device 60 and a fixing entrance guide 56 which guides the sheet p to the fixing device 60 next an explanation will be given of a basic imaging process in the image forming apparatus according to this exemplary embodiment in the image forming apparatus as shown in fig1 the image data produced from an image reading device not shown or a personal computer pc not shown after image processed by an image processing device not shown are imaged by the image forming units 1 y 1 m 1 c and 1 k in the image processing device the reflection coefficient data inputted are subjected to the image processing such as shading correction displacement correction brightness color space conversion gamma correction frame canceling and various image editions such as color edition or shift edition the image data image processed are converted into color material tone data of four colors of y m c and k which are in turn sent to the laser exposure device 13 in the laser exposure device 13 according to the color material tone data inputted the exposure beam bm emitted from e g a semiconductor laser is applied to each photoconductor 11 of the image forming unit 1 y 1 m 1 c 1 k in photoconductor 11 of the image forming unit 1 y 1 m 1 c 1 k its surface is charged by the charger 12 and thereafter scanning exposed by the laser exposure device 13 to form an electrostatic image the electrostatic latent image formed is developed by the developer.