Focusing servo system with focus servo acquisition enable which is operational within a predetermined time after the start of the movement of an objective lens

摘要

A method of focus search operation for focusing an objective lens in a focusing servo system for an optical recording/ reproducing apparatus. During an initialization stage, the objective lens is positioned for an initial up-search operation. When the objective lens is at an in-focus position, a focus acquisition operation is executed. If the focus acquisition operation is not completed successfully, the objective lens is continuously moved away from the recording surface to detect a focus point.