Developer unit with a replenish port

Details Developer unit with a replenish port Developer unit with a replenish port

1999-11-23

2001-04-24

Braun, Fred L. (Department: 2852)

Electrophotography

Image formation

Development

C399S119000, C399S120000

Reexamination Certificate

active

06223012

ABSTRACT:

FIELD OF THE DISCLOSURE
This disclosure relates generally to developer units and, in particular, to an improved replenishable developer unit.
BACKGROUND OF THE INVENTION
Developer units, also known as customer replaceable units or “CRU's”, are known. Typically, developer units are arranged for mounting in a host printing machine to develop a latent image present on a photosensitive member. A typical developer unit comprises a donor roll (also known as a “mag roll”) and contains a supply of developer compound, also known as “toner”. The developer unit is arranged for supplying developer compound to the donor roll. The donor roll, in turn, is arranged to provide developer compound to the photosensitive member. Ultimately, the host printing machine produces copies of the developed latent image.
It is desirable for a developer unit to be capable of producing a large number of copies before its supply of developer compound becomes exhausted. As a result, it is thus advantageous for a developer unit to be capable of storing a large quantity of developer compound.
Once a developer unit's supply of developer compound is exhausted, the developer unit must be refilled or replenished with additional developer compound. Some developer units include a replenish port for purposes of replenishing by the user. With this arrangement, the user adds developer compound to the replenish port in order to replenish the developer unit with additional developer compound.
Typical developer units comprise internal agitators arranged to push or propel the developer compound to the donor roll. In large-capacity developer units, typically two (2) or more agitators are used in tandem. With a two-agitator developer unit design, for example, a first agitator is arranged for propelling developer compound to a second agitator. The second agitator, in turn, is arranged for propelling developer compound to the donor roll.
It is known that the developer unit business (industry) is very competitive. To gain competitive advantage, therefore, it is desirable to minimize the unit manufacturing cost of a developer unit. A developer unit's manufacturing cost is based on many cost factors, one key cost factor being the total number of components comprised by the developer unit. As a result, reducing the developer unit's total component count generally also will reduce the developer unit's manufacturing cost.
One cost limitation of a developer unit comprising multiple agitators, therefore, is the cost of the multiple agitator components. Thus, it would be desirable to provide a replenishable developer unit with one (1) agitator.
The problem, therefore, is how to reduce the number of agitators required in a replenishable developer unit, hopefully to a single (1) agitator.
As a result, there is a need for an improved replenishable developer unit.
SUMMARY OF THE INVENTION
In one aspect of the invention, a developer unit comprises a donor roll and a lower housing. The lower housing comprises a developer pan for containing developer compound. The developer pan has a first end near the donor roll and a second end opposite the donor roll. The developer pan further comprises a ramp inclined downwards at a substantially fixed angle from the second end towards the first end, with the fixed angle exceeding the angle of repose of the developer compound.
In another aspect of the invention, a printing machine comprises a developer unit. The developer unit comprises a donor roll and a lower housing. The lower housing comprises a developer pan for containing developer compound. The developer pan has a first end near the donor roll and a second end opposite the donor roll. The developer pan further comprises a ramp inclined downwards at a substantially fixed angle from the second end towards the first end, with the fixed angle exceeding the angle of repose of the developer compound.


REFERENCES:
patent: 5448341 (1995-09-01), Nagahara et al.
patent: 5914209 (1999-06-01), Grushkin

Affiliated with

Also associated with

Rating

Developer unit with a replenish port does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Developer unit with a replenish port, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Developer unit with a replenish port will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2494453