US 12,306,564 B2
Power source device and image forming apparatus
Mitsunori Oshima, Shizuoka (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Oct. 18, 2023, as Appl. No. 18/489,318.
Claims priority of application No. 2022-187723 (JP), filed on Nov. 24, 2022.
Prior Publication US 2024/0176272 A1, May 30, 2024
Int. Cl. G03G 15/00 (2006.01); G03G 15/20 (2006.01); H02M 1/36 (2007.01); H02M 7/217 (2006.01)
CPC G03G 15/5004 (2013.01) [G03G 15/205 (2013.01); H02M 1/36 (2013.01); H02M 7/217 (2013.01)] 19 Claims
OG exemplary drawing
 
7. An image forming apparatus comprising:
an image forming portion configured to form a toner image on a recording material;
a fixing portion including a heating member and configured to fix the toner image formed by the image forming portion; and
a power source portion including:
a rectifying portion configured to fully rectify an AC voltage,
a switching portion including a switching element and configured to apply a voltage fully rectified by the rectifying portion, by a switching operation of the switching element to the heating member,
a detecting portion configured to detect a zero-cross point of the AC voltage,
a control portion configured to control the switching operation of the switching portion, and
a filter portion including a capacitor, provided between the rectifying portion and the switching portion and configured to absorb a switching noise generated in the switching portion,
wherein the control portion is configured to control the switching portion so as to execute a discharge operation to discharge the capacitor before starting the switching operation from a stop state of the switching operation and so as to start the switching operation when the zero-cross point is detected by the detecting portion, and
wherein an electric power output from the switching portion during the discharge operation is smaller than an electric power output from the switching portion during the switching operation.