On April 11, 2000, the Supreme Court rendeded a judgment affirming a Tokyo
High Court judgment that had found the patent in suit invalid in an infringement
case.
Originally, the complaint was filed by Fujitsu against TI seeking a declaratory
judgment of non-infringement. At the first instance, the Tokyo District
Court found no infringement because an element recited in the claim was
missing in the accused device. The appellate court, that is, the Tokyo
High Court, found no infringement, either, but on different grounds. After
it said that another element was missing in the accused device, it added
that TI could not enforce the patent against Fujitsu because it was invalid.
In the appeal filed by TI, the Supreme Court ruled that a court deciding
the question of patent infringement may find the patent in suit invalid
even if there is no decision by the Patent Office invalidating it.
Under the Japanese Patent Law, only the Patent Office has authority to
declare a patent invalid, and an accused infringer believing that the patent
in suit is invalid usually files a petition for invalidation with it. When
such a petition is filed, the court deciding the question of infringement
may stay the prceedings at its discretion. In the past, it was the practice
that the defendant should not directly use the invalidity defense before
the court.
However, the Supreme Court ruled that a party that was interested only
in defending him/herself, but not in absolutely invalidating the patent,
should be allowed to raise the question of invalidity before the court
without filing a petition for invalidation with the Patent Office. When
such a question is raised, the court must examine whether there is a clear
reason why the patent should be invalidated. If it is convinced that any
reasonable appeal board examiner of the Patent Office should find it invalid,
it may dismiss the patentee's claim based on the doctrine of abuse of right.
After this ruling by the Supreme Court, lower courts are quite positive
in taking up the question of invalidity in infringement cases. Because
of this new trend, the author expects that claim interpretation by the
courts will be more and more liberal. The Japanese courts' narrow claim
interpretations that foreign practitioners criticized much in the past
were largely a result of avoiding declaring them invalid.