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US5206694A Expired / Lapsed US ⏱️ 0.0 years remaining

Image forming apparatus

Assignee: Minolta Co Ltd
•
Filing: 1989-07-19
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Granted: 1993-04-27
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Expires: 2009-07-19
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Abstract

Abstract An image forming apparatus comprises an image forming portion for forming toner images on a sheet of paper, a fixing portion for fixing the toner images on the sheet of paper by heat, and a counter for counting the number of sheets on which images are fixed from the time of turning on of the power. The image forming portion forms toner images on the paper at a low speed until the counter counts a prescribed number. Since the number of sheets to be fixed is reduced at the start of operation, the temperature of the fixing portion is not very much lowered. Namely, the fixing operation can be started when the temperature of the fixing portion reaches a prescribed value. Therefore, the time required for warming up the image forming forming apparatus can be reduced.

Inventors

  • 👤 Tadashi Ohira
  • 👤 Masazumi Ito

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 06:07
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2064; G03G15/2039

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 185 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed temperature is detected by said sensor; counting means for counting the number of sheets on which the image is fixed by said fixing means after inhibition by said inhibiting means is released; and controlling means for reducing said prescribed image forming speed per unit time period until the value of said counter reaches a prescribed the value.
Claim 2
Dependent Claim 185 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed temperature is detected by said sensor; counting means for counting the number of sheets on which the image is fixed by said fixing means after inhibition by said inhibiting means is released; and controlling means for reducing said prescribed image forming speed per unit time period until the value of said counter reaches a prescribed the value.
Claim 3
Dependent Claim 52 words
An image forming apparatus according to claim 1, further comprising: paper feeding means for feeding said sheet of paper to said fixing means; wherein said paper feeding means feeds a plurality of said sheets of paper at a prescribed interval, and said controlling means changes said prescribed interval of said feeding means.
Claim 4
Dependent Claim 48 words
An image forming apparatus according to claim 1, further comprising: paper feeding means for feeding said sheet of paper to said fixing means; wherein said paper feeding means feeds said paper at a prescribed feeding speed, and said controlling means changes said feeding speed of said feeding means.
Claim 5
Dependent Claim 179 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed temperature is detected by said sensor; counter means for counting a time period after the inhibition by said inhibiting means is released; and controlling means for controlling said image forming means such that said image forming speed per unit time period is reduced until the count value reaches said time period.
Claim 6
Dependent Claim 179 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed temperature is detected by said sensor; counter means for counting a time period after the inhibition by said inhibiting means is released; and controlling means for controlling said image forming means such that said image forming speed per unit time period is reduced until the count value reaches said time period.
Claim 7
Dependent Claim 52 words
An image forming apparatus according to claim 4, further comprising: paper feeding means for feeding said sheet of paper to said fixing means; wherein said paper feeding means feeds a plurality of said sheet of paper by a prescribed interval, and said controlling means changes said prescribed interval of said feeding means.
Claim 8
Dependent Claim 50 words
An image forming apparatus according to claim 4, further comprising: paper feeding means for feeding a sheet of paper to said fixing means; wherein said paper feeding means feeds said sheet of paper at a prescribed feeding speed, and said controlling means changes said feeding speed of said feeding means.
Claim 9
Dependent Claim 174 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after the turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed first temperature is detected by said sensor; and controlling means for controlling said image forming means such that said image forming speed per unit time period is reduced after inhibition by said inhibiting means is released until a second temperature is detected by said sensor.
Claim 10
Dependent Claim 174 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper at a prescribed image forming speed; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller rotatable in contact with said heat roller; driving means for rotating said heat roller and said pressing roller; a sensor for detecting temperature of said heat roller; power switch for supplying power to said image forming means; power supply means for supplying power to said heating means after the turning on of said power switch; inhibiting means for inhibiting operation of said image forming means and of said driving means until a prescribed first temperature is detected by said sensor; and controlling means for controlling said image forming means such that said image forming speed per unit time period is reduced after inhibition by said inhibiting means is released until a second temperature is detected by said sensor.
Claim 11
Dependent Claim 52 words
An image forming apparatus according to claim 7, further comprising: paper feeding means for feeding said sheet of paper to said fixed means; wherein said paper feeding means feeds a plurality of said sheet of paper by a prescribed interval, and said controlling means changes said prescribed interval of said feeding means.
Claim 12
Dependent Claim 69 words
An image forming apparatus according to claim 7, further comprising: paper feeding means for feeding said sheet of paper to said fixing means; wherein said paper feeding means feeds said paper at a prescribed feeding speed, and said controlling means changes said feeding speed of said feeding means, said image forming apparatus further comprising: temperature setting means for making said first prescribed temperature equal to said second prescribed temperature.
Claim 13
Dependent Claim 25 words
An image forming apparatus according to claim 7, further comprising: temperature setting means for making said first prescribed temperature equal to said second prescribed temperature.
Claim 14
Dependent Claim 48 words
An image forming apparatus according to claim 7, further comprising: paper feeding means for feeding said sheet of paper to said fixing means; wherein said paper feeding means feeds said paper at a prescribed feeding speed, and said controlling means changes said feeding speed of said feeding means.
Claim 15
Dependent Claim 208 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; a sensor for detecting temperature of said heat roller; power supply means for supplying power to said heating means; a power switch for supplying power to said image forming means; a print switch for outputting an image formation starting signal; inhibiting means for inhibiting operation of said image forming means after the turning on of said power switch until a detection of a prescribed temperature by said sensor; counting means for counting a prescribed time period in response to the input of the image formation starting signal; and controlling means for operating said driving means in response to the input of said image formation starting signal for the first time after inhibition by said inhibiting means is released and for starting the operation of said image forming means after the prescribed time period has been counted by said counting means.
Claim 16
Dependent Claim 208 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; a sensor for detecting temperature of said heat roller; power supply means for supplying power to said heating means; a power switch for supplying power to said image forming means; a print switch for outputting an image formation starting signal; inhibiting means for inhibiting operation of said image forming means after the turning on of said power switch until a detection of a prescribed temperature by said sensor; counting means for counting a prescribed time period in response to the input of the image formation starting signal; and controlling means for operating said driving means in response to the input of said image formation starting signal for the first time after inhibition by said inhibiting means is released and for starting the operation of said image forming means after the prescribed time period has been counted by said counting means.
Claim 17
Dependent Claim 196 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; a sensor for detecting temperature of said heat roller; power supply means for supplying power to said heating means; a power switch for supplying power to said image forming means; a print switch for outputting an image formation starting signal; inhibiting means for inhibiting operation of said image forming means after said power switch is turned on until a prescribed first temperature is detected by said sensor; and controlling means for driving said driving means in response to the input of said image formation starting signal for the first time after the inhibition by said inhibiting means is released, and for starting the operation of said image forming means when a prescribed second temperature is detected by said sensor after the input of said image formation starting signal.
Claim 18
Dependent Claim 196 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper; said fixing means including a heat roller having heating means for heating said sheet of paper, and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; a sensor for detecting temperature of said heat roller; power supply means for supplying power to said heating means; a power switch for supplying power to said image forming means; a print switch for outputting an image formation starting signal; inhibiting means for inhibiting operation of said image forming means after said power switch is turned on until a prescribed first temperature is detected by said sensor; and controlling means for driving said driving means in response to the input of said image formation starting signal for the first time after the inhibition by said inhibiting means is released, and for starting the operation of said image forming means when a prescribed second temperature is detected by said sensor after the input of said image formation starting signal.
Claim 19
Dependent Claim 25 words
An image forming apparatus according to claim 13, further comprising: temperature setting means for making said first prescribed temperature equal to said second prescribed temperature.
Claim 20
Dependent Claim 164 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a pair of rollers and heating means for heating said rollers; sensing means for sensing temperature of said fixing means; power supply means for supplying power to said heating means; generating means for generating a start signal to start operation of the image forming means; inhibiting means for inhibiting the generation of said start signal until the temperature of the fixing means has risen a prescribed temperature after starting of the power supply; driving means for rotating said rollers in response to said start signal; determining means for determining after the generation of said start signal whether or not the fixing means achieves stable condition by the rotation of said rollers; and control means for starting operation of the image forming means when the fixing means achieves the stable condition.
Claim 21
Dependent Claim 164 words
An image forming apparatus comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a pair of rollers and heating means for heating said rollers; sensing means for sensing temperature of said fixing means; power supply means for supplying power to said heating means; generating means for generating a start signal to start operation of the image forming means; inhibiting means for inhibiting the generation of said start signal until the temperature of the fixing means has risen a prescribed temperature after starting of the power supply; driving means for rotating said rollers in response to said start signal; determining means for determining after the generation of said start signal whether or not the fixing means achieves stable condition by the rotation of said rollers; and control means for starting operation of the image forming means when the fixing means achieves the stable condition.
Claim 22
Dependent Claim 162 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; detecting means for detecting temperature of said heat roller; a print switch for outputting an image formation starting signal to start the operation of said image forming means; control means for operating said driving means and said image forming means when said image formation starting signal is inputted; counting means for counting a prescribed time period in response to the input of image formation starting signal; and inhibiting means for inhibiting operation of said image forming means after turning on of said print switch until said prescribed time has been counted by counting means.
Claim 23
Dependent Claim 162 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; detecting means for detecting temperature of said heat roller; a print switch for outputting an image formation starting signal to start the operation of said image forming means; control means for operating said driving means and said image forming means when said image formation starting signal is inputted; counting means for counting a prescribed time period in response to the input of image formation starting signal; and inhibiting means for inhibiting operation of said image forming means after turning on of said print switch until said prescribed time has been counted by counting means.
Claim 24
Dependent Claim 148 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; detecting means for detecting temperature of said heat roller; a print switch which when turned on outputs an image formation starting signal to start the operation of said image forming means; control means for operating said driving means and said image forming means when said image formation starting signal is inputted; and inhibiting means for inhibiting operation of said image forming means after the turning on of said print switch until a prescribed temperature is detected by said detecting means.
Claim 25
Dependent Claim 148 words
An image forming apparatus, comprising: image forming means for forming a toner image on a sheet of paper; fixing means for fixing said toner image on said sheet of paper, said fixing means including a heat roller having heating means for heating said sheet of paper and a pressing roller provided in contact with said heat roller; driving means for rotating said heat roller and the pressing roller; detecting means for detecting temperature of said heat roller; a print switch which when turned on outputs an image formation starting signal to start the operation of said image forming means; control means for operating said driving means and said image forming means when said image formation starting signal is inputted; and inhibiting means for inhibiting operation of said image forming means after the turning on of said print switch until a prescribed temperature is detected by said detecting means.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-04-26 1996-10-26 1997-04-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-04-26 2000-10-26 2001-04-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-04-26 2004-10-26 2005-04-27 $7700.00 Window Closed / Lapsed

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