Optical unit

Patent metadata

Field	Value
Publication number	US-9890910-B2
Application number	US-201314057129-A
Country	US
Kind code	B2
Filing date	Oct 18, 2013
Priority date	Apr 22, 2011
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

An optical unit includes a light source having both a first light emitting element for emitting light having a first color and a second light emitting element for emitting light having a second color that is different from the first color; and a rotating reflector configured to be rotated in one direction around a rotational shaft, while reflecting the light having the first color and the light having the second color, which have been emitted from the light source. In the rotating reflector, a reflecting surface is provided such that a predetermined light distribution pattern is formed with the light having the first color and the light having the second color, which have been reflected by the rotation of the rotating reflector, being superimposed one on another.

First claim

What is claimed is:

1. An optical unit comprising:
a light source including both a first light emitting element for emitting light having a first color and a second light emitting element for emitting light having a second color that is different from the first color;
a rotating reflector configured to be rotated in one direction around a rotational shaft defining a rotational axis, while reflecting the light having the first color and the light having the second color, which have been emitted from the light source; and
a projection lens arranged ahead of the rotating reflector, wherein
the rotating reflector includes:
a rotating part; and
a plurality of blades provided around the rotating part and functioning as a reflecting surface,

each of the plurality of blades having a twisted shape in which an angle between an optical axis and the reflecting surface is changed moving toward a circumferential direction around the rotational axis and being configured to project a scanning irradiation beam by passing in front of at least one of the first light emitting element and the second light emitting element, and
in the rotating reflector, the reflecting surface is provided such that a predetermined light distribution pattern is formed with the light having the first color and the light having the second color, which have been reflected by the rotation of the rotating reflector, being superimposed one on another.

2. The optical unit according to claim 1 , wherein
the second light emitting element emits, as the light having the second color, light having a color that is in a complementary color relationship with the light having the first color.

3. The optical unit according to claim 1 further comprising:
a current adjusting unit configured to adjust a current flowing through at least one of the first light emitting element and the second light emitting element.

4. The optical unit according to claim 1 , wherein the rotating reflector is configured to cause a light source virtual image formed by light reflected by the rotating reflector to be moved near a focal point of the projection lens.

5. The optical unit according to claim 4 , wherein a projected image is moved for scanning in a horizontal direction by the rotation of the rotating reflector.

6. The optical unit according to claim 1 , wherein the light source includes a first light source and a second light source, and
the first light source includes the first light emitting element and the second light emitting element;
the first light source and the second light source are arranged such that a position at which light emitted by the first light source is reflected by one of the plurality of blades is different from a position at which light emitted by the second light source is reflected by the one of the plurality of blades.

7. The optical unit according to claim 1 , wherein the optical unit is capable of changing a distributed light color of an arbitrary region in a light distribution pattern by periodically changing amounts of current flowing through the light source.

8. An optical unit comprising:
a light source including a first light emitting element for emitting light having a first color, a second light emitting element for emitting light having a second color different from the first color, and a third light emitting element for emitting light having a third color different from the first color and the second color;
a rotating reflector configured to be rotated in one direction around a rotational shaft defining a rotational axis, while reflecting the light having the first color, the light having the second color, and the light having the third color; and
a projection lens arranged ahead of the rotating reflector, wherein
the rotating reflector includes:
a rotating part; and
a plurality of blades provided around the rotating part and functioning as a reflecting surface,

each of the plurality of blades having a twisted shape in which an angle between an optical axis and the reflecting surface is changed moving toward a circumferential direction around the rotational axis and being configured to project a scanning irradiation beam by passing in front of at least one of the first light emitting element, the second light emitting element, and the third light emitting element, and
in the rotating reflector, the reflecting surface is provided such that a predetermined light distribution pattern having white color is formed with the light having the first color, the light having the second color, and the light having the third color, which have been reflected by the rotation of the rotating reflector, being superimposed one on another at the projection lens.

9. The optical unit according to claim 8 further comprising:
a current adjusting unit configured to adjust a current flowing through at least one of the first light emitting element, the second light emitting element, and the third light emitting element.

10. An automotive headlamp provided with the optical unit of claim 1 .

Assignees

• Koito Mfg Co Ltd

Inventors

• Yamamura Satoshi

Classifications

• F21S41/675

  by moving reflectors · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21S41/663

  by switching light sources (by switching incandescent light sources F21S41/162) · CPC title

• F21S41/67

  by acting on reflectors · CPC title

• F21V13/06

  a reflector being rotatable · CPC title