Lighting units and vehicle lighting fixtures

Abstract

The present invention provides a lighting unit capable of emitting light from the front end surface and side surfaces of a plate-shaped light guide. [Solution] The lighting unit 10 includes an LED 11, a plate-shaped light guide 16 which includes a light receiving section 21 that receives light from the LED 11, a reflecting section 22 that reflects the light incident from the light receiving section 21, and a light emitting section 23 that emits the light reflected by the reflecting section 22. The plate-shaped light guide 16 has a left side surface 16a and a right side surface 16b that face each other, an upper end surface 16c and a lower end surface that connect the left side surface 16a and the right side surface 16b and face each other, and a front end surface 16e surrounded by the left side surface 16a, the right side surface 16b, the upper end surface 16c and the lower end surface. The light receiving section 21 is provided on the left side surface 16a. The light emitting section 23 includes a side emission surface 28 and a front end surface 16e provided in a part of the left side surface 16a. The right side surface 16b has a plurality of steps 32 that direct the light traveling through the plate-shaped light guide 16 toward the side emission surface 28.

Description

Technical Field

[0001] The present invention relates to a lamp unit and a vehicle lamp. Background Art

[0002] Conventionally, a lamp unit combining a light source such as an LED and a plate-shaped light guide that controls light from the light source has been proposed. In such a lamp unit, light emitted from the light source enters the interior of the plate-shaped light guide through a light incident portion thereof, travels within the plate-shaped light guide, and is irradiated toward the front of the lamp from a front end face of the plate-shaped light guide. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2016-91825 Patent Document 2 Japanese Unexamined Patent Application Publication No. 2018-6091 Summary of the Invention Problem to be Solved by the Invention

[0004] Although a lamp unit that causes the front end face of a plate-shaped light guide to emit light as disclosed in the above patent documents is known, the present invention provides a lamp unit that causes not only the front end face of the plate-shaped light guide but also a side face of the plate-shaped light guide to emit light. Means for Solving the Problem

[0005] To solve the above problems, a lighting unit according to one aspect of the present invention comprises a plate-shaped light guide including a light source, a light-receiving section that receives light from the light source, a reflecting section that reflects light incident from the light-receiving section, and a light-emitting section that emits light reflected by the reflecting section. The plate-shaped light guide has a first side surface and a second side surface that face each other, a first end surface and a second end surface that connect the first side surface and the second side surface and face each other, and a front end surface surrounded by the first side surface, the second side surface, the first end surface and the second end surface. The light-receiving section is provided on the first side surface or the second side surface, and the light-emitting section includes a side-emitting surface and a front end surface provided in a part of the first side surface. The second side surface has a plurality of steps that direct the light traveling through the plate-shaped light guide towards the side-emitting surface. [Effects of the Invention]

[0006] According to the present invention, a lighting unit is provided that can cause the front end surface and side surfaces of a plate-shaped light guide to emit light. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic front view of a lighting unit according to an embodiment. [Figure 2] This is a schematic right side view of a lighting unit according to an embodiment. [Figure 3] This is a plan view of a lighting unit according to an embodiment. [Figure 4] This is a rear view of a lighting unit according to an embodiment. [Figure 5] This is a diagram showing a vehicle lighting fixture using a lighting unit. [Modes for carrying out the invention]

[0008] The present invention will be described below with reference to the drawings, based on preferred embodiments. The following configurations are for illustrative purposes to help understand the disclosure, and the scope of the disclosure is defined solely by the appended claims. Identical or equivalent components and members shown in each drawing are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate. In addition, the dimensions of members in each drawing are shown enlarged or reduced as appropriate for ease of understanding. Furthermore, some members that are not important to describing the embodiments are omitted in each drawing. In addition, when terms indicating direction such as "up," "down," "front," "rear," "left," "right," "inside," and "outside" are used in this specification, they refer to the direction in which the lighting unit or vehicle lighting is positioned when mounted on a vehicle.

[0009] Figure 1 is a schematic front view of the lighting unit 10 according to the embodiment. Figure 2 is a schematic right side view of the lighting unit 10 according to the embodiment. Figure 3 is a top view of the lighting unit 10 according to the embodiment. Figure 4 is a rear view of the lighting unit 10 according to the embodiment. The lighting unit 10 can be used, for example, in vehicle lighting such as taillights.

[0010] The lighting unit 10 includes an LED 11 as a light source and a plate-shaped light guide 16 that receives light from the LED 11 and emits it forward.

[0011] The LED 11 is mounted on the substrate 13. The LED 11 emits light when current is supplied from the substrate 13. In this embodiment, the LED 11 is positioned so that its optical axis Ax is oriented horizontally.

[0012] The plate-shaped light guide 16 includes a light-receiving section 21 that receives light from the LED 11, a reflecting section 22 that reflects the light incident from the light-receiving section 21, and a light-emitting section 23 that emits the light reflected by the reflecting section 22 forward of the lamp. The plate-shaped light guide 16 is formed from a transparent resin material such as acrylic or polycarbonate.

