JP2010135124A - Vehicle lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle lighting device capable of clearly illuminating an illumination pattern of a desired light distribution. <P>SOLUTION: An optical axis O' of a lens part 21 of an optical member 20 is inclined more downward than a horizontal direction (an optical axis O of each of LEDs 12) with a light emitting portion 12a of each of the LEDs 12 as a reference. With this, a region below the horizontal position of the lighting device 1 is illuminated by the lens part 21, while each of the LEDs 12 is arranged at an optically ideal position with respect to the lens portion 21. Further, each of reflection faces 22c, 23c of an upper-side reflector portion 22 and a lower-side reflector portion 23 of the optical member 20 is set up based on each of different parabolas P1, P2 with each of the LEDs 12 as each of focuses F1, F2. With this, the region horizontal or lower in relation to the lighting device 1 is illuminated by each of the reflector portions 22, 23, while each of the LEDs 12 is arranged at an optically ideal position with respect to each of the reflector portions 22, 23 also. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an illumination device for a vehicle that illuminates a preset irradiation region with a predetermined light distribution.

  Generally, a light emitting diode (LED) has an advantage of low power consumption and long life. Therefore, in recent years, with higher output of LEDs, it is expected that LEDs are applied as light sources even in lighting devices that require a large amount of light, such as in-vehicle headlights and fog lamps.

By the way, in the vehicular illumination device such as a headlamp and a fog lamp, the light distribution pattern of the emitted light is defined by the standard. As a technique for realizing this light distribution pattern, for example, Patent Document 1 discloses a vehicular lamp (vehicle illumination device) in which a prism lens is connected to a linear light source in which a plurality of LEDs are linearly arranged. The prism lens body is formed of a columnar member extending in a cross-sectional fan shape whose upper and lower surfaces are formed along a single parabola, and the top portion of the body is cut off. The incident surface is formed and the other end side is set as the exit surface, and a direct light exit portion having a convex cross section along the length direction is formed at the center in the width direction of the exit surface and the direct light exit portion. Discloses a technique in which a first reflected light emitting portion and a second reflected light emitting portion are formed on the upper side and the lower side. In this vehicular lamp, the light source is offset with respect to the focal point of the parabola that defines the upper and lower reflecting surfaces and the optical axis of the direct light emitting part, and the first reflected light emitting part and the second reflected light emitting part are inclined. By adjusting the angle, an irradiation pattern of a predetermined light distribution is applied to a region below the horizontal axis defined by law.
JP 2006-164923 A

  However, in the technique disclosed in Patent Document 1 described above, since the desired light distribution is realized by offsetting from the ideal position of the light source with respect to each functional unit of the prism lens, the sharpness of the irradiation pattern is reduced. There is a risk of doing.

  An object of this invention is to provide the illuminating device for vehicles which can irradiate clearly the irradiation pattern of desired light distribution.

  The present invention is a vehicle illumination device including a light source having an optical axis set in a horizontal direction and an optical member that controls light emitted from the light source, and the optical member is on the optical axis of the light source. The lens unit is disposed in the lens unit that emits the incident light from the light source that is changed by refraction, and is formed of a light transmissive material that is integral with the lens unit. The incident light from the light source is formed above the lens unit. The upper reflector portion that is totally reflected by the upper reflection surface and is emitted, and the lower reflection surface that is formed of a light-transmitting material integral with the lens portion and that forms incident light from the light source below the lens portion. A lower reflector portion that emits light, and the optical axis of the lens portion is inclined downward from the horizontal direction with respect to the light source, and the upper reflecting surface is focused on the light source or the vicinity of the light source. While comprising an aspherical surface, The side reflective surface, characterized by being configured in a different aspheric surface and the light source or the upside reflecting surface whose focal point the light source neighborhood.

  According to the vehicle lighting device of the present invention, it is possible to clearly irradiate a desired light distribution pattern.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is an exploded perspective view showing a schematic configuration of a vehicle lighting device, FIG. 2 is an exploded perspective view showing a main part of the vehicle lighting device, and FIG. FIG. 4 is an explanatory diagram showing a simulation result of behavior of light incident on an optical member, and FIG. 5 is an explanatory diagram showing an irradiation pattern.

  1 and 2, reference numeral 1 denotes a vehicular lighting device, and in the present embodiment, specifically denotes a vehicular fog lamp. The illuminating device 1 includes a light source unit 10 using a plurality of light emitting diodes (LEDs) 12 as a light source, and an optical member 20 that controls light emitted from each LED 12 of the light source unit 10, and these are not shown. It is housed in the body to form the main part.

