Patents Assigned to Impinj, Inc.
  • Patent number: 11062190
    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: August 30, 2019
    Date of Patent: July 13, 2021
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Joel Peshkin
  • Patent number: 11024936
    Abstract: Methods of RFID tag assembly include affixing an antenna to an integrated circuit (IC) by forming one or more capacitors coupling the antenna and the IC with the dielectric material of the capacitor(s) including a non-conductive covering layer of the IC, a non-conductive covering layer of the antenna such as an oxide layer, and/or an additionally formed dielectric layer. Top and bottom plates of the capacitor(s) are formed by the antenna traces and one or more patches on a top surface of the IC.
    Type: Grant
    Filed: October 23, 2018
    Date of Patent: June 1, 2021
    Assignee: Impinj, Inc.
    Inventors: Ronald L. Koepp, Ronald A. Oliver, William T. Colleran, Yanjun Ma, Jay M. Fassett, Vincent C. Moretti
  • Patent number: 11017349
    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: December 27, 2019
    Date of Patent: May 25, 2021
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Alberto Pesavento
  • Patent number: 11017187
    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: June 5, 2020
    Date of Patent: May 25, 2021
    Assignee: Impinj, Inc.
    Inventors: Mike Thomas, Omer Onen, Joe Tarantino, Christopher J. Diorio
  • Patent number: 10956693
    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: February 21, 2020
    Date of Patent: March 23, 2021
    Assignee: Impinj, Inc.
    Inventors: Balaji Shyamkumar, Kurt Sundstrom, Scott Cooper, Jayasuryan Iyer, Sandesh Doddameti, Christopher J. Diorio
  • Patent number: 10936929
    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: April 22, 2019
    Date of Patent: March 2, 2021
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Todd E. Humes, Ronald A. Oliver
  • Patent number: 10929734
    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: October 10, 2019
    Date of Patent: February 23, 2021
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 10916114
    Abstract: Methods and systems are described for authorizing an item with an RFID tag to leave a facility. In one embodiment, a mobile device receives or determines an exit code (EC) to write into the tag in response to providing authorizing information. The EC may be based on information stored in the tag such as the tag's item identifier or other tag information (collectively an item identifier or II), a ticket value, other information such as the OC, a mobile identity or location, or any other suitable information. Upon verification of the EC, the tagged item is allowed to leave the facility. In another embodiment, the mobile device stores an item identifier (II) associated with the tag and provides authorizing information. Upon verifying the authorizing information and confirming that the stored II corresponds to the tagged item's II, the tagged item is allowed to leave the facility.
    Type: Grant
    Filed: March 23, 2020
    Date of Patent: February 9, 2021
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Scott A. Cooper, Matthew Robshaw, Tan Mau Wu
  • Patent number: 10885417
    Abstract: Embodiments are directed to mitigating power-based impedance changes in Radio Frequency Identification (RFID) tags. The intrinsic impedance of components in an RFID tag front-end may change as incident RF power on the tag changes, causing the input impedance of the front-end to change and altering the RF properties of the RFID tag. A number of approaches can be used to mitigate input impedance variations due to power variations. One approach involves adjusting the operating point of one or more components in the RFID tag front-end to change their intrinsic impedances so as to counteract or mitigate the RF-power-based input impedance variation.
    Type: Grant
    Filed: February 21, 2020
    Date of Patent: January 5, 2021
    Assignee: Impinj, Inc.
    Inventors: Theron Stanford, Charles J. T. Peach, Jay A. Kuhn, Harley K. Heinrich, John D. Hyde, Christopher J. Diorio, Alberto Pesavento
  • Patent number: 10885421
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. A substrate of the RFID IC, or a portion of the IC substrate, electrically couples the first circuit block to at least one of the first and second antenna contacts. The IC includes one or more interfaces or barrier regions that at least partially electrically isolate the first circuit block from the rest of the IC substrate.
