HP Inc v. Memjet Technology Ltd

1. Case Identification

• Case #: IPR2016-00869
• Patent #: 8,662,636
• Filed: April 11, 2016
• Petitioner(s): HP Inc.
• Patent Owner(s): Memjet Technology Limited
• Challenged Claims: 1-20

2. Patent Overview

• Title: Inkjet Printhead
• Brief Description: The ’636 patent describes a pagewide inkjet printhead assembly. The technology centers on an elongated profile member that contains multiple parallel ink supply channels, which provide different colored inks to a series of printhead segment carriers and their corresponding printhead segments arranged in staggered, overlapping rows to enable seamless, full-width printing.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-20 - Claims 1-20 are anticipated under 35 U.S.C. § 102(b) by Silverbrook.

• Prior Art Relied Upon: Silverbrook (International Publication No. WO 01/02172).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Silverbrook, which has a disclosure described as "nearly identical" to that of the ’636 patent, anticipates every limitation of claims 1-20. The argument is predicated on establishing an earlier priority date for the patent that makes Silverbrook a valid prior art reference under §102(b).
    • For independent claim 1, Petitioner argued Silverbrook discloses a printhead with a first and second row of longitudinally spaced printhead segments. These rows are parallel, and the segments overlap in the media feed direction to provide "seamless printing" across the printhead's width, with each segment configured to eject multiple different colored inks.
    • For independent claim 12, Petitioner contended that Silverbrook’s disclosure of a profile member and an associated shim, which together provide structural support and supply ink, meets the limitations of the claimed "ink manifold." Petitioner further argued Silverbrook shows printhead segment carriers mounted on this manifold, which in turn supply different inks to a plurality of printhead segments.
    • For independent claim 16, Petitioner asserted Silverbrook teaches the claimed plurality of printhead segments arranged in two parallel, staggered, and overlapping rows, as well as a "shield plate" that covers the printhead and includes slots aligned with each segment.
    • Petitioner provided a detailed mapping showing that the elements of the dependent claims were also expressly or inherently disclosed in the Silverbrook reference.

4. Key Claim Construction Positions

• "ink manifold" (claims 6, 7, 12, 18, 19): Petitioner proposed the construction "a structure that supplies ink." Petitioner argued that because the term "manifold" does not appear in the patent's specification (outside of the claims), its meaning should be derived from the function of the structures described. The specification's profile member (10) and shim (25), which extend along the printhead and supply ink to the segment carriers, were identified as the structures corresponding to this functional definition.
• "ink channels" (claims 7, 19): Petitioner proposed the construction "paths for ink to flow." This construction was based on the specification's description of "ink supply channels" (20a-20d) within the profile member, which are explicitly shown as defining paths for different colored inks to flow from a source to the printhead segment carriers.

5. Key Technical Contentions (Beyond Claim Construction)

• Invalid Priority Claim: The central contention of the petition was that the ’636 patent is not entitled to its earliest purported priority date of June 30, 1999. Petitioner argued that the patent's priority chain was broken because a critical predecessor, the ’527 application, failed to make a timely priority claim to its grandparent, the ’140 application. An amendment filed more than two years later to add this priority claim was alleged to be statutorily deficient and therefore invalid. Petitioner contended the applicant failed to comply with the requirements of 35 U.S.C. § 120 (2000), which required payment of a surcharge and a showing that the delayed submission was "unintentional." The absence of both allegedly rendered the priority claim improper. This reset the ’636 patent’s effective priority date to no earlier than March 19, 2004, making the Silverbrook reference, published on January 11, 2001, a valid and anticipatory prior art reference under §102(b).

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of the ’636 patent as unpatentable.