Patents Assigned to The Board of Regents of the University of Colorado
  • Patent number: 6091462
    Abstract: This invention provides split-element liquid crystal polarization interference filters in wide-field, bandpass, cut-on, cut-off and notch filter embodiments. The split-element filters of this invention comprise a polarization interference stage defined by a pair of polarizers. Disposed within the stage are a center retarder, and first and a second split-element retarder, the split-element retarders having equal retardances and positioned in series with and on either side of the center retarder. The retarders can be liquid crystal variable retarders or can be fixed retarders used in combination with liquid crystal retarders. Double split-element filters in passive and tunable embodiments are provided comprising, within a polarization interference stage, a center retarder, an inside pair of split-element retarders and an outside pair of split-element retarders.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: July 18, 2000
    Assignee: The Board of Regents of the University of Colorado
    Inventors: Gary D. Sharp, Kristina M. Johnson
  • Patent number: 5876830
    Abstract: The present invention relates to methods and starting materials for forming molecular-sized grids or nets, or other structures based on such grids and nets, by creating molecular links between elementary molecular modules constrained to move in only two directions on an interface or surface by adhesion or bonding to that interface or surface. In the methods of this invention, monomers are employed as the building blocks of grids and more complex structures. Monomers are introduced onto and allowed to adhere or bond to an interface. The connector groups of adjacent adhered monomers are then polymerized with each other to form a regular grid in two dimensions above the interface. Modules that are not bound or adhered to the interface are removed prior to reaction of the connector groups to avoid undesired three-dimensional cross-linking and the formation of non-grid structures.
    Type: Grant
    Filed: September 6, 1996
    Date of Patent: March 2, 1999
    Assignee: Board of Regents of The University of Colorado
    Inventors: Josef Michl, Thomas F. Magnera, Donald E. David, Robin M. Harrison
  • Patent number: 5808743
    Abstract: This invention provides an inexpensive, sensitive sensor to measure target position, velocity and vibration based on optical feedback-induced fluctuations in the operating frequency of a diode laser. The sensor comprises a diode laser, an optical frequency discriminator to measure the laser operating frequency, and an electronic signal analyzer to obtain the modulation frequency of the laser operating frequency. This invention further includes two calibration mechanisms for vibration amplitude measurement. In a first calibration mechanism the diode laser is mounted on a laser vibrator, which vibrates the laser relative to the target. In a second calibration mechanism a frequency modulator is coupled to the diode laser to modulate the operating frequency.
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: September 15, 1998
    Assignee: Board of Regents of the University of Colorado
    Inventors: Michelle S. E. Stephens, Peter A. Roos, Carl E. Wieman, Eric A. Cornell
  • Patent number: 5781268
    Abstract: This invention provides polarization-independent optical filters that are Fabry-Perot filters. The inventive filters incorporate a phase modulator within the FP cavity and two quarter-wave plates, one on either side of the phase modulator, in the cavity. The quarter-wave plates are perpendicular to each other and oriented at .+-.45.degree. with respect to the optic axis of the phase modulator. A variety of phase modulators including those that incorporate nematic and smectic liquid crystal optical modulators can be employed in these FP filters. The filters of this invention are particularly useful in fiber optic systems and in telecommunications applications at 1550 nm.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: July 14, 1998
    Assignee: Board of Regents of the University of Colorado
    Inventors: Jian-Yu Liu, Charles S. Wong, Kristina M. Johnson, Gary D. Sharp
  • Patent number: 5751384
    Abstract: This invention provides a complementary color polarizer using a single polarizing film followed by a stack of two or more retarders. In a preferred embodiment, the color polarizers of this invention produce orthogonally polarized complementary primary colors (red/cyan, green/magenta, or blue/yellow). This invention further provides color filters which utilize the color polarizers of this invention in combination with a polarization separator to separate the orthogonally polarized colors. The polarization separator can be passive, such as a polarizing beam splitter, or active, such as a switchable polarizer. The switchable polarizer can employ a nematic or a smectic liquid crystal cell. Two color filters of this invention can be cascaded to provide a three color (RGB) filter with an off-state. In combination with a monochrome display or camera, the color filters of this invention provide color displays or cameras.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: May 12, 1998
    Assignee: The Board of Regents of the University of Colorado
    Inventor: Gary D. Sharp
  • Patent number: 5731470
    Abstract: Substituted borate and carborate anions having unusual properties of being exceptionally weakly nucleophilic and being soluble in non-polar solvents. One-electron oxidation of the anions yields the corresponding radicals. The compounds are useful, e.g., as electrolytes, catalysts, and electrochromic materials.
