Vehicle lighting
The vehicle lamp design with protruding ridges and curved emission surfaces addresses the issue of non-uniform light emission, achieving uniform and expanded light distribution using a rod-shaped light guide and diffusion lens.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- STANLEY ELECTRIC CO LTD
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-29
AI Technical Summary
Existing vehicle lamps with light guides struggle to emit light uniformly while expanding the light emission range in the diffusion direction, due to the use of convex steps that cause light to be emitted in different directions.
A rod-shaped light guide with a pair of protruding ridges and emission surfaces that are convexly curved, combined with a diffusion lens, to uniformly distribute light across a wider area.
The solution enables more uniform light emission and expands the light emission range of the rod-shaped light guide, ensuring consistent illumination across the diffusion direction.
Smart Images
Figure 2026105913000001_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 (for example, see 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.
[0004] For example, Patent Document 1 below discloses a vehicle lamp including a light guide arranged to extend in the vertical direction and a light source arranged to make light incident on the light guide from the upper and lower end faces in the vertical direction of the light guide, and configured to emit the light incident from the end face forward from the front portion of the light guide. In the vehicle lamp, a convex step is formed on the front portion of the light guide to deflect and emit a part of the light guided inside the light guide sideways.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] Incidentally, in the invention described in Patent Document 1 mentioned above, by obtaining lateral illumination light from the light emitted from the convex step, it is possible to ensure a large horizontal diffusion angle of the light emitted from the light guide extending in the vertical direction.
[0007] On the other hand, with the lateral deflection emission using the convex step described above, it is difficult to make the light guide emit light uniformly in the diffusion direction. That is, the emitted light emitted forward from the front of the light guide and the emitted light deflected laterally from the convex step have different emission directions. Therefore, it is difficult to make the light guide emit light uniformly while expanding its emission range in the diffusion direction with emitted light from these different emission directions.
[0008] This invention was proposed in view of the above-mentioned conventional circumstances, and aims to provide a vehicle light fixture that enables more uniform light emission while expanding the light emission range of a rod-shaped light guide in the diffusion direction. [Means for solving the problem]
[0009] To achieve the above objective, the present invention provides the following means. [1] Light source and The system comprises a rod-shaped light guide that guides the light emitted from the light source, The light guide body includes a light guide portion that extends from one end facing the light source toward the other end, An inlet portion is located at one end of the light guide portion and causes light emitted from the light source to enter the interior of the light guide portion, A plurality of reflection cuts are located on the back side of the light guide and reflect the light guided inside the light guide toward the front side of the light guide, The light guide portion has an output portion located on the front side of the light guide portion, which outputs the light reflected by the plurality of reflection cuts to the outside of the light guide portion, The light guide portion has a pair of protruding ridges located on both sides of the central part on the front side, projecting forward. The emission portion is located between the pair of protruding portions and has a first emission surface that is convexly curved in a cross-section perpendicular to the direction in which the light guide portion extends, A vehicle light fixture comprising: a second emitting surface located on the front side of each of the pair of protruding portions, which is curved in a convex shape in a cross-section perpendicular to the direction in which the light guide portion extends. [2] The first emission surface is a convex surface with a circular arc cross-section having a first radius of curvature that is larger than the reference radius of the light guide portion. The vehicle light fixture according to [1], wherein the second emission surface is a convex surface with a circular arc cross-section having a second radius of curvature smaller than the first radius of curvature. [3] The vehicle lamp according to [1], wherein, in a cross-section in a direction perpendicular to the direction in which the light guide extends, the width of the first emission surface between the pair of protrusions is greater than the width of the reflection cut. [4] The vehicle lamp according to [1], wherein the pair of protruding portions have connecting surfaces that connect the outer end of the second emission surface and the outer peripheral surface of the light guide portion. [5] The vehicle lamp according to [4], wherein the connecting surface is provided at a predetermined angle outward from the tangent at the position where it connects to the outer surface of the light guide, in a cross section perpendicular to the direction in which the light guide extends. [6] The vehicle light fixture according to [1], wherein the foremost part of the second emission surface is located on the front side of the outer end of the second emission surface. [7] The vehicle lamp according to [1], further comprising a diffusion lens positioned on the front side of the light guide for diffusing the light emitted from the first emission surface and the second emission surface. [Effects of the Invention]
[0010] As described above, the present invention provides a vehicle light fixture that enables more uniform light emission while expanding the light emission range of a rod-shaped light guide in the diffusion direction. [Brief explanation of the drawing]
[0011] [Figure 1]It is a perspective view of a vehicle lamp according to an embodiment of the present invention as seen from the front side. [Figure 2] It is a perspective view of the vehicle lamp shown in FIG. 1 as seen from the back side. [Figure 3] It is a cross-sectional view of the light guide by the line segment A-A shown in FIG. 1. [Figure 4] It is an optical path diagram of the light emitted from the light guide shown in FIG. 3. [Figure 5] It is an enlarged optical path diagram of the surrounded portion B shown in FIG. 4. [Figure 6] It is a cross-sectional view showing another configuration example of the vehicle lamp.
Mode for Carrying Out the Invention
[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, for the purpose of making each component easy to view, the scale of the dimensions may be made different depending on the component, and the dimensional ratios of each component are not necessarily the same as the actual ones.
[0013] As an embodiment of the present invention, for example, a vehicle lamp 1 shown in FIGS. 1 to 6 will be described. Note that FIG. 1 is a perspective view of the vehicle lamp 1 as seen from the front side. FIG. 2 is a perspective view of the vehicle lamp 1 as seen from the back side. FIG. 3 is a cross-sectional view of the inner lens 3 by the line segment A-A shown in FIG. 1. FIG. 4 is an optical path diagram of the light L emitted from the inner lens 3. FIG. 5 is an enlarged optical path diagram of the surrounded portion B shown in FIG. 4. FIG. 6 is a cross-sectional view showing another configuration example of the vehicle lamp 1.
[0014] Also, in the drawings shown below, 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 each is shown as such.
[0015] As shown in FIGS. 1 and 2, the vehicle lamp 1 of the present embodiment includes a light source 2, an inner lens 3, and a diffusion lens 4, and has a structure in which these are arranged inside a lamp body (not shown).
[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 to the above-described light source 2, inner lens 3, and diffusion lens 4, members such as extensions and brackets can be arranged inside the lamp body, and these members can be attached inside the lamp body.
[0018] The light source 2 is composed of a light-emitting element such as an LED. The light source 2 is mounted on one side of a circuit board (not shown) 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 FIGS. 1, 2, and 3, the inner lens 3 is a rod-shaped light guide (light guide rod) that guides the light L emitted from the light source 2, and is made of a light-transmissive member such as a transparent resin or glass, such as polycarbonate or acrylic.
[0020] In the present embodiment, the direction in which the inner lens 3 extends is the direction 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. Also, the front side of the inner lens 3 corresponds to the front side of the vehicle lamp 1, and the back side of the inner lens 3 corresponds to the rear side of the vehicle lamp 1. Further, the diffusion direction of the light L emitted from the front side of the inner lens 3 will be described as the up-down direction of the vehicle lamp 1.
[0021] Note that the inner lens 3 is not limited to being formed in a straight line, and at least a part thereof may be curved. Also, the orientation of the inner lens 3 can be appropriately changed.
[0022] The inner lens 3 has a light guide portion 5 with a substantially circular cross-section that extends from one end facing the light source 2 toward the other end, an incident portion 6 located on one end of the light guide portion 5, a plurality of reflection cuts 7 located on the back side of the light guide portion 5, and an outgoing portion 8 located on the front side of the light guide portion 5.
[0023] The light guide portion 5 is formed in a substantially circular shape with a reference radius R0 as a whole, in a cross-section perpendicular to the direction in which the light guide portion 5 extends (hereinafter referred to as the "vertical cross-section"). The light guide portion 5 also has a pair of protruding ridges 5a located on both sides of its central front portion, projecting forward. The pair of protruding ridges 5a have a symmetrical shape and are provided extending from one end to the other of the light guide portion 5.
[0024] The pair of protruding portions 5a have connecting surfaces 5c that connect the outer end T2 of the second emission surface 8b and the outer peripheral surface 5b of the light guide portion 5. The connecting surface 5c is an inclined surface that is continuous in the direction in which the light guide portion 5 extends. On the other hand, the outer peripheral surface 5b of the light guide portion 5 on the rear side of the connecting surface 5c forms a convex surface with a circular arc cross-section that is curved in a convex shape with a reference radius R0.
[0025] The connecting surface 5c is positioned inclined outward by a predetermined angle θ from the tangent line S at position T3 where it connects to the outer circumferential surface 5b of the light guide section 5 in the vertical cross-section of the light guide section 5. The connection position T3 between the outer circumferential surface 5b of the light guide section 5 and the connecting surface 5c is located at the upper and lower ends of the light guide section 5. Therefore, the tangent line S is in a direction parallel to the front-rear direction of the vehicle lamp 1 (horizontal direction). Furthermore, the angle θ of the connecting surface 5c is preferably 5° to 10°.
[0026] Furthermore, the connecting surface 5c is not limited to a straight surface (plane) formed in the vertical cross-section of the light guide section 5, but may also be composed of a convex or concave curved surface (curved surface).
[0027] The incident section 6 has a flat incident surface 6a facing the light source 2 at one end of the light guide section 5. That is, the incident surface 6a forms a plane perpendicular to the optical axis of the light L emitted from the light source 2.
[0028] In the incident section 6, light L emitted from the light source 2 is incident from the incident surface 6a into the interior of the light guide section 5. As a result, the light L incident from the incident surface 6a is guided to the other end of the light guide section 5 while repeatedly reflecting within the light guide section 5.
[0029] The multiple reflection cuts 7 are formed, for example, by having grooves with a roughly triangular cross-section located in the center of the back side of the light guide portion 5, and cut out in a direction perpendicular to the direction in which the light guide portion 5 extends (up and down in this embodiment), and these grooves being arranged in the direction in which the light guide portion 5 extends (left and right in this embodiment).
[0030] The multiple reflection cuts 7 reflect the light L that enters the back side of the light guide unit 5, out of the light L guided from one end to the other end of the light guide unit 5, toward the emission unit 8 on the front side of the light guide unit 5.
[0031] Furthermore, the multiple reflection cuts 7 only need to reflect light L incident on the back side of the light guide unit 5 at an angle that causes it to exit from the front side of the light guide unit 5 to the outside; their shape, size, number, etc., are not particularly limited.
[0032] Furthermore, with respect to the multiple reflection cuts 7, the spacing between adjacent grooves forming these reflection cuts 7 may gradually narrow as you move from one end of the light guide 5 to the other end, or the depth of the grooves forming these reflection cuts 7 may gradually increase. This makes it possible to bring the amount of light L traveling from one end of the light guide 5 to the other end of the light guide 5 closer together between the one end and the other end.
[0033] The emission section 8 has a first emission surface 8a located between a pair of protruding sections 5a and continuous in the direction in which the light guide section 5 extends, and a second emission surface 8b located on the front side of the pair of protruding sections 5a, adjacent to the first emission surface 8a and continuous in the direction in which the light guide section 5 extends.
[0034] The first emission surface 8a is a convex surface with a curved, arc-shaped cross-section in the vertical cross-section of the light guide 5. The first emission surface 8a has a first radius of curvature R1 that is larger than the reference radius R0 of the light guide 5. Furthermore, at the vertical end face of the light guide 5, the vertical width W1 of the first emission surface 8a is larger than the vertical width W0 of the reflection cut 7.
