Thermal control design and analysis of a zoom TV optical mechanical system

<p>In view of whether the optical system of a focal length 14?360mm continuous zoom TV can obtain high quality and high reliability images in high and low temperature environment, especially in extreme low temperature environment. The thermal design of zoom TV optical-mechanical system using passive thermal control and active thermal control is proposed. The passive thermal control uses polyimide as insulation material to increase the thermal resistance between the camera interior and the outside. Active thermal control uses electric heating film to dynamically heat the key parts of the camera lens. Under the condition of low temperature, the finite element method is used to establish the heat transfer model of the whole lens assembly in the workbench finite element software, and analyze the heat load composition, including the heating power load, the heat convection load and the heat radiation load, and carry on the steady state thermal analysis. Through thermodynamic analysis and experimental verification, the consistency of focal plane of zoom camera optical system is good after taking active thermal control measures at the extreme low temperature of-45&deg;C. The optical transfer function (OTF) of zoom lens at cut-off frequency (100lp/mm) is 0.25 higher than that before thermal design, which can meet the requirements of thermal control design with better transfer function distribution and higher imaging quality. The correctness of the simulation results and the rationality of the optical-mechanical design are verified. ? 2019 SPIE.</p>