2X Optical Digital Zoom Lens with Short Total Length and Extremely Small Front Aperture for Two Million pixel CMOS on Mobile Phone

Abstract

2X Optical Zoom lens on compact mobile phone have increasingly demand in recent years but few samples succeed to be compactable with very thin mobile phone, especially in CMOS pixels more than two millions. Most mobile phone finally are reluctant to increase the thickness of mobile phone to accommodate the optical zoom lens or whole mobile phone has to be redesigned to fit the large lens in right place. In this paper, a newly design is proposed that its overall total length is reasonably small compared to current mobile phone camera with two million CMOS pixels. The most important is that its diameter of front aperture is extremely small because the aperture stop is the first element of this 2X optical zoom lens. The result shows that its MTF (modulation transfer function) matches the requirement of optics lens for two million CMOS pixels.