is positioned on the optical path of at least one of the first light (L1) and the second light (L2) and which is optically transparent and has an optical power of substantially zero. The optical path adjustment part (40) gradually separates the first light (L1) and the second light (L2) relative to before at least one of the first light (L1) and the second light (L2) is incident on the optical path adjustment part (40), so that the first light (L1) forms a first virtual image (V1) that appears near from a driver's perspective, and the second light (L2) forms a second virtual image (V2) that appears farther away than the first virtual image (V1) from the driver's perspective.

Description

[Technical Field]

[0001] The present invention relates to a head-up display device, and more particularly to a head-up display device capable of displaying virtual images at both a relatively close position in front and a relatively far position in front. [Background technology]

[0002] In recent years, a head-up display device has become known that can display a virtual image that is displayed at a relatively close position in front of the windshield, as well as another virtual image that is further away than the virtual image, as described in Patent Document 1 below, for example. The head-up display device of Patent Document 1 has two image forming units (PGUs), one of which emits light that becomes a virtual image that appears close, and the other image forming unit emits light that becomes a virtual image that appears far away.

[0003] [Patent Document 1] International Publication No. 2015-159521 Summary of the Invention

[0004] However, the head-up display device described in Patent Document 1 requires two image forming units to display a distant virtual image and a close virtual image, which tends to increase the size of the device.

[0005] Therefore, an object of the present invention is to provide a head-up display device that can display a near virtual image and a far virtual image while suppressing an increase in the size of the device.

[0006] In order to achieve the above-mentioned object, the head-up display device of the present invention comprises one image forming unit that emits each of a first light and a second light, and an optical path adjustment unit that is arranged on the optical path of at least one of the first light and the second light, has optical transparency, and has almost zero optical power, and is characterized in that the optical path adjustment unit gradually separates the first light and the second light compared to before at least one of the first light and the second light enters the optical path adjustment unit, so that the first light becomes a first virtual image that appears closer to the driver, and the second light becomes a second virtual image that appears farther away than the first virtual image to the driver.

[0007] In order to separate the display positions of two virtual images enough for the driver to distinguish between near and far, it is generally necessary for the light that forms the far virtual image and the light that forms the near virtual image to be emitted from the image forming unit so that they are spaced apart from each other. However, because multiple light beams emitted from a single image generating unit generally tend to be nearly parallel to each other, it is difficult to form virtual images at a distance and a distance that are distinguishable by the driver using a single image generating unit. In contrast, in this head-up display device, the first light and the second light can be gradually separated from each other by the optical path adjusting unit, so that the first light becomes the first virtual image and the second light becomes the second virtual image, compared to before at least one of the first light and the second light enters the optical path adjusting unit. Therefore, two virtual images that allow the driver to distinguish between near and far can be formed by a single image forming unit. Note that an example of an optical path adjusting unit with nearly zero optical power as described above is a prism.

[0008] Thus, unlike the head-up display device of Patent Document 1, which uses two image forming units to form distant and near virtual images, this head-up display device can form distant and near virtual images using a single image forming unit, thereby reducing the number of image forming units and preventing the device from becoming larger.

[0009] Moreover, it is preferable that the head-up display device includes a reflecting section that reflects each of the first light and the second light toward the driver's viewpoint.

[0010] In this case, the optical path of the first light and the optical path of the second light can be changed to desired directions by the reflecting section, which can improve the degree of freedom in design.

[0011] Furthermore, when the head-up display device includes the reflecting portion, the reflecting portion may include a first reflecting portion and a second reflecting portion, and each of the first light and the second light may be reflected in that order from the first reflecting portion to the second reflecting portion.

[0012] In this way, by reflecting the light twice by the reflecting portion, it may become easier to adjust the light path to a desired direction.

[0013] Furthermore, when the reflecting section includes the first reflecting section and the second reflecting section, the optical path of the first light from the image forming unit to the first reflecting section and the optical path of the second light from the image forming unit to the first reflecting section may not intersect.

[0014] In addition, when the optical path of the first light from the image forming unit to the first reflecting section and the optical path of the second light from the image forming unit to the first reflecting section do not intersect, this head-up display device may have an intersection where the optical path of the first light from the image forming unit to the first reflecting section and the optical path of the second light from the first reflecting section to the second reflecting section intersect.

[0015] Furthermore, when the intersecting portion is provided, it is preferable that the optical path adjusting section is disposed on the optical path of the second light from the image forming unit to the first reflecting section.

[0016] As described above, the optical path of the second light from the image forming unit to the first reflecting unit does not have the intersection. Therefore, by disposing the optical path adjustment unit on the optical path of the second light from the image forming unit to the first reflecting unit, the optical path adjustment unit can be disposed so that it does not overlap with the intersection, even without separating the image forming unit from the first reflecting unit. This prevents the device from becoming too large.

[0017] Furthermore, when the reflecting section includes a first reflecting section and a second reflecting section, it is preferable that the first reflecting section is made up of a first convex mirror that reflects the first light and a second convex mirror that reflects the second light, and that the second reflecting section is made up of a single concave mirror that reflects both the first light and the second light.

[0018] Here, a single concave mirror refers to a concave mirror with one focal point on the first reflecting portion side. For this reason, for example, a reflecting member in which two recesses are connected to appear as one member does not qualify as a single concave mirror.

[0019] With this configuration, the first light and the second light can be reflected in the desired direction without increasing the curvature of the concave mirror, thereby suppressing the occurrence of aberrations caused by an increase in the curvature of the concave mirror.

[0020] Furthermore, it is preferable that the optical path adjustment unit reduces the amount of infrared light emitted from the optical path adjustment unit compared to the amount of infrared light before the infrared light was incident on the optical path adjustment unit.

[0021] With this configuration, even if infrared rays enter the head-up display device, the infrared rays can be reduced by the optical path adjusting unit, thereby suppressing a temperature rise in the image forming unit and the like due to the infrared rays.

[0022] In addition, in order to achieve the above-mentioned object, the present invention provides a head-up display device that displays a first virtual image that appears in front of the driver's viewpoint and a second virtual image that appears farther away than the first virtual image, and is characterized by comprising: one image forming unit that emits first light that becomes the first virtual image and second light that becomes the second virtual image; a prism that is arranged on the optical path of the second light; a first convex mirror that reflects the first light; a second convex mirror that reflects the second light; and one concave mirror that reflects the first light reflected by the first convex mirror and the second light reflected by the second convex mirror toward the windshield.

[0023] With this configuration, the first virtual image and the second virtual image can be formed by one image forming unit, which reduces the number of image forming units and prevents the device from becoming too large.

[0024] As described above, according to the present invention, a head-up display device is provided that is capable of displaying a near virtual image and a far virtual image while suppressing an increase in the size of the device. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram schematically illustrating a head-up display device according to an embodiment of the present invention, together with a part of a vehicle in which the head-up display device is mounted. [Figure 2] FIG. 2 is a diagram schematically illustrating the configuration of the head-up display device shown in FIG. 1, as viewed from the left and right directions. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments for carrying out a head-up display device according to the present invention will be described with reference to the accompanying drawings. The embodiments exemplified below are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be modified or improved from the following embodiments without departing from the spirit of the present invention. Furthermore, in this specification, the dimensions of each component may be exaggerated to facilitate understanding.

[0027] 1 is a diagram schematically illustrating a head-up display device 10 according to this embodiment together with a part of a vehicle 1 on which the head-up display device 10 is mounted, and is a diagram illustrating the vehicle 1 as viewed from the left and right. Note that the side in the traveling direction of the vehicle 1 is referred to as the front, the left side relative to the traveling direction as the left, and the right side relative to the traveling direction as the right.

[0028] 1, a head-up display device 10 can be installed in, for example, an instrument panel 1P of a vehicle 1. The head-up display device 10 can emit a first light L1 representing a first virtual image V1 and a second light L2 representing a second virtual image V2. As will be described later, the first virtual image V1 appears in front of the driver's viewpoint VP through the windshield 1F, and the second virtual image V2 appears farther away than the first virtual image V1 through the windshield 1F.

[0029] 2 is a diagram showing a schematic configuration of the head-up display device 10 as viewed from the left and right. As shown in FIG. 2, the head-up display device 10 mainly includes one image forming unit 20, a reflecting section 30, and an optical path adjusting section 40.

[0030] The image forming unit 20 includes a light source 21 and a display 22 .

[0031] The display 22 is disposed on the optical path of light emitted from the light source 21, and in this embodiment is a single plate-shaped liquid crystal display (LCD). The display 22 includes a first region 22A and a second region 22B that are adjacent to each other in the front-to-rear direction. The first region 22A is located in front of the second region 22B. The display 22 in this embodiment is configured so that voltages are applied to the first region 22A and the second region 22B independently of each other, and the orientation pattern of liquid crystal molecules in the first region 22A and the orientation pattern of liquid crystal molecules in the second region 22B change independently of each other. However, the configuration of the display 22 is not limited to this.

[0032] Light emitted from the light source 21 and incident on the first region 22A passes through the first region 22A and becomes first light L1 having a light distribution pattern corresponding to the orientation pattern of liquid crystal molecules in the first region 22A. In this embodiment, for example, the first light L1 is substantially collimated light, and the width of the first light L1 is wide enough to be visible to the human eye. In this embodiment, the first light L1 is emitted upward toward the reflector 30, tilted slightly rearward from the exit surface 22Au of the first region 22A. When irradiated onto a predetermined projection surface, the first light L1 is light that becomes an image representing, for example, a meter display such as the speed or RPM of the vehicle 1, or a road sign on the road on which the vehicle 1 is traveling. However, the image represented by the first light L1 may be an image representing information other than a meter display or a road sign.

[0033] Furthermore, the light emitted from the light source 21 and incident on the second region 22B passes through the second region 22B to become second light L2 having a light distribution pattern corresponding to the orientation pattern of liquid crystal molecules in the second region 22B. In this embodiment, for example, the second light L2 is substantially collimated light, and the width of the second light L2 is wide enough to be visible to the human eye. In this embodiment, the second light L2 is emitted upward from the exit surface 22Bu of the second region 22B toward the reflector 30 in a direction substantially parallel to the first light L1. The exit surface 22Bu is a horizontal plane substantially flush with the exit surface 22Au. When the second light L2 is irradiated onto a predetermined projection surface, it forms an image that is displayed farther away than the image represented by the first light L1. In this embodiment, the image represented by the second light L2 is larger than the image represented by the first light L1 as seen by the driver. An example of the image represented by the second light L2 is an image that can be recognized as augmented reality by being superimposed on the actual scene viewed by the driver of the vehicle 1 through the windshield 1F. However, the image represented by the second light L2 may be smaller than the image represented by the first light L1 as seen by the driver, and may not be an image that can be recognized as augmented reality.

[0034] The optical path adjustment unit 40 is disposed on the optical path of the second light L2 from the image forming unit 20 to the reflector 30. The optical path adjustment unit 40 is composed of an optical element that is optically transparent and has almost zero optical power, and is a so-called prism in this embodiment. Note that collimated light incident on an optical element with almost zero optical power exits the optical element in a state in which convergence and divergence are suppressed. The optical path adjustment unit 40 has an incident surface 40i onto which the second light L2 enters and an exit surface 40o from which the second light L2 exits. The incident surface 40i and the exit surface 40o are both flat and non-parallel to each other. The incident surface 40i is approximately parallel to the exit surface 22Bu of the display 22, and the exit surface 40o is an inclined surface that gradually rises from the front to the rear. Note that the shape of the prism serving as the optical path adjustment unit 40 is not limited to this.

