DYNAMIC PRESSURE BEARING, OPTICAL SCANNING DEVICE AND TEST EVALUATING DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve impact resistance by preventing the occurrence of seizure of a bearing when an impact is exerted during rotation of a dynamic pressure bearing and prevent the occurrence of a linking phenomenon in high temperature high humidity environment. ;SOLUTION: An optical scanning device is provided with a dynamic pressure bearing formed such that a rotary bearing surface on which a light deflecting system is disposed and which is rotationally driven by a drive motor and a fixed bearing surface disposed on a fixed shaft are positioned facing each other. Surface coarseness of the rotary bearing surface and surface coarseness of the fixed bearing surface are decided in a manner to correspond to coarseness within a region 17 formed between an upper limit wherein impact resisting performance in an XY coordinate having surface coarseness of the rotary bearing surface forming an X-axis and the surface coarseness of the fixed bearing surface forming Y-axis exceeds a specified value and a lower limit wherein environment performance exceeds a specified value.;COPYRIGHT: (C)2001,JPO