Optical information recording-reproducing method and apparatus including focusing and/or tracking control depending on a determined state of an optical spot
In an optical information recording-reproducing apparatus or method, a sum signal is generated from a divided sensor to be used for auto-focus (AF) and/or auto-tracking (AT) control. The AF servo is closed after an objective lens is moved to a location in the neighborhood of an in-focus position whi...
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Main Author | |
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Format | Patent |
Language | English |
Published |
12.12.1995
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Edition | 6 |
Subjects | |
Online Access | Get full text |
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Summary: | In an optical information recording-reproducing apparatus or method, a sum signal is generated from a divided sensor to be used for auto-focus (AF) and/or auto-tracking (AT) control. The AF servo is closed after an objective lens is moved to a location in the neighborhood of an in-focus position while working a position servo for an objective lens actuator using the sum signal. Further, the fact that a light spot is on a track is detected from the sum signal. If this fact is detected as well as the fact that a tracking error signal is in the neighborhood of zero, the AT servo is closed. |
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Bibliography: | Application Number: US19930022157 |