초록 ▼

An image-forming apparatus is provided that can form good images stably by uniformly and stably charging a non-magnetic single-component developer (such as a toner). In this apparatus, a DC power supply applies a positive voltage Vd to a development roller, and a DC power supply applies a positive v

An image-forming apparatus is provided that can form good images stably by uniformly and stably charging a non-magnetic single-component developer (such as a toner). In this apparatus, a DC power supply applies a positive voltage Vd to a development roller, and a DC power supply applies a positive voltage Vb to a layer thickness restricting blade. The voltages Vb and Vd satisfy the relationship Vb>Vd+Vt, where Vt is the potential difference in a thickness direction of the layer of toner T adhering to the development roller. The toner T is a suspension polymer toner excelling in fluidity. Accordingly, toner T charged with reverse polarity can be nicely removed. In addition, the action of injecting electric charge to the toner T by the application of the potential Vb to the layer thickness restricting blade 32 is not produced and, even without that action, the toner T can be sufficiently charged by friction-charging produced by the development roller and the supply roller working together. Thus the toner T can be uniformly and stably charged.

대표청구항 ▼

[ What is claimed is:] [1.] An image-forming apparatus comprising:an electrostatic latent image carrier having a surface on which electrostatic latent images are formed;development means for conveying charged non-magnetic single-component developer to the surface of the electrostatic latent image ca

[ What is claimed is:] [1.] An image-forming apparatus comprising:an electrostatic latent image carrier having a surface on which electrostatic latent images are formed;development means for conveying charged non-magnetic single-component developer to the surface of the electrostatic latent image carrier and developing the electrostatic latent images, the development means also having a surface;supply means for supplying the non-magnetic single-component developer to the development means; andlayer thickness restricting means for restricting a layer thickness of the non-magnetic single-component developer adhering to the surface of the development means before the non-magnetic single-component developer faces the electrostatic latent image carrier, at least a part of the layer thickness restricting means contacting the non-magnetic single-component developer adhering to the surface of the development means is made of an electrically conductive material, where the non-magnetic single-component developer that has developed the electrostatic latent images is transferred to a recording medium, thereby forming images; whereinthe non-magnetic single-component developer is roughly spheroidal in shape;the development means, the supply means, and the layer thickness restricting means are constituted so that the non-magnetic single-component developer can be sufficiently charged for development of the electrostatic latent images, even if the layer thickness restricting means is given a same electric potential as the development means; andthe image-forming apparatus further comprises:electrical potential control means for controlling a potential Vb of the layer thickness restricting means so that conditions noted below are satisfied, at least during image formation;condition 1 being the potential Vb satisfies the following relationships:Vb>Vd+Vt; when a positive-chargeable non-magnetic single-component developer is used, andVb