• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권5호
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• pp.234-241
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• 2002

An optical pickup actuator is an objective-lens-moving mechanism that provides a means to follow the disk displacement accurately(1). In this paper, a slim type optical pickup actuator for Notebook PCs is analyzed and designed to improve the driving sensitivity A three dimensional equivalent magnetic circuit network method (3D-EMCN method) is proposed for an analysis method which provides better characteristics in both precision and computation time of analysis comparing with a commercial three-dimensional finite element (3D-FEM) codes. To verify the validity of proposed method, we made a comparison between the analysis results and the experimental ones. We also compared this analysis results with 3D-FEM results. Among the several optimal algorithm, we adopt a niching genetic algorithm, which renders a set of the multiple optimal solutions. RCS (Restricted Competition Selection) niching genetic algorithm is used for optimal design of the actuator's performance. Recently, the pickup actuator needs additional driving structure for radial and tangential tilting motion to obtain better pick-up performance. So we applied the proposed method to the model containing tilting coils.

• 한국소음진동공학회논문집
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• 제18권1호
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• pp.11-19
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• 2008

This paper proposes small VCM(voice coil motor) type, auto-focusing and zoom actuators for mobile information devices. In order to meet the large output displacement within small height restriction, the proposed auto-focusing actuator adopts curved suspensions, which are similar to a leaf-spring type suspension of optical disk drives. The sensitivity of design parameters on output displacement and dynamic performance is implemented using ANSYS (3D FEM tool) to determine the optimal geometry and stiffness of the curved suspensions. This paper also investigates a new zoom actuator without a suspension supporting a bobbin. The zoom actuator uses a moving rail and a stoper mechanism by generating rotational force at lens holder. Magnetic flux density of the zoom actuator are calculated by both the FEM and permeance method. Experiments using prototypes of the proposed focusing and zoom models show that both actuators meet the required displacement and performance.

• 정보저장시스템학회논문집
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• 제2권3호
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• pp.208-213
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• 2006

The present state of the design of swing arm actuators for optical disc drives is to obtain the high efficient dynamic characteristics within a very compact volume. As a necessary consequence, the need of the small form factor (SFF) storage device has been arisen as major interests in the information storage technology. In this paper, we suggest the miniaturized swing arm type actuator that has high efficient dynamic characteristics for SFF optical disk drive (ODD). For the operating mechanism, it uses a tracking electromagnetic (EM) circuit for a focusing motion together. Moreover, due to the size constraint, the thermal stability of optical head is important. Therefore, the actuator is designed to emit the heat, which is generated by optical pick-up, along the actuator body easily. Initial model is designed based on the topology optimization method considering the thermal conductivity. Then, the structural parts of the actuator are modified to maintain the high sensitivity and to have wide control bandwidth by the design of experiments method (DOE) and new concept of decreasing mass and inertia. Finally, a swing arm type actuator for SFF ODD is suggested and its dynamic characteristics are verified.

• 한국항공우주학회지
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• 제49권2호
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• pp.107-120
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• 2021

전기동력 분산추진 비행체는 다수의 프로펠러로 인하여 복잡한 프로펠러 후류 유동 및 기체와의 상호간섭이 발생한다. 이에 따라 초기설계 단계에서는 다양한 형상과 비행 조건에 대하여 프로펠러 구동 효과를 반영한 신속 공력 및 하중 해석이 요구된다. 본 연구에서는 프로펠러 효과를 고려할 수 있는 패널 기반의 효율적인 공력해석 기법을 개발, 검증하였다. Actuator Disk Theory(ADT)에 기반하여 프로펠러 후류 영역의 유도 속도장을 계산하고, 이를 3차원 정상 용출-중첩 패널기법의 비행체 표면 경계조건에 반영하였다. 한국항공우주연구원의 Quad Tilt Propeller(QTP) 비행체 단독 프로펠러와 선행 실험 연구의 프로펠러-날개 형상을 벤치마크 문제로 선정하여 해석을 수행하였다. Actuator 기법 기반의 전산유체역학(CFD) 결과와의 비교를 통해 프로펠러의 후류 속도장과 프로펠러 구동에 따른 날개의 공력하중 분포 변화를 검증하였다. 자율비행 개인용 항공기(Optional Piloted PAV, OPPAV)와 QTP 공력해석에 기법을 적용하고, CFD와의 해석 소요 시간 및 결과 비교, 분석을 통해 기법의 실용성과 타당성을 확인하였다.

• 대한기계학회논문집A
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• 제24권3호
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• pp.728-734
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• 2000

An asymmetric actuator can be used to reduce the distance between the reflective mirror and objective lens of a small optical disk drive for use in the notebook-sized personal computer data storage devices. However, this asymmetric actuator is very sensitive to the subsidiary resonance which is caused by its rigid body motion. In this paper, an analytical approach using a simple lumped parameter system model is presented with a physical insight to investigate why the subsidiary resonance occurs. The finite element method is used to figure out the force and torque characteristics of the asymmetric actuator which are essential to understand the subsidiary vibration characteristics. The frequency responses are presented to examine how the subsidiary resonance is altered for various situations of having different thickness of a yoke and permanent magnet and of having a different magnet circuit. Finally, the design guidelines to avoid the subsidiary resonance will be presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.468-471
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• 2000

HDD가 비동작중 외부충격을 받았을 경우에 대해 수치해석을 이용하여 HSA(head stack ass'y)의 거동과 헤드가 디스크 면에서 멀어지는 Lift-off level을 고찰하고, actuator의 arm blade(primary system)의 끝단에 보조의 구조물(auxiliary system)을 붙여 반사인파의 가속도입력에 의해 발생되는 HSA의 진폭을 감소시키고 내충격성능을 향상시키고자 한다. 보조 구조물의 형태와 재료는 arm blade의 공진과 연계한 공진주파수의 최적화과정에 의해 결정된다. 실제 제품의 취급에서 가장 쉽게 발생할 수 있는 0.5ms의 duration time으로부터 제품의 성능평가 요건인 2ms의 duration time까지의 반사인파의 입력에 대한 응답을 고찰한 결과 보조의 구조물을 가졌을 경우 주 시스템보다 훨씬 높은 충격에서 헤드의 lift-off이 발생되어 전체 시스템의 내충격성능을 향상시킴을 알 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.351-355
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• 1996

In optical disc system, lens actuator of 4-wire has unwanted moment which occurs tilt. The moment around the axis pallet to the tangential direction of the disk occurs to the moving part. when the moving part is moved in tracking direction and focus driving force is applied. This paper analyzed coupled effect due to the moment based on structural analysis and magnetic field analysis, both using finite element method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.214-219
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• 2003

Recently, the optical disk drive that is thin in thickness has been demanded by the popularization of notebook PC. The device that controls the thickness of a drive is the height of optical pickup. Therefore, researches about this are going on and an asymmetric actuator is the good choice fur this target. However, the actuator of this design has troubles that a subsidiary resonance is likely to be actuated by discord between the center of force and the mass of renter. In this paper, relation between the tracking coil and the subsidiary resonance is analyzed and dynamic characteristics of an actuator are improved by using experiments design and response surface method.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.87-92
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• 1999

This paper was undertaken to do morphological analysis of wear particles for sliding members hydraulic rotary actuator. The lubricating wear test was performed under different experimental conditions using the wear test device and wear specimens of the pin on disk type was rubbed in paraffinic base oil by three kinds of lubricating materials, varying applied load, sliding distance. The four-shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) are used for morphological analysis of wear particles. The results showed that the four shape parameters of wear particles depend on a kind of the lubricating materials. It was capable of presuming wear volume for three kinds of materials on driving time.

• 한국정밀공학회지
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• 제15권7호
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• pp.52-60
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• 1998

In optical disc system, 4-wire actuator has undesired tilt which degenerates the performance of RF signal. This tilt occurs from moment around the axis parallel to the tangential direction of the disk. The main reason of the moment is the coupling effect between focus driving system and tracking driving system. This paper constructed tilt mechanism and analyzed tilt quantity due to the moment based on structural analysis and magnetic field analysis. And the experiment about tilt was executed. The results were compared and discussed about the difference. Then, the design method for reducing tilt angle was suggested.