Reduction of aero-acoustic noise originating from a high-speed polygon mirror scanner motor in a laser beam printer utilizing air-flow analysis

This research investigates the aero-acoustic noise originating from a high-speed polygon mirror of a laser beam printer by identifying its source and propagation numerically and experimentally. It calculates the air flow around the polygon mirror scanner motor of a laser printer operating at high speed. Simulated velocity of air flow around the polygon mirror is compared with the experimental velocity measured using a hot-wire anemometer. The frequency spectrum of the air flow around the polygon mirror matches that of the aero-acoustic noise. A significant number of discrete peaks and a broadband of aero-acoustic noise originate from the turbulent air flow around the polygon mirror. We propose the use of a cylindrical block to reduce turbulent air flow around the polygon mirror. The proposed design reduces not only the turbulent air flow but also the discrete peaks and the broadband of aero-acoustic noise.