Dependent claims are claims that have some type of direct connection to a previous claim. Considered a common element in patent law, the dependent claim is often a means of providing more specific data about a prior or independent claim. This approach is sometimes helpful because dependent claims allow the owner to retain some interest of control even if one or more of the foundations for the original or independent claim are later found to be flawed in some manner.
Within the bounds of patent law, dependent claims are part of what is known as the claim tree. The basis or root of the tree is the independent claim that is first structured by the individual seeking the patent. From there, a series of dependent or associated claims are also filed, with each claim narrowing the focus of the original independent claim. For example, if the original or independent claim is for a device that could conceivably be used in a number of different applications, the resulting dependent claims could focus on each of those applications. Even if the broader application in the original claim is later contested, one or more of the more focused applications named in the dependent or associated claims may still stand.
There is some danger of encountering issues with dependent claims. If the scope of the originating or independent claim is already somewhat narrow in scope, preparing several different dependent or associated claims for inclusion in the claim tree may be extremely difficult. In addition, if the associated claims are not judged to be unique enough in the addition of information that helps to narrow the scope, those claims may be rejected as worthless. For this reason, dependent claims should be prepared with care, making sure they comply in every way possible with currently existing patent laws.
The use of this combination of dependent claims along with an independent claim makes it possible to still obtain a patent even if the original claim is denied due to the device being similar to other devices already protected by a patent. While the device may be very similar to something already used widely in one setting, it may still be possible to hold a patent for that device in a completely different field. With this approach, inventors have more of an opportunity to lock in claims that help to protect the revenue that may be generated by the patented device in different settings.
