Can prior art invalidate existing patents?


Let's imagine a patent has been issued by the USPTO in 2008. However, in 2010, someone discovers the invention has already been mentioned in a book in 2005. For the sake of the argument, let's assume there is no doubt the invention is covered by prior art in 2005.

In other words, the USPTO and everyone missed the 2005 prior art, and the patent has been issued although it would not have been issued if the USPTO had been informed.

My questions are:

i) Can prior art invalidate existing patents (i.e., after they have been delivered)?

ii) If yes, how is the patent invalidated? Does one have to go to court? Is there a procedure at the USPTO?

iii) How is this impacted by the recent patent reform act of 2011? Is there a delay after which the patent cannot be invalidated by prior art?



asked Oct 8 '11 at 21:39
J Verstry
152 points

2 Answers


It's not uncommon for the USPTO to issue patents in areas where there is prior art or where a patent should not actually be issued. From my understanding there searches are not as exhaustive as you may think.

They would essentially have a patent on it, if they went to enforce their patent on another company then that company would use legal representation to prove that their patent is indeed not valid. Or at least the aspect invalidated by the 2005 stuff.

I don't know all the interpretations of the 2011 reform act. The 'first to file' aspect to me is confusing. What if I invented something but had no interest in patenting it because I thought the world deserved it and would be fine with others making it. Yet someone else then made and filed a patent for it. I've only casually seen the language for this (I'm not a lawyer) but the first to file seems a bit odd. And based on the language it seems that the inventor who didn't file would lose out. Which seems ridiculous. Has to be more to this then my understanding, because this seems to be taking the already broken patent system in the wrong direction.

answered Oct 8 '11 at 22:44
Ryan Doom
5,472 points
  • Thanks for your feedback. I came across the supplementary examination guidelines, following the 2011 reform act. It provides clarifications for this issue. – J Verstry 12 years ago


I am no lawyer, but I just came across the Supplementary Examination Guidelines.

The DATES paragraph on page 7163 says:

These guidelines and supplemental examination information apply to all
applications filed before, on or after the effective date of February
9, 2011.

Paragraph III on page 7172 says:

(...) if the prior art discloses a device that can inherently perform
the claimed function, a rejection under ยง 102 or 103 may be

So, it seems that the answer to my main question is yes. Of course, these are only guidelines for the USPTO in its reviewing process.
answered Nov 2 '11 at 03:15
J Verstry
152 points
  • if the idea mentioned in a book but didn't patented, and later on another company "take advantage of" the idea by commercializing it. then there is no way for the book author to sue the company, correct? – Tom 12 years ago
  • The way I read it (and I am not a lawyer): not on patent grounds. However, code can be protected by copyrights... If it is not released with a proper license, it could be tricky... Only a professional would provide a definitive answer. – J Verstry 12 years ago
  • An "idea" isn't patentable. To be patentable, the "idea" must be embodied. That is, you have to find a source which explains how to "do" the thing -- that's what is covered by the patent, not the "idea". The other thing is that an "idea" can't have any missing parts. The "wristwatch phone" from Dick Tracy isn't patentable since the microelectronics didn't exist then. A while back I was on a team that produced about 3 dozen applications. We had to be careful in our filings because some of the applications depended on others, and those applications had to be filed first. – Julie In Austin 11 years ago

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