The development device includes a toner carrier, a toner supplier, and a
surface electrical potential controller. When the toner supplier supplies
toner particles to the toner carrier, the toner carrier carries toner
particles to adhere to a latent image formed on the latent image carrier
and has a time constant .tau.1 of a surface electrical potential change
of the toner carrier. The surface electrical potential controller has a
time constant .tau.2 of a surface electrical potential change of the
toner carrier smaller than the time constant .tau.1. The toner carrier
includes a plurality of electrodes aligned in parallel and electrically
insulated from each other on the surface thereof, and a voltage supplier
for supplying each of the plurality of electrodes with a voltage to
periodically switch electrical fields therebetween, so that the toner
particles form a cloud on the surface of the toner carrier while hopping.