Abstract:
To meet the needs of mobile phone telephoto photography and address issues like short focal length, small aperture, long focusing distance, large volume and significant chromatic difference of the existing periscope mobile phone telephoto lens, a periscope telephoto macro mobile phone lens was designed, which with a 64-megapixel sensor, an image plane of 12.7 mm (1/2 inch) in size, an equivalent focal length of 100 mm, an
F-number of 2.3, and dimensions of 30 mm×8 mm×8.5 mm. A telephoto lens configuration with two reflective prisms to extend the optical path was adopted to achieve longer focal lengths, and a central single-movement group structure was adopted to achieve 100 mm macro focusing, which used a symmetric three-piece design and selected ultra-low-dispersion glass-bonded lenses as well as aspherical plastic lenses to achieve apochromatism and low-focusing aberration of the system. The design results show that, for telephoto and 100 mm macro photography, the modulation transfer function (MTF) of the central field of view at the Nyquist frequency of 356 lp/mm is greater than 0.39 and 0.22, respectively. The relative distortion of the system is less than 1.5%, and the relative illuminance is greater than 46.9%. The tolerance analysis results show that the manufacturing process is feasible and the yield rate is high. The design effectively meets the requirements of mobile phone telephoto lens in terms of long focal length, large aperture, macro photography and low chromatic aberration.