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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 16, Iss. 4 — Feb. 18, 2008
  • pp: 2533–2540

A miniaturized low-power VCM actuator for auto-focusing applications

Chien-Sheng Liu and Psang Dain Lin  »View Author Affiliations

Optics Express, Vol. 16, Issue 4, pp. 2533-2540 (2008)

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In keeping with consumer preferences for ever smaller electronic products, a requirement exists for compact, high-performance auto-focusing actuators for the camera modules deployed in cell phones. Accordingly, the present study proposes a miniaturized electromagnetic-based actuator comprising a voice coil motor (VCM) and a closed-loop position control system in which an auto-focusing capability is achieved by using a position feedback signal generated by a Hall element to dynamically adjust the position of the lens module. The experimental results show that the holding current required to maintain a lens module weighing 200 mgw in the vertical position is 17 mA ±2 mA. Compared to conventional VCM actuators deployed in cell phone camera applications, the actuator presented in this study has a smaller size (6.5 mm×6.5 mm×4 mm) and an improved power efficiency. In particular, the miniaturized actuator reduces the holding current required to maintain the lens module in the focusing position by around 75% of that required in a traditional actuator.

© 2008 Optical Society of America

OCIS Codes
(040.1490) Detectors : Cameras
(230.2090) Optical devices : Electro-optical devices
(260.5950) Physical optics : Self-focusing

ToC Category:
Imaging Systems

Original Manuscript: December 18, 2007
Revised Manuscript: February 3, 2008
Manuscript Accepted: February 6, 2008
Published: February 8, 2008

Virtual Issues
Vol. 3, Iss. 3 Virtual Journal for Biomedical Optics

Chien-Sheng Liu and Psang Dain Lin, "A miniaturized low-power VCM actuator for auto-focusing applications," Opt. Express 16, 2533-2540 (2008)

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