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US5225874A Expired / Lapsed US ⏱️ 0.0 years remaining

Image fixing apparatus having a pulsewisely energized heater

Assignee: Canon Inc
•
Filing: 1989-11-24
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Granted: 1993-07-06
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Expires: 2009-11-24
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Abstract

Abstract An image fixing apparatus including a heater having a linear heat generating layer; a film movable together with a recording medium carrying thereon a toner image which is heated by heat generated by the heat generating layer through the film; energizing device for pulsewisely energizing the heat generating layer and for controlling a pulse width of the pulsewise energization in accordance with a voltage level of power supplied thereto.

Inventors

  • 👤 Shokyo Koh
  • 👤 Yoshihiko Suzuki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 06:33
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039

Claims Analysis

Total Claims: 40
Claim 1
Independent Claim 56 words
An image forming apparatus comrsing: a fixign heater; a power soruce; power supply mens for supplying electric power in theform of pulses from siad power source to said fixing heater, said power supply means controlling a width of the pulses in acordance with a voltage thereof; and limiting means for limiting the width of the pulses.
Claim 2
Dependent Claim 56 words
An image forming apparatus comrsing: a fixign heater; a power soruce; power supply mens for supplying electric power in theform of pulses from siad power source to said fixing heater, said power supply means controlling a width of the pulses in acordance with a voltage thereof; and limiting means for limiting the width of the pulses.
Claim 3
Dependent Claim 33 words
An apparatus according to claim 1, further comprising a film movable together with a recording medium carrying thereon a toner image which is heated by heat generated by siad heater through siad fiml.
Claim 4
Dependent Claim 23 words
An apparatus acocridng to claim 2, further comprsing pressing means for imparting urging force among siad heater, siad film and the recording mateial.
Claim 5
Dependent Claim 25 words
An apparatus according to claim 3, wherein during a fixing operation, there is no air layer between said heat generating layer and the toner image.
Claim 6
Dependent Claim 24 words
An apparatus according to claim 2, wherein said heater comrpises a linear heat generating layer for generating heat upon the supply of power thereto.
Claim 7
Dependent Claim 25 words
An apparatus according to claim 5, wherein siad heat genrating layer extends in a direction substnatilly pependicuarl to a movemnet dierction of said recording mateiral.
Claim 8
Dependent Claim 22 words
An apparatus acocrding to claim 5, wherein siad heater is fixed during its fixing operation, and siad film slides on siad heater.
Claim 9
Dependent Claim 47 words
An apparatus according to claim 1, wherein siad supply means supplies the power to siad heat generating layer on the form of pulses, and a width of the pulse is determined by a resistor, a capacitor and a refernece voltage source in accordance with a pulse signal.
Claim 10
Dependent Claim 52 words
An apparatus according to claim 1, wherein siad supply measn supplies the power to said heat gneerting layer in the form of pulses, and said suply means controls a pulse width so as to make the power supplied to siad heat generating layer substnaially constant irrespective of the voltage level supplied thereto.
Claim 11
Dependent Claim 94 words
An image fixing apparatus, comrising: a heater having a linear heat generating layer; a film movabel together with arecording material carrying thereon a toner image which is heated by heat generated by said heat genrating layer through siad fim; energizing menas for pulsewisely energizing said heat generating layer wherin said enrgizing means supplies power to said heat genrgin alyer in the form of pulses having the same pulse width irrespective of a temperature of said heater during energization by siad energizing means; and adjusting means for adjusting a pulse width of the pulsewise energization.
Claim 12
Dependent Claim 94 words
An image fixing apparatus, comrising: a heater having a linear heat generating layer; a film movabel together with arecording material carrying thereon a toner image which is heated by heat generated by said heat genrating layer through siad fim; energizing menas for pulsewisely energizing said heat generating layer wherin said enrgizing means supplies power to said heat genrgin alyer in the form of pulses having the same pulse width irrespective of a temperature of said heater during energization by siad energizing means; and adjusting means for adjusting a pulse width of the pulsewise energization.
Claim 13
Dependent Claim 23 words
An apparatus according to claim 10, wherein said pulse width is adjusted in accordance with a resistance level of said heat generating layer.
Claim 14
Dependent Claim 23 words
An apparatus according to claim 10, further comprising pressing means for imparting urging force among said heater, said film and the recording material.
Claim 15
Dependent Claim 25 words
An apparatus according to claim 12, wherein during a fixing operation, there is no air layer between said heat generating layer and the toner image.
Claim 16
Dependent Claim 25 words
An apparatus according to claim 10, wherein said heat generating layer extends in a direction substantially perpendicular to a movement direction of said recording material.
Claim 17
Dependent Claim 22 words
An apparatus according to claim 10, wherein said heater is fixed during its fixing operation, and said film slides on said heater.
Claim 18
Dependent Claim 32 words
An apparatus according to claim 10, wherein siad adjusting measn includes a variable resistor, and wherein the pulse width of the energization is adjustd by changing the resistance of the variable resitro.
Claim 19
Dependent Claim 111 words
