The commonly known patent type is a utility patent. A utility patent is granted for a new and useful invention that has practical application. There are also design patents, for novel product designs.

Ultimately, the value of a patent is in its adoption by infringement. Litigation invariably results. A quality patent withstands attacks of invalidation by infringers, leading to licensing or other compensation.

Patentability

Patents "include anything under the sun that is made by man," the Supreme Court ruled in Diamond v. Chakrabarty.

An invention is patentable if it falls within one of four categories: a "useful process, machine, manufacture, or composition of matter." Novel man-made life forms are patentable, for example.

An abstract idea cannot be patented. To be patentable, a claimed process must produce a "useful, concrete and tangible result." Computer software is patentable as a process, as data transformation qualifies for patent protection, so long as a useful, practical result is claimed.

Patent Quality

Breakthrough consumer product patents can reap a few million dollars, while valuable high-technology patents, such as in software, may be worth hundreds of millions.

But most patents are worthless, for various reasons. Many are badly written, with the claims poorly drafted. Sometimes the claims are not broad enough to snare infringement; sometimes so broad as to encompass prior art, missed by the patent examiner, and thus not be enforceable.

A patent is merely a description. A quality patent is simply a well-written specification with a well-claimed novel invention. The clearer the conveyance, the better the patent.

Patents represent a guess in the direction that technology may veer; sometimes that guess is wrong, or, on rare occasion, way before its time. For example, spread spectrum wireless, now ubiquitous, was patented in 1942, but not adopted until the 1970s.

The best hedge for an enforceable patent is to capture a variety of possibilities in the technology area to which the patent applies.

A New Obviousness

In April 2007, the Supreme Court, in KSR v. Teleflex, declared that the standard of innovation for patents for the previous 40 years was too low. KSR raised the bar, making a majority of granted patents invalid as obvious. KSR requires a more clever level of invention than practically any time in U.S. history.

In essence, the Supreme Court ruled in KSR that a combination of elements previously known were not patentable unless there was some change in functioning, an unpredictable synergy. Further, modest improvements that might appear obvious are not patentable.

A court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions. The analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.

- KSR v. Teleflex, The Supreme Court

Prosecution

The patent prosecution process begins by filing an application with the USPTO, the patent office, which includes a specification, claims, and requisite forms, along with a filing fee. An applicant prosecutes patent claims through an examination process conducted by a PTO examiner.

Examination focuses almost exclusively on the claims. Patent prosecution typically consists of arguing in writing with an examiner about claims: over prior art, technical details, legal precedents, and claim language specifics.

The patent office has heightened examination rigor in the past few years, owing to perceived political pressure, and has done so poorly, as current PTO management is inept. It is considerably more difficult to have a patent granted than it was in 2003.

Read more about patent quality and the patent office.