Mirror unit and head-up display device

Abstract

To provide a reflector and a head-up display device.SOLUTION: A mirror unit 30 of the present disclosure reflects incident display light Li, and the mirror unit comprises: a first mirror 31 that forms a reflecting surface 31a reflecting the display light Li; a holder 32 that holds the first mirror 31; a shaft 33a that defines the axis of rotation A of the first mirror 31 and is formed in the holder 32; and a cover 34 that covers an upper end side face part of the first mirror 31. The upper end side face part is formed of a covered area 31b covered by the cover 34 and an exposed area 31c not covered by the cover 34.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a mirror unit and a head-up display device.

Background Art

[0002] In Patent Document 1, a reflection device having a mirror part (131) and a holder part (132) is disclosed. The holder part (132) has an outer peripheral part (132a), and the outer peripheral part (132a) covers the side surface of the mirror part (131) to prevent unnecessary light from reaching the driver. Further, the reflection device is configured as a part of a head-up display.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The reflection device provided in a head-up display may reflect display light. In order to stably reflect the display light, it is desirable that resonance hardly occurs in the reflection device. For this purpose, it is desirable to improve the resonance frequency indicated by the natural vibration of the reflection device. However, in conventional head-up display devices, there is still room for improvement in improving the resonance frequency.

[0005] An object of the present invention is to provide a head-up display device that is easy to improve the resonance frequency, paying attention to the above problems.

Means for Solving the Problems

[0006] To achieve the above object, the mirror unit according to the present invention is a mirror unit that reflects incident display light, A first mirror that forms a reflective surface that reflects the aforementioned display light, A holder for holding the first mirror, The rotation axis of the first mirror is defined, and the axis formed in the holder is defined. The first mirror comprises a cover that covers the upper end side portion of the first mirror, The upper end side portion is formed by a covered area that is covered by the cover and an exposed area that is not covered by the cover.

[0007] To achieve the above objective, the head-up display device according to the present invention A head-up display device that displays a virtual image by projecting the aforementioned display light onto a projection target member, A display that emits the aforementioned display light, The above-mentioned mirror unit that reflects the display light, A second mirror that reflects the aforementioned display light onto the projected member, The housing comprises an opening that allows the aforementioned display light to pass through and holds the mirror unit and the second mirror, The housing has a light-shielding wall that extends along the range through which the display light passes through the opening, The light-shielding wall covers the exposed area. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing a vehicle C according to an embodiment of this disclosure. [Figure 2] A diagram showing a cross-section of HUD1 according to an embodiment of this disclosure. [Figure 3a] A diagram showing the external appearance of the mirror unit 30 according to an embodiment of this disclosure. [Figure 3b] A diagram showing the external appearance of the mirror unit 30 according to an embodiment of this disclosure. [Figure 3c] A diagram showing the external appearance of the mirror unit 30 according to an embodiment of this disclosure. [Figure 4] A diagram showing the assembled state of the mirror unit 30 according to the embodiment of this disclosure. [Figure 5]A diagram showing the appearance of the HUD1 according to an embodiment of the present disclosure.

Embodiments for Carrying out the Invention

[0009] Hereinafter, a mirror unit and a head-up display device (HUD) of the present disclosure will be described by taking embodiments as examples and using the accompanying drawings. 1. First Embodiment <1-1. Regarding the Configuration> <1-2. Regarding the Holder 32> <1-3. Example of Effects> 2. Modified Example

[0010] [1. First Embodiment] <1-1. Regarding the Configuration> FIG. 1 is a diagram schematically showing a state in which a head-up display 1 (HUD1), which is an example of a head-up display device, is mounted on a vehicle C. The traveling direction of the vehicle C (right direction in the drawing) is represented by the direction F, and the opposite direction of the direction F is represented by the direction B. The gravitational direction (downward direction in the drawing) is represented by the direction D, and the opposite direction of the direction D is represented by the direction U. The left side (depth direction in the drawing) with respect to the traveling direction is represented by the direction L, and the opposite direction of the direction L is represented by the direction R. The axis along which the directions F and B are located is represented by the axis Z. The axis along which the directions D and U are located is represented by the axis Y. The axis along which the directions L and R are located is represented by the axis X. While the appearance of the vehicle C has an approximately bilaterally symmetric shape, the HUD1 is located closer to the left side from the center of the vehicle C. Also, the vehicle C is a so-called left-hand drive vehicle.

[0011] The HUD1 is mounted inside a covering member located substantially below the projection member (windshield WS) of the vehicle C. The covering member may be, for example, an instrument panel P that houses instruments and a center information display of the vehicle C, or an exterior case covered with synthetic resin or leather.

[0012] The HUD1 projects the display light Li onto the windshield WS. The display light Li is generated by the lighting means and display means inside the HUD1. The generated display light Li is transmitted through an optical system (the mirror unit 30 and concave mirror 40 described later), and is projected from the opening 51 of the upper case 50a. The occupant (user) can visually recognize the display light Li reflected by the windshield WS from the viewpoint EP, and can see a rectangular virtual image V at a position several meters to several tens of meters away from the windshield WS in the F direction. In this case, the user sitting in the driver's seat can utilize the display output by the HUD1.

[0013] Note that the light ray connecting the center of the display image on the display 10 (especially the display surface) and the eye box center, which is the center of the space where the virtual image V can be visually recognized, is called the gutter ray GR.

[0014] On the virtual image V, information that is highly necessary to attract the attention of the occupant (user) is displayed, such as vehicle information such as the speed of the vehicle C and the engine speed, route guidance displays such as turn-by-turn and maps, and warning displays such as blind spot indicators and speed limit violation warnings. As a result, a driving environment with reduced need for line-of-sight movement and eye focus distance adjustment is provided. The display of the virtual image V includes characters and icons indicating this information, as well as a background portion. The outer shape of the virtual image V is, for example, substantially rectangular in a plan view seen from the occupant. The virtual image V is inclined, with the lower end of the virtual image V imaging in the front and the upper end of the virtual image V imaging on the back side.

[0015] FIG. 2 is a diagram showing a cross-section of the HUD1 in the Y-axis - Z-axis plane. The HUD1 includes a display 10, a mirror unit 30, a concave mirror 40, a control board (not shown), a case 50, and a cover glass 52.

[0016] The display 10 emits display light Li toward the mirror unit 30. The display 10 can be configured to emit display light Li in a way that, for example, a display device such as a TFT (Thin Film Transistor) liquid crystal is illuminated by illumination light emitted from a light source such as an LED (Light Emitting Diode), causing the display light to emit from the display surface. In this case, the TFT liquid crystal or LED light source receives display control signals, light emission control signals, and power from control means on an electrically connected circuit board or from external control means to perform display operations.

[0017] Other possible configurations for display 10 include those using electronic displays such as organic EL, and configurations using projectors and screens with DMD (Digital Micro Mirror Device), LCOS (Liquid Crystal on Silicon), or TFT (Thin Film Transistor).

[0018] The mirror unit 30 and the concave mirror 40 constitute a projection optical system that reflects the incident display light Li. The projection optical system reflects the display light Li emitted by the display 10 to project it onto the windshield WS. The projection optical system forms an optical surface that increases the size of the virtual image V and reduces the distortion of the virtual image V.

[0019] The mirror unit 30 has a first mirror 31 and a holder 32. The first mirror 31 is formed from a reflective surface 31a and a substrate, and is, for example, a free-form mirror. The reflective surface 31a is formed from a visible light reflective film formed by aluminum vapor deposition or the like. The reflective surface 31a is formed on the surface of the substrate. The substrate holds the reflective surface 31a. The substrate can be made of synthetic resins such as PC-PET (polycarbonate polyethylene terephthalate) or PMMA (polymethyl methacrylate resin, acrylic), or inorganic glass. It is desirable that the substrate material be selected to maintain good surface accuracy of the reflective surface. The surface of the substrate has a gently concave shape, for example, to exert refractive power, and the reflective surface 31a is also formed along this shape. The holder 132 will be described in detail later. The first mirror 31 is pivotally supported by the case 50 (especially the bearing stay) and the motor unit 20 via the holder 32.

[0020] The first mirror 31 is roughly plate-shaped and therefore has side surfaces. In particular, as shown in Figure 3, the first mirror forms an upper side surface composed of a covered area 31b and an exposed area 31c. The covered area 31b is the portion of the upper side surface that is covered by the cover 34. The exposed area 31c is the portion of the upper side surface that is not covered by the cover 34. It is desirable for the side surfaces of the mirror to be covered in general, but if all side surfaces are covered, the holder will become bulky, and the possibility of a decrease in the resonant frequency will increase. Therefore, by partially covering the covered area, the size of the cover can be reduced, and the resonant frequency can be increased.

[0021] The motor unit 20 is a power device that provides a rotational moment to rotate the mirror unit 30. The motor unit 20 comprises, for example, a motor, a lead screw, and a slider. The motor rotates the lead screw. The lead screw moves the slider in a linear direction. The slider presses against the holder 32 (particularly the supported part 38) it contacts, thereby providing a rotational moment to the mirror unit 30. The motor unit 20 may take any other form as long as it is configured to rotate the mirror unit 30, and the rotational moment may be provided by transmitting the power of the motor to the mirror unit 30 via a reduction gear.

[0022] The concave mirror 40 is an example of a second mirror and reflects the display light Li toward the opening 51 (cover glass 52) of the case 50. The concave mirror 40 can be made from synthetic resins such as PC-PET (polycarbonate polyethylene terephthalate) or PMMA (polymethyl methacrylate resin, acrylic) or inorganic glass as a base material. These mirrors can be formed by applying aluminum vapor deposition or the like to the mirror surface. The concave mirror 40 is fixed to the case 50 with double-sided tape.

[0023] The mirrors constituting the optical system may be in other forms. For example, a multilayer interference film with varying thicknesses can be formed on one side of a plate-shaped glass substrate by methods such as vapor deposition. This can result in a cold mirror that transmits infrared light and reflects at least visible light, a mirror with polarization properties, or even a regular flat mirror.

[0024] A cover glass 52, which is an example of a light-transmitting cover, can be made of a transparent, plate-shaped material. The cover glass 52 is attached to the adhesive surface 50d while curving to cover the opening 51 of the case 50. The cover glass 52 has a base material, a hard coat layer, a light-shielding printing layer, etc.

[0025] The base material is a transparent, plate-shaped base material. The base material 53 is made from a material mainly composed of translucent synthetic resins such as polycarbonate or PMMA (polymethyl methacrylate resin, acrylic), and is molded into a plate with an approximately uniform thickness (for example, about 0.5 mm). The base material 53 is molded using methods such as rolling, injection molding, or die-cutting, depending on the material. The base material 53 is, for example, molded into a uniform flat plate shape during the molding process, and then given the configuration described later. The base material 53 may also be molded during the molding process to conform to the shape of the adhesive surface of the case 50.

[0026] The hard coat layer is made of a material that is harder than the base material, preventing scratches that may occur on the base material. The hard coat layer may be applied to one side or to both sides.

[0027] The light-shielding printed layer is applied to the back surface (the side in direction D) of the hard coat layer in an area where the display light Li does not need to pass through when the cover glass 52 is viewed from above. The light-shielding printed layer is formed, for example, by printing ink using screen printing. The light-shielding printed layer hides components that do not need to be visible from the outside of the device, such as the adhesive surface 50d on the upper case 50a to which the cover glass 52 is attached.

[0028] The control board can be a microcomputer equipped with a storage unit such as ROM or RAM (not shown) used for storing predetermined programs and various data, and as a memory area during calculations, a CPU for performing calculations according to the predetermined program, and input / output interfaces. Based on vehicle information received from external in-vehicle equipment, the control board generates images to be displayed on the display means, controls the display of the display means, and controls the illuminance of the lighting means.

