Keisen Associates generally files an information disclosure (similar to the Information Disclosure Statement, or IDS, in United States patent applications) of known related prior art for Japan patent applications. This is not necessarily what all Japanese patent law firms practice, but it is the best practice for a secure patent registration.

Why is an Information Disclosure Statement (prior art disclosure) needed in Japan?

The Japan Patent Office (JPO) has implemented an information disclosure system whereby applicants have a duty to disclose prior art that is known at the time of filing a patent application (see Patent Act Art. 36 [4][ii]). However, this requirement is not widely recognized. Many applicants do not file such a disclosure, because negligence toward the duty to disclose prior art in practice has no effect on the validity of the patent.

However, important thing is to guard against potential problems (see more on this below). We therefore highly recommend that everyone involved in the preparation of the application make an information disclosure to the JPO as well.

Is my application subject to the prior art disclosure requirement?

The information disclosure requirement in Japan applies to all Japanese domestic applications and all international applications’ national phase entries.

What do I need to submit in an Japanese patent IDS?

At least one publication should be listed in the "Background" section of a patent specification. Only publications or literature is acceptable, including electronically formatted documents available on the Internet.

If an applicant has a number of prior arts documents, an applicant may disclose only the more relevant, major ones.

If a prior art is a patent publication, the following information has to be provided: its application number, publication number or patent number. For a non-patent publication, the following information is required: the name of the document, name of the author(s) and/or organization, publisher, date of publication and/or presentation, volume/issue numbers, cited page number(s), and/or URL address and online publication date.

An applicant does not need to submit the original or duplicate copies of publications unless the examiner asks for document(s) for examination purposes.

Are there risks if I do not comply with the requirement to disclose prior art?

As noted above, there are plenty of applicants that do not do full disclosure on prior art. The JPO does not impose such strict requirements as the USPTO’s standard of candor by Information Disclosure Statement (IDS). Failure to disclose a particular document will not invalidate the patent once it has been issued. In other words, negligence toward the duty has no effect on the validity of the patent right. Therefore, even if a patentee knew the existence of prior art relevant to the invention in question but did not disclose it and is discovered after the patent is issued, there is no legal effect on the issued patent.

However, the requirement remains, and failing to name relevant prior art could weaken the reliability and speed of the examination process. It thus remains our policy to ask for and include major relevant prior art documents for Japanese patent applications.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.