CHEN Chen, LI Wei-shan, ZHANG Yu, LIU Xiao-chan. Optical Design of Short Focal Digital Projection Lens[J]. Acta Photonica Sinica, 2011, 40(12): 1855
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To meet the requirement of market, a short focal digital projection lens for 0.8 inch digital light processing(DLP) projectors is designed. The total length is 172.6 mm, and the full aperture is 70 mm. The lens uses a retrofocus structure, and it is composed of six glass lenses and one plastic lens (two even aspheric surfaces). Its FOV is 80°, F-number is 2.1, retrofocus proportion is 3.17∶1, and projection ratio is 0.76∶1. Its MTF in all field is less than 28° that is higher than 0.6 at the limiting spatial frequency of 37 lp/mm. The lateral color is less than 3.5 μm. The distortion of the full of view is less than 1.1%. Its image quality is excellent with advantages of simple structure, small size, easy process and low cost.