Research On The Key Techniques Of Thermal Microscope Imaging System

Thermal microscopy imaging technology enables detect the precise differences ofdifferent tissues and organs, has become an important tool for pathological analysis, clinicaltesting and life science. However, spacial resolution has been limited because ofwavelength of infrared. Designing of thermal microscopy also has to face to a lot ofapplication challenges due to the manufacturing process, nun-uniformities of infrareddetectors,low signal responsivity,low signal-to-noise ratio and cooling problems. On theother way, the conduction of heat leads to little differences in small area and changes ofheat distribution. For the above reason, it claims especially high spacial and temperatureresolution and real-time requirements of infrared imaging system.This index for the design basis, modules of infrared imaging system were developed.Design features and design performance were discussed based on analysing current infraredsystems at home and abroad, including optical and structural, infrared focal plane arraydetector, electric circuit and imaging algorithm.Among the parts, the combinational circuitis elaborated, which is the key in the system. Analog signal driver and filter design,optimum sample design were proposed to ensure low noise sampling circuit. In addition,real-time non-uniformity correction algorithms which based on two point calibration,change of integration time, one-point correction and real-time histogram equalizationwere achieved on the hardware platform of FPGA.The signal-to-noise ratio has beenimproved by designing of analog driver and filter circuits and optimal sampling plan.During the performance testing, the results show that NETD of thermal microscopesystem can as low as51mK,spacial resolution obtains55.7μm.By using super-resolutionmethod,special resolution can be improved to39.4μm.Designed thermal microscope hasgood performance in both temperature and spacial resolution, will have wide applicationprospect.