JP2022149177A - head-up display device - Google Patents

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

The present invention relates to a head-up display device.

2. Description of the Related Art As a conventional head-up display device, configurations disclosed in Patent Document 1 and Patent Document 2, for example, are known.

JP 2017-102305 A International Publication No. 2020-153474

In the conventional configuration, the cover glass covering the opening of the case of the head-up display device (the dustproof sheet (24) in Patent Document 1 and the translucent cover (50) in Patent Document 2) has variations in resistance to disturbance. There was a risk of it happening.
SUMMARY OF THE INVENTION An object of the present invention is to provide a head-up display device with improved resistance to disturbances, focusing on the above-described problems.

In order to achieve the above object, the head-up display device according to the present invention includes:
A head-up display device mounted inside a covering member positioned substantially below a windshield of a vehicle,
a display that produces display light that is projected onto the windshield;
a case containing the display and having 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 surrounding the light-transmitting region;
an adhesive member for attaching the translucent cover to the case;
with
The adhesive member adheres the translucent cover to a portion covered by the cover member.

The figure which shows the cross section of the head-up display 1 in this embodiment. FIG. 2 is a cross-sectional view of main parts of the head-up display 1; FIG. 3 is an external view of the head-up display 1 through the instrument panel P when viewed from a viewpoint EP. The figure which illustrates the conventional head-up display.

Hereinafter, a head-up display device of the present disclosure will be described as an embodiment with reference to the accompanying drawings.

1. First Embodiment <1-1. About the configuration>
<1-2. About Fig. 2>
2. Modification

[1. First Embodiment]
<1-1. About the configuration>
FIG. 1 is a cross-sectional view of a head-up display 1 (HUD1), taken along the YZ plane, which is an example of a head-up display device. The HUD 1 is mounted inside a cover member positioned substantially below the windshield WS of the vehicle C. As shown in FIG. The cover member may be, for example, an instrument panel P that accommodates instruments, a center information display, and the like of the vehicle C, or an exterior case covered with synthetic resin or leather.

The HUD 1 emits display light Li to the windshield WS. The display light Li is generated by illumination means and display means inside the HUD 1 . The generated display light Li is emitted from the opening 51 of the case 50 by traveling through an optical system (a correction mirror 31 and a concave mirror 32 which will be described later). 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 F direction by visually recognizing the display light Li reflected by the windshield WS from the viewpoint EP. . In this case, a user sitting in the driver's seat can use the display output from the HUD 1 .

A light ray connecting the center of a screen 23, which is an example of a display surface to be described later, and the center of an eyebox, which is the center of a space in which the virtual image V can be visually recognized, is called a gutray GR.

The virtual image V includes, for example, vehicle information such as the speed and engine speed of the vehicle C, route guidance displays such as turn-by-turn and maps, warning displays such as blind spot indicators and speed limit warnings, etc. Information that is highly necessary to call attention to is displayed. This provides a driving environment in which the need for eye movement and eye focal length adjustment is reduced. The virtual image V includes characters and icons indicating such information, as well as a background portion, and has, for example, a substantially rectangular shape when viewed from above by the occupant.

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

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

The projector 21 emits projection light PL by a field sequential method, and is composed of 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), and the like. A known projector can be applied.

The red light source, the green light source, and the blue light source are composed of LEDs of respective colors, and are sequentially lit according to signals transmitted from an electrically connected control board. When turned on, each color light beam (illumination light) is emitted toward a dichroic mirror positioned in the upper direction of the drawing of each light source. Instead of using LEDs of different colors, it is also possible to use white LEDs in which transmission type color filters of each color are provided in the emission direction, or to use rotating transmission type color filters in which each color is evenly applied to the outer edge.

The dichroic mirror is a reflecting/transmitting member capable of transmitting or reflecting light of a predetermined wavelength range, and transmits/reflects each color light in the direction in which the DMD is positioned.

A DMD, which is a digital micro-mirror device, reflects light in a predetermined direction by changing the angles of minute mirrors arranged in a matrix on the plane of incidence of illumination light according to the control signal from the control board. It is a light modulation element. In this embodiment, each color ray transmitted/reflected by the dichroic mirror is reflected in the direction of the prism and other directions that do not affect the display of the virtual image V according to the angle of the mirror.

A prism is a prism held to transmit each color of illumination light incident on the DMD and to reflect each color light reflected from the DMD toward the projection lens.

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 the screen.

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

The field lens 22 is arranged in the vicinity of the screen 23 and is a lens that adjusts the light distribution of the projection light PL in order to sharpen the image of the peripheral portion in particular. Therefore, it is desirable that the screen 23 and the field lens 22 are provided at substantially parallel positions.

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

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

The correcting mirror 31 and the concave mirror 32 constitute a reflecting optical system. The reflective optical system reflects the display light Li emitted from the screen 23 to the windshield WS.

Correction mirror 31 is, for example, a free-form surface mirror. The correcting mirror 31 is a mirror having a free-form curved surface that is concave in the longitudinal direction of the drawing and convex 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.

The concave mirror 32 is a reflecting member that magnifies the first display light and reflects it toward the opening of the case 50 (the cover glass 52). Synthetic resin such as PC-PET (polycarbonate polyethylene terephthalate) or PMMA (polymethyl methacrylate resin, acrylic) or inorganic glass can be used as the base material for the correction mirror 31 and the concave mirror 32 . These mirrors can be formed by subjecting the mirror surface to aluminum vapor deposition or the like.

The mirrors that make up the optical system may have other modes.
For example, a multilayer interference film with different film thickness is formed on one side of a plate-shaped glass substrate by a method such as vapor deposition, and a cold mirror that transmits infrared light and reflects at least visible light, or a cold mirror that has polarization characteristics. It may be a mirror having a mirror or a normal plane mirror.

The cover glass 52, which is an example of the translucent cover, can be made of a plate-shaped transparent synthetic resin substrate having a uniform thickness, and can be made of, for example, PMMA or polycarbonate. The cover glass 52 is attached while curving so as to cover the opening 51 of the case 50 . A detailed configuration will be described later.

The control board includes a storage unit such as ROM and RAM (not shown) used for storage of predetermined programs and various data and storage areas during calculation, a CPU for performing arithmetic processing according to the predetermined program, and a microcomputer provided with an input/output interface and the like. Computer can be applied. The control board generates an image to be displayed on the display means, controls the display of the display means, and controls the illuminance of the lighting means, based on the vehicle information received from the external vehicle-mounted device.

A case 50 is a container to which resin or metal moldings can be applied, has an opening 51 for emitting display light Li to the outside of the device, and has a cover glass 52 attached so as to cover the opening 51 . Inside, the projector 21, the field lens 22, the screen 23, the correction mirror 31, the concave mirror 32, and the control board are fixed by known means such as fitting, locking, bonding with adhesive members, and screwing with screws.

<1-2. About Fig. 2>
FIG. 2 is a cross-sectional view of the HUD 1 along the YZ plane. The configuration of the HUD 1 will be described with reference to FIG.

The cover glass 52 has a translucent area 52a and a light shielding area 52b.
The translucent area 52a is transparent so as to emit the display light Li to the windshield WS, as described above.

The light-blocking region 52b is a region through which light does not pass, unlike the light-transmitting region 52a. The light-shielding region 52b is a region for hiding a portion of a member constituting the HUD 1, such as the attachment surface 50a of the case 50, which does not need to be seen from the outside. The light-shielding region 52b is shown in this disclosure as being printed in a dark color (eg, black) on both the top and bottom surfaces of the cover glass 52 . It is not limited to this, and printing may be applied only to one of the surfaces, or it may be formed by pasting a dark-colored sheet such as baffle foam instead of printing.

A double-sided tape 53 , which is an example of an adhesive member, adheres the cover glass 52 to the adhesion surface 50 a of the case 50 . The adhesive member is not limited to the double-sided tape 53, and may be silicone-based adhesive or epoxy-based adhesive that does not have a base material.

Conventionally, in the configurations of Patent Documents 1 and 2, a configuration in which a cover glass is attached to a case in a light shielding region has been adopted. In addition, since the cover glass of the head-up display transmits the display light to the correct position through the translucent area in the center, it is undesirable for the cover glass to shift or vibrate. Therefore, as shown in prior art documents, the adhesive member is always adhered closely along the translucent area. FIG. 4 shows the head-up display 2 configured from the technical point of view.

However, the inventors of the present application have found that the configuration described above may rather reduce the resistance of the product to external disturbances. Specifically, the inventors have found that the state of the cover glass may change due to disturbance such as the incidence of sunlight.

