Patent attributes
Fusers for fusing toner on media, printing apparatuses, and methods of fusing toner on media in printing apparatuses are disclosed. An exemplary embodiment of the fusers comprises a fuser roll comprising a fusing imaging surface; at least one heating element for heating the fuser roll; a pressure roll including an outer surface, the outer surface and the fusing imaging surface defining a nip; a temperature sensor for sensing a temperature on the fusing imaging surface; a time delay calculator connected to the temperature sensor; a feedback controller connected to the temperature sensor and the heating element, the feedback controller receives a signal from the temperature sensor indicating the temperature on the fusing imaging surface and controls the heating element based on the temperature; and an open-loop controller connected to the heating element and the time delay calculator. The open-loop controller receives a time delay signal from the time delay calculator and bypasses the feedback controller to control the heating element to increase the temperature of the fusing imaging surface starting at about a time, t−Δt (where Δt is a time delay), which is before a medium arrives at the nip, and continuing until about a time, t, at which the medium arrives at the nip and is contacted by the fusing imaging surface. The feedback controller resumes control of the heating element at about the time t.
