JP7347142B2 - virtual image display device - Google Patents

Description

The disclosure herein relates to the display of virtual images in a vehicle.

2. Description of the Related Art Virtual image display devices are known that are configured to be mounted on a vehicle and project display light that is formed as a display virtual image. The device disclosed in Patent Document 1 includes an optical member, a support member, and an elastic member. The optical member rotates around the rotation axis. The elastic member has a fixed portion that is fixed to the support member and a displacement portion that can be displaced by elastic deformation, and the displacement portion elastically urges the optical member in the axial direction.

Here, the plastic deformation of the elastic member is regulated by fitting the protrusion protruding from the rotation shaft on the optical member side into the groove-shaped receiving portion provided in the bearing on the support member side.

Patent No. 6505280

However, in the fitting structure between the protrusion and the receiving part, the protruding part is always in contact with a part of the receiving part. For this reason, when rotating the optical member, friction occurs between the protrusion and the receiving portion, increasing the driving torque for rotating the optical member, and reducing the smoothness of rotation of the optical member. inhibited. Further, the protrusion and the receiving portion are gradually scraped and damaged due to friction during rotation and vibration of the vehicle, making it difficult to maintain the effect of suppressing plastic deformation of the elastic member over a long period of time.

One of the objects of the disclosure of this specification is to provide a virtual image display device in which optical members can be rotated smoothly. Another object of the present invention is to provide a virtual image display device that can maintain the effect of suppressing plastic deformation of an elastic member over a long period of time.

One of the aspects disclosed herein is a virtual image display device that is configured to be mounted on a vehicle (1) and projects display light that is formed as a display virtual image (VRI),
an optical member (41) formed to be able to change the optical path of display light by rotating around a rotation axis (44);
a support member (51R) that rotatably supports the optical member;
It has a fixed part (63) that is fixed to the support member, and an elastic displacement part (64) that can be displaced by elastic deformation, and the elastic displacement part elastically biases the optical member in the axial direction. A member (62);
One of the optical member and the support member has a protrusion (45, 257) that protrudes from one side toward the other of the optical member and the support member along the axial direction,
Transition between a state in which the protrusion is in contact with the other part that restricts the movement of the optical member that causes the elastic displacement part to reach the plastic deformation region, and an equilibrium state of the elastic displacement part in which the protrusion part is spaced apart from the other part. formed possible ,
The elastic member is arranged so that the elastic displacement part is sandwiched between the optical member and the support member at a position on or near the rotation axis,
The protrusion is arranged off-axis of the rotating shaft so as to avoid interference with the elastic member .

According to this aspect, the projection provided on one of the optical member and the support member projects in the axial direction toward the other of the optical member and the support member. The optical member, which is elastically biased in the axial direction by the elastic displacement part due to the axial protrusion, moves relative to the supporting member in the axial direction due to vibration during use or impact during transportation. In this case, the axial distance between the protrusion and the other member can be changed. This change in distance allows a transition between a contact state under vibration or impact and an equilibrium state under no vibration or impact. In the contact state, the protrusion comes into contact with the other member, thereby restricting movement of the optical member that causes the elastic displacement portion to reach the plastic deformation region. On the other hand, in an equilibrium state, the elastic displacement portion maintains an equilibrium state, and there is a gap between the protrusion and the other member. By bringing the protrusion and the other member into a non-contact state when the protrusion is not receiving a predetermined vibration or shock, the protrusion is prevented from constantly contacting the other member.

By avoiding constant contact, it is possible to reduce friction between the optical member and the support member when rotating the optical member. Therefore, it becomes possible to rotate the optical member smoothly.

Further, by avoiding constant contact, it is possible to suppress the protrusion from being gradually scraped and damaged due to friction during rotation or vibration of the vehicle. Therefore, it becomes possible to maintain the effect of suppressing plastic deformation of the elastic member over a long period of time.

Note that the symbols in parentheses exemplarily indicate correspondence with parts of the embodiment described later, and are not intended to limit the technical scope.

FIG. 3 is a diagram showing a state in which a HUD is mounted on a vehicle. It is a figure explaining rotation of a movable mirror. It is a front view showing a movable mirror unit. 4 is an enlarged view showing only the movable mirror in section IV of FIG. 3. FIG. FIG. 4 is an enlarged perspective view showing only the support portion in the V section of FIG. 3. FIG. FIG. 4 is an enlarged perspective view showing a support portion and a leaf spring in section VI of FIG. 3; 4 is an enlarged view of section VII in FIG. 3. FIG. It is a figure for explaining the transition between an equilibrium state and a contact state. FIG. 7 is a diagram corresponding to FIG. 6 in the second embodiment.

Hereinafter, a plurality of embodiments will be described based on the drawings. Note that redundant explanation may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiments previously described can be applied to other parts of the configuration. Furthermore, in addition to the combinations of configurations specified in the description of each embodiment, it is also possible to partially combine the configurations of multiple embodiments even if the combinations are not explicitly stated. .

(First embodiment)
As shown in FIG. 1, the virtual image display device according to the first embodiment of the present disclosure is configured to be mounted on a vehicle 1, and is housed in an instrument panel 2 of the vehicle 1. , HUD) 100. Here, the vehicle 1 is broadly understood to include various vehicles such as automobiles, railroad vehicles, aircraft, ships, and stationary game cabinets. In particular, the vehicle 1 of this embodiment is a four-wheeled vehicle.

The HUD 100 projects display light to be imaged as a display virtual image VRI toward a projection section 3a set on the windshield 3 of the vehicle 1. The display light reflected by the projection unit 3a reaches a viewing area EB set in the interior of the vehicle 1. Then, an occupant who is seated on the seat 4 facing the instrument panel 2 and whose eye point EP is located in the viewing area EB perceives the display light as a display virtual image VRI. The occupant can then recognize various information displayed in the virtual image. Examples of the various information displayed as a virtual image include information indicating the state of the vehicle 1 such as vehicle speed and remaining fuel amount, or navigation information such as visibility assistance information and road information.

In the following, unless otherwise specified, each direction indicated by front, rear, top, bottom, left, and right is expressed with reference to the vehicle 1 on the horizontal plane HP.

The windshield 3 of the vehicle 1 is formed into a translucent plate shape made of glass or synthetic resin, for example, and is arranged above the instrument panel 2. The windshield 3 is arranged so as to be inclined away from the instrument panel as it goes from the front to the rear. The windshield 3 has a projection portion 3a on which image display light is projected, which is formed into a smooth concave or planar shape. Note that the projection section 3a does not need to be provided on the windshield 3. For example, a combiner that is separate from the vehicle 1 may be installed in the vehicle 1, and the projector 3a may be provided on the combiner.

The viewing area EB is a spatial area in which the virtual image VRI displayed by the HUD 100 can be viewed so as to meet a predetermined standard (for example, so that the entire displayed virtual image VRI has a predetermined brightness or higher), and is also referred to as an eye box. . The visual recognition area EB is typically set to overlap with the eyelid set on the vehicle 1. The eye lip is set in a virtual ellipsoidal shape based on an eye range that statistically represents the spatial distribution of the occupant's eye point EP.

The specific configuration of such HUD 100 will be explained below, also using FIG. 2. The HUD 100 includes a housing 10, a display 20, a fixed mirror 30, a movable mirror unit 40, and a control unit 70.

The housing 10 has a hollow box shape that accommodates other elements of the HUD 100, and is installed within the instrument panel 2. The housing 10 has a window section 11 at the upper side facing the projection section 3a. The window portion 11 may be physically open, or may be covered with a dustproof sheet that allows display light to pass through.

The display 20 is, for example, a transmissive liquid crystal display device. The display device 20 is formed by housing a liquid crystal panel and a backlight in a casing. The display device emits display light by transmitting and illuminating the screen 21 of the liquid crystal panel using a backlight. Note that the display 20 may be a reflective liquid crystal display, a micro LED display in which self-luminous micro LEDs are arranged, a laser scanner display, or a DLP (Digital Micromirror Device) using a DMD (Digital Micromirror Device). It is also possible to employ a light processing (registered trademark) type display device or the like. The screen 21 of the display device 20 faces approximately upward, for example, and display light is emitted upward.

The fixed mirror 30 is fixed to the housing 10 and is formed into a rectangular plate shape, for example, from synthetic resin or glass. The fixed mirror 30 has a reflective surface 31 formed by depositing a metal film such as aluminum on its surface. As the fixed mirror 30, a plane mirror in which the reflecting surface 31 is formed into a smooth planar shape, a convex mirror in which the reflecting surface 31 is formed in a smooth convex shape, etc. can be adopted. The fixed mirror 30 is located approximately above the display 20, and its reflective surface 31 faces diagonally forward and downward. Display light that enters the fixed mirror 30 from the display 20 is reflected by the reflective surface 31 toward the movable mirror 41.