[0035] The second emission surface 8b is a convex surface with a curved, arc-shaped cross-section in the cross-section of the light guide portion 5. The second emission surface 8b has a second radius of curvature R2 that is smaller than the first radius of curvature R1. Furthermore, the foremost part T1 of the second emission surface 8b is located on the front side of the outer end T2 of the second emission surface 8b.
[0036] In the emission section 8, as shown in Figures 3, 4, and 5, of the light L reflected by the multiple reflection cuts 7, the first light L1 incident on the first emission surface 8a is refracted in the diffusion direction toward the forward diffusion lens 4 and emitted to the outside of the light guide section 5. On the other hand, the second light L2 incident on the second emission surface 8b is refracted in the diffusion direction toward the forward diffusion lens 4 and emitted to the outside of the light guide section 5.
[0037] Furthermore, in the emission section 8, of the light L reflected by the multiple reflection cuts 7, the third light L3 incident on the connection surface 5c is reflected toward the second emission surface 8b, and then the third light L3 incident on the second emission surface 8b is directed toward the forward diffusion lens 4, refracted in a wider angle direction than the second light L2, and emitted out to the outside of the light guide section 5.
[0038] In other words, the third light L3 reflected by the connecting surface 5c of the pair of protrusions 5a is emitted from each of the second emission surfaces 8b in directions intersecting each other, while being refracted at a wider angle than the second light L2 emitted from the second emission surface 8b.
[0039] The diffusion lens 4 consists of a flat, light-transmitting member provided with a plurality of diffusion cuts (not shown) for diffusing the light L (L1, L2, L3) emitted from the first emission surface 8a and the second emission surface 8b, or a flat, light-diffusing member in which light-diffusing particles are dispersed within a transparent resin.
[0040] Examples of diffusion cuts include lens cuts such as flute cuts and fisheye cuts, as well as uneven structures formed by knurling or textured finishes. Furthermore, by adjusting the shape of these diffusion cuts, it is possible to control the degree of light diffusion L.
[0041] The diffusion lens 4 transmits light L emitted from the first emission surface 8a and the second emission surface 8b while diffusing it. This makes it possible to make the front side of the diffusion lens 4 emit light more uniformly.
[0042] Furthermore, the diffusion lens 4 is not limited to the single lens described above; it may be configured with multiple lenses arranged in a front-to-back direction.
[0043] In the vehicle light fixture 1 of this embodiment, which has the above configuration, the first light L1 emitted from the first emission surface 8a and the second and third lights L2 and L3 emitted from the second emission surface 8b are diffused in the vertical direction of the inner lens 3, thereby expanding the light emission range of the inner lens 3 in the diffusion direction. Furthermore, the first light L1, second light L2 and third light L3 emitted in the diffusion direction make it possible to make the diffusion lens 4 emit light more uniformly.
[0044] Furthermore, in the vehicle lamp 1 of this embodiment, even when a pair of protrusions 5a are provided on the light guide portion 5 described above, the moldability of the inner lens 3 does not deteriorate, and the diffusion control of light L by the first emission surface 8a, the second emission surface 8b, and the connecting surface 5c is also easy.
[0045] As described above, the vehicle light fixture 1 of this embodiment makes it possible to broaden the light emission range of the inner lens 3, which is made of a rod-shaped light guide, in the diffusion direction while emitting light more uniformly.
[0046] 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, the vehicle light fixture 1 described above may have a configuration in which a reflector 10 is placed between the inner lens 3 and the diffusion lens 4, as shown in Figure 6.
[0047] The reflector 10, for example, has a concave reflective surface 10a based on a parabola in its vertical cross-section and is positioned above the inner lens 3. Meanwhile, the inner lens 3 is positioned with its emission section 8 facing upward. The diffusion lens 4 is positioned in front of the reflector 10.
[0048] The reflector 10 can be made of a reflective material having light-diffusing properties, such as a white glass epoxy resin, or a reflective material having a reflective film such as an aluminum vapor-deposited film.
