Vehicle lighting unit

Abstract

To provide a novel technique capable of reducing influence of heat of a light source.SOLUTION: A vehicular lighting fixture unit includes: a first light source 20a; a second light source 20b disposed adjacently to the first light source; a reflector 16 having a first reflection surface 17a for reflecting a part of light L1 emitted from the first light source toward the front of a lighting fixture, a second reflection surface 17b for reflecting a part of light L2 emitted from the second light source toward the front of the lighting fixture, and a main back surface 17c confronting an emission surface of the first light source 20a and an emission surface of the second light source 20b; and a metal plate having a main shielding portion 18f for shielding the light going from the first light source 20a to the main back surface 17c and the light going from the second light source 20b to the main back surface 17c.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle lighting unit. [Background technology]

[0002] Conventionally, there has been known a vehicle lamp in which a plurality of LEDs that form a low beam light distribution pattern and a high beam light distribution pattern are mounted in an array on a circuit board. For example, a vehicle lamp has been devised that includes a circuit board on which a plurality of LEDs arranged in two rows, one above the other, are mounted so that their light-emitting surfaces face forward of the vehicle lamp, a reflector that is disposed in front of the circuit board and reflects a portion of the light emitted from the LEDs to form a low beam light distribution pattern and a high beam light distribution pattern, and a projection lens that projects the light emitted from the LEDs forward of the lamp (Patent Document 1).

[0003] In this vehicle lamp, the LEDs arranged in the left-right direction on the upper row of two rows (upper and lower) emit light that mainly forms a low-beam light distribution pattern, while the LEDs arranged in the left-right direction on the lower row emit light that mainly forms a high-beam light distribution pattern. The reflector is made of a metal material such as aluminum that has high thermal conductivity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 22 / 009683 Pamphlet Summary of the Invention [Problem to be solved by the invention]

[0005] However, the reflector provided in the above-mentioned vehicle lamp is a single component made entirely of metal, which increases the weight of the component and tends to increase the material cost. Therefore, by constructing the reflector from a resin material, it is possible to reduce the weight and cost, but compared to a metal reflector, it is more susceptible to the heat of the light source.

[0006] The present invention has been made in view of the above circumstances, and one of its exemplary purposes is to provide a new technique for mitigating the influence of heat from a light source. [Means for solving the problem]

[0007] In order to solve the above problems, a vehicle lighting unit according to one embodiment of the present invention comprises a first light source, a second light source arranged adjacent to the first light source, a first reflective surface that reflects a portion of the light emitted from the first light source toward the front of the lamp, a second reflective surface that reflects a portion of the light emitted from the second light source toward the front of the lamp, a reflector having a main back surface facing the emission surface of the first light source and the emission surface of the second light source, and a metal plate having a main shielding portion that shields light traveling from the first light source toward the main back surface and light traveling from the second light source toward the main back surface.

[0008] According to this embodiment, the metal plate can block light from the first light source and the second light source toward the main rear surface of the reflector, thereby suppressing a rise in temperature of the reflector. Therefore, the reflector can be made of an inexpensive and lightweight material such as resin, rather than an expensive and heavy material such as a heat-resistant metal or ceramic material.

[0009] The metal plate may have a thickness of 0.2 to 0.6 mm, which allows each light source to be closer to the reflector in order to increase the efficiency of use of light emitted from the light source, even when the metal plate is disposed between the light source and the reflector.

[0010] The reflector may further include an upper reflector having a third reflecting surface facing the first reflecting surface and reflecting a portion of the light emitted from the first light source toward the front of the lamp, and a lower reflector having a fourth reflecting surface facing the second reflecting surface and reflecting a portion of the light emitted from the second light source toward the front of the lamp. The upper reflector may have an upper back surface facing the emission surface of the first light source. The lower reflector may have a lower back surface facing the emission surface of the second light source. The metal plate may have an upper shielding portion that blocks light traveling from the first light source toward the upper back surface and a lower shielding portion that blocks light traveling from the second light source toward the lower back surface. This allows the metal plate to block light traveling from the first light source toward the upper back surface of the reflector and light traveling from the second light source toward the lower back surface of the reflector, thereby suppressing temperature rise in the reflector.

[0011] The reflector may have shade portions at the tips of the first and second reflecting surfaces, which form cutoff lines of the light distribution pattern. The shade portions may be made of a resin made of a liquid crystal polymer and have a thickness of 0.2 mm or less. By forming the reflector from a resin made of a liquid crystal polymer, a reflector having a shade with a thickness of 0.2 mm or less can be formed by molding, thereby reducing the manufacturing cost of the reflector.

[0012] The lamp may further include a projection lens for projecting a light distribution pattern in front of the lamp using light emitted from at least one of the first light source and the second light source, and a circuit board on which the first light source and the second light source are mounted. A drive circuit for driving the first light source and the second light source is mounted below the first light source and the second light source on the circuit board, and the metal plate may further include a circuit protection part extending from the lower shielding part below the lamp so as to be positioned between the drive circuit and the projection lens. In this way, when sunlight enters from outside through the projection lens, the drive circuit, which is located in a position inside the lamp where light is likely to be collected, can be prevented from being damaged by heat by the circuit protection part.

[0013] The reflector may be fixed to the main shielding portion. Here, "fixed" includes cases where the reflector and each shielding portion are integrated by laser welding or adhesive bonding, or where the two parts are firmly integrated by insert molding, in which a metal plate is placed in a mold and a resin that will become the reflector is injected. This allows the reflector and main shielding portion to be used as a single part that has been precisely positioned in advance, and is used in assembling the vehicle lighting unit.

[0014] The reflector may be provided with a positioning pin protruding from the rear surface thereof toward the opposite side to the front of the vehicle, and the metal plate may be formed with a positioning hole into which the positioning pin is inserted, thereby directly positioning the metal plate relative to the reflector.

[0015] Any combination of the above components, and conversion of the present invention between a manufacturing method, a lighting fixture or lighting device, a light emitting module, a light source, etc. are also valid aspects of the present invention. [Effects of the Invention]

[0016] According to the present invention, the influence of heat from the light source on the reflector can be reduced. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a side view showing a schematic configuration of a vehicle lamp according to an embodiment of the present invention; [Figure 2] 1 is a perspective view of a main part of a vehicle lighting unit according to an embodiment of the present invention; [Figure 3] FIG. 3 is an exploded perspective view of the vehicle lighting unit shown in FIG. 2. [Figure 4] 10 is a schematic diagram of the area between the reflector and the circuit board as viewed from the side of the lamp fixture. FIG. [Figure 5] 3 is a schematic diagram showing the positional relationship of a reflector and a protector with respect to each light source. FIG. [Figure 6] FIG. 2 is an exploded perspective view illustrating the assembly positions of a reflector, a protector, and a heat sink. [Figure 7]FIG. 10 is a rear perspective view showing a state in which the protector is assembled to the reflector. [Figure 8] 5A and 5B are schematic diagrams for explaining the positioning of a reflector, a protector, and a heat sink. DETAILED DESCRIPTION OF THE INVENTION

[0018] 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.

[0019] Fig. 1 is a side view showing a schematic configuration of a vehicle lighting fixture according to this embodiment. Fig. 2 is a perspective view of a main part of a vehicle lighting unit according to this embodiment. Fig. 3 is an exploded perspective view of the vehicle lighting unit shown in Fig. 2. The vehicle lighting unit 10 shown in Figs. 2 and 3 is a vehicle headlamp provided at the front of a vehicle, and is configured to be able to form both a low beam and a high beam light distribution pattern.

[0020] The vehicle lighting fixture 100 comprises a lamp body 2, an outer lens 4 that covers the opening of the lamp body 2, a vehicle lighting unit 10 provided in a lamp chamber 6 surrounded by the lamp body 2 and the outer lens 4, and an aiming mechanism 8 that holds the vehicle lighting unit 10 so that it can be aimed. The vehicle lighting unit 10 comprises a projection lens 12, a lens holder 14, a reflector 16, a protector 18, a circuit board 20, a heat sink 22, and a fan 24.

