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Browse Prior Art Database

Doctor Blade Design for Monocomponent Nonmagnetic Developer

IP.com Disclosure Number: IPCOM000101973D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Pickering, GW: AUTHOR [+4]

Abstract

Disclosed is a device for metering a uniform, electrically charged, monolayer of xerographic toner onto a resilient developer roll prior to being brought in contact with a photoconductor carrying a latent electrostatic image.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 79% of the total text.

Doctor Blade Design for Monocomponent Nonmagnetic Developer

       Disclosed is a device for metering a uniform,
electrically charged, monolayer of xerographic toner onto a resilient
developer roll prior to being brought in contact with a
photoconductor carrying a latent electrostatic image.

      For nonmagnetic, monocomponent toners, magnetics cannot be used
for controlling the flow of toner against a photoconductor.  The
disclosed technique uses a combination of mechanics of particle flow
combined with electrostatics to meter toner.

      The figure shows a cross-section of a metallic doctor blade 1
loaded against a resilient developer roll 2.  A very thick layer of
charged toner 3 is carried to the doctor blade by virtue of the
rotation of the developer roll 2. Toner enters the wedge between the
doctor blade and the compressed developer roll at 4.  An electrical
bias is applied between the doctor blade and the developer roll to
ensure the proper polarity of toner is attracted to the developer
roll surface.  A combination of this electrical bias and the
mechanical forces results in a properly charged, thin toner layer
passing through the peak pressure point between the developer roll 2
and doctor blade 1.

      To ensure the proper mechanical characteristics at this peak
pressure point, a fine texture is applied to the surface 5 of the
doctor blade which interferes with the developer roll.  This texture
provides the appropriate resistance combine...