Patents by Inventor Jim J. Chang

Jim J. Chang 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: 8410396
    Abstract: A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: April 2, 2013
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: Jim J. Chang, Herbert W. Friedman, Brian J. Comaskey
  • Publication number: 20130075373
    Abstract: A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.
    Type: Application
    Filed: January 19, 2007
    Publication date: March 28, 2013
    Inventors: Jim J. Chang, Herbert W. Friedman, Brian J. Comaskey
  • Patent number: 7193175
    Abstract: A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: March 20, 2007
    Assignee: The Regents of the University of California
    Inventors: Jim J. Chang, Herbert W. Friedman, Brian J. Comaskey
  • Patent number: 6864459
    Abstract: A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: March 8, 2005
    Assignee: The Regents of the University of California
    Inventors: Jim J. Chang, Herbert W. Friedman, Brian J. Comaskey
  • Patent number: 6704341
    Abstract: A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: March 9, 2004
    Assignee: The Regents of the University of California
    Inventor: Jim J. Chang
  • Publication number: 20020104831
    Abstract: A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.
    Type: Application
    Filed: February 8, 2001
    Publication date: August 8, 2002
    Applicant: The Regents of the University of California
    Inventors: Jim J. Chang, Herbert W. Friedman, Brian J. Comaskey
  • Patent number: 5978407
    Abstract: A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: November 2, 1999
    Assignee: United States Enrichment Corporation
    Inventors: Jim J. Chang, Isaac L. Bass, Luis E. Zapata
  • Patent number: 5744780
    Abstract: A new material processing apparatus using a short-pulsed, high-repetition-rate visible laser for precision micromachining utilizes a near diffraction limited laser, a high-speed precision two-axis tilt-mirror for steering the laser beam, an optical system for either focusing or imaging the laser beam on the part, and a part holder that may consist of a cover plate and a back plate. The system is generally useful for precision drilling, cutting, milling and polishing of metals and ceramics, and has broad application in manufacturing precision components. Precision machining has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratios up to 1:40 have been consistently drilled with good surface finish on a variety of metals.
    Type: Grant
    Filed: September 5, 1995
    Date of Patent: April 28, 1998
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Jim J. Chang, Ernest P. Dragon, Bruce E. Warner
  • Patent number: 5444332
    Abstract: Several different cold cathode configurations for a gas discharge device each having a plurality of grooves of selected spacing, depth and width to improve the emission of electrons in a gas discharge device. Each of the cold cathode configurations can be machined from a single piece of a selected material. Several of the configurations can be assembled with individual elements which is easily seen from the various figures.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: August 22, 1995
    Inventors: Jim J. Chang, Terry W. Alger
  • Patent number: 5434882
    Abstract: A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: July 18, 1995
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Jim J. Chang