Design of iris recognition lens of mobile phone

With the rapid commercialization of image sensors and the development of biometric recognition algorithms in recent years, iris recognition function has been applied to mobile terminal devices. The iris image acquisition is the first and the key step in iris recognition. Here one group of iris recognition lens was designed for mobile phones by the ZEMAX optical design software. This design is composed of three chip aspherical lenses of optical plastic, with OmniVision_OV2281 sensor of Howe technologies. With designed F parameter of 2.3 and a viewing angle of 34°, the MTF values can all be greater than 0.39 at 1/2 Nyquist frequency 220 lp/mm. And the length of the whole system is only 3 mm. According to the ZEMAX image quality evaluation method and tolerance analysis, the optimized results show that the designed lens can match well with all the optical requirements, and has the characters of good image quality, small volume, light weight, low cost and easy processing.