The Thermal Analysis On Miniature CCD Space Camera

The miniature CCD (charge coupled device) space camera, as the unique payload in the small satellite, is in a complicated space thermal environment. Taking no thermal controlling measure will result in the temperature gradients in optical mirrors, which can cause thermal stress and thermal distortion. The stress and distortion will produce relative position error between optical elements and optical image surface distortion, which can effect the optical image quality. CCD camera's dimension and mass are strict limited. So how to adopt simple and effective thermal controlling to ensure the reliable optical performance and good image quality under space thermal environment, which means the exactly relative position between optical mirrors, the optical surface deformation within tolerance allowance and the circuit system at working temperature range, is researched in this paper.To ensure CCD camera work regularly and satisfy the resolution index, factors that influence the camera's temperature and temperature gradients and the space thermal environment around the camera are analyzed in this paper, tentative thermal controlling measures for the lens drum outer baffle and the camera body are taken by the use of thermal transfer theory. According to the design remand of optical lens, utilizing the finite element method and temperature-index method, non-sensitization design of the lens assembly is taken, the temperature index of the lens assembly is determined. Thermal design of the circuit housing is taken. Under given work conditions, the temperature field and deformation of the lens drum outer baffle and the temperature field of the camera body after and before adopting thermal-controlling are compared, which indicates the deformation of the lens drum outer baffle is within tolerance allowance, the lens assembly and the circuit housing assembly are at the working temperature ranges. Consequently the rationality of the thermal-controlling is proved, thermal controlling for CCD camera is necessary and effective and the image quality of the miniature CCD camera is ensured.