Patent ID: 6024438
Filing Date: 2000-02-15
Classification: B41J,H04N

Abstract:
An ink jet printer comprising:an ink chamber in which ink is filled;an ejection nozzle from which the ink said ink in chamber is ejected;a pressure generating means for loading pressure to the ink in said ink chamber;a plurality of ink ejecting means for ejecting the ink in said ink chamber from said ejection nozzle onto a receiving medium with pressure generated by said pressure generating means, and with a plurality of types of ink each having a different density of a same color stored therein;a control means for controlling said ink ejecting means so that a plurality of types of ink each having a different density are ejected with a desired dot diameter onto said receiving medium according to an input image signal and are ejected in a range of reflection density by superpositioning a plurality of types of ink having different densities on the same position, wherein a diameter of a dot formed with a first ink type is fixed to a value based on a minimum diameter of said ink, such that the diameter of the dot formed with the first ink type is the same diameter over the range of reflection density, and a diameter of a dot for another of said plurality types of ink is adjusted over the range of reflection density;a driving means for relatively moving said ink ejecting means to said receiving medium; andan administrating means for controlling said control means and said driving means so that said plurality of types of ink each having a different density will be ejected one above another onto a same specified position on said receiving medium with a desired dot diameter.