Display device

Abstract

To provide a display device that can prevent an optical element provided in a display device such as an HUD device from rattling to adjust a position at which an image is displayed, with high accuracy.SOLUTION: An HUD device 1 comprises a concave mirror 3 that projects image light of an image displayed on an image display part 2, where the concave mirror 3 is pivotally supported by rotating shafts 33 and 34 on a device body 5 and whose shaft can be axially rotated in a shaft-rotation direction by a rotating mechanism 4. The device further comprises a single elastic member 6 that energizes the concave mirror 3 in an axial direction of the rotating shafts 33 and 34 and in the shaft-rotating direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a display device disposed in a vehicle such as an automobile, and more particularly to a display device suitable for application to a head-up display.

Background Art

[0002] As a display device for an automobile, a head-up display (hereinafter referred to as a HUD device) that displays a required image for an automobile occupant has been proposed. In Patent Document 1, an image displayed on an image display such as a liquid crystal (LCD) is projected onto the windshield (front glass) of an automobile by an optical system, and a virtual image (hereinafter also referred to as a display image) formed in front of this windshield is configured to be visually recognized by an occupant. Further, this HUD device includes a concave mirror in a part of the optical system that projects an image, and this concave mirror is supported by a support portion. This HUD device is provided with a rotation mechanism for adjusting the angle of the concave mirror in order to change the position where the image light reflected by the concave mirror is projected onto the windshield and adjust the visual recognition position of the display image.

[0003] In the HUD device of Patent Document 1, although the rotation axis of the concave mirror is supported by the support portion, displacement of the display image is likely to occur due to play generated between the rotation axis and the support portion, and there is a risk that visibility will decrease. To prevent this, a configuration is adopted in which the rotation axis is pressed against the support portion by an elastic member. However, since it is a configuration in which the rotation axis is pressed in the radial direction, it is difficult to prevent play in the axial direction of the rotation axis.

[0004] On the other hand, Patent Document 2 proposes a technique for preventing play in the thrust direction (axial direction) and the radial direction of the rotation axis of a concave mirror by pressing the rotation axis of the concave mirror against a shaft receiver in the X direction and the Z direction perpendicular to each other by an elastic member in a HUD device.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-192962 [Patent Document 2] Japanese Patent No. 6642290 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] The technologies of Patent Documents 1 and 2 prevent rattling in the axial direction and radial direction of the rotation axis by pressing the rotation axis of the concave mirror against a support member such as a support part or a bearing with an elastic member. However, in a HUD device provided with a rotation mechanism for adjusting the angular position of the concave mirror, that is, the position around the rotation axis, even if the technologies of Patent Documents 1 and 2 are applied, it is difficult to prevent rattling between the rotation axis and the rotation mechanism connected thereto, especially rattling around the rotation axis. Therefore, when tilting the concave mirror, so-called backlash easily occurs between the rotation axis and the rotation mechanism, and there is a problem that it is difficult to control the angular position of the concave mirror with high accuracy. In order to solve this problem, in Patent Documents 1 and 2, it is necessary to separately arrange an independent elastic member for preventing rattling around the rotation axis, which results in an increase in the number of parts and complication of the assembly work.

[0007] An object of the present invention is to provide a display device such as a HUD device that prevents rattling in an optical element such as a concave mirror with a simple configuration. [Means for Solving the Problems]

[0008] The present invention is a display device including an optical element that projects image light of an image displayed on an image display unit onto a light-transmitting member of a vehicle. The optical element is pivotally supported by a device body and is pivotable around an axis by a rotation mechanism, and is characterized by including a single elastic member that biases the optical element in the axial direction and the direction around the axis.

[0009] As a preferred embodiment of the present invention, the optical element has a rotation axis, and the rotation axis is pivotally supported in a bearing provided in the device body so as to be rotatable and is connected to a rotation mechanism. Furthermore, the elastic member is constituted by a leaf spring, and has a fixed portion fixed to the device body and an elastic contact piece that elastically contacts the optical element and biases the optical element in the axial direction and in the circumferential direction around the axis, respectively.

[0010] For example, the elastic member is constituted by a leaf spring, and has a fixed portion fixed to the device body, a first elastic contact piece that biases the optical element in the axial direction, and a second elastic contact piece that biases the optical element in the circumferential direction around the axis. Alternatively, the elastic member is constituted by a leaf spring, and has a fixed portion fixed to the device body and an elastic contact piece that generates a biasing force component for biasing the optical element in the axial direction and in the circumferential direction around the axis.

