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China’s aversion to the means-plus-function feature narrows readings of patent claims, explains Xiaojun Guo of CCPIT Patent and Trademark Law Office.
The Supreme Court of China issued the Interpretation on Several Issues Concerning the Application of Law in the Trial of Disputes over Infringement of Patent Rights in 2009.
Article 4 reads: “Where a claim presents a technical feature expressed in terms of function or effect, the People’s Court shall determine the contents of such technical feature on the basis of the specific embodiment(s) of the function or effect as described in the description and the appended drawings and its or their equivalent embodiment(s).”
In short, a means-plus-function feature recited in a claim is essentially defined by the indispensable features in the specification for performing the function or effect and the equivalent features.
In spite of the provision, the courts in China have applied somewhat different criteria as to what constitutes a means-plus-function feature, as well as how to define its protection scope.
In response, article 8(1) of the second Interpretation on Several Issues Concerning the Application of Law in the Trial of Disputes over Infringement of Patent Rights, which came into effect in 2016, provides that: “A means-plus-function feature is a technical feature defining the structure, composition, step, condition or their relations, etc, by its function or effect in the invention-creation, unless a person skilled in the art can directly and explicitly determine the specific embodiment(s) for performing such function or effect by reading purely the claims.”
In a retrial case, Zui Gao Fa Min Shen No. 1804 (2017), about infringement of a utility model patent made by the Supreme Court in December 2018, one point at issue was whether the term “supporting rail” of the “sorting device of vegetables and fruits” defines a means-plus-function feature.
The Supreme Court said: “If a technical feature defines simultaneously the corresponding structural limitation besides the function or effect, and a person skilled in the art can directly and explicitly determine, by reading purely the claims, the specific embodiment(s) of the structural limitation which can perform the function or effect, such a technical feature of combining the ‘structure’ and the ‘function or effect’ doesn’t belong to the ‘means-plus-function feature’ as defined in the previous judicial interpretations.”
"The compared features shall perform ‘the same function’ to achieve ‘the same result’."
The court found that although the “supporting rail” is not a common term in the art, a person skilled in the art, upon reading the claims, can directly and explicitly determine that the “rail” is a structural limitation and the “supporting” is a function to be performed by the “rail”, and this person skilled in the art is familiar with any regular embodiments of the “rail”, which itself is usually sufficient to perform the function of “supporting”.
Since a person skilled in the art can directly and explicitly determine any “rail” of appropriate structure for performing the function of “supporting rail” in the context of the claims, the court held that the term “supporting rail” was not a means-plus-function feature, and was therefore not restricted to the “triangular supporting rail” in the specification and covered the trapezoidal supporting rail of the alleged infringing product.
Some courts had previously read article 8(1) of the Judicial Interpretation 2016 as meaning that if a technical feature contains both the function or effect and the structural limitation for performing the function or effect, it can be presumed that the technical feature is not a means-plus-function feature.
The Supreme Court, however, seemingly rejected such a presumption in the above case by maintaining the requirement of “a person skilled in the art can directly and explicitly determine the specific embodiment(s) for performing the function or effect by reading purely the claims”.
Article 8(2) of the Judicial Interpretation 2016 reads: “Where, as compared to the indispensable technical features recorded in the description and its appended drawings for performing the function or effect, the corresponding technical features of the accused infringing technical solution perform the same function in substantially the same way to achieve the same result, and can be contemplated without creative work by a person skilled in the art at the time of the accused infringement, the People’s Court shall determine that the corresponding technical features are identical with or equivalent to the means-plus-function feature.”
Article 17 of the Several Provisions of the Supreme People’s Court on Issues Relating to the Application of Law to Adjudication of Cases of Patent Disputes of 2001 has already provided that the general test for the doctrine of equivalents (DOE) is “substantial triple-identity” plus “no creative work”, ie, “an equivalent feature refers to the feature which performs substantially the same function in substantially the same way to achieve substantially the same result as the feature recited in the claim, and which can be contemplated by a person skilled in the art without creative work”.
"The courts in China have applied somewhat different criteria as to what constitutes a means-plusfunction feature, as well as how to define its protection scope."
Clearly, a means-plus-function feature defines a much narrower protection scope than that conferred by a normal structural or process feature.
In the above case, while holding that the worm transmission system of the alleged infringing product is equivalent to the sprocket transmission system in claim 1, the court articulated that the application of the DOE to a means-plus-function feature under article 8 of the Judicial Interpretation 2016 differs from that to a normal technical feature under article 17 of the Judicial Interpretation 2001 in two aspects.
First, the basis of comparison with the alleged infringing product is the “indispensable technical feature(s)” recorded in the description and its appended drawings for performing the function or effect of the means-plus-function feature instead of the technical feature itself recited in the claim. Second, the compared features shall perform “the same function” to achieve “the same result”.
Generally speaking, China discourages the use of the means-plus-function feature in claims, which means a much narrower and more literal reading of the patent claims. Notwithstanding the stricter “same function” and “same result” requirements, the Judicial Interpretation 2016 provides—and the above case shows—that the “substantially the same way” prong of the triple-identity test for a means-plus-function is assessed as compared to the indispensable technical features in the description and its appended drawings for performing the function or effect recited in the claim.
This seemingly further narrows the application of the DOE to a means-plus-function feature since the “equivalent embodiment(s)” is removed from the Judicial Interpretation 2009 definition.
Xiaojun Guo is a patent attorney at CCPIT Patent and Trademark Law Office. He has extensive experience in prosecuting patent applications for inventions, utility models and designs, and in patent litigation. He can be contacted at: email@example.com
CCPIT, patent claims, Supreme Court of China, invention, art, infringement, DOE, utility model patent, technical feature, rail, mean-plus-function feature