Analysis of the Frictional Vibration of a Cleaning Blade in Laser Printers Based on a Two-Degree-Of-Freedom Model

This research aims to analyze the dynamics of the self-excited vibration of a cleaning blade in a laser printer. First, it is experimentally indicated that that the self-excited vibration is not caused by the negative damping effect based on friction. Next, the excitation mechanism and dynamics of the vibration are theoretically clarified using an essential 2DOF link model, with emphasis placed on the contact between the blade and the photoreceptor. By solving the equations governing the motion of the analytical model, five patterns of static equilibrium states are obtained, and the effect of friction on the static states is discussed. It is shown that one of five patterns corresponds to the shape of the practical cleaning blade, and it is clarified through linear stability analysis that this state becomes dynamically unstable, due to both effects of friction and mode coupling. Furthermore, the amplitude of the vibration in the unstable region is determined through nonlinear analysis. The obtained results show that this unstable vibration is a bifurcation classified as a supercritical Hamiltonian-Hopf bifurcation, and confirms the occurrence of mode-coupled self-excited vibration on a cleaning blade when a constant frictional coefficient is assumed.