Image heating device including a controller that executes first and second heat controls based on temperatures detected by first and second detecting elements

Patent metadata

Field	Value
Publication number	US-10429776-B2
Application number	US-201816040839-A
Country	US
Kind code	B2
Filing date	Jul 20, 2018
Priority date	Jan 5, 2016
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A controller of an image heating apparatus executes a first heater control operation, when a sheet having a width such that the sheet passes both a position of a first temperature detector and a position of a second temperature detector, is heated in a nip, for controlling power supply to a heater so that a temperature detected by the second temperature detector is maintained at a heater target temperature, and a second heater control operation, when a sheet having a width such that the sheet passes through the position of the first temperature detector, but does not pass through the position of the second temperature detector, is heated in the nip, for controlling the power supply to the heater, so that the temperature detected by the first temperature detector, irrespective of the temperature detected by the second temperature detector, is maintained at a film target temperature.

First claim

What is claimed is:

1. An image heating apparatus for heating an image on a recording material, said image heating apparatus comprising:
(A) a cylindrical film;
(B) a heater contacting an inner surface of said film;
(C) a roller cooperative with said heater to form a nip with said film;
(D) a first temperature detecting element configured to detect a temperature of said film, said first temperature detecting element being provided in a position in an area of said film that is passed by a minimum width recording material that is capable of being fed by said apparatus;
(E) a second temperature detecting element configured to detect a temperature of said heater, said second temperature detecting element being provided in a position, with respect to a longitudinal direction of said heater that is perpendicular to a feeding direction of the recording material, relative to said heater (i) that is outside of an area of said heater, in the longitudinal direction of said heater, that is passed by the minimum width recording material, and (ii) that is within an area of said heater that is passed by a maximum width recording material that is capable of being fed by said apparatus;
(F) a third temperature detecting element configured to detect a temperature of said heater, said third temperature detecting element being provided in a position that is outside of the position of said second temperature detecting element with respect to a center of said heater in the longitudinal direction of said heater; and
(G) a controller configured to control power supply to said heater based on a temperature of said film detected by said first temperature detecting element, a temperature of said heater detected by said second temperature detecting element, and a temperature of said heater detected by said third temperature detecting element, and configured to execute:
(a) a first heater control operation, when a recording material having a width such that the recording material passes both the position of said first temperature detecting element and the position of said second temperature detecting element, is heated in the nip, for controlling power supply to said heater so that the temperature detected by said second temperature detecting element is maintained at a heater target temperature, wherein, when the first heater control operation is executed, said controller corrects the target temperature of said heater based on the temperature detected by said first temperature detecting element; and
(b) a second heater control operation, when a recording material having a width such that the recording material passes through the position of said first temperature detecting element, but does not pass through the position of said second temperature detecting element, is heated in the nip, for controlling the power supply to said heater, so that the temperature detected by said first temperature detecting element, irrespective of the temperature detected by said second temperature detecting element, is maintained at a film target temperature, while monitoring the temperature of the heater based on the temperature of the heater detected by said third temperature detecting element,
wherein, when the second heater control operation is executed, a feeding speed of the recording material in the nip is less than that when the first heater control operation is executed, and

wherein said apparatus heats the recording material carrying the image while the recording material passes through the nip.

2. The image heating apparatus according to claim 1 , wherein, in the first heater control operation, when the temperature detected by said first temperature detecting element is less than the film target temperature by a predetermined temperature amount, said controller increases the heater target temperature.

3. The image heating apparatus according to claim 1 , wherein, in the area of said heater that is passed by the minimum width recording material, said first temperature detecting element and said second temperature detecting element are not provided.

Assignees

• Canon Kk

Inventors

• Hashiguchi Shinji
• Hirota Yusuke

Classifications

• G03G15/2039 Primary

  with means for controlling the fixing temperature · CPC title

• G03G2215/2035

  the fixing nip having a stationary belt support member opposing a pressure member · CPC title

• G03G15/2042 Primary

  specially for the axial heat partition · CPC title