Patent ID: 7372546
Filing Date: 2008-05-13
Classification: G02B,G03H

Abstract:
1. An automatic optical axis adjustment system having a function of performing an automatic optical axis adjustment so that when there is a light beam along a reference optical path passing through predetermined incident and outgoing points in an XYZ three-dimensional coordinate system, an outgoing light keeps along said reference optical path even if an incident light runs out of said reference optical path, the system being composed of: an adjustment unit for performing an optical axis adjustment; a detection unit for detecting optical axis displacement; and a control unit for controlling said adjustment unit based on a detection result by said detection unit, said adjustment unit comprising: a first mirror having a reflective surface obtained by rotating a plane parallel to an XY plane around a rotation axis parallel to a Y axis by a predetermined angle of α (0°<α<90°); a second mirror having a reflective surface obtained by rotating a plane parallel to an XZ plane around a rotation axis parallel to an X axis by a predetermined angle of β (0°<β<90°); a support body for supporting said first and second mirrors in predetermined positions so that an incident light is reflected on at least both said mirrors to be output; position adjustment means for moving said first mirror with a parallel displacement in an X or Z axis direction and for moving said second mirror with a parallel displacement in a Y or Z axis direction relative to said support body; and angle adjustment means having a function of performing an inclining operation in a predetermined direction for at least one of either said first or second mirror, said detection unit having a function of detecting an angle and a position of a light beam output from said adjustment unit, and said control unit comprising: storage means for storing an angle and a position detected by said detection unit when an incident light runs along said reference optical path; and control means for controlling said angle adjustment means and said position adjustment means in such a manner, when an angle and a position detected by said detection unit are different from those stored in said storage means, as to eliminate a difference, wherein said detection unit comprises: first beam splitting means for extracting part of a light beam output from the adjustment unit as a detection-use light beam; second beam splitting means for splitting said detection-use light beam into two beams; angle detection means for detecting an angle based on a first split beam; and position detection means for detecting a position based on a second split beam, said angle detection means is composed of: a condenser lens for condensing parallel light beams onto a predetermined focal point; and a light-receiving element having a light-receiving surface arranged apart from said condenser lens by a focal distance thereof to detect a condensing position on said light-receiving surface, and said position detection means is composed of a light-receiving element for detecting a beam receiving position on a predetermined light-receiving surface.