US 12,405,558 B2
Fixing device provided with heater and image forming apparatus
Kohei Wakatsu, Kanagawa (JP); and Tsuguhiro Yoshida, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on May 2, 2024, as Appl. No. 18/653,877.
Application 18/653,877 is a division of application No. 17/884,480, filed on Aug. 9, 2022, granted, now 12,001,157.
Claims priority of application No. 2021-135856 (JP), filed on Aug. 23, 2021.
Prior Publication US 2024/0288807 A1, Aug. 29, 2024
Int. Cl. G03G 15/20 (2006.01)
CPC G03G 15/2039 (2013.01) 19 Claims
OG exemplary drawing
 
1. An image forming apparatus comprising:
an image forming unit configured to form an unfixed toner image on a recording material; and
a fixing unit for fixing the unfixed toner image on the recording material, wherein the fixing unit comprises:
a first rotatable member;
a heater provided, on a substrate, with a plurality of heat generating members, including a first heat generating member and a second heat generating member of which a length in a longitudinal direction is shorter than a length of the first heat generating member, and
configured to heat the first rotatable member;
a first temperature detecting unit configured to detect a temperature of the heater;
a second rotatable member configured to form a nip portion with the first rotatable member;
a switching unit configured to switch a power supply path from an AC power source to the first heat generating member or the second heat generating member;
a control unit configured to control the switching unit to supply power to the first heat generating member or the second heat generating member,
wherein when the control unit receives a print command to the recording material of which a length in a widthwise direction corresponds to the length of the second heat generating member, the control unit executes a first control in which the switching unit supplies the power only to the first heat generating member until the temperature detected by the first temperature detecting unit reaches a threshold temperature from receiving the print command, and switches a second control in which the switching unit supplies the power alternately to the first heat generating member or the second heat generating member after the temperature detected by the first temperature detecting unit reaches the threshold temperature.