Proceedings Article | 5 November 2020
KEYWORDS: Zoom lenses, Visible radiation, Imaging systems, Modulation transfer functions, Image processing, Distortion, Sensors, Image sensors, Glasses
In this paper, a TV component of 16 times visible light continuous zoom lens is presented based on 1280×1024@2.7 micron COMS device. The system adopts 4 groups of 12 lenses to achieve continuous zoom, the former fixed group consists of 1 set of adhesive lenses and 1 single lens, the zoom group use 2 single lenses and 1 set of adhesive lenses, the compensating group use 3 single lenses and 1 set of adhesive lenses, and the latter fixed group consists of 2 sets of adhesive lenses and 1 single lens. After selecting three focal length positions for calculation and simulation, when the focal length are 5mm, 40mm and 80mm, the MTF of each field of view is above 0.3 at 120lp/mm, the total length of the system is less than 200mm, the field Angle is 1.6°×24.1°, F# is 4, and the focal length can be up to 5mm-80mm. The root-mean-square value of the dispersion circle size of each focal length position of the 16-fold visible light continuous zoom TV lens is less than the size of one pixel, so the image quality of each focal length position of the system is better. When the system is in the short focus position, the variable doubling group and the compensation group are at two ends, and the distance between them is the largest. When the system changes from short focus to long focus, the variablesize group and the compensation group approach to the middle, and the distance between them becomes smaller. In the process of system zoom, the image quality is clear, the CAM curve is smooth and suitable for processing. Continuous zoom TV lens all adopt spherical mirror with the characteristic of manufacturing easily, and the glass materials of the system are all taken from Chengdu bright glass library that the materials are easy to obtain. The zoom curve of the continuous zoom lens is smooth and the image is clarity. The distortion of the full view field is less than 3%, which meets the system requirements of the TV lens components.
