Patents by Inventor Roger G. Stewart

Roger G. Stewart 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: 9406012
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Grant
    Filed: January 16, 2015
    Date of Patent: August 2, 2016
    Assignee: Ruizhang Technology Limited Company
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Publication number: 20150122898
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Application
    Filed: January 16, 2015
    Publication date: May 7, 2015
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Patent number: 8936201
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Grant
    Filed: May 22, 2013
    Date of Patent: January 20, 2015
    Assignee: Alien Technology, LLC
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Publication number: 20140091145
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Application
    Filed: May 22, 2013
    Publication date: April 3, 2014
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Patent number: 8464957
    Abstract: A tag receives a first code transmitted by an RFID reader. The first code is compared with a second code stored within the tag. If the first code and the second code match, the tag transmits a third code to the RFID reader.
    Type: Grant
    Filed: October 18, 2011
    Date of Patent: June 18, 2013
    Assignee: Alien Technology Corporation
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Patent number: 8350588
    Abstract: Integrated circuits and methods of permanently disabling integrated circuits are disclosed. An integrated circuit having an erasable non-volatile memory adapted to store an activation code and logic to disable the integrated circuit when the code in the erasable non-volatile memory has been altered or erased after it has been separated from a substrate, is placed into an electromagnetic field of sufficient power to erase or reprogram the erasable non-volatile memory. The entire integrated circuit is permanently disabled by erasing, altering, or reprogramming the erasable non-volatile memory. In preferred embodiments, the integrated circuit comprises a non-erasable non-volatile memory storing the activation code, and circuitry adapted to permanently disable the integrated circuit when the code in the erasable non-volatile memory does not match the activation code in the non-erasable non-volatile memory.
    Type: Grant
    Filed: April 4, 2011
    Date of Patent: January 8, 2013
    Assignee: Kovio, Inc.
    Inventor: Roger G. Stewart
  • Patent number: 8284034
    Abstract: Methods and apparatuses for identifying devices, such as RF tags, are described. In one exemplary embodiment, a reader identifies tags without requiring or determining whether a response to an interrogation was a single response from a single tag or multiple responses from multiple tags. In another exemplary embodiment, a method is performed by a tag in an identification system, and the method includes receiving a first data from a reader, and correlating the first data with a first corresponding portion of the tag's identification code, and specifying a match if the first data matches the first corresponding portion, and receiving second data which, combined with the first data, is correlated with a second corresponding portion of the tag's identification code.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: October 9, 2012
    Assignee: Alien Technology Corporation
    Inventors: Roger G. Stewart, John Stephen Smith
  • Patent number: 8279047
    Abstract: An identification system includes a reader and one or more tags. The reader identifies tags such as radio frequency (RF) tags. The system divides a number space into n bins, wherein each bin is associated with m unique bits of the number space, and the number space contains the identification codes of the tags. A command is issued to test v bits of the number space. A response is received from a tag, wherein the response occurs when a first portion of an identification code of the tag matches the v bits of the number space, a timing of the response corresponds to a particular bin and m unique bits associated with the particular bin correspond to a second portion of the identification code.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: October 2, 2012
    Assignee: Alien Technology Corporation
    Inventors: Curt Carrender, John M. Price, Frederick A. Nylander, John H. Rolin, Roger G. Stewart
  • Publication number: 20120146769
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Application
    Filed: October 18, 2011
    Publication date: June 14, 2012
    Inventors: Curtis L. Carrender, Roger G. Stewart, John H. Rolin, Ronald Gilbert
  • Publication number: 20120026817
    Abstract: Methods of testing and sorting integrated circuits in clusters are disclosed. Each cluster has power and data terminals connected to common power and data busses providing a common power supply. Each integrated circuit has a first non-volatile memory storing an activation code and a second programmable non-volatile memory that is capable of storing the activation code. If an integrated circuit passes testing, the activation code stored in the first non-volatile memory is written into the second non-volatile memory. An integrated circuit is independently functional upon separation from the cluster if the codes in the first and second non-volatile memories match. Upon separation, integrated circuits are queried to determine which respond. Each integrated circuit includes logic adapted to determine whether the codes in the first and second non-volatile memories match. If the codes do not match, the logic permanently disables the integrated circuit upon separation from the cluster.
    Type: Application
    Filed: October 10, 2011
    Publication date: February 2, 2012
    Inventor: Roger G. STEWART
  • Patent number: 8056818
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Grant
    Filed: April 28, 2008
    Date of Patent: November 15, 2011
    Assignee: Alien Technology Corporation
    Inventors: Roger G. Stewart, John Rolin
  • Patent number: 8059478
    Abstract: Methods of testing and sorting integrated circuits in clusters are disclosed. Each cluster has power and data terminals connected to common power and data busses providing a common power supply. Each integrated circuit has a first non-volatile memory storing an activation code and a second programmable non-volatile memory that is capable of storing the activation code. If an integrated circuit passes testing, the activation code stored in the first non-volatile memory is written into the second non-volatile memory. An integrated circuit is independently functional upon separation from the cluster if the codes in the first and second non-volatile memories match. Upon separation, integrated circuits are queried to determine which respond. Each integrated circuit includes logic adapted to determine whether the codes in the first and second non-volatile memories match. If the codes do not match, the logic permanently disables the integrated circuit upon separation from the cluster.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: November 15, 2011
    Assignee: Kovio, Inc.
