Patent litigation can be cost-prohibitive for startups.
Patent litigation can be cost-prohibitive for startups.

The costs of defending your business in a patent infringement lawsuit can easily exceed $1 million or more. Because each party must ordinarily pay its own costs, even successfully defending a patent infringement action can quickly bankrupt an early-stage company. While there is no way to completely eliminate the risk of patent infringement, that risk can be understood and mitigated by taking the following steps.

I.     Performing a Initial Patent Search

Performing an initial patent search will allow you to see what patents exist in your field and gauge your risk of infringement. Because there are millions of patents currently in force, the first step is to narrow your search, using these top-three tips.

1.       Keyword Search  

A keyword search consists of brainstorming keywords that describe your technology and searching for patents using those keywords.  Keyword searches can be conducted through the USPTO here or through Google Patents here.

While a keyword search can be effective in discovering issued patents in your field, a keyword search is only as effective as your ability to guess at the words used by the patentee to describe her invention.

2.         Search by Classification

A more comprehensive search also involves searching by classification. The classification system employed by the USPTO classifies patents according to the field of invention. A patent’s classifications are displayed on the first page of the patent. For example, U.S. Patent No. 7,044,039 (“Radial arm saw safety top”) is classified under U.S. Classification 83/100. Class 83 refers to cutting materials, while subclass 100 refers to cutting materials which include a suction means.

Searching by classification can be accomplished through the USPTO’s advanced search here or through Google Patents. 

3.         Search by Inventor/Assignee

Once you’ve found a relevant patent, it can be useful to search for other patents issued to the same inventor, as inventors often patent many related inventions. Similarly, the same company will often own a portfolio of related patents, so searching by assignee may also return relevant results.

II.       Analyzing Your Search Results

Virtually every technology start-up will encounter patents related to its technology. The next step is to identify which patents, if any, present a risk to your business model, using these top-five tips.

1.         Check to See that Your Search Returned Issued Patents, not Applications

A keyword or classification search on Google Patents may return both issued patents and published patent applications. While a published application may eventually issues as a patent in the future, only an issued patent can be infringed. The quickest way to determine whether you are viewing an issued patent versus a published application is to examine the number of the document.   An issued patent will have a 7 digit number, such as U.S. Patent 7,044,039.  A published application will have a number beginning with the year of publication.  On Google Patents, the webpage will indicate whether you are viewing an “appellation” or a “grant.”

Google Patents will indicate whether you are viewing a published application ("Application") or an issued patent ("Grant").
Google Patents will indicate whether you are viewing a published application (“Application”) or an issued patent (“Grant”).

2.         Check to See if the Patent Has Expired

With some exceptions, the term of a patent is generally 20 years from the filing date of its earliest U.S. application. The U.S. Patent and Trademark Office offers a calculator to estimate the expiration date for a patent.

3.         Check to See if the Patent Has Expired for Failure to Pay Maintenance Fees

A patent owner must pay maintenance fees to the USPTO by the 4th, 8th, and 12th year after the patent’s date of issuance. Failure to pay maintenance fees causes the patent to expire. A patent’s maintenance status is available online here.

4.         Compare the Words of Each of the Patent’s Claims to Your Product

Patent infringement occurs where a company’s product contains each and every element claimed in another’s patent. Therefore, to determine your risk of patent infringement, compare the words of the patent’s claims with your company’s device. A patent’s claims can be found at the end of the patent.

Because a patent’s claims exist in the form of words, there is necessarily uncertainty regarding the scope of those claims. In litigation, courts resolve that uncertainty by first turning to evidence contained in the claim language itself, the patent’s written description, and the patent’s prosecution history in the USPTO. Therefore, to predict how a court might interpret the scope of a patent’s claims, first turn to the claim language itself, the patent’s written description, and the prosecution history.

5.         Determine the Patent Owner

The history of a patent’s assignment is available on the USPTO website here.  This tool allows the public to view the current owner of a given patent.

Determining the identity of a patent’s owner can assist you in assessing the risk of litigation. For example, Twitter, Inc. states in its terms of use that, “[w]e will not use the patents from employees’ inventions in offensive litigation without their permission.”  In contrast, other businesses are based entirely around the model of purchasing patents for the sole purpose of offensive litigation.

III.       Conclusion

While there is no way to completely eliminate the risk of patent infringement, performing a basic patent search and analyzing your results will allow you to understand and mitigate risk of infringement.