Display device for vehicle

Abstract

A vehicle display device (1) is provided with: a housing (2) mounted on a vehicle (100) and having an opening (21a) facing a windshield (110); an image display device (3) that is disposed inside the housing and outputs display light (Lt) of an image; a mirror (4) that is disposed inside the housing, faces the windshield via the opening, and reflects the display light toward the windshield; a transparent cover (5) disposed in the opening and having a free-form surface formed so as to have an optical function; and a suppression means (6) that is disposed at the edge of the cover and suppresses reflection of light at the end surface (53) of the cover.

Description

Technical Field

[0001] The present invention relates to a display device for a vehicle. Background Art

[0002] In the past, there are display devices for vehicles. Patent document 1 discloses a HUD device that reflects image light that has passed through a cylindrical lens on a front windshield so that a vehicle occupant can visually recognize a virtual image of the image light. In the HUD device of patent document 1, the cylindrical lens is arranged obliquely with respect to the image light so that the external light reflected by the cylindrical lens does not reach the field of view of the vehicle occupant.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-268883 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In vehicle display devices, there is still room for improvement in terms of improving visibility by suppressing ghosting caused by external light, etc. For example, when display light is projected through a transparent cover, it is preferable to suppress reflection of light at the end surface of the cover.

[0008] An object of the present invention is to provide a vehicle display device capable of suppressing reflection at an end surface of a cover.

[0009] Means for solving problems

[0010] The vehicle display device of the present invention is characterized in that it comprises: a shell, which is mounted on the vehicle and has an opening opposite to the windshield; an image display device, which is arranged inside the shell and outputs display light of the image; a reflector, which is arranged inside the shell and is opposite to the windshield via the opening and reflects the display light toward the windshield; a transparent cover, which is arranged at the opening and has a free curved surface formed to have an optical function; and a suppression unit, which is arranged at the edge of the cover and suppresses reflection of light at the end face of the cover.

[0011] Effects of the Invention

[0012] The vehicle display device according to the present invention includes a suppressing unit disposed at an edge of a cover having an optical function to suppress reflection of light at an end surface of the cover. The vehicle display device according to the present invention can suppress reflection at the end surface of the cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing a vehicle equipped with the vehicle display device according to the embodiment.

[0014] Figure 2 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0015] Figure 3 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0016] Figure 4 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0017] Figure 5 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0018] Figure 6 It is a diagram showing the path of reflected light.

[0019] Figure 7 It is a diagram showing the path of reflected light.

[0020] Figure 8 It is a diagram showing the path corresponding to the position of the eye.

[0021] Fig. 9 It is a diagram showing the path corresponding to the position of the eye.

[0022] Fig.10 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0023] Fig.11 It is a cross-sectional view of a vehicle display device according to an embodiment.

[0024] Fig.12 It is a cross-sectional view of a vehicle display device according to an embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, the vehicle display device according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited to the embodiment. In addition, the constituent elements in the following embodiment include elements that can be easily thought of by those skilled in the art or substantially the same elements.

[0026] [Implementation Method]

[0027] Reference Figures 1 to 12 , an embodiment is described. This embodiment relates to a display device for a vehicle. Figure 1 FIG. 1 is a diagram showing a vehicle equipped with a vehicle display device according to an embodiment. Figures 2 to 5 is a cross-sectional view of a vehicle display device according to an embodiment, Figure 6 and Figure 7 is a diagram showing the path of reflected light, Figure 8 and Fig. 9 is a graph showing the path corresponding to the position of the eye, Figures 10 to 12 1 and 2 are cross-sectional views of a vehicle display device according to an embodiment. In each cross-sectional view, a cross section along the vehicle front-rear direction and the vehicle up-down direction is shown.

[0028] like Figure 1 As shown, the vehicle display device 1 involved in this embodiment is a head-up display device installed in a vehicle 100 such as an automobile. The vehicle display device 1 projects the display light Lt of the image toward the windshield 110. The windshield 110 is located in front of the vehicle relative to the eye point EP of the vehicle 100, and is opposite to the eye point EP in the front-rear direction X of the vehicle. The display light Lt is reflected toward the eye point EP by the reflection surface 110a of the windshield 110. The driver of the vehicle 100 can visually confirm the virtual image Vi through the display light Lt. The virtual image Vi can also be displayed overlapping with an object in front of the vehicle 100. The virtual image Vi can also be an instrument image of the vehicle 100.

[0029] The vehicle display device 1 includes a housing 2, an image display device 3, a reflector 4, a cover 5, and a suppression unit 6. The housing 2 is arranged in front of the vehicle relative to the eye point EP, for example, housed in the instrument panel 120. The housing 2 is formed of a light-shielding material. The housing 2 has an opening 21a that is opposite to the windshield 110 in the vertical direction of the vehicle. The opening 21a is located at the top end of the cylindrical portion 21. The cylindrical portion 21 protrudes upward from the main body of the housing 2. The shape of the cylindrical portion 21 is, for example, a square cylinder shape. The example opening 21a is arranged at the upper end of the housing 2 and is located at the front end of the housing 2.

[0030] The image display device 3 and the reflector 4 are arranged inside the housing 2. The image display device 3 is a device that outputs display light Lt of an image. The image display device 3 is, for example, a liquid crystal display device such as a TFT-LCD (Thin Film Transistor-Liquid Crystal Display). The image display device 3 generates display light Lt using light from a backlight unit, for example.

[0031] The reflector 4 is a reflective component that reflects the display light Lt toward the windshield 110. The reflector 4 has a concave reflective surface 41, and is configured to be able to magnify the image. The reflective surface 41 of the reflector 4 is, for example, a free-form surface having an image correction function. More specifically, the shape of the reflective surface 41 is designed to correct the distortion of the image generated when the display light Lt is reflected by the reflective surface 110a of the windshield 110. The display light Lt reflected by the reflective surface 41 is further reflected by the windshield 110 toward the eye point EP.

[0032] The cover 5 is disposed at the opening 21a of the housing 2 and closes the opening 21a. The cover 5 is a transparent member, for example, molded from a transparent resin. The cover 5 has an outer side surface 51 and an inner side surface 52. The outer side surface 51 is a surface facing the upper side of the vehicle and is opposite to the windshield 110. The inner side surface 52 is a surface facing the lower side of the vehicle and is opposite to the reflector 4.

[0033] The cover 5 of this embodiment has a free-form surface formed to have an optical function for the display light Lt. The free-form surface of the cover 5, for example, corrects at least one of the distortion or aberration of the image. The free-form surface of the cover 5 may also have a function of magnifying the image. The free-form surface may be the inner side surface 52, the outer side surface 51, or both the outer side surface 51 and the inner side surface 52. The thickness of the cover 5 having an optical function tends to be larger than the thickness of a cover without an optical function. The average value of the thickness of the cover 5 may be, for example, about 10 [mm].

[0034] The vehicle display device 1 of the present embodiment includes a suppressing unit 6 disposed at the edge of the cover 5. As described below, the suppressing unit 6 can suppress reflection of light at the end surface 53 of the cover 5 and improve visibility of the virtual image Vi.

[0035] Figure 2 The cover 5 shown in the example is fitted with the cylindrical portion 21 of the housing 2. More specifically, the cover 5 includes a main body 50 and a fitting portion 54. The main body 50 is a lens portion having an optical function, and includes an outer side surface 51 and an inner side surface 52. The fitting portion 54 protrudes from the edge of the inner side surface 52 and fits with the cylindrical portion 21 from the outside. The shape of the fitting portion 54 is, for example, a square tube shape.

[0036] The end face 53 of the cover 5 is a side face of the cover 5. The end face 53 extends in a manner surrounding the outer side face 51 and the inner side face 52. The end face 53 is continuous from the main body 50 to the fitting portion 54. External light L1, stray light L2, and L3 may be incident on the end face 53. The external light L1 is typically sunlight that passes through the windshield 110 toward the inside of the vehicle. The stray light L2 is light output from the image display device 3 and is light that directly travels toward the cover 5 without passing through the reflector 4. The stray light L3 is display light that is reflected by the reflector 4 toward the end face 53 of the cover 5. In addition, there is also stray light that is repeatedly reflected inside the cover 5, and repeatedly reflected on the inner side face 52, the reflector 4, the surface of the image display device 3, etc., and finally enters the end face 53. If the external light L1, the stray light L2, and L3 are reflected toward the eye point EP by the end face 53, so-called ghosting occurs, and the visibility of the virtual image Vi is reduced.

[0037] Figure 2The vehicle display device 1 shown has a frame member 7 as a suppression unit 6. The frame member 7 is a light-shielding member that covers the edge of the cover 5. The frame member 7 has a side wall portion 71 and a top wall portion 72. The side wall portion 71 is a wall portion that is opposite to the end face 53 and covers the end face 53. The side wall portion 71 may, for example, cover all the end faces 53 of the cover 5, or may cover a portion of the end faces 53 among all the end faces 53. The side wall portion 71 covers at least the portion of the end face 53 that corresponds to the main body 50. The illustrated side wall portion 71 covers not only the end face 53 of the main body 50, but also the end face 53 of the fitting portion 54, and is provided at the position of the opening 21a of the housing 2. The side wall portion 71 may also cover the entire fitting portion 54.

[0038] The top wall 72 covers the edge of the cover 5 from the windshield 110. The top wall 72 faces the edge of the outer surface 51 and is configured to shield the end surface 53 from the external light L1. Even if the stray light L2 and L3 are reflected by the end surface 53, the top wall 72 can block the reflected light.

[0039] The top wall portion 72 of the example is set to a position on the extension line of the flip portion 130. The flip portion 130 is a light shielding wall extending downward from the instrument panel 120. The shape of the flip portion 130 is, for example, a square cylinder. The flip portion 130 of the example protrudes toward the cylindrical portion 21 of the housing 2 along the vehicle vertical direction Z. The inner end 72a of the top wall portion 72 is opposite to the flip portion 130 in the vehicle vertical direction Z. That is, the top wall portion 72 is set in a range that does not interfere with the optical path of the display light Lt toward the eye point EP.

[0040] In the frame member 7, the surface facing the cover 5 preferably has low reflectivity. The facing surface of the frame member 7 may have, for example, a concave-convex shape for diffusing light, or may be painted to absorb light. The color of the facing surface may be a dark color such as black.

[0041] The frame member 7 can suppress the external light L1 and the stray lights L2 and L3 from being reflected toward the eye point EP, thereby improving the visibility of the virtual image Vi.

[0042] Figure 3 The vehicle display device 1 shown has a texture processing 55 applied to the end surface 53 of the cover 5 as the suppression unit 6. The end surface 53 having the texture processing 55 diffuses light. For example, when the external light L1, stray light L2, and L3 are incident on the end surface 53, these lights are diffused in various directions. Therefore, it is not easy to generate reflected light Lr toward the eye point EP. The texture processing 55 may be applied to all the end surfaces 53 of the cover 5, or to a part of the end surfaces 53 of all the end surfaces 53. In addition, the vehicle display device 1 may have both the texture processing 55 and the frame member 7 as the suppression unit 6.

[0043] Figure 4The vehicle display device 1 shown has a low-reflection agent 56 disposed on the end surface 53 as the suppression unit 6. The low-reflection agent 56 may be, for example, a paint having a low reflectivity, or a sheet having a low reflectivity. When external light L1, stray light L2, and L3 are incident on the end surface 53, the low-reflection agent 56 absorbs these lights and reduces the reflected light. The low-reflection agent 56 may be applied to all the end surfaces 53 of the cover 5, or to a part of the end surfaces 53 among all the end surfaces 53. In addition, the vehicle display device 1 may have both the low-reflection agent 56 and the frame member 7 as the suppression unit 6.

[0044] Figure 5 The vehicle display device 1 shown has a frame member 7 and an adhesive 57 as a suppression unit 6. The adhesive 57 bonds the frame member 7 to the cover 5. The illustrated adhesive 57 is filled between the end face 53 and the side wall portion 71 of the frame member 7. The value of the refractive index of the adhesive 57 is a value that can reduce the reflectivity of the end face 53 compared to the case where there is an air layer between the end face 53 and the frame member 7. The value of the refractive index of the adhesive 57 is selected in a manner that can sufficiently reduce the reflection of light at the end face 53. The refractive index of the adhesive 57 is preferably equal to the refractive index of the cover 5. The adhesive 57 can suppress the reflection of light at the end face 53 and guide the light to the frame member 7.

[0045] In addition, as described below, multiple paths are considered as the path of the reflected light toward the eye point EP. Figure 6 As shown, when the external light L1 is reflected by the end surface 53 of the cover 5 , there is a path in which the reflected light Lr is reflected by the reflecting surface 110 a of the windshield 110 toward the eye point EP.

