Is This Patent Any Good? How to Tell a Good Patent From a Bad One

Good or Bad?If you can’t understand a patent application, neither can the patent examiner, nor the infringer, nor anyone who will buy the company.

Sometimes, the technology is very, complicated, and the patent application will reflect that. But when the document is virtually unintelligible, the value is severely discounted.

Unintelligible patents are the hallmark of patents written by someone who does not understand the invention or by someone who wants to make the patent so obtuse that they need to go to court. In either case, the patent does not have much value.

Many inventors boast that they did not understand their patent application because their attorney used “legalese.” Some even joke that it was so dense that they did not even know if their invention was in there.

Make no mistake about it: a good patent is easy to read. It is difficult to write a clear description, and it takes ingenuity, thoughtfulness, and a big effort (read: motivation) to fully understand the invention, digest it to its essence, and write a clear description.

The key to good writing comes from sixth grade book reports: clear topic sentences for every paragraph, clear and simple sentence structure, and direct, active voice whenever possible.

Why does it hurt a patent when it is badly written? The first and foremost way it hurts is that the attorney did not understand the invention and probably made omissions or errors in describing the invention, not to mention the problems with examination and assertion that were covered elsewhere in this book.

Many people might say that they are not a technical or legal expert and incorrectly assume that they should not understand the patent. This is not true.

Patents are business documents that are read and understood by real people, not attorneys. When the patent is litigated, the patent is read by a judge and jury, who are common, ordinary people. If a normal person cannot understand the patent, neither can they.

For badly written patents, the risk factors include a higher possibility of Inter Partes Reexamination (IPR) reversal, difficulty of licensing or selling the patent, and general uncertainty about what the patent actually means. Discounting for all those risks, a badly written patent may have no value whatsoever.

References Cited

The best way to show that a patent has value is to have the examiner consider lots of prior art during the examination. In the US, we have the opportunity to send a list of patents, websites, scientific papers, and other documents for them to consider.

A patent with five references cited, all of which were found by the examiner, is a patent that is very weak and has a higher likelihood of being overturned by Inter Partes Reexamination.

A patent with twenty, forty, even 100 patents and prior art cited, is a patent that just “feels” strong.

Patents with lots of cited references are worth much more than those with few references.

investing-in-patents-2One of the easiest ways for infringers to challenge an issued patent is through the Inter Partes Reexamination process, commonly known as IPR. To successfully challenge a patent, someone has to produce a prior art document that would have changed the examiner’s mind.

The prior art can come from anywhere. A classic example is some dusty master’s degree thesis that sits on a dusty shelf of some foreign university.

The toolset used by examiners includes incredibly powerful search systems, but these are understandably focused on patent prior art and much less on scientific papers and websites, although these types of prior art are cited from time to time.

How to make a patent immune to Inter Partes Reexamination?

The best way is to get as much relevant prior art in front of the examiner and let them consider all of it. If a patent may be challenged by someone in the market based on their existing products, make sure the examiner has documentation about that product.

One of the reasons why people don’t do this is because they are afraid that their patent would not be granted if the examiner looked at all the prior art.

A startup wants the patent challenged as much as possible through the examination period. The more prior art considered by the examiner, the stronger that patent will be – and the less likely that it will be challenged by IPR.

When patent due diligence includes analyses of competing products and potential licensees, use that information to find documentation about competing products and send those to the examiner.

One quick way to assess patent quality is to look at the list of cited prior art for an issued patent. If there are only 4-5 references, all with little stars indicating that they were cited by the examiner, there is a good chance that a searcher could find something to challenge the patent for an IPR proceeding. If there are lots of references, especially non-patent references that show competitor’s products, the patent is probably very strong.

Please note that there are ways to game the system. Some people cite lots and lots of useless and irrelevant references in their cases. Even if the references are irrelevant, the resulting patent is much more impressive with the references, and it will score higher in the automated scoring systems that some big companies use to assess patent value.

Note: This is an excerpt from “Investing In Patents” by Russ Krajec. Russ is CEO and founder of BlueIron IP, an investment company that finances patents for startup companies.


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 Read more.

Join the Discussion

7 comments so far.

  • [Avatar for Robert]
    May 23, 2016 12:14 pm

    Strong support evidenced by prior art is desirable but I’m hard pressed to see anything above the high number of 30 as anything more than cumulative.

  • [Avatar for step back]
    step back
    May 22, 2016 01:38 pm


    While your story might seem like a made up up fiction to some, I’ve literally had that happen to me where the inventor could not see his invention in the patent app (one written up by another) and thought that is what we lawyers do; make it so obscure that even the inventor can’t see his own invention in the spec.

    signed –not laughing out loud over such situations

  • [Avatar for Benny]
    May 22, 2016 10:09 am

    Thank you for drawing my attention to 311(b).

  • [Avatar for TJM]
    May 22, 2016 10:01 am

    The prior art requirements are explicitly in the statute. 35 USC 311(b) says a petitioner can request “only on a ground that could be raised under section 102 or 103 and only on the basis of prior art consisting of patents or printed publications.” In some cases (possibly in the one you mentioned), movies have been considered printed publications. So, a petitioner definitely cannot rely on a product that was sold, but could potentially use the accompanying brochure/manual if it was available as prior art.

    You are correct that the fact that a reference was cited does not mean that it was considered. However, the author of this article seems to be under the impression that the fact that a document was cited means that it will be tougher to invalidate a claim. While district courts still apply the higher standard with respect to art cited during prosecution, the PTAB has not shown any willingness to do that. Several IPR petitioners have successfully invalidated claims based entirely (or at least primarily) on the exact same reference(s) that the examiner argued in making a rejection during prosecution. That is, knowing about the document wouldn’t have changed the examiner’s mind, since he did know about it and even applied it to the claims.

  • [Avatar for Benny]
    May 22, 2016 05:55 am

    You sure about that? I understood the law to state that prior art can be any form of public disclosure. (in 11/045461 a sci-fi movie was cited as prior art)
    Also, the fact that a prior art document was referred to by an examiner is not evidence that the examiner read the document in its’ entirety, or understood it.

  • [Avatar for TJM]
    May 21, 2016 08:49 pm

    I’m really not trying to pile on, but it just surprises me how misinformed the author is.

    “To successfully challenge a patent, someone has to produce a prior art document that would have changed the examiner’s mind.”

    This is really not true anymore. Many challengers have successfully invalidated claims in IPR (I mean actual IPR, not inter partes reexamination) using the same art that was before the examiner. This is especially true for patents that were granted prior to KSR.

    “The prior art can come from anywhere.”

    Again, not true. IPR can only be filed on the basis of 102/103 and the prior art must be a patent or printed publication.

  • [Avatar for TJM]
    May 21, 2016 07:07 pm

    This article is poorly written and/or edited. For one thing, IPR refers to inter partes REVIEW, not reexamination. Inter partes reexamination was a much different procedure than IPR and was legislated out of existence by the AIA. For another thing, the PTAB (the entity that oversees IPRs) has not shown much, if any, indication that it will give any deference that the claims are patentable over references that were cited during prosecution compared to those that were not. This distinction probably only has importance in litigation.

    This article is disappointing. I was actually thinking about looking at this book, but I think this has saved me the trouble.