US3870138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control unit for table-type electronic calculator with printer
Assignee: Ricoh Co Ltd
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Filing: 1973-07-13
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Granted: 1975-03-11
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Expires: 1993-07-13
Abstract
Abstract The motor operating a printer is on only for as long as necessary to print each keyed-in character, and shuts off for idle periods. The depression of a keyboard key produces a signal which discharges a capacitor, whereby a motor drive transistor is rendered conductive to start the motor. A control circuit is provided which responds to a signal produced for each revolution of the motor and to a clock pulse signal produced in response to a depressing operation of the keyboard to permit the passage of a character pulse synchronized with the rotation of a printer drum to thereby initiate a printing operation. After the printing operation, in the absence of a depressing operation of the keyboard, the charging of the capacitor causes the drive motor to stop, thus enabling an automatic start and stop of the motor in accordance with a depressing operation of the keyboard.
Inventors
- 👤 Yostbumi Sato
- 👤 Masaaki Ogura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:06
CPC Classifications
B; B41; B41J; B41J29/00; B41J29/38; B41J29/387
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
210 words
A motor control unit for a table-type electronic calculator with a printer and a keyboard providing character pulse trains in response to the operation of a keyboard key, said unit comprising: an integrating circuit including a capacitor which is discharged by a signal produced in response to the operation of a key on the keyboard and means for charging the capacitor at a defined rate, an electric motor for driving the printer, a drive circuit rendered conductive upon discharge of the capacitor for starting the motor, means for providing a home pulse for each revolution of the motor and a clock pulse train upon the operation of a keyboard key, a control circuit including means for providing an output signal in response to a defined home pulse and a clock pulse train and means for allowing the passage of said character pulse train to the printer during said output signal, said printer including means responding to the output signal from the control circuit to start a printing operation, means for resetting the control circuit upon the charging of the capacitor in the absence of an operation of the key, and means for Interrupting the drive circuit to thereby stop the motor in response to said resetting of the control circuit.
Claim 2
Dependent Claim
210 words
A motor control unit for a table-type electronic calculator with a printer and a keyboard providing character pulse trains in response to the operation of a keyboard key, said unit comprising: an integrating circuit including a capacitor which is discharged by a signal produced in response to the operation of a key on the keyboard and means for charging the capacitor at a defined rate, an electric motor for driving the printer, a drive circuit rendered conductive upon discharge of the capacitor for starting the motor, means for providing a home pulse for each revolution of the motor and a clock pulse train upon the operation of a keyboard key, a control circuit including means for providing an output signal in response to a defined home pulse and a clock pulse train and means for allowing the passage of said character pulse train to the printer during said output signal, said printer including means responding to the output signal from the control circuit to start a printing operation, means for resetting the control circuit upon the charging of the capacitor in the absence of an operation of the key, and means for Interrupting the drive circuit to thereby stop the motor in response to said resetting of the control circuit.
Claim 3
Dependent Claim
210 words
A motor control unit for a table-type electronic calculator with a printer and a keyboard providing character pulse trains in response to the operation of a keyboard key, said unit comprising: an integrating circuit including a capacitor which is discharged by a signal produced in response to the operation of a key on the keyboard and means for charging the capacitor at a defined rate, an electric motor for driving the printer, a drive circuit rendered conductive upon discharge of the capacitor for starting the motor, means for providing a home pulse for each revolution of the motor and a clock pulse train upon the operation of a keyboard key, a control circuit including means for providing an output signal in response to a defined home pulse and a clock pulse train and means for allowing the passage of said character pulse train to the printer during said output signal, said printer including means responding to the output signal from the control circuit to start a printing operation, means for resetting the control circuit upon the charging of the capacitor in the absence of an operation of the key, and means for Interrupting the drive circuit to thereby stop the motor in response to said resetting of the control circuit.
Claim 4
Dependent Claim
210 words
A motor control unit for a table-type electronic calculator with a printer and a keyboard providing character pulse trains in response to the operation of a keyboard key, said unit comprising: an integrating circuit including a capacitor which is discharged by a signal produced in response to the operation of a key on the keyboard and means for charging the capacitor at a defined rate, an electric motor for driving the printer, a drive circuit rendered conductive upon discharge of the capacitor for starting the motor, means for providing a home pulse for each revolution of the motor and a clock pulse train upon the operation of a keyboard key, a control circuit including means for providing an output signal in response to a defined home pulse and a clock pulse train and means for allowing the passage of said character pulse train to the printer during said output signal, said printer including means responding to the output signal from the control circuit to start a printing operation, means for resetting the control circuit upon the charging of the capacitor in the absence of an operation of the key, and means for Interrupting the drive circuit to thereby stop the motor in response to said resetting of the control circuit.
Claim 5
Independent Claim
161 words
A device including a printer, a keyboard, means for generating a key signal in response to the operation of each of a plurality of keyboard keys and for generating a character pulse train corresponding to the operated key, and a motor for driving the printer, wherein the improvment is in a motor control unit comprising: means for starting the motor in response to said key signal generated in response to the operation of a keyboard key; means for generating a train of home pulses synchronized with the motor revolutions; control means connecting the character pulse generating means and the printer and responsive to said home pulse train for applying the character pulse train corresponding to the operated key to the printer in synchronism with a time period starting with a first selected pulse of said home pulse train and ending with a subsequent second selected home pulse; and means for stopping the motor in response to said subsequent selected home pulse.
Claim 6
Independent Claim
161 words
A device including a printer, a keyboard, means for generating a key signal in response to the operation of each of a plurality of keyboard keys and for generating a character pulse train corresponding to the operated key, and a motor for driving the printer, wherein the improvment is in a motor control unit comprising: means for starting the motor in response to said key signal generated in response to the operation of a keyboard key; means for generating a train of home pulses synchronized with the motor revolutions; control means connecting the character pulse generating means and the printer and responsive to said home pulse train for applying the character pulse train corresponding to the operated key to the printer in synchronism with a time period starting with a first selected pulse of said home pulse train and ending with a subsequent second selected home pulse; and means for stopping the motor in response to said subsequent selected home pulse.
Claim 7
Dependent Claim
47 words
A device as in claim 2 wherein the first selected home pulse is the N-th home pulse after the motor is started and the second selected home pulse is M home pulses after the first selected home pulse, where N and M are integers of selected values.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |