Blackbird Tech LLC sued ELB Electronics for infringing a patent claim related to retrofitting existing light fixtures with a more energy-efficient lighting apparatus. Blackbird Tech LLC v. ELB Electronics, Inc., No. 17-1703, slip op. at 3 (Fed. Cir. July 16, 2018). The asserted claim read as follows:
An energy-efficient lighting apparatus for retrofit with an existing light fixture having a ballast cover, comprising:
a housing having an attachment surface and an illumination surface;
a plurality of illumination surface holes in the illumination surface;
a circuit board comprising a plurality of light-emitting diodes, wherein the circuit board is positioned adjacent the housing so that the plurality of light-emitting diodes protrude through the plurality of illumination surface holes in the illumination surface; and
a fastening mechanism for securing the attachment surface of the lighting apparatus to the illumination surface, wherein the lighting apparatus is coupled to a wall switch and wherein the illumination of the light-emitting diodes is controllable based upon the position of the wall switch.
Id. (emphasis in original). The parties’ dispute concerned the construction of the claim term “attachment surface” and whether the attachment surface of the lighting apparatus must be secured to the ballast cover of the existing light fixture. Id. at 4. Judge Andrews of the District of Delaware construed “attachment surface” as “layer of the housing that is secured to the ballast cover.” After claim construction, Blackbird stipulated to noninfringement and judgment was entered in favor of ELB Electronics. Blackbird appealed. Id.
On July 16, 2018, the Federal Circuit (Judges Moore and Prost) held that the district court erred in its construction of “attachment surface” by requiring the attachment surface be secured to the ballast cover. The court therefore vacated the judgment of non-infringement and remanded. Id. at 4, 9.
First, the court found that the plain language of claim 12 requires only one fastening mechanism, in which the attachment surface must be secured to the illumination surface; the claim does not also require that the attachment surface be secured to the ballast cover. Id. at 4-5.
Second, nothing in the specification or prosecution history suggests that a fastening mechanism for securing the attachment surface to the ballast cover was so important as to merit importing that limitation into the claim. The court noted that the specification acknowledges that fastening can be achieved by a variety of fastening mechanisms. Additionally, no party argued that there was a technologically significant reason to have the fastening mechanism secure the attachment surface to the ballast cover. “Without any evidence that the fastener is important, essential, or critical to the invention, it should not be read in as a claim limitation.” Id. at 7.
Lastly—and according to the court, most importantly—the limitation requiring attachment to the ballast cover had been expressly removed from the claim during prosecution to overcome a rejection. Id. After an examiner’s interview and to “resolve [35 U.S.C. §] 112 issues,” the applicant deleted from claim 12 a fastening mechanism that secures the attachment surface to the ballast cover and replaced it with a fastening mechanism for securing the attachment surface to the illumination surface. Id. Therefore, no skilled artisan would understand that the claim required a fasting mechanism for securing the attachment surface to the ballast cover “when that very limitation was expressly removed from the claim to secure patentability with the examiner’s blessing and agreement.” Id. at 8.
Defendants argued that the preamble, “[a]n energy-efficient lighting apparatus for retrofit with an existing light fixture having a ballast cover,” required reading into the claim the precise mechanism by which retrofitting can be achieved. Id. at 9 (emphasis added). The court rejected this argument finding that claim 12 is an apparatus claim, not a method claim, and the apparatus described in claim 12 is structurally complete. Id. “An apparatus claim is not required to include all elements necessary for the claimed structure’s installation.” Id.
Judge Reyna dissented, finding that the plain meaning of claim 12 “implicitly requires the attachment surface be secured to the ballast cover to achieve the retrofit function.” Id. at 11. In his opinion, skilled artisans would necessarily conclude that the attachment surface is secured to the ballast cover because the only feature described of the existing light fixture in claim 12 is the ballast cover. He noted that every embodiment of the retrofit lighting apparatus describes securing the attachment surface to the ballast cover and no other explanation is provided for how retrofitting may otherwise be achieved. Id. at 12. The majority’s decision, in his opinion, “opens the door” for future lack of written description and enablement challenges. Id. at 13.