In keeping with consumers' preferences for electronic products of ever smaller size and enhanced functionality, it is necessary to reduce the profile of the auto-focusing actuators used in camera phones without sacrificing their performance. Accordingly, this study modifies the Voice Coil Motor (VCM) actuator proposed by the current group in a previous study (C. S. Liu and P. D. Lin, Opt. Express, 16, 2533-2540, 2008) to accomplish a miniaturized auto-focusing actuator for cell phone camera modules with minimal power consumption. The proposed device comprises a VCM, a closed-loop position control system, a magnetoconductive plate, and a lens support structure to drive the lens to the optimal focusing position. The experimental results show that the actuator has a zero holding current when maintaining the lens in the specified focusing position. Overall, it is shown that compared to existing VCM actuators, the proposed actuator has both a higher power efficiency and an improved positioning repeatability.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics