FIXING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a fixing device where the surface temperature of a roller can be accurately detected while restraining a charge in constitution where the press-contact force of one roller with the other roller is switched by displacing either roller positionally and the surface temperature of the displaced roller is detected by using a non-contact type sensor. SOLUTION: The fixing device is constituted so that a fixing roller 31 can move and rotate from a 1st position (solid line) to a 2nd position (broken line) and from the 2nd position to the 1st position so as to draw a circular arc with a point 73 as center, whereby the press-contact force of the fixing roller 31 with a pressure roller not illustrated is switched. A thermopile 33 for detecting the surface temperature of the fixing roller 31 is constituted so that its detection part (element) 331 may be arranged on a line 82 orthogonal to a plane 81 (which looks like a line because of a front view) including a rotary shaft 71 obtained when the fixing roller 31 exists at the 1st position and a rotary shaft 72 obtained when the fixing roller 31 exists at the 2nd position, and positioned at a nearly equal distance L from both the rotary shafts 71 and 72. COPYRIGHT: (C)2006,JPO&NCIPI