Seiko Epson Corporation

Yukio Takayama

Yoichi Yamada

Tomoe Aruga

Tahei Ishiwatari

Hidenori Kin

Kazuhiro Ichikawa

Yoshihiro Nakashima

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. The toner is mixed by conveying fins which have phases that are different in such a manner that the loads are uniform in rotation

Developing unit

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. A conveying fin is supported by the case so as to convey toner to the surface of the supply roller wherein the developing roller, the supply roller, and the conveying fin are sequentially disposed in a horizontal direction. The number of revolutions of the conveying fin per unit time is between {fraction (1/50)} and {fraction (1/20)} of the supply roller.

Developing unit having a conveying fin for loading a supply roller with toner

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. The toner contains a first and second additive having a specific covering ratio to the surface matrices in the toner.

Developing unit using specific developer composition

A plurality of developing units each includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller and a conveying fin. The developing roller, supply roller, and conveying fin for each developing unit are angularly arranged in a particular manner.

Image forming apparatus having a plurality of developing units

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller having chamfered ends and formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. Also a first sealing member is disposed on the side ends faces of the developing roller and supply roller so as to prevent leakage to the outside portion of the case. Further, a second sealing member in the form of a film is pressed against a lower surface of the developing roller in order to prevent leakage of toner, wherein a quantity &dgr; of displacement of the sealing member due to its abutment against the developing roller satisfies 0.1 mm<&dgr;<0.8 mm, and the thickness t of the second sealing member satisfies 50 &mgr;m<t<500 &mgr;m.

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, and a supply roller formed of an elastic material arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. A sealing member is disposed on the side ends of the developing roller and supply roller so as to prevent leakage to the outside portion of the case. A blade at least longer than the developing roller restrains the quantity of toner on the developing roller. The blade has a radius of curvature between 30 .mu.m and 150 .mu.m.

Developing unit having developing roller with restraining blade

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. Moreover, the percentage of open cells in the elastic supply roller is made to be 30% or higher and depth of engagement of the supply roller to the developing roller is made to 0.4 mm or smaller. The toner has shape factors SF-1 of 150 or smaller and SF-2 of 140 or smaller.

Developing unit using elastic supply roller

A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller having chamfered ends and formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. The side surfaces of the developing roller have a surface roughness of 0.5 .mu.m or smaller in Rmax.

Growing community of inventors

Nagano, Japan

Yukio Takayama