Head-up display device

Abstract

The purpose of the present invention is to provide a head-up display device that enables a reduction in size.　A head-up display device (100) according to the present invention comprises: a display unit (10) that emits display light (L); a first mirror (20) that reflects the display light (L) from the display unit (10); a second mirror (30) that reflects the display light (L) reflected by the first mirror (20); and a mirror driving unit (50) that rotates the first mirror (20) about a rotation axis (Ax).

Description

Technical Field

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

Background Art

[0002] For example, the head-up display device described in Patent Document 1 includes a display unit that emits display light, a folding mirror member that reflects the display light emitted from the display unit, a mirror unit that reflects the display light reflected by the folding mirror member toward a front glass, and a mirror drive unit that rotates the mirror unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1 above, since the display light emitted from the display unit is expanded through the folding mirror member and the mirror unit, the mirror unit located on the rear stage side in the optical path of the display light becomes large, and accordingly, the mirror drive unit, and thus the head-up display device, may become large.

[0005] The present disclosure has been made in view of the above actual situation, and an object thereof is to provide a head-up display device that can be miniaturized.

Means for Solving the Problems

[0006] To achieve the above object, the head-up display device according to the present disclosure includes a display unit that emits display light, a first mirror that reflects the display light from the display unit, A second mirror that reflects the display light reflected by the first mirror A head-up display device comprising: a mirror driving unit that rotates the first mirror about a rotation axis and comprises a mirror holder for supporting the first mirror, the mirror holder includes a cover portion formed to cover the upper surface of the first mirror. Also, the head-up display device according to the present disclosure includes a display unit that emits display light, a first mirror that reflects the display light from the display unit, a second mirror that reflects the display light reflected by the first mirror, and a mirror driving unit that rotates the first mirror about a rotation axis, and is a head-up display device comprising: comprises a mirror holder for supporting the first mirror, the mirror holder is formed between an optical path through which the display light passes in the head-up display device and the mirror driving unit, and includes a light shielding wall portion that hides the mirror driving unit from the optical path. Also, the head-up display device according to the present disclosure includes a display unit that emits display light, a first mirror that reflects the display light from the display unit, a second mirror that reflects the display light reflected by the first mirror, and a mirror driving unit that rotates the first mirror about a rotation axis, and is a head-up display device comprising: the first mirror is a concave mirror, the width of the first mirror in the direction along the rotation axis is smaller than the width of the second mirror in the direction along the rotation axis, the first mirror is positioned to face a part of the second mirror, and the mirror driving unit is positioned to face the remaining part of the second mirror.

Advantages of the Invention

[0007] According to the present disclosure, in a head-up display device, miniaturization can be achieved.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 10

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Figure 13

Embodiments for Carrying Out the Invention

[0009] An embodiment of a head-up display device according to the present disclosure will be described with reference to the drawings. As shown in FIG. 1, the head-up display device 100 is mounted in the dashboard of the vehicle 5. The head-up display device 100 emits display light L representing an image toward the windshield 6, which is an example of a projection member of the vehicle 5. The display light L is reflected by the windshield 6 and reaches the viewer 1 (mainly the driver of the vehicle 5). Thereby, the head-up display device 100 displays a virtual image V including vehicle information so as to be visible to the viewer 1.

[0010] As shown in FIGS. 2 and 3, the head-up display device 100 includes a display unit 10, a first mirror 20, a mirror holder unit 40, a second mirror 30, a housing 60, a mirror drive unit 50, and a control board 70.

[0011] As shown in FIG. 2, the display unit 10 emits display light L representing an image under the control of the control board 70. The display unit 10 includes, for example, a TFT (Thin Film Transistor) type liquid crystal display panel (not shown) and a backlight (not shown) that illuminates the liquid crystal display panel.

[0012] As shown in FIG. 4, the first mirror 20 is a concave mirror that is concave in the width direction W along the rotation axis Ax of the first mirror 20. The first mirror 20 reflects the display light L from the display unit 10 toward the second mirror 30. In this example, the first mirror 20 reflects the display light L that travels upward from the display unit 10 forward and downward of the vehicle. As shown in FIG. 5, the width W1 along the width direction W of the first mirror 20 is formed smaller than the width W2 along the width direction W of the second mirror 30. That is, in the width direction W, the reflecting surface 20a of the first mirror 20 faces the first range N1 of the reflecting surface 30a of the second mirror 30, and the mirror drive unit 50 faces the remaining second range N2 of the reflecting surface 30a of the second mirror 30. As shown in FIG. 4, the height H1 of the first mirror 20 is formed smaller than the height H2 of the second mirror 30. Further, the curvature of the first mirror 20 is formed to be smaller than the curvature of the second mirror 30. Further, the first mirror 20 causes the reflected display light L to reach the second mirror 30 while expanding it in the width direction W.

[0013] As shown in FIG. 2, the mirror holder unit 40 rotatably supports the first mirror 20 about the rotation axis Ax. The specific configuration of the mirror holder unit 40 will be described later. The mirror drive unit 50 rotates the mirror holder unit 40 together with the first mirror 20 about the rotation axis Ax under the control of the control board 70. The specific configuration of the mirror drive unit 50 will also be described later.

[0014] As shown in FIG. 2, the second mirror 30 reflects the display light L reflected by the first mirror 20 while expanding it toward the front glass 6 (see FIG. 1). The second mirror 30 is fixedly installed in the housing 60 so as not to rotate.

[0015] The control board 70 acquires vehicle information from the outside and controls the display unit 10 and the mirror drive unit 50 based on the acquired vehicle information. The control board 70 is a printed circuit board on which various electronic components such as a CPU (Central Processing Unit ), GDC (Graphics Display Controller), ROM (Read Only Memory), and RAM (Random Access Memory) are mounted.

[0016] As shown in FIG. 2, the housing 60 is formed in a box shape by a light-shielding member such as resin. Each component of the head-up display device 100 is housed in the housing 60. Specifically, the housing 60 includes an upper case 61, a lower case 68, and a cover 67.

[0017] The lower case 68 is box-shaped and opens upward. A control board 70 and a display unit 10 are mounted on the outer bottom surface of the lower case 68. The cover 67 is mounted on the outer bottom surface of the lower case 68 so as to cover the control board 70. A light passage hole 68a through which the display light L emitted by the display unit 10 passes is formed on the inner bottom surface of the lower case 68. As shown in FIG. 4, a mirror holder unit 40 that supports the first mirror 20, a second mirror 30, and a mirror drive unit 50 are housed in the lower case 68. An optical path Sc through which the display light L passes is formed between the first mirror 20 and the second mirror 30 in the lower case 68. Side wall portions 69a, 69b facing each other in the width direction W are formed in the lower case 68 via the optical path Sc.

[0018] As shown in FIG. 2, the upper case 61 functions as a lid for the lower case 68 so as to close the opening of the lower case 68. An opening 61h is formed in the upper case 61 at a position facing the front glass 6 (see FIG. 1). The upper case 61 includes a curved plate-shaped window portion 65 that closes the opening 61h. The window portion 65 is made of a light-transmissive member such as an acrylic resin through which the display light L passes.

[0019] Next, the specific configuration of the mirror holder unit 40 will be described. As shown in FIG. 6, the mirror holder unit 40 includes a mirror holder 41, a first shaft support member 44, a second shaft support member 45, and fixing members 46, 47. As shown in FIG. 7, the mirror holder 41 includes a mirror support portion 41a, a cover portion 41b, a light-shielding wall portion 42, a shaft portion 41d, a gripped portion 41e, and a shaft portion 41f as shown in FIG. 11. As shown in Fig. 7, the mirror support portion 41a supports the first mirror 20 from the back surface on the side opposite to the reflecting surface 20a of the first mirror 20. The mirror support portion 41a extends along the width direction W and has a substantially rectangular plate shape that is long in the width direction W. The mirror support portion 41a includes a plurality of contact portions 41a1 and a plurality of connecting portions 41a2. The contact portion 41a1 has a rectangular plate shape. A plurality, in this example two, of the contact portions 41a1 are arranged in the width direction W and are adhered to the back surface of the first mirror 20 via an adhesive means such as an adhesive or double-sided tape. Each connecting portion 41a2 connects between the shaft portion 41d, each contact portion 41a1, and the light-shielding wall portion 42 while being separated from the back surface of the first mirror 20.

[0020] As shown in Figs. 7 and 8, the cover portion 41b is formed so as to cover at least the edge portion of the upper side surface of the first mirror 20. This edge portion is the corner between the reflecting surface 20a of the first mirror 20 and the upper side surface of the first mirror 20. The cover portion 41b is long in the width direction W and has a rectangular plate shape facing the upper side surface of the first mirror 20.

[0021] As shown in Fig. 7, the shaft portion 41d is located at the first end portion (the left end portion in Fig. 7) along the rotation axis Ax of the mirror holder 41 and has a substantially cylindrical shape extending along the rotation axis Ax. As shown in Fig. 13, the shaft portion 41d is supported by the second shaft support member 45 so as to be rotatable about the axis. As shown in Fig. 11, the shaft portion 41f is located at the second end portion opposite to the first end portion along the rotation axis Ax of the mirror holder 41 and is supported by the first shaft support member 44 (see Fig. 12) so as to be rotatable about the axis. The shaft portion 41f has a substantially triangular pyramid-shaped receiving hole 41h. A spherical portion 44d, which will be described later, of the first shaft support member 44 contacts each inner surface of the receiving hole 41h. With the spherical portion 44d contacting each inner surface of the receiving hole 41h, the shaft portion 41f is supported by the first shaft support member 44 so as to be rotatable about the rotation axis Ax.

[0022] As shown in FIG. 8, the light shielding wall portion 42 is located between the optical path Sc through which the display light L passes and the mirror driving unit 50, and blocks sunlight or display light L traveling from the optical path Sc toward the mirror driving unit 50. The light shielding wall portion 42 suppresses the mirror driving unit 50 from being illuminated by sunlight or display light L. As shown in FIG. 5, the light shielding wall portion 42 is located above a portion of the side wall portion 69a of the lower case 68 that is close to the first mirror 20.

[0023] As shown in FIG. 9, the light shielding wall portion 42 includes a first plate portion 42a, a second plate portion 42b, and a third plate portion 42c. The first plate portion 42a is inclined so as to follow the light expansion of the display light L reflected by the first mirror 20. The first plate portion 42a is connected to the second end side (the right end side in FIG. 7) of the mirror support portion 41a and extends along the light emission direction and the light expansion direction of the display light L reflected by the first mirror 20. As shown in FIG. 8, the first plate portion 42a is located inside the width direction W from the side wall portion 69a of the lower case 68.

[0024] As shown in FIG. 10, the second plate portion 42b surrounds the shaft portion 41f from above. The second plate portion 42b is formed on the back surface of the first plate portion 42a on the side opposite to the optical path Sc.

[0025] As shown in FIG. 9, the third plate portion 42c is formed so as to hide the gripped portion 41e from the optical path Sc. The third plate portion 42c extends in a direction intersecting the width direction W, is located farther from the mirror holder 41 than the first plate portion 42a, and is located outside the width direction W from the first plate portion 42a. As shown in FIG. 8, the third plate portion 42c is located outside the width direction W from the side wall portion 69a of the lower case 68.

[0026] As shown in FIG. 12, the first shaft support member 44 includes a fixing portion 44a, a holding member support portion 44b, and a shaft support portion 44c. The fixing portion 44a is fixed inside the lower case 68. The holding member support portion 44b extends upward from the fixing portion 44a and supports a holding member 55 (to be described later) of the mirror driving unit 50. The shaft support portion 44c supports the shaft portion 41d so that the mirror holder 41 can rotate about the rotation axis Ax. The shaft support portion 44c includes a spherical portion 44d that contacts the receiving hole 41h (see FIG. 11) of the shaft portion 41f, and a cylindrical portion 44f that is located on the outer circumferences of the spherical portion 44d and the shaft portion 41f. The spherical portion 44d is integrally formed as a part of the first shaft support member 44. Thereby, the number of components can be reduced as compared with forming the spherical portion 44d separately. The spherical portion 44d is formed in a substantially hemispherical shape. In this example, the spherical portion 44d has a substantially hemispherical shape with three divided portions in the rotational direction about the rotation axis Ax, and the three divided portions contact the respective surfaces of the substantially triangular pyramid-shaped receiving hole 41h. Thereby, the shaft portion 41f is supported by the shaft support portion 44c. By forming the shaft support portion 44c in a substantially hemispherical shape, it is possible to suppress wear of the shaft support portion 44c as the mirror holder 41 rotates about the rotation axis Ax. As shown in FIG. 10, the fixing member 46 fixes the shaft support portion 44c and the shaft portion 41f to be relatively rotatable about the rotation axis Ax in a state where the shaft portion 41f is supported by the shaft support portion 44c. The fixing member 46 is formed as a substantially U-shaped metal clip and sandwiches the shaft support portion 44c and the shaft portion 41f from the outside.

[0027] As shown in FIG. 13, the second shaft support member 45 is fixed in the lower case 68 and supports the shaft portion 41d to be rotatable about the rotation axis Ax from below. The fixing member 47 is a metal plate material and presses the shaft portion 41d upward toward the second shaft support member 45.

[0028] Next, the specific configuration of the mirror driving unit 50 will be described. As shown in FIG. 9, the mirror driving unit 50 includes a motor 52, a conversion mechanism 53 that converts the rotational motion of the motor 52 into a linear motion, a holding member 55 that holds the motor 52 and the conversion mechanism 53, and a position detection unit 57.

[0029] The conversion mechanism 53 has a lead screw 53a and a slider 53b. The holding member 55 is fixed to the holding member support portion 44b of the first shaft support member 44, rotatably holds the lead screw 53a, and has a motor 52 mounted thereon. For example, the holding member 55 includes a first plate portion 55a, a second plate portion 55b extending from the lower end of the first plate portion 55a in a direction orthogonal to the first plate portion 55a, and a third plate portion 55c extending from the upper end of the first plate portion 55a in the same direction as the second plate portion 55b. Between the second plate portion 55b and the third plate portion 55c, a lead screw 53a extending in a rod shape along the height direction H is rotatably supported. Threads are cut on the outer periphery of the lead screw 53a. The motor 52 is fixed to the lower surface of the second plate portion 55b. The motor 52 is driven under the control of the control board 70 to axially rotate the lead screw 53a.

[0030] The slider 53b has a shape that sandwiches the gripped portion 41e of the mirror holder 41. The slider 53b is engaged with the outer periphery of the lead screw 53a and moves along the axial direction of the lead screw 53a as the lead screw 53a axially rotates. When the slider 53b moves along the axial direction (height direction H) of the lead screw 53a, the mirror holder 41 rotates about the rotation axis Ax together with the first mirror 20 via the gripped portion 41e. The rotation angle about the rotation axis Ax of the mirror holder 41 and the first mirror 20 is set to 10° to 20°, for example, 15°.

[0031] The position detection unit 57 detects, for example, that the slider 53b has reached the lower end portion (the end portion on the motor 52 side) of the lead screw 53a, and outputs the detection result to the control board 70. The position detection unit 57 is composed of a push switch pushed by the slider 53b.

[0032] Next, the operation of the head-up display device 100 will be described. The mirror holder 41 rotates about the rotation axis Ax together with the first mirror 20 under the control of the control board 70 by the mirror drive unit 50. When the first mirror 20 rotates about the rotation axis Ax, the irradiation range Ar (see FIG. 4) of the display light L reflected by the first mirror 20 on the reflection surface 30a of the second mirror 30 moves in the height direction H. As a result, the irradiation position of the display light L with respect to the viewer 1 moves in the height direction H.

[0033] (Effect) According to the above-described embodiment, the following effects can be obtained. (1) The head-up display device 100 includes a display unit 10 that emits display light L, a first mirror 20 that reflects the display light L from the display unit 10, a second mirror 30 that reflects the display light L reflected by the first mirror 20, and a mirror drive unit 50 that rotates the first mirror 20 about the rotation axis Ax. According to this configuration, the first mirror 20 on the front stage side of the two mirrors, the first mirror 20 and the second mirror 30, can rotate about the rotation axis Ax. As a result, since the display light L reaches the first mirror 20, which is a rotating mirror, before it expands, the first mirror 20, which is a rotating mirror, can be downsized. Along with this, the force required when the first mirror 20 rotates is reduced, and the mirror drive unit 50 can be downsized. Therefore, the head-up display device 100 can be downsized.

[0034] (2) The head-up display device 100 includes a mirror holder 41 that supports the first mirror 20. The mirror holder 41 includes a cover portion 41b formed so as to cover the upper surface of the first mirror 20. According to this configuration, it is possible to suppress sunlight or the display light L from reaching the upper end of the first mirror 20 and becoming stray light. Thereby, the generation of stray light can be suppressed, and the display quality of the virtual image V can be improved. In particular, since light tends to gather at the edge portion of the first mirror 20, it is preferable that this edge portion is hidden by the cover portion 41b.

[0035] (3) The head-up display device 100 includes a mirror holder 41 that supports the first mirror 20. The mirror holder 41 is formed between the optical path Sc through which the display light L passes in the head-up display device 100 and the mirror drive unit 50, and includes a light-shielding wall portion 42 that hides the mirror drive unit 50 from the optical path Sc. According to this configuration, the light-shielding wall portion 42 suppresses sunlight or the display light L from reaching the mirror drive unit 50. Thereby, the generation of stray light can be suppressed, and the display quality of the virtual image V can be improved.

[0036] (4) The head-up display device 100 has a shaft portion 41f located at an end in the direction along the rotation axis Ax of the first mirror 20, and includes a mirror holder 41 that supports the first mirror 20 and a first shaft support member 44 that is an example of a shaft support portion that rotatably supports the shaft portion 41f. A spherical portion 44d is formed on the first shaft support member 44, and a receiving hole 41h into which the spherical portion 44d fits is formed on the shaft portion 41f. According to this configuration, friction or wear between the mirror holder 41 and the first shaft support member 44 associated with the rotation of the mirror holder 41 can be reduced.

[0037] (5) The first mirror 20 is a concave mirror, and the width W1 in the direction along the rotation axis Ax of the first mirror 20 is smaller than the width W2 in the direction along the rotation axis Ax of the second mirror 30. According to this configuration, the first mirror 20 can be downsized.

[0038] (6) The first mirror 20 is positioned to face a first range N1 that is a part of the second mirror 30. The mirror drive unit 50 is positioned to face a second range N2 that is the remaining part of the second mirror 30. According to this configuration, since both the first mirror 20 and the mirror drive unit 50 are arranged to face the second mirror 30, the head-up display device 100 can be downsized.

[0039] Note that the present disclosure is not limited to the above embodiments and drawings. Modifications (including deletion of components) can be appropriately made without changing the gist of the present disclosure. An example of a modification will be described below.

[0040] (Modification example) In the above embodiment, the head-up display device 100 includes two mirrors (the first mirror 20 and the second mirror 30), but the number of mirrors is not limited to this, and may be three or more. For example, when the head-up display device 100 includes three mirrors, among the three mirrors, the mirror in the front stage closest to the display unit 10 in the optical path of the display light L, or the mirror in the middle stage located in the middle of the optical path, is configured to be rotatable.

[0041] In the above embodiment, the first shaft support member 44 and the second shaft support member 45 are formed separately from the lower case 68, but are not limited to this, and may be formed integrally with the lower case 68. In the above embodiment, the light shielding wall portion 42 may be omitted.

[0042] In the above embodiment, a spherical portion 44d is formed on the first shaft support member 44, and a receiving hole 41h into which the spherical portion 44d fits is formed in the shaft portion 41f. However, the present invention is not limited to this, and a spherical portion 44d may be formed on the shaft portion 41f, and a receiving hole 41h into which the spherical portion 44d fits may be formed in the first shaft support member 44. Also, in the above embodiment, the shaft portion 41f has a receiving hole 41h, and the receiving hole 41h is formed so that the spherical portion 44d of the first shaft support member 44 fits therein. However, the present invention is not limited to this configuration, and the shaft portion 41f and the first shaft support member 44 may be configured in the same manner as the shaft portion 41d and the second shaft support member 45. In the above embodiment, the head-up display device 100 emits the display light L toward the front glass 6, which is an example of the projection member. However, as an example of the projection member, the display light L may be emitted toward a dedicated combiner. Also, the head-up display device 100 may be mounted on a vehicle other than the vehicle 5.

Description of Signs

[0043] 1 Viewer 5 Vehicle 6 Windshield 10 Display unit 20 First mirror 20a Reflecting surface 30 Second mirror 30a Reflecting surface 40 Mirror holder unit 41 Mirror holder 41a Mirror support part 41b Cover part 41a1 Contact part 41a2 Connecting part 41d, 41f Shaft part 41e Gripped part 41h Receiving hole 42 Light-shielding wall part 42a First plate part 42b Second plate part 42c Third plate part 44 First shaft support member 44a Fixed part 44b Holder member support part 44c Shaft support part 44d Spherical part 45 Second shaft support member 46, 47 Fixing member 50 Mirror drive part 52 Motor 53 Conversion mechanism 53a Lead screw 53b Slider 55 Holder member 55a First plate part 55b Second plate part 55c Third plate part 57 Position detection part 60 Housing 61 Upper case 61h Opening 65 Window part 67 Cover 68 Lower case 68a Light passage hole Side wall parts 69a and 69b Control substrate 70 Head-up display device 100 Height direction H Display light L First range N1 Second range N2 Virtual image V Width direction W Irradiation range Ar Optical path Sc Rotation axis Ax

Claims

1. A display unit that emits display light, A first mirror that reflects the display light from the display unit, A second mirror that reflects the display light reflected by the first mirror, A head-up display device comprising a mirror drive unit that rotates the first mirror about a rotation axis, Comprising a mirror holder that supports the first mirror, The mirror holder includes a cover portion formed to cover the upper surface of the first mirror, Head-up display device.

2. A display unit that emits display light, A first mirror that reflects the display light from the display unit, A second mirror that reflects the display light reflected by the first mirror, A head-up display device comprising a mirror drive unit that rotates the first mirror about a rotation axis, Comprising a mirror holder that supports the first mirror, The mirror holder is formed between an optical path through which the display light passes in the head-up display device and the mirror drive unit, and includes a light-shielding wall portion that hides the mirror drive unit from the optical path, Head-up display device.

3. The mirror holder having a shaft portion located at an end in a direction along the rotation axis of the first mirror, Comprising a shaft support portion that rotatably supports the shaft portion, A spherical portion is formed on either the shaft portion or the shaft support portion, A receiving hole into which the spherical portion fits is formed on the other of the shaft portion and the shaft support portion, The head-up display device according to claim 1 or 2.

4. A display unit that emits display light, A first mirror that reflects the display light from the display unit, A second mirror that reflects the display light reflected by the first mirror, A head-up display device comprising a mirror drive unit that rotates the first mirror about a rotation axis, The first mirror is a concave mirror, The width of the first mirror in a direction along the rotation axis is smaller than the width of the second mirror in a direction along the rotation axis, The first mirror is positioned to face a part of the second mirror, The mirror drive unit is positioned to face the remaining part of the second mirror, Head-up display device.

Images