| 摘要 |
PURPOSE: To accurately focus at the position of an object by guiding one optical beam via another objective lens in each direction, and optimally regulating the whole optical system at each individual beam. CONSTITUTION: The optical beams 12, 13 from semiconductor lasers 10, 11 are periodically deflected by the rotation of an octahedral mirror 15, and passed via a measuring field. The size of an object 3 can be estimated in two directions X, Y from the continuous time when the beam is shut off by the object 3 in the two directions X, Y. To separately guide the beams 12, 13 of one light source having an intrinsic collimator via the mirror 15 and objective lenses 8, 9, two optical systems can be optimally regulated without depending upon one another. Thus, the laser beam can be accurately focused at the position of the object 3. For example, the size of 80μm to 32mm can be sufficiently accurately measured by one unit. |
