A patent document is the starting point for a patent. A patent is a legal monopoly on a technical implementation of an idea. It is not possible to get a patent on the idea alone. A patent starts out as an application. When the patent application has been approved by the patent office, often after a long search for prior art by examiners, it becomes a legal monopoly on the techniques claimed in the document. It can be used to sue anyone who infringes on the claims. Even if anyone can write the document, a lawyer will help in covering all potential issues. There are different types of patents, most notably utility patents, which protect a way to do something, and design patents, which protect how something looks. This How To covers how to write a utility patent. To be patentable, an invention has to be useful, new and not obvious. It is usually considered obvious if "a practitioner skilled in the art" could already realize it. What can be patented are processes, machines, articles of manufacture, compositions of matter and improvements on any of these.
Investigate Your Idea
Go to any of several of the free patent databases, like PatentStorm, Google Patents, etc., and search for your idea. Try different formulations. Use Google Scholar to search for scholarly publications of the idea. If there are any documents describing the same concept, you may want to rethink getting a patent.
A patent document is required to have several parts: claims, description and diagrams supporting the claims. Start with the claims: What is the idea you want to protect, and how do you plan to implement it?
After writing the claims, draw the diagrams. The requirements for the diagrams depend on the technical subject. For computer-related inventions, a drawing of the functional machinery implementing the idea and a flow diagram of how the functions are applied is usually required.
When the drawings are completed, write the specification. It consists of a description of the known technology (the state of the art), and a verbal description of how the functional elements described are combined to produce the result described.
Note that for inventions in chemistry and life sciences, the description should be different than in physical sciences and computer science.
If the patent is about genes, the nucleotides or amino acids expressed have to be listed.
The U.S. Patent and Trademark Office requires the patent application to contain the specification (technical description), which includes the claim or claims. Then drawings if needed. There must be an oath or declaration that must follow formal requirements. These elements must be in that order, otherwise the application is invalid.
There are a number of formal requirements for a patent document. It must be written in English, or there has to be an English translation if it was originally written in a different language. If translated, there has to be a statement that the translation is accurate. You must also pay a fee.
The document must be typewritten or printed from a computer with black ink. The paper must be white, without holes, not shiny, single-sided and in portrait orientation. The paper has to be either 8.5 inches by 11 inches, or 8.26 inches by 10.98 inches. The left margin must be at least 1 inch, and the margins at the top, bottom and right at least 0.75 inches.
All forms and documents are available from the USPTO website.
Patent Attorney Review and Assistance
Once you are finished, let a licensed patent attorney review the document. She can also help you with all the formalities. There are several documents that must be submitted to the USPTO with the patent application.
If you are granted a patent, it means that your invention is unique not only in the U.S., but also the rest of the world, as far as the patent examiner has been able to determine. So when a patent is approved, it pays to apply for patents in other countries as well. A patent attorney will know what has to be done.
A patent has a duration of 20 years, but maintenance fees must be paid after 3 1/2 years, 7 1/2 years and 11 1/2 years. If you don't pay these fees, the patent is "dead"--not expired, but no longer an active document. A patent attorney can explain the significance.