Lighting unit

Abstract

This invention provides a new luminaire unit that improves the uniformity of brightness in the light distribution pattern. [Solution] The lighting unit comprises a first light source 30a having multiple light-emitting elements 28a arranged in a line with their light-emitting surfaces facing the front of the vehicle lighting device, a primary lens into which light emitted from the first light source 30a enters, and a projection lens that projects the light emitted from the primary lens forward of the vehicle. The primary lens has a light-gathering section 42a that focuses a portion of the light emitted from the light source and a light-diffusing section 42b that diffuses a portion of the light emitted from the light source. The light-emitting section 42b has an emission surface 42c with repeated irregularities in one direction.

Description

Technical Field

[0001] The present invention relates to a lamp unit, for example, to a lamp unit used for a vehicle lamp.

Background Art

[0002] Conventionally, a condensing lens has been devised which is disposed in the vicinity of a light source in which a plurality of light emitting elements are arranged in an array, and condenses light emitted from each of the light emitting elements (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] However, each lens portion of the above-described condensing lens is entirely convex, and the plurality of light emitting elements are arranged at intervals, so there is room for improvement in the brightness uniformity of the light distribution pattern.

[0005] The present invention has been made in view of such circumstances, and one of its exemplary objects is to provide a new lamp unit that improves the brightness uniformity of a light distribution pattern.

Means for Solving the Problems

[0006] To solve the above problems, a lighting unit according to one aspect of the present invention comprises a light source having a plurality of light-emitting elements arranged in a line, with their light-emitting surfaces facing the front of the vehicle lighting unit; a primary lens into which light emitted from the light source enters; and a projection lens that projects the light emitted from the primary lens forward of the vehicle. The primary lens has a light-gathering portion that focuses a portion of the light emitted from the light source and a light-diffusing portion that diffuses a portion of the light emitted from the light source. The light-emitting portion has an emission surface with repeated irregularities in one direction.

[0007] According to this embodiment, it is possible to suppress the difference in brightness within and near the boundary of the light distribution pattern formed by light passing through the diffuser.

[0008] The diffuser may have a first diffuser located above the light-gathering section in a front view, configured such that the emitted light forms a low-beam light distribution pattern. The light source may have a plurality of first light-emitting elements arranged in a line that emit light incident on the first diffuser. The first diffuser may have repeated irregularities in the direction D1 in which the plurality of first light-emitting elements are arranged in a line in a front view. As a result, the light that passes through the first diffuser can illuminate the low-beam light distribution pattern such that the area closer to the vehicle is wider in the vehicle width direction, compared to the light that passes through the light-gathering section.

[0009] The uneven surface may have a spacing of 0.050 mm to 0.400 mm between adjacent protrusions, and a height of 0.050 mm to 0.200 mm between protrusions. This allows the area illuminated by light passing through the first diffuser to be moderately widened.

[0010] In the first diffusion section, the spacing between the protrusions in the central part is greater than the spacing between the protrusions at the ends. This improves the contrast (light streaks) on the front of the vehicle while widening the illumination range in the left-right direction of the vehicle.

[0011] The light-gathering section is configured such that the emitted light forms a high-beam light distribution pattern, and the diffuser section may have a second diffuser section located below the light-gathering section in a front view, configured such that the emitted light forms an additional light distribution pattern that illuminates an area above the area illuminated by the high-beam light distribution pattern. The light source may have a plurality of second light-emitting elements arranged in a line that emit light incident on the light-gathering section and the second diffuser section. The second diffuser section may have repeated irregularities in a direction D2 that intersects the direction D1 in which the plurality of second light-emitting elements are arranged in a line in a front view.

[0012] The unevenness may have a spacing of 0.050 mm to 0.400 mm between adjacent protrusions, and a height of 0.050 mm to 0.200 mm between protrusions. This makes it possible to suppress the difference in brightness inside and near the boundary of the additional light distribution pattern formed by the light that has passed through the second diffuser.

[0013] Any combination of the above components, or any conversion of the expression of the present invention between manufacturing methods, devices such as luminaires and lighting fixtures, light-emitting modules, light sources, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0014] According to the present invention, the uniformity of the brightness of the light distribution pattern can be improved. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of a vehicle light fixture according to this embodiment. [Figure 2] Figure 1 is an exploded perspective view of a vehicle lighting fixture. [Figure 3] This is a front view of the resin plate according to this embodiment. [Figure 4] Figure 3 is a perspective view of the main part of the resin plate shown. [Figure 5] This is a longitudinal cross-sectional view showing the schematic configuration of the lighting unit according to this embodiment. [Figure 6]This is a diagram showing an example of a light distribution pattern formed by the lamp unit according to the present embodiment. [Figure 7] This is a top view of the diffusing unit shown in Figure 4, viewed from above. [Figure 8] This is an enlarged cross-sectional view of the vicinity of the light collecting unit and the diffusing unit. [Modes for Carrying Out the Invention]

[0016] Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. Identical or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate. In addition, the embodiments are illustrative rather than limiting the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the nature of the invention.

[0017] Figure 1 is a perspective view of the vehicle lamp according to the present embodiment. Figure 2 is an exploded perspective view of the vehicle lamp shown in Figure 1. The vehicle lamp shown in Figure 1 and Figure 2 is a vehicle headlamp, and is configured to be capable of forming both a low-beam light distribution pattern and a high-beam light distribution pattern.

[0018] The vehicle lamp 10 includes 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 attached at a predetermined position of the lens holder 14. Further, the projection lens 12 is manufactured by injection molding using a resin material with high transparency and high heat resistance, such as acrylic or polycarbonate. The lens holder 14 is fastened to the heat sink 20 by screws 22.

[0019] The reflector 16 is made of a resin material. The reflector 16 has a horizontally long base surface portion 16a facing the front-rear direction, an opening 16b formed at the center of the reflector 16, side reflection portions 16d provided to protrude forward from both left and right sides of the opening 16b, and a pair of fastening portions 16c formed on the outer side of the side reflection portions 16d.

[0020] A shade 24, which is a plate-shaped member, is attached to the lower surface of the side reflection portion 16d, and projects forward from the opening 16b. The shade 24 is held by the reflector 16 such that its plate surface extends along the horizontal direction of the vehicle.

[0021] The circuit board 18 includes a first light source 30a in which a plurality of light emitting elements 28a for forming a low-beam light distribution pattern are arranged in a horizontal row, a second light source 30b in which a plurality of light emitting elements 28b for forming a high-beam light distribution pattern are arranged in a horizontal row, and a drive circuit (not shown) that drives each of the light emitting elements. Note that the number and layout of the light emitting elements shown in FIG. 3 are merely examples, and the lamp unit may be provided with a first light source and a second light source that differ in the number and layout of the light emitting elements.

[0022] The second light source 30b is disposed adjacent to the first light source 30a. The first light source 30a is located on the upper stage side, and the second light source 30b is located on the lower stage side. Here, the light source located on the upper stage side refers to the light source in the upper stage in the vertical direction of the vehicle when the vehicular lamp is mounted on the vehicle among the plurality of stages of light sources, and the lower stage side refers to the light source in the lower stage in the vertical direction of the vehicle when the vehicular lamp is mounted on the vehicle among the plurality of stages of light sources. The drive circuit is a combination of passive elements such as capacitors and coils, active elements such as transistors and diodes, IC chips, memories, and the like, and functions as a control unit that controls lighting and extinguishing of the first light source 30a and the second light source 30b. In addition, the control unit detects the positions of preceding vehicles and pedestrians by a camera (not shown), and controls the lighting and extinguishing of each light emitting element 28b of the second light source 30b so as not to irradiate the individual irradiation regions corresponding to the positions, thereby realizing ADB (Adaptive Driving Beam) that prevents glare from being given to the drivers of preceding vehicles and pedestrians. The circuit board 18 is a mounting portion on which each light source is mounted, and is fixed at a predetermined position of the heat sink 20.

[0023] A resin plate 32 is positioned in front of the first light source 30a and the second light source 30b, functioning 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 corresponding to each light source, the first light source 30a and the second light source 30b, arranged laterally, deflecting 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 by 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. 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 by fastening the reflector 16 to the heat sink 20 with screws 36. Although silicone resin or other resins are used for the resin plate, it is not limited to resin and may be made of glass.

[0024] The lighting unit 40 according to this embodiment includes a first light source 30a having multiple light-emitting elements 28a arranged in a line with their light-emitting surfaces facing the front of the vehicle lighting unit 10, a second light source 30b having multiple light-emitting elements 28b arranged in a line, a resin plate 32 into which the light emitted from each light source enters, and a projection lens 12 that projects the light emitted from the resin plate 32 forward of the vehicle.

[0025] Figure 3 is a front view of the resin plate according to this embodiment. Figure 4 is a perspective view of the main part of the resin plate shown in Figure 3. The resin plate 32 according to this embodiment functions as a primary lens into which light emitted from a plurality of light-emitting elements 28a for forming a low-beam light distribution pattern and light emitted from a plurality of light-emitting elements 28b for forming a high-beam light distribution pattern are incident. The primary lens according to this embodiment controls the spread and direction of the light emitted from each light source before it is incident on the projection lens 12.

