Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-23T14:47:26.883Z Has data issue: false hasContentIssue false
  • English
  • Français

Simplified Numerical Model for Rapid Design of AF Module Spring Shape Parameters

Published online by Cambridge University Press:  28 June 2017

D. S. Liu ,
C. J. Lu ,
S. H. Chen ,
C. S. Liu  and
T. W. Liao
D. S. Liu
Affiliation:
Department of Mechanical EngineeringAdvanced Institute of Manufacturing for High-tech InnovationsNational Chung Cheng UniversityChiayi, Taiwan
C. J. Lu*
Affiliation:
Department of Mechanical EngineeringAdvanced Institute of Manufacturing for High-tech InnovationsNational Chung Cheng UniversityChiayi, Taiwan
S. H. Chen
Affiliation:
Department of Mechanical EngineeringAdvanced Institute of Manufacturing for High-tech InnovationsNational Chung Cheng UniversityChiayi, Taiwan
C. S. Liu
Affiliation:
Department of Mechanical EngineeringAdvanced Institute of Manufacturing for High-tech InnovationsNational Chung Cheng UniversityChiayi, Taiwan
T. W. Liao
Affiliation:
Department of Mechanical EngineeringAdvanced Institute of Manufacturing for High-tech InnovationsNational Chung Cheng UniversityChiayi, Taiwan
*
*Corresponding author ([email protected])
Get access

Abstract

The autofocusing (AF) performance of cell phone cameras is critically dependent on the design of the voice-coil motor (VCM) used to drive the lens module. Also, the metal springs in the AF module should combine high stiffness with a good actuation response and a light weight. The present study utilizes a reverse engineering approach to construct three-dimensional finite element models of the top and bottom springs in the VCM mechanism. Simulations are then performed to investigate the von Mises stress distribution and stiffness characteristics of the two springs given horizontal and vertical orientations of the AF module, respectively. In performing the simulations, the actuation force is computed using two different analysis methods, namely a simplify structure method and a coupled electromagnetic-structural method. It is shown that the simplify structure method has the advantages of a lower computational complexity and a more comprehensive modeling capability. A further series of simulations is thus to examine the effects of the spring shape parameters on the reaction force developed by the spring stiffness. The results show that the spring stiffness increases with an increasing thickness and a decreasing rib length. The simulation results obtained for different spring shape parameter settings are summarized in the form of a parameter design chart for predicting the reaction force given known values of the spring rib length and spring thickness.

Keywords

Autofocus (AF) moduleFinite Element Analysis (FEA)Simplify structure methodCoupled electromagnetic-structural method
Type
Research Article
Information
Journal of Mechanics , Volume 34 , Issue 5 , October 2018 , pp. 591 - 600
Copyright
Copyright © The Society of Theoretical and Applied Mechanics 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Sohn, S. M. et al., “Soc Design of an Auto-Focus Driving Image Signal Processor for Mobile Camera Applications,” IEEE Transactions on Consumer Electronics, 52, pp. 10–16 (2006).Google Scholar
2. Yu, H. C. et al., “Design of a Voice Coil Motor Used in the Focusing System of a Digital Video Camera,” IEEE Transactions on Magnetics, 41, pp. 3979–3981 (2005).Google Scholar
3. Yu, H. C. et al., “Low Power Consumption Focusing Actuator for a Mini Video Camera,” Journal of Applied Physics, DOI: 10.1063/1.2158927 (2006).Google Scholar
4. Kusaka, H., Tsuchida, Y. and Shimohata, T., “Control Technology for Optical Image Stabilization,” SMPTE Motion Imaging Journal, 111, pp. 609–615 (2002).Google Scholar
5. Song, M. G. et al., “Development of Small Sized Actuator with Compliant Mechanism for Optical Image Stabilization,” IEEE Transactions on Magnetics, 46, pp. 2369–2372 (2010).Google Scholar
6. Chung, M. J. and Son, S. Y., “Development of Compact Auto Focus Actuator for Camera Phone by Applying New Electromagnetic Configuration,” Journal of Mechanical Science and Technology, 20, pp. 2087–2093 (2006).Google Scholar
7. Chao, P. C. P., Chiu, C. W., Liang, H. K. and Kao, N. Y. Y., “Intelligent Actuation Strategy Via Image Feedbacks for a Magnetically Actuated Autofocusing Module in Mobile Phones,” Journal of Applied Physics, DOI: 10.1063/1.2835451 (2008).Google Scholar
8. Liu, C. S. et al., “Design and Characterization of Miniature Auto-Focusing Voice Coil Motor Actuator for Cell Phone Camera Applications,” IEEE Transactions on Magnetics, 45, pp. 155–159 (2009).Google Scholar
9. Liu, C. S. and Lin, P. D., “A Miniaturized Low-Power VCM Actuator for Auto-Focusing Applications,” Optics Express, 16, pp. 2533–2540 (2008).Google Scholar
10. Chiu, C. W., Chao, P. C. P. and Wu, D. Y., “Optimal Design of Magnetically Actuated Optical Image Stabilizer Mechanism for Cameras in Mobile Phones Via Genetic Algorithm,” IEEE Transactions on Magnetics, 43, pp. 2582–2584 (2007).Google Scholar
11. Bissal, A., Eriksson, A., Magnusson, J. and Engdahl, G., “Hybrid Multi-Physics Modeling of an Ultra-Fast Electro-Mechanical Actuator,” Actuators, 4, pp. 314–335 (2015).Google Scholar