Advanced Ground Information Systems, Inc. v. Life360, Inc., 830 F.3d 1341

AGIS owns U.S. Patents 7,031,728 (’728) and 7,672,681 (’681), which claim systems/devices for displaying symbols representing mobile-device users on a map and enabling interactions via touching those symbols.
The asserted claims (’728 claims 3 and 10; ’681 claims 5 and 9) recite a “symbol generator” and, in the apparatus claims, “CPU software” that generate symbols on a touchscreen display.
Life360 developed a family-location mobile app and was sued by AGIS for infringement; Life360 responded that the terms “symbol generator” and “CPU software” invoke means-plus-function treatment under 35 U.S.C. § 112, para. 6 and lack corresponding structure in the specification.
The district court ruled that “symbol generator” (and “CPU software”) are means-plus-function terms under § 112, ¶ 6 and that the asserted claims are indefinite under § 112, ¶ 2 for failure to disclose corresponding structure/algorithm; parties later stipulated to invalidity.
On appeal, the Federal Circuit reviewed whether (1) the claim term invokes § 112, ¶ 6 and (2) whether the specification discloses corresponding structure/algorithm sufficient to avoid indefiniteness.

Issue	Plaintiff's Argument (AGIS)	Defendant's Argument (Life360)	Held
Whether the term “symbol generator” invokes means-plus-function treatment under § 112, ¶ 6	The term is a known class-name to those skilled in the art; Dr. Goldberg testified it denotes a well-known software module and thus connotes structure (rebutting the presumption against § 112, ¶ 6).	The term is functional/abstract (equivalent to “means for generating symbols”), not a recognized structural name; AGIS’s expert conceded the compound term was coined in the patents.	The court held the presumption that § 112, ¶ 6 does not apply was rebutted; “symbol generator” invokes § 112, ¶ 6.
Whether the specification discloses corresponding structure/algorithm for the means-plus-function term so claims are definite under § 112, ¶ 2	Specification describes data sources (databases, GPS, maps) and that symbols are generated from latitude/longitude; AGIS argued persons of skill would know structures/modules to perform the function.	The spec lacks any algorithm or sufficiently definite structure for a computer-implemented “symbol generator”; relying on a general-purpose computer or generic software is pure functional claiming.	The court held the specification fails to disclose an algorithm or corresponding structure for the claimed function; the means-plus-function limitation is indefinite and the asserted claims are invalid.

Robert Bosch, LLC v. Snap-On Inc., 769 F.3d 1094 (Fed. Cir.) (framework for whether claim term invokes § 112, ¶ 6 and for construing means-plus-function terms)
Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir.) (en banc) (presumption against means-plus-function when ‘means’ not used; test whether term connotes structure)
Aristocrat Techs. Austl. Pty Ltd. v. Int’l Game Tech., 521 F.3d 1328 (Fed. Cir.) (a computer-implemented means-plus-function requires disclosure of a special-purpose computer programmed with an algorithm)
NetMoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359 (Fed. Cir.) (requirement that specification disclose an algorithm for computer-implemented functions)
Finisar Corp. v. DirecTV Grp., Inc., 523 F.3d 1323 (Fed. Cir.) (algorithms may be disclosed in prose, flowcharts, formulas, or other understandable forms)
Blackboard, Inc. v. Desire2Learn, Inc., 574 F.3d 1371 (Fed. Cir.) (patentee must disclose corresponding structure when using means-plus-function language)
Lighting World, Inc. v. Birchwood Lighting, Inc., 382 F.3d 1354 (Fed. Cir.) (a coined term not used in the art may be treated as functional/indefinite)
Personalized Media Commc’ns v. ITC, 161 F.3d 696 (Fed. Cir.) (contrast where a term like “digital detector” conveys to skilled artisans a variety of known structures and thus is not means-plus-function)