Can I access the documents in the file of a Japanese patent application?

Yes. Japanese file histories are available for public inspection once an application has been published. The first publication of an application normally takes place 18 months after the application date (or in cases where a priority or domestic priority is claimed, 18 months after the earliest priority date). The public can access the 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.

File histories are available via the Japanese web pages of the JPO’s free Industrial Property Digital Library (IPDL) and via the Global Dossier in the EPO’s Espacenet.