Thin and Tiny Focus-tunable Lens for Mobile Devices and Its Measurement System

摘要

This paper presents a thin, tiny, and electrically focus-tunable lens module for mobile devices and proposes its focal length measurement system. Previously, we have developed a thin and electrically tunable lens whose focus changes under applied voltage. One of the most important thing in developing electrically tunable lenses is to easily and conveniently measure its focal length as we change applied voltage. Therefore, we suggest a new measurement system which automatically obtains the focal length and its variation via image processing technique. The new measurement system is composed of a collimated light, a target lens, a detection screen, a camera, and a user interface software with an image processing module. We measured the focal lengths of the developed electrically tunable lens with a custom built optical setup and with the proposed system. The results with two different measurement setups for focal length addressed that the proposed system would be very helpful and effective for electrically tunable lenses in terms of swiftness, ease, and convenience. It is expected that the results of this study would be beneficial to researchers and developers in the area of thin electrically tunable lenses.