JP7601670B2 - Display device - Google Patents

Description

The present invention relates to a display device installed in a vehicle such as an automobile, and in particular to a display device suitable for use as a head-up display.

As a display device for an automobile, a head up display (hereinafter referred to as a HUD device) that displays a required image to the automobile occupants has been proposed. For example, in Patent Document 1, an image displayed on an image display element such as a liquid crystal display (LCD) is projected onto the automobile's windshield (e.g., the front glass) by an optical system, and a virtual image (hereinafter also referred to as a display image) formed by the image light reflected by the windshield is visually recognized by the occupants.

Such HUD devices typically have a concave mirror as part of the optical system that projects the image, and are provided with a device that adjusts the position at which the image light reflected by the concave mirror is projected onto the windshield so that passengers with different eye heights can view an appropriate displayed image. For example, a tilting arm is connected to a rotation axis provided on the concave mirror, and the angle of the reflective surface of the concave mirror is adjusted by tilting this tilting arm with an actuator, thereby adjusting the reflection direction of the image light.

In this HUD device, if there is a dimensional difference or assembly error in the connection between the rotation axis and the tilting arm, a rattle will occur between the tilting angle of the tilting arm and the concave mirror, making it impossible to adjust the angular position of the concave mirror with high precision. In addition, the angle of the concave mirror may change due to vibrations that occur when the car is traveling, causing the image position of the image viewed to fluctuate and reducing display quality.

Technologies for preventing rattling at the connection of a rotating shaft include those described in Patent Documents 2 and 3. Both Patent Documents 2 and 3 have a structure in which an elastic member is elastically inserted between a rotating shaft with a spline structure and a shaft hole into which the rotating shaft is fitted, and the elastic force of this elastic member is used to press the rotating shaft against one of the inner surfaces of the shaft hole, preventing rattling.

JP2018-173589A Japanese Patent Application Publication No. 8-49726 Japanese Utility Model Application Publication No. 60-185725

In order to minimize the space required for mounting the HUD device in an automobile, it is required to configure the optical system as compact as possible. For example, it is possible to shorten the rotation axis of the concave mirror and reduce the plate thickness of the arm to which the rotation axis is connected as much as possible. However, if this is done, the axial dimension of the rotation axis and the shaft hole that constitute the connection part will be extremely short, and it will be difficult to prevent the rotation axis and the shaft hole from wobbling by inserting an elastic member into the gap between the rotation axis and the shaft hole as in Patent Documents 2 and 3. In other words, if the axial dimension of the rotation axis and the shaft hole is short, even if a linear spring is inserted as in Patent Document 2, it is difficult to ensure sufficient elastic force because the spring length will be short. In addition, it is difficult to insert a coil spring as in Patent Document 3 into the gap between the rotation axis and the shaft hole, and even if it is inserted, it is difficult to maintain the state stably and continuously.

Furthermore, the technology in Patent Documents 2 and 3 involves inserting an elastic member into the gap between the rotating shaft and the shaft hole, which makes the task of monitoring the deterioration state of the elastic member or replacing it when it is damaged extremely cumbersome. In particular, as mentioned above, it is difficult to directly apply the technology in Patent Documents 2 and 3 to an adjustment mechanism in which the axial dimensions of the rotating shaft and shaft hole are made as small as possible, making it difficult to realize a small HUD device.

The object of the present invention is to provide a display device that can adjust the display position with high precision by preventing rattling at the connection between a reflector such as a concave mirror and a tilting member such as a tilting arm. Another object of the present invention is to provide a display device such as a small HUD device.

The present invention relates to a display device that includes an image display unit that displays an image, and a reflector that projects image light of the displayed image onto a windshield of a vehicle, allowing a virtual image of the image to be viewed by the light reflected by the windshield. The display device includes a tilting unit for tilting the reflector around its rotation axis as a fulcrum, and the tilting unit includes a tilting member that is connected to the rotation axis and tilts the reflector integrally when tilted. The rotation axis has an elastic contact surface formed in a part of the circumferential direction in a direction intersecting the radial direction, and has a connecting shaft portion that is inserted into a connecting hole provided in the tilting member and connected to the tilting member. The tilting member also holds an elastic member that is in elastic contact with the elastic contact surface and urges the connecting shaft portion radially against the inner surface of the connecting hole.

