Image forming apparatus with image adding function

Claim 1

An image forming appartus with an image adding function, said apparatus comprising: an original table on which an original is placed, the original being capable of transmitting light therethrough; light-transmitting means for emitting the light onto the original placed on said original table while the light is moved therealong; additional image formation specifying means for specifying a desired additional image formation, an additional image formed by the additional image formation being comprised of pixel elements having a variable width and length which are determined at a desired portion of the original on said original table when the light emitted from said light-transmitting means moves; first controlling means for calculating positional data for an image area outside the desired additional image formation specified by said additional image formation specifying means, based on movement of the light emitted by said light-transmitting means, and for storing the calculated positional data; original scanning means, movable along said original table, for optically scanning the original placed on said original table and for forming a reflected light image thereof; image forming means for focusing the reflected light image obtained by said original scanning means, developing the image, and forming a corresponding image on an image forming medium; image forming medium feed-back means for selectively feeding back said image forming medium on which an image is formed by said image forming means; image erasing means for selectively erasing the image formed by said image forming means; second controlling means for enabling said original scanning means and said image forming means, and for disabling said image erasing means and said image forming medium feed-back means during formation of a first image; third controlling means for disabling said original scanning means and enabling said image forming medium feed-back means, said image forming means, and said image erasing means during formation of a second image; and fourth controlling means for, during formation of the second image, reading out positional data of an image portion outside the desired additional image formation from said first controlling means and supplying the readout positional data to said image erasing means, thereby allowing said image forming means to form a desired additional image in a corresponding portion image forming range on said image forming medium, which has been fed back.