October 29, 2014

Board Denies IPR Challenge Based on Insufficient Chemical Range Overlap

Despite a long history of precedence, chemical ā€œrangeā€ cases still generate contested issues and inter partesĀ review proceedingsĀ are no different. The Board considered an issue relative to an overlap of ranges inĀ E Ink Corporation v. Research Frontiers Incorporated, IPR2014-00422, involving US Pat. No. 6,606,185. Because the prior art cited by PetitionerĀ did not disclose, with sufficient specificity, ranges that overlapped with the claimed ranges of the ā€˜185 invention, the Petition seeking IPR was denied.

The ā€˜453 patent relates generally to films comprising heat-reflective particles, and key limitations of the claimed invention recite ranges for particular particle sizes. Of relevance to the range issue of this article, claim 1 of the challenged patent requires ā€œparticles hav[ing] an average length in a range between about 1 micron and about 50 nanometers.ā€

Both Patent Owner and PetitionerĀ acknowledged that the art cited by PetitionerĀ described particle size ranges thatĀ overlapped with the ranges claimed in the ā€˜185 patent. Ā Specifically, the prior art disclosed ā€œanisometric particles having an average particle size of about 0.2 microns or less, preferably about 0.1 microns or less.ā€ Despite this overlap, Patent Owner argued that (1) the cited art failed to recognize the importance of the claimed lower limit of the ā€˜185 particle size range; and (2) that the overlap between the art-described ranges and the ā€˜185 claimed ranges were insufficient for anticipation.

The Board agreed, finding that the cited art did not disclose a lower limit to a particle size range, as required by the ā€˜185 patent.Ā  The Board also found that the lower limit of the particle size range was key to the ā€˜185 invention, as Patent Owner emphasized that particle sizes smaller than the lower limit could lead to problems with the invention.Ā  Therefore, because of lack of disclosure of a lower limit to the particle size range, and because the cited artā€™s range was larger than the ā€˜185 patent, the Board found that there was no anticipation of the ā€˜185 claims.

Accordingly, the Board was unpersuaded by Patent Challengerā€™s range-based anticipation arguments, and denied the petition for inter partes review.