Patent ID: 9678460
Date: 2017-06-13
CPC Classifications: G03G

Claim:
1. A fixing device comprising: a fixing rotator rotatable in a predetermined direction of rotation; a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, the fixing nip through which a recording medium bearing a toner image is conveyed; a primary heater disposed opposite a primary heating span of the fixing rotator to heat the primary heating span of the fixing rotator; a secondary heater disposed opposite a secondary heating span of the fixing rotator to heat the secondary heating span of the fixing rotator, the secondary heating span being outboard from the primary heating span in an axial direction of the fixing rotator; a tertiary heater disposed opposite a tertiary heating span of the fixing rotator to heat the tertiary heating span of the fixing rotator, the tertiary heating span being outboard from the secondary heating span in the axial direction of the fixing rotator; a primary temperature detector disposed opposite the primary heating span of the fixing rotator to detect a temperature of the primary heating span of the fixing rotator; a secondary temperature detector disposed opposite the secondary heating span of the fixing rotator to detect a temperature of the secondary heating span of the fixing rotator; a tertiary temperature detector disposed opposite a tertiary heating span of the pressure rotator which corresponds to the tertiary heating span of the fixing rotator, the tertiary temperature detector to detect a temperature of the tertiary heating span of the pressure rotator; and a controller to selectively perform a primary control mode to de-energize the tertiary heater and a secondary control mode to connect the secondary heater and the tertiary heater in series to energize the primary heater, the secondary heater, and the tertiary heater, the controller to energize the secondary heater and the tertiary heater in the secondary control mode based on the temperature of the fixing rotator and the pressure rotator detected by the secondary temperature detector and the tertiary temperature detector, respectively.