[0011] In the present invention, the rotation axis has a flange portion adjacent in the axial direction and a connection portion connected to the rotation mechanism, and the elastic member may be configured to bias the flange portion so as to axially contact the bearing. Further, the optical element has an arm portion extending in the radial direction of the rotation axis, and the elastic member may be configured to bias the arm portion in the circumferential direction around the rotation axis. Furthermore, the rotation mechanism includes a tilting bracket that is tilted by an actuator with a shaft connection portion as a fulcrum, and the connection portion of the rotation axis may be integrally connected in the circumferential direction at this shaft connection portion.

Advantages of the Invention

[0012] According to the present invention, since the optical element is biased in the axial direction and in the circumferential direction around the axis by a single elastic member, the positions of the optical element in the axial direction and in the circumferential direction around the axis are regulated, rattling between the optical element and the rotation mechanism connected thereto is prevented, and a high-quality display device that prevents fluctuations in the displayed image can be obtained.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0014] Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual configuration diagram of a HUD device applied to an automobile, and is a configuration viewed from the left side of the automobile. The HUD device 1 is disposed in the dashboard DB of the automobile, and the image light L emitted from the HUD device 1 is projected onto the front glass (referred to as a windshield) WS of the automobile through the upper surface opening of the dashboard DB. The projected image light L is reflected by the windshield WS and directed toward the occupant M such as the driver of the automobile. When this image light L enters the eyes of the occupant M, the occupant M can visually recognize an image (virtual image) I formed by the image light at a position in front of the automobile through the windshield WS, and the display of the image is performed.

[0015] The HUD device 1 includes an image display unit 2 and an optical element 3 that projects the image displayed on the image display unit 2 onto the windshield WS shown in FIG. 1. The image display unit 2 is configured to display a desired image and emit the image light, and is, for example, constituted by a liquid crystal display device. The optical axis element 3 is a reflecting mirror, here a concave mirror, that reflects the image light emitted from the image display unit 2. This concave mirror 3 includes a reflecting surface portion 30 formed of a spherical surface or a free-form surface having a curvature that provides a required focal length, and this reflecting surface portion 30 is disposed opposite to the image display unit 2. As a result, the light emitted from the image display unit 2 and reflected by the reflecting surface portion 30 of the concave mirror 3 is projected onto the windshield WS, where it is reflected and configured to enter the eyes of the occupant M.

[0016] Further, the HUD device 1 is provided with a rotation mechanism for tilting the concave mirror 3 as will be described later. By adjusting the angle of the concave mirror 3 by this rotation mechanism, as shown by the chain line, the direction of the light reflected by the concave mirror 3 is changed, and the position and direction of the light projected onto the windshield WS are changed. As a result, due to differences in height and the like, the direction of the light entering the eyes of the occupant Mm with a high line-of-sight position is changed, and it becomes possible for the occupant M and the occupant Mm to visually recognize the image I at the same position.

[0017] FIG. 2 is a schematic perspective view of the HUD device 1, and FIG. 3 is a schematic plan view thereof. Hereinafter, the left-right direction and the up-down direction are based on FIG. 2. The HUD device 1 includes a shallow dish-shaped device body 5. The image display 2 is mounted on a part of the inner bottom 50 of the device body 5, and the concave mirror 3 is mounted at a position facing this. The concave mirror 3 has a first arm portion 31 and a second arm portion 32 that protrude rearward at both left and right ends of the reflecting surface portion 30 and have a tapered shape in which the width dimension is reduced toward the tip at the upper and lower edges, and a first rotation shaft 33 and a second rotation shaft 34 that protrude outward in the horizontal left-right direction from the tips of the first arm portion 31 and the second arm portion 32, respectively.

[0018] And on the inner bottom portion 50 of the device body 5, wall-shaped first bearings 51 and second bearings 52 are erected at positions corresponding to the respective rotary shafts 33, 34. These first bearings 51 and second bearings 52 are configured such that semi-circular concave grooves are formed at their upper edges, and the respective rotary shafts 33, 34 are supported by the concave grooves of the corresponding bearings 51, 52 so as to be rotatable about the axes. Therefore, the concave mirror 3 is tilted about the axis Ax connecting the two rotary shafts 33, 34 as a fulcrum when these rotary shafts 33, 34 are rotated, and the tilting angle of the reflecting surface portion 30 in the vertical direction is changed.

[0019] A tilting bracket 42 of the rotation mechanism 4 is connected to the first rotary shaft 33. This rotation mechanism 4 includes an actuator 40 fixed to the lower side surface of the inner bottom portion 50 of the device body 5. This actuator 40 includes a drive rod 41 having a screw configuration that is advanced by a motor (not shown in FIGS. 2 and 3), for example. The drive rod 41 protrudes upward from the inner bottom portion 50 of the device body 5 and is moved in the axial direction, that is, in the vertical direction. The tilting bracket 42 is connected to the upper tip of the drive rod 41 by a ball joint, and is tilted by the vertical movement of the drive rod 41. By this tilting, the first rotary shaft 33 to which it is connected is rotated, and the concave mirror 3 can be tilted.

[0020] FIG. 4 is a perspective view of a portion in the vicinity of the first rotary shaft 33 of the concave mirror 3, FIG. 5 is a plan view thereof, and FIG. 6 is a partially exploded perspective view thereof. A flange portion 35 and a connecting portion 36 are integrally formed in the axial direction on the first rotary shaft 33. The flange portion 35 is formed as a circular flange having a larger diameter than the first rotary shaft 33. The connecting portion 36 is formed as a non-circular shaft with a part of its circumferential surface cut off to be planar. When the first rotary shaft 33 is pivotally supported by the first bearing 51, the flange portion 35 and the connecting portion 36 protrude to the outside (left side) of the first bearing 51, and the connecting portion 36 is connected to the tilting bracket 42.

[0021] The tilting bracket 42 has a middle portion 43 in the longitudinal direction formed in a plate shape. One end of this middle portion 43 is configured as a shaft connecting portion 44 that connects to the first rotating shaft 33, and the other end is configured as an actuator connecting portion 45 that connects to the drive rod 41 of the actuator 4. The shaft connecting portion 44 is formed in a cylindrical shape with substantially the same diameter as the flange portion 35 and is pivotally supported by a second bearing 53 erected on a part of the inner bottom portion 50 of the device body 5. Thereby, the tilting bracket 42 is capable of tilting in the circumferential direction of the shaft with this shaft connecting portion 44 as a fulcrum.

[0022] On the inner (right) end face of the shaft connecting portion 44, a connecting hole 46 is formed, which is composed of a concave hole having a cross-sectional shape with a flat surface on a part of the inner circumferential surface, the same as the connecting portion 36 integrated with the first rotating shaft 33. The connecting portion 36 is inserted into the connecting hole 46 in the axial direction, whereby the connecting portion 36, that is, the first rotating shaft 33, is integrated with the shaft connecting portion 44 in the circumferential direction of the shaft. Further, the actuator connecting portion 45 is connected to the drive rod 41 by a ball joint as described above. Thereby, when the actuator 40 is driven and the drive rod 41 is moved in the vertical direction, the tilting bracket 42 is tilted vertically with the shaft connecting portion 44 as a fulcrum, and by this tilting, the first rotating shaft 33 is rotated around the shaft, making it possible to tilt the concave mirror 3.

[0023] Furthermore, on the inner bottom portion 50 of the device body 5, a boss portion 54 is erected at a portion facing the first rotating shaft 33, and an elastic member 6 is disposed on this boss portion 54. This elastic member 6 is composed of a leaf spring bent into a required shape and includes a fixing portion 60 fixed to the boss portion 54 and an elastic contact portion 61 extending from this fixing portion 60. The fixing portion 60 of this leaf spring 6 is fixed to the boss portion 54 by two screws 7, and the elastic contact portion 61 is elastically contacted with the first arm portion 31 of the concave mirror 3.

[0024] Figs. 7(a) and 7(b) are cross-sectional views taken along the a-a line and b-b line of Fig. 5, respectively. The elastic contact portion 61 of the leaf spring 6 includes a first elastic contact piece 62 that is elastically contacted with the outer surface, i.e., the left side surface, of the first arm portion 31, and a second elastic contact piece 63 that is elastically contacted with the tapered upper edge of the first arm portion 31. The first elastic contact piece 62 is composed of a small tongue piece protruding downward from one edge of the second elastic contact piece 63 and is elastically contacted with the outer surface (left side surface) of the first arm portion 31. As a result, the first elastic contact piece 62 biases the first arm portion 31 inward in the axial direction, i.e., toward the right side in Fig. 7(a).

