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You are here: Home / Patent Applications / Functional language invalidates patent claim

Functional language invalidates patent claim

October 20, 2016 by James Yang

cellphonenavigationIn AGIS, Inc. v. Life360, Inc. (Fed. Cir. July 28, 2016), AGIS (patent owner) held a patent directed to a cellular communication system that allows multiple cellular phone users to monitor the location of others and their status via a visual display. Symbols generated on the visual display (e.g., user’s cellular phone) represented the locations of the other users. In the asserted patent claim, one of the limitations was a “symbol generator” which was construed as function, and thus a means plus function limitation and unfortunately for the patent owner now deemed indefinite and the patent claim invalid.

Life360 (accused infringer) created a mobile app designed to allow families to stay better connected. The mobile app operated on a mobile device designed to allow users to view their family members on a map, communicate with them and receive alerts when their loved ones arrive at home, school or work.

AGIS filed a complaint alleging that the mobile app created by Life360 infringed on the claims of AGIS’s patent. In order to avoid patent infringement liability, Life360 alleged that the claims were indefinite and thus invalid.

The indefiniteness line of argument was based on the claimed limitation “symbol generator”. This claim language was deemed to be functional language because one of ordinary skill in the art, in this case computer technology, could not be sure of the structure associated with those words.  Functional language is permitted in the claims under 35 USC 112, paragraph 6 but if functional language is used then it is limited only to the structure associated with the function and disclosed in the patent.  If the patent does not mention any structure, then the claim is indefinite for attempting to claim the invention in terms of its function, instead of its structure because the patent specification fails to disclose any structure.

Life360 alleged that the “symbol generator” limitation was not a phrase associated with a particular structure generally known by the public or by persons of ordinary skill in the pertinent art. During litigation, AGIS’s (patent owner) expert confirmed this understanding by testifying that:

“those skilled in the art would have understood a “symbol generator” to refer to a class of structures instead of a particular structure.” (Emphasis added).

Even though the “symbol generator” language referred to a class of structures, this was not sufficient to identify any particular structure associated with the symbol generator. Hence, “symbol generator” was deemed functional language.  Purely functional language in claims are construed as a means plus function limitation as permitted by 35 USC 112, 6th paragraph for pre-AIA application and 35 USC 112(f) for AIA applications.

Under 35 U.S.C 112, 6th paragraph for pre-AIA application and 35 USC 112(f) for AIA applications, means plus function claims are limited to the structure disclosed IN the patent and associated with the stated function.  If the patent does not disclose any structure, competitors and defendants would not know whether they are infringing the claim or not. The claim would then be indefinite under 35 U.S.C 112, second paragraph which requires:

The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.

In this case, the court described the “symbol generator” limitation as being analogous to “means for generating a symbol” or in other words an attempt to claim the invention in terms of its function.

An inventor or patent owner may claim the invention in terms of its function but doing so is not as broad as a layperson might think the claim is. 35 U.S.C. 112, 6th paragraph recites that:

an element in a claim for combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or ask and support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

Section 112, paragraph 6 permits claims to include functional language. However, in claiming the invention in terms of its function and not the particular structure, the functional language used in the claim is limited to the particular structure recited in the patent application and associated with the function.  If the patent application does not describe or disclose any particular structure associated with the functional language recited in the claim, then the claim is deemed to be indefinite. In this case, the Court held that the claims of the patent were indefinite because the “system generator” language was pure functional language and no particular structure was disclosed in the patent application regarding the stated function.

This case highlights the need for clarity in claiming an invention and the need to carefully express the structure of functional aspects of the invention that might be included in the claims from the start or mid stream during patent prosecution. In particular, this case highlights the need to read and reread the claim language to determine if any of the claim language could be construed as functional, and thus a means or step plus function limitation which would require additional disclosure in the patent application to satisfy 35 USC 112, paragraph 6 for pre-AIA applications or subsection (f) for AIA applications.

This case also highlights problems in preparing and prosecuting a patent application.  The patent owner can invoke a claim limitation as a means plus function limitation by using the word means.  However, the patent owner did not want the claim language to be construed as a means plus function limitation because they didn’t use that operative trigger word but the court did construe it that way against the patent owner’s desire.  When preparing and prosecuting a patent application, one must be cognizant of the words used and whether it could be construed as a means plus function limitation but not always possible because of the uncertainty of litigation.

I invite you to contact me with your patent questions at (949) 433-0900. Please feel free to forward this article to your friends. As an Orange County Patent Attorney, I serve Orange County, Irvine, Los Angeles, San Diego and surrounding cities.

Author

James Yang is a patent attorney. For more than 16 years, James Yang has been representing clients to secure patent protection for their inventions and register trademarks to protect their brands. If you need help, call him at (949) 433-0900. Read More…

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