Patents Assigned to Impinj, Inc.
  • Patent number: 11893446
    Abstract: A Radio Frequency Identification (RFID) tag IC stores an identifier and a check code. The IC determines whether the stored identifier is corrupted by comparing it to the check code. If the stored identifier does not correspond to the check code then the IC may terminate operation or indicate an error. The IC may also reconstruct the correct identifier from the check code.
    Type: Grant
    Filed: May 20, 2022
    Date of Patent: February 6, 2024
    Assignee: Impinj, Inc.
    Inventor: Christopher J. Diorio
  • Patent number: 11853826
    Abstract: An RFID IC may operate at a relatively low clock frequency while impedance matching to an antenna is being tuned to increase the amount of power that the IC can extract from an incident RF wave. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna. The IC may power-up with a low clock frequency or reduce its current clock frequency to a lower clock frequency prior to tuning or during the tuning process, and may increase its clock frequency upon completion of tuning or during the tuning process.
    Type: Grant
    Filed: July 19, 2022
    Date of Patent: December 26, 2023
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 11797813
    Abstract: RFID tag ICs in a population can adjust the impedance values used to backscatter-modulate reply signals to increase the distribution or spread of backscattered signal parameters, thereby facilitating the recovery of collided tag replies. An RFID tag IC may adjust its impedance value(s) based on a reader command or independently.
    Type: Grant
    Filed: May 7, 2020
    Date of Patent: October 24, 2023
    Assignee: Impinj, Inc.
    Inventors: Joshua F. Ensworth, Alberto Pesavento, Harley K. Heinrich, Theron Stanford, Thomas G. Anderl
  • Patent number: 11798392
    Abstract: RFID ICs sense and indicate changes in their surrounding environment, such as changes in temperature, humidity, chemical presence, RF signals, and similar. An RFID IC indicates when a significant environmental change has occurred, for example by adjusting the value of a flag, writing data to memory, transmitting a message to an external entity, exiting a sleep state, and/or responding repeatedly to an inventorying reader. In some cases, RFID IC actively notifies an external entity that a significant environmental change has been sensed. For example, RFID IC may alert the external entity by participating in a special inventory process meant for RFID ICs sending environmental change. The RFID IC may alert the external entity by interjecting itself into an inventory round, re-participating in an inventory round, refraining from entering a sleep state after inventorying, and/or adjusting timing of a scheduled reply to communicate with an RFID reader ahead of schedule.
    Type: Grant
    Filed: May 20, 2022
    Date of Patent: October 24, 2023
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Harley Heinrich, Matthew Robshaw, Theron Stanford, Charles J. T. Peach, John D. Hyde, Tan Mau Wu
  • Patent number: 11790206
    Abstract: RFID inlays or straps may be assembled using impulse heating of metal precursors. Metal precursors are applied to and/or included in contacts on an RFID IC and/or terminals on a substrate. During assembly of the tag, the IC is disposed onto the substrate such that the IC contacts physically contact either the substrate terminals or metal precursors that in turn physically contact the substrate terminals. Impulse heating is then used to rapidly apply heat to the metal precursors, processing them into metallic structures that electrically couple the IC contacts to the substrate terminals.
    Type: Grant
    Filed: March 25, 2022
    Date of Patent: October 17, 2023
    Assignee: Impinj, Inc.
    Inventors: Ronald Lee Koepp, Harley Heinrich, Christopher J. Diorio
  • Patent number: 11790192
    Abstract: Techniques are provided to estimate the location of an RFID tag using tag read information, such as a tag read count or a tag read rate, and an opportunity metric, such as an inventory cycle duration, inventory cycle rate, or inventory cycle count. A tag tracking system determines read information for a tag in a zone and an opportunity metric associated with the tag and the zone. The tag tracking system then computes a success rate based on the tag read information and opportunity metric, and uses the success rate to estimate the location of the tag.
    Type: Grant
    Filed: April 29, 2022
    Date of Patent: October 17, 2023
    Assignee: Impinj, Inc.
    Inventors: Alberto Pesavento, Thomas G. Anderl, Robert J. Ascani
  • Patent number: 11783140
    Abstract: RFID tags may compensate for non-RFID power sources by automatically enforcing data or state persistence even while powered. A tag may measure a time interval between successive detected modulated reader transmissions. If the interval exceeds a minimum time, then the tag may deassert a protocol flag, erase data, and/or change tag operating states, even if the tag would normally not perform these actions while powered.
    Type: Grant
    Filed: December 10, 2021
    Date of Patent: October 10, 2023
    Assignee: Impinj, Inc.
    Inventors: Theron Stanford, Christopher J. Diorio
  • Patent number: 11748703
    Abstract: An RFID loss-prevention system (LPS) may monitor RFID-tagged items in a facility. An RFID reader transmits a first inventory command configured to cause tags in a first state to respond, receive a reply from a first tag, determine that the first tag has a low transition risk, and cause the first tag to switch to a second state. The reader may also receive a reply from a second tag, determine that the second tag has a high transition risk, and cause the second tag to remain in the first state. The reader may then transmit a second inventory command configured to cause tags in the first state to respond, receive a reply from the second tag in response to the second inventory command, determine that the second tag has inappropriately exited the facility, and issue an alert.
    Type: Grant
    Filed: February 4, 2022
    Date of Patent: September 5, 2023
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Alberto Pesavento
  • Patent number: 11734540
    Abstract: Backflow in rectifiers may be reduced via biasing. Upon determining that backflow within a rectifier is likely, one or more rectifying elements in the rectifier may be debiased, via analog or digital means. The debiased rectifying elements become less conductive or nonconductive, thereby reducing or preventing backflow. The determination of backflow likelihood may be performed based on a signal to be backscattered or the amplitude-modulated envelope of an incident RF wave, and may be digital or analog in nature.
    Type: Grant
    Filed: November 24, 2021
    Date of Patent: August 22, 2023
    Assignee: Impinj, Inc.
    Inventors: Amita Patil, Jay A. Kuhn, Charles J. T. Peach, John D. Hyde, Jaskarn Johal
  • Patent number: 11681889
    Abstract: RFID technology may be used to provide digital identities for physical items. An RFID IC attached to or integrated into a physical item contains an identifier for the physical item. Digital identity information associated with the item, such as ownership information, history, properties, and the like, may be located on one or more networks. An entity, after authenticating itself and/or the item, may use the identifier to locate, retrieve, and/or update the item's digital identity information on the network.
    Type: Grant
    Filed: January 21, 2022
    Date of Patent: June 20, 2023
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Matthew Robshaw, Tan Mau Wu
  • Patent number: 11651180
    Abstract: A method is provided to determine unique identifiers. A physical item has an RFID integrated circuit (IC) having a unique identifier and a secret. The RFID IC may be configured to provide an identifier portion and a response to a previously sent challenge, where the identifier portion by itself is insufficient to completely identify the IC or item and the response is based on the challenge and the secret. Attempts are made to verify the response using a set of potential secrets determined using the identifier portion. If the response is successfully verified using a certain secret, the secret may then be used to determine one or more other identifier portions. The unique, complete identifier may then be determined from a combination of at least the identifier portions.
    Type: Grant
    Filed: September 13, 2021
    Date of Patent: May 16, 2023
    Assignee: Impinj, Inc.
    Inventors: Matthew Robshaw, Tan Mau Wu, Christopher J. Diorio
  • Patent number: 11562322
    Abstract: RFID systems may be configured to use session-dependent replies. When an RFID tag is involved in a certain inventorying session, the tag may respond to inventorying commands with a reply that is at least partly generated based on the session. For example, the tag may generate a reply with a string that has parity based on the session or includes an identifier for the session. The string may be a random number, a tag identifier or item identifier, or any other suitable data sent from the tag.
    Type: Grant
    Filed: December 28, 2020
    Date of Patent: January 24, 2023
    Assignee: Impinj, Inc.
    Inventors: Theron Stanford, Alberto Pesavento, Vadim Lobanov, Christopher J. Diorio
  • Patent number: 11514255
    Abstract: RFID readers may be configured to supply power to tags during frequency hops. When a reader is supplying power to a passive RFID tag via a first RF waveform having a first radio frequency and determines that it is to frequency-hop, the reader may determine whether the tag requires power during the hop. If so, the reader begins (or continues) to synthesize a second RF waveform with a second radio frequency while also synthesizing the first RF waveform, and frequency-hops by transitioning from transmitting the first RF waveform to transmitting the second RF waveform such that the power transmitted during the transition is sufficient for the tag to operate.
    Type: Grant
    Filed: May 21, 2021
    Date of Patent: November 29, 2022
    Assignee: Impinj, Inc.
    Inventors: Mike Thomas, Omer Onen, Joe Tarantino, Christopher J. Diorio
  • Patent number: 11514254
    Abstract: RFID-tagged items can be filtered based on relevance estimation or user input. A device reads digital identifiers for multiple RFID-tagged items. The device estimates and selects an item that an individual desires based on one or more metrics, then presents data about the selected item to the individual. If the device receives feedback that the selected item is not the desired item, then the device may estimate and select another item and/or present information about multiple items to allow the individual to select the desired item. When the desired item is selected, the device may perform some associated action.
    Type: Grant
    Filed: October 30, 2020
    Date of Patent: November 29, 2022
    Assignee: Impinj, Inc.
    Inventor: Christopher J. Diorio
  • Publication number: 20220358337
    Abstract: RFID tag ICs may be configured with privacy modes. When a tag IC is in a privacy mode, it will not respond to commands unless a previous command includes correct verification information or specifies a recycling indicator of the tag IC. If the previous command includes correct verification information, then the tag IC will respond to one or more subsequent commands as normal, for example by responding with one or more identifiers. If the previous command does not include correct verification information but specifies a recycling indicator and the privacy mode is recycling-enabled, the tag IC may respond to one or more subsequent commands with recycling information. The recycling information identifies whether or how an item associated with the RFID IC can be recycled or disposed but does not otherwise identify the RFID IC or item. Otherwise, the tag IC may remain silent.
    Type: Application
    Filed: October 28, 2020
    Publication date: November 10, 2022
    Applicant: Impinj, Inc.
    Inventors: Christopher J. DIORIO, Jesse Paul COOKE, Christopher Dean PETERSON
  • Patent number: 11481591
    Abstract: Embodiments are directed to rectifiers using a single bias current or bias current path to bias multiple rectifying elements. A rectifier that has multiple rectifier stages coupled together serially includes a bias current path coupled to each of the rectifier stages. The bias current path is configured to simultaneously bias rectifying elements in each of the rectifier stages by using a bias current to bias a first rectifying element and reusing the bias current to bias other rectifying elements.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: October 25, 2022
    Assignee: Impinj, Inc.
    Inventors: Charles J. T. Peach, John D. Hyde, Jay A. Kuhn, Theron Stanford, Amita Patil
  • Patent number: 11481592
    Abstract: RFID tags capable of transitioning between a private state and one or more public states are provided. In the private state, tags may participate in an inventory round without restriction. In a public state, tags may be prevented from participating in an inventory round, allowed to participate without providing actual identifying information, or allowed to participate providing an alternate identifier. Whether and how the tag responds in a public state may depend on certain conditions including if one or more of the tag's flags are asserted or deasserted. A reader may select a public tag for inventorying by verifying itself, and the tag then asserting or deasserting one or more of its flags accordingly. The asserted or deasserted flag(s) may be used to determine whether and how a tag in a public state participates in an inventory round.
    Type: Grant
    Filed: July 9, 2021
    Date of Patent: October 25, 2022
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Joel Peshkin
  • Patent number: 11461570
    Abstract: An RFID-based item tracking system may use statistical methods to determine whether a tag or tagged item that does not respond when inventoried is present in a particular zone or reader antenna field-of-view. In one embodiment, the item tracking system may determine an observability of an item based on one or more initial trials. Upon not detecting the item in one or more subsequent trials, the item tracking system may estimate whether the item is still present based on the observability.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: October 4, 2022
    Assignee: Impinj, Inc.
    Inventors: Balaji Shyamkumar, Kurt Sundstrom, Scott Cooper, Jayasuryan Iyer, Sandesh Doddameti, Christopher J. Diorio
  • Patent number: 11423278
    Abstract: A Radio Frequency Identification (RFID) integrated circuit (IC) is at least partially covered by a repassivation layer that is, in turn, at least partially covered by a large, electrically conductive contact pad. The repassivation layer is disposed so as to leave uncovered at least one IC contact. The large contact pad is disposed so as to cover the IC IC contact. The large contact pad forms a first galvanic coupling to the IC contact and a second galvanic coupling to a tag antenna. The surface area of the first galvanic coupling is substantially smaller than the surface area of the second galvanic coupling.
    Type: Grant
    Filed: March 23, 2021
    Date of Patent: August 23, 2022
    Assignee: Impinj, Inc.
    Inventors: Ronald L. Koepp, Harley K. Heinrich, Christopher J. Diorio, Tan Mau Wu
  • Patent number: 11403505
    Abstract: An RFID integrated circuit, in addition to having conductive pads to electrically couple to an antenna, may also include a conductive bridge configured to electrically connect different portions of the antenna together. In some embodiments, the conductive bridge may be used to form a multi-turn antenna segment.
    Type: Grant
    Filed: February 26, 2021
    Date of Patent: August 2, 2022
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Todd E. Humes, Ronald A. Oliver