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February 8, 2019

Patent News

The Intellectual Property High Court ("the IP High Court") holds that the clarity requirement is satisfied for amended claims of a patent (the IP High Court's judgment of September 6, 2018 (Case No. 2017 (gyo-ke) 10210)), which was previously found not to satisfy the clarity requirement by the IP High Court.

In the first appeal case, the IP High Court held that a patent concerned did not satisfy the clarity requirement and thus invalid because a term used in the claims of the patent was ambiguous and thus unclear. The patentee removed the harmful description in the specification of the patent that could lead to ambiguity of the term concerned, and held that the patent satisfies the clarity requirement in the second appeal case.



1. Background

(1) The patent concerned in this case is Japanese Registered Patent No. 5403850 entitled "refreshing composition for ophthalmology" ("the Patent"). The claims of the Patent required "chondroitin sulfate or its salts of average molecular weight ("the average MW") of 5,000 ~ 40,000" (later amended into "chondroitin sulfate or its salts of average MW of 20,000 ~ 40,000" by the Amendment (defined below). The main issue in this case was whether the term "average MW" of the claims of the Patent was clear and satisfied the clarity requirement under Article 36, paragraph (6), item (ii) of the Patent Act.

(2) An individual (demandant) filed a request for invalidation trial against the Patent with the JPO on February 5, 2015 (Invalidation trial No. 2015-800023). In the decision of December 1, 2015, the JPO found that the Patent had not been granted in violation of the clarity requirement, the enablement requirement, etc., and rejected the demandant's request ("the JPO's First Decision"). The demandant filed a lawsuit to the IP High Court for rescinding the JPO's First Decision.

The Plaintiff sought damages totaling 4.724 million JPY: 2.724 million JPY as the profit obtained by selling the Defendant's Products, 2 million JPY as attorney fees.

As discussed below in Section 2 (1), in the judgment of January 18, 2017, the IP High Court found that the term "average MW" was not clear and thus the Patent had been granted in violation of the clarity requirement, and rescinded the JPO's First Decision (the IP High Court's judgment of January 18, 2017 (Case No. 2016 (gyo-ke) 10005), "the First Judgment").

After the finalization of the First Judgment whereby the JPO's First Decision was rescinded, this case was brought back to the invalidation trial before the JPO.

During the invalidation trial, the patentee filed a written request for amendment for the Patent on September 4, 2017 ("the Amendment") and amended the claims and the specification of the Patent. More specifically, the patentee limited the term "chondroitin sulfate or its salts of average MW of 5,000 ~ 40,000" into "chondroitin sulfate or its salts of average MW of 20,000 ~ 40,000" and deleted the statement in the specification of the Patent concerning Maruha's sodium chondroitin sulfate (for details, see Section 2(1)).

In the decision of October 11, 2017, while the JPO approved the Amendment, the JPO held that the term "average MW" in the amended claims of the Patent still remained unclear, and found that the Patent as amended did not satisfy the clarity requirement ("the JPO's Second Decision"). The patentee filed a lawsuit to the IP High Court for rescinding the JPO's Second Decision.

The IP High Court then held that the term "average MW" was not unclear and the amended claims of the Patent satisfied the clarity requirement, and thus, rescinded the JPO's Second Decision ("the Second Judgment").

2. The First Judgment

(1) In the First Judgment, for the reasons summarized below, the IP High Court held that it could not be reasonably understood whether the term "average MW" of the claims of the Patent meant "weight-average molecular weight" ("the weight-average MW") or "viscosity-average molecular weight" ("the viscosity-average MW") and thus the claims of the Patent did not satisfy the clarity requirement.

First, the specification of the Patent disclosed the average MW of polymers such as hydroxyethyl cellulose and methyl cellulose, and the IP High Court found that these MW could be considered "weight-average MW".

On the other hand, the specification of the Patent also stated that "sodium chondroitin sulfate and its salts, etc. sold by Maruha Corporation (average MW of approximately 7,000 etc.) can be utilized". Concerning this statement about chondroitin sulfate, it was held in the First Judgment that the average MW of the sodium chondroitin sulfate sold by Maruha Corporation ("Maruha") at the application date of the Patent was approximately 20,000 ~ 25,000 in weight-average MW and approximately 6,000 ~ 10,000 in viscosity-average MW and thus the average MW of the sodium chondroitin sulfate of Maruha disclosed in the specification of the Patent could be considered to be "viscosity-average MW".

In addition, in the First Judgment, it was indicated (1) that Maruha was one of the two companies which monopolized the manufacture and sale of sodium chondroitin sulfate, and Maruha measured only the viscosity-average MW of the sodium chondroitin sulfate when contacted by users, and (2) that there were articles showing that the weight-average MW of Maruha's sodium chondroitin sulfate was approximately 20,000 ~ 25,000, which was apparently different from the statement "sodium chondroitin sulfate and its salts, etc. sold by Maruha Corporation (average MW of approximately 7,000 etc.) can be utilized" in the specification of the Patent.

For these reasons, it was held in the First Judgment that a person skilled in the art would have understood that the "average MW" of "sodium chondroitin sulfate (average MW of approximately 7,000, etc.)" in the specification of the Patent possibly indicated "viscosity-average MW" and he would have been doubtful that the "average MW" of chondroitin sulfate or its salts" claimed in the Patent meant "weight-average MW".

Consequently, the IP High Court found that the meaning of the term "average MW" of the claims of the Patent was unclear, and concluded that the Patent had been granted in violation of the clarity requirement and thus should be invalidated.

3. The Second Judgmentt

(1) First, the IP High Court noted that the purpose of the clarity requirement under Article 36, paragraph (6), item (ii) of the Patent Act and criterion on assessing the clarity requirement.
  • "Article 36, paragraph (6), item (ii) (of the Patent Act) provides that an invention for which a patent is sought must be clear. If the invention described in a patent claim is not clear, the technical scope of the patented invention will not be clear, and this can harm a third party's interest such as predictability on the extent to which the right holder has the exclusive right. The purpose of said item is to prevent such an undesirable consequence. Thus, whether an invention for which a patent is sought should be assessed from the viewpoint of whether the description of a patent claim is so unclear that a third party's interest is harmed by considering the description of the patent claim as well as the description of the specification and the drawings which are attached to the application request and based on common technical knowledge of a person skilled in the art at the time of the application."


(2) Based on the above criterion, in the Second Judgment, the IP High Court held that although there was no express statement in the amended specification of the Patent showing whether the term "average MW" of the amended claim meant "weight-average MW" or "viscosity-average MW", it could be reasonably understood based on the amended specification of the Patent and the common technical knowledge that the term "average MW" meant "weight-average MW". Thus, contrary to the First Judgment, the IP High Court concluded that the amended claim of the Patent satisfied the clarity requirement.
  • "...It is stated in the amended specification that '... for example, sodium chondroitin sulfate sold by Seikagaku Kougyo K.K. (the average MW of approximately 10,000, the average MW of approximately 20,000, the average MW of approximately 40,000, etc.) can be utilized' (paragraph [0021] (of the amended specification of the Patent))
    Regarding 'sodium chondroitin sulfate sold by Seikagaku Kougyo K.K. (the average MW of approximately 10,000, the average MW of approximately 20,000, the average MW of approximately 40,000, etc.)' above, as of the application date, Seikagaku Kogyo K.K. provided the value of the weight-average MW as the average MW of sodium chondroitin sulfate of that company, and the value that was publicly known by a person skilled in the art as the average MW of sodium chondroitin sulfate of that company was the value of the weight-average MW. ...Considering this, it can be reasonably understood that the 'average MW' is the weight-average MW. Thus, the average MW of 'chondroitin sulfate or its salts of average MW of 20,000 ~ 40,000' of the claim after the Amendment can be presumed to mean the weight-average MW. In addition, the fact that (1) the average MW of other polymers ... disclosed in the amended specification can be reasonably understood to be weight-average MW... and that (2) it was common technical knowledge at the application date that the average MW of polymers were generally described with the weight-average MW can sufficiently support the above conclusion that the average MW of 'chondroitin sulfate or its salts of average MW of 20,000 ~ 40,000' of the claim after the Amendment indicates the weight-average MW."


4. Comments

(1) As introduced above, although the IP High Court held in the First Judgment that the patent was invalid due to violation of the clarity requirement, it held in the Second Judgment that the Patent satisfied the clarity requirement after the Amendment.

In the Second Judgment, as mentioned above, the IP High Court noted the criterion of assessing the clarity requirement, namely, "whether an invention for which a patent is sought should be assessed from the viewpoint of whether the description of a patent claim is so unclear that a third party's interest is harmed considering the description of the patent claim as well as the description of the specification and the drawings which are attached to the application request and based on common technical knowledge of a person skilled in the art at the time of the application". The same criterion was also provided in the First Judgment as well as in the IP High Court's Judgment of August 30, 2017 (Case No. 2016 (gyo-ke) 10187) ["reversible thermal discoloration aqueous ink composition" case], the IP High Court's Judgment of December 6, 2016 (Case No. 2015 (gyo-ke) 10150) ["carbonated beverage" case], etc.

(2) In the First Judgment, the IP High Court held that it was unclear whether the claimed term "average MW" indicated "weight-average MW" or "viscosity-average MW". This is because the specification of the Patent included a statement suggesting that the term "average MW" should be "viscosity-average MW" (i.e. the statement about the average MW of chondroitin sulfate of Maruha).

By the Amendment, the patentee removed the above description from the specification of the Patent and changed the range of "average MW of 5,000 ~ 40,000" of chondroitin sulfated into the range of "average MW of 20,000 ~ 40,000". It can be thought that the patentee limited the range of the average MW into "20,000 ~ 40,000" of the claim in order to make it consistent with the statement "sodium chondroitin sulfate sold by Seikagaku Kougyo K.K. (the average MW of approximately 10,000, the average MW of approximately 20,000, the average MW of approximately 40,000, etc.)" in the amended specification of the Patent which can be understood to indicate "weight-average MW". In contrast, the statement "sodium chondroitin sulfate (the average MW of approximately 7,000, etc.)" of Maruha in the specification of the Patent was removed because this statement can be considered to indicate "viscosity-average MW" but not "weight-average MW", which can lead to the conclusion that it is unclear whether the claimed term "average MW" indicated "weight-average MW" or "viscosity-average MW".

As a result of the Amendment, the IP High Court held in the Second Judgment that the claimed "average MW" could be reasonably understood to mean "weight-average MW" and that the claim of the Patent satisfied the clarity requirement.

This case is interesting in that the issue of the violation of the clarity requirement was successfully overcome by removing harmful statements in the specification of the patent, and this case can practically be of reference to a patentee who faces the issue of the violation of the clarity requirement under Article 36, paragraph (6), item (ii) of the Patent Act.

The Second Judgment (in Japanese):-
The First Judgment (in Japanese):-

Written by: Mr. Masahito Imai (Attorney at Law and Patent Attorney)