Optical unit, reflector, and method for manufacturing optical unit

Abstract

A reflector (16) is a resin reflector that has a base surface part (16a) disposed in a state of facing forward of a vehicle and that is fastened to a heat sink. The reflector has: an opening (16b) that is formed at the center in the longitudinal direction so as to allow light emitted from a light source to pass therethrough; a pair of fastening parts (16c) that are formed at both ends in the longitudinal direction and that are fastened to the heat sink; and lateral reflection parts (16d) that are formed in a manner protruding forward from between the pair of fastening parts (16c) and the opening (16b), and that reflect the light having passed through the opening (16b). Deformation transmission suppressing parts that prevent the influence of deformation at the fastening parts (16c) from being transmitted to the lateral reflection parts (16d) are formed between the fastening parts (16c) and the lateral reflection parts (16d).

Description

Optical Unit, Reflector, and Method for Manufacturing Optical Unit

[0001] The present disclosure relates to an optical unit, a reflector, and a method for manufacturing an optical unit.

[0002] Conventionally, a lamp unit including a heat sink, a substrate, a reflector unit, a projection lens, and a holder has been devised (see Patent Document 1). In the lamp unit, the substrate is fixed to the heat sink by pressing the reflector unit against the heat sink. The reflector unit is formed with an opening through which light emitted from a light-emitting element mounted on the substrate passes forward, and a reflecting surface provided so as to project forward from both left and right sides of the opening.

[0003] International Publication No. 2024 / 004959

[0004] However, when a plurality of components including optical components are mounted on the heat sink in the lamp unit, if the shapes of the components, the portions where the components contact each other, the portions where the components are fastened, etc. are not properly considered, the reflecting surface may be deformed when the lamp unit is assembled.

[0005] One object of the present disclosure is to provide a new technique for suppressing deformation of a reflector.

[0006] To solve the above problems, an optical unit according to an aspect of the present disclosure includes a metal heat sink, a substrate on which a light source is mounted and placed at a predetermined position of the heat sink, a lens placed at a predetermined position above the substrate and through which light emitted from the light source passes, and a resin reflector having a seating portion that seats on the substrate with the lens interposed therebetween. The reflector has a pair of fastening portions formed outside the longitudinal end portions of the lens and having a gap with the heat sink in a state where the seating portion seats on the substrate, and a reflecting portion formed between the pair of fastening portions and reflecting the light transmitted through the lens. A deformation transmission suppression portion is formed between the fastening portion and the reflecting portion to suppress the influence of deformation at the fastening portion from being transmitted to the reflecting portion. The pair of fastening portions forms a contact surface that contacts the heat sink when fastened to the heat sink with screws.

[0007] According to this embodiment, the effects of deformation at the fastening point when the reflector is fastened to the heat sink are less likely to be transmitted to the reflective part.

[0008] The deformation transmission suppression section may be a slit formed near the fastening section. This allows the deformation transmission suppression section to be realized with a simple shape.

[0009] The reflector may have a recessed step on the contact surface side between the fastening portion and the area where the slit is formed. This reduces the gap between the fastening portion of the reflector and the heat sink before fastening.

[0010] Another aspect of the present disclosure is a reflector. The reflector is made of resin and is positioned with its main surface facing the front of the vehicle and fastened to a heat sink, and has an opening formed in the center in the longitudinal direction through which light emitted from a light source passes, a pair of fastening parts formed at both ends in the longitudinal direction and fastened to the heat sink, and a reflective part formed to protrude forward from between the pair of fastening parts and the opening and to reflect the light that has passed through the opening, and a deformation transmission suppression part is formed between the fastening parts and the reflective part to suppress the transmission of the effects of deformation at the fastening parts to the reflective part.

[0011] According to this embodiment, the effects of deformation at the fastening point when the reflector is fastened to the heat sink are less likely to be transmitted to the reflective part.

[0012] A further aspect of this disclosure is a method for manufacturing an optical unit. This method includes the steps of: placing a substrate on which a light source is mounted in a predetermined position on a metal heat sink; placing a lens through which light emitted from the light source is transmitted in a predetermined position on the substrate; seating a resin reflector on the substrate with the lens in between; and fastening the reflector to the heat sink. The reflector has a pair of fastening portions located outside the lens, with a gap between them and the heat sink when seated on the substrate. The fastening step involves fastening the fastening portions to the heat sink while flexing them.

[0013] In this embodiment, the lens is securely fixed between the reflector and the heat sink by fastening the reflector to the heat sink while allowing the fastening portion of the reflector to bend.

[0014] The reflector may have a reflective portion between a pair of fastening portions that reflects light that has passed through the lens.

[0015] Any combination of the above components, as well as conversions of the expressions of this disclosure between manufacturing methods, devices such as luminaires and lighting fixtures, light-emitting modules, light sources, etc., are also valid embodiments of this disclosure.

[0016] According to this disclosure, the reflector is less likely to deform when manufacturing an optical unit consisting of multiple components.

[0017] This is a perspective view of a vehicle light fixture according to this embodiment. This is an exploded perspective view of the vehicle light fixture shown in Figure 1. This is a front view of the reflector according to this embodiment. This is a horizontal cross-sectional view of the optical unit according to this embodiment. This is an enlarged cross-sectional view showing the state of the fastening portion in area A of Figure 4 before it is fastened with screws. This is an enlarged cross-sectional view showing the state of the fastening portion in area A of Figure 4 after it has been fastened with screws.

[0018] The present disclosure will be described below with reference to the drawings, based on preferred embodiments. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant descriptions will be omitted as appropriate. Furthermore, the embodiments are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention.

[0019] Figure 1 is a perspective view of a vehicle light fixture according to this embodiment. Figure 2 is an exploded perspective view of the vehicle light fixture shown in Figure 1. The vehicle light fixture 10 shown in Figures 1 and 2 is a vehicle headlight and is configured to form both low beam and high beam light distribution patterns.

[0020] The vehicle light fixture 10 comprises a projection lens 12, a lens holder 14, a reflector 16, a circuit board 18, and a heat sink 20. The projection lens 12 is mounted in a predetermined position on the lens holder 14. The projection lens 12 is manufactured by injection molding using a resin material with high transparency and heat resistance, such as acrylic or polycarbonate. The lens holder 14 is fastened to the heat sink 20 by screws 22.

[0021] Figure 3 is a front view of a reflector according to this embodiment. The reflector 16 is made of a resin material. The reflector 16 has a horizontally elongated base surface portion 16a facing in the front-rear direction, an opening 16b formed in the center of the reflector 16, and lateral reflective portions 16d provided so as to protrude forward from both the left and right sides of the opening 16b.

[0022] A plate-shaped member, a shade 24, is attached to the lower surface of the lateral reflector 16d. The shade 24 protrudes forward from the opening 16b. The shade 24 is held by the reflector 16 so that its plate surface is aligned with the horizontal direction of the vehicle.

[0023] The circuit board 18 includes a first light source 30a, a second light source 30b, and a drive circuit (not shown) for driving each light-emitting element. The first light source 30a has a plurality of light-emitting elements 28a arranged in a horizontal row to form a light distribution pattern for low beam. The second light source 30b has a plurality of light-emitting elements 28b arranged in a horizontal row to form a light distribution pattern for high beam.

[0024] The second light source 30b is positioned adjacent to the first light source 30a. The first light source 30a is located on the upper side, and the second light source 30b is located on the lower side. The drive circuit is a combination of passive elements such as capacitors and coils, active elements such as transistors and diodes, an IC chip, memory, etc. The drive circuit functions as a control unit that controls the on / off switching of the first light source 30a and the second light source 30b. The circuit board 18 is the mounting section on which each light source is mounted, and is fixed to a predetermined position on the heat sink 20.

[0025] In front of the first light source 30a and the second light source 30b, a resin plate 32 is positioned which functions as a lens that deflects the light emitted from the first light source 30a and the second light source 30b. Specifically, the resin plate 32 has lens portions formed laterally, corresponding to the number of light sources in the first light source 30a and the second light source 30b. The lens portions deflect the light from the light sources in a predetermined direction. The light transmitted through the resin plate 32 forms the light distribution pattern of the vehicle lamp 10, consisting of a component that directly enters the projection lens 12 and a component that is reflected by the shade 24 or the side reflector 16d before entering the projection lens 12. The resin plate 32 is sandwiched between the reflector 16 and the circuit board 18. In this state, the positional relationship of each component is determined when the reflector 16 is fastened to the heat sink 20 with screws 36.

[0026] The optical unit 40 according to this embodiment comprises a metal heat sink 20, a circuit board 18, a resin plate 32, and a resin reflector 16, which are components of the vehicle lighting device 10 described above. The circuit board 18 is mounted on a first light source 30a and a second light source 30b, which are placed at predetermined positions on the heat sink 20. The resin plate 32 functions as a lens through which light emitted from each light source placed at predetermined positions on the circuit board 18 is transmitted. The reflector 16 has a seating portion that sits on the circuit board 18 with the resin plate 32 in between.

[0027] Figure 4 is a horizontal cross-sectional view of the optical unit according to this embodiment. Figure 5A is an enlarged cross-sectional view showing the state of the fastening portion in area A of Figure 4 before it is fastened with screws. Figure 5B is an enlarged cross-sectional view showing the state of the fastening portion in area A of Figure 4 after it has been fastened with screws.

[0028] As shown in Figure 4, the reflector 16 has a seating portion 16e on the side opposite to the side on which the lateral reflecting portion 16d is provided. The seating portion 16e sits on the upper surface of the circuit board 18. The reflector 16 also has a pair of fastening portions 16c formed outside the longitudinal end (left-right direction in Figure 4) of the resin plate 32. In other words, the lateral reflecting portion 16d is formed between the pair of fastening portions 16c and reflects light that has passed through the resin plate 32.

[0029] Next, the fastening portion 16c will be described in detail. As shown in Figure 5A, in each of the pair of fastening portions 16c, when the seating portion 16e is seated on the circuit board 18 and before fastening with the screws 36, a gap G is formed between it and the heat sink 20. When the fastening portion 16c is fastened to the heat sink 20 with the screws 36 (see Figure 5B), the contact surface 16f on the back side of the fastening portion 16c comes into contact with the heat sink 20. At that time, the fastening portion 16c deforms in the direction of arrow B, so the lateral reflecting portion 16d in the center of the reflector 16 may be displaced in the direction of arrow C. If the lateral reflecting portion 16d is displaced in the direction of arrow C, the light reflected by the lateral reflecting portion 16d will be deviated from the desired direction, which may cause glare to pedestrians or oncoming vehicles.

[0030] Therefore, in the reflector 16 according to this embodiment, a deformation transmission suppression portion is formed between the fastening portion 16c and the lateral reflecting portion 16d to suppress the transmission of the deformation effect at the fastening portion 16c to the lateral reflecting portion 16d. As a result, the deformation effect at the fastening portion 16c when the reflector 16 is fastened to the heat sink 20 is less likely to be transmitted to the lateral reflecting portion 16d. Therefore, the influence of the shift in the direction of the light reflected by the lateral reflecting portion 16d on the light distribution pattern can be suppressed. Specifically, the deformation transmission suppression portion according to this embodiment is a slit 16g formed near the fastening portion 16c. This makes it possible to realize the deformation transmission suppression portion with a simple shape. It should be noted that the deformation transmission suppression portion can also be realized by providing a thin-walled portion or a hollowed-out portion between the fastening portion 16c and the lateral reflecting portion 16d.

[0031] Furthermore, the reflector 16 is provided with an arc-shaped step 16h recessed on the contact surface 16f side between the fastening portion 16c and the region where the slit 16g is formed. This reduces the gap G between the fastening portion 16c of the reflector 16 and the heat sink 20 before fastening. In other words, the amount of deflection of the reflector 16 in the B direction when fastened is reduced.

[0032] Furthermore, the reflector 16 can also be considered as a component having the following characteristics. For example, in the reflector 16 according to this embodiment, the main surface, the base surface portion 16a, is positioned so as to face the front of the vehicle and is a resin component fastened to the heat sink 20. An opening 16b is formed in the center of the longitudinal direction through which light emitted from each light source passes. A pair of fastening portions 16c are formed at both ends in the longitudinal direction and fastened to the heat sink 20. A lateral reflecting portion 16d is formed so as to protrude forward from between the pair of fastening portions 16c and the opening 16b and reflects the light that has passed through the opening 16b. A slit 16g is formed between the fastening portion 16c and the lateral reflecting portion 16d to suppress the influence of deformation at the fastening portion 16c from being transmitted to the lateral reflecting portion 16d.

[0033] It can also be considered as a method for manufacturing the optical unit 40 equipped with the reflector 16 described above. For example, the method for manufacturing the optical unit 40 according to this embodiment includes the steps of: placing a circuit board 18 on which each light source is mounted in a predetermined position on a metal heat sink 20; placing a resin plate 32 through which light emitted from each light source is transmitted in a predetermined position on the circuit board 18; seating a resin reflector 16 on the circuit board 18 with the resin plate 32 in between; and fastening the reflector 16 to the heat sink 20 with screws 36. The fastening step involves fastening the fastening portion 16c to the heat sink 20 while bending it toward the heat sink 20. By doing so, the resin plate 32 can be firmly fixed between the reflector 16 and the heat sink 20 by fastening the fastening portion 16c of the reflector 16 to the heat sink 20 while bending it.

[0034] Although the present disclosure has been described above with reference to the embodiments described above, the present disclosure is not limited to the embodiments described above, and includes combinations and substitutions of the configurations of the embodiments as appropriate. Furthermore, it is possible to rearrange the combinations and processing order in the embodiments or to make various design changes and other modifications to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included in the scope of the present disclosure.

[0035] This application claims priority under Japanese Patent Application No. 2024-199999, filed on November 15, 2024, and incorporates all the provisions contained herein.

Claims

1. An optical unit comprising: a metal heat sink; a substrate on which a light source is mounted, placed at a predetermined position on the heat sink; a lens through which light emitted from the light source is transmitted, placed at a predetermined position on the substrate; and a resin reflector having a seating portion that sits on the substrate with the lens in between, wherein the reflector has a pair of fastening portions formed outside the longitudinal end of the lens, with a gap between them and the heat sink when the seating portion is seated on the substrate; and a reflective portion formed between the pair of fastening portions that reflects light transmitted through the lens, wherein a deformation transmission suppression portion is formed between the fastening portion and the reflective portion to suppress the transmission of the effect of deformation at the fastening portion to the reflective portion, and the pair of fastening portions form a contact surface that abuts against the heat sink when fastened to the heat sink with screws.

2. The optical unit according to claim 1, wherein the deformation transmission suppression portion is a slit formed near the fastening portion.

3. The optical unit according to claim 2, wherein the reflector is provided with a recessed step on the contact surface side between the fastening portion and the region where the slit is formed.

4. A resin reflector positioned with its main surface facing the front of the vehicle and fastened to a heat sink, wherein an opening is formed in the center of the longitudinal direction through which light emitted from a light source passes, a pair of fastening parts are formed at both ends in the longitudinal direction and fastened to the heat sink, and a reflective part is formed to protrude forward from between the pair of fastening parts and the opening and reflects the light that has passed through the opening, and a deformation transmission suppression part is formed between the fastening parts and the reflective part to suppress the transmission of the effect of deformation at the fastening parts to the reflective part.

5. A method for manufacturing an optical unit, comprising the steps of: placing a substrate on which a light source is mounted in a predetermined position on a metal heat sink; placing a lens through which light emitted from the light source is transmitted in a predetermined position on the substrate; seating a resin reflector on the substrate with the lens in between; and fastening the reflector to the heat sink, wherein the reflector has a pair of fastening portions provided outside the lens, with a gap between them and the heat sink when seated on the substrate, and the fastening step includes fastening the fastening portions to the heat sink while bending them.

6. The method for manufacturing an optical unit according to claim 5, wherein the reflector has a reflective portion between the pair of fastening portions that reflects light transmitted through the lens.

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