Head-up display device

Abstract

To provide a head-up display device capable of suppressing distortion in a dust-proof cover.SOLUTION: A head-up display device displays a virtual image by projecting display light onto a windshield. The head-up display device includes: a case 50 that has an opening through which the display light passes toward the windshield; a dust-proof cover 52 that covers the opening and transmits the display light; an elastically deformable double-sided adhesive tape 71 which has an adhesive surface 71b formed on one surface, and an adhesive surface 71a formed on the other surface, and in which the adhesive surface 71b adheres to the case 50; and an elastically deformable double-sided adhesive tape 72 which has an adhesive surface 72b formed on one surface, and an adhesive surface 72a formed on the other surface, and in which the adhesive surface 72b adheres to the adhesive surface 71a, and the adhesive surface 72a adheres to the dust-proof cover 52.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In the head-up display device described in Patent Document 1, a cover glass is attached to an upper case with double-sided tape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-149177 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, there is a risk that distortion will occur in the cover glass due to the difference in thermal expansion coefficient between the cover glass and the upper case caused by temperature changes.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a head-up display device that can suppress distortion of a dust cover. [Means for solving the problem]

[0006] In order to achieve the above object, a head-up display device according to the present disclosure includes: A head-up display device that displays a virtual image by projecting display light onto a projection member, a case having an opening through which the display light passes toward the projection member; a dust cover that covers the opening and through which the display light passes; a first double-sided tape that is elastically deformable and has a first adhesive surface formed on one side and a second adhesive surface formed on the other side, the first adhesive surface being attached to the case; and a second elastically deformable double-sided tape having a third adhesive surface formed on one side and a fourth adhesive surface formed on the other side, the third adhesive surface adhering to the second adhesive surface and the fourth adhesive surface adhering to the dust cover. Effect of the Invention

[0007] According to the present disclosure, distortion of the dust cover can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a head-up display device mounted on a vehicle according to a first embodiment of the present disclosure. [Diagram 2] 2 is a schematic cross-sectional view of an upper case, a double-sided tape, and a dust cover according to the first embodiment of the present disclosure. FIG. [Diagram 3] 1 is a schematic plan view of a head-up display device according to a first embodiment of the present disclosure. [Figure 4] FIG. 3 is a schematic enlarged view of an area III in FIG. 2 according to the first embodiment of the present disclosure. [Diagram 5] FIG. 3 is a schematic enlarged view of area IV in FIG. 2 according to the first embodiment of the present disclosure. [Figure 6] FIG. 3 is a schematic enlarged view of region IV in FIG. 2 according to a modified example of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) A head-up display device according to a first embodiment of the present disclosure will be described with reference to the drawings. 1, the head-up display device 1 is mounted inside an instrument panel P, which is an example of a covering member located substantially below a windshield WS of a vehicle C. This covering member is not limited to the instrument panel P, and may be an exterior case covered with synthetic resin or leather.

[0010] The head-up display device 1 emits display light Li that displays an image toward a windshield WS, which is the front glass of a vehicle C. The display light Li is reflected by the windshield WS and reaches an eye point EP of a viewer (mainly a driver of the vehicle C). As a result, a virtual image V is displayed so as to be visible to the viewer. The virtual image V includes vehicle information such as vehicle speed.

[0011] The head-up display device 1 includes a display device 20, a concave mirror 32, a correction mirror 31, a case 50, and a dust cover 52.

[0012] The display device 20 is a projector that emits display light Li. The display device 20 may be any of a type having a liquid crystal display panel and a lighting device, a type having an organic EL (Electro Luminescence), a type having a DMD (Digital Micro mirror Device), and a type having a MEMS (Micro Electro Mechanical Systems) mirror.

[0013] 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 display device 20 so that the display light Li is emitted to the windshield WS.

[0014] The correction mirror 31 is, for example, a free-form mirror. The correction mirror 31 is a mirror having a free-form shape that is concave in the height direction and convex in the vehicle width direction (perpendicular to the paper surface of FIG. 1). Due to this shape, the display light Li is reflected so as to cross in the height direction. The correction mirror 31 reflects the display light Li toward the concave mirror 32. The correcting mirror 31 may be a plane mirror, or the correcting mirror 31 may be omitted.

[0015] The concave mirror 32 is a reflecting member that reflects the display light Li toward the dust cover 52 so as to magnify the display light Li. The display light Li that has passed through the dust cover 52 is reflected by the windshield WS and reaches the viewer.

[0016] The case 50 is made of light-shielding resin or metal, and is a hollow, approximately rectangular parallelepiped. The resin is, for example, polypropylene (PP), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), or polybutylene terephthalate (PBT). The metal is, for example, magnesium (Mg) or aluminum (Al).

[0017] The case 50 includes a lower case 53, an upper case 54, a dust cover 52, and a plurality of double-sided tapes 71 and 72 (see FIGS. 2 and 3).

[0018] 1, the lower case 53 is box-shaped and opens upward. The concave mirror 32 and the correction mirror 31 are housed inside the lower case 53. The display device 20 is provided on the outer lower surface of the lower case 53. The lower case 53 is formed with a through hole 53h through which the display light Li from the display device 20 passes.

[0019] The upper case 54 functions as a lid that closes the upper opening of the lower case 53. An opening 51 is formed in the upper case 54 at a position facing the windshield WS. In other words, the upper case 54 has a generally rectangular frame shape that surrounds the opening 51. The opening 51 is closed by a dust cover 52. The edge of the opening of the instrument panel P is located opposite the outer periphery of the upper surface of the dust cover 52.

[0020] 2, the upper case 54 has an attachment surface 50a to which the double-sided tapes 71 and 72 are attached. The attachment surface 50a faces upward, is located on the periphery of the opening 51, is concavely curved in the front-to-rear direction of the vehicle (the forward direction F and the rear direction B in FIG. 2), and has a uniform shape in the vehicle width direction (the direction perpendicular to the paper surface of FIG. 2).

[0021] The dust cover 52 is made of a light-transmitting material through which the display light Li passes, for example, a light-transmitting resin such as acrylic or polycarbonate, or transparent glass. The dust cover 52 is curved in a concave shape in the front-rear direction of the vehicle and has a curved plate shape that is uniform in the vehicle width direction. The end of the dust cover 52 in the rear direction B (the direction closer to the viewer) is located higher in the height direction than the end of the dust cover 52 in the front direction F.

[0022] 2 and 3, the dust cover 52 includes a light-shielding region 52b formed on the outer periphery of the dust cover 52, and a light-transmitting region 52a that is an area surrounded by the light-shielding region 52b. The light-transmitting region 52a is transparent so that the display light Li passes through toward the windshield WS.

[0023] The light-shielding area 52b is an area that does not transmit light. The light-shielding area 52b is an area for hiding parts of the members constituting the head-up display device 1 that do not need to be visible from the outside, such as the attachment surface 50a of the case 50. The light-shielding area 52b is formed by printing a dark color (e.g., black) on both the upper and lower surfaces of the dust cover 52. In addition, the light-shielding area 52b may be formed by attaching a dark-colored sheet such as a baffle form instead of printing. Also, the light-shielding area 52b may be formed on only one of the upper and lower surfaces of the dust cover 52.

[0024] 4 and 5, the two double-sided tapes 71, 72 are elastically deformable adhesive members that fix the dust cover 52 to the attachment surface 50a of the case 50. The double-sided tapes 71, 72 are made of the same material and have the same thickness, and are laminated between the outer periphery of the lower surface of the dust cover 52 and the attachment surface 50a.

[0025] The double-sided tapes 71 and 72 are made of the same material, that is, a base material made of polyolefin (PO) or polyethylene (PE), and have adhesive surfaces 71a, 71b, 72a, and 72b with an acrylic adhesive formed on both sides of the base material. The adhesive strength of each of the adhesive surfaces 71a, 71b, 72a, and 72b of the double-sided tapes 71 and 72 is the same. The thickness of each of the double-sided tapes 71 and 72 is 0.1 mm to 2.0 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm, or 1.1 mm. The double-sided tapes 71 and 72 are arranged so as to overlap over the entire area when viewed in the thickness direction. The material of the base material of the double-sided tapes 71 and 72 is not limited to polyolefin (PO) or polyethylene (PE), but may be made of acrylic or polyurethane (PU).

[0026] As shown in FIG. 3, each of the double-sided tapes 71 and 72 has a rectangular plate shape and is arranged in a frame shape over the entire periphery of the application surface 50a. As shown in FIGS. 4 and 5, the double-sided tapes 71 and 72 have upper adhesive surfaces 71a and 72a (on the light-shielding area 52b side) and lower adhesive surfaces 71b and 72b (on the attachment surface 50a side). The adhesive surface 71b of the double-sided tape 71 is adhered to the attachment surface 50a. Specifically, the adhesive surface 71b of the double-sided tape 71 is adhered to the outer periphery of the attachment surface 50a. An adhesive surface 71 a of the double-sided tape 71 is adhered to an adhesive surface 72 b of the double-sided tape 72 . An adhesive surface 72a of the double-sided tape 72 is adhered to the dust cover 52. Specifically, the adhesive surface 72a of the double-sided tape 72 is adhered to the outer periphery of the lower surface of the light-shielding area 52b, which faces the attachment surface 50a.

