Apple Inc v. Neodron Ltd

1. Case Identification

• Case #: IPR2020-01287
• Patent #: 9,411,472
• Filed: August 17, 2020
• Petitioner(s): Apple Inc.
• Patent Owner(s): Neodron, Ltd.
• Challenged Claims: 1, 5-7, 11-13, and 17-23

2. Patent Overview

• Title: Touch Sensor with Grounding Determination
• Brief Description: The ’472 patent describes a touch sensor system for electronic devices that addresses inaccuracies caused by different electrical grounding states. The system determines whether the device is in a "grounded" or "floating" state and adjusts a stored touch-detection threshold accordingly to improve touch recognition reliability.

3. Grounds for Unpatentability

Ground 1: Claims 1, 7, 13, 22, and 23 are obvious over Sleeman in view of Westerman ’787.

• Prior Art Relied Upon: Sleeman (Application # 2011/0001708) and Westerman ’787 (Application # 2009/0160787).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Sleeman taught a mutual capacitance touch sensor with a controller that adjusts an internal detection threshold based on the determined "signature shape" of a touch (e.g., lowering the threshold for a small finger or stylus). However, Sleeman did not account for signal distortions caused by poor grounding. Westerman ’787 addressed this known problem, teaching that poor grounding reduces the change in capacitance, weakens adjacent pixel signals, and can create "negative pixels." Westerman ’787 disclosed determining the grounding status by computing a ratio of positive to negative touch output values to identify an ungrounded state.
  • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would have been motivated to incorporate Westerman ’787’s grounding detection into Sleeman’s system. Since poor grounding causes weaker capacitance signals, Sleeman's signature analysis would be less reliable. A POSITA would combine the teachings to improve the robustness of Sleeman's sensor, ensuring legitimate touches are not missed in poor grounding conditions by adjusting the threshold based on the detected grounding state, not just the touch signature.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as the modification would involve a predictable firmware change to implement a known solution (grounding compensation) for a known problem (grounding-related signal distortion) in a known type of system (capacitive touchscreens).

Ground 2: Claims 1, 7, 13, 19, 20, 22, and 23 are obvious over Sleeman in view of Hotelling.

• Prior Art Relied Upon: Sleeman (Application # 2011/0001708) and Hotelling (Application # 2011/0012840).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground was presented as an alternative to Ground 1. While Sleeman taught the base system, Hotelling provided another method for determining grounding status. Hotelling taught monitoring device parameters indicative of grounding, such as detecting whether the device is physically connected to a power source via a cable. For dependent claims 19 and 20, which require analyzing capacitance graph shapes, Hotelling taught analyzing a "touch image"—including its location, orientation, and shape—to determine the grounding state.
  • Motivation to Combine: The motivation was similar to Ground 1: to solve the known problem of poor grounding in Sleeman's system to achieve improved accuracy and reliability. Hotelling taught that determining the grounding status provides advantages like improved accuracy and power savings. A POSITA would have been motivated to enable Sleeman’s controller to determine grounding status using Hotelling’s methods to gain these same benefits.
  • Expectation of Success: The combination was argued to be a predictable integration of known techniques. A POSITA would have understood that configuring Sleeman's controller to determine grounding status as taught by Hotelling was a straightforward modification with a high likelihood of success.

• Additional Grounds: Petitioner asserted that claims 5, 6, 11, 12, 17, 18, and 21 were obvious over the combinations of Sleeman/Westerman ’787 or Sleeman/Hotelling in further view of Griffin (Application # 2011/0248948). Griffin was cited for its teaching of periodically drifting a threshold value back to an original value at a predetermined rate, a feature of certain dependent claims.

4. Key Claim Construction Positions

• Petitioner argued that the key limitation "determine a grounding status of the touch sensor based on a strength of a charge return path between the touch sensor and a ground" should be construed broadly.
• Based on the patent’s specification, dependent claims, and prosecution history, Petitioner asserted the term should not be limited to a single method but should encompass analyzing any data indicative of the sensor's grounding state. This includes, for example, determining if the device is plugged in, analyzing the location of a touch relative to sensor nodes, or analyzing the shape of capacitance graphs, all of which are described in the ’472 patent. This broad construction was argued to be necessary to read the independent claims consistently with the dependent claims that recite these specific methods.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) based on Fintiv factors would be inappropriate.
• The parallel district court litigation had been stayed pending the finality of a related ITC investigation. Petitioner argued that because the trial date in the district court was years away, the Board’s Final Written Decision (FWD) would issue long before any trial.
• Furthermore, Petitioner contended that the ITC investigation was not a true parallel proceeding that could result in claim cancellation, and thus it did not raise the same efficiency concerns as parallel district court litigation. Minimal investment had been made in the district court case before it was stayed, and any overlap with the ITC proceeding was limited, further weighing in favor of institution.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1, 5-7, 11-13, and 17-23 of the ’472 patent as unpatentable.