Head-up display

Abstract

To provide a head-up display capable of providing light shielding parts at a plurality of positions while suppressing cost.SOLUTION: A head-up display which comprises a display device for displaying an image, a plane mirror for reflecting the display light from the display device, a concave mirror for reflecting the display light via the plane mirror, a cover glass for transmitting the display light via the concave mirror, and a blind cover formed as an integral member, and displays a virtual image by the display light projected from the display device onto an object via a predetermined optical path via the plane mirror, the concave mirror, and the cover glass, wherein the blind cover comprises a first light-shielding part for shielding the display light deviating from the predetermined optical path between the display device and the plane mirror, a second light-shielding part for preventing external light via the cover glass from entering the interior, and an attaching part for attaching the plane mirror to the blind cover.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to head-up displays. [Background technology]

[0002] Head-up displays are known that project display light from a liquid crystal display onto an object, such as a vehicle windshield, through a cover glass to display a virtual image in front of the object. To improve display quality, head-up displays may be provided with a light-shielding section to prevent the display light from the liquid crystal display from reaching the cover glass via a path other than a predetermined optical path. Patent Document 1 discloses such a light-shielding section provided near a liquid crystal display element. Furthermore, display quality can be improved by providing a light-shielding section that prevents washout, a phenomenon in which external light, such as sunlight, enters the liquid crystal display and makes the virtual image difficult to see. Patent Document 2 discloses a head-up display in which a light-shielding section (light-shielding wall) is formed near a window to prevent washout. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-175574 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-151249 Summary of the Invention [Problem to be solved by the invention]

[0004] The members constituting the light-shielding portion need to be subjected to processing such as printing (painting) or graining to reduce light reflection. Therefore, when multiple light-shielding portions are provided, the above processing needs to be performed on each of the multiple members, which increases costs.

[0005] The present disclosure aims to provide a head-up display that can have light-blocking portions in multiple locations while suppressing costs. [Means for solving the problem]

[0006] On one side, a display device for displaying an image; a flat mirror that reflects display light from the display device; a concave mirror that reflects the display light that has passed through the flat mirror; a cover glass that transmits display light passing through the concave mirror; a blind cover formed as an integral member; Equipped with a head-up display that displays a virtual image by display light projected onto an object through a predetermined optical path from the display device via the flat mirror, the concave mirror, and the cover glass, The blind cover is a first light-shielding portion that blocks the display light that deviates from the predetermined optical path between the display device and the flat mirror; a second light-shielding portion that prevents external light from entering the interior through the cover glass; an attachment portion that attaches the plane mirror to the blind cover; A head-up display is provided. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a head-up display that can have light-blocking portions in multiple locations while suppressing costs. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing the appearance of a head-up display according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view showing a configuration of a part of a head-up display. [Figure 3]FIG. 2 is a perspective view showing a configuration of a part of a head-up display. [Figure 3A] FIG. 2 is a perspective view showing a configuration of a part of a head-up display. [Figure 4] FIG. [Figure 4A] FIG. [Figure 4B] FIG. [Figure 4C] FIG. [Figure 4D] FIG. 4 is a cross-sectional view showing the vicinity of the adhesive surface of the upper case. [Figure 5] FIG. [Figure 5A] FIG. [Figure 5B] FIG. [Figure 5C] FIG. [Figure 6] FIG. 2 is a perspective view showing a support mechanism for a concave mirror. [Figure 7] FIG. 2 is an enlarged perspective view showing a support mechanism for the concave mirror. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings.

[0010] Fig. 1 is a perspective view showing the appearance of the head-up display of this embodiment, Fig. 2 is a cross-sectional view showing a partial configuration of the head-up display, and Fig. 3 and Fig. 3A are perspective views showing a partial configuration of the head-up display. Note that XYZ coordinates are common to Figs. 1 to 7.