  The light source unit 10 includes, for example, an LED substrate 11 having a long planar substantially rectangular shape, and a plurality of (for example, seven) LEDs 12 are mounted on the mounting surface of the LED substrate 11. In the present embodiment, each LED 12 is configured by a surface-mount type LED having a single convex lens fixed to the emission surface side, and each LED 12 is arranged in a line along the longitudinal direction of the LED substrate 11. Here, when the lighting device 1 is mounted on the vehicle, the LED substrate 11 stands up with its mounting surface directed toward the front of the vehicle such that its long side extends in the vehicle width direction and its short side extends in the vertical direction. Arranged in a state. Thus, the LEDs 12 are arranged in a line along the vehicle width direction, and the optical axis O of each LED 12 is set along the front in the horizontal direction. In the present invention, the horizontal direction in which the optical axis O or the like of each LED 12 is set does not require a strict horizontal direction, and a predetermined error range is allowed.

  The optical member 20 is arranged on the optical axis O of each LED 12, and is configured by a lens portion 21 that emits light incident on the LED 12 while being changed by refraction, and a light transmissive material that is integral with the lens portion 21. The upper reflector part 22 that totally reflects and emits incident light from the LED 12 above the lens part 21, and a light-transmitting material that is integral with the lens part 21, and incident light from each LED 12 is below the lens part 21. And a lower reflector portion 23 that totally reflects and emits light.

  As shown in FIGS. 2 and 3, the incident surface 21 a of the lens unit 21 is constituted by, for example, a substantially rectangular plane extending along the longitudinal direction of the LED substrate 11, and the incident surface 21 a has each optical axis O. The LED 12 is arranged upright so as to face each LED 12. In addition, the exit surface 21b of the lens unit 21 is constituted by, for example, a cylindrical lens surface extending along the longitudinal direction of the LED substrate 11, and is directly opposed to the entrance surface 21a. Here, as shown in FIG. 3, the optical axis O ′ of the lens unit 21 is set to be inclined at a predetermined angle below the horizontal direction (the optical axis O of each LED 12) with respect to the light emitting unit 12a of each LED 12. ing. Here, the curvature of the exit surface 21b, the inclination angle of the optical axis O 'of the lens unit 21, and the like are set to appropriate values based on experiments, simulations, and the like. Thereby, for example, as shown in FIG. 4, the lens unit 21 mainly emits light emitted from each LED 12 in a vertical direction with respect to the optical axis O at a predetermined radiation angle or less. The light is incident at 21a, and the radiation angle in the vehicle width direction is maintained at a predetermined value, and the radiation angle in the vertical direction is changed so as to be close to parallel light by the refraction of the incident surface 21a and the emission surface 21b. At that time, due to the inclination of the optical axis O ′, the emitted light from the lens unit 21 is directed obliquely downward in the front of the vehicle. For example, at a point where the irradiation distance is 10 m or more, the horizontal position of the illumination device 1 or less (the optical axis O or less). ).

  As shown in FIGS. 2 and 3, the incident surface 22 a of the upper reflector portion 22 is configured by a substantially rectangular plane extending along the longitudinal direction of the LED substrate 11, for example. The incident surface 22a is disposed above each LED 12 in a lying state so that the front end edge portion is connected to the upper end edge portion of the incident surface 21a of the lens portion 21 and the base end edge portion is in contact with the LED substrate 11. Has been. Moreover, the output surface 22b of the upper reflector part 22 is configured by, for example, a gentle surface extending along the short side direction of the LED substrate 11. The emission surface 22b is disposed in a state where it rises at a predetermined angle with respect to the vertical direction so that the lower edge thereof is connected to the upper edge of the emission surface 21b of the lens unit 21. Furthermore, the upper surface of the upper reflector portion 22 is formed as a reflective surface (upper reflective surface) 22c that totally reflects incident light from the incident surface 22a and guides it in the direction of the outgoing surface 22b (front of the vehicle). The upper reflecting surface 22c is formed of an aspherical surface extending in the longitudinal direction of the LED substrate 11 and having a cross-sectional shape along a curve with the light emitting portion 12a of each LED 12 or the vicinity thereof as a focal point F1, and its front edge portion. Is connected to the upper edge of the emission surface 22b. In the present embodiment, the upper reflecting surface 22c is configured, for example, by a parabolic surface extending in the longitudinal direction of the LED substrate 11 having a cross-sectional shape along the parabola P1 with the light emitting portion 12a of each LED 12 as the focal point F1. ing. Here, the shape of the parabola P1 that defines the upper reflection surface 22c, the shape of the emission surface 22b, the inclination angle, and the like are set to appropriate values based on experiments, simulations, and the like. Thereby, for example, as shown in FIG. 4, the upper reflector unit 22 mainly receives light emitted from each LED 12 at an angle greater than or equal to a predetermined radiation angle upward with respect to the optical axis O. The incident light is incident on the surface 22a, and the radiation angle in the vehicle width direction is maintained at a predetermined value. The light is emitted so as to be close. At that time, due to the shape of the upper reflection surface 22c, the inclination of the emission surface 22b, and the like, the emitted light from the upper reflector portion 22 is directed obliquely downward in the front of the vehicle, for example, at a point where the irradiation distance is 10 m or more. An area below the horizontal position (optical axis O or less) is irradiated.

  As shown in FIGS. 2 and 3, the incident surface 23 a of the lower reflector portion 23 is configured by a substantially rectangular plane extending along the longitudinal direction of the LED substrate 11, for example. The incident surface 23 a is disposed below each LED 12 in a lying state so that the front end edge portion is connected to the lower end edge portion of the incident surface 21 a of the lens portion 21 and the base end edge portion is in contact with the LED substrate 11. Has been. Moreover, the output surface 23b of the lower reflector part 23 is configured by, for example, a gentle surface extending along the short direction of the LED substrate 11. The emission surface 23b is arranged in a state where it rises at a predetermined angle with respect to the vertical direction so that the upper edge thereof is connected to the lower edge of the emission surface 21b of the lens unit 21. Furthermore, the lower surface of the lower reflector portion 23 is formed as a reflective surface (lower reflective surface) 23c that totally reflects incident light from the incident surface 23a and guides it in the direction of the exit surface 23b (front of the vehicle). The lower reflecting surface 23c is formed of an aspherical surface extending in the longitudinal direction of the LED substrate 11 and having a cross-sectional shape along a curve having the light emitting portion 12a of each LED 12 or the vicinity thereof as a focal point F2. The portion is connected to the lower end edge of the emission surface 23b. In the present embodiment, the lower reflective surface 23c is configured by, for example, a parabolic surface extending in the longitudinal direction of the LED substrate 11 having a cross-sectional shape along the parabola P1 with the light emitting portion 12a of each LED 12 as the focal point F2. Has been. Here, the lower reflective surface 23c is formed of a reflective surface different from the upper reflective surface 22c. That is, as shown in FIG. 2, a parabola different from the parabola P1 defining the upper reflection surface 22c is set in the parabola P2 defining the lower reflection surface 23c. Here, the shape of the parabola P2 that defines the lower reflection surface 23c, the shape of the emission surface 23b, the inclination angle, and the like are set to appropriate values based on experiments, simulations, and the like. Thereby, for example, as shown in FIG. 4, the lower reflector unit 23 mainly emits light emitted from each LED 12 in a downward direction with respect to the optical axis O at a predetermined radiation angle or more. Incident light is incident on the incident surface 23a, and the radiation angle in the vertical direction is made parallel by refraction at the incident surface 23a and the exit surface 23b, total reflection at the lower reflective surface 23c, etc., while maintaining a predetermined radiation angle in the vehicle width direction. The light is emitted so as to be close to light. At that time, due to the shape of the lower reflection surface 23c, the inclination of the emission surface 23b, and the like, the emitted light from the lower reflector portion 23 is directed obliquely downward to the front of the vehicle. Irradiate an area of 1 horizontal position or less (optical axis O or less).

  Here, each of the incident surfaces 21 a, 22 a, 23 a constituting the lens unit 21, the upper reflector unit 22, and the lower reflector unit 23 forms a groove (concave) on the base side of the optical member 20, and the LED substrate 11. The front and rear and upper and lower sides of each LED 12 are surrounded by Thereby, the light radiated | emitted from each LED12 injects into the optical member 20 efficiently in the state without a leak. Further, as shown in FIG. 2, an antireflection layer 25 is formed on each of the incident surfaces 21a, 22a, and 23a. In the present embodiment, the antireflection layer 25 is composed of an antireflection film using a light transmissive material having a predetermined refractive index. The formation of the antireflection layer 25 suppresses the generation of stray light due to the Fresnel reflection component when the light from each LED 12 enters the incident surfaces 21a, 22a, and 23a. Note that the antireflection layer 25 is not limited to the antireflection film, and may be formed, for example, by performing fine uneven processing on each of the incident surfaces 21a, 22a, and 23a.

