Completely Describe Your Invention in a Patent Application

In order for any patent application to be complete the invention must be described with great particularity. Many times an inventor will only generally describe the invention in a patent application, which creates a significant problem.

This problem recently presented itself to me when an inventor provided me with an extremely vague description of their invention and wanted me to do a patent search and prepare a provisional patent application. I explained to the inventor that I needed much more detailed information. The inventor told me that he supplied plenty of information and was not going to supply any more because he wanted to keep the description very general. That is, of course, his right, but a general description is a recipe for failure. I declined representation. I don’t need those type of headaches.

This interaction is more common than you might think. Inventors not only frequently think they know more about patents than a patent attorney, but inventors also frequently think it is best to have the broadest most vague description of an invention possible. Conceptually a general description may seem best, but if you have any knowledge of U.S. patent law you realize that general, non-informative and vague descriptions are unacceptable. The law simply requires more.

It is imperative that the invention be described with the level of detail required by U.S. patent laws, not merely the level of description that the untrained inventor thinks is appropriate.  Indeed, there needs to be considerable time spent describing the structure of the components that make up the invention, as well as the mechanical and electrical connections necessary for the components of the invention to fit together and ultimately perform the specified function. It is critical to describe any and all variations. See Drilling Down on Variations in Patent Applications.

Simply said, a patent application is only as good as what is included within the application, and general or vague descriptions do nothing more than guarantee that no patent will ever issue. Beyond that, how can you realistically do a patent search on a first level, vague articulation of an invention? At present there have been more than 8.7 million U.S. utility patents granted and over 700,000 design patents granted. I can guarantee that if you vaguely describe your invention it will be easy to find prior art that will be exactly what you have described. Of course, when you see it you will say: “that isn’t anything like my invention.” But if you say your invention is multi-purpose knife, for example, and that is all you say then any multi-purpose knife would be prior art that would prevent you from obtaining a patent.

With patents the devil is in the details. What is the structure of the components? What is the overall structure of the unit? How are things connected? How do they interact? How would they be made? How are the pieces assembled? What are the alternatives for making, connection, interaction? What materials can be used? What optional features are present? What could be present? These and other descriptive questions, including what is specifically unique compared to the prior art (more on that in a moment), need to be answered in order to particularly define the invention in a way that maximizes the likelihood of obtaining a patent. Failure to consider the various combinations and alternatives that make up an invention is unfortunately a common mistake, but one that cannot be made without severe consequences.

If you do not fully describe the invention the patent application you file will will wind up be worth little. This is true because once you file a non-provisional patent application you cannot add additional description to the application. If you want to add additional description to explain how your invention is unique you must file a new non-provisional patent application, but any time you file a new patent application with new disclosure that means you get a new priority date for prior art purposes. Under a first-to-file system like the U.S. system now is a new priority date in many instances will create a fatal impediment to ever obtaining a patent. For that reason it is essential that when you file your patent application you make that first application as complete and detailed as possible.

Many times inventors believe the details and variations of their invention will be clear, but the patent law does not expect the reader of the patent to be a mind reader. Further, under tried and true principles of patent law you can always patent a new and non-obvious improvement. Thus, if you leave something out of your patent application because of a vague or otherwise inferior description someone else could file a patent application claiming that which you left out for themselves.


The patent laws say you need only enable one who is skilled in the relevant field, it is always the best practice to try and provide a disclosure that would allow a reasonably educated person to understand what the invention is and how the invention can be made and used. This being the case, before you ever file a patent application, whether a provisional patent application or a non-provisional patent application, take a critical look to see if someone who is unfamiliar with your invention would understand how to make and use the invention after reading your disclosure and reviewing any associated drawings. Also makes sure to describe the invention in a way that specifically describes your invention so that the reader will understand all the various permutations and that you are indeed in possession of all variations. In other words, you need to provide something of an instruction manual for making and using, paying particular attention to describing modifications, specific versions and alternatives.

It is also very important to explain your invention while paying particular attention to unobvious or counter-intuitive steps, connections or limitations. You also need to pay particular attention to any preparations that may be necessary prior to beginning the making or using process. Perhaps you should try and describe your invention in words in a way that would convey meaning to someone who is blind. This is a tough task no doubt, but the goal of the written disclosure is to provide verbal description that is much like a step by step how to manual. If you are trying to describe your invention to someone who cannot see then you will invariably find creative and enlightening ways to verbally get your message across. This is the type of detail that should be in an application.

Having said this, do not let the suggest about describing your invention to someone who is blind fool you into thinking that drawings are not essential. Good patent illustrations are the best way to cheaply expand any patent disclosure. Anything included in your drawings filed as part of the application are considered a part of the disclosure. Pictures really are worth at least 1,000 words. So absolutely use as many patent illustrations as you can. Then when you are describing those drawings in text employ the aforementioned advice about describing what is shown in the patent drawing to someone who is blind. If you do this you will wind up with an exceptionally detailed and very useful description of your invention. For more on the proper use of drawings see:

As you are describing your invention you want to be careful.  Many inventors will embark upon the onerous task of describing and then distinguishing the prior art.  This is not something that any patent attorney would do, although there are texts for inventors that suggest you do this very thing.  If you positively describe the prior art you will make admissions that will be difficult, if not impossible, to back away from later on.  You never say anything in a patent application or during prosecution that is not necessary.  If and when the patent examiner makes a rejection over certain prior art then you will need to distinguish that prior art from your invention.  You will, however, have the benefit of knowing what the rejection is and why the examiner finds it to be similar.  That will allow you to make crisp and direct distinguishing statements rather than making over-broad generalizations that might come back to haunt you.


Notwithstanding the cautionary note about prior art above, it is quite important for inventors to somehow articulate what the patentable feature and/or unique contribution the invention is making to the industry.  Why is it invention different and/or unique?  This should be explained in the text of an application because in order to obtain a patent an invention must be new (i.e., never before done) and it must not be obvious (i.e., not a trivial combination of things already known to exist in the prior art).  You don’t want to have the reader of your patent application left wondering why your invention is both new and why it is non-obvious. First, what is unique about your invention?  What sets it apart from what is already available in the prior art?  Second, it is important to understand that in order to obtain a patent it is not enough that an invention be new and/or different when compared to the prior art, it must also be non-obvious, which means that one of skill in the art would not have thought to make the invention prior to seeing it described.

One of the common mistakes that many inventors make is that they spend a tremendous amount of time discussing common, everyday components, but fail to really focus in on those components, combinations or steps that really set the invention apart from the pack. The recommendation here is that you specifically and explicitly mention that which sets your invention apart and will indeed make the invention patentable.  As with everything else in patent law, you do need to be careful.  I recommend that you stay away from saying things like “the only thing that makes the present invention unique is…”  Rather, consider saying something like “one of the things that makes the present invention unique is…”  The second alternative is only slightly different, but leaves the door open for you to argue later during prosecution there are other aspects that make the invention patentable.  The first alternative would likely be construed as an admission and could be very difficult, if not impossible, to get around.

Even if you never embark upon drafting your own patent application the better you can describe your invention the better the resulting patent application.  As the inventor you are the one who has the most information about the invention.  You know your invention best.  If you are going to hire a patent attorney to represent you the more you give them to work with the better the patent search will be and the better any resulting patent application will be, which will undoubtedly make the patent obtained as strong and useful as possible.

Happy inventing!


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Join the Discussion

One comment so far.

  • [Avatar for MaxDrei]
    May 11, 2014 06:04 am

    I can see advantage in reciting all the variations you can imagine, all the equivalents, and all the optional features you can imagine. What I don’t see Gene, in your teaching how to write a patent application, is the advantage of including in the specification a mention of all the ways you can think of, in which any particular optional feature enhances performance..

    Paul Cole in his book on how to draft reminds us that for patentability we need “A difference (novelty) that makes a difference (for non-obviousness)”. Claim the novelty and describe the non-obviousness. Indeed, everywhere in the world that is influenced by EPO-think, obviousness is explored by toggling between technical features (in the claim) and the effects they deliver (disclosed in the specification).

    So back to those optional features, ie, the dependent claims. When drafting for the AIA new world USA, would you recommend pairing each one with an explanation (in the specification) of the enhanced performance it can bring?

    You know, as insurance, just in case the independent claim turns out to be obvious and you need to salvage something non-obvious from the wreckage.