Everett N Bates

US Patent:

47196106, Jan 12, 1988

Filed:

Apr 2, 1986

Appl. No.:

6/847328

Inventors:

Everett N. Bates - Fountain CO
Gregory V. Hofer - Colorado Springs CO

Assignee:

Optotech, Inc. - Colorado Springs CO

International Classification:

G11B 1700
G11B 2110

US Classification:

369 32

Abstract:

An objective lens velocity control system for use in an optical data storage system. The optical data storage system includes an optical disk with servo tracks for storing data, an objective lens, and a tracking drive for driving the objective lens along the tracking axis in response to tracking drive signals. The tracking error detector is responsive to the objective lens and produces tracking error signals representative of the position of the objective lens along the tacking axis. The tracking error signal also defines measurement periods which are representative of an actual velocity of the objective lens. A velocity control is responsive to the tracking error detector and produces the tracking drive signals in a form tending to cause the objective lens to have a desired velocity. For each measurement period, the tracking control produces a first tracking drive signal during a first portion but for no longer than a time duration which is a function of the desired velocity. During the remaining second portion of the measurement period, the velocity control produces a second tracking drive signal.