The movable mirror unit 40 is a unit that reflects the display light from the fixed mirror 30 toward the projection section 3a, and has a function of changing the position of the display virtual image VRI and the viewing area EB. As shown in FIG. 3, the movable mirror unit 40 includes a movable mirror 41, a drive output section 48, a support section 50, a leaf spring 62, a tension spring 68, and the like.

The movable mirror 41 is an optical member formed so that the optical path of the display light can be changed by rotating around the rotation axis 44 . The movable mirror 41 is formed into a rectangular plate shape of, for example, synthetic resin or glass. The movable mirror 41 has a reflective surface 43 formed by depositing a metal film such as aluminum on its surface. As the movable mirror 41, for example, a concave mirror in which the reflective surface 43 is formed into a smooth concave shape may be employed. The movable mirror 41 is located approximately in front of the display 20 and the fixed mirror 30, and its reflective surface 43 faces diagonally backward and upward.

The display light that enters the movable mirror 41 from the fixed mirror 30 is reflected by the reflective surface 43 toward the projection section 3a above. The displayed virtual image VRI is enlarged by reflection on the concave reflecting surface 43 having a concave central portion. Furthermore, since the reflective surface 43 is formed into a free-form surface shape, distortion of the enlarged display virtual image VRI can be reduced.

The display light reflected on the reflective surface 43 of the movable mirror 41 is transmitted through the window section 11 and emitted to the outside of the HUD 100, and then enters the projection section 3a of the windshield 3. When the display light reflected by the projection unit 3a reaches the passenger's eye point EP, the passenger can visually recognize the displayed virtual image VRI.

The movable mirror 41 is arranged to sandwich the movable body part 42 on which the reflective surface 43 is formed in the horizontal direction (left and right) along the horizontal plane HP, and a pair of rotating shaft ends 44R and 44L are integral with the movable body part 42. is formed. Each rotating shaft end 44R, 44L is provided in a cylindrical shape protruding from the movable main body 42 to the left or right, moving away from the other rotating shaft end 44L, 44R. The movable mirror 41 is rotatable around the rotation shaft 44 because the pair of rotation shaft ends 44R, 44L are each supported by the support portion 50. That is, the rotating shaft 44, which forms the center of rotation of the movable mirror 41, is configured to connect the pair of rotating shaft end portions 44R, 44L.

As shown in FIG. 2, as the movable mirror 41 rotates, the direction of the reflective surface 43 and the optical path of the display light are changed. In an angular posture in which the reflective surface 43 faces more upward (that is, the movable mirror 41 lies down), the projection position in the projection unit 3a shifts further forward, and the position of the displayed virtual image VRI moves upward. At the same time, the position of the viewing area EB moves downward. On the other hand, in an angular posture in which the reflective surface 43 faces more downward (that is, the movable mirror 41 stands up), the projection position in the projection unit 3a shifts further backward, and the position of the displayed virtual image VRI moves downward. At the same time, the position of the viewing area EB moves upward. Therefore, as the direction of the movable mirror 41 is changed, the spatial display conditions of the displayed virtual image VRI are changed.

In addition, as shown in FIG. 4, the movable mirror 41 has an off-axis portion of the rotating shaft 44, more specifically, one (in this embodiment, the right side) of the pair of rotating shaft ends 44R, 44L. A protrusion 45 that protrudes along the axial direction from the lower corner 42b of the movable body 42 below 44R is integrally formed with the movable body 42. The protrusion 45 has a prismatic shape as shown in FIG. 5, and its tip 46 is formed into a planar shape. As the movable mirror 41 rotates, the protrusion 45 moves along an arcuate rotation trajectory RT1 (see the broken line in FIG. 6) with the rotation axis 44 as the center of curvature.

The drive output section 48 shown in FIG. 3 is coupled to the other (left side in this embodiment) of the pair of rotating shaft ends 44R, 44L. The drive output section 48 is formed by housing a stepping motor and a reduction gear mechanism in a casing. The stepping motor is a permanent magnet motor with a claw pole structure, and rotates a motor shaft in response to a drive signal from the control unit 70. The reduction gear mechanism is formed by meshing a plurality of transmission gears in series. The reduction gear mechanism reduces the rotation of the motor shaft and transmits it to the rotating shaft 44. The rotation shaft 44 rotates within a predetermined angular range together with the movable main body portion 42 and its reflective surface 43. The predetermined angular range is defined by mechanically providing a stopper inside the reduction gear mechanism, by controlling the drive of the stepping motor by the control unit 70, or by a combination thereof. By defining such an angular range, the rotation trajectory RT1 as the trajectory of the protrusion 45 is defined in a predetermined range in an oblique direction below and behind the rotation axis 44.

The support portion 50 has a pair of bearing stands 51R, 51L that respectively correspond to the pair of rotating shaft end portions 44R, 44L. A pair of bearing stands 51R, 51L are provided with the movable main body part 42 of the movable mirror 41 in the horizontal direction (left and right) so as to bear the corresponding rotating shaft ends 44R, 44L. The bearing stands 51R, 51L may be formed integrally to constitute one support member, or may be formed separately to constitute two support members with their mutual positional relationship fixed. You can leave it there. In this embodiment, in the rear space of the movable mirror 41 on the opposite side of the reflecting surface 43 with the movable main body 42 in between, a coupling part 59 for coupling the pair of bearing stands 51R, 51L is arranged, so that the pair The bearing stands 51R, 51L and the coupling portion 59 constitute one integrally formed support member. The supporting member is, for example, a plate made of metal, and is formed by bending, punching, etc., on a plate formed to have a thickness greater than a predetermined thickness so as to have strength enough to support the movable mirror 41. , is formed.

Each bearing stand 51R, 51L has a mounting portion 58 and a bearing body portion 52, as shown in FIGS. 5 and 6. The mounting portion 58 is connected to the lower end of the bearing body 52, is bent perpendicularly to the bearing body 52, and has a flat plate shape along the bottom of the housing 10. Each bearing stand 51R, 51L is fixedly attached to the housing 10 by fastening the mounting portion 58 to the housing 10 with a screw.

The bearing main body portion 52 is formed into an upright plate shape. A bearing groove 54 is formed in the upper portion 53 of the bearing body 52 and extends linearly from the upper end of the bearing body 52 forward and downward, diagonally downward. A round bearing hole 55 is formed at the bottom of the bearing groove 54 . The rotating shaft ends 44R, 44L are inserted through the bearing groove 54 and disposed in the bearing hole 55, thereby being supported by the bearing. As shown in FIG. 3, the distance between the pair of bearing stands 51R and 51L is made smaller than the axial dimension from the tip of the rotating shaft end 44R to the tip of the rotating shaft end 44L, and the movable main body 42 is larger than the axial dimension of. Therefore, the pair of bearing stands 51R, 51L can stably support the rotating shaft 44 at two points, and at the same time can leave a gap between them and the movable main body part 42. Furthermore, the distance between the pair of bearing stands 51R and 51L is made larger than the axial dimension from the side of the movable main body section 42 on the drive output section 48 side to the tip 46 of the projection section 45.

As shown in FIGS. 5 and 6, in the bearing stand 51R on the opposite side of the movable body 42 from the drive output unit 48, the bearing body 52 faces the side 42a of the movable body 42 in the axial direction. A planar opposing wall surface 57 is formed. The opposing wall surface 57 has a width such that it axially faces the entire area of the rotation trajectory RT1 in order to include the entire area of the rotation trajectory RT1 of the protrusion 45 as the movable mirror rotates within a predetermined angular range. It has been extended in a secure manner.

In order to realize such a facing wall surface 57, the bearing stand 51R has a staggered structure in which the bearing hole 55 and the center of the mounting portion 58 are deviated from each other in the front-rear direction. A lower portion 56 of the bearing main body portion 52 that connects the upper portion 53 and the attachment portion 58 extends downward toward the attachment portion 58 . Here, when a width is defined in the front-rear direction in the lower portion 56, the central axis CC can be defined to form the center of the width and extend in the up-down direction perpendicular to the horizontal plane HP. With respect to the central axis CC, the bearing hole 55 is eccentric toward the rear and shifted in the horizontal direction. Due to the eccentric arrangement of the bearing hole 55 with respect to the central axis CC, the lower part 56 is located in an obliquely downward range behind and below the bearing hole 55, in other words, in a range where contact with the protrusion 45 is expected. , forming an opposing wall surface 57.

Further, the above-mentioned connecting portion 59 extends diagonally downward and forward so as to be bifurcated from the upper portion 53 to the lower portion 56, and extends in the axial direction from a bent position to avoid interference with the movable mirror 41. The bearing base 51L is bent so as to extend to the other bearing stand 51L.

