JP7739752B2 - Head-up display device - Google Patents

Description

This disclosure relates to a head-up display device.

Head-up display devices are known that have a reflector (concave mirror) made from a cyclic olefin resin, such as cycloolefin polymer (COP). Cyclic olefin resins have high fluidity and hardness, allowing for good positioning accuracy, and are widely used in optical system components.

Japanese Patent Application Laid-Open No. 2016-218163

However, cyclic olefin resins can crack due to long-term loads, etc. Therefore, when rotating the reflector as in Patent Document 1, it is necessary to prepare a separate holder that is made of a resin with lower rigidity than cyclic olefin resin and can hold the back surface of the reflector, and to connect the reflector to the rotational drive unit via the holder.

The present disclosure therefore aims to provide a head-up display device that rotates a reflector made of cyclic olefin resin, but does not require a holder to hold the back of the reflector.

In one aspect, the following solution is provided.
(1) A head-up display device comprising a display that emits display light representing an image, a reflecting unit that reflects the display light, and a rotational drive unit that rotates the reflecting unit around a rotational axis, wherein the reflecting unit is made of a cyclic olefin resin, has a first shaft portion integrally formed at one end along the rotational axis direction, and a separate shaft member connected to the other end, the shaft member being made of a resin with lower rigidity than the cyclic olefin resin, has a second shaft portion along the rotational axis direction, and a connecting lever portion connected to the rotational drive unit, and further comprises a first rotational support portion that rotatably supports the first shaft portion, and a second rotational support portion that rotatably supports the second shaft portion, and the first rotational support portion determines the position of the reflecting unit in the rotational axis direction .

In another aspect, the following solution is provided.
(2) A head-up display device comprising a display that emits display light representing an image, a reflecting unit that reflects the display light, and a rotational drive unit that rotates the reflecting unit around a rotational axis, wherein the reflecting unit is made of a cyclic olefin resin, has a first shaft portion integrally formed at one end along the rotational axis direction, and a separate shaft member is connected to the other end, the shaft member is made of a resin having lower rigidity than the cyclic olefin resin, has a second shaft portion along the rotational axis direction, and a connecting lever portion connected to the rotational drive unit, and the other end of the reflecting unit has an integral plate-shaped fixing portion that is fixed to the shaft member via a screw, and the fixing portion is screwed to the shaft member while being sandwiched between the shaft member and a washer formed of a resin having lower rigidity than the cyclic olefin resin .

In yet another aspect, the following solution is provided.
(3) A head-up display device comprising a display that emits display light representing an image, a reflecting section that reflects the display light, and a rotational drive section that rotates the reflecting section around a rotational axis, wherein the reflecting section is made of a cyclic olefin resin, has a first shaft section integrally formed at one end along the rotational axis direction, and has a separate shaft member connected to the other end, the shaft member is made of a resin with lower rigidity than the cyclic olefin resin, has a second shaft section that extends along the rotational axis direction, and a connecting lever section that is connected to the rotational drive section, and wherein silicone grease is applied to the first shaft section .

This disclosure makes it possible to rotate a reflector made of cyclic olefin resin, while eliminating the need for a holder to hold the back surface of the reflector.

1 is a schematic cross-sectional view showing a configuration of a head-up display device according to an embodiment of the present invention. FIG. 2 is a perspective view showing a reflector and a reflector rotation mechanism included in the head-up display device. FIG. 2 is a perspective view showing a first shaft portion and a first rotation support portion of the reflecting portion. FIG. 2 is an exploded perspective view showing a first shaft portion and a first rotation support portion of the reflecting portion. FIG. 2 is a perspective view showing a support body of the first rotation support portion; 4 is a cross-sectional view showing a first shaft portion and a first rotation support portion of the reflecting portion. FIG. 10 is a perspective view showing a second shaft portion (shaft member) of the reflecting portion, a second rotation support portion, and a rotation drive portion. FIG. 10 is an exploded perspective view showing a second shaft portion (shaft member) of the reflecting portion, a second rotation support portion, and a rotation drive portion. FIG.

The head-up display device 100 of this embodiment will be described in detail below with reference to the accompanying drawings.

[Outline of head-up display device]
The head-up display device 100 is mounted, for example, on an automobile, and as shown in Figures 1 and 2, comprises a housing 1, a display 2, a plane mirror 3, a reflecting unit 4, a reflecting unit rotation mechanism 5, and a circuit board (not shown).

The head-up display device 100 reflects display light L, which represents a predetermined image emitted by the display device 2, using a plane mirror 3 and a reflector 4, and projects it onto the windshield 200 of the vehicle on which the head-up display device 100 is mounted. The information displayed by the head-up display device 100 in this manner includes vehicle information such as the vehicle's traveling speed and various warnings, navigation information, etc.

The housing 1 is made of, for example, black synthetic resin and houses the display 2, plane mirror 3, reflector 4, reflector rotation mechanism 5, and circuit board (not shown). An opening 10 is formed in the part of the housing 1 facing the windshield 200, allowing display light L (described below) to pass through to the windshield 200, and this opening 10 is covered by a translucent cover 11.

The display device 2 emits display light L that displays an image (announcement image) to notify predetermined information (various vehicle information, navigation information, etc.), and is composed of, for example, a transmissive liquid crystal display consisting of a liquid crystal panel and a backlight light source, or a self-emissive display.

The plane mirror 3 reflects the display light L emitted by the display device 2 toward the reflector 4.

The reflector 4 further reflects the display light L reflected by the plane mirror 3 and emits it toward the windshield 200. The reflector 4 is a concave mirror with a reflective film formed by vapor deposition or other means on the surface of a base material made of synthetic resin. The reflector 4 has a first shaft S1 and a second shaft S2 at both ends in the direction of the rotation axis A, and adjusts the reflection angle of the display light L by rotating around the direction of the rotation axis A with the first shaft S1 (see Figure 4) and the second shaft S2 as fulcrums. The reflector 4 will be described in more detail later.

The display light L reflected by the reflector 4 passes through a light-transmitting cover 11 provided at the opening 10 of the housing 1 and heads toward the windshield 200. The display light L that reaches the windshield 200 and is reflected forms a virtual image of the notification image (a display image visible to an observer E) at a position F in front of the windshield 200 (see Figure 1), while also transmitting light from the front. In this way, the head-up display device 100 allows the observer E (mainly the driver of the vehicle) to view both the virtual image and the external scenery that actually exists ahead.

The reflector rotation mechanism 5 rotates the reflector 4 around the rotation axis A, and as shown in FIG. 2 etc., includes a first rotation support part 7 that rotatably supports the first shaft part S1 of the reflector 4, a second rotation support part 8 that rotatably supports the second shaft part S2 of the reflector 4, and a rotation drive part 9 that is connected to the second shaft part S2 side of the reflector 4 and drives the reflector 4 to rotate. The reflector rotation mechanism 5 will be described in detail later.

In Figures 1 to 8, the direction parallel to the rotation axis A is designated as the Y direction (vehicle width direction), the direction perpendicular to the Y direction on a horizontal plane as the X direction (vehicle length direction), and the direction perpendicular to the Y and X directions as the Z direction (vehicle height direction). In the following, to facilitate understanding of the configuration of the reflecting unit 4 and the reflecting unit rotation mechanism 5, the direction indicated by the arrow indicating the Y direction will be designated as the "+Y direction" and the opposite direction as the "-Y direction," and the various components of the reflecting unit 4 and the reflecting unit rotation mechanism 5 will be described accordingly. Similarly, the direction indicated by the arrow indicating the X direction will be designated as the "+X direction" and the opposite direction as the "-X direction," and the direction indicated by the arrow indicating the Z direction will be designated as the "+Z direction" and the opposite direction as the "-Z direction."

The circuit board (not shown) is disposed in a predetermined position within the housing 1, for example, and is a printed circuit board on which a control unit (not shown) consisting of a microcontroller that combines a CPU, RAM, ROM, and other computing devices and storage devices is mounted. The control unit of the circuit board is electrically connected to each of the display 2 and the rotation drive unit 9. The control unit acquires vehicle status information transmitted via a communication line from an external device (not shown), such as a vehicle ECU (Electronic Control Unit), and drives the display 2 accordingly (i.e., causes the display 2 to display a predetermined notification image). The head-up display device 100 also includes an input means (not shown) that allows a user, such as an observer E, to adjust the angle of the reflector 4 (this input means may be an external device electrically connected to the control unit). The control unit drives the rotation drive unit 9 to rotate the reflector 4 by the desired angle around the rotation axis A in response to the user's input via the input means. Adjusting the angle of the reflector 4 in this manner allows a virtual image to be displayed at an appropriate position that matches the height of the occupant's line of sight.

[Details of the Reflection Unit and Reflection Unit Rotation Mechanism]
The reflecting unit 4 and the reflecting unit rotating mechanism 5 will now be described in detail with reference to FIGS.

(Reflector)
The reflecting portion 4 is a concave mirror in which a reflective film is formed by vapor deposition or other means on the surface of a substrate made of a synthetic resin material. A cyclic olefin resin, which has high fluidity and hardness and therefore good positioning accuracy, is selected as the synthetic resin material that forms the substrate of the reflecting portion 4. Specific examples of cyclic olefin resins include cycloolefin polymer (COP) and cyclic olefin copolymer (COC).

The reflecting unit 4 integrally comprises a concave mirror portion 41 formed on the surface, rear reinforcing ribs 42 protruding from the periphery of the rear surface, a first shaft portion S1 protruding in the +Y direction from the +Y end, and a plate-shaped fixing portion 43 protruding in the -Y direction from the -Y end. The first shaft portion S1 is rotatably supported by a first rotation support portion 7, and a separate shaft member 6 is screwed to the fixing portion 43. The fixing structure of the fixing portion 43 and shaft member 6 will be described in detail later.

The shaft member 6 is made of a resin with lower rigidity than cyclic olefin resin, such as polycarbonate (PC) or a polymer alloy of polycarbonate and polyethylene terephthalate (PET) (PC/PET).

The shaft member 6 integrally comprises a fixed support portion 61, a second shaft portion S2, and a connecting lever portion 62. The fixed support portion 61 fixedly supports the fixed portion 43 of the reflector 4. The second shaft portion S2 protrudes from the fixed support portion 61 in the -Y direction and is rotatably supported by the second rotation support portion 8. The connecting lever portion 62 protrudes from the fixed support portion 61 in the +X direction and is connected to the rotation drive portion 9.

With this configuration, the reflector 4 made of cyclic olefin resin is rotated, but a holder for holding the back surface of the reflector 4 is not required. Furthermore, the second shaft S2 side, which receives the driving force of the rotational drive unit 9, is constructed from a separate shaft member 6 with lower rigidity than the cyclic olefin resin, reducing the possibility of cracks occurring in the reflector 4 due to the driving force of the rotational drive unit 9. Furthermore, the first shaft S1 side, which does not receive the driving force of the rotational drive unit 9, is integrally formed with the reflector 4, reducing the number of parts and simplifying the structure compared to when the first shaft S1 side is constructed from a separate member.

As shown in Figures 2 and 8, the fixed support portion 61 of the shaft member 6 has a fixed portion abutment surface (not shown), a reinforcing rib 61a, a positioning protrusion 61b, and a screw hole (not shown). The +X side surface of the fixed portion 43 of the reflector 4 abuts against the fixed portion abutment surface. The reinforcing rib 61a protrudes in the -X direction from the edge of the fixed portion abutment surface. The reinforcing rib 61a not only reinforces the shaft member 6 but also functions to position the fixed portion 43. Multiple positioning protrusions 61b are formed on the fixed portion abutment surface and engage with positioning holes 43a formed in the fixed portion 43 to position the fixed portion 43. Multiple screw holes are formed on the fixed portion abutment surface, and screws 63 that connect the fixed portion 43 of the reflector 4 and the fixed support portion 61 of the shaft member 6 are threaded into them.

The fixing portion 43 of the reflector 4 includes multiple positioning holes 43a and multiple screw insertion holes 43b. The multiple positioning holes 43a engage with the positioning protrusions 61b to position the fixing portion 43. The screw insertion holes 43b are holes through which screws 63 are inserted. The screws 63 thread into threaded holes on the shaft member 6 through the screw insertion holes 43b, thereby connecting the fixing portion 43 of the reflector 4 to the fixing support portion 61 of the shaft member 6. At this time, a resin washer 64 is interposed between the screw head 63a of the screw 63 and the fixing portion 43 of the reflector 4. The washer 64 is a resin washer made of a resin with lower rigidity than cyclic olefin resin. The fixing portion 43 of the reflector 4 is screwed to the shaft member 6 while sandwiched between the shaft member 6, which has lower rigidity than cyclic olefin resin, and the washer 64. This reduces the load acting on the fixing portion 43 of the reflector 4, which is made of cyclic olefin resin, and suppresses the occurrence of cracks, compared to when the fixing portion 43 is screwed to the shaft member 6 without using a resin washer 64.

As shown in Figures 2 to 4, the first shaft portion S1 is integrally formed with the reflecting unit 4 at the +Y-direction end via the pedestal portion 44. The pedestal portion 44 has a generally U-shape when viewed from the X direction, with the first shaft portion S1 protruding from its tip surface. The first shaft portion S1 has a cylindrical shaft portion 45 with a through hole 45a and three spherical portions 46 arranged at 120° intervals around the cylindrical shaft portion 45. An inclined surface 45b is formed at the tip of the cylindrical shaft portion 45. The cylindrical shape of the first shaft portion S1 and the provision of multiple spherical portions 46 at predetermined intervals reduce the occurrence of sink marks (dents or depressions caused by molding shrinkage) during molding using a mold, such as injection molding.

(First rotation support part)
2 to 6, the first rotation support section 7 includes a first support member 71 and a first elastic member 72. The first support member 71 is made of, for example, a predetermined synthetic resin, and is attached to the housing 1 to make it immobile relative to the housing 1. The first elastic member 72 is made of a metal leaf spring such as aluminum, having a generally U-shaped cross section. The first elastic member 72 is disposed so as to press the first shaft section S1 against the first support member 71.

As shown in FIG. 5, the first support member 71 has a first hole 71a consisting of a cylindrical hole slightly larger than the cylindrical shaft portion 45, and a second hole 71b that communicates with the first hole 71a. The cylindrical shaft portion 45 is inserted through the first hole 71a and the second hole 71b, with the first hole 71a accommodating the cylindrical shaft portion 45 and the second hole 71b accommodating the spherical portion 46. Furthermore, the inner surface forming the second hole 71b is formed with sliding surfaces shaped along the side surfaces of a triangular pyramid with a height in the direction of the rotation axis A, and these sliding surfaces abut in pairs against the spherical portion 46. The +Y-direction end face of the first support member 71 is formed with a protrusion 71c that surrounds the first hole 71a and protrudes in the +Y direction.

As shown in Figures 4 and 6, the first elastic member 72 is a leaf spring with a U-shaped cross section that is sandwiched between one end 72a and the other end 72b. One end 72a of the first elastic member 72 has a hole 72c, and the other end 72b has a spherical convex portion 72d that is convex toward the hole 72c. In addition, one end 72a of the first elastic member 72 has an inclined portion 72e that is bent outward, and the other end 72b of the first elastic member 72 has a hook portion 72f on the inside of the end.

As shown in Figure 6, the first shaft portion S1 is assembled to the first support member 71 so that the cylindrical shaft portion 45 is inserted into the first hole portion 71a and the tip end portion (inclined surface 45b) of the cylindrical shaft portion 45 protrudes from the first hole portion 71a.

The first elastic member 72 is attached to the first shaft portion S1 assembled to the first support member 71. The first elastic member 72 is attached so that the inner surface of one end portion 72a contacts or is close to the convex portion 71c of the first support member 71, the tip end of the cylindrical shaft portion 45 is inserted into the hole portion 72c, and the convex portion 72d of the other end portion 72b contacts or is close to the base end peripheral portion of the through-hole 45a.

When the first elastic member 72 is attached to the first shaft S1 assembled to the first support member 71 in this manner, the first support member 71 and the first shaft S1 are sandwiched between the inner surfaces of one end 72a and the other end 72b of the first elastic member 72, and the first shaft S1 is pressed and fixed to the first support member 71. This positions the reflector 4 in the direction of the rotation axis A. The first support member 71 and the first shaft S1 are in substantial point or line contact with the spherical portion 46 and the second hole portion 71b, and the first shaft S1 is rotatably supported by the first support member 71 with contact resistance minimized.

