US3582887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable character reader to compensate for varying print density
Assignee: Farrington Electronics Inc
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Filing: 1968-03-20
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Granted: 1971-06-01
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Expires: 1988-03-20
Abstract
Abstract A character reader is disclosed, the operation of which is adjustable to thereby compensate for varying print densities of the characters. The raw video pulses generated during the scanning of a character are applied to a plurality of video quantizers, the clipping levels of the quantizers respectively corresponding to different values of print density. The print density of the scanned character is determined by measuring the stroke width of the vertical lines of the characters, the stroke width, in turn, being measured by counting the number of successive scanning frames in which at least one short vertical segment occurs, the length of such segments exceeding some predetermined standard. A plurality of outputs are developed from the counter, the counter outputs respectively corresponding to the plurality of video quantizers whereby the energization of a selected one of the counter outputs will cause the corresponding video quantizer to be actuated and only that quantizer. The recognition circuitry operates only upon that video quantizer output selected by the point density measuring circuit.
Inventors
- 👤 John G Guthrie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:39
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/20; G06V10/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
188 words
A character reader for reading characters of variable print density, said reader comprising: scanning means for generating a series of raw video pulses corresponding to the shapes of the characters scanned by the scanning means; clipping means, the clipping level of which is adjustable, said clipping means being responsive to said raw video pulses for developing quantized video pulses; recognition means responsive to said quantized video pulses for distinguishing various combinations thereof to thereby discriminate the characters from one another and effectuate the recognition thereof; print density measuring means for determining the stroke width of the scanned character, said measuring means being responsive to said raw video pulses to thereby control said adjustable level clipping means in accordance with the print density measured and said print density measuring means counting the number of successive scanning frames in which at least one short vertical stroke occurs, said short vertical stroke having a length which is at least greater than the nominal stroke width of said characters: whereby the operation of the character reader is compensated for in accordance with the varying degrees of print density encountered by the reader.
Claim 2
Dependent Claim
188 words
A character reader for reading characters of variable print density, said reader comprising: scanning means for generating a series of raw video pulses corresponding to the shapes of the characters scanned by the scanning means; clipping means, the clipping level of which is adjustable, said clipping means being responsive to said raw video pulses for developing quantized video pulses; recognition means responsive to said quantized video pulses for distinguishing various combinations thereof to thereby discriminate the characters from one another and effectuate the recognition thereof; print density measuring means for determining the stroke width of the scanned character, said measuring means being responsive to said raw video pulses to thereby control said adjustable level clipping means in accordance with the print density measured and said print density measuring means counting the number of successive scanning frames in which at least one short vertical stroke occurs, said short vertical stroke having a length which is at least greater than the nominal stroke width of said characters: whereby the operation of the character reader is compensated for in accordance with the varying degrees of print density encountered by the reader.
Claim 3
Dependent Claim
55 words
A reader as in claim 1 including means responsive to said recognition circuitry for generating a reject control signal whenever said recognition means fails to recognize a character processed thereby; and control means responsive to said print density measuring means and said reject control signal source to select said clipping level of the clipping means.
Claim 4
Dependent Claim
65 words
A reader as in claim 1 including delay means for delaying the signal in the clipping means channel for a length of time equal to at least the amount of time required for the scanning means to scan one of the characters; whereby the selection of the clipping level is effectuated after the print density measurement has been made by the print density measuring means.
Claim 5
Dependent Claim
22 words
A reader as in claim 1 where said print density measuring means measures the width of vertical strokes occurring in the characters.
Claim 6
Dependent Claim
37 words
A reader as in claim 1 where said counting means includes a plurality of counters respectively corresponding to different print densities; and control means responsive to said plurality of counters to control said adjustable level clipping means.
Claim 7
Dependent Claim
58 words
A reader as in claim 5 where said clipping means comprises a plurality of clippers respectively associated with said plurality of counters, the clipping levels of said clippers respectively corresponding to said different print densities whereby the selection of one of said counters by said control means causes the corresponding one of said clipping means to be selected.
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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |