Image heating apparatus

• US 6,173,131 B1
• Filed: 12/18/1997
• Issued: 01/09/2001
• Est. Priority Date: 12/19/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Noguchi, Junichi, Watanabe, Nobuyuki, Kitamura, Shingo
• Primary Examiner(s): Royer, William J.
• Application Number:
  US08/993,157
• Time in Patent Office: 1,118 Days
• Field of Search: 399/33, 399/69, 399/70, 399/328, 399/330, 399/335, 219/216, 219/469, 219/470, 219/471, 323/369, 374/153, 374/183, 374/185
• US Class Current: 399/33
• CPC Class Codes: G03G 15/2003 using heat
• CPC Class Codes: G03G 15/2039 with means for controlling the fixing temperature

Abstract

An image heating apparatus includes a heating member for heating an image on a recording material, a first temperature detecting element for detecting a first temperature of the heating member, a second temperature detecting element for detecting the second temperature of the heating member, wherein a thermal property of the second temperature detecting element differs from a thermal property of the first temperature detecting element, and a power supply controller for controlling the power supply to the heating member by utilizing the first temperature detecting element and the second temperature detecting element.

Claims

1. An image heating apparatus comprising:

a heating member for heating an image on a recording material;

a first temperature detecting element for detecting a temperature of said heating member;

a second temperature detecting element for detecting the temperature of said heating member, a thermal property of said second temperature detecting element differing from a thermal property of said first temperature detecting element; and

a power supply control means for controlling an electrical power supplied to said heating member by utilizing said first temperature detecting element and said second temperature detecting element;

wherein, when the temperature of said heating member is lower than a predetermined reference temperature, said power supply control means controls the electrical power in accordance with the temperature detected by said first temperature detecting element, and when the temperature of said heating member is not less than the reference temperature, said power supply control means controls the electrical power is accordance with the temperature detected by said second temperature detecting element.

2. An image heating apparatus comprising:

a heating member for heating an image on a recording material;

a first temperature detecting element for detecting a temperature of said heating member;

a second temperature detecting element for detecting the temperature of said heating member, a thermal property of said second temperature detecting element differing from a thermal property of said first temperature detecting element;

a power supply control means for controlling an electrical power supplied to said heating member by utilizing said first temperature detecting element and said second temperature detecting element;

an abnormality detecting means for detecting an abnormality of said apparatus; and

wherein said abnormality detecting means judges that said apparatus is abnormal if, while the electrical power is supplied to the heating member, a rate of temperature change of said heating member is smaller than a predetermined rate.

3. An image heating apparatus, comprising:

a heating member for heating an image on a recording material;

a temperature detecting element for detecting a temperature of said heating member;

power supply control means for controlling an electrical power supplied to said heating member in accordance with the temperature detected by said temperature detecting element;

plural resistances connected to said temperature detecting element;

resistance value switching means for switching a resultant resistance value of said plural resistances in accordance with the temperature of said heating member.

4. An image heating apparatus according to claim 3, wherein said resistance value switching means sets the resultant resistance value high when the temperature of said heating member is low and sets the resultant resistance value low when the temperature of said heating member is high.