Industrial Technology Research Institute

Kuo-Ding Shin

Feng-Hsiang Lo

Chih-Chung Wu

Yong-Long Lee

Kai-Wen Cheng

Jyh-Shong Ju

Chao-Lin Su

Ching-Ping Kuei

Kuang-Yang Chuang

Shin-Bo Wang

Chin-Shou Huang

Shu-Tai Lu

Shin-Huei Wu

An automatic detecting device of land pre-pits signal is disclosed. The device adjusts gain of push-pull signals to raise the signal to noise ratio of the land pre-pits signal to the wobble signal. Digital logic computation is also utilized to recognize the practical position of the land pre-pits. The level automatic detection of the RC circuit and the fixed slice level compose an automatic slice level, which is the basis for detecting the land pre-pits. The disclosed device eliminates the drawback of not easy to obtain correct land pre-pits signal from written disks by the conventional of fixed land pre-pits slice level technology.

Automatic detecting device for land pre-pits signals

The invention provides a method for adjusting a speed-detection device for an object lens in an optical pickup head. The invention provides an adjusted optical disc drive, wherein the optical pickup head is accelerated/decelerated and the speed-detection device outputs a standard signal level. Next, the optical pickup head of an unadjusted optical disc drive is accelerated/decelerated under the same condition, and the speed-detection device outputs a speed signal level. Finally, the gain of a programmable gain amplifier is adjusted until the speed signal is equal to the standard signal.

Method for adjusting a speed-detection device for an object lens in an optical pickup head

This specification discloses an automatic calibration method for the output power of a pickup head for an optical information recording apparatus, which avoids laser diode thermal effects using duty cycle control and obtains the correct conversion function between the output current of a front monitor diode and the output power of the pickup head by curve fitting. This method only needs to measure one set of front monitor diode output current and output power conversion function of the pickup head. The same conversion function is applicable to all pickup heads of the same type. The optical information recording apparatus automatically detects the corresponding parameter for the pickup head. Each optical information recording apparatus can also automatically detect the specific power control parameters for each set of power control channel to obtain the optimal recording characteristics.

Automatic calibration of the output power of a pickup head for an optical information recording apparatus

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Hsinchu, Taiwan

Kuo-Ding Shin