Tips for filing patent applications in Japan

The purpose of this white paper is to introduce some points to keep in mind before and after filing an application in Japan. We will address the following matters: (1) before filing: patentable invention, types of claims, contents of specification and grace period (2) after filing: the scope of amendment and how to accelerate the examining procedure.

Filing a patent application

In order to be granted a Japanese patent, the claimed invention must be a statutory “invention" (Article 2(1) of the Patent Law) and must be "industrially applicable" (Article 29(1)).

Examples of non-statutory inventions are:

  • A law of nature as such (ex. a law of preservation of energy, etc.);
  • Mere discoveries and not creations (e.g. discoveries of natural things like an ore or natural phenomena, etc.);
  • Those contrary to a law of nature (e.g. the so-called perpetual motion, etc.); and
  • Those in which a law of nature is not utilized (e.g. a rule for playing a game as such, methods for doing business as such, etc.).

Examples of industrially inapplicable inventions are:

  • Methods of surgery, therapy or diagnosis of humans (including administering a drug to a human being)*;
  • An invention applied only for personal use, such as a method of smoking, etc.; and
  • Practically inapplicable inventions (Example: a method for preventing an increase in ultraviolet rays associated with the destruction of the ozone layer by covering the whole earth's surface with an ultraviolet ray-absorbing plastic film).