Patents by Inventor An Zhang

An Zhang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6822893
    Abstract: An electrochromic molecular colorant and a plurality of uses as an erasably writeable medium. Multitudinous types of substrates, such as paper, are adaptable for receiving a coating of the colorant. Electrical fringe field or through fields are used to transform targeted pixel molecules between a first, high color state and transparent state, providing information content having resolution and viewability at least equal to hard copy document print. The scope of the invention includes both the liquid coating and the combination of coating on substrate.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: November 23, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Kent D. Vincent, Xiao-An Zhang, R. Stanley Williams
  • Publication number: 20040227605
    Abstract: A molecular system is provided for nanometer-scale reversible electronic and optical switches, specifically, electric field-activated molecular switches that have an electric field induced band gap change that occurs via rotation of rotor units connected to immobile stator units. The molecular system has two branches on one side of an immobile junction unit and one or two branches on the opposite side to thereby provide “Y” and “X” configurations, respectively. The ends of the branches opposite the junction unit are connected to, or electrically associated with, other molecular systems or substrates, such as electrodes. The rotor units each rotate between two states as a function of an externally-applied field. Both multi-stable molecular mechanical devices and electric field-activated optical switches are provided.
    Type: Application
    Filed: March 3, 2004
    Publication date: November 18, 2004
    Inventors: Xiao-An Zhang, Zhang Lin Zhou, R. Stanley Williams, Kent D. Vincent
  • Patent number: 6815706
    Abstract: An optical sensor is provided, comprising (a) a silicon nanowire of finite length having an electrical contact pad at each end thereof; and (b) a plurality of self-assembled molecules on a surface of the silicon nanowire, the molecules serving to modulate electrical conductivity of the silicon nanowire by either a reversible change in dipole moment of the molecules or by a reversible molecule-assisted electron/energy transfer from the molecules onto the silicon nanowire. Further, a method of making the optical sensor is provided. The concept of molecular self-assembly is applied in attaching functional molecules onto silicon nanowire surfaces, and the requirement of molecule modification (hydroxy group in molecules) is minimal from the point view of synthetic difficulty and compatibility. Self-assembly will produce well-ordered ultra-thin films with strong chemical bonding on a surface that cannot be easily achieved by other conventional methods.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: November 9, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Zhiyong Li, Yong Chen, Sean Xiao-An Zhang
  • Patent number: 6809956
    Abstract: An electrochromic molecular colorant and a plurality of uses as an erasably writeable medium. Multitudinous types of substrates, such as paper, are adaptable for receiving a coating of the colorant. Electrical fringe field or through fields are used to transform targeted pixel molecules between a first, high color state and transparent state, providing information content having resolution and viewability at least equal to hard copy document print. The scope of the invention includes both the liquid coating and the combination of coating on substrate.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: October 26, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Kent D. Vincent, Xiao-An Zhang, R. Stanley Williams
  • Publication number: 20040209448
    Abstract: A method is provided for printing electronic and opto-electronic circuits. The method comprises: (a) providing a substrate; (b) providing a film-forming precursor species; (c) forming a substantially uniform and continuous film of the film-forming precursor species on at least one side of the substrate, the film having a first electrical conductivity; and (d) altering portions of the film with at least one conductivity-altering species to form regions having a second electrical conductivity that is different than the first electrical conductivity, the regions thereby providing circuit elements. The method employs very simple and continuous processes, which make the time to produce a batch of circuits very short and leads to very inexpensive products, such as electronic memories (write once or rewriteable), electronically addressable displays, and generally any circuit for which organic electronics or opto-electronics are acceptable.
    Type: Application
    Filed: April 21, 2003
    Publication date: October 21, 2004
    Inventors: Xiao-An Zhang, R. Stanley Williams, Yong Chen
  • Patent number: 6805817
    Abstract: An electric field activated molecular system, preferably bi-stable, configured within an electric field generated by a pair of electrodes is provided for use, e.g., as electronic ink or other visual displays. The molecular system has an electric field induced band gap change that occurs via a change (reversible or irreversible) of the extent of the electron conjugation via chemical bonding change to change the band gap, wherein in a first state, there is substantial conjugation throughout the molecular system, resulting in a relatively smaller band gap, and wherein in a second state, the substantial conjugation is destroyed, resulting in a relatively larger band gap. The changing of substantial conjugation may be accomplished in one of the following ways: (1) charge separation or recombination accompanied by increasing or decreasing electron localization in the molecule; or (2) change of substantial conjugation via charge separation or recombination and&pgr;-bond breaking or making.
    Type: Grant
    Filed: August 17, 2001
    Date of Patent: October 19, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Xiao-An Zhang, Alexandre Bratkovski, Yong Chen, R. Stanley Williams, Kent D. Vincent
  • Patent number: 6806453
    Abstract: A scan-print device is hand-held and is scanned over the surface of a paper-like rewritable sheet. The sheet has a colorant responsive to a linear array of pixel-sized electric fields written over the sheet by the scan-print device during each scan, producing a bistable pixel (e.g., black or white) in response to field polarity. The bi-stable, rewritable colorant is highly energy efficient, requiring energy only to change an image, not to hold or illuminate it. Once a series of scans sufficient to cover the entire sheet has been made, the printed image appears as if printed conventionally. The print remains stable until reprinted or intentionally erased. Combined with hand-held scanner-copier technology, a portable copier is also implemented.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: October 19, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Kent D. Vincent, Xia-An Zhang, R. Stanley Williams, Philip J. Kuekes
  • Publication number: 20040165806
    Abstract: A bistable molecular switch can have a highly conjugated first state and a less conjugated second state. The bistable molecular switch can be configured such that application of an electric field reversibly switches the molecular switch from the first state to the second state. Additionally, the bistable molecular switch can include a hydrophobic moiety and a hydrophilic moiety. Such molecular switches can be incorporated into a thin film as part of a molecular switch system which can include a layer of molecular switches between a first electrode layer and a second electrode layer. The layer of molecular switches can have substantially all of the molecular switches having their hydrophilic moiety oriented in the same direction. An electric potential can then be induced between the first and second electrode layers sufficient to switch the molecular switches from the first or second state to the second or first state, respectively.
    Type: Application
    Filed: February 24, 2004
    Publication date: August 26, 2004
    Inventors: Zhang-Lin Zhou, Sean Xiao-An Zhang
  • Patent number: 6763158
    Abstract: Molecular systems are provided for electric field activated switches, such as optical switches. The molecular system has an electric field induced band gap change that occurs via one of the following mechanisms: (1) molecular conformation change; (2) change of extended conjugation via chemical bonding change to change the band gap; or (3) molecular folding or stretching. Nanometer-scale reversible optical switches are thus provided that can be assembled easily to make a variety of optical devices, including optical displays.
    Type: Grant
    Filed: April 27, 2001
    Date of Patent: July 13, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Xiao-An Zhang, R. Stanley Williams, Kent D. Vincent
  • Patent number: 6757457
    Abstract: An electrochemically-activated optical switch is provided, comprising a molecular system configured between a pair of electrodes. The molecular system includes a moiety that is oxidizable or reducible in the presence of an electric current.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: June 29, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Xiao-An Zhang, R. Stanley Williams
  • Publication number: 20040122233
    Abstract: Bistable molecules are provided with at least one photosensitive functional group. As thus constituted, the bistable molecules are photopatternable, thereby allowing fabrication of micrometer-scale and nanometer-scale circuits in discrete areas without relying on a top conductor as a mask. The bistable molecules may comprise molecules that undergo redox reactions, such as rotaxanes and catenanes, or may comprise molecules that undergo an electric-field-induced band gap change that causes the molecules, or a portion thereof, to rotate, bend, twist, or otherwise change from a substantially fully conjugated state to a less conjugated state. The change in states in the latter case results in a change in electrical conductivity.
    Type: Application
    Filed: October 30, 2003
    Publication date: June 24, 2004
    Inventors: Patricia A. Beck, Xiao-An Zhang, Zhang-Lin Zhou
  • Publication number: 20040113165
    Abstract: An optical sensor is provided, comprising (a) a silicon nanowire of finite length having an electrical contact pad at each end thereof; and (b) a plurality of self-assembled molecules on a surface of the silicon nanowire, the molecules serving to modulate electrical conductivity of the silicon nanowire by either a reversible change in dipole moment of the molecules or by a reversible molecule-assisted electron/energy transfer from the molecules onto the silicon nanowire. Further, a method of making the optical sensor is provided. The concept of molecular self-assembly is applied in attaching functional molecules onto silicon nanowire surfaces, and the requirement of molecule modification (hydroxy group in molecules) is minimal from the point view of synthetic difficulty and compatibility. Self-assembly will produce well-ordered ultra-thin films with strong chemical bonding on a surface that cannot be easily achieved by other conventional methods.
    Type: Application
    Filed: December 17, 2002
    Publication date: June 17, 2004
    Inventors: Zhiyong Li, Yong Chen, Sean Xiao-An Zhang
  • Patent number: 6751365
    Abstract: A molecular system is provided for nanometer-scale reversible electronic and optical switches, specifically, electric field-activated molecular switches that have an electric field induced band gap change that occurs via a molecular conformation change or a tautomerization. Changing of extended conjugation via chemical bonding change to change the band gap is accomplished by providing the molecular system with one rotating portion (rotor) and two or more stationary portions (stators), between which the rotor is attached. The molecular system of the present invention has three branches (first, second, and third branches) with one end of each branch connected to a junction unit to form a “Y” configuration. The first and second branches are on one side of the junction unit and the third branch is on the opposite side of the junction unit.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: June 15, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Xiao-An Zhang, Zhang-Lin Zhou, R. Stanley Williams, Kent D. Vincent
  • Publication number: 20040101232
    Abstract: Molecular systems are provided for electric field activated switches, such as optical switches. The molecular system has an electric field induced band gap change that occurs via one of the following mechanisms: (1) molecular conformation change; (2) change of extended conjugation via chemical bonding change to change the band gap; or (3) molecular folding or stretching. Nanometer-scale reversible optical switches are thus provided that can be assembled easily to make a variety of optical devices, including optical displays.
    Type: Application
    Filed: July 10, 2003
    Publication date: May 27, 2004
    Inventors: Sean Xiao-An Zhang, R. Stanley Williams, Kent D. Vincent
  • Publication number: 20040095309
    Abstract: Method and apparatus for document content publishing, distribution, and display, including a method of doing business. An electronic display includes at least one reusable imaging stratum forming a pixel array of a bi-modal molecular colorant. Preferably, the molecules have bistable orientations. The imaging stratum having a viewing surface and a back surface. Adjacent said back surface is a background stratum. An addressing device is mounted for selectively switching colorant molecules of the imaging stratum between a transparent orientation and a color-exhibiting orientation. The present invention is adaptable to reflective light, back lit, and projection implementations.
    Type: Application
    Filed: October 30, 2003
    Publication date: May 20, 2004
    Inventors: Kent D. Vincent, R. Stanley Williams, Xiao-An Zhang
  • Publication number: 20040084661
    Abstract: An electrochemically-activated optical switch is provided, comprising a molecular system configured between a pair of electrodes. The molecular system includes a moiety that is oxidizable or reducible in the presence of an electric current.
    Type: Application
    Filed: October 30, 2003
    Publication date: May 6, 2004
    Inventors: Xiao-An Zhang, R. Stanley Williams
  • Patent number: 6731532
    Abstract: An electrochromic molecular colorant and a plurality of uses as an erasably writeable medium. Multitudinous types of substrates, such as paper, are adaptable for receiving a coating of the colorant. Electrical fringe field or through fields are used to transform targeted pixel molecules between a first, high color state and transparent state, providing information content having resolution and viewability at least equal to hard copy document print. The scope of the invention includes both the liquid coating and the combination of coating on substrate.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: May 4, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Kent D. Vincent, Xiao-An Zhang, R. Stanley Williams
  • Publication number: 20040080804
    Abstract: A molecular light valve controlled color display. The display is formed through a layer of such molecules between a crossbar array of transparent electrodes, the crossbar intersections forming addressable pixels. A rapid sequencing of primary colors is controlled by molecular light valves congruent with display pixels. Native display resolution for a full gamut of colors is maintained for each pixel via a temporally distributed color pixel scheme. Both still and motion images can be displayed. Molecular valves, or switches, transition between two optically distinct states, e.g., transparent and black.
    Type: Application
    Filed: October 25, 2002
    Publication date: April 29, 2004
    Inventors: Kent D. Vincent, Xiao-An Zhang, R. Stanley Williams
  • Publication number: 20040066677
    Abstract: A molecular system is provided for electric field activated switches, such as a crossed-wire device or a pair of electrodes to which the molecular system is linked by linking moieties. The crossed-wire device comprises a pair of crossed wires that form a junction where one wire crosses another at an angle other than zero degrees and at least one connector species connecting the pair of crossed wires in the junction. The connector species comprises the molecular system, which has an electric field induced band gap change, and thus a change in its electrical conductivity, that occurs via one a molecular conformation change, based on a rotor/stator construction of the molecular system, involving a rotating portion (rotor) connected between to stationary portions (stators). Nanometer-scale reversible electronic switches are thus provided that can be assembled easily to make cross-bar circuits, which provide memory, logic, and communication functions.
    Type: Application
    Filed: September 10, 2003
    Publication date: April 8, 2004
    Inventors: Xiao-An Zhang, R. Stanley Williams, Robert G. Walmsley, Kent Vincent
  • Publication number: 20040041799
    Abstract: An electronic writing instrument for rewritable electronic writing surfaces. A self-powered, untethered, pencil-like instrument uses a perpendicular fringe field for changing the orientation of pixels composed of bistable, bichromal colorant elements. An appendix hereto describes bistable, bichromal, molecular colorant.
    Type: Application
    Filed: September 25, 2003
    Publication date: March 4, 2004
    Inventors: Kent D. Vincent, R. Stanley Williams, Xiao-An Zhang