As shown in FIGS. 6 and 7, the leaf spring 62 is an elastic member made of metal, for example, and attached to the bearing stand 51R in a clip shape. The leaf spring 62 integrally includes a fixed portion 63 and an elastic displacement portion 64. The fixing portion 63 is fixed to the bearing pedestal 51R in such a manner that it engages, for example, with the entrance of the bearing groove 54 located upwardly from the rotating shaft 44, and sandwiches the bearing pedestal 51R in the plate thickness direction along the axial direction. has been done.

The elastic displacement portion 64 extends from the fixed portion 63 so as to intersect with the rotating shaft 44, and is formed in a V-shape. The elastic displacement portion 64 bifurcates into two just before reaching the rotation shaft 44, so that the elastic displacement portion 64 is arranged to sandwich the rotation shaft 44 approximately horizontally while avoiding contact with the rotation shaft 44. The elastic displacement portion 64 protrudes in the axial direction from the bearing pedestal 51R to a maximum at the intersection 65 with the rotating shaft 44, and at the spring tip 66 extending linearly from the intersection 65, the elastic displacement portion 64 extends from the bearing pedestal 51R It has a bendable shape so that it comes into contact with the

Thereby, the elastic displacement portion 64 can be displaced along the axial direction (change the amount of protrusion) by elastic deformation. The elastic displacement portion 64 presses the side portion 42a of the movable main body portion 42 on the axis via the intersection point 65, thereby moving the movable mirror 41 in the axial direction toward the bearing stand 51L side where the drive output portion 48 is disposed. is elastically biased.

In this way, the movable mirror unit 40 maintains the balanced state of the elastic displacement portion 64 (the state shown in FIG. 8) in a state where no external force is applied. The axial protrusion dimension Lp of the protrusion 45 and the spring constant of the elastic displacement portion 64 are set so that the protrusion 45 is spaced apart from the opposing wall surface 57 of the bearing stand 51R in an equilibrium state. There is.

Note that the external force referred to here is a force exerted on the movable mirror unit 40 from the vehicle 1 side due to vibrations of the vehicle 1 when the product is used (or when the product is transported in a vehicle for factory shipment, etc.). The vibrations of the vehicle 1 include vibrations received from the road surface while the vehicle 1 is running, vibrations caused by driving the engine of the vehicle 1, and the like. In addition, in the equilibrium state, the elastic displacement section 64 can be displaced to both sides in the axial direction, and the force exerted by the elastic displacement section 64 on the movable mirror 41 and the force exerted on the elastic displacement section 64 by the movable mirror 41 are balanced, and the elastic This means a state in which the displacement portion 64 is not substantially vibrating. The equilibrium state is achieved in the direction of gravity assumed when the product is used (for example, the downward direction of gravity perpendicular to the axial direction).

On the other hand, the movable mirror unit 40 can transition to a contact state (a state in which the protrusion 45 moves in the direction of the arrow in FIG. 8) when receiving an external force of a predetermined value or more. The contact state is a state that can be transitioned when the movable mirror 41 is moved toward the bearing stand 51R in the axial direction by an external force, and is a state in which the protrusion 45 and the opposing wall surface 57 are in contact.

In recent years, the size of the reflective surface 43 of the movable mirror 41 has increased as the display size of the displayed virtual image VRI has increased, and its weight has tended to increase. Therefore, in the movable mirror unit 40 of the present embodiment, the load on the movable mirror 41 expected from vibrations of the vehicle 1 is greater than the load that the leaf spring 62 can withstand. Therefore, when the movable mirror 41 moves toward the bearing stand 51R, the movement of the movable mirror 41 that causes the elastic displacement portion 64 to reach the plastic deformation region is restricted by coming into contact with the movable mirror 41.

In order to restrict the movement of the movable mirror 41, the axial protrusion dimension Lp of the protrusion 45 is a critical dimension Lc at which the elastic displacement portion 64 compressed by the movement of the movable mirror 41 reaches a critical point in the plastic deformation region. is set larger than . A gap is ensured to avoid plastic deformation of the leaf spring 62 sandwiched between the bearing stand 51R and the movable main body portion 42.

