SYSTEM FOR ADJUSTING THE SPOT SIZE IN AN OPTICAL RECORDING SYSTEM

摘要

A system for adjusting the spot size of an optical recording system includes a variable magnification lens assembly (8) for adjusting the beam size while obtaining feedback of the actual beam size through an image device (10). The variable magnification lens assembly (8) includes a beam expander (30) with manual or motor-driven actuators for positioning a beam sizing lens (33) while viewing an image of the spot. An acousto-optic modulator may be combined with the spot sizing function to reduce the number of lenses. The image device (10) may include a charge coupled device camera (60) connected to an image viewer or to a computer having image processing software. An operator may adjust the spot size while viewing an image of the spot, or the computer may control the beam size motors according to the measurement of the spot size.