基于光机集成分析的火情监察红外变焦镜头主动消热差设计  

Active Athermalization Design of Infrared Zoom Lens for Fire Monitoring Based on Opto-mechanical Integration Analysis

作　　者：尹晶 刘旭 徐晓影 崔艳群 王强 郭富城 YIN Jing;LIU Xu;XU Xiaoying;CUI Yanqun;WANG Qiang;GUO Fucheng(Changchun College of Electronic Technology,Changchun 130114,China)

机构地区：[1]长春电子科技学院,吉林长春130114

出　　处：《红外技术》2021年第11期1073-1080,共8页Infrared Technology

摘　　要：红外变焦监视镜头的F数与焦深相对较小,因此温度变化极易导致离焦现象,导致成像质量下降。本文针对火情监察红外变焦镜头在-40℃~50℃范围内成像清晰的技术要求,采用有限元法分析温度变化下各光学镜片前后镜面的刚体位移与旋转量,将刚体位移导入至Sigit光机集成分析软件中仿真出温度变化工况下镜头的离焦量,分析结果表明焦距值变量在-0.16~+0.4 mm之间,调焦量为0.108~0.188。针对上述情况,采用两个凸轮两套执行机构来分别控制变倍组和补偿组的移动,实现镜头的主动消热差保证温度变化下成像仍旧清晰。最终通过温度可靠性实验对镜头光学分辨率温度适应性的进行考核,实验结果表明在温度变化过程中空间分辨率均大于30 lp/mm,变焦过程成像质量基本清晰。The F-number and focal depth of infrared monitoring zoom lens are relatively small;therefore,the temperature change can easily cause defocusing,resulting in the deterioration of imaging quality.This article is aimed at the technical requirements for the clear imaging of the fire monitoring infrared zoom lens in the range of-40℃to 50℃.The finite element method is used to analyze the rigid body displacement and rotation of the front and rear mirrors of each lens under temperature changes and import the rigid body displacement into the Sigit optical-mechanical integrated analysis software to simulate the defocus of the lens under temperature change conditions.The analysis result shows that the focal length variable is between-0.16 to 0.4 mm and the focusing amount is 0.108 to 0.188.In response to the above situation,two cams and two sets of actuators are used to control the movement of the zoom group and the compensation group respectively,for realizing the active athermalization design of the lens to ensure that the imaging is still clear under the condition of temperature change.Finally,the temperature adaptability of the lens optical resolution is evaluated through a temperature reliability experiment.The experimental results show that the spatial resolution is greater than 30 lp/mm during temperature change.The image quality is basically clear during zooming process.

关 键 词：火情监察 光机集成分析 红外变焦镜头 主动消热差 

分 类 号：O439[机械工程—光学工程]