IP Law Daily PTAB correctly found claims for imaging device unpatentable for obviousness
Tuesday, February 25, 2020

PTAB correctly found claims for imaging device unpatentable for obviousness

By Thomas Long, J.D.

The patent owner waived a claim construction challenge by failing to timely raise it, and substantial evidence supported the Board’s finding that prior art disclosed a key limitation of the patent at issue.

Substantial evidence supported two Patent Trial and Appeal Board’s decisions finding invalid as obvious 18 claims of a patent directed to a solid-state imaging device with light-sensitive elements arranged in a matrix, the U.S. Court of Appeals for the Federal Circuit has held. Because the patent owner failed to timely raise a challenge to the Board’s construction of a key claim term, the court declined to consider it on appeal. In addition, a majority of the appellate court panel concluded that the Board correctly found that prior art disclosed a "trapezoidal reflecting wall," as found in the patent claims at issue. One judge dissented from that determination, opining that the review petitioner had merely arbitrarily drawn a structure onto a figure in the prior art patent that looked like a trapezoid, and had not shown that the prior art actually disclosed a reflecting wall having that shape (Collabo Innovations, Inc. v. Sony Corp., February 25, 2020, Prost, S.).

Patent at issue. The patent at issue was U.S. Patent No. 7,023,034 ("the ’034 patent"), which described and claimed a pair of "reflecting walls" that exist over each light-sensitive element (such as a photodiode), partitioning each element from neighboring light-sensitive elements. Light that approaches the photodiode at an oblique angle reflects off of the reflecting walls onto the aperture of the desired photodiode, preventing color mixing and minimizing variation across the image.

Inter partes review. Sony Corp. filed two petitions for inter partes review (IPR), alleging (1) that each of claims 1–18 was either anticipated by Japanese Patent Application Publication No. 2001-237404 ("Tomoda"), or obvious over Tomoda in view of various additional references, including Japanese Patent Application Publication No. H11-087674 ("Abe"); and (2) that the same claims were rendered obvious by U.S. Patent Application Publication No. 2001/0026322 ("Takahashi") in view of various secondary references, including Abe. The Board instituted review on both petitions, held a consolidated hearing, and issued two final written decisions concluded that the challenged claims were unpatentable under each of the asserted grounds. The patent owner appealed.

Arguments on appeal. The patent owner presented two arguments to the Federal Circuit. First, it argued that the Board erred by adopting an unreasonably broad construction of "reflecting walls." Second, it contended that the Board’s decision with respect to claims 3 and 12 must be reversed because the Board’s finding that Abe discloses a trapezoidal reflecting wall is not supported by substantial evidence.

Claim construction. The court noted that during an IPR, claims are given their broadest reasonable interpretation consistent with the specification. The Board construed the term "reflecting walls" as "structures having approximately vertical surfaces that reflect light." According to the patent owner, that term should have been construed more narrowly to mean "a wall that reflects oblique light from a micro lens onto a corresponding light-sensitive element." Sony responded by arguing that the patent owner waived its claim construction argument by failing to timely raise it before the Board. The court agreed. The patent owner failed to raise its claim construction challenge until the Board hearing, which was too late. Prior to that point, the patent owner had acquiesced to Sony and the Board’s construction and had applied that construction in its analysis. Moreover, it had not proposed its alternative construction of the term until the appeal. The patent owner was not entitled to raise the argument at this late date, and the Federal Circuit declined to address its merits.

Obviousness. Next, with respect to claims 3 and 12, the court held that substantial evidence, including Abe’s figures and text, supported the Board’s conclusion that Abe disclosed "a vertical cross section of the reflecting wall is a trapezoid whose upper base is longer than a lower base." Although the patent owner presented an alternative explanation of the Abe reference, that was insufficient for reversal under the substantial evidence standard, the court said. Figure 3 of Abe showed a reflecting wall featuring a light shielding film that had lateral faces forming a trapezoidal shape. The court was not persuaded by the patent owner’s contention that Abe disclosed a U-shaped, cup-shaped, or bowl-shaped design instead of a trapezoid. The Board’s interpretation of Abe was bolstered by expert testimony as well as the text of Abe. Accordingly, the court affirmed the Board’s conclusion that claims 3 and 12 were unpatentable as obvious.

Dissenting opinion. Circuit Judge Raymond C. Clevenger dissented in part, disagreeing with the majority’s conclusion that Abe disclosed a "reflecting wall" having a vertical cross section that "is a trapezoid whose upper base is longer than a lower base." According to Judge Clevenger, The question was not whether Figure 3 of Abe, on its face, disclosed a "trapezoidal shape," but whether substantial evidence supported the Board’s finding that Abe disclosed combining multiple, separately designated, structures such that their combination formed a trapezoidal "reflecting wall"—a structure having approximately vertical surfaces that reflects light. In Judge Clevenger’s view, Abe did not disclose this structure, and Sony had arbitrarily drawn a structure onto Figure 3 that looked like a trapezoid, rather than showing that Abe disclosed an actual reflecting wall having that shape. In addition, Judge Clevenger said, the prior art and Sony’s expert did not explain why a person of ordinary skill in the art at the time of the invention would find it necessary to combine Abe’s light shielding film with portions of the insulating film so as to form a trapezoidal "reflecting wall." Therefore, according to Judge Clevenger, the court should reverse the Board’s finding of obviousness with respect to claims 3 and 12 of the ’034 patent.

This case is No. 19-1152.

Attorneys: Daniel Fletcher Olejko (Bragalone Conroy PC) for Collabo Innovations, Inc. Andrew Baluch (Smith Baluch LLP) for Sony Corp.

Companies: Collabo Innovations, Inc.; Sony Corp.

MainStory: TopStory Patent FedCirNews

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