PTAB

IPR2020-00515

Samsung Electronics Co Ltd v. Neodron Ltd

Key Events

Petition

petition

Title: Capacitive Keyboard with Non-Locking Reduced Keying Ambiguity
Brief Description: The ’790 patent discloses a method for determining key selection on a capacitive touch keyboard when a user's finger overlaps multiple keys. It uses control logic that applies a "bias" in favor of an already-selected key to prevent undesirable rapid switching ("dithering") between keys with similar signal strengths.

Prior Art Relied Upon: Jahier (Patent 5,525,980).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Jahier anticipates or renders obvious claims 1-2, 5-8, 12-14, and 18-24. Jahier disclosed a capacitive keyboard with a state machine that determines a "preselected" key (analogous to the '790 patent's "first active key") based on the greatest capacitance signal. The system was non-locking, allowing a second key to become preselected if its signal grew larger than the first key's signal and also exceeded a "High Threshold."
- Motivation to Combine (for §103 grounds): This ground was asserted primarily as a single-reference obviousness challenge.
- Key Aspects: Petitioner contended that Jahier's requirement for a new key's signal to exceed a High Threshold—in addition to exceeding the current key's signal—functions identically to the "bias" claimed in the ’790 patent. This bias prevents a new key selection unless its signal is stronger by a significant, defined amount.

Prior Art Relied Upon: Jahier (Patent 5,525,980) and Senk (Patent 5,760,715).
Core Argument for this Ground:
- Prior Art Mapping: This ground asserted that claims 4, 10, 11, 16, and 17 are obvious over Jahier in view of Senk. Senk taught a method for managing multi-touch scenarios by temporarily adjusting the "no key touch" reference level for individual keys, which effectively decreases their measured signal strength.
- Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references to improve the stability of Jahier's key selection system. If a preselected key in Jahier had a signal very close to the High Threshold, the bias would be small, leading to potential dithering. A POSITA would apply Senk's technique to Jahier's system to enhance this bias.
- Expectation of Success: Petitioner argued a POSITA would expect success because applying Senk's method of adjusting reference values to decrease the signals of non-preselected keys (for claims 11, 17) or increase the signal of the preselected key (for claims 4, 10, 16) is a straightforward modification that would directly stabilize the system.

Prior Art Relied Upon: Jahier (Patent 5,525,980) and QT60161 (a Quantum Research Group datasheet).
Core Argument for this Ground:
- Prior Art Mapping: This ground, for claims 5, 12, and 18, addressed the limitation of an "associated counter" for each key. The QT60161 datasheet described a specific integrated circuit (IC) for capacitive keypads that included a "detection integrator" counter for each key. This counter increments with each detection sample and confirms a touch only when a user-defined limit is reached, filtering out noise.
- Motivation to Combine: A POSITA would be motivated to implement the general system of Jahier using the specific, commercially available controller IC disclosed in QT60161. This combination would inherently provide the claimed per-key counters.
- Expectation of Success: Using the programmable target values of QT60161's counters to require longer or shorter touches for different keys would directly implement the claimed method of biasing the key selection analysis.

Prior Art Relied Upon: Jahier (Patent 5,525,980) and West (Patent 5,831,597).
Core Argument for this Ground:
- Prior Art Mapping: This ground asserted that claims 3, 9, and 15, which require a "guard ring," are obvious. West disclosed a keypad with a guard ring surrounding the capacitive touch pads. When the guard ring detects the proximity of an object (e.g., a mouse), it suppresses readings from all the key pads to prevent erroneous inputs.
- Motivation to Combine: A POSITA would add the guard ring from West to the Jahier system to provide an additional, robust mechanism for reducing the probability of erroneous touch interpretations, such as when a user's palm or another object is near the keypad.
- Expectation of Success: The combination was argued to be a predictable integration of two known solutions for improving the reliability of capacitive touchpads.

"Control logic operatively coupled..." (Claim 1): Petitioner noted this term was construed in a parallel ITC proceeding as a means-plus-function term under pre-AIA §112(6). The identified function was analyzing signals to determine a first key, assigning it, and then analyzing subsequent signals with a bias to determine a second key. The corresponding structure was identified as a microprocessor programmed to execute the logic shown in Figures 5A and 5B of the ’790 patent.
"[analyze/analyzing]... being biased in favor of the first key": Petitioner asserted this term was construed in the parallel ITC case to mean the analysis is skewed in favor of, but not locked to, the previously determined active key. This "non-locking" aspect was central to Petitioner's argument that prior art teaching similar ambiguity reduction was applicable.

Priority Date Entitlement: A central contention was that the ’790 patent was not entitled to its claimed 2002 priority date. Petitioner argued the key inventive concept—the "non-locking" system that uses a bias to allow smooth rollover between keys—was first disclosed in a provisional application filed on December 21, 2005. This position, if accepted, would establish several key references, including the QT60161 datasheet (published Feb. 2002), as prior art.

Petitioner requested institution of an inter partes review and cancellation of claims 1-24 of Patent 9,024,790 as unpatentable under 35 U.S.C. §103.