US4834541A
Expired / Lapsed
US
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Color sensor
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1988-01-21
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Granted: 1989-05-30
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Expires: 2008-01-21
Abstract
Abstract A color sensor makes a color distinction based on outputs from three primary optical sensing devices for receiving light having three primary colors under a fluorescent lamp by calculating a relative composition ratio of the three primary colors in an integrator. The operation of the integrator is controlled by a pulse generated by detecting a peak value of the light based on an output from a complementary optical sensing device sensitive to visible light.
Inventors
- 👤 Kazuo Yamaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:08
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/02; G01J3/027; G01J3/10; G01J3/46; G01J3/50; G01J3/51; G01J3/513
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
175 words
A color sensor comprising: three optical filters each having a peak in wavelength of three primary colors; three primary optical sensing devices for receiving light passed through said optical filters; three integrators for integrating outputs from said primary optical sensing devices; a complementary optical sensing device sensitive to visible light; control means comprising a peak detector and a pulse generator for controlling the operation of said three integrators, said peak detector detecting a peak value of light from a light source having a flicker from an output of said complementary optical sensing device, said pulse generator controlling the operation of said three integrators by a pulse signal generated based on the peak value detected so that the integrating operation is performed during the generation of the peak value; means for calculating a composition ratio of the three primary colors on the basis of outputs from said three integrators; and means for distinguishing color by comparing the composition ratio obtained of the three primary colors with each composition ratio of three standard primary colors stored beforehand.
Claim 2
Dependent Claim
175 words
A color sensor comprising: three optical filters each having a peak in wavelength of three primary colors; three primary optical sensing devices for receiving light passed through said optical filters; three integrators for integrating outputs from said primary optical sensing devices; a complementary optical sensing device sensitive to visible light; control means comprising a peak detector and a pulse generator for controlling the operation of said three integrators, said peak detector detecting a peak value of light from a light source having a flicker from an output of said complementary optical sensing device, said pulse generator controlling the operation of said three integrators by a pulse signal generated based on the peak value detected so that the integrating operation is performed during the generation of the peak value; means for calculating a composition ratio of the three primary colors on the basis of outputs from said three integrators; and means for distinguishing color by comparing the composition ratio obtained of the three primary colors with each composition ratio of three standard primary colors stored beforehand.
Claim 3
Dependent Claim
18 words
The color sensor according to claim 1 wherein each of said optical sensing devices is a PIN photodiode.
References Cited (Backward Citations)
US4547074A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |