Abstract: Disclosed herewith is a method of compensating for the seek errors of a pickup assembly. The method includes the steps of calculating a target track number to read data stored in an optical disc by transferring a pickup assembly across the optical disc; determining whether a seek error has to be compensated for in a radially outward direction of the optical disc; if the seek error has to be compensated for in a radially inward direction, compensating for the seek error; transferring the pickup assembly in the radially inward direction, reading an address of a current position of the pickup assembly, and determining whether the current position of the pickup assembly coincides with a target position; if the current position of the pickup assembly coincides with the target position, calculating the seek error in a radially inward direction and calculating an error compensation value in a radially inward direction; and storing the calculated error compensation value and using it to perform a next seek operation.

Abstract: Disclosed herein is a method of compensating for variations in the track pitches of optical discs. The method includes the step of activating a focus servo and inactivating a tracking servo so as not to trace the tracks of the optical disc. Thereafter, the pickup assembly is transferred across the optical disc to generate the traverse signal caused by differences between the amounts of light reflected by the tracks of the optical disc and the other portions of the optical disc. The traverse signal is shaped into a pulse wave, and the number of pulses of the traverse signal is counted. The rotation number of the optical disc is measured and stored. The track pitch of the rotating optical disc is calculated. Finally, a target track number is calculated, and a seek operation is performed.

Abstract: A device for opening and closing a lid of an optical disk player is disclosed, which is intended to decrease manufacturing cost, to improve assembling efficiency and productivity, and to minimize rejection rate of products by reduction of components. The device includes a player body having a button and a locking hole, a lid hingedly coupled to an end of the player body to cover the player body, and biased upwardly by a spring, the lid having a hook projected downwardly, a pickup disposed in the player body to be moved back and forth, and provided with a pusher, a catcher disposed in the player body to be moved back and forth, and having a catching protrusion to be engaged with the hook and a contact plate to be in contact with the pusher, and having a connecting rod connected between the catching protrusion and the contact plate, and a spring disposed in the player body to bias the catcher forwardly.

Abstract: The invention relates to a method of detecting the amount of rotational vibration generated from the rotation of the disk so that the amount of rotational vibration due to the unbalance of the disk can be correctly detected without the additional circuit using the vibration sensor thereby providing data which can assist a series of reactions to prevent a noise or vibration generated from the device. The method comprises the following steps of: the first step of counting number of a traverse signal in a low rotational velocity of a record medium; the second step of counting number of the traverse signal in a high rotational velocity of the disk after completing the first step; the third step of calculating the difference between the numbers of the traverse signals counted in the first and second steps; and the fourth step of converting the traverse signal number difference calculated in the third step into the amount of rotational vibration.