Research On The Design Of CCD Module Lens For Scanner

In the context of today’s information society, scanners as a computer peripherals which can fast and convenient turn graphic information into digital signals that computers can recognize and transmit, get people’s attention. In various scanners widely used today, the resolution of the conventional scanner which in the main scanning linear sweep mode requires a new breakthrough.This paper analyzed the A4 plate-type scanner optical path principle of imaging system, determined the type of two lens that respectively to be designed, and combining with the CCD specifications, and the resolution of the scanner and other requirements, determined the design indicators of the optical system. Based on the primary aberration theory, the appropriate aberration equation was deduced, and structured equations, and then in the Matlab software, by structuring the Fsolve function to solve the equations, then got the initial structure, and then in ZEMAX software, aberration analysis and the optimization of the initial structure were done, finally completed the meet with the design requirements in the two lenses. Various aberrations were well controlled and the system effectively diffuse spot radius was less than 7μm and closed to the diffraction limit, and full field modulation transfer function (MTF) was more than 20%　in 96 line pairs, and the imaging quality matched the CCD resolution so that the entire scanner resolution reached to 4800dpi.Considering about the actual production and assembly, after designing we complete the set of templates, and tolerance analysis and distribution of the lens. Finally we completed the production of the sample and its optical Modulation Transfer Function (MTF) was detected.