What It Takes To Infringe a Patent

By: Mark R. Malek

My last article discussed the permissibility of designing around a patent. To summarize, in order to design around a patent, also known as reverse engineering a patent, the product/device/method, etc., in question must not include all of the elements of just one of the claims of the patent in question.  If your product includes three of the four elements that can be found in the claims, then you should be in the clear.

Naturally, the next question comes from the perspective of the patent holder.  At this point, the patent holder may have discovered your invention that has purportedly designed around the patent.  The only issue is that the patent holder does not necessarily believe that your invention does design around the patent.  More particularly, the patent holder thinks that your invention reads on at least one of the claims in the patent.  Time to conduct an investigation.

The investigation for the patent holder is very similar to the investigation that I discussed in my previous article about designing around a patent.  In other words, the patent holder’s first step should be to create a claims chart and analyze every element of each claim to make sure that the allegedly infringing device meets all the claim limitations.   Please don’t begin to think that I am insisting that the patent holder much go through the chore of doing a claims chart – it is just that I cannot think of a better way to ensure that the patent holder is sure that the device in question actually infringes.  When analyzing the limitations of the claim, the patent holder may try to broadly interpret certain portions of the claims, i.e., the patent holder may try to give some elements of the claims a broader interpretation than would be normally provided just by looking at the English language.  This could be possible depending on the way that these terms are defined in the specification.  For example, suppose that one of the elements of the claim is that a portion of the device must have a rounded shape, but in the specification, there is a specific note that although the device is depicted as having a rounded shape, the term “rounded shape” is intended to include shapes that have rounded corners.

Prosecution history estoppel, however, is something that could prevent broader interpretations of claims, but that is a topic for another article – actually, it is a topic that can fill up several articles.  For more information on prosecution history estoppel, check out this article by Gene Quinn on IPWatchdog, which includes a discussion on the doctrine of equivalents.  A more updated article on the doctrine of equivalents can be found here.

As you can see, the analysis for the patent holder is similar.  In short, if the allegedly infringing device does not include all of the elements of at least one of the claims, then the patent holder should not go running down the path of patent infringement yet.  In another article, I will start to discuss the various options available for the patent holder once it is determined that the device in question does infringe.  In that article, I will also discuss some strategies (all opinion) for patent holders that find a device that is pretty darn close to the claims of the patent.