PTAB

IPR2025-01596

Shenzhen Qianfenyi Intelligent Technology Co Ltd v. Wacom Co Ltd

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petition

1. Case Identification

2. Patent Overview

  • Title: Pointer, Position Detection Apparatus and Position Detection Method
  • Brief Description: The ’277 patent relates to a pen-shaped position indicator (stylus) for use with a sensor surface. The stylus includes at least two electrodes configured to transmit distinguishable signals that are capacitively coupled to the sensor surface to determine not only the pointer's position but also its angular information, such as tilt.

3. Grounds for Unpatentability

Ground 1: Obviousness over Yoshida and Ikeda - Claims 1-5, 7-12, 14-18, and 20-24 are obvious over Yoshida in view of Ikeda and the knowledge of a POSITA.

  • Prior Art Relied Upon: Yoshida (Patent 5,798,756) and Ikeda (Japanese Patent Application Publication No. H10-11206).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Yoshida disclosed the core elements of a pen-shaped position indicator with multiple electrodes, including a rod-shaped inner electrode and a surrounding outer electrode at the pen tip, driven by distinguishable (opposite phase) signals to capacitively couple with a sensor. Ikeda was argued to teach a capacitive stylus specifically designed for angle detection, using a first electrode at the pen tip and a second, ring-shaped electrode on the pen body, offset from the central axis. Petitioner contended that combining Yoshida's basic multi-electrode stylus with Ikeda's explicit use of a spatially and axially distinct second electrode for angle detection rendered the claimed invention obvious. The combination supplied the key limitations of having first and second electrodes at different positions, with the second being off-axis to generate signals from which angle information is obtainable.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to enhance the functionality of a capacitive stylus. Both Yoshida and Ikeda operated in the same technical field and addressed the common goal of improving stylus input accuracy. Petitioner asserted that combining Yoshida’s electrode structure with Ikeda’s specific tilt-detection method was a logical step to create a more precise stylus capable of simultaneously detecting position and tilt, thereby meeting the growing commercial demand for more advanced input devices without adding the complexity of mechanical sensors.
    • Expectation of Success: The combination was presented as a predictable application of known techniques. A POSITA would have reasonably expected that incorporating Ikeda’s proven method for angle detection into Yoshida’s stylus framework would successfully yield a single, more capable device with enhanced sensitivity and control.

Ground 2: Obviousness over Yoshida and Iguchi - Claims 1-5, 8-12, 14-18, and 21-24 are obvious over Yoshida in view of Iguchi and the knowledge of a POSITA.

  • Prior Art Relied Upon: Yoshida (Patent 5,798,756) and Iguchi (Patent 5,736,980).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in Ground 1, Yoshida was asserted to provide the foundational multi-electrode capacitive stylus. Petitioner argued Iguchi disclosed a similar system with a main electrode at the pen tip and an auxiliary electrode arranged around it. Crucially, Iguchi taught that when the pen is tilted, the signals from these spatially separated electrodes are detected at different times. Iguchi explicitly disclosed that "inclination data of the pen shaft can be taken out by a difference between timing signals." Petitioner argued this directly taught generating distinguishable signals (based on time difference, as recited in claim 8) from two electrodes to obtain angle information, rendering the key claim limitations obvious.
    • Motivation to Combine: Petitioner argued a POSITA would be motivated to combine these teachings to achieve more robust stylus tracking and angle detection. Both references addressed the same technical problem, were filed in the same year (1995), and were assigned to the same entity (Sharp), which Petitioner argued provided a strong motivation for designers to integrate the complementary technologies. Combining Iguchi’s sophisticated method of using signal timing for tilt detection with Yoshida’s foundational design would predictably improve performance, reduce errors, and meet commercial demand for more advanced styluses.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination. Integrating Iguchi's time-differentiated signal processing into Yoshida's capacitive framework was a straightforward enhancement using well-understood principles of capacitive sensing to achieve accurate tilt detection without resorting to mechanical sensors.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-5, 7-12, 14-18, and 20-24 of the ’277 patent as unpatentable.