Vehicle lighting equipment

Abstract

To provide a lighting device for a vehicle which is capable of guiding incident light effectively while performing positioning of a light guide body with respect to a light source adequately.SOLUTION: A lighting device for a vehicle comprises: a light guide body 14 which is formed in an elongated shape and on which light of a light source is incident through a light incident part 14a formed on one end in a longitudinal direction and which emits a light from a light emission surface 14b formed along the longitudinal direction while guiding the incident light from the light source; and a positioning member 24 which includes an insertion hole 28c configured to allow a portion of one end side of the light guide body 14 to be inserted therein, and then positions the light incident part 14a with respect to the light source. The light guide body 14 is configured to include a projection 34 which extends from the one end side toward the other end side. The insertion hole 28c of the positioning member 24 is formed in s shape that contains a projection fitted part 28b into which the projection 34 is fitted. The projection 34 is formed in a shape with height being tapered as proceeding toward the other end side.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a vehicle lighting device

Background Art

[0002] The following Patent Document 1 describes an example of a vehicle lighting device. The vehicle lighting device described in the following Patent Document 1 includes a light source, a longitudinal light guide having a light incident portion into which light is incident from one end, and a positioning member having an insertion hole into which a portion on one end side of the light guide is inserted to determine the position of the light incident portion with respect to the light source. The vehicle lighting device described in the following Patent Document 1 includes a case for housing the light source, the light guide, and the positioning member, and a structure for preventing misassembly when housing them in the case is provided between the case and the light guide

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vehicle lighting device described in the above Patent Document 1 has a pair of claw portions on both side surfaces of a portion on one end side of the light guide, and a configuration is disclosed in which the pair of claw portions are fitted into a positioning member for attachment. However, since the cross section of the light guide is generally square, in such a configuration, it may be possible to fit it into the positioning member even in a state where it is inverted up and down (rotated 180° around the axis). That is, it is desirable to adopt a configuration that does not allow the light guide to be incorrectly assembled with respect to the positioning member (light source).

[0005] One possible configuration for this is to provide a projection that extends outward from one surface on one end of the light guide, and to shape the insertion hole on the positioning member so that the projection fits into it, thereby determining the orientation of the light guide relative to the positioning member. In a vehicle lighting device with this configuration, because the projection is provided on one end, there is a risk that light may leak from the projection that enters the light guide, or that the surface of the projection may refract the light in a direction different from the light guide direction of the light guide. In other words, problems arise such as the need to provide a separate member to block the leaked light, or that uniform light emission from the light emission part is hindered.

[0006] This invention has been made in view of such circumstances, and aims to provide a vehicle lighting device that can effectively guide incident light while appropriately positioning the light guide relative to the light source. [Means for solving the problem]

[0007] To solve the above problems, the vehicle lighting device of the present invention is Light source and A light guide is formed along the longitudinal direction, into which light from the light source is incident, and which guides the incident light from the light source and emits light from a light emission surface formed along the longitudinal direction. A positioning member having an insertion hole for inserting the portion of the light guide at one end, and which determines the position of the light incident portion relative to the light source, Equipped with, The light guide has a projection extending from one end toward the other end, The insertion hole of the positioning member is shaped to include a protruding fitting portion into which the protrusion fits, The aforementioned protrusion is characterized by having a shape in which its height gradually decreases towards the other end.

[0008] In the vehicle lighting device disclosed in this application, when the light guide is inserted into the positioning member, the relative orientation of the positioning member and the light guide is determined by the presence of a projection on the light guide. In conventional vehicle lighting devices, in order to determine the relative orientation of the positioning member and the light guide, a projection was sometimes provided only on the part of the positioning member that is inserted into the insertion hole. For example, the projection may have an end face perpendicular to the longitudinal direction of the light guide, and in such cases, there was a risk that the incident light would leak out from the end face of the projection or be reflected and leak out from a place that was not the light emission surface. In contrast, the vehicle lighting device disclosed in this application has a projection with a shape in which the height gradually decreases towards the other end, so that the incident light can be properly guided along the longitudinal direction of the light guide.

