A set of claims of a patent or patent application will have independent and dependent claims. An independent claim is a claim that does not depend on another claim. A dependent claim is a claim that depends on another claim. The independent claim is broader in scope compared to a dependent claim. A claim set can have one or more independent and dependent claims for the purpose of increasing patentability during the examination process and surviving invalidity challenges during litigation.
What is an independent claim?
An independent claim is a claim that can stand alone without any reference to another claim.
For example, as shown below, Claim 1 recites “1. An eye protector having a center portion defining a center of gaze of a wearer.” Claim 1 does not refer to any other claim. Here is a link to the full patent: US Pat. No. 9295297. After clicking the link, you will see that Claim 11 also does not refer to any other claim. Claims 1 and 11 are independent claims of this patent.
What is the purpose of having multiple independent claims?
The purpose of having multiple independent claims is to claim different aspects of the invention so that you can sue different entities up and down the supply chain. You might think that all you have is a new product that can be patented. A more sophisticated view of your patentable product is that you can get a patent on the product but also on:
- a way to manufacture the product (sue the manufacturer);
- a way to use the product (sue the end user);
- only a unique patentable component of the product (sue a component manufacturer);
- a system in which the product is used (sue a distributor or system’s company);
- the product itself (sue the retailer, manufacturer, distributor);
As you can see, you can patent different aspects of the product. To do so broadly, you may need to have an independent claim for each different aspect. Be aware that the examiner might give you a restriction requirement. As such, oftentimes, multiple independent claims are more closely related to each other to avoid the restriction requirement.
What is a dependent claim?
A dependent claim is a claim that refers to another claim in the claim set. The dependent claim can refer back to an independent claim or to another dependent claim. For example, Claim 2 shown above is a dependent claim because it depends on Claim 1.
Dependent claims are narrower in scope compared to independent claims. Here’s why. To infringe a dependent claim, the infringer must incorporate all aspects of the claimed invention described in both Claims 1 and 2. In contrast, to infringe an independent claim, the infringer need only incorporate all aspects of the independent claim only.
What is the purpose of a dependent claim?
The purpose of a dependent claim is to increase the patentability of the invention during the examination. The examiner is supposed to review the claims and determine whether each claim is patentable. The idea is that you present independent and multiple dependent claims so that you can give the examiner the option to allow a dependent claim in the event an independent claim is not patentable.
During litigation, a similar logic applies but in a slightly different manner. The infringer will raise multiple prior art references to show that the claims are not novel or are obvious. Because dependent claims are narrower compared to independent claims, it is more difficult to invalidate an independent claim compared to a dependent claim. As such, it is beneficial to have multiple dependent claims to increase the likelihood that it will survive an invalidity challenge by an infringer during litigation.