Headlight for in-vehicle use
View Patent ↗In a headlight for in-vehicle use, an LED serving as an optical source is provided in which one edge side of its light-emitting face is formed into a linear portion and placed at a side of an optical axis so that the center of the light-emitting face is displaced from the optical axis. A projection lens is constituted by a radiation-side convex lens and an LED-side convex lens that are arranged in a direction of the optical axis. Between the LED and the projection lens, a light distribution member is placed that is formed using a transparent material and has, on its inner surface, a reflection face for reflecting light emitted by the LED.
1. A projector-type headlight for in-vehicle use that radiates light emitted by an optical source, ahead of a vehicle using a projection lens, comprising:
an LED (light Emitting Diode) that constitutes the optical source and has a light-emitting face whose one edge side is linearly formed and placed at a side of an optical axis so that a center of the light-emitting face is displaced from the optical axis;
two convex lenses that are arranged in a direction of the optical axis to constitute the projection lens; and
a light distribution member that is placed between the LED and the projection lens, that is formed using a transparent material and that has, on its inner surface, a reflection face for reflecting the light emitted by the LED, so as to form a cut-off line at an edge in a side of the projection lens, of the reflection face.
2. The headlight for in-vehicle use of claim 1 , wherein a focal point in a side of the LED, of the projection lens as a set being formed of the two convex lenses, is placed within a predetermined distance from the edge in the side of the projection lens, of the light distribution member.
3. The headlight for in-vehicle use of claim 1 , wherein the light distribution member has:
an incident face facing toward the LED, on which the light emitted by the LED is incident; and
an outgoing face facing toward the projection lens, through which the incident light goes out to the projection lens;
wherein either one of the incident face and the outgoing face, or each of these faces, is inclined with respect to a plane perpendicular to the optical axis.
4. The headlight for in-vehicle use of claim 3 , wherein the incident face of the light distribution member is inclined to be more toward the projection lens as a distance increases from the optical axis.
5. The headlight for in-vehicle use of claim 1 , wherein the light distribution member is fixed to the convex lens nearer to the LED in the two convex lenses constituting the projection lens.
6. The headlight for in-vehicle use of claim 1 , wherein either one or each of the two convex lenses constituting the projection lens differs in size between its upper side and its lower side relative to the optical axis.
7. The headlight for in-vehicle use of claim 1 , wherein either one or each of lens faces of the two convex lenses constituting the projection lens has a curvature in up-down direction and a curvature in right-left direction that are different to each other.
8. The headlight for in-vehicle use of claim 1 , wherein a second LED different to the above LED is placed on an opposite side by which the optical axis is sandwiched.
9. The headlight for in-vehicle use of claim 1 , wherein either one or each of the two convex lenses constituting the projection lens is an aspherical lens.
10. The headlight for in-vehicle use of claim 1 , wherein either one or each of the two convex lenses constituting the projection lens is a Fresnel lens.
11. The headlight for in-vehicle use of claim 1 , wherein the light distribution member has a shape in which, in the edge in the side of the projection lens of the reflection face, a portion in a driving lane-side is inclined downward.
12. The headlight for in-vehicle use of claim 1 , wherein the projection lens and the light distribution member are formed of a same type of resin.