红外技术, 2018, 40 (7): 691, 网络出版: 2018-08-04
像增强器阴极脉冲与屏极亮度稳定性关系研究
Study on the Relationship between Image Intensifier Cathode Pulse and Plate Brightness Stability
微光像增强器 自动门控电源 高压脉冲 人眼视觉特性 image intensifier auto-gating power source high voltage pulse human visual system
摘要
针对装配有自动门控电源的像增强器在高照度的情况下会出现闪烁的现象,结合自动门控电源阴极高压脉冲信号的离散特性和人眼视觉特性,分析了整管在高照度的情况下出现人眼可见闪烁现象的原因及解决办法,提出亮度最小可觉差和视觉暂留效应是有关人眼观察舒适性的重要特性。在高照度的情况下,由于自动亮度控制功能的介入,阴极高压脉冲信号的占空比会自动降到一个较低的值,但是由于器件的限制,阴极高压脉冲信号占空比的步进值是一个固定的常数,故阴极高压脉冲信号的占空比越低,其步进值对阴极高压脉冲信号的影响越大,最终也就对像增强器的屏极亮度稳定性影响越大。通过对人眼视觉特性的分析及对阴极高压脉冲信号的计算,给出了阴极脉冲信号允许的最小占空比及最小开启脉冲宽度的要求,并给出了计算方法。
Abstract
In the case of high illumination, an image intensifier with an auto-gating power source may flicker. Based on the discrete characteristics of the high voltage pulse signals of the auto-gating power source and the human visual system, the cause and solution of the flicker phenomenon of the human eye under high illumination are analyzed. The minute difference in luminance and the persistence of vision is an important characteristic of human eye comfort. In the case of high illumination, the duty cycle of the cathode high voltage pulse will automatically drop to a lower value due to the automatic brightness control function. However, due to the limitations of the device, the step value of the duty-cycle of the high voltage pulse signal is constant. Therefore, the cathode of the high voltage pulse duty ratio is lower and the step value on the cathode of the high voltage pulse is greater. Ultimately, it has larger effect on the intensifier brightness stability. Based on the analysis of the human visual system and the calculation of the cathode high voltage pulse signal, the minimum duty cycle and the minimum open pulse width of the cathode pulse signal are determined in addition to the calculation method.
杨晔, 倪小兵, 延波, 智强, 李军国. 像增强器阴极脉冲与屏极亮度稳定性关系研究[J]. 红外技术, 2018, 40(7): 691. YANG Ye, NI Xiaobing, YAN Bo, ZHI Qiang, LI Junguo. Study on the Relationship between Image Intensifier Cathode Pulse and Plate Brightness Stability[J]. Infrared Technology, 2018, 40(7): 691.