Cellwitch Inc. v. Tile, Inc.

Background

Cellwitch alleged that Tile infringed United States Patent No. 8,872,655, which describes a system for tracking personal items. The patent covers wireless devices associated with monitored items, wireless communication terminals that monitor proximity and generate alerts, and a processing system that stores related data. The asserted claims also include claims involving a “buddy” terminal that can monitor another user’s wireless device.

Tile petitioned the Patent Trial and Appeal Board for inter partes review, a proceeding in which the Board reviews patentability based on prior art. The Board found claims 1, 12, and 23, along with several dependent claims, unpatentable as obvious. It did not find claims 4 and 16 unpatentable, and claims 5–9 and 17–21 were not found unpatentable because they depended on claims 4 and 16. The Federal Circuit affirmed the Board’s decision, and the district court later lifted its stay. Cellwitch asserted infringement of claims 4–9 and 16–21.

Evidentiary Rulings

Tile objected to Cellwitch’s use of an incomplete copy of the patent’s prosecution history. The court admitted and considered a different docket filing as the complete file history.

Tile also asked the court to exclude the declaration of Cellwitch’s expert, Dr. Goldberg, under Federal Rule of Evidence 702 and the standards governing expert reliability. The court declined to exclude the declaration. It found that Tile’s criticisms concerned the weight to give the expert’s opinions rather than whether the opinions were admissible. The court nevertheless gave some of Dr. Goldberg’s opinions less weight where he had not considered relevant evidence, including claim 10.

Claim Constructions

“Wireless communication terminal”

Cellwitch proposed construing this term as “wireless enabled mobile device.” Tile argued that no construction was necessary. The court agreed with Tile. It held that the plain and ordinary meaning of “wireless communication terminal” is not limited to a mobile device and requires no construction. The court reasoned in part that Cellwitch’s proposed construction would make the separate limitation in claims 10 and 22—that at least one terminal is a wireless-enabled mobile device—meaningless.

“Monitor the proximity of”

Cellwitch proposed “keep track of whether the wireless device is within range of or a defined distance from the wireless communication terminal.” Tile proposed no construction and argued that Cellwitch was barred from relitigating the issue based on the earlier Patent Trial and Appeal Board proceeding.

The court rejected Tile’s issue-preclusion argument because the Board had not actually construed “monitor the proximity of” under the claim-construction standard used by the district court. The court adopted this construction: “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 explained that monitoring involves more than a single detection, although detection may be part of monitoring.

“When the proximity . . . meets or exceeds a proximity threshold”

The Patent Trial and Appeal Board had previously construed this language for embodiments using periodic polling messages. The district court held that the Board’s decision bound the parties for those embodiments but declined to adopt Tile’s proposed construction verbatim because it could exclude disclosed embodiments using continuous transmission.

The court adopted this construction: “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 collected data” and other terms not reached

The court did not reach the dispute over “the collected data” because it found claims 5–9 and 17–21 invalid for indefiniteness. For the same reason, it did not reach the disputes over the user-default-profile term in claims 6–9 and 18–21 or the language concerning providing an option not to generate an alert in claims 7–9 and 19–21.

“Alert,” “notification,” and “alarm”

Tile argued that these terms were indefinite, meaning that the patent did not inform a skilled person about the scope of the claims with reasonable certainty. The court held that Tile did not prove indefiniteness by clear and convincing evidence.

The court rejected Tile’s proposed requirement that an alert be “urgent” or observable regardless of whether the user was actively using the terminal. It also rejected Cellwitch’s proposed limitation that an alert must be visual, auditory, or haptic. The court construed “alert” as “signal indicating an event.” Because the patent uses “notification” interchangeably with “alert,” the court gave “notification” the same construction. It construed “alarm” as “visual or auditory signal indicating an event.”

“Learning module”

The disputed language appears in claims 5 and 17 and in claims that depend on them. Tile argued that “learning module” is a means-plus-function limitation under pre-2009 patent-law provisions, specifically former 35 U.S.C. § 112, paragraph 6. Under that rule, a claim may describe a function instead of structure, but the patent must disclose the corresponding structure and its equivalents.

Although the claims did not use the word “means,” the court found that “learning module” did not communicate sufficiently definite structure to a person of ordinary skill in the field. The specification referred to a learning module only a few times and described what it did without explaining its structure. The court also rejected Cellwitch’s argument that the term necessarily meant a software component, finding that the patent did not clearly limit “module” to software rather than hardware.

The court therefore held that “learning module” is subject to the means-plus-function requirements of former § 112, paragraph 6. Cellwitch agreed that the claims would be indefinite if that provision applied. The court concluded that claims 5 and 17, and all asserted claims depending on them—claims 5–9 and 17–21—are invalid for indefiniteness.

Disposition

The order construed the disputed claim terms as described above and held claims 5–9 and 17–21 invalid for indefiniteness. It did not reach the additional claim-term disputes relating only to those invalid claims.