A patent is a type of intellectual property that gives the owner of the intellectual property or holder of the patent the legal right to exclude others from making, using, or offering for sale the patented idea or invention without first obtaining the express permission from the patent owner.
This means that once a patent is registered with the United States Patent and Trademark Office (“USPTO”), the owner of that patent has the exclusive rights to utilize their patent. This includes the right of the patent owner to sue others to enforce and protect their patented idea or invention.
After an inventor first files for a provisional patent application that documents the concepts of their idea or invention, the USPTO will issue the patent. This patent application will then be disclosed and made public on the USPTO’s database. Then their patent will be considered to be enforceable and patent pending.
At this point, the inventor will have a right to sue another person or company who makes use of their patent-pending property. It is important to note that not every idea or invention can be patented, as there are specific requirements that must be met for the USPTO to issue a patent.
It is also important to note that per international agreements with the World Trade Organization (“WTO”), member nations are expected to recognize and enforce legal patents that were executed and registered in the United States.
What Types of Inventions Can Be Patented?
In order to receive patent protections from the USPTO, the invention or idea that is submitted to the USPTO must be new, unique, and generally unobvious. As such, one of the first things an individual seeking to receive a provisional patent should do is search the USPTO database to ensure that their idea or invention meets the new and uniqueness requirements.
After a prospective patent owner determines that their idea or invention is in fact new, unique, and generally unobvious, they can then apply to receive one of four different patents:
- Utility Patent: Utility patents are the most common type of patent in which the invention involves a process or method with a concrete result, a machine, a chemical or biological composition of matter, or an improvement on an existing invention;
- Design Patent: A design patent is another common patent that covers how a product appears;
- Plant Patent: Plant patents cover new species of plants and prevent others from breeding that specified plant, without express permission from the patent holder.
- In order to patent the new plant species, the plant must be both novel and non-obvious.
- Importantly, naturally occurring substances and laws of nature cannot be patented, but new species can; and
- Software Patent: Software patents are patents that cover how a certain computer process works to achieve a specified result.
What Is Assignor Estoppel?
Assignor estoppel is a legal doctrine in United States patent law that prevents the seller, or assignor, of a patent from challenging the patent’s validity during any subsequent patent infringement litigation. In other words, if an inventor sells their patent rights to another party, they are barred from claiming that the assigned patent is invalid or worthless in court at any later point in time.
For example, if Jack invents and patents a product and then sells the patent rights to Jill, if Jill ends up suing Jack for patent infringement as the new owner, then Jack cannot challenge the validity of the patent itself, as Jack was the original inventor of the product.
As such, the doctrine of assignor estoppel prevents an inventor who sells their patent rights to assert later that what they sold was essentially worthless. Importantly, the doctrine of assignor estoppel also extends to any person that is “in privity” with the assignor of the patent rights.
Why Would An Inventor Wish to Challenge a Patent’s Validity?
As mentioned above, one of the main reasons that an inventor may wish to challenge the validity of a patent is to avoid patent infringement risks. In other words, if an inventor has sold their patent rights to another party, they cannot then not later decide to sell or manufacture their invention. This is because they no longer possess the rights to their own invention.
However, by challenging a patent’s validity, an inventor can avoid litigation and prevent unintentional infringement on the patent if they decide to utilize their invention. An inventor may also wish to utilize their invention in the development of a new invention. In this case, the inventor’s new idea might not be novel enough to be considered a new invention and then may then be sued for patent infringement.
Are There any Exceptions to Assignor Estoppel?
In short, yes, there are a few exceptions to assignor estoppel. Once again, assignor estoppel generally prevents an inventor, or later assignor, from challenging the validity of a patent they previously assigned. However, notable exceptions to doctrine of assignor estoppel include:
- If the assignment occurs before an inventor is able to make a warranty of validity regarding specific patent claims, assignor estoppel may not apply.
- In other words, if an employee prospectively assigns patent rights to their employer for any future inventions developed during their employment, then assignor estoppel may not apply in such cases;
- If the claims of a patent that was assigned become broader than those initially made in the original patent, and the inventor could not have known about these broader claims at the time that they assigned the patent, then assignor estoppel might not apply; and/or
- If the intellectual property laws regarding patent validity change after the patent is assigned, the assignor may challenge the patent’s validity under the new laws.
It is important to note that the doctrine of assignor estoppel is pretty rigidly applied. As such, the chances of an assignor successfully challenging a patent’s validity on their own invention is very low and often requires legal representation.
What Is Patent Infringement?
Patent infringement is a legal action that occurs when another individual or company makes, uses, or sells a piece of intellectual property without first obtaining the express permission or license from the patent owner. In the case of assignor estoppel, an inventor can be sued for patent infringement if they attempt to utilize their invention without the express permission of the party they assigned their patent to.
When proving patent infringement occurred, the party seeking the enforcement of the patent must demonstrate that the unauthorized product matches the “claims” that of the invention. Alternatively, the patent owner may demonstrate that the unauthorized product is “sufficiently equivalent” to their patent and would cause a likelihood of confusion to consumers.
Due to there being many different types of patents, there are also many different types of patent infringement, such as direct and indirect patent infringement. As such, in order to avoid being sued for patent infringement, a party wishing to use the intellectual property should seek permission from a patent owner or obtain a license to use the property.
In the case of an original inventor, they may also choose to simply limit the amount of time that their patent is assigned to another party. Inventors should be careful in permanently assigning their invention or idea to a party, especially if they feel they may wish to later use their invention or idea.
Do I Need a An Attorney for Help With Assignor Estoppel and Patent Invalidity?
If you are an assignor or an assignee of patent rights and are having issues involving assignor estoppel or patent invalidity, it may be in your best interests to consult with an experienced patent attorney. An experienced patent attorney can help you understand how assignor estoppel may affect you, and help you avoid potential civil liability. Additionally, an attorney can also initiate a civil lawsuit on your behalf and represent you in court, as needed.