[0009] Furthermore, in the vehicle lighting device disclosed in this application, "gradual decrease" means a continuous (gradual) decrease without a step-by-step reduction, and the "protrusion" in the vehicle lighting device disclosed in this application has a shape in which the top of the protrusion slopes down smoothly without any steps. In addition, this "protrusion" may extend to the other end of the light guide, or it may extend to the middle part in the longitudinal direction of the light guide.

[0010] In the above configuration, the protrusion is formed on the surface opposite to the light-emitting surface, and a plurality of prisms that refract light toward the light-emitting surface are formed in the longitudinal direction on the other end of the protrusion from the portion inserted into the insertion hole.

[0011] This configuration of vehicle lighting device is limited to the location where a protrusion is formed. In this configuration of vehicle lighting device, it is desirable that the protrusion be shaped to appropriately guide the light that enters the protrusion to the prism, or to reflect it longitudinally from the end face of the protrusion. In this configuration of vehicle lighting device, the prism may be a convex shape that protrudes outward from the top surface of the protrusion (in the opposite direction from the exit surface), or it may be a concave shape with a recessed top surface of the protrusion.

[0012] In the above configuration, each of the prisms is shaped to protrude outward from the top surface of the projection, and the prisms on the other end can be shaped to protrude to a greater height.

[0013] This type of vehicle lighting system is limited to those with a convex prism shape. Furthermore, the height of this convex prism increases with increasing distance from the light source, allowing more light to be reflected towards the emission surface and ensuring uniformity of the brightness of the light emitted by the light guide along its longitudinal direction. In other words, this vehicle lighting system is configured such that, as the distance from the light source increases, the height of the projection decreases, but the height of the prism increases.

[0014] In the above configuration, each of the prisms is shaped like a mountain, and the length of the prism on the other end is larger.

[0015] With this configuration of vehicle lighting device, the greater the distance from the light source, the more light enters the prism, allowing more light to be reflected towards the emission surface, thus achieving uniformity in the longitudinal direction of the brightness of the emitted light in the light guide.

[0016] In the above configuration, the vehicle lighting device may be configured to include a cover member that covers the outside of the protrusions of the light guide.

[0017] With this configuration of vehicle lighting device, even if the height of the prism increases towards the other end, the height of the protrusion decreases. Therefore, even if the cover member is shaped to follow the light guide, it is possible to secure a certain gap between the inner surface of the cover member and the prism.

[0018] In the above configuration, the protrusion may be configured such that the cross-sectional shape in the perspective view from the longitudinal direction is a rectangular shape with a constant width smaller than the width of the light guide, and the side wall surfaces on both sides are perpendicular to the light emission surface.

[0019] In the vehicle lighting device with this configuration, the side wall surfaces on both sides of the protrusion are difficult to reflect light toward the emission surface, and the light that enters the protrusion will generally travel toward the top surface side. Therefore, the light can be appropriately guided by reflecting it toward the light emission surface by the prism provided on the top surface or by total reflection along the longitudinal direction.

Advantages of the Invention

[0020] According to the present invention, it is possible to provide a vehicle lighting device that can effectively guide the incident light while appropriately positioning the light guide with respect to the light source.

Brief Description of the Drawings

[0021] [Figure 1] A diagram showing the vehicle lighting device according to an embodiment of the present invention from the perspective of the indoor side [Figure 2] A side view of the vehicle lighting device according to the embodiment [Figure 3] A side cross-sectional view of the vehicle lighting device according to the embodiment [Figure 4] A diagram showing an enlarged view of the light source unit side in FIG. 3 [Figure 5] A perspective view showing the state where the light source unit and the light guide rod are assembled [Figure 6] A perspective view showing the state where the light source unit and the light guide rod are removed [Figure 7] A cross-sectional view of the light guide insertion portion in the light source unit [Figure 8] A side view showing an enlarged view of one end side of the light guide rod [Figure 9] A side view showing an enlarged view of the center in the longitudinal direction of the light guide rod [Figure 10] A side view showing an enlarged view of the other end side of the light guide rod [[ID=A7]] [Figure 11] A diagram showing an example of the progress of light in the light guide rod of the comparative example [Figure 12] Diagram showing the propagation of light in the light guide rod of this embodiment. [Figure 13] A magnified side cross-sectional view showing the prism located at one end of the light guide rod. [Figure 14] A magnified side cross-sectional view showing the prism located at the other end of the light guide rod. [Figure 15] Plan view illustrating the function of the tapered section of the light guide rod. [Modes for carrying out the invention]

[0022] A vehicle lighting device 10, which is an embodiment of the vehicle lighting device of the present invention, will be described with reference to Figures 1 to 15. As shown in Figure 1, the lighting device 10 is installed on the ceiling of a vehicle and is a line lighting device that emits light in a line shape extending in the front-rear direction of the vehicle from the end in the width direction of the vehicle.

[0023] As shown in Figures 2 and 3, the lighting device 10 of this embodiment comprises a light source unit 12, a long, rectangular light guide rod (light guide body) 14 that guides light from the light source unit 12, a lens member 16 that diffuses the light emitted from the light guide rod 14 towards the interior of the vehicle, and a cover member 18 that covers the exterior side of the light guide rod 14. In this lighting device 10, the light source unit 12, the light guide rod 14, and the cover member 18 are arranged on the exterior side of the ceiling material 20, with the lens member 16 covering an elongated hole 20a extending in the front-rear direction provided in the ceiling material 20. The cover member 18 is provided with a plurality (five in this embodiment) of mounting claws 18a. The lighting device 10 of this embodiment is fixed to the ceiling by attaching these mounting claws 18a to a bracket on the vehicle body side (not shown). In reality, the lower surface of the lens member 16 is positioned at an angle from the vertically downward direction. However, in the following description, the side of the lighting device 10 in this embodiment on which the lens member 16 is located (the lower side in Figures 2 and 3) may be referred to as the lower side, and the side on which the cover member 18 is located (the upper side in Figures 2 and 3) may be referred to as the upper side.

[0024] As shown in Figures 2-5, the light source unit 12 is provided at one end (front end, left end in Figures 2 and 3) of the light guide rod 14. As shown in Figure 4, the light source unit 12 consists of a point light source LED 22 and a light-shielding case 24 that houses the LED 22. As shown in Figures 4 and 5, the case 24 has a generally rectangular parallelepiped light source housing section 26 that houses the LED 22, and a light guide insertion section 28 that opens into the light source housing section 26 and extends from the light source housing section 26 into which one end of the light guide rod 14 is inserted. When one end of the light guide rod 14 is inserted into the light guide insertion section 28 of the case 24, one end of the light guide rod 14 and the LED 22 are positioned opposite each other.

[0025] As shown in Figures 6 and 7, the light guide rod 14 mainly consists of a rectangular, elongated main body portion 30. A pair of claw portions 32 are formed on one end of the main body portion 30, protruding from both sides, and a generally rectangular ridge 34 is formed on the upper surface of the main body portion 30. On the other hand, the case 24 has a light guide insertion portion 28 that has a generally rectangular cylindrical portion 36 that communicates with the inside of the light source housing portion 26, and a pair of vertical wall portions 38 that are erected from the upper surface of the cylindrical portion 36 at a distance smaller than the width of the cylindrical portion 36. With this shape, the light guide insertion portion 28 allows the main body portion 30 of the light guide rod 14 to be inserted into the cylindrical portion 36, and the ridge 34 of the light guide rod 14 to be inserted between the pair of vertical wall portions 38. The case 24 determines the orientation of the light guide rod 14 relative to itself (the rotational position around the axis extending in the longitudinal direction). In other words, case 24 is positioned so that the light incident portion 14a, which is one end of the light guide rod 14, and the LED 22 are facing each other, and it functions as a positioning member that determines the position of the light incident portion 14a relative to the light source LED 22.

[0026] In this embodiment, the space formed by combining the internal space 28a of the cylindrical portion 36 of the light guide insertion section 28 and the space 28b formed between the pair of vertical wall portions 38 functions as an insertion hole 28c. Furthermore, the space 28b between the pair of vertical wall portions 38 functions as a protruding fitting portion in the insertion hole 28c into which the protruding portion 34 fits. The light source housing section 26 has a through hole 26a that communicates with the space inside the cylindrical portion 36. Only the tip of the main body portion 30 of the light guide rod 14 is inserted into this through hole 26a. In addition, the cylindrical portion 36 has a pair of locking holes 36a formed on both sides for locking the pair of claw portions 32 of the light guide rod 14, making it possible to assemble the light source unit 12 and the light guide rod 14. The main body portion 30 and one end of the protrusion 34 abut against a part of the case 24, and the pair of claw portions 32 are locked into the locking holes 36a, thereby determining the longitudinal position relative to the case 24.

[0027] The light guide rod 14 is made of a synthetic resin material that has a refractive index sufficiently higher than that of air and is almost transparent. In this embodiment, the light guide rod 14 is exemplified as being made of acrylic resin having a critical angle of approximately 42.2°. The light guide rod 14 is configured such that when light traveling inside is incident at an incident angle greater than the critical angle at the interface with the external air layer, it undergoes total internal reflection and propagates through the interior.

[0028] As explained earlier, the light guide rod 14 extends in the longitudinal direction of the vehicle, and its cross-sectional shape (cross-sectional shape of the main body 30) in the longitudinal direction is approximately square. As will be explained in more detail later, in the portion of the light guide rod 14 that is not inserted into the light guide insertion part 28 of the case 24, prisms 40 are formed on the upper surface of the protrusions 34, generally extending in the width direction and protruding, and are arranged at intervals in the longitudinal direction. The light guide rod 14 is configured such that the light propagating inside is directed upward toward the light emission surface 14b on the lower side by these multiple prisms 40, or in other words, the angle with respect to the emission surface is smaller than the critical angle. The directed light then exits from the light emission surface 14b, passes through the lens member 16, and is emitted into the vehicle interior.

[0029] As shown in Figures 5 and 6, the light guide rod 14 has flange portions 42 protruding from both sides of the main body portion 30, except for the portion inserted into the light guide insertion portion 28, and is assembled to the cover member 18 so as to lock the flange portions 42. A detailed explanation is omitted, but the cover member 18 is a longitudinal member with a U-shaped cross-section that opens downwards and extends along the light guide rod 14, covering three surfaces of the light guide rod 14 excluding the light-emitting surface 14b. The lens member 16 is umbrella-shaped and closes the elongated hole 20a of the ceiling material 20, and consists of a lens body portion 16a that emits light and a pair of wall portions 16b that are erected on the back surface of the lens body portion 16a and are spaced apart from each other in the width direction (direction perpendicular to the longitudinal direction). Then, the pair of wall sections 16b are inserted into the elongated holes 20a of the ceiling material 20 from the passenger compartment side, and each of these wall sections 16b can be fixed to the cover member 18.

[0030] Next, the characteristic configuration of the vehicle lighting device 10 of this embodiment will be described in detail. The protrusion 34 of the light guide rod 14 described earlier is intended to prevent incorrect assembly of the case 24 in the direction in which it is attached to the light guide insertion part 28. However, this protrusion 34 extends not only to the portion inserted into the light guide insertion part 28, but also toward the other end of the light guide rod 24 (the right end in Figures 2 and 3) 14c, and as shown in Figure 3, it extends to the vicinity of the other end 14c. Furthermore, the portion of the protrusion 34 inserted into the light guide insertion part 28 is of a constant height, but the portion not inserted into the light guide insertion part 28 has a shape in which the height gradually decreases toward the other end, as shown in Figures 8 to 10, that is, the top surface of the protrusion 34 slopes downward smoothly without any steps.

[0031] Here, we compare the light guide rod 14 in this embodiment with the light guide rod 100 shown in Figure 11. The light guide rod 100 in this comparative example is provided with a rib 102 on its upper surface to prevent misassembly, such that only the portion inserted into the light guide insertion section 28 protrudes upward. As shown in Figure 11, the other end of this rib 102 has a stepped shape. In other words, an end face 102a is formed that is perpendicular to the longitudinal direction of the light guide rod 100. This end face 102a causes the light incident from the light source 104 to be emitted to the outside of the light guide rod 100 or reflected in the vertical direction, resulting in the light being emitted from a location other than where it is intended to be emitted. In such a case, problems arise, such as the need for a member to block the leaked light. In contrast, the lighting device 10 in this embodiment has a shape in which the height of the protrusion 34 gradually decreases towards the other end, so that, as shown in Figure 12, total internal reflection occurs inside the light guide rod 14, and the light can be effectively propagated inside.

[0032] As mentioned above, the projection 34 is formed to protrude upward from the surface (top surface) opposite to the light-emitting surface 14b. Multiple prisms 40 are arranged in a longitudinal direction on the top surface 34a of the projection 34. These multiple prisms 40 extend in a direction intersecting the longitudinal direction and have a V-shaped cross-section. The direction in which these multiple prisms 40 extend is not perpendicular to the longitudinal direction, but in a direction inclined with respect to the longitudinal direction, in order to equalize the light in the longitudinal direction.

[0033] As shown in Figure 13 for one end and Figure 14 for the other end, the multiple prisms 40 are arranged so that the protruding height H increases towards the other end. In addition, the multiple prisms 40 are shaped so that the longitudinal dimension L increases towards the other end. With these configurations, as the distance from the LED 22 increases, more light enters the interior of the prism 40, and the surface area facing the light emission surface 14b increases, allowing more light to be reflected towards the light emission surface 14b, thus achieving uniformity in the longitudinal direction of the brightness of the emitted light from the light guide rod 14.

[0034] As described above, the light guide rod 14 has a shape in which the height of the prism 40 increases towards the other end, while the height of the protrusion 34 gradually decreases towards the other end. Therefore, even if the shape of the cover member 18 is made to conform to the shape of the main body 30 of the light guide rod 14, as shown in Figures 8 to 10, it is possible to secure a nearly constant width between the upper end of the light guide rod 14 (the top of the prism 40) and the cover member 18 covering the light guide rod 14. There is no need to enlarge the other end of the cover member 18 on the outside of the vehicle interior, and there is no need to increase the mounting space for this lighting device 10.

[0035] Furthermore, the projection 34 of the light guide rod 14 has a rectangular cross-sectional shape of a constant width smaller than the width of the main body 30 when viewed from the longitudinal direction, and the side walls 34b on both sides are shaped to be perpendicular to the light emitting surface 14b. As a result, the lighting device 10 has side walls 34b of the projection 34 that do not easily reflect light toward the light emitting surface 14b, and the light that enters the projection 34 is directed almost entirely toward the top surface 34a of the projection 34. Therefore, the light can be reflected toward the light emitting surface 14b by the prism 40 provided on the top surface 34a, or totally reflected along the longitudinal direction and guided appropriately.

[0036] Furthermore, as shown in Figure 15, the light guide rod 14 is provided with a tapered portion 50 on the other end of the pair of claw portions 32. This tapered portion 50 is shaped to widen in the width direction, which is the direction in which the claw portions 32 protrude, as it approaches the other end. This tapered portion 50 is also continuous with the flange portion 42 described earlier. In Figure 15, a protrusion 52 is formed that further protrudes outward; this protrusion 52 is for positioning relative to the cover member 18. In this light guide rod 14, the presence of the pair of claw portions 32 results in light being generated at an angle smaller than the critical angle with respect to the longitudinal direction. If the tapered portion 50 were absent and the side wall surface extended parallel to the longitudinal direction, this light would be emitted from the side wall surface. However, in the lighting device 10 of this embodiment, the tapered portion 50 allows light at an angle smaller than the critical angle with respect to the longitudinal direction to be reflected toward the other end, thereby suppressing light leakage due to the presence of the claw portions 32.