The elastic member in the present invention is configured such that a fitting portion that fits and is held in a retaining hole provided in the tilting member and an elastic contact portion that elastically contacts the elastic contact surface of the connecting shaft portion and biases the connecting shaft portion in the radial direction are integrally formed. The elastic member is configured so that it can be attached and detached from the tilting member when the connecting shaft portion is inserted into the connecting hole.

In a preferred embodiment of the present invention, the reflector is a concave mirror that is tilted so that the angle of its reflecting surface is changed relative to the windshield. For example, the device is configured as a head-up display for an automobile, and the windshield is the front glass of the automobile.

According to the present invention, the connecting shaft having an elastic contact surface is inserted into the connecting hole provided in the tilting member and is biased radially against the inner surface of the connecting hole by the elastic member elastically contacting the elastic contact surface, thereby preventing rattling between the reflector and the tilting member. Also, by configuring the elastic member to be held by the tilting member at the fitting portion and elastically contacting the elastic contact surface of the connecting shaft at the elastic contact portion, the length of the connecting shaft can be shortened, thereby making it possible to configure the display device compact.

1 is a conceptual configuration diagram of a HUD device to which the present invention is applied. FIG. 1 is a schematic perspective view of a HUD device according to a first embodiment. FIG. 4 is a perspective view of a connection portion between a concave mirror and a tilting arm in the first embodiment. FIG. 4 is a partially exploded perspective view of a connection portion between the concave mirror and the tilt arm in the first embodiment. 1A is a side view of a connecting portion of a tilting arm according to the first embodiment, and FIG. 1B is a cross-sectional view taken along line b1-b1 thereof. FIG. 11 is a schematic perspective view of a HUD device according to a second embodiment. FIG. 11 is a perspective view of a connection portion between a concave mirror and a sector gear arm in the second embodiment. FIG. 11 is a partially exploded perspective view of a connection portion between a concave mirror and a sector gear arm in a second embodiment. 13A is a side view of a connecting portion of a tilting arm of the second embodiment, and FIG.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram of a HUD device applied to an automobile, as viewed from the left side of the automobile. A HUD device 1 is disposed within the dashboard DB of the automobile, and image light L emitted from the HUD device 1 is projected onto the automobile's windshield (called the windshield) WS through an upper opening Ho of the dashboard. The projected image light L is reflected by the windshield WS and directed toward an 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 a virtual image I created by the image light at a position in front of the automobile through the windshield WS, and the image is displayed.

(Embodiment 1)
Fig. 2 is a schematic perspective view of the HUD device 1 of embodiment 1. The HUD device 1 is assembled to a frame 10 as a device mounting portion, and includes an image display unit 2 and an optical system 3 that projects an 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 image light, and is configured, for example, by a liquid crystal display device.

The optical system 3 has two reflecting mirrors: a convex mirror 4 that reflects the image light of the image displayed on the image display unit 2, and a concave mirror 5 that further reflects the light reflected by the convex mirror 4 and projects it onto the windshield WS shown in FIG. 1. The convex mirror 4 is provided to improve the aberration of the concave mirror 5 and to substantially extend the focal length of the concave mirror 5, but the convex mirror 4 is not necessarily required.

The concave mirror 5 is constructed of a spherical surface or a free-form surface with a curvature that results in the required focal length. The HUD device 1 is configured so that the image displayed on the image display unit 2 is located within the focal length of the concave mirror 5. The light reflected by the concave mirror 5 is reflected by the windshield WS as shown in FIG. 1 and enters the eyes of the occupant M, allowing the occupant M to visually recognize a virtual image I in front of the windshield WS.

The HUD device 1 is provided with a tilting unit 6 for tilting the concave mirror 5. By adjusting the angle of the concave mirror 5 with this tilting unit 6, as shown by the dashed line in FIG. 1, the direction of the light reflected by the concave mirror 5 is changed, and the position and direction of the light projected onto the windshield WS are changed. This also changes the direction of the light entering the eyes of the occupant M, as shown by the chain line, and changes the position and direction of the virtual image I that is viewed.

The tilting section 6 includes a tilting arm 7, one end of which is connected to the concave mirror 5, and an actuator 8 that tilts the other end of the tilting arm 7 relative to the one end. The tilting arm 7 constitutes the tilting member of the present invention, and is formed in a long, thin plate shape here, with one end of the arm integrally connected to the concave mirror 5 and the other end engaged with the actuator 8.

The concave mirror 5 has a pair of rotation shafts 51, 52 protruding outward from the left and right side edges. These pair of rotation shafts 51, 52 are rotatably supported by a frame 10 provided on the HUD device 1, and the concave mirror 5 can rotate, i.e. tilt, at a required angle in the vertical direction relative to the frame 10 with these rotation shafts 51, 52 as fulcrums. The concave mirror 5 is also connected to the tilt arm 7 at one of the pair of rotation shafts 51, 52, the rotation shaft 51.

Figure 3 is a perspective view of the joint between the concave mirror 5 and the tilt arm 7, and Figure 4 is a partially exploded perspective view thereof. The pair of rotating shafts 51, 52 of the concave mirror 5 are supported by the frame 10 at a location that may be configured with plain bearings or ball bearings, but in this case, to simplify the structure, they are configured as plain bearings in which the rotating shafts 51, 52 are inserted into bearing holes 11 opened in the frame 10.

The rotating shaft 51 connected to the concave mirror 5 has a portion that protrudes from the position where it is supported by the frame 10 and is configured as a connecting shaft portion 53 with the tilting arm 7. This connecting shaft portion 53 is formed to have a non-circular shape when viewed from the axial direction. Here, a portion of the circumferential direction of the cylindrical rotating shaft 51 is removed to form a semicircular shape with a flat surface 54 in a direction that intersects with the radial direction. This flat surface 54 is configured as the elastic contact surface in the present invention, and will be referred to as the elastic contact surface 54 hereinafter.

On the other hand, a semicircular connecting hole 71 corresponding to the semicircular shape of the connecting shaft 53 is opened in the plate thickness direction at one end of the tilting arm 7. Then, by inserting the connecting shaft 53 into this connecting hole 71, the connecting hole 71 and the connecting shaft 53 are fitted together, and the tilting arm 7 is integrated with the concave mirror 5 in its tilting direction. Here, the length dimension of the connecting shaft 53 and the thickness dimension of the tilting arm 7 are approximately the same, but by making these dimensions as short as possible, the dimensions of the tilting part 6, particularly the dimension in the width direction of the concave mirror 5 (axial direction of the rotation shafts 51, 52) can be shortened, thereby making the HUD device 1 more compact.

In addition, at one end of the tilting arm 7, a rectangular spring retaining hole 72 is opened in the thickness direction at a position adjacent to the connecting hole 71, into which a plate spring 9 configured as the elastic member of the present invention is fitted and supported. This plate spring 9 is configured by bending a leaf spring material such as an elastic metal plate, for example a SUS plate, in the thickness direction of the plate, and has a fitting portion 91 bent into an approximately U-shape and a semicircular arc-shaped elastic contact portion 92.

Figure 5(a) is a side view of this connection, and Figure 5(b) is a cross-sectional view taken along line b1-b1. By fitting the fitting portion 91 of the plate spring 9 into the spring holding hole 72 in a thick-fit state, the plate spring 9 is supported by the tilting arm 7 by the elastic return force of the fitting portion 91. The elastic contact portion 92 is elastically contacted in the radial direction against the elastic contact surface 54 of the connecting shaft portion 53 by its own elastic force. By the plate spring 9 being elastically contacted against the elastic contact surface 54, the connecting shaft portion 53 is biased in the radial direction inside the connecting hole 71. And, because the circumferential surface of the connecting shaft portion 53 abuts against the inner circumferential surface of the connecting hole 71, the rotating shaft 51 and the tilting arm 7, in other words the concave mirror 5 and the tilting arm 7, are integrated in the tilting direction of both.

