| 摘要 |
<p>Disclosed is a radiant energy optoelectronic position monitor system which detects the angular position of a "galvanometer mirror" (beam scanner) (gm) used in an optical disk memory arrangement.</p><p>Using a single infra-red monitor beam, angular motion is converted to linear displacement of an image on a detector cell (31) so as to produce a corresponding electrical signal. This. signal is presented to a processing circuit with an analog divid- er to normalize output scale factor. The result is a high gain electrical circuit for recovering output signals in an environment with strong magnetic interference.</p><p>Such a position sensor is described as especially apt for use in a "three beam" laser optical system comprising a writing beam and two reading beams all incident on the same track of a rotating disk optical recording medium. One of these reading beams is incident on the track ahead of the writing beam so as to serve as a "read-before-write" beam, while the other reading beam is incident on the track behind the recording beam so as to serve as a "read-after-write" beam.</p> |
