Patents by Inventor Rama Nand Singh

Rama Nand Singh 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: 20110173577
    Abstract: Techniques for improving circuit design and production are provided. In one aspect, a method for virtual fabrication of a process-sensitive circuit is provided. The method comprises the following steps. Based on a physical layout diagram of the circuit, a virtual representation of the fabricated circuit is obtained that accounts for one or more variations that can occur during a circuit production process. A quality-based metric is used to project a production yield for the virtual representation of the fabricated circuit. The physical layout diagram and/or the production process are modified. The obtaining, using and modifying steps are repeated until a desired projected production yield is attained.
    Type: Application
    Filed: February 1, 2008
    Publication date: July 14, 2011
    Applicant: International Business Machines Corporation
    Inventors: Ching-Te K. Chuang, Fook-Luen Heng, Rouwaida Kanj, Keunwoo Kim, Jin-Fuw Lee, Saibal Mukhopadhyay, Sani Richard Nassif, Rama Nand Singh
  • Patent number: 7962865
    Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: June 14, 2011
    Assignee: International Business Machines Corporation
    Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
  • Publication number: 20090089726
    Abstract: A method for layout design includes steps or acts of: receiving a layout for design of an integrated circuit chip; designing mask shapes for the layout; transmitting the mask shapes to a litho simulator for generating wafer shapes; receiving the wafer shapes; calculating electrically equivalent gate lengths for the wafer shapes; analyzing the gate lengths to check for conformity against a threshold value, wherein the threshold value represents a desired value of electrically equivalent gate lengths; placing markers on the layout at those locations where the gate length violates the threshold value; and generating a histogram of gate lengths for comparing layouts for electrically equivalent gate lengths for layout quality.
    Type: Application
    Filed: October 1, 2007
    Publication date: April 2, 2009
    Applicant: International Business Machines Corporation
    Inventors: Fook-Luen Heng, Mark A. Lavin, Jin-Fuw Lee, Thomas Ludwig, Rama Nand Singh, Fanchieh Yee
  • Publication number: 20080301624
    Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.
    Type: Application
    Filed: July 17, 2008
    Publication date: December 4, 2008
    Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
  • Patent number: 7448018
    Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.
    Type: Grant
    Filed: September 12, 2006
    Date of Patent: November 4, 2008
    Assignee: International Business Machines Corporation
    Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
  • Publication number: 20080066047
    Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 13, 2008
    Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
  • Patent number: 7018746
    Abstract: A method of verifying the placement of sub-resolution assist features (SRAFs) in a photomask layout is described. SRAFs are added to the photomask layout to enhance the process window for semi-isolated and isolated features. Rules are provided to automatically place the SRAFs into the layout. When deficiencies are detected in the assist feature design or in the automated SRAF placement program, the placement of SRAFs requires verification. The method verifies the correct placement by defining a unique image property linked to the accurate placement of the assist features, and combines it with in-situ image simulation of the individual layout.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: March 28, 2006
    Assignee: International Business Machines Corporation
    Inventors: Yuping Cui, Rama Nand Singh
  • Patent number: 6985169
    Abstract: An image capture system for mobile communications systems includes an imaging device for capturing optical image data and a data transfer apparatus coupled to a communications device communications device for transferring the optical image data to the communications device for transmittal over a communications network.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: January 10, 2006
    Assignee: Lenovo (Singapore) Pte. Ltd.
    Inventors: Zhong John Deng, Sudhir Muniswamy Gowda, John P. Karidis, Dale Jonathan Pearson, Rama Nand Singh, Hon-Sum Philip Wong, Jungwook Yang
  • Patent number: 6816225
    Abstract: A display device and method for fabricating a liquid crystal cell are disclosed. A liquid crystal cell includes a first substrate, and a second substrate attached to the first substrate. The first substrate has a same thickness as the second substrate. The first substrate is lapped at a first rate while concurrently lapping the second substrate at a second rate, which is different from the first rate. The first substrate and the second substrate are thinned to different thicknesses. The thinner of the first and second substrates is provided on a viewer side of a collimate and post diffuse type liquid crystal cell to reduce depixelization.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: November 9, 2004
    Assignee: International Business Machines Corporation
    Inventors: Evan George Colgan, Fuad Elias Doany, Tomohito Jounai, Satoshi Maruyama, Hideo Ohkuma, Rama Nand Singh, Masaru Suzuki
  • Publication number: 20040209169
    Abstract: A method of verifying the placement of sub-resolution assist features (SRAFs) in a photomask layout is described. SRAFs are added to the photomask layout to enhance the process window for semi-isolated and isolated features. Rules are provided to automatically place the SRAFs into the layout. When deficiencies are detected in the assist feature design or in the automated SRAF placement program, the placement of SRAFs requires verification. The method verifies the correct placement by defining a unique image property linked to the accurate placement of the assist features, and combines it with in-situ image simulation of the individual layout.
