Browse Prior Art Database

Control of Toner Loading in Monocomponent Development

IP.com Disclosure Number: IPCOM000111924D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 4 page(s) / 79K

Publishing Venue

IBM

Related People

Lee, M: AUTHOR [+3]

Abstract

Fig. 1 Disclosed is a method to control the amount of toner on the developer roll in an electrophotographic printer using monocomponent development.

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Control of Toner Loading in Monocomponent Development

      Fig. 1 Disclosed is a method to control the amount of toner
on the developer roll in an electrophotographic printer using
monocomponent development.

      In electrophotography it is necessary to control the amount of
toner on the developer roll (DR).  For monocomponent development the
toner layer must be smooth and uniform.  The layer must also be thin
enough that all the toner can be charged, but thick enough to ensure
solid blacks.  The task is usually accomplished with a flexible
polymeric or metal doctor blade (DB) pressed against the DR.  [1]
discusses some silicone rubbers that could be used for the DB.  [2]
teaches using the edge of an elastic DB to more accurately meter the
layer.

      In the IBM 4019 LaserPrinter the DB is a solid, hard steel bar.
This is pressed against an elastic DR.  The toner should be about 1.5
monolayers thick, corresponding to 0.7 mg/cm(2)  for 10 &mu.m
diameter particles.  This was successfully achieved in the IBM 4019
where the DR is made of nitrile, coated with a thin urethane layer.
For cost reasons, a simpler cast urethane development roller has been
adopted.  However, the toner layer increased to 1 mg/cm(2), 40% above
the desired value.  The extra toner is largely wasted because overly
thick images on paper are produced.  In addition, the excess
development contributes to copy quality problems, such as the
inability to print single white dots in a black backgr...