and the transfer charger 12 through the transfer guide 11 in timed relationship with the emission of the laser by the pair of register rollers 10 thereby the toner image borne on the photosensitive drum 21 is transferred onto the sheet material p the sheet material p onto which the toner image has been transferred is then separated from the photosensitive drum 21 is conveyed to the fixing device 15 by the conveying member 13 and passes 10 through the nip portion between a fixing roller 15a and a pressing roller 15b in the fixing device 15 whereby the sheet material p is subjected to a toner image fixing process and is discharged onto the sheet discharge tray 17 by the sheet discharging roller 16 any residual toner remaining on the outer peripheral surface of the photosensitive drum 21 after the transfer of the toner image may be surface removed by blade 25a of the cleaning device 25 and used in the next cycle of image formation fig1 is a cross sectional view of one end portion of the developing sleeve 23a and fig2 is a cross sectional view of the sleeve 23a taken along the line a a of fig1 as shown a magnet 23d having a plurality of magnetic poles is inserted in the hollow developing sleeve 23a and the developing sleeve 23a is rotated about the magnet 23d whereby as previously described the toner is carried on the developing sleeve 23a and is used for development thus in the present embodiment the developing sleeve 23a is integrally formed with.