    Type: Application
    Filed: April 15, 2003
    Publication date: October 21, 2004
    Applicant: International Business Machines Corporation
    Inventors: Yuping Cui, Rama Nand Singh
  • Patent number: 6803972
    Abstract: A class of novel structures which make novel use of polymer based reflective polarizing films in an improved polarization conversion system which are useful in liquid crystal projection systems that are easily manufactured, of lower cost, and permit the versatility of higher numerical aperture polarization conversions. Another aspect of the present invention are polarization modulating liquid crystal projection display systems utilizing the polarization conversion systems of the present invention.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: October 12, 2004
    Assignee: International Business Machines Corporation
    Inventors: Russell Alan Budd, Derek Brian Dove, Rama Nand Singh
  • Patent number: 6791639
    Abstract: In a liquid crystal display device of a direct view type, a lenticular lens sheet is provided in the backside of a liquid crystal display panel. Light emitted to a lens of the lenticular lens sheet is first converged in the liquid crystal display panel, and then diffused. When the light is emitted from the liquid crystal display panel, the radiation distribution thereof is widened. Thus, a bright display screen even when seen from a wide angle can be realized.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: September 14, 2004
    Assignee: International Business Machines Corporation
    Inventors: Evan George Colgan, Fuad Elias Doany, Rama Nand Singh, Masaru Suzuki
  • Publication number: 20030214615
    Abstract: In a liquid crystal display device of a direct view type, a lenticular lens sheet is provided in the backside of a liquid crystal display panel. Light emitted to a lens of the lenticular lens sheet is first converged in the liquid crystal display panel, and then diffused. When the light is emitted from the liquid crystal display panel, the radiation distribution thereof is widened. Thus, a bright display screen even when seen from a wide angle can be realized.
    Type: Application
    Filed: May 14, 2002
    Publication date: November 20, 2003
    Applicant: International Business Machines Corporation
    Inventors: Evan George Colgan, Fuad Elias Doany, Rama Nand Singh, Masaru Suzuki
  • Publication number: 20030165013
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Application
    Filed: March 11, 2003
    Publication date: September 4, 2003
    Applicant: International Business Machines Corporation
    Inventors: Fuad Elias Doany, Rama Nand Singh
  • Patent number: 6587151
    Abstract: On a portable computer, a video camera is integrated as a feature by mounting the camera as an assembly made up of a lens and associated pixel electronics in a camera base that is positioned on the perphery of the display in the cover of the portable computer when the cover is open, and the providing of a cavity in the base portion of the portable computer positioned so that the camera assembly enters the cavity when the cover of the portable computer is closed.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: July 1, 2003
    Assignee: International Business Machines Corporation
    Inventors: Thomas Mario Cipolla, Rama Nand Singh
  • Publication number: 20020196405
    Abstract: A display device and method for fabricating a liquid crystal cell are disclosed. A liquid crystal cell includes a first substrate, and a second substrate attached to the first substrate. The first substrate has a same thickness as the second substrate. The first substrate is lapped at a first rate while concurrently lapping the second substrate at a second rate, which is different from the first rate. The first substrate and the second substrate are thinned to different thicknesses. The thinner of the first and second substrates is provided on a viewer side of a collimate and post diffuse type liquid crystal cell to reduce depixelization.
    Type: Application
    Filed: June 26, 2001
    Publication date: December 26, 2002
    Applicant: International Business Machines Corporation
    Inventors: Evan George Colgan, Fuad Elias Doany, Tomohito Jounai, Satoshi Maruyama, Hideo Ohkuma, Rama Nand Singh, Masaru Suzuki
  • Patent number: 6310713
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: October 30, 2001
    Assignee: International Business Machines Corporation
    Inventors: Fuad Elias Doany, Rama Nand Singh
  • Publication number: 20010026398
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Application
    Filed: June 7, 2001
    Publication date: October 4, 2001
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Fuad Elias Doany, Rama Nand Singh
  • Publication number: 20010013972
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Application
    Filed: April 7, 1997
    Publication date: August 16, 2001
    Inventors: FUAD ELIAS DOANY, RAMA NAND SINGH
  • Patent number: 6247816
    Abstract: An optical system for a projection display employing three reflective spatial light modulations (SLM's) is described. Two or the three SLM imaging paths employ typical image combining and projection optical techniques. However, the third SLM imaging path employs a relay lens to produce an intermediate image of the SLM which is subsequently combined with the other two images. Each color component is directed onto one of three SLM's, each through its own polarizing beamsplitter (PBS) cube. In two of the three SLM's, image forming light is reflected from each SLM and passes through its respective PBS, and the two colors are then recombined using a dichroic coating. A lens then images the two-color image, and projects it onto a screens. The third SLM traverses a completely separate path. In this case, the image forming light reflected by the SLM and passing through the PBS is first imaged by a relay lens of approximately unity magnification to produce an intermediate image plane.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: June 19, 2001
    Assignee: International Business Machines Corporation
    Inventors: Thomas Mario Cipolla, Fuad Elias Doany, Robert Lee Melcher, Rama Nand Singh