Automatic Focus Control for Head Alignment
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
This article describes an automatic focus control system which will maintain an actuator lens focused on an alignment target despite small head movements. During alignment of an optical head, it is necessary to maintain focus while the optical components are being adjusted. The beam from the head is focused on a chromium target. This focus condition must be maintained within a 0.2 micron tolerance during optical component adjustment. Because the optical components are moved mechanically, some movement of the head always occurs. The head must be focused again and another attempt made to adjust the optical components. As a result, the alignment of the head is a complicated process, requiring much time.