[0049] In this configuration, the light L emitted from the first emission surface 8a and the second emission surface 8b of the inner lens 3 is reflected by the reflective surface 10a of the reflector 10 toward the diffusion lens 4. The light L reflected by the reflective surface 10a of the reflector 10 is transmitted forward while being diffused by the diffusion lens 4.
[0050] In this configuration as well, the first light L1 emitted from the first emission surface 8a and the second and third lights L2 and L3 emitted from the second emission surface 8b expand the light emission range of the inner lens 3, which is made up of a rod-shaped light guide, in the diffusion direction, while making the diffusion lens 4 emit light more uniformly. Furthermore, by using the reflector 10, it is possible to change the arrangement of the light source 2 and the inner lens 3.
[0051] In the configuration shown in Figure 6 above, since the optical path lengths from the pair of protrusions 5a to the reflective surface 10a of the reflector 10 are different, the shapes of the second emission surface 8b and the connecting surface 5c may be controlled by making the pair of protrusions 5a asymmetrical to each other in accordance with this difference in optical path length.
[0052] Furthermore, the vehicle lighting fixtures to which the present invention can be applied are not particularly limited. For example, the present invention can be broadly applied to taillights, position lights, brake lights, reverse lights, daytime running lights (DRL), turn signals, and other similar fixtures.
[0053] Furthermore, the color of the light L emitted by light source 2 can be changed as appropriate depending on the intended use of the vehicle lighting, such as red light, white light, or orange light. [Explanation of symbols]
[0054] 1...Vehicle lighting fixture 2...Light source 3...Inner lens (light guide) 4...Diffusing lens 5...Light guide section 5a...Protruding section 5c...Connecting surface 6...Indicating section 7...Reflection cut 8...Emitting section 8a...First emission surface 8b...Second emission surface 10...Reflector L...Light L1...First light L2...Second light L3...Third light
Claims
1. Light source and The system comprises a rod-shaped light guide that guides the light emitted from the light source, The light guide body includes a light guide portion that extends from one end facing the light source toward the other end, An inlet portion is located at one end of the light guide portion and causes light emitted from the light source to enter the interior of the light guide portion, A plurality of reflection cuts are located on the back side of the light guide and reflect the light guided inside the light guide toward the front side of the light guide, The light guide portion has an output portion located on the front side of the light guide portion, which outputs the light reflected by the plurality of reflection cuts to the outside of the light guide portion, The light guide portion has a pair of protruding ridges located on both sides of the central part on the front side, projecting forward. The emission portion is located between the pair of protruding portions and has a first emission surface that is convexly curved in a cross-section perpendicular to the direction in which the light guide portion extends, A vehicle light fixture comprising: a second emitting surface located on the front side of each of the pair of protruding portions, which is curved in a convex shape in a cross-section perpendicular to the direction in which the light guide portion extends.
2. The first emission surface is a convex surface with a circular arc cross-section having a first radius of curvature that is larger than the reference radius of the light guide portion. The vehicle light fixture according to claim 1, wherein the second emission surface is a convex surface with a circular arc cross-section having a second radius of curvature smaller than the first radius of curvature.
3. The vehicle lamp according to claim 1, wherein in a cross-section in a direction perpendicular to the direction in which the light guide portion extends, the width of the first emission surface between the pair of protrusions is greater than the width of the reflection cut.
4. The vehicle lamp according to claim 1, wherein the pair of protruding portions have connecting surfaces that connect the outer end of the second emission surface and the outer peripheral surface of the light guide portion.
5. The vehicle lamp according to claim 4, wherein the connecting surface is provided at a predetermined angle outward from the tangent at the position where it connects to the outer circumferential surface of the light guide, in a cross-section perpendicular to the direction in which the light guide extends.
6. The vehicle light fixture according to claim 1, wherein the foremost part of the second emission surface is located on the front side of the outer end of the second emission surface.
7. The vehicle lamp according to claim 1, further comprising a diffusion lens positioned on the front side of the light guide for diffusing the light emitted from the first emission surface and the second emission surface.