A new and useful invention is patentable only if it is not obvious to an unimaginative person of ordinary skill in the field of the invention. Obviousness assessment is based on the “state of the art” and the common general knowledge of the skilled person at the claim date of the invention.
At the core of obviousness analysis is the identification of the “inventive concept” of the claimed invention, and whether the difference between the inventive concept and the state of the art would require the skilled person to take any inventive step or conduct arduous searching and testing.
The obviousness analysis may involve consideration of a number of factors, including:
- The interpretation of patent claim at issue.
- The hypothetical skilled person and the common knowledge of this person.
- The prior art and the climate or trends in the relevant field.
- Any motivation at relevant time to combine or modify prior art to arrive at the claimed invention.
- The time and effort involved in the claimed invention.
- Whether the claimed invention was obvious to try.
- Commercial success of the claimed invention.
The Canadian Federal Court of Appeal has cautioned against relying on hindsight when challenging a patent for obviousness:
Every invention is obvious after it has been made, and to no one more so than an expert in the field. Where the expert has been hired for the purpose of testifying, his infallible hindsight is even more suspect. It is so easy, once the teaching of a patent is known, to say, “I could have done that”; before the assertion can be given any weight, one must have a satisfactory answer to the question, “Why didn’t you?”
Even if an invention is directed to a particular combination of well-known parts, the combination itself is not necessarily obvious. In addition, the simplicity and easiness of an invention does not render it obvious. After all, a mere scintilla of invention is sufficient to support the validity of a patent.