How to read a utility patent
Utility patents can be confusing to understand. You have the claims which read like a foreign language, and the description which typically discloses details that are more specific than the patent owner would prefer. How do we make sense of these various parts of a utility patent? Let me try to shed some light.
Claims vs. disclosure
There is a fundamental difference between the purpose of patent claims and the purpose of the invention disclosure in a utility patent. I’ve discussed those differences here. Essentially, claims define the legal rights while the description provides support for the claims. Infringement is determined by the claims.
The description does not define the IP rights of a patent. You cannot determine infringement by comparing the description to a product. We frequently hear inventors share a common misguided concern over the description being too specific, as if the description would limit their patent rights. The descriptions in a utility patent are typically written with specific details so that the disclosed features may be claimed if and when necessary.
Are you trying to determine infringement or patentability?
When reading a utility patent, therefore, you need to first determine whether you focused on infringement or patentability. If infringement is your concern, your focus should be on the claims. If you’re trying to figure our whether your invention is patentable, you should focus on the disclosure which include the drawings and the Detailed Description of the Preferred Embodiments (discussed below).
What is an embodiment?
Embodiment is a fancy word for example. If you were asked – “What would your invention look like?” or “How would your invention work?” – your answer would be to show an embodiment of your invention. An embodiment gives concrete details to an abstract concept. In a utility patent, embodiments are important because they help show specific examples of how the invention would be created, used or practiced.
What is the Detailed Description of Preferred Embodiments?
While a utility patent contains several parts, the most important sections of a utility patent comprise the:
- Detailed Description of the Preferred Embodiments; and
The Detailed Description of Preferred Embodiments (“detailed description”) should describe in sufficient detail each significant embodiment of your invention. The keyword here is significant. It may not be practicable to describe all possible embodiments of your invention.
You will typically find numerals referenced in the detailed description that refer back to the drawings, known as patent figures. For example, the detailed description may discuss how part 1 is connected to part 2 and how the parts work together.
Helpful tip: When reading the detailed description, print a hard copy of both the figures and the description and place them side-by-side. As you read through the detailed description, you can refer to the juxtaposed drawings to make sense of what you’re reading.
How to understand patent drawings
We sometimes hear folks saying that they reviewed the patent drawings and, therefore, have no concerns regarding patentability or infringement based on the patent figures. Is that a proper way to view patent illustrations?
The answer is most likely no. Patent drawings would be helpful in determining infringement or patentability if we were talking about design patents. With utility patents, however, the figures generally provide context and a visual representation of an embodiment of the invention. The drawings are part of the disclosure of the invention and, as disclosure, they are not the same as the claims.
Therefore, it would be wrong to assume that infringement is not a concern because your concept looks different than what is shown in the patent drawings.
It could also be a mistake to assume your invention is patentable because you failed to see a particular feature in the drawings. Sometimes, a patentee will disclose a feature only in the written description, but not necessarily in the figures. To be thorough, you should check the detailed description to make sure that it does not discuss the key features you believe are unique to your invention.
Lastly, if you are reviewing the drawings of your own utility patent, keep in mind that your patent figures do not define your utility invention. The claims do. In a utility patent, your drawings provide examples with specific features and details that may support your claims.