【作者】 李莉；

【导师】 曾延安；

【作者基本信息】 华中科技大学 ， 光电信息工程， 2017， 硕士

【摘要】 随着现代光电子技术的飞速发展,微光夜视仪的性能质量大大提高,广泛地应用于军用和民用等多个领域。但受到强光照射后,其核心器件——像增强器容易“散焦”,出现图像模糊的现象,持续的强光还会严重损伤像增强器,导致仪器完全失效。由此可见,研究微光夜视仪的强光保护装置具有较强实用意义。论文在研究微光夜视仪在强光作用下疲劳与损伤机理的基础上,对基于“选通电源”技术的微光夜视仪强光防护装置展开了研究,并进行了实际应用和检测。在大量检索国内外相关文献和调研了该产品的技术指标和实现原理的基础上,论证了微光夜视仪强光保护装置主要技术途径,研究了基于选通电源技术的微光夜视仪强光保护方案。当强光照射时,荧光屏屏电流较大,以此作为取样信号,反馈控制阴极工作电压持续供电时间较短;当处于弱光照射时,反馈信号较弱,阴极工作电压近似为直流高压。针对像增强器电路系统,设计自动门控电源,实现了对微光观察镜中的像增强器的改造,在保证整体结构没有改变,充分利用原电路的情况下,通过FPGA技术控制的选通电源技术实现PWM信号输出,利用脉宽可调的TTL信号控制IGBT器件输出近似为矩形平顶的240V直流高压,实现了强光保护。最后研究了像增强器调制传递函数检测的方法,对改造前后像增强器调制传递函数进行了对比检测,对改进的微光夜视仪整机性能进行检测,并与未经实施改造的微光夜视仪工作性能进行了比对试验,结果达到了设计要求。更多还原

【Abstract】 With the rapid development of modern photoelectronic technology,the performance of LLL night vision device has been greatly improved,and it has been widely used in military,civilian and other fields.But the core device—the image intensifier is easy to defocus after it is exposured by highlight,which the image is blurry.The continuous highlight will seriously damage the image intensifier so that the instrument runs out completely.Therefore,it is of great practical significance to study the highlight protection device of LLL night vision device.Based on the study of the fatigue and damaged mechanism of the LLL night vision device in the effect of the bright light,the light protection equipment of the LLL night vision device under the the technology of the “gating power” is studied,and the actual application and detection are carried out.On the basis of firstly researching a large number of relevant literatures at home and abroad and probing into the technology index and the realization principle of the product,the author demonstrates the main technical way of the highlight protection equipment of the LLL night vision device and investigates the highlight protection schemes of the LLL night vision device with the gating power technology.When the highlight irradiates,the electric current of fluorescent screen is large,regarding the sample as a signal to feedback that the continuous power supply time of the control cathode working voltage is short;when it is in low light irradiation,the feedback signal is weak,and the working voltage is approximate to the direct current high voltage.At the aim of the image intensifier circuit system,the design of auto-gated power achieves the transformation to the image intensifier in the mirror through the helmet-mounted glimmer observation.In the case of ensuring the overall structure unchanged and making full use of the original circuit meter,the PWM signal output is achieved with the FPGA technology controlling the gating power technology.Utilizing the TTL signal of the pulse width modulation to control the output of the IGBT device that is approximately the 240 V direct current high voltage of the rectangular flat,the highlight protection is achieved.Focus on studying the MTF inspect methods of image intensifier,conducting the comparison test to the MTF of image intensifier remoulded before and after,and comparing the detection on the performance of the improved helmet-mounted LLL night vision device of complete machine with that of the unmodified LLL night vision device to test,the results meet the design requirements.更多还原