Lite-On It Corporation

Yi-Shih Wang

Tao-Yen Wei

Ching-Hsiang Chang

Ling-Feng Chen

Kuo-Chiang Chang

Yung-Yu Chang

Chih Wei Huang

A label side of a light-scribe optical disc includes a control feature zone recording therein reference information of the optical disc and a label zone to be marked based on the reference information. An optical head is moved in the label zone to determine a first FE gain and a first sub-beam addition (SBAD) signal by way of focusing servo technology. The optical head is further moved in the control feature zone to determine a second SBAD Signal. The first and second SBAD signals are operated to obtain a ratio. The ratio is used with the first FE gain to estimate a second FE gain for accessing to the control feature zone.

Method for determining focusing error gain for accessing to optical disc

A method of erasing an erasable disc. When an optical drive is erasing a DVD-RW disc, a write mode, instead of a conventional erase mode, is used to execute an erase operation. In the write mode, the invention sets current values of individual current paths in a laser diode drive circuit such that a laser diode always outputs a constant erase power (Pe) onto the DVD-RW disc-no matter how a write pulse signal changes. Thus, after a starting position of the DVD-RW disc is determined, the optical drive only needs to write a data amount of n ECC blocks to complete the disc erasing operation without continuously detecting the LPP (Land Pre-Pit) data block to obtain a stop erasing position on the disc in the conventional optical drive.

Method of erasing an erasable disc

An inner ring signal and an outer ring signal according to specific patterns formed on the label side of the optical disc are generated. Timing starts when the outer ring signal reveals the end of a positioning pattern and stops to obtain a timing value when the inner ring signal reveals the start of a square wave defining a specified spoke. A starting spoke is defined according to the inner ring signal and the specified spoke. A deviation bit value is calculated according to the timing value and a bit number of a data to be marked on a certain track of the optical disc. The data is rotated according to the deviation bit value, and then marked on the certain track, starting with the starting spoke.

Control method for marking label side of optical disc

A method of adjusting the write speed of a CD drive includes writing data from a CD drive to a disk at a first speed during a first preset time. If, at the end of the first preset time, the data error rate at the first speed is larger than the error allowance upper limit for the first preset time, then writing of the data will be completed at the first speed. However, if at the end of the first preset time, the data error rate at the first speed is smaller than the error allowance upper limit for the first preset time, then the writing speed will be adjusted to a second higher speed. The same process can be repeated for the second higher speed.

Growing community of inventors

Hsinchu, Taiwan

Yi-Shih Wang