[0037] <Other Embodiments> The present invention is not limited to the embodiments described above, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. For example, the following embodiments are also included within the technical scope of the present invention.

[0038] (1) In the above embodiment of the vehicle lighting device 10, the projection 34 extended to the vicinity of the other end 14c of the light guide rod 14. However, the length of the projection 34 in the longitudinal direction may be such that the height gradually decreases, taking into account the critical angle of the material of the light guide rod 14, so that the angle of inclination prevents light leakage. For example, the projection may extend to the vicinity of the center in the longitudinal direction, or it may extend to the other end. (2) In the above embodiment, the vehicle lighting device 10 had a prism 40 that protruded outward from the top surface 34a of the projection 34, but it may also have a shape in which a groove is provided on the top surface 34a.

[0039] (3) In the above embodiment of the vehicle lighting device 10, the protrusion 34 was formed on the surface opposite to the light-emitting surface 14b, but it is not limited to this. For example, the protrusion may be provided on the side or bottom surface. In other words, the prism does not necessarily have to be provided on the top surface of the protrusion.

[0040] (4) Although the vehicle lighting device 10 of the above embodiment was intended to be provided for a vehicle (automobile), it is not limited thereto, and the lighting device of the present invention can be applied to various vehicles. [Explanation of Symbols]

[0041] 10...Vehicle lighting device [Lighting device for vehicles], 14...Light guide rod [Light guide body], 14a...Light incident part (one end), 14b...Light emission surface, 18...Cover member, 22...LED [Light source], 24...Case [Positioning member], 28...Light guide body insertion part, 28b...Protruding fitting part, 28c...Insertion hole, 34...Protrusion, 40...Prism

Claims

1. Light source and A light guide is formed along the longitudinal direction, into which light from the light source is incident, and which guides the incident light from the light source and emits light from a light emission surface formed along the longitudinal direction. A positioning member having an insertion hole for inserting the portion of the light guide at one end, and which determines the position of the light incident portion relative to the light source, Equipped with, The light guide has a projection extending from one end toward the other end, The insertion hole of the positioning member is shaped to include a protruding fitting portion into which the protrusion fits, The aforementioned projection is characterized in that the portion inserted into the positioning member is of a constant height, while the portion not inserted into the positioning member has a shape in which the height gradually decreases towards the other end.

2. Light source and A light guide is formed along the longitudinal direction, into which light from the light source is incident, and which guides the incident light from the light source and emits light from a light emission surface formed along the longitudinal direction. A positioning member having an insertion hole for inserting the portion of the light guide at one end, and which determines the position of the light incident portion relative to the light source, Equipped with, The light guide has a projection extending from one end toward the other end, The insertion hole of the positioning member is shaped to include a protruding fitting portion into which the protrusion fits, The aforementioned protrusion has a shape in which its height gradually decreases towards the other end. The aforementioned protrusion is formed on the surface opposite to the light-emitting surface, A vehicle lighting device in which a plurality of prisms that refract light toward the light-emitting surface are formed in the longitudinal direction on the other end of the protrusion from the portion inserted into the insertion hole.

3. The vehicle lighting device according to claim 2, wherein each of the prisms is shaped to protrude outward from the top surface of the projection, and the height of the projection is greater on the other end.

4. The vehicle lighting device according to claim 3, wherein each of the prisms is shaped like a mountain, and the length of the prism on the other end is larger.

5. The vehicle lighting device according to claim 3 or claim 4, further comprising a cover member that covers the outside of the protrusion of the light guide body.

6. The vehicle lighting device according to any one of claims 2 to 4, wherein the projection has a rectangular cross-sectional shape with a constant width smaller than the width of the light guide, as viewed from the longitudinal direction, and the side wall surfaces on both sides are shaped to be perpendicular to the light emitting surface.

Images