Development of Compact Auto Focus Actuator for Camera Phone by Applying New Electromagnetic Configuration

  • Chung, Myung-Jin (Department of Mechatronics Engineering, Korea Polytechnic University) ;
  • Son, Sung-Yong (Department of Electric and Information Engineering, Kyungwon University)
  • Published : 2006.12.01

Abstract

In this paper, auto focus actuator, which is used to move a lens module in the mobile phone having a camera module, is developed. Camera module containing auto focus actuator requires to minimize total size because of characteristics of the application area such as mobile phone, digital camera, and personal digital assistant. There are stepping motor, voice coil motor, and piezoelectric motor as auto focus actuator. In this paper, voice coil motor having new electromagnetic configuration is proposed. And actuator using proposed voice coil motor is developed by optimal design method using magnetic circuit analysis. The sectional area of the developed actuator is reduced to 32.4% compared with actuator using general electromagnetic configuration. From the performance test, the developed actuator has moving stroke of 0.64 mm for 2.1 volt, hysteresis of 40 $\mu$m, full stroke current of 54 mA, and unit step motion of 3 $\mu$m.

Keywords

References

  1. ?Choi, I. M., Kim, S. H., Kwak, Y. K. and Choi, K. B., 1999, 'A New Optical Disk Actuator Combining Coarse and Precise Fine Motion in a Single Actuation System,' KSME, Vol. 23, No.3
  2. Chung, M. J. and Gweon, D. G., 2003, 'Optimal Design and Development of Elecrtomagnetic Linear Actuator for Mass Flow Controller,' KSME International Journal, Vol. 17 , No. 1
  3. Chung, M. J. and Gweon, D. G., 2002, 'Modeling of the Amrture Slotting Effect in the Magnetic Field Distribution of a Linear Permanent ?Magnet Motor,' Electrical Engineering, Vol. 84
  4. Chung, M. J., 2005, 'Actuators for Optical Zoom and Auto-Focus in the Camera Phone,' Electronic parts and components, No.3
  5. Hanselman, D. C., 1994, Brushless PermanentMagnet Motor Design, McGraw-Hill, New York
  6. Kim, H. S., In, C. H., Yoon, G. H. and Kim, J. W., 2005, 'Design and Fabrication of a Micro PZT Cantilever Array Actuator for Applications ?in Fluidic Systems,' Journal of Mechanical Science and Technology, Vol. 19, No.8
  7. Kim, K. H., Lee, M. G. and Gweon, D. G., 2001, 'The Design and Performance Test of Tracking Actuator for NFR System,' KSPE, Vol. 18, No.8
  8. Lee, S. J., 2004, Industry of Camera module, Industry outlook