As shown in FIG. 2, the actuator 8 is supported by the frame 10, and although its internal structure is not shown, it is equipped with a ring nut that is rotated at a reduced speed by the rotation of the pulse motor, and a screw rod 81 that is screwed into the ring nut. The tip of the screw rod 81 is engaged with the other end of the tilting arm 7 in a state in which it can move freely. For example, it is engaged via a ball joint 70. When the ring nut of the actuator 8 is rotated by the reciprocating rotation of the pulse motor, the screw rod 81 that is screwed into it is moved back and forth in the rod axial direction, and the other end of the tilting arm 7 that is engaged with the screw rod 81 is moved vertically with one end as a fulcrum.

As described above, in the HUD device 1 equipped with the tilting unit 6, as described with reference to FIG. 1, the image light of the image displayed on the image display unit 2 is reflected in sequence by the convex mirror 4 and concave mirror 5 of the optical system 3, and projected onto the windshield WS of the vehicle. The projected image light L is reflected by the windshield WS and directed toward the vehicle occupant M, who views the image (virtual image) I at a position in front of the vehicle through the windshield WS.

At this time, in the HUD device 1, the actuator 8 of the tilting section 6 is controlled to change and control the axial position of the screw rod 81, and the other end of the tilting arm 7 engaged therewith is moved vertically around one end as a fulcrum, adjusting the tilting angle of the tilting arm 7. This tilting of the tilting arm 7 also causes the connected concave mirror 5 to tilt integrally, adjusting its angle. By adjusting the angle of the concave mirror 5 in this way, the position and direction of the image light projected onto the windshield WS shown in FIG. 1 are changed, and adjustments are made so that the image (virtual image I) can be viewed appropriately for each of the occupants M with different line of sight positions.

During this angle adjustment, even if a gap occurs between the connected connecting shaft 53 and the connecting hole 71 due to dimensional errors or assembly errors, the elastic contact surface 54 of the connecting shaft 53 is biased radially by the plate spring 9, and its circumferential surface is pressed against the circumferential surface of the connecting hole 71, preventing rattling between the connecting shaft 53 and the connecting hole 71. Therefore, the tilting motion of the tilting arm 7 is transmitted directly to the connecting shaft 53, i.e., the rotating shaft 51, and the concave mirror is tilted, making it possible to adjust the angle of the concave mirror 5 with high precision, and enabling an optimal display regardless of differences in the height of the occupants' eyes.

In this state, if vibrations caused by the vehicle traveling are transmitted to the HUD device 1, there is a risk that the angle of the concave mirror 5 will fluctuate due to these vibrations. However, because the connecting shaft 53 of the concave mirror 5 is connected to the tilting arm 7 by the plate spring 9 inside the connecting hole 71, and the tilting of the tilting arm 7 is restricted by the actuator 8, the angle of the concave mirror 5 is prevented from fluctuating, and fluctuations in the displayed image while the vehicle is traveling are prevented.

In this way, the plate spring 9 radially biases the elastic contact surface 54 provided on the connecting shaft 53 at the connecting portion, maintaining the close contact between the connecting shaft 53 and the connecting hole 71 and preventing rattling between them. Furthermore, the plate spring 9 can be formed to any dimensions regardless of the plate thickness of the tilting arm 7 or the axial length of the connecting shaft 53. Therefore, compared to the techniques of Patent Documents 2 and 3 in which a spring material is inserted between the shaft and the shaft hole, there are no restrictions on the dimensions or shape of the spring material, and sufficient elastic force to prevent rattling can be secured.