An image fixing apapraus, comrsing: a heater having a linear heat genrating layer; a film movable together with a recording material carrying thereon a toner image which is heated by heat genrated by siad hat generign layer thorugh siad film; energizing means for pulsewisely energizing siad heat genrgin layer; temperature detecting measn for detecting a temperaure of siad heater; wherein siad energizing menas controls a period of the eenergization pulse in accordance with an output of siad temperture detedting measn and wherien a conveying speed Vp of the recordnig mateial, a width of siad heat generaigngg layer d and energiztion period Tmax in which a minimum energy is supplied, satisfy: Vp×Tmax≦d.
Claim 20
Dependent Claim 111 words
An image fixing apapraus, comrsing: a heater having a linear heat genrating layer; a film movable together with a recording material carrying thereon a toner image which is heated by heat genrated by siad hat generign layer thorugh siad film; energizing means for pulsewisely energizing siad heat genrgin layer; temperature detecting measn for detecting a temperaure of siad heater; wherein siad energizing menas controls a period of the eenergization pulse in accordance with an output of siad temperture detedting measn and wherien a conveying speed Vp of the recordnig mateial, a width of siad heat generaigngg layer d and energiztion period Tmax in which a minimum energy is supplied, satisfy: Vp×Tmax≦d.
Claim 21
Dependent Claim 24 words
An apparatus according to claim 17, wheein further comirsing pressing measn for imparing urging force among siad heaer, siad film and the recording material.
Claim 22
Dependent Claim 25 words
An apparatus according to claim 18, wherein during a fixing operation, there is no air layer between said heat generating layer and the toner image.
Claim 23
Dependent Claim 25 words
An apparatus according to claim 17, wherein said heat generating layer extends in a direction substantially perpendicular to a movement direction of said recording material.
Claim 24
Dependent Claim 22 words
An apparatus according to claim 17, wherein said heater is fixed during its fixing operation, and said film slides on said heater.
Claim 25
Dependent Claim 17 words
An apparatus according to claim 17, wherein said energizing means controls a width of the pulsewise energization.
Claim 26
Dependent Claim 24 words
An apparatus according to claim 22, wherein the width of the pulsewise energization is controlled in accordance with variation of a voltage supplied thereto.
Claim 27
Dependent Claim 72 words
An image fixing apparatus, comprising: a fixing heater; power supply menas for supplying power to said fixin heater; conrol menas for controlling the duty ratio of the power to said fixing heater by siad power supply means; and shutting measn for shutting off the power supply to siad heater by siad power suppyl means, wherein said shutting means shuts off the power supply to siad heater in accordane with the duty ratio.
Claim 28
Dependent Claim 72 words
An image fixing apparatus, comprising: a fixing heater; power supply menas for supplying power to said fixin heater; conrol menas for controlling the duty ratio of the power to said fixing heater by siad power supply means; and shutting measn for shutting off the power supply to siad heater by siad power suppyl means, wherein said shutting means shuts off the power supply to siad heater in accordane with the duty ratio.
Claim 29
Dependent Claim 27 words
An apparatus according to claim 24, wherein siad supply means supplies the power in the form of pulses, and said control measn controls width of the pulses.
Claim 30
Dependent Claim 35 words
An apparatus according to claim 25, further comrising temerpaue detecting means for detecting a temeprature of siad heaer, and the energization pulse time is changed in accordance with an output of siad temperature detecting means.
Claim 31
Dependent Claim 22 words
An apparatus according to claim 25, wherein siad shutting measn shuts the energization when the pulse energization time exceeds a predetermined level.
Claim 32
Dependent Claim 34 words
An apparatus according to claim 24, wherein siasd shutting measn is disposed in a power supply passage by siad energizing means to siad heater, and it shuts the power supply by opening the passage.
Claim 33
Dependent Claim 33 words
An apparatus according to claim 24, further comprising af ilm movable together with a reording medium carrying thereon a toner image which is heated by heat generated by siad heater through siad film.
Claim 34
Dependent Claim 15 words
An apparatus according to claim 29, wherein said heater includes a ilnear heat generating layer.
Claim 35
Dependent Claim 24 words
An apparatus according to claim 30, whrein further comirsing pressing measn for imparting urging force among siad heater, siad film and the recording material.
Claim 36
Dependent Claim 25 words
An apparatus according to claim 30, wherin siad heat genrign layer extends in a direction substatially perpendicualr to a movement dierction of isad reording mateiral.
Claim 37
Dependent Claim 22 words
An apparatus according to claim 30, wherein said heater is fixed uring its fixing operation, and siad film slides on siad heater.
Claim 38
Dependent Claim 25 words
An apparatus according to claim 29, wherein during a fixing operation, there is no air layer between siad heat generagtng layer and the toner image.
Claim 39
Dependent Claim 24 words
An apparatus according to claim 24, wherein siad shutting means includes a fuse which blows out when a curent therethrough exceeds a predetemrined level.
Claim 40
Dependent Claim 21 words
An apparatus according to claim 24, wherein said shutting means shuts the energization when the duty ratio exceeds a predetermined level.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-07-05 1997-01-04 1997-07-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-07-05 2001-01-04 2001-07-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-07-05 2005-01-04 2005-07-06 $7700.00 Window Closed / Lapsed

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