[0011] As shown in FIG. 1, the head-up display of this embodiment includes a lower case 1 and an upper case 2 attached to the lower case 1. The lower case 1 and the upper case 2 are formed of an opaque resin such as a PC / PET resin, which is an alloy of polycarbonate (PC) resin and polyethylene terephthalate (PET) resin. The upper case 2 has an opening that functions as an outlet for display light. This opening is covered with a light-transmitting cover glass 3. The cover glass 3 is a dustproof cover made of a highly light-transmitting acrylic resin, polycarbonate resin, or the like, and is bonded to the upper case 2. In addition, a circuit mounting unit 9 including a main circuit board (not shown) and a metal insulator case 91 that houses the main circuit board is attached to the lower case 1.

[0012] As shown in Figures 2 to 3A, inside the lower case 1 and the upper case 2, there are provided a blind cover 4, a liquid crystal display 5 and an image generating unit 51 supported by the blind cover 4, a flat mirror (first mirror) 6 supported by the blind cover 4, and a concave mirror (second mirror) 7.

[0013] In the head-up display of this embodiment, display light from the liquid crystal display 5 is reflected by the plane mirror 6 and the concave mirror 7 in order along predetermined optical paths P1, P2, and P3 (FIG. 2), and is emitted through the cover glass 3. By projecting the display light emitted through the cover glass 3 onto an object such as a windshield of a vehicle, a virtual image is displayed in front of the object.

[0014] The blind cover 4 is constructed as a single, opaque resin component such as PC / PET resin. The surface of the blind cover 4 is subjected to a process to reduce light reflection, such as black printing (painting), a textured finish, or the application of a low-reflection sheet. The low-reflection sheet is preferably a sheet composed of a laminate of a black, opaque foamed resin layer such as a urethane foam resin and an adhesive layer. The foamed resin layer used as the low-reflection sheet has a foamed structure containing minute voids that diffuses light and reduces reflection. The foamed structure also has high thermal insulation properties, making it difficult for heat generated by sunlight to be transmitted to the blind cover 4. As described below, the blind cover 4 functions as a light-shielding portion in multiple locations. In other words, because multiple light-shielding portions are formed by the single blind cover 4, the above process can be completed in a single step. Furthermore, the reduced number of components reduces the burden of assembly work.

[0015] Figures 4 to 4C are perspective views showing the blind cover, Figure 4D is a cross-sectional view showing the vicinity of the adhesive surface of the upper case, Figures 5 to 5C are perspective views showing the upper case, Figure 6 is a perspective view showing the mounting portion of the concave mirror, and Figure 7 is a perspective view showing the mounting mechanism of the concave mirror.

[0016] As shown in FIGS. 4 to 4C, blind cover 4 is formed with mounting portion 41 (FIG. 4A) in which opening 41A corresponding to the display screen of liquid crystal display 5 is formed. Liquid crystal display 5 is attached to mounting portion 41 with its display screen facing opening 41A. Because liquid crystal display 5 is attached to blind cover 4 via mounting portion 41, there is no need to provide a holding portion for holding liquid crystal display 5 on other members such as image generation unit 51.

[0017] The blind cover 4 is also provided with an attachment portion 42 for attaching the plane mirror 6. An opening 42A is formed in the attachment portion 42 so as to face the reflective surface of the plane mirror 6. The opening 42A forms an optically effective opening, and the attachment portion 42 has the function of masking the outer peripheral edge of the plane mirror 6 around the opening 42A.

[0018] Furthermore, the blind cover 4 has a notch 43 (FIGS. 2, 3A, 4A, 4C, and 6) formed therein that corresponds to the reflective surface of the concave mirror 7. The concave mirror 7 is attached so that the opening formed by the notch 43 in the blind cover 4 is closed by the reflective surface.

[0019] The blind cover 4 also has an opposing surface 45 that faces the cover glass 3 adhered to the upper case 2, and guide surfaces 46A and 46B that are formed on both sides of the opposing surface 45 (the left and right sides in Figure 4C) and abut against the upper case 2 (Figures 4B and 4C).

