In the related art, there are image forming apparatuses that cause a toner image to be fixed on an image formation medium (hereinafter referred to as a “sheet”) using a fixation roller and a pressurization roller that is pressure-contacted with the fixation roller. In this case, a fixation roller and a pressurization roller are rotated with the sheet being squeezed between the fixation roller and the pressurization roller, and thus heat of the fixation roller is transferred to the sheet. With the heating by the fixation roller, the toner image is fixed to the sheet. In this case, the image forming apparatus controls a temperature of the fixation roller, and rotation speeds of the fixation roller and the pressurization roller, in such a manner that the toner image is suitably fixed on the sheet.
On the other hand, for the purpose of saving energy, image forming apparatuses are being developed that transition to an operation mode for low power if a state of the image forming apparatus satisfies a predetermined condition. A state where the image forming apparatus operates in a low power mode is hereinafter referred to as a “sleep state”. However, if the image forming apparatus is in the sleep state for a predetermined time or longer, there is a likelihood that transformation will occur between a pressure contact portion between the pressurization roller and the fixation roller. This is because the pressurization roller that is hardened by the heat of the fixation roller is left unattended (naturally cooled) and thus is hardened in a state of being pressure-contacted with the fixation roller. This transformation is generally referred to as a creep, and is known to be a cause of the occurrence of various defects in the image forming apparatus and printed sheets produced by the image forming apparatus.
In the related art, although research is conducted on the technology of reducing the number of defects that occur due to this creep, suppression of strange sounds of a drive unit, which occur when the fixation roller is rotated have not yet been achieved.
USPTO Backgrounds
USPTO Backgrounds