• The Optical Journal
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• v.11 no.6 s.64
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• pp.49-59
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• 1999

지난 호에 있어서 태전위부 박사(송하전기산업주식회사 광디스크개발센타)의 '광메모리' 강의(한$\cdot$일 광학산업 기술협력 세미나)를 연재한다. 9월호에는 광메모리 매체의 역할, 광디스크 드라이브 시스템의 구성, 위상변화 광오버라이트 메모리의 원리, 위상변화재료를 다뤘다. 이번 호에는 위상변화 광디스크의 구성재료, 위상변화 공디스크의 오버라이트 특성, 위상변화 광디스크와 광자기디스크의 비교, DVD를 실현하는 기술 등을 소개한다.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.676-681
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• 2003

In this paper, we investigated the disc warping in high-speed slim-type optical disc drive. Recently, the information storage devices are increasing track density and higher rotation speed to enhance their recording capacity and their data transfer rate. Generally, ODD used in the Lap-top Computer has small inner space. So, the flow instability of inner space is rapidly increased as its higher rotation speed. An extreme case, the flow instability causes the malfunction of readout at pick-up of drives. The experiments and numerical analysis were carried out for several cases, the result shows the influence of airflow to the disc warping.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1789-1794
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• 2004

The present study investigates flow characteristics in an optical disc drive. Detailed knowledge of the flow characteristics is essential to analyze flow-induced noise and vibration, forced convection and flow friction loss. The ODD used in the personal computer is used for the experiment and rotating velocity of disc is under the 4500 rpm. Time-resolved velocity components and velocity spectrum are obtained using the laser Doppler anemometry (LDA). The results show that the front holes reduce now-induced noise and the position of pickup body affects flow near the window. In addition, il is possible for cooling of heat sources in an optical disc drive through measuring the flow fields under the tray.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5412-5419
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• 2011

The need is growing for high-speed spindle because various equipment are becoming more precise, miniaturization and high speed with the development of industries. Air-lubricated dynamic bearings are widely used in the optical lithographic manufacturing of wafers to realize nearly zero friction for the motion of the stage. Air-lubricated dynamic bearing can be used in high-speed, high-precision spindle system and hard disk drive(HDD) because of its advantages such as low frictional loss, low heat generation, averaging effect leading better running accuracy. In the paper, numerical analysis is undertaken to calculate the performance of air-lubricated dynamic bearing with herringbone groove. The static performances of herringbone groove bearings which can be used to support the thrust load are calculated. Electrochemical micro machining($EC{\mu}M$) which is non-contact ultra precision machining method has been developed to fabricate the air-lubricated dynamic bearing and optimum parameters which are inter electrode gap size, concentration of electrolyte, machining time are simulated using numerical analysis program.