| 摘要 |
PURPOSE:To process at a high speed and to inexpensively provide a configuration by sensing the intensity of an optical beam emitted from a light emitting element and passed through a lens by a photodetector, and regulating the relative position between the element and the lens so that the intensity becomes maximum. CONSTITUTION:A photodetector 6 having a microscopic photodetecting area is disposed at a position of a distance L from a lens 4, and the light receiving amount is monitored by a light reception amount monitor 7. When a relative position between a light emitting element 2 and the lens 4 is regulated in this state, an optical beam spot shape at the position of the distance L from the lens 4 is varied, and an incident light receiving amount to the photodetector 6 is varied. The light intensity becomes maximum when the diameter of the beam becomes minimum at the photodetecting position. Accordingly, the element 2 and the lens 4 may be regulated at the positions so that the incident light intensity at the photodetector 6 disposed at the position of the distance L from the lens 4 becomes maximum while monitoring it by the monitor 7. |
