Lessons on trade secret, trademark, copyright & patent law for entrepreneurs

There is a fine art to reading patents. And it’s far harder than you might imagine.

The devil is really in the details.

Today, I’m explaining how to read a patent like a pro, including identifying the most important parts and considerations for interpretation. My primary goal is to help you get a better understanding of how to determine what a patent actually covers.  Frequently, it’s not what you’d initially think.

Part 1:  Patent Anatomy

Patents have several common sections:

• the front page basics including the patent number, title, inventor’s name, owner if different, patent filing date, patent issue date, and cited references.
• the abstract, which gives a snapshot of the type of invention and what it does;
• the specification, which explains how to make and use the invention;
• the drawings, which illustrate the invention; and
• the claims, which define the legal boundaries of the patent’s coverage.

For example, see Patent No.4,833,729, a patent for a Shark Protector Suit.

From the front page, you can get a general idea about what the invention does. Here, the abstract describes the invention as a rubber suit with spikes “to prevent a shark from clamping its jaws over a wearer.”

But if you want to read a patent like a pro, after quickly reading the title and the abstract, you need to start at the end of the patent — with the claims.

The claims are the most critical part of a patent.

Shark Protector Suit Claim 1

It is the claims as issued that determine the scope of the patent’s reach. And the claims may have undergone major modifications during the patent prosecution process with the PTO. The specification may describe a general invention that seems to have broad coverage. Indeed, the initial claims may have been very broad and far reaching — too far reaching. Because of conflict with prior art, the inventor may have significantly narrowed what is being claimed to get the patent granted. And the issued patent may not even cover some of the “preferred embodiments,” examples of the invention described in the specification.

Don’t be fooled by broad language in the specification. You need to first look at the claims to get a sense of what is actually covered by the patent rights.

Then, you need to try to figure out what the claim language actually means — the claim construction.

Part 2:  Claim Construction for Beginners

Claims come in two flavors:  1) independent, stand alone claims; and 2) dependent, me-too type claims that incorporate an earlier claim with an additional element.

Claim construction is all about the meaning of individual words and phrases in the claims. Don’t be thrown off by the awkward wording or use of the term “said.” Drafters are trying to define the invention clearly and doing so can make the wording strange.

A definitive claim construction can be hard, very hard. Indeed, according to the Federal Circuit Court of Appeals, even district court judges in patent infringement suits get the claim construction wrong around half of the time. (In patent cases, the judge decides the claim construction after briefing by the attorneys, who try to persuade the judge of their particular interpretation. See example of a judicial claim construction analysis.) Moreover, millions of dollars are paid to attorneys who fight over the meaning of a few claim words. Amazingly nuanced, claim construction can be a high stakes squabble with billions of dollars in damages hinging on the meaning.

So how do you determine what a patent’s claim terms mean, especially when you’re not a lawyer?

First, start with the plain meaning of the words. How are they generally understood by a person skilled in the art? How are they defined in a standard or technical dictionary? Is there any ambiguity as to the meaning?

Second, read the specification very, very carefully. Have certain terms been coined or defined by the inventor? Examine the drawings and examples for clues about the meaning of the terms.

Third, and most importantly for infringement considerations, review the prosecution file history — the paperwork between the PTO and inventor as the patent application was examined. (You can find it on-line). The inventor may have had to distinguish the invention from prior art. She may have had to tell the examiner what the invention is not.  These limitations can be critical. The inventor cannot go back and try to insist that the invention covers what was disclaimed, although I’ve seen some plaintiff’s who have tried.

From these sources, you will have a basic idea about what the claims mean and what is covered or not covered. You’ll be able to read a patent like a pro.

(There are some special types of claims that get a different analysis, but in general you can understand the scope of the patent from the claims and specification.)

Jill Hubbard Bowman is a patent attorney who often ponders about the meaning of patent claims.

The information provided in this legal blog is not intended as legal advice and does not create an attorney-client relationship. Please do not submit questions or comments seeking legal advice or submit confidential information through this blog. By communicating through this blog, you understand and agree that the information will not be treated as confidential and the publisher has no duty to keep it confidential.

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