(1)       Post-grant opposition

–           The opposition can be filed against a granted patent right (“post-grant opposition”).

–           Time limit of filing of the opposition is six (6) months from the publication date of the patent gazette.

–           Any person can be the opponent but a name of opponent must be described (the opponent can be “dummy”).

(2)       Flow of the opposition

Attached herewith please find a brief flow chart of the opposition procedure.

–           Patent Proprietor can file “Argument” and/or “Request for Correction”.

–           Opponent has a chance to argue against the Patent Proprietor’s Argument and/or Request for Correction filed.

–           Final Decision of Opposition (Revocation or Maintenance of a patent right) is issued when decision is matured.

(3)       Correction

* (In the opposition procedure, a term of “Amendment” is not used but wording “Request for Correction” is used)

Correction is limited to following four purposes (a to d) only:

a          to narrow claim ranges

b          to correct errors in typing and translation

c          to correct unclear description

d          to correct dependency in claims

Corrected claims must satisfy following requirements also:

i           new matters can’t be added.

ii          correction should neither changes nor enlarges the scope of invention

iii         corrected claims must be patentable claims (novelty, inventive step)


(4)       Appeal for Invalidation or Opposition

–           “Appeal for Invalidation” can be filed independently from the “Opposition”.

There are several differences between “Appeal for Invalidation” and “Opposition”

Appeal for Invalidation

no time limit

limited to interested parties

examined by oral hearing



|time limit of 6 months from publication

anyone can file

no oral hearing (paper examination only)

–           When “Appeal for Invalidation” and “opposition” are filed at the same time, the “Appeal for Invalidation” takes precedence.

A detail of the new opposition system is explained in following web page of JPO:



Flow chart of the opposition procedure