In the mechanism for suppressing plastic deformation of the leaf spring 62 as in this embodiment, the need for providing a complicated structure on and near the rotating shaft 44 on which the leaf spring 62 is arranged is suppressed. It is also possible to suppress an increase in the manufacturing cost of parts such as the movable mirror 41 and the support member including the bearing stand 51R. Note that in this embodiment, a position on or near the rotating shaft 44 is a position that is less than a predetermined distance from the rotating shaft 44, and a position off the axis of the rotating shaft 44 is a position that is a predetermined distance or more from the rotating shaft 44. It is a position where For example, the predetermined distance may be defined as the distance from the rotation axis 44 to the farthest position on the leaf spring 62 from the rotation axis 44 .

The tension spring 68 elastically urges the movable mirror 41 in the rotational direction, and suppresses positional deviation of the displayed virtual image VRI due to backlash that may occur in the reduction gear mechanism of the drive output section 48. The tension spring 68 has one end fixed to the lower corner 42c of the movable main body 42 on the opposite side from the protrusion 45. The tension spring 68 has its other end extending in the axial direction from the lower end of the bearing stand 51L of the pair of bearing stands 51R, 51L, which is opposite to the bearing stand 51R to which the leaf spring 62 is fixed, toward the bearing stand 51R. It is fixed to a tension spring holding portion 60 formed in an extended manner. Note that the rotation direction is the direction of rotation around the rotating shaft 44.

As shown in FIG. 2, the control unit 70 includes an adjustment switch 71, a control circuit section 73, and the like. The adjustment switch 71 is installed outside the housing 10, for example on the steering wheel of the vehicle 1, and can be operated by a passenger. The adjustment switch 71 includes two types of push-type operating members 72U and 72D, for example. Specifically, the up operation member 72U is an operation member for moving the position of the displayed virtual image VRI upward. The down operation member 72D is an operation member for moving the position of the displayed virtual image VRI downward. The control circuit section 73 outputs a drive signal to the stepping motor of the drive output section 48 based on the electric signal input from the adjustment switch 71 in response to the operation of the operation members 72U and 72D, and rotates the motor shaft. make it move. At this time, if the equilibrium state is maintained, the protrusion 45 and the bearing stand 51R are in a non-contact state, so the movable mirror 41 can be rotated with a small driving torque.

(effect)
The effects of the first embodiment described above will be explained again below.

According to the first embodiment, the projection 45 provided on the movable mirror 41 as an optical member projects in the axial direction toward the bearing stand 51R that constitutes a part of the support member. Due to the axial protrusion, the movable mirror 41, which is elastically biased in the axial direction by the elastic displacement portion 64, becomes axially relative to the bearing stand 51R due to vibration during use or impact during transportation. , the axial distance between the protrusion 45 and the bearing stand 51R can be changed. This change in distance allows a transition between a contact state under vibration or impact and an equilibrium state under no vibration or impact. In the contact state, the projection 45 contacts the bearing stand 51R, thereby restricting the movement of the movable mirror 41 that causes the elastic displacement portion 64 to reach the plastic deformation region. On the other hand, in an equilibrium state, the elastic displacement portion 64 maintains an equilibrium state, and the protrusion 45 and the bearing stand 51R are spaced apart from each other. By keeping the protrusion 45 and the bearing pedestal 51R in a non-contact state when the bearing pedestal 51R is not receiving a predetermined vibration or shock, the protrusion 45 is prevented from constantly contacting the bearing pedestal 51R.

By avoiding constant contact, it is possible to reduce friction between the movable mirror 41 and the bearing stand 51R when the movable mirror 41 is rotated. Therefore, it becomes possible to rotate the movable mirror 41 smoothly.

Further, by avoiding constant contact, it is possible to suppress the protrusion 45 from being gradually scraped and damaged due to friction during rotation or vibration of the vehicle. Therefore, it is possible to maintain the effect of suppressing plastic deformation of the leaf spring 62 as an elastic member over a long period of time.

Further, according to the first embodiment, the leaf spring 62 is arranged such that the elastic displacement portion 64 is sandwiched between the movable mirror 41 and the bearing stand 51R at a position on or near the rotating shaft 44. be done. With respect to such a leaf spring 62 , the protrusion 45 is arranged outside the rotating shaft 44 so as to avoid interference with the leaf spring 62 . Due to the structure that avoids interference between the protrusion 45 and the plate spring 62, when the protrusion 45 transitions from an equilibrium state to a contact state, or when the protrusion 45 rotates together with the movable mirror 41, the protrusion 45 Collision with the leaf spring 62 and damage to the protrusion 45 and the leaf spring 62 can be suppressed.

