US3896313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodetector apparatus with a zero cut-off response to absolute zero at a specified light frequency
Assignee: Westinghouse Electric Corp
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Filing: 1974-01-16
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Granted: 1975-07-22
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Expires: 1994-01-16
Abstract
Abstract A photodetector apparatus is provided having an output only when exposed to electromagnetic radiation above or below a specified cut-off frequency. At least first and second light sensor means produce electrical signals responsive to electromagnetic radiation of first and second overlapping frequency ranges, respectively, and peak electrical responses at different first and second peak frequencies, respectively. Electrical means compare the electrical signals from at least said first and second light sensor means and produces an electrical signal preferably of only one polarity and equal to a product of a first constant times the amplitude of the electrical signal produced by said first light sensor means minus a product of a second constant times the amplitude of the electrical signal produced by said second light sensor. The apparatus is particularly useful in ultraviolet detection where the sensor means are comprised of separate silicon carbide semiconductor bodies each containing a PN junction.
Inventors
- 👤 Herbert A Berman
- 👤 Robert B Campbell
- 👤 Wallace D Loftus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:14
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4228
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
160 words
A photodetector apparatus comprising: A. at least first and second light sensor means, said first light sensor means capable of producing electrical signals responsive to electromagnetic radiation of a first frequency range and producing a peak electrical response at a first peak frequency, and said second light sensor means capable of producing electrical signals responsive to electromagnetic radiation of a second frequency range and producing a peak electrical response at a second peak frequency, said first and second frequency ranges being overlapping and said first and second peak frequencies being different; and B. an electrical means for electrically comparing the electrical signals from at least said first and second light sensor means and producing an electrical signal equal to a product of a first constant times the amplitude of the electrical signal produced by said first light sensor means minus a product of a second constant times the amplitude of the electrical signal produced by said second light sensor means.
Claim 2
Dependent Claim
160 words
A photodetector apparatus comprising: A. at least first and second light sensor means, said first light sensor means capable of producing electrical signals responsive to electromagnetic radiation of a first frequency range and producing a peak electrical response at a first peak frequency, and said second light sensor means capable of producing electrical signals responsive to electromagnetic radiation of a second frequency range and producing a peak electrical response at a second peak frequency, said first and second frequency ranges being overlapping and said first and second peak frequencies being different; and B. an electrical means for electrically comparing the electrical signals from at least said first and second light sensor means and producing an electrical signal equal to a product of a first constant times the amplitude of the electrical signal produced by said first light sensor means minus a product of a second constant times the amplitude of the electrical signal produced by said second light sensor means.
Claim 3
Dependent Claim
23 words
A photodetector apparatus as set forth in claim 1 wherein: the electrical signal produced by the electrical means is of only one polarity.
Claim 4
Dependent Claim
70 words
A photodetector apparatus as set forth in claim 1 wherein: the light sensor means each are comprised of a semiconductor body having opposed first and second major surface, said body having a first impurity region of a given conductivity adjoining the first major surface, and a second impurity region of an opposite conductivity adjoining the second major surface and adjoining said first impurity region to form a PN junction therewith.
Claim 5
Dependent Claim
61 words
A photodetector apparatus as set forth in claim 3 wherein: the electrical signals produced by said first and second light sensor means are of opposite polarity, and the electrical signal produced by said electrical means is the sum of the products of the first and second constants times the respective electrical signals produced by said first and second light sensor means.
Claim 6
Dependent Claim
60 words
A photodetector apparatus as set forth in claim 3 wherein: the electrical signals produced by said first and second light sensor means are of same polarity, and the electrical signal produced by said electrical means is the difference of the products of the first and second constants times the respective electrical signals produced by said first and second sensor means.
Claim 7
Dependent Claim
180 words
An ultraviolet photodetector apparatus comprising: A. at least first and second light sensor means each comprised of a silicon carbide semiconductor body having a PN junction therein, said first sensor means capable of producing electrical signals responsive to electromagnetic radiation of a first frequency range and producing a peak electrical response at a first peak ultraviolet frequency, and said second sensor means capable of producing electrical signals responsive to electromagnetic radiation of a second frequency range and producing a peak electrical response at a second peak ultraviolet frequency, said first and second frequency ranges being overlapping and said first and second peak ultraviolet frequencies being different; and B. an electrical means for electrically comparing the electrical signals from at least said first and second light sensor means and producing an electrical signal of only one polarity and equal to a product of a first constant times the amplitude of the electrical signal produced by said first light sensor means minus a product of a second constant times the amplitude of the electrical signal produced by said second light sensor means.
Claim 8
Dependent Claim
180 words
An ultraviolet photodetector apparatus comprising: A. at least first and second light sensor means each comprised of a silicon carbide semiconductor body having a PN junction therein, said first sensor means capable of producing electrical signals responsive to electromagnetic radiation of a first frequency range and producing a peak electrical response at a first peak ultraviolet frequency, and said second sensor means capable of producing electrical signals responsive to electromagnetic radiation of a second frequency range and producing a peak electrical response at a second peak ultraviolet frequency, said first and second frequency ranges being overlapping and said first and second peak ultraviolet frequencies being different; and B. an electrical means for electrically comparing the electrical signals from at least said first and second light sensor means and producing an electrical signal of only one polarity and equal to a product of a first constant times the amplitude of the electrical signal produced by said first light sensor means minus a product of a second constant times the amplitude of the electrical signal produced by said second light sensor means.
Claim 9
Dependent Claim
62 words
An ultraviolet photodetector apparatus as set forth in claim 6 wherein: the electrical signals produced by said first and second light sensor means are of opposite polarity and the electrical signal produced by said electrical means is the sum of the products of the first and sEcond constants times the respective electrical signals produced by said first and second light sensor means.
Claim 10
Dependent Claim
61 words
An ultraviolet photodetector apparatus as set forth in claim 6 wherein: the electrical signals produced by said first and second light sensor means are of same polarity and the electrical signals produced by said electrical means is the difference of the products of the first and second constants times the respective electrical signals produced by said first and second sensor means.
References Cited (Backward Citations)
US3504181A
Cited
US3609364A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |