Patents by Inventor James K. Walker

James K. Walker 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).

  • Publication number: 20120241630
    Abstract: Embodiments of the invention provide a scintillator material, a scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material that comprises chromophores. Additional embodiments provide a scintillator material, scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material having one, two, three, or more, organic dyes dissolved therein wherein the polymer material having the one, two, three, or more dyes dissolved therein comprises chromophores. At least one of the dyes, termed the base dye, has a concentration in the range 0.5 to 3.5 mol/L. In a specific embodiment, the base dye has a concentration in the range 1.0 to 3.0 mol/L. This base dye concentration is high enough to achieve a substantial triplet-triplet state annihilation rate despite the negligible diffusion of the dye in the rigid polymer matrix.
    Type: Application
    Filed: March 26, 2012
    Publication date: September 27, 2012
    Applicant: NANOPTICS, INCORPORATED
    Inventors: JAMES K. WALKER, YOUNGWOOK NOH, RICHARD T. FARLEY
  • Patent number: 7135133
    Abstract: The present invention relates to a method and apparatus for manufacturing plastic optical transmission medium. The subject method and apparatus can produce a variety of optical transmission medium, including for example, graded refractive index polymer optical fiber, graded refractive index rod lens, and step index polymer optical fiber. The subject optical transmission medium have improved characteristics and efficiency, due, at least in part, to better control of the profile of the refractive index distribution and stable high temperature operation of the medium. High efficiency of manufacturing can be achieved by the subject method and apparatus which can permit continuous extrusion at high speed.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: November 14, 2006
    Assignee: Nanoptics, Inc.
    Inventors: James K. Walker, Jacob Ralph Tymianski, Bongsoo Lee, Stephan A. Tuchman, Won Young Choi
  • Patent number: 6892011
    Abstract: This invention concerns a method and apparatus for manufacturing a sheet and a two-dimensional matrix of plastic optical fibers. The fibers may be of the step-index or graded-index type. Co-extrusion through a specially designed die is used to produce a sheet composed of a fiber array. The fiber sheet (ribbon) can be used for transmitting optical signals. These arrays may also be stacked and fused at high temperatures to form the two-dimensional matrix required for many applications such as large area image transfer. In addition, a high-speed, continuous manufacturing method is disclosed to produce a massive two-dimensional matrix of fibers. The method of manufacture permits high quality image transfer at low manufacturing cost in a wide array of geometries.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: May 10, 2005
    Inventors: James K. Walker, Jacob R. Tymianski, Yongcheng Li, Bongsoo Lee, Jonathan Couch
  • Publication number: 20040179798
    Abstract: The present invention relates to a method and apparatus for manufacturing plastic optical transmission medium. The subject method and apparatus can produce a variety of optical transmission medium, including for example, graded refractive index polymer optical fiber, graded refractive index rod lens, and step index polymer optical fiber. The subject optical transmission medium have improved characteristics and efficiency, due, at least in part, to better control of the profile of the refractive index distribution and stable high temperature operation of the medium. High efficiency of manufacturing can be achieved by the subject method and apparatus which can permit continuous extrusion at high speed.
    Type: Application
    Filed: March 19, 2004
    Publication date: September 16, 2004
    Inventors: James K. Walker, Jacob Ralph Tymianski, Bongsoo Lee, Stephan A. Tuchman, Won Young Choi
  • Publication number: 20030016856
    Abstract: An apparatus and method for acquiring and processing digital images obtained and displayed through an electrically operated device. Image data may be processed in real time to include features of magnification, contrast brightness, image inversion, edge enhancement, quantitative measurement, image equalization, computer assisted diagnosis, voice recognition, and a high resolution display. The apparatus includes a power zoom lens, imaging chip, digital signal processing, LCD display, and rechargeable battery pack.
    Type: Application
    Filed: July 1, 2002
    Publication date: January 23, 2003
    Inventors: James K. Walker, Stephan A. Tuchman, William E. Loeffler, Kelvin D. Walker, Fredric F. Derwitsch
  • Publication number: 20020168157
    Abstract: This invention concerns a method and apparatus for manufacturing a sheet and a two-dimensional matrix of plastic optical fibers. The fibers may be of the step-index or graded-index type. Co-extrusion through a specially designed die is used to produce a sheet composed of a fiber array. The fiber sheet (ribbon) can be used for transmitting optical signals. These arrays may also be stacked and fused at high temperatures to form the two-dimensional matrix required for many applications such as large area image transfer. In addition, a high-speed, continuous manufacturing method is disclosed to produce a massive two-dimensional matrix of fibers. The method of manufacture permits high quality image transfer at low manufacturing cost in a wide array of geometries.
    Type: Application
    Filed: December 14, 2001
    Publication date: November 14, 2002
    Inventors: James K. Walker, Jacob R. Tymianski, Yongcheng Li, Bongsoo Lee, Jonathan Couch
  • Publication number: 20020041043
    Abstract: The present invention is a continuous process of producing an object with radially-varying material properties. These objects can be cylindrical forms made from polymeric materials. This process requires a novel device. The device can be used to produce high bandwidth gradient-index plastic optical fiber (GRIN-POF). This fiber is highly advantageous for use in high speed local area networks (LANs) as well as other short-range optical communication applications. The device can also be used to produce GRIN lenses which can be used in the focusing and transmission of images.
    Type: Application
    Filed: May 21, 2001
    Publication date: April 11, 2002
    Inventors: Chang-Won Park, James K. Walker
  • Publication number: 20020041042
    Abstract: The present invention relates to a method and apparatus for manufacturing plastic optical transmission medium. The subject method and apparatus can produce a variety of optical transmission medium, including for example, graded refractive index polymer optical fiber, graded refractive index rod lens, and step index polymer optical fiber. The subject optical transmission medium have improved characteristics and efficiency, due, at least in part, to better control of the profile of the refractive index distribution and stable high temperature operation of the medium. High efficiency of manufacturing can be achieved by the subject method and apparatus which can permit continuous extrusion at high speed.
    Type: Application
    Filed: April 12, 2001
    Publication date: April 11, 2002
    Inventors: James K. Walker, Jacob Ralph Tymianski, Bongsoo Lee, Stephan A. Tuchman, Won Young Choi
  • Patent number: 6267915
    Abstract: The present invention is a continuous process of producing an object with radially-varying material properties. These objects can be cylindrical forms made from polymeric materials. This process requires a novel device. The device can be used to produce high bandwidth gradient-index plastic optical fiber (GRIN-POF). This fiber is highly advantageous for use in high speed local area networks (LANs) as well as other short-range optical communication applications. The device can also be used to produce GRIN lenses which can be used in the focusing and transmission of images.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: July 31, 2001
    Assignee: University of Florida
    Inventors: Chang-Won Park, James K. Walker
  • Patent number: 6158888
    Abstract: This invention pertains to novel methods of radiography and novel screen-film cassettes with wide exposure latitude and/or high film contrast for use in radiography. The materials and methods of the subject invention can be used in mammography. In a specific example, this invention concerns the design of novel screen-film cassettes which can use at least one phosphor screen and multiple x-ray films in a single cassette. When used in mammography, this novel design enables additional breast images to be obtained on the faster, or slower, speed film from the same x-ray exposure used to produce a normal breast image on the normal speed film. These additional breast images provide high contrast information on the dense regions of the breast and in the edge areas of the compressed breast. These dense regions currently cause many missed diagnoses in breast cancer screening.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: December 12, 2000
    Assignee: University of Florida
    Inventors: James K. Walker, Zhenxue Jing
  • Patent number: 6115523
    Abstract: The subject invention pertains to a system for imaging the human airway having highly advantageous optical and physical characteristics. In a specific embodiment, the human airway can be imaged during the intubation procedure. The excellent characteristics of the imaging system of the subject invention result, in part, from the use of plastic optic fibers. Plastic fibers are more robust than the glass optical fibers used in currently available imaging systems, and are therefore capable of being bent and/or twisted with less concern of breakage. In addition, the lower costs of plastic fibers enables scopes of the subject invention, in a specific embodiment, to be manufactured for single patient use thereby eliminating the requirement for cleaning, special care, the maintenance of expensive inventory, and most importantly eliminating the opportunity for cross contamination between patients.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: September 5, 2000
    Assignee: University of Florida
    Inventors: Won Young Choi, Dietrich Gravenstein, Samsun Lampotang, Richard Melker, James K. Walker
  • Patent number: 5881195
    Abstract: The present invention is an image guide which has applications in such areas as endoscopy and industrial imaging. This invention utilizes gradient-index optical fiber in order to produce an image guide with improved performance characteristics. These improved performance characteristics include increased brightness, enhanced resolution, greater flexibility, and smaller diameter. The smaller diameter of the image guide permits access through smaller apertures in order to image inaccessible locations.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: March 9, 1999
    Assignee: Nanoptics, Inc.
    Inventor: James K. Walker
  • Patent number: 5751787
    Abstract: This invention pertains to novel methods of radiography and novel screen-film cassettes with wide exposure latitude and/or high film contrast for use in radiography. The materials and methods of the subject invention can be used in mammography. In a specific example, this invention concerns the design of novel screen-film cassettes which can use at least one phosphor screen and multiple x-ray films in a single cassette. When used in mammography, this novel design enables additional breast images to be obtained on the faster, or slower, speed film from the same x-ray exposure used to produce a normal breast image on the normal speed film. These additional breast images provide high contrast information on the dense regions of the breast and in the edge areas of the compressed breast. These dense regions currently cause many missed diagnoses in breast cancer screening.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: May 12, 1998
    Assignee: Nanoptics, Inc.
    Inventors: Zhenxue Jing, James K. Walker
  • Patent number: 5606638
    Abstract: A class of polycyclic aromatic compounds containing at least two fused rings, is used to produce very bright liquid or plastic scintillators. When a member of this class, such as pyrene, is added at high concentration to a liquid or polymeric organic solvent, scintillation light output may be increased by between 40 and 100% as compared to existing commercial scintillating compositions. These new bright scintillator compositions can be used in scintillating optical fibers and plates made therefrom. These new scintillating optical fiber plates are particularly useful for diagnostic medical X-ray detection, and superior spatial resolution particle detection and measurement of high energy particles and radiation.
    Type: Grant
    Filed: December 26, 1995
    Date of Patent: February 25, 1997
    Assignee: Nanoptics Incorporated
    Inventors: Jacob R. Tymianski, James K. Walker
  • Patent number: 5420959
    Abstract: A new scintillating optical fiber is used in an array as a scintillator plate for imaging with high energy radiation, particles and the like. The scintillating optical fiber has an inner plastic core fiber which is transparent to visible radiation and has an index of refraction of about 1.45 or greater. The inner plastic core fiber has a plastic cladding material which has an index of refraction less than that of the inner plastic core fiber. The inner plastic core fiber contains a polymeric matrix material; a metal moiety; and an organic fluorescent material. The scintillator plates are useful in producing high efficiency and high resolution radiographic systems for x-ray medical diagnosis or non-destructive inspection as well as non-destructive inspection with thermal neutrons.
    Type: Grant
    Filed: November 17, 1993
    Date of Patent: May 30, 1995
    Assignee: Nanoptics Incorporated
    Inventors: James K. Walker, Jacob R. Tymianski
  • Patent number: 5308986
    Abstract: A new scintillating optical fiber is used in an array as a scintillator plate for imaging with high energy radiation, particles and the like. The scintillating optical fiber has an inner plastic core fiber which is transparent to visible radiation and has an index of refraction of about 1.45 or greater. The inner plastic core fiber has a plastic cladding material which has an index of refraction less than that of the inner plastic core fiber. The inner plastic core fiber contains a polymeric matrix material; a metal moiety; and an organic quench-resistant fluorescent material. The scintillator plates are useful in producing high efficiency and high resolution radiographic systems for x-ray medical diagnosis or non-destructive inspection as well as non-destructive inspection with thermal neutrons.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: May 3, 1994
    Assignee: Nanoptics Incorporated
    Inventor: James K. Walker
  • Patent number: 5110500
    Abstract: A plastic scintillator useful for detecting ionizing radiation comprising a matrix which comprises an optically transparent polysiloxane having incorporated therein at least one ionizing radiation-hard fluor capable of converting electromagnetic energy produced in the polysiloxane upon absorption of ionizing radiation to detectable light.
    Type: Grant
    Filed: March 13, 1990
    Date of Patent: May 5, 1992
    Assignee: University of Florida
    Inventor: James K. Walker
  • Patent number: 5010833
    Abstract: An edge detector for detecting the edge of fabric in a textile folding or guiding device for an industrial sewing machine. The detector includes a light source mounted adjacent to one surface of the fabric as the fabric enters the folder. The light source is positioned for directing light onto the surface of the fabric. A photodetector is located adjacent to the light source for receiving light reflected from the surface of the fabric. The photodetector provides an output signal in response to the light reflected from the surface of the fabric which is indicative of the position of the fabric in the folder.
    Type: Grant
    Filed: September 6, 1988
    Date of Patent: April 30, 1991
    Assignee: Wrangler
    Inventors: James T. Spencer, III, James K. Walker