JP2020205147A - Light guide and vehicle lamps - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light guide body capable of suppressing the generation of leaked light from a curved portion and preventing the generation of spot light in the curved portion. SOLUTION: The light guide body 3 guides the light L emitted from the light source 2, and guides the incident portion 5 on which the light L emitted from the light source 2 is incident and the light L incident from the incident portion 5. Located between the first light guide unit 6, the second light guide unit 7 and the third light guide unit 8 to be illuminated, and the first light guide unit 6 and the second light guide unit 7. Between the inclined surface 10 that reflects the light L guided by the first light guide unit 6 toward the second light guide unit 7 and the second light guide unit 7 and the third light guide unit 8. It has a curved portion 11 that guides the light L guided by the second light guide portion 7 toward the third light guide portion 8, and the inclined surface 10 is the inclined surface 10. It has a light diffusing portion 15 that reflects the light L incident on the light L while diffusing it. [Selection diagram] Fig. 2

Description

The present invention relates to a light guide and a vehicle lamp.

Conventionally, as a vehicle lamp mounted on a vehicle, a combination of a light source such as a light emitting diode (LED) and a long light guide body such as an inner lens has been known (for example, Patent Document 1 below). See.).

In such a vehicle lamp, the light emitted from the light source is incident on the inside of the light guide from the end surface (hereinafter, referred to as "incident surface") on the base end side of the light guide, and is inside the light guide. While repeating the reflection with, the light is guided toward the tip side of the light guide body. Further, the light reflected by the plurality of reflection cuts provided on the back surface (hereinafter referred to as “reflection surface”) side of the light guide body is external from the front surface (hereinafter referred to as “emission surface”) side of the light guide body. It emits to. As a result, it is possible to make the light emitting surface side of the light guide body emit light in a line shape as a light emitting portion of the vehicle lamp.

Japanese Unexamined Patent Publication No. 2016-115398

By the way, in the above-mentioned vehicle lighting equipment, a part of the light guided toward the tip end side of the light guide body may be emitted to the outside from the curved portion of the light guide body as leakage light. When leaked light is generated in the curved portion, there is a problem that the portion where the leaked light is generated appears to shine more strongly than the surroundings, that is, the so-called spotlight makes the light emitting portion of the vehicle lighting fixture look worse.

In the invention described in Patent Document 1, in order to prevent the occurrence of such spotlight, an expansion portion that expands toward the back side is provided on the curved portion of the light guide body, and the curved portion is provided with light leakage from the front side. Is being suppressed.

On the other hand, in such a configuration, a large expansion portion must be secured between the incident surface and the reflecting surface of the light guide body, and the curvature of the curved portion increases, so that from the incident surface of the light guide body. The distance to the exit surface will increase. Therefore, there is a drawback that the area (exit surface) that becomes the light emitting portion when the vehicle lamp is viewed from the front side is relatively short.

The present invention has been proposed in view of such conventional circumstances, and is a light guide body capable of suppressing the generation of leaked light from the curved portion and preventing the generation of spot light in the curved portion. , As well as vehicle lighting fixtures equipped with such a light guide.

In order to achieve the above object, the present invention provides the following means.
[1] A light guide body that guides light emitted from a light source.
An incident part where the light emitted from the light source is incident and
A first light guide unit, a second light guide unit, and a third light guide unit that guide light incident from the incident portion.
An inclination that is located between the first light guide unit and the second light guide unit and reflects the light guided by the first light guide unit toward the second light guide unit. Face and
Located between the second light guide unit and the third light guide unit, the light guided by the second light guide unit is directed toward the third light guide unit. Has a curved part and
The inclined surface is a light guide body having a light diffusing portion that diffuses and reflects light incident on the inclined surface.
[2] The light guide body according to the above [1], wherein the light diffusing portion has a degree of light diffusing that decreases from the inside to the outside of the inclined surface.
[3] The feature is that the light reflected by the plurality of reflection cuts provided on the back surface side of the first light guide unit is emitted from the emission unit provided on the front side of the first light guide unit. The light guide according to the above [1] or [2].
[4] The feature is that the light reflected by the plurality of reflection cuts provided on the back surface side of the third light guide unit is emitted from the emission unit provided on the front side of the third light guide unit. The light guide body according to the above [3].
[5] A fourth light guide portion located between the incident portion and the first incident portion to guide light incident from the incident portion, and a fourth light guide portion.
An inclined surface located between the fourth light guide portion and the first incident portion and reflecting the light guided by the fourth light guide portion toward the first light guide portion. The light guide according to any one of the above [1] to [4].
[6] Light source and
A vehicle lamp provided with the light guide according to any one of the above [1] to [5].

As described above, according to the present invention, a light guide body capable of suppressing the generation of leaked light from the curved portion and preventing the generation of spot light in the curved portion, and such a light guide body It is possible to provide a vehicle lamp equipped with it.

It is a perspective view which shows the structure of the lighting fixture for a vehicle which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the vehicle lamp shown in FIG. It is a top view which shows the structure of the light diffusion part. It is sectional drawing which shows the structure of the light diffusing part by the line segment AA shown in FIG. It is sectional drawing which shows another structure of the light diffusing part by the line segment AA shown in FIG. It is sectional drawing which shows the specific example of the prism cut shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings used in the following description, in order to make each component easier to see, the scale of the dimensions may be different depending on the component, and the dimensional ratio of each component is not always the same as the actual one. Absent.

As an embodiment of the present invention, for example, the vehicle lamp 1 shown in FIGS. 1 and 2 will be described.
Note that FIG. 1 is a perspective view showing the configuration of the vehicle lamp 1. FIG. 2 is a cross-sectional view showing the configuration of the vehicle lamp 1.

As shown in FIGS. 1 and 2, the vehicle lamp 1 of the present embodiment is mounted on both corners on the rear end side of the vehicle (not shown) (corners on the left rear end side in the present embodiment). Among the rear combination lamps to be used, it constitutes a direction indicator (turn lamp). The turn lamp is arranged inside the lamp body 100 constituting the rear combination lamp. The lamp body 100 is composed of a housing 101 having an open front surface and an outer lens 102 serving as a lens cover covering the opening of the housing.

In the following explanation, the descriptions "front", "rear", "left", "right", "top", and "bottom" are used when the vehicle lamp 1 is viewed from the front (rear of the vehicle) unless otherwise specified. It shall mean each direction of. Therefore, the directions when the vehicle is viewed from the front (front of the vehicle) are the directions in which the front, rear, left, and right are reversed.

In the vehicle lamp 1 of the present embodiment, a light source 2 that emits light L and a long light guide body 3 that guides the light L emitted from the light source 2 are arranged inside the lamp body 100. It has a configuration.

The light source 2 is composed of an LED that emits orange light as light L. Further, as the LED, a high output (high brightness) type LED (for example, SMD LED) for vehicle lighting is used. The light source 5 is mounted on the front side of a circuit board 4 provided with a drive circuit for driving the LED, and emits light L radially forward.

The vehicle lamp 1 may be provided with a heat sink that dissipates heat generated by the light source 2 to the outside in a state of being in contact with the back surface side of the circuit board 4. Further, as the light source 2, a light emitting element such as a laser diode (LD) can be used in addition to the above-mentioned LED.

The light guide body 3 is made of a rod-shaped light transmitting member having a substantially circular cross section as an inner lens. As the light transmissive member, a material having a refractive index higher than that of air, such as transparent resin such as polycarbonate or acrylic or glass, can be used.

The light guide body 3 includes an incident portion 5 on which the light L emitted from the light source 2 is incident, a first light guide portion 6 for guiding the light L incident from the incident portion 5, and a second light guide portion 7. It is located between the third light guide unit 8 and the fourth light guide unit 9, and the first light guide unit 6 and the second light guide unit 7, and the first light guide unit 6 guides the light. The second light L is located between the first inclined surface 10 that reflects the light L toward the second light guide 7 and the second light guide 7 and the third light guide 8. Positions between the curved portion 11 that guides the light L guided by the light guide portion 7 toward the third light guide portion 8 and the fourth light guide portion 9 and the first incident portion 6. Then, it has a second inclined surface 12 that reflects the light L guided by the fourth light guide unit 9 toward the first light guide unit 6.

The light guide body 3 includes a fourth light guide portion 9 extending forward from the incident portion 5 facing the light source 2, and a first light guide portion 6 extending inward in the vehicle width direction. The space is bent at a substantially right angle via a second inclined surface 12 that is inclined at an angle. The second inclined surface 12 is a reflecting surface inclined at an angle of 45 ° with respect to the optical axis of the light L emitted from the light source 2.

