Patent ID: 6250741
Filing Date: 2001-06-26
Classification: B41J,G03G

Abstract:
An image forming apparatus at least comprising:a developer supply device including a developer support having a surface adapted to carry a layer of a developer material;an opposing electrode disposed facing at least a portion of the developer support surface;a high voltage power source supplying a high voltage for creating a potential difference between the developer support and the opposing electrode;a control electrode comprising:an insulative substrate disposed between the developer support and the opposing electrode, said insulative substrate defining a plurality of gates extending transversely therethrough; andone or more electrode groups provided around each of the plurality of gates; andcontrol means for applying predetermined voltages to each of the electrodes of the groups thereof so as to create predetermined electrical potential states in each of the gates such that a desired image may be formed on a surface of a recording medium simultaneously conveyed over the opposing electrode by developer material selectively jumping from the developer support surface through predetermined neighboring ones of the plurality of gates,the apparatus being further characterized in that, the control means controls the layer of developer material carried on the surface of the developer support at each position (Q) corresponding to the predetermined neighboring ones of the plurality of sates (m), or in the vicinity thereof, such that only developer material facing the predetermined neighboring ones of the plurality of gates and residing in a topmost part of the layer of the developer material carried by the developer support, or in the vicinity thereof, simultaneously jumps through the plural gates, andwhen developer material present at a position (Q) on the surface of the developer support is allowed simultaneously to jump through the predetermined neighboring ones of the plurality of gates, the control means controls the jumping of the developer material such that the amount of the developer material jumping through each gate is respectively given by the relation qn(1.ltoreq.n.ltoreq.m) and the amount of the developer material originally present at each position (Q) satisfies the formula: ##EQU4##