A patent is an exclusive right granted by a sovereign state (national government) to an inventor or their assignee for a limited period of time in exchange for a public disclosure of an invention, the invention being understood as a technical teaching. Hence it is a monopoly granted for a period of time.
The procedure for granting patents, the requirements placed on the applicant (patentee), and the extent of the exclusive right vary between countries according to their national laws and international agreements. Typically, however, a patent application must include one or more claims defining the invention, which subject matter must be new, non-obvious, and useful or industrially applicable. In many countries, certain subject areas are excluded from patentability, such as business methods, treatment of the human body, mathematical methods and mental acts. The exclusive right granted to a patentee in most countries is the right to prevent others from making, using, selling, or distributing the patented invention without permission. Thus, the patent is a means to prevent others' use of the patented invention. A patent does not give the proprietor of the patent the right to use the patented invention, should it fall within the scope of an earlier patent.
Under the World Trade Organization's (WTO) Agreement on
Trade-Related Aspects of Intellectual Property Rights, patents
should be available in WTO member states for any inventions, in all fields of
technology, and the term of protection available should be the minimum twenty
years. Different types of patents may have varying patent terms
A patent is requested by filing a written application at the relevant patent office. The person or company filing the application is referred to as "the applicant". The applicant may be the inventor or its assignee. The application contains a description of how to make and use the invention that must provide sufficient detail for a person skilled in the art (i.e., the relevant area of technology) to make and use the invention. In some countries there are requirements for providing specific information such as the usefulness of the invention, the best mode of performing the invention known to the inventor, or the technical problem or problems solved by the invention. Drawings illustrating the invention may also be provided.
The application also includes one or more claims, although it is not always a requirement to submit these when first filing the application. The claims set out what the applicant is seeking to protect in that they define what the patent owner has a right to exclude others from making, using, or selling, if and when the patent is granted. In other words, the claims define what a patent covers or the "scope of protection".
After filing, an application is often referred to as "patent pending". While this term does not confer legal protection, and a patent cannot be enforced until granted, it serves to provide warning to potential infringers that if the patent is issued, they may be liable for damages. In many countries a “patent pending” notice may only be validly issued when a first publication of the patent application (usually after 18 months) has taken place.
For a patent to be granted, that is to take legal effect in a particular country, the patent application must meet the patentability requirements of that country. Most patent offices examine the application for compliance with these requirements. If the application does not comply, objections are communicated to the applicant or their patent agent or attorney and one or more opportunities including a term to respond to the objections to bring the application into compliance are usually provided.
Once granted the patent is subject in most countries to renewal fees to keep the patent in force. These fees are generally payable on a yearly basis, although the US is a notable exception. Some countries or regional patent offices (e.g. the European Patent Office) also require annual renewal fees to be paid for a patent application before it is granted.
Patents can generally only be enforced through civil lawsuits (for example, for a U.S. patent, by an action for patent infringement in a United States federal court; for a German patent, by an action for patent infringement in a German court). Although many countries have criminal penalties for continued infringement such penalties have not been applied for many years. Typically, the patent owner will seek an injunction prohibiting the defendant from engaging in future acts of infringement and will seek monetary compensation for past infringement. To prove infringement, the patent owner must establish that the accused infringer practices all the requirements of at least one of the claims of the patent. In many jurisdictions the scope of the patent may not be limited to what is literally stated in the claims, for example due to the "doctrine of equivalents".
An important limitation on the ability of a patent owner to successfully assert the patent in civil litigation is the accused infringer's right to challenge the validity of that patent. Civil courts hearing patent cases can and often do declare patents not valid. A patent can be found invalid on grounds that are set out in the relevant patent legislation that vary between countries. Often, the grounds are a subset of requirements for patentability in the relevant country. Although an infringer is generally free to rely on any available ground of invalidity (such as a prior publication, for example), some countries have sanctions to prevent the same validity questions being relitigated. An example is the UK Certificate of contested validity.
Patent licensing agreements are contracts in which the patent owner (the licensor) agrees to waive his right to sue the licensee for infringement of the licensor's patent rights, usually in return for a royalty or other compensation. It is common for companies engaged in complex technical fields to enter into dozens of license agreements associated with the production of a single product. Moreover, it is equally common for competitors in such fields to license patents to each other under cross-licensing agreements in order to share the benefits of using each other's patented inventions.
Therefore, patents may be enforced through litigation, and a common defense is an invalidity challenge. Patents may also be subject to licensing agreements. The vast majority of patents are however never litigated or even licensed.
The type of patent usually refers to a type of exclusive right granted to anyone who invents any new, useful, and non-obvious process, machine, article of manufacture, or composition of matter, or any new and useful improvement thereof, and accordingly claims to a process, machine, article of manufacture, or composition of matter are available and will be granted by the respective patent offices. The additional qualification “utility patent” is used in the United States to distinguish it from other types of patents (e.g. design patents) but should not be confused with utility models granted in other countries. Examples of particular species of patents for inventions include biological patents, business method patents, chemical patents and software patents.
Some other types of intellectual property rights are referred to as patents in some jurisdictions: industrial design rights are called design patents in some jurisdictions (they protect the visual design of objects that are not purely utilitarian), plant breeders' rights are sometimes called plant patents, and utility models (or Gebrauchsmuster) are sometimes called petty patents or innovation patents. While the present article relates primarily to the patent for an invention, so-called petty patents and utility models may also be granted for inventions.
Patents grants made by the sovereign state are sometimes called letters patents, which is a government notice to the public of a grant of an exclusive right to ownership and possession and a certificate is issued to the holder or patentee.