I am wondering about whether or not my idea has already been patented. In particular, I have combed over the patents that have been issued, but it remains a possibility that a patent, which eliminates my chances, is filed either as provisional or simply has not been issued yet. I suppose I want to avoid the cost and pain of creating a patent, if someone already has something filed. My question is, does Google patent search return patents that have not been issued? How do I search against patents that are filed but not issued? What about provisional patents? It seems strange that there can be all these filed patents lurking away, eliminating our chances but we cannot see them.
It isn't only patent documents that can cause your invention to be seen as not new. Your idea may not be patented but may be described in a patent, a patent application, a magazine article or on-line. It may be in a Russian patent or patent application. Google patents is good but it is not close to exhaustive. Really, no search can prove a negative, that something isn't out there somewhere. So we do the best we can in searching. Most patent applications on a worldwide basis are published after 18 months. So at the time you file there are 18 months of things on a ww basis that are "secret prior art" to your application.