How to write a patent specification?


Title of the invention. The title of the invention is designed to describe the essence of the invention in a few words. The title must clearly and concisely indicate the subject matter to which the invention/innovation relates and must be the same as the title on the Request Form and Abstract.

Cross-reference to related applications. In this section, the applicant lists any provisional patent applications that they are claiming priority to, or if the application is a continuation, the parent application number(s). This is a general broad statement describing the art or technology to which the invention/innovation relates.

Background of the invention. The background of the invention is typically drafted for a jury audience. Selected art in the field is discussed to emphasize differences with the current invention, and to point needed improvements that are provided by the current invention. This should include a summary of any background art known to the applicant which may be useful for understanding the invention/innovations.

Summary of the invention. The summary of the invention, which is distinct from the abstract, is meant to discuss the invention (i.e., the claims) rather than the disclosure as a whole. Often, the summary will discuss advantages of the invention or how it solves the problems existing in the art, such as those presented in the background of the invention. This normally includes a statement of the essential and optional features of the invention and any advantages of the invention or innovation over the known art

Description of the drawings. If drawings are included in the application, a brief description of each drawing is required.

Detailed description of the invention. The detailed description of the invention is the meatiest section of a patent. Its purpose is to adequately and accurately describe the invention. There are generally two sections:

  • A general explanation of the invention and how to practice it.  The invention is described in its broadest sense, to show that the inventors have a broad view of the scope of the elements. Often, preferred embodiments of the invention are described. Such embodiments are generally more limited versions of the broadest concept and are provided for support for a fall-back position of narrower claims if the broader concept is not patentable. Definitions of key terms are often provided and are extremely important in interpreting the scope of the claims.
  • Specific examples of how to practice the invention.  A patent application does not require examples, however in practice, examples can often assist in showing patentability (e.g., enablement). The examples may or may not have been performed by the inventors. “Working” examples present completed undertakings. “Prophetic” examples are hypothetical undertakings and are always written in the present or future tense. Typically, the examples demonstrate practice of one or more specific embodiments of the invention.

(Many new readers find the purposes of these two sections confounding and assume that the examples set forth how the invention will be practiced. Rather, examples are meant only to illustrate, but in no way to limit, the claimed invention).

The Claims

The major function of the claim or claims is to clearly define the scope of protection granted. The claims must be clear and concise and must be supported by and agree with the inven­tion/innovation disclosed in the descriptive part of the patent specifi­cation.

The claims are probably the most important part of the patent speci­fication and, because of their legalistic nature, are probably the most difficult to prepare. For example, it is possible for the patent speci­fication to describe a commercially successful invention but, because of poor or incorrect drafting, the claim (s) may be invalidated because they are drafted too broadly resulting in a lack of newness or inventive step or, conversely, the claims may be drafted too narrowly thus making it easy for competitors to benefit from the invention without infringing the claims.

The claims should commence on a new page and each claim should be written as a single sentence. Whenever appropriate the claim should define the invention/innovation first by indicating the background prior art, followed by a “characterising” portion which defines the features of the invention/innovation which, in combination with the prior art features it is desired to protect. Each technical feature mentioned in the claim (s) and illustrated in the drawings should, wherever possible, be followed by its reference numeral i parenthesis. Only one claim is allowed in a utility innovation specification whereas a plurality of claims are allowed in a patent specification. However, the claims of a patent specification must relate to the same invention. An example of a set of patent claims can be found at Sample of Patent Specification.

Abstract. The abstract is a brief summary of the entire specification.