Multiple sets of time limits govern patent infringement actions. These include the period of the patent grant, as well as the statute of limitations and certain exceptions to it. First, the patent must be active at the time of the alleged infringement for it to form the basis of an infringement action. Utility patents last for about 20 years, while design patents and plant patents last for a shorter period. You can read more here about the duration of patent protection. Also, you should be aware that you will need to pay periodic maintenance fees to the U.S. Patent and Trademark Office to keep the patent in effect.
The other important deadline to bear in mind is the statute of limitations provided by Section 286 of the Patent Act. Since this is a federal law, the statute of limitations does not vary by state, as it does in many other civil claims. Under Section 286, the patent owner has six years to file their infringement action after the infringement occurs. Sometimes the owner and the alleged infringer will agree to extend this period during settlement negotiations. Any fraud or concealment by the infringer does not extend the statute of limitations, though.
An alleged infringer cannot use the doctrine of laches to defeat an infringement action. This is a historical doctrine based on the equitable principle that a plaintiff cannot take so long to bring a claim that the delay undermines the defendant’s ability to defend the claim. Laches does not have the precision of a statute of limitations. Determining whether it applies depends on the specific facts of a case. While alleged infringers traditionally could use laches as a defense, the Supreme Court recently has determined that this should not be an option.
Having six years to sue is a long time, but you should not plan on waiting until the end of this period to bring a lawsuit. You should explore your legal options as soon as you discover that someone may have infringed on your rights, especially if it appears that the infringement may be affecting your business. (For example, if your competitor is duplicating a patented product or process, you may start losing profits if you delay in taking action.) Just filing a lawsuit or even writing a cease and desist letter may provide the infringer with sufficient incentive to stop the infringement. Many infringers are not willing to assume the costs of a legal battle, and they may not want to face the publicity that comes with it.
In addition, preserving evidence of the infringement and your ownership of the patent is critical to establishing liability. Both tangible documents and electronic evidence can decay and disappear over time. If your case relies in part on the testimony of witnesses, they will remember events more clearly if you take action sooner. Bringing the matter to the attention of an attorney sooner rather than later also will give the attorney some time to analyze the case and develop their arguments. While you can pursue a patent infringement action on your own, the sophistication of these cases usually means that litigants benefit from professional representation.
