International Business Machines Corporation

Lexmark International, Inc.

Robert B Champ

Meredith David Shattuck

Donald A Stremel

Weimei Luo

Mark Thomas Bellino

Michael Thomas Moore

Robert L Vollmer

Howard W Anderson

Larry D Bowden

Karl John Fowler

Yau T Chen

Karin Else Bredfeldt

A photoconductor for use in electrophotographic reproduction devices is disclosed. This photoconductor exhibits reduced room light and cycling fatigue without any corresponding negative impact on the sensitivity of the photoconductor. The photoconductor of the present invention includes specifically defined fluorenyl-azine derivatives in its charge transport layer. These materials have the formula: ##STR1## wherein R.sub.1 and R.sub.2 independently selected from C.sub.1 -C.sub.4 alkyl and phenyl, and R.sub.3 is selected from hydrogen, C.sub.1 -C.sub.4 alkyl, and phenyl.

Electrophotographic photoconductor containing fluorenyl-azine

An aggregate xerographic photoconductor having light sensitive squarylium dye and a binder for said dye is chosen from a mixture of bisphenol molecules to form a noncrystalline, nonpolymeric product. A layered photoconductor utilizing this generation layer formulation in conjunction with a hole transporting surface layer is described.

Squarylium photoconductors with noncrystalline bisphenol a binders

An organic photoconductor comprising a charge generation layer and on top thereof a charge transport layer having a higher concentration of charge transport molecules nearer the charge generation layer than in the topmost portion.

Organic photoconductors with improved wear

A squarylium dye molecule is synthesized from a phenolic precursor. The resulting hydroxy pyrrolidino squarylium (OHPYRRSQ) dye does not have to be purified in order to provide the dye with a negative response in the Ames test for mutagenicity. A xerographic photoconductor using the molecule shows superior electrophotographic performance.

Squarylium charge generating dye and electrophotographic photoconductor

An aggregate-type xerographic photoconductor wherein primary or secondary amines are used not only to solubilize the photoconductor's light sensitive organic dye, but also to act as a cross-linker for an epoxy binder of the bisphenol class. A combined CTL/CGL layer is described, having both hole transport and charge generating dye molecules. The resulting layer is useful either as single-layer, bimodal photoconductor, or as the CGL of a two-layer photoconductor.

Xerographic photoconductors with cross-linked epoxy binder

A process for electrophotographic reproduction, and a layered electrophotographic plate having a conventional charge generation layer and a p-type hydrazone containing charge transport layer, in which the surface of the charge transport layer is selectively discharged by actinic radiation as a result of the migration through the transport layer of charges generated in the charge generation layer as a result of the actinic radiation and injected into the transport layer, the hydrazone having the composition p-diethylaminobenzaldehyde-(diphenylhydrazone), i.e., ##STR1## and the charge transport layer including DEASP or Acetosol Yellow in an amount not exceeding 13 wt. % of the hydrazone.

Hydrazone and pyrazoline or acetosol yellow containing charge transport

A layered electrophotographic plate having a triaryl pyrazoline containing charge transport layer and a charge generation layer having a photogenerating dye of the composition: ##STR1##

Layered electrophotographic plate having tetramethyl benzidene based

This invention relates to a reversible display device based upon the electrochromic properties of certain thienylidene pyrazoline compounds when used in conjunction with a complementary redox material.

Electrochromic display devices comprising thienylidene pyrazoline

A visual image display device with improved resolution contains a pair of conductive electrodes in spaced relationship. Adjacent one electrode is a first barrier layer which is typically a resin such as polyamide containing a readily oxidizable and reducible material such as zinc nitrate. Adjacent the other electrode is a thin film of solvent, for example, 1,2-dichloroethane. Positioned between the film of solvent and the first barrier layer is a second barrier layer which is a normally light transmitting recording medium. The second barrier layer is both photoionizable and capable of electrochemically producing a colored species. Typically the second barrier layer is a solid containing a resin such as polyvinyl butyral, an active material such as 1-p-anisyl-3 diethylamino styryl-5-diethylaminophenyl-2-pyrazoline and, in selected embodiments, an activator such as carbon tetrachloride.

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Boulder, CO, United States of America

Robert B Champ