Beware Background Pitfalls When Preparing a Patent Application

Periodically I write articles aimed at giving inventors some information about preparing a patent application, such as primers on writing patent claims, writing method claims, describing your invention completely and language difficulties, to name but a few.  Every time I do this I cringe a little out of fear that inventors will get the wrong idea.  For the typical inventor who might have several inventions over the course of a lifetime.  This level of experience makes it unrealistic to believe you can do it yourself without any assistance and do it just as well as a patent attorney or patent agent would or could.

I like drawing an analogy to the commercial where the man is sitting at the table with a butter knife and the surgeon on the phone is telling him how to perform the surgery.  He asks: “Shouldn’t you be doing this?”  A wise question for sure!  Preparing a patent application on your own is a lot like doing surgery on yourself.  You are going to make mistakes, it is not a good idea and only in the most extreme of circumstances should it be attempted.

Having said this, if you have no other choice — for whatever reason — you should be armed with the best information you can obtain.  For that reason I write these articles, and I also write because I am convinced that the more you know the better you will be as an inventor.  So even if you never plan on representing yourself if you understand the common mistakes and likely pitfalls it will make you a better consumer of legal services, and it will make you a better inventor because you will learn what is important and why, thereby giving your patent attorney or patent agent far more useful information than you otherwise would.


Without further ado, here are some pitfalls to be on the lookout for when you are preparing the Background of the Invention.

1. Don’t Describe the Prior Art

When describing what is commonly referred to as the prior art you should, as a general rule, stay away from describing what the prior art is or does.  This is a fairly common mistake that many inventors make, and a mistake that some inventor books and advocates actually encourage.  It is certainly fine to discuss the prior art, and in fact many inventors will find it useful to discuss deficiencies in the prior art.  However, as with many things, there is a right way to talk about the prior art and many wrong ways to talk about the prior art.

The concern centers on what is called an admission.  If you talk about what the prior art does, if and when it is necessary to engage in patent prosecution with the patent examiner, you may find it exceptionally difficult to back away from positive, descriptive statements that have previously been made.  For this reason, I suggest that you not describe what the prior art is or does, just explain what it is lacking.  Explaining what it is lacking will in a subtle way demonstrates the importance of your invention, which is the goal.  Your patent application is about YOUR invention, not the prior art.

The other concern here is that the more you explain about the prior art the more likely you will be making it easy for the patent examiner to issue an obviousness rejection.  Obviousness is not supposed to be a hindsight inquiry because, after all, everything is obvious in hindsight once it has been explained.  It would, however, be naive not to notice that over the last 5 years the law of obviousness has been trending toward an inquiry that allows a decision maker, such as a patent examiner, to employ some hindsight.  If you explain the prior art and the problems too well then your solution, and hence your invention, could seem obvious.  So you must tread lightly. Less is more when you are discussing the prior art.

2. Invention Compared with Prior Art

There is a great tendency among inventors to want to compare their invention directly with the prior art that they know about.  This is a huge mistake.  You want to say as little as possible about the prior art, as discussed above.  Sure, you want to know what else is out there and you absolutely should describe your invention to accentuate the positive and likely patentable aspects, but direct comparisons with the prior art are full of danger.

The best thing to do is explain why your invention solves problems and/or is important for the relevant consumer audience.  In order to accomplish this you do not explain what else available to consumers and why it is inferior, missing functionality or missing parts.  Remember, the focus of the application MUST be on your invention.  It can be extremely helpful to create a comparison chart or write text comparing the prior art you know about with your invention, but this should be used by you or provided to your patent attorney or agent.  It will be exceptionally helpful to have this information, and I ask my clients to provide it to me whenever they are willing to be so involved.  This information informs how you describe the invention, and will be helpful later during prosecution, but it is not appropriate in a patent application.

3. Don’t Call it Prior Art

Although it is appropriate to describe the deficiencies of the relevant prior art, at least in cursory terms and only to the extent that it facilitates your discussion of what it important to know about your invention, actually using the term “prior art” is not considered appropriate.  This is because if you use the term “prior art” it will be considered to be an admission that the reference is in fact prior art for your invention.  This may seem like a small point, but during prosecution it can come back to haunt you.  For example, what if you are wrong and the reference you are discussing is not really prior art?

While using the term “prior art” might not be an issue too frequently I am always in favor of avoiding things that could be potentially problematic.  Furthermore, it makes no sense to do something when there is no upside and only potential downside.  For example, do you really need to use the term “prior art”?  No.  That term comes with a lot of baggage and a specific legal meaning.  I suggest that you consider describing the prior art in a different way.

The same is not true for language such as: “some attempted solutions have tried X, but this has not sufficiently addressed the needs of the industry owing to its awkwardness and fragility.” Notice this does not say anything positive about what the prior art is or does, but mentions vaguely why it is not sufficient for the industry.  Saying this one would expect that you have an invention that is elegant and sturdy, for example.  So you only vaguely explain the prior art and only to the extent that it sets up an opportunity to accentuate the positive relative to your invention.

4. Understand the Purpose of the Background

Earlier I wrote that you should not compare your invention with the prior art, which is a good general rule not only for the Background, but also for anywhere in the patent application.  Typically when inventors compare their invention to the prior art it is in the Background, but not always.  Sometimes I see inventors weave in and out of describing their invention, discussing the prior art and comparing their invention to the prior art all through the application, but certainly in the Summary of the Invention.  Leave discussion of your invention to the Summary and the Detailed Description of the Drawings.

This error is enabled because most inventors are unfamiliar with the purpose of the Background of the Invention.  In fact, many (if not most) inventors write the Backround as if it is a history of the invention, which causes the Background to be written as an invention record.  The Background, however, is NOT about your invention.  Further, you should never describe the history of your invention in a patent application.  If that is ever going to be relevant that will be relevant during prosecution of the patent application with the patent examiner.

The Background is supposed to be about the prior art, or at least that is what the Patent Office would like for you to do, but you won’t because of the pitfalls already discussed. You will only discuss in vague, cursory terms the prior art and only to the extent that it can be useful and NOT harmful.  You must always remember the rampant problems inventors face when they lock themselves into a particular articulation of structural features and when they trivialize their own invention by making it seem obvious.

The Background is preferred to be broken down into two sections: (1) The Field of the Invention and (2) the Background of the Prior Art.  For the Field of the Invention you will likely say something straightforward and simple: “The invention generally relates to INSERT TITLE.”  The Field of Invention is optional, so typically if you include it you want to keep it short and sweet, and inserting the title here offers nothing new you haven’t already said.

You will NEVER refer to the Background of the Prior Art!  You will have a section labeled Background and section “A” will be the Field of the Invention, and section B will be “Background.”  Why?  Because you NEVER want to use the term “prior art.”


If you follow these rules you will undoubtedly wind up with a brief Background that says little or nothing substantive.  That is not only fine, but it is perfect!

Happy inventing!


Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of

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2 comments so far.

  • [Avatar for patent enforcement]
    patent enforcement
    November 1, 2011 02:03 pm

    I think you are doing a great service for inventors … though, of course, your best advice of all is that one should never draft one’s own patent application unless one absolutely, positively has to. It’s better left to an experienced attorney.

  • [Avatar for Lawrence S. Cohen]
    Lawrence S. Cohen
    October 24, 2011 03:12 pm

    Nicely written. I almost regret the goal of helping an inventor do his own, as you so well explained, by telling her how to do it right because it will be done badly, possibly fatally so. Incidentally I omit the Summary. A common summary style is to state some of the claims’ content in a narrative style. But then as the claims are amended or new are claims added there is a disconnect.