Abstract: A method and device for searching a recording medium are provided. The recording medium has a management information area of which location information is overlapped with that of a program area. The method for determining an area on a recording medium having an overlapped time range between two areas reads a time address from a current position on the recording medium, obtains additional information from the recording medium or from a recording medium driving unit, if the read time address belongs to the overlapped range, and determines, based on the obtained additional information, to which one the areas the current position belongs. Therefore, it prevents wrong track jumps that are caused from time-overlapped areas on a capacity-expanded recording medium.

Abstract: A method for checking the existence of an optical disk using a focusing signal is provided. The method in accordance with the present invention prevents misjudgement of the existence of an optical disk which is caused by noise contained in a focus error signal or by the low reflection ratio of a disk.

Abstract: The present invention relates to method and apparatus of measuring axial vibration of a rotating disk. The present axial vibration measuring method selects a plurality of equally-spaced (45°˜120°-spaced) angular positions of a disk recording medium to conduct focusing operation at, conducts focusing operation at each selected position, measures focusing time from each start of the focusing operation to exactness in focus, and calculates axial vibration of the disk recording medium based on a deviation of the measured focusing times. The present method can measure exactly how much a rotating disk vibrates axially.

Abstract: This invention provides method and apparatus for controlling reproduction speed of an optical disk, which detects the magnitude of a disk vibration after initial operation of an optical disk and adjusts the disk rotation speed based upon the vibration magnitude. The method according to this invention comprises the steps of rotating an installed optical disk; detecting the quantity of signal derived from tracking error signals which are combined from signals reproduced from the optical disk when the rotation speed reaches to a predetermined speed; and deciding whether to increase the rotation speed above the predetermined speed based upon the detected quantity of the signal. This invention is able to reproduce an optical disk at the possible maximum speed within allowable speed limit through detecting accurate disk vibration magnitude at the initial operation stage and adjusting the reproduction speed to higher speed.

Abstract: A method and device for searching a recording medium are provided. The recording medium has a management information area of which location information is overlapped with that of a program area. The method for determining an area on a recording medium having an overlapped time range between two areas reads a time address from a current position on the recording medium, obtains additional information from the recording medium or from a recording medium driving unit, if the read time address belongs to the overlapped range, and determines, based on the obtained additional information, to which one the areas the current position belongs. Therefore, the present invention prevents wrong track jumps that are caused from time-overlapped areas on a capacity-expanded recording medium.

Abstract: The present invention relates to method and apparatus of measuring axial vibration of a rotating disk. The present axial vibration measuring method selects a plurality of equally-spaced (45°˜120°-spaced) angular positions of a disk recording medium to conduct focusing operation at, conducts focusing operation at each selected position, measures focusing time from each start of the focusing operation to exactness in focus, and calculates axial vibration of the disk recording medium based on a deviation of the measured focusing times. The present method can measure exactly how much a rotating disk vibrates axially.

Abstract: A method and apparatus for controlling the movement of an optical pickup between tracks in an optical disc player, which makes it possible to access to a target track quickly by adjusting a sled motor driving signal on the basis of the load applied to the sled motor that moves the optical pickup. The method and apparatus controls the moving distance of the optical pickup accurately by taking into account the load applied to the sled motor thus facilitating access to a target track at high speeds.