Public domain

Cross-referenced

Intellectual property (IP)

The legal category covering intangible creations of the mind that receive some form of legal protection. The four main types are patents (inventions), copyright (creative works), trademarks (brand identifiers), and trade secrets (confidential business information). Each type has different rules, durations, and protections — and they can overlap on the same product.

Cross-referenced

Patent expiry

The point at which a patent's term ends and the invention enters the public domain — either at full term or early, when maintenance fees go unpaid. Once a patent expires, anyone may make, use, or sell what it covered: a drug patent expiring is what lets generic versions enter the market. Expired patents amount to a free, fully documented library of proven technology.

Cross-referenced

Patent term

The length of time a patent stays in force. A U.S. utility patent's term runs 20 years from its earliest non-provisional filing date, provided maintenance fees are paid; a design patent lasts 15 years from grant. Patent Term Adjustment can add back days lost to USPTO delays, and a terminal disclaimer can shorten the term. When the term ends, the invention enters the public domain.

Patent family

The set of related patents and applications that share a common priority claim — an original application plus its continuations, divisionals, and foreign counterparts. Members of a family typically share the same earliest filing (priority) date.

Post-grant review (PGR)

A USPTO proceeding to challenge a recently granted patent, within nine months of grant, on almost any ground of invalidity — including eligibility and written description. It is broader than inter partes review, which is narrower and becomes available later.

Patent

A government-granted right that gives an inventor the exclusive right to prevent others from making, using, selling, or importing a patented invention within the country that granted the patent, for a limited time. A patent does not give the owner the right to practice the invention — only the right to exclude others. The US issues three types: utility, design, and plant patents.