Rotating data carrier lens control - has mechanism for stepwise displacement of lens under electronic circuit control

摘要

The mechanism for shifting the lens - with which the light beam scans concentric rings or a spiral track of the storage disc - ensures recording or playback of the stored data. The design provides an enhanced mechanical ridigity with a slow advance for scanning the disc content and with a fast approach to the data tracks. The lens is shifted while the light beam from a source passes through a prism on its way to the lens. The lens focusses the beam for scanning the data, and a collecting lens controls the illumination of the large-area detector. The displacement mechanism may include a diaphragm and piezo clamps for the step-and-repeat operation of moving the lens with the prism.