Mobile phone camera lens design with reduced flare

Abstract

Optimization of a mobile imaging lens, which is for 5-megapixel, 1.4μm, CMOS image sensor, with multiple configurations to reduce flare is presented. The most severe flare, which could cause artifacts such as "purple flare" in images, is due to totally internal reflection (TIR) from optical surfaces in a mobile phone camera lens. We illustrate how to optimize the lens for good performance and manufacturable tolerances to reduce flare due to TIR. The MTF, distortion, relative illumination, lateral color, cumulative probability function for lens with tolerances and flare amount is shown for the starting lens. An optimization method for lens design to reduce TIR flare is proposed and described. The resulting optimized lens performance, tolerances and flare are compared with that of the starting lens.