Fixing structure and fixing method

Abstract

To provide a novel technique which makes it hard that dust or water infiltrates into an opening of a case of a head-up display.SOLUTION: A fixing structure fixes a translucent sheet 18 covering an opening of a case 16 constituting a head-up display to a case with a fixing member 28. A part of an edge of the opening has a curved shape. The fixing member 28 biases the translucent sheet 18 from its outer edge part toward its center, and fixes the translucent sheet 18 to the case 16 with the translucent sheet 18 bent along the curved shape of the opening.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a technique for fixing a light-transmitting sheet to a case of a head-up display. [Background technology]

[0002] Head-up displays (hereinafter sometimes referred to as HUDs) have been devised that project images onto the windshield to enable the driver to read information when viewing the road ahead of the vehicle. HUDs generate display light that shows an image on a display device, which is then reflected by a reflective member such as a concave mirror and emitted to the outside of the device through an opening in the case. The emitted display light illuminates a transmissive reflective member such as a windshield, and the light reflected by the transmissive reflective member causes the viewer to view a virtual image.

[0003] The opening of the case is covered with a light-transmitting sheet to prevent dust and water from entering the case. The opening of the case covered with the light-transmitting sheet is curved so that external light reflected by the light-transmitting sheet is not directed toward the area illuminated by the display light on the windshield. Therefore, some ingenuity is required when attaching the light-transmitting sheet to the opening of the case.

[0004] For example, a HUD has been devised in which the positions of multiple holes on each side of a light-transmitting sheet are aligned with the positions of holes on the edge of the opening of the case, and a fixing frame with fixing pins corresponding to each hole is fixed to the case from above the light-transmitting sheet (see Patent Document 1). The fixing frame is fixed to the case with the light-transmitting sheet sandwiched between them by welding the fixing pins that pass through each hole and protrude from the back side of the case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-50817 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when fixing a light-transmitting sheet to a case with fixing pins as in the above-mentioned HUD, if the spacing between the fixing pins is too wide or if the positions of the holes in the light-transmitting sheet or the holes on the edge of the opening are misaligned due to manufacturing variations, the light-transmitting sheet will not follow the curved shape of the opening, and a gap may form between the light-transmitting sheet and the case.In addition, the above-mentioned HUD requires a fixing frame and a process for welding the fixing pins, which increases material costs and manufacturing costs.

[0007] The present invention has been made in consideration of these circumstances, and one of its exemplary purposes is to provide a new technology that makes it difficult for dust and water to enter through the opening of the case of a head-up display. [Means for solving the problem]

[0008] In order to solve the above problems, one embodiment of the fixing structure of the present invention is a fixing structure in which a light-transmitting sheet covering an opening of a case constituting a head-up display is fixed to the case with a fixing member, wherein part of the edge of the opening has a curved shape, and the fixing member biases the light-transmitting sheet from the outer edge toward the center, fixing the light-transmitting sheet to the case in a state in which the light-transmitting sheet is bent to conform to the curved shape of the opening.

[0009] According to this embodiment, the light-transmitting sheet can be fixed along the shape of the opening, making it difficult for dust and water to enter through the opening of the case.

[0010] The light-transmitting sheet is a rectangular sheet having a pair of opposing sides that follow the curved shape and two other sides different from the pair of sides, and at least one of the other two sides may have a recess or hole formed in the outer edge portion thereof for holding the fixing member, thereby allowing the light-transmitting sheet to hold the fixing member in a state where it is biased from the outer edge portion toward the center.

[0011] The case may have a locking portion that locks the fixing member at a predetermined position, whereby the fixing member is locked at a predetermined position on the case when the light-transmitting sheet is in a deformed state.

[0012] The opening may have a rectangular edge in a front view, and the edge may have a pair of opposing straight portions and a pair of opposing curved portions. The locking portions may be provided on the outer sides of the pair of opposing straight portions. This allows the direction in which the fixing member is inserted into the locking portions to be aligned with the direction in which the fixing member biases the light-transmitting sheet.

[0013] The fixing member may be formed with a plurality of convex or concave portions in a direction that biases the light-transmitting sheet from the outer edge toward the center, and the locking portion may be formed with a plurality of concave or convex portions corresponding to the plurality of convex or concave portions, so that the fixing member is locked at a predetermined position selected from a plurality of positions, thereby making it possible to adjust the amount of biasing and deflection of the light-transmitting sheet.

[0014] The curved shape may have a radius of curvature of 50 to 500 mm, which allows the light-transmitting sheet to easily conform to the shape of the opening due to the restoring force of the bent light-transmitting sheet.

[0015] Another aspect of the present invention is a fixing method for fixing a light-transmitting sheet covering an opening of a case constituting a head-up display to the case with a fixing member, the opening having a curved edge, and the fixing member biasing the light-transmitting sheet from the outer edge toward the center, bending the light-transmitting sheet to conform to the curved shape of the opening, thereby fixing the light-transmitting sheet to the case.

[0016] According to this embodiment, the light-transmitting sheet can be fixed along the shape of the opening, making it difficult for dust and water to enter through the opening of the case.

[0017] Any combination of the above components, and any conversion of the present invention between a manufacturing method, an apparatus such as an image projection device or an image display device, a light emitting module, a light source, etc. are also effective as aspects of the present invention. [Effects of the Invention]

[0018] According to the present invention, dust and water are less likely to enter through the opening of the case of the head-up display. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic cross-sectional view of a head-up display (HUD) according to an embodiment of the present invention, viewed from the side. [Figure 2] FIG. 2 is a top view of the case according to the present embodiment, seen from the front of the opening. [Figure 3] FIG. 2 is a top view of a light-transmitting sheet according to the present embodiment. [Figure 4] FIG. 2 is a perspective view of a fixing member according to the present embodiment. [Figure 5] 10A and 10B are schematic diagrams illustrating a locking portion that locks a fixing member. [Figure 6] 10 is a schematic diagram showing a state in which the light-transmitting sheet is bent to conform to the curved shape of the opening portion. FIG. [Figure 7] 10A and 10B are schematic diagrams for explaining a method for fixing the light-transmitting sheet to the case with a fixing member. [Figure 8] 10 is a perspective view showing a state in which the light-transmitting sheet is fixed to the case by the fixing member, as viewed from below the straight portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, the embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0021] FIG. 1 is a schematic cross-sectional side view of a head-up display (HUD) according to this embodiment. The HUD 10 shown in FIG. 1 is an image projection device that projects an image onto a windshield 12. The HUD 10 is configured to display predetermined information as an image to a vehicle user so that the image is superimposed on the real space outside the vehicle (particularly, the surrounding environment ahead of the vehicle). The image information displayed by the HUD 10 is, for example, vehicle driving information related to the driving of the vehicle and / or surrounding environment information related to the surrounding environment of the vehicle (particularly, information related to objects present outside the vehicle).

[0022] At least a portion of the HUD 10 is located inside the vehicle. Specifically, the HUD 10 is installed in a predetermined location inside the vehicle. For example, the HUD 10 is disposed in the dashboard of the vehicle.

[0023] As shown in FIG. 1, the HUD 10 includes an image display main body 14. The image display main body 14 has a case 16 and a light-transmitting sheet 18. The light-transmitting sheet 18 is made of a flexible material that transmits visible light (e.g., polycarbonate resin or acrylic resin). The image display main body 14 has an image output unit 20, a plane mirror 22, and a concave mirror 24 inside the case 16. Note that the plane mirror 22 may be replaced with a concave mirror or a convex mirror.

[0024] The image output unit 20 is installed within the case 16 so as to emit light upward. Specifically, the image output unit 20 has an image display unit such as a liquid crystal display or an organic EL display at its upper part. The plane mirror 22 is arranged on the optical path of the light emitted from the image output unit 20. Specifically, the plane mirror 22 is arranged above the image output unit 20 and is configured to reflect the light emitted from the image output unit 20 toward the concave mirror 24.

[0025] The concave mirror 24 is disposed on the optical path of light emitted from the image output unit 20 and reflected by the plane mirror 22. Specifically, the concave mirror 24 is disposed in front of the image output unit 20 and the plane mirror 22 within the case 16. The concave mirror 24 is configured to reflect the light emitted from the image output unit 20 toward the windshield 12. The concave mirror 24 has a reflective surface that is concavely curved to form a predetermined image, and reflects the light image emitted from the image output unit 20 and formed thereon at a predetermined magnification. The concave mirror 24 includes, for example, a drive mechanism 26, and is configured to change the position and orientation of the concave mirror 24 based on a control signal transmitted from the display control unit. The display control unit is housed within the image output unit 20.

[0026] Light emitted from the image output unit 20 is reflected by the plane mirror 22 and the concave mirror 24, and passes through the light-transmitting sheet 18 that covers the opening 16a of the case 16 before being emitted to the outside. The light emitted from the light-transmitting sheet 18 is irradiated onto the windshield 12. A portion of the light irradiated onto the windshield 12 is reflected toward the user's viewpoint E. As a result, the user perceives the light emitted from the image display main body 14 as a virtual image formed at a predetermined distance in front of the windshield 12. As a result of the image displayed by the windshield 12 being superimposed on the real space in front of the vehicle through the windshield 12, the user can visually perceive a virtual image object I formed by the predetermined image as floating above the road outside the vehicle.

[0027] As described above, the light-transmitting sheet 18 according to this embodiment has a curved shape so that external light reflected by the light-transmitting sheet 18 is not directed toward the area illuminated by the display light on the windshield 12. Therefore, some ingenuity is required when fixing the light-transmitting sheet 18 to the case in a curved state.

[0028] Fig. 2 is a top view of the case according to this embodiment, seen from the front of the opening. Fig. 3 is a top view of the light-transmitting sheet according to this embodiment. Fig. 4 is a perspective view of the fixing member according to this embodiment. Fig. 5 is a schematic diagram for explaining a locking portion that locks the fixing member. Fig. 6 is a schematic diagram showing a state in which the light-transmitting sheet is bent to follow the curved shape of the opening.

[0029] As shown in FIG. 2, the opening 16a of the case 16 has a flange (edge) 16b that is rectangular in shape when viewed from the front. The flange 16b has a pair of opposing straight portions 16c and a pair of opposing curved portions 16d. The straight portion 16c has a plurality of through-holes 16e formed therein that correspond to the shape of a fixing member, which will be described later. The through-holes 16e according to this embodiment are provided one on each side of the longitudinal center of the straight portion 16c. Note that the through-holes 16e may extend to the outer edge of the flange 16b.

[0030] As shown in Fig. 3, the light-transmitting sheet 18 is a rectangular sheet having a pair of opposing sides 18a, 18a that follow a curved shape and two other sides 18b, 18b that are different from the pair of sides. Recesses (notches) 18c that hold fixing members (described later) are formed on the outer edges of the other two sides 18b, 18b. Note that the recesses 18c may be replaced by holes that do not extend to the outer edges. Note that the light-transmitting sheet 18 may also be a fan-shaped sheet.

[0031] 4, fixing member 28 has rectangular plate-shaped base 28b with protrusions 28a formed on the top thereof for pinching or pressing with fingers, columnar portion 28c extending downward from the bottom of plate-shaped base 28b, and protrusions 28d protruding to the left and right from the tip of the columnar portion. Notches 28e are formed on the top surface of protrusion 28d, with multiple protrusions and recesses arranged alternately in a direction that urges light-transmitting sheet 18 from the outer edge toward the center.

[0032] 5 shows the through-hole 16e formed in the straight portion 16c of the case 16 as viewed from the back side. On the outer side of the lower surface (back side) of the straight portion 16c, a locking portion 16f is formed, which has a plurality of recesses or protrusions corresponding to the shape of the notch 28e of the fixing member 28. This allows the locking portion 16f to lock the fixing member 28 at a predetermined position selected from a plurality of positions.

[0033] The fixing member 28 is attached to the recess 18c of the light-transmitting sheet 18, and as shown in Fig. 6, two sides 18b, 18b of the light-transmitting sheet 18 are biased from the outer edge toward the center, and the light-transmitting sheet 18 is fixed to the case 16 in a state where it is bent to fit along the curved shape of the curved portion 16d of the flange 16b of the case 16. In other words, the fixing structure according to this embodiment fixes the light-transmitting sheet 18, which covers the opening 16a of the case 16 that constitutes the head-up display, to the case 16 with the fixing member 28. As a result, the fixing structure according to this embodiment can fix the light-transmitting sheet 18 along the shape of the opening 16a, making it difficult for dust and water to enter the inside of the case 16 through the opening 16a of the case 16.

[0034] Fig. 7 is a schematic diagram illustrating a method for fixing a light-transmitting sheet to a case with a fixing member. Fig. 8 is a perspective view of the state in which the light-transmitting sheet is fixed to the case with the fixing member, viewed from below the linear portion 16c. As shown in Fig. 7, with the fixing member 28 attached to the recess 18c of the light-transmitting sheet 18, the protruding portion 28d of the fixing member 28 is inserted from above into the wide insertion portion 16g of the through-hole 16e. This allows the light-transmitting sheet 18 to hold the fixing member 28 while being biased from the outer edge toward the center.

[0035] In this state, as shown in Fig. 8, the protruding portion 28d is shifted in the direction of the arrow while the guide portion 16h, which is narrower than the insertion portion 16g, guides the columnar portion 28c, and the protruding portion 28d is stopped at a predetermined position where the bent light-transmitting sheet 18 follows the shape of the curved portion 16d of the case 16. This makes it possible to adjust the amount of bias applied to the light-transmitting sheet 18 to bend. At this time, the restoring force of the bent light-transmitting sheet 18 biases the notch 28e of the fixing member 28 into the locking portion 16f, thereby engaging the notch 28e, and the fixing member 28 is fixed to the case 16. Furthermore, the direction in which the fixing member 28 is inserted into the locking portion 16f and the direction in which the fixing member 28 biases the light-transmitting sheet 18 can be aligned.

[0036] The shape of the curved portion 16d of the case 16 may have a radius of curvature R shown in Fig. 6 in the range of 50 to 500 mm. This allows the restoring force of the bent light-transmitting sheet 18 to easily conform to the curved shape of the opening 16a. The portion surrounding the opening 16a of the case 16 may be entirely flat, with no curved portion. In this case, the radius of curvature R of the light-transmitting sheet 18 is substantially infinite.

[0037] The fixing method according to this embodiment is a method in which the light-transmitting sheet 18, which covers the opening 16a of the case 16 constituting the HUD 10, is fixed to the case 16 with a fixing member 28. In this method, at least a portion of the curved portion 16d of the opening 16a has a curved shape, and the fixing member 28 biases the light-transmitting sheet 18 from the outer edge toward the center, causing the light-transmitting sheet 18 to bend along the curved shape of the opening 16a, thereby fixing the light-transmitting sheet 18 to the case 16.

[0038] In the HUD 10 according to the present embodiment, each of the pair of straight portions 16c is provided with through-holes 16e for holding two fixing members 28, but it is also possible to provide a through-hole 16e on only one of the pair of straight portions 16c, and provide an abutment portion on the other that abuts against the side 18b of the light-transmitting sheet 18. This reduces the number of fixing members used and also reduces the amount of work required during manufacturing.

[0039] Although the present invention has been described above with reference to the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and suitable combinations and substitutions of the configurations of the embodiments are also included in the present invention. Furthermore, it is possible to suitably rearrange the combinations and processing orders in the embodiments based on the knowledge of those skilled in the art, and to make modifications to the embodiments such as various design changes, and such modified embodiments are also included in the scope of the present invention. [Explanation of symbols]

[0040] 10 HUD, 12 windshield, 16 case, 16a opening, 16b flange, 16c straight portion, 16d curved portion, 16e penetration portion, 16f locking portion, 18 light-transmitting sheet, 18a two sides, 18b two sides, 18c recess, 28 fixing member, 28e notch.

Claims

1. A fixing structure for fixing a light-transmitting sheet covering an opening of a case constituting a head-up display to the case with a fixing member, The opening has a curved edge, a fixing structure characterized in that the fixing member urges the light-transmitting sheet from its outer edge toward its center, and fixes the light-transmitting sheet to the case in a state in which the light-transmitting sheet is bent to conform to the curved shape of the opening.

2. 2. The fixing structure according to claim 1, wherein the light-transmitting sheet is a rectangular sheet having a pair of opposing sides that follow the curved shape and two other sides different from the pair of sides, and a recess or a hole for holding the fixing member is formed in the outer edge of at least one of the other two sides.

3. 3. The fixing structure according to claim 1, wherein the case has a locking portion that locks the fixing member at a predetermined position.

4. The opening has a rectangular edge in a front view, the edge has a pair of opposing straight portions and a pair of opposing curved portions; 4. The fixing structure according to claim 3, wherein the locking portions are provided on the outer sides of the pair of opposing linear portions.

5. the fixing member has a plurality of protrusions or recesses formed in a direction that biases the light-transmitting sheet from an outer edge portion toward a center, 5. The fixing structure according to claim 4, wherein the locking portion has a plurality of recesses or convex portions formed thereon corresponding to the plurality of protrusions or concave portions, and is configured to lock the fixing member at a predetermined position selected from a plurality of positions.

6. 3. The fixing structure according to claim 1, wherein the curved shape has a radius of curvature of 50 to 500 mm.

7. A fixing method for fixing a light-transmitting sheet covering an opening of a case constituting a head-up display to the case with a fixing member, comprising: The opening has a curved edge, The fixing member biases the light-transmitting sheet from its outer edge toward its center, The light-transmitting sheet is bent to conform to the curved shape of the opening, A fixing method characterized by fixing the light-transmitting sheet to the case.

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