• Design & Manufacturing
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• v.11 no.3
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• pp.13-18
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• 2017

The injection molding analysis of VCM (Voice Coil Motor) housing for smart phone cameras were performed. We conducted the analysis in terms of injection molding pressure, the formation of weld lines, flow marks, and flow patterns. The goal of the analysis was targeted for the prediction of the optimal gate locations. Because the quality of VCM housing is strongly dependent on the precise control of the camera lens by its nature, we focused on the lens guiding lanes in the VCM housing. We first calculated the maximum injection molding pressure in terms of the filled volumes. The injection molding pressure were calculated within 146MPa at about 90% volume filled. We also investigated the possibility of the occurrence of design-related defects such flow marks, weld lines. Filling patterns regarding the design of the gate locations were delineated to find the weld lines. Throughout the simulations, the final deformations of the lens guiding lanes for the VCM housing were calculated. The deformations distribute ranging from $0.5{\mu}m$ to $2.50{\mu}m$, which were used to find the optimal design of the gates.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1003-1006
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• 2005

Demand of Auto Focus for Camera module is increased very fast in these days and will be adapted to most of mobile phones in next few years instead of traditional method, fixed focus. To make auto focus function, 2 kinds of solutions, VCM(Voice Coil Motor) and Piezo linear motor are normally used. In this paper, VCM which commercially strong candidate for Auto focus mechanism was investigated to verify principles are match up to the actual operation. Auto focus algorithm is different between 1 chip and 2 chip solution. Normally 2 chip is more complicate than the other. To have best performance on this function, hysteresis and depth of field(DOF) table should be optimized.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.605-610
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• 1994

This paper discusses the solution to the precise positioning control problem applied to a simple model of a dual stage or redundant positioner. The dual stage actuator presented here uses a VCM(Voice Coil Motor) as a coarse actuator and a piezoelectric actuator as a fine actuator. By adopting controllers with two-degree-of-freedom and by optimizing H$_{2}$ faster precise tracking can be realized. Experimental and numerical results are presented to demonstrate the control effects.

• Journal of the Korean Magnetics Society
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• v.20 no.6
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• pp.234-238
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• 2010

Solenoid diaphragm fuel pump, which to replace mechanical fuel pump system by utilizing cam-shaft driving force, is in the spotlight for being a high efficient green car component. However, there is a drawback in power consumption as a solenoid diaphragm fuel pump only relies on solenoid for its flux needed in reciprocating motion. Therefore, this research proposes permanent magnet type VCM (Voice Coil Motor) fuel pump system to minimized power consumption. Furthermore, the study compares and analyzes power consumption and dynamic performance between the current and the former solenoid diaphragm pump by conducting finite element analysis with the commercial electromagnetic solver, MAXWELL.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.51-58
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• 2008

This paper presents a new design of the precision stage for the reticle in lithography process and a low hunting control method for the stage. The stage has three axes for X, Y, ${\theta}_z$ those actuated by three voice coil motors individually. The designed reticle stage system has three gap sensors and voice coil motors, and supported by four air bearings and the forward/inverse kinematics of the stage were solved to get an accurate reference position. When a stage is in regulating control mode, there always exist small fluctuations(stage hunting) in the stage movement. Because the low stage hunting characteristic is very important in recent lithography and nano-level applications, a special regulating controller for ultra low hunting is proposed in this paper. Also this research proposed the 2-step transmission system for preventing the noise infection from environmental devices. The experimental results showed the proposed regulating control system reduced hunting noise as 35nm(rms) when a conventional PID generates 77nm(rms) in the same mechanical system. Besides the reticle stage has 100nm linear accuracy and $1{\mu}rad$ rotation accuracy at the control frequency of 8kHz.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.615-620
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• 2018

Evaluation of clinical usefulness of current perception threshold test and vibration sense perception threshold test in diagnosing the diabetic poly-neuropathy patients is one of the diagnosis methods for diabetic poly-neuropathy. Up to the present, some diagnostic methods were used for diabetic poly neuropathy patients. For example, there are neuropathy impairment score test of lower limbs, nerve conduction test, cooling detection threshold test, heat-pain threshold test and so on. However, most of the above tests require very expensive cost and take a lot of time in test. In this paper, a new apparatus estimating vibration sense ability is introduced. For this purpose, the VCM(voice coil motor) stimulating patient's peripheral nerve and current amplifier were manufactured. Also, softwares sensing and driving the vibration detection threshold test in order to measure the quantitative vibration sensory levels in diabetic poly-neuropathy patients were developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.780-785
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• 2003

Recently the trends in information storage devices need small size, mobility, high capacity, and low power consumption etc. To satisfy those, the development of high performance actuator is an important issue. Compared with general linear actuator for optical disk drive, swingarm type rotary actuator is suitable to design in small form factor and has fast access time for random access. Swingarm actuator is designed considering the structural problem and the actuating force of VCM(Voice Coil Motor). The increase of mass caused by optical components makes vibration problems of swing-arm, therefore resonance frequency should be increased and inertia has to be reduced. ANSYS FEM tool is employed in optimizing swingarm. The VCM is designed using 3-D electro-magnetic analysis, and parameters of magnetic circuit are determined to matte large flux density. The large flux density enables to achieve low power consumption. VCM holder is designed to get the mass balance of total actuator and this balance reduces the magnitude of critical mode relative to pivot bearing, It is expected that swingarm type rotary actuator designed by this method is available to variable type of micro optical disk drives.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.5
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• pp.399-406
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• 2001

This paper presents a dynamic modeling and a sliding mode controller for the high-speed/high-accuracy position control system. The selected target system is the wire bonder assembly which is used in the semiconductor assembly process. This system is a reciprocating one around the pivot point that consists of VCM(voice coil motor) as an actuator and transducer horn as a bonding tool. For the modeling elements, the sys-tem is divided into electrical circuit, magnetic circuit and mechanical system. Each system is modeled using the bond graph method and united into the full system. Two major aims are considered in the design of the controller. The first one is that the horn must track the given reference trajectory. The second one is that the controller must be realizable by using the DSP board. Computer simulation and experimental results show that the designed sliding mode controller provides better performance than the PID controller.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.564-568
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• 2006

Smooth picture module is operated by vibration to tilt the light from the DMD (digital micro mirror device) of DLP projection TV, which makes the screen of the TV smoother and DMD chip cost lower. To satisfy the vibration characteristics of smooth picture module, it is designed by optimizing moment of inertia, spring constant and damping coefficient, using structural and fluid dynamic simulation that showed a good agreement with experimental data. To reduce the material cost and moment of inertia, engineering plastic is used and the reliability is estimated. A VCM (voice coil motor) type actuator for smooth picture has to satisfy performance requirements such as higher driving force, lower power consumption, and lower cost. The initial design and optimization for VCM was performed using FE analysis. It allowed us to optimize the design of magnetic circuit of the proposed actuator to obtain higher force while maintaining a lower cost.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.664-669
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• 2003

This paper proposes a swing-arm type dual-stage actuator, which consists of a PZT actuator for fine motion and a VCM(Voice Coil Motor) for coarse motion, for SFF ODD(Small Form Factor Optical Disk Drive), in order to achieve fast access speed and precise track following control. We focus our attention on the design and control of the PZT actuator, because there have been a lot of previous researches related to the VCM and dual-stage actuators. Due to the dual cantilever structure, the PZT actuator can generate precise translational tracking motion at its tip where optical pickup is attached at, and the effect of hysteric behavior of the PZT element is reduced. The dynamic model of the PZT actuator is derived by using the Hamilton's principle, and verified by comparing with the experimental frequency response. The sliding mode control is designed in order to be robust against modeling uncertainties. Simulations and experimental results confirm the effectiveness of the suggested control scheme.