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November 23, 2020by Yanhong Hu

A threshold issue for the Patent Trial and Appeal Board (“Board”) to resolve is often claim interpretation.  It is well-settled that claims must be “given their broadest reasonable interpretation consistent with the specification” during patent examination.  In Ex parte Awad (Appeal 2019-005866), the Board reversed the Examiner’s obviousness rejection because the Board found the rejection was based on an unreasonably broad claim interpretation when the relevant claim language was read in light of the specification.

Claim 1 was illustrative and was drawn to a flexible solar panel, which contained a polymer matrix and a plant extract completely incorporated in the polymer matrix and “being a green-colored extract of B. vulgaris subsp. cicla, wherein the extract includes chloroplasts.”

The Examiner rejected the claimed solar panel as obvious over Ochiai in view of Pavokovic and Yang.  In particular, the Examiner found Ochiai taught a solar panel containing a PVA matrix and a plant extract completely incorporated in the polymer matrix wherein the extract included green-colored chloroplasts.  The Examiner admitted Ochiai did not disclose that the plant extract was “a green-colored extract of B. vulgaris subsp. cicla.”  However, the Examiner found Pavokovic taught that betalains, such as those from B. vulgaris subsp. cicla, were useful as “natural pigments” in solar cells and found Yang taught that incorporating chlorophyll-containing plant extracts in a PVA polymer matrix stabilized the extracts against light- and oxygen-induced damage.

In response to Appellant’s arguments that betalains described in Pavokovic were “classified in two groups: red-violet betacyanins and yellow betaxanthins” and that Pavokovic did not teach “the usage of a green, chloroplast-containing extract of B. vulgaris subsp. [cicla] in a [dye-sensitized solar cell],” the Examiner argued he did not rely on Pavokovic “for teaching the entirety of the claimed plant extract,” instead, he relied on Pavokovic “only to teach that betalain extracts of B. vulgaris subsp. cicla are useful as natural pigments in solar cells to convert radiant energy into electric energy.”  The Examiner argued “Ochiai teaches a plant extract that is green and includes chloroplasts” and further argued “even if the betalains of B. vulgaris subsp. cicla are colors other than green, the final product created from the combination of the prior art references still contains a plant extract comprising the green-colored chlorophyll chloroplasts taught by Ochiai because these betalains are added to Ochiai’s plant-extract composition.”

Therefore, as noted by the Board, the Examiner interpreted the claim limitation of the plant extract “being a green-colored extract of B. vulgaris subsp. cicla, wherein the extract includes chloroplasts” to encompass any combination of plant extracts “as long as the final combination (a) is green-colored, (b) includes a B. vulgaris subsp. cicla extract, and (c) includes chloroplasts.”

The Board found such interpretation was broader than what was reasonable when the claim language was read in light of the specification.  Specifically, the Board noted that the specification stated that the field of the invention related “particularly to a flexible solar panel including an extract of chard (B. vulgaris subsp. cicla)” and that at no point did the specification discuss extracts from any plant other than B. vulgaris subsp. cicla.  The Board further found the specification specifically taught “a green colored extract of B. vulgaris subsp. cicla” and each of the working examples used an extract from B. vulgaris subsp. cicla, not from any other plant and not mixed with any other plant extract.

The Board thus concluded that, when the claim language was interpreted in light of the specification, the broadest reasonable interpretation of the claim limitation required “an extract from B. vulgaris subsp. cicla that itself is green-colored and also contains chloroplasts; i.e., the chloroplasts are derived from B. vulgaris subsp. cicla.”  The Board further explained “‘being’ in the quoted limitation is construed to mean ‘consisting of’: the plant extract consists of a green-colored extract of B. vulgaris subsp. cicla, wherein the extract includes chloroplasts.”  The Board explicitly pointed out that “[to] interpret the quoted limitation to encompass a mixture of plant extracts would be inconsistent with the specification’s disclosure.”

With the correct claim interpretation, the Board further found none of the cited references disclosed a green-colored extract from B. vulgaris subsp. cicla that included chloroplasts as required by the claim limitation.  Because the Board did not find the Examiner had shown the plant extract as required by the claim would have been obvious over the cited references or that the prior art would have provided a reason to use such an extract in the claimed solar panel, the Board reversed the obviousness rejection.

Takeaway:  U.S. examiners are required to give claims their broadest reasonable interpretation in light of the specification.  However, in practice, they sometimes fail to consider whether their “broadest” interpretation of the claim language is “reasonable in light of the specification.”  Therefore, it is advisable to scrutinize an Examiner’s claim interpretation especially when there is a complicated claim limitation that includes multiple sub-features.  As illustrated by Awad, examiners sometimes fail to recognize that sub-features are related, instead treating them separately. This approach can lead to unreasonably broad interpretations.

JudgesE. B. Grimes, L. M. Gaudette, and L. Ren

Yanhong Hu

by Yanhong Hu

Yanhong (Claire) Hu, Ph.D., is a patent attorney and partner at Element IP. She is active in patent preparation and prosecution, post-grant proceedings, and legal opinions and counseling. Her knowledge and experience in a wide variety of technical fields, combined with her legal expertise, allow her to appreciate various technologies to successfully and efficiently assist her clients.