Patent ID: 7616910

Claim:
An image forming system for forming a toner image on a sheet comprising: a color image forming device configured to form a color toner image on the sheet with color toner during an image formation job; a transparent image forming device configured to form a transparent toner image on the sheet, on which the color toner image is formed, with transparent toner during the image formation job; a fixing device configured to fix the color toner image and the transparent toner image on the sheet; an executing device configured to execute a test mode in which a test pattern including a plurality of transparent toner images which are different in amount of the transparent toner per unit area from each other is formed on the sheet by said transparent image forming device during a period between adjacent ones of a plurality of the image formation jobs; a detector configured to detect glossiness of the test pattern which is fixed on the sheet by said fixing device; and a correcting device configured to correct an image forming condition of said transparent image forming device by one of increasing the amount of the transparent toner per unit area of the transparent toner image to be formed during the image formation job depending on a detection result of said detector and decreasing the amount of the transparent toner per unit area of the transparent toner image to be formed during the image formation job depending on the detection result of said detector.