[0027] The two double-sided tapes 71, 72 deform due to stress caused by the difference in thermal expansion coefficient between the dustproof cover 52 and the upper case 54. This makes it possible to suppress distortion of the dustproof cover 52 and the decrease in visibility of the virtual image V caused by this distortion. A heat resistance test was performed at 110°C for 1000 hours on the upper case 54 to which the dustproof cover 52 was attached by the double-sided tapes 71, 72, but no distortion of the dustproof cover 52 was observed.

[0028] Next, a description will be given of the operation of attaching the dust cover 52 to the upper case 54 with the double-sided tapes 71 and 72. This operation is performed by a person or a robot. Before this operation, release paper (not shown) is attached to the adhesive surfaces 71a and 72a of the double-sided tapes 71 and 72. First, the adhesive surface 71b of the double-sided tape 71 is adhered to the attachment surface 50a. Then, the release paper (not shown) is peeled off from the adhesive surface 71a of the tape 71. Next, the adhesive surface 72b of the double-sided tape 72 is adhered onto the adhesive surface 71a of the double-sided tape 71. Then, the release paper (not shown) is peeled off from the adhesive surface 72a of the double-sided tape 72. Next, the outer periphery of the lower surface of the dust cover 52 is adhered onto the adhesive surface 72a of the double-sided tape 72. This fixes the dust cover 52 to the upper case 54 via the double-sided tapes 71 and 72. In this example, the same double-sided tapes 71 and 72 are oriented in the same direction, so that the double-sided tapes 71 and 72 can be easily stacked. This completes the installation of the dust cover 52 onto the upper case 54.

[0029] (effect) According to the first embodiment described above, the following effects are achieved. (1) The head-up display device 1 displays a virtual image V by projecting the display light Li onto a windshield WS, which is an example of a projection target member. The head-up display device 1 includes a case 50 having an opening 51 through which the display light Li passes toward the windshield WS, a dust cover 52 that covers the opening 51 and through which the display light Li passes, a double-sided tape 71 that is an example of a first elastically deformable double-sided tape, which has an adhesive surface 71b that is an example of a first adhesive surface formed on one side and an adhesive surface 71a that is an example of a second adhesive surface formed on the other side, and the adhesive surface 71b is adhered to the case 50, and a double-sided tape 72 that is an example of a second elastically deformable double-sided tape, which has an adhesive surface 72b that is an example of a third adhesive surface formed on one side and an adhesive surface 72a that is an example of a fourth adhesive surface formed on the other side, and the adhesive surface 72b is adhered to the adhesive surface 71a and the adhesive surface 72a is adhered to the dust cover 52. According to this configuration, the double-sided tapes 71 and 72 are elastically deformed, so that distortion of the dustproof cover 52 due to the difference in thermal expansion coefficient between the dustproof cover 52 and the upper case 54 can be suppressed.

[0030] (2) The double-sided tapes 71 and 72 are formed to have the same thickness, material, and orientation. According to this configuration, the double-sided tapes 71 and 72 can be attached easily.

[0031] (3) When the case 50 is made of metal and the dust cover 52 is made of resin, the difference in thermal expansion coefficient between the case 50 and the dust cover 52 becomes large. This makes it easy for the dust cover 52 to warp. Therefore, as described above, it is particularly useful to suppress the warping of the dust cover 52 by stacking a plurality of double-sided tapes 71, 72.

[0032] Second embodiment A head-up display device according to a second embodiment of the present disclosure will be described with reference to the drawings. This embodiment differs from the first embodiment in that the adhesive strengths of the two sides of the double-sided tape are different. The following description will focus on the differences from the first embodiment.

[0033] The adhesive strength between the adhesive surfaces 71b and 72a is greater than the adhesive strength between the adhesive surfaces 71a and 72b that are bonded to each other. The adhesive surfaces 71a, 72b are made of the same material and have adhesive on both sides, so that even if the adhesive strength is weak, it is unlikely to lead to peeling. On the other hand, the attachment surface 50a and the dust cover 52 have no adhesive strength themselves and are made of different materials from the adhesive surfaces 71b and 72a, so that the adhesive strength of the adhesive surfaces 71b and 72a needs to be high.