This is because when the adhesive member is attached at a location along the light-transmitting region under the light-shielding region, it is attached at a location that is not covered by the instrument panel. As a premise, the opening (second opening) of the instrument panel is generally provided wider than the translucent area. This is because, as described above, the member through which the display light passes should not interfere with the passage of the display light. This is because it is necessary to provide a wide opening by holding the
Therefore, in the conventional configuration, the adhesive member is adhered to a portion of the light shielding area that is not covered by the instrument panel.

However, in the conventional configuration, there is a risk that the adhesive member positioned at a location not covered by the instrument panel will be heated by the light shielding area heated by the sunlight, causing gas or deformation.

Therefore, in the present disclosure, a mode is disclosed in which the double-sided tape 53 is attached at a location where the instrument panel P covers the double-sided tape 53 . Moreover, the double-sided tape 53 is desirably attached at a position spaced apart from the translucent area 52 a and the opening 51 .

FIG. 3 is a diagram showing the appearance of the HUD 1 through the instrument panel P when viewed from near the viewpoint EP.
In the above description, the structure in which the double-sided tape 53 is provided on the portion covered with the instrument panel P is shown in order to avoid being heated by the sunlight SL. It will be located so that it may protrude to the side, and the size of an apparatus will increase.

Therefore, in the present disclosure, the light-transmitting region 52a is formed in a shape surrounded by curved lines and straight lines, and this shape is the first side E (light-transmitting The double-sided tape 53 is attached to the instrument panel P on the side corresponding to the first side E (the edge of the cover glass 52 on the first side E side). The cover glass 52 is attached to the case 50 at the covered light shielding area 52b, and the double-sided tape 53 attaches the cover glass 52 to the other side along the light transmitting area 52a.

The first side E is the side located behind the vehicle in the outer shape of the translucent area 52a, and the light shielding area 52b near this side is more likely to be exposed to sunlight than other locations. This is because the HUD 1 is housed inside the instrument panel P.
Therefore, only the double-sided tape 53 corresponding to the first side E is provided at a location covered with the instrument panel P, and the other double-sided tapes 53 are provided at locations not covered with the instrument panel P. . This arrangement minimizes the increase in the size of the device.
[2. Modification]

Although the vehicle head-up display of the present invention has been described with the configuration of the above-described embodiment as an example, the present invention is not limited to this, and the present invention can be applied to other configurations as well. Of course, various improvements and display changes are possible without departing from the above.

For example, although the projector 21, the field lens 22, and the screen 23 have exemplified the aspect which comprises a display, it is not restricted to this. For example, in Section 1-1, since the field lens 22 is not an essential configuration, 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.

Further, the projector 21 may adopt a mode in which LCOS (Liquid Crystal On Silicon) or TFT (Thin Film Transistor) is applied as an optical modulation element.

Moreover, a mode is shown in which the correction mirror 31 and the concave mirror 32 are applied as the mirrors constituting the optical system. However, they may also be other mirror members, for example plane mirrors or cold mirrors.

Moreover, a mode in which the projection light PL is directly projected onto the screen 23 has been shown. The projection light PL may be appropriately reflected by a mirror between the screen 23 and the projector 21 .

C Vehicle V Virtual image EP Viewpoint WS Windshield P Instrument panel (cover member)
E first side

PL projection light Li display light SL sunlight GR Gatley

1 Head-up display (HUD)
21 Projector 22 Field lens 23 Screen 31 Correction mirror 32 Concave mirror 50 Case 50a Attachment surface 51 Opening 52 Cover glass (Translucent cover)
52a Translucent area 52b Print area 53 Double-sided tape (adhesive member)

Claims (3)

A head-up display device mounted inside a covering member positioned substantially below a windshield of a vehicle,
a display that produces display light that is projected onto the windshield;
a case containing the display and having 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 surrounding the light-transmitting region;
an adhesive member for attaching the translucent cover to the case;
with
The head-up display device, wherein the adhesive member adheres the translucent cover to a portion covered by the cover member. The translucent region is formed in a shape surrounded by curved lines or straight lines,
the shape includes a first side located behind the vehicle;
The adhesive member
On the side corresponding to the first side, the translucent cover is attached to a portion covered by the cover member,
The head-up display device according to claim 1, wherein the light-transmitting cover is attached to the other sides along the light-transmitting region. The head-up display device according to claim 1, wherein the covering member is an instrument panel.

Images