Vehicle lamp

Abstract

To provide a vehicle lamp capable of reducing the likelihood of creating an uneven luminous intensity distribution.SOLUTION: A vehicle lamp is provided with: a light source; and a lens body that is provided on the light output side of the light source and that includes, on an output surface side from which light introduced from the light source is output, a plurality of prisms 31 each having a hexagonal truncated pyramid shape extending along the optical axis of the light source. The plurality of prisms 31 each has a distal end portion 32 composed of a curved surface that serves as the distal end of the prism 31 and that refracts and outputs the introduced light, a reflecting portion 33 serving as a side surface of the prism 31 and totally reflecting light along the optical axis, and a root portion 34 serving as the root side of the prism 31 and composed of a curved surface that refracts and outputs the introduced light, the plurality of prisms comprising a plurality of types having different heights along the optical axis due to the reflecting portions 33 having different angles with respect to the optical axis.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle lamp. [Background technology]

[0002] Conventionally, a light source unit has been proposed that includes a light source and a lens body provided on the light emission side of the light source (for example, Patent Document 1). The lens body has a plurality of truncated quadrangular pyramid prisms arranged in a lattice pattern on the emission side of the lens body. Each prism has an emission surface that is the tip of the truncated quadrangular pyramid and a total reflection surface that forms the side of the truncated quadrangular pyramid. In the light source unit, the lens body takes in light from the light source so that it becomes parallel light along the optical axis. The taken-in light reaches the plurality of prisms, and some of the light is emitted directly from the tip surface, and the rest is reflected by the total reflection surface and then emitted from the tip surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-69620 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the light source unit described in Patent Document 1, because the multiple prism shapes are all the same, the luminous intensity is high at the front of the lens body and at a position at a specific angular direction relative to the lens body. Therefore, the luminous intensity of the light source unit is low at angles other than the specific angular direction relative to the lens body, resulting in an uneven appearance to the viewer. That is, the light source unit ensures luminous intensity at the front by light emitted directly from the tip face, and ensures luminous intensity in a specific angular direction by light emitted from the tip face via the total reflection surface. The specific angular direction corresponds to the angle of the total reflection surface. Therefore, because the multiple prism shapes are all the same, the light source unit has low luminous intensity at other angles, resulting in an uneven luminous intensity distribution.

[0005] The present disclosure has been made to solve such conventional problems, and its purpose is to provide a vehicle lamp that can reduce the possibility of an uneven luminous intensity distribution. [Means for solving the problem]

[0006] The vehicle lamp according to the present disclosure comprises a light source, and a lens body provided on the light emission side of the light source, the lens body having a plurality of prisms of a truncated cone or truncated polygonal pyramid shape extending along the optical axis of the light source on the emission surface side from which light is introduced from the light source, the plurality of prisms each having a tip portion which is the tip of the prism and is constituted by a curved surface that refracts and outputs the introduced light, a reflecting portion which is the side of the prism and totally reflects light along the optical axis, and a base portion which is the base side of the prism and is constituted by a curved surface that refracts and outputs the introduced light, and the prisms are constituted by a plurality of types whose heights along the optical axis differ due to the different angles of the reflecting portions with respect to the optical axis. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a vehicle lamp that can reduce the possibility of an uneven luminous intensity distribution. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an external perspective view showing a vehicle lamp according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of FIG. [Figure 3] FIG. 2 is a perspective view showing a plurality of prisms, illustrating a perspective view of only a partial region on the light-emitting side of the lens body. [Figure 4] FIG. 10 is a conceptual front view showing the types of prisms in a partial region of the lens body. [Figure 5] 5 is a view showing a cross section of the configuration in the first row of FIG. 4 taken along line II-II. [Figure 6]3 is a cross-sectional view of the configuration in the second row of FIG. 4 taken along line III-III. [Figure 7] 3 is a conceptual diagram showing an example of a luminous intensity distribution in the vehicle lamp according to the first embodiment. FIG. [Figure 8] FIG. 10 is a conceptual diagram showing an example of a luminous intensity distribution in a vehicle lamp according to a comparative example. [Figure 9] FIG. 6 is a cross-sectional view showing a vehicle lamp according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Vehicle lighting devices according to embodiments of the present disclosure will be described below, but the present disclosure is not limited to the following embodiments and can be modified as appropriate without departing from the spirit of the present disclosure. Furthermore, in the embodiments, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content described below.

[0010] Fig. 1 is an external perspective view showing a vehicle lamp according to a first embodiment, and Fig. 2 is a cross-sectional view taken along line II of Fig. 1. The vehicle lamp 1 shown in Fig. 1 is used, for example, as a signal lamp such as a turn signal lamp provided at the front or rear of a vehicle, and as a decorative lamp that displays information toward the surroundings of the vehicle. As shown in Figs. 1 and 2, the vehicle lamp 1 includes a housing H, a light source 10, an inner panel 20, and a lens body 30.

[0011] The housing H is a member that houses each element such as the light source 10, and has a rectangular opening O on the light output side. As shown in Fig. 1, the opening O is rectangular with rounded corners. Note that, although the housing H is box-shaped with the opening O in the first embodiment, the shape of the housing H is not limited to a box shape.

[0012] The light source 10 is an LED (Light-Emitting Diode) or the like that emits light, and is mounted on a substrate CB and fixedly housed within the housing H. The inner panel 20 is a member provided on the substrate CB so as to cover the periphery of the light source 10, and is formed in a cylindrical shape extending in the light emission direction.

[0013] The lens body 30 is provided on the light emission side of the light source 10 and emits the light introduced from the light source 10 in multiple directions. The lens body 30 is made of a clear lens with a transparency equal to or greater than a predetermined value. The lens body 30 has a plurality of prisms on the light emission surface side.

[0014] FIG. 3 is a perspective view showing the plurality of prisms, illustrating only a partial region on the light-emitting side of the lens body 30. As shown in FIG. 3, the plurality of prisms 31 each have a hexagonal truncated pyramid shape extending along the optical axis of the light source 10 (see FIG. 2). The hexagonal truncated pyramid has rounded corners, but the corners may not be rounded. The prisms 31 are not limited to a hexagonal truncated pyramid shape, and may instead have a circular truncated cone shape or a polygonal truncated pyramid shape other than a hexagon. Furthermore, when the plurality of prisms 31 have a polygonal truncated pyramid shape, it is preferable that the polygonal truncated pyramid shape have more than six sides.

[0015] Each of the multiple prisms 31 has a tip portion 32, a reflecting portion 33, and a base portion 34. The tip portion 32 is the tip of the prism 31 and is configured with a curved surface that refracts and emits light introduced from the light source 10. The tip portion 32 is configured with a curved surface that is convex toward the light emission side, but is not limited to this, and may be a curved surface that is convex in the direction opposite to the light emission side, or may be configured with multiple curved surfaces. Furthermore, the tip portion 32 may be a roughly curved surface configured by a combination of many flat surfaces.

[0016] The reflecting portion 33 is a portion that becomes a side surface of the prism 31, and is set at an angle that totally reflects light along the optical axis. The reflecting portion 33 may have a linear shape in a cross section along the optical axis, or may be configured with a curved surface, as long as the angle is set so that the light along the optical axis is totally reflected.

[0017] The base portion 34 is the base side of the prism 31 and is formed of a curved surface that refracts and emits light introduced from the light source 10. The base portion 34 is formed of a curved surface that is convex in the direction away from the light emission side, but is not limited to this. The base portion 34 may be a curved surface that is convex toward the light emission side, or may be formed of multiple curved surfaces. The base portion 34 may also be a roughly curved surface formed by combining multiple flat surfaces. In the first embodiment, the base portion 34 is hexagonal when the lens body 30 is viewed from the front, because the prism 31 has a hexagonal truncated pyramid shape.

[0018] Here, the plurality of prisms 31 are made up of a plurality of types of prisms, each having a different angle of the reflecting portion 33 relative to the optical axis. Specifically, in the first embodiment, the plurality of prisms 31 are made up of four types. However, the number of types of the plurality of prisms 31 is not limited to four, and may be two, three, five or more types.

[0019] 3, the height h1 of the first prism 31a is different from the height h2 of the second prism 31b. Since the areas of the bottom surfaces 35 of the multiple prisms 31 are uniform, the differences in heights h1 and h2 result in different angles of the reflecting portions 33. Similarly, the heights h3 and h4 of the third prism 31c and the fourth prism 31d are different, and the angles of the reflecting portions 33 are different.

[0020] It should be noted that the prisms 31 do not need to be formed using microfabrication technology, and for example, the tips 32 are formed at a pitch of 0.5 mm or more and 4 mm or less.

[0021] Fig. 4 is a conceptual front view showing the types of prisms 31 in a partial region of the lens body 30. Fig. 5 is a diagram showing a II-II cross section of the configuration in the first row (specific row) ST1 in Fig. 4, and Fig. 6 is a diagram showing a III-III cross section of the configuration in the second row (adjacent row) ST2 in Fig. 4.

[0022] As shown in Fig. 4, the four types of prisms 31a to 31d are regularly arranged with the sides of their hexagonal bases 34 (see Fig. 3) facing each other. That is, the four types of prisms 31a to 31d are arranged in a honeycomb pattern. As a result, the multiple prisms 31 are arranged in rows along the vertical direction (specific intersecting direction) that intersects with the optical axis. Note that vertices of the hexagon exist in the horizontal direction (orthogonal direction) that is perpendicular to the vertical direction. Therefore, the multiple prisms 31 are arranged with greater distances between them in the horizontal direction than in the vertical direction.

[0023] The plurality of prisms 31 are arranged in a regular pattern in the vertical direction, with four types of prisms 31a to 31d. As shown in Figures 4 and 5, in a first row ST1, which is a vertical row, the plurality of prisms 31 are arranged in the order of the fourth prism 31d, the third prism 31c, the second prism 31b, and the first prism 31a from bottom to top, and this sequence is repeated. In other words, the plurality of prisms 31 are arranged so that their heights gradually increase in the first row ST1.

[0024] 4 and 6, in a second row ST2 adjacent to the first row ST1, the prisms 31 are arranged in the order of the first prism 31a, the second prism 31b, the third prism 31c, and the fourth prism 31d from bottom to top, and this arrangement is repeated. That is, the prisms 31 are arranged so that their heights gradually decrease in the second row ST2.

[0025] The same applies to the third and subsequent rows. Therefore, the plurality of prisms 31 are arranged in such a manner that rows whose height gradually increases from bottom to top and rows whose height gradually decreases from bottom to top are alternately arranged.

[0026] The vehicle lamp 1 equipped with the lens body 30 described above is less likely to produce uneven visibility. The operation of the vehicle lamp 1 according to the first embodiment will now be described.

[0027] First, the light source 10 shown in Fig. 2 emits light. As a result, light from the light source 10 enters the lens body 30. The incident light is emitted as shown in Figs. 5 and 6. First, as shown in Fig. 5, the incident light L1 to L4 directly reaches the tip portions 32 of the multiple prisms 31. The tip portions 32 are formed with curved surfaces. Therefore, the light L1 to L4 is refracted in multiple directions by the curved surfaces before being emitted.

[0028] Furthermore, the incident light beams L5 and L6 reach the base portion 34. The base portion 34 is also formed with a curved surface, similar to the tip portion 32. Therefore, the light beams L5 and L6 are refracted in multiple directions by the curved surface and are emitted.

[0029] Furthermore, the incident light L7 to L10 reaches the reflecting portion 33. In FIG. 5, the light L7 to L10 is parallel light along the optical axis, and is therefore reflected by the reflecting portion 33. The reflected light is emitted from the tip portion 32 or the reflecting portion 33 on the opposite side. In particular, the light reflected by the reflecting portion 33 and emitted from the reflecting portion 33 on the opposite side may be blocked by the adjacent prism 31 (see FIG. 3). However, the multiple types of prisms 31a to 31d (see FIG. 3) are arranged so that their height gradually increases from bottom to top, as shown in FIG. 5. Therefore, the light emitted from the reflecting portion 33 is less likely to be blocked, at least downward, and is preferably emitted.

[0030] The same is true for the example shown in Fig. 6. Light L11 to L14 directly reach the tip portions 32 of the multiple prisms 31, are refracted in multiple directions by the curved surfaces, and are then emitted. Similarly, light L15 and L16 reach the base portions 34, are refracted in multiple directions by the curved surfaces, and are then emitted.

[0031] Furthermore, the light L17 to L20 reaches the reflecting portion 33, is reflected, and is emitted from the tip portion 32 or the opposite reflecting portion 33. In particular, as shown in Fig. 6, the multiple types of prisms 31a to 31d are arranged so that their heights gradually decrease from bottom to top. Therefore, the light emitted from the reflecting portion 33 is less likely to be blocked, at least in the upward direction, and is emitted favorably.

[0032] Fig. 7 is a conceptual diagram showing an example of the luminous intensity distribution in the vehicular lamp 1 according to the first embodiment, and Fig. 8 is a conceptual diagram showing an example of the luminous intensity distribution in a vehicular lamp according to a comparative example. As shown in Fig. 7, for example, a first region A1, which is the front surface of the vehicular lamp 1, receives a large amount of light emitted from the tip portion 32 (see Fig. 3, etc.) or the base portion 34 (see Fig. 3, etc.). Furthermore, a second region A2, which is concentrically adjacent to the first region A1, receives a large amount of light emitted through, for example, the reflecting portion 33 of the tallest first prism 31a.

[0033] Similarly, a large amount of light emitted through the reflecting portion 33 of the second prism 31b reaches the third region A3, which is concentrically adjacent to the second region A2, and a large amount of light emitted through the reflecting portion 33 of the third prism 31c reaches the fourth region A4, which is concentrically adjacent to the third region A3. Furthermore, a large amount of light emitted through the reflecting portion 33 of the fourth prism 31d reaches the fifth region A5, which is concentrically adjacent to the fourth region A4.

[0034] As described above, the vehicle lamp 1 according to the first embodiment includes multiple types of prisms 31a-31d with different angles of the reflecting portion 33, and therefore it is possible to set ranges in which the luminous intensity increases successively in a concentric manner, such as the second to fifth regions A2-A5. Furthermore, since light can be emitted to the first region A1 not only from the tip portion 32 but also from the base portion 34, the luminous intensity at the front is also ensured.

[0035] In contrast, as shown in Fig. 8, the vehicle lamp according to the comparative example cannot achieve the wide luminous intensity distribution shown in Fig. 7. Note that the vehicle lamp according to the comparative example has one type of prism, as shown in Patent Document 1, and further has no base portion and a flat tip portion.

[0036] As shown in Fig. 8, a large amount of light emitted from the tip reaches the first area A11, which is, for example, the front of the vehicle lamp. However, because the tip is flat, the light is not refracted and illuminates a slightly narrower first area A11 than the example shown in Fig. 7. Furthermore, since there is no base portion 34, there is a concern that the luminous intensity in the first area A11 may be insufficient depending on the area of ​​the tip. Furthermore, because there is only one type of prism, almost no light reaches the second, third, and fifth areas A12, A13, and A15, and only the fourth area A14, for example, is illuminated.

[0037] Therefore, the vehicle lamp according to the comparative example cannot illuminate the second, third, and fifth areas A12, A13, and A15, resulting in unevenness in the luminous intensity distribution. On the other hand, the vehicle lamp 1 according to the first embodiment does not have areas like the second, third, and fifth areas A12, A13, and A15 in the comparative example, and is configured to suppress unevenness in the luminous intensity distribution.

[0038] Thus, in the vehicle lamp 1 according to the first embodiment, the lens body 30 includes a plurality of prisms 31 on the light-emitting surface side, and not only are the tip portions 32 of the prisms 31 configured with curved surfaces that refract and emit light, but the base portions 34 are also configured with curved surfaces that refract and emit light. Therefore, the lens body 30 can easily emit light in various angular directions due to the refraction and emission of light by the tip portions 32 and the base portions 34. Furthermore, the plurality of prisms 31 are configured with a plurality of types of reflecting portions 33 with different angles. Therefore, the light can be emitted in various directions through reflection by the reflecting portions 33, making it easier to emit light in various angular directions. Therefore, a vehicle lamp 1 can be provided that can reduce the possibility of an uneven luminous intensity distribution.

