Public Disclosures, Grace Periods, and Patent Rights

Disclosing your invention to others before filing a patent application can have severe consequences, not only in the U.S. but all over the world. It is important that inventors be aware of these consequences and follow proper procedure to maintain patent rights for inventions.

What is a Public Disclosure?

A public disclosure refers to a non-confidential conveying of information pertaining to your invention, and may include both documents and activities. Some common examples of disclosures that may be considered “public” include disclosing the invention at a trade show, on a website, in a publicly accessible printed publication (e.g., advertising and marketing materials, a magazine, a brochure, etc.), in a dissertation accessible by the public (e.g., on a shelf in a library), in meetings or verbal discussions with people outside of your company without a non-disclosure agreement (e.g., a presentation), in a contest submission, and in a grant proposal (that is available to the public). Disclosing the invention in an email may also be considered a public disclosure depending on its content and recipient. A good general rule in determining whether a disclosure is public is to consider whether the disclosure itself is accessible by the public.

Why is a Public Disclosure Bad?

First, disclosing your invention, before filing a patent application, has the more obvious risk that the invention might be stolen by others. Second, in the U.S., if you publicly disclose your invention a one-year clock begins to run. If you do not file a patent application (e.g., provisional, nonprovisional, or international PCT patent application) within one year of the public disclosure, you lose your rights to the invention forever, and neither you nor anyone else can obtain a patent on the invention. Note that this same one-year clock is triggered if you publicly use your invention or offer your invention for sale. This one-year clock is known as the grace period.

The Grace Period, a World View

Unfortunately, the grace period permitted in U.S. patent practice is not followed by all other jurisdictions. For example, except for very rare situations, European countries do not provide any grace period, and thus a public disclosure bars the filing of a patent application (note that Germany may provide a six-month grace period in certain situations). China and India also do not provide a grace period, except in very rare situations.

Similar to U.S. practice, Canada offers a one-year grace period; however, the grace period is only permissible within one year before the “actual filing date” (i.e., the Canadian filing date or PCT filing date) rather than the “effective filing date” (i.e., the priority application filing date). Thus, you must file a Canadian patent application or an international PCT patent application within one year of the public disclosure to maintain your rights in Canada. This same practice is followed in South Korea.

Japan follows a similar practice to that of Canada and South Korea, but further requires the Japanese patent application to clarify, at the time of filing, that the applicant will use the grace period and submit evidence of the earliest date of public disclosure with detailed facts.

Below is a chart summarizing the grace period in some jurisdictions:

Country Grace Period Notes
U.S. 1 year The grace period is triggered if 1) the invention is publicly disclosed, 2) the invention is publicly used, or 3) the invention is offered for sale.
Canada (CA) 1 year Grace period runs from CA national utility or PCT application. The 1-year grace period runs from the priority application date for design applications.
South Korea (KR) 1 year Grace period runs from KR national or PCT application.
Japan (JP) 1 year Grace period runs from JP national or PCT application. Detailed evidence of the public disclosure must be submitted with the JP application.
China (CN) None CN may provide a 6-month grace period if the disclosure 1) is exhibited at an international exhibition recognized by the Chinese government, 2) is published at a specified conference, or 3) occurred without consent of the applicant.
India (IN) None IN may provide a 12-month grace period if the disclosure occurred 1) in a journal or an exhibition organized by the Indian government or 2) before a learned society (e.g., IEEE).
Europe (EPO) None The EPO may provide a 6-month grace period for evident abuse or international exhibitions. Germany may provide a 6-month grace period in certain situations.

Best Practices

It is always best to file a patent application before publicly disclosing your invention, and the determination of which patent application to file requires careful consideration of the global extent of protection sought, and each country’s grace period, if available. In addition or alternative to first filing a patent application, requiring the recipients of the disclosed material to sign a non-disclosure agreement may prevent the disclosure from being considered public (note that in the U.S. offering the invention for sale will still trigger the one-year clock even if the offer is made under a non-disclosure agreement). Lastly, any possible public disclosure should be analyzed from an enablement standpoint (i.e., is the disclosure sufficient to enable a person of skill in the art to make or use the invention), as a non-enabling disclosure may not be considered a public disclosure.

Please contact a member of our Intellectual Property Team if you have questions regarding a past or future disclosure, or wish to discuss a patent strategy that can best fit your needs.

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