Vehicle lighting
By dividing the parabolic reflecting surface into regions with varying F-values and angles, the vehicle lighting device ensures uniform light emission, addressing the issue of brightness unevenness in existing technologies.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- STANLEY ELECTRIC CO LTD
- Filing Date
- 2024-11-25
- Publication Date
- 2026-06-04
AI Technical Summary
Existing vehicle lighting devices with a single parabolic reflecting surface struggle to achieve uniform light emission without brightness unevenness due to the formation of dark areas caused by stepped portions between reflective surfaces.
The vehicle lighting device employs a parabolic reflecting surface divided into multiple reflective regions with varying F-values and angles, featuring segmented cuts and stepped portions designed to minimize height differences, ensuring uniform light emission.
The configuration allows for a visually uniform light distribution across the entire reflecting surface, reducing dark areas and achieving consistent brightness without luminance unevenness.
Smart Images
Figure 2026091404000001_ABST
Abstract
Description
[Technical Field]
[0001] This disclosure relates to vehicle lighting equipment. [Background technology]
[0002] A vehicle light fixture comprising a light source and a reflective surface is known (see, for example, Patent Document 1). In Patent Document 1, a light-emitting region is formed on the reflective surface by the reflection of light from the light source by the reflective surface. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2023-073767 [Overview of the Initiative] [Problems that the invention aims to solve]
[0004] However, since the reflective surface is a single parabolic reflecting surface (not including multiple subdivisions) obtained by cutting out a portion of the paraboloid of revolution with the light source as the focal point, there is a challenge in making it appear as if the entire reflective surface is emitting light uniformly without any brightness unevenness.
[0005] This disclosure is made to solve these problems and aims to provide a vehicle lighting device that allows the entire reflective surface to appear to emit light uniformly without brightness unevenness. [Means for solving the problem]
[0006] The vehicle lighting device according to this disclosure comprises a light source and a parabolic reflecting surface that reflects light from the light source, wherein the parabolic reflecting surface is divided into at least one reflective region, the reflective region includes a plurality of segmented cuts, and the F-values of each of the plurality of segmented cuts are different from each other.
[0007] With such a configuration, it is possible to provide a vehicle lamp that can make the entire reflecting surface appear to emit light uniformly without luminance unevenness.
[0008] In the above vehicle lamp, the parabolic reflecting surface is a cylindrical reflecting surface having the same shape as the locus obtained by sweeping a parabola having the light source as the focus and the horizontal axis as the axis along the design line. A plurality of combinations of the light source and the reflection region are arranged along the design line, and the F value of each of the plurality of divided cuts is set to be larger for the divided cuts on the outer side in the vehicle width direction. The angle formed by the optical axis of the reflection region and the reference axis extending in the vehicle longitudinal direction may be larger for the reflection region on the outer side in the vehicle width direction.
[0009] Also, in the above vehicle lamp, the angle formed by the design line and the optical axis of at least a part of the reflection region is larger for the reflection region on the inner side in the vehicle width direction.
[0010] Also, in the above vehicle lamp, the design line may extend while curving from the inner side in the vehicle width direction toward the outer side in the vehicle width direction and toward the rear or the front of the vehicle.
Advantages of the Invention
[0011] According to the present disclosure, it is possible to provide a vehicle lamp that can make the entire reflecting surface appear to emit light uniformly without luminance unevenness.
Brief Description of the Drawings
[0012] [Figure 1] It is a perspective view of the vehicle lamp 10. [Figure 2] It is a front view of the vehicle lamp 10. [Figure 3] It is a cross-sectional view taken along the line A - A of FIG. 2. [Figure 4] It is a cross-sectional view taken along the line B - B of FIG. 2. [Figure 5] It is a front view of the parabolic reflecting surface 31. [Figure 6](a) An example of the F value of the segmented cut 32 included in the reflection region 31a1, and (b) An example of the F value of the segmented cut 32 included in the reflection region 31a13. [Figure 7] This diagram illustrates the angle θ1 between the optical axis AX31a of the reflection region 31a and the reference axis AX. [Figure 8] Figure 5 is a cross-sectional view of CC. [Figure 9] (a) Simulation results showing the luminance distribution when viewing the parabolic reflective surface 31 from the direction of arrow AR1 in Figure 7 (30° outward in the vehicle width direction with respect to the reference axis AX), and (b) Simulation results showing the luminance distribution when viewing a parabolic reflective surface of the conventional technology. [Figure 10] This is a longitudinal cross-sectional view of a modified vehicle light fixture 10. [Figure 11] This is an example of a design (luminescent area) with significant width variations. [Modes for carrying out the invention]
[0013] Hereinafter, a vehicle lighting device 10, which is an embodiment of the present disclosure, will be described with reference to the attached drawings. In each figure, corresponding components are denoted by the same reference numerals, and redundant explanations are omitted.
[0014] Figure 1 is a perspective view of the vehicle lighting fixture 10. Figure 2 is a front view of the vehicle lighting fixture 10. Figure 3 is a cross-sectional view AA of Figure 2, and Figure 4 is a cross-sectional view BB of Figure 2. In Figure 4, reference numeral 50 denotes a member provided to prevent light leakage, such as an extension or bracket.
[0015] The vehicle light fixture 10 of this embodiment is, for example, a vehicle signal light fixture that functions as a DRL lamp and is mounted on both the left and right sides of the front end of a vehicle (not shown), such as an automobile.
[0016] Since the vehicle lights 10 mounted on both the left and right sides are symmetrical, the vehicle lights 10 mounted on the left side of the front end of the vehicle (left side when facing forward) will be described below as a representative example. For the sake of explanation, the X, Y, and Z axes will be defined below. The X axis extends in the longitudinal direction of the vehicle, the Y axis extends in the width direction of the vehicle, and the Z axis extends in the vertical direction.
[0017] As shown in Figures 4 and 5, the vehicle lighting fixture 10 has a light source 20 (201-20 13 ) and a parabolic reflecting surface 31 (311~31) that reflects light from the light source 20. 13 It is equipped with a parabolic reflecting surface 31 (311~31 13 ) is provided in the reflector 30 (see Figure 1). Light sources 201-20 13 Each subscript indicates that the larger the subscript, the further out the light source is positioned in the vehicle width direction (see Figure 5). Below, light sources 201-20 13 If not distinguished, it will be written as light source 20. Similarly, parabolic reflecting surfaces 311-31 13 Each subscript indicates that the larger the subscript, the further out the surface is located in the vehicle width direction (see Figure 5). Below, parabolic reflecting surfaces 311-31 13 If not distinguished, the parabolic reflecting surface 31 is described.
[0018] Multiple combinations (13 in this case) of light source 20 and reflective area 31a are arranged along the design line L1 (see Figure 7). The design line L1 curves and extends from the inside in the vehicle width direction to the outside in the vehicle width direction and towards the rear (or front) of the vehicle.
[0019] The light source 20 is, for example, a semiconductor light-emitting element such as an LED. The light source 20 has a light-emitting surface (for example, a rectangular light-emitting surface with dimensions of 1 mm on each side). As shown in Figure 4, the optical axis AX of the light source 20 20 The beam extends through the center of the light-emitting surface and perpendicular to the light-emitting surface. The substrate K on which the light source 20 is mounted is attached to a housing (not shown) or the like with the light-emitting surface of the light source 20 facing downwards. The distance between light source 201 and light source 202 is, for example, 20 mm. The distance between other light sources 20 is similar.
[0020] Figure 5 is a front view of the parabolic reflector 31.
[0021] The parabolic reflector 31 is a reflecting surface formed based on a smooth cylindrical base surface having the same shape as the locus obtained by sweeping a parabola with the light source 20 (light source center) as the focus and the horizontal axis as the axis along the design line L1. The parabolic reflector 31 can be designed by using predetermined simulation software.
[0022] As shown in FIG. 5, the parabolic reflector 31 corresponds to a plurality of light sources 201 to 20 13 and is partitioned into a plurality of reflection regions 31a1 to 31a 13 Hereinafter, when the reflection regions 31a1 to 31a 13 are not distinguished, they are referred to as the reflection region 31a.
[0023] The reflection region 31a is a reflection region having a rectangular outer shape. The longitudinal length L2 (see FIG. 5) is, for example, 15 to 20 mm, and the lateral length L3 (see FIG. 5) is, for example, 20 mm. Also, in a front view, the distance L4 (see FIG. 5) between the light source 20 and the reflection region 31a is, for example, 2 mm.
