What Can Be Patented
Patent eligibility is a threshold issue before examining other requirements of patentability, such as whether the claimed invention is useful, novel, nonobvious, adequately described, and properly claimed. Even though many discoveries are eligible for patenting, some subject matter cannot be patented – even if it meets the other requirements. The mutually exclusive categories of eligible and noneligible subject matter are well defined in patent law. In the United States, almost every invention with a practical, concrete, or tangible application is eligible for patenting.
The general rule is that all useful subject matter is eligible for patenting. The Supreme Court has carved-out common-sense exceptions to this general rule: “laws of nature, natural phenomena, and abstract ideas.” Diamond v. Diehr, 450 U.S. 175, 185 (1980).
The statute (Section 101) sets forth in positive terms four general categories of patent-eligible subject matter:
1) processes,
2) machines,
3) manufactures, and
4) compositions of matter.