The Smith-Leahy America Invents Act, otherwise known as the patent reform act, changes the U.S. patent system from first-to-invent to first-to-file. What does this mean?

The short answer is that there are two changes:

1. More things are prior art to patents under the new law.
2. There are no interferences under the new law.

To see how this happens, let's look first at how the current law works in terms of prior art, and then look at the new law.

Introduction: How Patents Are Filed

The law assumes a standard pattern for obtaining a patent: first, the inventor comes up with the invention, and then the inventor files a patent application, which is examined and possibly granted as a patent.

• At t_invent, the inventor comes up with the invention.
• At t_file, the inventor files a patent application, where t_invent ≤ t_file.

These two times may be months or even years apart.

Prior Art Under the Current Law

Prior art is anything that teaches some or all of the relevant features of a patent, and predates the filing date of the patent in certain ways. Patents are invalid if the prior art teaches or renders obvious all of the relevant features of the patented invention.

Prior art can be patents, patent publications, printed publications, websites, actually used products, and many other things, and the type of item can affect whether or not it is prior art under the law. For simplicity's sake, we will just consider patents and printed publications here.

Under Section 102 of the current patent law, there are three basic ways that a patent or printed publication can be prior art, depending on the date of the document. Let's say that a particular document was made public at t_priorart. Furthermore, if the document is a patent, say it was filed at t_{file-priorart}.

• The document was published before the inventor came up with the invention, t_priorart < t_invent.
• The document was published more than a year before the patent was filed, t_priorart < t_file – 1 year.
• The document is a patent that was filed before the inventor came up with the invention, t_{file-priorart} < t_invent.

Under this system, there are many documents that predate the filing of a patent but are nevertheless not prior art to that patent. For example, if a document was published six months before a patent was filed, but the inventor on the patent came up with the invention nine months before filing, then the document is not prior art.

Prior Art Under the New Law

Under the new law, the date when the inventor came up with the invention becomes mostly irrelevant. Generally there are two ways that a document can be prior art according to the new law:

• The document was published before the patent was filed, t_priorart < t_file.
• The document is a patent that was filed before the inventor came up with the invention, t_{file-priorart} < t_file.

Because we know that t_invent ≤ t_file, it is trivial to prove that practically everything that was prior art under the old law is still prior art under the new law, and that some things are prior art under the new law that were not prior art under the old law. In the example given in the last section, the six-months-prior reference would be prior art under the new law. Thus, the new patent law enlarges the set of prior art for affected patents.

The End of Interferences

An interference occurs under the current law when two inventors file patent applications on the same invention. When this happens, a special patent court decides, generally speaking, which inventor came up with the invention first.

But you might ask, wouldn't one of the patents be invalid simply because the other one is prior art? The answer is no, because under the current law, two patents can cover the same invention, with neither being prior art to the other.

Consider the following situation: two inventors come up with the same invention in January 2005. One files a patent application (App 1) in February 2005, the other files a patent application (App 2) in March 2005. Both patent applications are published some time in 2007.

Is App 2 prior art to App 1? Let's apply our three tests from above:

• Was App 2 published before the inventor came up with the invention of App 1? No. 2007 !< January 2005.
• Was App 2 published more than a year before App 1 was filed? No. 2007 !< February 2005 – 1 year.
• Was App 2 filed before the inventor came up with the invention of App 1? No. March 2005 !< January 2005.

Similarly, App 1 is not prior art to App 2. Thus, neither patent is invalid due to prior art. Since there should not be two patents for the same invention, an additional restriction on patents is required, namely that the first to come up with the invention (usually) wins. Thus, the interference is required to decide the question.

Under the new law, though, it is clear that App 1 is prior art to App 2. Thus, App 2 is invalid simply for prior art, and no interference is required.

Conclusion, and Disclaimer

Based on the above, I think that the overall result of the first-to-file system will be that it will be harder to obtain a patent. Prior art is the most substantial way of rejecting a patent application or invalidating a patent, so increasing the amount of prior art will put up more roadblocks to patents. True, the elimination of interference proceedings removes one avenue for invalidating patents. But interferences are rare, because they only occur when two patent applications are filed that both cover the same invention.

If you were hoping to invalidate patents by filing your own applications to provoke an interference, then under the new law you take a much simpler approach: file applications or publish your inventions early, because they will be prior art to any subsequently-filed patents.

Note that the above is just a quick analysis from a simplified reading of the relevant law. There are many nuances not reflected above. There are likely also mistakes (if you find any, please email me). If you have questions about your particular facts, you should hire and consult an attorney.