• Journal of KSNVE
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• v.7 no.3
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• pp.354-361
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• 1997

본 글에서는 HDD에 관련된 기술 중 기계적 요소와 관련된 내용을 소개하는데 중점을 두었다. HDD의 기본 요소들을 2절에서 간략히 소개하고 3절에서는 동역학.서보 기술을 기술하였다. 4절에서는 HDD의 진동과 충격에 관련된 문제와 기술적 사항을 설명하였다. 그리고 마지막으로 장래 기술전망에 대해 간략하게 기술하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.216-217
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.508-509
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.504-505
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• 2012

• Journal of the Korean Magnetics Society
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• v.7 no.2
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• pp.97-102
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• 1997

Off-track capability is used to determine the track pitch of hard disk drive system, and the off-track capability as a function of track pitch is called 747 curve. In this paper, 747 curves were simulated with computer. Side reading and recording parameters were obtained by magnetic field analysis using 3-D finite element method. Head read signal and noise voltages for calculation of signal to noise ratio (SNR) were obtained using reciprocity theorem. According to the 747 curves thus obtained, the off-track capability was increased as erase band width increased and as effective signal to noise ration $(SNR_{eff}}$ decreased. A simulated 747 curve and a measured 747 curve (using spin stand) of a planar silicon head with track width of 4.1 um were very similar, which indicated that the simulation was carried out properly.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.25-31
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• 2003

Airborne contaminant particles are intruded into optical disk drives(ODD) due to the flow caused by disk rotation and can be adhered to lens or disk surfaces, which causes decrease of laser power and increase of read/write errors. Such a phenomenon can be more serious as the space between the disk and the lens is reduced fur high-density storage devices. The purpose of this paper is to understand design parameters to reduce the particle intrusion into an ODD. Suggestions are made to prevent the particle intrusion that can decrease the stability of an ODD and also prevent the potential heat build-up problem. The sealing effect of drive and the forced injection of clean air (using HEPA filter) into the drive minimizes intrusion of the outside air and dusts in an ODD remarkably. Moreover it is proved by experiments that the installation of a heatproof pad to isolate heat generation part (PCB) from information read/write sections and the forced injection of dust-free air reduce the gas temperature inside the drive as well as the amount of particles intruded.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1545-1551
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• 2002

The optical storage device has recently experienced significant improvement, especially for the aspects of high capacity and fast transfer rate. However, it is necessary to study a new shape of air bearing surface for the rotary type actuator because the optical storage device has the lower access time than that of HDD (Hard Disk Drives). In this study, we proposed the air bearing shape by using SA (Simulated Annealing) algorithm which is very effective to achieve the global optimum instead of many local optimums. The objective of optimization is to minimize the deviation in flying height from a target value 100nm. In addition, the pitch and roll angle should be maintained within the operation limits.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.1 s.94
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• pp.87-95
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• 2005

This paper proposes a method to calculate the characteristics of a coupled hydrodynamic journal and thrust bearing of a HDD spindle motor. The governing equations for the journal and thrust bearings are the two dimensional Reynolds equations in $\theta z$ and $ r\theta$ planes, respectively. Finite element method is appropriately applied to analyze the coupled journal and thrust bearing by satisfying the continuity of mass and pressure at the interface between the journal and thrust bearings. The pressure in a coupled bearing is calculated by applying the Reynolds boundary condition and compared with that by using the Half-Sommerfeld boundary condition. The static characteristics are obtained by integrating the pressure along the fluid film. The flying height of spindle motor is measured to verify the proposed analytical result. This research shows that the proposed method can describe HDB in a HDD system more accurately and realistically than the separate analysis of a journal or thrust bearing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1284-1287
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• 2007

Recently, the need for slim type optical disk drive(ODD) has increased with popularization of lightweight notebook. Because of its lightweight and small structure, slim type ODD has low structural stiffness and it is weak to high-speed disk vibration. In this paper, Finite Element(FE) Model of slim type ODD is constructed and verified by experimental modal analysis. Additionally, sensitivity analysis is performed about structural parameters. As a result of sensitivity analysis, improved characteristic is verified by experiments using a sample of new model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.474-478
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• 2006

It is becoming more significant to develop a rotary voice coil motor(VCM) type's actuator for small form factor (SFF) optical disk drive(ODD), as portables are getting more and more popularized nowadays. The actuator which is applicable to small-sized ODD with a compact flash(CF) II card size was developed and fabricated. The experimental results showed that the finite element(FE) model is different from the fabricated model. And so flexible mode frequencies did not satisfy specifications of small-sized ODD, and tuning. Tuning procedures were required to improve dynamic characteristics of the fabricated actuator through finite difference method(FDM). At first, design variables were extracted through parameter study and the tuned FE model was improved by design of experiment(DOE). Consequently, It was confirmed that the improved model was applicable to SFF ODD.