Using An Inventor's Notebook to Protect Your Invention

U.S. Patent Law provides that patent rights should belong to the inventor who is the first to invent the invention. Patent rights include the right to exclude others from, among other things, making, using, or selling the invention. Before other companies or individuals can make, use, or sell a patented product, they have to seek permission or license from the patent holder or the patent holder can enforce his rights in a court of law. In determining who the first to invent is, the "date of conception," the "reasonable diligence," and the "date of reduction to practice" are considered. All these terms are terms of the art used by patent attorneys but are explained in general here.

The "date of conception" means the date when the idea was first thought about or when the inventor's light bulb first sparked on the subject. The "date of reduction to practice" means the date when the inventor first formed a concrete and at least minimally useful form of the idea. It can also mean the date an inventor files an application that enables a person of ordinary skill to make and use the invention based on reading the application (also referred to as an "enabling disclosure"). After the date of conception, the inventor has to exercise reasonable diligence to reduce the invention to practice, which means the inventor has to be diligent in creating a prototype or an enabling disclosure. Generally, between two inventors, the first to invent is the inventor who has the earlier date of conception and who can show reasonable diligence between the conception date and the reduction to practice date.

An "inventor's notebook" is a notebook that may contain the inventor's description of his invention, the components involved, unique methods or techniques, progress notes, problems encountered, observations, diagrams, and sketches with their respective dates of entry. An "inventor's notebook" is valuable for two main reasons. First, it helps a company establish that its inventor was the first to invent, which is often a critical issue in patent litigation or in proceedings before the United States Patent and Trademark Office (USPTO) involving ownership disputes. For instance, in an interference proceeding where two companies are asserting ownership of a particular invention, the USPTO may rely on the dates entered on the inventors'notebooks to find the earliest conception date and the earliest reduction to practice date. The USPTO may rely on the dates entered on the notebook to determine whether the inventors exercised reasonable diligence.

Second, inventor's notebooks are valuable because they help companies determine the proper inventor to list in a patent application. 35 U.S.C. 102 (f) states that an inventor cannot be entitled to a patent if he did not himself invent the subject matter sought to be patented. Thus, a patent can be invalid if it lists the wrong inventors. Generally, an inventor is defined as one who conceived of the invention. Commonly, however, many people mistake technicians who build prototypes as inventors; many people think that inventors are similar to company owners or company executives whom the inventors report to. With inventor's notebooks, a company's representative can determine whether an employee should be classified as an inventor based on the work the employee memorializes in his notebook.

The following serves as a general guideline for companies in using inventor's notebooks as a tool to protect their intellectual property rights.

  • Use thread-bound notebooks. Thread-bound notebooks, as opposed to a binder holding three-hole punched notes, are more reliable or trustworthy as the judge or the jury can see whether any pages were torn out or if any pages were later added. Thread-bound notebooks with page numbers are much superior and are more likely considered "credible" evidence than binders with loose pages.
  • Make entries traceable. A notebook is credible when it allows a judge or a jury to trace what was originally entered in the notebook. Inventors should use permanent ink. Deletions to the notebook should be done only by striking through once the affected word or phrase. Additionally, the inventor must fill in all the lines on a page and cross-hatch empty lines.
  • Have inventor enter as much relevant information as possible. The inventor should list the problem he is trying to solve, co-workers on the project and their roles, possible solutions he foresees, tests conducted, observations (both negative and positive), calculations, discussions, and conclusions.
  • Have the inventor sign and date each page. This is probably the most important step a company should encourage its inventor to take. A notebook that is not signed and not dated is worthless because it does not speak for itself with regard to the relevant dates of the invention.
  • Have a regular schedule for a witness to review, understand, sign, and date the pages of the notebook. A witness's attestation would bolster the credibility of the date entered. It would further bolster the date of reduction to practice because the witness' signature may be a proof of reduction to practice, i.e. that one of ordinary skill can understand, make, and use the invention at that time.

The information offered in this article is generalized and is not a substitute for the individual legal research and personalized consultation with an attorney, which is essential in every case. The information offered in this article further does not create a lawyer-client relationship.

If you have any questions regarding this article, please contact the Roland Tong at 949-298-6867 or Mr. Tong is a Registered Patent Attorney and has prepared and filed numerous patent applications for clients with inventions in the fields of gaming, electrical, mechanical, computer hardware and software, optics, medical devices, and biomedical technologies. He is admitted to practice in the United States Patent and Trademark Office and all state courts of California and Nevada. You can visit his website at