Developing device and image forming apparatus and toner supply control method using the same
AssigneeSharp Kabushiki Kaisha
InventorHiroshi TANISAWA
Life of this patent
Estimating the term…
Abstract
A developing device includes: a first conveying passage (developer conveying passage) through which a developer containing a toner and a magnetic carrier is conveyed; a first conveying member (developer conveying member) provided in the first conveying passage for agitating and conveying the developer in a predetermined direction; and a toner supply pipe for leading supplementary toner to the first conveying passage. The developing device further includes electromagnets for forming a magnetic field inside the toner supply pipe to create a magnetic brush shutter by means of the electromagnets.
Claims7
A developing device comprising:
- a developer conveying passage through which a developer containing a toner and a magnetic carrier is conveyed;
- a developer conveying member disposed in the developer conveying passage to agitate and convey the developer in a predetermined direction;
- and,
- a toner supply passage for leading supplementary toner into the developer conveying passage,
- characterized in that an electromagnet(s) for forming a magnetic field inside the toner supply passage is provided along the outer periphery of the toner supply passage.
A toner supplying method for supplying toner from a toner supply device to a developing device which includes:
- a developer conveying passage through which a developer containing a toner and a magnetic carrier is conveyed;
- and a toner supply passage for leading supplementary toner into the developer conveying passage, by way of the toner supply passage, comprising the steps of:
- generating a magnetic field inside the toner supply passage when toner supply from the toner supply device to the developing device is not performed;
- and
- generating no magnetic field inside the toner supply passage when toner supply from the toner supply device to the developing device is performed.
Dependencies are inferred from the claim text.