The scope or coverage of a patent is determined by its claims, which are the
numbered paragraphs at the end of each patent. In order for a claim to be literally
infringed, there must be a literal correspondence, element for element, with the
allegedly infringing device. Even in there is not a one-to-one correlation between the
patent claims and the allegedly infringing device, infringement can exist if the missing
element or elements are found in the device in an equivalent manner. The claims can be
viewed as a checklist for determining whether a product infringes. Only one claim of
the patent need be infringed for liability to arise.
In order for a patent to be infringed, it must be enforceable and valid. These
issues require a detailed review of the materials filed by the inventor and his or her
attorney, correspondence between the inventor and the Patent and Trademark Office
and the prior art relevant to the subject matter of the patent. If a question arises as to
the validity or infringement of a patent belonging to you or another person, such
questions should be referred to an attorney who is experienced and familiar with
patents and patent enforcement.