What's hot at the EQE online forum


US patent law for the EQE: A closer look at Section 102(b)

This post deals with some aspects of US Law and is based on how I understand it works.

Section 102(b) says that a person shall be entitled to a patent unless

"the invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States"

This section as I understand it, although it does not say so explicitly, refers to acts by both the inventors and third parties.
An important aspect of this provision is that it refers explicitly to the "date of application for patent in the United States". This date is the actual US filing date and not the priority date in case priority is claimed from a non US patent application.

A further important aspect is that the provision allows a "grace period" of one year from "disclosure" of the invention. This grace period only applies if the disclosure was done by the inventors. Note that in case of public use, this public use needs to be in the US. So, public use outside the US does not fall under the provision of 102(b).

An interesting situation arises when the invention concerns a process and where the products from this process are sold more than one year before filing of a patent application. Here is what the Federal Circuit Court of Appeals said (D.L. Auld Co. v. Chroma Graphics Corp.):

"An inventor's commercial sale of a product produced by a novel or patentable process prior to the critical date not only results in the forfeiture of patent rights to the product itself; but, also forfeits any patent rights in the underlying process. Interestingly, if the process remains secret, however, the sale will not bar another inventor from patenting that very same process."

A nice and more complete overview can be found here:

So, let's consider the following example:

Product A was made using method B for a long time. At a certain moment in time method B is improved to (patentable) method B', the improvement resulting for example in a higher yield. Product A has not changed. By disclosing (for example selling) product A made with method B' in the US a one year period is triggered for filing a patent application on method B'. If this application is filed later, no valid US patent right on method B' can be  obtained.

It becomes even more interesting if method B' is carried out outside the US. Does the same reasoning as above then still apply? Unfortunately I did not get a definitive answer on that so far. However, assuming it does apply, most probably a lot of US method patents would be invalid for the reason that these are typically filed in the US near the end of the priority year (assuming the priority application was not  filed in the US). It is very likely that the inventive process is a few months older than the priority date and that some products made with this process have already been sold. Again, the catch is that 102(b) refers to a US filing date.

To overcome this potential problem one could (or should) consider filing a US provisional application a.s.a.p. after filing of the non US priority application. Doing so will result in an "early" US filing date, which by the way will also be beneficial in view of Section 102(e). (I'll come back to this provision later)

I'm not sure if you should you know all of this for the EQE, but at least I hope it is a bit more clear how this "grace period" works......

As I mentioned above, this post is based on how I understand it works. There is probably a lot more to say, so feel free to comment ...

Print this post


  1. Thank you for your interesting post. However, I think that some of your assessments are not right.

    Firstly, it seems to me that §102b) refers to anyone's prior art or activities. That is, a publication done by anybody else 1 year prior to US filing bares patentability of the invention.

    See here:

    Second, regarding patentability of method B' when carried out outside of US 1 year before filing, according to my understanding, such a public use would not fall under §102b) since it does not take place within the US. Am I right?

    If the products are sold in the US, then I have no clue.


  2. Thanks, indeed the statutory bar under 102(b) is without regard to who was responsible for the event. Not sure what went wrong when I wrote the post, must have been late :-). Anyway, I made the correction (in grey)

  3. Hi. You say: "This grace period only applies if the disclosure was done by the inventors." How do you reach this conclusion? My understanding is that no disclosure, by anybody, in the 12 months before filing is considered prior art. Of course, if you weren't actually the first to invent, then you may be open to interference proceedings, but that's a quite different matter.


Related Posts with Thumbnails