    Inventor: Roger G. Stewart
  • Publication number: 20110181316
    Abstract: Integrated circuits and methods of permanently disabling integrated circuits are disclosed. An integrated circuit having an erasable non-volatile memory adapted to store an activation code and logic to disable the integrated circuit when the code in the erasable non-volatile memory has been altered or erased after it has been separated from a substrate, is placed into an electromagnetic field of sufficient power to erase or reprogram the erasable non-volatile memory. The entire integrated circuit is permanently disabled by erasing, altering, or reprogramming the erasable non-volatile memory. In preferred embodiments, the integrated circuit comprises a non-erasable non-volatile memory storing the activation code, and circuitry adapted to permanently disable the integrated circuit when the code in the erasable non-volatile memory does not match the activation code in the non-erasable non-volatile memory.
    Type: Application
    Filed: April 4, 2011
    Publication date: July 28, 2011
    Inventor: Roger G. Stewart
  • Publication number: 20110122718
    Abstract: Methods of testing and sorting integrated circuits in clusters are disclosed. Each cluster has power and data terminals connected to common power and data busses providing a common power supply. Each integrated circuit has a first non-volatile memory storing an activation code and a second programmable non-volatile memory that is capable of storing the activation code. If an integrated circuit passes testing, the activation code stored in the first non-volatile memory is written into the second non-volatile memory. An integrated circuit is independently functional upon separation from the cluster if the codes in the first and second non-volatile memories match. Upon separation, integrated circuits are queried to determine which respond. Each integrated circuit includes logic adapted to determine whether the codes in the first and second non-volatile memories match. If the codes do not match, the logic permanently disables the integrated circuit upon separation from the cluster.
    Type: Application
    Filed: December 4, 2008
    Publication date: May 26, 2011
    Inventor: Roger G. Stewart
  • Publication number: 20110115521
    Abstract: Integrated circuits and methods of permanently disabling integrated circuits are disclosed. An integrated circuit having an erasable non-volatile memory adapted to store an activation code and logic to disable the integrated circuit when the code in the erasable non-volatile memory has been altered or erased after it has been separated from a substrate, is placed into an electromagnetic field of sufficient power to erase or reprogram the erasable non-volatile memory. The entire integrated circuit is permanently disabled by erasing, altering, or reprogramming the erasable non-volatile memory. In preferred embodiments, the integrated circuit comprises a non-erasable non-volatile memory storing the activation code, and circuitry adapted to permanently disable the integrated circuit when the code in the erasable non-volatile memory does not match the activation code in the non-erasable non-volatile memory.
    Type: Application
    Filed: December 5, 2008
    Publication date: May 19, 2011
    Inventor: Roger G. STEWART
  • Patent number: 7940073
    Abstract: Integrated circuits and methods of permanently disabling integrated circuits are disclosed. An integrated circuit having an erasable non-volatile memory adapted to store an activation code and logic to disable the integrated circuit when the code in the erasable non-volatile memory has been altered or erased after it has been separated from a substrate, is placed into an electromagnetic field of sufficient power to erase or reprogram the erasable non-volatile memory. The entire integrated circuit is permanently disabled by erasing, altering, or reprogramming the erasable non-volatile memory. In preferred embodiments, the integrated circuit comprises a non-erasable non-volatile memory storing the activation code, and circuitry adapted to permanently disable the integrated circuit when the code in the erasable non-volatile memory does not match the activation code in the non-erasable non-volatile memory.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: May 10, 2011
    Assignee: Kovio, Inc.
    Inventor: Roger G. Stewart
  • Patent number: 7737825
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit by maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFD system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: June 15, 2010
    Assignee: Alien Technology Corporation
    Inventors: Roger G. Stewart, John Rolin
  • Publication number: 20080197981
    Abstract: The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence.
    Type: Application
    Filed: April 28, 2008
    Publication date: August 21, 2008
    Inventors: Roger G. Stewart, John Rolin
  • Patent number: 7411503
    Abstract: The disclosed embodiments of the present invention are used to permanently disable or destruct an RFID so that it is no longer possible to read some or all of the data encoded on the RFID tag. In one method for disabling data on a radio frequency identification (RFID) tag, an RFID tag is identified and its identity is confirmed. Verification that a prerequisite event has occurred is obtained, occurrence of which is required prior to disablement of the data. A destruct instruction is transmitted to the RFID tag. The RFID tag verifies that the destruct instruction is valid and disables the data upon verifying validity of the destruct instruction. The tag may disable the data by erasing the data, disabling the data, auto-destructing, or performing any operation that makes the data unreadable.
    Type: Grant
    Filed: September 26, 2006
    Date of Patent: August 12, 2008
    Assignee: Alien Technology
    Inventors: Roger G. Stewart, John Rolin, Curtis Carrender
  • Patent number: RE40738
    Abstract: An active matrix electroluminescent display (AMELD) having an improved light emitting efficiency and methods of operating the AMELD to produce gray scale operation comprises a plurality of pixels, each pixel including a first transistor having its gate connected to a select line, its source connected to a data line and its drain connected to the gate of a second transistor, the second transistor having its source connected to the data line and its drain connected to a first electrode of an electroluminescent (EL) cell. The EL cell's second electrode is connected to alternating high voltage means. A method for producing gray scale performance including the step of varying the length of time the second transistor is on while the alternating voltage is applied to the EL cell is also disclosed.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: June 16, 2009
    Inventor: Roger G. Stewart