[0020] As shown in FIGS. 2, 4B, and 4C, a first light-shielding portion S1 is provided near the mounting portion 41 of the blind cover 4. The first light-shielding portion S1 blocks display light that deviates from the predetermined optical path P1 (FIG. 2) on its way from the liquid crystal display 5 to the flat mirror 6. This prevents display light that deviates from the predetermined optical path P1 from reaching the cover glass 3 via another path, improving the display quality of the head-up display. The first light-shielding portion S1 is also provided from the light outlet of the upper case 2 to the top end of the flat mirror 6, blocking direct viewing of the flat mirror 6 and the liquid crystal display 5 from the light outlet of the upper case 2. In other words, the first light-shielding portion S1 blocks sunlight (external light) entering through the light outlet of the upper case 2 from directly irradiating the flat mirror 6 and the liquid crystal display 5. This prevents external light from being reflected by the plane mirror 6 or the liquid crystal display 5 and traveling through the predetermined optical path P1 to reach the cover glass 3 together with the display light, thereby improving the display quality of the head-up display.

[0021] 2, 4B, and 4C, a second light-shielding portion S2 is provided on the surface of the blind cover 4 facing the cover glass 3 (light outlet). The second light-shielding portion S2 has a function of preventing stray light so that the inside of the head-up display is not directly illuminated by external light entering through the cover glass 3 (light outlet). Note that in reality, the area that can function as the second light-shielding portion S2 is not limited to the surface shown in the drawings, but includes the entire range that is visible from the outside through the cover glass 3 (light outlet).

[0022] The upper case 2 has an adhesive surface 21 (FIGS. 4D and 5) formed thereon to which the cover glass 3 is adhered. The outer peripheral edge of the cover glass 3 is adhered to the adhesive surface 21, and the cover glass 3 is fixed to the upper case 2 while forming a predetermined curved shape.

[0023] 4D, opposing surface 45 of blind cover 4 faces the back surface (the bottom surface in FIG. 4D) of cover glass 3 at the outer peripheral edge of cover glass 3. A clearance is ensured between opposing surface 45 of blind cover 4 and the back surface of cover glass 3, preventing damage to cover glass 3 due to contact with blind cover 4, both during and after assembly.

[0024] A mask portion 31 is formed on the rear surface of the outer peripheral edge of the cover glass 3 (the surface facing the inside of the head-up display). The mask portion 31 is, for example, a black printed layer applied to the rear surface of the cover glass 3, and is provided in an area including the portion facing the boundary between the facing surface 45 and the adhesive surface 21. The mask portion 31 has the effect of preventing stray light caused by extraneous light from outside. In addition, the facing surface 45 and the adhesive surface 21, and particularly the boundary line between the facing surface 45 and the adhesive surface 21, become invisible, improving the appearance.

[0025] As shown in FIGS. 4B and 4C, guide surfaces 46A and 46B of blind cover 4 are formed on both sides of blind cover 4 (on both the left and right sides in FIG. 4C) at positions farther from the rear surface of cover glass 3 than opposing surface 45. When blind cover 4 and upper case 2 to which cover glass 3 is adhered are assembled, guide surface 46A or guide surface 46B abuts against upper case 2, thereby regulating the position of upper case 2. This prevents blind cover 4 from contacting cover glass 3 and damaging it. As shown in FIGS. 5A to 5C, upper case 2 is formed with guide surfaces 23A and 23B that face guide surfaces 46A and 46B of blind cover 4, respectively. Guide surfaces 46A, 46B, 23A, and 23B all extend in the direction of arrow 40 in FIGS. 4B and 5A to 5C.