[0035] Furthermore, the optical path adjustment unit 40 of this embodiment is configured to reduce the infrared rays emitted from the optical path adjustment unit 40 compared to before the infrared rays entered the optical path adjustment unit 40. Such an optical path adjustment unit 40 can be formed from a predetermined resin containing an infrared absorbing material, such as a tungsten oxide or phthalocyanine-based material, or can be formed by vapor-depositing an infrared absorbing material on the incident surface 40i or the exit surface 40o of the optical path adjustment unit 40. Examples of the predetermined resin include acrylic resin, polycarbonate (PC) resin, cycloolefin polymer (COP) resin, cyclic olefin copolymer (COC) resin, and silicone. Furthermore, the optical path adjustment unit 40, which reduces the infrared rays emitted from the optical path adjustment unit 40 compared to before the infrared rays entered the optical path adjustment unit 40, can also be formed from glass.

[0036] The second light L2 emitted from the image forming unit 20 in a direction substantially parallel to the first light L1 passes through the optical path adjustment unit 40 and exits from the exit surface 40o so as to be gradually separated from the first light L1 compared to before the second light L2 entered the optical path adjustment unit 40. Therefore, the second light L2 exiting from the exit surface 40o and reaching the reflecting unit 30 is tilted rearward compared to the first light L1 exiting from the image forming unit 20 and reaching the reflecting unit 30. In this way, the section of the second light L2 from the exit surface 40o to the reflecting unit 30 gradually becomes farther away from the first light L1 as it goes upward. Furthermore, because the optical power of the optical path adjustment unit 40 is substantially zero, the second light L2 incident on the optical path adjustment unit 40 exits from the optical path adjustment unit 40 in a state in which convergence and divergence are suppressed. Furthermore, even if the second light L2 diverges or converges somewhat before and after passing through the optical path adjusting unit 40, this is to an extent that is not noticeable to the human eye. Thus, the second light L2 is emitted from the exit surface 40o as a substantially collimated light.

[0037] The reflecting unit 30 is disposed on the optical paths of the first light L1 emitted from the image forming unit 20 and the second light L2 emitted from the optical path adjusting unit 40, and reflects each of the first light L1 and the second light L2 to the driver's viewpoint VP. In this embodiment, the reflecting unit 30 includes a first reflecting unit 31 made of a convex mirror and a second reflecting unit 32 made of a single concave mirror.

[0038] The first reflecting section 31 is disposed on the optical paths of the first light L1 emitted from the image forming unit 20 and the second light L2 emitted from the optical path adjusting section 40, and reflects the first light L1 and the second light L2 toward the second reflecting section 32. In this embodiment, the first reflecting section 31 includes a first convex mirror 31A and a second convex mirror 31B that are spaced apart from each other. The first convex mirror 31A is disposed forward and above the second convex mirror 31B. The first convex mirror 31A and the second convex mirror 31B may be connected. The first convex mirror 31A is disposed approximately directly above the first region 22A and reflects the first light L1 forward and downward. The first light L1 reflected by the first convex mirror 31A enters an area above the vertical center of the second reflecting section 32. The second convex mirror 31B is generally opposed to the exit surface 40o of the optical path adjusting unit 40, and reflects the second light L2 forward and downward. The second light L2 reflected by the second convex mirror 31B enters a region below the center of the second reflecting unit 32 in the vertical direction.

[0039] In this embodiment, the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 does not intersect with the optical path of the second light L2 from the image forming unit 20 to the first reflecting section 31. Furthermore, in this embodiment, the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 intersects with the optical path of the second light L2 from the first reflecting section 31 to the second reflecting section 32, forming an intersection Lx.

[0040] The second reflecting portion 32 is disposed on the optical paths of the first light L1 and the second light L2 reflected by the first reflecting portion 31. The second reflecting portion 32 reflects the first light L1 substantially directly upward, and reflects the second light L2 backward and upward.

[0041] In this way, in the reflecting portion 30, the first light L1 and the second light L2 are each reflected from the first reflecting portion 31 to the second reflecting portion 32 in this order.

[0042] As shown in FIG. 1 , the first light L1 reflected by the second reflector 32 is irradiated onto a predetermined region P1 on the windshield 1F. The second light L2 reflected by the second reflector 32 is irradiated onto a region P2 on the windshield 1F above the predetermined region P1. The first light L1 and the second light L2 guided to the windshield 1F are reflected toward the driver's eye box E at the regions P1 and P2, respectively, and propagate to the eye box E. By positioning the driver's viewpoint VP within the eye box E, the driver of the vehicle 1 can view a first virtual image V1 represented by the first light L1 reflected from the region P1, in front of the viewpoint VP through the windshield 1F. By positioning the driver's viewpoint VP within the eye box E, the driver of the vehicle 1 can view a second virtual image V2 represented by the second light L2 reflected from the region P2, at a distance farther than the first virtual image V1, through the windshield 1F. Since the second light L2 is irradiated onto an area P2 above the area P1 irradiated by the first light L1, the second virtual image V2 appears above the first virtual image V1. In this manner, in this embodiment, the windshield 1F can be considered as a projection surface for displaying the first virtual image V1 and the second virtual image V2. As long as the first virtual image V1 and the second virtual image V2 are visible, the projection surface is not limited to the windshield 1F and may be, for example, a combiner provided inside the vehicle 1.

[0043] As described above, the head-up display device 10 of this embodiment includes one image forming unit 20 that emits each of the first light L1 and the second light L2, and the optical path adjustment unit 40 that is optically transparent and has almost zero optical power and is disposed on the optical path of the second light L2. The optical path adjustment unit 40 gradually separates the first light L1 and the second light L2 from their positions before the second light L2 is incident on the optical path adjustment unit 40, so that the first light L1 becomes a first virtual image V1 that appears closer to the driver, and the second light L2 becomes a second virtual image V2 that appears farther away than the first virtual image V1 to the driver.

[0044] The head-up display device 10 of this embodiment includes one image forming unit 20 that emits a first light L1 that becomes a first virtual image V1 and a second light L2 that becomes a second virtual image V2 that appears farther away than the first virtual image V1, a prism as an optical path adjustment unit 40 that is arranged on the optical path of the second light L2, a first convex mirror 31A that reflects the first light L1, a second convex mirror 31B that reflects the second light L2, and a second reflecting unit 32 that is made up of one concave mirror that reflects the first light L1 reflected by the first convex mirror 31A and the second light L2 reflected by the second convex mirror 31B toward the windshield 1F.

[0045] In order to separate the display positions of two virtual images enough for the driver to distinguish between near and far, it is generally necessary for the light that forms the far virtual image and the light that forms the near virtual image to be emitted from the image forming unit so that they are separated from each other. However, because multiple light beams emitted from a single image generating unit generally tend to be emitted nearly parallel to each other, it is difficult to form virtual images at a distance and a near distance that the driver can distinguish using a single image generating unit. In contrast, in this head-up display device, the first light L1 and the second light L2 can be gradually separated from each other by the optical path adjusting unit 40, so that the first light L1 becomes the first virtual image V1 and the second light L2 becomes the second virtual image V2, compared to before the second light L2 enters the optical path adjusting unit 40. This makes it possible to form two virtual images that allow the driver to distinguish between near and far using a single image forming unit.

[0046] Thus, with this head-up display device 10, unlike when, for example, two image forming units are used to form a distant virtual image and a near virtual image, a single image forming unit can form a distant virtual image and a near virtual image, thereby reducing the number of image forming units and preventing the device from becoming larger.

[0047] Furthermore, as described above, the head-up display device 10 of this embodiment includes the reflector 30 that reflects each of the first light L1 and the second light L2 to the viewpoint VP, and therefore the optical paths of the first light L1 and the second light L2 can be changed to desired directions by the reflector 30, thereby increasing the degree of freedom in design. Furthermore, the reflector 30 includes a first reflector 31 and a second reflector 32 that sequentially reflect the first light L1 and the second light L2, respectively. In this way, by reflecting the light twice by the reflector 30, it may be easier to adjust the optical path to a desired direction.

[0048] Furthermore, in the head-up display device 10 of this embodiment, as described above, the optical path of the first light L1 from the image forming unit 20 to the first reflecting portion 31 and the optical path of the second light L2 from the image forming unit 20 to the first reflecting portion 31 do not intersect, and the head-up display device 10 has an intersection Lx where the optical path of the first light L1 from the image forming unit 20 to the first reflecting portion 31 and the optical path of the second light L2 from the first reflecting portion 31 to the second reflecting portion 32 intersect. With this configuration, in this embodiment, there is no intersection Lx on the optical path of the second light L2 from the image forming unit 20 to the first reflecting portion 31. Therefore, by arranging the optical path adjustment unit 40 on the optical path of the second light L2 from the image forming unit 20 to the first reflecting portion 31 as in this embodiment, the optical path adjustment unit 40 can be arranged so that it does not overlap the intersection Lx, even if the image forming unit 20 is not spaced apart from the first reflecting portion 31. Therefore, it is possible to effectively prevent the device from becoming large.

[0049] Furthermore, in the head-up display device 10 of this embodiment, the first reflecting unit 31 is composed of a first convex mirror 31A that reflects the first light L1 and a second convex mirror 31B that reflects the second light L2, and the second reflecting unit 32 is composed of a single concave mirror that reflects both the first light L1 and the second light L2. With this configuration, the first light L1 and the second light L2 can be reflected in the desired direction without increasing the curvature of the concave mirror. This makes it possible to suppress the occurrence of aberrations caused by an increase in the curvature of the concave mirror.

[0050] Furthermore, in the head-up display device 10 of this embodiment, the optical path adjustment unit 40 is configured to reduce the amount of infrared light emitted from the optical path adjustment unit 40 compared to before the infrared light entered the optical path adjustment unit 40. With this configuration, even if infrared light enters the head-up display device, the infrared light can be reduced by the optical path adjustment unit. Therefore, it is possible to suppress a temperature rise in the image forming unit and the like due to infrared light.

[0051] One possible method for displaying an image at a greater distance in the head-up display device 10 described above is to configure the reflector 30 with a mirror having a large curvature. However, sunlight may enter the head-up display device 10. In this case, if the sunlight is reflected by the mirror having a large curvature, the sunlight may be concentrated in a narrow area on the display 22 of the image forming unit 20. In this case, the portion of the display 22 that is irradiated with the sunlight may be heated by infrared rays. However, as described above, the optical path adjustment unit 40 of this embodiment is configured to reduce infrared rays and is disposed on the optical path of the second light L2 that forms an image displayed at a greater distance. Therefore, even if the curvatures of the first reflector 31 and the second reflector 32 in the reflector 30 are increased to display an image of the second light L2 at a greater distance, the infrared rays irradiating the display 22 can be reduced via the optical path adjustment unit 40, thereby suppressing a temperature rise in the display 22.

[0052] Another possible method for displaying a larger image in the head-up display device 10 described above is to configure the reflector 30 using a mirror with a large reflective surface. However, if the reflective surface is made larger, the amount of sunlight reflected by the reflective surface and irradiating the display 22 increases, and the large amount of infrared light may cause the display 22 to heat up. However, as described above, the optical path adjustment unit 40 of this embodiment is configured to reduce infrared light and is disposed on the optical path of the second light L2 that forms a large image. Therefore, even if the reflective surfaces of the first reflector 31 and the second reflector 32 in the reflector 30 are increased to enlarge the image of the second light L2, the infrared light irradiating the display 22 can be reduced via the optical path adjustment unit 40, thereby suppressing a temperature rise in the display 22.

[0053] Although the present invention has been described above using the above embodiment as an example, the present invention is not limited to this.

[0054] For example, in the above embodiment, an example has been described in which the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 and the optical path of the second light L2 from the image forming unit 20 to the first reflecting section 31 do not intersect, and the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 and the optical path of the second light L2 from the first reflecting section 31 to the second reflecting section 32 intersect. However, for example, the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 and the optical path of the second light L2 from the image forming unit 20 to the first reflecting section 31 may intersect, or the optical path of the first light L1 from the image forming unit 20 to the first reflecting section 31 and the optical path of the second light L2 from the first reflecting section 31 to the second reflecting section 32 may not intersect.

[0055] In the above embodiment, an example has been described in which the reflecting unit 30 includes the first reflecting unit 31, which is a convex mirror, and the second reflecting unit 32, which is a concave mirror. However, the configuration of the reflecting unit 30 is not limited to this. For example, both the first reflecting unit 31 and the second reflecting unit 32 may be convex mirrors or concave mirrors, or the first reflecting unit 31 may be a concave mirror and the second reflecting unit 32 may be a convex mirror, or at least one of the first reflecting unit 31 and the second reflecting unit 32 may be a plane mirror. In the above embodiment, an example has been described in which the first reflecting unit 31 is composed of the first convex mirror 31A and the second convex mirror 31B, but the first reflecting unit 31 may be a single mirror. In the above embodiment, an example has been described in which the second reflecting unit 32 is composed of a single concave mirror, but the second reflecting unit 32 may be two mirrors, one for the first light L1 and one for the second light L2.

[0056] Furthermore, the reflecting unit 30 may be composed of only one reflecting unit, or may be composed of three or more reflecting units that sequentially reflect the first light L1 and the second light L2. By increasing the number of times that the first light L1 and the second light L2 are sequentially reflected by the reflecting units, the optical paths of the first light L1 and the second light L2 can be finely changed, thereby improving the degree of freedom in design.

[0057] Furthermore, in the above embodiment, an example has been described in which the light path adjustment unit 40 is disposed on the optical path of the second light L2 from the image forming unit 20 to the reflecting unit 30, but this is not limiting. For example, instead of on the optical path of the second light L2 from the image forming unit 20 to the reflecting unit 30, the light path adjustment unit may be disposed on the optical path of the first light L1 from the image forming unit 20 to the reflecting unit 30. In this case, the light path adjustment unit gradually separates the first light L1 and the second light L2 from their positions before the first light L1 is incident on the light path adjustment unit so that the first light L1 becomes a first virtual image V1 that appears closer to the driver, and the second light L2 becomes a second virtual image V2 that appears farther away than the first virtual image V1 from the driver. Alternatively, the light path adjustment unit may be disposed on the optical path of the first light L1 from the image forming unit 20 to the reflecting unit 30 in addition to on the optical path of the second light L2 from the image forming unit 20 to the reflecting unit 30. In this case, the optical path adjustment unit gradually separates the first light L1 and the second light L2 from their positions before they enter the optical path adjustment unit so that the first light L1 becomes a first virtual image V1 that appears closer to the driver, and the second light L2 becomes a second virtual image V2 that appears farther away than the first virtual image V1 from the driver. However, as described above, when there is an intersection Lx where the optical path of the first light L1 from the image forming unit 20 to the first reflecting unit 31 and the optical path of the second light L2 from the first reflecting unit 31 to the second reflecting unit 32 intersect, it is preferable to not dispose the optical path adjustment unit 40 on the optical path of the first light L1 from the image forming unit 20 to the reflecting unit 30, but to dispose the optical path adjustment unit 40 on the optical path of the second light L2 from the image forming unit 20 to the reflecting unit 30. This may make it easier to dispose the optical path adjustment unit 40 so that it does not overlap with the intersection Lx.

[0058] Furthermore, when an optical path adjustment unit is placed on the optical path of the first light L1, it is preferable that this optical path adjustment unit is configured to reduce the infrared rays emitted from the optical path adjustment unit compared to before the infrared rays entered the optical path adjustment unit.

[0059] Furthermore, in the above embodiment, an example has been described in which the head-up display device 10 includes the reflector 30. However, by disposing the optical path adjustment unit 40 on the optical path of at least one of the first light L1 and the second light L2, the first light L1 and the second light L2 can be gradually spaced apart from each other compared to before at least one of the first light L1 and the second light L2 is incident on the optical path adjustment unit 40 so that the first light L1 becomes a first virtual image V1 that appears closer to the driver and the second light L2 becomes a second virtual image V2 that appears farther away than the first virtual image V1 to the driver, so that it is not essential to provide the reflector 30.

[0060] Furthermore, in the above embodiment, an example was described in which the optical path adjustment unit 40 is a prism, but by arranging the optical path adjustment unit 40 on the optical path of at least one of the first light L1 and the second light L2, the first light L1 and the second light L2 can be gradually spaced apart compared to before they enter the optical path adjustment unit 40 so that the first light L1 becomes a first virtual image V1 that appears closer to the driver and the second light L2 becomes a second virtual image V2 that appears farther away than the first virtual image V1 to the driver, so that the optical path adjustment unit 40 may be an optical element other than a prism with almost zero optical power.

[0061] In the above embodiment, the image forming unit 20 has an exit surface 22Au and an exit surface 22Bu that are horizontal, and the first light L1 and the second light L2 are emitted generally upward from the exit surface 22Au and the exit surface 22Bu. However, this is not limiting. For example, the head-up display device may be configured such that the image forming unit 20 has an exit surface that is vertical, and the first light L1 and the second light L2 are emitted generally forward or backward from the exit surface.

[0062] According to the present invention, a head-up display device capable of displaying a near virtual image and a far virtual image while suppressing an increase in size of the device is provided, and can be used in the automotive field, for example.

Claims

1. one image forming unit that emits each of the first light and the second light; an optical path adjusting unit that is disposed on an optical path of at least one of the first light and the second light, has optical transparency, and has substantially zero optical power; Equipped with The optical path adjustment unit is made of a resin mixed with an infrared absorbing material, and gradually separates the first light and the second light from each other compared to before at least one of the first light and the second light is incident on the optical path adjustment unit, so that the first light becomes a first virtual image that appears close to the driver and the second light becomes a second virtual image that appears farther away than the first virtual image from the driver, and reduces the infrared rays emitted from the optical path adjustment unit compared to before the infrared rays are incident on the optical path adjustment unit. A head-up display device.

2. a reflecting portion that reflects each of the first light and the second light toward the driver's viewpoint; 2. The head-up display device according to claim 1.

3. the reflecting portion includes a first reflecting portion and a second reflecting portion, The first light and the second light are reflected in this order from the first reflecting portion to the second reflecting portion.

3. The head-up display device according to claim 2.

4. An optical path of the first light from the image forming unit to the first reflecting section and an optical path of the second light from the image forming unit to the first reflecting section do not intersect with each other.

4. The head-up display device according to claim 3.

5. an intersection at which an optical path of the first light from the image forming unit to the first reflecting section and an optical path of the second light from the first reflecting section to the second reflecting section intersect; 5. The head-up display device according to claim 4.

6. The optical path adjustment unit is disposed on an optical path of the second light from the image forming unit to the first reflecting unit.

6. The head-up display device according to claim 5.

7. the first reflecting unit includes a first convex mirror that reflects the first light and a second convex mirror that reflects the second light, The second reflecting portion is formed of a single concave mirror that reflects both the first light and the second light.

7. The head-up display device according to claim 3, wherein the head-up display device is a head-up display.

8. A head-up display device that displays a first virtual image that appears in front of a driver's viewpoint and a second virtual image that appears farther away than the first virtual image, an image forming unit that emits a first light beam that forms the first virtual image and a second light beam that forms the second virtual image; a prism disposed on an optical path of the second light; a first convex mirror that reflects the first light; a second convex mirror that reflects the second light; a concave mirror that reflects the first light reflected by the first convex mirror and the second light reflected by the second convex mirror toward a windshield; Equipped with The prism is made of a resin mixed with an infrared absorbing material, and reduces the infrared rays emitted from the prism compared to before they entered the prism. A head-up display device.

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