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Prior art

Definition

All publicly available information that existed before a patent's priority datepriority dateThe earliest date used to compare the patent against prior art. Usually equals the filing date.Read more → that is relevant to the noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → and non-obviousnessnon-obviousnessThe requirement that an invention not be an obvious combination of existing prior art to someone skilled in the field.Read more → of the claimed invention. Prior artprior artEarlier patents, publications, or products that existed before this patent's filing date. Patent claims must be novel over the prior art.Read more → includes earlier patents, published patent applications, journal articles, product manuals, conference presentations, and anything that was publicly known or in use. Searching prior art before filing is one of the most valuable steps an inventorinventorThe person who actually conceived the invention. Listed on the patent regardless of who owns it.Read more → can take.

Related terms

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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.

Patent Cooperation Treaty (PCT)

An international treaty allowing inventors to file a single "PCT application" that preserves the right to seek patent protection in 150+ member countries. A PCT filing buys time — typically 30 months from the priority date — before the applicant must commit to specific national filings. It is not a "world patent"; each country still examines and grants its own patent under its own laws.

Patent pending

A notice that a patent application has been filed with the USPTO but has not yet been examined or granted. "Patent pending" provides no legal protection against copying — it simply puts the public on notice that a patent may issue. If a patent does issue, the patentee may be able to collect reasonable royalties going back to the publication date of the application.

Plant patent

A patent covering a new, distinct variety of plant that has been asexually reproduced (through cuttings, grafting, or budding — not seeds). Plant patents are rare, with fewer than 1,500 issued per year. Most plant protection in agriculture uses a separate system: the Plant Variety Protection Act, administered by the USDA rather than the USPTO.

Priority date

The date that determines whether a piece of prior art counts against a patent application. In the US, the priority date is typically the filing date of the earliest application in a patent family to which the current application claims priority. Under the first-to-file system (post-AIA), the inventor with the earliest priority date wins if two people file on the same invention.

Prosecution

The entire process of applying for a patent at the USPTO — from filing to grant or abandonment. Prosecution includes submitting the application, responding to office actions, amending claims, conducting examiner interviews, and ultimately receiving a notice of allowance or deciding to appeal or abandon. The full record of prosecution is preserved in the file wrapper.

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