https://www.j-platpat.inpit.go.jp/c1801/PU/JP-4974971/15/en
Intellectual Property High Court Case No. 10026 (Ne) 2024, March 4, 2025 (Presiding Judge Miyasaka), (the Prior Instance Court: Osaka District Court Case No. 9521 (Wa) 2022)
(1) Claim 1
“A thermoplastic acrylic resin having … an ultraviolet absorber having a hydroxyphenyl triazine skeleton and a molecular weight of 700 or more”
(2) Difference from the defendant’s product
The defendant’s product has a molecular weight of “699.91848,” so it does not have a “molecular weight of 700 or more.”
(1) ① Concerning Literal Infringement(Round off theory) ⇒ not satisfied
“The numerical range of ‘700 or more’ (molecular weight of the UV absorber) at issue in this case is one that the rights holder (applicant) established to define the scope of rights, and is nothing less than a demarcation line drawn to distinguish what falls within the technical scope of the patented invention (the scope of exclusivity) from what does not. Given this, the lower limit of the above numerical range, ‘700,’ should be interpreted as an integer value in its truest sense, possessing neither rounded-up decimal fractions nor rounded-down decimal fractions. If the applicant intends to assign a different purpose or function to the numerical range, the applicant should explain in the claims or the specification the method for calculating the molecular weight or the method for treatment of decimal places. As previously stated, the specification etc., contains no such description. Therefore, the requirement of ‘molecular weight of 700 or more’ must be interpreted as not being satisfied (i.e., not falling within its technical scope) if the molecular weight falls below 700 by just 0.00001.”
(2) Doctrine of Equivalents ˗ the first requirement is satisfied; the fifth requirement is not satisfied
“The above numerical range is not of critical significance. The molecular weight that holds technical significance in relation to the effects of the present inventions is not a pinpoint value of 700, but rather a value spanning a rather wide range. Thus, it can be understood that the numerical limit of ‘700 or more’ was adopted as a sort of ‘round number’ … Furthermore, it is difficult to imagine that the properties as a UV absorber would be substantially different between a molecular weight of 699.91848 and one of 700 … Therefore, the difference in molecular weight described above cannot be considered to relate to the essential part of the inventions in question. In this case, the first requirement of the doctrine of equivalents is satisfied.”
“The appellant deliberately used the integer value ‘700 or more,’ and since the molecular weight of 700 holds no critical significance, this figure can be considered one arbitrarily selected and established by the appellant. Moreover, the appellant could easily have set the numerical range to ‘699.5 or higher’ and specified how to handle decimal places in molecular weights, yet deliberately chose not to make such provisions. This is based on the understanding that decimal places are not technically meaningful numbers, and further assumes that they have no particular legal implication (i.e., they are not assigned special meaning). In light of the foregoing, it is reasonable to conclude that by defining a numerical range of ‘700 or more’ for molecular weight in the claims, the appellant objectively and formally acknowledged that the technical scope of the patented invention is delineated by the boundary between ‘700 or more’ and ‘less than 700,’ thereby excluding from that technical scope any substance with a molecular weight even slightly below the lower limit of ‘700.’ Therefore, the fifth requirement of the doctrine of equivalents is not satisfied.”
【Note】The first instance court, Osaka District Court Decision (Case No. 9521 (Wa) 2022) denied the first requirement of the doctrine of equivalents, stating that “for an invention for which it is meaningful to set numerical values, the limitation of the technical scope by those numerical values constitutes an essential part of the patented invention, unless there are special circumstances.”
The issue was whether the defendant’s product (molecular weight 699.91848) satisfied the numerical limitation of a molecular weight “of 700 or more.” Ultimately, since the applicant “deliberately” specified an integer in “700 or more,” round off theory cannot be applied. The court denied the fifth requirement of the doctrine of equivalents, finding that the applicant objectively and formally acknowledged the exclusion from the scope of the invention.
Based on the reasoning in this judgment, would a claim stating “700.0 or more” have satisfied the requirement for 699.95 or more due to rounding?
According to the logic of this judgment, in many cases the fifth requirement would likely be denied in line with theory of numerical equality. Thus, as with previous court cases, regarding numerical values the round off theory still retains a stronger possibility for success than the doctrine of equivalents. (However, in Japan, there are no court precedents where the round off theory has been determined in favor of the patent holder.) Based on this judgment, to satisfy the fifth requirement of the doctrine of equivalents regarding numerical values, explicitly stating that the disclosure does not intend to limit the scope may be beneficial. For example, the disclosure could specify that the numerical values are merely indicative for the purpose of the enablement and support requirements, and do not constitute an active limitation.
That said, in patents that balance foreseeability by third parties, neither the round off theory nor the doctrine of equivalents can be interpreted in the same way as scientific concepts. In the end, the conclusion of this judgment may well be appropriate. (Certainly, interpreting “700 or more” as an approximate figure that includes 650 or more is unreasonable.)
Writer: Hideki TAKAISHI
Attorney at Law & Patent Attorney