Samsung Electronics Co., Ltd.

Ki-bong Yun

Pyong-yong Seong

Sung-ro Go

Jong-hoon Lee

Chul-ho Jeon

Jong-ryull Kim

Bong-hwoan Choi

Kyoung-bok Jin

No-jun Kwak

A method and an apparatus for identifying the type of an optical recording medium are provided. The method includes detecting a surface reflected signal Sand a writable-surface reflected signal Sof an optical recording medium while performing a focus search using a first optical system, counting a time difference DTbetween a high peak and a low peak of the surface reflected signal S, counting a time difference DTbetween the high peak of the surface reflected signal and a high peak of the writable-surface reflected signal S, obtaining DT by substituting DTand DTinto the following equation: and comparing DT with a reference time T, and driving the first optical system if DT is greater than T and driving a second optical system if DT is not greater than T.

Method and apparatus for identifying the type of optical recording medium

An automatic power control (APC) apparatus reducing time necessary for stabilizing an APC circuit at the initial stage of automatic power control of a disc drive is provided. The APC circuit is designed such that a voltage of a predetermined percent of an expected output voltage is previously added to an APC output voltage of the APC circuit of a laser diode, thereby greatly reducing a stabilizing time necessary for stabilizing an APC output voltage at an initial stage in a write or read mode. Therefore, the loss of data in a high speed write or read mode can be reduced. Particularly, the loss of data in a high speed write mode can be greatly reduced.

Automatic power control apparatus of disc drive

A method for controlling the speed of a sled motor for an optical disk drive, wherein the sled motor is first driven according to a predetermined target velocity profile stored in a microcomputer. Then, a frequency of a sinusoidal wave output by a Hall-effect sensor is detected and it is determined whether the frequency of the sinusoidal wave is greater or smaller than a predetermined value. The target speed is incremented by a predetermined amount when the frequency of the sinusoidal wave is greater than the predetermined value, and is decremented by the predetermined amount when the frequency of the sinusoidal wave is smaller than the predetermined value.

Method for controlling speed of sled motor in optical disk drive

Growing community of inventors

Gyeonggi-do, South Korea

Ki-bong Yun