Generation of fine dry toner and its charging characteristics

Ultra-fine dry toner particles for electrophotography were obtained using a new system which is composed of an ultrasonic atomizer and a drying system. Atomized droplets produced by the ultrasonic transducer were dried using a microwave oven. The diameter of fine dry toner particles obtained using this system was less than 1 /spl mu/m. The dried particles were charged by the induction charging method. In the case of applying -3 kV to the induction electrode, the surface charge density of the fine dry toner particle was 20.9 /spl mu/C/m/sup 2/. Using these dry toner particles, the system is considered to be able to obtain developed images of ultra-high resolution.