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).
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Publication number: 20120236447Abstract: 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: ApplicationFiled: July 8, 2011Publication date: September 20, 2012Inventors: Michael P. MACK, Sunetra Mendis
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Method of acquiring an image from an optical structure having pixels with dedicated readout circuits
Patent number: 7105371Abstract: 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: GrantFiled: November 12, 2003Date of Patent: September 12, 2006Assignee: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny -
Publication number: 20050030394Abstract: 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: ApplicationFiled: June 29, 2001Publication date: February 10, 2005Inventors: Sunetra Mendis, Tzi-Hsiung Shu
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Publication number: 20040160522Abstract: 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: ApplicationFiled: November 12, 2003Publication date: August 19, 2004Applicant: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
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Patent number: 6744068Abstract: 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: GrantFiled: March 12, 2003Date of Patent: June 1, 2004Assignee: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
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Publication number: 20030160238Abstract: 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: ApplicationFiled: March 12, 2003Publication date: August 28, 2003Applicant: California Institute of Technology, a California corporationInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
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Patent number: 6555842Abstract: 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: GrantFiled: June 27, 2000Date of Patent: April 29, 2003Assignee: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
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Patent number: 6538456Abstract: 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: GrantFiled: January 11, 2000Date of Patent: March 25, 2003Assignee: Veridicom, Inc.Inventors: Alexander G. Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross
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Patent number: 6101232Abstract: 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: GrantFiled: November 16, 1995Date of Patent: August 8, 2000Assignee: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny
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Patent number: 6049620Abstract: 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: GrantFiled: May 13, 1997Date of Patent: April 11, 2000Assignee: Veridicom, Inc.Inventors: Alexander G. Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross
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Patent number: 6016355Abstract: 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: GrantFiled: December 15, 1995Date of Patent: January 18, 2000Assignee: Veridicom, Inc.Inventors: Alexander George Dickinson, Ross McPherson, Sunetra Mendis, Paul C. Ross, John A. Tyson
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Patent number: 5471515Abstract: 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: GrantFiled: January 28, 1994Date of Patent: November 28, 1995Assignee: California Institute of TechnologyInventors: Eric R. Fossum, Sunetra Mendis, Sabrina E. Kemeny