[0029] The upper case 50a and lower case 50b form a housing and can be made of synthetic resin or a rigid metal. The upper case 50a has an opening 51 for emitting display light Li to the outside of the device, and a cover glass 52 is attached to cover this opening 51. Inside the housing, the display 10, mirror unit 30, concave mirror 40, and control board are fixed by known means such as fitting, locking, bonding with adhesive members, and screwing with screws. The upper case 50a forms a light-shielding wall 50c that extends along the passage range (travel range, travel direction) of the display light Li. Since the light-shielding wall 50c is a particularly visible area from the viewpoint EP, it is desirable that light reflection be particularly suppressed by baffle foam or paint.

[0030] <1-2. Regarding Holder 32> The detailed configuration of holder 32 will be explained with reference to Figures 3a to 5. The holder 32 has a shaft 33a, a connecting portion 33b, an adhesive surface 33c, a cover 34, a reinforcing portion 35, a shaft cover 36, a connecting portion 36a, and a second shaft cover 37. The shaft 33a is the axis that defines the rotation center of the first mirror 31. The shaft 33a is formed in two places that sandwich the holder 32 in the longitudinal direction. One shaft 33a is pivotally supported in the case 50. The other shaft 33a is pivotally supported in the mirror unit 30. This pivoting allows the mirror unit 30 to rotate around the rotation axis A.

[0031] The connecting portion 33b is a component that forms the main part of the holder 32, linearly connecting the two shafts 33a. The strength of the connecting portion 33b greatly affects the resonant frequency exhibited by the mirror unit 30. Specifically, the more the strength of the connecting portion 33b is improved by forming ribs or the like, the higher the resonant frequency of the mirror unit 30.

[0032] The adhesive surface 33c is the surface to which the first mirror 31 is attached, formed in the middle of the connecting portion 33b. The shape of the adhesive surface 33c may be flat or curved. The adhesive surface 33c is formed in two places in the middle of the connecting portion 33b, preferably at positions that straddle the center of gravity of the first mirror.

[0033] The cover 34 is a cover that covers the area of ​​the mirror held by the holder 32 that is not visible. For example, the cover 34 covers only the covered area 31b of the upper side surface of the first mirror 31. In this way, by having the cover 34 cover only a portion of the upper side surface (the covered area 31b), the size of the holder 32 can be minimized, and the resonant frequency of the holder 32 can be easily increased.

[0034] The cover 34 may contact the covered area 31b to position the first mirror 31. In this case, it is desirable that the cover 34 be formed not only on the upper side surface but also on either the left or right side surface so that the first mirror 31 can be positioned in multiple directions.

[0035] The beam 34b is a reinforcing portion of the cover 34 that extends from the end 34a on the boundary side between the covered area 31b and the exposed area 31c toward the axis 33a.

[0036] The reinforcing section 35 is a reinforcing beam that increases the rigidity of the holder 32. In particular, it is formed to follow the perpendicular line drawn from the end 34a of the cover 34 to the connecting section 33b, and is formed to be thicker than the cover 34.

[0037] The shaft cover 36 is formed on the connecting portion 33b and, together with the second shaft cover 37, covers the shaft 33a. The shaft cover 36 and the second shaft cover 37 cover not only the shaft 33a but also the space where the motor unit 20 and other components are located so that they are not visible. The connecting portion 36a is a connecting portion that connects the shaft cover 36 and the second shaft cover 37.

[0038] As shown in Figure 5, the axis cover 36 is visible from the viewpoint EP regardless of the orientation of the mirror unit 30. On the other hand, the second axis cover 37 is formed to overlap with the gap in the light-shielding wall 50c so as to prevent areas that do not need to be visible from being seen through the gap between the axis cover 36 and the light-shielding wall 50c.

[0039] The supported portion 38 is the point that contacts the mirror unit 30 in order to transmit the power generated by the motor unit 20 to the mirror unit 30.