According to the first embodiment, the lower portion 56 connecting the mounting portion 58 and the upper portion 53 of the bearing stand 51R faces the protrusion 45 in the axial direction and is in contact with the protrusion 45. The opposing wall surface 57 to be abutted is formed in a range axially opposed to the entire area of the rotation locus RT1. Therefore, a smooth transition between the equilibrium state and the contact state is realized for any angular posture that the movable mirror 41 can take. Therefore, the reliability in suppressing plastic deformation of the leaf spring 62 can be increased.

(Second embodiment)
As shown in FIG. 9, the second embodiment is a modification of the first embodiment. The second embodiment will be described focusing on the differences from the first embodiment.

The protrusion 257 of the second embodiment is provided not on the movable mirror but on the bearing stand 51R. Specifically, the protrusion 45 protrudes in the axial direction from the lower portion 56 of the bearing body 52 toward the movable body 42 .

The protrusion 45 comes into contact with an off-axis portion of the side portion of the movable body portion 42 that is deviated from the portion facing the leaf spring 62 toward the outer periphery, and is axially opposed to the lower portion 56. This is the part where it is done. The contact target moves along a fan-shaped rotation locus RT2 about the rotation axis 44 as the movable mirror 41 rotates in the same angular range as in the first embodiment.

The projection 257 provided on the lower portion 56 of the bearing body 52 is formed by pressing the plate-shaped bearing body 52 made of metal, for example, so that the protrusion 257 is attached to the planar wall portion of the lower portion 56. This is an elongated protrusion that swells toward the movable main body portion 42 side. The protrusion 257 is formed so as to extend across the entire area of the rotation locus RT2 of the movable main body 42 in the rotation direction of the movable mirror 41 and a range corresponding to the axial direction. In particular, the protrusion 257 of this embodiment extends in an arc shape with the rotation axis 44 as the center of curvature.

The movable mirror unit 40 of the second embodiment is also formed to be able to transition between the equilibrium state and the contact state, similarly to the first embodiment.

According to the second embodiment described above, the protrusion 257 provided on the bearing stand 51R, which constitutes a part of the support member, protrudes in the axial direction toward the movable mirror 41 as an optical member. Due to the axial protrusion, the movable mirror 41, which is elastically biased in the axial direction by the elastic displacement portion 64, becomes axially relative to the bearing stand 51R due to vibration during use or impact during transportation. , the axial distance between the projection 257 and the movable mirror 41 can be changed. This change in distance allows a transition between a contact state under vibration or impact and an equilibrium state under no vibration or impact. In the contact state, the protrusion 257 contacts the movable mirror 41, thereby restricting the movement of the movable mirror 41 that causes the elastic displacement portion 64 to reach the plastic deformation region. On the other hand, in the balanced state, the elastic displacement part 64 maintains the balanced state, and the projection part 257 and the movable mirror 41 are spaced apart from each other. By keeping the protrusion 257 and the movable mirror 41 out of contact in a situation where they are not receiving a predetermined vibration or shock, the protrusion 257 is prevented from constantly contacting the movable mirror 41.

By avoiding constant contact, it is possible to reduce friction between the movable mirror 41 and the bearing stand 51R when the movable mirror 41 is rotated. Therefore, it becomes possible to rotate the movable mirror 41 smoothly.

Further, by avoiding constant contact, it is possible to prevent the protrusion 257 from being gradually scraped and damaged due to friction during rotation or vibration of the vehicle. Therefore, it is possible to maintain the effect of suppressing plastic deformation of the leaf spring 62 over a long period of time.

Further, according to the second embodiment, at the lower part 56 that connects the mounting part 58 and the upper part 53 in the bearing stand 51R, the protrusion 257 covers the entire area of the rotation locus RT2 and the range facing in the axial direction. It is formed to cross. Therefore, a smooth transition between the equilibrium state and the contact state is realized for any angular posture that the movable mirror 41 can take. Therefore, the reliability in suppressing plastic deformation of the leaf spring 62 can be increased.

(Other embodiments)
Although multiple embodiments have been described above, the present disclosure is not to be construed as being limited to those embodiments, and may be applied to various embodiments and combinations within the scope of the gist of the present disclosure. I can do it.

Specifically, as a first modification, instead of the plate spring 62, a coil spring inserted through the rotating shaft end 44R may be employed as the elastic member. As long as the coil spring elastically biases the movable mirror 41 in the axial direction, the movable mirror 41 may be biased by a tensile force instead of a pressing force.

