PTAB

IPR2025-01495

Shenzhen QIanfenyi Intelligent Technology Co Ltd v. WACom Co Ltd

Key Events

Petition

petition

Title: ACTIVE STYLUS WITH HIGH VOLTAGE
Brief Description: The ’866 patent discloses an active stylus that wirelessly transmits signals to a touch-sensitive device. The stylus generates "high-voltage signals" from a lower voltage source (e.g., a battery) to improve signal detection and enable features like differentiating stylus contact from other objects.

Prior Art Relied Upon: Kremin (Application # 20120105362).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Kremin discloses all limitations of the challenged claims. Kremin describes a stylus with a "booster" that amplifies a low battery voltage (e.g., 1.5V from AAA cells) to a higher voltage (10-20V). This high voltage is applied to a tip driver to generate a signal transmitted from the stylus tip, enabling robust detection and "hovering" functionality. This directly maps to the claimed "component operable to convert the voltage" and the transmission of "high-voltage signals" from an electrode at the stylus tip. For dependent claims, Kremin's 10-20V range anticipates claim 3, and its use of the signal to locate the stylus anticipates claim 4.
- Key Aspects: Petitioner contended that even if not explicitly stated, the presence of an "electrode" at the tip is inherently disclosed in Kremin, as it is the conventional component required for the described capacitive coupling.

Prior Art Relied Upon: Kremin (Application # 20120105362) and Partow (Patent 6,377,248).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that to the extent Kremin's "booster" is not sufficiently detailed, Partow provides explicit teachings of a suitable high-voltage generation circuit. Partow discloses an improved stylus that uses a transformer to convert a low-voltage input into a high-voltage output signal of approximately 20 volts peak-to-peak. Partow's transformer circuit is a specific implementation of the "component operable to convert the voltage" that a POSITA would readily integrate into Kremin's system.
- Motivation to Combine: A POSITA would combine Kremin’s stylus system with Partow’s detailed high-voltage generation techniques for the obvious benefit of creating a more robust and reliable high-voltage signal. Partow is directed to the same technical problem of improving stylus signal strength for better detection.
- Expectation of Success: A POSITA would have a high expectation of success, as combining a known voltage-boosting circuit (Partow) into a stylus system (Kremin) uses well-understood electrical engineering principles to achieve a predictable improvement in signal strength.

Prior Art Relied Upon: Westhues (Application # 20120050207).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Westhues discloses an active stylus that uses a transmit/receive circuit to generate a high voltage (e.g., around 100V) from a low battery voltage (e.g., approx. 3V). The circuit explicitly includes a transformer (L2) in a flyback configuration to generate the high voltage, which is then applied to an electrode at the stylus tip for transmission. This system anticipates the core limitations of independent claims 1 and 15. Westhues further discloses using its high-voltage signals to localize the stylus and distinguish it from a finger touch, mapping to limitations in dependent claims 4, 5, and 6.
- Key Aspects: Petitioner emphasized that Westhues's disclosure of a transformer-based flyback circuit directly anticipates claim 2, which specifies the voltage-converting component is a transformer.
Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1-7 and 15-16 over Westhues in view of Kremin. The motivation argued that a POSITA would modify Westhues's high-voltage (100V) system with Kremin's more moderate high-voltage range (10-20V) to achieve the benefit of reduced power consumption while still retaining high-voltage features like hover detection.

Petitioner argued that the term "component operable to convert the voltage of approximately 1 to 3 volts to the high voltage" (claims 1 and 15) should be construed as a means-plus-function limitation under 35 U.S.C. § 112(f).
The corresponding structure disclosed in the ’866 patent specification for performing this function is a transformer or a charge pump, and their equivalents. This construction is central to Petitioner's argument that the boosters and transformers in the prior art meet this limitation.

Petitioner noted that pursuant to recent PTAB guidance, it did not address arguments relating to discretionary denial under §314(a) or §325(d).
Petitioner stated it would address such issues if the Board requests supplemental briefing.

Petitioner requested the institution of an inter partes review and cancellation of claims 1-7 and 15-16 of the ’866 patent as unpatentable.