[0025] Further, the second elastic contact piece 63 is configured as a cantilever piece extending along the first arm portion 31 from the fixed portion 60, and the tip thereof is elastically contacted with the upper edge of the first arm portion 31. The length dimension of the second elastic contact piece 63 is formed longer than the diameter dimension of the first rotation shaft 33 and is elastically contacted at a portion closer to the reflecting surface portion 30 of the concave mirror 3 than the first rotation shaft 33. As a result, the second elastic contact piece 63 biases the base end side of the first arm portion 31, i.e., the reflecting surface portion 30 side, downward. In other words, it biases the first rotation shaft 33 in the clockwise direction in Fig. 7(b).

[0026] In this way, the concave mirror 3 is biased in the direction along the axis Ax from the side of the first rotation shaft 33 toward the second rotation shaft 34 by the first elastic piece 62 of the leaf spring 6. Further, the concave mirror 3 is biased in the circumferential direction around the axis Ax so that the reflecting surface portion 30 faces downward by the second elastic piece 63.

[0027] In the HUD device 1 described above, as described with reference to FIG. 1, the image light of the image displayed on the image display unit 2 is reflected by the concave mirror 3 and further projected onto the windshield WS of the automobile. Therefore, the occupant M visually recognizes the display image (virtual image) I at the front position of the automobile through the windshield WS. Further, by controlling the actuator 40 of the rotation mechanism 4, the tilting bracket 42 is tilted in the vertical direction with the shaft coupling portion 44 as a fulcrum. Due to this tilting, the first rotating shaft 33 connected to the shaft coupling portion 44 is integrally rotated, and the concave mirror 3 is tilted via the first arm portion 31, and the tilting angle of the reflecting surface portion 30 is changed. By controlling the change in the tilting angle of the reflecting surface portion 30, the position and direction of the image light projected onto the windshield WS are changed, and adjustment is performed so that the occupant M with different line-of-sight positions can also visually recognize the image I at the same position.

[0028] By the way, in this HUD device 1, the first rotating shaft 33 and the second rotating shaft 34 of the concave mirror 3 are respectively supported by the first bearing 51 and the second bearing 52 provided in the device body 5. The axial dimensions of these first rotating shaft 33 and second rotating shaft 34 are designed to be approximately the same as the axial directions of the corresponding first bearing 51 and second bearing 52. However, actually, in order to allow the rotation of both rotating shafts 33 and 34, a predetermined margin is provided in the design dimensions. Therefore, the first rotating shaft 33 and the second rotating shaft 34 are moved axially in the first bearing 51 and the second bearing 52 by this margin dimension, and as a result, axial play along the axis Ax of the concave mirror 3 may occur. Due to this axial play, the left-right position of the concave mirror 3 is changed, and the position of the display image fluctuates in the left-right direction.

[0029] In this embodiment, a flange portion 35 is provided adjacent to the first rotating shaft 33, and this flange portion 35 is disposed at a position facing the left side surface of the first bearing 51. Further, the first elastic contact piece 62 of the elastic contact portion 61 of the leaf spring 6 is elastically contacted with the left side surface of the first arm portion 31. Therefore, when the first arm portion 31 is urged in the right direction in the axial direction by the first elastic contact piece 62, and the first rotating shaft 33 integrated therewith is also urged in the right direction, the integrated flange portion 35 is further brought into contact with the left side surface of the first bearing 51. By this contact, the axial movement of the first rotating shaft 33 and the first arm portion 31 is restricted, and the axial movement of the concave mirror 3 is restricted, thereby preventing rattling in the axial direction, that is, the left - right direction.

[0030] Also, regarding the circumferential direction around the axis of the first rotating shaft 33, the connecting portion 36 integrated with the first rotating shaft 33 and the connecting hole 46 of the shaft connecting portion 44 of the tilting bracket 42 are each formed in a non - circular shape having a flat surface on a part of the circumferential surface. When the connecting portion 36 is fitted into the connecting hole 46, the first rotating shaft 33 and the shaft connecting portion 44 are integrated in the circumferential direction around the axis. Therefore, the first rotating shaft 33 and the tilting bracket 42 are integrated in the circumferential direction around the axis. However, if a dimensional error occurs between these connecting portion 36 and connecting hole 46, rattling in the circumferential direction around the axis occurs between the first rotating shaft 33 and the tilting bracket 42. Due to this rattling in the circumferential direction around the axis, the vertical angle of the concave mirror 3 is not stable, and the position of the displayed image fluctuates in the vertical direction.

