Head-up display device

Abstract

To provide a head-up display device which achieves improvement of durability against disturbance.SOLUTION: A head-up display 1 is mounted on the interior of an instrument panel P located substantially below a windshield WS of a vehicle C and includes: a display which generates display light Li projected on the windshield WS; a case 50 which houses the display and has an opening 51 for allowing the display light Li to pass to the windshield WS; a cover glass 52 which covers the opening 51 and has a light transmission area 52a, through which the display light Li passes, and a light shielding area 52b which is formed so as to surround the light transmission area 52a; and a double side tape 53 which sticks the cover glass 52 to the case 50. The double side tape 53 sticks a translucent cover P at a portion covered with the instrument panel P.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a head-up display device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, head-up display devices have been known having configurations as disclosed in, for example, Patent Document 1 and Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-102305 A [Patent Document 2] International Publication No. 2020-153474 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional configurations, there was a risk of variation in resistance to external disturbances in the cover glass (the dustproof sheet (24) in Patent Document 1 and the light-transmitting cover (50) in Patent Document 2) covering the opening of the case of the head-up display device. SUMMARY OF THE PRESENT EMBODIMENT In view of the above-mentioned problems, an object of the present invention is to provide a head-up display device having improved resistance to disturbances. [Means for solving the problem]

[0005] In order to achieve the above object, a head-up display device according to the present invention comprises: A head-up display device mounted inside a cover member located substantially below a windshield of a vehicle, a display that generates display light that is projected onto the windshield; a case that houses the display and has an opening through which the display light passes to the windshield; a light-transmitting cover covering the opening and having a light-transmitting region through which the display light passes and a light-shielding region positioned so as to surround the light-transmitting region; an adhesive member for attaching the light-transmitting cover to the case; Equipped with The adhesive member adheres the light-transmitting cover to the area covered by the covering member. [Brief description of the drawings]

[0006] [Figure 1] 1 is a diagram showing a cross section of a head-up display 1 according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a main portion of a head-up display 1. FIG. [Diagram 3] An external view of a head-up display 1 through an instrument panel P when viewed from a viewpoint EP. [Figure 4] FIG. 1 is a diagram illustrating a conventional head-up display. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a head-up display device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. 1. First embodiment <1-1. About the composition> <1-2. About Figure 2> 2. Variations

[0008] [1. First embodiment] <1-1. About the composition> 1 is a diagram showing a cross section in the YZ plane of a head-up display 1 (HUD1), which is an example of a head-up display device. The HUD1 is mounted inside a covering member located substantially below a windshield WS of a 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.

[0009] The HUD1 emits display light Li to the windshield WS. The display light Li is generated by lighting means and display means inside the HUD1. The generated display light Li travels through an optical system (a correction mirror 31 and a concave mirror 32 described below) and is emitted from an opening 51 in a case 50. By visually recognizing the display light Li reflected by the windshield WS from a viewpoint EP, an occupant (user) can see a rectangular virtual image V at a position several meters to several tens of meters away from the windshield WS in the direction F. In this case, the user in the driver's seat can use the display output by the HUD1.

[0010] In addition, the ray connecting the center of a screen 23, which is an example of a display surface described later, and the center of the eye box, which is the center of the space in which the virtual image V is visible, is called Gatley GR.

[0011] The virtual image V displays information that is highly necessary to alert the occupant (user), such as vehicle information such as the speed and engine RPM of the vehicle C, route guidance displays such as turn-by-turn and maps, and warning displays such as blind spot indicators and speed limit exceeding warnings. This provides a driving environment that reduces the need to move the viewpoint and adjust the focal length of the eyes. The virtual image V includes characters and icons indicating this information as well as a background portion, and when viewed from the occupant in a plan view, it has, for example, a substantially rectangular shape.

[0012] The HUD 1 includes a projector 21 , a field lens 22 , a screen 23 , a correction mirror 31 , a concave mirror 32 , a control board (not shown), a case 50 , and a cover glass 52 .

[0013] The projector 21, the field lens 22, and the screen 23 are an example of a configuration of a display that emits display light Li from a display surface (screen 23), and are not limited to the following configuration.

[0014] The projector 21 emits projection light PL by a field sequential method, and may be a known projector that includes a red light source, a green light source, a blue light source, a dichroic mirror, a DMD (Digital micro-mirror Device), a prism, a projection lens (including an exit pupil), etc.

[0015] The red, green, and blue light sources are composed of LEDs of each color, and are turned on in sequence according to signals sent from an electrically connected control board. When turned on, each light source emits a light beam of each color (illumination light) toward a dichroic mirror located above the light source in the drawing. Instead of being composed of LEDs of each color, it can also be composed of a white LED with a transmissive color filter of each color provided in the emission direction, or it can be composed of a rotating transmissive color filter with each color evenly applied to the outer edge.

[0016] The dichroic mirror is a reflective / transmissive member that can transmit or reflect light in a specific wavelength range, and transmits / reflects each color light beam in the direction where the DMD is located.

[0017] A DMD (Digital Micro-mirror Device) is a light modulation element that reflects light in a specified direction by changing the angle of tiny mirrors arranged in a matrix on the incidence surface of the illumination light in response to a control signal from a control board. In this embodiment, the light rays of each color that are transmitted / reflected by the dichroic mirror are reflected in the direction of the prism or in other directions that do not affect the display of the virtual image V in accordance with the angle of the mirror.

[0018] The prism transmits each color of illumination light incident on the DMD, and each color of light reflected from the DMD is held by the prism so as to be reflected toward the projection lens.

[0019] The projection lens is composed of at least one lens, and emits the light reflected by the prism as projection light PL so as to form an image on a screen.

[0020] The projector 21 emits projection light PL by selectively reflecting the light from each color light source with the above configuration.

[0021] The field lens 22 is disposed near the screen 23 and is a lens that adjusts the light distribution of the projection light PL to make the image particularly clear in the peripheral portion. For this reason, it is desirable that the screen 23 and the field lens 22 are disposed in positions that are approximately parallel to each other.

[0022] The screen 23 is a transmissive screen that can be composed of a microlens array, a diffusion plate, etc., and is a member that diffuses and transmits the projection light PL as display light toward the correction mirror 31. The screen 23 is illuminated by the projection light PL and emits display light Li.

[0023] With the above configuration, a display that emits display light Li from the display surface (screen 23) is configured.

[0024] The correction mirror 31 and the concave mirror 32 constitute a reflective optical system. The reflective optical system reflects the display light Li emitted by the screen 23 so that the light is emitted to the windshield WS.

[0025] The correction mirror 31 is, for example, a free-form mirror. The correction mirror 31 is a mirror having a free-form shape, particularly a concave shape in the vertical direction of the drawing and a convex shape in the depth direction of the drawing. Due to this shape, the display light Li is reflected so as to cross in the vertical direction of the drawing.

[0026] The concave mirror 32 is a reflective member that magnifies the first display light and reflects it toward the opening (cover glass 52) of the case 50. The correcting mirror 31 and the concave mirror 32 can be made of synthetic resin 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 performing aluminum deposition on the mirror surface.

[0027] The mirrors that make up the optical system may take other forms. For example, a multilayer interference film with different film thicknesses may be formed on one side of a plate-shaped glass substrate by a method such as vapor deposition, and the film may be a cold mirror that transmits infrared light and reflects at least visible light, a mirror with polarizing properties, or an ordinary flat mirror.

[0028] The cover glass 52, which is an example of a light-transmitting cover, can be made of a transparent synthetic resin base material having a uniform thickness and a plate shape, such as PMMA or polycarbonate. The cover glass 52 is attached while being curved so as to cover the opening 51 of the case 50. The detailed structure will be described later.

[0029] The control board may be a microcomputer equipped with a memory unit such as a ROM or RAM (not shown) used for storing predetermined programs and various data, a memory area during calculations, a CPU for performing calculations according to the predetermined programs, an input / output interface, etc. 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, based on vehicle information received from an external in-vehicle device.

[0030] The case 50 is a container for which a resin or metal molded product can be used, and has an opening 51 for emitting the display light Li to the outside of the device, with a cover glass 52 affixed so as to cover this opening 51. Inside, the projector 21, field lens 22, screen 23, correction mirror 31, concave mirror 32, and control board are fixed by known means such as fitting, locking, adhesion with an adhesive member, or screwing with screws.

[0031] <1-2. About Figure 2> 2 is a cross-sectional view of a main part of the HUD 1 taken along the YZ plane. The configuration of the HUD 1 will be described with reference to FIG.

[0032] The cover glass 52 has a light-transmitting region 52a and a light-shielding region 52b. As described above, the light-transmitting region 52a is transparent so as to emit the display light Li to the windshield WS.

[0033] The light-shielding area 52b is an area that does not transmit light, unlike the light-transmitting area 52a. The light-shielding area 52b is an area for hiding parts of the members constituting the HUD 1 that do not need to be visible from the outside, such as the attachment surface 50a of the case 50. In the present disclosure, the light-shielding area 52b is shown in an embodiment in which both the upper and lower surfaces of the cover glass 52 are printed in a dark color (e.g., black). However, the present disclosure is not limited to this, and printing may be performed on only one of the surfaces, or the light-shielding area 52b may be formed by attaching a dark-colored sheet such as a baffle form instead of printing.

[0034] Double-sided tape 53, which is an example of an adhesive member, attaches cover glass 52 to attachment surface 50a of case 50. The adhesive member is not limited to double-sided tape 53, and may be a silicone adhesive or epoxy adhesive that does not have a base material.

[0035] Conventionally, the configurations of Patent Document 1 and Patent Document 2 have adopted a configuration in which a cover glass is attached to a case in a light-shielding area. Moreover, since the cover glass of the head-up display transmits display light to the correct position through a light-transmitting area in the center, it is undesirable for the position to shift or vibrate. Therefore, as shown in the prior art documents, the adhesive member is attached close to the light-transmitting area so as to always follow the light-transmitting area. Note that FIG. 4 shows a head-up display 2 configured from this technical viewpoint.

