A product-by-process (PBP) claim (scope of claim) generally refers to a claim in which the manufacturing method for the invention of a product is described. In the Patent Act, the subject of an invention is stipulated as being an invention of a product, an invention of a method, or an invention of a manufacturing method, but a PBP claim is an invention of a product. For example, Product B (a semiconductor device heat-treated in a nitrogen atmosphere at 200°C to 300°C) is formed through Manufacturing Method A.
On June 5, 2015, the Supreme Court handed down two important decisions regarding PBP claims.
One is about the technical scope of PBP claims, where the Supreme Court stated that “it is reasonable to understand that the technical scope of the patented invention is determined to be the same in structure, characteristics, etc. as a product manufactured through the manufacturing method.” In short, this means that although the manufacturing method may be different, the alleged infringing product is included in the PBP claim if it has the same structure (what we call identity theory).
The other is related to the patentability (validity) of PBP claims. Because the relationship between the description of the manufacturing method and the structure and characteristics of the product is unclear if the PBP claims contain a description of the manufacturing method, regardless of whether for the invention of a product, in order for the PBP claims for the clarity requirement (Article 36.6(2) of the Patent Act) to be patentable (valid), it was ruled true “only when it is impossible or not practicable to directly identify the product by its structure or properties at the time of filing.” That is, the Supreme Court ruled that PBP claims are not patentable (are invalid) in principle, and on top of that, are only patentable (valid) exceptionally when it is impossible or not practicable to directly identify the product by its structure or properties at the time of filing.
However, the IP High Court decision on December 21, 2017 ruled that the validity of PBP claims was as follows.
“Even if the manufacturing method of the product is described in the scope of claims, unlike the general case above, if it is unambiguously clear from the scope of claims, specifications, descriptions in the drawings and common technical knowledge what kind of structure or characteristic of the product the manufacturing method depicts, the interests of a third party will not be unduly harmed, so it does not constitute a violation of the clarity requirement.” (underlines added)
In addition, in this specific application, it was ruled that “it is reasonable to understand that the statement ‘polished by friction-type milling’ in the scope of patent claim 1 after the correction of this Matter means friction-type milling is used when producing polished rice having the structure or characteristics in the above-mentioned C(a) and (b), which is the previous stage for pre-washed rice (musenmai) according to the Invention, and the description ‘with a musenmai machine (21)’ means a musenmai machine is used when producing musenmai having the structure or characteristics in the above-mentioned C(c) from the polished rice above, and other than the above-mentioned C(a) to (c), does not depict the structure or characteristics of musenmai according to the Invention.
In the case of the musenmai according to the Invention, everything from the surface layer of the brown rice grain to the aleurone cell layer is removed, the semi-aleurone cell layer is exposed on the surface of the rice grain, and the ‘embryo with its surface scraped off’ or ‘germinal disk’ remains on 50% or more of the rice grain, and can be said to be rice where the surface bran (hadanuka) attached to the surface of the rice grain has been separated and removed while the aleurone granules in the aleurone cell layer have been bonded to the rice surface (maihada).
Then, even if the manufacturing methods “polished by friction-type milling” and “in a musenmai machine (21)” are described in claim 1, it is unambiguously clear from the descriptions in the scope of claims and specifications what kind of structure or characteristic of the musenmai according to the Invention is being depicted. Accordingly, the description above in claim 1 cannot be said to violate the clarity requirement.”
The Supreme Court decision above regarding the validity of PBP claims (the latter) is that the PBP claims are, in principle, non-patentable (invalid), which is equivalent to saying that PBP claims are virtually useless as patents.
However, the above-mentioned IP High Court decision ruled that it does not violate the clarity requirement if it is unambiguously clear from the scope of claims, specifications, descriptions in the drawings and common technical knowledge what kind of structure or characteristic of the product the manufacturing method depicts, and left a way for the patentability (validity) of PBP claims.
It is unpredictable how decisions will be further judged by the Supreme Court, but it is of great interest in that it puts the patentability (validity) of PBP claims in a positive light.