  According to such an embodiment, the optical axis O ′ of the lens portion 21 of the optical member 20 is tilted downward from the horizontal direction (the optical axis O of each LED 12) with respect to the light emitting portion 12a of each LED 12. The area below the horizontal position of the illuminating device 1 can be suitably irradiated by the lens unit 21 while the LEDs 12 are arranged at optically ideal positions with respect to the lens unit 21. Further, by setting the respective reflecting surfaces 22c, 23c of the upper reflector portion 22 and the lower reflector portion 23 of the optical member 20 based on different parabolas P1, P2 with the respective LEDs 12 at the respective focal points F1, F2. The reflectors 22 and 23 can suitably irradiate areas below the horizontal position of the lighting device 1 while the LEDs 12 are disposed at optically ideal positions for the reflectors 22 and 23. . Thereby, for example, as shown in FIG. 5, in the illumination device 1 of the present embodiment adopted as a headlight for a vehicle, the illumination light is emitted in an irradiation pattern suitable for the headlight distributed below the horizontal position. It can be irradiated clearly. Here, the focal points F1 and F2 may be set in the vicinity of the focal point 12a of the LED 12 depending on the shapes of the reflecting surfaces 22c and 23c.

  In this case, by forming the antireflection layer 25 on each of the incident surfaces 21a, 22a, and 23a, generation of stray light due to the Fresnel reflection component can be accurately suppressed. Therefore, it is possible to prevent bright lines due to stray light from being generated above and below the irradiation pattern, and to realize a highly visible light distribution pattern.

  Moreover, by forming the antireflection layer 25, the incident efficiency from the LED 12 to the optical member 20 can be improved, and the luminance of the irradiation pattern can be improved.

  Further, some of the visible light reflected by the incident surfaces 21a, 22a, and 23a is absorbed by the LED substrate 11 and changed into heat, but by suppressing the Fresnel reflection by the antireflection layer 25, the LED by reflection Return light to the substrate 11 or the like can be reduced. Therefore, in particular, even when the output of the LED 12 is increased, it is possible to prevent problems such as the LED substrate 11 being overheated and damaging the optical member 20 or reducing the light emission efficiency of the LED 12.

  In the above-described embodiment, an example in which the present invention is applied to a fog lamp has been described. However, the present invention is not limited to this, and can be applied to, for example, a headlight. is there.

Exploded perspective view showing schematic configuration of vehicular lighting device The exploded perspective view which shows the principal part of the illuminating device for vehicles Explanatory drawing showing the optical axis of the lens unit Explanatory drawing which shows the simulation result of the behavior of the light which injected into the optical member Explanatory drawing showing irradiation pattern

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 10 ... Light source unit, 11 ... LED board, 12 ... Light emitting diode (light source), 12a ... Light emitting part, 20 ... Optical member, 21 ... Lens part, 21a ... Incident surface, 21b ... Outer surface, 22 ... Upper reflector part, 22a ... incident surface, 22b ... outgoing surface, 22c ... upper reflective surface, 23 ... lower reflector part, 23a ... incident surface, 23b ... outgoing surface, 23c ... lower reflective surface, 23c, 25 ... antireflection Layer, P1 ... Parabola, F1 ... Focus, P2 ... Parabola, F2 ... Focus, O ... Optical axis (optical axis of light source), O '... Optical axis (optical axis of lens unit)

Claims (2)

A vehicular illumination device comprising a light source having an optical axis set in a horizontal direction and an optical member for controlling light emitted from the light source,
The optical member is disposed on the optical axis of the light source, and a lens unit that changes incident light from the light source by refraction and emits the light, and
An upper reflector part that is made of a light-transmitting material integral with the lens part and that totally reflects and emits incident light from the light source on an upper reflecting surface formed above the lens part;
A lower reflector portion that is made of a light-transmitting material that is integral with the lens portion, and that reflects incident light from the light source and that is totally reflected by a lower reflecting surface formed below the lens portion;
Inclining the optical axis of the lens unit below the horizontal direction with respect to the light source,
The upper reflection surface is constituted by an aspherical surface focusing on the light source or the vicinity of the light source,
The vehicular illuminating device, wherein the lower reflecting surface is formed of an aspherical surface different from the upper reflecting surface having the light source or the vicinity of the light source as a focal point.   The vehicle lighting device according to claim 1, wherein an antireflection layer is formed on an incident surface of the optical member on which light emitted from the light source is incident.

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