Patent ID: 7973944

Claim:
An image forming apparatus, comprising: a document image generating portion that generates a document image which is instructed to be printed; a code image generating portion that generates a code image by generating a plurality of pattern images to indicate plural kinds of codes, and one kind of the plural codes being a positional code for indicating a position on a medium; an accepting portion that accepts information indicating one of a first mode and a second mode, wherein the code image generating portion generates the plurality of pattern images by generating first pattern images and second pattern images, wherein the first pattern images and the second pattern images are not superimposed, each first pattern image is formed of a visible image part and a substantially invisible part, each second pattern image is formed of a substantially invisible part without having a visible image part, and the visible image parts of the first pattern images forms a character, a symbol, or a figure which are unrelated to the plural kinds of codes.