[0026] During assembly, the upper case 2 is easily guided to the predetermined assembly position by sliding the upper case 2 in the direction of arrow 40 while bringing guide surface 46A of blind cover 4 into contact with guide surface 23A of upper case 2 and guide surface 46B of blind cover 4 into contact with guide surface 23B of upper case 2. In this embodiment, the dimensions of each part are set so that guide surfaces 46A and 46B of blind cover 4 first come into contact with guide surfaces 23A and 23B of upper case 2, and opposing surface 45 of blind cover 4 and the like do not come into contact with cover glass 3. This prevents damage to cover glass 3.

[0027] During assembly, the upper case 2 may be fixed and the blind cover 4 may be slid in the direction opposite to the arrow 40 .

[0028] 2, in this embodiment, the upper case 2 is provided with a wall portion 25 shaped to fit along the blind cover 4 near the surface that forms the second light-shielding portion S2. This allows the blind cover 4 and the upper case 2 to easily interfere with each other, and the blind cover 4 and the upper case 2 can be assembled by sliding the upper case 2 relative to the blind cover 4 so that the second light-shielding portion S2 is inserted between the cover glass 3 and the wall portion 25. In other words, the upper case 2 needs to be assembled by sliding it relative to the blind cover 4 in the direction of arrow 40. However, providing guide surfaces 46A and 46B on the blind cover 4 enables smooth assembly.

[0029] As shown in FIGS. 5A and 5B, the upper case 2 is provided with guide portions 24A and 24B, each formed as a pair of protrusions. Guide portions 24A and 24B are engageable with wall portions 47A and 47B of the blind cover 4, respectively, during assembly. That is, wall portions 47A and 47B of the blind cover 4 are inserted between the pair of protrusions of guide portions 24A and 24B, thereby restricting the position of the upper case 2 relative to the blind cover 4. By sliding the upper case 2 in the direction of arrow 40 in this state, the position of the upper case 2 (the left-right position in FIG. 4C and the up-down position in FIG. 5B) is restricted until the upper case 2 reaches a predetermined assembly position, allowing for smooth assembly. Note that even in the final assembly position, wall portions 47A and 47B of the blind cover 4 may remain inserted between the pair of protrusions of guide portions 24A and 24B.

[0030] Guide surface 46A, guide surface 46B, guide surface 23A, guide surface 23B, guide portion 24A and guide portion 24B all regulate the relative position between upper case 2 and blind cover 4 in a direction perpendicular to the above-mentioned sliding direction.

[0031] In this embodiment, the first light-shielding portion S1 is provided on the blind cover 4, not on the upper case 2. This makes it easy to visually check the condition of the first light-shielding portion S1 before assembling the upper case 2 and the blind cover 4, and makes it easy to remove dust and other particles adhering to the first light-shielding portion S1. In particular, in a configuration in which a low-reflection sheet having a foamed resin layer is attached to the first light-shielding portion S1, a configuration in which the blind cover 4 has the first light-shielding portion S1 is effective because the foamed resin layer has high dust adsorption properties and there is a high risk of dust getting mixed in during assembly.

[0032] 6, the concave mirror 7 is attached to the blind cover 4 by having a rotation axis 71 attached to the concave mirror 7 supported at both ends by mounting parts 73 and a mounting mechanism 80. The concave mirror 7 is rotatable around the rotation axis 71, and the angle of the concave mirror 7 can be adjusted by a motor (not shown).

[0033] As shown in FIG. 7 , the mounting mechanism 80 includes a bearing 81 that supports one end of the rotating shaft 71, a leaf spring 82 that has one end 82a fixed to the bearing 81 and the other end supported so as to abut against the support portion 81a of the bearing 81, and an abutment portion 48 (stopper portion) that is formed as part of the blind cover 4 and is disposed near the rotating shaft 71. The bearing 81 has two abutment surfaces that open in a V-shape and support the rotating shaft 71 with these surfaces. The leaf spring 82 is disposed opposite the abutment surface of the bearing 81 across the rotating shaft 71. The rotating shaft 71 supported by the bearing 81 also contacts the leaf spring 82 and is pressed against the two abutment surfaces of the bearing 81 by the elastic force of the leaf spring 82. In this way, the rotating shaft 71 is supported from three directions.

