PTAB

IPR2016-00839

HP Inc v. Memjet Technology Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Printhead Assembly With Ink Distribution Assembly
  • Brief Description: The ’096 patent relates to a pagewidth inkjet printhead assembly featuring a modular ink distribution system. The system uses a longitudinal distribution molding with separate ink ducts to supply multiple inks to a laminated stack of distribution sheets, which then route the inks to a plurality of replaceable printhead chips.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1-7 over Boyd, Waller, and Sugitani

  • Prior Art Relied Upon: Boyd (Patent 6,322,206), Waller (Patent 6,250,738), and Sugitani (Patent 4,905,017).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of Boyd, Waller, and Sugitani rendered the limitations of independent claim 1 and dependent claims 2-7 obvious. Boyd was asserted to disclose the core "laminated ink distribution stack" through its substrate 32, which consists of multiple bonded layers (70, 72, 73) that distribute ink to printhead dies. Petitioner mapped Boyd’s sub-layers (72+73a, 73b, 73c+70) to the claimed first, second, and third layers, respectively. Waller, a continuation-in-part of Boyd, was argued to supply the "longitudinal distribution molding" via its molded plastic ink manifold 33, which contains channels extending along the printhead. The combination of Boyd's laminated substrate with Waller's manifold was alleged to meet the primary structural elements of claim 1. Sugitani was introduced for its teachings on forming laminated stacks from thin, flat plastic sheets, which Petitioner argued would be an obvious material choice for the stack in Boyd. Petitioner further contended that Boyd’s aligned openings (e.g., 86a and 100 aligned with 112) met the "direct path" limitation, contrary to the patent owner's prosecution arguments.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Boyd and Waller because they address similar technology, with Waller being a continuation-in-part of Boyd. Specifically, a POSITA would integrate Waller's ink manifold design with Boyd's substrate to improve ink delivery performance across an extended pagewidth printhead. The motivation to incorporate Sugitani stemmed from the known benefits of using molded plastic layers, such as reduced weight, lower manufacturing cost, and improved chemical compatibility with inks. Applying Sugitani’s teachings to Boyd's laminated stack was presented as a predictable design improvement.
    • Expectation of Success: A POSITA would have had a high expectation of success in combining these references, as they all relate to conventional fluid routing in inkjet printheads and involve the predictable assembly of mechanical components.

Ground 2: Obviousness of Claim 8 over Boyd, Waller, Sugitani, and Allen

  • Prior Art Relied Upon: Boyd (Patent 6,322,206), Waller (Patent 6,250,738), Sugitani (Patent 4,905,017), and Allen (Patent 5,469,199).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination in Ground 1 and introduced Allen to address the additional limitation of dependent claim 8, which requires that "each print chip is electrically connected to a printed circuit board via a tape automated bond (TAB) film." Petitioner argued that while Boyd addresses the challenge of creating numerous electrical interconnections for its printhead dies using a complex network of vias and traces within its substrate layers, Allen explicitly discloses using a TAB film for precisely this purpose in a wide inkjet printhead. Allen teaches connecting silicon dies to a printed circuit board via conductive traces on a polymer tape using an automatic TAB bonder.
    • Motivation to Combine: Petitioner contended that the interconnection problem identified in Boyd was a known design challenge with a finite number of predictable solutions. Allen's TAB film method represented a well-known, readily available alternative to Boyd's integrated via-and-trace approach. A POSITA would be motivated to substitute Allen's TAB film solution into the Boyd/Waller system to simplify the design, reduce the size and complexity of the laminated substrate, and improve manufacturing efficiency.
    • Expectation of Success: The use of TAB film for connecting integrated circuits was a conventional and reliable technique at the time of the invention. Therefore, a POSITA would have had a high expectation of success in implementing this known connection method in the printhead assembly of the primary references.

4. Key Claim Construction Positions

  • "laminated ink distribution stack": Petitioner argued for the construction "an ink distribution structure manufactured by layering thin, flat sheets one on top of the other and gluing or otherwise bonding them together." This construction was asserted to be consistent with the specification's description of "laminated layers" and supported by dictionary definitions. Petitioner argued this narrower construction was critical to properly apply the prior art and to counter a potentially overly broad interpretation proposed by the Patent Owner in related litigation.
  • "in a direct path": Petitioner proposed construing this term as "along a linear route." This position was based on the prosecution history, where the applicant amended the claims to include this phrase to distinguish over the "tortuous path" of ink flow in the Boyd reference. Petitioner argued that the applicant's own statements defined the term as requiring a straight, linearly aligned path for ink through the layers.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-8 of Patent 8,696,096 as unpatentable under 35 U.S.C. §103.