US 5,619,312 A · Developing device with developer-supplying mechanism

Abstract

A developing device incorporating a developer supply unit and a developer discharge section, in which a supply developer including a mixture of toner and carrier is successively supplied to a developer container from the developer supply unit and a deteriorated developer in the developer container is discharged through the developer discharge section. The developer supply unit has a sponge roller for selectively attracting toner to a surface thereof, a magnet roller for selectively attracting carrier to a surface thereof, and a member for scraping and bringing the toner and carrier attracted to these rollers into the developer container. The developer including toner and carrier in a predetermined ratio is thus stably supplied to the developer container. In another example of the developer supply unit, agitating of the developer is performed while shovelling the developer deposited in a lower part of the unit by a transport screw. With this structure, since the toner and carrier are evenly mixed in the unit, the developer having a uniform toner concentration is supplied to the developer container, thereby continuing satisfactory development.

Claims56

Dependent claims

A developing device for developing an electrostatic latent image, comprising:

a developer container for storing a developer including toner and carrier;
agitating means for agitating the developer in said developer container;
a developing roller for bringing the developer in said developer container agitated by said agitating means into contact with the electrostatic latent image;
developer supply means for successively supplying a supply developer including toner and carrier to said developer container;
and
developer discharge means for discharging the developer in said developer container as the supply developer is supplied to said developer container by said developer supply means,
said developer supply means including:
a single supply-developer storage section, disposed above said developer container, for storing the supply developer including a mixture of toner and carrier;
a toner attracting member, disposed at a bottom of said supply-developer storage section, for selectively attracting toner to a surface thereof;
a carrier attracting member, disposed at a bottom of said supply-developer storage section, for selectively attracting carrier to a surface thereof;
and
a scraper means for scraping and bringing the toner and the carrier from the surfaces of said toner attracting member and said carrier attracting member into said developer container,
wherein both said toner attracting member and said carrier attracting member are disposed at the bottom of said single supply-developer storage section.

10 more elements

A developing device for developing an electrostatic latent image, comprising:

a developer container for storing a developer including toner and carrier;
agitating means for agitating the developer in said developer container;
a developing roller for bringing the developer in said developer container agitated by said agitating means into contact with the electrostatic latent image;
developer supply means for successively supplying a supply developer including toner and carrier to said developer container;
and
developer discharge means for discharging the developer in said developer container as the supply developer is supplied to said developer container by said developer supply means,
said developer supply means including:
a supply-developer storage section for storing the supply developer including a mixture of toner and carrier;
at least one transporting means, disposed in said supply-developer storage section, for transporting the developer deposited in a lower part of said supply-developer storage section toward an upper part thereof;
and
driving means for changing relative positions of said transporting means in said supply-developer storage section and said supply-developer storage section by driving at least one of said supply-developer storage section and said transporting means, for agitating the supply developer in said supply-developer storage section,
wherein the toner and the carrier in said supply-developer storage section are evenly mixed by changing the relative positions of said transporting means and said supply-developer storage section by said driving means while transporting the developer deposited in the lower part of said supply-developer storage section toward the upper part thereof by said transporting means.

9 more elements

A developing device for developing an electrostatic latent image, comprising:

a developer container for storing a developer including toner and carrier;
agitating means for agitating the developer in said developer container;
a developing roller for bringing the developer in said developer container agitated by said agitating means into contact with the electrostatic latent image;
developer supply means for successively supplying a supply developer including toner and carrier to said developing container;
and
developer discharge means for discharging the developer in said developer container as the supply developer is supplied to said developer container by said developer supply means,
said developer supply means including:
a supply-developer storage section for storing the supply developer including a mixture of toner and carrier;
developer transporting means, disposed in said supply-developer storage section, for transporting the developer in said supply-developer storage section to said developer container;
and
developer providing means, provided in said supply-developer storage section, for agitating the developer while rotating around the circumference of said developer transporting means and providing the developer in said supply-developer storage section to said developer transporting means.

8 more elements

Dependencies are inferred from the claim text.

Developing device with developer-supplying mechanism

Life of this patent

Developing device with developer-supplying mechanism

Life of this patent

Abstract

Claims56