[0034] (effect) According to the second embodiment described above, the following effects are achieved. (1) The adhesive surfaces 71b and 72a each have a first adhesive strength, and the adhesive surfaces 71a and 72b each have a second adhesive strength that is weaker than the first adhesive strength. According to this configuration, peeling of the double-sided tapes 71 and 72 can be suppressed.

[0035] The present disclosure is not limited to the above-described embodiments and drawings. Modifications (including deletion of components) can be made as appropriate within the scope of the present disclosure. An example of a modification will be described below.

[0036] (Modification) In the above embodiment, the double-sided tapes 71 and 72 are made of the same material, but they may be made of different materials. By using the double-sided tapes 71 and 72 made of different materials, the characteristics of the double-sided tapes 71 and 72 can be mixed. For example, the adhesive surface 71b of the double-sided tape 71 may be made of an adhesive having better adhesive performance to the case 50 than the adhesive surface 72b of the double-sided tape 72, and the adhesive surface 72a of the double-sided tape 72 may be made of an adhesive having better adhesive performance to the dust cover 52 than the adhesive surface 71a of the double-sided tape 71. In this way, by using double-sided tapes 71 and 72 with different specifications according to the objects to be adhered, more suitable adhesive performance can be achieved. The above-mentioned adhesive performance can be measured by the peel strength of the double-sided tapes 71 and 72.

[0037] In the above embodiment and modified example, the two double-sided tapes 71, 72 are formed to have the same thickness, but this is not limiting, and they may be formed to have different thicknesses. For example, as shown in Fig. 6, the thickness of the double-sided tape 171 may be formed to be thicker than the thickness of the double-sided tape 172. Because the double-sided tape 171 is thick, it is easy to elastically deform so as to absorb distortion of the dust cover 52. Furthermore, when attaching the thin double-sided tape 171 to the thick double-sided tape 172, the double-sided tape 171 is less likely to become misaligned with respect to the double-sided tape 172. This improves workability. The present invention is not limited to this modification, and the double-sided tape 171 may be formed thinner than the double-sided tape 172.

[0038] In the above embodiment and modified example, two double-sided tapes are laminated, but this is not limiting, and three or more double-sided tapes may be laminated. For example, when one new double-sided tape is added between the two double-sided tapes 71 and 72, the upper adhesive surface of this new double-sided tape is adhered to the adhesive surface 72b, and the lower adhesive surface of this new double-sided tape is adhered to the adhesive surface 71a.

[0039] In the above embodiment, the head-up display device 1 is mounted on a vehicle C, but it may be mounted on a vehicle other than the vehicle C, such as an airplane or a ship, or it may not even be mounted on a vehicle. Furthermore, the projected member is not limited to the windshield WS, but may be a dedicated combiner. [Explanation of symbols]

[0040] 1 Head-up display device 20 Display device 31 Correction mirror 32 concave mirror 50 cases 50a Attachment surface 51 Opening 52 Dust cover 52a Translucent area 52b Shading area 53 Lower case 53h through hole 54 Upper case 71,72,171,172 Double-sided tape 71a,71b,72a,72b Adhesive surface C Vehicle Li display light P. Instrument panel V Virtual Image EP Eyepoint WS Windshield

Claims

1. A head-up display device that displays a virtual image by projecting display light onto a projection member, a case having an opening through which the display light passes toward the projection member; a dust cover that covers the opening and through which the display light passes; a first double-sided tape that is elastically deformable and has a first adhesive surface formed on one side and a second adhesive surface formed on the other side, the first adhesive surface being attached to the case; a second double-sided tape that is elastically deformable and has a third adhesive surface formed on one side and a fourth adhesive surface formed on the other side, the third adhesive surface adhering to the second adhesive surface, and the fourth adhesive surface adhering to the dust cover; Head-up display device.

2. The first double-sided tape and the second double-sided tape are formed to have the same thickness and are made of the same material. The head-up display device according to claim 1 .

3. the first adhesive surface and the fourth adhesive surface each have a first adhesive strength; The second adhesive surface and the third adhesive surface each have a second adhesive strength that is weaker than the first adhesive strength. The head-up display device according to claim 1 or 2.

4. The first double-sided tape and the second double-sided tape are formed of different materials and / or thicknesses. The head-up display device according to claim 1 or 2.

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