[0013] The plate-shaped light guide 16 is a substantially plate-shaped body configured such that its longitudinal direction faces the front-to-back direction and its short direction faces the up-to-down direction. The plate-shaped light guide 16 has a left side (first side) 16a and a right side (second side) 16b that face each other, an upper end surface (first end surface) 16c and a lower end surface (second end surface) 16d that connect the left side 16a and the right side 16b and face each other, a front end surface 16e surrounded by the left side 16a, the right side 16b, the upper end surface 16c and the lower end surface 16d, and a rear end surface 16f that faces the front end surface 16e.

[0014] The light-receiving portion 21 and the reflecting portion 22 are provided at or near the rear end of the plate-shaped light guide 16. The light-receiving portion 21 is formed to protrude from the left side surface 16a of the plate-shaped light guide 16. The light-receiving portion 21 faces the LED 11 and causes light from the LED 11 to enter the interior of the plate-shaped light guide 16. In this embodiment, the light-receiving portion 21 is provided on the left side surface 16a of the plate-shaped light guide 16, but it may also be provided on the right side surface 16b.

[0015] In this embodiment, the reflective portion 22 includes a first reflective surface 24 provided facing the light-receiving portion 21, and second reflective surfaces 25 provided on both sides of the first reflective surface 24.

[0016] The first reflective surface 24 is formed as a recess created by indenting the right side surface 16b of the plate-shaped light guide 16 inward. Note that if the light-receiving portion 21 is provided on the right side surface 16b, the first reflective surface 24 is formed as a recess created by indenting the left side surface 16a of the plate-shaped light guide 16 inward.

[0017] The first reflective surface 24 is divided into a front reflective surface 26 positioned in front of the optical axis Ax of the LED 11 and a rear reflective surface 27 positioned behind the optical axis Ax of the LED 11. The front reflective surface 26 is configured to totally reflect a portion of the light incident into the plate-shaped light guide 16 from the light-receiving section 21 toward the front end of the plate-shaped light guide 16. On the other hand, the rear reflective surface 27 is configured to totally reflect a portion of the light incident into the plate-shaped light guide 16 from the light-receiving section 21 toward the second reflective surface 25.

[0018] The second reflecting surface 25 is provided at the upper part and the lower part of the rear end surface 16f of the plate-shaped light guide 16. The second reflecting surface 25 is configured to totally reflect the light reflected by the rear reflecting surface 27 toward the front end direction of the plate-shaped light guide 16.

[0019] In the present embodiment, the front reflecting surface 26 is provided with a plurality of cylindrical steps 26a for diffusing and reflecting light from the light incident portion 21. The second reflecting surface 25 is also provided with a plurality of cylindrical steps 25a for diffusing and reflecting light from the rear reflecting surface 27. In this way, by providing cylindrical steps on a part of the reflecting portion 22 to diffuse the light traveling toward the front end direction of the plate-shaped light guide 16, the uniformity of light emission in the light emitting portion 23 can be improved.

[0020] In the lamp unit 10 according to the present embodiment, the light emitting portion 23 includes a front end surface 16e of the plate-shaped light guide 16, and a side light exit surface 28 provided in a partial region of the left side surface 16a of the plate-shaped light guide 16.

[0021] The front end surface 16e has a narrow rectangular shape extending in the vertical direction. The front end surface 16e emits, toward the front of the lamp, the light that travels through the plate-shaped light guide 16 and reaches the front end portion of the plate-shaped light guide 16. In the present embodiment, the front end surface 16e is formed as an inclined surface that inclines rearward from below to above, but may be formed as a vertical surface. The front end surface 16e may be provided with a plurality of steps (for example, fish-eye steps) for diffusing emitted light.

[0022] The side light exit surface 28 is provided in a region on the front side of the lamp on the left side surface 16a of the plate-shaped light guide 16. A decorative film 30 that transmits light emitted from the side light exit surface 28 may be provided on the side light exit surface 28. By providing the decorative film 30 that imparts colors or patterns on the side light exit surface 28, the designability of the lamp unit 10 can be improved.

[0023] Multiple steps 32 are formed on the right side surface 16b of the plate-shaped light guide 16, directing a portion of the light traveling through the plate-shaped light guide 16 toward the side emission surface 28. The steps 32 may be fisheye steps. The multiple steps 32 are arranged in the region of the right side surface 16b facing the side emission surface 28. These steps 32 allow a portion of the reflected light from the reflecting part 22 to be emitted from the side emission surface 28 toward the side of the luminaire.

[0024] As shown in Figure 3, the right side surface 16b is inclined with respect to the left side surface 16a such that the plate-shaped light guide 16 tapers from the rear end to the front end. By inclining the right side surface 16b with respect to the left side surface 16a in this way, a portion of the light traveling through the plate-shaped light guide 16 can be suitably directed onto the step 32 on the right side surface 16b and directed towards the side emission surface 28.

