Microsoft Corp v. TS Optics Corp

1. Case Identification

• Case #: IPR2025-00767
• Patent #: 7,266,055
• Filed: March 31, 2025
• Petitioner(s): Microsoft Corporation
• Patent Owner(s): TS-Optics Corporation
• Challenged Claims: 1-8, 10-15, 17, 19, 21, 23-24, 26, 28, 36-38, 40-45

2. Patent Overview

• Title: Optical Pickup Actuator
• Brief Description: The ’055 patent discloses an optical pickup actuator for use in optical disc drives. The technology involves a blade holding an objective lens, which is movably supported on a base by suspension wires, and driven by an electromagnetic force generated by the interaction between magnets and various coils.

3. Grounds for Unpatentability

Ground 1: Obviousness over Choi - Claims 1-4, 7-8, 10-13, 15, and 40 are obvious over Choi alone or in view of Applicant Admitted Prior Art (AAPA).

• Prior Art Relied Upon: Choi (Korean Patent Application Publication No. 2001-0038068A).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Choi, which describes an optical pickup assembly, disclosed all elements of the challenged claims. Choi’s assembly included a base, a bobbin (argued to be equivalent to the claimed "blade") holding an objective lens, and an elastic support material (suspension wires) for movable support. Choi further taught magnets positioned on the base that interact with a focusing coil, tracking coils, and tilt coils on the bobbin to drive the objective lens. Petitioner contended that Choi's combination of a focusing coil and tilt coils met the limitation of "a coil...divided into a plurality of subcoils," as they are vertically separated from each other. For dependent claims, Petitioner asserted Choi’s tracking coils met the "second coil" limitation, and that the arrangement of magnets for both focusing and tilting inherently or obviously required a "unipolar" configuration for proper operation.
  • Motivation to Combine: The argument relied primarily on Choi alone. AAPA was cited to confirm that elements like suspension wires and spindle motors were well-known and conventional components in the field, making their inclusion in Choi's system obvious.
  • Key Aspects: This ground established Choi as a comprehensive primary reference disclosing nearly all key structural elements of the independent claims.

Ground 2: Obviousness over Choi and Ogata - Claims 1-4, 7-8, 10-13, 15, 40, and 43-45 are obvious over Choi in view of Ogata.

• Prior Art Relied Upon: Choi (as in Ground 1) and Ogata (Japanese Patent Application Publication No. H4-113524A).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon Choi by adding Ogata’s teachings to more explicitly meet certain limitations. Petitioner argued Ogata expressly taught dividing a single focus coil into two vertically separated subcoils. This modification created space between the subcoils for improved mounting of other components, such as tracking coils or suspension wire hinges. The combination therefore provided a stronger basis for the limitation of claim 1 requiring a coil to be "divided into a plurality of subcoils, where each subcoil is separated from an adjacent subcoil in a vertical direction." For claim 40, placing the suspension wire hinges in this newly created space was argued to be an obvious design choice taught by Ogata.
  • Motivation to Combine: A POSITA would combine Ogata with Choi to improve the design and manufacturability of Choi’s actuator. Ogata addressed the problem of unstable bonding when attaching tracking coils directly to a focus coil, a configuration similar to Choi's. A POSITA would have been motivated to adopt Ogata's solution—separating the focus coil to create dedicated mounting space—to improve the stability, performance, and ease of assembly of Choi’s device.
  • Expectation of Success: Petitioner asserted a high expectation of success, as the combination involved applying a known solution (Ogata's coil separation) to a known problem in a similar optical pickup device (Choi), using routine mechanical and electrical modifications.

Ground 3: Obviousness over Choi, Ogata, and Santo - Claims 41-42 are obvious over the combination of Choi, Ogata, and Santo.

• Prior Art Relied Upon: Choi (as in Ground 1), Ogata (as in Ground 2), and Santo (Patent 6,344,936).
• Core Argument for this Ground:
  • Prior Art Mapping: This combination targeted claims 41 and 42, which require at least six suspension wires and the division of a coil into three or more subcoils. Petitioner argued that Santo disclosed using six suspension wires connected to multiple hinges on the blade. This configuration allowed separate electrical currents to be supplied to different sets of coils (e.g., focus, tracking, and tilt). The resulting combination would have more than three subcoils (e.g., two from Ogata’s focus coil plus Choi’s tilt and tracking coils).
  • Motivation to Combine: A POSITA would augment the Choi-Ogata combination with Santo's teachings to improve structural stability and electrical control. Since the Choi-Ogata device already had multiple distinct coil types, using Santo's six-wire system was an obvious way to provide a more secure, balanced platform and allow for dedicated, independent electrical current to each coil type, enhancing performance and longevity.
• Additional Grounds: Petitioner asserted numerous additional obviousness challenges based on combinations including Ikeda, Kamata, Kabasawa, Miura, and Sugiyama to address specific claim features, such as the use of unipolar magnets and the structure of inner yokes.

4. Key Technical Contentions (Beyond Claim Construction)

• Unipolar Magnets: Petitioner contended that in the context of optical pickup actuators, a "unipolar magnet" does not refer to a physically unipolar magnet (which does not exist), but rather to an arrangement where a conventional bipolar magnet is oriented such that only one of its poles (either North or South, but not both) faces and interacts with a specific coil. Petitioner argued this arrangement was inherent or at least obvious in Choi's design to achieve the described focusing and tilting motions, as forces in a consistent direction (e.g., up or down) would require interaction with a magnetic field of the same polarity.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) and the Fintiv factors would be inappropriate. The parallel district court litigation was in its infancy, with a trial date set for August 2026, well after a Final Written Decision would issue. Petitioner also made a broad Sotera stipulation, agreeing not to pursue in district court any invalidity ground that was raised or reasonably could have been raised in the IPR. Petitioner also argued against denial under §325(d), noting that none of the asserted prior art was cited or considered during the original patent examination.

6. Relief Requested

• Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-8, 10-15, 17, 19, 21, 23-24, 26, 28, 36-38, and 40-45 of the ’055 patent as unpatentable under 35 U.S.C. §103.