PTAB

IPR2016-00867

HP Inc v. Memjet Technology Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Inkjet Printhead for a Pagewide Printer
  • Brief Description: The ’636 patent describes a pagewide inkjet printhead featuring an elongated profile member that defines multiple internal ink supply channels. This member supports numerous printhead segment carriers, which hold the printhead segments (dies) and are arranged in two parallel, overlapping rows to achieve seamless, page-width printing.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claim 1 is anticipated by Waller

  • Prior Art Relied Upon: Waller (Patent 6,250,738).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Waller disclosed every limitation of independent claim 1. Waller teaches a thermal inkjet printhead assembly with two parallel rows of printhead dies. Petitioner asserted that these dies constitute the claimed "printhead segments," are longitudinally spaced apart, contain multiple nozzle rows for different colored inks, and are arranged in a staggered, overlapping configuration in a direction transverse to the rows. This overlapping arrangement, as disclosed in Waller, was intended to provide the seamless printing recited in the claim.

Ground 2: Obviousness over Waller, Fabbri, and Silverbrook

  • Claims 3-7 and 12-14 are obvious over Waller in view of Fabbri and Silverbrook EP ’292.
  • Prior Art Relied Upon: Waller (Patent 6,250,738), Fabbri (Patent 6,068,367), and Silverbrook (European Patent Pub. No. 0 498 292 A2).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that this combination taught all elements of the challenged claims. Waller provided the basic architecture of a pagewide printhead with two staggered rows of print dies. Fabbri taught the improvement of mounting individual print dies onto discrete "printhead segment carriers" (Fabbri's "modules"), a feature absent in Waller's integrated design. Silverbrook taught the specific internal structure for such a carrier, disclosing ink galleries defined by non-parallel, converging walls that efficiently channel ink from larger supply lines to the print die. This structure is recited in dependent claims 3 and 12.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Waller and Fabbri to create a modular printhead, which simplifies manufacturing, testing, and replacement of individual segments. The POSITA would then be motivated to incorporate Silverbrook’s converging ink gallery design to solve the known challenge of efficiently routing multiple ink colors from larger manifold structures to the microscopic feed slots on the print dies. Silverbrook’s design also addressed the known problem of managing air bubbles in ink channels.
    • Expectation of Success: The proposed combination involved integrating known, compatible technologies to achieve predictable benefits. Combining Fabbri's modularity with Waller's layout and using Silverbrook's established ink-flow design would have been a straightforward engineering task with a high expectation of success.

Ground 3: Obviousness over Waller and Murakami

  • Claims 11 and 16 are obvious over Waller in view of Murakami.

  • Prior Art Relied Upon: Waller (Patent 6,250,738) and Murakami (Patent 6,435,648).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground focused on the "shield plate" limitation recited in independent claim 16 and dependent claim 11. Petitioner argued that while Waller taught the staggered, two-row printhead array, it did not explicitly disclose a shield plate. Murakami, however, taught this feature with its "cover plate 208," which is described as covering the printhead and having slots that align with the individual ink-jet heads.
    • Motivation to Combine: A POSITA would have been motivated to add a protective cover plate, as taught by Murakami, to the printhead assembly of Waller. The motivation was clear: to protect the fragile printhead dies from physical damage, prevent debris contamination, and provide a uniform capping surface, all of which are common and desirable objectives in printhead design.
    • Expectation of Success: Adding a simple mechanical shield plate to an existing printhead assembly is a conventional design step with a highly predictable and successful outcome.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds that claims 2 is obvious over Waller and Fabbri; claims 8-10 are obvious over Waller and Silverbrook EP ’292; claims 15 and 17-20 are obvious over Waller, Fabbri, Silverbrook EP ’292, and Murakami; and an anticipation challenge that claim 16 is anticipated by Toganoh (Patent 4,559,543).

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 patent specification does not use or define the term, its meaning should be derived from its function as claimed. The claims require the manifold to extend along the printhead, have carriers mounted on it, and supply ink. Petitioner identified the "profile member 10" and "shim 25" in the ’636 patent’s specification as structures that perform this function, supporting the proposed broad, functional construction.
  • "ink channels" (claims 7, 19): Petitioner proposed the construction "paths for ink to flow."
    • This construction follows from the proposed definition of "ink manifold." Petitioner argued this interpretation is consistent with the specification’s description of "ink supply channels 20a-20d," which provide paths for different colored inks to flow from the main profile member to the printhead segment carriers.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-20 of the ’636 patent as unpatentable under 35 U.S.C. §§ 102 and 103.