Fixing temperature controller for controlling a heater relative to two preset temperature levels
First Claim
1. A fixing temperature controller comprising:
- heater means for heating a fixing unit;
sensing means for sensing a fixing temperature of said fixing unit and for periodically producing temperature data representing a sensed temperature; and
control means for detecting the temperature data produced by said sensing means, said control means including means for enabling said heater means when said control means detects that the sensed fixing temperature has not increased above a first preset temperature level, and means for disabling said heater means when said control means detects that the sensed fixing temperature has increased above the first preset temperature level, said disabling of the heater means by said control means being continued until the sensed fixing temperature has decreased to a second preset temperature level which is lower than said first preset temperature level;
said control means further including;
data generating means for generating first and second reference data respectively representing said first and second preset temperature levels;
selecting means for selecting one of said first and second reference data, said first reference data being selected initially; and
a single comparator for comparing the temperature data produced by said sensing means with the one selected reference data selected by said selecting means, for generating a first-level signal when said temperature data produced by said sending means is less than the one selected reference data, and for generating a second-level signal when said temperature data produced by said sensing means is greater then the one selected reference data.
1 Assignment
0 Petitions
Accused Products
Abstract
A fixing temperature controller comprising a heater for heating a fixing roller, a measuring circuit for detecting the fixing temperature of the fixing roller to produce detected temperature data, a first register for storing reference data for designating a fixing temperature for the fixing roller, a control circuit for comparing the reference data with the detected temperature data from the measuring circuit, and selectively activating the heater based on the comparison result. Particularly, the controller further comprises a second register for storing second reference data lower than the first reference data, and a selector for selecting one of the first and second reference data. The selector selects the first reference data and the control circuit activates the heater when it is detected that the detected temperature data<the reference data, and the selector selects the second reference data and the control circuit deactivates the heater when it is detected that the detected temperature≧the reference data.
22 Citations
21 Claims
-
1. A fixing temperature controller comprising:
-
heater means for heating a fixing unit; sensing means for sensing a fixing temperature of said fixing unit and for periodically producing temperature data representing a sensed temperature; and control means for detecting the temperature data produced by said sensing means, said control means including means for enabling said heater means when said control means detects that the sensed fixing temperature has not increased above a first preset temperature level, and means for disabling said heater means when said control means detects that the sensed fixing temperature has increased above the first preset temperature level, said disabling of the heater means by said control means being continued until the sensed fixing temperature has decreased to a second preset temperature level which is lower than said first preset temperature level; said control means further including; data generating means for generating first and second reference data respectively representing said first and second preset temperature levels; selecting means for selecting one of said first and second reference data, said first reference data being selected initially; and a single comparator for comparing the temperature data produced by said sensing means with the one selected reference data selected by said selecting means, for generating a first-level signal when said temperature data produced by said sending means is less than the one selected reference data, and for generating a second-level signal when said temperature data produced by said sensing means is greater then the one selected reference data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A fixing temperature controller comprising:
-
heater means for heating a fixing unit; sensing means for sensing a fixing temperature of said fixing unit and for periodically producing digital temperature data representing a sensed temperature; and a single comparator for comparing the digital temperature data produced by said sensing means with respective digital reference data representing first and second preset temperature levels, said first preset temperature level being higher than said second present temperature level; and control means for enabling said heater means when said single comparator detects that the sensed fixing temperature has not increased above said first preset temperature level, and for disabling said heater means when said single comparator detects that the sensed fixing temperature has increased above said first preset temperature level, said disabling of said heater means being continued until the sensed fixing temperature has decreased to said second preset temperature level which is lower than said first preset temperature level. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification