Patent ID: 6181891
Filing Date: 2001-01-30
Classification: G03G

Abstract:
An apparatus for fixing a toner image to a sheet, comprising:a fixing roller;a pressing roller held in rolling contact with said fixing roller under a predetermined pressure for pressing a sheet with an unfixed toner image carried on a surface thereof against said fixing roller to fix the unfixed toner image to said sheet when said sheet passes in one direction through a rolling contact region between said fixing roller and said pressing roller;a heating roller disposed on one side of said fixing roller opposite to said pressing roller;a heating source disposed in said heating roller for heating said heating roller;an endless heat transfer belt trained around said heating roller and said fixing roller for transferring heat from said heating source to heat the unfixed toner image on said sheet when said sheet passes through said rolling contact region; anda control device for carrying out a standby mode control process to keep a surface temperature of said heating roller in a predetermined temperature range when the apparatus is in a standby mode, and carrying out a sheet feed mode control process to keep a surface temperature of said fixing roller in a predetermined temperature range when the apparatus is in a sheet feed mode, said control device including a first detecting device for detecting the surface temperature of said heating roller and a second detecting device for detecting the surface temperature of said fixing roller, said control device including a controller for controlling said heating source based on the surface temperature detected by said first detecting device in said standby mode control process, and controlling said heating source based on the surface temperature detected by said second detecting device in said sheet feed mode control process.