高时间分辨sCMOS成像系统

High Time-Resolution sCMOS Imaging System

为使科学级CMOS图像传感器适用于高速瞬态过程成像,研制了基于像增强器的高时间分辨科学级成像系统。首先,对不同模式下科学级CMOS图像传感器曝光时间与像增强器选通时间的关系进行了分析,得到全局快门模式和全局复位卷帘快门模式下曝光时间与选通时间的相对关系;其次,根据曝光时间和选通时间的相对关系设计了相应的时序控制方法,给出了像增强器选通信号的生成方法;再次,设计了基于像增强器的高时间分辨科学级成像系统总体框架,将成像系统分为相机端、传输端和PC端3个部分,分别用于图像采集、数据传输和图像处理与显示;最后,基于硬件实现了该成像系统,并在脉冲氙灯下进行了成像实验。实验结果表明,该成像系统的时间分辨率为25 ns,像素量化位数为16 bit,帧频率为43 fps(1 fps为1帧/s)。该成像系统在保持科学级图像传感器特性的基础上具备了高时间分辨率,可用于高速瞬态过程成像。

In this paper,a high time-resolution scientific CMOS(sCMOS)imaging system with an imaging intensifier is developed,which is suitable for high speed transient process imaging.Firstly,the relationship between the exposure time of the sCMOS imaging sensor and the gating time of the imaging intensifier in different modes is analyzed,and the relative relationship between the exposure time and the gating time in global shutter mode and global-reset-rolling-shutter mode is obtained.Secondly,according to the relative relationship between exposure time and gating time,the corresponding timing control method is designed,and the generation method of gating signal of image intensifier is given.Then,the overall framework of high time-resolution scientific imaging system based on image intensifier is designed.The imaging system consists of three parts:camera module,transmission module,and PC module,which are used for image acquisition,data transmission,and image processing and display,respectively.Finally,the imaging system in experiment is carried out under the pulse xenon lamp.The experiment results show that the time-resolution of the imaging system is 25 ns,the quantization bits of pixels are 16 bits,and the frame rate is 43 fps.On the basis of maintaining the characteristics of scientific image sensor,the imaging system has high time-resolution,which can be used for high speed transient process imaging.