In addition, because the plate spring 9 is exposed, it can be attached and detached even when the connecting shaft portion 53 is inserted into the connecting hole 71, and the assembly work of the plate spring 9 is easy. Therefore, it is easy to monitor the condition of the plate spring 9 or to replace it when it is damaged.

Furthermore, the plate spring 9 is held with its fitting portion 91 fitted into the spring retaining hole 72 provided in the tilting arm 7, so there is a high degree of freedom in the design of the fitting portion 91, resulting in a plate spring 9 that has high retention force and can be held stably. In addition, the elastic contact portion 92 can be designed without being affected by the shape and dimensions of the fitting portion 91, so the biasing force against the flat surface 54 of the connecting shaft portion 53 can be set as desired.

In order to prevent wobble between the tilting arm 7 and the concave mirror 5, it is possible to mold the tilting arm 7 integrally with the concave mirror 5. However, in that case, the materials for the concave mirror 5 and the tilting arm 7 would be limited to materials that can be molded integrally, such as resin, which would be difficult to realize due to problems with mechanical strength and durability due to deterioration over time. It is also possible to integrally connect the tilting arm 7 and the concave mirror 5 with a fixing means such as a screw, but this would make the assembly process more tedious than the configuration in this embodiment, in which assembly can be completed simply by fitting the connecting shaft into the connecting hole and attaching the plate spring.

(Embodiment 2)
6 is a perspective view of a tilting portion 6A of a HUD device 1A of the second embodiment. Parts equivalent to those of the first embodiment are given the same reference numerals. As in the first embodiment, a pair of rotation shafts 51, 52 protrude from the left and right side edges of the concave mirror 5, and the concave mirror 5 is supported by the frame 10 at these rotation shafts 51, 52, so that the concave mirror 5 can be tilted in the vertical direction. On the other hand, in the tilting portion 6A of the second embodiment, a sector gear arm 7A as a tilting member according to the present invention is connected to the concave mirror 5, and the actuator 8A tilts the sector gear arm 7A to adjust the angle of the concave mirror 5. The sector gear arm 7A is connected to the concave mirror 5 at one end, and a sector gear (fan-shaped gear) 75 is integrally formed at the other end.

The actuator 8A is composed of a pulse motor equipped with a reduction mechanism, and a small gear 82 attached to its rotating shaft is meshed with the sector gear 75 of the sector gear arm 7A. When the pulse motor 8A is driven and the small gear 82 rotates, the meshed sector gear 75 rotates at a small angle, and the sector gear arm 7A is tilted.

Figure 7 is a perspective view of the connection between the concave mirror 5 and the sector gear arm 7A, and Figure 8 is a partially exploded perspective view of the same. Of a pair of rotating shafts 51, 52 that protrude from the left and right side edges of the concave mirror 5, one of the rotating shafts 51 is configured with a connecting shaft portion 55, and the sector gear arm 7A is connected to this connecting shaft portion 55.

In the second embodiment, the connecting shaft portion 55 and the sector gear arm 7A are connected by a spline structure. That is, the connecting shaft portion 55 has a petal-shaped spline structure with five protrusions 56 arranged in the circumferential direction when viewed from the axial direction, and the dimension of the circumferential interval between two predetermined protrusions 56 is made relatively larger than the other intervals, and a flat elastic contact surface 57 is formed in this interval.

On the other hand, a connecting hole 73 into which the connecting shaft portion 55 is inserted is opened at one end of the sector gear arm 7A. This connecting hole 73 is formed in a spline structure having five recesses 74 corresponding to the cross-sectional shape of the connecting shaft portion 55. Then, by inserting the connecting shaft portion 55 into this connecting hole 73, the connecting hole 73 and the connecting shaft portion 55 are fitted together by the spline structure, and the sector gear arm 7A is integrated with the concave mirror 5 in its tilting direction.

