Patent US3917142A successfully refreshed from Google Patents.
US3917142A
Expired / Lapsed
US
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Paper motion sensor apparatus
Assignee: Ricoh Printing Systems America Inc
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Filing: 1974-04-04
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Granted: 1975-11-04
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Expires: 1994-04-04
Abstract
Abstract Apparatus useful in a printer for monitoring paper movement to stop operation of the printer when a paper jam is detected. The monitoring apparatus includes a friction wheel mounted adjacent to a paper path such that the paper engages the wheel and rotates the wheel as the paper is stepped. The friction wheel is secured to a rotatable shaft carrying an encoder disc mounted in an optical path between a light source and light sensor. As the encoder disc rotates in response to the paper movement, it periodically interrupts the optical path causing the light sensor to produce an electrical pulse train. The pulse train is coupled to the reset input terminal of a counter which is incremented in response to paper feed commands supplied by the printer control logic. In normal operation, the counter is reset after each feed command. In the event of a paper jam, however, the feed commands will continue but there will be no corresponding paper motion to reset the counter. Consequently, the counter will count to a predetermined level at which a paper fault signal is generated to terminate further operation of the printer.
Inventors
- 👤 Fernando V Guarderas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:57
CPC Classifications
B; B41; B41J; B41J29/00; B41J29/46; B41J29/48; B65; B65H; B65H2553/00; B65H2553/51; B65H2557/00; B65H2557/30; B65H2557/33
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
144 words
In a printer including (1) control means for periodically generating paper feed command and (2) drive means responsive to said commands for moving a paper web along a prescribed path, the improvement comprising: friction wheel means tangentially engaged with said paper web for rotating in response to linear movement of said paper web; transducer means for generating a pulse in response to each unit of rotation of said friction means; counter means for counting the number of paper feed commands supplied by said control means; means responsive to each pulse generated by said transducer means for resetting said counter means; said counter means including means for generating a fault signal in response to a predetermined number of paper feed commands occurring between successive pulses generated by said transducer means; and means responsive to said fault signal for inhibiting generation of said paper feed commands.
Claim 2
Dependent Claim
144 words
In a printer including (1) control means for periodically generating paper feed command and (2) drive means responsive to said commands for moving a paper web along a prescribed path, the improvement comprising: friction wheel means tangentially engaged with said paper web for rotating in response to linear movement of said paper web; transducer means for generating a pulse in response to each unit of rotation of said friction means; counter means for counting the number of paper feed commands supplied by said control means; means responsive to each pulse generated by said transducer means for resetting said counter means; said counter means including means for generating a fault signal in response to a predetermined number of paper feed commands occurring between successive pulses generated by said transducer means; and means responsive to said fault signal for inhibiting generation of said paper feed commands.
Claim 3
Dependent Claim
51 words
The improvement of claim 1 wherein said transducer means includes an encoder disc having a plurality of marks annularly distributed thereon; means mounting said encoder disc for rotation with said friction wheel; and sensor means supported adjacent said encoder disc for generating a pulse in response to each mark moving therepast.
Claim 4
Dependent Claim
70 words
The improvement of claim 1 wherein said transducer means includes an encoder disc having a plurality of annularly distributed openings defined therein; means mounting said encoder disc for rotation with said friction wheel; a light source supported adjacent one side of said disc; and light sensor means supported adjacent a second side of said disc for generating a pulse signal in response to the passage of one of said openings.
Claim 5
Dependent Claim
148 words
A printing apparatus including: paper drive means for supporting a paper web for linear movement along a defined path; control means for periodically supplying paper feed commands to said paper drive means for incrementally stepping said paper web along said path; friction wheel means supported adjacent to said path and tangentially engaged with said paper web for rotational movement in response to said linear movement of said paper web; transducer means for sensing unit movements of said friction wheel means; counter means for counting the number of paper feed commands supplied by said control means between successive unit movements of said friction wheel means; said counter means including means for generating a fault signal in response to a predetermined number of paper feed commands occurring between successive pulses generated by said transducer means; and means responsive to said fault signal for inhibiting generation of said paper feed commands.
Claim 6
Dependent Claim
148 words
A printing apparatus including: paper drive means for supporting a paper web for linear movement along a defined path; control means for periodically supplying paper feed commands to said paper drive means for incrementally stepping said paper web along said path; friction wheel means supported adjacent to said path and tangentially engaged with said paper web for rotational movement in response to said linear movement of said paper web; transducer means for sensing unit movements of said friction wheel means; counter means for counting the number of paper feed commands supplied by said control means between successive unit movements of said friction wheel means; said counter means including means for generating a fault signal in response to a predetermined number of paper feed commands occurring between successive pulses generated by said transducer means; and means responsive to said fault signal for inhibiting generation of said paper feed commands.
Claim 7
Dependent Claim
51 words
The apparatus of claim 4 wherein said transducer means includes an encoder disc having a plurality of marks annularly distributed thereon; means mounting said encoder disc for rotation with said friction wheel; and sensor means supported adjacent said encoder disc for generating a pulse in response to each mark moving therepast.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |