What is a patent application and how is it prepared?

A patent application is individually written for a specific invention, and thus can be a complicated and involved document. An application must include a written description of the invention that would enable a person skilled in the relevant technical field to both make and use the invention. This description virtually always includes illustrations of the invention and also describes the best manner known to the inventor for practicing the invention. The application includes an oath signed by the inventors that attests that they believe the application complies with the requirements of the patent laws, and the application concludes with claims that lay out the scope of protection that is provided for the disclosed technology.

A patent application is intended to be written for a person of ordinary skill in the relevant field of technology to the invention. An application, therefore, does not need to be a manufacturing blueprint since many minute details of a particular machine are not necessary to the invention that is incorporated into that machine. Specific dimensions or tolerances are normally unnecessary. In some instances, however, specific dimensions or tolerances may be critical to the performance of the invention or may actually be what sets the invention apart from prior technology and, therefore, would have to be included in the application. Although a patent is legally to be directed towards a person of ordinary skill in the relevant art, ultimately patents are evaluated by judges without technical backgrounds or by lay juries with no technical experience whatsoever. For this reason, the patent attorneys writing the application will employ a balancing act between explaining the invention in simplistic terms that can be grasped by a lay person while still complying with the technical disclosure requirements of the patent law.

Patent drawings are governed by rules specific to the Patent Office that permit the drawings to be later printed in the issued patent. Often, copies of conventional engineering drawings or simply rough sketches can be used for the preparation and initial filing of a patent application. Although, eventually, formalized drawings must be submitted for utility and design patent applications in order to meet Patent Office requirements.

The patent application, oath, and fee are filed with the Patent Office. After the original filing, no new information can be added to the application, even if it is later decided that insufficient information on the invention was originally provided. The particular way the information is stated can be amended or the focus changed for the claimed scope of protection, but no substantive information can be added. It is, therefore, important to make a complete disclosure in the first instance.

Patent applications are initially maintained in secret by the Patent Office, however, utility patent applications are published eighteen months after their filing date, unless the owner elects never to file the application outside of the United States. Also, design patents are published at the time of issuance. These types of patents provide different forms of patent protection and more than one of each may be filed on a particular invention. Essentially, a utility patent protects an article’s functional, while a design patents protects an article’s ornamental design or appearance. Accordingly, utility patent applications include a specification that describes how to make and use the invention and claims that define the legal bounds of protection of the invention, while the drawings of a design patent applications define the protection.

There is also a form of place-holder application, called a "provisional" patent application that may establish an early filing date for an invention. A provisional application does not undergo examination, and will not result in a patent, unless a formal utility patent application is be filed within one year of the provisional application filing date. A provisional application has fewer formalities, typically resulting a lower preparation cost, and lets the applicant claim "patent pending" on the invention during its 12 month life. There are a variety of reasons for filing a provisional application. These reasons often relate to time restrictions on preparation for filing, cost, uncertain value of an invention, and/or urgency to obtain an early filing date.