The following is the information about invalidation procedures in Japan:

(1) An invalidation request may be made by interested parties anytime after completion (i.e., after three weeks – one month from the payment) of payment of the registration fee of a patent (even after expiration of the patent term).

(2) The decisions are made by three examiners at the Japanese Patent Office.

(3) Both parties are involved as adversaries during the procedure.

(4) The name of the requestor is disclosed.

(5) The invalidation procedure is based on submitted documents, however, oral testimony is also possible.

(6) First, the requestor files an invalidation request. Then, the patentee files a written reply. Thereafter, the requestor files a response to the patentee’s reply.

(7) The requestor may submit prior art references that have he or she has found.

(8) The Official fee for filing a request for invalidation is calculated as 49,500 yen + (5,500 yen per claim).

(9) The patentee may file a correction and narrow the scope of claims if the patentee believes the patent will be invalidated.

(10) The requestor may withdraw the request and terminate the process.

(11) The requestor may appeal the decision to the Tokyo High Court if the patent is determined to be valid. The patentee may appeal the decision to the Tokyo High Court if the patent is determined to be invalid.

This table shows the differences: