Fitzpatrick, Cella, Harper & Scinto
Developing apparatus and image forming apparatus having first and second voltages applied to a developing satisfying predetermined relationships
 A developing apparatus includes a developer bearing member for bearing and carrying developer to a developing area. A developer is borne on the developer bearing member, wherein the developer has a weight average particle size not exceeding 6.5 .mu.m and contains an external additive of a charging polarity opposite to that of the developer. A voltage application device applies a voltage to the developer bearing member, wherein the voltage including at least a first voltage V1 for acting on the developer in a direction from the developer bearing member toward an image bearing member and a second voltage V2 for acting on the developer in a direction from an image bearing member toward said developer bearing member, and a charged potential VL of the image bearing member, a latent image potential VD a distance H between the developer bearing member and an image bearing member, and wherein the voltages V1 and V2 satisfy a following relationships: EQU .vertline.V1-VL.vertline./H.ltoreq.3.7.times.10.sup.-6 V/m; and EQU .vertline.V2-VD.vertline./H.ltoreq.2.9.times.10.sup.-6 V/m. 
Canon Kabushiki Kaisha
G G G
G03G G03G G03G
inventional inventional inventional
Gaku Yasushi Akira Hiroshi Masanobu Satoru Keiji
Konishi Shimizu Domon Satoh Saito Motohashi Okano