Light source for headlight and headlight
View Patent ↗In an LED 2 having a directionality in an emission direction of emitted light, light emitted from a light emitting surface of the LED 2 is refracted by a semi-cylindrical concave lens 3 to be enlarged in the circumference direction of an optical axis of a headlight 1 ; thus, even when the LED 2 is applied to a headlight that is constituted by optical members that are similar to optical members that are compatible with conventional light sources having no directionality, such as an incandescent lamp, a discharge lamp and the like, it can be used as a light source for headlight that is capable of illuminating the right and left directions ahead of a vehicle with a sufficient brightness.
1. A light source for headlight to be used for a headlight provided with an optical member that irradiates light to the front side of a vehicle, comprising:
a light emitting element having a light emitting surface that is substantially planar and elongated in an optical axis direction of the headlight; and
a semi-cylindrical concave lens having a focal axis in substantially the same direction as the optical axis direction of the headlight,
wherein the semi-cylindrical concave lens is placed between the optical member and the light emitting element.
2. The light source for headlight according to claim 1 , wherein the light emitting surface of the light emitting element is placed with shifted on the opposite side of a reflection mirror that is the optical member with respect to the optical axis of the headlight.
3. The light source for headlight according to claim 1 , wherein a light-emitting direction of the light emitting element is placed with rotated by a predetermined angle about the optical axis direction of the headlight as a rotation axis.
4. The light source for headlight according to claim 1 , wherein a focal length of the semi-cylindrical concave lens is shorter at the front side of the headlight than at the rear side thereof.
5. The light source for headlight according to claim 1 , further comprising integrally a lighting circuit that lights the light emitting element.
6. The light source for headlight according to claim 1 , wherein the light emitting element includes a plurality of light emitting elements that can be lighted arbitrarily.
7. The light source for headlight according to claim 6 , wherein the light emitting element includes a first light-emitting element placed at the front side of a focal point of the reflection mirror that is the optical member, and a second light-emitting element placed at the rear side of the focal point.
8. The light source for headlight according to claim 1 , wherein the semi-cylindrical concave lens is formed of a glass or a resin.
9. The light source for headlight according to claim 1 , wherein the light emitting element is an LED.
10. The light source for headlight according to claim 1 , further comprising a fixing part that can be attached or detached arbitrarily to the optical member.
11. The light source for headlight according to claim 10 , wherein the fixing part has substantially the same shape as a fixing part of an in-vehicle incandescent lamp or discharge lamp.
12. A headlight provided with an optical element that irradiates light emitted from a light source for headlight to the front of a vehicle,
wherein the light source for headlight comprises:
a light emitting element having a light emitting surface that is substantially planar and elongated in an optical axis direction of the headlight; and
a semi-cylindrical concave lens having a focal axis in substantially the same direction as the optical axis direction of the headlight,
wherein the semi-cylindrical concave lens is placed between the optical member and the light emitting element.
13. The headlight according to claim 12 , further comprising a mechanism that, among the light emitted from the light source for headlight, shields light emitted toward the dark side in a bright and dark boundary at the front side to which the headlight irradiates, or reflects the light in a direction so as not to be irradiated to the front side of the headlight.