Multivariate predictive control of fuser temperatures

A method comprising:

• providing a fuser roll having first and second heating elements;
• monitoring a temperature of a first portion of the fuser roll;
• monitoring a temperature of a second portion of the fuser roll which is axially spaced from the first portion;
• supplying a first amount of power to the first heating element, the first amount of power being a function of the monitored temperatures of the first and second portions, the first heating element preferentially heating the first portion;
• and
• supplying a second amount of power to the second heating element, the second amount of power being a function of the monitored temperatures of the first and second portions, the second heating element preferentially heating the second portion.

A fusing apparatus comprising:

• a fuser roll;
• a first heating element which heats a first portion of the fuser roll more than a second portion of the fuser roll;
• a second heating element which heats the second portion of the fuser roll more than the first portion of the fuser roll;
• a first temperature sensor which monitors a temperature of the first portion of the fuser roll;
• a second temperature sensor which monitors a temperature of the second portion of the fuser roll;
• and
• a control system which determines a first amount of power to supply to the first heating element for heating the fuser roll, the first amount of power being a first function of the monitored temperatures of the first and second portions, and determines a second amount of power to supply to the second heating element for heating the fuser roll, the second amount of power being a second function of the monitored temperatures of the first and second portions, wherein the first function weights the monitored temperature of the first portion more than the monitored temperature of the second portion and the second function weights the monitored temperature of the second portion more than the monitored temperature of the first portion.