In this paper,the dielectric barrier discharge fingerprint acquisition technique isintroduced.The filament discharge phenomena were observed in the process of fingerprint ac-quisition.The filament discharge reduced the quality of fingerprint images.Obviously,it wasnecessary to eliminate streamer discharges in order to get good fingerprint images.The streamerdischarge was considered to be the cause of the filament discharge in the experiment.The rela-tionship between the critical electric field and the discharge gap was calculated with the Raether'smodel of streamer discharge.The calculated results and our experiment proved that it would bedifficult for the streamer discharge to occur when the discharge gap was narrow.With a narrowdischarge gap,the discharge was homogeneous,and the fingerprint images were clear and largein area.The images obtained in the experiment are very suitable for fingerprint identification asthey contain more information.
