Patent ID: 7380900

Claim:
An image forming system comprising: an image data supply apparatus for supplying image data; and a printing apparatus for, based on the received image data, employing an ink jet printing head to perform printing, wherein the image data supply apparatus includes: generating means for generating amount information that corresponds to an amount of ink to be used for printing an image data as an image on a printing medium based on the image data; storage means for storing amount information corresponding to a predicted amount of ink to be used; analysis means for analyzing an image information parameter of the image data; and transmitting means for transmitting amount information, as well as the image data, to the printing apparatus, wherein said transmitting means transmits the amount information generated by said generating means or the amount information stored in said storage means based on the analysis of the image information parameter, and wherein the printing apparatus includes: a main tank, which serves as a source for supplying ink to the ink jet printing head; a sub-tank for receiving ink from the main tank, and for supplying the ink to the ink jet printing head; supplying means for supplying ink from the main tank to the sub-tank; detecting means for detecting the amount of ink in the sub-tank; receiving means for receiving the amount information and the image data; and determining means for, prior to printing the image data, based on the received amount information and the amount of ink in the sub-tank as detected by the detecting means, determining whether the supply of ink by the supplying means should be performed.