When people ask whether an invention can be patented, there are really several different questions.
Patent Eligibility Is Only the Starting Point
First, is the invention the type of subject matter the patent system can protect? U.S. patent law generally recognizes processes, machines, manufactured articles, compositions of matter, and improvements to them.
But being the right type of subject matter does not automatically make an invention patentable.
A useful way of thinking about patentability is through five basic questions:
Is It Patent Eligible?
Some subject matter, such as abstract ideas, laws of nature, and natural phenomena, can face patent-eligibility limitations.
Is the Invention New?
Is it new? If a single qualifying prior-art reference already discloses every required feature of a patent claim, that claim may lack novelty.
Is the Difference Nonobvious?
Is it nonobvious? Even if no single reference discloses the complete invention, a claim may still be rejected if the differences would have been obvious in view of the prior art.
Has the Invention Been Adequately Described?
Was the invention adequately described? The patent application must provide sufficient technical disclosure to support the claims and enable the invention to be made and used.
Can Meaningful Patent Claims Be Obtained?
For engineers, an especially important point is that the inventive feature is not always a new component. It may be a new arrangement, control relationship, sequence, interaction, or combination of known components.
For businesses, the more practical question is often not merely, "Can we obtain some patent claim?" It is whether the application can support patent claims broad enough to provide meaningful commercial protection.