• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1439-1443
• /
• 2007

In this paper, vibration reduction techniques of a voice coil motor (VCM) actuator are presented for AFM imaging system. The damping coefficient of the actuator driven by VCM with a flexure hinge is quite low and it cause the about 30dB peak amplitude response at the resonance frequency. To decrease this peak response, we design and apply elliptical band-stop filters to xy and z axis VCM actuator. Frequency response of each actuator with filter is measured to verify the effect of the filters. As a sensor, capacitive sensor is used. Vibration reduction rate of the xy actuator with the filter is also measured while real AFM scanning condition. As another method, closed loop control with the capacitive sensor is applied to the xy axis actuator to add an electrical damping effect and vibration reduction rate measured. These vibration reduction rates with each method are compared. In the case of z axis actuator, the frequency response of force (gap) control loop is measured. For comparison, the frequency response using a conventional PID controller is also obtained. Finally, the AFM image of a standard grid sample is measured with the designed controller to analyze the effect in the AFM imaging.

• 한국정밀공학회지
• /
• 제18권4호
• /
• pp.203-208
• /
• 2001

In this paper, a novel dual-type positioning mechanism using a voice coil motor(VCM) and a piezoelectric actuator is proposed for optical disk drive or near-field recording type drive. The VCM is used for a coarse motion actuator and the piezoelectric actuator, "S" configuration deflection motion when voltage applied, is used for a fine motion actuator with self-sensing technique, which allows it to sense and actuate simultaneously in a closed loop frame work. When the VCM rotates and stops, a position feedback control algorithm is adopted to further control residu vibration. The performance of the control scheme is confirmed through simulations and experiments.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.750-755
• /
• 2005

This paper proposes a small VCM (Voice coil motor) type actuator using curved suspensions for auto-focusing and zoom motions for mobile information devices. 1'he proposed focusing actuator adopts a nontraditional type of suspension using curved beams in order to extend output displacement within small height restriction. The curved beam is similar to the leaf spring type which is usually used in optical disk drives. In addition, three different materials are considered for the curved suspension model, and Aluminum shows the best dynamic characteristics. The proposed zoom actuator does not use a suspension supporting bobbin but a moving rail and a sloper mechanism by generating rotational force at lens holder. The sensitivity of design parameters on output performance is studied using ANSYS (3D FEM tool). Experiments using a prototype of the proposed actuator model verified the analytical prediction and performance.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2011년도 춘계학술대회
• /
• pp.307-309
• /
• 2011

최근 출시되는 고사양의 Hand-phone 적용되어진 Camera Module은 대부분 Auto Focusing기능이 탑재되어 있으며 Camera Module의 화소수가 높아지면서 좀 더 정밀하고 안정적인 AF구동제품이 소비자에 의해 요구되고 있다. 본 논문은 현재 출시되고 있는 Camera Module적용 VCM(Actuator)의 문제점인 Auto Focusing시 Lens 초점위치 및 Module 자세에 따른 해상도편차 발생으로 해상도 보증 및 안정된 Actuator 구동을 위해 개선된 구조의 Hybrid VCM을 제안한다.

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

• 디지털융복합연구
• /
• 제10권11호
• /
• pp.331-335
• /
• 2012

핸드폰에 사용되는 카메라의 발달로 자동초점용 렌즈에 대한 많은 연구가 진행되어 왔다. 다양한 종류의 자동초점용 액추에이터 중에서 VCM(Voice Coil Motor)이 가장 많이 사용되고 있다. 이 VCM은 자석, 코일, 요크 등의 모양에 따라서 구성되는 자계의 흐름을 달리하여 원하는 수준의 자동초점 조절이 가능한 핸드폰용 카메라가 만들어지고 있다. 본 연구에서는 유한요소 해석프로그램인 ANSYS$^{TM}$를 이용하여 산업체에서 사용되는 다양한 구조의 렌즈 중 가장 경제적인 모델을 선택하여 전자기 분석을 수행하였다. 이 전자기 해석을 통하여 효율적인 렌즈 모듈 설계 방법을 제시한다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.475-480
• /
• 2000

A new positioning mechanism with Parallel type actuator using piezoelectric material and with dual type actuators using voice coil motor (VCM) and piezoactuator is proposed for optical disk drive or near-field recording type drive, and high speed position and vibration control are investigated. Parallel type bimorph piezoactuator is used as a fine motion actuator with self-sensing technique, which allows a piezoelectric material to concurrently sense and actuate in a closed loop frame work, and positive position feedback control algorithm is adopted to further control residual vibration. For positioning control of VCM, PID control algorithm is adopted.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 추계학술대회논문집
• /
• pp.748-753
• /
• 2000

Nowadays, many studies and researches in data storage have been carried out and storage capacity is increased. But the limitation of storage capacity is happened for several problems. One of them is spot & pit size in optical and magnetic data storage and another is the resolution of actuators. The problems in spot & pit size is covered by new data storage methods- for example, NFR{Near-Field Recoding) system. But the resolution limit of an actuator doesn't follow up the development of spot & pit size. Because of them, we should improve a resolution of an actuator. Especially, in this paper an actuator is studied and designed for NFR(in using SIL(Solid Immersion Lens) system. It is a dual stage actuator, which consists of a Fine actuator and a Coarse actuator, and should desire 100nm accuracy. But, our actuator system only includes tracking mechanism execpt focusing mechanism which is controlled by slider mechanism used in HDD. Its actuating force generation method is VCM(Voice Coil Motor). The Fine actuator is composed of 4-leaf springs and a bobbin wrapped by coil. The Coarse actuator has Coils and 3-Roller bearings.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.375-378
• /
• 2005

Voice Coil Motor is used linear motion actuator system that require precision positioning control. In order to control precision positioning of voice coil motor, Mathematical model of voice coil motor is needed. Mathematical model is obtained by combining voice coil motor's equation of motion with the equation of circuit and characteristic of voice coil motor. The induced model can predict output displacement according to duty ratio and amplitude. The model is verified by experimental test. Simulated results have tracking errors of less than 10 percent of experimental results.

• 정보저장시스템학회논문집
• /
• 제6권2호
• /
• pp.74-78
• /
• 2010

In this paper, 2-axis driving mechanism, which uses voice coil motor (VCM), is proposed to measure the friction force. The proposed VCM actuator consists of two parts; structural part and magnetic circuit part. Structural part is simplified to perform the friction experiments. Magnetic circuit part is composed of two parts. The experiments are accomplished by changing the mass of moving part. Through the experiments, optimal dimension is selected. Finally, the experimental results are verified and the optimal case is applied to the 2-axis driving mechanism, optical image stabilization actuator.