[0024] The reflection region 31a includes a plurality of divided cuts 32 arranged (partitioned) in a grid pattern in the vertical and horizontal directions. The divided cut 32 has a longitudinal length of about 1.5 mm and a lateral length of about 1.2 mm. Although there are processing problems, it is desirable to make the longitudinal length and the lateral length of the divided cut 32 as short as possible. By doing so, the height H1 (see FIG. 3) of the stepped portion 33 between the divided cuts 32 can be further reduced, so that the dark portion caused by the stepped portion 33 between the divided cuts 32 is suppressed, and the parabolic reflector 31 can be visually recognized as emitting light uniformly (substantially uniformly) without luminance unevenness. Therefore, it is desirable that the longitudinal length of the divided cut 32 is 1.5 mm or less and the lateral length is 1.2 mm or less.
[0025] The divided cut 32 is a parabolic reflector with the light source 20 (light source center) as the focus and the horizontal axis as the axis (optical axis).
[0026] The F-values of each of the multiple segmented cuts 32 are different from each other. Specifically, as shown in Figures 6(a) and 6(b), the F-values of each of the multiple segmented cuts 32 are set to gradually increase as the segmented cuts 32 move outward in the vehicle width direction. The F-value is calculated based on the distance (focal length) between the centroid point of the segmented cut 32 and the light source 20 (center of the light source) combined with the parabolic reflecting surface 31 to which the segmented cut 32 belongs.
[0027] Figure 6(a) shows an example of the F-values of the segmented cuts 32 included in the reflective region 31a1. In Figure 6(a), "3.9" represents the F-value of the innermost and lowest segmented cut 32 in the vehicle width direction, "4.6" represents the F-value of the innermost and highest segmented cut 32 in the vehicle width direction, "10.2" represents the F-value of the outermost and lowest segmented cut 32 in the vehicle width direction, "7.2" represents the F-value of the outermost and highest segmented cut 32 in the vehicle width direction, and "4.5" represents the F-value of the segmented cut 32 in the center in the vehicle width direction. Figure 6(b) shows the reflective region 31a 13 This is an example of the F-values of the segment cuts 32 included in the diagram. In Figure 6(b), "2.3" represents the F-value of the segment cut 32 at the innermost bottom in the vehicle width direction, "3.3" represents the F-value of the segment cut 32 at the innermost top in the vehicle width direction, "13.1" represents the F-value of the segment cut 32 at the outermost bottom in the vehicle width direction, "6.6" represents the F-value of the segment cut 32 at the outermost top in the vehicle width direction, and "4.4" represents the F-value of the segment cut 32 in the center in the vehicle width direction.
[0028] As described above, in the reflective region 31a, the F value is set to increase with increasing distance between the segmented cuts 32 on the outer side in the vehicle width direction. Therefore, a step portion 33 (see Figure 3) is formed between adjacent segmented cuts 32 in the Y-axis direction. The segmented cuts 32 are curved surfaces that are convex in the direction of light reflection (longitudinal section radius of R8 mm, transverse section radius of R1.1 mm) for aiming purposes.
[0029] Furthermore, stepped portions 34 (see Figure 3) are also formed between adjacent reflective regions 31a. The height H2 (see Figure 3) of these stepped portions 34 between reflective regions 31a is greater than the height H1 (see Figure 3) of the stepped portions 33 between the divided cuts 32. This is because the difference in F values between adjacent divided cuts 32 separated by a boundary line B (see Figure 5) extending in the Z-axis direction is greater than the difference in F values between adjacent divided cuts 32 separated by a stepped portion 33 within the same reflective region 31a.
[0030] It is desirable to make the heights H1 and H2 of the stepped portions 33 and 34 as low as possible. In this way, dark areas caused by the stepped portions 33 and 34 are suppressed, and the parabolic reflective surface 31 can be seen as emitting light uniformly (or nearly uniformly) without brightness unevenness.
[0031] The inventors have determined that the optical axis AX of the reflective region 31a on the outer side in the vehicle width direction is approximately AX 31a The angle θ1 (θ11~θ1) between the reference axis AX extending in the longitudinal direction of the vehicle and the reference axis AX. 13 (See Figure 7) By setting a large angle, it was found that the heights H1 and H2 of the stepped sections 33 and 34 (especially the height H2 of the stepped section 34) could be reduced. 13 Each subscript corresponds to light source 201-20 13 and reflection regions 31a1~31a 13 Each subscript corresponds to a specific element. For example, angle θ11 corresponds to the optical axis AX of the reflection region 31a1. 31a This represents the angle θ1 between the reference axis AX and the other angles θ12~θ1. 13 The same applies below. Below, angles θ11~θ1 13 If not distinguishing between them, the angle is written as θ1.
