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.You Can't Be Too Obvious
Even if you don't find the prior art to prove it - you will not get a patent if your invention is not different enough from similiar inventions that are already out there. A patent maybe refused if the differences between your invention and another invention are too obvious. Your invention must be sufficiently different from what has been used or described before that it may be said to be nonobvious to a person having ordinary skill in the area of technology related to your invention . For example, the substitution of one material for another, or changes in size, are ordinarily not patentable. You can't paint it red and make it twice as big and expect a patent. Another example of "nonobvious to a person having ordinary skill in the area of technology related to your invention" could be the following. An electronics engineer looks at a circuit board and observes that it is just like another circuit board except that a few parts are substituted. Someone who is not familiar with circuit boards may not understand that the two boards are very similar, however, someone with training thinks that it is obvious. You would want the electronics engineer to look at the circuit board that you want to patent and say, "heah, why didn't I think of that!"Filing and Examination Process
The USPTO accepts applications filed electronically as well as paper applications delivered by mail. However, since 2011, the USPTO charges an additional fee for non-electronic applications. Fees cover the USPTO's cost to examine your application and are non-refundable regardless of whether the examiner grants your application. Fees vary depending on the size of your organization and the number of claims you make. Because the amount changes every year, the USPTO recommends checking the current fee schedule before you file your application. The backlog of applications means it can take one to two years before an examiner takes his first action on your application. If he rejects any or all of your claims, you have the opportunity to reply and amend your application before a final decision is made. If the examiner grants your patent, you must pay additional fees for the patent to be issued and published.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.Direct-Hire Professional Search
If you want to save lawyer fees and mark-ups, consider going directly to a patent search firm. Searchers are best found through inventor grapevines, inventor associations, or university intellectual property departments. In larger cities, you can also check the Yellow Pages under "patent searchers." But be careful not to fall into a trap set by some disreputable invention marketing organizations. They list themselves in the phone book under "patent searchers" with a toll-free number. This is another way they hook unsuspecting inventors into service contracts. Get all the facts up front. Some reputable searchers ask for money up front if they don't know you. This is understandable. Just be sure you get the cost of the search beforehand, and get—and check—references. The cost to search a utility patent in the Washington, D.C., area runs between $500 and $1,000. It is roughly $100 per hour for a competent search. Once the search has been completed, if you want to obtain an opinion on the patentability of your invention, add the cost of your lawyer. If you need to show a prospective licensee that your invention has a good shot at a patent or that it's unlikely to infringe on an existing product, a letter from competent patent counsel may do the trick.