室内用双CCD交汇精度靶平板光源设计及实现

Design and Realization of Plate Light Source Used in Dual CCD Intersection Precision Target

针对现有室内双CCD交汇精度靶光源存在的发光不均匀、亮度低等问题,提出了由小功率LED、导光板、散射板、棱镜膜等单元组成的适用于室内双CCD交汇精度靶的平板光源解决方案,通过对导光板中的网点半径及分布进行计算,建立其数学模型进行网点排列,设计了适用于此平板光源的导光板.选择合适的扩散板和棱镜膜对导光板发出的光线进行扩散汇聚.通过高速CCD相机采集平板光源所产生的背景光图像实验,经过Matlab进行数字图像处理,分析其灰度值曲线.研究结果表明:光源与CCD相机相距1.5m处高灰度值为35,灰度值均匀度为±5.根据实验验证平板光源具有发光均匀、稳定,且功耗低的优点.

In view of the uneven lighting and low brightness of the existing indoor dual CCD intersection precision target source,a flat light source for indoor dual CCD intersection precision target is presented. The flat light source is composed of small power LED, light guide plate, scattering plate and prism film unit. The dot radius and distribution are calculated to get the mathematical model by which the outlets are arranged and the light guide plate is designed. The suitable diffusion plate and prism film are selected for diffusion and aggregation of the emiting light from light guide plate. Background light images generated by flat light source is acquisited using a high-speed CCD camera, the gray value curve is obtained through the Matlab digital image processing. Research shows： While the distance of the light source and the CCD camera is 1.5m,the high gray value is 35 and gray value uniformity is ±5. According to the experimental verification, the flat light source is lighting uniform and stable, and with low power consumption.