[0032] Note that the optical axis AX of the reflection region 31a 31a This refers to the optical axis of the segmented cut 32 included in the reflection region 31a. For example, the optical axis AX of the reflection region 31a1. 31a This refers to the optical axis of the segmented cut 32 included in the reflection region 31a1.
[0033] Figure 7 shows the optical axis AX of the reflection region 31a.31a This diagram illustrates the angle θ1 formed between the reference axis AX and the axial reference axis.
[0034] In this embodiment, as shown in Figure 7, the optical axis AX of the reflective region 31a on the outer side in the vehicle width direction is approximately AX 31a The angle θ1 between the reference axis AX extending in the longitudinal direction of the vehicle and the reference axis AX was set to be large. For example, angles θ11~θ14=0°, angles θ17=5°, angles θ19=14°, and angle θ1 13 It was set to =26°. Ideally, θ1 should be around 30° at most.
[0035] The reason for setting the angles θ11~θ14=0° is to control the reflection direction of the light from the light source 20 reflected in the reflection regions 31a1~31a4 mainly in the direction of the reference axis AX, thereby forming a predetermined light distribution pattern (in this case, a light distribution pattern for DRLs) with the brightness required by regulations.
[0036] Angle θ15~θ1 13 The reason for setting the reflective area 31a on the outer side in the vehicle width direction to be as large as the design line L1 and the parabolic reflective surfaces 315-31 13 Each optical axis AX 31 The angle between θ21 and θ2 13 This is to make at least a portion of (see Figure 7) 40° or more. Alternatively, it is to make the angle θ2 larger towards the inside in the vehicle width direction (reflection area on the inside in the vehicle width direction) (for example, to make angle θ21=61°>angle θ24=46°). In Figure 7, θ21=61°, θ24=46°, θ27=38°, θ29=39°, θ2 13 =40°. Furthermore, as a result of the inventor's investigation, it was confirmed by simulation that by making at least some of the angles θ2 40° or more, or by making the angle θ2 larger towards the inside in the vehicle width direction (reflection area on the inside in the vehicle width direction), the heights H1 and H2 of the stepped portions 33 and 34 can be reduced (in particular, the height H2 of the stepped portion 34 can be kept to about 1.5 mm), and that as a result, the reflection area 31a can be seen as emitting light uniformly (generally uniformly) without brightness unevenness (see Figure 9(b)).
[0037] An example of the operation of the vehicle lighting device 10 with the above configuration will be described below.
[0038] Figure 8 is a cross-sectional view of CC in Figure 5.
[0039] When the light source 20 is turned on, the light emitted downward from the light source 20 is reflected by the parabolic reflecting surface 31 (reflection region 31a) along the optical axis AX of the reflection region 31a. 31a The light is reflected in the direction (diffuse reflection) (see Figure 8), passes through the diffusion lens 40, and is then projected in front of the vehicle. As a result, although not shown, a predetermined light distribution pattern is formed on a virtual vertical screen (located approximately 25 m in front of the vehicle) directly facing the front of a vehicle (not shown) on which the vehicle light fixture 10 is mounted.
[0040] Next, the effects of the vehicle lighting device 10 with the above configuration will be explained in comparison with the vehicle lighting device described in Patent Document 1.
[0041] Patent Document 1 describes a vehicle lighting device in which multiple combinations of light sources and reflective surfaces are arranged in the vehicle width direction. The reflective surface is a single parabolic reflective surface obtained by cutting out a part of a paraboloid of revolution with the light source as the focal point. The reflective surface in Patent Document 1 does not include any segmented cuts (multiple) corresponding to segmented cuts 32. In Patent Document 1, adjacent reflective surfaces are connected by vertical walls (steps) that are larger than the stepped portions 33 and 34. Therefore, in Patent Document 1, although a light-emitting region is formed on the reflective surface when light from the light source is reflected by the reflective surface, dark areas are also formed due to the vertical walls, so there is a problem that the entire reflective surface cannot be made to appear to emit light uniformly without brightness unevenness.
[0042] In contrast, with the vehicle lighting device 10 configured as described above, light from the light source 20 is reflected by the parabolic reflective surface 31 (reflection region 31a), thereby forming a light-emitting region on the parabolic reflective surface 31 (reflection region 31a). At that time, because the heights H1 and H2 of the stepped portions 33 and 34 are low (especially the height H2 of the stepped portion 34 is kept to about 1.5 mm), dark areas caused by the stepped portions 33 and 34 are suppressed, and the entire parabolic reflective surface 31 (reflection region 31a) can be seen as emitting light uniformly (approximately uniformly) without brightness unevenness (see Figure 9(a)). Figure 9(a) is a simulation result showing the brightness distribution when the parabolic reflective surface 31 is viewed from the direction of arrow AR1 in Figure 7 (30° outward in the vehicle width direction with respect to the reference axis AX). On the other hand, Figure 9(b) is a simulation result showing a brightness distribution with brightness unevenness when the parabolic reflective surface of the comparative example is viewed from the same direction. The parabolic reflecting surface of the comparative example has angles θ11 to θ1 13 It has the same configuration as the parabolic reflecting surface 31, except that all angles are 0°.
[0043] As described above, according to this embodiment, it is possible to provide a vehicle light fixture 10 that can be visually perceived as having uniform illumination (approximately uniform illumination) without uneven brightness across the entire parabolic reflective surface 31 (reflective region 31a).
[0044] Next, I will explain some variations.
[0045] In the above embodiment, an example was described in which multiple combinations of one light source 20 and one parabolic reflecting surface 31 (see Figure 4) are arranged along the design line L1 (see Figure 5), but the embodiment is not limited to this.
[0046] For example, as shown in Figure 10, multiple combinations of one light source 20 and one parabolic reflecting surface 31 (upper row), and combinations of the same configuration rotated 180° (lower row), may be arranged along the design line L1. Figure 10 is a longitudinal cross-sectional view of a modified vehicle lighting fixture 10.
[0047] This method allows for a wider emission width W1 (emission width of the emission area) in the vertical direction (Z-axis direction).
[0048] Furthermore, by reducing the vertical emission width W1, it is possible to accommodate designs (emission areas) with significant width changes, as shown in Figure 11. For example, by arranging two tiers of reflective surfaces 31 as shown in Figure 10 in areas with a large emission width (vertical width in Figure 11) (see rectangle B3 in Figure 11), and arranging one tier of reflective surfaces as shown in Figure 4 in areas with a small emission width (see rectangle B4 in Figure 11), it is possible to accommodate various changes in emission width. Figure 11 is an example of a design (emission area) with significant width changes.
[0049] Furthermore, although the above embodiments describe an example in which the vehicle lighting equipment of this disclosure is applied to DRL lamps, the invention is not limited to this. For example, the vehicle lighting equipment of this disclosure may be applied to vehicle signaling lights other than DRL lamps, such as turn signals, position lamps, stop lamps, or taillights.
[0050] All the numerical values shown in the above embodiments are examples only, and it goes without saying that other appropriate numerical values can be used.
[0051] The embodiments described above are in all respects merely illustrative. The description of the embodiments above should not be construed as limiting the disclosure. The disclosure can be implemented in a variety of other ways without departing from its spirit or main features. [Explanation of symbols]
[0052] 10… Vehicle lighting equipment 20(20a1~20a 13 )…light source 30…Reflector 31... Parabolic reflecting surface 31a...reflection area 31a(31a1~31a 13 )…reflection area 32...divided cut 33... Stepped section 34... Stepped section 40... Diffusion lens 50... Components θ1(θ11~θ1 13 )…angle θ2(θ21~θ2 13 )… angle
Claims
1. Light source and It comprises a parabolic reflecting surface that reflects light from the aforementioned light source, The parabolic reflecting surface is divided into at least one reflecting region, The reflective region includes a plurality of segmented cuts, A vehicle light fixture in which the F-values of each of the multiple aforementioned segment cuts are different from each other.
2. The parabolic reflective surface is a reflective surface formed based on a cylindrical base surface having the same shape as the trajectory obtained by sweeping a parabola with the light source as the focal point and the horizontal axis along the design line. Multiple combinations of the light source and the reflection region are arranged along the design line. The F-value for each of the multiple aforementioned segment cuts is set to increase as the segment cuts move outward in the vehicle width direction. The vehicle lamp according to claim 1, wherein the angle between the optical axis of the reflective region and the reference axis extending in the longitudinal direction of the vehicle is larger for the reflective region that is on the outer side in the vehicle width direction.
3. The vehicle lamp according to claim 2, wherein the angle between the design line and the optical axis of at least a portion of the reflective region is larger for reflective regions that are on the inside in the vehicle width direction.
4. The vehicle lamp according to claim 2, wherein the design line extends from the inside in the vehicle width direction to the outside in the vehicle width direction and curves toward the rear or front of the vehicle.
5. The vehicle light fixture according to claim 1, wherein the aforementioned division cut has a vertical length of 1.5 mm or less and a horizontal length of 1.2 mm or less.