US3668636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and circuit arrangement for the recognition of characters
Assignee: US Philips Corp
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Filing: 1970-08-05
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Granted: 1972-06-06
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Expires: 1990-08-05
Abstract
Abstract A method of recognition of signs in which a scanning beam, passed circularly across the overall line width of a sign, is caused to follow up the contour of a sign and in which a signal sequence significant of the sign is derived from further circular scanning ramifications, uninterrupted lines and termini of the signs being recognized from the number of black-white transitions per scanning period. The arc determined by the width and phase of the scanning pulse and covering a line last scanned within a scanning cycle is stored and compared with the arcs of the lines covered during the next-following scanning cycle for assessing coincidence. The coinciding arcs are used as recognition criteria so that no coincidence for one or more scanning cycle indicate a terminus of a sign, one coincidence per scanning cycle indicates the presence of a non-ramified line and a plurality of coincidences per scanning cycle indicate a ramification. The angular value for the direction of follow-up of the scanning circle is derived from the values of beginning and termination of the coinciding arcs.
Inventors
- 👤 Reinhart Blucher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:47
CPC Classifications
G; G06; G06V; G06V30/00; G06V30/10; G06V30/18; G06V30/182
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
187 words
A method of recognition of characters in which a scanning beam, passed circularly across the overall line width of a sign is caused to follow up the contour of a sign and in which a signal sequence significant of the sign is derived from further circular scanning ramifications, uninterrupted lines and termini of the signs being recognized from the number of black-white transitions per scanning period comprising the steps of moving said beam at a constant angular speed, storing the arc determined by the width and phase of the scanning pulse and covering a line last scanned within a scanning cycle, comparing said arc with subsequent arcs of the lines covered during the next-following scanning cycle for assessing coincidence, recognizing coinciding arcs such that no coincidence for one or more scanning cycles indicate a terminus of a sign, one coincidence per scanning cycle indicates the presence of a non-ramified line and a plurality of coincidences per scanning cycle indicate a ramified line, and deriving the angular value for the direction of followup of the scanning circle from the values of beginning and termination of said coinciding arcs.
Claim 2
Independent Claim
187 words
A method of recognition of characters in which a scanning beam, passed circularly across the overall line width of a sign is caused to follow up the contour of a sign and in which a signal sequence significant of the sign is derived from further circular scanning ramifications, uninterrupted lines and termini of the signs being recognized from the number of black-white transitions per scanning period comprising the steps of moving said beam at a constant angular speed, storing the arc determined by the width and phase of the scanning pulse and covering a line last scanned within a scanning cycle, comparing said arc with subsequent arcs of the lines covered during the next-following scanning cycle for assessing coincidence, recognizing coinciding arcs such that no coincidence for one or more scanning cycles indicate a terminus of a sign, one coincidence per scanning cycle indicates the presence of a non-ramified line and a plurality of coincidences per scanning cycle indicate a ramified line, and deriving the angular value for the direction of followup of the scanning circle from the values of beginning and termination of said coinciding arcs.
Claim 3
Dependent Claim
237 words
A circuit arrangement for recognizing line characters comprising means for optically scanning said characters in a series of character line crossing arc scans, photoelectric means responsive to said optical scanning for providing an electrical signal in response to a character line crossing, means applying said electrical signal to a first input of a plurality of multiple input conjunctive logic devices, first and second of said conjunctive devices each having a further input thereof connected to a respective output of a bistable trigger, means connecting the outputs of said first and second conjunctive devices to first and second delay circuits respectively, each of said delay circuits having a delay time of one scanning cycle and reset to an initial position in response to each incoming pulse, means connecting the outputs of each of said delay circuits to an input of third and fourth multi-input conjunctive devices, means connecting the outputs of said thiRd and fourth conjunctive devices to a first disjunctive device for producing the desired output, fifth and sixth multi-input conjunctive devices, each having at least two inverted inputs, each inverted input responsive to said electrical signal, and a further input non-inverted of each of said fifth and sixth conjunctive devices respectively connected to each of said delay circuits for alternate excitation thereby, the output of said fifth and sixth conjunction devices respectively coupled to said bistable trigger for alternate excitation of said first and second conjunctions.
Claim 4
Dependent Claim
237 words
A circuit arrangement for recognizing line characters comprising means for optically scanning said characters in a series of character line crossing arc scans, photoelectric means responsive to said optical scanning for providing an electrical signal in response to a character line crossing, means applying said electrical signal to a first input of a plurality of multiple input conjunctive logic devices, first and second of said conjunctive devices each having a further input thereof connected to a respective output of a bistable trigger, means connecting the outputs of said first and second conjunctive devices to first and second delay circuits respectively, each of said delay circuits having a delay time of one scanning cycle and reset to an initial position in response to each incoming pulse, means connecting the outputs of each of said delay circuits to an input of third and fourth multi-input conjunctive devices, means connecting the outputs of said thiRd and fourth conjunctive devices to a first disjunctive device for producing the desired output, fifth and sixth multi-input conjunctive devices, each having at least two inverted inputs, each inverted input responsive to said electrical signal, and a further input non-inverted of each of said fifth and sixth conjunctive devices respectively connected to each of said delay circuits for alternate excitation thereby, the output of said fifth and sixth conjunction devices respectively coupled to said bistable trigger for alternate excitation of said first and second conjunctions.
Claim 5
Dependent Claim
18 words
A circuit arrangement as described in claim 2, wherein said delay circuits are formed by monostable trigger circuits.
Claim 6
Dependent Claim
17 words
A circuit arrangement as described in claim 2, wherein said delay circuits are formed by binary counters.
Claim 7
Dependent Claim
35 words
A method as claimed in claim 1 characterized in that the duration and the time shift of the pulses for the follow-up of the scanning circle towards the center of the output pulses are constant.
Claim 8
Dependent Claim
91 words
A method as claimed in claim 5 characterized in that a binary converter is switched on from an initial position by a clock pulse of the frequency f as soon as the output pulse corresponding to the coinciding arcs starts, the converter being switched on by double the frequency 2f up to the initial position as soon as the output pulse has terminated and in that when the initial position is attained, a monostable trigger circuit is changed over, which supplies the pulse (z) for the follow-up of the scanning circle.
Claim 9
Dependent Claim
56 words
A method as claimed in claim 1 characterized in that the angular co-ordinates of the scanning circle are divided into n sectors by applying counting pulses of the frequency 1/T.n to the input of a binary counter, the position of which at the beginning of the shift is recorded, wherein T duration of the scanning period.
Claim 10
Dependent Claim
19 words
A method as claimed in claim 1 characterized in that the scanning beam is formed by a light ray.
Claim 11
Dependent Claim
33 words
A method as claimed in claim 1 characterized in that the signs to be scanned are previously stored in an electrostatic image storage, and the scanning beam is formed by a cathode ray.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |