In TF3 Ltd. v. Tre Milano, LLC, Appeal 2016-2285 (Fed. Cir. July 13, 2018), the Federal Circuit reversed the Patent Trial and Appeal Board’s final written decision canceling claims directed to a hair styling device as anticipated by prior art.  The court concluded that the Board improperly broadened two claim terms beyond the description in the patent specification.  Using the correct claim construction, the court concluded that prior art does not anticipate the claims.  In part, the court relied upon the abbreviation “i.e.” in determining the proper scope of the claim terms.  The decision serves as an important reminder for patent practitioners to choose their words carefully. A difference in one term, such as a choice between commonly-confused abbreviations, may be determinative of claim scope.

The patent concerns a hair styling device in which a strand of hair is placed within a chamber through a primary opening, wrapped around a heated elongate member by a rotatable element, and then  slid off  the elongate member and removed from the chamber through a secondary opening. Conair® currently manufactures a device that it identifies as being covered by the patent, the Infinitipro by Conair® Curl Secret®, and provides a video demonstrating how the device functions.  The product was awarded a Best of Beauty Breakthrough Award by Allure in 2014.

The Board instituted IPR on all challenged claims on two grounds: anticipation by a first prior art reference and anticipation by a second prior art reference.  Both prior art references describe a curling device in which removal of hair placed into the device requires disassembly of the device and unwinding of the curled hair from around a curler.  In contrast, claim 1 recites a hair styling device that includes a “chamber having a secondary opening through which the length of hair may pass out of the chamber, the secondary opening being located adjacent to the free end [of an elongate member around which a length of hair is wound].”  The Board construed two claim terms: “the length of hair can pass through the secondary opening” and “free end.”  In construing these terms, the Board explicitly rejected the patent owner’s argument that the challenged claims require that the length of hair be allowed to slide along the elongate member towards and subsequently off its free end.  The Board concluded that both prior art references anticipated the challenged claims.

In reviewing the Board’s claim construction, the court relied upon the following portion of the specification (emphasis added) describing how the curled hair is removed from the device:

It is arranged that the abutment 52 in its open position allows the styled length of hair to pass out of the secondary opening 50, i.e., to slide along the elongate member 20 towards and subsequently off its free end.  Little force is required to separate the hair styling device from the length of hair which has been styled…the length of hair is not required to pass any obstructions or otherwise be forced to uncurl during its removal from the hair styling device 10…

The court also relied upon a statement in the specification that describes the device as improving curl retention by permitting a formed curl to be slid off the end of the elongate member without being uncurled.  The court concluded that the challenged claims, properly construed in light of the specification, do not read on the prior art and are not anticipated by either prior art reference.

In view of this decision, patent practitioners would be wise to brush up on the meaning of the commonly used abbreviations “i.e.” and “e.g.”  In this case, the court noted that  “the usage ‘i.e.’ (‘id est’ or ‘that is’) signals an intent to define the word to which it refers.”  In contrast, in Interval Licensing LLC v. AOL, LLC., Appeals 2013-1282, -1283, -1284, -1285 at 1373-74 (Fed. Cir. Sept. 10, 2014), the court stated that “a person of ordinary skill in the art would not understand the ‘e.g.’ phrase to constitute an exclusive definition.”  Patent practitioners would do well to brush up on  Latin abbreviations before drafting patent specifications.