[0039] Furthermore, since the vehicle lamp 1 is unlikely to have an uneven luminous intensity distribution, it is not necessary to use, for example, a milky white lens, and a clear lens can be used.

[0040] Furthermore, the multiple types of prisms 31a to 31d are arranged so that their heights gradually increase or decrease in the vertical direction. This makes it easier for the lower prisms 31 to be located at least on one side of the vertical direction. This makes it less likely that light from the prisms 31a to 31d will be blocked in the direction in which the lower prisms 31 are adjacent. This reduces the possibility that too much light will be blocked, resulting in an uneven appearance.

[0041] Furthermore, the multiple types of prisms 31a-31d are arranged so that their heights gradually increase in the first row ST1 and gradually decrease in the adjacent second row ST2. Therefore, the prisms 31 in the first row ST1 are less likely to block light downward (one side) in the vertical direction. Furthermore, the prisms 31 in the second row ST2 are less likely to block light upward (the other side) in the vertical direction. Therefore, the prisms 31 in the first row ST1 and the second row ST2 are more likely to emit light upward and downward. This further reduces the possibility of uneven visibility.

[0042] Furthermore, the multiple types of prisms 31a-31d each have a hexagonal truncated pyramid shape with a hexagonal root 34, and are regularly arranged with the sides of the hexagonal root 34 facing each other. Therefore, each prism 31 is adjacent to six other prisms 31 corresponding to its six sides. Furthermore, each prism 31 has valleys between the six other prisms 31, so the six valleys are close to each other. Here, if the multiple prisms 31 were arranged in a lattice pattern, four valleys would be close to each other. However, because the multiple prisms 31 each have a hexagonal truncated pyramid shape with a hexagonal root 34, light from each prism 31 is easily emitted in at least six directions through the six valleys. In addition, because the multiple prisms 31 each have a hexagonal truncated pyramid shape with a hexagonal root 34, they are arranged in rows in the vertical direction, but valleys are located in the horizontal direction, making the distance between each prism 31 greater. For this reason, when multiple prisms 31 are arranged in a grid pattern, it is difficult for light to be emitted in both the up and down and left and right directions, whereas the vehicle lamp 1 according to this embodiment easily emits light at least in the left and right direction. As a result, compared to a grid-like arrangement, it is easier for light to be emitted in more directions, and the possibility of uneven visibility can be further reduced.

[0043] Next, a second embodiment of the present disclosure will be described. The vehicle lamp according to the second embodiment is similar to that of the first embodiment, but has a partial configuration different from that of the first embodiment. The differences from the first embodiment will be described below.

[0044] Fig. 9 is a cross-sectional view showing a vehicle lamp according to the second embodiment. As shown in Fig. 9, the vehicle lamp 2 according to the second embodiment includes a condensing lens 40 between a light source 10 and a lens body 30. The condensing lens 40 has a lens portion 41 having a condensing function and a piece portion 42 extending from the lens portion 41. The piece portion 42 is fixedly attached to a substrate CB on which the light source 10 is mounted. Furthermore, in the second embodiment, the inner panel 20 is mounted on the piece portion 42.

[0045] The condenser lens 40 may have any shape as long as it can increase the directivity of the light from the light source 10, and may be a cylindrical lens, a collimator lens, or the like.

[0046] Here, the inner panel 20 is made black or the like, a color that is difficult to recognize from the outside. For this reason, there is a concern that the light from the light source 10 will be absorbed by the inner panel 20, reducing the light utilization efficiency. However, the vehicle lamp 2 according to the second embodiment is provided with the condenser lens 40, which increases the directionality of the light from the light source 10 and reduces the amount of light that reaches the inner panel 20.

[0047] Here, if the lens body 30 and the light source 10 are placed close to each other, all of the light from the light source 10 can be incident on the lens body 30. However, in this case, the light from the light source 10 cannot be evenly irradiated over the entire area of ​​the lens body 30, and only specific parts of the lens body 30 appear to be shining from the outside. For this reason, it is necessary to space the lens body 30 and the light source 10 apart to a certain extent. However, if the lens body 30 and the light source 10 are spaced apart, the light will be absorbed by the inner panel 20, resulting in a decrease in brightness.

