ELECTRIFYING DEVICE, IMAGE FORMING APPARATUS, AND METHOD FOR ELECTRIFYING IMAGE CARRIER

PROBLEM TO BE SOLVED: To provide an electrifying device which does not produce ozone, nitrogen oxide and external additive memory. SOLUTION: The electrifying device includes: a first electrifying brush which comes into contact with an image carrier on which a toner image is formed with a toner obtained by adding an external additive to toner base particles, and electrifies an opposed image carrier surface to a first potential; a second electrifying brush which is arranged more in the moving direction of the image carrier from the first electrifying brush and comes into contact with the image carrier, and electrifies the opposed image carrier surface to a second potential; and a corotron electrifier which is arranged more in the moving direction of the image carrier from the second electrifying brush and to which charge having a reverse polarity to that of a potential by electrification of the toner is applied so as to electrify the opposed image carrier surface to a third potential. The relationship of, the first potential < the second potential < the third potential