Toner replenishing method for use in development process, and development unit employing the toner replenishing method

A method for replenishing toner in a development unit including a developer supply member which supplies a two part dry developer from a developer container to an electrophotographic photoconductor, whereby toner in the developer is diminished, thereby leaving a used dry developer portion with a decreased toner concentration, said method comprising the step of:

• scraping the used dry developer portion from said developer supply member;
• discharging substantially all of the scraped developer to a mixing chamber;
• supplying toner to the mixing chamber;
• mixing the toner and the used dry developer portion in the mixing chamber to form a mixed developer;
• and
• transporting the mixed developer from said mixing chamber to said developer container by causing the mixed developer to flow over an overflow edge of the mixing chamber.

A development unit for developing latent electrostatic images formed on an electrophotographic photoconductor using a two component dry developer comprising a toner and a carrier, comprising:

• a developer container for holding a two part dry developer;
• a developer supply member which supplies the developer from the developer container to the electrophotographic photoconductor, whereby toner in the developer is diminished, thereby leaving a used dry developer portion with a decreased toner concentration;
• a mixing chamber receiving the used dry developer portion;
• a toner replenishing opening positioned at said mixing chamber to introduce at least part of the toner into said mixing chamber at substantially a lowermost portion of said mixing chamber;
• a mixer in said mixing chamber for mixing the toner and the used dry developer portion;
• a scraper positioned to scrape the used dry developer portion from said developer supply member and discharge the scraped developer to said mixing chamber to be mixed with toner;
• and
• developer transport means for transporting the mixed developer from said mixing chamber to said developer container.

A method for replenishing toner in a development unit including a developer supply member which supplies a two part dry developer from a developer container to an electrophotographic photoconductor, whereby toner in the developer is diminished, thereby leaving a used dry developer portion with a decreased toner concentration, said method comprising the steps of:

• scraping the used dry developer portion from said developer supply member;
• discharging the scraped developer to a mixing chamber;
• supplying at least part of the toner into said mixing chamber at substantially a lowermost portion of said mixing chamber;
• mixing the toner and the used dry developer portion in the mixing chamber to form a mixed developer;
• and
• transporting the mixed developer from said mixing chamber to said developer container.