Patents by Inventor C. Chu

C. Chu 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: 4050937
    Abstract: Disclosed is an imaging method which comprises:A. providing a film of an organic polymer as matrix material having uniformly dispersed therein:I. a photochemically reactive organo diselenide characterized by the formula:R.sub.1 --Se--Se--R.sub.2wherein R.sub.1 and R.sub.2 are aralkyl or alkyl hydrocarbon moieties;Ii. a tertiary phosphine or phosphite characterized by the formula: ##STR1## wherein each n is 0 in the case of phosphine and 1 in the case of a phosphite and R.sub.3, R.sub.4 and R.sub.5 are independently substituted or unsubstituted aryl hydrocarbon moieties; andIii. an organic peroxide characterized by the formula: ##STR2## wherein R.sub.6 and R.sub.7 are aryl or substituted aryl; B. EXPOSING THE FILM IN AN IMAGEWISE MANNER TO ULTRAVIOLET RADIATION TO FORM AN IMAGE THEREIN; ANDC. heating the exposed film to a temperature of at least about 100.degree. C for a time sufficient to enhance the image contrast.
    Type: Grant
    Filed: December 13, 1976
    Date of Patent: September 27, 1977
    Assignee: Xerox Corporation
    Inventors: Dana G. Marsh, Joseph Y. C. Chu
  • Patent number: 4050939
    Abstract: Disclosed is a microimaging composition which comprises a film of an organic polymer as a matrix material having uniformly dispersed therein:I. a photochemically reactive organo diselenide characterized by the formula:R.sub.1 --Se--Se--R.sub.2wherein R.sub.1 and R.sub.2 are aralkyl or alkyl hydrocarbon moieties;Ii. a tertiary phosphine or phosphite characterized by the formula: ##STR1## wherein each n is 0 in the case of a phosphine and 1 in the case of a phosphite and R.sub.3, R.sub.4 and R.sub.5 are independently substituted or unsubstituted aryl hydrocarbon moieties; andIii. an organic peroxide characterized by the formula: ##STR2## wherein R.sub.6 and R.sub.7 are aryl or substituted aryl.
    Type: Grant
    Filed: December 13, 1976
    Date of Patent: September 27, 1977
    Assignee: Xerox Corporation
    Inventors: Dana G. Marsh, Joseph Y. C. Chu
  • Patent number: 4049567
    Abstract: Photochromic plastic materials are disclosed which comprise a polymeric matrix containing a multiplicity of activated silver halide particles less than 1000 Angstroms in size. The matrix may contain a retained amount of plasticizer which optimizes the desirable photochromic properties and may be sealed to prevent loss of plasticizer. The materials are made by forming activated silver halide particles in the presence of a film forming polymer dissolved in a plasticizer and removing the plasticizer to produce a supple, shape-retaining element.
    Type: Grant
    Filed: March 17, 1976
    Date of Patent: September 20, 1977
    Assignee: American Optical Corporation
    Inventors: Nori Y. C. Chu, Peter G. Piusz
  • Patent number: 4047947
    Abstract: Process for preparation of transparencies from a solid phase dispersion of photoconductive particles in an insulating binder matrix. In this process, a dispersion is initially formed from an insulating polymer resin and an organoselenium compound capable of undergoing selective decomposition in response to an appropriate stimulus, whereby elemental selenium is extruded from said organoselenium compound and deposited within the polymeric resin. As a result of this deposition of elemental selenium within the insulating layer, the layer is rendered photoresponsive and can be used in conventional electrophotographic processes. Subsequent to the development and fusion of a developer image on this imaging member, the extrusion/deposition reaction can be reversed and the selenium deposit erased thus leaving a toner image fused to a substantially transparent polymeric film.
    Type: Grant
    Filed: October 23, 1974
    Date of Patent: September 13, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, Wolfgang H. H. Gunther
  • Patent number: 4046586
    Abstract: Inorganic photochromic crystalline particles which are particularly useful in ophthalmic quality plastic host materials are formed for instance utilizing a silver halide crystal whose dimensions lie generally in the range between 30 Angstroms and 10,000 Angstroms. The surface of the silver halide crystal is coated with an inorganic material in an effective thickness to render the coating resistant to diffusion from within and to protect the crystal from interaction with host material. The stabilized coated particles can be introduced by known schemes into plastic host materials in order to form photochromic plastic articles useful in the preparation of films, sheets, filters for cameras, wall panels and ophthalmic lenses and other optical devices.
    Type: Grant
    Filed: January 27, 1975
    Date of Patent: September 6, 1977
    Assignee: American Optical Corporation
    Inventors: Donald R. Uhlmann, Elias Snitzer, Richard J. Hovey, Nori Y. C. Chu, Joseph T. Fournier, Jr.
  • Patent number: 4030991
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: June 21, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4030993
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: June 21, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4030992
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: June 21, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4028203
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: June 7, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4018602
    Abstract: Method for in situ preparation of photoconductive composite having an electronically active hole transport layer, an electronically active electron transport layer and a layer of charge transfer complex sandwiched therebetween. According to this method, a film containing either an electron donor or an electron acceptor is initially formed directly on a supportive (preferably conductive) substrate. After this film has been allowed to set, a second film is solvent coated on the previously formed film. The solvent used in preparation of the second film causes softening of the previously formed layer which permits interaction of an electron acceptor or an electronic donor in the casting solvent with an electron acceptor or an electron donor of the previously formed layer, thereby forming a charge transfer complex at the interface of these two films. Only a portion of the donor and acceptor interact along this common boundary during the formation of the photoconductive composite.
    Type: Grant
    Filed: April 17, 1975
    Date of Patent: April 19, 1977
    Assignee: Xerox Corporation
    Inventor: Joseph Y. C. Chu
  • Patent number: 4016058
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organoselenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: April 5, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4014768
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: March 29, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4013528
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organoselenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: March 22, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4013529
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: March 22, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4013530
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: March 22, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4007100
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: February 8, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 4007101
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organoselenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: February 8, 1977
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, Wolfgang H. H. Gunther
  • Patent number: 3994791
    Abstract: Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
    Type: Grant
    Filed: March 26, 1974
    Date of Patent: November 30, 1976
    Assignee: Xerox Corporation
    Inventors: Joseph Y. C. Chu, W. H. H. Gunther
  • Patent number: 3993123
    Abstract: A gas encapsulated cooling unit is provided for one or more heat generating components mounted on a substrate. A heat conductive cap is sealed to the substrate enclosing the heat generating components. The wall of the cap opposite the substrate contains elongated openings therein extending towards the heat generating components and on the same centers with respect thereto. A resilient member is located in the cap in communion with the inner end of the openings. A thermal conductive element is located in each of the openings forming a small peripheral gap between each opening wall and the associated thermal conductive element. The resilient member urges the thermal conductive elements into pressure contact with the heat generating components. A thermal conductive inert gas is located within the cap filling the peripheral gaps and the interfaces between the heat generating elements and the thermal conductive elements. The heat is removed from the cap by external heat removal means.
    Type: Grant
    Filed: October 28, 1975
    Date of Patent: November 23, 1976
    Assignee: International Business Machines Corporation
    Inventors: Richard C. Chu, Omkarnath R. Gupta, Un-Pah Hwang, Robert E. Simons
  • Patent number: 3984770
    Abstract: An automatic transfer oscillator system for frequency measurement using a single sampler is described. Two signals, of frequencies f.sub.1 and f.sub.2, are alternately used to drive the sampler. The two frequencies are sufficiently close by design so that the intermediate frequency signals generated arise from the same harmonic number when sampling a signal of unknown frequency f.sub.x. The resulting average IF output is accurately measured and used to compute the unknown frequency f.sub.x. Accurate measurement of the average IF output is made possible because the transition between f.sub.1 driving the sampler and f.sub.2 driving the sampler only occurs when the two signals are in phase. As a result, the IF signal transitions are also in phase and spurious signals are not produced. This technique is referred to as phase continuous switching.
    Type: Grant
    Filed: February 5, 1975
    Date of Patent: October 5, 1976
    Assignee: Hewlett-Packard Company
    Inventor: David C. Chu