Patent ID: 8922608

Claim:
A decolorizing device, comprising: a paper feed unit configured to feed a sheet on which an image has been formed using a color-erasable colorant; a decolorizing unit configured to heat the sheet at a first heating temperature in order to decolorize the image on the sheet; a scanner configured to scan a surface of the sheet on which the image was formed and to output an image density of the image before decolorizing and after decolorizing; a reject determination unit configured to determine that the sheet is rejected based on the image density of the image after decolorizing; and a decolorization condition setting unit configured to control the decolorization unit to heat the sheet that is determined to be rejected at a second heating temperature that is higher than the first heating temperature when it is determined that the image density after decolorizing is lower than the image density before decolorizing.