Patent ID: 7634210
Filing Date: 2009-12-15
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image forming section to form a toner image based on print data; a transfer section to transfer the toner image onto a transfer sheet; a fixing section to fix the toner image transferred onto the transfer sheet; a cleaning section to clean at least one of the image forming section, the transfer section and the fixing section; and a control section comprising: (i) an image determination section to determine an existence area of a real image in a print image based on the print data, (ii) a transfer sheet size determination section to determine a size of the transfer sheet onto which the print image is printable; and (iii) a cleaning control section to control the cleaning device based on determinations of the image determination section and the transfer sheet size determination section; wherein the cleaning control section is configured to: (i) calculate a print ratio of an area of the real image to be formed in a circumference area of the transfer sheet against the circumference area, the circumference area being a predetermined area from an edge of the transfer sheet, (ii) compare the print ratio with a predetermined value set in advance, (ii) activate the cleaning section when the print ratio is at least equal to the predetermined value, (iii) not activate the cleaning section when the print ratio is less than the predetermined value, (iv) set an interval between the transfer sheet and a next transfer sheet to a first interval when the print ratio is at least equal to the predetermined value, and (v) set the interval between the transfer sheet and the next transfer sheet to a second interval which is shorter than the first interval when the print ratio is less than the predetermined value.