US 11,809,106 B2
Image forming apparatus
Sadaharu Kato, Kariya (JP); Shuhei Fukue, Nagoya (JP); Hirotaka Imaeda, Nagoya (JP); Shunsuke Ueki, Nagoya (JP); and Yusuke Mizuno, Nagoya (JP)
Assigned to BROTHER KOGYO KABUSHIKI KAISHA, Nagoya (JP)
Filed by BROTHER KOGYO KABUSHIKI KAISHA, Nagoya (JP)
Filed on Jun. 15, 2022, as Appl. No. 17/807,023.
Claims priority of application No. 2021-100650 (JP), filed on Jun. 17, 2021.
Prior Publication US 2022/0404745 A1, Dec. 22, 2022
Int. Cl. G03G 15/20 (2006.01)
CPC G03G 15/2039 (2013.01) [G03G 15/2017 (2013.01); G03G 15/2064 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An image forming apparatus, comprising:
a first fixing member including a roller that receives a driving force from a motor;
a second fixing member including a belt configured to form a nip in combination with the first fixing member;
a heater configured to heat the first fixing member;
a pressure control mechanism configured to be capable of changing a nip pressure exerted at the nip formed between the first fixing member and the second fixing member, to a first nip pressure and to a second nip pressure, the first nip pressure and the second nip pressure being exerted at the nip when the first fixing member is in contact with the second fixing member, and the second nip pressure being smaller than the first nip pressure; and
a controller configured to cause the first fixing member to heat up to a standby temperature lower than a fixing temperature, through a control process executed from a state in which rotation of the first fixing member is stopped and the nip pressure is set at the second nip pressure, the control process comprising:
a first process of activating and controlling the heater to cause the first fixing member to heat up toward a target temperature;
a second process of activating the motor, with the nip pressure at the second nip pressure, to start the rotation of the first fixing member and cause the second fixing member to rotate by friction with the first fixing member;
a third process of changing the nip pressure from the second nip pressure to the first nip pressure;
a fourth process of changing the nip pressure from the first nip pressure to the second nip pressure; and
a fifth process of stopping the rotation of the first fixing member,
wherein the first, second, third, fourth and fifth processes are executed in this sequence, and
wherein the controller does not cause a sheet to be supplied between the first fixing member and the second fixing member while the first, second, third, fourth and fifth processes are being performed.