Fixing device and image forming apparatus
First Claim
1. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
- a heat source;
a heating member heated by said heat source so as to heat said recording medium;
a pressing member disposed in contact with said heating member so as to form a contact portion between said pressing member and said heating member,a cover provided so as to cover said heating member, said cover having an insertion opening through which said recording medium is fed into said cover and an election opening through which said recording medium is fed out of said cover,said cover having a partition wall so that a substantially enclosed space is formed by said partition wall and a surface of said heating member, said partition wall being configured to isolate said substantially enclosed space from said insertion opening and said ejection opening;
a first temperature detecting unit that detects a temperature of said heating member and is remote from said heating member;
a second temperature detecting unit disposed in said substantially enclosed space, said second temperature detecting unit being disposed in the proximity of said first temperature detecting unit and disposed above a portion of the circumferential surface of said heating member in opposition to said contact portion; and
a control unit that controls said heat source according to detected temperatures detected by said first and second temperature detecting units.
1 Assignment
0 Petitions
Accused Products
Abstract
A fixing device includes a non-contacting thermistor (54) disposed in the vicinity of the surface of a heat roller (21) and an upper cover temperature thermistor (60) for detecting the temperature of a pressure roller (22). The calculated surface temperature (T) of the heat roller 21 is calculated based on the detected temperature (T1) detected by the non-contacting thermistor (54), the detected temperature (T2) detected by the upper cover temperature thermistor (60), the distance (L1) from the non-contacting thermistor (54) to the surface of the heat roller (21) and the distance (L2) from the non-contacting thermistor (54) to the upper cover (51).
15 Citations
16 Claims
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1. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
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a heat source; a heating member heated by said heat source so as to heat said recording medium; a pressing member disposed in contact with said heating member so as to form a contact portion between said pressing member and said heating member, a cover provided so as to cover said heating member, said cover having an insertion opening through which said recording medium is fed into said cover and an election opening through which said recording medium is fed out of said cover, said cover having a partition wall so that a substantially enclosed space is formed by said partition wall and a surface of said heating member, said partition wall being configured to isolate said substantially enclosed space from said insertion opening and said ejection opening; a first temperature detecting unit that detects a temperature of said heating member and is remote from said heating member; a second temperature detecting unit disposed in said substantially enclosed space, said second temperature detecting unit being disposed in the proximity of said first temperature detecting unit and disposed above a portion of the circumferential surface of said heating member in opposition to said contact portion; and a control unit that controls said heat source according to detected temperatures detected by said first and second temperature detecting units. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
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a heat source; a heating member heated by said heat source so as to heat said recording medium; a first temperature detecting unit that detects a temperature of said heating member and is remote from said heating member; a second temperature detecting unit disposed in the proximity of said first temperature detecting unit; and a control unit that controls said heat source according to detected temperatures detected by said first and second temperature detecting units, wherein said control unit controls said heating member based on a calculated surface temperature T of said heating member determined by the following equation;
T=T1+(T1−
T2)×
(L1/L2)×
Cwhere T1 indicates a detected temperature detected by said first temperature detecting unit, T2 indicates a detected temperature detected by said second temperature detecting unit, L1 indicates a distance between said heating member and said first temperature detecting unit, L2 indicates a distance between said first and second temperature detecting units in a radial direction of said heating member, and C is a constant.
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11. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
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a heat source; a heating member heated by said heat source so as to heat said recording medium; a pressing member disposed in contact with said heating member so as to form a contact portion between said pressing member and said heating member, a cover provided so as to cover said heating member, said cover having a partition wall so that a substantially enclosed space is formed by said partition wall and a surface of said heating member; a first temperature detecting unit that detects a temperature of said heating member and is remote from said heating member; a second temperature detecting unit disposed in said substantially enclosed space, said second temperature detecting unit being disposed in the proximity of said first temperature detecting unit and disposed above a portion of the circumferential surface of said heating member in opposition to said contact portion; a control unit that controls said heat source according to detected temperatures detected by said first and second temperature detecting units; and an adjusting mechanism for adjusting the distance between a surface of said heating member and said first temperature detecting unit.
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12. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
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a heat source; a heating member heated by said heat source so as to heat said recording medium; a first temperature detecting unit that detects a temperature of said heating member and is remote from said heating member; a second temperature detecting unit disposed in the proximity of said first temperature detecting unit; a cover that supports said heating member or covers said heating member to reduce radiation of heat from said heating member, said second temperature detecting unit detecting a temperature of said cover; and a control unit that controls said heat source according to detected temperatures detected by said first and second temperature detecting units, wherein said first and second temperature detecting units are constituted by a common temperature detecting unit, wherein said fixing device further comprises a moving mechanism that moves said common temperature detecting unit between a first position in the vicinity of a surface of said heating member and a second position in which said common temperature detecting unit contacts said cover, and wherein said common temperature detecting unit acts as said first temperature detecting unit when said common temperature detecting unit is in said first position, and acts as said second temperature detecting unit when said common temperature detecting unit is in said second position.
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13. A fixing device for fixing a developer image to a recording medium, said fixing device comprising:
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a heat source; a heating member heated by said heat source so as to heat said recording medium; a first temperature detecting unit that detects a temperature of said heating member, and is remote from said heating member; a third temperature detecting unit that detects a temperature transmitted from said heating member; and a control unit that compensates a detected temperature detected by said first temperature detecting unit based on a detected temperature detected by said third temperature detecting unit, and controls said heat source based on a compensated detected temperature, wherein said control unit controls said heating member based on a calculated surface temperature T of said heating member based on the following equation;
T=T1+a×
T3+bwhere T1 indicates a detected temperature detected by said first temperature detecting unit, T3 indicates a detected temperature detected by said third temperature detecting unit, and a and b are constants. - View Dependent Claims (14, 15, 16)
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Specification