Patent ID: 6499830
Filing Date: 2002-12-31
Classification: B41J,G03G

Abstract:
An image forming apparatus for forming an image by attaching charged particles (5) to an image receiving medium (9), comprising:a charging means (3, 4) for applying charges to particles for forming an image; a supporting element (2) for supporting and carrying the charged particles (5) having the charges applied thereto by the charging means (3, 4); an opposing electrode (6) provided at a position facing a position on the supporting element (2) to which the charged particles are carried; an insulating member (17) provided between the supporting element (2) and the opposing electrode (6) and having a plurality of openings (16) for passing the charged particles (5) therethrough; a control electrode (19) provided around each opening (16) of the insulating member (17); a transfer-electrostatic-field forming means (12) for providing a potential difference so as to form between the supporting element (2) and the opposing electrode (6) a transfer electrostatic field for transferring the charged particles (5) on the supporting element (2) toward the opposing electrode (6); and a voltage control means (22) for applying a voltage to the control electrodes (19) around the respective openings (16) according to an image signal so as to control passage of the charged particles (5) through the respective openings (16) that is caused by the transfer electrostatic field, wherein a percentage of an area of the opening (16) to a sum of an area of an extent of the control electrode (19) around the opening (16) and the area of the opening (16) is 8% or more.