| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fixing device capable of stabilizing a fixing performance by accurately detecting the changes of nip width due to the thermal expansion of an elastic layer of a fixing roller to adjust the nip width, an image forming device, and a controlling method of the fixing device. <P>SOLUTION: When the nip width changes due to the thermal expansion of an elastic layer 15b of a fixing roller 15 during printing, the fixing roller 15 changes a position to a second position, and a fixing roller position change detecting sensor 19 is switched on. A control portion 20 controls the action of a pressurizing roller moving mechanism 18 to move a pressurizing roller 17 in a direction separating from the fixing roller 15, when the fixing roller position change detecting sensor 19 is switched on during printing. Therefore, even if the nip width changes due to the thermal expansion of the elastic layer 15b of the fixing roller 15 during printing, the changes of the nip width can be accurately detected to adjust the nip width to be a proper value, and the fixing performance can be stabilized. <P>COPYRIGHT: (C)2012,JPO&INPIT |
