Federal Circuit Affirms PTAB Decision Upholding Imaging Lens Patent

The U.S. Court of Appeals for the Federal Circuit (CAFC) on Monday in Motorola Mobility LLC v. Largan Precision Co., Ltd. affirmed a Patent Trial and Appeal Board (PTAB) decision that upheld claims 1-27 of Largan Precision Co., Ltd.’s U.S. Patent No. 9,696,519, which Motorola Mobility LLC had challenged via inter partes review (IPR).

The ‘519 patent concerns an imaging optical lens assembly comprising five lens elements arranged from object side to image side. The representative claim requires specific configurations, including:

• A first lens element with negative refractive power having a concave object-side surface;
• A second lens element having positive refractive power;
• A third lens element having negative refractive power;
• A fourth lens element having positive refractive power; and
• A fifth lens element with negative refractive power has an image-side surface that is concave in a paraxial region.

The claims specify mathematical relationships including |R4/R3|<1.0, f5/f3<1.0, and -10.0<R1/f<0.

Motorola filed the IPR petition challenging claims 1-27 as unpatentable under 35 U.S.C. § 103 over Chung (U.S. Patent Application Publication No. 2015/0098137) in view of Sekine (U.S. Patent Application Publication No. 2013/0182339). Motorola argued that “Chung Embodiments 11 and 12 met all claim limitations except the final R1/f limitation, which Sekine disclosed.”

Motorola contended that a skilled artisan would have been motivated to apply Sekine’s R1/f teaching to Chung to maintain image quality while increasing the field of view. Motorola’s expert presented ZEMAX modeling evidence to demonstrate that “‘a [skilled artisan] would have had a reasonable expectation of success and required no undue experimentation’ in applying Sekine’s R1/f teachings to Chung.”

The Board found that Motorola failed to prove motivation to combine the references, highlighting “significant differences” between the systems. Specifically, Chung’s embodiments had a negative first lens and a positive second lens, while Sekine had the opposite configuration. The Board also determined that Sekine “disclosed an inferior lens system with poorer image quality and field of view.”

The Board did not consider Motorola’s ZEMAX evidence, determining it was “relied on in the Petition only for the purpose of showing a reasonable expectation of success.” As the Board found no motivation to combine, it did not address reasonable expectations of success.

The CAFC opinion found no reversible error. The court noted that the Board had expressly acknowledged Motorola’s asserted motivation but rejected it for fact-based reasons supported by substantial evidence.

The court addressed Motorola’s argument that the Board improperly limited its ZEMAX optimization evidence to a reasonable expectation of success rather than motivation to combine.

The CAFC found that “Motorola’s ZEMAX evidence simply confirms the combination’s feasibility–that a skilled artisan could apply Sekine’s teaching to Chung–not that a skilled artisan would have been motivated to do so.”

The opinion cited Adidas AG v. Nike, Inc., which reiterated that “the obviousness inquiry does not merely ask whether a skilled artisan could combine the references, but instead asks whether ‘they would have been motivated to do so.'” The PTAB’s decision was therefore affirmed.