Impinj Inc v. NXP BV

1. Case Identification

• Case #: IPR2020-01422
• Patent #: 7,257,092
• Filed: August 6, 2020
• Petitioner(s): Impinj, Inc.
• Patent Owner(s): NXP BV.
• Challenged Claims: 1-22

2. Patent Overview

• Title: Method of Communicating Between a Communication Station and a Data Carrier
• Brief Description: The ’092 patent discloses a method for radio-frequency identification (RFID) communication that aims to reduce latency. The alleged invention combines the transmission of a data carrier's identification data with its "useful data" into a single transmission during the initial identification phase, known as the "inventorization procedure."

3. Grounds for Unpatentability

Ground 1: Claims 1-5 and 7-22 are obvious over MacLellan

• Prior Art Relied Upon: MacLellan (Patent 5,940,006).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that MacLellan, a prior art patent directed to RFID technology, discloses every element of the challenged claims. MacLellan teaches an "Interrogator" (communication station) that communicates with "Tags" (data carriers). In MacLellan’s system, tags respond to an interrogation signal with an "Uplink Signal" that contains both a "Tag ID" (analogous to the ’092 patent’s identification data block) and "optional data" (analogous to "useful data"). Petitioner asserted that because the Tag ID and optional data are transmitted together in the same Uplink Signal, MacLellan teaches the core concept of the ’092 patent: combining identification and useful data in a single transmission during the tag identification process, which corresponds to the claimed "inventorization procedure."
  • Key Aspects: This ground asserted that a single prior art reference renders all challenged claims obvious because it describes an RFID system that inherently performs the same combined data transmission function claimed in the ’092 patent.

Ground 2: Claims 1-22 are obvious over MacLellan in view of Rodgers

• Prior Art Relied Upon: MacLellan (Patent 5,940,006) and Rodgers (Patent 6,362,737).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative based on a potentially narrow claim construction. Petitioner argued that if the claim term "at least one part of a block region" is construed to require transmitting a subpart of the identification data block (rather than the entire block, as taught by MacLellan), then Rodgers supplies this missing element. Rodgers disclosed a system with hierarchical "access codes" where a transceiver could respond to an interrogation by sending only a part of its full identification number, such as the next access code in the hierarchy or the "final portion" of the ID. Claim 6, which recites that the length of the transmitted identifier becomes smaller with successive procedure runs, was argued to be directly taught by Rodgers’s method of using a sequence of interrogation messages to identify increasingly narrow groups of transceivers, with each response containing a shorter portion of the total ID.
  • Motivation to Combine: A POSITA would combine Rodgers’s hierarchical identification method with MacLellan’s system to achieve greater efficiency. MacLellan disclosed that it was desirable to identify specific subgroups of tags (e.g., "all Tags 102 which represent cargo containers of a common type"). Rodgers provided a known technique to do this efficiently by structuring tag IDs with hierarchical codes, allowing an interrogator to target and communicate with specific subgroups. The structural and functional similarities of the two RFID systems would have further prompted a POSITA to integrate Rodgers's teachings to improve MacLellan's system.
  • Expectation of Success: A POSITA would have had a high expectation of success, as incorporating a known data structuring method (Rodgers) into a standard RFID communication protocol (MacLellan) was a straightforward design choice to achieve the predictable result of more efficient subgroup identification.

Ground 3: Claims 1-5 and 7-22 are obvious over Gallagher

• Prior Art Relied Upon: Gallagher (Patent 6,963,270).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Gallagher, like MacLellan, independently disclosed all limitations of the challenged claims. Gallagher described an RFID system where a reader (communication station) communicates with transponders (data carriers). In response to a "fast read request," each tag sent a single "fast read response" that included its "Transponder ID" (identification data) and "Fast Read Field" data (useful data). Petitioner contended that this single, combined response for identification and useful data during the initial inventory process directly maps to the method claimed in the ’092 patent. The arbitration process in Gallagher, which identifies individual tags, was argued to be an "inventorization procedure."
• Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1-22 based on the combination of Gallagher and Rodgers, which relied on the same combination rationale articulated in Ground 2.

4. Key Claim Construction Positions

• "inventorization procedure": Petitioner proposed this term be construed according to its definition in the specification as "an exact identification of each data carrier." This construction was central to arguing that the tag identification and inventory processes in MacLellan and Gallagher met this limitation.
• "inventorization means" (claims 7, 11): For this means-plus-function term, Petitioner identified the corresponding structure as a "microcomputer or logic circuit programmed to receive identification data for a data carrier and use that data to identify the carrier." This construction allowed Petitioner to argue that the processors and logic circuitry disclosed or made obvious in the prior art interrogators met this limitation.
• "processing means" (claims 7, 11): For this means-plus-function term, Petitioner identified the structure as a "general purpose microcomputer or logic circuit" or one programmed to receive and store useful data. Petitioner argued the digital signal processors and other processing circuitry in the prior art met this limitation.
• "output means" (claims 15, 19): For this means-plus-function term on the data carrier, Petitioner identified the structure as "transmission means 25, i.e., the antenna element... and equivalents." This allowed Petitioner to map the limitation to the antenna and transmitter elements disclosed in the prior art tags.

5. Relief Requested

• Petitioner requests institution of IPR and cancellation of claims 1-22 of the ’092 patent as unpatentable.