1. Evaluation criteria for determination on clarity requirements
(An excerpt of summary of the judgment)
“Article 36, Paragraph 6, Item 2 of the Patent Act stipulates that an invention for which a patent is sought must be clear in the statement of the scope of claims. The intent of the provision of this Item is to prevent the occurrence of unfavorable results arising out of a case where a third party’s interests can be unjustly harmed due to the technical scope of an invention, for which a patent was granted, being unclear because the invention was not clearly stated in the scope of claims. Whether or not the invention for which a patent is sought is clear should be determined by taking into consideration not only the statements of the scope of claims but also the statements in the patent specification and drawings attached to the written application, and also on the basis of the common general technical knowledge of a person ordinarily skilled in the art at the time of the application, from the perspective of whether or not the aforementioned statements are unclear to the extent of unjustly harming a third party’s interests as a result.”
The foregoing judgment is established in court cases as evaluation criteria for determination on clarity requirements.
2. Determination on fulfillment of clarity requirements based on statements in the patent specification (it was concluded that clarity requirements were not fulfilled)
(An excerpt of Summary of the Judgment)
“…The patent specification does not include the definition of, or the measuring method for, the median particle size which is ‘measured by the mass’ of the tungsten carbide particle that is ‘contained’ in the ‘tool surface’ of a ‘crushing tool’ which is integrated with a cobalt binder by sintering.
From what is described above, even when the statements of the patent specification are taken into consideration, and even based on the common general technical knowledge at the time when an application for the patent was filed, it is impossible to understand the meaning of the median particle size which is ‘measured by the mass’ of the tungsten carbide particle ‘contained’ in the ‘tool surface’ of a ‘crushing tool’ ‘having the surface that contains tungsten carbide’ of the invention, and it must be said that the technical scope of the invention is unclear.”
Measuring methods for “parameter” or “numerical value” must be contained in the detailed description of the invention of the patent specification. In addition to the matter as to whether or not clarity requirements are fulfilled, there are many court cases (as listed below) involving the matter as to whether or not an alleged infringing product satisfies constituent elements of the patented invention in which the court found that it is required that parameters or numerical values of the patented invention be satisfied by any reasonable measurement methods. Some of those cases, in which the court found constituent elements of the patented invention to be satisfied based on the foregoing framework, were decided against the patent holder. In any event, there are few disadvantages in describing measuring methods of numerical values.
3. Identification of the “measuring method” based on extraneous evidence other than the patent specification (it was concluded that the measuring method could not be identified)
(An excerpt of Summary of the Judgment)
“A sedimentation method by which a stokes diameter is obtained is well known as a method of measuring the particle size, and even if particle size distribution based on a weight (mass) standard can be obtained by the sedimentation method, it is impossible to measure the storks diameter of the tungsten carbide particle by the sedimentation method as long as the tungsten carbide particle ‘contained’ in the ‘tool surface’ of a crushing tool is integrated with a cobalt binder by sintering. Therefore, it cannot be understood that the ‘median particle size which is measured by the mass of the tungsten carbide particle’ of the present invention is the median particle size of the storks diameter which is obtained based on the sedimentation method.”
As described below, there are some cases in which a parameter or numerical value described in claims could not be measured with regard to the defendant’s product in the first place, and thus it was impossible to establish that an alleged infringing product satisfies constituent elements of the patented invention; therefore, describing a “parameter” or a “numerical value” in claims that is practically difficult to measure should be avoided.
1. ① In the case where measurement results differ depending on measurement conditions for numerical value (parameter):
(1) If measurement conditions can be derived from the descriptions of the patent specification or common general knowledge at the filing date, whether an alleged infringing product falls within the technical scope of the patented invention is determined based on the measurement result according to the measurement conditions.
There are two cases in which the aforementioned point was at issue, and the court decided in favor of a patent holder:
(ii) The “absorbents for oral administration” case (the Tokyo District Court Case No. 2007 [Wa] 3493), in which the court found that the measurement conditions for diffraction intensity can be understood because measuring methods specified by JIS, the Japanese Pharmacopoeia, and the Japan Society for the Promotion of Science are in common.
(2) On the other hand, there are three cases in which the aforementioned point was at issue, and the case was decided against a patent holder because of violation of clarity requirements:
(ii) The “antiglare film” case (the IP High Court Case No. 2011 [Gyo-ke] 10418), and
(iii) the “water-based ink composition” case (the IP High Court Case No. 2016 [Gyo-ke] 10187), in which the court found that the measurement conditions cannot be derived from the descriptions of the patent specification or common general knowledge at the filing date.
(3) In addition, there are four cases in which the court found, based on measurement results submitted by an alleged infringer (the defendant), that the defendant’s product does not satisfy constituent elements of the plaintiff’s invention, stating that “the defendant’s product is not considered to infringe the plaintiff’s patent unless the defendant’s product satisfies numerical values described in claims of the plaintiff’s patent irrespective of the method adopted from among conventionally known measurement methods”:
(ii) the “maltitol crystal-containing molasses” case (the Tokyo District Court Case No. 2003 [Ne] 3746),
(iii) the “siliceous filler” case (the Tokyo District Court Case No 2011 [Wa] 6868, and
(iv) the “tissue paper” case (the IP High Court Case No. 2015 [Ne] 10016).
2. ② In the case where the technical meaning of parameter itself is ambiguous:
It is considered to constitute a violation of clarity requirements (Article 36, Paragraph 6, Item 2 of the Patent Act).
For example, in the “refreshing composition for eyes” case (the IP High Court Case No. 2016 [Gyo-ke] 10005), the court found that the patent specification violates clarity requirements because “average molecular weight” referred to in the statement of claims of the patent at issue is unclear in terms of whether it means “weight-average molecular weight” or “viscosity-average molecular weight”.
As stated above, with respect the ambiguity of parameter, there are cases where ① measurement result differs depending on measurement conditions for parameter, and where ② the technical meaning of parameter itself is ambiguous. With regard to case ①, the main issue is whether or not a plurality of conventionally known methods exist, and the plaintiff’s claims were dismissed in every case in which such methods were found to exist.
With regard to case ②, the issue is the interpretation of the term “parameter” of patent claim, therefore, it will be discussed pursuant to Article 70, Paragraphs 1 and 2 of the Patent Act as usual. In this respect, as cases ① and ② differ in allegation and matters to be proved, it is important to consider these cases without confusing the details of which with each other.
Writer: Hideki TAKAISHI
Supervising editor: Kazuhiko YOSHIDA
Contact information for inquiries: firstname.lastname@example.org
Hideki TAKAISHI (The person in charge of this article)
Attorney at Law & Patent Attorney
Nakamura & Partners
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