A patent is an exclusive right or set of exclusive rights granted to a patentee by a state, in exchange for the public disclosure of specific details of an "invention". The exact exclusive right(s) differ in different countries, but in most countries a patent results in protection in two distinct fields. On the one hand it grants protection against unauthorised use of the invention. Which means in theory any use, such as renting, selling, researching or production, of the patent can be restricted or prevented in the country where the invention is patented. On the other hand it grants protection of the technical aspects of the patent. Which means the invention itself, and the production process to produce the invention, are protected. Both the unauthorised production and unauthorised use of a patent can result in patent infringement.
In the United States of America, the Patent Act allows patents of four categories: process, machine, manufacture, or composition of matter.[1]
The extent of protection granted through a patent,what is and what is not protected through a patent, is dependent on the interpretation one uses. In general it is possible to discern two different interpretation methods. One the one hand a teleological interpretation, the intent underlying the patent is most important, to ensure that the individual rights of the patentee are protected as much as possible. On the other hand a grammatical interpretation, the text of the patent application is most important, to ensure that the rights of third parties are protected as much as possible. In Europe, German courts tend to make use of a more teleological interpretation, whereas British courts tend to make use of a more grammatical interpretation. Because of these differences in interpretation, the European Patent Convention (EPC) contains an "interpretation" protocol for those situations where it is not clear what is and what is not protected under patent.
In the United States of America, the duration of a patent is:[2]
Patents for products such as food additives and drugs that require approval by federal entities such as the US Food and Drug Administration prior to marketing, can have a maximum of 5 years extended to the patent to compensate for marketing time lost while waiting for approval."[3] In all cases, the total patent life for the product with the patent extension cannot exceed 14 years from the product’s approval date, or in other words, 14 years of potential marketing time. "[2][4]
US patents (other than design patents) are eligible for patent term extensions due to USPTO administative delay.[5] (This calculation appears on the Notice of Allowance.)
A patent infringement can take two forms, either a direct or an indirect infringement. If the exact same (production) procedure is used this constitutes a direct patent infringement. Which means if a company other than Philips were to produce a “Senseo” coffee machine that company would be directly infringing on Philips' patent. However if a part of a patented invention is produced this can constitute an indirect patent infringement. If for instance companies other than those licensed by Philips were to produce coffee pads for the “Senseo” machine that company could be indirectly infringing on Philips' patent.
There is controversy as to whether patents impede medical research.[6]