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US4500893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal-printing device with defective resistive heating element detection mode
Assignee: Tokyo Electron Ltd
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Filing: 1984-04-18
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Granted: 1985-02-19
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Expires: 2004-04-18
Abstract
Abstract A thermal-printing device prints by selectively supplying a current to a plurality of heat generating elements in accordance with printing data. In a check mode, the thermal-printing device sequentially supplies a check current to the heat generating elements through a light-emitting diode and a current-limiting resistor.
Inventors
- 👤 Yasuhiro Sakura
- 👤 Yoshihiro Takai
- 👤 Michio Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:00
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/35
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
181 words
A thermal-printing device comprising: a power supply terminal set at a predetermined potential; a pluraltiy of heat generating means; a first current path; a second current path including current limiting means; current detecting means for generating a control output signal upon detecting a flow of a current through said second current path; switching means set to connect one terminal of each of said plurality of heat generating elements to said power supply terminal through said first and second paths in a printing mode and a check mode, respectively; and potential setting means, having a plurality of output terminals each connected to the other terminal of a corresponding one of said plurality of heat generating elements, for selectively setting potentials at said output terminals at a predetermined potential level in accordance with input data to selectively flow a current through said plurality of heat generating elements in the printing mode, and for sequentially setting the potentials at said output terminals at said predetermined potential level to sequentially flow a check current through said plurality of heat generating elements in the check mode.
Claim 2
Dependent Claim
181 words
A thermal-printing device comprising: a power supply terminal set at a predetermined potential; a pluraltiy of heat generating means; a first current path; a second current path including current limiting means; current detecting means for generating a control output signal upon detecting a flow of a current through said second current path; switching means set to connect one terminal of each of said plurality of heat generating elements to said power supply terminal through said first and second paths in a printing mode and a check mode, respectively; and potential setting means, having a plurality of output terminals each connected to the other terminal of a corresponding one of said plurality of heat generating elements, for selectively setting potentials at said output terminals at a predetermined potential level in accordance with input data to selectively flow a current through said plurality of heat generating elements in the printing mode, and for sequentially setting the potentials at said output terminals at said predetermined potential level to sequentially flow a check current through said plurality of heat generating elements in the check mode.
Claim 3
Dependent Claim
27 words
A thermal-printing device according to claim 1, wherein said potential setting means has a latch circuit and inverting means for inverting output data from said latch circuit.
Claim 4
Dependent Claim
27 words
A thermal-printing device according to claim 2, wherein said switching means has first and second switching elements which are series-connected to said first and second current paths.
Claim 5
Dependent Claim
34 words
A thermal-printing device according to claim 3, wherein said current detecting means has a light-emitting diode series-connected to said second current path, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 6
Dependent Claim
22 words
A thermal-printing device according to claim 3, wherein said current detecting means has a light-emitting diode series-connected to said second current path.
Claim 7
Dependent Claim
48 words
A thermal-printing device according to claim 3, wherein said current limiting means has first and second resistors, and said current detecting means has first and second light-emitting diodes respectively series-connected to said first and second resistors, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 8
Dependent Claim
34 words
A thermal-printing device according to claim 2, wherein said current detecting means has a light-emitting diode series-connected to said second current path, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 9
Dependent Claim
22 words
A thermal-printing device according to claim 2, wherein said current detecting means has a light-emitting diode series-connected to said second current path.
Claim 10
Dependent Claim
48 words
A thermal-printing device according to claim 2, wherein said current limiting means has first and second resistors, and said current detecting means has first and second light-emitting diodes respectively series-connected to said first and second resistors, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 11
Dependent Claim
50 words
A thermal-printing device according to claim 1, wherein said potential setting means has a shift register circuit, and a plurality of NAND gates each of which receives corresponding bit data from said shift register circuit at one input terminal thereof and a strobe signal at the other input terminal thereof.
Claim 12
Dependent Claim
34 words
A thermal-printing device according to claim 1, wherein said current detecting means has a light-emitting diode series-connected to said second current path, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 13
Dependent Claim
22 words
A thermal-printing device according to claim 1, wherein said current detecting means has a light-emitting diode series-connected to said second current path.
Claim 14
Dependent Claim
48 words
A thermal-printing device according to claim 1, wherein said current limiting means has first and second resistors, and said current detecting means has first and second light-emitting diodes respectively series-connected to said first and second resistors, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 15
Dependent Claim
34 words
A thermal-printing device according to claim 13, wherein said current detecting means has a light-emitting diode series-connected to said second current path, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 16
Dependent Claim
22 words
A thermal-printing device according to claim 13, wherein said current detecting means has a light-emitting diode series-connected to said second current path.
Claim 17
Dependent Claim
48 words
A thermal-printing device according to claim 13, wherein said current limiting means has first and second resistors, and said current detecting means has first and second light-emitting diodes respectively series-connected to said first and second resistors, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 18
Dependent Claim
27 words
A thermal-printing device according to claim 13, wherein said switching means has first and second switching elements which are series-connected to said first and second current paths.
Claim 19
Dependent Claim
34 words
A thermal-printing device according to claim 17, wherein said current detecting means has a light-emitting diode series-connected to said second current path, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
Claim 20
Dependent Claim
22 words
A thermal-printing device according to claim 17, wherein said current detecting means has a light-emmiting diode series-connected to said second current path.
Claim 21
Dependent Claim
48 words
A thermal-printing device according to claim 17, wherein said current limiting means has first and second resistors, and said current detecting means has first and second light-emitting diodes respectively series-connected to said first and second resistors, and a phototransistor which, together with said light-emitting diode, constitutes a photocoupler.
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) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |