Samsung Display Co Ltd v. Solas OLED Ltd

1. Case Identification

• Case #: IPR2019-01668
• Patent #: 9,256,311
• Filed: September 30, 2019
• Petitioner(s): Samsung Display Co., Ltd.
• Patent Owner(s): Solas OLED, Ltd.
• Challenged Claims: 1-20

2. Patent Overview

• Title: Flexible Touch Sensor
• Brief Description: The ’311 patent relates to capacitive touch sensors for touchscreen devices. The technology uses "metal-mesh" electrodes on a substantially flexible substrate, which allows the touch sensor to be wrapped around one or more edges of a display.

3. Grounds for Unpatentability

Ground I: Claims 1–13, 15–16, and 18 are obvious over Kuriki and Mikladal.

• Prior Art Relied Upon: Kuriki (Patent 8,722,314) and Mikladal (Patent 9,395,851).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kuriki discloses a capacitive touch sensor with all the core features of the challenged claims, including a flexible PET substrate and silver mesh electrodes. However, while Kuriki teaches wrapping the sensor's non-sensitive "terminal wiring regions" around the edge of an LCD panel, it does not explicitly disclose wrapping the touch-sensitive electrode area. Petitioner contended that Mikladal remedies this by expressly teaching a flexible capacitive touch sensor that is "bent or formed to extend to the device edges" to create touch-sensitive regions on the sides of the device.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Mikladal's teaching of wrapping a touch-sensitive film with Kuriki's similar mesh-electrode sensor. The motivation, as stated in Mikladal, was to achieve known benefits such as creating side-sensing regions to replace conventional mechanical buttons, thereby expanding the user interface area.
  • Expectation of Success: Petitioner asserted a POSITA would have had a high expectation of success. Both Kuriki and Mikladal describe sensors made of similar, known-flexible materials (metal conductors on a PET substrate). Since Kuriki already demonstrated the feasibility of bending its sensor's wiring regions, extending this known technique to the touch-sensitive portions, as taught by Mikladal, would be a predictable and straightforward modification.

Ground IV: Claims 1–13, 15–16, and 18 are obvious over Moran and Joo.

• Prior Art Relied Upon: Moran (International Publication No. WO 2010/099132) and Joo (Application # 2008/0223708).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner presented this as an alternative ground, noting that Moran and Joo pre-date Kuriki and Mikladal. Moran was argued to disclose a flexible capacitive touch sensor using silver/copper mesh electrodes on a flexible PET substrate, similar to the ’311 patent. Joo was cited for its disclosure of a mobile device with a touch input portion formed on a flexible support member that is bent around the curved edge of a display, creating a "side display portion."
  • Motivation to Combine: A POSITA would combine Joo's wrap-around display technique with Moran's mesh sensor to realize the advantages taught by Joo. These benefits included simplifying the manufacturing process, reducing costs, and enhancing the device’s appearance by eliminating the need for separate side keys.
  • Expectation of Success: Success was argued to be highly predictable. The proposed modification involved applying a known technique (wrapping a flexible sensor from Joo) to a suitable device (Moran's flexible mesh sensor). Both references operate in the same technical field of transparent touch sensors for displays and describe similar underlying structures, making the combination straightforward for a POSITA.

• Additional Grounds: Petitioner asserted additional obviousness challenges for the remaining dependent claims. These grounds relied on the same core combinations of Kuriki/Mikladal and Moran/Joo, with the addition of Philipp (Application # 2011/0102361) for its teaching of non-linear conductive lines to avoid moiré patterns, and Rappoport (Application # 2012/0218219) for its teaching of widening conductive lines at bend axes to prevent cracking and damage.

4. Key Claim Construction Positions

• Petitioner argued that the claim limitation "configured to wrap around one or more edges of a display" does not specify which portion of the touch sensor must be wrapped. Petitioner contended that under a broad interpretation, this limitation is met by prior art like Kuriki, which wraps the sensor's non-sensitive tracking portions. Under a narrower interpretation requiring the touch-sensitive portion to be wrapped, the limitation is met by the combinations with Mikladal or Joo. Petitioner asserted that because the prior art teaches both configurations, the claims are obvious regardless of the specific construction adopted.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate because the petition raised new prior art and arguments not considered by the Examiner. Specifically, Petitioner noted that during prosecution, the claims were allowed only after the "wrap around" limitation was added. The primary references relied upon in the petition (Mikladal and Joo) explicitly teach this very limitation, which Petitioner asserted was missing from the art before the Examiner.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-20 of the ’311 patent as unpatentable.