Any process, machine, manufacture, compound, or composition of matter, or a new and useful improvement on any of those, may be patentable – provided the inventor discloses the invention, which would enable a person of ordinary skill in the art to make and use the invention without undue research or experimentation. The invention must also be useful, novel and not obvious.
Novelty - An invention must be new. If it has been publicly known, used, sold or described in printed material available anywhere in the world before the date of patent application filing, then such an invention cannot be patented.
Utility - In addition to being novel, it also must be useful. The invention must perform a function, do what you say it does, and benefit society in some way.
Non-obvious - An invention must not be obvious to a person of ordinary skill. It may not be merely a collection of known elements or steps, nor may it consist of known equivalents in an old machine, compound, composition, or process. Since the terms “obvious” and “person of ordinary skill” are subjective, frequently there is disagreement about the fulfillment of this requirement. It is important to consider why your invention might not have been obvious to others reasonably skilled in the field.
The three legal classes of patentability are:
Utility Patents: Granted to inventions that involve a new and useful process, device, machine, manufactured item, chemical compound or formula. Utility patents, which apply to virtually anything that can be made, are granted for a period of 20 years from the date of filing a patent application, after which the patent to an invention becomes public property.
Design Patent: Granted to a new, original or ornamental design for a manufactured item. Patents on ornamental designs last 14 years, and they protect only the appearance of the item.
Plant Patent: Granted to an invented or discovered new plant variety that can be asexually reproduced. Plant patents are granted for a 20-year period.