Supreme Court decision in Case No. 2020 Hu 11059 (Patent Scope Confirmation, January 28, 2021) is related to the interpretation of the scope of patent rights of product-by-process claims. The substance of the decision is as follows.

The invention of a claim whose subject is a product and includes the description of a process of manufacture (“product-by-process claim”) is regarded as a product invention, even if the claim describes the process. The claimed subject matter is not the process, but the product itself obtained at the end.

Since a product claim should specify product features, the method recited in a product-by-process claim is merely one way to identify the structure or properties of the claimed product. Thus, the scope of a product-by-process claim should be determined by the construction, properties, or the like specified by the process, not by the process itself.

The patented invention relates to a tablet prepared by direct compression, comprising polaprezinc as an active ingredient, having a particle size where the 90th percentile of maximum particle size (that is, d90) in a particle size cumulative distribution is less than or equal to 500μm.’ The defendant filed a scope confirmation trial against the patentee. The Intellectual Property Trial and Appeal Board rendered a decision in favor of the demandant, finding that the demandant’s invention in question neither includes ‘direct compression’ nor its equivalent. The patentee was dissatisfied with the decision and filed for a revocation of the administrative decision.

The patented and the demandant/defendant’s inventions are identical in that both are tablets, including polaprezinc, where d90 is less than or equal to 500μm, as an active ingredient. They are different merely in terms of the process: a direct compression and a wet process. In the revocation action, both parties argued over whether the processes were different, whether the claim was limited to direct compression, and whether the wet process was consciously excluded from the claim.

The Patent Court found that, considering the descriptions in the specification and other exhibits, the patented invention is a ‘tablet that is characterized by the structure, properties, and the like prepared by a direct compression and by including polaprezinc as an active ingredient, having a particle size where the 90th percentile of a maximum particle size (that is, d90) in a particle size cumulative distribution being less than or equal to 500μm.’ Accordingly, the Court held that the patented invention and the defendant’s invention are distinguished; thus, literal infringement is not established.

In particular, the Patent Court stated that: in view of the known art, the unique solution of the patented invention is ‘to improve storage stability of the tablet, etc. by the preparation through a direct compression by adjusting the particle size cumulative distribution (d90) of the polaprezinc which is an active ingredient to be less or equal to 500μm,’ whereas the defendant’s invention ‘improves storage stability of the tablet by limiting polaprezinc which is an active ingredient such that the particle size cumulative distribution (d90) is less than or equal to 500μm by preparation through a wet process,’; both inventions have different essentials of the technical ideas, and thus their problem-solving principles are different from each other; there are differences in the characteristics of the tablets in terms of uniformity, disintegration time, fluidity, hardness, amount of related substances generated, etc.; as such, the effects of the inventions are substantially different; and they are not in an equivalent relation; and thus, infringement by equivalents is not established.

Therefore, the Court held that the defendant’s invention does not fall within the scope of the patented invention.

The Supreme Court upheld the Patent Court decision.

Before the Supreme Court en banc decision in Case No. 2011 Hu 927 (January 22, 2015), the courts looked into whether or not there were exceptional circumstances where a process can only define the product. If there were no such exceptional circumstances in determining the inventiveness of a product-by-process claim, the courts considered only the stated product features without considering the recited process.

However, ambiguities were noted in determining such exceptional circumstances. Further, the applicant included a product-by-process claim, whereas the Patent Act only allows product claims and method claims. Thus, it is reasonable to construe that the product-by-process claim includes the structure, properties, and the like specified by the process regardless of whether or not the product could be specified without the process descriptions.

The 2020 Hu 11059 Supreme Court decision confirms again that ‘in determining whether an accused product falls within the scope of a product-by-process claim, a patented invention should be construed to include the technical features of a product including the structure, properties, and the like specified by the process, without limiting the scope to the recited process itself.’