US Patent 8233017 - Electrostatic printing with nanocarbon image generator

http://www.freepatentsonline.com/8233017.html

Xerox continues its efforts in using nanostructured materials to improve the operability of electrophotographic printers. This latest patent teaches using graphene or carbon nanotubes in forming an electrostatic image for smaller, more energy efficient printers. Claim 1 reads:

1. An electrostatic latent image generator comprising:

a substrate;

an array of pixels disposed over the substrate, wherein each pixel of the array of pixels comprises a layer of one or more nano-carbon materials, and wherein each pixel of the array of pixels is electrically isolated and is individually addressable; and

a charge transport layer disposed over the array of pixels, wherein the charge transport layer comprises a surface disposed opposite to the array of pixels, and wherein the charge transport layer is configured to transport holes provided by the one or more pixels to the surface.

US Patent 8204407 - CNT corona wires

http://www.freepatentsonline.com/8204407.html

Corona wires are important components of electrophotographic laser printers used for creating electric charge on a photosensitive drum. This patent from Xerox teaches how carbon nanotubes can produce corona wires with improved durability. Claim 1 reads:

1. A charging device comprising:

a receptor; and

a wire coronode disposed opposing and spaced apart from the receptor,

wherein the wire coronode comprises one or more carbon nanotube yarns arranged to emit a corona charge to the receptor using a low operating voltage, and each of the one or more carbon nanotube yarns has a minor dimension of about 100 microns or less and a resistivity of about 4×10⁻⁴ Ω-cm or less.                             

US Patent 8202607 - Transfer belt formed from nanodiamond

http://www.freepatentsonline.com/8202607.html

This is the latest in a series of patents from Xerox focusing on the use of nanomaterials to improve the operation and lifespan of laser printers. Specifically this patent teaches an improved image transfer belt formed from graphene coated nanodiamond material. Claim 1 reads:

1. An intermediate transfer member comprised of a nano diamond comprised of a diamond core and a graphite shell thereover, and wherein said nano-diamond core is present in an amount of from about 20 to about 99.9 weight percent and said shell includes functional groups thereon.

US Patent 8177897 - Phase change inks containing CNTs

http://www.freepatentsonline.com/8177897.html

This patent from Xerox teaches using carbon nanotubes to improve the thermal stability and blackness of phase change inks used in inkjet printers. Claim 1 reads:

1. A phase change ink comprising

(a) a phase change ink carrier and

(b) a colorant wherein the colorant comprises carbon nanotubes wherein the carbon nanotubes have a length of about 500 micrometers to about 1,000 micrometers.

US Patent 8164089 - Organic thin film transistor including graphene

http://www.freepatentsonline.com/8164089.html

This patent from Xerox teaches a variation of organic thin film transistors using graphene to increase the carrier mobility and improve switching speeds. Claim 1 reads:

1. A thin-film transistor comprising

a semiconducting layer, the semiconducting layer comprising an organic semiconductor and graphene;

wherein the graphene concentration in the semiconducting layer is lower than the critical concentration for a percolation network.

US Patent 8099035 - CNT heat layer for printer fuser

http://www.freepatentsonline.com/8099035.html

This patent from Xerox teaches a way to use carbon nanotubes to form a heater layer in a fuser of a printer. Claim 1 reads:

1. A fuser member comprising:

a substrate;

a continuous phase metal heat inductive layer disposed on the substrate, the continuous phase metal heat inductive layer comprising an interpenetrating network of carbon nanotubes dispersed therein; and

an outer layer comprising a fluoropolymer disposed on the heat inductive layer.

US Patent 8088544 - Polyester core-shell nanoparticles

http://www.freepatentsonline.com/8088544.html

Perhaps the most widely used application of microparticles is in toners for laser printers. This patent from Xerox teaches nanosized toner particles which lowers the temperature necessary to fuse the toner to paper. Claim 1 reads:

1. Core-shell nano-sized particles comprising particles having a core and a shell,

wherein the core of the particles comprises crystalline polyester and the shell of the particles comprises amorphous polyester and is substantially to completely free of crystalline material,

wherein the shell encapsulates the core, and wherein the nano-sized particles have an average particle size of about 1 nm to about 250 nm.

US Patent 7893495 - Zinc oxide nanodisk FET

http://www.freepatentsonline.com/7893495.html

Zinc oxide has been used as a channel material for thin film transistors but has low electron mobility. This patent teaches fabricating zinc oxide nanodisks which can improve the mobility. Claim 1 reads:

1. A thin film transistor, comprising:

a substrate;

a gate electrode a source electrode and a drain electrode;

a dielectric layer; and

a semiconductor layer;

wherein the semiconductor layer comprises zinc oxide nanodisks oriented with their c-axis perpendicular to the dielectric layer or the substrate; and

wherein the zinc oxide nanodisks have a height of from about 1 nanometer to about 100 nanometers.

US Patent 7754408 - CNT developer for laser printers

http://www.freepatentsonline.com/7754408.html

This patent from Xerox teaches using carbon nanotubes to enhance the conductivity and extend the lifetime of the developer used in laser printers. Claim 1 reads:

1. A carrier including carrier particles comprising

a binder,

at least one magnetic material and

at least one conductive material,

wherein the conductive material is substantially uniformly dispersed within the carrier particles and the conductive material includes at least one carbon nanotube.

