Vehicle lighting
The vehicle lighting device addresses uneven brightness by employing a multi-part light guide structure with varying dimensions to uniformly distribute light, improving the uniformity and appearance of the light-emitting surface.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- STANLEY ELECTRIC CO LTD
- Filing Date
- 2024-11-14
- Publication Date
- 2026-05-26
AI Technical Summary
Conventional vehicle lamps using light guides experience uneven brightness due to differences in optical path lengths, leading to non-uniform light emission.
A vehicle lighting device with a complex light guide structure comprising a rod-shaped first portion, a plate-shaped second portion, and a third portion connecting them, featuring varying thickness, length, and groove depth to uniformly distribute light across the emitting surface.
The device achieves more uniform light emission by adjusting optical path lengths and light distribution, reducing brightness unevenness and enhancing the appearance of the light-emitting portion.
Smart Images
Figure 2026086259000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to vehicle lamps.
Background Art
[0002] Conventionally, as vehicle lamps mounted on vehicles, those combining a light source such as a light-emitting diode (LED) and a light guide in the form of a plate or a rod are known (see, for example, Patent Document 1 below).
[0003] In such vehicle lamps, the light emitted from the light source is incident from the base end side of the light guide, and the light is guided toward the tip end side of the light guide while being repeatedly reflected inside the light guide. Further, the light reflected by a plurality of reflection cuts provided on the back side of the light guide is emitted from the front side of the light guide. Thereby, it is possible to cause the light emitting portion provided on the front side of the light guide to emit light in a line shape or a surface shape.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] By the way, in the above-described conventional vehicle lamps, uneven brightness may occur in the light emitting portion due to the difference in the optical path length of the light guided from the base end side to the tip end side of the light guide. That is, when uneven brightness occurs in the light emitting portion of the light guide, in the direction in which the light guide extends, the amount of light relatively decreases due to light attenuation or the like on the tip end side where the optical path length from the light source is longer than the base end side where the optical path length from the light source is shorter. Therefore, since such a difference in the amount of light (brightness) is recognized as uneven brightness of the light emitting portion, it is difficult to cause the entire area of the light emitting portion to emit light uniformly.
[0006] This invention was proposed in view of the above-mentioned conventional circumstances, and aims to provide a vehicle lighting device that enables more uniform light emission. [Means for solving the problem]
[0007] To achieve the above objective, the present invention provides the following means. [1] Light source and The system comprises a light guide that guides the light emitted from the light source, The light guide body includes a rod-shaped first light guide portion extending from one end facing the light source toward the other end, A plate-shaped second light guide portion extends in a first direction in which the first light guide portion extends, and in a second direction intersecting the first direction, A third light guide extends in the first direction and in a third direction intersecting the first and second directions, and connects the first light guide and the second light guide across the first direction, An inlet portion is located at one end of the first light guide portion and causes light emitted from the light source to enter the interior of the first light guide portion, A reflecting portion located on one side of the second light guide portion, which reflects the light guided inside the second light guide portion toward the other side of the second light guide portion, An emission unit located on the other side of the second light guide unit, which emits the light reflected by the reflecting unit to the outside of the second light guide unit, The second light guide portion has a groove that extends in the first direction, located on one side of the second light guide portion closer to the third light guide portion than the reflective portion, A vehicle light fixture wherein the depth of the groove gradually decreases as you move from one end to the other end of the first light guide. [2] The vehicle lamp according to [1], wherein the length of the third light guide in the third direction gradually decreases as you move from one end of the first light guide towards the other end. [3] The vehicle lamp according to [1], wherein the thickness of the first light guide gradually decreases from one end to the other end of the first light guide. [4] The reflective portion includes a plurality of reflective cuts arranged in the first direction, The vehicle lamp according to [1], wherein the reflection cut gradually increases from one end to the other end of the first light guide. [Effects of the Invention]
[0008] As described above, the present invention makes it possible to provide a vehicle lighting device that enables more uniform light emission. [Brief explanation of the drawing]
[0009] [Figure 1] This is a front view showing the configuration of a vehicle lighting device according to one embodiment of the present invention. [Figure 2] Figure 1 is a rear view showing the configuration of the vehicle lighting fixture. [Figure 3] Figure 2 shows a cross-sectional perspective view of a vehicle light fixture along the line segment AA. [Figure 4] Figure 2 shows a cross-sectional perspective view of a vehicle light fixture along the line segment BB. [Modes for carrying out the invention]
[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings used in the following explanation, the dimensions of each component may be shown on a different scale to make them easier to see, and the dimensional ratios of each component may not necessarily be the same as in reality.
[0011] As an embodiment of the present invention, for example, a vehicle lighting device 1 shown in Figures 1 to 4 will be described. Figure 1 is a front view showing the configuration of the vehicle lighting fixture 1. Figure 2 is a rear view showing the configuration of the vehicle lighting fixture 1. Figure 3 is a cross-sectional perspective view of the vehicle lighting fixture 1 along the line segment AA shown in Figure 2. Figure 4 is a cross-sectional perspective view of the vehicle lighting fixture 1 along the line segment BB shown in Figure 2.
[0012] In the following drawings, an XYZ orthogonal coordinate system is set, and the X-axis direction is the front-rear direction of the vehicle lamp 1, the Y-axis direction is the left-right direction of the vehicle lamp 1, and the Z-axis direction is the up-down direction of the vehicle lamp 1, and they are respectively shown as such.
[0013] The vehicle lamp 1 of the present embodiment is, for example, an application of the present invention to a tail lamp that emits red light among the rear combination lamps mounted on both corner portions on the rear end side of a vehicle (not shown).
[0014] In the following description, unless otherwise specified, the descriptions of "front", "rear", "left", "right", "up", and "down" mean the respective directions when the vehicle lamp 1 is viewed from the front (rear of the vehicle). Therefore, the respective directions when the vehicle is viewed from the front (front of the vehicle) are the directions with the front-rear and left-right reversed.
[0015] As shown in FIGS. 1 and 2, the vehicle lamp 1 of the present embodiment includes a light source 2 and an inner lens 3, and has a structure arranged inside a lamp body (not shown) that constitutes a rear combination lamp.
[0016] The lamp body is composed of a housing with an open front surface and an outer lens (cover lens) that covers the opening of the housing. Note that the shape of the lamp body can be appropriately changed according to the design of the vehicle or the like.
[0017] In addition, inside the lamp body, in addition to the above-described light source 2 and inner lens 3, for example, members such as extensions and brackets can be arranged, and these members can be attached inside the lamp body.
[0018] As shown in FIG. 2, the light source 2 is composed of a light-emitting element such as an LED that emits, for example, red light. The light source 2 is mounted on one side of a circuit board 4 provided with a drive circuit (not shown) for driving the light source 2, and emits light L radially toward the side (+Y-axis side) of the vehicle lamp 1.
[0019] As shown in Figures 1 to 4, the inner lens 3 is a long light guide that guides the light L emitted from the light source 2, and is made of a light-transmitting material such as a transparent resin such as polycarbonate or acrylic, or glass.
[0020] The inner lens 3 has an overall curved shape, with the outer side receding more in the direction of receding than the inner side in the vehicle width direction, in accordance with the slant shape applied to the corner portion at the front or rear end of the vehicle. In this embodiment, the inner side in the vehicle width direction will be described as one end of the inner lens 3, and the outer side in the vehicle width direction will be described as the other end of the inner lens.
[0021] The inner lens 3 has a rod-shaped first light guide portion 5 extending from one end facing the light source 2 toward the other end, a plate-shaped second light guide portion 6 extending in a first direction in which the first light guide portion 5 extends and in a second direction intersecting the first direction, and a third light guide portion 7 extending in a first direction and in a third direction intersecting the first and second directions, connecting the first light guide portion and the second light guide portion across the first direction.
[0022] In this embodiment, the first direction is along the optical axis of the light L emitted from the light source 2 and corresponds to the left-right direction of the vehicle lamp 1. The second direction corresponds to the up-down direction of the vehicle lamp 1, which is perpendicular to the first direction. The third direction corresponds to the front-rear direction of the vehicle lamp 1, which is perpendicular to the first and second directions.
[0023] The first light guide portion 5 is formed in a substantially circular cross-section, and its thickness (outer diameter) gradually decreases from one end to the other.
[0024] The second light guide portion 6 is located in front of and above the first light guide portion 5, and is formed in a substantially rectangular flat plate shape with substantially constant thickness.
[0025] The third light guide portion 7 is formed in a flat plate shape with a substantially constant thickness, and connects the upper end of the first light guide portion and the lower end of the second light guide portion in the front-to-back direction (third direction) across the left-to-right direction (first direction). Furthermore, the length of the third light guide portion 7 in the front-to-back direction (third direction) gradually decreases from one end to the other.
[0026] The inner lens 3 has an incident portion 8 located on one end side of the first light guide portion 5, a reflecting portion 9 located on the back side which is one surface of the second light guide portion 6, an outgoing portion 10 located on the front side which is the other surface of the second light guide portion 6, and a groove portion 11 located on the back side of the second light guide portion 6, closer to the third light guide portion 7 (lower) than the reflecting portion 9.
[0027] The incident section 8 has a flat incident surface 8a facing the light source 2 at one end of the first light guide section 5. That is, the incident surface 8a forms a plane perpendicular to the optical axis of the light L emitted from the light source 2.
[0028] In the incident section 8, light L emitted from the light source 2 is incident from the incident surface 8a into the interior of the first light guide section 5. As a result, the light L incident from the incident surface 8a is guided to the other end of the first light guide section 5 while repeatedly reflecting within the interior of the first light guide section 5.
[0029] Furthermore, a portion of the light L guided within the first light guide 5 is reflected repeatedly within the third light guide 7 before entering the second light guide 6. The light L that enters the second light guide 6 is then guided from the lower end to the upper end of the second light guide 6, while being reflected repeatedly within the second light guide 6.
[0030] The reflective section 9 has a plurality of reflective cuts 9a arranged in the left-right direction (first direction) on the back side of the second light guide section 6. The plurality of reflective cuts 9a only need to reflect the light L incident on the back side of the second light guide section 6 at an angle that causes it to exit from the front side of the second light guide section 6 to the outside, and there are no particular limitations on their shape, size, number, etc.
[0031] For example, in this embodiment, multiple reflection cuts 9a are formed by substantially conical recesses formed on the back surface of the second light guide 6, which are aligned in the left-right direction (first direction) of the second light guide 6, thereby forming a row of reflection cuts. Furthermore, two of these rows of reflection cuts are arranged parallel to each other to form a group of reflection cuts.
[0032] Furthermore, the recesses forming the reflection cuts 9a gradually increase in size as you move from one end of the first light guide 5 to the other end. Alternatively, the spacing between adjacent recesses forming the reflection cuts 9a may gradually decrease.
[0033] In the reflecting section 9, light L incident on the back side of the second light guide section 6 is reflected toward the emission section 10 on the front side of the second light guide section 6 by multiple reflection cuts 9a.
[0034] The emission section 10 has a flat emission surface 10a formed by the front surface of the second light guide section 6. Furthermore, the emission surface 10a is a curved surface that is generally curved from one end to the other of the second light guide section 6, in accordance with the slant shape of the inner lens 3 described above.
[0035] In the emission section 10, the light L reflected by the multiple reflection cuts 9a is emitted from the emission surface 10a to the outside of the second light guide section 6.
[0036] The groove 11 extends in the left-right direction (first direction) of the second light guide 6, forming a curved recess in cross-sectional view. Furthermore, the depth of the groove 11 gradually decreases as you move from one end of the second light guide 6 to the other end. On the other hand, the thickness of the portion of the second light guide 6 where the groove 11 is formed gradually increases as you move from one end of the second light guide 6 to the other end.
