Firebug runs into “one big world full of no” at the Federal Circuit

Firebug v Stride Rite Appeal Nos. 2019-1622, 2019-1623, Fed. Cir. June 25, 2020

Shoes by Firebug (“Firebug”) owns US Patent Nos. 8,992,038 (“‘038 patent”) and 9,301,574 (“‘574 patent”), directed to improved illumination systems for footwear.  Specifically, both patents describe footwear comprising a sole and three-layer upper – including a liner, interfacing layer and light diffusing layer.  The light sources are connected to the interfacing layer between the interfacing layer and the light diffusing layer.  The preamble is the same in the main independent claim for both patents, and recites “An internally illuminated textile footwear”, though only the ‘038 patent then proceeds to recite “footwear” in the body of the claim.

Firebug asserted the ‘038 and ‘574 patent against Stride Rite Children’s Group, LLC (“Stride Rite”), whereupon Stride Rite filed petitions for inter partes review of both patents, alleging the claims thereof would have been obvious over US Patent 5,894,686 (“Parker”) and US Patent Appl. Pub. 2011/0271558 (“Rosko”).

Before PTAB, Stride Rite argued that a skilled worker would have replaced the fragile fiber optic layer disclosed by Parker with the LED-based diffuser of Rosko to reduce cost and improve structural integrity of the footwear.  The Board instituted trial on both petitions.  In their final decisions, the Board held the preamble non-limiting, concluded that the references otherwise rendered the challenged claims obvious and rejected Firebug’s evidence of secondary considerations.  Firebug appealed to the Federal Circuit and fared no better.

Preamble as limiting

The Federal Circuit agreed with Firebug that the preamble of the ‘038 patent was limiting (apparently solely on the bases that the term “footwear” in the preamble provided antecedent basis for the term in the body of the claim):

While antecedent basis alone is not determinative of whether a preamble is limiting, use of preamble terms to define positive limitations in the body of claims can evince an inventor’s intent that the preamble limit the scope of the claim.  That is the case here.  Because the claim requires that the illumination system be housed in the textile footwear recited in the preamble, the preamble is essential to understanding the structural limitations of the illumination system.


Unfortunately for Firebug, the Court held it didn’t matter and that even when so construed, the references still rendered the claims of the ‘038 patent obvious.

With regard to the obviousness rejection, Firebug argued that removal of the fiber optic layer of Parker would necessarily remove a back reflector of Parker, read on the interfacing layer of the claims.  Firebug further argued that Rosko taught no such layer, and would have no reason to disassemble the optical fibers of Parker to leave such a layer, as the LED’s of Rosko’s LED’s already include a reflective sheet.  Compelling, no?  Stride Right showed up with drawings showing their proposed modification, stripping the optical fibers of their back reflector and leaving it behind after replacement with LED’s of Rosko.  Firebug argued that the Board must be reversed for lack of substantial evidence, but the Federal Circuit really liked the visual aid:

Firebug argues that we must reverse the Board because its finding is not supported by substantial evidence.  We disagree.  The Board was presented with two alternative theories as to whether a skilled artisan would or would not have substituted Rosko’s LEDs for Parker’s optical fibers as proposed by Stride Rite.  Our task is not to determine which theory we find more compelling.  “[I]t is not for us to second-guess the Board’s assessment of the evidence.” Velander v. Garner 348 F.3d 1359, 1378 (Fed. Cir. 2003).  Rather, the only question before us is whether the conclusion adopted by the Board is supported by substantial evidence.  Here, we conclude that is is …

Firebug raised a hail Mary with the argument that, since the back reflector of Parker was coextensive with the fibers, even if one of skill in the art removed the fiber and for some reason left the back reflector behind it would remain coextensive with Rosko’s LED’s and thus could not meet another recitation of the claim, i.e., that the back reflector be “adjacently connected” to the light diffusing layer.  And again, Firebug was rebuffed:

Ultimately, Firebug’s argument ultimately asks us to perform fact-finding.  We are not in a position to evaluate the correctness of Firebug’s argument, but rather must determine whether the Board’s conclusion was supported by substantial evidence…[petitioner’s expert] presented a modified structure in which the back reflector extended beyond the between the individual LED’s.

Firebug presented their own expert, who testified that the modified structure proposed by Stride Rite would not survive the manufacturing process as the back reflector, stripped from its optical fibers, would be too weak.  The Board chose to accept the contrary testimony of Stride Rite’s expert that the proposed modification would in fact increase the durability of the footwear, and the Federal Circuit held:

The Board was within its discretion to weight the credibility of expert testimony…and Firebug has not otherwise demonstrated that the Board’s determination is unsupported by substantial evidence.

Secondary Considerations

Firebug then proceeded to argue that their evidence of secondary considerations have been afforded insufficient weight in the Board’s obviousness analysis.  In particular, Firebug argued that the Board erred in failing to consider two license agreements, as well as the testimony of the individual that negotiated the agreements, as sufficient to establish a nexus between the challenged claims and the agreements.  The Federal Circuit first denied that nexus had been established, stating:

The agreements presented by Firebug license eight patents, two patent applications, and one trademark…Because the licenses include numerous intellectual property rights in addition to the ‘038 and ‘574 patents, the agreements on their face do not establish a nexus between the commercial interest in Firebug’s products and the claims of the ‘038 and ‘574 patents.

And then agreed with Stride Rite that even if the Board erred in determining that Firebug had not established nexus, “Firebug’s evidence of secondary considerations is weak, and THAT conclusion is supported by substantial evidence added.”  Emphasis added.

Specifically, Firebug had provided evidence in the form of declarations from a Firebug salesman and Firebug’s owner, the named inventor of the challenged patents.  The Board struck the salesman’s declaration because he refused to be deposed and that of the owner for self interest.  Finally, the Board afforded little weight to Firebug’s allegation of copying, as Firebug failed to demonstrate that Stride Rite had access to a copy of the claimed footwear that it could reverse engineer.  The Federal Circuit once again found no error in the Board’s conclusion of obviousness.