US4281932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light absorptivity measuring device
Assignee: Individual
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Filing: 1979-06-14
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Granted: 1981-08-04
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Expires: 1999-06-14
Abstract
Abstract A light source is arranged with a light sensing device in such a way that the sensing device receives transmitted light for a translucent medium or reflected light for an opaque medium. The reading of the sensor is stored, then the same source and sensing device are moved over a reference medium whose absorptivity varies unidirectionally. A comparator compares the reading of the sensor with the stored reading and indicates when they are equal. The relative position of the reference and sensor indicates the absorptivity of the medium. One embodiment uses multiple devices and filters to determine composite color.
Inventors
- 👤 Thomas A. Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:03
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/86; G01J; G01J1/00; G01J1/10; G01J1/20; G01J1/22; G01J1/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
135 words
A device for measuring the light absorptivity characteristics of a medium over some substantially continuous range, comprising one or more absorptivity measuring devices, each consisting of a light source-sensor, a means for limiting the range of color response, a means for storing the sensor output representative of the medium under test, a reference consisting of a medium unidirectionally varying in absorptivity, a comparator to indicate equality of the sensor output representative of said reference and that output stored by said storing means, and a means for moving said light source-sensor combination over the medium under test and then over said reference medium using the same color range, the position on said reference medium relative to the light source-sensor combination when said comparator indicates equality being the measure of the absorptivity of said medium under test.
Claim 2
Independent Claim
135 words
A device for measuring the light absorptivity characteristics of a medium over some substantially continuous range, comprising one or more absorptivity measuring devices, each consisting of a light source-sensor, a means for limiting the range of color response, a means for storing the sensor output representative of the medium under test, a reference consisting of a medium unidirectionally varying in absorptivity, a comparator to indicate equality of the sensor output representative of said reference and that output stored by said storing means, and a means for moving said light source-sensor combination over the medium under test and then over said reference medium using the same color range, the position on said reference medium relative to the light source-sensor combination when said comparator indicates equality being the measure of the absorptivity of said medium under test.
Claim 3
Dependent Claim
29 words
A device as described in claim 1, comprising one absorptivity measuring device as described in claim 1, for measurement of the absorptivity of a medium in one color range.
Claim 4
Dependent Claim
37 words
A device as described in claim 1, comprising two or more absorptivity measuring devices, each responsive to a different color range for measurement of the light absorptivity of the medium under test at more than one color.
References Cited (Backward Citations)
US3661462A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |