If you intend to file a patent application, you are advised to search for prior art relevant to your invention through a patent information database or have prior art searched by a patent information search company in your country before filing an application. If your invention has lost its novelty (and is already publicly known) at the time of the filing of the application, you cannot obtain a patent for the invention (Article 29(1) of the Patent Act). Almost all inventions for which patent applications are filed with a patent office in the world are published in patent gazettes. A patent examiner searches those gazettes and other patent information when he/she performs the substantive examination for your patent application. If he/she finds another invention already published in those gazettes identical to your invention, your invention is determined to be a publicly-known art, and it is often the case that your patent application is refused by the examiner. The Patent Act in English is available through the following URL.