US 12,461,480 B2
Image forming apparatus
Hiroki Hanayama, Kanagawa (JP); and Hiroki Asano, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Aug. 20, 2024, as Appl. No. 18/810,112.
Application 18/810,112 is a division of application No. 17/979,819, filed on Nov. 3, 2022, granted, now 12,092,983.
Claims priority of application No. 2021-187247 (JP), filed on Nov. 17, 2021; and application No. 2021-187248 (JP), filed on Nov. 17, 2021.
Prior Publication US 2024/0411260 A1, Dec. 12, 2024
Int. Cl. G03G 15/08 (2006.01); G03G 15/00 (2006.01)
CPC G03G 15/80 (2013.01) [G03G 15/0808 (2013.01); G03G 15/0812 (2013.01); G03G 15/5004 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An image forming apparatus comprising:
a photosensitive member;
a charging member configured to charge the photosensitive member;
a developing member configured to develop an electrostatic latent image formed on the photosensitive member so as to form a toner image on the photosensitive member;
a contacting member configured to contact the developing member;
a first power source configured to generate a first voltage and to apply the first voltage to the charging member;
a second power source configured to generate a second voltage lower than the first voltage from the first voltage generated by the first power source and to apply the second voltage to the contacting member;
a third power source configured to generate a third voltage lower than the second voltage from the second voltage generated by the second power source and to apply the third voltage to the developing member;
a switch configured to switch between a first state in which a potential difference between the second voltage and the third voltage becomes a first potential difference and a second state in which the potential difference becomes a second potential difference greater than the first potential difference; and
a controller configured to control the switch so as to be in the first state or the second state,
wherein the developing member is capable of moving between a contacting position where the developing member contacts the photosensitive member and a separating position where the developing member is separated from the photosensitive member,
wherein the contacting member contacts the developing member in a contacting state and is separated from the developing member in a separating state,
wherein the controller controls the switch so as to be in the first state when the contacting member is in the separating state and so as to be in the second state when the contacting member is in the contacting state,
wherein the controller controls the third power source by outputting a pulse signal, and
wherein the third voltage is a negative polarity and the controller controls so that an absolute value of the third voltage becomes higher as a low duty ratio of the pulse signal increases.