If you have a patent, you should be aware of what constitutes infringement of your patent and how to identify its occurrence. According to the U.S. Patent and Trademark Office, patent infringement may happen when someone makes, sells, uses or offers to sell a patented invention without the permission of the true patent owner. Additionally, patent infringement can also take place if a product or production method that is covered by a patent is imported into the U.S., again without permission of the owner of the patent. This means that you can be the victim of infringement for a long period of time without being aware there is even a problem.
Unfortunately, there is no enforcing body in use in the U.S. to monitor the use of patented products and processes. This means that it is your responsibility to remain aware of the competition in your sector to determine whether or not other businesses may be infringing on your patents. Without sufficient proof, you will be unable to make a claim to stop the infringement from occurring.
One of the clearest ways to determine if infringement has actually occurred is by using the doctrine of equivalents. This involves comparing the two inventions in question to determine if they are sufficiently equivalent in how they work and their purpose. If these two findings align, the devices may be sufficiently alike enough to warrant an infringement claim. Additionally, infringement has clearly occurred in cases where a device or process is blatantly stolen from the original patent design. This information is educational only and should not be taken as legal advice.