[0031] In this embodiment, the second elastic contact piece 63 of the elastic contact portion 61 of the leaf spring 6 is elastically contacted with the upper edge of the first arm portion 31, and the first arm portion 31 is urged in the clockwise direction. By this urging force, the connecting portion 36 integrated with the first rotating shaft 33 is urged in the clockwise direction with respect to the connecting hole 46 of the shaft connecting portion 44. That is, the flat surface portions of the connecting portion 36 and the connecting hole 46 are brought into contact with each other and restricted in the circumferential direction around the axis. Thereby, rattling of the first rotating shaft 33 in the circumferential direction around the axis with respect to the tilting bracket 42 is prevented, and a change in the vertical angle of the concave mirror 3 is prevented.

[0032] As described above, in the embodiment, the elastic contact portion 61 of one leaf spring 6 is provided with a first elastic contact piece 62 and a second elastic contact piece 63. The first elastic contact piece 62 prevents the axial rattling of the concave mirror 3, and the second elastic contact piece 63 prevents the rattling of the tilting angle of the concave mirror 3. Therefore, the rattling in the axial direction and the circumferential direction around the axis of the concave mirror 3 can be prevented by one leaf spring 6, that is, one elastic member, and an HUD device with a simple configuration can be configured to reduce the number of parts and the assembly man-hours.

[0033] FIG. 8 is a diagram for explaining a modification of the embodiment, where (a) is a schematic perspective view of the main part and (b) is a schematic front view for explaining the operation. As shown in FIG. 8(a), an inclined surface portion 31a inclined in both the axial direction and the circumferential direction around the axis of the first rotation axis 33 is integrally formed on the first arm portion 31. Further, the elastic contact portion 61 of the leaf spring 6 which is an elastic member is formed as a single elastic contact piece 64 that elastically contacts the inclined surface portion 31a in the circumferential direction around the axis. At the portion where the elastic contact piece 64 elastically contacts the inclined surface portion 31a, a shape that can slide in the axial direction and the circumferential direction along the inclined surface portion 31a, for example, a spherical protrusion 64a, is integrally formed. Note that the length dimension from the fixed portion 60 of the leaf spring 6 to the protrusion 64a in the elastic contact piece 64 is made longer than the length from the fixed portion 60 to the axis center of the first rotation axis 33.

[0034] As shown in FIG. 8(b), when the protrusion 64a of the elastic contact piece 64 elastically contacts the inclined surface portion 31a in the circumferential direction around the axis, a component force of the elastic contact force indicated by the arrow is generated in the axial direction on the inclined surface portion 31a. Thereby, the first arm portion 31 integrated with the inclined surface portion 31a is urged in the circumferential direction and the axial direction by the elastic contact force of the elastic contact piece 64. Therefore, similar to the embodiment, the rattling in the circumferential direction around the axis of the first rotation axis 33 with respect to the tilting bracket 42 is prevented, and the change in the vertical angle of the concave mirror 3 is prevented. Further, in this modification, the connecting portion 36a integrated with the first rotation axis 33 has a spline structure. In this case, the connecting hole 46 of the shaft connecting portion 44 of the tilting bracket 42 also has a spline structure.

[0035] Even in this modification example, the leaf spring 6 as one elastic member prevents the axial play and the circumferential play around the axis of the concave mirror 3, and prevents the fluctuation of the tilting accuracy of the concave mirror 3 or the fluctuation of the positional accuracy of the displayed image. Therefore, a high-quality HUD device with a simple configuration that reduces the number of parts and the assembly man-hours can be configured.

[0036] In the present invention, the elastic member is not limited to a leaf spring as long as it is configured to bias the concave mirror in the axial direction and the circumferential direction around the axis with one member, and may be configured with a wire spring. For example, it may be configured to bias the concave mirror in the axial direction and the circumferential direction around the axis with a torsion spring. Further, in the case of a configuration in which the concave mirror is biased in the axial direction and the circumferential direction around the axis by utilizing the component force generated by one elastic member as in the modification example, the elastic member may be configured with a coil spring.

