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PROCESS AND APPARATUS FOR TEMPERATURE COMPENSATION IN LIQUID ELECTROSTATOGRAPHIC DEVELOPING SYSTEMS

IP.com Disclosure Number: IPCOM000023608D
Original Publication Date: 1978-Jun-30
Included in the Prior Art Database: 2004-Mar-31
Document File: 4 page(s) / 771K

Publishing Venue

Xerox Disclosure Journal

Abstract

An improved process and apparatus for liquid development of electrostatic latent images adjusts doctoring pressure in response to ambient temperature to provide appropriate devel-oping quantities of liquid developer over a range of operating temperatures. The process and apparatus are particularly useful in those embodiments wherein liquid developer is transferred from an applicator member to an electrostato-graphic imaging surface, including means for loading the applicator with the developer and blade means for doctoring the applicator to provide developing quantities of liquid developer thereon.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 51% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

PROCESS AND APPARATUS FOR TEMPER-~
ATURE COMPENSATION IN LIQUID
ELECTROSTATOGRAPHIC DEVELOPING

SYSTEMS

Stephen C,P, Hwa

EXPOSURE

OPTICS /6

Proposed Classification

U.S. Cl~ 118/644
mt. Cl. B05b 5/02

An improved process and apparatus for liquid development of
electrostatic latent images adjusts doctoring pressure in
response to ambient temperature to provide appropriate devel~
oping quantities of liquid developer over a range of operating
temperatures. The process and apparatus are particularly
useful in those embodiments wherein liquid developer is
transferred from an applicator member to an electrostato~
graphic imaging surface, including means for loading the
applicator with the developer and blade means for doctoring
the applicator to provide developing quantities of liquid
developer thereon.

Generally, means are provided for automatically adjusting the
pressure of the doctoring blade means against the applicator
member in response to changes in ambient temperature. The
pressure of the doctoring blade is responsive to the effect of
temperature upon liquid developer viscosity or doctoring blade
viscoelasticity.

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46

30

33

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Volume 3 Number 3 May/June 1978 145

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Page 2 of 4

PROCESS AND APPARATUS FOR TEMPERATURE COMPENSATION IN LIQUID
ELECTROSTATOGRAPHIC DEVELOPING SYSTEMS (Cont'd)

Referring to the drawing, a typical rotatable xerographic drum
10 having an outer layer or imaging surface 12 of photo~
conductive insulating material such as vitreous selenium is
moved in the direction indicated by the arrow. The surface of
photoconductive layer 12 is uniformly charged by a conven~
tional corona charging device 14 and exposed to a pattern of
activating electromagnetic radiation, such as light and shadow
image at exposure station 16. The latent electrostatic image
formed by the exposure optics 16 is developed by rotating drum
10 by means of a conventional driving system through the
developing apparatus indicated generally by numeral 18. The
developing apparatus includes a patterned applicator roll 20
which is positioned adjacent to imaging surface 12, Liquid
developer is maintained in reservoir 22 from which it is
picked up and transferred to applicator roll 20 by means of a
rotating loading or feed roll 24. The liquid developer which
is carried on the applicating surface 26 is subjected to a
doctoring step whereby substantially all the liquid developer
is removed from the raised portions of the applicator surface,
This type of system is clearly described in such patents as
U.S. Patent No, 3,084,043.

The doctoring step most preferably includes a slight wiping
action of the recessed portions of the applicating surface to
maintain the level of liquid developer in the recessed
portions ~f applicating surface 26 slightly below the level of
the raised portions. The developed image which emerges from
the developing apparatus may be transferred by means of a
pressure transfer roll 28 to a suitable subst...