Cypress Semiconductor Corp v. Neodron Ltd

1. Case Identification

• Case #: IPR2021-01296
• Patent #: 9,372,580
• Filed: July 26, 2021
• Petitioner(s): Cypress Semiconductor Corp.
• Patent Owner(s): Neodron Ltd.
• Challenged Claims: 1-12

2. Patent Overview

• Title: Enhanced Touch Detection Methods
• Brief Description: The ’580 patent discloses methods for improving the accuracy of capacitive touch sensors. The core technology involves using signal values from a first type of capacitance measurement (e.g., self or cross-capacitance) to compensate for signal values from a second type (e.g., mutual capacitance), thereby correcting errors caused by phenomena like signal "retransmission" from a poorly grounded user touching multiple points.

3. Grounds for Unpatentability

Ground 1: Claims 1-12 are obvious over Yousefpor in view of Chang.

• Prior Art Relied Upon: Yousefpor (Application # 2010/0060608) and Chang (Patent 8,587,555).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Yousefpor teaches the core invention of using two different capacitance measurements to correct for touch-sensing errors. Yousefpor discloses a mutual-capacitance measurement (driving horizontal lines, sensing vertical lines) to get a "second set of signals" and a self-capacitance measurement it calls "reverse stimulation" (driving and sensing the vertical lines) to get a "fourth set of signals." Petitioner argued that Yousefpor's iterative algorithm uses the self-capacitance data to "adjust" or "compensate" the mutual-capacitance data, thereby removing errors from "negative pixels" and determining a more accurate touch location. This process allegedly maps to the key limitations of independent claims 1, 5, and 9.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references because both address the same well-known problem of retransmission in touch sensors, which Yousefpor calls "negative pixels" and Chang calls "water stains" or "conductive impurities." Petitioner argued that a POSITA would recognize these as symptoms of the same underlying issue. Chang was cited to show the known interchangeability of drive and sense lines, which would motivate a POSITA to apply Yousefpor’s self-capacitance technique to either set of lines as a simple and predictable design choice.
  • Expectation of Success: Success was expected because the combination involves routine hardware configurations and predictable software algorithms to solve a widely understood problem in the field of capacitive touch sensing.

Ground 2: Claims 1-12 are obvious over Yousefpor in view of Krah.

• Prior Art Relied Upon: Yousefpor (Application # 2010/0060608) and Krah (Patent 9,746,967).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground uses Yousefpor as the primary reference for the same reasons as Ground 1. However, it substitutes Krah for Chang to teach the second capacitance measurement. Krah discloses using "cross-capacitance"—measuring capacitance between two electrode lines on the same axis (e.g., stimulating one drive line and measuring on an adjacent drive line)—to detect and compensate for the "negative pixel effect." Petitioner contended that Krah’s use of cross-capacitance measurements to adjust mutual-capacitance data directly teaches the claimed steps of generating a "fourth set of signals" and using it to compensate the "second set of signals."
  • Motivation to Combine: Petitioner argued the motivation to combine Yousefpor and Krah is exceptionally strong. Both references address the identical problem of retransmission from poorly grounded touches, share a common inventor (Mardouk Yousefpor), and were assigned at issuance to the same entity (Apple Inc.). This indicates the technologies stem from a common design effort and share a similar architecture, making their combination logical and intuitive for a POSITA.
  • Expectation of Success: A POSITA would have had a high expectation of success in combining these highly interrelated teachings, which represent well-understood, routine approaches to compensating for known measurement errors in touch sensors.

4. Key Claim Construction Positions

• Petitioner stated that no new claim constructions were necessary but noted constructions from prior litigation involving the ’580 patent. Key adopted positions crucial to its arguments included:
  • "after sending the third set of signals...": This was construed as "after (not while)," establishing a sequential, non-concurrent relationship between the measurement steps that Petitioner argued was taught by the prior art flowcharts.
  • "adjusting the second set of measured values... with the fourth set of measured values...": This was construed as "changing the second set of measured values... with the fourth set of measured values," which Petitioner mapped to the mathematical compensation algorithms disclosed in the prior art.

5. Arguments Regarding Discretionary Denial

• Petitioner presented extensive arguments that the Board should not exercise discretionary denial under 35 U.S.C. §314(a) (based on Fintiv factors) or §325(d).
• Arguments Against Fintiv Denial (§314(a)): Petitioner argued the petition was filed at a very early stage of a parallel International Trade Commission (ITC) investigation and a related district court case. It asserted that the district court case would be stayed, the ITC has a different burden of proof and cannot cancel patent claims, and that Petitioner would stipulate not to pursue the same invalidity grounds in the parallel proceedings if the inter partes review (IPR) was instituted, thereby avoiding overlap and preserving resources.
• Arguments Against §325(d) Denial: Petitioner contended that denial under §325(d) was inappropriate because a prior IPR on the same patent and grounds (IPR2020-00865) was dismissed after institution due to settlement. As the Board never reached a final written decision on the merits in the prior case, Petitioner argued that instituting this new petition would not be duplicative and would serve the interest of resolving the patentability challenge for the first time.

6. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1-12 of Patent 9,372,580 as unpatentable under 35 U.S.C. §103.