Cleaning device for a photosensitive element

A cleaning device removes residual toner on the outer surface of a photosensitive element by bringing a brush into contact with the outer surface of the photosensitive element after an electrostatic latent image on the outer surface of the photosensitive element is developed into a toner image by the reversed development method. The electric resistance value between the brush and photosensitive is in the range of 103 to 108 OMEGAcm, and the density thereof is in the range of 30000 to 100000 bristles/(inch)2. A DC voltage having a polarity opposite from the charging polarity of the toner and being in the range of 100 to 300 V in absolute value is applied to the brush after an AC voltage having a frequency of 100 to 2000 Hz and an interpeak voltage of 400 to 700 V is superimposed thereon. Further, the brush is rotated in a direction opposite from the rotating direction of the photosensitive element in its portion held in contact with the photosensitive element. Accordingly, the cleaning device can suppress the adhesion of the toner to the outer surface of the photosensitive element by fusion and the scraping of the photosensitive element while maintaining a satisfactory cleaning performance.