IMAGE FORMING APPARATUS WITH AN UNAPPROVED COPY PREVENTING MEANS

An image forming apparatus, such as a copier, includes an unapproved copy preventor mechanism. The image forming apparatus includes a support such as a platen glass for supporting an original document; a light irradiation source for irradiating the original document with a light beam; and a detectors for detecting predetermined wavelength components of a reflected light from the original document which is irradiated with the irradiating light beam. The detector generates detection signals based on the detection of the predetermined wavelength components of the reflected light. An evaluator circuit determines whether the original document is a document which prohibits a production of an unapproved copy based on the detection signals.