Head-up display

Abstract

To provide a head-up display that suppresses an increase in weight and manufacturing cost.SOLUTION: A head-up display 1 is provide, comprising: an image generation unit 20 configured to emit display light for forming a display image; a second reflective mirror 40-40g configured to guide the display light emitted by the image generation unit 20 to a windshield 3 so as to form a virtual image on a side of the windshield 3 opposite a viewer; and a housing 10 for accommodating the image generation unit 20 and the second reflecting mirror 40-40g. The second reflecting mirror 40-40g comprises an elongate base 45 having a first surface 141 with a reflective surface for guiding the display light to the windshield 3 and a second surface 142 on a side opposite the first surface 141, and a standing wall 46 erecting from an edge of the second surface 142 along a longitudinal direction of the base 45. Center portions 41a, 42a of the standing wall 46 in the longitudinal direction are lower in height than end portions 41b, 42b of the standing wall 46 in the longitudinal direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a head-up display mounted on, for example, a vehicle. [Background technology]

[0002] Head-up displays mounted on vehicles, for example, have been proposed (see Patent Document 1). Patent Document 1 discloses a head-up display including a display unit that emits display light that becomes a display image, and a first mirror that guides the image displayed by the display unit to a display medium, thereby forming a virtual image on the side of the display medium opposite to the viewer. The first mirror has a first surface and a second surface that is the reverse side of the first surface, a base having an edge with ribs, and a reflective surface provided on the first surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-139310 Summary of the Invention [Problem to be solved by the invention]

[0004] In the head-up display of Patent Document 1, ribs are provided on the base to ensure the rigidity of the first mirror, thereby making it possible to prevent the weight of the first mirror and the manufacturing costs from increasing.

[0005] However, there is a demand for further weight reduction and lower manufacturing costs for head-up displays.The head-up display of Patent Document 1 has a problem in that if the rib becomes larger, the weight of the first mirror increases, which makes the head-up display heavier and increases manufacturing costs.

[0006] Therefore, an object of the present disclosure is to provide a head-up display that can suppress increases in weight and manufacturing costs. [Means for solving the problem]

[0007] A head-up display according to one embodiment of the present disclosure is a head-up display that projects a virtual image onto a display medium, and includes an image generating unit that emits display light that becomes the display image, a mirror that forms a virtual image on the opposite side of the display medium from a viewer by guiding the display light that becomes the display image emitted by the image generating unit to the display medium, and a housing that houses the image generating unit and the mirror, wherein the mirror has an elongated base having a first surface with a reflective surface that guides the display light to the display medium and a second surface that is the back side of the first surface, and a standing wall that rises from an edge of the second surface along the longitudinal direction of the base, and the longitudinal central portion of the standing wall is shorter in height than both longitudinal end portions of the standing wall. [Effects of the Invention]

[0008] According to a head-up display according to one aspect of the present disclosure, it is possible to suppress an increase in weight and an increase in manufacturing costs. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a head-up display according to an embodiment mounted on a vehicle. [Figure 2] FIG. 2 is a cross-sectional view showing a windshield and a head-up display. [Figure 3] FIG. 3 is a diagram showing a head-up display. [Figure 4] FIG. 4 is a diagram showing a head-up display having a first rib in which a recess is formed and a second rib in which a recess is formed. [Figure 5] FIG. 5 is a diagram showing a head-up display in which the central portion of the first rib and the central portion of the second rib are not formed. [Figure 6] FIG. 6 is a diagram showing a head-up display in which the central portion of the first rib and the central portion of the second rib are formed so as to be misaligned. [Figure 7] FIG. 7 is a diagram showing a head-up display having a second reflecting mirror in which the first rib is shorter than the second rib. [Figure 8] FIG. 8 is a diagram showing a head-up display having a second reflecting mirror in which the second rib is shorter than the first rib. [Figure 9] FIG. 9 is a diagram showing a head-up display having a diamond-shaped second reflecting mirror. [Figure 10] FIG. 10 is a diagram showing a head-up display having a second reflecting mirror in the shape of a polygon with one side missing. [Figure 11] FIG. 11 is a schematic explanatory diagram showing the relationship between the housing and the second reflecting mirror of the head-up display according to the present embodiment and the relationship between the housing and the second reflecting mirror of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0011] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in the independent claims are described as optional components.

[0012] In addition, each drawing is a schematic diagram and is not necessarily an exact illustration. In addition, the same components are denoted by the same reference numerals in each drawing.

[0013] In the following embodiments, in Fig. 2, the front side of the vehicle is defined as the positive X-axis direction, the right side when viewed along the front of the vehicle is defined as the positive Y-axis direction, and the direction perpendicular to the positive X-axis and positive Y-axis directions, and vertically upward, is defined as the positive Z-axis direction. The directions in Fig. 2 also apply to Fig. 3 and subsequent figures.

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

[0015] (Embodiment) <Configuration> A head-up display 1 according to an embodiment will be described below with reference to FIGS.

[0016] FIG. 1 is a perspective view showing a head-up display 1 according to an embodiment mounted on a vehicle. FIG. 2 is a cross-sectional view showing a windshield 3 and the head-up display 1. FIG. 3 is a diagram showing the head-up display 1. FIG. 3(a) shows a top view of the second reflecting mirror 40. FIG. 3(b) shows a front view of the second reflecting mirror 40. FIG. 3(c) shows a bottom view of the second reflecting mirror 40. FIG. 4 is a diagram showing the head-up display 1 having a first rib 41 with recesses 41e and 42e formed therein and a second rib 42 with recesses formed therein. FIG. 4(a) shows a top view of the second reflecting mirror 40a. FIG. 4(b) shows a front view of the second reflecting mirror 40a. FIG. 4(c) shows a bottom view of the second reflecting mirror 40a. FIG. 5 is a diagram showing the head-up display 1 in which the central portion 41a of the first rib 41 and the central portion 42a of the second rib 42 are not formed. FIG. 5(a) shows a top view of the second reflecting mirror 40b. FIG. 5(b) shows a front view of the second reflecting mirror 40b. FIG. 5(c) shows a bottom view of the second reflecting mirror 40b. FIG. 6 shows a head-up display 1 in which the central portion 41a of the first rib 41 and the central portion 42a of the second rib 42 are misaligned. FIG. 6(a) shows a top view of the second reflecting mirror 40c. FIG. 6(b) shows a front view of the second reflecting mirror 40c. FIG. 6(c) shows a bottom view of the second reflecting mirror 40c. FIG. 7 shows a head-up display 1 having a second reflecting mirror 40d in which the first rib 41 is shorter than the second rib 42. FIG. 8 shows a head-up display 1 having a second reflecting mirror 40e in which the second rib 42 is shorter than the first rib 41. FIG. 9 shows a head-up display 1 having a diamond-shaped second reflecting mirror 40f. Fig. 10 is a diagram showing a head-up display 1 having a second reflecting mirror 40g in a polygonal shape with one side missing. Fig. 11 is a schematic explanatory diagram showing the relationship between the housing 10 and the second reflecting mirror 40 of the head-up display 1 according to the present embodiment and the relationship between the housing and the second reflecting mirror of a comparative example.

[0017] 1, the head-up display 1 is disposed, for example, on a dashboard 5 (also referred to as an instrument panel) of a vehicle 2. A windshield 3 (also referred to as a front shield) is disposed above the dashboard 5 of the vehicle 2. The head-up display 1 is disposed within the dashboard 5.

[0018] The head-up display 1 is mounted on a vehicle 2. The head-up display 1 can project a virtual image onto a display medium. Specifically, the head-up display 1 projects a display image onto an object that is transmissive and reflective to form a virtual image on the opposite side of the display medium from a viewer. For example, the head-up display 1 can display a virtual image represented by the display light to a user such as a driver by reflecting display light representing the display image emitted from an image generation unit 20 onto a windshield 3 that is a display medium. In other words, the head-up display 1 projects the display light emitted by the image generation unit 20 forward onto the windshield 3, thereby displaying the display image represented by the display light on the windshield 3. As a result, the display image projected onto the windshield 3 of the vehicle 2 can be viewed by the user.

[0019] Here, the display light is light that represents information of a display image including numbers, letters, figures, etc., and is displayed as a virtual image in front of the windshield 3. The display image is a still image or a moving image, and is an image of numbers, letters, figures, etc.

[0020] As shown in FIGS. 2 and 3, the head-up display 1 includes a housing 10, an image generating unit 20, a first reflecting mirror 30, a second reflecting mirror 40, a driving mechanism 50, and a cover 70.

[0021] The housing 10 is a housing that houses the image generation unit 20, the first reflecting mirror 30, and the second reflecting mirror 40. The housing 10 forms the outer shell of the head-up display 1. The housing 10 is fixed to the vehicle 2 in a state where it is attached to the dashboard 5 or in a state where it is attached to a bracket arranged on a vehicle reinforcement. The housing 10 is made of a resin material or a metal material.

[0022] An opening 11 for arranging the cover 70 is formed on the positive Z-axis direction side of the housing 10. Display light consisting of the display image generated by the image generation unit 20 passes through the opening 11.

[0023] The image generation unit 20 generates a display image and outputs display light that becomes the generated display image so that the display image is projected on the windshield 3. Specifically, the image generation unit 20 emits display light from the display unit. The display light emitted from the display unit of the image generation unit 20 is reflected by the first reflecting mirror 30, then reflected by the second reflecting mirror 40, passes through the opening 11, enters and transmits through the cover 70, and is then emitted from the head-up display 1 to be projected onto the windshield 3. In other words, by emitting display light, the image generation unit 20 can project a predetermined display image onto the windshield 3. The display light is reflected by the windshield 3, allowing the user to recognize a virtual image. The image generation unit 20 is, for example, a liquid crystal display device having a liquid crystal display or the like.

[0024] The image generating unit 20 includes a display unit, a container, a light emitting module, and a condenser lens.

[0025] The display unit is a liquid crystal display element such as a liquid crystal display. The display unit may be a device other than a liquid crystal display, such as an organic light-emitting diode (electroluminescence), a fluorescent display device (seven segments), etc. In the display unit, the light emitting module is irradiated from the rear side, causing the light emitting surface to emit light. In the display unit, display light showing a display image including numbers, letters, figures, etc. is emitted from the light emitting surface in accordance with control instructions from an ECU (Electronic Control Unit) mounted on the vehicle 2. The display unit is driven by DC power obtained from a power supply unit in the vehicle 2.

[0026] The container is a container that houses the display unit, the light emitting module, and the condenser lens. The container is disposed on the bottom plate of the housing 10.

[0027] The light-emitting module includes a light source and a substrate on which the light source is mounted. The light source is mounted on the substrate. The substrate is held so that light is irradiated from the rear side of the display unit toward the display unit via a condenser lens. The light source is, for example, a light-emitting diode. For example, the light source is driven by DC power obtained from a power supply unit in the vehicle 2.

[0028] The condenser lens is disposed on the light path between the light source and the display unit, in the direction of light emission from the light source, and directs the light emitted from the light source toward the display unit.

[0029] The first reflecting mirror 30 reflects the display light emitted by the image generating unit 20 toward the second reflecting mirror 40. The second reflecting mirror 40 also reflects the display light emitted by the image generating unit 20 toward the cover 70 via the opening 11. In other words, the second reflecting mirror 40 can form a virtual image on the opposite side of the windshield 3 from the viewer by guiding the display light that becomes the display image emitted by the image generating unit 20 to the windshield 3.

[0030] Specifically, the first reflecting mirror 30 and the second reflecting mirror 40 are arranged in the housing 10 so as to face each other with a predetermined distance between them. More specifically, the first reflecting mirror 30 is arranged on the negative X-axis side of the housing 10 so as to face the exit surface of the image generating unit 20 and the second reflecting mirror 40, which are arranged on the negative X-axis side of the housing 10. The first reflecting mirror 30 and the second reflecting mirror 40 are arranged between the image generating unit 20 and the opening 11. The second reflecting mirror 40 faces the first reflecting mirror 30 and is arranged on the positive X-axis side of the first reflecting mirror 30. In other words, the second reflecting mirror 40 is arranged to be aligned with the first reflecting mirror 30 along the X-axis direction.

[0031] The first reflecting mirror 30 and the second reflecting mirror 40 are concave mirrors, convex mirrors, or plane mirrors. In this embodiment, each of the first reflecting mirror 30 and the second reflecting mirror 40 is a concave mirror having a free-form surface. In this embodiment, each of the first reflecting mirror 30 and the second reflecting mirror 40 is a rectangular mirror that is elongated in the Y-axis direction. The shapes of the first reflecting mirror 30 and the second reflecting mirror 40 are not particularly limited, and may be polygonal or circular.

[0032] The second reflecting mirror 40 can swing around the Y-axis direction as its axis. In this case, the position of the display image reflected (projected) on the windshield 3 can be adjusted. The second reflecting mirror 40 may be swingable by manual operation or by electric operation using the drive mechanism 50. In this embodiment, the second reflecting mirror 40 swings by electric operation using the drive mechanism 50.

[0033] The second reflecting mirror 40 has a long base body 45 , a standing wall 46 , and a shaft portion 146 .

[0034] The base 45 is made of a resin molded product formed by injection molding a resin such as polycarbonate, or glass.

[0035] The base 45 has a rectangular shape. However, the shape of the base 45 is not limited to a rectangular shape. The shape of the base 45 may be any other known shape.

[0036] The base 45 has a first surface 141 having a reflective surface that guides display light to the windshield 3, and a second surface 142 that is the back surface of the first surface 141.

[0037] The first surface 141 is mirror-finished so as to be able to reflect display light. A reflective surface may be formed on the first surface 141 using a light-reflecting film, a light-reflecting plate, or the like. The entire surface of the first surface 141 or the central portion of the first surface 141 may be a reflective surface.

[0038] In this embodiment, first surface 141 has a concave shape. Therefore, first surface 141 has a spherical or aspherical shape. Note that first surface 141 may also have a convex or flat shape. Such first surface 141 is a concave mirror, a convex mirror, or a flat mirror.

[0039] The standing wall 46 rises from the edge of the second surface 142 along the longitudinal direction of the base 45. In other words, the standing wall 46 is a frame-shaped body formed along the outer peripheral edge of the base 45. The standing wall 46 may be formed around the entire outer peripheral edge of the base 45, or may be not formed by cutting out a portion. In this embodiment, the longitudinal direction is a direction parallel to the Y-axis direction.

[0040] Specifically, the height of the central portion of the standing wall 46 in the longitudinal direction is lower than both end portions 41b, 42b of the standing wall 46 in the longitudinal direction. For example, as shown in (a) and (c) of FIG. 3, when the side of the second reflecting mirror 40 is viewed along the short side direction of the second reflecting mirror 40, the standing wall 46 in the central portion in the longitudinal direction is cut out to form a plane that is approximately parallel to the long side direction of the base 45. Specifically, the standing wall 46 has a first rib 41 extending along the long side direction and a second rib 42 extending along the long side direction. In this embodiment, the short side direction is a direction perpendicular to the long side direction.

[0041] The first rib 41 is disposed closer to the windshield 3 than the second rib 42 on the base 45, i.e., closer to the opening 11 of the housing 10 (positive Z-axis direction side) than the second rib 42. The second rib 42 is disposed farther from the windshield 3 than the first rib 41, and farther from the opening 11 of the housing 10 than the first rib 41 (negative Z-axis direction side). In this embodiment, the first rib 41 and the second rib 42 are approximately parallel to each other.

[0042] The second reflecting mirror 40 is rotatably disposed inside the housing 10, and is rotatably supported so as to be substantially directly opposite a wall surface 12 inside the housing 10. Even when the second reflecting mirror 40 rotates, the first rib 41 is supported by the housing 10 in an orientation such that it is closer to the wall surface 12 than the second rib 42. The wall surface 12 is on the positive side of the X-axis of the housing 10, and is a wall surface on the front side of the vehicle 2.

[0043] The second reflecting mirror 40 rotates inside the housing 10, but does not come into contact with (interfere with) the housing 10 even when it rotates.

[0044] Specifically, even when the second reflecting mirror 40 rotates, the first rib 41 does not come into contact with the wall surface 12 of the housing 10. The height of the central portion 41a of the first rib 41 is set so that the second reflecting mirror 40 does not come into contact with the wall surface 12 even when the second reflecting mirror 40 rotates. In other words, a notch is formed in the central portion 41a of the first rib 41.

[0045] Furthermore, even when the second reflecting mirror 40 rotates, the second rib 42 does not come into contact with the bottom wall surface 13 of the housing 10. In other words, the height of the central portion 42a of the second rib 42 is set so that the second reflecting mirror 40 does not come into contact with the wall surface 13 even when it rotates. In other words, a notch is formed in the central portion 42a of the second rib 42.

[0046] The notches in the central portions 41a of the first rib 41 and the central portions 42a of the second rib 42 are linear. The notches in the central portions 41a of the first rib 41 and the central portions 42a of the second rib 42 are not limited to being linear. For example, the notches in the central portions 41a of the first rib 41 and the central portions 42a of the second rib 42 may have a curved shape or the like. Furthermore, the notches in the central portions 41a of the first rib 41 and the central portions 42a of the second rib 42 may have other known shapes.

[0047] 4(a) to 4(c), in the second reflecting mirror 40a, recesses 41e, 42e may be formed in the notch in the central portion 41a of the first rib 41 and the notch in the central portion 42a of the second rib 42. In other words, the notch in the central portion 41a of the first rib 41 and the notch in the central portion 42a of the second rib 42 may be further partially cut out.

[0048] 4(a) to 4(c), the shape of the recesses 41e in the central portion 41a of the first rib 41 may be any shape, and the number of recesses 41e in the central portion 41a of the first rib 41 is not particularly limited as long as it is 1 or more. The shape of the recesses 42e in the central portion 42a of the second rib 42 may be any shape, and the number of recesses 42e in the central portion 42a of the second rib 42 is not particularly limited as long as it is 1 or more.

[0049] 5(a) to 5(c), in the second reflecting mirror 40b, the height of the notch in the central portion 41a of the first rib 41 and the notch in the central portion 42a of the second rib 42 may be zero in part. In other words, the second reflecting mirror 40b may be formed with a portion where the height of the first rib 41 and the height of the second rib 42 are the same (flush) as the second surface 142 of the base 45.

[0050] Compared to conventional head-up displays in which the central portions of the first rib and the second rib are not cut out, in the head-up display 1 of the present embodiment, the second reflecting mirror 40b can be disposed as close to the wall surface 12 of the housing 10 as possible (the wall surface 12 on the front side of the vehicle 2). Therefore, the second reflecting mirror 40b is disposed in the housing 10 so that the distance between the central portion 41a of the first rib 41 and the wall surface 12 is shorter than the distance between both end portions 41b of the first rib 41 in the longitudinal direction and the wall surface 12.

[0051] As shown in (a) to (c) of FIG. 6, in the second reflecting mirror 40c, the central portion 41a of the first rib 41 in the longitudinal direction may be positioned differently from the central portion 42a of the second rib 42 in the longitudinal direction. That is, in the second reflecting mirror 40c, the central portion 41a of the first rib 41, which has the smallest height (the dash-dotted line passing through the center of the notch of the first rib 41), is formed at a different position from the central portion 42a of the second rib 42, which has the smallest height (the dash-dotted line passing through the center of the notch of the second rib 42). That is, the dash-dotted line O1 and the dash-dotted line O2 are parallel to each other but do not coincide with each other. As shown in (a) to (c) of FIG. 6, the second reflecting mirror 40c can also be said to have an asymmetric shape with respect to a line along the short side that intersects with the longitudinal direction.

[0052] 7 and 8, the second reflecting mirrors 40d and 40e may have a shape that is asymmetric with respect to a line along the longitudinal direction (a line parallel to the Y-axis direction). In other words, the second reflecting mirrors 40d and 40e are not line-symmetric with respect to a line parallel to the Y-axis direction.

[0053] For example, the length of the first rib 41 and the length of the second rib 42 may be different. As shown in FIG. 7, in a second reflecting mirror 40d, the length of the first rib 41 may be shorter than the length of the second rib 42. In this case, the second reflecting mirror 40d may have a trapezoidal shape in which the first rib 41 and the second rib 42 are substantially parallel to each other. Furthermore, as shown in FIG. 8, in a second reflecting mirror 40e, the length of the first rib 41 may be longer than the length of the second rib 42. In this case, the second reflecting mirror 40e may have a trapezoidal shape in which the first rib 41 and the second rib 42 are substantially parallel to each other.

[0054] 9 and 10, the second reflecting mirror 40 may have a shape that is asymmetric with respect to a line along the short-side direction (Z-axis direction) that intersects with the long-side direction (Y-axis direction). In other words, the second reflecting mirror 40 is not line-symmetric with respect to a line that is perpendicular to the Y-axis direction.

[0055] For example, as shown in FIG. 9, in a second reflecting mirror 40f, the length of the first rib 41 may be equal to the length of the second rib 42, and the lengths of the pair of third ribs 43 may be equal to each other. In this case, the second reflecting mirror 40f may be rhombic. As shown in FIG. 10, a second reflecting mirror 40g may be polygonal with a portion cut out. In this case, the first rib 41 or the second rib 42 may be bent. FIG. 10 illustrates an example in which the first rib 41 is bent and the second rib 42 is straight. Note that in the second reflecting mirror 40f, the length of the first rib 41 may be different from the length of the second rib 42, and the lengths of the pair of third ribs 43 may be different from each other.

[0056] 3(a) and 3(c), the height H1 of the first rib 41 is greater than the height H2 of the second rib 42. In other words, the height of the central portion 41a of the first rib 41 is greater than the height of the central portion 42a of the second rib 42, and the height of the end portions 41b of the first rib 41 is greater than the height of the end portions 42b of the second rib 42.

[0057] 11, the second reflecting mirror 40 has a structure in which the central portion of the standing wall 46 is cut out. Therefore, the second reflecting mirror 40 can be disposed as close as possible to the wall surface 12 of the housing 10. Since the second reflecting mirror 40 can be disposed closer to the wall surface 12 of the housing 10, it is expected that the housing 10 can be made smaller in size.

[0058] The standing wall 46 further has a pair of third ribs 43 that are disposed at both end portions 41b of the first rib 41 and at both end portions 42b of the second rib 42 and extend in the lateral direction.

[0059] One of the pair of third ribs 43 connects one end (end on the positive Y-axis direction) of the first rib 41 to one end (end on the positive Y-axis direction) of the second rib 42. The other of the pair of third ribs 43 connects the other end (end on the negative Y-axis direction) of the first rib 41 to the other end (end on the negative Y-axis direction) of the second rib 42.

[0060] The height of the pair of third ribs 43 may be equal to the height of both end portions 41b of the first rib 41 and the height of both end portions 42b of the second rib 42. The heights of the pair of third ribs 43 may also be equal to each other. The heights of the pair of third ribs 43 may be different from the heights of both end portions 41b of the first rib 41 and the heights of both end portions 42b of the second rib 42. The heights of the pair of third ribs 43 may also be different from each other.

[0061] The shaft portions 146 are disposed at both ends in the longitudinal direction of the second reflecting mirror 40, i.e., at both ends in the Y-axis direction. The shaft portions 146 are connected to the pair of third ribs 43 and the base 45. Since the shaft portions 146 are rotatably supported by the housing 10, the second reflecting mirror 40 is rotatably supported by the housing 10.

[0062] The standing wall 46 is made of glass or a resin molded product formed integrally with the base body 45 by injection molding a resin such as polycarbonate.

[0063] Although the second reflecting mirror 40 has been described above, the first reflecting mirror 30 may have the same configuration and function as the second reflecting mirror 40.

[0064] The driving mechanism 50 is provided on the side surface of the second reflecting mirror 40. In this embodiment, the driving mechanism 50 is provided on the second rib 42 of the second reflecting mirror 40.

[0065] As shown in FIG. 2, the drive mechanism 50 includes a gear 60 and a drive unit 61.

[0066] The gear 60 can rotate the second reflecting mirror 40 around an axis along the longitudinal direction. The gear 60 is disposed on the second rib .

[0067] The driving unit 61 is disposed at the bottom of the housing 10 below the second reflecting mirror 40, and is connected to the gear 60. In this embodiment, the driving unit 61 is an electric motor that can rotate the second reflecting mirror 40 by transmitting a driving force to the gear 60. The driving unit 61 can adjust the angle (attitude) of the second reflecting mirror 40 by driving it.

[0068] The cover 70 is supported by the housing 10 so as to cover the opening 11 of the housing 10. The cover 70 is disposed on the positive Z-axis direction side of the first reflecting mirror 30, the second reflecting mirror 40, and the image generating unit 20.

[0069] The cover 70 is made of a translucent resin material such as polycarbonate (PC), acrylic, or a laminate thereof, or a polarizing plate. Since the display light passes through the opening 11, the display light that has passed through the cover 70 is projected onto the windshield 3.

[0070] The cover 70 also serves as an anti-fouling cover that prevents dust and dirt from entering the housing 10. For example, the surface of the cover 70 facing the windshield 3 may be hard coated. In this case, even if dust and dirt adhere to this surface, the dirt can be easily wiped off. The surface of the cover 70 facing the windshield 3 is the surface of the cover 70 facing the positive direction of the Z axis, and is the exit surface from which image light is emitted. In addition, the surface of the cover 70 may be anti-reflective coated.

[0071] <Action and effect> Next, the effects of the head-up display 1 according to this embodiment will be described.

[0072] As described above, the head-up display 1 according to this embodiment is a head-up display 1 that projects a virtual image onto a display medium (windshield 3), and includes an image generating unit 20 that emits display light that becomes a display image, a mirror (second reflecting mirror 40 to 40g) that forms a virtual image on the side of the display medium (windshield 3) opposite to the viewer by guiding the display light that becomes a display image emitted by the image generating unit 20 to the display medium (windshield 3), and a mirror (second reflecting mirror 40 to 40g) that reflects the virtual image on the side of the display medium (windshield 3) opposite to the viewer. The display device includes a housing 10 that houses a mirror (second reflecting mirror 40-40g), and the mirror (second reflecting mirror 40-40g) has an elongated base 45 that has a first surface 141 with a reflective surface that guides display light to a display medium (windshield 3) and a second surface 142 that is the back surface of the first surface 141, and a standing wall 46 that rises from the edge of the second surface 142 along the longitudinal direction of the base 45, and longitudinal central portions 41a, 42a of the standing wall 46 are shorter in height than longitudinal end portions 41b, 42b of the standing wall 46.

[0073] In this case, the central portions 41a, 42a of the standing walls 46 of the second reflecting mirrors 40-40g have a partially cut-out structure, which helps prevent the weight of the second reflecting mirrors 40-40g from increasing, and therefore reduces the material costs of the second reflecting mirrors 40-40g.

[0074] Therefore, according to this head-up display 1, it is possible to suppress an increase in weight and manufacturing costs.

[0075] In particular, since the second reflecting mirrors 40-40g are formed with the upright walls 46, the rigidity of the second reflecting mirrors 40-40g is ensured, thereby suppressing distortion of the second reflecting mirrors 40-40g. Therefore, when the head-up display 1 is mounted on a vehicle, even if the second reflecting mirrors 40-40g vibrate within a predetermined frequency band, the rigidity of the second reflecting mirrors 40-40g is ensured, thereby suppressing the vibration. Therefore, degradation in the image quality of the image reflected by the second reflecting mirrors 40-40g and displayed on the windshield 3 can be suppressed.

[0076] Furthermore, in the head-up display 1 according to this embodiment, the standing wall 46 has a first rib 41 extending along the longitudinal direction and a second rib 42 extending along the longitudinal direction and positioned farther from the display medium (windshield 3) than the first rib 41, and the mirror (second reflecting mirror 40-40g) is rotatably supported approximately directly facing the wall surface 12 inside the housing 10, and is supported in an orientation such that the first rib 41 is closer to the wall surface 12 than the second rib 42, and the height of the central portion 41a of the first rib 41 and the height of the central portion 42a of the second rib 42 are such that the mirror (second reflecting mirror 40-40g) does not come into contact with the housing 10 even when rotated.

[0077] With this, even if the second reflecting mirrors 40 to 40g are rotatably supported inside the housing 10, the first ribs 41 and second ribs 42 of the second reflecting mirrors 40 to 40g are less likely to come into contact with the housing 10.

[0078] Furthermore, because the central portions 41a of the first rib 41 and the central portions 42a of the second ribs 42 are cut out, the second reflecting mirrors 40 to 40g can be disposed closer to the wall surface 12 of the housing 10 than the reflecting mirrors of the comparative example, as shown in Fig. 11. In other words, the second reflecting mirrors 40 to 40g can be disposed closer to the wall surface 12 of the housing 10 by the distance corresponding to the height at which the central portions 41a of the first rib 41 and the central portions 42a of the second ribs 42 are cut out. This allows the housing 10 to be smaller by the width of the closer mirrors.

[0079] Furthermore, in the head-up display 1 according to this embodiment, the standing wall 46 has a first rib 41 extending along the longitudinal direction and a second rib 42 extending along the longitudinal direction and positioned farther from the display medium (windshield 3) than the first rib 41, the mirror (second reflecting mirror 40-40g) is rotatably supported approximately directly facing the wall surface 12 inside the housing 10, and is supported in an orientation such that the first rib 41 is closer to the wall surface 12 than the second rib 42, and the distance between the central portion 41a of the first rib 41 and the wall surface 12 is shorter than the distance between both end portions 41b of the first rib 41 in the longitudinal direction and the wall surface 12.

[0080] This allows the second reflecting mirrors 40 to 40g to be arranged in an inclined position in the housing 10. This prevents the housing 10 from becoming larger in size in the height direction (Z-axis direction) compared to when the second reflecting mirrors 40 to 40g are arranged in an upright position in the housing 10.

[0081] Furthermore, because the central portions 41a of the first rib 41 and the central portions 42a of the second ribs 42 are cut out, the second reflecting mirrors 40 to 40g can be disposed closer to the wall surface 12 of the housing 10 than the reflecting mirrors of the comparative example, as shown in Fig. 11. In other words, the second reflecting mirrors 40 to 40g can be disposed closer to the wall surface 12 of the housing 10 by the distance corresponding to the height at which the central portions 41a of the first rib 41 and the central portions 42a of the second ribs 42 are cut out. This allows the housing 10 to be smaller by the width of the closer mirrors.

[0082] In the head-up display 1 according to the present embodiment, the mirrors (second reflecting mirrors 40d to 40g) have shapes that are asymmetric with respect to a straight line along the longitudinal direction.

[0083] This is expected to improve the balance of resin filling when injection molding the second reflecting mirrors 40d to 40g, thereby making hardening shrinkage uniform during cooling, and therefore it is expected that the second reflecting mirrors 40d to 40g having high-quality first surfaces 141 can be obtained.

[0084] Furthermore, even if the second reflecting mirrors 40d to 40g have an asymmetrical shape, the display image can be displayed on the windshield 3. Therefore, the degree of freedom in the shape of the head-up display 1 is unlikely to be impaired.

[0085] In the head-up display 1 according to the present embodiment, the height H1 of the first rib 41 is greater than the height H2 of the second rib .

[0086] This is expected to improve the balance of resin filling when injection molding the second reflecting mirrors 40 to 40g, which will result in uniform hardening and shrinkage during cooling, and therefore it is expected that the second reflecting mirrors 40 to 40g having high-quality first surfaces 141 can be obtained.

[0087] In addition, the head-up display 1 according to this embodiment further includes a gear 60 that rotates the mirror (second reflecting mirror 40 to 40g) around an axis along the longitudinal direction, and a drive unit 61 that is arranged at the bottom of the housing 10 below the mirror (second reflecting mirror 40 to 40g) and is connected to the gear 60.

