DYNAMIC-PRESSURE AIR BEARING TYPE POLYGON SCANNER AND ITS PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a dynamic-pressure air bearing type polygon scanner equipped with a ceramic-made rotary sleeve-integrated polygon mirror the flatness of which does not deteriorate even when the temperature of a rotary body varies and which can maintain high-precision mirror surfaces. SOLUTION: The dynamic-pressure air bearing type polygon scanner supports a rotary body having the polygon mirror formed on a metallic outer circumferential member by using a dynamic-pressure air bearing. The polygon mirror is arranged axially overlapping with a ceramic-made rotary sleeve, a through hole which is larger than the diameter of the dynamic-pressure air bearing is formed in the metallic outer circumferential member, and further a shrink- fitting stress removal part is formed between the polygon mirror and ceramic- made rotary sleeve.