The sector gear arm 7A also has a rectangular spring retaining hole 72 in the thickness direction at a position adjacent to the connecting hole 73, as in the first embodiment, into which the plate spring 9 is fitted and supported. As in the first embodiment, this plate spring 9 has a fitting portion 91 in which the leaf spring material is bent in the thickness direction into an approximately U-shape, and a tongue-shaped elastic contact portion 92. Note that here, the width of the elastic contact portion 92 is smaller than that of the fitting portion 91 to match the dimensions of the elastic contact surface 57.

Figure 9(a) is a side view of the connecting part, and Figure 9(b) is a cross-sectional view taken along line b2-b2. The plate spring 9 is held by its own elastic force on the sector gear arm 7A by inserting the fitting part 91 of the plate spring 9 thickly into the spring holding hole 72. The elastic contact part 92 of the plate spring 9 is elastically contacted with the elastic contact surface 57 of the connecting shaft part 55, and the connecting shaft part 55 is biased radially inside the connecting hole 73, so that the petal part of the connecting shaft part 55 opposite the elastic contact surface 57 abuts against the inner peripheral surface of the connecting hole 73. Therefore, even if there is a dimensional difference between the connecting shaft part 55 and the connecting hole 73, rattling caused by relative movement of the connecting shaft part 55 inside the connecting hole 73 is suppressed or prevented, and the concave mirror 5 and the sector gear arm 7A are integrated in the tilting direction.

In the second embodiment, when adjusting the angle of the concave mirror 5, the actuator 8A of the tilting unit 6A shown in FIG. 6 is driven and controlled to rotate the small gear 82, and the sector gear 75 meshed with it is rotated by the required angle. This tilts the sector gear arm 7A, tilts the concave mirror 5 connected at one end, and adjusts its angle.

During this angle adjustment, the connecting shaft 55 is biased radially by the plate spring 9 inside the connecting hole 73, so that the part of the connecting shaft 55 opposite the elastic contact surface 57 abuts against the inner surface of the connecting hole 73. Therefore, even if there is a dimensional difference between the connecting shaft 55 and the connecting hole 73, rattling between the connecting shaft 55 and the connecting hole 73 is suppressed or prevented, and rattling between the concave mirror 5 and the sector gear arm 7A is prevented.

As a result, the tilting motion of the sector gear arm 7A is transmitted directly to the rotation axis of the concave mirror 5 to tilt the concave mirror 5, making it possible to adjust the angle of the concave mirror 5 with high precision, enabling an optimal display regardless of the difference in eye height of the passenger viewing the image. Furthermore, even if vibrations caused by the vehicle traveling are transmitted to the concave mirror 5, the concave mirror 5 is not tilted, preventing fluctuations in the displayed image while the vehicle is traveling.

In this embodiment 2, even if the plate thickness of the sector gear arm 7A is reduced to reduce the axial dimension of the connecting shaft portion 55, the plate spring 9 can be formed to any dimension, so that sufficient elastic force can be secured to prevent rattling. Also, as in embodiment 1, the plate spring 9 can be attached and detached even when the connecting shaft portion 55 is inserted into the connecting hole 73, and since the plate spring 9 is exposed, the assembly work of the plate spring 9 is easy, and the monitoring work and replacement work are also easy. The degree of freedom in the design of the fitting portion of the plate spring 9 is increased, so that the plate spring 9 can be held stably with high holding force, and the degree of freedom in the design of the elastic contact portion 92 is also increased, so that the elastic contact force against the elastic contact surface 57 of the connecting shaft portion 55 can be set arbitrarily.

Furthermore, in the second embodiment, the elastic contact surface 57 is formed between the protrusions 56 that make up the spline structure, so that when the connecting shaft portion 55 is inserted into the connecting hole 73, the elastic contact surface 57 is positioned inside the connecting hole 73 of the sector gear arm 7A. Therefore, the elastic contact portion 92 of the plate spring 9 is elastically contacted with the elastic contact surface 57 inside the connecting hole 73, i.e., within the plate thickness of the sector gear arm 7A. This makes it possible to further reduce the axial dimension of the connecting shaft portion 55 and at the same time reduce the protruding dimension of the plate spring 9, which is advantageous for further miniaturization of the HUD device 1.

