Optical sensor with directivity controlled

• US 6,521,882 B1
• Filed: 03/10/2000
• Issued: 02/18/2003
• Est. Priority Date: 03/27/1998
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Horiba, Keiji, Takashima, Masaki, Sumiya, Kazuyoshi, Toyoda, Inao
• Primary Examiner(s): Allen, Stephone
• Assistant Examiner(s): SPEARS, ERIC J
• Application Number:
  US09/522,604
• Time in Patent Office: 1,075 Days
• Field of Search: 250/208.2, 250/208.6, 250/203.4, 250/203.3, 126/572, 126/573, 356/139.01, 315/82
• US Class Current: 250/208.2
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0418 using attenuators
• CPC Class Codes: G01J 1/0437 using masks, aperture plates, spatial light modulators, spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light
• CPC Class Codes: G01J 1/1626 Arrangements with two photodetectors, the signals of which are compared
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02

Abstract

Plural photodetectors for receiving light and generating detection signals. A light amount controlling portion is arranged above the photodetectors for controlling an amount of the light to the photodetectors according to an incident angle. A weighting portion for weighting sensitivities of the photodetectors respectively. The sensitivities are weighted to provide a total output characteristic of the weighted detection signals of which magnitude varies according to the incident angle. Weighting is provided by a signal processing circuit by controlling gains, or a translucent film on the photodetectors for controlling transparencies portions above respective photodetectors, or opaque films on the photodetectors for controlling amounts of the light to respective photodetectors. A first function signal may be obtained from a part of photodetectors for an air conditioner and a second function signal may be obtained from all of photodetectors for head lamp on/off controlling. Each coaxially arranged photodetector is divided to provide a semicircle or a semi-ring shape arranged with respect to the front direction of the vehicle to provide orientation angle data to control the air conditioner.

Claims

1. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident angle of said light; and

weighting means for respectively weighting sensitivities of said photodetectors and outputting a weighted detection signal from said detection signals, wherein a characteristic of said weighted detection signal varies in accordance with said incident angle;

wherein;

said weighting means comprises film means on said optical detection means for controlling light transmittances of portions of said film means above respective photodetectors.

2. An optical sensor as claimed in claim 1, wherein said weighting means comprises a signal processing circuit for controlling gains of said detection signals.

3. An optical sensor as claimed in claim 1, wherein said film means comprises opaque film means on said optical detection means for controlling amounts of said light to respective photodetectors by controlling ratios between existence and inexistence of said opaque film means per a unit area on portions of said film means above respective photodetectors.

4. An optical sensor as claimed in claim 1, wherein said film means comprises a translucent film controlling said light transmittance by controlling thicknesses of said portions of said translucent film above respective photodetectors.

5. An optical sensor as claimed in claim 1, wherein said light amount controlling means comprises a meniscus lens.

6. An optical sensor as claimed in claim 1, wherein said photodetectors respectively have different output characteristics in response to the same amount of said light.

7. An optical sensor as claimed in claim 1, wherein said photodetectors are arranged coaxially.

8. An optical sensor as claimed in claim 7, wherein said photodetectors are arranged on a plane surface of said optical sensor, said optical sensor further comprising an outputting circuit for outputting one of said detection signals from one of said photodetectors arranged closest to the center of said photodetectors coaxially arranged as a first sunlight amount detection signal indicative of a first amount of said light having a first directivity, wherein said weighting means comprises a signal processing circuit for controlling gains of said detection signals and outputting a second sunlight amount signal indicative of a second amount of said light having a second directivity.

9. An optical sensor as claimed in claim 7, wherein one of said photodetectors arranged closest the center of said photodetectors is apart from the other photodetectors by a predetermined interval and said weighting means comprises a signal processing circuit arranged between said one of said photodetectors and the other photodetectors.

10. An optical sensor as claimed in claim 7, wherein said photodetectors are arranged on a plane surface of said optical sensor, and wherein said light amount controlling means controls said amounts of said light to said photodetectors such that said detection signals from a first portion of photodetectors other than a second portion of said photodetectors closest to a center of said coaxially arranged photodetectors show a first set of magnitudes when said incident angle is substantially zero and show a second set of magnitudes when said incident angle is apart from zero which are respectively lower than said first sets of magnitudes.

11. An optical sensor as claimed in claim 7, wherein said photodetectors are arranged on a plane surface of said optical sensor, and wherein said light amount controlling means has shading means for shading a portion of said light to a first portion of said photodetectors other than a second portion of said photodetectors closest to a center of said coaxially arranged photodetectors when said incident angle is substantially zero.

12. An optical sensor as claimed in claim 7, wherein said detection signals of a plurality of said photodetectors are summed to generate a first function signal and are combined to provide a second function signal, said first function signal is provided to control an air conditioner of a vehicle mounting said optical sensor, and said second function signal is provided to control turning on and off of a head lamp unit of said vehicle.

13. An optical sensor as claimed in claim 12, wherein said first function signal is obtained by using a part of a plurality of said photodetectors and said second function signal is obtained by using all of a plurality of said photodetectors.

14. An optical sensor as claimed in claim 13, wherein said optical sensor further comprises a semiconductor chip including a plurality of said photodetectors, said first function signal is obtained from a first one of said photodetectors arranged at a center of said photodetectors and a second one of said photodetectors arranged at the most outer peripheral position of said photodetectors, and said second function signal is obtained from all of a plurality of said photodetectors.

15. An optical sensor as claimed in claim 1, wherein said detection signals of a plurality of said photodetectors are summed to generate a first function signal and are combined to provide a second function signal, said first function signal is provided to control an air conditioner of a vehicle on which said optical sensor is mounted, and said second function signal is provided to control turning on and off of a head lamp unit of said vehicle.

16. An optical sensor as claimed in claim 15, wherein said first function signal is obtained by using a part of a plurality of said photodetectors and said second function signal is obtained by using all of a plurality of said photodetectors.

17. An optical sensor as claimed in claim 16, wherein said optical sensor further comprises a semiconductor chip including a plurality of said photodetectors which are coaxially arranged with each other, said first function signal is obtained from first one of said photodetectors arranged at a center of said photodetectors and second one of said photodetectors arranged at the most outer peripheral position of said photodetectors, and said second function signal is obtained from all of a plurality of said photodetectors.

18. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident angle of said light; and

signal generation means for generating a first function signal regarding at least an incident angle of said light from one part of a plurality of said photodetectors and generating a second function signal regarding a total amount of said light from another part of photodetectors including said one part of a plurality of said photodetectors, wherein said detection signals of a plurality of said photodetectors are summed to generate said first function signal and are combined to provide said second function signal, said first function signal is provided to control an air conditioner of a vehicle on which said optical sensor is mounted, and said second function signal is provided to control turning on and off of a head lamp unit of said vehicle, and wherein said first function signal is obtained by using a part of a plurality of said photodetectors and said second function signal is obtained by using all of a plurality of said photodetectors.

19. An optical sensor as claimed in claim 18, wherein said optical sensor further comprises a semiconductor chip including a plurality of said photodetectors which are coaxially arranged with each other, said first function signal is obtained from a first one of said photodetectors arranged at a center of said photodetectors and a second one of said photodetectors arranged at the most outer peripheral position of said photodetectors, and said second function signal is obtained from all of a plurality of said photodetectors.

20. An optical sensor as claimed in claim 19, wherein said optical sensor further comprising weighting means for respectively weighting sensitivities of said photodetectors and outputting a weighted detection signal from said detection signals, wherein a characteristic of said weighted detection signal varies in accordance with said incident angle, wherein said weighting means comprises a signal processing circuit for controlling gains of said detection signals.

21. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident elevation angle of said light;

first signal generation means for generating and outputting a first sensor signal including data of an incident elevation angle of said light from a part of said detection signals; and

second signal generation means for generating and outputting a second sensor signal including data of a total amount of said light from said detection signals;

wherein;

said photodetectors are arranged coaxially; and

said photodetectors includes a first pair of photodetectors as first right and left photodetectors, a second pair of photodetectors as second right and left photodetectors, and third pair.of photodetectors as third right and left photodetectors, said first to third right photodetectors are arranged symmetrically with said first to third left photodetectors respectively regarding a direction on a plane on which said photodetectors are arranged, said first signal generation means includes a first circuit for generating a right side direction sensor signal from at least one of said first to third right photodetectors and a second circuit for generating a left side direction sensor signal from at least one of said first to third left photodetectors, said second signal generation means generates said second sensor signal from said first to third pairs of photodetectors.

22. An optical sensor as claimed in claim 21, wherein said second left and right photodetectors are physically connected.

23. An optical sensor as claimed in claim 21, further comprising weighting means for respectively weighting said first and second sensor signals and outputting first and second weighted detection signals, wherein characteristics of said first and second weighted sensor signals vary in accordance with said incident elevation angle.

24. An optical sensor as claimed in claim 21, said light amount control means includes a first opaque ring arranged just above peripheral portions of said first pair of photodetectors to prevent said light from entering said first pair of photodetectors at a right elevation angle and a second opaque ring arranged just above said third pair of photodetectors to prevent said light from entering said third pair of photodetectors at a right elevation angle.

25. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident angle of said light; and

weighting means for respectively weighting sensitivities of said photodetectors and outputting a weighted detection signal from said detection signals, wherein a characteristic of said weighted detection signal varies in accordance with said incident angle;

wherein;

said photodetectors are arranged coaxially; and

one of said photodetectors arranged closest to the center of said photodetectors is apart from the other photodetectors by a predetermined interval and said weighting means comprises a signal processing circuit arranged between said one of said photodetectors and the other photodetectors.

26. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident angle of said light; and

weighting means for respectively weighting sensitivities of said photodetectors and outputting a weighted detection signal from said detection signals, wherein a characteristic of said weighted detection signal varies in accordance with said incident angle;

wherein;

said detection signals of a plurality of said photodetectors are summed to generate a first function signal and are combined to provide a second function signal, said first function signal is provided to control an air conditioner of a vehicle on which said optical sensor is mounted, and said second function signal is provided to control turning on and off of a head lamp unit of said vehicle.

27. An optical sensor comprising:

optical detecting means including a plurality of photodetectors for receiving light and generating detection signals;

light amount controlling means arranged above said optical detecting means for controlling amounts of said light to said photodetectors in accordance with an incident angle of said light; and

weighting means for respectively weighting sensitivities of said photodetectors and outputting a weighted detection signal from said detection signals, wherein a characteristic of said weighted detection signal varies in accordance with said incident angle;

wherein;

said photodetectors are arranged coaxially; and

said detection signals of a plurality of said photodetectors are summed to generate a first function signal and are combined to provide a second function signal, said first function signal is provided to control an air conditioner of a vehicle mounting said optical sensor, and said second function signal is provided to control turning on and off of a head lamp unit of said vehicle.