When attaching the first elastic member 72, the inclined portion 72e is guided along the inclined surface 45b of the cylindrical shaft portion 45, making it easier to attach. After attachment, one end 72a of the first elastic member 72 is prevented from falling off by inserting the tip of the cylindrical shaft portion 45 into the hole portion 72c, and the other end 72b is prevented from falling off by engaging the hook portion 72f with the base portion 44.

Lubricating grease is applied to the sliding area between the first shaft portion S1 and the first rotation support portion 7. Because cyclic olefin resin melts in oil-based grease, silicone-based grease is selected for the grease applied to the sliding area between the first shaft portion S1 and the first rotation support portion 7. This makes it possible to lubricate the sliding area between the first shaft portion S1 and the first rotation support portion 7 while avoiding melting of the first shaft portion S1, which is made of cyclic olefin resin.

(Second rotation support part)
7 and 8 , the second rotation support portion 8 includes a second support member 81 and a second elastic member 82. The second support member 81 is made of, for example, a predetermined synthetic resin, and is attached to the housing 1 to be immobile relative to the housing 1. The second elastic member 82 is made of a leaf spring made of metal such as aluminum. The second elastic member 82 is disposed so as to press the second shaft portion S2 against the second support member 81.

The second support member 81 has a support portion 81a, a screw hole portion 81b, and a locking portion 81c. The support portion 81a is a bearing that supports the second shaft portion S2. The screw hole portion 81b is a hole for screwing the second support member 81 together with the second elastic member 82 to the housing 1. The locking portion 81c is a through hole into which the hook portion 82b of the second elastic member 82, described below, is locked.

The second elastic member 82 is a leaf spring with a through-hole 82a on the +X direction side and a hook 82b at its -X direction end. When the second elastic member 82 is fixed by inserting a screw (not shown) into the through-hole 82a and the screw hole 81b with the hook 82b inserted into the locking portion 81c, the pressing portion 82c comes into contact with the second shaft S2 supported by the support portion 81a. In other words, the through-hole 82a and hook 82b are formed perpendicular to the rotation axis A and sandwich the support portion 81a, and the pressing portion 82c is positioned opposite the support portion 81a. This presses the second shaft S2 against the support portion 81a.

Furthermore, the second elastic member 82 has a bent portion 82d formed between the through-hole portion 82a and the pressing portion 82c. If this bent portion 82d were not formed, and the second elastic member 82 were to be distorted around the through-hole portion 82a due to tightening with the screw, a gap could be created between the second shaft portion S2 and the pressing portion 82c. In this case, vibrations caused by the vehicle traveling, etc., could be transmitted to the head-up display device 100, causing it to vibrate, potentially resulting in abnormal noise.

On the other hand, if the bent portion 82d is formed, even if distortion occurs in the second elastic member 82 around the through-hole portion 82a due to tightening with the screw, this distortion will not be transmitted to the pressing portion 82c on the -X direction side of the bent portion 82d, reducing the possibility of a gap occurring between the second shaft portion S2 and the pressing portion 82c.

Furthermore, a handle portion 82e that bends and extends upward (in the +Z direction) is formed at the end of the second elastic member 82 in the +X direction. The worker assembling the head-up display device 100 can hold this handle portion 82e while assembling the device, improving assembly ease.

(Rotational drive unit)
The rotation drive unit 9 includes a frame 91, a motor 92, a feed screw shaft 93, and a feed member 94. The frame 91 fixedly supports the motor 92 and rotatably supports the feed screw shaft 93. The frame 91 also restricts rotation of the feed member 94 around the feed screw shaft 93. The motor 92 is a stepping motor that generates a driving force for rotating the reflecting unit 4 around a rotation axis A. The feed screw shaft 93 is connected to an output shaft (not shown) of the motor 92 and rotates forward and reverse in response to the drive of the motor 92. The feed member 94 includes a threaded portion 94a that threadably engages with the feed screw shaft 93 and a connecting portion 94b that abuts and connects to the connecting lever portion 62 of the shaft member 6. When the feed screw shaft 93 rotates in response to the drive of the motor 92, the feed member 94, whose rotation around the feed screw shaft 93 is restricted by the frame 91, moves in the +Z direction and the −Z direction along the axis of the feed screw shaft 93. As a result, the reflecting portion 4 rotates around the rotation axis A via the connecting lever portion 62, and the reflection angle of the reflecting portion 4 is changed.

Although the embodiments have been described in detail above, they are not limited to specific embodiments, and various modifications and variations are possible within the scope of the claims. It is also possible to combine all or several of the components of the above-described embodiments.

REFERENCE SIGNS LIST 100 Head-up display device 1 Housing 10 Opening 11 Light-transmitting cover 2 Display 3 Plane mirror 4 Reflecting portion 41 Concave mirror portion 42 Rear surface reinforcing rib 43 Fixing portion 43a Positioning hole 43b Screw insertion hole 44 Base portion 45 Cylindrical shaft portion 45a Through hole 45b Inclined surface 46 Spherical portion 5 Reflecting portion rotation mechanism 6 Shaft member 61 Fixed support portion 61a Reinforcing rib 61b Positioning protrusion 62 Connecting lever portion 63 Screw 63a Screw head 64 Washer 7 First rotation support portion 71 First support member 71a First hole portion 71b Second hole portion 71c Convex portion 72 First elastic member 72a One end portion 72b Other end portion 72c Hole portion 72d Convex portion 72e Inclined portion 72f Hook portion 8 Second rotation support portion 81 Second support member 81a Support portion 81b Screw hole portion 81c Locking portion 82 Second elastic member 82a Through hole portion 82b Hook portion 82c Pressing portion 82d Bent portion 82e Handle portion 9 Rotation drive portion 91 Frame 92 Motor 93 Feed screw shaft 94 Feed member 94a Threaded portion 94b Connecting portion S1 First shaft portion S2 Second shaft portion

Claims (3)

a display (2) that emits display light that displays an image;
a reflecting portion (4) that reflects the display light;
A head-up display device (100) including a rotation drive unit (9) that rotates the reflecting unit around a rotation axis,
The reflecting portion is made of a cyclic olefin resin, has a first shaft portion (S1) integrally formed at one end along the rotation axis direction, and has a separate shaft member (6) connected to the other end,
the shaft member is made of a resin having lower rigidity than a cyclic olefin resin, and has a second shaft portion (S2) along the rotation axis direction and a connecting lever portion (62) connected to the rotation drive portion ,
a first rotation support portion (7) that rotatably supports the first shaft portion;
and a second rotation support portion (8) that rotatably supports the second shaft portion,
The first rotation support portion determines the position of the reflecting portion in the direction of the rotation axis . a display (2) that emits display light that displays an image;
a reflecting portion (4) that reflects the display light;
A head-up display device (100) including a rotation drive unit (9) that rotates the reflecting unit around a rotation axis,
The reflecting portion is made of a cyclic olefin resin, has a first shaft portion (S1) integrally formed at one end along the rotation axis direction, and has a separate shaft member (6) connected to the other end,
the shaft member is made of a resin having lower rigidity than a cyclic olefin resin, and has a second shaft portion (S2) along the rotation axis direction and a connecting lever portion (62) connected to the rotation drive portion,
The other end of the reflecting part integrally has a plate-shaped fixing part (43) that is fixed to the shaft member via a screw,
The fixing portion is fixed to the shaft member by a screw while being sandwiched between the shaft member and a washer (64) formed of a resin having lower rigidity than cyclic olefin resin . a display (2) that emits display light that displays an image;
a reflecting portion (4) that reflects the display light;
A head-up display device (100) including a rotation drive unit (9) that rotates the reflecting unit around a rotation axis,
The reflecting portion is made of a cyclic olefin resin, has a first shaft portion (S1) integrally formed at one end along the rotation axis direction, and has a separate shaft member (6) connected to the other end,
the shaft member is made of a resin having lower rigidity than a cyclic olefin resin, and has a second shaft portion (S2) along the rotation axis direction and a connecting lever portion (62) connected to the rotation drive portion,
The head-up display device , wherein silicone grease is applied to the first shaft portion .