    Type: Grant
    Filed: May 13, 2019
    Date of Patent: January 5, 2021
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver
  • Patent number: 10878685
    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: April 12, 2019
    Date of Patent: December 29, 2020
    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: 10878371
    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: September 5, 2018
    Date of Patent: December 29, 2020
    Assignee: Impinj, Inc.
    Inventors: Theron Stanford, Alberto Pesavento, Vadim Lobanov, Christopher J. Diorio
  • Patent number: 10860819
    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: May 22, 2019
    Date of Patent: December 8, 2020
    Assignee: Impinj, Inc.
    Inventors: Alberto Pesavento, Thomas G. Anderl, Robert J. Ascani
  • Patent number: 10846583
    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: October 20, 2017
    Date of Patent: November 24, 2020
    Assignee: Impinj, Inc.
    Inventors: Ronald Lee Koepp, Harley Heinrich, Christopher J. Diorio
  • Patent number: 10824824
    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: January 27, 2020
    Date of Patent: November 3, 2020
    Assignee: Impinj, Inc.
    Inventor: Christopher J. Diorio
  • Patent number: 10819319
    Abstract: A level shifter circuit configured to convert a digital input signal with a first high logic level to a digital output signal having a second high logic level substantially higher than the first high logic level is provided. The level shifter circuit may include a PMOS latch circuit configured to receive the digital input signal and having first and second latch outputs and a current mirror circuit having a mirror input and a mirror output. The mirror input may be at least partly gated by a switch having a control input. The mirror output may be coupled to the first latch output. The control input may be coupled to the first or second latch outputs, and the digital output signal is provided from the first and/or second latch outputs.
    Type: Grant
    Filed: November 20, 2019
    Date of Patent: October 27, 2020
    Assignee: Impinj, Inc.
    Inventor: John D. Hyde
  • Patent number: 10740574
    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: August 5, 2019
    Date of Patent: August 11, 2020
    Assignee: Impinj, Inc.
    Inventors: Theron Stanford, Christopher J. Diorio
  • Patent number: 10733395
    Abstract: Embodiments are directed to restricting access to Radio Frequency Identification (RFID) tag information based on location. Access to RFID tag information may be restricted at the reader level, at the requester level, and at the network level. When reader-level restrictions exist, devices may be prevented from inventorying tags and retrieving information from tags. When requester-level restrictions exist, a requester or device may be prevented from receiving tag information from inventoried tags or a network. When network-level restrictions exist, a network may discard or otherwise restrict tag information received from devices.
    Type: Grant
    Filed: February 8, 2019
    Date of Patent: August 4, 2020
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Scott A. Cooper, Kurt E. Sundstrom, Todd E. Humes, Alberto Pesavento
  • Patent number: 10719671
    Abstract: Messages may be passed between Radio Frequency Identification (RFID) tags using RFID readers. A first tag with a message intended for a second tag sends the message to an RFID reader. The reader then determines that the destination of the message is the second tag and sends the message to the second tag. The second tag may confirm receipt of the message by sending a receipt confirmation message to the reader for forwarding to the first tag, and/or the reader may itself confirm that the message was sent to the second tag by sending a transmit confirmation message to the first tag.
    Type: Grant
    Filed: July 16, 2018
    Date of Patent: July 21, 2020
    Assignee: Impinj, Inc.
    Inventors: Matthew Robshaw, Tan Mau Wu
  • Patent number: 10720700
    Abstract: A synthesized-beam transceiver system steers a beam of a two-dimensional antenna array by activating a first subset of antenna elements to orient the beam in a first direction and subsequently activating a second subset of the antenna elements to orient the beam in a different direction. The system also electrically connects antenna elements that are inactive, not in the first subset, or not in the second subset to a reference potential of the array.
    Type: Grant
    Filed: March 26, 2018
    Date of Patent: July 21, 2020
    Assignee: Impinj, Inc.
    Inventors: Vincent Moretti, Omer Onen, Ronald A. Oliver