JP6520819B2 - Display position adjustment unit and head-up display device - Google Patents

Description

  The present invention relates to a display position adjustment unit and a Head Up Display (hereinafter referred to as HUD) device.

  Conventionally, in a HUD device mounted on a vehicle, a display position adjustment unit is widely used to adjust a virtual image display position for reflecting a display light image projected from a projection unit to display a virtual image. For example, in the display position adjusting unit disclosed in Patent Document 1, the direction in which the reflecting mirror reflects the display light image changes as the rotation axis provided to the reflecting mirror is rotationally driven by the stepping motor. As a result, the virtual image display position of the display light image is adjusted in accordance with the change in the reflection direction of the display light image.

  Now, in the display position adjustment unit of Patent Document 1, it is possible to finely adjust the virtual image display position by decelerating the rotation of the stepping motor by the reduction gear mechanism and transmitting it to the rotation shaft of the reflecting mirror. . Furthermore, in the display position adjustment unit of Patent Document 1, backlash of the transmission gears engaged in meshing connection in the reduction gear mechanism is removed by urging the rotation shaft to one side in the rotation direction by one or a pair of elastic members. It is possible to improve the adjustment accuracy of the virtual image display position.

JP 2011-131651 A

  However, in the display position adjustment unit of Patent Document 1, the transmission gear is high in the vehicle under the condition that the urging of the rotation shaft by the restoring force from one or a pair of elastic members continues on one side of the rotation direction. If the gear is exposed to light, the transmission gear may be subject to creep deformation.

  Specifically, as shown in FIG. 17A, the transmission gears 100 and 101 undergo creep deformation so as to widen the backlash at the meshing and connecting point of the transmission gears 100 and 101 with each other. Then, as shown in FIG. 17B, the transmission gears 100 and 101 rotate so as to fill the backlash by the restoring force from one or a pair of elastic members, so that the virtual image display position is shifted.

  Here, as the maximum value of the restoring force that biases the rotation shaft increases under the use condition, creep deformation occurs and the virtual image display position is easily shifted, but one or a pair of the biasing directions becomes constant. It is difficult to reduce the maximum value depending on the elastic member of the above. This ensures that the minimum value of recovery force under use condition is a removable size of the backlash, the maximum value of recovery force under use condition is the spring constant of one elastic member or that of a pair of elastic members. It is because it increases depending on the synthetic spring constant.

  The present invention has been made in view of the problems described above, and its object is to include a display position adjustment unit for suppressing displacement of a virtual image display position of a display light image in a vehicle, and the display position adjustment unit. It is in providing a HUD device.

  Hereinafter, the technical means of the invention for achieving a subject is demonstrated. Note that the claims disclosing the technical means of the invention and the reference numerals in the parentheses described in this section indicate the correspondence with the specific means described in the embodiments detailed later, It does not limit the technical scope of the invention.

The first invention disclosed to solve the above-mentioned problems is
Display position adjustment unit (3) for adjusting a virtual image display position where a display light image (5) projected from the projection unit (20) is reflected and displayed as a virtual image in the head-up display device (1) mounted on a vehicle And
A reflecting mirror (32) provided with a rotation axis (33) and changing the direction of reflecting the display light image by forward and reverse rotation of the rotation axis;
A stepping motor (37) for driving the rotary shaft in forward and reverse rotation in a rotational drive range (A) between an initial rotational position (R0) and a maximum rotational position (Rmax) under use conditions;
A reduction gear mechanism (38) in which transmission gears (380, 381, 382, 383, 383, 384, 385, 386, 387) mesh with one another for decelerating and transmitting the rotation of the stepping motor to the rotating shaft;
A first elastic member (35) for increasing a first restoring force (F1) for urging the rotation shaft in the reverse rotation direction (Dr) in the rotation drive range as the rotation shaft rotates forward from the initial rotation position;
A second elastic member (39) for reducing a second restoring force (F2) for urging the rotation shaft in the positive rotation direction (Dn) in the rotation drive range as the rotation shaft rotates positively from the initial rotation position; Equipped
The first elastic member and the second elastic member are set in a state in which the second restoring force is smaller than the first restoring force at the initial rotational position.

In addition, the second invention disclosed to solve the above-mentioned problems is:
A head-up display device (1) mounted on a vehicle,
A projection unit (20) for projecting a display light image (5);
And a display position adjustment unit (3) configured to adjust a virtual image display position for reflecting a display light image projected from the projection unit to cause a virtual image to be displayed,
Display position adjustment unit is
A reflecting mirror (32) provided with a rotation axis (33) and changing the direction of reflecting the display light image by forward and reverse rotation of the rotation axis;
A stepping motor (37) for driving the rotary shaft in forward and reverse rotation in a rotational drive range (A) between an initial rotational position (R0) and a maximum rotational position (Rmax) under use conditions;
A reduction gear mechanism (38) in which transmission gears (380, 381, 382, 383, 383, 384, 385, 386, 387) mesh with one another for decelerating and transmitting the rotation of the stepping motor to the rotating shaft;
A first elastic member (35) for increasing a first restoring force (F1) for urging the rotation shaft in the reverse rotation direction (Dr) in the rotation drive range as the rotation shaft rotates forward from the initial rotation position;
A second elastic member (39) for reducing a second restoring force (F2) for urging the rotation shaft in the positive rotation direction (Dn) in the rotation drive range as the rotation shaft rotates positively from the initial rotation position; Equipped
The first elastic member and the second elastic member are set in a state in which the second restoring force is smaller than the first restoring force at the initial rotational position.

  According to each aspect of the invention, the rotation axis of the reflecting mirror in the rotational drive range between the initial rotational position and the maximum rotational position in the use state is the first recovery force of the first elastic member which increases according to the positive rotation. Depending on the direction of rotation. At this time, the rotation shaft is biased in the positive rotation direction by the second restoring force of the second elastic member which decreases according to the normal rotation and becomes smaller than the first restoring force at the initial rotating position. As a result, in the initial rotational position, the resultant force of the restoring forces is minimized with respect to the first restoring force which is the minimum value in the operating rotating condition and the second restoring force which is the maximum value in the operating rotating condition. . Therefore, by ensuring that the resultant force minimum value of the first and second recovery forces can be reduced to such a size that the backlash of the transmission gears engaged in meshing connection in the reduction gear mechanism can be eliminated, the size is large even in the entire rotation drive range. It can be secured. In addition, at the maximum rotation position where the combined force of the first and second restoring forces reaches the maximum value under the state of use, the second restoring force in the direction opposite to the first restoring force is generated, and the resultant force is the first restoring force. It can be reduced below the maximum of force alone.

  From the above, it is possible to adjust the set load of each elastic member at the initial rotational position so that the first and second restoring forces always occur in the rotational drive range and secure the above-mentioned magnitude, Regardless of the spring constant of each elastic member, combined force reduction can be achieved in combination with backlash removal. Therefore, even if the transmission gear is exposed to high environmental temperature in the vehicle, creep deformation of the transmission gear is less likely to occur, so that displacement of the virtual image display position of the display light image can be suppressed.

It is a schematic block diagram which shows the HUD apparatus which applied the display position adjustment unit of one Embodiment. It is a schematic diagram which shows the virtual-image display state of the display light image by the HUD apparatus of FIG. It is a front view which shows the display position adjustment unit of FIG. It is a top view which shows the display position adjustment unit of FIG. It is the VV sectional view taken on the line of FIG. It is the VI-VI line sectional view of FIG. It is a graph which shows the characteristic in the display position adjustment unit of FIG. FIG. 2 is a cross-sectional view showing the stepping motor and the speed reduction mechanism of FIG. 1; It is a graph which shows the drive signal applied to the stepping motor of FIG. FIG. 2 is an electric circuit diagram showing a state of electrical connection between the stepping motor of FIG. 1 and a control unit. It is a graph which shows the modification of FIG. It is a graph which shows the modification of FIG. It is a graph which shows the modification of FIG. It is a graph which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is a schematic diagram for demonstrating the conventional subject.

  As shown in FIG. 1, the HUD device 1 provided with the display position adjustment unit 3 according to the embodiment of the present invention is mounted on a vehicle and displays a display light image 5 in a virtual image in the vehicle. The HUD device 1 includes a housing 10, a projection unit 20, an optical system 30, an adjustment switch 80, and a control unit 90.

  The housing 10 is formed in a hollow shape and installed on the instrument panel 2 in the vehicle. The housing 10 accommodates the components 20, 30 and the like of the HUD device 1 in front of the driver's seat of the vehicle. The housing 10 has a translucent exit window 14 at a position facing up and down with the windshield 4 as a projection member in front of the driver's seat of the vehicle.

  The projection unit 20 is mainly composed of a transmissive illumination type liquid crystal panel or an organic EL panel, and has a screen 22. The screen 22 is transmitted and illuminated by a backlight incorporated in the projection unit 20. An image displayed as a real image on the screen 22 is projected as the display light image 5 by receiving the transmitted illumination and emitting light. The display light image 5 projected from the projection unit 20 represents vehicle related information related to the vehicle. The display light image 5 of the present embodiment represents navigation information such as the traveling direction of the vehicle, as shown in FIG. However, the display light image 5 may represent vehicle condition information such as vehicle speed, fuel remaining amount, cooling water temperature and the like, and vehicle external condition information such as the traffic condition, in addition to the navigation information.

  As shown in FIG. 1, the optical system 30 is composed of a plurality of optical units including the display position adjustment unit 3. However, in FIG. 1, the components of the optical system 30 other than the display position adjustment unit 3 are not shown. As shown in FIGS. 1 and 3 to 6, the display position adjustment unit 3 includes a bearing body 34, a reflecting mirror 32, a drive source 36 and elastic members 35 and 39.

  The bearing body 34 is formed in a frame shape by metal. The bearing body 34 has a fixed base 340, a holding base 341 and a bearing base 342. A fixed base 340 in the form of a band-shaped flat plate is fixed to the bottom of the housing 10 below the reflecting mirror 32. The holding base 341 having a substantially rectangular flat shape protrudes substantially vertically upward from one end of the fixed base 340. The bearing base 342 in the form of a substantially rectangular flat plate protrudes substantially vertically upward from the other end of the fixed base 340 opposite to the holding base 341.

  As shown in FIGS. 1, 3 and 4, the reflecting mirror 32 is a so-called concave mirror having a reflecting surface 32a concaved in a smooth curved surface in the present embodiment. The reflective surface 32a is formed by metal deposition or the like on a resin base material. As shown in FIG. 1, the reflecting surface 32a enlarges the display light image 5 directly or indirectly incident on the reflecting surface 32a from the projection unit 20, and reflects it toward the emission window 14 side. The display light image 5 thus reflected is projected onto the windshield 4 by passing through the exit window 14. As a result, the display light image 5 is displayed as shown in FIG. 2 as a virtual image formed in front of the windshield 4 toward the driver's seat in the vehicle.

  As shown in FIGS. 3 to 6, in the outer peripheral frame 32b made of resin that surrounds the outer peripheral side of the reflecting surface 32a in the reflecting mirror 32, a rotation shaft 33 made of the same resin is integrally provided. The rotary shaft 33 is separated on both sides sandwiching the reflection surface 32 a in the lateral direction, to form a first shaft portion 331 and a second shaft portion 332. The first shaft portion 331 and the second shaft portion 332 are formed in a cylindrical shape coaxial with each other, and protrude in opposite directions from the outer peripheral frame 32 b. The first shaft portion 331 is integrally and rotatably coupled to an output shaft 388 of the drive source 36 held by the holding base 341 in the bearing body 34. The second shaft portion 332 is supported by the bearing base 342 in the bearing body 34 so as to be capable of rotating in the forward and reverse directions.

  Under such a configuration, the drive source 36 rotationally drives the first shaft portion 331 of the rotation shaft 33 in one of the normal rotation direction Dn and the reverse rotation direction Dr, whereby the display light image 5 is reflected by the reflection surface 32 a The direction in which the light is reflected changes. As a result, the virtual image display position of the display light image 5 is adjusted up and down with respect to the windshield 4 as shown in FIG. Specifically, the virtual image display position of the display light image 5 is adjusted between the lower limit display position Pl shown by a solid line in FIG. 2 and the upper limit display position Pu shown by a broken line in FIG. Here, among the rotational positions of the rotational shaft 33, the initial rotational position R0 shown in FIGS. 3 to 7 is set to a rotational position corresponding to the upper limit display position Pu under the use condition of the display position adjustment unit 3. On the other hand, among the rotational positions of the rotary shaft 33, the maximum rotational position Rmax shown in FIG. 7 is set to a rotational position corresponding to the lower limit display position Pl under the use condition.

  As shown in FIGS. 1 and 8, the drive source 36 has a stepping motor 37 and a reduction gear mechanism 38. The stepping motor 37 is a permanent magnet type motor having a claw pole structure. As shown in FIG. 8, in the stepping motor 37, the A and B two-phase coils 370 and 371 are energized by the drive signal and excited, whereby the rotor magnet 372 rotates integrally with the motor shaft 373. Here, as shown by a thick solid line graph in FIG. 9, a drive signal is applied to the A-phase coil 370 in accordance with a cosine function that alternates the amplitude according to the electrical angle. On the other hand, a drive signal is applied to the B-phase coil 371 according to a sine function that alternates the amplitude according to the electrical angle, as shown by a thin solid line graph in FIG. Therefore, the rotational position of the motor shaft 373 is a position corresponding to the electrical angle of the drive signal applied to the coils 370 and 371 of the A and B phases.

  The reduction gear mechanism 38 meshes and connects the plurality of transmission gears 380, 381, 382, 383, 384, 385, 386, 387 as shown in FIG. 8 in the casing 380 held by the holding base 341 as shown in FIG. I will do it. The whole of the transmission gears 380, 381, 382, 383, 383, 385, 386, 387, including the teeth 380a, 381a, 382a, 383a, 384a, 385a, 386a, 387a, is made of resin.

  Specifically, the first transmission gear 380 is integrally provided on the motor shaft 373. The first idler transmission gear 381 and the first pinion transmission gear 382 are integrally formed and supported by a casing 380. The tooth profile 381a of the first idler transmission gear 381 is interlocked with the tooth profile 380a of the first stage transmission gear 380 by meshing. The second idler transmission gear 383 and the second pinion transmission gear 384 are integrally formed and supported by the casing 380. The toothed portion 383a of the second idler transmission gear 383 is interlocked with the toothed portion 382a of the first pinion transmission gear 382 by meshing. The third idler transmission gear 385 and the third pinion transmission gear 386 are integrally formed and supported by the casing 380. The toothed portion 385a of the third idler transmission gear 385 is interlocked with the toothed portion 386a of the second pinion transmission gear 384 by meshing. The final stage transmission gear 387 is integrally provided on the output shaft 388. The tooth profile 387a of the final stage transmission gear 387 is interlocked with the tooth profile 386a of the third pinion transmission gear 386 by meshing.

  In the reduction gear mechanism 38, the rotation of the motor shaft 373 in the stepping motor 37 is decelerated and transmitted from the output shaft 388 to the first shaft portion 331 of the rotating shaft 33. As a result, when the motor shaft 373 rotates forward, the rotary shaft 33 is rotationally driven in the forward rotation direction Dn such that the virtual image display position of the display light image 5 changes toward the lower limit display position P1 below. . On the other hand, when the motor shaft 373 reversely rotates, the rotary shaft 33 is rotationally driven in the reverse rotation direction Dr so that the virtual image display position of the display light image 5 changes toward the upper upper limit display position Pu. Here, particularly in the reduction gear mechanism 38, a stopper (not shown) is provided so as to restrict the rotational drive range A (see, for example, FIG. 7) of the rotary shaft 33 between the display positions Pu and Pl and the corresponding rotational positions R0 and Rmax. A structure is provided.

  As shown to FIGS. 3-5, the 1st elastic member 35 is comprised from the metal spiral spring. The first elastic member 35 is swirled in the reverse rotation direction Dr from the inner peripheral end 350 toward the outer peripheral end 351 when viewed from the protruding tip end side of the second shaft 332 (for example, see FIG. 5) . The inner peripheral end 350 of the first elastic member 35 is locked by the first specific portion S <b> 1 on the second shaft portion 332 of the rotation shaft 33 in the entire region of the rotational drive range A. The outer peripheral end 351 of the first elastic member 35 is locked by the locking pin 342 a provided on the bearing base 342 of the bearing body 34 in the entire region of the rotational drive range A.

  The first elastic member 35 configured as described above twists and deforms between the rotary shaft 33 and the bearing body 34 to attach the rotary shaft 33 in the reverse rotation direction Dr in the entire range of the rotary drive range A shown in FIG. The first restoring force F1 is applied to the first specific portion S1 as a point of action so as to be biased. The first recovery force F1 gradually increases as the rotary shaft 33 rotates forward from the initial rotational position R0 throughout the rotational drive range A. As a result, the first recovery force F1 becomes the minimum value F1 min which exceeds the zero value at the initial rotational position R0, and becomes the maximum value F1 max at the maximum rotational position Rmax. Here, particularly, the minimum value F1min is set as a set load of the first recovery force F1 at the initial rotational position P0.

  As shown in FIGS. 3, 4 and 6, the second elastic member 39 is composed of a metal spiral spring. The second elastic member 39 is given a spring constant smaller than that of the first elastic member 35 (see, for example, FIG. 7). The second elastic member 39 is spiraled in the positive rotation direction Dn from the inner peripheral end 390 to the outer peripheral end 391 when viewed from the protruding tip end side of the second shaft 332 (for example, see FIG. 6) . The inner circumferential end portion 390 of the second elastic member 39 is locked by the second specific portion S2 axially shifted from the first specific portion S1 of the rotation shaft 33 in the entire region of the rotational drive range A. The outer peripheral end 391 of the second elastic member 39 is locked by the locking pin 342 a provided on the bearing base 342 of the bearing body 34 in the entire region of the rotational drive range A.

  The second elastic member 39 configured as described above twists and deforms between the rotary shaft 33 and the bearing body 34 to attach the rotary shaft 33 in the forward rotation direction Dn in the entire range of the rotary drive range A shown in FIG. The second restoring force F2 is applied to the second specific portion S2 as a point of action so as to be biased. The second restoring force F2 gradually decreases from the initial rotation position R0 as the rotation shaft 33 rotates forward in the entire range of the rotation drive range A. As a result, the second recovery force F2 has the maximum value F2max at the initial rotational position R0, and has the minimum value F2min exceeding zero at the maximum rotational position Rmax. Here, in particular, the maximum value F2max is set as a set load of the second restoring force F2 at the initial rotational position P0 to a value smaller than the minimum value F1min of the first restoring force F1 and exceeding the half value F1h of the minimum value F1min. ing. That is, the first and second elastic members 35 and 39 are set in a state in which the second resilience F2 is smaller than the first resilience F1 and larger than the half value F1h at the initial rotational position P0. In addition, a set of the first and second elastic members 35 and 39 allows the second recovery force F2 to be smaller than the first recovery force F1 at the same rotational position of the rotation shaft 33 over the entire range of the rotational drive range A. Is to be maintained at

  The adjustment switch 80 shown in FIGS. 1 and 10 is installed so as to be operable by a passenger around the driver's seat of the vehicle. The adjustment switch 80 has operation members 82 and 83 such as a lever type or a push type. The up operation member 82 is operated by an occupant who wants to change the virtual image display position of the display light image 5 upward. In response to this operation, the adjustment switch 80 outputs a command signal for giving an up adjustment command. On the other hand, the down operation member 83 is operated by an occupant who wants to change the virtual image display position of the display light image 5 downward. In response to this operation, the adjustment switch 80 outputs a command signal for giving a down adjustment command.

  The control unit 90 is installed outside or inside the housing 10. The control unit 90 includes a display control circuit 92 and a switching circuit 93. The display control circuit 92 is mainly configured of a microcomputer. The display control circuit 92 is electrically connected to the projection unit 20 and the adjustment switch 80. As shown in FIG. 10, the switching circuit 93 includes a plurality of transistors as the switching element 94. The collector of each switching element 94 is electrically connected to one of the coils 370 and 371 of the stepping motor 37. The emitter and the base of each switching element 94 are electrically connected to the ground terminal of the vehicle and the display control circuit 92, respectively. Each switching element 94 changes the drive signal applied to the coils 370 and 371 of each phase of A and B in accordance with the base signal input from the display control circuit 92 in response to the command signal from the adjustment switch 80.

  According to the present embodiment described above, the rotation shaft 33 of the reflecting mirror 32 in the rotation drive range A between the initial rotation position R0 and the maximum rotation position Rmax in the use state increases according to the positive rotation. The first recovery force F1 of the member 35 is biased in the reverse rotation direction Dr. At this time, the rotation shaft 33 is biased in the positive rotation direction Dn by the second recovery force F2 of the second elastic member 39 which decreases with forward rotation and becomes smaller than the first recovery force F1 at the initial rotation position R0. Be done. Thus, at the initial rotational position R0, the first restoring force F1 which is the minimum value F1 min under the operating rotation condition and the second restoring force F2 which is the maximum value F2 max under the operating rotation condition The resultant force Fr of F2 becomes the minimum value Frmin as shown in FIG. Therefore, the minimum value Frmin of the resultant force Fr is secured to a size capable of removing the backlash between the transmission gears 380, 381, 382, 383, 383, 385, 386, 387 engaged in meshing connection in the reduction gear mechanism 38. The said magnitude | size can be ensured also in the whole area of the rotational drive range A. FIG. In addition, as shown in FIG. 7 at the maximum rotation position Rmax where the combined force Fr reaches the maximum value Frmax under the use condition, the combined force Fr is equal to the amount by which the second recovery force F2 in the opposite direction to the first recovery force F1 is generated. It may be reduced below the single maximum value F1max of the recovery force F1. In FIG. 7, the lower limit value of the urging force capable of removing the backlash is indicated by the symbol Fe.

  From the above, if the set loads of the elastic members 35 and 39 at the initial rotational position R0 are adjusted such that the first and second restoring forces F1 and F2 are always generated in the rotational drive range A, Regardless of the spring constants of the respective elastic members 35 and 39, it is possible to achieve total force reduction in combination with the removal of backlash. Therefore, even if the transmission gears 380, 381, 382, 383, 383, 385, 386, 387 are exposed to high environmental temperatures in the vehicle, creep deformation of the gears is less likely to occur, so the virtual image display position of the display light image It becomes possible to suppress the displacement.

  Further, a spring constant smaller than that of the first elastic member 35 is given to the second elastic member 39 of the present embodiment. According to this, with respect to the resultant force Fr in which the minimum value Frmin at the initial rotation position R0 is secured to a size that can remove the backlash, the maximum value Frmax at the maximum rotation position Rmax is the maximum value F1max of the first recovery force F1 alone. It becomes easier to reduce. Therefore, it is possible to make the creep deformation of the transmission gears 380, 381, 382, 383, 383, 385, 386, 387 less likely to occur, and to ensure the reliability of the shift suppressing effect of the virtual image display position.

  Furthermore, according to the second elastic member 39 of the present embodiment, the second recovery force F2 is adjusted to a magnitude exceeding the half value F1h of the first recovery force F1 at the initial rotational position R0. According to this, with respect to the resultant force Fr in which the minimum value Frmin at the initial rotation position R0 is secured to a size that can remove the backlash, the maximum value Frmax at the maximum rotation position Rmax is the maximum value F1max of the first recovery force F1 alone. The smaller amount can be increased as much as possible. Therefore, it is possible to reliably prevent the creep deformation of the transmission gears 380, 381, 382, 383, 383, 385, 386, and 387 and to improve the reliability of the effect of suppressing the displacement of the virtual image display position.

