Since 01 July 1995, it has been possible to file a patent application in English. However, a Japanese translation of the English application has to be furnished to the Japan Patent Office (JPO) within two months of application date.

Currently, the prescribed time limit for submitting a request for examination is three years from application date. For applications filed before 01 October 2001, this time period was seven years from application date. If no request for examination is filed within the prescribed period, the application is deemed to be withdrawn. 

Japanese file histories are available for public inspection once an application has been published. Usually, the first publication of an application takes place 18 months after the application date (or in case a priority or domestic priority is claimed, 18 months after the earliest priority date). The public can gain access to a file history either by doing a legal status search or by ordering a copy of the "file wrapper".  Copies of "file wrappers" can be ordered from the Japan Patent Information Organization (Japio) via the EPO in Vienna (asiainfo@epo.org). Since March 2006, file histories and the text of communications from the JPO to applicants dating from July 2003 onwards have been available via the JPO’s free “Industrial Property Digital Library (IPDL)”. The IPDL is available at http://www.ipdl.ncipi.go.jp/homepg.ipdl Please note that currently the electronic file histories can only be accessed via the Japanese page of the IPDL. An easy, step-by-step guide is available in the “Tips & tricks for searching” section: Tips& tricks for searching databases

Average patent pendency in Japan is currently between five and six years. The average time required from request to examination until the first office action is approximately 26 months. However, in recent years legislation has been passed and measures introduced to reduce patent pendency and to streamline granting procedures in Japan.

Before 1994, the term of a Japanese utility model was defined as "10 years from the date of examined publication but not in excess of 15 years from filing date". In 1994, the term of a utility model was reduced to only six years from the application date. However, a revision of the Japanese utility model law, which will be effective as of 1 April 2005, increases the term of utility models to 10 years from the application date. (The new 10-year term applies to all utility models filed on or after 1 April 2005.)

If the applicant misses the deadline for payment of the annual fees, there is a grace period for payment of six months. If the patent owner fails to renew the annual fees within this grace period, the patent right lapses. However, if the reasons for failure to make the payment are beyond the control of the patent owner, he has another six-month period from the lapse date during which he can have the lapsed patent right restored.

The opposition system was abolished on 01 January 2004 and invalidation is thus now the only means of challenging a granted patent in Japan. Invalidation procedures can be requested by anyone at any time (even after expiration of the patent term). 

 "Patent Abstract of Japan" or “PAJ” are English abstracts of Japanese unexamined patent applications. Patent Abstracts of Japan are produced by the JPO and Japio and include the bibliographic information, abstract and a representative drawing of Japanese unexamined patent publications from 1976 to date.  Due to the translation work involved, the time delay between publication of an unexamined patent application in Japan and the availability of the corresponding PAJ abstract is approximately four months.  Further information on Patent Abstracts of Japan is available at: http://patentinfo.european-patent-office.org/prod_serv/far_east/japan/index.en.php#12

You can obtain English machine-translations for Japanese patent and utility model documents from 1993 onwards on the Japan Patent Office's free-of-charge "IPDL" (Industrial Property Digital Library) internet service at http://www.ipdl.inpit.go.jp/homepg_e.ipdl. From the IPDL homepage, please choose the "Patent & Utility Model Gazette DB" link. A simple number search will - as a first search result – return the PAJ English abstract, where available. Clicking the "Detail" button on the top of the result screen will start the machine-translation of the original Japanese unexamined application. Alternatively, clicking the "Japanese" button will display the original Japanese document. In cases where no PAJ English abstracts exist you will immediately get the machine-translation from the Japanese.