[0040] Figure 5 shows the appearance of the HUD1. In particular, the HUD1 shown in Figure 5 is in the state where the mirror unit 30 is in the parking position.

[0041] As mentioned above, the mirror unit 30 is held in a rotatable position, and this rotation allows adjustment of the projection range on the windshield WS. This adjustment widens the visible area of ​​the virtual image V. The position of the mirror unit 30 in which such a virtual image V can be seen from the viewpoint EP is called the display position.

[0042] On the other hand, the mirror unit 30 can also be positioned in a location where the display light does not reach the windshield WS. This position is called the parking position. In this parking position, the reflective surface (reflective surface 31a) of the rotatable mirror (first mirror 31) is often facing downwards (direction D), so that the display light Li is not reflected in the direction of the windshield WS. When the mirror is in the parking position, sunlight that enters through the windshield WS is prevented from reaching the display 10 via reflection from the mirror and heating the display 10.

[0043] In this disclosure, the range in which the cover 34 covers the upper side surface of the first mirror 31 is set based on the state in which the mirror unit 30 is in the parking position (Figure 5). In other words, the range in which the cover 34 is formed is set based on the parking position in which the upper side surface is most exposed when the mirror is facing downwards. This makes it easy to set the most effective range in which the cover 34 is formed.

[0044] Furthermore, as shown in Figure 5, the exposed area 31c of the first mirror 31 is covered by the light-shielding wall 50c formed on the upper case 50a. This covers the exposed area 31c that cannot be completely covered by the cover 34, thereby suppressing the generation of stray light.

[0045] In particular, the cover 34 covers the upper side portion, especially the outside of the vehicle C. The HUD1 of this disclosure is for a left-hand drive vehicle, and since Figure 5 is a view from the direction F of the vehicle C, the outside of the vehicle C is in the right direction L in the drawing. This configuration makes it easier to achieve miniaturization of both the cover 34 and the entire device.

[0046] <1-3. Examples of Effects> Firstly, the mirror unit of this disclosure is A mirror unit 30 that reflects incident display light Li, A first mirror 31 that forms a reflective surface 31a that reflects the display light Li, A holder 32 that holds the first mirror 31, The rotation axis A of the first mirror 31 is defined, and the axis 33a formed in the holder 32, The first mirror 31 is equipped with a cover 34 that covers the upper side portion of the first mirror 31, The upper side portion is formed by a covered area 31b that is covered by the cover 34 and an exposed area 31c that is not covered by the cover 34.

[0047] This configuration minimizes the area where a cover is formed over the sides of the mirror, resulting in a mirror unit that is more likely to improve its resonant frequency.

[0048] Secondly, the mirror unit of this disclosure, in the first configuration, The holder 32 forms a beam 34b that connects the end portion 34a of the cover 34 to the shaft 33a.

[0049] This configuration results in a mirror unit that is more effective at improving the resonant frequency.

[0050] Thirdly, the mirror unit of this disclosure, in the first configuration, The cover 34 also covers the reflective surface 31a from the upper side.

[0051] This configuration results in a mirror unit that not only easily improves the resonant frequency but also more effectively prevents stray light generated at the edge of the reflective surface 31a.

[0052] Fourthly, the mirror unit of this disclosure is The first mirror 31 is positioned in at least one direction by contacting the cover 34. Mirror unit according to claim 1

[0053] This configuration results in a mirror unit that allows for easy positioning of the mirror while also improving the resonant frequency.

[0054] Fifth, the head-up display device of the present disclosure is A head-up display device 1 that displays a virtual image V by projecting display light Li onto a windshield WS, A display 10 that emits display light Li, A mirror unit consisting of one of the first to fourth configurations that reflects the display light Li, A concave mirror 40 that reflects the display light Li onto the windshield WS, It comprises an aperture 51 that allows display light Li to pass through, and a case 50 that holds the mirror unit 30 and the concave mirror 40, Case 50 forms a light-shielding wall 50c that extends along the direction of propagation of the display light Li passing through the aperture 51. The light-shielding wall 50c covers the exposed area formed by the upper side surface of the first mirror.

[0055] This configuration results in a head-up display device that can effectively suppress stray light generation while improving the resonant frequency.

[0056] Sixth, the head-up display device of the present disclosure, in the fifth configuration, It was installed in vehicle C, The cover covers only the portion of the upper side of the first mirror 31 that is on the outside relative to the center of the vehicle C.

[0057] This configuration results in a head-up display device that achieves both improved resonant frequency and miniaturization.

[0058] Seventh, the head-up display device of the present disclosure, in the fifth configuration, The mirror unit 30 is rotatable to a display position in which the display light Li reaches the windshield WS, and a parking position in which the display light Li does not reach the windshield WS. The cover 34 covers the covered area 31b when the mirror unit 30 is in the parking position.

[0059] This configuration allows for a head-up display device that improves the resonant frequency while also achieving miniaturization by minimizing the cover.

[0060] [2. Variant] Although the head-up display device of the present invention has been described using the configuration of the above-described embodiment as an example, the present invention is not limited thereto, and various improvements and changes to the display are possible in other configurations without departing from the spirit of the present invention.

[0061] For example, Figure 3a shows an example where only the left side of the upper end of the first mirror 31 is exposed as the exposed area 31c. However, the first mirror may have only the right side exposed as the exposed area, or both sides in the left-right direction may have exposed areas. In this case, it is desirable to form a beam between the right end formed on the cover and the corresponding axis.

[0062] An embodiment in which a mirror unit 30 and a concave mirror 40 are applied as mirrors constituting the optical system is shown. However, these may be other mirror members, such as a plane mirror or a cold mirror. [Explanation of Symbols]

[0063] C Vehicle V Illusion EP perspective WS Windshield P Instrument panel (covering component) E First side PL projection light Li display light SL solar GR Gutley 1. HUD (Head-Up Display) 10 displays 20 Motor Units 30 Mirror Unit 31 First Mirror 31a Reflective surface 31b Covered area 31c exposed area 32 holders 33a axis 33b Connection part 33c Adhesive surface 34 Cover 34a Cover end 34b Beam 35 Reinforcement section 36 Axis cover 36a Connecting part 37. Second axis cover 38 Supported part 40 concave mirror 50 cases 50a Upper case 50b Lower case 50c light-blocking wall 50d adhesive surface 51 Aperture 52 Cover glass (translucent cover)

Claims

1. A mirror unit that reflects incident display light, A first mirror that forms a reflective surface that reflects the aforementioned display light, A holder for holding the first mirror, The rotation axis of the first mirror is defined, and the axis formed in the holder is defined. The first mirror comprises a cover that covers the upper end side portion of the first mirror, The upper end side portion is formed by a covered area covered by the cover and an exposed area not covered by the cover. Mirror unit.

2. The holder forms a beam that connects the end of the cover and the shaft. The mirror unit according to claim 1.

3. The cover extends from the upper side portion to the reflective surface. The mirror unit according to claim 1.

4. The first mirror, by contacting the cover, positions itself toward at least one direction. The mirror unit according to claim 1.

5. A head-up display device that displays a virtual image by projecting the aforementioned display light onto a projection target member, A display that emits the aforementioned display light, A mirror unit according to claim 1 that reflects the aforementioned display light, A second mirror that reflects the aforementioned display light onto the projected member, The housing comprises an opening that allows the aforementioned display light to pass through, and a housing that holds the mirror unit and the second mirror, The housing has a light-shielding wall that extends along the range through which the display light passes through the opening, The light-shielding wall covers the exposed area. Head-up display device.

6. It is mounted on the vehicle, The cover covers only the portion of the upper side surface that corresponds to the outside of the vehicle. The head-up display device according to claim 5.

7. The mirror unit is rotatable to a display position in which the display light reaches the projection target and a parking position in which the display light does not reach the projection target. The cover covers the covering area when the mirror unit is positioned in the parking position. The head-up display device according to claim 5.

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