Furthermore, when the coil spring has fixed parts at both ends, one end is fixed to the bearing stand 51R, and the other end is fixed to the movable mirror 41, when the protrusion part 45 is in contact with the coil spring, Reaching the plastic deformation region not only on the compression side of the spring but also on the expansion side may be restricted.

As a second modification, instead of the leaf spring 62, synthetic rubber, sponge, or the like may be used as the elastic member.

As a third modification, the HUD 100 has a configuration in which, instead of the movable mirror 41 having the reflective surface 43, a lens, a prism, a diffractive optical element, etc. is used as an optical member formed to be able to change the optical path of the display light. It's okay.

As a fourth modification, the control unit 70 detects the occupant's eye point EP with a camera installed in the vehicle 1 instead of operating the adjustment switch 71, and based on the detection result, the control unit 70 detects the eye point EP from the eye point EP. The drive output unit 48 may be operated so that the displayed virtual image VRI can be visually recognized.

As a fifth modification of the second embodiment, the protrusion 257 can be formed in various ways as long as it is formed to cross the entire area of the rotation locus RT2 by the side part 42a of the movable main body part 42 and the range corresponding to the axial direction. It may be in the shape of The protrusion 257 may be a protrusion that extends linearly or a protrusion that extends in a zigzag manner. Furthermore, the protrusion 257 does not need to be a protrusion as long as it protrudes toward the movable main body 42 with respect to the upper portion 53 to which the leaf spring 62 is fixed. For example, the entire lower portion 56 may be configured to protrude toward the movable main body portion 42 with respect to the upper portion 53.

1: Vehicle, 41: Movable mirror (optical member), 44: Rotating shaft, 45, 257: Projection, 51R: Bearing stand (part of support member), 62: Leaf spring (elastic member), 63: Fixed part , 64: Elastic displacement part, VRI: Display virtual image

Claims (3)

A virtual image display device configured to be mounted on a vehicle (1) and projecting display light that is formed as a display virtual image (VRI),
an optical member (41) formed to be able to change the optical path of the display light by rotating around a rotation axis (44);
a support member (51R) that rotatably supports the optical member;
It has a fixing part (63) that is fixed to the support member, and an elastic displacement part (64) that can be displaced by elastic deformation, and the elastic displacement part elastically attaches the optical member in the axial direction. an elastic member (62) that pushes the
One of the optical member and the support member has a protrusion (45, 257) that protrudes from the one toward the other of the optical member and the support member along the axial direction,
a state in which the protrusion is brought into contact with the other one such that movement of the optical member is restricted to cause the elastic displacement part to reach a plastic deformation region; and a state in which the protrusion is spaced apart from the other part of the elastic displacement part. The equilibrium state of
The elastic member is arranged so that the elastic displacement portion is sandwiched between the optical member and the support member at a position on or near the rotation axis,
In the virtual image display device, the protrusion is disposed outside the rotation axis so as to avoid interference with the elastic member . The protrusion is provided on the optical member,
As a trajectory of the protrusion defined as the optical member rotates within a predetermined angular range, an arc-shaped rotation trajectory (RT1) is defined at a position obliquely downward with respect to the rotation axis. ,
The support member is
a mounting portion (58) attached to the housing (10);
an upper part (53) of a bearing main body (52) that bears the rotating shaft;
a lower part of the bearing main body extending from the upper part toward the mounting part and connecting the upper part and the mounting part, the abutting part facing the protrusion in the axial direction; A lower portion (56) forming an opposing wall surface (57) that comes into contact with the protrusion in a state in which the opposing wall surface (57) comes into contact with the protrusion in the entire area of the rotation locus and in the range that opposes the axial direction. Item 1. The virtual image display device according to item 1 . The optical member has a side portion (42a) facing the support member in the axial direction as a contact target with the protrusion in the contact state,
As a locus of the side portion defined as the optical member rotates within a predetermined angular range, a fan-shaped rotation locus (RT2) is defined at a position diagonally downward with respect to the rotation axis. ,
The support member is
a mounting portion (58) attached to the housing (10);
an upper part (53) of a bearing main body (52) that bears the rotating shaft;
A lower portion of the bearing main body that extends diagonally downward from the upper portion toward the attachment portion and connects the upper portion and the attachment portion, the protrusion portion extending across the entire region of the rotation locus. The virtual image display device according to claim 1, further comprising: and a lower portion (56) formed so as to cross the range facing each other in the axial direction.

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