[0037] The display device of the present invention is not limited to the HUD device described in the embodiment, and can be applied to a display device including an optical element pivotally supported on a device body by a rotation axis and tilted around the axis of the rotation axis. Further, when configuring the present invention as a HUD device, it may be configured using a transparent plastic disk such as a combiner. Furthermore, the optical element in the present invention is not limited to a concave mirror, and can be applied as long as it is an optical element pivotally supported on a device body and pivoted by a rotation mechanism to control the change of the display position and the display direction of a displayed image.

Explanation of Reference Numerals

[0038] 1 HUD device (display device) 2 Image display unit 3 Concave mirror (optical element) 4 Rotation mechanism 5 Device body 6 Leaf spring (elastic member) 30 Reflective surface portion 31, 32 Arm portions 33, 34 Rotation axes 35 Flange portion 36 Connecting portion 40 Actuator 41 Drive rod 42 Tilt Bracket 44 Shaft Connection Part 46 Connection Hole 51, 52, 53 Bearings 61 Elastic Contact Part 62, 63 Elastic Contact Pieces

Claims

1. A display device comprising an optical element that projects image light of an image displayed on an image display unit onto a light-transmitting member of a vehicle, wherein the optical element is pivotally supported on a device body and is pivotable in a direction around the axis by a rotation mechanism, and includes a single elastic member that biases the optical element in the axial direction and the direction around the axis. The optical element includes a rotation axis, and the rotation axis is pivotally supported so as to be pivotable in a bearing provided in the device body and is connected to the rotation mechanism. The elastic member is constituted by a leaf spring, and includes a fixing portion fixed to the device body and an elastic contact piece that elastically contacts the optical element and biases the optical element in the axial direction and the direction around the axis, respectively. The display device is characterized by the above.

2. A display device comprising an optical element that projects image light of an image displayed on an image display unit onto a light-transmitting member of a vehicle, wherein the optical element is pivotally supported on a device body and is pivotable in a direction around the axis by a rotation mechanism, and includes a single elastic member that biases the optical element in the axial direction and the direction around the axis. The optical element includes a rotation axis, and the rotation axis is pivotally supported so as to be pivotable in a bearing provided in the device body and is connected to the rotation mechanism. The elastic member is constituted by a leaf spring, and includes a fixing portion fixed to the device body and an elastic contact piece that elastically contacts the optical element and biases the optical element in the axial direction and the direction around the axis, respectively. The rotation axis includes a flange portion adjacent in the axial direction and a connection portion connected to the rotation mechanism. The elastic member biases the flange portion to axially contact the bearing. The rotation mechanism includes a tilting bracket that is tilted by an actuator with a shaft connection portion as a fulcrum. The connection portion of the rotation axis is integrally connected in a direction around the axis at the shaft connection portion. The display device is characterized by the above. **Claim 3**: A display device comprising an optical element that projects the image light of an image displayed on an image display unit onto a light-transmitting member of a vehicle, wherein the optical element is pivotally supported on a device body and is pivotable around the axis by a rotation mechanism, and includes a single elastic member that biases the optical element in the axial direction and in the circumferential direction around the axis. The optical element includes a rotation axis, and the rotation axis is pivotally supported in a bearing provided on the device body so as to be pivotable and is connected to the rotation mechanism. The elastic member is configured as a leaf spring and includes a fixing portion fixed to the device body and an elastic contact piece that elastically contacts the optical element and biases the optical element in the axial direction and in the circumferential direction around the axis, respectively. The optical element includes an arm portion extending in the radial direction of the rotation axis, and the elastic member biases the arm portion in the circumferential direction around the rotation axis. The rotation mechanism includes a tilting bracket that is tilted by an actuator with a shaft connection portion as a fulcrum, and a connection portion of the rotation axis is integrally connected in the circumferential direction at this shaft connection portion. The display device is characterized by this. **Claim 4** The display device according to claim 1, wherein the elastic contact piece of the elastic member includes a first elastic contact piece that biases the optical element in the axial direction and a second elastic contact piece that biases the optical element in the circumferential direction around the axis. **Claim 5** The display device according to claim 1, wherein the elastic contact piece of the elastic member generates a component force that biases the optical element in the axial direction and in the circumferential direction around the axis. **Claim 6** The display device according to any one of claims 1 to 3, wherein the optical element is a concave mirror and is tilted so that the angle of its reflecting surface is changed with respect to a windshield as the light-transmitting member. **Claim 7** The display device according to claim 6, configured as a head-up display of an automobile, wherein the windshield is the front glass of the automobile.

Images