[0046] In addition, if Figure 7 As shown, when external light L1 is reflected by end surface 53, there is a path where reflected light Lr directly enters eye point EP. Similarly, stray light L2 and L3 have a path where reflected light is reflected by windshield 110 toward eye point EP and a path where reflected light directly enters eye point EP.

[0047] In addition, the path of the reflected light also differs depending on the position of the eye point EP. Figure 8 The eyellipse EL of the vehicle 100 is shown. The eyellipse EL has an upper end position ELu and a lower end position ELd in the vehicle vertical direction Z. The visible range of the end surface 53 is different when the eye point EP is located at the upper end position ELu and the eye point EP is located at the lower end position ELd.

[0048] Fig. 9The range 53v of the end surface 53 that can be visually recognized from the upper end position ELu is shown. The visually recognized range 53v indicates the range that can be visually recognized by the driver, and is the range in the vehicle up-down direction Z. When the driver's eyes are located at the upper end position ELu of the eyellipse EL, the driver can see the visually recognized range 53v through the reflecting surface 110a of the windshield 110. In other words, the visually recognized range 53v is the range of the entire range of the end surface 53 that can reflect light toward the upper end position ELu.

[0049] In contrast, when the driver's eyes are at the lower end position ELd, they can visually recognize only a narrow range near the lower end 53d of the end surface 53. That is, when the eye point EP is at the lower end position ELd, the range that the driver can visually recognize is narrower than when it is at the upper end position ELu.

[0050] The cover 5 may be designed to suppress reflected light toward the eye point EP even under the most stringent conditions. For example, the cover 5 may be designed based on the positional relationship of each part when the eye point EP is at the upper end position ELu as described below.

[0051] exist Fig.10 An example of the cover 5 is shown in FIG. Fig.10 The cover 5 shown has an inclined portion 58 that inclines the end surface 53 as a suppressing unit. The inclined portion 58 is inclined so as to be away from the center C1 of the cover 5 as it moves from the outer side surface 51 toward the inner side surface 52. The inclination angle θ of the inclined portion 58 relative to the reference line AX is determined so as to suppress the generation of reflected light toward the eye point EP. The reference line AX is, for example, the vehicle up-down direction Z. The lower limit value of the inclination angle θ is determined based on, for example, an imaginary line IL described below.

[0052] Fig.10 The imaginary line IL shown is determined by the upper end position ELu of the eyellipse EL and the position of the lower end 130a of the flip portion 130. The imaginary line IL is the light path from the lower end 130a reflected by the reflection surface 110a of the windshield 110 to the upper end position ELu. Fig.10 In the cross section shown, the imaginary line IL is inclined at an angle θ1 with respect to the reference line AX. The inclination angle θ of the inclined portion 58 is, for example, an angle greater than the angle θ1. The inclined portion 58 can effectively suppress the generation of reflected light toward the eyellipse EL.

[0053] Fig.10 The inclined portion 58 shown is provided on the front end surface 53F in the vehicle front-rear direction X. In addition, the inclined portion 58 may be provided on the left and right end surfaces 53 of the cover 5 or on the rear end surface 53R in the vehicle front-rear direction X.

[0054] like Fig.11As shown, the position of the turning portion 130 can also be adjusted as the restraining unit 6 . Fig.11 The shown flip portion 130 is arranged at a position further to the rear of the vehicle than a position 130b facing the cylindrical portion 21 of the housing 2. The position of the flip portion 130 is set, for example, so that the virtual line IL does not intersect the front end surface 53F.

[0055] like Fig.12 As shown, the cover 5 can also be extended according to the position of the flip portion 130 . Fig.12 The cover 5 shown has an extension portion 5x as the suppression unit 6. The extension portion 5x is located forward of the flip portion 130 in the vehicle front-rear direction X. The front end surface 53F is located closer to the front of the vehicle than the position 53a facing the flip portion 130. The position of the front end surface 53F is set, for example, in a manner that the front end surface 53F does not intersect the imaginary line IL. In addition, Figures 10 to 12 The damping units 6 shown can also be combined with one another.

