Patents by Inventor Sunetra Mendis

Sunetra Mendis 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: 20120236447
    Abstract: A method and apparatus for protecting an input-out (I/O) circuit against electro-static discharge (ESD) events. An ESD circuit used to protect the I/O circuit against an ESD event is coupled to the I/O circuit. The ESD circuit includes a diode clamp circuit that couples an I/O pad to a power supply and a ground pad. The ESD circuit further includes an active clamp circuit that is configured to clamp the I/O pad without turning on the diode clamp circuit during the ESD event.
    Type: Application
    Filed: July 8, 2011
    Publication date: September 20, 2012
    Inventors: Michael P. MACK, Sunetra Mendis
  • Patent number: 7105371
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: September 12, 2006
    Assignee: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Publication number: 20050030394
    Abstract: Effectively defect free images are obtained from CMOS image sensors through a two step method in which the addresses of bad pixels are recorded during sensor testing and stored in an on-chip directory. Then, during sensor readout, each pixel address is checked to determine if it represents that of a bad pixel. If this is determined to be the case, the bad pixel value is replaced by another value. This replacement value is generated from an average of the nearest-neighbors that are not defective. If testing is performed at the wafer level, said bad pixel and nearest neighbor data may be used to modify the final level wiring so that bad pixels are disconnected and replaced by their nearest neighbors.
    Type: Application
    Filed: June 29, 2001
    Publication date: February 10, 2005
    Inventors: Sunetra Mendis, Tzi-Hsiung Shu
  • Publication number: 20040160522
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Application
    Filed: November 12, 2003
    Publication date: August 19, 2004
    Applicant: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Patent number: 6744068
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: June 1, 2004
    Assignee: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Publication number: 20030160238
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Application
    Filed: March 12, 2003
    Publication date: August 28, 2003
    Applicant: California Institute of Technology, a California corporation
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Patent number: 6555842
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: April 29, 2003
    Assignee: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Patent number: 6538456
    Abstract: The present invention relates to a fingerprint sensing device comprising a planar array of closely-spaced capacitive sense elements. When a finger is placed in close proximity to the sensing device, the capacitive sense elements measure a capacitance between the finger and a single capacitor plate in each sense element. This is accomplished by precharging each capacitor plate, and then using a known current source to remove a fixed amount of charge from each capacitor plate. The measured capacitance varies as a function of the distance between the capacitor plate and the finger surface. Thus, a capacitance measurement allows the distance between the capacitor plate and the finger surface to be determined. Distance measurements across the array of sense elements are combined to produce a representation of the pattern of ridges on the finger surface which comprise a fingerprint.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: March 25, 2003
    Assignee: Veridicom, Inc.
    Inventors: Alexander G. Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross
  • Patent number: 6101232
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: August 8, 2000
    Assignee: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
  • Patent number: 6049620
    Abstract: The present invention relates to a fingerprint sensing device comprising a planar array of closely-spaced capacitive sense elements. When a finger is placed in close proximity to the sensing device, the capacitive sense elements measure a capacitance between the finger and a single capacitor plate in each sense element. This is accomplished by precharging each capacitor plate, and then using a known current source to remove a fixed amount of charge from each capacitor plate. The measured capacitance varies as a function of the distance between the capacitor plate and the finger surface. Thus, a capacitance measurement allows the distance between the capacitor plate and the finger surface to be determined. Distance measurements across the array of sense elements are combined to produce a representation of the pattern of ridges on the finger surface which comprise a fingerprint.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: April 11, 2000
    Assignee: Veridicom, Inc.
    Inventors: Alexander G. Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross
  • Patent number: 6016355
    Abstract: An apparatus for detecting topographic variations on an object such as a finger includes an array of sensing elements disposed on a substrate which each have a parasitic capacitance. An insulating receiving surface is disposed over the array of sensing elements and is adapted to receive the object such that a sensing element and a portion of the object located thereabove creates a measurable change in capacitance with respect to the parasitic capacitance. An electronic circuit is coupled to the array of sensing elements for measuring the measurable change in capacitance.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: January 18, 2000
    Assignee: Veridicom, Inc.
    Inventors: Alexander George Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross, John A. Tyson
  • Patent number: 5471515
    Abstract: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: November 28, 1995
    Assignee: California Institute of Technology
    Inventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny