Patent ID: 7298679
Filing Date: 2007-11-20
Classification: G11B

Abstract:
1. A write power determining method of an optical disk inserted in an optical disk drive before writing to the inserted optical disk, the method comprising: obtaining a push-pull signal amplitude at at least two measuring positions, including an inner circumferential portion and an outer circumferential portion of a recording surface, in a radial direction of the inserted optical disk; determining a relationship of an optimum write power with respect to a radial position of the inserted disk based on the obtained push-pull signal; and controlling the optimum write power depending on the radial position of the inserted optical disk based on the determined relationship; wherein, with respect to the optimum write power information associated with the radial position of the disk, if the optimum write power at an arbitrary outer circumferential measuring position relative to an inner circumferential reference measuring position is defined as PO, PO is calculated and determined by an equation of: where: PPI: the push-pull signal amplitude obtained at the inner circumferential reference measuring position or at a position in proximity to the inner circumferential reference measuring position; PPO: the push-pull signal amplitude obtained at the arbitrary outer circumferential measuring position; PUP: a ratio coefficient of power up based on a disk radius; and PI: the optimum write power by test writing at the inner circumferential reference measuring position.