How to Read a Patent: Guidelines for Non-Lawyers

Those who have suffered through enough technical journal articles to gain fluency in the language of scientific discourse will have no trouble learning how to read patents.

Written by lawyers, not scientists, patents frequently are far more syntactically and grammatically sound than the average technical paper. Furthermore, anyone who possesses the dedication and self-discipline to learn how to understand a phrase like "amorphous silicon (a-Si) has two important advantages compared with bulk crystalline silicon: the luminescence efficiency in bulk a-Si is higher than that in crystalline silicon due to its structural disorder" should, with enough practice, be able to read a phrase like "the indirect-bandgap-semiconductor, light-emitting diode (401) of Claim 1, wherein said indirect-bandgap semiconductor is selected from the group consisting of silicon, germanium and a silicon-germanium alloy" with equal ease. It's English, not rocket science.

Now that you have been duly encouraged to persevere, let's move on to the technical details.

There are four main parts of a patent: the title, the abstract, the claims, and the description. This installment provides a general overview of these four parts, with editorial commentary.

Title

This provides a high-level description of the invention. People who are accustomed to scientific journal articles are usually disappointed by patent titles' overall lack of specificity, as they generally provide only a vague sketch of the subject matter. Often, the title will allow the reader to determine if the patent is at least tangentially related to the reader's interest; however, maddeningly broad titles like "Laser devices" are also common.

Abstract

According to the USPTO, a patent's abstract should be:

...a summary of the disclosure as contained in the description, the claims, and any drawings; the summary shall indicate the technical field to which the invention pertains and shall be drafted in a way which allows the clear understanding of the technical problem, the gist of the solution of that problem through the invention, and the principal use or uses of the invention.

Patent abstracts are generally quite informative and usually suffice as a comprehensive overview of the patented invention. It is nevertheless important to read them mindfully: In some cases, patent abstracts intentionally obfuscate the elements of the patent that are most relevant to the company's targeted products. (This is more common when an invention could reasonably be used in a number of different ways, for a number of different applications.) A trained scientist or engineer will recognize the cross-applicability of the invention, however, and can easily check the claims and description for additional information -- if she or he is paying attention.

A simple, visual explanation of dependent and independent claims. The independent claim describes the substance of the invention, and the dependent claims describe enhancements or uses of the invention. The dependent claims necessarily depend on the independently claimed invention and do not stand on their own as separate inventions. Click here for a larger version.

Claims

If a patent is the "deed" to an intellectual property, the patent's claims are the property's street address. No matter what its abstract says, and regardless of the extraneous information provided in its description, a patent's claims define the nature of the protected invention.

There are two types of patent claims: independent claims, which stand alone as unique descriptors of an invention; and dependent claims, which elaborate on various embodiments of the invention. It is very easy to tell them apart, as a dependent claim will invariably begin with a phrase like, "The invention as described in claim 1, where..." An independent claim, by definition, does not reference (i.e., does not depend on) any other claims.

Description

This section defines the invention described by the patent's claims. For example, if the patent claims, "A white shirt," the description might specify that the shirt could be made out of cotton, linen, or any other natural fiber. Similarly, the description might mention that the shirt has a collar, or that the material can be treated with a stain-resistant finish. A patent's description therefore provides both boundaries and speculation. It is often designed to push the boundaries of the imagination, to incorporate all possible embodiments and uses of the patented inventions.

The most important thing to remember, when reading a patent's description, is that the patent's assignee owns only the intellectual property that is described by the patent's claims. Furthermore, the patent's claims are only valid to the extent that they are supported by the patent's description. The claims define the ownership rights, and the description defines the claims.

Disclaimer

The author is a scientist, not an attorney, and this information should not be construed as legal advice. It is the author's opinion that, as patents are intended to be understood by those who are "skilled in the art" -- i.e., by scientists and engineers, who do not necessarily have a legal background -- factual interpretation does not require the assistance of a legal professional. Technically adept non-lawyers are fully capable of discerning whether or not two patents contain similar information; however, bar-certified counsel is certainly recommended for those who have questions regarding legal issues, such as infringement or patentability.