Imaging system for vehicle headlamp control

• US 20040031907A1
• Filed: 08/14/2003
• Published: 02/19/2004
• Est. Priority Date: 06/09/1998
• Status: Active Grant

• Current Assignee: John K. Roberts, Jon H. Bechtel, Joseph S. Stam
• Original Assignee: John K. Roberts, Jon H. Bechtel, Joseph S. Stam
• Inventors: Roberts, John K., Stam, Joseph S., Bechtel, Jon H.
• Granted Patent: US 6,924,470 B2
• Time in Patent Office: Days
• US Class Current: 250/208.1
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• 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 2300/052 Switching delay, i.e. the beam is not switched or changed instantaneously upon occurrence of a condition change
• CPC Class Codes: B60Q 2300/21 Manual control
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: G01J 1/0214 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/0488 with spectral filtering
• CPC Class Codes: G01J 1/0492 using at least two different filters
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 2001/0276 Protection
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04N 3/1562 : for selective scanning, e.g. windowing, zooming

Abstract

An imaging system for use in a vehicle headlamp control system includes an opening, an image sensor, a red lens blocking red complement light between the opening and the image sensor, and a red complement lens blocking red light between the opening and the image sensor. Each lens focuses light onto a different subwindow of the image sensor. The imaging system allows processing and control logic to detect the presence of headlamps on oncoming vehicles and tail lights on vehicles approached from the rear for the purpose of controlling headlamps. A light sampling lens may be used to redirect light rays from an arc spanning above the vehicle to in front of the vehicle into substantially horizontal rays. The light sampling lens is imaged by the image sensor to produce an indication of light intensity at various elevations. The processing and control logic uses the light intensity to determine whether headlamps should be turned on or off. A shutter may be used to protect elements of the imaging system from excessive light exposure.

Claims

1. A vehicular vision system, comprising:

an image sensor comprising an array of pixel sensors and an image plane; and

a first lens and a second lens, said first lens being configured to project light rays onto a first portion of said image plane and said second lens being configured to project light rays onto a second portion of said image plane, wherein a red spectral filter is located between said first portion of said image plane and a scene to be imaged.

2. A vehicular vision system as in claim 1 wherein each of said lenses is shaped such that the focal length of each lens at the spectral frequency pass of said lens is the same as the focal length of the other lens.

3. A vehicular vision system as in claim 1 further comprising a means to distinguish red light rays from white light rays.

4. A vehicular vision system as in claim 1 further comprising a means to detect a blue sky.

5. A vehicular vision system as in claim 1 further comprising a housing having an opening, wherein said opening is configured to limit a field of view of said image sensor.

6. A vehicular vision system as in claim 1 further comprising a controller configured to generate an exterior light control signal as a function of at least one image.

8. A vehicular vision system as in claim 5 further comprising a lower threshold point to turn on and, or, off a vehicle light for a blue sky than for a cloudy sky.

9. A vehicular vision system as in claim 6, said means for distinguishing a blue sky from a cloudy sky comprising at least one lens configured to project at least a portion of a scene of the sky onto said image sensor such that a portion of associated light rays pass through a spectral filter.

7. A vehicular vision system, comprising:

an image sensor comprising an array of pixel sensors and an image plane; and

a means for distinguishing a blue sky from a cloudy sky.

10. A vehicular vision system as in claim 7 further comprising a housing having an opening, wherein said opening is configured to limit a field of view of said image sensor.

11. A vehicular vision system as in claim 7 further comprising a controller configured to generate an exterior light control signal as a function of at least one image.

12. A vehicular vision system, comprising:

an image sensor comprising an array of pixel sensors;

at least one lens for gathering light rays from a region substantially in front of the vehicle and focusing the gathered light rays on said image sensor; and

a housing in which said at least one lens and said image sensor are housed, said housing having an opening positioned several focal lengths in front of said at least one lens for limiting the field of view of said image sensor.

13. A vehicular vision system as in claim 12 wherein an optical axis of said at least one lens passes through said opening.

14. A vehicular vision system as in claim 12 further comprising a controller configured to generate an exterior light control signal as a function of at least one image.

15. A vehicular vision system as in claim 12 where said at least one lens has a focal length of approximately 4 mm.

16. A vehicular vision system as in claim 12 wherein said at least one lens includes more than two lenses each for gathering light rays from a region substantially in front of the vehicle and focusing the gathered light rays on said image sensor, each of said lenses being associated with a different spectral band.

17. A vehicular vision system as in claim 12 wherein said at least one lens includes a first lens and a second lens, said system further comprising a baffle extending along a line from a position between first and second regions of said image sensor to a position between said first and second lenses so as to block light transmitted through said first lens from impinging upon the second region of said image sensor.

18. A vehicular vision system as in claim 12 wherein said at least one lens images a scene in front of the vehicle within a field of view of about 22°

wide by about 9°

high onto said image sensor.

19. A vehicular vision system as in claim 12 further comprising a shutter between the image sensor and the imaged scene, said shutter operative to attenuate the intensity of light from the scene, and wherein a control circuit controls the shutter attenuation of light based on detected light levels.

20. A vehicular vision system, comprising:

a housing defining an opening;

an image sensor positioned in said housing spaced from said opening to view a scene through said opening; and

at least one lens positioned in said housing, said at least one lens is operative to focus light rays from a scene viewed through said opening onto said image sensor, wherein a field of view of said image sensor is limited by said opening and an axis normal to an image plane of said image sensor passes through said opening.

21. A vehicular vision system as in claim 20 further comprising a controller configured to generate an exterior light control signal as a function of at least one image.