Control of thermal heating in a belt fuser

A method for fixing images on narrow gauge recording media using an image-fixing apparatus comprising a heater which is stationary in use;

• a film slideable on said heater;
• and a backup member which cooperates with said heater to form a nip, with said film being interposed between said backup member and said heater, wherein an image carried on a recording medium is heated through said film while in the nip by heat from said heater;
• comprising the following steps;
• determining whether the recording medium being fed into the fixing apparatus is of narrow gauge;
• deactivating said heater when a recording medium of narrow gauge has exited the nip;
• measuring the temperature of the heater, when said heater is deactivated, at predetermined intervals;
• determining the amount of time required for the heater to reach its operational temperature from its measured temperature (ramp time);
• determining, at predetermined intervals, the amount of time it will take the next recording medium to enter the nip (transit time);
• activating said heater when the ramp time is greater than or equal to its corresponding transit time;
• and
• repeating the process for each narrow gauge recording medium to be fed into the image-fixing apparatus.

A method for fixing images on narrow gauge recording media using an image-fixing apparatus comprising a heater which is stationary in use;

• a film, slideable on said heater;
• and a back-up member which cooperates with said heater to form a nip, with said film being interposed between said back-up member and said heater, wherein an image carried on a recording medium is heated through said film while in the nip by heat from said heater;
• comprising the following steps:
• determining whether the recording medium being fed into the fixing apparatus is of narrow gauge;
• deactivating said heater when a recording medium of narrow gauge has exited the nip;
• and
• reactivating said heater prior to the next recording medium entering the nip.