In a case I managed, a foreign SME sued a large Japanese company for infringement in Japan based on its utility model rights. The patent applied to a health appliance, and the accused device was a similar appliance. As you’ll read, the Patent “Doctrine of Equivalents” is vitally important in all countries.
In fact, there were multiple types of accused devices. The main accused device was that with the highest sales and a clear copy of the patent (utility model). Other accused devices were also similar machines, however, they avoided the scope of the patent,
The IP right-infringement proceedings of the court in Japan consist of two stages. First is the “infringement discussion” to determine whether infringement is actually established. Second is the “damage discussion” to determine how much damage is caused by the infringement. If, as in this case, the plaintiff (patentee) does not win the “infringement discussion” in the district court, any lawsuit proceedings will end at that point. Note that in the infringement discussion stage, patent attorneys, who are proficient in patent discussions and technology will be mainly in charge – not attorneys-at-law,
However, there is one problem here that involves the “doctrine of equivalents” in Japan. Be aware that there are two types of infringement: “literal infringement” and “infringement of the doctrine of equivalents”. “Literal infringement” means that the allegedly infringing property satisfies the wording of the claim as it is: so to speak, it is a “full copy”.
Of course, there are very few such “literal infringement” cases, and in most cases the alleged infringing product is slightly different from that in the claim. In these cases, it is not possible to prosecute for literal infringement, so it is necessary to consider prosecution based on the doctrine of equivalents.
The doctrine of equivalents was officially accepted in court in Japan from a 1997 Supreme Court ruling. In the district court and the high court, there are still very few cases where the doctrine of equivalents is accepted, or used successfully. This is different from the situation of doctrine of equivalents in the United States and Europe. As a result, in Japan we think that the requirements for establishing the doctrine of equivalents are very strict compared to other countries. This has very important implications for all parties involved in Patent matters.
In this case, the main accused device was successfully judged as “literal infringement.”However, for the other devices, it proved too difficult to claim literal infringement. Therefore, we used the equivalent infringement theory, in other words, the doctrine of equivalents, in the lawsuit.
In the district court, the literal infringement was affirmed, but the infringement of the doctrine of equivalents was not. Personally, I was of the expert view that the other accused devices had the same function as the patent, and had only minor differences in composition. I had high expectations for the infringement of the doctrine of equivalents. However, our assertion did not successfully result in a breakthrough for our client.
At present, the acceptance rate of the doctrine of equivalents is about 1 out of 10 cases in Japan. The Japan Patent Office IP protection system is very rigorous and detailed examinations are typically carried out. However, at the court stage of exercising Patent rights, the patentee received a strict judgment against them.
In my view, this situation goes against the general direction of so-called Pro- Patent. As a result, the number of IP infringement suits in Japan is decreasing – which clearly underscores this problematic situation. I hope that the courts will understand the significance of the IP protection system and become a user-friendly court system that protects rights holders here in Japan.
Especially for SME’s, who are the majority of our clients, and who sometimes battle big companies with bigger resources, this change would level the playing field and increase their competitiveness. Once again, the Patent “Doctrine of Equivalents” is vitally important in all countries.
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