NB: It is best to keep an invention strictly confidential, at least until you file a patent application. If the invention is placed on sale, or advertised for sale, or sold or generally placed in the public domain through presentations made at seminars or a paper or poster presented at a conference and more than one year passes, the invention is no longer patentable in the United States.
A patent search is usually done before the application. This ensures that the invention about to be patented is, in fact, new.
A patent application must be complete since it is not permissible to add new material to an application after it has been filed. In the case of utility patents, the application must include a detailed and complete description of the invention and a set of drawings (if the invention can be illustrated by drawings). The application also includes a set of claims, which are carefully written, single-sentence paragraphs that precisely define what the proposed patent will and will not cover— the scope of the protection.