Research On Image Acquisition Device For Finger Vein

With the advent of the information age,the personal identity authentication gradually gets more and more opportunities to combine with computers and networks.Personal identity informatization has become a trend.While the traditional methods of individual identification expose their defects gradually,such as inconvenience to carry,easy to spoil,easy wastage or to forget,etc,it is urgent to develop a more safe,more convenient,and high efficient way to identity authentication.One finger vein authentication system provides a new solution to meet the demand.The finger vein authentication system has some advantages,e.g.,higher recognition accuracy,higher security,and more convenience than traditional authentication methods,thus it has a broad market prospect.In foreign countries,finger vein authentication systems have been widely used in the financial system.At present,however,in China most relevant researches in the system still stay on the stage of theory and algorithm study.The first and most important step of developing a finger vein authentication system is designing the image acquisition device for finger vein.It is very obvious that high-quality finger vein images have good influence on fast recognition and high recognition rate of the system.This paper focuses on research in and designing high-quality finger vein image acquisition devices,and finally implements a software and hardware system with high-speed transmission,which can obtain high-quality finger vein images.This paper starts from the optical component selection,the image sensor selection,and the light source driving scheme analysis,then analyzes the system requirements,and finally gives the whole system design program.Based the above analysis,some concrete work includes the circuit design of LED drive circuit,the infrared detection filter circuit,and peripheral circuit of the chip.Advices about USB transfer module's PCB design are also given.Based on STM32F103 controller,by adopting the PWM dimming method and the PID control algorithm,the precise and stable adjustment of luminous intensity is realized for three infrared light channels.Concretely the particle swarm algorithm is online used to set the PID controller parameters,and CY7C6013 A microcontroller is utilized to realize that the high-quality images,which are collected by the image sensor MT9V034,are transmitted to PC at a high speed.Visual Studio 2010 is used to conduct a program for displaying in real time and saving the obtained finger vein images.