Under U.S. patent law, when two people file patent applications for the same invention, the person who invented the invention first is entitled to the patent. As a result, you may not be entitled to a U.S. patent on one of your inventions even if you file a patent application on that invention before anyone else. It is always possible that someone else who files a patent application after you will be able to prove that he or she actually invented the invention before you did.

One way to protect yourself against this risk is to begin documenting your inventions as early as possible in the inventive process. Such documentation, if prepared and maintained correctly, can be used as evidence of the date on which you first "conceived" of an invention. If you were ever to become involved in a legal dispute with someone else over who is the first inventor of a particular invention, and the other person has filed a patent application before you did, then your documented date of "conception" could be critical (in conjunction with other required evidence) to proving that you are the first inventor and therefore entitled to the patent.

The most legally defensible method of documenting a date of conception is for each potential inventor to maintain a lab notebook with bound (e.g., not loose-leaf) and numbered pages. As each potential invention is conceived, a description of it should be written at the next available location in the lab notebook, and be signed and dated. The author should explain the description to someone else with a confidential relationship (such as a co-employee), who should then sign and date the description as a witness.

Lab notebooks are available that are specially designed for documenting inventions for use in patent disputes. Even when using such notebooks, however, certain steps must be taken to guard against allegations of fraud or tampering. For example, no large spaces should be left between entries.

We regularly advise our clients on these and other techniques for creating and maintaining legally-defensible documentation of inventions. Please do not hesitate to contact us should you have any questions about the information provided herein.