A patent's duration is fairly standard in Japan: 20 years
from the filing date. (For a PCT international application that
enters the national phase in Japan, that is 20 years from the
international filing date.) Sometimes, though, an applicant
might not be able to work the invention right away and want to
extend the expiration date of the patent. What then?
(When) can I extend my patent's duration?
Unlike with the USPTO, the JPO does not automatically give an
extension based on delays in the examination process. However, the
Japanese Patent Act allows for an extension if there is a period
when the patented invention cannot be worked by means of producing,
using and assigning the invention of a product, due to specific
regulative delays caused by other laws (Article 67 [2]). A Japanese
patent attorney can request to extend the expiration date of a
patent up to 5 years.
