Decolorizing device and decolorization condition setting method

摘要

A decolorizing device includes a paper feed unit that feeds a sheet, on which an image has been formed using a color-erasable colorant, into a conveying path. A decolorization unit conveys the sheet fed by the paper feed unit into the conveying path while heating the sheet to a prescribed heat source setting temperature to decolorize the image on the sheet. A scanner reads and electronically processes the image and outputs an image density before and after decolorizing. A reject determination part determines the sheet, on which the image remains, as a reject sheet based on the image density after decolorizing. For the sheet determined as a reject sheet by the reject determination unit, when it is determined that the image density after decolorizing is lower than the image density before decolorizing, a decolorization condition setting part controls the heat source setting temperature in the decolorization unit to be higher.