Patent ID: 8417139
Filing Date: 2013-04-09
Classification: G03G

Abstract:
1. A fixing device comprising: a fixing member including a cylindrical core pipe and an elastic layer covering an outer surface of the cylindrical core pipe, the fixing member being rotatably provided around an axis extending in which the cylindrical core pipe extends; a pressure member which pressures the fixing member; an internal heating section, provided inside the fixing member, for heating the fixing member from within; an external heating section, provided so as to face an outer surface of the fixing member, for heating the outer surface of the fixing member; a first temperature sensing section for detecting a temperature of a contact surface of the fixing member, the contact surface making contact with the pressure member; a second temperature sensing section for detecting a temperature of a facing surface of the external heating section, the facing surface facing the fixing member; and a control section for controlling the internal heating section and the external heating section in accordance with results detected by the respective first and second temperature sensing sections, said fixing device causing a recording material, inserted between the fixing member and the pressure member, to be carried while the recording material is being sandwiched so that an unfixed image on the recording material is fixed onto the recording material, said control section having (i) a warm-up mode in which a surface of the fixing member is heated up to a predetermined warm-up completion temperature, (ii) a standby mode in which the surface of the fixing member is maintained within a predetermined standby temperature range, during a time period in which no fixing process is carried out and after the warm-up mode is completed, and (iii) a fixing process mode in which a fixing process is carried out with respect to the recording material, and, said control section changing, in accordance with a time period between an end of the warm-up mode and a start of the fixing process mode, at least one of (i) a set fixing temperature which is a set temperature of the contact surface of the fixing member in a fixing process and (ii) a set external heating temperature which is a set temperature of the facing surface of the external heating section in a fixing process, in a case where a fixing process is carried out, in the fixing process mode, with respect to a predetermined type of recording material for which the set fixing temperature needs to be set higher, by a predetermined temperature or more, than the warm-up completion temperature.