What is reissue?
Patent law states "On taking up an application for examination or a patent in a reexamination proceeding, the examiner shall make a thorough study thereof and shall make a thorough investigation of the available prior art relating to the subject matter of the claimed invention." This means that prior art could disqualify your application for a patent.USPTO Fees
The USPTO charges fees at every step of the patent process and these fees are the only fixed cost in the process. The USPTO charges a required $330 to file an application, $540 for a search, $220 for an examination, $1,510 to issue the patent if it passes the examination, plus $7,750 in maintenance fees over the 20 years that the patent is in force. Hence, the total to file and go through the process is $1,090, but the total to receive the patent and keep it in force is $10,350. Note that independent inventors and small businesses receive a 50 percent discount on fees but that the USPTO charges more for extra or late paperwork.More on Prior Art
Remember, while patent searching is a big part of prior art , it is not everything. If someone has made your invention before you without patenting that still counts against your patentablity. A complete search for prior art might include for example: searching non-patent literature such as any magazine, newspaper, or trade paper article written about inventions like yours also a complete search would include international patent documents (online) and not just those found at the USPTO. Do not make the mistake of believing that just because no one else is selling your product that it does not already exist. After determining that your idea is patentable and qualifies for a patent - you now need to decide if the expense of patenting is worth it.How long does patent protection last? (As of year 2005)
Utility and plant patents are granted for a term which begins with the date of the grant and usually ends 20 years from the date the applications were filed. You must make the timely payment of the appropriate maintenance fees. Design patents last 14 years from the date you are granted the patent. No maintenance fees are required for design patents.How to Patent an Idea - US Patent
Bring your invention to life and protect it with a US patent. The property rights that a US patent gives your invention means the right to prevent others who do not have your permission from making, using, offering for sale, or selling your invention in the United States or importing your invention into the United States. To get a US patent, all applications must be filed in the US Patent and Trademark Office.