[0036] However, the inventors of the present application have found that the above-mentioned configuration may actually reduce the product's resistance to disturbances. Specifically, the inventors have found that there is a risk that the state of the cover glass may change due to disturbances such as the incidence of sunlight.

[0037] This is because, when the adhesive member is attached at a location below the light-shielding area and along the light-transmitting area, the adhesive member is attached at a location that is not covered by the instrument panel. As a prerequisite, the opening (second opening) of the instrument panel is generally made wider than the light-transmitting area. This is because, as described above, it is not preferable for a member through which the display light passes to obstruct the passage of the display light, and a member such as the instrument panel, which has a relatively lower positioning accuracy than the cover glass, needs to have an opening wider than the light-transmitting area with a margin. Therefore, in the conventional configuration, the adhesive member is attached to a portion of the light-shielding area that is not covered by the instrument panel.

[0038] However, in the conventional configuration, the adhesive member located in the area not covered by the instrument panel is heated by the light-shielded area heated by sunlight, which may cause gas generation or deformation.

[0039] Therefore, the present disclosure discloses a mode in which the double-sided tape 53 is attached to a location covered by the instrument panel P. In addition, it is desirable to attach the double-sided tape 53 at a position separated from the light-transmitting region 52a and the opening 51.

[0040] FIG. 3 is a diagram showing the appearance of the HUD 1 through the instrument panel P when viewed from the vicinity of a viewpoint EP. In the above explanation, a configuration has been shown in which double-sided tape 53 is provided in a location covered by instrument panel P to avoid heating by sunlight SL. However, in this configuration, attachment surface 50a is positioned so as to protrude outside the device, which increases the size of the device.

[0041] Therefore, in the present disclosure, the light-transmitting area 52a is formed in a shape surrounded by curves and straight lines, and this shape includes a first edge E (the boundary edge between the light-transmitting area 52a and the light-shielding area 52b) of the light-transmitting area 52a located at the rear (driver's seat side) of the vehicle C, and the double-sided tape 53 attaches the cover glass 52 to the case 50 at the location of the light-shielding area 52b covered by the instrument panel P on the side corresponding to the first edge E (the edge at the end of the cover glass 52 on the first edge E side), and the double-sided tape 53 attaches the cover glass 52 at locations along the light-transmitting area 52a on the other sides.

[0042] The first side E is a side of the outer shape of the light-transmitting area 52a that is located at the rear of the vehicle, and the light-shielding area 52b near this side is more likely to be exposed to sunlight than other parts. This is because the HUD 1 is housed inside the instrument panel P. Therefore, the double-sided tape 53 corresponding to the first side E is provided only in a location covered by the instrument panel P, and the other double-sided tape 53 is provided in locations not covered by the instrument panel P. With this configuration, the increase in size of the device is kept to a minimum. [2. Modifications]

[0043] Although the vehicle head-up display of the present invention has been described using the configuration of the above-mentioned embodiment as an example, the present invention is not limited to this, and it goes without saying that various improvements and changes in display are possible in other configurations as well without departing from the gist of the present invention.

[0044] For example, although the embodiment in which the projector 21, the field lens 22, and the screen 23 constitute the display has been exemplified, the present invention is not limited to this. For example, in section 1-1, the field lens 22 is not an essential component, so a display using an electronic display such as a liquid crystal display element or an organic EL display element as a display surface may be applied.

[0045] Furthermore, the projector 21 may be configured to use liquid crystal on silicon (LCOS) or thin film transistors (TFTs) as light modulation elements.

[0046] Also, the embodiment has been shown in which the correction mirror 31 and the concave mirror 32 are used as the mirrors that make up the optical system, but these may be other mirror members, such as a plane mirror or a cold mirror.

[0047] Also, a mode has been shown in which the projection light PL is directly projected onto the screen 23. The projection light PL may be appropriately reflected by a mirror between the screen 23 and the projector 21. [Explanation of symbols]

[0048] C Vehicle V Virtual Image EP Perspective WS Windshield P Instrument panel (covering material) E First side PL projection light Li display light SL solar GR Gatley 1 Head-up display (HUD) 21 Projector 22 Field Lens 23 Screens 31 Correction mirror 32 concave mirror 50 cases 50a Attachment surface 51 Aperture 52 Cover glass (translucent cover) 52a Translucent area 52b Print area 53 Double-sided tape (adhesive material)

Claims

1. A head-up display device mounted inside a covering member located substantially below a windshield of a vehicle, a display that generates display light that is projected onto the windshield; a case that houses the display and has an opening through which the display light passes to the windshield; a light-transmitting cover covering the opening and having a light-transmitting region through which the display light passes and a light-shielding region positioned so as to surround the light-transmitting region; an adhesive member for attaching the light-transmitting cover to the case; Equipped with The adhesive member adheres the light-transmitting cover to the area covered by the covering member. Head-up display device.

2. The adhesive member is In a portion of the outer shape of the light-transmitting region that is located at the rear of the vehicle, the light-transmitting cover is attached to a portion that is covered by the covering member; In the other portions, the light-transmitting cover is attached along the light-transmitting region. The head-up display device according to claim 1 .

3. The cover member is an instrument panel. The head-up display device according to claim 1 .

Images