| abstract |
(57) [Summary] [Purpose] Multi-gradation printing is performed on the surface of containers using electrophotography. [Structure] A surface of a material to be printed is charged while being fed and driven, and then an electrostatic latent image pulse-width modulated with multiple gradations for each dot according to a desired image is exposed with an exposure width according to the pulse width. Expose. Further, the exposed portion is developed, and the toner particles used at this time are 1/5 to 5 times the minimum exposure width. The range is set to 5 times, and heat fixing is performed after this development. |