US Patent 7740997 - Photoreceptor including polymeric material embedded in CNTs

http://www.freepatentsonline.com/7740997.html

In order to improve the lifetime and image quality for photosensitive drums used in laser printers this patent from Xerox teaches polymer on carbon nanotube material as an enhanced charge storage medium. Claim 1 reads:

1. An electrophotographic imaging member comprising:

a substrate,

a photogenerating layer, and

an optional overcoating layer

wherein the photogenerating layer comprises a multi-block polymeric charge transport material at least partially attached to a surface of a carbon nanotube material, and

the multi-block polymeric charge transport material comprises a charge transport block and a non-charge transport block, wherein the charge transport block is attached to the surface of the carbon nanotube material.

US Patent 7588872 - CNT photoreceptor

http://www.freepatentsonline.com/7588872.html

This is one of a series of patents from Xerox which teaches that carbon nanotubes are useful to enhance the imaging properties of photoreceptive sheets which are important to laser printers. Claim 1 reads:

1. An electrophotographic imaging member comprising:

a substrate,

an optional intermediate layer,

a photogenerating layer that performs both charge generating and hole transport functions, and

an optional overcoating layer,

wherein the photogenerating layer comprises a carbon nanotube material that is from about 0.1 to about 50 nanometers in diameter and from about 0.01 to about 500 micrometers in length;

and the photogenerating layer contains about 5 to about 20 percent by weight carbon nanotube material.

US Patent 7534821 - Polymeric aerogel nanocomposite moisture barrier

http://www.freepatentsonline.com/7534821.html

Laser printers and copiers are usually highly susceptible to environmental changes which can alter image quality. This patent from Xerox teaches how aerogel nanocomposites can be used as a coating to counteract such effects. Claim 1 reads:

1. A nanocomposite composition comprising:

one or more aerogel components, and one or more polymeric resin components;

wherein the nanocomposite composition is capable of absorbing water in an amount that is less than an amount that can be absorbed by the polymeric resin components, and wherein the one or more aerogel components comprise aerogel particles having an average particle size of less than about 500 Å.

US Patent 7531277 - Self-erasing photoreceptor containing electroluminescent nanoparticles

http://www.freepatentsonline.com/7531277.html

In xerography processes a photoreceptor is a necessary component in forming images to be printed. this patent from Xerox takes advantage of the electrical conductivity and optical transparency of carbon nanotube material to achieve improved photoreceptors provided with self erasing. Claim 1 reads:

1. An electrophotographic photoreceptor comprising:

a conductive layer comprising a plurality of electroluminescent nanomaterials, wherein the plurality of electroluminescent nanomaterials comprises a plurality of carbon nanotubes;

a first contact electrically connected to a first edge of the conductive layer and an electrical ground;

a second contact electrically connected to a second edge of the conductive layer and D.C. power supply; and

a photosensitive layer disposed over the conductive layer, wherein the photosensitive layer comprises a charge generation material and a charge transport material.

US Patent 7398035 - Nanotube array charging device for electrophotography

http://www.freepatentsonline.com/7398035.html

In many printers a variety of charging devices are required to charge belts and drums to facilitate the transfer of toner or paper during printing processes. A variety of nanomaterials such as carbon nanotubes have been noted to have high efficiency election emission properties. This patent from Xerox teaches the incorporation of such nanomaterials in charging devices for printing. Claim 1 reads:

1. An electrophotographic charging device comprising:

a dielectric layer;

a first electrode disposed adjacent to a first surface of the dielectric layer;

a second electrode, wherein the second electrode has a first surface disposed adjacent to a second surface of the dielectric layer; and

a plurality of nanostructures, wherein each of the plurality of nanostructures has an end in electrical contact with a second surface of the second electrode, wherein at least one of the first electrode and the second electrode includes a plurality of electrodes disposed essentially parallel to each other.

US Patent 7328851 - Quantum dot color coding

US Patent 7328851

This patent from Xerox (priority 10/31/2006) includes some broad claims focusing on quantum dots to achieve a multicolor fluorescent glyph for marking items. Claim 1 reads:

1. Machine readable code comprising a set of distinguishable symbols including at least a first symbol for encoding zeroes and a second symbol for encoding ones, wherein the first symbol exhibits a first color during machine reading and the second symbol exhibits a second color during machine reading, wherein the first color and the second color are recognized as different by the machine under machine reading conditions, wherein the first color and the second color are provided by fluorescent marking materials including quantum nanoparticles.

Based on the file history the "novel" feature that the attorney argued was that the marking material was quantum nanoparticles.

Unfortunately there seems to be many pieces of prior art that were overlooked such as:

US Patent 6617583- "A novel encoding system and methods for determining the location and/or identity of a particular item or component of interest is provided. In particular, the present invention utilizes a "barcode" comprising one or more sizes of semiconductor nanocrystals (quantum dots) having characteristic spectral emissions, to either "track" the location of a particular item of interest or to identify a particular item of interest. " (from abstract)

US Patent 6633370-"Quantum dots, semiconductor nanocrystals and semiconductor particles used as fluorescent coding elements" (title)

US Patent 7077329- "Spectral coding by fluorescent semiconductor nanocrystals for document identification and security applications" (title)