Patents by Inventor Michael J. O'Callaghan

Michael J. O'Callaghan 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: 8134771
    Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroeleletric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: March 13, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Mark A. Handschy, Michael J. O'Callaghan
  • Patent number: 8107344
    Abstract: A spatial light modulator (SLM) having a phase mask that is provided as an internal component thereof. The phase mask can be provided as a multilevel surface of relatively higher index of refraction material on an inner surface of a transmissive cover window or as a separate transmissive window between the cover window and the pixels of the SLM. If the phase mask is to be used with a liquid crystal SLM, then it may be desirable to planarize the surface of the cover window contacting the liquid crystal by providing a layer of relatively lower index of refraction material adjacent the multilevel surface. The phase mask can also be provided on the transmissive cover window by patterned ion deposition, exposing patterned light to a photopolymeric material, or in some other suitable fashion. Arranging for the pixel electrodes to be at one of multiple levels rather than lying in an exactly planar relationship can also effectively create the phase mask.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: January 31, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Mark A. Handschy, Michael J. O'Callaghan, Christopher M. Walker
  • Publication number: 20100296380
    Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroeleletric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.
    Type: Application
    Filed: April 29, 2010
    Publication date: November 25, 2010
    Inventors: Mark A. Handschy, Michael J. O'Callaghan
  • Patent number: 7733557
    Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroelectric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: June 8, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Mark A. Handschy, Michael J. O'Callaghan
  • Publication number: 20100091631
    Abstract: A spatial light modulator (SLM) having a phase mask that is provided as an internal component thereof. The phase mask can be provided as a multilevel surface of relatively higher index of refraction material on an inner surface of a transmissive cover window or as a separate transmissive window between the cover window and the pixels of the SLM. If the phase mask is to be used with a liquid crystal SLM, then it may be desirable to planarize the surface of the cover window contacting the liquid crystal by providing a layer of relatively lower index of refraction material adjacent the multilevel surface. The phase mask can also be provided on the transmissive cover window by patterned ion deposition, exposing patterned light to a photopolymeric material, or in some other suitable fashion. Arranging for the pixel electrodes to be at one of multiple levels rather than lying in an exactly planar relationship can also effectively create the phase mask.
    Type: Application
    Filed: December 16, 2009
    Publication date: April 15, 2010
    Inventors: Mark A. Handschy, Michael J. O'Callaghan, Christopher M. Walker
  • Patent number: 7656768
    Abstract: A spatial light modulator (SLM) having a phase mask that is provided as an internal component thereof. The phase mask can be provided as a multilevel surface of relatively higher index of refraction material on an inner surface of a transmissive cover window or as a separate transmissive window between the cover window and the pixels of the SLM. If the phase mask is to be used with a liquid crystal SLM, then it may be desirable to planarize the surface of the cover window contacting the liquid crystal by providing a layer of relatively lower index of refraction material adjacent the multilevel surface. The phase mask can also be provided on the transmissive cover window by patterned ion deposition, exposing patterned light to a photopolymeric material, or in some other suitable fashion. Arranging for the pixel electrodes to be at one of multiple levels rather than lying in an exactly planar relationship can also effectively create the phase mask.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: February 2, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Mark A. Handschy, Michael J. O'Callaghan, Christopher M. Walker
  • Publication number: 20080284973
    Abstract: A method of fabricating a liquid crystal display device by introducing a ferroelectric liquid crystal (FLC) between two substrates, contacting the FLC to a molecularly smooth edge, and aligning the FLC by introducing a temperature gradient normal to the edge. In one embodiment, the FLC is aligned by cooling it from an isotropic phase to a smectic phase at a rate that is relatively slow. For example, the cooling rate may be less than about 3 degrees Celsius per hour. In one embodiment, smectic layers are formed that are parallel to the edge. In one embodiment, the molecularly smooth edge is an air bubble.
    Type: Application
    Filed: May 16, 2008
    Publication date: November 20, 2008
    Inventors: Bentley Wall, Dmylro Reznikov, Philip Bos, Michael J. O'Callaghan, Mark A. Handschy
  • Patent number: 6580078
    Abstract: A liquid crystal infrared light chopper includes a polarizer that receives and polarizes incoming infrared light, a layer of ferroelectric liquid crystal material switchable between at least two states, a pair of IR transparent, conductive substrates positioned on either side of the liquid crystal layer and an analyzer that blocks IR light of one polarization state and passes IR light of an opposite polarization state. The liquid crystal layer acts on polarized IR light by changing its polarization if the liquid crystal is in a first state and by not changing its polarization if the liquid crystal is in a second state. Voltages applied to the conductive substrates drive the liquid crystal layer to one of the two states. The analyzer blocks IR light when the liquid crystal layer is in one of the states and passes IR light when the liquid crystal layer is in the second state.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: June 17, 2003
    Assignee: Displaytech, Inc.
    Inventors: Michael J. O'Callaghan, William N. Thurmes
  • Patent number: 6525709
    Abstract: A display system includes a spatial light modulator having an array of individually controlled pixels switchable between a first and a second state for producing modulated light having gray scale during a given period of time. The system generates a reference signal that varies in a predetermined way during the given period of time. The system also generates analog pixel image signals associated with each of the pixels for the given period of time. The analog pixel image signal representing a desired gray scale level for each associated pixel during the given period of time. Each of the pixels includes an arrangement for receiving the reference signal and an arrangement for receiving the analog pixel image signal associated with that pixel.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: February 25, 2003
    Assignee: Displaytech, Inc.
    Inventor: Michael J. O'Callaghan
  • Patent number: 6369933
    Abstract: An optical correlator includes a first reflective mode spatial light modulator for inputting an input image and a second reflective mode spatial light modulator for inputting a reference image for comparing with the input image. The optical correlator also includes an optics arrangement for (i) directing light into the first spatial light modulator, (ii) directing light along a first optical path from the first spatial light modulator into the second spatial light modulator, and (iii) directing light along a second optical path from the second spatial light modulator into an image plane. The optics arrangement includes a first lens having a focal length f1 and a second lens having a focal length f2. The first lens is positioned substantially adjacent the first spatial light modulator and the second lens is positioned substantially adjacent the second spatial light modulator.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: April 9, 2002
    Assignee: Display tech, Inc
    Inventor: Michael J. O'Callaghan
  • Patent number: 6247037
    Abstract: An optical correlator includes a compound electro-optical component having a first and a second reflective spatial light modulator for forming electro-optical patterns of light. Each spatial light modulator has a reflective backplane with the reflective backplanes of the spatial light modulators being substantially coplanar. The spatial light modulators having their individual respective backplanes formed as two separate portions of a single integrated circuit die. The optical correlator may also include an imager for imaging the output of the optical correlator that is substantially coplanar with the spatial light modulators. The compound electro-optical component may include at least a part of the imager that is formed as a separate portion of the single integrated circuit die that contains the backplanes of the two spatial light modulators.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: June 12, 2001
    Assignee: Displaytech, Inc
    Inventor: Michael J. O'Callaghan
  • Patent number: 5552916
    Abstract: An arrangement (apparatus and method) for selectively modulating incident unpolarized light passing through a birefringent material, such as ferroelectric crystal. The apparatus includes a plate having one or more birefringent layers corresponding to first and second alignment regions. The birefringent layer corresponding to the first alignment region has a first optic axis selectably set in a first orientation and a second orientation. The birefringent layer corresponding to the second alignment region has a second optic axis selectably set in a third orientation and a fourth orientation. A switching means controls the optical axis states of the birefringent material by applying switching voltages to the areas of the birefringent layer. Light having passed through the birefringent layer at locations having the first orientation has a different phase from, and same polarization as, light having passed through locations with the third orientation, independent of a polarization state of the incident light.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: September 3, 1996
    Assignee: Displaytech, Inc.
    Inventors: Michael J. O'Callaghan, Mark A. Handschy
  • Patent number: 5182665
    Abstract: An arrangement (apparatus and method) for selectively modulating incident unpolarized light passing through a birefringent material, such as ferroelectric crystal. The apparatus includes a plate having one or more birefringent layers. The birefringent layer has an optic axis selectably set in a first orientation and a second orientation. A switching means controls the optical axis state of voltages to the areas of the birefringent layer. Light having passed through the birefringent layer at locations having the first orientation have a different phase from, and same polarization as, light having passed through locations with the second orientation, independent of a polarization state of the incident light. As a result, the birefringent material has a uniform state at locations where the corresponBACKGROUND OF THE INVENTIONGovernment Contract ClauseThis invention was made with Government support un contract F29601-89-C-0075 awarded by the Department of the Air Force.
    Type: Grant
    Filed: September 7, 1990
    Date of Patent: January 26, 1993
    Assignee: Displaytech, Inc.
    Inventors: Michael J. O'Callaghan, Mark A. Handschy