PTAB

IPR2025-01246

BOE Technology Group Co Ltd v. Paneltouch Technologies LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: DISPLAY DEVICE WITH TOUCH PANEL
  • Brief Description: The ’836 patent describes a display device integrated with a resistive touch panel. The technology focuses on a specific structural arrangement of substrates, metal detection lines, and polarizing plates, purportedly to improve touch feeling and performance.

3. Grounds for Unpatentability

Ground 1: Obviousness over Nakamura - Claims 1 and 3-15 are obvious over Nakamura.

  • Prior Art Relied Upon: Nakamura (Application # 2008/0303798).
  • Core Argument for this Ground: Petitioner asserted that the challenged claims are unpatentable because the ’836 patent’s specification repeatedly and expressly admits that the core touch panel structure it describes was adopted from Nakamura. The petition highlighted that figures in the ’836 patent are explicitly described as being copied from Nakamura, and that the only alleged improvement over the prior art—a resin film for "excellent touch feeling"—is not recited in any of the challenged claims.
    • Prior Art Mapping: Petitioner argued that Nakamura discloses every limitation of independent claims 1 and 8. For claim 1, Nakamura was alleged to teach a touch panel with two opposed substrates (SUB1, SUB2), each having detection and outside areas, a plurality of metal first and second lines, black coloring for the first lines to improve contrast, a polarizing plate arranged on a substrate, and wiring groups where at least two lines are combined. For claim 8, Petitioner argued Nakamura discloses the required touch panel structure adhered to an "organic luminescence electric device panel" (describing Nakamura’s organic EL display) and a circular polarizing plate adhered to the touch panel opposite the display.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the argument focused on direct disclosure. Petitioner contended that since the ’836 patent itself directs a person of ordinary skill in the art (POSITA) to Nakamura for the details of the claimed structure, all claimed features were already present in that single reference, making them obvious.
    • Expectation of Success (for §103 grounds): A POSITA would have had a complete expectation of success because they would simply be implementing the exact structure already disclosed and proven to work in Nakamura.

Ground 2: Obviousness over Nakamura and Slobodin - Claim 2 is obvious over Nakamura alone or in view of Slobodin.

  • Prior Art Relied Upon: Nakamura (Application # 2008/0303798) and Slobodin (Application # 2008/0266273).
  • Core Argument for this Ground: Claim 2 depends on claim 1 and adds the limitation that the polarizing plate is a "linear polarizing plate." Nakamura discloses a polarizing plate and shows a "circularly polarizing plate" in its preferred embodiment. Petitioner argued it would have been an obvious design choice for a POSITA to use a linear polarizer—one of the two most common types—in Nakamura's system. Slobodin was introduced as secondary support to demonstrate the known trade-offs between linear and circular polarizers.
    • Prior Art Mapping: Nakamura provides the base display device with a touch panel and a polarizing plate for suppressing ambient light reflection, as established in Ground 1. Slobodin teaches the use of both linear and circular polarizers for this same purpose in similar touch screen displays.
    • Motivation to Combine (for §103 grounds): A POSITA would combine the teachings because both references are in the same field, address the identical problem of reducing reflections on touch displays, and use standard optical principles. Slobodin explicitly discusses the pros and cons of linear versus circular polarizers, explaining that in certain situations (e.g., with birefringent materials), the benefits of a circular polarizer are limited. A POSITA would therefore have been motivated to substitute the simpler and less expensive linear polarizer taught by Slobodin into Nakamura’s device for applications where it provided sufficient performance, or to reduce cost and complexity.
    • Expectation of Success (for §103 grounds): The substitution of one well-known type of polarizer for another is a simple, predictable modification, and a POSITA would have had a high expectation of success in achieving a functional touch display with adequate reflection suppression.

4. Key Claim Construction Positions

  • Petitioner argued that claim 8, which recites a touch panel including a "first substrate" and both "first lines" and "second lines," does not require both sets of lines to be on that single first substrate. Petitioner contended that the plain language and prosecution history confirm that claim 8 covers a two-substrate embodiment, like that shown in Nakamura, where the first lines are on a first substrate and the second lines are on a second, separate substrate. This construction was presented as critical to mapping Nakamura's two-substrate structure onto the limitations of claim 8.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-15 of the ’836 patent as unpatentable.