Patent ID: 6137568
Filing Date: 2000-10-24
Classification: G01C,G02B

Abstract:
An optical axis compensator, comprising a liquid sealing container with a transparent liquid sealed therein so as to form a free liquid surface, an optical axis compensating unit for allowing a light beam to pass through the liquid sealing container at a predetermined angle and for performing optical axis compensation within a range based on changes of an exit optical axis according to angular change of said free liquid surface with respect to an incident optical axis, a tilting mechanism for tilting said optical axis compensating unit, tilt detecting means for detecting tilt of said optical axis compensating unit to the extent that said range of optical axis compensation that said optical axis compensating unit can perform is exceeded, and a control unit for driving said tilting mechanism according to a signal from said tilt detecting means and for tilting said optical axis compensating unit within the broadest range of optical axis compensation.