基于TIR透镜的动态星模拟器照明光学系统设计

TIR Lens-based Optical System Design for Dynamic Star Simulator Illumination

动态星模拟器对DMD芯片有效工作区域内的光斑均匀度有着极高的要求,对LED发出的光线进行准直有利于提高DMD处均匀度。为了提高光线的准直度且简化动态星模拟器照明光学系统结构,采用自由曲面的TIR准直透镜作为照明光线准直器件。首先根据空间全反射定律、折射定律及三角函数关系解算出全反射曲面母线和折射曲面母线上各点的递推关系,并根据DMD芯片参数和LED发光面尺寸确定合理的初始值及边界值,采用迭代法计算出曲线上各点的坐标,从而拟合出全反射曲面母线及折射曲面母线。利用三维建模软件CATIA建模,得到TIR透镜的三维模型,采用理想光源及拓展光源在光学软件Lighttools中对TIR透镜的准直效果进行模拟仿真。结果表明,LED发出的光线经TIR透镜准直后发散角在±5°之内。基于设计的TIR透镜建立照明光学系统进行模拟仿真,结果显示DMD芯片有效工作区域内的光斑均匀度为98.6%,并基于此照明系统,分别对DMD芯片在On状态下和Off状态下进行光线追迹模拟,验证了其可行性。

The dynamic star simulator has high requirements for the spot uniformity in the effective working area of the DMD chip,and the collimation of the light emitted from the LED is helpful to improve the uniformity at the DMD.In order to improve the light collimation and simplify the structure of the dynamic star mode illumination optical system,a free-form TIR collimating lens is used as the illumination light collimation device.Firstly,the recurrence relationship of the points on the total reflection surface bus and the refraction surface bus is solved according to the law of total reflection,the law of refraction and the trigonometric relationship,and the reasonable initial and boundary values are determined according to the DMD chip parameters and the LED light-emitting surface size,and the coordinates of the points on the curve are calculated by the iterative method to fit the total reflection surface bus and the refraction surface bus.The 3D modeling software CATIA is used to obtain the 3D model of the TIR lens,and the collimation effect of the TIR lens is simulated in the optical software Lighttools using the ideal light source and the extended light source.The results show that the light emitted from the LED is within±5°of the dispersion angle after collimation by the TIR lens.Based on the designed TIR lens,the lighting optical system is simulated,and the results show that the spot uniformity in the effective working area of the DMD chip is 98.6%,and based on this lighting system,the light tracing simulation of the DMD chip in the On state and Off state is carried out respectively to verify its feasibility.