[0037] In the vehicle lighting device 1 of this embodiment, which has the above configuration, the light L reflected by the multiple reflection cuts 9a is emitted from the emission surface 10a, making it possible to make this emission surface 10a emit red light as the light-emitting part of a tail lamp.
[0038] By the way, in the vehicle lighting device 1 of this embodiment, the amount of light is relatively less at the other end of the inner lens 3, where the optical path length from the light source 2 is longer, as shown in Figure 4, compared to the one end of the inner lens 3, where the optical path length from the light source 2 is shorter, due to attenuation of light L, etc.
[0039] In contrast, in the vehicle lamp 1 of this embodiment, as shown in Figures 3 and 4, in order to make the light-emitting part (emitting surface 10a) of the tail lamp light up more uniformly, the thickness (outer diameter) of the first light guide part 5 gradually decreases from one end to the other as the distance from the light source 2 increases. As a result, the amount of light L traveling from one end to the other of the first light guide part 5 increases relatively compared to when the thickness of the first light guide part 5 is constant.
[0040] Furthermore, in the vehicle lighting device 1 of this embodiment, in order to make the light-emitting part (emitting surface 10a) of the tail lamp light up more uniformly, the length of the third light guide part 7 in the front-rear direction (third direction) gradually decreases from one end to the other end of the third light guide part 7. That is, the optical path length of the light L from the first light guide part 5 to the second light guide part 6 gradually decreases from one end to the other end of the third light guide part 7.
[0041] Specifically, at one end of the inner lens 3 shown in Figure 3, the optical path length of the light L traveling from the first light guide 5 to the second light guide 6 of the third light guide 7 becomes relatively longer. As a result, the amount of light L becomes relatively less due to attenuation of the light L traveling from the first light guide 5 to the second light guide 6 while repeatedly reflecting within the third light guide 7.
[0042] Furthermore, as the light L traveling from the first light guide 5 to the second light guide 6 repeatedly reflects within the third light guide 7, some of it is reflected at the corner 12 between the first light guide 5 and the third light guide 7, and at the corner 13 between the third light guide 7 and the second light guide 6. As a result, it is returned to the first light guide 5, and the amount of light L traveling from the first light guide 5 to the second light guide 6 in the third light guide 7 becomes relatively less.
[0043] Furthermore, these corners 12 and 13 may be provided with reflective surfaces, such as C-shaped or R-shaped surfaces, to reflect the light L guided inside the third light guide 7. By changing the size and angle of these reflective surfaces, it is possible to adjust the amount of light L that travels from the first light guide 5 to the second light guide 6 of the third light guide 7.
[0044] On the other hand, at the other end of the inner lens 3 shown in Figure 4, the optical path length of the light L traveling from the first light guide 5 to the second light guide 6 of the third light guide 7 becomes relatively shorter. As a result, the amount of light L traveling from the first light guide 5 to the second light guide 6 increases relatively as it repeatedly reflects within the third light guide 7.
[0045] As a result, in the vehicle lighting device 1 of this embodiment, the amount of light L directed from the first light guide 5 to the second light guide 6 can be brought closer together between one end and the other end of the third light guide 7. In other words, it is possible to reduce the difference in the amount of light L directed from the first light guide 5 to the second light guide 6 between one end and the other end of the third light guide 7.
[0046] Furthermore, in the vehicle lamp 1 of this embodiment, in order to make the light-emitting part (emitting surface 10a) of the tail lamp light up more uniformly, the depth of the groove 11 gradually decreases from one end to the other end of the second light guide 6. On the other hand, the thickness of the portion of the second light guide 6 in which the groove 11 is formed gradually increases from one end to the other end of the second light guide 6.
[0047] Specifically, at one end of the inner lens 3 shown in Figure 3, the thickness of the portion where the groove 11 of the second light guide 6 is formed becomes relatively smaller, so the amount of light L passing through this portion toward the second light guide 6 becomes relatively smaller. In addition, some of the light L going from the third light guide 7 toward the second light guide 6 is reflected by the groove 11 and returned to the first light guide 5 side.
[0048] On the other hand, at the other end of the inner lens 3 shown in Figure 4, the thickness of the portion where the groove 11 of the second light guide portion 6 is formed becomes relatively larger, so the amount of light L passing through this portion toward the second light guide portion 6 increases relatively.
[0049] As a result, in the vehicle lighting device 1 of this embodiment, the amount of light L directed from the third light guide 7 to the second light guide 6 can be brought closer together between one end and the other end of the third light guide 7. In other words, it is possible to reduce the difference in the amount of light L directed from the third light guide 7 to the second light guide 6 between one end and the other end of the third light guide 7.
[0050] As described above, in the vehicle lamp 1 of this embodiment, it is possible to make the amount of light L reflected by the multiple reflection cuts 9a more uniform between one end and the other end of the second light guide 6, so that uneven brightness does not occur in the light-emitting part (emitting surface 10a) of the tail lamp due to differences in the optical path length of the light L guided from one end to the other end of the inner lens 3.
[0051] As a result, in the vehicle lighting device 1 of this embodiment, it is possible to suppress the occurrence of brightness unevenness in the light-emitting part (emitting surface 10a) of the taillight and to make the light-emitting part (emitting surface 10a) of the taillight emit red light more uniformly. Furthermore, by preventing the occurrence of brightness unevenness, it is possible to improve the appearance of the taillight when it is illuminated.
[0052] It should be noted that the present invention is not necessarily limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, a vehicle lighting device 1 to which the present invention is applied to the tail lamp constituting the rear combination lamp described above is illustrated. However, the vehicle lighting device to which the present invention is applied is not limited to the tail lamp described above. It is possible to broadly apply the present invention to vehicle lighting devices such as side marker lights (position lamps), daytime running lights (DRL), reverse lights, brake lights (stop lamps), and turn signals (turn lamps).
[0053] Furthermore, the color of the light L emitted by the light source is not limited to the red light mentioned above; it can be changed as appropriate depending on the intended use of the vehicle's lighting fixture, such as to white light or orange light. [Explanation of Symbols]
[0054] 1...Vehicle lighting fixture 2...Light source 3...Inner lens (light guide) 4...Circuit board 5...First light guide section 6...Second light guide section 7...Third light guide section 8...Incident section 9...Reflective section 9a...Reflection cut 10...Output section 11...Groove section L...Light
Claims
1. Light source and The system comprises a light guide that guides the light emitted from the light source, The light guide body includes a rod-shaped first light guide portion extending from one end facing the light source toward the other end, A plate-shaped second light guide portion extends in a first direction in which the first light guide portion extends, and in a second direction intersecting the first direction, A third light guide extends in the first direction and in a third direction intersecting the first and second directions, and connects the first light guide and the second light guide across the first direction, An inlet portion is located at one end of the first light guide portion and causes light emitted from the light source to enter the interior of the first light guide portion, A reflecting portion located on one side of the second light guide portion, which reflects the light guided inside the second light guide portion toward the other side of the second light guide portion, An emission unit located on the other side of the second light guide unit, which emits the light reflected by the reflecting unit to the outside of the second light guide unit, The second light guide portion has a groove that extends in the first direction, located on one side of the second light guide portion closer to the third light guide portion than the reflective portion, A vehicle light fixture wherein the depth of the groove gradually decreases as you move from one end to the other end of the first light guide.
2. The vehicle lamp according to claim 1, wherein the length of the third light guide portion in the third direction gradually decreases as you move from one end of the first light guide portion to the other end.
3. The vehicle lamp according to claim 1, wherein the thickness of the first light guide portion gradually decreases from one end to the other end.
4. The reflective portion includes a plurality of reflective cuts arranged in the first direction, The vehicle lamp according to claim 1, wherein the reflection cut gradually increases from one end to the other end of the first light guide.