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: March 24, 1998
    Assignee: Board of Regents of the University of Colorado
    Inventors: Josef Michl, Benjamin T. King, Zbynek Janousek
  • Patent number: 5728162
    Abstract: A surgical method for reducing post-operative knee failure in a knee undergoing arthroplasty by determining the pre-operative lateral displacement of the trochlear groove with respect to the femoral condyles, inserting a prosthetic implant with the condylar members having a lateral displacement which is a function of the determined pre-operative lateral displacement of the sulcus. The invention further includes an device which includes condyle members that are joined by an arched region, said region have a lateral displacement of between 1 mm and 15 mm with respect to said condyle members. The subject device addresses the problems of implant failure due to compressive force on the patella.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: March 17, 1998
    Assignee: Board of Regents of University of Colorado
    Inventor: Donald G. Eckhoff
  • Patent number: 5681354
    Abstract: An asymmetric distal femoral prosthetic component is provided for use in arthroplasty having a sulcus angled laterally upward, and preferably laterally displaced from the midline. This design more closely approximates the configuration of the natural knee and reduces patellar maltracking and excessive wear and failure of the component.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: October 28, 1997
    Assignee: Board of Regents, University of Colorado
    Inventor: Donald G. Eckhoff
  • Patent number: 5669914
    Abstract: This invention provides a rotation alignment device for aligning the tibia with the femur of a patient prior to placement of prosthetic knee components. The device allows the patient's normal, habitual rotation of the tibia with respect to the femur to be preserved when the prosthesis is placed. It also allows the bones to be moved to any desired position prior to placement of the prosthetic components, including a position dictated by alignment of the long axes of the tibia and femur.
    Type: Grant
    Filed: February 16, 1996
    Date of Patent: September 23, 1997
    Assignee: Board of Regents of the University of Colorado
    Inventor: Donald G. Eckhoff
  • Patent number: 5670545
    Abstract: Bucillamine and N-2,2-dimethyl-3-mercaptopropionyl)-L-cysteine or related compounds can be used to prevent damage to living tissue from the formation or presence of reactive oxygen species. These reactive oxygen species are formed when tissue is first rendered hypoxic due to interruption of blood flow and then reoxygenated by restoration of blood flow. In particular, the invention is directed to the administration of bucillamine and N-2,2-dimethyl-3-mercaptopropionyl)-L-cysteine prior to or coincidental with reperfusion to prevent damage to myocardium from formation of reactive oxygen species. Also presented are application of these compounds to similar ischemia-related cell injury in other organs.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: September 23, 1997
    Assignee: Board of Regents of the University of Colorado
    Inventor: Lawrence D. Horwitz
  • Patent number: 5658490
    Abstract: This invention provides achromatic liquid crystal compound retarders, achromatic polarization switches, and achromatic shutters using the liquid crystal compound retarders. It further provides achromatic variable retardance smectic liquid crystal retarders. The compound retarder of this invention comprises a central liquid crystal retarder unit and two external passive retarders positioned in series with and on either side of the liquid crystal retarder unit. The liquid crystal retarder unit comprises either (1) a rotatable smectic liquid crystal half-wave retarder or (2) first and second liquid crystal variable retarders having retardance switchable between zero and half-wave. The external passive retarders are equal in retardance and orientation to each other. Design equations determine the retardance of the external elements and their orientation relative to the central retarder to obtain a particular achromatic retardance for the compound structure.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: August 19, 1997
    Assignee: Board of Regents of the University of Colorado
    Inventors: Gary D. Sharp, Kristina M. Johnson
  • Patent number: 5646177
    Abstract: Disclosed herein are new anthracyclines which are derived from conjugation with glutathione, for example from conjugation of adriamycin, daunomycin and menogaril with glutathione: compounds 7 I, 7 II, 8 I, 8 II, 9 I and 9II, are obtained by reduction of the anthracycline followed by reaction of the reduced product with glutathione in aqueous (H.sub.2 O or D.sub.2 O) or organic solvent. The invention also provides salts of these glutathione derivatives, particularly salts formed from anthracycline glutathione anions with anthracycline cations. These anthracycline derivatives are useful as antibiotics, as antitumor agents, and in the treatment of AIDS. These derivatives are particularly useful in the treatment of cancer when multiple drug resistance is present.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: July 8, 1997
    Assignees: Board of Regents of The University of Colorado, Consiglio Nazionale Delle Richerche
    Inventors: Tad H. Koch, Giorgio Gaudiano
  • Patent number: 5639441
    Abstract: Methods and apparatuses are provided for forming fine particles of a desired substance comprising dissolving said substance in a fluid such as water to form a solution and mixing the solution with a second fluid such as supercritical carbon dioxide which becomes a gas upon rapid pressure release, and with which the first fluid is at least partially immiscible, and releasing the pressure to form an air-borne dispersion or aerosol comprising particles having an average diameter between about 0.1 and about 6.5 .mu.m.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: June 17, 1997
    Assignee: Board of Regents of University of Colorado
    Inventors: Robert E. Sievers, Uwe Karst
  • Patent number: 5627666
    Abstract: This invention provides a phase modulator comprising an electro-optically rotatable smectic liquid crystal half-wave retarder in combination with a cholesteric liquid crystal circular polarizer. Rotation of the half-wave retarder varies the phase delay of the modulator. A polarizing interferometer is provided utilizing the phase modulator of this invention in combination with a second cholesteric circular polarizer and a linear polarizer. A tunable Fabry-Perot resonator which does not require ordinary mirrors is provided utilizing the phase modulator of this invention in combination with a second cholesteric circular polarizer.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: May 6, 1997
    Assignee: Board of Regents of the University of Colorado
    Inventors: Gary D. Sharp, Jay E. Stockley, Kristina M. Johnson
  • Patent number: 5561287
    Abstract: A semiconductor device comprising a dual photodetector for use in an array to locate points of peak intensities incident upon the array. Each pixel in the array is comprised of a dual photodetector element. An n-type well is located within a p-substrate with highly doped p-contact areas located along the periphery of the n-well at the surface. A metal or polysilicon gate electrode covers the surface between the p-contacts and an applied gate voltage creates an inverted p-channel to form a lateral effect phototransistor. A second photodetector is formed at the junction of the n-well and p-substrate. The second photodetector from each pixel produces a current which is connected to a processing circuit to determine which pixel is the brightest above a designated threshold. All pixels above the threshold are sequentially identified.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: October 1, 1996
    Assignee: Board of Regents of the University of Colorado
    Inventors: Richard M. Turner, Kristina T. Johnson, David A. Jared
  • Patent number: 5552912
    Abstract: The present invention provides optical modulators which comprise aligned chiral smectic liquid crystal cells within an optical resonance cavity. The cavity configurations include symmetric and asymmetric Fabry-Perot etalons. The liquid crystal cells can be planar- or homeotropically-aligned and can be discrete state or analog cells. The device configurations of the present invention provide discrete or continuous optical modulation of the phase, intensity, and wavelength of elliptically polarized light, without requiring polarization analyzers. The modulators are optically or electronically addressable in single pixels or arrays of multiple pixels. Certain homeotropically-aligned cells are provided as an aspect of this invention, as are certain variable retarders comprised of planar-aligned cells in combination with birefringent elements.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: September 3, 1996
    Assignee: Board of Regents of the University of Colorado
    Inventors: Gary D. Sharp, Kristina M. Johnson
  • Patent number: 5381253
    Abstract: The present invention provides optical modulators which comprise aligned chiral smectic liquid crystal cells within an optical resonance cavity. The cavity configurations include symmetric and asymmetric Fabry-Perot etalons. The liquid crystal cells can be planar- or homeotropically-aligned and can be discrete state or analog cells. The device configurations of the present invention provide discrete or continuous optical modulation of the phase, intensity, and wavelength of elliptically polarized light, without requiring polarization analyzers. The modulators are optically or electronically addressable in single pixels or arrays of multiple pixels. Certain homeotropically-aligned cells are provided as an aspect of this invention, as are certain variable retarders comprised of planar-aligned cells in combination with birefringent elements.
    Type: Grant
    Filed: November 14, 1991
    Date of Patent: January 10, 1995
    Assignee: Board of Regents of University of Colorado
    Inventors: Gary D. Sharp, Kristina M. Johnson, Mark O. Freeman