[0021] The lens holder 14 has a substantially cylindrical lens holding portion 14a and three legs 14b protruding from the lens holding portion 14a toward the rear of the vehicle. The projection lens 12 is a transparent member integrally formed with a lens main body 12a that controls the optical path of light emitted from the light source and a flange-shaped mounting portion 12b that protrudes outward from the outer periphery of the lens main body 12a. The projection lens 12 is held in the lens holder 14 by aligning the mounting portion 12b of the projection lens 12 with the lens holding portion 14a of the lens holder 14 and fixing them with screws 26. The projection lens 12 is manufactured by injection molding using a highly transparent and heat-resistant resin material such as acrylic or polycarbonate.

[0022] The reflector 16 according to this embodiment is made of a resin material to reduce costs and weight. The reflector 16 has a horizontally long base surface portion 16a facing the front-to-rear direction, side reflecting portions 16c provided so as to protrude forward from both the left and right sides of an opening 16b formed in the center of the reflector 16, an upper reflector 16d whose inner surface of a beam-shaped portion above the opening 16b serves as a reflective surface, and a shade 16e protruding forward from the lower edge of the opening 16b.

[0023] The protector 18 is a component formed, for example, by bending a plate-like metal material into a predetermined shape, and is disposed between the reflector 16 and the circuit board 20. The protector 18 also has a rectangular shielding portion 18c in which two openings 18a, 18b are formed, and a circuit protection portion 18d that protrudes forward in a crank shape from the bottom of the shielding portion 18c. The circuit protection portion 18d prevents sunlight that is incident from outside and concentrated through the projection lens 12 from irradiating a drive circuit for the light source, which will be described later.

[0024] The circuit board 20 includes a first light source 20a having a plurality of light-emitting elements 21a arranged in a horizontal row for forming a low-beam light distribution pattern, a second light source 20b having a plurality of light-emitting elements 21b arranged in a horizontal row for forming a high-beam light distribution pattern, and a drive circuit 20c for driving each of the light-emitting elements. The second light source 20b is disposed adjacent to the first light source 20a. The first light source 20a is located on the upper side, and the second light source 20b is located on the lower side. The drive circuit 20c is a combination of passive elements such as capacitors and coils, active elements such as transistors and diodes, IC chips, memory, etc., and is mounted in a region of the circuit board 20 below the regions where the light sources 20a and 20b are mounted.

[0025] Light emitted from the first light source 20a passes through the opening 18a of the protector 18 and the opening 16b of the reflector 16. At that time, a portion of the light is reflected by the reflective surfaces of the side reflector 16c, the upper reflector 16d, and the shade 16e, and is irradiated toward the projection lens 12 with light distribution control performed. The projection lens 12 projects the light directly arriving from the first light source 20a and the light whose light distribution has been controlled by each reflective surface in a desired light distribution pattern ahead of the vehicle. As a result, on a screen in front of the vehicle, the area below the horizon is mainly illuminated with light of the low-beam light distribution pattern.

[0026] Similarly, light emitted from the second light source 20b passes below the opening 18b of the protector 18 and the shade 16e of the reflector 16. At this time, a portion of the light is reflected by the reflective surface on the lower side of the shade 16e and is irradiated toward the projection lens 12 with light distribution control. The projection lens 12 projects the light directly arriving from the second light source 20b and the light whose light distribution has been controlled by each reflective surface as a desired light distribution pattern ahead of the vehicle. As a result, on the screen in front of the vehicle, the area above the horizon is mainly illuminated with light of the high beam light distribution pattern. In this way, the projection lens 12 projects a light distribution pattern ahead of the lamp using light emitted from at least one of the first light source 20a and the second light source 20b.

