Basic Patent Law: III. How to Read a Patent
Third in a series of articles aimed at scientists, engineers, business managers, non-patent lawyers, and other professionals that desire or need to understand basic principles of patent law and practice.
Most scientists and engineers I know would rather suffer a root canal procedure than try to decipher a handful of patents. I’m here to convince you that patent reading need not require Tylenol® with codeine. It’s a matter of having the right approach. In particular, how you read a patent should depend on why you’re reading.
Scientists (and others) often have multiple concerns when they’re looking at a patent. For instance, they may have invented something similar, and they want to understand whether their own invention is patentable. Coincidentally, they may also wonder whether they (or their employer) would be able to practice their own invention given the existence of this patent. Frequently, scientists are appalled that a competitor was able to get a patent at all, and they wonder whether the competitor could successfully sue an alleged infringer. Often, the scientist simply wants to understand what the patentee accomplished and how it improves on known technology. To get the most out of your technical reading, you’ll need to separate these thoughts and read the patent from one perspective at a time.
1. Reading for Technical Information. When reading to understand what the patentee accomplished technically, pay attention to the “Background” section, which normally puts the invention in perspective. Ignore the wordy “Detailed Description” in favor of the “Summary” section, especially if the summary is only a paragraph or two. Usually, the experimental examples will help to show what the patentee accomplished and how it improves (if at all) on prior art. After you have a grip on the basics, dive into the detailed description to understand things like process steps, preferred reagents, and reaction conditions.
2. Reading for Patentability. The question is, “Given that this patent exists, is my own invention patentable?” The entire disclosure of the patent is relevant to patentability. Does the reference disclose every aspect of what I would claim as my invention? If so, my invention lacks novelty. Would my invention have been obvious to a skilled person given what this patent teaches? As “prior art” to my as-yet-unfiled application, the entire patent is good for all it discloses and reasonably conveys to the person of ordinary skill. A common mistake is to consider only what a reference patent claims: “They didn’t claim it, so I can patent it.” Wrong!
3. Reading for Infringement. Now the question is, “Given this patent, am I free to practice what I want to do?” Infringement is measured using the claims of a patent. When your composition, process, or apparatus, meets every claim limitation, the claim is infringed. Transitional language (“comprising” versus “consisting of” or “consisting essentially of”) has special meaning and needs to be taken into account. For instance, “comprising” is open-ended, so an infringing product could have elements not recited in the claim. “A chair comprising a back, a seat, and three legs” covers a four-legged chair having armrests and a cupholder, while “A chair consisting of a back, a seat, and three legs” cannot have a fourth leg. Neither claim covers a three-legged stool, because both claims require a back. When reading for infringement, the claims should be the focus of attention.
4. Reading for Validity. We’ve all seen patents that have impossibly broad claims. “What examiner allowed this?” The focus is again the claims, but now we ask whether there are other references available that would satisfy us that the claims lack novelty and the patent should not have been granted in the first place. The goal is to find a single reference that discloses every claim limitation of the apparently troublesome patent. If we find one or more novelty-destroying references, we might just choose to ignore a patent that, as granted, has claims broad enough to raise a potential concern. We need to be confident that given all of the facts (and the novelty-destroying references), a court would not enforce the patent.
Importantly, items 2-4 above call for a legal conclusion. Consequently, the scientist should seek advice from a patent agent or attorney whenever patentability, infringement, or validity are at issue.
In sum, patent reading is fundamental; incredible as it may seem, sometimes, it’s even fun. Patents are never going to replace the latest Grisham, Baldacci, or Patterson novel for enjoyment, but if you follow some of the pointers here, you’ll tackle that patent pile with ease and reach less often for an analgesic.
Stay tuned for Part IV of our Basic Patent Law series!
– Jon Schuchardt
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This article is for informational purposes, is not intended to constitute legal advice, and may be considered advertising under applicable state laws. The opinions expressed in this article are those of the author only and are not necessarily shared by Dilworth IP, its other attorneys, agents, or staff, or its clients.