Imaging Circuit Design For Weak Targets Based On BCCD

The weak targerts mean that the light of the targets is dim.The detection of weaktargets is widely used in aerospace remote sensing, military surveillance, medicalresearch and other fields. In this paper, imaging system based on back-illuminatedCCD47-10is designed to achieve the goal of detecting weak targets.With the special structure and technology，its response sensitivity is very high.First,The principle of back-illuminated CCD and the performance of CCD47-10isanalyzed.Combined with the principle and structure of front-illuminated CCDimaging system, imaging system based on back-illuminated CCD47-10is designed.The system consists of power supply module, CCD driver module, signalpre-processing module, video processing module, data transfer module and thesoftware module. This paper describes the role and structure of each module clearly.Then three PCB boards is made to complete the hardware design of imaging system.VHDL language is used to design logic circuit in the FPGA, including digital imagedata reception, commands sending, parameters configuration, CCD driving timinggenerator, and data transmission. C language is used to design the firmware forconfigurating the USB interface chip. VC++language is used to programmedsoftware.And the program is to send controlling commands from the hostcomputer,receive the image data,store and real-time display the digital image.Finally, a experiment platform is built for imaging experiment. The oscilloscope isused to observe the driving pulses and the output signal of CCD. The image data is saved and displayed by computer for further analysis.The experiment shows that, the imaging system based on back-illuminatedCCD47-10is simple, stable. When the light is weak The image is clear and the SNRis113.So the system can meet the application command of detecting and imaging theweak targets.