Patent is a document issued by a national government granting an inventor exclusive rights to an invention for a limited time. A patent allows an inventor to prevent others from making, selling, or using the invention in the country that granted the patent.

To be eligible for a patent, an invention must be new, useful, and original. Inventions include machines,methods, manufactured products, compositions, and new uses of inventions in each of these categories. Improvements on inventions can also be patented.

HOW PATENTS PROTECT INVENTORS

A patent gives the inventor a legal monopoly of an invention for a limited time. In most countries this is between 15 band 20 years, but in some countries there is a shorter period for particularly useful inventions. Once a patent has been applied for, a lengthy examination may be carried out to determine whether or not the invention is original.

To avoid delay in getting a newly invented product on the market, many manufacturers start to produce it after filing for a patent. The manufacturer marks the product "Patent Pending" or "Patent Applied For". This warning has no legal value, but it discourages imitation. A patent invention may be marked "Patent", together with the patent number. Copying a patented invention without permission is called infringement. The patent owner may sue for damages and an injunction to order the infringer to stop copying the invention.

An inventor may sell all or part of the rights given by a patent. The inventor may also license these rights to a manufacturer. Licensing gives the inventor a fee or royalties(payments based on sales), or both.

NATIONAL PATENTS

Patent laws vary from country to country. Most patent laws follow the principle that a patent is a bargain between the inventor and society. Inventors reveal their secrets in exchange for a monopoly for a limited time. Society receives the benefit of sharing their secrets.

Differences in the patent laws of various countries include the period a patent remains in force. The laws also vary on the conditions under which applicants may make public their inventions before receiving a patent. some governments force the patent owner to grant licenses. Others force mandatory licensing if the invention is not manufactured in the country within a certain period after the patent has been granted.

INTERNATIONAL PATENT AGREEMENTS

A patent treaty went into effect by almost 100 nations in 1884. Each nation agrees to give citizens of the other countries the same rights to obtain a patent as it gives its own citizens. The treaty established a principle that is called the right of priority. This principle benefits people who apply for a patent in their own country and then apply in any of the other countries within a year. Their later applications are considered as having been made on the same date as the one made in in their own country.

A second patent agreement, the Patent Cooperation Treaty(PCT), took effect in 1978. Under this treaty, each nation retains its own patent laws, but the standard application replaces an individual nation's application. The international application is given the same treatment as the national application. The PCT was last modified in 2001.