OPTICAL UNIT, VEHICLE MONITOR, AND OBSTRUCTION DETECTOR

• US 20130038736A1
• Filed: 04/12/2011
• Published: 02/14/2013
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Yamamura, Satoshi
• Granted Patent: US 10,192,124 B2
• Time in Patent Office: Days
• US Class Current: 348/148
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/056 Special anti-blinding beams, e.g. a standard beam is chopped or moved in order not to blind
• CPC Class Codes: B60Q 2300/3321 Detection of streetlights
• CPC Class Codes: B60Q 2300/40 Indexing codes relating to other road users or special conditions
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: F21S 41/147 the main emission direction of the LED being angled to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/153 arranged in a matrix
• CPC Class Codes: F21S 41/155 Surface emitters, e.g. organic light emitting diodes [OLED]
• CPC Class Codes: F21S 41/25 Projection lenses
• CPC Class Codes: F21S 41/36 Combinations of two or more separate reflectors
• CPC Class Codes: F21S 41/365 successively reflecting the light
• CPC Class Codes: F21S 41/37 characterised by their material, surface treatment or coatings
• CPC Class Codes: F21S 41/675 by moving reflectors
• CPC Class Codes: G01S 13/426 Scanning radar, e.g. 3D radar G01S13/66 takes precedence
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93277 : in the lights
• CPC Class Codes: G06V 20/584 : of vehicle lights or traffic lights
• CPC Class Codes: H04N 7/183 : for receiving images from a single remote source

Abstract

Disclosed is an optical unit wherein a rotating reflector rotates about a rotation axis in one direction, while reflecting light emitted from a light source. The rotating reflector is provided with a reflecting surface such that the light reflected by the rotating reflector, while rotating, forms a desired light distribution pattern, said light having been emitted from the light source. The light source is composed of light emitting elements. The rotation axis is provided within a plane that includes an optical axis and the light source. The rotating reflector is provided with, on the periphery of the rotation axis, a blade that functions as the reflecting surface.

Claims

1. An optical unit comprising:

a rotating reflector that is rotated about a rotation axis in one direction while reflecting light emitted from a light source, wherein

the rotating reflector is provided with a reflecting surface so that the light of the light source reflected by the rotating reflector while the rotating reflector is rotated forms a desired light distribution pattern.

2. The optical unit according to claim 1, further comprising:

a light source that is formed of a light emitting element, wherein

the rotation axis is provided substantially parallel to a scan plane of an irradiation beam that performs scanning in a left and right direction by rotation.

3. The optical unit according to claim 1, wherein

the rotating reflector includes blades that function as the reflecting surface and are provided around the rotation axis, and

the blades have a twisted shape so that an angle between an optical axis and the reflecting surface is changed in a circumferential direction having a center on the rotation axis.

4. The optical unit according to claim 3, further comprising:

the plurality of blades that are arranged in a circumferential direction of the rotation axis; and

partition members that are provided between the adjacent blades and extend in a direction of the rotation axis, wherein

the partition members are formed so as to suppress the incidence of the light emitted from the light source upon the reflecting surface of the other adjacent blade when the light emitted from the light source enters the reflecting surface of one adjacent blade.

5. The optical unit according to claim 1, further comprising:

a projection lens that projects the light reflected by the rotating reflector in a light irradiation direction of the optical unit, wherein

the projection lens corrects an image of the light source distorted by being reflected on the reflecting surface to a shape close to the shape of the light source.

6. The optical unit according to claim 5, wherein

the light source includes a rectangular light emitting surface, and

each side of the light emitting surface is inclined with respect to a vertical direction so that an image of the light source projected forward by the projection lens is substantially erected.

7. The optical unit according to claim 1, further comprising:

a plurality of light sources that are formed of light emitting elements, wherein

the plurality of light sources are disposed so that light emitted from the respective light sources is reflected at different positions on the reflecting surface.

8. The optical unit according to claim 7, further comprising:

a first projection lens that projects light, which is emitted from one light source of the plurality of light sources and reflected by the rotating reflector, in a light irradiation direction of the optical unit as a first light distribution pattern; and

a second projection lens that projects light, which is emitted from the other light source of the plurality of light sources and reflected by the rotating reflector, in the light irradiation direction of the optical unit as a second light distribution pattern.

9. The optical unit according to claim 2, wherein

the light source includes a light concentrating member where a light emitting element is disposed on a bottom and a rectangular opening portion is formed,

the light concentrating member includes light concentrating surfaces that are formed from the bottom toward the opening portion in order to concentrate the light of the light emitting element, and

the light concentrating surfaces are formed so that the heights of end portions of the opening portion in a longitudinal direction of the opening portion are higher than the heights of end portions of the opening portion in a width direction of the opening portion.

10. The optical unit according to claim 1, wherein

the optical unit is formed so as to be used for a vehicle lamp.

11. An optical unit that is used for a vehicle lamp, the optical unit comprising:

a heat dissipation part that radiates heat of a light source; and

a cooling fan, wherein

the cooling fan includes blades that form a light distribution pattern by reflecting light, which is emitted from the light source, forward and causes convection near the heat dissipation part.

12. A vehicle monitor comprising:

an optical unit that forms a light distribution pattern by scanning an irradiation beam to the front of a vehicle;

a camera that takes an image of a region in front of the vehicle; and

a determining device that determines whether a reflective body reflecting the irradiation beam is present in a partial region on the basis of an image that is taken by the camera when the partial region included in the light distribution pattern is irradiated with the irradiation beam and an image that is taken by the camera when the partial region is not irradiated with the irradiation beam.

13. The vehicle monitor according to claim 12, wherein

the optical unit scans an irradiation beam so that a region irradiated with an irradiation beam varies at each of the timing of plural times of imaging that are performed by the camera.

17. The vehicle monitor according to claim 13, wherein

assuming that the number of times of scanning of the optical unit is represented by A [times/s], scanning speed is represented by B [deg/s], the width of an irradiation beam is represented by C [deg], and the number of times of imaging of the camera is represented by D [times/s], an expression C≦

(decimal part of A/D)×

(B/A)≦

(B/A)−

C is satisfied.

18. The vehicle monitor according to claim 12, wherein

the optical unit includes a rotating reflector that is rotated about a rotation axis in one direction while reflecting light emitted from a light source, and

the rotating reflector is provided with a reflecting surface so that the light of the light source reflected by the rotating reflector while the rotating reflector is rotated forms a desired light distribution pattern.

19. The vehicle monitor according to claim 18, further comprising

a controller that controls the rotational speed of the rotating reflector.

14. A vehicle monitor comprising:

a plurality of optical units that form a light distribution pattern by scanning irradiation beams to the front of a vehicle;

a camera that takes an image of a region in front of the vehicle; and

a determining device that determines whether a reflective body reflecting the irradiation beam is present in a partial region on the basis of an image that is taken by the camera when the partial region included in the light distribution pattern is irradiated with the irradiation beam and an image that is taken by the camera when the partial region is not irradiated with the irradiation beam.

15. The vehicle monitor according to claim 14, wherein

each of the plurality of optical units scans an irradiation beam so that a region irradiated with irradiation beams varies at each of the timing of plural times of imaging that are performed by the camera.

16. The vehicle monitor according to claim 14, wherein

assuming that the number of times of scanning of a first optical unit of the plurality of optical units is represented by A1 (times/s), the number of times of scanning of a second optical unit of the plurality of optical units is represented by A2 (times/s), the number of times of imaging of the camera is represented by D (times/s), and m and n are natural numbers, the following expressions (1) and (2) are satisfied:

mD<

A1<

(m+0.5)D or (m+0.5)D<

A1<

(m+1)D 

 

Expression (1)

nD<

A2<

(n+0.5)D or (n+0.5)D<

A2<

(n+1)D 

 

Expression (2).

20. An obstruction detector comprising:

an invisible-light radar;

a rotating reflector that is rotated about a rotation axis in one direction while reflecting invisible light sent from the invisible-light radar; and

a projection lens that focuses the invisible light reflected by the rotating reflector and projects the invisible light to a surrounding region, wherein

the rotating reflector is provided with a reflecting surface so that a surrounding region is scanned with the invisible light reflected by the rotating reflector while the rotating reflector is rotated.

21. The obstruction detector according to claim 20, further comprising:

a light source that is formed of a light emitting element, wherein

the rotating reflector is provided with a reflecting surface so as to form a desired light distribution pattern in front of a vehicle by reflecting light emitted from the light source while being rotated, and

the projection lens projects the light, which is reflected by the rotating reflector, in a light irradiation direction.

22. The obstruction detector according to claim 21, wherein

the invisible-light radar is a millimeter-wave radar,

the light source is provided so that the position of a virtual image formed by the rotating reflector is positioned near a focal point of the projection lens corresponding to visible light, and

the millimeter-wave radar is provided so that the position of a virtual image formed by the rotating reflector is positioned near a focal point of the projection lens corresponding to a millimeter wave that is different from the focal point of the projection lens corresponding to visible light.

23. The obstruction detector according to claim 22, wherein

the millimeter-wave radar includes a waveguide, and

the waveguide is provided so that the position of a virtual image of an end portion of the waveguide formed by the rotating reflector is positioned closer to the projection lens than the focal point corresponding to visible light.

24. The obstruction detector according to claim 20, wherein

the projection lens is made of a resin material.