What is a patent claim?

A patent claim is the precise legal definition of the invention, identifying the specific elements of the invention for which the inventor is claiming rights and seeking protection. The information in the claims of a patent is what determines what rights the patent holder has. In other words, if an inventor wants to protect specific element of his invention, that element needs to be included in the claims. There are two specific types of claims:

First there are independent claims, which are claims that do not refer to any other claims in the patent application. For example, if you have a patent on the pencil, a dependent claim might start out, in legalese, as “a device comprising a cylindrical piece of wood with a piece of lead inserted into the center of the wood….”

Second, there are dependent claims, which refer to and rely upon another claim in the paten.  Using the pencil example from above, if that was the patent’s first claim, the second claim may be for the same pencil with an eraser and might start out, in legalese, as “a device as described in Claim 1, wherein a piece of rubber is attached to one end of the cylindrical piece of wood….”