Patent ID: 8041237
Filing Date: 2011-10-18
Classification: G03G

Abstract:
1. A fixing apparatus that causes a recording material to pass through a nip portion formed by a rotating hot roller and a rotating pressure roller being in contact so as to perform a fixing operation to fix an unfixed image on the recording material, the fixing apparatus comprising: a pressing portion for applying bias to the pressure roller toward the hot roller so as to create a pressure applied state by pressing the pressure roller against the hot roller, a switching portion, including a turnable cam, for switching to a pressure released state in which a pressing force applied by the pressure roller toward the hot roller is reduced by turning the cam in a forward rotational direction with respect to the pressing portion that is in the pressure applied state so that the pressure roller applies pressure to the pressing portion in a direction opposite to a direction in which the bias is applied to the pressure roller so as to press the pressing portion back, and switching to the pressure applied state by turning the cam in a backward rotational direction with respect to the pressing portion that is in the pressure released state so as to release the pressure to the pressing portion; a pressure state detection portion for detecting the pressure applied state and the pressure released state; and a control portion for controlling processing for, wherein, when shifting from the pressure applied state to the pressure released state, where the cam is turned in the forward rotational direction with respect to the switching portion that is in the pressure applied state for a first predetermined time period, but the pressure state detection portion does not detect the pressure released state, the control portion performs forward rotational direction retry control according to which the cam is again turned in the forward rotational direction after the cam is turned in the backward rotational direction for a second predetermined time period.