Getting a Patent: The Devastating Consequences of Not Naming All Inventors

“A joint inventor of just one claim enjoys a presumption of ownership of the entire patent. So, an inventor of just one dependent claim can own the patent equally to the inventor of 99% of the patent.”

Naming the correct inventors is critical when drafting a U.S. patent. Patents must have all inventors properly named. Deciding who is an inventor is a complicated task and great care must be taken to not add or omit people who are not inventors. It is possible that failure to properly name the inventors could result in losing your patent or its value.

Correcting the Inventors

inventors, RejectedIf inventors have been improperly added or omitted, the patent must be corrected or it could be declared invalid.

You can correct the inventors. This can be done by the United States Patent and Trademark Office (USPTO) or by court order. The USPTO requires a petition stating that it was an error and all the parties and assignees must make the application, agreeing it should be corrected. If all parties don’t agree, the assignee can file a request for reissue of the patent naming the correct inventors. A court can also order the USPTO to make the correction. If the inventors can be corrected, the error won’t invalidate the patent. If it cannot be corrected, the patent is lost.

Having the wrong inventors often arises when the patent becomes valuable—when the product or process is successful and those involved feel they’ve been wrongly excluded and want to be included.

Owners vs. Inventors

Owning a patent is different than being an inventor. An owner doesn’t have to be an inventor, but an inventor can be an owner. Owning a patent allows the owner to enjoy the value of the patent and to prevent others from infringing. Ownership is acquired from the inventors, typically through an assignment of their rights. An assignment is a legal document transferring the rights of the inventors (assignors) to the owner (assignee).

Initially, every inventor owns an equal right to the patent, no matter what they contributed. This means that each inventor can do what they want with the patent. They can sell it, license it, make and sell the product or process covered by the invention, all without the permission of any other inventor. They can also frustrate any lawsuits, since all owners have to be joined in a lawsuit.

To prevent each inventor from doing what they want, the rights are assigned to a single person or entity. Once assigned, that person or entity owns all rights.

However, even with an assignment, if you missed an inventor, you may find that someone else owns the same rights that you own in the patent. Each inventor owns a pro rata undivided interest in the entire patent, no matter their respective contributions. A joint inventor of just one claim enjoys a presumption of ownership of the entire patent. So, an inventor of just one dependent claim can own the patent equally to the inventor of 99% of the patent.


Can This Really Happen?

In 1989, Ethicon, a manufacturer of surgical instruments, filed a patent infringement suit against a competitor, United States Surgical, over U.S. Patent No. 4,535,773. The inventor named on the patent was Dr. Inbae Yoon. Yoon granted Ethicon an exclusive license to practice his invention. The patent had 55 claims but only two claims were asserted against U.S. Surgical: claims 34 and 50.

During the lawsuit, U.S. Surgical learned of a co-inventor named Young Jae Choi. Choi was an electronics technician who collaborated with Dr. Yoon for 18 months. US Surgical asked the court to add Choi as an inventor. The court agreed finding that Choi had co-invented claims 33 and 47. Two claims that were not even involved in the lawsuit.

The court found that there was corroborating evidence that supported Choi’s assertions that he was an inventor. The evidence was dated notes and drawings that Choi had along with his technical abilities as an electronics technician.

The court dismissed Ethicon’s lawsuit because Choi had granted U.S. Surgical a retroactive license to the patent. OUCH!

Collaborating with Others Can Create These Issues

Businesses often collaborate with outside experts. These experts can become inventors. Many business owners think that because they have hired and paid someone to assist in developing a product, they own the results. Or, they think that it was their idea, and they don’t need to add the experts. Many times, they don’t even mention it to their lawyers, thinking it isn’t important. But that outsider might be an inventor of just one claim and have equal rights to the patent. Whether they are listed as an inventor or not, they may be able to license their patent just like Choi did.

How Do You Avoid This?

To avoid this, carefully identify all inventors and have them sign an assignment agreement. This agreement transfers their rights to a single entity, such as an individual or the company that is going to exploit the patent. In the Ethicon case, Yoon should have entered into an agreement when he started working with Choi. That agreement would have required Choi to assign his rights to Yoon.

Even better, have all employees sign an agreement requiring them to assign any IP rights to the business and cooperate in the patent process. Consultants should enter into similar agreements when they are hired. If Choi had assigned his rights to Yoon, Ethicon would have been able to continue their lawsuit.

Corroborating Evidence

If everyone doesn’t agree the inventors should be changed, the Court will require evidence to corroborate the requested change. This is where invention records are important. Keeping detailed, dated records of the development and the contributions of everyone can provide important evidence for the court to make its decision. Choi used these to convince the court to add him as an inventor.

The Takeaway

Correctly naming the inventors is critical in a patent. Care should be taken to record the contributors and the dates of the developments in the process. Have everyone involved in the development sign agreements to transfer their rights to a single entity. Keep a list of everyone involved and their respective contributions. Review this with your counsel to determine the inventors are named. You don’t want unwelcome inventors showing up later.

It requires planning and a little record keeping, but it will ensure that you don’t lose your patent.

Image Source: Deposit Photos
Copyright: draskovic
Image ID: 5687178


Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of

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