US3694629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System of reading out information upon recording medium in optical information reader
Assignee: Ricoh Co Ltd
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Filing: 1971-03-15
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Granted: 1972-09-26
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Expires: 1991-03-15
Abstract
Abstract The outputs of a plurality of photoelectric effect elements arrayed so as to correspond to the marking positions in a column or row on a recording medium for detecting a marked or unmarked information are applied to a plurality of difference amplifiers through respective logarithmic amplifiers. To these difference amplifiers are applied a signal representative of the brightness upon the recording medium, this signal being selected from two or more than two outputs selected from the outputs of a plurality of logarithmic amplifiers so that the outputs from the difference amplifiers are not influenced by the brightness on the recording medium and accurately represent the marked or unmarked information of the marking positions on the recording medium.
Inventors
- 👤 Mutsuo Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:57
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10851
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
A system for reading out information upon a recording medium in an optical information reader comprising a. a plurality of photoelectric effect elements arrayed so as to correspond to marking positions in a column or row on a recording medium for detecting coded marks thereon and producing first output signals, b. a pluraLity of logarithmic amplifiers for converting the first output signal from each of said photoelectric effect elements into a second output signal which logarithmically represents said first output of said each photoelectric effect element, c. first means for selecting at least two outputs from said plurality of logarithmic amplifiers and deriving from said selected outputs of said logarithmic amplifiers an electrical output signal representative of the brightness of said recording medium, and d. second means for deriving an electrical signal representative of the difference between the second output from each of said logarithmic amplifiers and the output of said first means, said selected second outputs from said logarithmic amplifiers including at least one output representative of the brightness of said recording medium.
Claim 2
Independent Claim
174 words
A system for reading out information upon a recording medium in an optical information reader comprising a. a plurality of photoelectric effect elements arrayed so as to correspond to marking positions in a column or row on a recording medium for detecting coded marks thereon and producing first output signals, b. a pluraLity of logarithmic amplifiers for converting the first output signal from each of said photoelectric effect elements into a second output signal which logarithmically represents said first output of said each photoelectric effect element, c. first means for selecting at least two outputs from said plurality of logarithmic amplifiers and deriving from said selected outputs of said logarithmic amplifiers an electrical output signal representative of the brightness of said recording medium, and d. second means for deriving an electrical signal representative of the difference between the second output from each of said logarithmic amplifiers and the output of said first means, said selected second outputs from said logarithmic amplifiers including at least one output representative of the brightness of said recording medium.
Claim 3
Dependent Claim
40 words
The system as claimed in claim 1 wherein said first means comprises a maximum voltage detector responsive to the highest voltage of said selected second outputs from said logarithmic amplifiers, and said second means comprise a plurality of difference amplifiers.
Claim 4
Dependent Claim
29 words
The system as claimed in claim 2, comprising a plurality of threshold circuits, respective ones of said threshold circuits connected to respective ones of said plurality of difference amplifiers.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |