Head-up display

Abstract

To provide a head-up display that can suppress the need for larger sizes. [Solution] The head-up displays 1, 1a, and 1b are head-up displays 1, 1a, and 1b that perform local dimming control and are mounted on a substrate 62 and include a plurality of light sources 61 that emit light, and a display 53 that changes the light emitted by the plurality of light sources 61 into a display image and emits it as display light. The substrate 62 has a first region R1 and a second region R2. The plurality of light sources 61 include one or more first light sources 61a mounted in the first region R1 and one or more second light sources 61b mounted in the second region R2. The one or more first light sources 61a provided in the first region R1 are lit more frequently than the one or more second light sources 61b provided in the second region R2, and the heat dissipation of the first region R1 is higher than that of the second region R2.

Description

Technical Field

[0001] The present disclosure relates to a head-up display for a vehicle.

Background Art

[0002] As a conventional technique, in order to allow a driver to recognize information related to a vehicle, a head-up display (HUD) with excellent visibility may be mounted on the vehicle.

[0003] For example, Patent Document 1 discloses a vehicle display device including a display unit that displays visible information, a white light-emitting diode that illuminates the display unit, and at least one light reflection unit disposed on an optical path that guides light including the visible information displayed on the display unit to a predetermined projection surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a conventional vehicle display device, when a white light-emitting diode illuminates a display unit, it may emit light with a high luminance. In this case, since the amount of heat generated by the white light-emitting diode increases, a large heat dissipation structure has to be used, resulting in a problem that the head-up display becomes large-sized.

[0006] Therefore, an object of the present disclosure is to provide a head-up display that can suppress an increase in size.

Means for Solving the Problems

[0007] A head-up display according to one aspect of the present disclosure is a head-up display that performs local dimming control and comprises a plurality of light sources mounted on a substrate and emitting light, and a display that changes the light emitted by the plurality of light sources into a display image and emits it as display light, wherein the substrate has a first region and a second region, and the plurality of light sources include one or more first light sources mounted in the first region and one or more second light sources mounted in the second region, the one or more first light sources provided in the first region are lit more frequently than the one or more second light sources provided in the second region, and the heat dissipation of the first region is higher than that of the second region. [Effects of the Invention]

[0008] The head-up display of this disclosure can suppress the need for larger sizes. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing an example of the use of a head-up display according to an embodiment mounted on a vehicle. [Figure 2] Figure 2 is a perspective view showing a head-up display according to an embodiment. [Figure 3A] Figure 3A is a cross-sectional view showing a windshield-type head-up display along line AA in Figure 2. [Figure 3B] Figure 3B is another cross-sectional view showing a windshield-type head-up display. [Figure 4] Figure 4 is an exploded perspective view showing the display unit. [Figure 5] Figure 5 is an enlarged cross-sectional view showing the display unit. [Figure 6] Figure 6 is an enlarged cross-sectional view showing a display unit in which the first heat dissipation mechanism is located only in the area corresponding to the first region. [Figure 7] Figure 7 is a plan view showing the first and second regions of a substrate on which multiple light sources are mounted. [Figure 8]Figure 8 is a plan view showing the third and fourth regions of the display. [Figure 9] Figure 9 is an enlarged cross-sectional view showing a display unit having a first substrate and a second substrate. [Figure 10] Figure 10 is a cross-sectional view showing a combiner-type head-up display. [Figure 11] Figure 11 is an enlarged cross-sectional view showing a display unit of another modified example. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the drawings.

[0011] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0012] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Also, the same component is denoted by the same reference numeral in each figure.

[0013] Furthermore, in the following explanation, in Figure 2, the longitudinal direction of the vehicle in the head-up display is defined as the X-axis direction, the vertical direction perpendicular to the X-axis direction is defined as the Z-axis direction, and the direction perpendicular to both the X-axis and Z-axis directions is defined as the Y-direction. The directions in Figure 2 may also be applied in Figures 3A and later.

[0014] In the following embodiments, expressions such as rectangular, substantially parallel, and the X-axis direction are used. For example, rectangular, substantially parallel, and the X-axis direction do not only mean completely rectangular, completely parallel, and completely in the X-axis direction, but also mean substantially rectangular, substantially parallel, and substantially in the X-axis direction, that is, including an error of about a few percent. Also, rectangular, substantially parallel, and the X-axis direction mean rectangular, parallel, and in the X-axis direction within the range where the effects according to the present disclosure can be achieved. The same applies to other expressions using "shape", "substantially", and "direction".

[0015] (Embodiment) <Configuration> First, referring to FIGS. 1 to 8, the configuration of the head-up display 1 according to the present embodiment will be described.

[0016] FIG. 1 is a schematic diagram showing an example of use of the head-up display 1 according to the embodiment mounted on the vehicle 2. FIG. 2 is a perspective view showing the head-up display 1 according to the embodiment. FIG. 3A is a cross-sectional view showing the windshield type head-up display 1 taken along the line A-A in FIG. 2. FIG. 3B is another cross-sectional view showing the windshield type head-up display 1b. FIG. 4 is an exploded perspective view showing the display 50. FIG. 5 is an enlarged cross-sectional view showing the display 50. FIG. 6 is an enlarged cross-sectional view showing the display 50 in which only the first heat dissipation mechanism 71 is arranged at the location corresponding to the first region R1. FIG. 7 is a plan view showing the first region R1 and the second region R2 of the substrate 62 on which a plurality of light sources 61 are mounted. FIG. 8 is a plan view showing the third region R3 and the fourth region R4 of the display 53. On the display 53 in FIG. 8, a display image indicating speed, a guiding arrow, etc. are displayed.

[0017] The head-up display 1 of the present embodiment may be a combiner type or a windshield type.

[0018] First, the windshield type head-up display 1 will be described.

[0019] As shown in Figure 1, the head-up display 1 is located on the dashboard 5 of a vehicle 2, such as an automobile. Above the dashboard 5 (also called the instrument panel) of the vehicle 2 is the windshield 3.

[0020] The head-up display 1 is a device that can project images onto the windshield 3 for the driver or passenger. In other words, the head-up display 1 projects the display light emitted by the display unit 50 onto the windshield 3, thereby displaying the image indicated by the display light to the user. The display light is light that represents a display image including numbers, characters, and figures, and is displayed as a virtual image 8 on the windshield 3. The head-up display 1 of this embodiment is capable of local dimming control.

[0021] As shown in Figures 2 and 3A, the head-up display 1 comprises a housing 10, a light-transmitting member 15, a first reflective mirror 81, a second reflective mirror 82, and a display unit 50.

[0022] The housing 10 is a housing that contains the first reflective mirror 81, the second reflective mirror 82, the light-transmitting member 15, and the display unit 50. The housing 10 constitutes the outer shell of the head-up display 1. The housing 10 is fixed to the vehicle 2 while mounted inside the dashboard 5 in Figure 1. The housing 10 is made of a resin such as polybutylene terephthalate (PBT), for example.

[0023] An engagement portion is formed inside the housing 10 to support the display unit 50. In this embodiment, the display unit 50 is fixed to the housing 10 by being fixed to the engagement portion.

[0024] A housing opening 14 is formed on the end face of the housing 10 on the Z-axis positive side. A light-transmitting member 15 is placed in the housing opening 14. Specifically, the light-transmitting member 15 is fixed to the housing 10 so as to cover the housing opening 14. The light-transmitting member 15 is positioned on the Z-axis positive side of the second reflective mirror 82 in a position that is approximately parallel to the XY plane. In other words, the light-transmitting member 15 is located in the optical path of the display light between the windshield 3 and the second reflective mirror 82. The light-transmitting member 15 is a translucent thin plate that is curved in part.

[0025] The light-transmitting member 15 also serves as an anti-fouling cover to suppress dust, debris, and other contaminants from entering the housing 10. For example, the surface of the light-transmitting member 15 on the windshield 3 side may be treated with a hard coat. In this case, even if dust, debris, and other contaminants adhere to the surface of the light-transmitting member 15 (the surface on the X-axis positive side), it becomes easier to wipe away the dirt.

[0026] As shown in Figure 3A, the first reflective mirror 81 is positioned in the optical path between the display unit 50 and the second reflective mirror 82, and the second reflective mirror 82 is positioned in the optical path between the first reflective mirror 81 and the windshield 3 via the light-transmitting member 15.

[0027] Specifically, the first reflective mirror 81 is positioned on the positive X-axis side of the housing 10 so as to face the output surface of the display unit 50, which is located on the negative X-axis side of the housing 10. The first reflective mirror 81 is also positioned on the positive Z-axis side of the display unit 50. The second reflective mirror 82 is positioned on the negative X-axis side of the housing 10 so as to face the first reflective mirror 81, which is located on the positive X-axis side of the housing 10. In other words, the second reflective mirror 82 is positioned parallel to the first reflective mirror 81 along the X-axis direction. The second reflective mirror 82 is also positioned on the positive Z-axis side of the display unit 50 in the Z-axis direction. The first reflective mirror 81 and the second reflective mirror 82 are positioned on the housing 10 so as to face each other at a predetermined distance apart.

[0028] As the first reflective mirror 81 and the second reflective mirror 82 are arranged in the housing 10 in this manner, the display light emitted from the display unit 50 enters the first reflective mirror 81, is reflected by the first reflective mirror 81, then enters the second reflective mirror 82, is reflected by the second reflective mirror 82, passes through the light-transmitting member 15, and enters the windshield 3. Since the display light is irradiated onto the windshield 3, an image is projected onto it.

[0029] The first reflective mirror 81 and the second reflective mirror 82 are convex or concave mirrors. In this embodiment, the first reflective mirror 81 and the second reflective mirror 82 are rectangular mirrors that are elongated in the Y-axis direction. The shapes of the first reflective mirror 81 and the second reflective mirror 82 are not particularly limited and may be polygonal or circular.

[0030] The second reflective mirror 82 may also be able to swing about the Y-axis as its axis. In this case, the position of the image projected onto the windshield 3 can be adjusted. The second reflective mirror 82 may be able to swing by manual operation or by electric operation using a drive mechanism.

[0031] As shown in Figures 4 and 5, the display unit 50 emits display light that represents information, thereby projecting the image indicated by the display light onto the windshield 3. The display unit 50 is, for example, a liquid crystal display device such as a liquid crystal display.

[0032] Specifically, the display unit 50 includes a light-emitting module 60, a first heat dissipation mechanism 71, a lens support 63, a lens cover 65, a condensing lens 64, a frame 51, a light-transmitting cover 52, a second heat dissipation mechanism 72, a display 53, and a heat-dissipating light-transmitting body 54.

[0033] The light-emitting module 60 has a plurality of light sources 61 and a substrate 62.

[0034] Each of the multiple light sources 61 is mounted on the substrate 62 in a position that emits light towards the light-transmitting cover 52, display 53, and heat-dissipating light-transmitting body 54 via a focusing lens 64 and lens cover 65. Each of the multiple light sources 61 is composed of, for example, a light-emitting diode (LED). For example, each of the multiple light sources 61 is driven by power obtained from a power source (not shown) in the vehicle 2. The multiple light sources 61 light up in response to an ON signal from a control unit (not shown) mounted in the vehicle 2, and turn off in response to an OFF signal from the control unit.

[0035] As shown in Figures 4 and 7, the multiple light sources 61 include one or more first light sources 61a mounted in the first region R1 of the substrate 62 and one or more second light sources 61b mounted in the second region R2 of the substrate 62. The one or more first light sources 61a provided to correspond to the first region R1 are lit more frequently than the one or more second light sources 61b provided to correspond to the second region R2. In other words, the lighting frequency of the multiple light sources 61 differs depending on their location.

[0036] The substrate 62 may be a rigid substrate made of a material such as glass epoxy, a ceramic substrate made of a sintered body of a ceramic material such as alumina, a metal-based substrate obtained by applying an insulating film to the surface of a metal substrate made of a metal material such as aluminum or copper, or a flexible substrate made of a material such as polyimide and a plastic film such as liquid crystal polymer.

[0037] The substrate 62 is connected to the lens support 63 in a position that is tilted downward in the positive X-axis direction with respect to the ZY plane. Multiple light sources 61 are mounted on the surface of the substrate 62 that faces the condensing lens 64 and the lens cover 65.

[0038] Specifically, the substrate 62 has a first region R1 and a second region R2. One or more first light sources 61a from among multiple light sources 61 are mounted in the first region R1. One or more second light sources 61b from among multiple light sources 61 are mounted in the second region R2. The one or more second light sources 61b are separate light sources that are independent of the one or more first light sources 61a.

[0039] A first heat dissipation mechanism 71 is fixed to the back surface of the substrate 62 (the side opposite to the light source 61).

[0040] The first heat dissipation mechanism 71 is a heat sink made of materials such as aluminum, iron, magnesium, and heat dissipation resin.

[0041] Specifically, the first heat dissipation mechanism 71 has a main body 71a and a plurality of fins 71b.

[0042] The main body portion 71a is a plate-shaped member positioned to be in close contact with the back surface of the substrate 62. Multiple fins 71b are formed on the side of the main body portion 71a opposite to the substrate 62 side.

[0043] Multiple fins 71b extend upward from the side of the main body 71a opposite to the substrate 62 side.

[0044] In the first heat dissipation mechanism 71, the heat generated by the multiple light sources 61 is conducted to the main body 71a via the substrate 62, and the heat is then conducted from the main body 71a to the multiple fins 71b and released into the outside air.

[0045] Here, the first heat dissipation mechanism 71, the substrate 62, and the multiple light sources 61 will be described in more detail.

[0046] As shown in Figures 5 and 6, the first heat dissipation mechanism 71 is positioned to correspond to at least the first region R1 of the substrate 62. In other words, the first heat dissipation mechanism 71 is in close contact (thermally connected) with the back surface of the substrate 62 so as to overlap with at least the first region R1 of the substrate 62. For this reason, the heat dissipation performance of the first region R1 of the substrate 62 is set to be higher than that of the second region R2. Figure 6 shows the case in which the first heat dissipation mechanism 71 of the display unit 50a is positioned to correspond only to the first region R1 of the substrate 62. Specifically, the main body 171a and the multiple fins 71b of the first heat dissipation mechanism 71 are positioned to correspond only to the first region R1 of the substrate 62.

[0047] Furthermore, in this embodiment, the first heat dissipation mechanism 71 may be arranged to correspond to the first region R1 and the second region R2 of the substrate 62, as shown in Figure 5. In other words, the first heat dissipation mechanism 71 may be in close contact with the back surface of the substrate 62 so as to overlap with the first region R1 and the second region R2 of the substrate 62. In this case as well, the heat dissipation performance of the first region R1 of the substrate 62 will be set to be higher than that of the second region R2. In other words, the first heat dissipation mechanism 71 may be designed so that the heat dissipation performance of the area corresponding to the first region R1 of the substrate 62 is higher than that of the area corresponding to the second region R2 of the substrate 62. Specifically, in the first heat dissipation mechanism 71, the number of fins 71b formed in the area corresponding to the first region R1 of the substrate 62 may be greater than that of the area corresponding to the second region R2 of the substrate 62. In other words, the density of fins 71b formed in the area corresponding to the first region R1 of the substrate 62 may be higher than that of the area corresponding to the second region R2 of the substrate 62. Furthermore, in the first heat dissipation mechanism 71, the thickness of the main body portion 71a in the area corresponding to the first region R1 of the substrate 62 may be greater than the thickness of the main body portion 71a in the area corresponding to the second region R2 of the substrate 62.

[0048] Thus, the size of the first heat dissipation mechanism 71 may be changed according to the frequency of illumination of the light source 61. In other words, the more frequently the light source 61 is illuminated in a given region, the larger the size of the first heat dissipation mechanism 71 positioned in that region may be.

[0049] As described above, since one or more first light sources 61a provided in the first region R1 are lit more frequently than one or more second light sources 61b provided in the second region R2, the amount of heat generated by one or more first light sources 61a provided in the first region R1 is higher than that generated by one or more second light sources 61b provided in the second region R2. However, as described above, the heat dissipation performance of the first region R1 of the substrate 62 is higher than that of the second region R2, so it is expected that the temperature of the first region R1 will not rise higher than that of the second region R2, and the temperatures of the first region R1 and the second region R2 will be kept equal or lower.

[0050] The lens support 63 is a component for supporting the condensing lens 64 and the lens cover 65. The lens support 63 is fixed to the frame 51 by fastening members. The lens support 63 is positioned so that it is superimposed on the second heat dissipation mechanism 72, and a portion of it is covered by the second heat dissipation mechanism 72.

[0051] The lens support 63 has an aperture 63a positioned opposite the aperture 72a of the second heat dissipation mechanism 72. The aperture 63a of the lens support 63 is located in the optical path between the light-emitting module 60 and the first reflective mirror 81.

[0052] A lens cover 65 and a condensing lens 64 are positioned in the opening 63a of the lens support 63, and the opening 63a of the lens support 63 is covered by the lens cover 65 and the condensing lens 64. The opening 63a of the lens support 63 is positioned to correspond to the opening 72a of the second heat dissipation mechanism 72. In other words, the lens cover 65 and the condensing lens 64 are positioned to correspond to the light-transmitting cover 52, the display 53, and the heat-dissipating light-transmitting body 54.

[0053] The condensing lens 64 and lens cover 65 are positioned on the side of the light emission direction from the multiple light sources 61, and are located in the optical path between the multiple light sources 61, the light-transmitting cover 52, the display 53, and the heat-dissipating light-transmitting body 54.

[0054] The condensing lens 64 is a lens assembly that, via a lens cover 65, focuses light emitted from multiple light sources 61 toward the heat-dissipating light-transmitting body 54, the display 53, and the light-transmitting cover 52. In this embodiment, the condensing lens 64 is supported by the lens support 63 such that the central axis of each of the multiple lenses included in the condensing lens 64 substantially coincides with the optical axis J of the light source 61.

[0055] The condensing lens 64 is made of glass and transparent resin, etc. In this embodiment, the condensing lens 64 is a convex lens.

[0056] The lens cover 65 is positioned in the opening 63a so as to cover the multiple lenses included in the condensing lens 64. Specifically, the lens cover 65 is located on the opposite side of the condensing lens 64 from the light-emitting module 60 side (the negative X-axis direction side), between the condensing lens 64 and the heat-dissipating light-transmitting body 54, and is positioned in the opening 63a of the lens support 63.

[0057] In this embodiment, the condensing lens 64 and lens cover 65 are supported by the lens support 63 in such a position that they are tilted downward in the positive X-axis direction with respect to the YZ plane. In other words, the condensing lens 64 and lens cover 65 are positioned approximately parallel to the plane perpendicular to the optical axis J of the light-emitting module 60.

[0058] The frame 51 is a member for supporting the light-transmitting cover 52 in a predetermined position. Specifically, the frame 51 has an opening 51a. The light-transmitting cover 52 is fitted into the opening 51a of the frame 51, and the opening 51a of the frame 51 is covered by the light-transmitting cover 52. For this reason, the light-transmitting cover 52 also serves as a stain-resistant cover. For example, the surface of the light-transmitting cover 52 on the side facing the first reflective mirror 81 may be treated with a hard coat. In this case, even if dust, dirt, etc. adhere to this surface, it becomes easier to wipe off the dirt.

[0059] The frame 51 is held in the housing 10 such that the light-transmitting cover 52 faces the first reflective mirror 81.

[0060] The frame 51 has a plurality of engaging portions (not shown) for engaging with the engaged portion of the second heat dissipation mechanism 72. The frame 51 supports the second heat dissipation mechanism 72 by the engagement of the plurality of engaging portions with the engaged portion of the second heat dissipation mechanism 72.

[0061] The second heat dissipation mechanism 72 is a heat sink made of materials such as aluminum, iron, magnesium, and heat dissipation resin.

[0062] The second heat dissipation mechanism 72 can function as a first heat dissipation mechanism 71 capable of dissipating heat generated in the display 53. The second heat dissipation mechanism 72 overlaps with the frame 51, so that a portion of it is covered by the frame 51 and is supported by the frame 51. Specifically, the second heat dissipation mechanism 72 has an opening 72a that is positioned opposite the opening 51a of the frame 51. In other words, the opening 72a of the second heat dissipation mechanism 72 and the opening 51a of the frame 51 are located on the optical path between the light-emitting module 60 and the first reflective mirror 81.

[0063] A display 53 and a heat-dissipating light-transmitting body 54 are positioned in the opening 72a of the second heat dissipation mechanism 72, and the opening 72a of the second heat dissipation mechanism 72 is covered by the display 53 and the heat-dissipating light-transmitting body 54. When the second heat dissipation mechanism 72 is superimposed on the frame 51, the second heat dissipation mechanism 72 and the frame 51 can sandwich the display 53 and the heat-dissipating light-transmitting body 54 between the second heat dissipation mechanism 72 and the light-transmitting cover 52 supported by the frame 51.

[0064] The heat-dissipating light-transmitting body 54 is, for example, a light-transmitting heat-dissipating glass, and is in the shape of a plate.

[0065] The heat-dissipating light-transmitting body 54 is positioned between the display 53 and the second heat dissipation mechanism 72. The heat-dissipating light-transmitting body 54 is superimposed on the display 53, so that one side of the heat-dissipating light-transmitting body 54 opposite to the light-emitting module 60 (the side in the positive X-axis direction) is in close contact with the display 53. The heat-dissipating light-transmitting body 54 is attached to the second heat dissipation mechanism 72 so as to cover the opening 72a of the second heat dissipation mechanism 72, and a part of the other side on the side of the light-emitting module 60 (the side in the negative X-axis direction) is in close contact with the second heat dissipation mechanism 72. Therefore, when the display 53 generates heat due to irradiation from multiple light sources 61, the heat from the display 53 is conducted to the heat-dissipating light-transmitting body 54, and then from the heat-dissipating light-transmitting body 54 to the second heat dissipation mechanism 72. The heat-dissipating light-transmitting body 54 can dissipate the heat from the display 53, thus preventing the display 53 from becoming overheated.

[0066] The display 53 is a liquid crystal display element (LCD: also called a liquid crystal display) such as a light-transmitting or light-semitransmitting TFT liquid crystal (Thin Film Transistor Liquid Crystal Display). The display 53 can convert the light emitted by multiple light sources 61 into a display image and emit it as display light. Specifically, in the display 53, light emitted by the light-emitting module 60 is irradiated onto the back surface, and the light that passes through the interior causes the front surface (the surface on the positive X-axis side), which is the emission surface, to emit light. At this time, the display 53 emits display light from the emission surface that shows a display image including numbers, characters, and graphics, etc., in response to control instructions from the control unit mounted on the vehicle 2 in Figure 1. For example, the display 53 is driven by power obtained from a power source (not shown) inside the vehicle 2.

[0067] These light-transmitting covers 52, displays 53, and heat-dissipating light-transmitting bodies 54 are supported by the frame 51 and the second heat dissipation mechanism 72 so as to be positioned approximately parallel to the ZY plane, which is inclined with respect to the plane perpendicular to the optical axis J of the light-emitting module 60.

[0068] As shown in Figures 5 and 8, the display 53 has a third region R3 and a fourth region R4.

[0069] The third region R3 is the region into which light emitted from one or more first light sources 61a is incident. Therefore, the third region R3 corresponds to the first region R1. The fourth region R4 is the region into which light emitted from one or more second light sources 61b is incident. Therefore, the fourth region R4 corresponds to the second region R2.

[0070] Since region 1 R1 has a higher illumination frequency than region 2 R2, it can be said that region 3 R3 has a higher illumination frequency than region 4 R4. For this reason, region 3 R3 is in an environment where the temperature tends to be higher than region 4 R4.

[0071] Therefore, at least the third region R3 is thermally connected to the second heat dissipation mechanism 72. In this embodiment, the fourth region R4 is also thermally connected to the second heat dissipation mechanism 72.

[0072] In the third region R3, which corresponds to the first region R1 with a high frequency of illumination, the display image must always show the latest content. For example, the display light emitted shows the speed, or in the case of a vehicle equipped with active cruise control, the vehicle being followed ahead. In the fourth region R4, which corresponds to the second region R2 with a low frequency of illumination, the display image must be displayed when vehicle 2 detects some kind of information. For example, the display light emitted shows the driving route guidance arrows, road signs, etc.

[0073] In the above description, the substrate 62 was divided into two regions, the first region R1 and the second region R2, but this embodiment is not limited to this. For example, the substrate 62 may be divided into three or more regions, such as a third region. Therefore, the substrate 62 may be divided into three or more substrates, not just the first substrate 62a and the second substrate 62b. Consequently, the display 53 may also be divided into three or more regions, not just the third region R3 and the fourth region R4. In this case, there is a one-to-one correspondence between the multiple regions in the substrate 62, the number of substrates 62, and the multiple regions in the display 53.

[0074] Next, although this embodiment mainly describes the case where the light-emitting module 60 has a single substrate 62, the substrate 62 may be divided into multiple parts. The substrate 62 of the display unit 50b will be described in more detail with reference to Figure 9.

[0075] Figure 9 is an enlarged cross-sectional view showing a display unit 50b having a first substrate 62a and a second substrate 62b.

[0076] The substrate 62 may include a first substrate 62a provided in the first region R1 and a second substrate 62b provided in the second region R2. In other words, the first substrate 62a corresponding to the first region R1 and the second substrate 62b corresponding to the second region R2 may be separate and independent substrates 62. In this case, one or more first light sources 61a are mounted on the first substrate 62a, and one or more second light sources 61b are mounted on the second substrate 62b.

[0077] A gap S (air layer) may be formed between the first substrate 62a and the second substrate 62b. In other words, since the first substrate 62a is not connected to the second substrate 62b, heat is less likely to be conducted from the first substrate 62a, where the first light source 61a, which is frequently switched on, is located, to the second substrate 62b, where the second light source 61b, which is less frequently switched on, is located.

[0078] Furthermore, since the heat dissipation performance of the first region R1 of the substrate 62 is higher than that of the second region R2, the heat dissipation performance of the first substrate 62a may be higher than that of the second substrate 62b. In this case, the first substrate 62a may be made of a different material than the second substrate 62b. For example, the first substrate 62a may be a metal-based substrate with high heat dissipation, and the second substrate 62b may be a substrate other than a metal-based substrate (ceramic substrate, flexible substrate, etc.).

[0079] In this case as well, the first heat dissipation mechanism 71 may be placed on at least the first substrate 62a, but the first heat dissipation mechanism 71 may also be placed on the second substrate 62b.

[0080] As shown in Figure 3B, the head-up display 1b does not necessarily have the first reflective mirror 81 shown in Figure 3A. In this case, the display unit 50 may be positioned on the X-axis positive side of the second reflective mirror 82 so as to face the second reflective mirror 82. In this case, the display unit 50 can emit display light directly toward the second reflective mirror 82.

[0081] Next, with reference to Figure 10, a combiner-type head-up display 1a without a combiner 41 will be described.

[0082] Figure 10 is a cross-sectional view showing a combiner-type head-up display 1a.

[0083] The head-up display 1a differs from the windshield-type head-up display 1 in Figure 3A in that it does not have a combiner 41 and also has a second reflective mirror 82. Regarding the description of the combiner-type head-up display 1a, explanations of components identical to those of the windshield-type head-up display 1 in Figure 3A will be omitted as appropriate.

[0084] The combiner-type head-up display 1a further comprises a combiner 41 in addition to the housing 10a, the first reflective mirror 81, and the display unit 50. The combiner-type head-up display 1a does not have a second reflective mirror 82 and a light-transmitting member 15 like the windshield-type head-up display 1 shown in Figure 3A above.

[0085] An opening recess 11 for accommodating the combiner 41 is formed in the central part of the housing 10a on the Z-axis positive side. The combiner 41 can be displaced between an upright position and a reclining position relative to the housing 10a, but the opening recess 11 is formed to a size that can accommodate the combiner 41 when it is in the reclining position. When the head-up display 1a is mounted on the dashboard 5 in Figure 2, the housing 10a is fixed to the vehicle 2.

[0086] The opening recess 11 is a rectangular recess in plan view. The opening recess 11 is positioned between the combiner 41 and the display unit 50, thereby separating the combiner 41 and the display unit 50.

[0087] A combiner 41 is positioned on the Z-axis positive side of the opening recess 11. The Z-axis positive side, which is the bottom surface of the opening recess 11, is exposed from the opening recess 11 and is visible from outside the head-up display 1a. The opening recess 11 blocks ambient light and prevents stray light generated by the display unit 50 from emitting outside the head-up display 1a through the opening recess 11 of the housing 10a.

[0088] Furthermore, a pair of support parts (not shown) are formed in the opening recess 11 to rotatably support the combiner 41. The pair of support parts support both ends of the combiner support part 42 in the Y-axis direction, thereby rotatably supporting the combiner 41 and the combiner support part 42, which fixes the combiner 41. Specifically, the combiner support part 42 is a long rod shape in the Y-axis direction. The combiner support part 42 is rotatably supported by the pair of support parts formed in the opening recess 11, so that it can rotate around an axis substantially parallel to the Y-axis direction. Therefore, when the combiner support part 42 rotates with respect to the opening recess 11 with respect to the Y-axis direction as its axis, the combiner 41 also rotates in the same way, so that the combiner 41 can be in an upright position or a lying position.

[0089] Furthermore, the opening recess 11 has a notch 12.

[0090] The notch 12 is formed on the X-axis positive side of the opening recess 11 and is designed to allow the display light emitted from the display unit 50 to pass through and be incident on the first reflective mirror 81, and to reflect the incident display light toward the combiner 41.

[0091] The combiner 41 of the head-up display 1 is positioned between the dashboard 5 and the windshield 3. The combiner 41 is, for example, a half-mirror and is composed of a plate made of plate glass or resin material and a semi-transparent film such as aluminum deposited or sputtered onto one side of the plate made of plate glass or resin material. The combiner 41 is semi-transparent and is formed so that the user can visually see the direction of travel of the vehicle 2 through the combiner 41. For example, the combiner 41 is a convex plate or a concave plate.

[0092] The combiner 41 is a display panel that displays the virtual image 8 in Figure 1 by projecting the display light reflected by the first reflective mirror 81. The combiner 41 has a rectangular shape in plan view, but its shape is not particularly limited and may be polygonal, circular, or the like.

[0093] When the combiner 41 is in a reclining position, it is stored in the opening recess 11 of the housing 10a. When the combiner 41 is in an upright position, it is in an upright position relative to the opening recess 11. In the reclined state, the surface 41a of the combiner 41 is approximately parallel to the XY plane. In the upright state, the surface 41a of the combiner 41 is approximately parallel to the ZY plane.

[0094] The surface 41a of the combiner 41 is the projection surface onto which the display light reflected by the first reflection mirror 81 is incident, the surface facing the user, and the surface on the positive X-axis side.

[0095] The first reflective mirror 81 is supported by the housing 10a so as to be in a position approximately parallel to the ZY plane. The first reflective mirror 81 is positioned in the notch 12 of the opening recess 11 so as to face the display unit 50 and the combiner 41. The first reflective mirror 81 is located below the combiner 41 (towards the negative Z-axis direction) and above the display unit 50 (towards the positive Z-axis direction) in the Z-axis direction.

[0096] Since the first reflective mirror 81 is positioned opposite the display unit 50 and the combiner 41, it can reflect the display light emitted from the display unit 50 toward the combiner 41. Specifically, the first reflective mirror 81 reflects the display light emitted from the display unit 50 toward the surface 41a of the combiner 41, that is, it can project the display light onto the surface 41a of the combiner 41.

