PTAB

IPR2017-01268

Fujifilm Corp v. Sony Corp

Log In
Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Magnetic Recording Medium with Controlled Backside Surface Topography
  • Brief Description: The ’774 patent relates to a magnetic recording medium, such as data tape, with a backside surface configured to reduce pitting or "embossment" of the front-side recording surface when the tape is wound. The invention is defined by specific statistical measurements of the backside surface roughness, including skew, kurtosis, peak height mean, and peak-to-valley roughness.

3. Grounds for Unpatentability

Ground 1: Anticipation over Ishikawa - Claims 15 and 17 are anticipated under 35 U.S.C. §102 by Ishikawa.

  • Prior Art Relied Upon: Ishikawa (Application # 2003/0054203).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ishikawa discloses a magnetic tape with a backcoating layer designed to be as smooth as possible to prevent its surface profile from being transferred to the magnetic layer, which is the same purpose as the ’774 patent. Ishikawa’s disclosed examples inherently meet the claimed limitations. Specifically, Ishikawa teaches a peak-to-valley roughness (Rz) of 50-200 nm, which satisfies the <325 nm and <300 nm limitations of claims 15 and 17. Petitioner contended that the claimed peak height mean of <200 nm is inherently disclosed because peak height mean (average height of peaks) is necessarily less than peak-to-valley roughness (average of largest peak-to-valley separations).

Ground 2: Obviousness over Aonuma - Claims 1-11 and 15-20 are obvious under 35 U.S.C. §103 over Aonuma.

  • Prior Art Relied Upon: Aonuma (Japanese Patent Publication JP2003-036520).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner’s core argument for this ground was based on experimental replication. Petitioner manufactured three tape samples (A, B, and C) following the formulation and processes for a bimodal (fine and coarse particle) backcoat taught by Aonuma. Blind-test measurements of these replicated tapes’ backside surfaces were performed using an optical interferometer. Petitioner asserted that the measurement data demonstrated that each of the replicated Aonuma tapes had at least one measurement for skew, kurtosis, peak height mean, peak-to-valley roughness, and plateau ratio that fell within the ranges recited in the challenged claims.
    • Motivation to Combine (for §103 grounds): This ground is based on a single reference. The argument was that Aonuma’s teachings alone are sufficient to render the claims obvious. Petitioner contended that the ’774 patent merely claimed inherent characteristics of a prior art magnetic tape composition (Aonuma’s) that a POSITA would have found obvious to produce. The improved skirt signal-to-noise ratio and small error rate of dependent claims were argued to be the obvious and expected results of the smoother backcoat taught by Aonuma.
    • Expectation of Success (for §103 grounds): A POSITA would have a reasonable expectation of success in producing a tape according to Aonuma's teachings that would exhibit the claimed surface properties, as confirmed by Petitioner's physical replication.

Ground 3: Obviousness over Aonuma in view of Abe - Claims 1-11 and 15-20 are obvious over Aonuma in view of Abe.

  • Prior Art Relied Upon: Aonuma (JP2003-036520) and Abe (EP Application # 0494793A1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Aonuma teaches a magnetic tape with a bimodal backcoat whose surface characteristics fall within the claimed ranges, as shown by the replication evidence in Ground 2. Abe’s teachings further confirm that Aonuma’s backcoat, with its specific ratio of fine-to-coarse carbon black particles (97.1/2.9), is configured to prevent embossment. Abe explicitly teaches using ratios of fine-to-coarse particles in the range of 99.9/0.1 to 70/30 to create a smooth surface that minimizes damage to the magnetic layer.
    • Motivation to Combine (for §103 grounds): A POSITA would combine Aonuma and Abe because both references address the identical problem of preventing embossment from backcoat protrusions in magnetic tape using the same solution: a bimodal backcoat with a high ratio of fine-to-coarse carbon black particles. Abe’s disclosure would have confirmed to a POSITA that the specific particle ratio used in Aonuma was well-suited for creating a smooth surface to prevent embossment, making the combination straightforward and logical.
    • Expectation of Success (for §103 grounds): Because both references teach using similar bimodal backcoat compositions to solve the same known problem, a POSITA would have expected the combination to successfully produce a magnetic tape with a smooth backcoat that prevented embossment and exhibited the claimed surface properties.

4. Key Claim Construction Positions

  • Petitioner argued that the key statistical terms—"skew," "kurtosis," "peak height mean," "peak-to-valley roughness," and "plateau ratio"—should be construed as their corresponding R-notation measurements (Rsk, Rku, Rpm, Rz, and Rpm/Rz, respectively) obtained from an optical interferometer trace, consistent with the patent’s specification and industry standards like ISO 4287.
  • Critically, Petitioner contended that a claim limitation such as "a backside surface having a skew less than about 0.5" is satisfied if the surface has at least one such measurement within the recited range. This interpretation does not require an average of multiple measurements to be within the range, which was central to Petitioner's argument that its replicated Aonuma tapes met the claim limitations despite some outlier measurements.

5. Relief Requested

  • Petitioner requests institution of inter partes review and cancellation of claims 1-11 and 15-20 of the ’774 patent as unpatentable.