Novelty

• When applying for a patent, the most important characteristic your invention must demonstrate is novelty. Your invention must be unique, without exception. No other patents or patent applications must apply. According to the University of Colorado College System's Technology Transfer Office, "an invention is 'novel' if nothing identical previously existed."
  
  

Non-obvious

• The University of Colorado College System's Technology Transfer Office says that "nonobviousness measures the degree to which an invention differs from the totality of previous knowledge, and the degree to which an invention could not have been anticipated from that knowledge." They recommend you ask yourself the following questions to be certain your innovation qualifies for a patent: (1) At the time it was conceived, why might your invention not have been obvious to people reasonably skilled in the field? (2) What is the difference between the proposed invention and what has previously existed? Your invention must be significantly different to qualify, not simply a variation on an existing patent.
  
  

Utility

• "Usefulness" is a key criteria of patents, according to the U.S. Patent and Trademark Office. The Ohio State Office of Research offers a helpful definition, noting that the proposed invention "must perform some function, be operable, and must be beneficial to society."
  
  

Burden of Proof

• When filing for a U.S. patent, or when defending an existing patent against infringement, the applicant has the burden of proof. This means you must prove novelty, non-obviousness and utility in order to be approved. Some applicants have used expert witnesses and fact-based evidence to support their cases.
  
  

Choose the Correct Application Type

• The nature of your invention will determine the patent application type required. The U.S. Patent and Trademark Office offers three types of patent applications. You may file for a design patent, a plant patent or a utility patent. A design patent relates to ornamental characteristics. A plant patent is used to patent a new variety of asexually produced plant. A utility patent--the most common patent application--covers all useful process, machine, article of manufacture and composition of matter inventions.