[0048] However, since the vehicle lamp 2 according to the second embodiment includes the condenser lens 40, it is difficult to reduce brightness, and it is easy to make the light from the light source 10 irradiate the entire area of ​​the lens body 30 evenly.

[0049] In terms of design, it is preferable that the condenser lens 40 allows the light from the light source 10 to be incident on the entire area of ​​the lens body 30, rather than directly reaching the inner panel 20. This is because it is possible to minimize absorption by the inner panel 20 and increase the light utilization efficiency, while still allowing the light from the light source 10 to be evenly irradiated onto the entire area of ​​the lens body 30.

[0050] Thus, according to the second embodiment, as with the first embodiment, a vehicle lamp 2 can be provided that can reduce the possibility of an uneven luminous intensity distribution. Furthermore, light from each prism 31a-31d is less likely to be blocked in the direction of at least the lower prisms 31, reducing the possibility of a large amount of light being blocked and resulting in an uneven appearance. Furthermore, the prisms 31 in the first row ST1 and the second row ST2 tend to emit light both upward and downward, further reducing the possibility of an uneven appearance. Furthermore, compared to a grid-like arrangement, light is more likely to be emitted in multiple directions, further reducing the possibility of an uneven appearance.

[0051] Furthermore, according to the second embodiment, a focusing lens 40 is provided that focuses light from the light source 10, so that even if the lens body 30 and the light source 10 are spaced apart, the brightness is not reduced and it is easy to evenly irradiate the light from the light source 10 over the entire lens body 30.

[0052] The present disclosure has been described above based on the embodiments, but the present disclosure is not limited to the above embodiments, and modifications may be made or publicly known or well-known technologies may be combined within the scope of the present disclosure.

[0053] For example, in the above embodiment, adjacent prisms 31 are in contact with each other via the base portions 34, but this is not a limitation, and the prisms 31 may be spaced apart and have flat portions between them.

[0054] Furthermore, instead of the flat surface, a prism or a lens having an irregular shape different from the prism 31 may be disposed. [Explanation of symbols]

[0055] 1,2: Vehicle lighting fixtures 10:Light source 30: Lens body 31: Prism 31a: First prism 31b: Second prism 31c: Third prism 31d: 4th prism 32:Tip 33:Reflector 34: Root part 40: Condenser lens ST1: 1st column (specific column) ST2: 2nd column (adjacent column) h1~h4: height

Claims

1. A light source and a lens body provided on the light output side of the light source, the lens body having a plurality of prisms in a truncated cone or truncated polygonal pyramid shape extending along the optical axis of the light source on an output surface side from which light is output from the introduced light source; The plurality of prisms are Each of the prisms has a tip portion that is the tip of the prism and is configured with a curved surface that refracts and emits the introduced light, a reflecting portion that is the side surface of the prism and totally reflects the light along the optical axis, and a base portion that is the base side of the prism and is configured with a curved surface that refracts and emits the introduced light, The reflecting portion is configured to have different angles relative to the optical axis, and therefore has different heights along the optical axis. A vehicle lamp characterized by:

2. The plurality of prisms are arranged in a row along a specific intersecting direction intersecting the optical axis, with three or more types of prisms having different heights, and the heights gradually increase or decrease in the specific intersecting direction.

2. A vehicle lamp according to claim 1.

3. The plurality of prisms are arranged such that the height in a specific row increases gradually in the specific cross direction, and the height in an adjacent row adjacent to the specific row decreases gradually in the specific cross direction.

3. A vehicle lamp according to claim 2.

4. The plurality of prisms have a hexagonal truncated pyramid shape with the base being hexagonal, and are regularly arranged with the sides of the hexagonal base portions facing each other.

2. A vehicle lamp according to claim 1.

5. The optical system further includes a condenser lens disposed between the light source and the lens body, for condensing the light from the light source.

2. A vehicle lamp according to claim 1.

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