Patents 101: How to figure out if a patent has expired – Part I

So you’ve got a U.S. patent in your hands, and you’d like to know if it has already expired. You may have heard that U.S. patents have a 17 or 20 year term. Not sure which is correct? Well, the answer is – it depends. You need to know the earliest filing date to know which term applies.

But first things first. It’s always a good idea to consult with an experienced patent attorney or patent agent if you want to be sure of a patent’s status.

Also, this part of the article is focused on U.S. utility patents. I’ll touch on design patents in a future part of this article.

How do you know if the patent that you’re looking at is a U.S. utility patent? Well, the top of the first page should look something like this:

patent header

Note that it says “Patent” and not “Application Publication.” If your document says “Application Publication,” then it’s not an issued patent. It’s just a published copy of a patent application that may or may not have issued as a patent.

Also note that the number is only preceded by a US. If you patent number starts with a D, P, or RE, then you have a design, plant, or reissue patent, and this article will not apply. (Well, for the reissue it may be very similar, but consult an attorney or agent to be sure.)

Once you’re confident that you are looking at a U.S. utility patent, here are some steps you can follow to help you determine whether the patent is expired or still enforceable.

1. Determine the Earliest Filing Date

Again, sounds simple, right? Well, again: it can be rather complicated. But here are some basics that should get you through most cases.

The face of the patent will show a filing date. However, that’s not the whole story. You will also need to look at the first page of the patent for any mention of related applications and/or PCT applications. If you find information about related applications and/or PCT applications, then you should take into consideration the filing dates of these related/PCT applications as well.

For example, here is a portion of the face of an issued patent that has a related application:

related application

The blue rectangle indicates the date that the application itself was filed. However, there is a related application, as noted in the red rectangle, so that needs to also be considered. In this case, the patent’s application was filed on Aug. 6, 2009, but the related application was filed earlier on September 8, 2006. So the September 8, 2006 date is the earliest filing date.

Here’s an example with a PCT in the application’s history:

PCT application

The above example has several dates being shown. There’s a PCT Filed date of Jan. 14, 2008 (blue rectangle). There’s also a 371 date of Nov. 13, 2009 (red rectangle). Without going into an explanation of the what’s and how’s of PCT’s, just know that it’s the PCT filing date that matters here.

You may also be wondering about the Foreign Application in the green rectangle. In short – you can ignore it when you’re determining a patent’s expiration date.

You can also ignore related applications that are “provisional” applications, such as in the blue rectangle in the example shown below:

provisional application

In the example above, you can see the application’s filing date of March 18, 2011 (red rectangle). You can also see that there are several related U.S. applications (green and blue rectangles) this time. There are three continuation-type related applications (green rectangle), and two provisional applications (blue rectangle).

In short, ignore the provisionals and look for the earliest continuation (or divisional or continuation-in-part) in the list. Here, the earliest filing date is March 17, 2004.

In summary…

The earliest filing date is the earliest of (1) the date the application was filed, (2) the PCT filing date, and (3) the date a related U.S. continuation, division, or continuation-in-part type of related application was filed.

Ignore filing dates of related provisional applications and foreign applications.

Next Steps

Once you’re confident that you have established the earliest filing date, you can figure out whether your patent has a 17 or 20 year term, and in the latter case, when the 20 year term will come to an end.

But that’s only the beginning of the story….

You’ll also need to take into consideration several other issues, such as whether maintenance fees have been paid, and whether there is a terminal disclaimer or patent term extension. And then there’s also the issue of whether the patent’s been the subject of litigation, re-examination, etc. I’ll explain how you can work through at least some of these issues in Part II.


Be Sociable, Share!
This entry was posted in Patents 101 and tagged , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *