FOCUS CONTROLLER

PURPOSE:To easily adjust the characteristic by setting the focus off the just- focus position of a light spot by a focus position offset circuit and adjusting the characteristic of focus servo in this state. CONSTITUTION:The focus error signal to which an offset is given to a focus error signal to s...

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Bibliographic Details
Main Author EDAHIRO YASUAKI
Format Patent
LanguageEnglish
Published 05.07.1991
Subjects
INFORMATION STORAGE
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER
PHYSICS
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Summary:PURPOSE:To easily adjust the characteristic by setting the focus off the just- focus position of a light spot by a focus position offset circuit and adjusting the characteristic of focus servo in this state. CONSTITUTION:The focus error signal to which an offset is given to a focus error signal to set the focus servo position to xa or xb has not a tracking groove signal mixed, and the characteristic of focus servo can be adjusted in the offset generating circuit 10. A signal added into a focus servo loop is detected by a servo characteristic adjusting circuit 91 to perform FFT or the like, and the characteristic of a servo system is obtained, and the focus servo gain, the characteristic of a phase compensating circuit, or the like is so adjusted that focus servo has a prescribed characteristic. Thus, the characteristic of focus servo is easily adjusted.
Bibliography:Application Number: JP19890296537