[0097] The first reflective mirror 81 is a convex or concave mirror. In this embodiment, the first reflective mirror 81 is a rectangular mirror that is elongated in the Y-axis direction. The shape of the first reflective mirror 81 is not particularly limited and may be polygonal or circular.

[0098] Next, the second heat dissipation mechanism 172 will be described with reference to Figure 11.

[0099] For example, the second heat dissipation mechanism 172 of the head-up display according to the above embodiment may have the configuration shown in Figure 11. Figure 11 is an enlarged cross-sectional view showing a display unit 50c of another modified example. For example, the second heat dissipation mechanism 172 may consist of a main body 172a and a plurality of fins 172b provided on the main body 172a.

[0100] <Effects and Effects> Next, the effects and advantages of the head-up displays 1, 1a, and 1b according to this embodiment will be described.

[0101] As described above, the head-up displays 1, 1a, and 1b of Technology 1 according to this embodiment are head-up displays 1, 1a, and 1b that perform local dimming control and are mounted on a substrate 62 and comprise a plurality of light sources 61 that emit light, and a display 53 that changes the light emitted by the plurality of light sources 61 into a display image and emits it as display light. The substrate 62 has a first region R1 and a second region R2, and the plurality of light sources 61 include one or more first light sources 61a mounted in the first region R1 and one or more second light sources 61b mounted in the second region R2. The one or more first light sources 61a provided in the first region R1 are lit more frequently than the one or more second light sources 61b provided in the second region R2, and the heat dissipation of the first region R1 is higher than that of the second region R2.

[0102] According to this, since the heat dissipation capacity of the first region R1 is higher than that of the second region R2, even if the lighting frequency of one or more first light sources 61a is high, it can be expected that the heat generated by one or more first light sources 61a will be dissipated. For this reason, even if a heat dissipation mechanism is installed on the substrate 62, the heat dissipation mechanism in the area corresponding to the second region R2 can be made smaller or eliminated compared to the heat dissipation mechanism in the area corresponding to the first region R1.

[0103] Therefore, with these head-up displays 1, 1a, and 1b, it is possible to suppress the increase in size. In particular, because the increase in size of the head-up displays 1, 1a, and 1b can be suppressed, it is possible to suppress the increase in manufacturing costs and weight of the head-up displays 1, 1a, and 1b.

[0104] Furthermore, the head-up displays 1, 1a, and 1b of Technology 2 according to this embodiment are the head-up displays 1, 1a, and 1b described in Technology 1, further comprising a first heat dissipation mechanism 71 that is thermally connected to the substrate 62 so as to correspond to the first region R1.

[0105] According to this, the temperature rise of the first region R1 can be suppressed simply by positioning the first heat dissipation mechanism 71 to correspond to the first region R1 where the first light source 61a, which is frequently lit, is located. Therefore, the size of the head-up displays 1, 1a, and 1b can be suppressed compared to the case where the first heat dissipation mechanism 71 is positioned in both the first region R1 and the second region R2.

[0106] Furthermore, since the first heat dissipation mechanism 71 is positioned to correspond to the first region R1, which has a high frequency of illumination, it is possible to suppress the temperature rise of the first region R1. Therefore, it is possible to suppress the deterioration of the performance and lifespan of one or more first light sources 61a due to the temperature rise of one or more first light sources 61a.

[0107] Furthermore, the head-up displays 1, 1a, and 1b of Technology 3 according to this embodiment are the head-up displays 1, 1a, and 1b described in Technology 1 or 2. In this case, the substrate 62 includes a first substrate 62a corresponding to a first region R1 and a second substrate 62b corresponding to a second region R2, the first substrate 62a is formed of a different material from the second substrate 62b, and the heat dissipation performance of the first substrate 62a is higher than that of the second substrate 62b.

[0108] According to this, since one or more frequently used first light sources 61a are mounted on the first substrate 62a, which has better heat dissipation than the second substrate 62b, it is possible to suppress the overheating of one or more first light sources 61a and the first substrate 62a.

[0109] Furthermore, if the heat dissipation of the first substrate 62a is to be further improved, the first heat dissipation mechanism 71 can be provided for the first substrate 62a to suppress the overheating of one or more first light sources 61a and the first substrate 62a. In this case, the first heat dissipation mechanism 71 can be provided only for the first substrate 62a, or the size of the second heat dissipation mechanism 72 can be made smaller than that of the first heat dissipation mechanism 71, thereby suppressing the need to enlarge the head-up displays 1, 1a, and 1b accordingly.

[0110] Furthermore, compared to using a second substrate 62b made of the same material as the first substrate 62a (for example, an expensive metal-based substrate), the increase in manufacturing costs for head-up displays 1, 1a, and 1b can be suppressed.

[0111] Furthermore, since the first substrate 62a on which one or more first light sources 61a with high illumination frequency are mounted can be minimized, it is possible to suppress the enlargement of the first heat dissipation mechanism 71 and the first substrate 62a, and also to suppress the soaring manufacturing costs of the head-up displays 1, 1a, and 1b.

[0112] Furthermore, the head-up displays 1, 1a, and 1b of Technology 4 according to this embodiment are the head-up displays 1, 1a, and 1b described in any one of Technologies 1 to 3. In this case, the substrate 62 includes a first substrate 62a provided in the first region R1 and a second substrate 62b provided in the second region R2, and a gap S is formed between the first substrate 62a and the second substrate 62b.

[0113] According to this, since the first substrate 62a is not connected to the second substrate 62b, even if the first substrate 62a, on which one or more first light sources 61a that are frequently lit are located, generates heat, that heat is less likely to be conducted to the second substrate 62b, on which one or more second light sources 61b that are less frequently lit are located.

[0114] Therefore, by separating and making independent multiple substrates 62, such as a first substrate 62a corresponding to the first region R1 and a second substrate 62b corresponding to the second region R2, it is easy to suppress the overheating of one or more second light sources 61b and second substrates 62b.

[0115] Furthermore, the head-up displays 1, 1a, and 1b of Technology 5 according to this embodiment are the same as the head-up displays 1, 1a, and 1b described in Technology 2. In this case, the substrate 62 includes a first substrate 62a provided in the first region R1 and a second substrate 62b provided in the second region R2, and the first heat dissipation mechanism 71 is thermally connected to the first substrate 62a.

[0116] According to this, even in an environment where the first substrate 62a, on which one or more first light sources 61a with a high frequency of illumination are located, is prone to overheating, the first heat dissipation mechanism 71 can dissipate the heat, thereby suppressing overheating of one or more first light sources 61a and the first substrate 62a.

[0117] Furthermore, the head-up displays 1, 1a, and 1b of Technology 6 according to this embodiment are the head-up displays 1, 1a, and 1b described in any one of Technologies 1 to 5. In this case, the display 53 has a third region R3 into which light emitted from one or more first light sources 61a is incident, and a fourth region R4 into which light emitted from one or more first light sources 61a is incident, and further comprises second heat dissipation mechanisms 72 and 172 that are thermally connected to the third region R3 of the display 53.

[0118] According to this, since light from one or more first light sources 61a is incident on the third region R3, which corresponds to the first region R1 with a high illumination frequency, the third region R3 is more likely to become hotter than the fourth region R4, which corresponds to the second region R2 with a low illumination frequency. However, in this embodiment, since the third region R3 is thermally connected to the second heat dissipation mechanisms 72 and 172, it is possible to suppress the overheating of the third region R3.

[0119] Furthermore, the head-up displays 1, 1a, and 1b of Technology 7 according to this embodiment are head-up displays 1, 1a, and 1b described in any one of Technology 1 to 6, further comprising a heat-dissipating light-transmitting body 54 disposed between the display 53 and the second heat dissipation mechanisms 72 and 172.

[0120] According to this, when the heat-dissipating light-transmitting body 54 is placed on top of the display 53, one side of the heat-dissipating light-transmitting body 54 is in close contact with the display 53, and a portion of the other side of the heat-dissipating light-transmitting body 54 is in close contact with the second heat dissipation mechanisms 72 and 172. Therefore, when the display 53 is heated, the heat-dissipating light-transmitting body 54 can conduct the heat from the display 53 to the second heat dissipation mechanisms 72 and 172. As a result, the heat-dissipating light-transmitting body 54 can suppress the display 53 from becoming overheated.

[0121] (Other variations, etc.) Although the present disclosure has been described above based on embodiments, the present disclosure is not limited to the embodiments described above.

[0122] Furthermore, this disclosure also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art could conceive, and forms realized by arbitrarily combining the components and functions of the embodiments without departing from the spirit of this disclosure. [Industrial applicability]

[0123] The head-up display of this disclosure can be used in moving objects such as vehicles. [Explanation of Symbols]

[0124] 1, 1a, 1b Head-up display 53 displays 54 Heat dissipation transparent body 61 Light source 61a 1st light source 61b 2nd light source 62 circuit boards 62a First substrate 62b Second board 71 1st heat dissipation mechanism 72, 172 Second heat dissipation mechanism R1 1st area R2 2nd area R3 3rd area R4 4th area S Gap

Claims

1. A head-up display that uses local dimming control, Multiple light sources mounted on a substrate and emitting light, The system comprises a display that converts the light emitted from multiple light sources into a display image and emits it as display light, The substrate has a first region and a second region. The plurality of light sources include one or more first light sources mounted in the first region and one or more second light sources mounted in the second region. The one or more first light sources provided in the first region are illuminated more frequently than the one or more second light sources provided in the second region. The heat dissipation performance of the first region is higher than that of the second region. Head-up display.

2. The system further comprises a first heat dissipation mechanism thermally connected to the substrate so as to correspond to the first region. The head-up display according to claim 1.

3. The substrate includes a first substrate corresponding to the first region and a second substrate corresponding to the second region. The first substrate is formed from a different material than the second substrate. The heat dissipation performance of the first substrate is higher than that of the second substrate. The head-up display according to claim 1 or 2.

4. The substrate comprises a first substrate provided in the first region and a second substrate provided in the second region. A gap is formed between the first substrate and the second substrate. The head-up display according to claim 1 or 2.

5. The substrate includes a first substrate corresponding to the first region and a second substrate corresponding to the second region. The first heat dissipation mechanism is thermally connected to the first substrate. The head-up display according to claim 2.

6. The display has a third region into which light emitted from one or more first light sources is incident, and a fourth region into which light emitted from one or more first light sources is incident. The display further comprises a second heat dissipation mechanism thermally connected to the third region of the display. The head-up display according to claim 1 or 2.

7. The system further comprises a heat-dissipating light-transmitting body disposed between the display and the second heat dissipation mechanism. The head-up display according to claim 6.

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