Samsung Electronics Co., Ltd.

Cheol-won Lee

Jeong-il Park

An apparatus for compensating a track when a track crossing signal is not generated due to an offset detection flag (ODF) region or a defect of a disk, comprises a missed track compensating processor for compensating a missed track signal generated when the light beam passes through the ODF region, and a track counter for mixing a pulse signal of a monostable multivibrator with a compensation signal output from the missed track compensation processor and counting the number of tracks. Thus, the missed track signal which is generated due to the ODF region and disk defects is compensated, thereby accurately counting the number of tracks over which the light beam cross.

Track compensation apparatus of magnetooptical disk apparatus

An optical disk high-speed control device and method performs a coarse seek which controls the crossing speed of optical tracks by counting a track traverse signal of an optical head in order to make the optical head reach a target track quickly and accurately in one driving operation, to reduce access time and simplify the driving circuit of an access device by minimizing the time required for fine seeking.

Optical disk high-speed search control device

A velocity error signal generation method for controlling a velocity by comprising an actual velocity signal from an actual velocity generator with a command velocity signalfrom a command velocity generator includes removing a direct current component from the actual velocity signal, adding the direct current component of the command velocity signal to the alternating current component of the actual velocity signal, adding a minute voltage to the command velocity signal, subtracting the minute voltage from the command velocity signal, comparing a first signal obtained by adding the direct current component of the command velocity signal to the alternating current component of the actual velocity signal with a second signal obtained by adding the minute voltage to the command velocity signal, comparing the first signal with a thrid signal obtained by subtracting the minute voltage from the command velocity signal, and determining whether the actual velocity or the command velocity will be used an an input for generating a velocity error signal. In a velocity generating apparatus for realizing the method, when the difference between the actual and command velocity signals is outside a predetermined range, the actual velocity is regarded as being erroneously measured and is then replaced with the command velocity to detect a velocity error, thereby enhancing the reliability of a control system.

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Euiwang, South Korea

Cheol-won Lee