Patent ID: 7831160

Claim:
An image forming apparatus comprising: an apparatus main body; an image creating unit that is provided in the apparatus main body and creates an image to be printed on recording paper; a paper feeding mechanism on which plural pieces of the recording paper are stacked as a paper bundle, wherein the paper feeding mechanism is a paper feeding cassette that stores the plural pieces of the recording paper; a paper-type distinguishing device that distinguishes a type of the recording paper from the paper bundle stacked on the paper feeding mechanism, the paper-type distinguishing device including, a light irradiating unit that irradiates light on a plane of the paper bundle; a leaking-light detecting unit that receives, on an end face of the paper bundle, light from the light irradiating unit that is transmitted through the paper bundle and leaking from spaces between the pieces of recording paper; and a paper-type distinguishing unit that distinguishes a type of the recording paper of the paper bundle by detecting a characteristic of the recording paper from an electric signal corresponding to a light intensity of the leaking light; and a printing unit that changes conditions of printing on the recording paper according to the type of the recording paper distinguished by the paper-type distinguishing device and prints the image created by the image creating unit.