[0034] If the head-up display receives a strong impact, the rotating shaft 71 bounces off the bearing portion 81 and presses against the leaf spring 82. At this time, the leaf spring 82 cannot withstand the impact load and undergoes plastic deformation. However, by providing the abutment portion 48, which is a mechanical stop within the range of elastic deformation of the leaf spring 82, the leaf spring 82 abuts against the abutment portion 48, suppressing deformation of the leaf spring 82. This prevents the rotating shaft 71 from coming off the bearing portion 81 and causing loss of function of the concave mirror 7, i.e., the head-up display. Furthermore, because the abutment portion 48 is formed as part of the blind cover 4, no cosmetic issues arise. For example, if the abutment portion 48 (stopper portion) were formed on the upper case 2, a tall rib would be required, which would likely cause sink marks at the base of the rib due to the draft angle, resulting in poor cosmetic appearance. In this embodiment, by providing the abutment portion 48 on the blind cover 4, a tall rib is unnecessary, eliminating cosmetic issues.

[0035] As described above, in this embodiment, at least two light-shielding portions are provided on the blind cover 4. However, according to this embodiment, the blind cover 4 is provided with the first light-shielding portion S1 and the second light-shielding portion S2, so that processes such as black printing (painting), graining, and attachment of a low-reflection sheet can be completed in a single process. Furthermore, the reduced number of parts reduces the burden of the assembly work.

[0036] Furthermore, the blind cover 4 is formed with an attachment portion 42 for attaching the plane mirror 6, and the blind cover 4 supports the plane mirror 6. Therefore, the attachment portion 42 is located between the first light-shielding portion S1 and the second light-shielding portion S2, and can be effectively used as a portion for connecting the first light-shielding portion S1 and the second light-shielding portion S2. In particular, because the attachment portion 42 and the second light-shielding portion S2 are close to each other, a complex shape is not required for the blind cover 4 to connect the attachment portion 42 and the second light-shielding portion S2. For example, as in this embodiment, the attachment portion 42 and the second light-shielding portion S2 can be configured to have a continuous shape.

[0037] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments.

[0038] In the above embodiment, the first mirror is a flat mirror and the second mirror is a concave mirror, but this is not limiting. For example, both the first mirror and the second mirror may be concave mirrors. [Explanation of symbols]

[0039] 2 Upper Case 3 Coverslip 4 blind covers 5 LCD display 6. Plane mirror 7. Concave mirror 23A, 23B guide surface 24A, 24B guide section 25 Wall 31 Mask Section 42 Mounting part 46A, 46B guide surface 48 Contact part 80 Mounting mechanism 81 Bearing section 82 Leaf spring S1 First light-shielding part S2 Second light blocking part

Claims

1. a display device for displaying an image; a mirror that reflects display light from the display device; a mounting mechanism for supporting the mirror; A head-up display comprising: The attachment mechanism includes: a bearing portion supporting a rotation shaft that rotatably supports the mirror; a leaf spring that is provided opposite the bearing portion across the rotation shaft and against which the rotation shaft abuts; a stopper portion that limits deformation of the leaf spring; Equipped with a head-up display.

2. The head-up display includes a blind cover having a light-blocking portion and formed as an integral member, 2. The vehicle of claim 1, wherein the mounting mechanism attaches the mirror to the blind cover. Head-up display.

3. 3. The method according to claim 2, wherein the stopper portion is formed as a part of the blind cover. Head-up display.

4. The head-up display a first mirror that reflects display light from the display device; a second mirror that reflects the display light that has passed through the first mirror; Equipped with A head-up display according to any one of claims 1 to 3, wherein the mirror points towards the second mirror.

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