Patent ID: 6188424
Filing Date: 2001-02-13
Classification: B41J,G02B

Abstract:
A light beam scanning apparatus comprising:means for generating a light beam;means for reflecting said light beam to a scanning surface and making said light beam to scan said scanning surface in the main scanning direction;means for shifting said light beam in a sub-scanning direction when said light beam is made to scan by said means for reflecting;means for sensing a passing position in the sub-scanning direction of said light beam made by said means for reflecting;means for controlling said means for shifting on the basis of a result of sensing at said means for sensing so that the passing position of said light beam on said scanning surface may be within a target range;means for, after said means for controlling has brought the passing position of the light beam on said scanning surface into the target range, measuring the passing position of said light beam scanning said scanning surface a specific number of times using said means for sensing and judging whether all of said passing positions lie in said target range; andmeans for making said means for controlling to execute passing position control of the light beam again when the result of measuring said light beam passing position said specific number of times includes a value outside said target range.