Jepson claim strategies demands varieties of claim types which are often selected based on the subject matter that needs protection by means of the patent claims.
Jepson claim is a method or product claim where one or more limitations are specifically identified as a point of novelty, distinguishable over at least the contents of the preamble. The Jepson claim can be used for method claims as well as product claims. A Jepson claim is one where the preamble makes some kind of statement that relates to the state of the prior art, and then claims an improvement over the prior art. That is, a Jepson claim describes the prior art, before specifying an improvement to it.
The Jepson format claim recites all or at least some elements of a known article, process, or combination in its preamble. The preamble is usually rather lengthy, in contrast to the short preamble used in other claim formats. Following its preamble, the Jepson claim includes a transition clause that states, “wherein the improvement comprises,” or “the combination with the old article, etc. of.” A simple example of the Jepson form is “In a process for making widgets, with elements A, B, and C [the prior art], wherein the improvement comprises [the transitional phrase], element D [the inventive element(s)].”
The Jepson claim format may read, for instance, “A system for storing information having (…) wherein the improvement comprises:”.
The Jepson format is good and proper, but the occasion is rare when it is the recommended format. Its use is optional, but sometimes the Patent Office encourages its use in independent claims. For example, this style of claim is the preferred form in European practice, where they are called “two-part format” claims, and the transitional phrase is “characterized by…” or “characterized in that…” Jepson claims are most often used when the invention is an improvement on an existing product. All said, it is seldom used in practice other than the European patent applications, and even there its use is declining.