Patent ID: 7817942

Claim:
An image forming apparatus that forms an image on a recording medium, comprising: an ink image forming section that forms an ink image by depositing ink particles on an electrostatic latent image; an intermediate transfer section to which the ink image formed in the ink image forming section is transferred; a transfer section that transfers the ink image that has been transferred to the intermediate transfer section to the recording medium; a recording medium feed section that feeds the recording medium to the transfer section; and a discharge section that discharges the recording medium having the ink image transferred thereto to an outside of the image forming apparatus; wherein the ink image forming section comprises: an ink storing section which stores therein an ink comprising ink particles charged with a first polarity dispersed in a solvent; an ink particle bearing section that has a photosensitive layer comprising a photocatalyst and that is arranged so as to rotate while being at least partially immersed in the ink; an irradiation section that irradiates the ink particle bearing section with light to activate the photocatalyst, thereby forming an electrostatic latent image on the ink particle bearing section that has a second polarity that is opposite to the first polarity; a counter electrode that is immersed in the ink in the ink storing section and that is arranged facing the ink particle bearing section, wherein the counter electrode comprises a plurality of elongated spiral shaped electrodes that are arranged in the ink storing section in an array that faces a surface of the ink particle bearing section, wherein longitudinal axes of the plurality of elongated spiral shaped electrodes are arranged parallel to a longitudinal axis of the ink particle bearing section, wherein an external diameter of each of the plurality of spiral shaped electrodes is approximately 5-7 mm, and wherein a spacing between adjacent ones of the plurality of spiral shaped electrodes is approximately 1-2 mm; and an applying section that applies a voltage to the counter electrode having the first polarity, which is the same polarity as the charged ink particles.