Head-up display

Abstract

To provide a head-up display improved in dust resistance while fixing a translucent sheet.SOLUTION: A head-up display includes: a display device 20 which outputs display light L; a translucent sheet 60 which has light transmissivity and is made of a sheet having a sheet peripheral edge 60c; a case 50 which has an opening 56 which is covered with the translucent sheet 60 and emits display light L to the outside through the translucent sheet 60 and a sheet holding section 70 which is positioned at a peripheral edge of the opening 56 and holds the sheet peripheral edge 60c and stores the display device 20; and a fixing frame 80 which covers the sheet peripheral edge 60c and fixes the translucent sheet 60 to the sheet holding section 70. The fixing frame 80 has a fixing pin 84. The translucent sheet 60 has a through hole 62 through which the fixing pin 84 is passed. The sheet holding section 70 fixes the fixing pin 84 to a fixing hole 73 provided in the case 50 so as to fix the translucent sheet 60 between the sheet holding section and the fixing frame 80.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a head-up display mounted on a vehicle or the like. [Background technology]

[0002] A head-up display generates an image by reflecting light from a reflective member such as a concave mirror, and then emits the light from an opening in the case to the outside of the device. The emitted light then illuminates a transmissive reflective member such as a windshield, allowing the viewer to view a virtual image.

[0003] The opening of the case is curved and covered with a light-transmitting sheet. For example, in Patent Document 1, the light-transmitting sheet is fixed by a fixing frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020-9092 Summary of the Invention [Problem to be solved by the invention]

[0005] In the head-up display of Patent Document 1, the fixing pins are exposed to the outside. Exposing the fixing points to the outside may reduce dustproof performance.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a head-up display that has improved dust resistance while still fixing a translucent sheet. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the head-up display according to the present invention comprises: a display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on a periphery of the opening and holding a periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through hole through which the fixing pin passes, The sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case. death, The fixing frame has a first wall that abuts against the periphery of the through hole. do. In order to solve the above-mentioned problems, a head-up display according to another aspect of the present invention comprises: a display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on a periphery of the opening and holding a periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through hole through which the fixing pin passes, the sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case; The sheet holding portion has a second wall that is inserted into the through-hole and is higher than the light-transmitting sheet. In order to solve the above-mentioned problems, a head-up display according to another aspect of the present invention comprises: a display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on a periphery of the opening and holding a periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through hole through which the fixing pin passes, the sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case; the light-transmitting sheet is fixed in a curved state, The fixing frame is provided at a portion of the light-transmitting sheet that has the greatest curvature among portions corresponding to the curvature of the light-transmitting sheet, and has a locking portion that is locked to the case. [Effects of the Invention]

[0008] In the head-up display according to the present invention, productivity can be improved when attaching the light-transmitting sheet. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view illustrating an external configuration of a head-up display according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic cross-sectional view showing the internal configuration of the head-up display. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is an enlarged cross-sectional view particularly showing the upper case 51, the light-transmitting sheet 60, and the fixing frame 80. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a head-up display according to the present invention will be described with reference to the accompanying drawings. In this embodiment, an example in which a head-up display according to the present invention is mounted on an automobile will be described, but the present invention can also be applied to head-up displays mounted on motorcycles, ships, agricultural machinery, construction machinery, etc.

[0011] FIG. 1 is a perspective view illustrating an external configuration of an embodiment of a head-up display according to the present invention.

[0012] FIG. 2 is a schematic cross-sectional view showing the internal configuration of the head-up display 1. As shown in FIG.

[0013] The head-up display 1 (HUD1) reflects projected display light L toward the viewer (driver) of the vehicle by the windshield of the vehicle, which is a transmissive and reflective member, and allows the viewer to view a virtual image (display image). This allows the viewer to observe the virtual image superimposed on the scenery.

[0014] The HUD 1 is disposed inside the instrument panel of a vehicle and mainly includes a display device 20, a plane mirror 30, a concave mirror 40, and a case 50, as shown in FIG.

[0015] The display device 20 mainly includes a light source 21 and a liquid crystal display element 22. The display device 20 outputs display light L. The light source 21 is a light-emitting diode mounted on a wiring board 23. The liquid crystal display element 22 is a TFT-type liquid crystal display element. The liquid crystal display element 22 is disposed in front of (above the illustration) the light source 21 so as to transmit illumination light from the light source 21 to form display light L. That is, the liquid crystal display element 22 displays display information such as numerical values ​​and symbols (for example, vehicle speed and engine RPM) using light emitted from the light source 21 under the control of an element drive circuit. The display device 20 is fixed and held within the case 50 so that the surface from which the display light L is emitted faces the plane mirror 30 and the optical axis of the display light L intersects with the plane mirror 30.

[0016] The plane mirror 30 (reflecting mirror) has a base material made of a synthetic resin material and a reflective film formed on the surface of the base material by vapor deposition, etc. The plane mirror 30 reflects the display light L output from the display device 20 toward the concave mirror 40.

[0017] The concave mirror 40 has a base material made of a synthetic resin material and a reflective film formed on the surface of the base material by vapor deposition or the like. The concave mirror 40 further reflects the display light L reflected by the plane mirror 30 toward the windshield. The concave mirror 40 functions as a magnifying mirror, magnifying the display image and reflecting it toward the windshield. This allows the viewer to view an enlarged image of the display image displayed by the display device 20. The concave mirror 40 is rotated around a rotation axis by an actuator. By rotating the concave mirror 40, the actuator adjusts the angle of the concave mirror 40 to adjust the irradiation position of the display light L or to adjust the angle so that external light is not reflected by the concave mirror 40 toward the display device 20.

[0018] Case 50 is made of a light-blocking synthetic resin (for example, polybutylene terephthalate (PBT)), and has an upper case 51 and a lower case 52. Case 50 forms a box by combining upper case 51 and lower case 52, and has an internal space 55 (FIG. 2) that mainly houses display device 20, plane mirror 30, and concave mirror 40.

[0019] The upper case 51 has an opening 56 provided in a portion facing the windshield. The opening 56 is covered with a light-transmitting sheet 60. The structure for attaching the light-transmitting sheet 60 to the upper case 51 will be described later.

[0020] The lower case 52 mainly has a structure for mounting the display device 20, the plane mirror 30, and the concave mirror 40.

[0021] The light-transmitting sheet 60 is a flat sheet made of a synthetic resin material (for example, acrylic resin). The light-transmitting sheet 60 has a sheet peripheral edge 60c (FIG. 4). The light-transmitting sheet 60 is formed in a curved shape (curved surface shape) and is attached to the upper case 51 via the sheet peripheral edge 60c. The light-transmitting sheet 60 has translucency that allows the display light L reflected by the concave mirror 40 to pass through (pass through). That is, the opening 56 covered with the light-transmitting sheet 60 emits the display light L reflected by the concave mirror 40 to the outside via the light-transmitting sheet 60. The emitted display light L is projected onto the windshield, thereby displaying a virtual image to the viewer.

[0022] The curved shape of the light-transmitting sheet 60 is designed so that external light reflected by the light-transmitting sheet 60 is not directed toward the area on the windshield that is irradiated with the display light L.

[0023] Next, the structure for attaching the light-transmitting sheet 60 to the upper case 51 will be described in detail.

[0024] FIG. 3 is an exploded perspective view particularly showing the upper case 51 and the light-transmitting sheet 60. As shown in FIG.

[0025] FIG. 4 is a perspective view showing the fixed frame 80. As shown in FIG.

[0026] FIG. 5 is an enlarged view for particularly explaining the upper case 51, the light-transmitting sheet 60, and the fixing frame 80. As shown in FIG.

[0027] The opening 56 of the upper case 51 is covered by a light-transmitting sheet 60 on the outer surface of the upper case 51. A sheet peripheral edge 60c of the light-transmitting sheet 60 is covered by a fixed frame 80. The sheet peripheral edge 60c includes at least an area overlapping with the sheet holding portion 70 and an area covered by the fixed frame 80.

[0028] The upper case 51 has a sheet holding portion 70 located on the periphery of the opening 56 as an area for holding the sheet periphery 60c of the light-transmitting sheet 60. The sheet holding portion 70 has four sides that define the opening 56. That is, the sheet holding portion 70 has two opposing sides 75 extending along the Y direction in FIG. 3, which is a first direction, and two opposing sides 76 extending along the X direction, which is a second direction perpendicular to the Y direction. These sides 75, 76 have a constant width from the opening periphery 56c. The sheet holding portion 70 is a convex portion on the surface 51a facing upward (Z direction) of the upper case 51, and this convex portion is formed to correspond to the shape of the light-transmitting sheet 60. The sheet holding portion 70 has fixing holes 73.

[0029] The sheet holding portion 70 is provided at a position corresponding to each fixing pin 84, and has fixing holes 73 through which the fixing pins 84 pass. As shown in Fig. 4, the sheet holding portion 70 has recesses 73a around the fixing holes 73. The recesses 73a are the locations where the tips 84a of the fixing pins 84, which have been melted for welding, join.

[0030] The fixing holes 73 are formed at locations corresponding to the fixing pins 84. In the present disclosure, the fixing holes 73 are formed at 16 locations. A total of three or more fixing holes 73 must be formed, and include reference fixing holes and elongated fixing holes.

[0031] The reference fixing hole has approximately the same diameter as the fixing pin 84, and serves as a reference for positioning the fixing frame 80 relative to the upper case 51. The reference fixing hole preferably has a diameter large enough to allow the fixing pin 84 to be inserted while still allowing positioning.

[0032] Two or more oblong fixing holes are formed, each elongated in the direction toward the reference fixing hole, so that even if the position is determined by the reference fixing hole and the fixing frame 80 expands or contracts when heated or cooled, excessive stress is not generated, reducing the risk of breakage.

[0033] In addition, the fixing holes 73 other than the reference fixing holes and the elongated hole fixing holes may be fixing holes that can be fixed by welding the fixing pins 84, that do not interfere with the expansion and contraction of the fixing frame 80, and that have a diameter larger than the diameter of the fixing pins 84.

[0034] When fixing the fixing frame 80 to the upper case 51, the locking portions 53 temporarily fix the flat light-transmitting sheet 60 to the curved sheet holding portions 70 until the fixing frame 80 is fixed by the fixing holes 73. That is, when the temporary fastening hooks 86 are temporarily fastened to the locking portions 53, the light-transmitting sheet 60 is temporarily fixed between the fixing frame 80 and the sheet holding portions 70. The locking portions 53 are provided at the locations of each side 76 where the curvature is greatest. That is, the locking portions 53 are provided at locations that correspond to the curvature of the light-transmitting sheet 60.

[0035] The fixing pins 84 are firmly joined to the sheet holding part 70 by welding after the light-transmitting sheet 60 and the fixing frame 80 are placed on the sheet holding part 70 with the fixing pins 84 passing through the corresponding sheet holes 62 (an example of through holes) and fixing holes 73 in the light-transmitting sheet 60 and the sheet holding part 70. The fixing pins 84 are provided at 16 locations in total, four on each side 75, 76, and are preferably evenly distributed on the sheet holding part 70. When the fixing pin 84 is fixed to the fixing hole 73, it is desirable that the fixing point be positioned on the internal space 55 side of the device. In the embodiment shown in Patent Document 1, when the fixing pin is welded to the fixing hole, the welding point is welded at a position exposed to the outside. If the fixing point is exposed to the outside in this way, dust and water are likely to enter through this fixing point if the fixation is incomplete for some reason. However, if the fixing pin is covered by the fixing frame 80 and fixed at a position on the internal space 55 side, it becomes easy to configure a dustproof and waterproof structure on the external side of the device, thereby achieving improved dustproofness.

[0036] The light-transmitting sheet 60 has sheet holes 62 that correspond to the fixing pins 84 .

[0037] The sheet holes 62 are provided at positions corresponding to the fixing pins 84, and the fixing pins 84 pass through them. The sheet holes 62 are formed to have a certain gap with respect to the fixing pins 84. This reduces the possibility of the fixing pins 84 interfering with the light-transmitting sheet 60 (the periphery of the sheet holes 62) due to vibration or thermal expansion, and thus reduces distortion of the light-transmitting sheet 60 caused by the fixing pins 84.

[0038] The fixing frame 80 is made of a synthetic resin material with light-blocking properties, and is made of a resin (for example, black polypropylene) with a lower melting point than the upper case 51. The fixing frame 80 covers the sheet peripheral edge 60c and fixes the light-transmitting sheet 60 to the sheet holding part 70. The fixing frame 80 also has the function of shielding the sheet holding part 70 from viewers. The fixing frame 80 has a main body 81, outer edge side legs 82, inner edge side legs 83, and a first wall 85.

[0039] The main body 81 has a frame shape that corresponds to the curved shape of the sheet holding portion 70 .

[0040] The outer edge leg 82 protrudes and extends substantially perpendicularly from the outer edge 81c (outer edge 81c side) of the main body 81 toward the back surface 81b of the main body 81 (extending substantially in the -Z direction). The outer edge leg 82 forms a single convex portion relative to the back surface 81b. The outer edge leg 82 protrudes downward in the Z axis beyond the convex surface 70a of the sheet holding portion 70, and forms a labyrinth structure together with the first wall 85 and the second wall 73b to provide dustproof and waterproof protection. As a result, the outer edge leg 82 can reduce the amount of dust and moisture that enters the inside of the HUD 1 through the opening 56.

[0041] The inner edge leg 83 protrudes and extends substantially perpendicularly from the inner edge 81d side of the main body 81 toward the back surface 81b of the main body 81 (extending substantially in the -Z direction). The inner edge leg 83 is a single protrusion on the back surface 81b. The inner edge leg 83 is in continuous line contact with the sheet peripheral edge 60c (the sheet peripheral edge 60c on the front surface 60a of the light-transmitting sheet 60) and is more dustproof and waterproof than the inner edge leg 83 is with respect to the outer edge 81c. Thus, like the outer edge leg 82, the inner edge leg 83 can reduce dust and moisture from entering the inside of the HUD1 through the opening 56. Furthermore, the inner edge leg 83 is located closer to the outer edge 81c than the inner edge 81d of the main body 81. This reduces the influence of the chips on the inside of the sheet periphery 60c, which is the visible range of the light-transmitting sheet 60, even if the HUD1 vibrates due to vibrations of the vehicle and resin chips are generated due to friction between the inner edge leg 83 and the light-transmitting sheet 60.

[0042] The first wall 85 is a protrusion provided to surround the periphery of the sheet hole 62. The first wall 85 is in line contact with the light-transmitting sheet 60 so as to surround the periphery of the sheet hole 62, thereby preventing dust and water from entering through the opening 56. The second wall 73b is inserted through the sheet hole 62 and forms a wall that is higher than the light-transmitting sheet 60. The first wall 85, which contacts the light-transmitting sheet 60 from above, and the second wall 73b, which protrudes from below relative to the light-transmitting sheet 60, separate the fixing hole 73 from the outside, preventing dust and water from entering through the fixing hole 73.

[0043] The temporary fixing hooks 86 are hooks that are locked to the locking portions 53. During assembly, after the fixed frame 80 and the light-transmitting sheet 60 are placed on the sheet holding portion 70, the temporary fixing hooks 86 temporarily fix the fixed frame 80 and the light-transmitting sheet 60 so that the fixed frame 80 does not shift position relative to the upper case 51 or fall off until the fixing pins 84 are welded to the fixing holes 73.

[0044] Next, the procedure for attaching the light-transmitting sheet 60 to the upper case 51 will be described.

[0045] First, the light-transmitting sheet 60 is attached so that the sheet holes 62 fit into the fixing pins 84 of the fixing frame 80. At this time, if the fixing pins 84 have a temporary fastening barb structure so that the light-transmitting sheet 60 is temporarily fastened to the fixing frame 80, workability can be improved. The temporary fastening barb structure is preferably a push-pull type structure that can lock the light-transmitting sheet 60 once it has passed through the sheet holes 62, preventing it from falling off, on the fixing pins 84 that are provided at positions corresponding to the non-curved edges 75. As a result, the light-transmitting sheet 60 is temporarily fixed to the sheet holding part 70 while maintaining its curved shape.

[0046] After that, or at almost the same time, the light-transmitting sheet 60 attached to the fixing frame 80 is placed on the sheet holding portion 70 of the upper case 51. At the same time, the fixing pins 84 are inserted into the fixing holes 73 of the sheet holding portion 70 and penetrate the upper case 51. As a result, the light-transmitting sheet 60 is sandwiched between the upper case 51 and the fixing frame 80.

[0047] At this time, the temporary fixing hooks 86 are locked into the locking portions 53. This locking temporarily secures the fixed frame 80 and the light-transmitting sheet 60 without causing them to fall off the upper case 51. The temporary fixing hooks 86 and the locking portions 53 are provided corresponding to curved portions of the light-transmitting sheet 60 so as to fit into the concave side of the upper case 51, thereby efficiently suppressing the force that attempts to restore the sheet from bending.

[0048] Thereafter, the tip 84a of the fixing pin 84 protruding from the fixing hole 73 is welded to the recess 73a of the sheet holding part 70, thereby joining the fixing pin 84 and the sheet holding part 70. At this time, because the upper case 51 is made of a material with a higher melting point than the material of the fixing pin 84, the upper case 51 does not melt together with the fixing pin 84 during welding. By being fixed to the fixing pin 84, the upper case 51 sandwiches and fixes the light-transmitting sheet 60 together with the fixing frame 80. As a result, the light-transmitting sheet 60 is securely held on the upper case 51 so that it will not fall off from the upper case 51 when a load is applied, for example, in the inward direction of the HUD1 (in the -Z direction).

[0049] Such a HUD 1 can improve the dustproofness of the light-transmitting sheet 60. That is, if the fixing pins are configured to be exposed to the outside of the device, dust and water from the outside can easily enter the inside of the device. In contrast, in the HUD 1 of this embodiment, the fixing pins 84 provided on the fixing frame 80 pass through the fixing holes 73 of the upper case 51 (sheet holding portion 70) and are welded inside the device, which makes it easier to configure the fixing frame 80 and the upper case 51 with a structure that further improves dustproofness and waterproofness, thereby achieving improved dustproofness.

[0050] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0051] For example, the fixed frame 80 may be fixed by a method other than welding. For example, the fixed frame 80 may be fixed by press-fitting a packing such as an O-ring onto the tip 84a of the fixing pin 84 protruding from the fixing hole 73, and sandwiching the fixed frame 80 between the packing and the upper case 51 (seat holding portion 70). [Explanation of symbols]

[0052] 1 Head-up display (HUD) 20 Display device 21 Light source 22 Liquid crystal display element 23 Wiring board 30 plane mirror 40 concave mirror 50 cases 51 Upper case 51a surface 52 Lower case 53 Locking part 55 Interior Space 56 Aperture 56c Opening periphery 60 Translucent sheet 60a surface 60c seat perimeter 62 Sheet hole (an example of a through hole) 62a Gap 63 Temporary fixing notch 70 Seat holding part 70a convex surface 73 Fixing hole 73a Recess 73b Second Wall 80 fixed frames 81 Main Unit 81b Back 81c outer edge 81d Common-law marriage 82 Outer edge leg 83 Inner edge leg 84 Fixing pin 85 The First Wall 86 Temporary fixing hook L display light

Claims

1. a display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on the periphery of the opening and holding the periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through-hole through which the fixing pin passes, the sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case; The fixing frame has a first wall that abuts against the periphery of the through hole. Head-up display.

2. The sheet holding portion has a second wall that is inserted into the through hole and is higher than the light-transmitting sheet. The head-up display according to claim 1 .

3. A display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on the periphery of the opening and holding the periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through-hole through which the fixing pin passes, the sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case; The sheet holding portion has a second wall that is inserted into the through hole and is higher than the light-transmitting sheet. Head-up display.

4. The fixing frame has a first wall that abuts against the periphery of the through hole. The head-up display according to claim 3 .

5. A display device that outputs display light; a light-transmitting sheet having a light-transmitting property and a sheet periphery; a case for accommodating the display device, the case including: an opening covered with the light-transmitting sheet and for emitting the display light to the outside through the light-transmitting sheet; and a sheet holding portion located on the periphery of the opening and holding the periphery of the sheet; a fixing frame that covers the periphery of the sheet and fixes the light-transmitting sheet to the sheet holding portion, The fixing frame has a fixing pin, the light-transmitting sheet has a through-hole through which the fixing pin passes, the sheet holding portion fixes the light-transmitting sheet between the fixing frame and the fixing pin by fixing the fixing pin to a fixing hole provided in the case; the light-transmitting sheet is fixed in a curved state, The fixing frame is provided at a portion of the light-transmitting sheet that has the largest curvature among portions corresponding to the curvature of the light-transmitting sheet, and has a locking portion that is locked to the case. Head-up display.

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