US5497218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three point thermistor temperature set up
Assignee: Xerox Corp
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Filing: 1994-08-24
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Granted: 1996-03-05
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Expires: 2014-08-24
Abstract
Abstract Thermistors are calibrated by taking three thermistor resistance measurements at various temperatures. The resistance values are converted or transferred to Analog to Digital (A/D) bits or bit values which the machine's microprocessor can relate to temperature. The three values are utilized for constructing a calibration curve in the microprocessor for a specific thermistor bead. Use of the curve allows for mathematical interpolation by the microprocessor between calibration points, providing a wider and more accurate range to set the fuser roll temperatures. This increased accuracy over a wider range than before allows the sensor to become a common part for a family of products which may require different standby and runtime temperatures.
Inventors
- 👤 Mark S. Amico
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:23
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G15/205; G05; G05D; G05D23/00; G05D23/19; G05D23/1917; G05D23/20; G05D23/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
144 words
A method of controlling the surface temperature of a heated fuser member having a heater structure operatively supported internally thereof, said method including the steps of: supporting a heated fuser member in pressure engagement with a pressure roller for fusing toner images heating said heated fuser member using a heater structure supported internally thereof; supporting at least one thermistor in temperature sensing relationship with said heated fuser member; establishing calibration bit values at three different temperatures for said at least one thermistor; storing said calibration bit values in non-volatile memory storing standby and runtime bit values in non-volatile memory using said bit values and standby and runtime bit values for calculating said runtime and standby target values for said at least one thermistor; storing said target values in non-volatile memory; and utilizing said target values for controlling the operating characteristics of said heat structure.
Claim 2
Independent Claim
144 words
A method of controlling the surface temperature of a heated fuser member having a heater structure operatively supported internally thereof, said method including the steps of: supporting a heated fuser member in pressure engagement with a pressure roller for fusing toner images heating said heated fuser member using a heater structure supported internally thereof; supporting at least one thermistor in temperature sensing relationship with said heated fuser member; establishing calibration bit values at three different temperatures for said at least one thermistor; storing said calibration bit values in non-volatile memory storing standby and runtime bit values in non-volatile memory using said bit values and standby and runtime bit values for calculating said runtime and standby target values for said at least one thermistor; storing said target values in non-volatile memory; and utilizing said target values for controlling the operating characteristics of said heat structure.
Claim 3
Dependent Claim
28 words
The method according to claim 1 wherein said steps of storing said calibration but value and storing standby and runtime bit values comprises using a user interface keyboard.
Claim 4
Dependent Claim
18 words
The method according to claim 2 wherein said step of calculating comprises using a linear interpolation/extrapolation approximation algorithm.
Claim 5
Dependent Claim
21 words
The method according to claim 3 wherein said step of storing said target values non-volatile memory is effected using a microprocessor.
Claim 6
Dependent Claim
24 words
The method according to claim 1 including the step of supporting a plurality of thermistors in temperature sensing relationship with said heated fuser member.
Claim 7
Dependent Claim
20 words
The method according to claim 5 wherein said heater structure comprises two heater members controlled using said plurality of thermistors.
Claim 8
Dependent Claim
28 words
The method according to claim 6 wherein said steps of storing said calibration bit values and storing standby and runtime bit values comprises using a user interface keyboard.
Claim 9
Dependent Claim
18 words
The method according to claim 7 wherein said step of calculating comprises using a linear interpolation/extrapolation approximation algorithm.
Claim 10
Dependent Claim
22 words
The method according to claim 8 wherein said step of storing said target values in non-volatile memory is effected using a microprocessor.
Claim 11
Dependent Claim
153 words
Heat and pressure fuser apparatus comprising: a fuser roll; a heating structure disposed internally of said fuser roll for elevating the surface temperature of said fuser roll to a fusing temperature; a pressure roll cooperating with said fuser roll to form a nip through which copy substrates carrying toner images pass with said toner images contacting said fuser roll, said rolls having inboard and outboard ends; a thermistor supported in temperature sensing relationship with said heated fuser member; means for establishing calibration bit values at three different temperatures for said thermistor; means for storing said calibration bit values in non-volatile memory means for storing standby and runtime bit values in non-volatile memory means stored in memory for calculating runtime and standby target values for each of said thermistors; means for storing said target values in non-volatile memory; and means for utilizing said target values for controlling the operating characteristics of said heat structure.
Claim 12
Dependent Claim
153 words
Heat and pressure fuser apparatus comprising: a fuser roll; a heating structure disposed internally of said fuser roll for elevating the surface temperature of said fuser roll to a fusing temperature; a pressure roll cooperating with said fuser roll to form a nip through which copy substrates carrying toner images pass with said toner images contacting said fuser roll, said rolls having inboard and outboard ends; a thermistor supported in temperature sensing relationship with said heated fuser member; means for establishing calibration bit values at three different temperatures for said thermistor; means for storing said calibration bit values in non-volatile memory means for storing standby and runtime bit values in non-volatile memory means stored in memory for calculating runtime and standby target values for each of said thermistors; means for storing said target values in non-volatile memory; and means for utilizing said target values for controlling the operating characteristics of said heat structure.
Claim 13
Dependent Claim
27 words
Apparatus according to claim 10 wherein said means for storing said calibration bit values and storing standby and runtime bit values comprises using a user interface keyboard.
Claim 14
Dependent Claim
17 words
Apparatus according to claim 11 wherein said means stored in memory comprises a linear interpolation/extrapolation approximation algorithm.
Claim 15
Dependent Claim
19 words
Apparatus according to claim 12 wherein said means for storing said target values in non-volatile memory comprises a microprocessor.
Claim 16
Dependent Claim
18 words
Apparatus according to claim 1 including another thermistor supported in temperature sensing relationship with said heated fuser member.
Claim 17
Dependent Claim
17 words
Apparatus according to claim 14 wherein said heating structure comprises two heater members controlled using said thermistors.
Claim 18
Dependent Claim
26 words
Apparatus according to claim 15 wherein said means for storing said calibration bit values and storing standby and runtime bit values comprises a user interface keyboard.
Claim 19
Dependent Claim
17 words
Apparatus according to claim 16 wherein said means stored in memory comprises a linear interpolation/extraporation approximation algorithm.
Claim 20
Dependent Claim
19 words
Apparatus according to claim 17 wherein said means for storing said target values in non-volatile memory comprises a microprocessor.
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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) | 1999-03-05 | 1999-09-04 | 2000-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-05 | 2003-09-04 | 2004-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-05 | 2007-09-04 | 2008-03-05 | $7700.00 | Window Closed / Lapsed |