[0027] When each of the above light sources is driven, heat is generated from the light sources, the components constituting the drive circuit 20c, wiring, etc. Part of the heat generated from the light sources 20a, 20b, etc. is transferred to the heat sink 22 and dissipated to the outside from various parts of the heat sink 22, particularly the fins 22a. At this time, cooling air generated by the rotation of the cooling fan 24 flows along the fins 22a, improving heat dissipation. The lens holder 14 is fixed to the heat sink 22 with screws 28.

[0028] Next, the positional relationship between the reflector 16 and each light source will be described. Fig. 4 is a schematic diagram of the area between the reflector and the circuit board as viewed from the side of the lamp. As shown in Fig. 4, in the vehicle lamp unit 10 according to this embodiment, the reflector 16 and each light source 20a, 20b are very close to each other. In particular, the shade 16e, which is a part of the reflector 16, is close to both the emission surface (light-emitting surface) of the upper light-emitting element 21a and the emission surface (light-emitting surface) of the lower light-emitting element 21b.

[0029] The shade 16e has a first reflecting surface 17a that reflects a portion of the light L1 emitted from the first light source 20a toward the front of the lamp, a second reflecting surface 17b that reflects a portion of the light L2 emitted from the second light source 20b toward the front of the lamp, and a main back surface 17c that faces the emission surfaces of the light-emitting elements 21a and 21b. Therefore, in this embodiment, a protector 18 having a main shielding portion 18f that shields the light L1' from the light-emitting element 21a toward the main back surface 17c of the reflector 16 and the light L2' from the light-emitting element 21b toward the main back surface 17c is disposed between the circuit board 20 and the reflector 16.

[0030] Therefore, the protector 18 can block light from the first light source 20a and the second light source 20b toward the main back surface 17c of the reflector 16, thereby suppressing a temperature rise in the reflector 16. Therefore, the reflector can be made of an inexpensive and lightweight material such as resin, rather than an expensive and heavy material such as a heat-resistant metal material or ceramic material.

[0031] The reflector 16 according to this embodiment further includes an upper reflector 16d having a third reflecting surface 17d that faces the first reflecting surface 17a and reflects a portion of the light emitted from the first light source 20a toward the front of the lamp. Although not shown in the reflector 16 shown in Figures 2 and 3, the reflector 16 may further include a lower reflector 16g that faces the second reflecting surface 17b and has a fourth reflecting surface 17g that reflects a portion of the light emitted from the second light source 20b toward the front of the lamp.

[0032] The upper reflector 16d has an upper back surface 17h facing the emission surface of the first light source 20a. The lower reflector 16g has a lower back surface 17k facing the emission surface of the second light source 20b. The protector 18 has an upper shielding portion 18g that blocks light traveling from the first light source 20a toward the upper back surface 17h and a lower shielding portion 18h that blocks light traveling from the second light source 20b toward the lower back surface 17k. This allows the protector 18 to block light traveling from the first light source 20a toward the upper back surface 17h of the reflector 16 and light traveling from the second light source 20b toward the lower back surface 17k of the reflector 16, thereby suppressing a temperature rise in the reflector 16.

[0033] The shade 16e forms a cutoff line of the light distribution pattern at the tip portions of the first reflecting surface 17a and the second reflecting surface 17b. The thickness D1 of the tip portion of the shade 16e is 0.2 mm or less and is made of a resin made of a liquid crystal polymer. Liquid crystal polymers exhibit good fluidity even when the molded product is thin, making them suitable for manufacturing parts such as the shade 16e of this embodiment by injection molding. By forming the reflector 16 from a resin made of a liquid crystal polymer in this way, a reflector 16 having a shade 16e with a thickness of 0.2 mm or less can be molded using a mold, thereby reducing the manufacturing cost of the reflector 16.

[0034] The protector 18 according to this embodiment further includes a circuit protection portion 18k extending from the lower shielding portion 18h below the lamp so as to be positioned between the drive circuit 20c and the projection lens 12. As a result, when sunlight S enters from outside through the projection lens 12, the lower shielding portion 18h can prevent damage to the drive circuit 20c, which is located in a place in the lamp where light is likely to be collected, from being caused by heat.

[0035] FIG. 5 is a schematic diagram showing the positional relationship of the protector with respect to the reflector and each light source. Protector 18 according to this embodiment preferably has a metal plate thickness D2 of 0.2 to 0.6 mm. This allows each light source 20a, 20b to be closer to reflector 16, even when protector 18 is disposed between reflector 16 and the light sources 20a, 20b. Furthermore, distance D3 between light-emitting surface S1 of light-emitting elements 21a, 21b and each shielding portion (main shielding portion 18f, upper shielding portion 18g, lower shielding portion 18h) of protector 18 is preferably 0.5 to 0.9 mm. In other words, the shortest distance D4 between light-emitting surface S1 of light-emitting element 21a and main back surface 17c is 0.1 to 0.7 mm, and the shortest distance D5 between light-emitting surface S2 of light-emitting element 21b and main back surface 17c is 0.1 to 0.7 mm.

[0036] Furthermore, it is preferable that the distance between each rear surface (main rear surface 17c, upper rear surface 17h, lower rear surface 17k) of the reflector 16 and the protector 18 is as small as possible, and they may be in contact with each other. As a result, the proportion of light emitted from the light sources that is blocked by the protector 18 decreases, and the efficiency with which the light emitted from each light source is used for actual illumination of the lamp increases.

[0037] The reflector 16 may also be fixed to each shielding portion. Here, "fixed" includes cases where the reflector and each shielding portion are integrated by laser welding or adhesive bonding, or cases where the two parts are firmly integrated by insert molding, in which a metal plate is placed in a mold and a resin that will become the reflector is injected. This allows the reflector and main shielding portion to be positioned accurately in advance as a single part that can be used in assembling the vehicle lighting unit, eliminating the need to align the reflector and protector during assembly.

[0038] Furthermore, if light from each light source toward the first reflecting surface 17a or the second reflecting surface 17b is blocked by the main shielding portion 18f, the desired light distribution pattern may not be formed. Therefore, the width W1 of the main shielding portion 18f for the emitted light is set to be approximately 0.04 to 0.08 mm smaller than the width W2 of the main back surface 17c. In addition, the main shielding portion 18f is arranged so as not to extend beyond the area between two lines A1 and A2 connecting the shortest distance between the exit surface S1 of each light source and the main back surface 17c. Here, the exit surface S1 (S2) is the surface area from which light actually exits.

[0039] In other words, in protector 18, opening width W3 between main shielding portion 18f and upper shielding portion 18g is larger than opening width W4 between first reflecting surface 17a and third reflecting surface 17d. Also, in protector 18, opening width W5 between main shielding portion 18f and lower shielding portion 18h is larger than opening width W6 between second reflecting surface 17b and fourth reflecting surface 17g.

[0040] By setting the size of each part of protector 18 within the range of the above-mentioned conditions, the light traveling from each light source toward first reflecting surface 17a and second reflecting surface 17b is no longer blocked by main shielding portion 18f, and it is possible to avoid vignetting of some of the light necessary to form the desired light distribution pattern.

[0041] As described above, the positioning accuracy of protector 18 relative to reflector 16 is important. For example, if the position of protector 18 relative to reflector 16 is deviated from the correct position, some of the light that would otherwise be vignetted and proceed toward first reflecting surface 17a or second reflecting surface 17b may be blocked by main shielding portion 18f. For example, when positioning reflector 16 and protector 18 relative to heat sink 22, the positioning accuracy of protector 18 relative to reflector 16 is affected by both a positioning error of reflector 16 relative to the heat sink and a positioning error of protector 18 relative to the heat sink.

[0042] Therefore, the vehicle lighting unit 10 according to this embodiment employs a configuration for positioning the protector 18 relative to the reflector 16. Fig. 6 is an exploded perspective view illustrating the assembly positions of the reflector, protector, and heat sink. Fig. 7 is a rear perspective view showing the state in which the protector is assembled to the reflector. Fig. 8 is a schematic view illustrating the positioning of the reflector, protector, and heat sink.

[0043] As shown in Figures 6 and 7, the reflector 16 is provided with a positioning pin 16h that protrudes from the rear surface toward the opposite side to the front of the vehicle. The protector 18 is formed with a positioning hole 18m into which the positioning pin 16h is inserted. The heat sink 22 is formed with a positioning hole 22b into which the positioning pin 16h is inserted. The positioning pin 16h is inserted into the positioning hole 18m and the positioning hole 22b, and they are fixed to each other with a fastening member such as a screw. As a result, as shown in Figure 8, the protector 18 is directly positioned relative to the reflector 16, which improves the positioning accuracy of the protector 18 relative to the reflector 16 compared to when the reflector 16 and the protector 18 are individually positioned relative to the heat sink 22.

[0044] 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]

[0045] 10 vehicle lighting unit, 12 projection lens, 14 lens holder, 16 reflector, 16b opening, 16d upper reflector, 16e shade, 16g lower reflector, 16h pin, 17a first reflecting surface, 17b second reflecting surface, 17c main rear surface, 17d third reflecting surface, 17g fourth reflecting surface, 17h upper rear surface, 17k lower rear surface, 18 protector, 18c shielding portion, 18d circuit protection portion, 18f main shielding portion, 18g upper shielding portion, 18h lower shielding portion, 18k circuit protection portion, 20 circuit board, 20a first light source, 20b second light source, 20c driving circuit, 21a light-emitting element, 21b Light-emitting element.

Claims

1. a first light source; a second light source disposed adjacent to the first light source; a reflector having a first reflecting surface that reflects a portion of the light emitted from the first light source toward the front of the lamp, a second reflecting surface that reflects a portion of the light emitted from the second light source toward the front of the lamp, and a main back surface that faces the emission surface of the first light source and the emission surface of the second light source; a metal plate having a main shielding portion that shields light from the first light source toward the main rear surface and light from the second light source toward the main rear surface; A vehicle lighting unit comprising:

2. 2. The vehicle lighting unit according to claim 1, wherein the metal plate has a thickness of 0.2 to 0.6 mm.

3. The reflector is an upper reflector having a third reflecting surface facing the first reflecting surface and reflecting a portion of the light emitted from the first light source toward the front of the lamp; a lower reflector having a fourth reflecting surface facing the second reflecting surface and reflecting a portion of the light emitted from the second light source toward the front of the lamp; the upper reflector has an upper back surface facing the emission surface of the first light source, the lower reflector has a lower back surface facing the emission surface of the second light source, 3. The vehicle lighting unit according to claim 1, wherein the metal plate has an upper shielding portion that shields light from the first light source toward the upper rear surface, and a lower shielding portion that shields light from the second light source toward the lower rear surface.

4. the reflector has a shade portion at a tip end of the first reflecting surface and the second reflecting surface, the shade portion forming a cutoff line of a light distribution pattern, 3. The vehicle lighting unit according to claim 1, wherein the shade portion is made of a resin made of a liquid crystal polymer and has a thickness of 0.2 mm or less.

5. a projection lens for projecting a light distribution pattern in front of the lamp using light emitted from at least one of the first light source and the second light source; a circuit board on which the first light source and the second light source are mounted, a drive circuit for driving the first light source and the second light source is mounted on the circuit board below the first light source and the second light source; 4. The vehicle lamp unit according to claim 3, wherein the metal plate further includes a circuit protection portion extending from the lower shielding portion below the lamp so as to be positioned between the drive circuit and the projection lens.

6. 3. The vehicle lighting unit according to claim 1, wherein the reflector is fixed to the main shielding portion.

7. The reflector is provided with a positioning pin that protrudes from the rear surface toward the opposite side to the front of the vehicle, 3. The vehicle lighting unit according to claim 1, wherein the metal plate has a positioning hole formed therein into which the positioning pin is inserted.

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