IMAGE PICKUP UNIT AND VEHICLE IN WHICH IMAGE PICKUP UNIT IS MOUNTED

• US 20140303853A1
• Filed: 10/25/2012
• Published: 10/09/2014
• Est. Priority Date: 11/02/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Itoh, Izumi, Hirai, Hideaki
• Granted Patent: US 9,057,683 B2
• Time in Patent Office: Days
• US Class Current: 701/49
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: B60R 2011/0026 Windows, e.g. windscreen
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: G01N 21/17 Systems in which incident light is modified in accordance with the properties of the material investigated where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: H04N 5/72 Modifying the appearance of television pictures by optical filters or diffusing screens

Abstract

An image pickup lens has a focal length far from a position of a transparent member. An image pickup device is put on the side of the transparent member the same as that of a light source and takes reflected light including regular reflection from an interface between an adhered object on the other surface of the transparent member and air. Assuming an incident angle of the emitted light on the transparent member when the light reflected in regular reflection by the other surface of the transparent member is incident on the image pickup lens being θs, an incident angle of a typical light beam of the emitted light falls within θs−30 deg through θs and an incident angle of a main element of the emitted light is less than θs.

Claims

1. An image pickup unit comprising:

a light source that emits light toward a transparent member from a side of one surface of the transparent member;

an image pickup lens having a focal length that is set far from a position of the transparent member;

an image sensor that includes plural pixels arranged two-dimensionally; and

an image pickup device that is put on the side of the transparent member the same as that of the light source, wherein

the image pickup device takes an image of reflected light that includes regular reflection of the emitted light reflected by an interface between an adhered object that adheres to the other surface of the transparent member and air by using the image sensor, and

the light source is put in a position such that in a case where an incident angle of the emitted light on the transparent member when the light reflected in a regular reflection manner by the other surface of the transparent member is incident on the image pickup lens is θ

s, an incident angle of a typical light beam of the emitted light on the transparent member falls within a range θ

s−

30 deg through θ

s and an incident angle of a main element of the emitted light on the transparent member is less than θ

s.

2. The image pickup unit as claimed in claim 1, further comprising

an optical filter that is put subsequent to the image pickup lens, wherein

light having passed through the optical filter is received by the image sensor,

the optical filter includes a substrate that transmits incident light that is incident via the image pickup lens, and

a spectral filter layer that is formed at a part of an effective image pickup area on the substrate and selectively transmits light of a wavelength band including an oscillation wavelength range of the light source from the incident light, and

the image pickup device takes the image of reflected light that includes regular reflection of the emitted light reflected by the interface between the adhered object that adheres to the other surface of the transparent member and air by using pixels corresponding to an area at which the spectral filter layer is formed.

3. The image pickup unit as claimed in claim 1, the image pickup unit

emitting light from the side of the one surface of the transparent member toward a second adhered object that adheres to the one surface of the transparent member, and

taking an image of scattered light of the emitted light reflected by the second adhered object.

4. The image pickup unit as claimed in claim 3, the image pickup unit

taking an image of the reflected light via a polarization filter layer that transmits only a p-polarized element, and

taking an image of the scattered light via a polarization filter layer that transmits only an s-polarized element.

5. The image pickup unit as claimed in claim 1, wherein

the light source is put in such a manner that in a case where an angle of view for image pickup for the adhered object is θ

u, an incident angle of horizontal direction of the emitted light on the transparent member falls within a range θ

u−

20 deg through θ

u+20 deg.

6. The image pickup unit as claimed in claim 1, further comprising

another light source, wherein

the other light source is put in such a manner that in a case where an angle of elevation of the image pickup lens with respect to a normal of the transparent member which intersects an optical axis of the image pickup lens is θ

a, an incident angle of vertical direction of the emitted light on the transparent member falls within a range θ

a−

50 deg through θ

a+20 deg.

7. The image pickup unit as claimed in claim 1, wherein

the image pickup device is put in such a manner that regular reflection from the one surface of the transparent member from the emitted light is prevented from being incident on the image pickup lens.

8. The image pickup unit as claimed in claim 2, wherein

an incident position on the one surface of the transparent member of the emitted light is included in the effective image pickup area.

9. The image pickup unit as claimed in claim 1, further comprising:

a signal processing part that processes a signal of the image sensor at a time of emitting light from the light source and outputs an image signal; and

an image analysis unit that carries out image processing based on an output of the signal processing part and outputs a signal as to whether a raindrop has been detected.

10. A vehicle having the image pickup unit claimed in claim 1 mounted in the vehicle, wherein

the vehicle detects an adhered object that adheres to the other surface of the transparent member by the image pickup unit.

11. The vehicle as claimed in claim 10, further comprising:

a wiper control unit that controls a wiper, wherein

the wiper control unit controls the wiper based on a detection result of the adhered object and removes the adhered object.