| 摘要 |
Three scanners are disclosed; common to all is an argon ion laser. In the first two versions, light passes through a telescope, which is provided to expand and collimate the laser beam, through a servo-driven iris whose function is to adjust the length of the slit image to be formed by the optics. The beam enters a rotating cradle, passes through a cylindrical lens, and strikes a galvanometer-driven mirror. Rotating the galvanometer about its axis deflects the image of the laser beam on the main scanning mirror. A second lens images the galvanometer mirror onto the CRT panel. In the first version, the main scanning mirror is a flat reflector; in the second version, the scanning mirror is either a prism or a mirror set at 45 degrees to the incident laser beam. In both versions, a motor-driven optical rotator is between the galvanometer-driven mirror and the scanning mirror. Several important features include the servo-driven image rotator and the motor-driven iris. In the third version, the optical rotator has been replaced by a motor-driven rotating mount for the cylindrical lens. The servo-driven iris has been replaced by a simple aperture, preferably elliptical or rectangular-shaped mounted coaxially to the cylindrical lens. The second lens has been replaced by a pair of adjustable diverging-converging lens. The main scanning mirror is linkage driven by a D.C. motor rather than directly coupled to the motor shaft.
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