[0056] As described above, the vehicle display device 1 of the present embodiment includes a housing 2, an image display device 3, a reflector 4, a transparent cover 5, and a suppression unit 6. The housing 2 is mounted on the vehicle 100 and has an opening 21a opposite to the windshield 110. The image display device 3 is arranged inside the housing 2 and outputs the display light Lt of the image. The reflector 4 is arranged inside the housing 2 and is opposite to the windshield 110 via the opening 21a. The reflector 4 reflects the display light Lt toward the windshield 110. The cover 5 is arranged at the opening 21a and has a free-form surface formed to have an optical function. The suppression unit 6 is arranged at the edge of the cover 5 to suppress the reflection of light at the end face 53 of the cover 5. The vehicle display device 1 of the present embodiment can improve the visibility of the virtual image Vi by suppressing the reflection of light at the end face 53.

[0057] The suppression unit 6 is, for example, a frame member 7 that covers the edge of the cover 5. The frame member 7 has a side wall portion 71 and a top wall portion 72. The side wall portion 71 is opposite to the end face 53 of the cover 5 and covers the end face 53. The top wall portion 72 covers the edge of the cover 5 from the windshield 110 side. The frame member 7 can suppress reflection of light at the end face 53. The frame member 7 can suppress reflection by, for example, preventing light from entering the end face 53. In addition, the top wall portion 72 of the frame member 7 can block reflected light toward the eye point EP.

[0058] The suppression means 6 is, for example, a texture processing 55 applied to the end surface 53 of the cover 5. The texture processing 55 can diffuse the light on the end surface 53 and suppress the reflection toward the eye point EP.

[0059] The suppression means 6 is, for example, an inclined portion 58 that inclines the end surface 53 of the cover 5. The inclined portion 58 is inclined so as to be separated from the center C1 of the cover 5 as it moves from the outer surface 51 toward the inner surface 52. The inclined portion 58 can suppress reflection toward the outside of the housing 2.

[0060] In addition, the cover 5 may not have the fitting portion 54. In this case, for example, it is preferable that the housing 2 has a holding structure for holding the cover 5 and a positioning structure for positioning the cover 5.

[0061] The contents disclosed in the above-mentioned embodiments can be executed in combination as appropriate.

[0062] Description of Reference Numerals

[0063] 1: Display device for vehicle;

[0064] 2: housing; 3: image display device; 4: reflector; 5: cover; 6: suppression unit; 7: frame member;

[0065] 21: cylindrical portion; 21a: opening;

[0066] 50: main body; 51: outer side; 52: inner side;

[0067] 53: end face; 53F: front end face; 53R: rear end face; 54: fitting portion; 55: texture processing; 56: low reflective agent; 57: adhesive; 58: inclined portion; 71: side wall portion; 72: top wall portion;

[0068] 100: vehicle; 110: windshield; 110a: reflective surface;

[0069] 120: instrument panel; 130: flip panel;

[0070] EP: eye point; EL: eye ellipse; ELu: upper end position; ELd: lower end position; L1: external light; L2, L3: stray light;

[0071] Lt: display light; Lr: reflected light;

[0072] Vi: virtual image;

[0073] X: the front and rear direction of the vehicle; Z: the up and down direction of the vehicle.

Claims

1. A vehicle display device, characterized in that: have: a housing, the housing being mounted on the vehicle and having an opening facing the windshield; An image display device, which is disposed inside the housing and outputs display light of an image; a reflector, the reflector being disposed inside the housing and facing the windshield via the opening, and reflecting the display light toward the windshield; a transparent cover, the cover being arranged at the opening and having a free-form surface formed to have an optical function; as well as The suppression unit is disposed at an edge of the cover and suppresses reflection of light at an end surface of the cover.

2. The vehicle display device according to claim 1, wherein: The suppression unit is a frame member covering the edge of the cover. The frame member includes a side wall portion that faces the end surface of the cover and covers the end surface, and a top wall portion that covers the edge portion from one side of the windshield.

3. The vehicle display device according to claim 1, wherein: The suppression means is a texture process applied to the end surface of the cover.

4. The vehicle display device according to claim 1, wherein: The cover has an outer side surface facing the windshield and an inner side surface facing the reflector. The suppression unit is an inclined portion that inclines the end surface of the cover. The inclined portion is inclined so as to become farther away from the center of the cover as it moves from the outer side surface toward the inner side surface.

Images