  Furthermore, the first and second restoring forces F1 and F2 of the present embodiment are shifted in the axial direction on the rotation shaft 33 by the first and second elastic members 35 and 39 configured from opposing spiral springs in the spiral direction. By acting on the specific portions S1 and S2, the resultant force Fr as described above can be generated. In addition, with respect to the first and second elastic members 35 and 39 configured from spiral springs, the axial size on the rotation shaft 33 can be reduced as much as possible. According to these, the shift suppression effect of the virtual image display position can be achieved by the small display position adjustment unit 3.

  In addition, the transmission gears 380, 381, 382, 383, 383, 385, 58, 387 according to the present embodiment include tooth-shaped portions 380a, 381a, 382a, 383a, 384a, 385a, 386a, 387a engaged in meshing connection. The whole is formed of resin. As a result, in the transmission gears 380, 381, 382, 383, 383, 384, 385, 386, 387, which can be formed relatively inexpensively, the possibility of creep deformation increases as the environmental temperature rises. However, even if the transmission gears 380, 381, 382, 383, 383, 384, 385, 386, 387 are formed entirely of resin including the teeth 380a, 381a, 382a, 383a, 384a, 385a, 386a, 387a, Creep deformation hardly occurs due to the principle of Therefore, the shift suppression effect of the virtual image display position can be achieved.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited and interpreted to the said embodiment, It can apply to various embodiment and combination in the range which does not deviate from the summary of this invention. .

  Specifically, as a first modification, as shown in FIG. 11, a spring constant equal to that of the first elastic member 35 may be given to the second elastic member 39. As a second modification, as shown in FIG. 12, a spring constant larger than that of the first elastic member 35 may be given to the second elastic member 39.

  As a third modification, as shown in FIG. 13, the second elastic member 39 may adjust the second recovery force F2 to a magnitude equal to the half value F1h of the first recovery force F1 at the initial rotational position R0. . As a fourth modification, as shown in FIG. 14, the second elastic member 39 may adjust the second recovery force F2 to a size below the half value F1 h of the first recovery force F1 at the initial rotational position R0. .

  As a fifth modification, as shown in FIGS. 15 and 16, the spiral direction of the first and second elastic members 35 and 39 may be set opposite to the direction of the above-described embodiment shown in FIGS. In this case, the initial rotational position R0 is set to the rotational position corresponding to the lower limit display position Pl, and the maximum rotational position Rmax is set to the rotational position corresponding to the upper limit display position Pu. Under these settings, the rotary shaft 33 is rotationally driven in the positive rotation direction Dn so that the virtual image display position changes toward the upper limit display position Pu, while the virtual image display position changes toward the lower limit display position Pl The rotation shaft 33 is rotationally driven in the reverse rotation direction Dr.

  As a sixth modification, the entire gear including the tooth profile may be formed of a material other than resin for gears excluding at least one of the transmission gears 380, 381, 382, 383, 383, 384, 385, 386, and 387. . As a seventh modification, at least one of the transmission gears 380, 381, 382, 383, 383, 384, 385, 386, and 387 may be formed of resin only with a portion including the tooth profile. As a modification 8, at least one gear of at least one of the transmission gears 380, 381, 382, 383, 383, 384, 385, 386, 387 may be formed of resin only.

  As a modification 9, at least one of the first and second elastic members 35 and 39 may be configured by a torsion coil spring. As a modification 10, a laser scanner which projects a laser beam to be a display light image 5 by a micro-electro-mechanical system, or an image display system to project visible light or a laser beam to be a display light image 5 by a digital mirror device The function of the projection unit 20 may be fulfilled. As a modification 11, the display light image 5 reflected by the reflecting mirror 32 may be projected toward a combiner or the like exclusively installed in the HUD device 1 in the vehicle.

Reference Signs List 1 HUD device, 3 display position adjusting unit, 5 display light image, 20 projection unit, 30 optical system, 32 reflecting mirror, 33 rotating shaft, 35 first elastic member, 36 driving source, 37 stepping motor, 38 reduction gear mechanism, 39 second elastic member, 380, 381, 382, 383, 383, 385, 386, 387 transmission gear, 380a, 381a, 382a, 383a, 384a, 385a, 386a, 387a tooth shape, 331 first shaft, 332 first Biaxial part, 350, 390 inner peripheral end, 351, 391 outer peripheral end, A rotation drive range, Dn forward rotation direction, Dr reverse rotation direction, F1 first recovery force, F1h half value, F2 second recovery force, Fr Total force, R0 initial rotation position, Rmax maximum rotation position, S1 first specified location, S2 second specified location

Claims (6)

Display position adjustment unit (3) for adjusting a virtual image display position where a display light image (5) projected from the projection unit (20) is reflected and displayed as a virtual image in the head-up display device (1) mounted on a vehicle And
A reflecting mirror (32) provided with a rotating shaft (33), and changing the direction of reflecting the display light image by forward and reverse rotation of the rotating shaft;
A stepping motor (37) for driving the rotary shaft in forward and reverse rotation in a rotational drive range (A) between an initial rotational position (R0) and a maximum rotational position (Rmax) under use conditions;
A reduction gear mechanism (38) in which transmission gears (380, 381, 382, 383, 383, 384, 385, 386, 387) mesh with one another in order to decelerate the rotation of the stepping motor and transmit it to the rotating shaft. When,
A first elastic member (35) for increasing a first restoring force (F1) for urging the rotary shaft in the reverse rotation direction (Dr) in the rotary drive range as the rotary shaft rotates forward from the initial rotary position )When,
A second elastic member (39) configured to reduce a second restoring force (F2) for urging the rotary shaft in the positive rotation direction (Dn) in the rotary drive range as the rotary shaft rotates forward from the initial rotation position; ) And,
The display position adjustment unit, wherein the first elastic member and the second elastic member are set in a state in which the second restoring force is smaller than the first restoring force at the initial rotational position.   The display position adjustment unit according to claim 1, wherein a spring constant smaller than the first elastic member is given to the second elastic member.   The display position adjustment unit according to claim 2, wherein the second elastic member adjusts the second restoring force to a size exceeding the half value of the first restoring force at the initial rotational position.   The first elastic member and the second elastic member are composed of opposing spiral springs in a spiral direction, and the first elastic member and the second elastic member are respectively connected to the first and second working points (S1, S2) shifted in the axial direction on the rotation axis. The display position adjustment unit according to any one of claims 1 to 3, wherein one restoring force and the second restoring force act.   The display according to any one of claims 1 to 4, wherein the tooth forms (380a, 381a, 382a, 383a, 384a, 385a, 386a, 387a) engaged in meshing connection in the transmission gear are formed of resin. Position adjustment unit. A head-up display device (1) mounted on a vehicle,
A projection unit (20) for projecting a display light image (5);
And a display position adjustment unit (3) configured to adjust a virtual image display position for reflecting the display light image projected from the projection unit to cause a virtual image to be displayed,
The display position adjustment unit is
A reflecting mirror (32) provided with a rotating shaft (33), and changing the direction of reflecting the display light image by forward and reverse rotation of the rotating shaft;
A stepping motor (37) for driving the rotary shaft in forward and reverse rotation in a rotational drive range (A) between an initial rotational position (R0) and a maximum rotational position (Rmax) under use conditions;
A reduction gear mechanism (38) in which transmission gears (380, 381, 382, 383, 383, 384, 385, 386, 387) mesh with one another in order to decelerate the rotation of the stepping motor and transmit it to the rotating shaft. When,
A first elastic member (35) for increasing a first restoring force (F1) for urging the rotary shaft in the reverse rotation direction (Dr) in the rotary drive range as the rotary shaft rotates forward from the initial rotary position )When,
A second elastic member (39) configured to reduce a second restoring force (F2) for urging the rotary shaft in the positive rotation direction (Dn) in the rotary drive range as the rotary shaft rotates forward from the initial rotation position; ) And,
The head-up display device in which the first elastic member and the second elastic member are set in a state in which the second restoring force is smaller than the first restoring force at the initial rotational position.

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