高性能分离式远程EMCCD成像系统研制

Design of Distributed EMCCD Image System with High Sensitivity and Remote Data Acquisition

论述了基于一种1 024×1 024像素EMCCD图像传感器CCD201的高性能分离式远程成像系统设计方法。采用光纤通信技术,系统分为成像端与控制端,使系统可用于远程监测场合。利用CPLD器件产生CCD逻辑时序及视频同步处理控制时序,采用集成器件与分立器件相结合的方式实现EMCCD垂直驱动时序,获得视频信号;使用带有CDS功能的16位模数转换器对CCD视频信号进行数字化;数字化图像经由光纤发送到远程控制采集端。采用全双工通信,实现电子增益、放大倍数、温度等参数的远程控制。文中详细介绍了驱动电路、视频处理电路、数据远程交互单元与控制采集单元等关键组成部分的技术实现方法。设计的成像系统采用USB方式进行数据实时采集,能够连续获取16位数字图像数据,光动态范围大于70 d B,增益倍数最高能够大于0.1e-/ADU,控温精度达到±0.5℃。设计方法可应用于类似CCD成像系统的设计中,并使系统能够在微光成像及辐射场诊断中应用。

A design method of high performance distributed remote image system around a back illuminated 1024×1024 pixels EMCCD image sensor was proposed.Adopting optical fiber communication technology, the system was divided into the imaging unit and control unit.The system can be used in remote monitoring fields.A CPLD was adopted to generate the CCD driver timing and video processing timing.The integrated device and diacrete device were combined to realize EMCCD perpendicular drive, and the video signal was acqired.Adopting a CCD analog front-end chip with CDS function, the CCD video signal was sampled and digitized into 16bits digital image data.The image data was transmitted to a USB data acquire card via fibers cable.With full-duplex communication, the remote control of EM gain, temperature and other parameters is achieved.The design method of driver circuit, video processing circuit, data communication circuit and system control unit was introduced.The image system can acquire 16 bits digital image data simultaneously via a USB port.Experimental resuhs show that the optical dynamic range can exceed 70 dB, and the remote programmable control electron multiplication can operate at the gain more than 0. 1e^-/ADU.h can keep the setting temperature value in the scope of the error（±0.5℃ ） .The design is used in the remote EMCCD imaging system which can be applied in the low light level imaging area and radiation diagnosis field.