Field of The Invention

The Field of the Invention (or simply "Field") should be carefully chosen to balance among competing considerations. On the one hand the Field should be sufficiently broad to encompass all contemplated embodiments of the claimed invention. For example, if it has been discovered that a particular ceramic is useful for filling dental caries, the Field may properly be worded as "dentistry". But if the inventors contemplate that the ceramic may also be used for filling voids in bone elsewhere in the body, the Field should probably be worded more broadly as "bone repair, including orthopedics and dentistry". Still further, if the ceramic itself comprises the principal novelty, the Field is more properly worded as "medical ceramics" or merely "ceramics".

One competing consideration is that designation of the Field can be viewed as an admission on the part of the patentee that one of ordinary skill in the art would look in that entire field for guidance in solving the problem addressed by the invention. A patentee may therefore want to describe the Field narrowly enough to support a future argument for excluding prior art. Consider, for example, a novel software approach for attacking viruses in computer systems. If the Field is described as "antiviral systems and methods", there is a substantial possibility that a patent examiner will cite references from the biological world against the claims. In that instance it is probably better to limit the Field to "antiviral software".

Some patent attorneys try to satisfy these competing needs by describing the Field from a hierarchical perspective. Typical language along those lines might be "The field of the invention is athletics, more particularly sporting goods, more particularly basketballs, and more particularly methods of inflating basketballs". That sounds nice, and possibly even sophisticated. But I have never discovered any justification for such verbosity. From my perspective it is better to invest the effort to develop simpler language. In the example just cited, the patent attorney could far more simply have stated, "The field of the invention is basketballs" or "The field of the invention is inflatable devices".

A key reason for drafting the Field (and indeed the entire Specification) in simple terms is that it prevents the attorney from hiding sloppy thinking among a morass of words. Simple writing forces the attorney to ask himself the difficult questions. I recently reviewed a draft application that claimed methods for increasing the water absorbency of polymers, and possibly other materials. The Specification disclosed some applications with respect to filtration of fluids, and the draft recited the Field of the Invention as a hierarchy of uses, culminating in use of the modified polymers for water treatment. But that wasn't the invention. The water treatment aspect was merely a particularly interesting application of the invention. The Field was more properly characterized as "absorbent materials". Use of hierarchical listings is not necessarily wrong. But it does beg the question of whether the attorney adequately thought through all the considerations.

Another consideration in delineating the Field is the potential for licensing to different companies. It is not at all unusual for inventors, managers, or major shareholders to have interests in related but distinct companies. In those instances it may be very important to separate out related technologies by filing overlapping patents in different fields. Thus, in the example above it may be advantageous to draft a patent for one company that focuses on the absorbent materials, and to draft another patent for a second company that focuses on the equipment needed to modify the materials. Making the Field too broad can result in unnecessary conflict.

Still another consideration is that the description of the Field can affect what examining group gets assigned to the matter. The business methods and Internet-related examining groups are currently backlogged seven to ten years, while other groups may not be backlogged much at all. I recently wrote a group of three applications relating to wireless communication among computer components. I specifically drafted the Field of the Invention sections with the goal of landing the applications in different examining groups. That way there is at least a chance of getting something allowed in the short term. In another instance I successfully petitioned to move the case from a slower examining group to a faster examining group, based in part on how the Field was described.