Patent Japan

Friday, August 18, 2006

From Archives - Doctrine of Equivalents - "Ball Spline Case"

On February 24, 1998, the Supreme Court ruled on the doctrine of equivalents.
This case was the first major decision by the Supreme Court, and is still a leading case, on this issue.

Case No. 1083, 1994 (o)
Judgment by the Third Panel, Supreme Court

Summary of the Judgment
In determining whether an allegedly infringing product falls within the scope of the patent, its scope must be determined based on the claims. If there are different technical features in the claims from the product, said product cannot be regarded as falling within the scope of the patent.
However, even if there are different technical features in the claims from the product, if (a) this different part is not essential for the patented invention, (b) the purpose of the patented invention could be achieved by replacing this part with the one in said product, and an identical function and effect could be obtained, (c) a person skilled in the art could have easily come up with the idea of such replacement at the time of the manufacturing of the product, (d) the product did not belong to the public domain, or could have been easily conceived by a skilled person, at the time of the filing of the patent, and (e) there were no other special circumstances such as the fact that the product had been intentionally excluded from the scope of the claims during the patent application process, then, said product should be regarded to fall within the scope of the claims. 
This is because (1) considering that it is extremely difficult to foresee all variants of infringements which might occur in the future and formulate claims so as to cover them, if a third party could easily avoid infringement by replacing a part of the patented claim by what came to be known after the filing, it would seriously reduce the incentive for invention in the society at large, which is not only against the purposes of Patent Law, i.e. the promotion of industrial development through the protection and encouragement of inventions, but is also against social justice and fairness. (2) Taking this into account, the substantive value of the patented invention should extend to the technology which a third party could easily conceive as substantially the same invention, and he should be expected to foresee this. (3) On the other hand, concerning the technologies which were in the public domain or which a person skilled in the art could have easily conceived at the time of the filing, they could not be regarded to fall within the scope of the patent, since no one could have obtained a patent for them. (4) Furthermore, when the patent holder had once admitted or he had objectively behaved during patent prosecution, e.g. by intentionally excluding it from the patent, that a technology did not belong to the scope of the patent, the he could not entitled to claim otherwise afterwards due to the doctrine of estoppel.

0 Comments:

Post a Comment

<< Home