Cellwitch Inc. v. Tile, Inc.

Background

Cellwitch alleged that Tile infringed U.S. Patent No. 8,872,655, which describes a system for tracking personal items. The patent involves wireless devices associated with monitored items, wireless communication terminals associated with users, proximity monitoring, alerts, and a processing system that stores related data.

Tile petitioned the Patent Trial and Appeal Board (PTAB) for review of the patent. The PTAB found claims 1, 12, and 23 and several dependent claims unpatentable as obvious, but did not find claims 4 and 16 unpatentable. The Federal Circuit affirmed the PTAB, and the district court later lifted the stay in the case. Cellwitch then asserted claims 4–9 and 16–21.

Evidentiary rulings

The court admitted and considered the complete patent file history. It declined to exclude Cellwitch expert Dr. Goldberg’s declaration under the standards governing expert testimony. The court found that Tile’s objections concerned the weight of the opinions rather than their admissibility, although it gave some of Dr. Goldberg’s opinions less weight.

Claim constructions

“Wireless communication terminal”

The court adopted Tile’s position that no construction was necessary. It held that the term’s ordinary meaning is not limited to a mobile device. The court reasoned that limiting the term to a mobile device would make separate claim limitations requiring a wireless-enabled mobile device meaningless or repetitive.

“Monitor the proximity of”

The court rejected Tile’s argument that Cellwitch was barred from litigating this term based on the earlier PTAB proceeding. The PTAB had not actually construed “monitor the proximity of” under the same claim-construction standard used by the district court.

The court construed the term to mean: “keep track of, including by periodic or continuous detection of, whether the wireless device is within range of or a defined distance from the wireless communication terminal.” The court concluded that monitoring involves more than a single detection, although periodic or continuous detection can be part of monitoring.

“When the proximity . . .”

The court construed the term to mean: “at a time close to when it is determined that the wireless device is out of range of the wireless communication terminal or otherwise is estimated to be at or beyond a defined distance from the wireless communication terminal.”

The court relied in part on the PTAB’s earlier construction for embodiments using periodic polling messages, but did not adopt Tile’s proposed construction verbatim because it could exclude patent embodiments using continuous transmission instead of periodic polling.

“The collected data”

The court did not reach this claim-construction dispute because it found claims 5–9 and 17–21 invalid for indefiniteness. The dispute concerned only those claims.

“Alert,” “notification,” and “alarm”

The court rejected Tile’s argument that these terms were indefinite. It construed “alert” as “signal indicating an event” and gave “notification” the same construction because the patent uses the terms interchangeably. It construed “alarm” as “visual or auditory signal indicating an event.”

The court rejected proposed additional requirements that an alert be urgent, observable regardless of whether the communication terminal was actively being used, or limited to visual, auditory, or haptic signals.

“Learning module”

The disputed language appears in claims 5 and 17 and in claims depending on them. Tile argued that “learning module” should be treated as a function-based limitation under pre-America Invents Act 35 U.S.C. § 112, paragraph 6. That provision requires the patent to disclose corresponding structure when a claim describes a function without sufficiently identifying the structure that performs it.

The court agreed with Tile. Although the claims did not use the word “means,” the court found that “learning module” did not identify sufficiently definite structure. The patent described what the learning module does but did not disclose enough structure or an algorithm to show what the module is. The court also found that the term “module” could refer to software or hardware and therefore did not, by itself, provide adequate structure.

Cellwitch agreed that the claims would be indefinite if § 112, paragraph 6 applied. The court therefore held claims 5 and 17, as well as all asserted claims depending on them, invalid for indefiniteness. The opinion identifies the affected asserted claims as claims 5–9 and 17–21.

Unresolved claim terms and disposition

Because claims 5–9 and 17–21 were invalid for indefiniteness, the court did not reach the disputes over the user-default-profile term in claims 6–9 and 18–21 or the option not to generate an alert in claims 7–9 and 19–21.

The order construes the disputed terms addressed above and concludes that claims 5–9 and 17–21 are invalid for indefiniteness.