On the other hand, because the connecting shaft portion 55 and the connecting hole 73 in the second embodiment have a spline structure, the rattle between them is higher than in the first embodiment. That is, in the first embodiment, if there is a radial dimensional difference between the connecting shaft portion 53 and the connecting hole 71, this dimensional difference directly becomes the rattle dimension. In the second embodiment, the spline structure is used, and the outer peripheral surface of the connecting shaft portion 55 and the inner peripheral surface of the connecting hole 73 are divided in the circumferential direction by a plurality of protrusions 56 and recesses 74, respectively, so the rattle dimension is also divided and reduced.

In the present invention, the configuration of the connecting shaft portion 53 and the connecting hole 71 in the first embodiment may be configured similarly to the second embodiment, that is, the elastic contact portion 92 of the press spring 9 may be configured to elastically contact the elastic contact surface inside the connecting hole 71. This allows the axial dimension of the connecting shaft portion 53 to be reduced.

In the first and second embodiments, an example has been described in which a pair of rotating shafts 51, 52 on both sides of the concave mirror 5 are supported by bearings, but if stable support is possible with only one of the rotating shafts, the concave mirror 5 may be supported only by one of the rotating shafts (e.g., rotating shaft 52), and the other rotating shaft (e.g., rotating shaft 51) may not be supported, and a connecting shaft portion for connecting a tilting arm or a sector gear arm may be formed on part of it.

The tilting member of the present invention is not limited to the tilting arm or sector gear arm described in the embodiment, but may be configured as, for example, a gear (rotating gear) rotated by an actuator. In addition, the actuator in the present invention may be an actuator of another configuration, such as an electromagnetic actuator, as long as it has the function of tilting the tilting member.

1,1A HUD device 2 Image display unit 3 Optical system 4 Convex mirror 5 Concave mirror (reflector)
6 Tilting portion 7 Tilting arm (tilting member)
7A Sector gear arm (tilting member)
8, 8A Actuator 9 Plate spring (elastic member)
51, 52 Rotating shaft 53, 55 Connecting shaft portion 54, 57 Elastic contact surface 91 Fitting portion 92 Elastic contact portion

Claims (7)

a tilting part for tilting the reflecting mirror about its rotation axis as a fulcrum, the tilting part including a tilting member connected to the rotation axis and tilting the reflecting mirror integrally when tilted, the rotation axis having an elastic contact surface formed in a part of its circumferential direction in a direction intersecting a radial direction, the connecting shaft part being inserted into a connecting hole provided in the tilting member and connected to the tilting member, the tilting member holding an elastic member that is elastically contacted with the elastic contact surface and biases the connecting shaft part in a radial direction against an inner surface of the connecting hole, the elastic member being a plate spring integrally formed with an engagement part that is fitted and held in a retaining hole provided in the tilting member, and an elastic contact part that is elastically contacted with the elastic contact surface of the connecting shaft part and biases the connecting shaft part in a radial direction . The display device according to claim 1 , wherein the elastic member is detachable from the tilting member when the connecting shaft portion is inserted into the connecting hole. 3. The display device according to claim 1 , wherein the connecting shaft portion of the rotating shaft is cylindrical and has the elastic contact surface formed on a portion of its circumference. 3. The display device according to claim 1, wherein the connecting shaft portion of the rotating shaft has a spline structure, and the elastic contact surface is formed on a part of the circumference sandwiched between a plurality of protrusions that constitute the spline. 5. A display device as described in any one of claims 1 to 4, wherein the tilting member is configured as a tilting arm connected at one end to a rotation axis of the reflector and engaged at the other end to an actuator, the other end being tilted in a direction around the axis of the rotation axis of the reflector by the actuator. 6. A display device according to claim 1 , wherein said reflecting mirror is a concave mirror, and is tilted so that the angle of its reflecting surface with respect to said windshield is changed. 7. The display device according to claim 6 , configured as a head-up display for an automobile, the windshield being a front glass of the automobile.

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