Samsung Electronics Co., Ltd.

Yonsei University

Young-jae Park

Jae-Cheol Bae

In-Joo Kim

Tatsuhiro Otsuka

Taek-Seong Jeong

Sung-hyun Kim

Jong-hyun Shin

Hyun-seok Yang

Joong-gon Kim

Noh-cheol Park

Dong-hwan Lee

A method and apparatus to control a position in which data is to be recorded on a holographic data recording medium by using interference between a reference light and a signal light, the method including: irradiating the reference light and the signal light on the holographic data recording medium; generating a focus error signal that indicates a distance difference between a first focus corresponding to a focus of the reference light on the holographic data recording medium and a second focus corresponding to a focus of the signal light on the holographic data recording medium, based on information about a reflective signal light generated when the irradiated signal light is reflected from a reflective transmission layer of the holographic data recording medium; and moving the second focus to a position of the first focus, based on the focus error signal.

Method and apparatus for controlling position in which data is to be recorded

An apparatus for compensating for a defect of a storage medium of an optical driving includes a memory to store sample values of a servo driving signal during at least one track sampled by a first signal and cycle information about the first signal; a servo driving signal estimator to estimate a servo driving signal during at least one next track using the sample values, the cycle information about the first signal, and cycle information based on a second signal; and a transmitter to transmit the servo driving signal estimated by the servo driving signal estimator to a servo driver of the optical driving device during a defect section of the storage medium; wherein the first signal is synchronized with a radial direction of the storage medium; and the second signal has a frequency higher than the first signal.

Method and apparatus for compensating for defect of storage medium

A gap servo control method and apparatus for increasing a disturbance cancellation capability and decreasing the occurrence of an overshoot in a near-field optical disc drive include: generating an actuator driving signal of a transient response process by using a signal obtained by removing a disturbance contained in the gap error signal using a first band when a level of a gap error signal reaches a first level; and generating the actuator driving signal of the transient response process by using a signal obtained by removing the disturbance contained in the gap error signal using a second band when the level of the gap error signal reaches a second level.

Gap servo control method and apparatus in near-field optical disc drive

A focusing control method of an optical information storage media recording and/or reproduction apparatus controlling a focusing operation by moving an objective lens upwards or downwards in a direction towards or away from an optical information storage medium having a plurality of data layers includes receiving a focusing lead-in command signal to focus an optical beam on a target data layer, compensating for spherical aberration with respect to the target data layer, detecting a focus error signal based on an intensity of the optical beam reflected from the optical information storage medium and condensed by an optical detector, identifying the target data layer using an amplitude or a frequency of the focus error signal, and focusing the optical beam on the target data layer by moving the objective lens in an opposite direction from a direction in which the objective lens is initially moved.

Method of controlling focus of optical information storage media recording and/or reproduction apparatus and apparatus therefor

An apparatus for recording/reproducing holographic data and a method of adjusting a position of a recording layer. While an objective lens focusing first and second lights having different wavelengths on a holographic data storage medium including first and second reflective layers reciprocatingly moves in a direction of an optical axis, a focus movement unit, which moves a focus of the second light in the direction of the optical axis until a time difference between a first detection signal generated when the first light is reflected from the first reflective layer and a second detection signal generated when the second light is reflected from the second reflective layer becomes a value corresponding to a position of a desired recording layer, is controlled to move a focal position of the second light so that the focal position of the second light can be adjusted to the position of a desired recording layer.

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Yongin-si, South Korea

Young-jae Park