[0088] This is expected to improve the balance of resin filling when injection molding the second reflecting mirrors 40 to 40g, which will result in uniform hardening and shrinkage during cooling, and therefore it is expected that the second reflecting mirrors 40 to 40g having high-quality first surfaces 141 can be obtained.

[0089] In the head-up display 1 according to the present embodiment, the position of the central portion 41a of the first rib 41 in the longitudinal direction is different from the position of the central portion 42a of the second rib 42 in the longitudinal direction.

[0090] This is expected to improve the balance of resin filling when injection molding the second reflection mirror 40c, which will result in uniform hardening and shrinkage during cooling, and therefore it is expected that the second reflection mirror 40c having the first surface 141 with excellent quality will be obtained.

[0091] In the head-up display 1 according to the present embodiment, the mirrors (second reflecting mirrors 40f, 40g) have a shape that is asymmetric with respect to a straight line along the short-side direction that intersects with the long-side direction.

[0092] This makes it possible to reduce the length of the second reflecting mirrors 40f, 40g in the height direction (Z-axis direction) when the rotation axes of the second reflecting mirrors 40f, 40g are arranged with an inclination with respect to the bottom surface of the housing 10. This makes it possible to prevent the housing 10 from becoming large in the height direction.

[0093] (Other variations, etc.) While the head-up display according to the present disclosure has been described based on the above-described embodiments, the present disclosure is not limited to these embodiments. As long as the modifications do not deviate from the spirit of the present disclosure, various modifications conceivable by those skilled in the art may also be included in the scope of the present disclosure.

[0094] In addition, this disclosure also includes forms obtained by making various modifications to the above embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions of the embodiments within the scope that does not deviate from the intent of this disclosure. [Industrial Applicability]

[0095] The present disclosure can be used in mobile objects such as vehicles. [Explanation of symbols]

[0096] 1 Head-up display 3 Windshield (display medium) 10. Cabinet 12 Wall 20 Image generation unit 40~40g Second reflection mirror (mirror) 41 First Rib 41a Center part of the first rib 41b Both ends of the first rib 42 Second Rib 42a Center part of second rib 42b Both ends of the second rib 45 Base 46 Standing Wall 60 gears 61 Drive unit 141 Page 1 142 2nd page

Claims

1. A head-up display that projects a virtual image onto a display medium, an image generating unit that emits display light that becomes a display image; a mirror that guides the display light, which becomes the display image and is emitted from the image generation unit, to the display medium, thereby forming a virtual image on the side opposite to the viewer with respect to the display medium; a housing that houses the image generating unit and the mirror, The mirror is an elongated substrate having a first surface having a reflective surface that guides the display light to the display medium, and a second surface that is the reverse side of the first surface; a standing wall rising from an edge of the second surface along the longitudinal direction of the base body, The height of the central portion of the standing wall in the longitudinal direction is lower than the height of both end portions of the standing wall in the longitudinal direction. Head-up display.

2. the standing wall has a first rib extending along the longitudinal direction and a second rib extending along the longitudinal direction and disposed at a position farther from the display medium than the first rib; The mirror is a support member rotatably supported substantially directly facing the inner wall surface of the housing; The first rib is supported in a position closer to the wall surface than the second rib, The height of the central portion of the first rib and the height of the central portion of the second rib are set so that the mirror does not come into contact with the housing even when the mirror rotates. The head-up display according to claim 1 .

3. the standing wall has a first rib extending along the longitudinal direction and a second rib extending along the longitudinal direction and disposed at a position farther from the display medium than the first rib; The mirror is a support member rotatably supported substantially directly facing the inner wall surface of the housing; The first rib is supported in a position closer to the wall surface than the second rib, The distance between the central portion of the first rib and the wall surface is shorter than the distance between both end portions of the first rib in the longitudinal direction and the wall surface. The head-up display according to claim 1 .

4. The mirror has an asymmetric shape with respect to a straight line along the longitudinal direction. The head-up display according to any one of claims 1 to 3.

5. The height of the first rib is greater than the height of the second rib. The head-up display according to claim 3 .

6. a gear that rotates the mirror around an axis along the longitudinal direction; a drive unit that is disposed at the bottom of the housing below the mirror and that is connected to the gear. The head-up display according to claim 5 .

7. The position of a central portion of the first rib in the longitudinal direction is different from the position of a central portion of the second rib in the longitudinal direction. The head-up display according to claim 3 .

8. The mirror has an asymmetric shape with respect to a line along a short direction intersecting the long direction. The head-up display according to any one of claims 1 to 3.

Images