多通道热释电IRFPA图像拼接采集系统

Pyroelectric IRFPA mosaic image acquisition system with multi channels

为了实现分辨率高的大规模热释电IRFPA探测器,设计了多路通道并行输出的读出电路。针对多路输出的热释电IRFPA探测器,依据热释电探测的时序要求,设计了图像拼接采集系统。利用外部驱动信号控制采集卡的触发及采样时钟,由斩波器同步信号判断热释电探测器的亮场及暗场信号。构造PC-DAQ虚拟仪器系统对多通道输出的热释电型IRFPA进行多路并行图像采集,并对每路图像信号进行亮、暗场判断后进行差分处理,通过软件拼接处理成一副完整的图像,最终在软件平台上显示。对实验室研制的160列×120行双通道读出及320列×120行四通道读出的热释电读出电路进行了图像采集实验,对于同样阵列大小的单通道读出探测器,双通道结构读出速度提高了1倍,四通道结构读出速度提高了3倍。通过采集成像实验验证了系统的可行性。

In order to achieve large-scale pyroelectric infrared focal plane array(IRFPA)detector with high resolution,the readout circuit with multi-channel parallel output was designed.Based on the pyroelectric IRFPA detector of multiple-output and the pyroelectric detecting timing requirements,the system of mosaic imaging acquisition was designed.The external driving signals were used to control the trigger and sampling clock of acquisition card,and a chopper synchronizing signal was used to judge the bright field and dark field signal of the pyroelectric detector.The system was constructed with PC-DAQ virtual instrument system to acquire multi-channel parallel image,judge the bright and dark field for differential processing on each channel,and display a whole image after mosaic processing on software platform.The experimental image acquisition of the pyroelectric readout circuit with 160 × 120two-channels readout and 320×120four-channels readout were taken and the output signal waveform and image were showed after connecting the two-channels and four-channels signals.Compared with the single channel readout structure of the same scale detector,the readout speed of two channels structure doubles,and the four channels readout speed improves 3times.