• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.563-578
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• 2014

Purpose: The purpose of this paper is integrated tolerance design process by advantages of engineering design and 6 sigma statistical tolerances design. Methods: Integrated tolerance design process can determine the goals by using engineer's experience and clarify tolerance by 6 Sigma statistical methods. Integrated design process can be applied by using non-linear simulations. Results: We applied integrated design process to the optical disc drive spindle motor and get good result. Conclusion: If this method is applied test method in the early stages of development, then Design can be reduced development time and cost.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.452-457
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• 2003

An add-on type output regulator is proposed in this paper. By an add-on controller we mean an additional controller which operates harmonically with a pre-designed one. The role of the add-on controller is to reject a sinusoidal disturbance of unknown magnitude and phase but with known frequency. Advantages of the proposed controller include that (1) it can be used only when the performance of disturbance rejection needs to be enhanced, (2) when it is turned on or off, unwanted transient can be avoided (i.e., bumpless transfer), (3) it is designed for perfect disturbance rejection not just for disturbance reduction, (4) ability for perfect rejection is preserved even with uncertain plant model. This design may be promising for optical disc drive (ODD) systems in which disc eccentricity results in a sinusoidal disturbance. For ODD systems, the sensitivity function obtained by the pre-designed controller, which may have been designed by the lead-lag, $H_{\infty}$, or DOB (disturbance observer) technique, does not change much with the add-on controller except at the frequency of the disturbance. Since the add-on controller does the job of rejecting major eccentricity disturbance, the gain of the pre-designed controller does not have to be too high.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.83-88
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• 2000

multi-beam optical drive is a method to improve the data transfer rate for the optical disc systems by parallel recording and reading on neighboring multi-tracks. In this paper, the beam rotating actuator, which is necessary for the multi-bean optical disc drive to from beam spots on multi-tracks simultaneously, has been developed. The Voice Coil Motor is used as a drive mechanism for high resolution and small size of the actuator. And rotating guide based on link structure is designed for frictionless and axisless rotation of rotating part including dove prism and for rotating in axis of geometric center of dove prism. The characteristics of the actuator are experimented by laser vibrometer, Polytec OFV1102 and a dynamic analyzer, HP35670A. It shows that the actuator has good linearity, rotating range $\pm0.34^\circ$, minimum rotating angle $0.0066^\circ$and natural frequency 113.9Hz. Therefore the actuator can be applied in a multi-beam optical disc system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.177-182
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• 2004

Electronic products are subjected to many different types of shock environment. As the Optical Disc Drive (ODD) market grows, the number of failures related to shock increases. Therefore, it is necessary to improve the performance of cushion package as well as the product design. Cushion materials such as expanded polystyrene are often used to protect electronic products from shock environment. In this paper, the drop analysis of the cushion package f3r optical disc drives was carried out with the explicit method of LS-DYNA and verified by the drop test. For the optimization of package, response surface approximation model was created using central composite design. As a result, cushioning performance was improved under the critical condition and practical design guidelines of cushion package were suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.977-982
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• 2001

In this paper, we deal with the analysis and optimum design of a disc drive feeding system. Using this proposed design method, we can determine an optimal step motor and lead-screw for the shorter seek time and required seek resolution. Simulation results show that this method can be potentially implemented in the design of a feeding system.

• Transactions of the Society of Information Storage Systems
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• v.11 no.1
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• pp.6-10
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• 2015

Optical library system consists of disc magazines, cabinets, transfer robot and drive. Transfer robot delivers desired disc or magazine in cabinet to drive which reads data of disc. Conventional archive system stores discs in a line and transfer robot moves in one dimension. However, to store more discs, new optical archive system, optical library system, is developed which stores discs in two dimension like bookcase. Transfer robot should know the position and stored data of desired magazine to get correct data. In this paper, addressing algorithm using optical character recognition is proposed. Proposed algorithm is evaluated by experiments with implemented system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.793-796
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• 2010

The equalizer compensates a signal distorted by transmission lines and amplifying stages, so the signal can have uniform characteristics over all frequency range. The equalizer in ODD(Optical Disc Drive) improves the stability of the extracted clock from a received signal and the readability of an inserted disc by suppressing noise and ISI(Inter-Symbol Inference). The length of marks-spaces and track pitch on discs becomes shorter as the recording density of an optical media is higher, which causes noise and ISI. And, the sensitivity about the fluctuation of physical systems is higher as the optical devices become more complicate. This paper proposes a method to select the coefficient of built-in equalizer of ODD in order to maintain the quality of signals against noise and ISI caused by system fluctuation.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.191-199
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• 1999

In designing the tracking system of an optical disc drive, it is first necessary to eliminate the undesired influence of any visible mechanical vibrations. In this paper a geometrical method to analyze the frequency response of an elastically supported planar rigid body has been presented. Using the theory of screw, a geometrical expression of a compliant transfer function which describes the effects of the locations of an applied force and observation on the response has been derived. Applying the substructure synthesis method, a technique to stabilize the tracking mechanical system has been presented with a numerical example.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.401-405
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• 2003

Sound quality is becoming a major concern in optical disc drives (ODD). In order to improve the sound quality of slim type ODDs, we changed lead screw pitch and firmware algorithm in the seek mode. To evaluate the sound quality, the PCM (Paired Comparison Method) was adopted and the result was compared with the time-averaged loudness spectrum. Sound signals were also recorded and modified by increasing or decreasing selected frequency bands to verify their sensitivities to the sound quality. As a result of jury test, preferred frequency bands are associated with the time-averaged loudness spectrum.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.1010-1014
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• 2002

A new type actuator has been designed and investigated to overcome thermal problems in slim optical disc drive which is adopted in mobile storage devices. Recently, in optical storage device technical trends, the size of optical disc drives is slimmer to adopt notebook computer and the spindle rotate velocity is faster to achieve high transfer rate and the power of actuator is higher to perform tilting, etc. However, these trends of optical disc drives tend to raise the environment temperature of drives, actuator power and parts temperature. Moreover, it is more difficult to remove the heat inside a drive and the temperature of an actuator increases and drive slims. As a result, increase of surface temperature of actuator body caused that second resonance of an actuator moves down to a lower frequency band and the performance of optical parts also deteriorates. Especially objective lens, coil and magnet of the actuator parts are easily damaged. To manage these thermal problems, in this paper an actuator with a hybrid blade, which is composed of vectra which has low thermal conductivity and magnesium which has high thermal conductivity, has been suggested and verified. Despite the high temperature environment, the proposed actuator showed good dynamic performance.