US3676687A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shadow edge position detector using linear array of diodes with logic to generate gray code
Assignee: Warner and Swasey Co
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Filing: 1970-09-04
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Granted: 1972-07-11
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Expires: 1990-09-04
Abstract
Abstract A system for detecting shadow edges by use of a linear array of photodiodes whose output is a Gray Type Code is described. Because of the unique connections of the diodes into pairs and the appropriate use of logic circuitry, the diodes can be arranged in a linear, or single line, array. As a result of the Gray Code type of output, the shadow edge is unambiguously located within a single diode spacing.
Inventors
- 👤 Morris D Freedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:19
CPC Classifications
G; G06; G06K; G06K11/00; H; H03; H03M; H03M1/00; H03M1/12; H03M1/22; H03M1/24; H03M1/26
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
96 words
A system for detecting the edges of radiation patterns comprising: an array of radiation sensitive elements arranged in a line; logic means connecting the individual elements into pairs, said logic means yielding a logic 1 output when one of the elements of a pair are illuminated and a logic 0 for all other illuminations of said pairs of elements, the pairing of said elements being selected so that at least one other element lies between the two elements of a pair to cause the output logic of said system to follow a Gray type of code.
Claim 2
Independent Claim
96 words
A system for detecting the edges of radiation patterns comprising: an array of radiation sensitive elements arranged in a line; logic means connecting the individual elements into pairs, said logic means yielding a logic 1 output when one of the elements of a pair are illuminated and a logic 0 for all other illuminations of said pairs of elements, the pairing of said elements being selected so that at least one other element lies between the two elements of a pair to cause the output logic of said system to follow a Gray type of code.
Claim 3
Dependent Claim
21 words
The system of claim 1 wherein said radiation patterns are shadows cast in light and said radiation sensitive elements are photodiodes.
Claim 4
Dependent Claim
20 words
The system of claim 1 wherein said logic means performs a threshold function, an inverting function and an AND function.
Claim 5
Dependent Claim
40 words
The system of claim 1 wherein said logic means includes a transistor, said one of said elements being connected to the base of said transistor and the other element of said pair being connected to the emitter of said transistor.
Claim 6
Dependent Claim
118 words
The system of claim 1 wherein said Gray Code has a pair of 1 and 0 logic conditions for each output bit, and the 1 and 0 logic conditions for the pairs are arranged into columns, said 1 and 0 logic conditions in each row being arranged so that the 1 and 0 combination within a column differs from adjacent columns by a single 1 or p; and wherein said elements aRe paired so that the one element of a pair represents an occurrence of one of said logic conditions in a row and the other element of a pair represents the first occurrence of the other logic condition after said one logic condition in the same row.
Claim 7
Dependent Claim
64 words
The system of claim 1 wherein pairs of said elements are grouped so that one pair of elements within each group yields a code bit for each code position within said Gray Code, and an output terminal means commonly connected to the pairs within a group so that all output pulses within a row of said Gray Code appear on a particular output terminal.
Claim 8
Dependent Claim
22 words
The system of claim 6 wherein said elements and said logic means are fabricated by integrated circuit techniques onto a single chip.
Claim 9
Dependent Claim
57 words
The system of claim 1 wherein said Gray Type Code has n bit accuracy, said system having n output terminals, said pairs of elements being grouped into n groups, and all the pairs within a group being connected to one of said output terminals so that each of said groups provides one bit for each code position.
Claim 10
Dependent Claim
19 words
The system of claim 8 wherein said radiation patterns are shadows cast in light, and said elements are photodiodes.
Claim 11
Dependent Claim
96 words
The system of claim 9 wherein said logic means includes a transistor, the second of said diodes in a pair being connected to the base of said transistor, the first of said diodes in a pair being connected to the emitter of said transistor, and further including biasing means connected to said base and emitter through said diodes, and resistance means connecting the base and collector of said transistor to ground so that said transistor yields said 1 output when said first diode is illuminated and said 0 output for all other illuminations of said diodes.
References Cited (Backward Citations)
US3046407A
Cited
US3466602A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |