(1) Prosecution history serves as intrinsic evidence for purposes of claim construction even “in construing patent claims before the PTO,” such that an “examiner err[s] by resorting to extrinsic evidence that [is] inconsistent with the more reliable intrinsic evidence.” (2) “[W]here claims have already been adjudicated invalid [in an inter-partes reexamination], a cross-appeal regarding additional invalidity arguments is generally improper.”
Background / Facts: The patent on appeal here from an inter partes reexamination relates to a stair-step lighting apparatus that uses a reflective strip of material to alert users to the edge of a step in darkened or low-light environments. During original examination, the patentee explained that it had amended the claims “to disclose ‘a material that is inert to light’ as a positive limitation indicating that the material for the second portion is non-photoluminescent and not activated to glow by absorbing ambient light.” Nevertheless, the Examiner on reexamination, in maintaining his rejection, interpreted the “intert to light” limitation under a broadest reasonable interpretation in accordance with a dictionary definition as “a material that does not react, e.g., by degrading, when exposed to light or a material that does not react because it has been treated with or includes some additive, which inhibits degradation of the material when exposed to light.” On appeal to the PTAB, the third-party requestor defended the examiner’s interpretation in this regard, but in the same briefing rather than on cross-appeal offered alternative arguments for holding the disputed claims unpatentable.
Issue(s): (1) Whether the broadest reasonable interpretation rubric for claim interpretation at the PTO allows for elevating extrinsic dictionary evidence over intrinsic prosecution history evidence, and (2) whether a third-party requestor’s alternative arguments for holding disputed claims unpatentable in inter partes reexamination must be raised separately in a cross-appeal before the PTAB to avoid waiver.
Holding(s): No on both accounts. (1) “[T]he prosecution history, while not literally within the patent document, serves as intrinsic evidence for purposes of claim construction. This remains true in construing patent claims before the PTO. … Here, the prosecution history shows that [the patentee] meant for material that is ‘inert to light’ to be ‘non-photoluminescent and not activated to glow by absorbing ambient light.’ … This extrinsic evidence [cited by the examiner] is not irrelevant, but has relatively little probative value in view of the prevailing intrinsic evidence. … [T]he examiner erred by resorting to extrinsic evidence that was inconsistent with the more reliable intrinsic evidence.” (2) “[O]ne of the threshold conditions for a cross-appeal is a final decision favorable to patentability. In this case, the examiner rejected all the claims. Thus, the record presented no decision favorable to patentability for [the third-party requestor] to appeal. Contrary to the Board’s assertion, each of the examiner’s determinations against [the third-party requestor’s] proposed rejections is not a distinct decision favorable to patentability necessitating an appeal. … Contrary to the Board’s decision … [the third-part requestor’s] conduct does not rise to the level of waiver or invoke judicial estoppel.”