how to check if an idea has been patented
There is no EASY way. If your invention is a new can opener, an existing patent for the same idea may never use the words can opener. For example, it may be described in broader terms: container de-sealer or metal wall scissor. The patent offices classification system helps a bit, but not much. Inventors tend not to want to find their invention, so, they type in --can opener-- and look at a few and say they couldn't find it. You have to look for it like you want to find it. try different search terms. when you find one thats close, look at the references cited in that application and look for other patents wherein the close one was cited.The Do-It-Yourself Patent Search
If you decide to do the patent search yourself, you have several search methods available: The USPTO (United States Patent Trade Office) Public Search Facility. The USPTO operates a Patent Public Search Facility located in Alexandria, Virginia. Here every U.S. patent granted since 1790 may be searched and examined. Many inventors like to make at least one pilgrimage to the Patent Public Search Facility. It's located fewer than 15 minutes from National Airport by taxi; Metro Rail serves it off the Blue and Yellow lines, King Street Station; and several hotels are within walking distance, so it's easy to get to and around.Why is classification so important?
While it is possible to search patents using keywords, the best way to conduct a comprehensive patent search is by classification. Classification helps bring together similar devices and concepts, even when different terms have been used to describe them. When a device is truly new, terminology is not set. For example, before personal computers a mouse was nothing more than a rodent. The inventor of the first "Computer Input and Display Control" would not have found related devices by searching the keyword "mouse." A classification is used both as a tool for finding patents (patentability searches), and for assisting in the assignment of patent applications to examiners for examination purposes. Classifications have definitions. Classifications have hierarchical relationships to one another.Is my invention already patented?
Determine if your invention is novel by doing a "prior art" or patent search, find out if someone else has already patented your idea. An inventor or hired professional can conduct a search of the USPTO records.What cannot be patented?
Laws of nature, Physical phenomena, Abstract ideas, Inventions which are considered not useful or possible by the USPTO for example perpetual motion machines; or offensive to public morality.