Method for controlling writing power in optical drive and its equipment

Abstract

It is an object of the present invention to provide a method of and an apparatus for controlling writing power to an optical medium to perform running optimum power control (OPC). A deficiency in dynamic ranges of monitored writing power and a write radio frequency (RF) signal, which is difficult to compensate in hardware, is compensated for in firmware (or software) and a normalized write RF signal having a constant linear characteristic is obtained to control the writing power of a laser diode while an optical drive is in a write mode, thereby attaining an optimum writing characteristic even if the writing environment of the optical drive changes. The method comprises detecting a first normalized write signal having a linear characteristic with respect to the corresponding writing power by using the predetermined condition values, wherein the predetermined condition values are set taking into account the dynamic ranges of monitored writing power and a write RF signal, deficiency in the dynamic ranges not being compensated for in hardware in the optical drive, and setting the first normalized write signal as a reference signal; detecting a second normalized write signal having a linear characteristic with respect to the corresponding writing power using the predetermined condition values, while writing data to an user area on the optical medium; and controlling the writing power of the light source based on the result of determining whether the second normalized write signal is approximate in value to a value of the first normalized write signal.

Description

technical field [0001] The present invention relates to a method and device for controlling write power in an optical drive, and more particularly to such a write power control method and device for controlling the power to drive a laser diode (LD) in a write mode, so that even in Optimum write characteristics can still be obtained when the writing environment changes. Background technique [0002] In write mode, conventional optical drives employ a Power Calibration Area (PCA) on the optical media that controls the data on which data can be additionally written or rewritten, such as a compact disc recordable (CD-R) or rewritable The level of laser power (or write power) necessary to write data on an optical medium such as a compact disc (CD-RW). This control is called Optimal Power Control (OPC). [0003] Even if the optimum writing power is obtained by OPC, if the writing environment changes in the actual writing mode, satisfactory writing charact...

AI Technical Summary

Problems solved by technology

Thus, the difference in land jitter between the inner track and the outer track increases, making it difficult to obtain satisfactory writing characteristics

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