[0026] As shown in Figures 3 and 4, the resin plate 32 has a back surface 41 into which light emitted from the first light source 30a is incident, a light-gathering section 42a that focuses a portion of the incident light, and a diffusion section 42b that diffuses a portion of the incident light. The light-gathering section 42a has a shape that is like a series of cylindrical lenses split in the axial direction, and is a region that mainly focuses light by refraction, reducing its spread in the vertical direction.

[0027] The diffusing section 42b has an emission surface 42c in which the irregularities are repeated along the direction D1 in which the plurality of first light-emitting elements 28a are arranged in a line when viewed from the front. Furthermore, the diffusing section 42b is provided above the light-concentrating section 42a when viewed from the front, and is configured so that the emitted light forms at least a part of the low-beam light distribution pattern.

[0028] The central and lower regions of the resin plate 32 include a light-gathering section 44a configured to form a high-beam light distribution pattern, and a diffuser section 44b located below the light-gathering section 44a in a front view, configured to form an additional light distribution pattern in which the emitted light illuminates an area above the region illuminated by the high-beam light distribution pattern. The second light source 30b has a plurality of second light-emitting elements 28b arranged in a line that emit light incident on the light-gathering section 44a and the diffuser section 44b. The diffuser section 44b has an emission surface 44c in which irregularities are repeated along a direction D2 that intersects (is perpendicular to) direction D1 in a front view.

[0029] Figure 5 is a longitudinal cross-sectional view showing the schematic configuration of the luminaire unit according to this embodiment. Figure 6 is a diagram showing an example of a light distribution pattern formed by the luminaire unit according to this embodiment. The axis Ax shown in Figure 5 is intended to be the optical axis, the central axis of the projection lens, or the reference axis of the optical system including the lens, but it is shown only for the convenience of explanation. Light L1 emitted from the light-gathering section 42a enters the projection lens 12 at a position above the region where the projection lens 12 and axis Ax intersect, and is refracted at the exit surface 12a to form mainly the upper region PL1 of the low-beam light distribution pattern PL. Light L2 emitted from the diffuser section 42b enters the projection lens 12 at a position above light L1, and is refracted at the exit surface 12a to form mainly the lower region PL2 of the low-beam light distribution pattern PL.

[0030] Due to the irregularities along direction D1 formed on the emission surface 42c, a portion of the light L2 becomes light L2', which is diffused in direction D1. This suppresses the difference in brightness inside and near the boundary of the low-beam light distribution pattern formed by the light that has passed through the diffusion section 42b. Furthermore, compared to the light L1 that has passed through the focusing section 42a, the light L2 and L2' that have passed through the diffusion section 42b can illuminate the area PL2 closest to the vehicle in the low-beam light distribution pattern PL in a way that widens in the vehicle width direction.

[0031] Figure 7 is a top view of the diffusion section 42b shown in Figure 4, viewed from above. When multiple light-emitting elements 28a are scattered at intervals, as in the first light source 30a, there is a large difference in brightness between the area in front of the light-emitting elements 28a and the area in front of the space between the light-emitting elements 28a in the low-beam light distribution pattern, which can result in streaks of light. There is room for improvement in the uniformity of the brightness of the low-beam light distribution pattern.

[0032] Therefore, the irregularities in the diffusion section 42b are such that the spacing G1 and G2 between adjacent protrusions are 0.050 mm to 0.400 mm, and the heights H1 and H2 of the protrusions are 0.050 mm to 0.200 mm. This improves the uniformity of the brightness of the low beam light distribution pattern PL. In addition, it is possible to appropriately widen the area (region PL2) illuminated by light that has passed through the diffusion section 42b.

[0033] In the diffusion section 42b, the spacing G1 between the protrusions and the height H1 of the protrusions in the central section C are greater than the spacing G2 between the protrusions and the height H2 of the protrusions in the end section E. This improves the contrast (light streaks) on the front of the vehicle while widening the illumination range in the left-right direction of the vehicle.

[0034] Next, the diffusion section related to the light distribution pattern for high beams will be described. Figure 8 is an enlarged cross-sectional view of the vicinity of the light-gathering section 44a and the diffusion section 44b. As shown in Figures 5 and 8, the light H1 emitted from the light-gathering section 44a enters the projection lens 12 at a position below the region where the projection lens 12 and axis Ax intersect, and is refracted at the exit surface 12a to form the light distribution pattern PH for high beams.

[0035] Furthermore, the light H2 emitted diagonally downward from the light-emitting element 28b enters the resin plate 32 from the back surface 41, undergoes total internal reflection at the first reflective surface 45a which is part of the back surface 41 of the resin plate 32, and exits from the upper region 44b1 of the diffusion section 44b. The light H2 emitted from the upper region 44b1 enters the projection lens 12 at a position lower than that of the light H1, is refracted at the exit surface 12a, and forms the lower region PH1 of the additional light distribution pattern PH' which illuminates above the area irradiated by the high-beam light distribution pattern PH.

[0036] Furthermore, light H3 emitted from the light-emitting element 28b at an even more oblique angle downward than light H2 enters the resin plate 32 from the back surface 41, undergoes total internal reflection by the second reflective surface 45b which is part of the back surface 41 of the resin plate 32, and exits from the lower region 44b2 of the diffusion section 44b. Light H3 emitted from the lower region 44b2 enters the projection lens 12 at a position lower than light H2, is refracted by the exit surface 12a, and forms the upper region PH2 of the additional light distribution pattern PH'. The additional light distribution pattern PH' illuminates a region approximately 2 to 7° above the HH line.

[0037] The irregularities of the diffuser 44b are such that the spacing between adjacent protrusions is 0.050 mm to 0.400 mm, and the height of the protrusions is 0.050 mm to 0.200 mm. This suppresses the difference in brightness inside and near the boundary of the additional light distribution pattern PH' formed by light passing through the diffuser 44b. Furthermore, the spacing between protrusions and the height of the protrusions in the upper region 44b1 of the diffuser 44b are greater than those in the lower region 44b2. This further suppresses the difference in brightness inside and near the boundary of the lower region PH1 of the additional light distribution pattern PH'. The shape of the irregularities of the diffuser 42b and diffuser 44b is not limited to a wave shape; other shapes such as a sawtooth shape may also be used.

[0038] Although the present invention has been described above with reference to the embodiments described above, the present invention is not limited to the embodiments described above, and the present invention also includes combinations and substitutions of the configurations of the embodiments as appropriate. Furthermore, it is possible to appropriately 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 invention. [Explanation of Symbols]

[0039] 10 Vehicle lighting fixture, 12 Projection lens, 12a Emitting surface, 28a First light-emitting element, 28b Second light-emitting element, 30a First light source, 30b Second light source, 32 Resin plate, 40 Light fixture unit, 41 Rear part, 42a Light-gathering part, 42b Diffusing part, 42c Emitting surface, 44a Light-gathering part, 44b Diffusing part, 44c Emitting surface.

Claims

1. A light source consisting of multiple light-emitting elements arranged in a line, with their light-emitting surfaces facing the front of the vehicle's lighting fixture, A primary lens into which light emitted from the aforementioned light source is incident, The system comprises a projection lens that projects light emitted from the primary lens onto the front of the vehicle, The primary lens has a light-gathering section that focuses a portion of the light emitted from the light source, and a light-diffusing section that diffuses a portion of the light emitted from the light source. The luminaire unit is characterized in that the diffusion section has an emission surface in which irregularities are repeated in one direction.

2. The diffusion section is located above the light-gathering section in a front view and has a first diffusion section configured such that the emitted light forms a light distribution pattern for the low beam. The light source has a plurality of first light-emitting elements arranged in a line that emit light incident on the first diffuser, The lamp unit according to claim 1, characterized in that the first diffusion portion has repeated irregularities in the direction D1 in which the plurality of first light-emitting elements are arranged in a line when viewed from the front.

3. The lamp unit according to claim 2, characterized in that the aforementioned irregularities have a spacing of 0.050 mm to 0.400 mm between adjacent protrusions and a height of 0.050 mm to 0.200 mm between protrusions.

4. The luminaire unit according to claim 3, characterized in that the distance between the protrusions in the central part of the first diffusion part is greater than the distance between the protrusions at the ends.

5. The light-gathering unit is configured such that the emitted light forms a light distribution pattern for high beams. The diffusion portion is located below the light-gathering portion in a front view and has a second diffusion portion configured to form an additional light distribution pattern in which the emitted light illuminates an area above the area illuminated by the high-beam light distribution pattern. The light source has a plurality of second light-emitting elements arranged in a line, which emit light incident on the light-collecting portion and the second diffusion portion. The luminaire unit according to any one of claims 1 to 4, characterized in that the second diffusion portion has repeated irregularities in a direction D2 that intersects with the direction D1 in which the plurality of second light-emitting elements are arranged in a line when viewed from the front.

6. The lamp unit according to claim 5, characterized in that the aforementioned irregularities have a spacing of 0.050 mm to 0.400 mm between adjacent protrusions and a height of 0.050 mm to 0.200 mm between protrusions.

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