What is Prior Art?
The trouble with explaining what prior art is stems from the fact that everyone already thinks they know what it is. Conceptually we do not want to issue patents for inventions that are not considered new, which seems fair enough. The trouble is defining what is “new.” For now, let’s just say that prior art must be a reference of some type (i.e., a patent or a printed publication) or some type of knowledge or event (i.e., public knowledge, public use or a sale of a product) that demonstrates that the invention in question is not new.
Now comes the curve ball you have probably been expecting. Not all references, knowledge or events that can demonstrate that an invention is “old” or already known can be used by examiners or during litigation against an invention.