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Patent Enforcement FAQ

Once you have a patent, you have powerful legal tools on your side to combat infringement upon your patent rights. This article answers some of the most frequently asked questions about patent enforcement.

Q: What Rights Do I Have as a Patent Owner?

A patent is basically a government awarded monopoly for an invention. The patent grants what's known as a negative right (or right to exclude): no one else can create, use, sell, or import your invention for any purpose without your consent.

Once a patent is granted, no other party can even legally argue that they independently created it. What this means is you have an iron-clad lock on all uses of the patented invention. If anyone violates the patent, you can bring an enforcement action and a court can issue an injunction preventing the other party from continuing their actions and award damages (see below for remedies).

Q: How Long Do Patents Last?

Today, patents last 20 years from the filing date of the application. For patents that existed before June 8, 1995, the duration of the patent was 17 years from the issuance of the patent or 20 years from the filing date, whichever was longer. Design patents are limited to 14 years from the date of issuance, while plant patents last 17 years from the date of issuance.

Patents can also expire if patent holders don't make their regularly scheduled maintenance fees to the USPTO. Once a patent expires, whether from a time limit or a failure to pay fees, the patent goes into the public domain and can be used, sold or imported by anyone. At this point, however, enforcement actions are still available to the original patent holder for infringement that occurred during the life of the patent.

Q: What are My Rights During the Patent Application Process?

Your rights before, during and after the patent application process are a bit like the life cycle of a star. They start from nothing, eventually gather their strength and burn so brightly they engulf everything around them, and then suddenly flame out, leaving only remnants of their past power. Your rights during the patent process can be broken down as follows.

Before the patent application: You have no "negative" rights as outlined above. Anyone can create the invention and you would have little recourse to stop them. The only circumstance where you would have a legal ground to stop others from creating, using, or selling the same or similar invention would be under trade secret law.

Trade secrets are protected under state law, which is designed to protect business or technical information of any sort that provides value. The only requirements are that the secret have value and that the owner takes steps to keep it confidential. So if you have an invention and you've taken reasonable steps to try to maintain its secrecy and another person comes along, takes your idea and uses or markets it, you can sue them under trade secret law. However, if you haven't tried to keep the invention a secret (i.e., you've told others about your idea, exchanged ideas with others in your industry, etc.), you will have no trade secret protection, and certainly no patent protection.

After you've submitted your patent application: Once your application has been submitted to the USPTO, you can stamp all your products and marketing material as "Patent Pending." While this designation itself has no legal effect, it does put others on notice that your product is under review at the USPTO and, once approved, no one else will have a right to the invention. The patent pending designation serves as a warning that others' use of your invention may have serious consequences once the patent is approved. Note, however, that fraudulent use of the patent pending designation can be fined $500 for each use of the deceptive mark.

Eighteen months after a patent application is submitted, the USPTO will publish the application, at which point others can analyze the description of the invention.

Patent approved: After a patent has been approved, the patent owner has a limited-time monopoly on the creation, use, sale and importation of the invention. Once the USPTO grants the patent, enforcement lies with the patent owner. Owners have the right to sue anyone who makes, uses, or sells the invention without the owner's consent for patent infringement. These rights last 20 years from the date of the application.

If another invention is found to infringe upon the patent, courts can issues injunctions and award large damages, particularly for "willful" infringers (those who knew of the patent, should have known they were infringing, and did it anyway).

After a patent expires: Once a patent expires, so do the exclusive rights of the patent holder. At this point, anyone can use, sell, and import the invention as they please. Patent infringement lawsuits can still be filed, however, for infringement that occurred during the life of the exclusive patent.

Q: How is Patent Infringement Determined?

In order to determine whether there has been an infringement of a patent, it's necessary to familiarize yourself with patent terminology. Patents are made up of "claims," which are different elements that make the invention unique. "Prior art" is a term that refers to any document, or article that was available to public before the date of priority of the application. In other words, if invention has been described previously and openly known to the public, a patent on that invention is not valid. Another example is if a person's invention was  known to the public, but not necessarily patented or published, this would be considered "prior art."  Prior art includes previously awarded patents.

If another invention has the exact same claims as a patented invention, then there is literal infringement (copying of every claim). Literal infringement means that the elements of a patented claim are present (as recited in the claim) in an infringing article or product. When we analyze features of an article/product, we compare them with claims of a patent. Hence, this happens by checking each independent claim in the patent and seeing if each claim feature is found in your product or invention. 

 There is another type of infringement called the Doctrine of Equivalents, which means that the invention is so close to the claims described in a patent that a court will find it to be substantially similar and therefore infringing.

  • Literal Infringement. If you take all of the claims of a prior art and add elements, you are still infringing. On the other hand, if you take some, or even most, elements of a prior art, then you are not infringing.
    For example, a patent has claims A, B, C and an accused invention has claims A, B, C, and D. It literally infringes because it incorporates all the elements, even though it adds another. But if the accused devise has claims A and C, then there is no literal infringement because it is missing claim B.
  • Doctrine of Equivalents. Courts found that limiting infringement to only literal infringement was very restrictive (and often unfair) and came up with this doctrine to combat substantially similar inventions. The basic rule is that patent holders can claim infringement if:
    • the accused device performs substantially the same function,
    • in substantially the same way,
    • to obtain the same result.

There are, however, limits to the doctrine of equivalents. During the back and forth of the application stage, owners and the USPTO argue about certain elements of the prospective patent. Courts prevent patent owners from going back and claiming protection for claims that they had to give up during the application stage. If a claim is made or amended during the application of the patent to avoid prior art, then the patent owner can't argue infringement on that clam. If the patent owner can prove, however, that the amendment was made for a reason other than avoiding prior art and it was not meant to be surrendered, then the owner can a still argue infringement under the Doctrine of Equivalents.

Q: What Can I Do if I Believe Another Party is Infringing on My Patent?

If you believe another party is infringing on your patent, you will have to consult a patent attorney to bring a patent infringement lawsuit. The USPTO is not an enforcement agency, it simply approves or denies patent applications. Enforcement of patents is solely at the patent holder's discretion.

A patent attorney can help evaluate the merits of your case, as well as give you an idea of your chances of winning or losing. Also, patent lawsuits are difficult, involving complicated legal and scientific issues, and practically speaking cannot be successfully brought by an individual on their own.

Q: What Happens During a Patent Infringement Case?

After a patent owner brings an infringement case, the accused infringer has a number of defenses. They can argue that the patent was "disclosed" over a year prior to the patent application, that the accused device doesn't actually infringe, or that the patent is invalid.

The most common defense to a patent infringement lawsuit is that the patent was wrongly approved by the USPTO and is therefore invalid. Basically, the lawsuit will boil down to a patent holder defending the validity of his patent against the legal onslaught of the allegedly infringing party. Accused infringers will attack each of the 5 requirements for a patent (patentable subject matter, utility, novelty, non-obviousness, and prior disclosure).

If a patent is determined by a court to be invalid, the patent holder loses all exclusive rights to the invention. Many patent holders may choose to settle for a royalty or lump sum payment to avoid this potentially devastating prospect.

Let a Patent Law Attorney Help Protect Your Inventions

Just having your idea patented is no guarantee that it will be protected, particularly if you don't know your idea has been stolen. If you need help with patent enforcement or want to learn more about protecting your inventions, talk to a patents attorney in your area.

See FindLaw's Patents section for a wide selection of related articles and resources.

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