This post is part of a series of posts entitled A Guide To Intellectual Property Protection. For a comprehensive list of articles contained in this series, click here.

The issues of patentability and infringement are entirely separate. A patent granted by the U.S. Patent Office confers upon the owner the exclusive right to exclude others from “making, using, and selling” the patented invention. The issuance of the patent does not confer upon the owner the right to make, use, and sell the patented invention. One reason for this distinction is that the patented invention may be an improvement over a prior, valid patented invention. In that case, making, using, and selling the improvement is subject to the prior patent. For example, assume that a first inventor develops a fixed blade knife (e.g., a knife having a handle and a blade). The first inventor applies for and obtains a patent. Later, during the term of the patent, a second inventor develops a pocketknife that is identical in every way to the fixed blade knife — with the exception that the blade rotates and folds into the handle. On these facts, it is possible that the first inventor’s patent may be broad enough to cover the second inventor’s pocketknife. This is true regardless of whether the second inventor applies for and/or receives a patent from the U.S. Patent Office. The question of whether a license is required is based on the claim language of the first inventor’s patent — not the patent status of the second inventor’s invention.