Further, in the light guide body 3, the space between the first light guide portion 6 and the second light guide portion 7 extending toward the front is substantially inclined via the first inclined surface 10 which is inclined obliquely. It is bent at a right angle. Further, in the light guide body 3, the distance between the second light guide portion 7 and the third light guide portion 8 extending inward in the vehicle width direction is substantially perpendicular to each other via the curved curved portion 11. It is folded into.

In the vehicle lamp 1 of the present embodiment, the light L emitted from the light source 2 is incident on the inside of the fourth light guide portion 9 from the incident portion 5 on the proximal end side of the light guide body 3. The light L incident on the inside of the fourth light guide unit 9 is guided toward the second inclined surface 12. The light L incident on the second inclined surface 12 is reflected toward the first light guide unit 6. The light L reflected toward the first light guide unit 6 is guided toward the first inclined surface 10. The light L incident on the first inclined surface 10 is reflected toward the second light guide portion 7. The light L reflected toward the second light guide portion 7 is guided toward the curved portion 11. The light L incident on the curved portion 11 is guided toward the third light guide portion 8. The light L guided toward the third light guide unit 8 is guided toward the tip end side of the light guide body 3.

In the vehicle lamp 1 of the present embodiment, the light L reflected by the plurality of reflection cuts 13 provided on the back side of the first light guide unit 6 and the third light guide unit 8 is converted into the first light guide unit. The light is emitted to the outside from the exit portion 14 provided on the front side of the sixth and third light guide portions 8. As a result, as the light emitting portion of the above-mentioned turn lamp, the emitting portion 14 of the light guide body 3 can emit orange light in a line shape.

The incident portion 5 is composed of an end surface on the proximal end side of the light guide body 3 (fourth light guide portion 9). Further, the incident portion 5 is not limited to a flat surface, and may have a shape of incident on the inside of the light guide body 3 while parallelizing or condensing the light L radially emitted from the light source 2.

In the present embodiment, the incident portion 5 has a shape that parallelizes the light L radially emitted from the center of the light source 2. However, even in this case, the light L that cannot be parallelized and has an angle is also guided. It is considered that this is because the light source 2 has a finite size, and therefore, strictly speaking, the light L deviating from the center of the light source 2 is also incident. The plurality of reflection cuts 13 provided on the back surface side of the first light guide unit 6 emit the unparallelized light L to the outside.

Further, the incident portion 5 is located at the center of a portion facing the light source 2, for example, a convex first condensing incident surface on which a part of the light L emitted from the light source 2 is incident, and a first condensing incident surface. A second condensing light having a substantially cylindrical shape, which is located on the inner peripheral side of a portion protruding toward the light source 2 from a position surrounding the surrounding of the incident surface, and in which a part of the light L emitted from the light source 2 is incident. It has a first condensing surface and a conical condensing reflection surface that is located on the outer peripheral side of the protruding portion and reflects the light L incident from the second condensing incident surface. The light L incident from the incident surface may be focused toward the optical axis, and the light L incident from the second focused incident surface may be reflected by the focused reflecting surface to be condensed toward the optical axis.

The plurality of reflection cuts 13 have an angle (light guide body 3) at which the light L incident on the back surfaces of the first light guide unit 6 and the third light guide unit 8 is less than the critical angle with respect to the front surface of the light guide body 3. It suffices as long as it is reflected at an angle (angle at which light L is transmitted from the emitting portion 14 of the above), and the shape, size, number and the like thereof are not particularly limited.

For example, in the present embodiment, the plurality of reflection cuts 13 are configured by arranging prism cuts having a substantially triangular cross section in the extending direction of the first light guide portion 6 and the third light guide portion 8. Further, in the present embodiment, the adjacent intervals of the plurality of reflection cuts 13 are equal. On the other hand, since the plurality of reflection cuts 13 make the light emitting unit (emission unit 14) of the turn lamp emit light more uniformly, the first light guide unit 6 and the third light guide unit are matched to the shape of the light emitting unit. The degree of diffusion of the light L emitted from the front side of No. 8 may be controlled. Specifically, the adjacent distance between the plurality of reflection cuts 13 may be gradually narrowed from the proximal end side to the distal end side of the light guide body 3.

The light guide body 3 is attached to the inside of the housing 101 together with the circuit board 4 via a bracket (not shown). Further, the cowl portion 101a constituting the front surface side of the housing 101 covers a portion facing the light source 2 (including the fourth light guide portion 9 and the second inclined surface 12) when viewed from the front side. It is arranged on the front side of the outer lens 102.

The vehicle lamp 1 may be provided with a reflector (not shown) facing the back surface of the light guide body 3. As a result, the light L emitted from the back surface side of the light guide body 3 to the outside can be reflected by the reflector, and the light L can be incident on the inside from the back surface side of the light guide body 3 again.

By the way, the first inclined surface 10 has a light diffusing portion 15 that diffuses and reflects the light L incident on the first inclined surface 10. Specifically, this light diffusing portion has a shape as shown in FIGS. 3 and 4. Note that FIG. 3 is a plan view showing the configuration of the light diffusing unit 15. FIG. 4 is a cross-sectional view showing the configuration of the light diffusing portion 15 by the line segments AA shown in FIG.

The light diffusing portion 15 is composed of a plurality of lens cuts 15a arranged concentrically from the inside to the outside of the first inclined surface 10. The plurality of lens cuts 15a are made of a ring-shaped cylindrical lens. The light diffusing portion 15 is formed with reference to the 45-degree surface of the first inclined surface 10 (the incident angle of the light L on the optical axis of the light source 2 reflected by the second inclined surface 12 is 0 degree). It has a plurality of lens cuts 15a.

Further, the plurality of lens cuts 15a have radii of curvature from the inside to the outside of the first inclined surface 10 so that the degree of diffusion of light L decreases from the inside to the outside of the first inclined surface 10. Is gradually increasing. On the other hand, the spacing between the lens cuts 15a is constant.

In this case, the lens cut 15a inside the first inclined surface 10 has a relatively large radius of curvature, so that the degree of diffusion of light (diffusion spread angle) is relatively large. On the other hand, the lens cut 15a on the outside of the first inclined surface 10 has a relatively large radius of curvature, so that the degree of diffusion of light (diffusion spread angle) is relatively small.

Here, the spot of the light L incident on the first inclined surface 10 has the highest luminous intensity on the inside (center) of the spot, and the luminous intensity decreases toward the outside (outer circumference) of the spot. This is because the luminous intensity distribution of the light L emitted from the light source 2 has the highest luminous intensity near the optical axis, and the light spread from the optical axis (with an angle) becomes weaker. Such a luminous intensity distribution is reflected even in the light L that guides the fourth light guide unit 9 and the first light guide unit 6.

Therefore, the light L diffused by the light diffusing unit 15 is in a state in which the luminous intensity is more uniform between the inside and the outside. As a result, it is possible to prevent a part of the light L guided toward the curved portion 11 from being emitted from the curved portion 11 to the outside as a point light.

On the other hand, when there is no lens cut 15a, that is, when the first inclined surface 10 is a flat reflecting surface, the light L near the optical axis of the light source 2 is likely to be emitted from the curved portion 11. On the other hand, when the lens cut 15a is provided, the difference between the light L emitted from the curved portion 11 and the light L emitted from the third light guide portion 8 to the outside is reduced.

Further, the light diffusing portions 15 are not limited to the case where they are composed of the plurality of lens cuts 15a described above, and are arranged concentrically from the inside to the outside of the first inclined surface 10, for example, as shown in FIG. It may be composed of a plurality of prism cuts 15b. The prism cut 15b is formed by forming a ring-shaped prism having a substantially triangular cross section.

The plurality of prism cuts 15b are formed from the inside to the outside of the first inclined surface 10 so that the degree of diffusion of light L decreases from the inside to the outside of the first inclined surface 10. The size (height in this embodiment) is small. On the other hand, the spacing between the lens cuts 15a is constant.

In this case, the prism cut 15b inside the first inclined surface 10 has a relatively large size, so that the degree of diffusion of light (diffusion spread angle) is relatively large. On the other hand, the prism cut 15b on the outside of the first inclined surface 10 has a relatively small size, so that the degree of diffusion of light (diffusion spread angle) is relatively small.

In this case as well, the light L diffused by the light diffusing unit 15 is in a state in which the luminous intensity is more uniform between the inside and the outside. As a result, it is possible to prevent a part of the light L guided toward the curved portion 11 from being emitted from the curved portion 11 to the outside as leakage light.

The light diffusing unit 15 controls the degree of diffusion of the light L by adjusting the radius of curvature of the lens cut 15a and the size of the prism cut 15b described above, but the lens cut 15a and the prism cut 15b are lined up. It is also possible to control the degree of diffusion of the light L by adjusting the interval. Specifically, by widening the spacing between the lens cuts 15a and the prism cuts 15b from the inside to the outside of the first inclined surface 10, the light L is emitted from the inside to the outside of the first inclined surface 10. It is also possible to reduce the degree of diffusion.

Further, it is preferable that the surface of the prism cut 15b changes within the total reflection angle with respect to the light L on the optical axis of the light source 2 reflected by the second inclined surface 12. For example, as shown in the enlarged view of FIG. 6, the surface of the prism cut 15b can be changed within a range of 48 ° or less (incident angle is 42 ° or more) when the total reflection angle is 42 ° or more. Good.

As described above, in the vehicle lamp 1 of the present embodiment, it is possible to suppress the generation of leaked light from the curved portion 11 and prevent the generation of spot light in the curved portion 11.

The present invention is not necessarily limited to that of the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the vehicle lighting tool 1, the shape of the light guide body 3 and the like can be appropriately changed according to the actual vehicle design and the like. For example, with respect to the light guide body 3, the fourth light guide portion 9 and the second inclined surface 12 are omitted, and the incident portion facing the light source 2 at the end portion of the first light guide portion 6 on the proximal end side. It is also possible to have a configuration in which 5 is provided.

Further, the light guide body to which the present invention is applied is not limited to the one made of the long light guide body (light guide rod) described above, but is made of a plate-shaped light guide body (light guide plate). May be good. Further, a plurality of incident portions 5 corresponding to the plurality of light sources 2 may be provided on the light guide body.

The vehicle lighting equipment to which the present invention is applied is not limited to the turn lamps described above, and for example, vehicle headlights (headlamps), vehicle side lights (position lamps), and auxiliary headlights (sub-headlamps). ), Front (rear) fog lamp (fog lamp), daytime lighting lamp (DRL), lid lamp, tail lamp (tail lamp), back lamp, direction indicator (winker lamp), etc. The present invention can be widely applied to vehicle lamps. Further, the color of the light emitted by the light source is not limited to the orange light described above, and can be appropriately changed according to the use of the light source such as white light or red light.

1 ... Vehicle lighting 2 ... Light source 3 ... Light guide 4 ... Circuit board 5 ... Incident part 6 ... First light guide 7 ... Second light guide 8 ... Third light guide 9 ... Fourth Light guide part 10 ... First inclined surface 11 ... Curved part 12 ... Second inclined surface 13 ... Reflection cut 14 ... Emission part 15 ... Light diffusing part 15a ... Lens cut 15b ... Prism cut 100 ... Lamp 101 ... Housing 102 … Outer lens

Claims (6)

A light guide that guides the light emitted from the light source.
An incident part where the light emitted from the light source is incident and
A first light guide unit, a second light guide unit, and a third light guide unit that guide light incident from the incident portion.
An inclination that is located between the first light guide unit and the second light guide unit and reflects the light guided by the first light guide unit toward the second light guide unit. Face and
Located between the second light guide unit and the third light guide unit, the light guided by the second light guide unit is directed toward the third light guide unit. Has a curved part and
The inclined surface is a light guide body having a light diffusing portion that diffuses and reflects light incident on the inclined surface. The light guide according to claim 1, wherein the light diffusing portion has a degree of light diffusing that decreases from the inside to the outside of the inclined surface. The claim is characterized in that the light reflected by a plurality of reflection cuts provided on the back surface side of the first light guide unit is emitted from an emission unit provided on the front side of the first light guide unit. The light guide body according to 1 or 2. The claim is characterized in that the light reflected by the plurality of reflection cuts provided on the back surface side of the third light guide portion is emitted from the exit portion provided on the front side of the third light guide portion. The light guide body according to 3. A fourth light guide portion located between the incident portion and the first incident portion to guide light incident from the incident portion, and a fourth light guide portion.
An inclined surface located between the fourth light guide portion and the first incident portion and reflecting the light guided by the fourth light guide portion toward the first light guide portion. The light guide according to any one of claims 1 to 4. Light source and
A vehicle lamp provided with the light guide according to any one of claims 1 to 5.

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