[0025] Multiple diffusion steps 29 may be provided between the reflective portion 22 on the left side 16a or the right side 16b and the side emission surface 28. The diffusion steps 29 may be cylindrical steps. By providing diffusion steps 29 between the reflective portion 22 and the side emission surface 28 and diffusing the light directed toward the front end of the plate-shaped light guide 16, the uniformity of light emission in the light-emitting portion 23 can be improved.

[0026] Figures 2 and 3 illustrate an exemplary optical path of light emitted from the LED 11. A portion of the light emitted from the LED 11 and incident into the plate-shaped light guide 16 from the light-receiving section 21 is reflected by the front reflective surface 26 toward the front end of the plate-shaped light guide 16. A portion of the reflected light from the front reflective surface 26 reaches the front end of the plate-shaped light guide 16 and is emitted from the front end surface 16e toward the front of the luminaire (ray L1). Another portion of the reflected light from the front reflective surface 26 is directed toward the side emission surface 28 by a step 32 formed on the right side surface 16b and is emitted toward the side of the luminaire from the side emission surface 28 (ray L2).

[0027] Another portion of the light emitted from the LED 11 and incident into the plate-shaped light guide 16 from the light-receiving section 21 is reflected by the rear reflective surface 27 toward the second reflective surface 25, and further reflected by the second reflective surface 25 toward the front end of the plate-shaped light guide 16. A portion of the reflected light from the second reflective surface 25 reaches the front end of the plate-shaped light guide 16 and is emitted from the front end surface 16e toward the front of the luminaire (light ray L3). Another portion of the reflected light from the second reflective surface 25 is directed toward the side emission surface 28 by the step 32 formed on the right side surface 16b, and is emitted toward the side of the luminaire from the side emission surface 28 (light ray L4).

[0028] Thus, according to this embodiment, a lighting unit 10 can be realized in which not only the front end surface 16e of the plate-shaped light guide 16 but also the side emission surface 28 of the plate-shaped light guide 16 can emit light. By providing a decorative film 30 on the side emission surface 28, the design of the lighting unit 10 can be improved.

[0029] Figure 5 shows a vehicle lighting fixture 100 using the lighting unit 10. The vehicle lighting fixture 100 can be used, for example, as a taillight.

[0030] The vehicle light fixture 100 comprises a lamp body 102, a transparent cover (not shown) covering the front opening of the lamp body 102, and a plurality of light fixture units 10 provided within a light chamber 104 formed by the lamp body 102 and the cover. The plurality of light fixture units 10 are arranged horizontally (left-right direction) with their front end surfaces 16e extending in the vertical direction. Decorative films may be provided on the side emission surfaces 28. The vehicle light fixture 100 may be configured to satisfy the required light quantity for a vehicle light fixture through light emission from the front end surface 16e of each light fixture unit 10. By using the light fixture units 10 according to this embodiment, light emission from the side emission surfaces 28 can be achieved, thereby enhancing the design aesthetics of the vehicle light fixture 100.

[0031] The present invention has been described above based on the embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of each component and each processing process, and that such modifications also fall within the scope of the present invention. [Explanation of symbols]

[0032] 10 Lighting unit, 11 LED, 16 Plate-shaped light guide, 21 Light-receiving part, 22 Reflecting part, 23 Light-emitting part, 24 First reflective surface, 25 Second reflective surface, 26 Front reflective surface, 27 Rear reflective surface, 28 Side emission surface, 29 Diffusion step, 30 Decorative film, 32 Step, 100 Vehicle lighting fixture.

Claims

1. Light source and A plate-shaped light guide includes a light-receiving section that receives light from the light source, a reflective section that reflects the light incident from the light-receiving section, and a light-emitting section that emits the light reflected by the reflective section. The plate-shaped light guide is The first and second sides facing each other, The first side and the second side are connected and the first end face and second end face are opposite to each other, It has a front end face surrounded by the first side surface, the second side surface, the first end face and the second end face, The light-receiving portion is provided on the first side or the second side, The light-emitting portion includes a side emission surface provided in a part of the first side surface and the front end surface, The second side surface has a plurality of steps for directing the light traveling through the plate-shaped light guide towards the side emission surface. A lighting unit characterized by the following features.

2. The light-receiving portion and the light-reflecting portion are provided at or near the rear end of the plate-shaped light guide, The luminaire unit according to claim 1, characterized in that the second side surface is inclined with respect to the first side surface such that the plate-shaped light guide body tapers from the rear end to the front end.

3. The lighting unit according to claim 1, further comprising a decorative film provided on the first side surface.

4. The luminaire unit according to claim 1, further comprising a plurality of diffusion steps provided between the reflective portion on the first or second side surface and the side emission surface.

5. The luminaire unit according to claim 1, characterized in that the reflective portion includes a cylindrical step for diffusing and reflecting light from the light-receiving portion.

6. A vehicle lighting device comprising a plurality of lighting units according to any one of claims 1 to 5, A vehicle lighting device characterized in that multiple lighting units are arranged horizontally with their front end surfaces extending in the vertical direction.

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