US4590362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive circuit for temperature control heater in ink jet printer
Assignee: Ricoh Co Ltd
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Filing: 1984-04-18
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Granted: 1986-05-20
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Expires: 2004-04-18
Abstract
Abstract A circuit for controllably driving a heater in order to speed up temperature elevation at a buildup stage of a liquid which is to be maintained at a predetermined temperature heated by the heater, particularly ink in an ink jet printer. A voltage developed by doubling an output voltage of an atmospheric temperature sensor by an amplifier is compared with a reference voltage, which is adapted to decide power to be supplied to the heater in the event of a buildup of the ink temperature. A temperature-sensitive element responsive to an atmospheric temperature has a temperature coefficient which is double the temperature coefficient of a temperature-sensitive element responsive to a heater temperature. The output voltages of the two elements are weighted by a same amount and then added together, the summation output being compared with the reference voltage.
Inventors
- 👤 Kazumi Ishima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:44
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/17; B41J2/195; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1927; G05D23/193; G05D23/1931; G05D23/20; G05D23/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
198 words
A heater drive circuit for controllably driving a heater to maintain a temperature of an object at an optimum level, comprising: an atmospheric temperature sensor for sensing an atmospheric temperature; a heater temperature sensor for sensing a temperature of the heater; an amplifier having a first input supplied with an output of said atmospheric temperature sensor and a second input supplied with a predetermined and variable first reference voltage, said amplifier supplying the heater with power necessary for a startup of the heater, said amplifier having an amplification ratio larger than "1"; a comparator having a first input supplied with an amplified output of said amplifier and a second input supplied with an output of the heater temperature sensor; and an error amplifier having a first input supplied with an output of the heater temperature sensor and a second input supplied with a predetermined and variable second reference voltage, said error amplifier supplying the heater with power necessary for a stationary operation of the heater to maintain the object at the optimum temperature; outputs of said comparator and said error amplifier being connected to the heater for supplying said startup power and said stationary operating power respectively thereto.
Claim 2
Dependent Claim
198 words
A heater drive circuit for controllably driving a heater to maintain a temperature of an object at an optimum level, comprising: an atmospheric temperature sensor for sensing an atmospheric temperature; a heater temperature sensor for sensing a temperature of the heater; an amplifier having a first input supplied with an output of said atmospheric temperature sensor and a second input supplied with a predetermined and variable first reference voltage, said amplifier supplying the heater with power necessary for a startup of the heater, said amplifier having an amplification ratio larger than "1"; a comparator having a first input supplied with an amplified output of said amplifier and a second input supplied with an output of the heater temperature sensor; and an error amplifier having a first input supplied with an output of the heater temperature sensor and a second input supplied with a predetermined and variable second reference voltage, said error amplifier supplying the heater with power necessary for a stationary operation of the heater to maintain the object at the optimum temperature; outputs of said comparator and said error amplifier being connected to the heater for supplying said startup power and said stationary operating power respectively thereto.
Claim 3
Dependent Claim
16 words
A heater drive circuit as claimed in claim 1, in which the object is a liquid.
Claim 4
Dependent Claim
21 words
A heater drive circuit as claimed in claim 2, in which the liquid is ink used with an ink jet printer.
Claim 5
Dependent Claim
25 words
A heater drive circuit as claimed in claim 1, in which each of the atmospheric temperature sensor and the heater temperature sensor comprises a thermistor.
Claim 6
Dependent Claim
26 words
A heater drive circuit as claimed in claim 1, in which each of the atmospheric temperature sensor and the heater temperature sensor comprises a temperature-sensitive resistor.
Claim 7
Dependent Claim
19 words
A heater drive circuit as claimed in claim 1, in which the amplification ratio of the amplifier is "2".
Claim 8
Dependent Claim
19 words
A heater drive circuit as claimed in claim 1, in which the amplification ratio of the amplifier is adjustable.
Claim 9
Dependent Claim
217 words
A heater drive circuit for controllably driving a heater to maintain a temperature of an object at an optimum level, comprising: an atmospheric temperature sensor for sensing an atmospheric temperature and having a predetermined temperature coefficient; a heater temperature sensor for sensing a temperature of the heater and having a temperature coefficient which is larger than the temperature coefficient of the atmospheric temperature sensor; an adder for summing an output of said atmospheric temperature sensor and an output of said heater temperature sensor after weighing said outputs by a same amount; a comparator having a first input supplied with a summation output of said adder and a second input supplied with a predetermined and variable first, reference voltage, said comparator supplying the heater with power necessary for a startup of the heater; and an error amplifier having a first input supplied with a summation voltage of outputs of the atmospheric temperature sensor and the heater temperature sensor and a second input supplied with a predetermined second reference voltage, said error amplifier supplying the heater with power necessary for a stationary operation of the heater to maintain the object at the optimum temperature; outputs of said comparator and said error amplifier being connected to the heater for supplying said startup power and said stationary operating power respectively thereto.
Claim 10
Dependent Claim
217 words
A heater drive circuit for controllably driving a heater to maintain a temperature of an object at an optimum level, comprising: an atmospheric temperature sensor for sensing an atmospheric temperature and having a predetermined temperature coefficient; a heater temperature sensor for sensing a temperature of the heater and having a temperature coefficient which is larger than the temperature coefficient of the atmospheric temperature sensor; an adder for summing an output of said atmospheric temperature sensor and an output of said heater temperature sensor after weighing said outputs by a same amount; a comparator having a first input supplied with a summation output of said adder and a second input supplied with a predetermined and variable first, reference voltage, said comparator supplying the heater with power necessary for a startup of the heater; and an error amplifier having a first input supplied with a summation voltage of outputs of the atmospheric temperature sensor and the heater temperature sensor and a second input supplied with a predetermined second reference voltage, said error amplifier supplying the heater with power necessary for a stationary operation of the heater to maintain the object at the optimum temperature; outputs of said comparator and said error amplifier being connected to the heater for supplying said startup power and said stationary operating power respectively thereto.
Claim 11
Dependent Claim
16 words
A heater drive circuit as claimed in claim 8, in which the object is a liquid.
Claim 12
Dependent Claim
21 words
A heater drive circuit as claimed in claim 9, in which the liquid is ink used with an ink jet printer.
Claim 13
Dependent Claim
25 words
A heater drive circuit as claimed in claim 8, in which each of the atmospheric temperature sensor and the heater temperature sensor comprises a thermistor.
Claim 14
Dependent Claim
26 words
A heater drive circuit as claimed in claim 8, in which each of the atmospheric temperature sensor and the heater temperature sensor comprises a temperature-sensitive resistor.
Claim 15
Dependent Claim
29 words
A heater drive circuit as claimed in claim 8, in which the temperature coefficient of the heater temperature sensor is double the temperature coefficient of the atmospheric temperature sensor.
References Cited (Backward Citations)
US4167663A
Cited
US4459469A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |