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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.

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In practice

Patents that use “Prior art”

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biotech

US 4235871 · 1980

How to Encapsulate Active Materials in Lipid Bubbles Efficiently

Related terms

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Obviousness

A grounds for rejection under 35 USC § 103 when an invention, while not identical to any single prior art reference, would have been obvious to a person having ordinary skill in the art at the time of invention. Examiners frequently combine two or more prior art references to make an obviousness rejection. It is the single most common rejection in patent prosecution.

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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.

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Abstract

A brief summary (300 words or fewer) that appears at the top of every patent. The abstract describes what the invention does in general terms. Legally, it has almost no weight — courts use the claims to determine what a patent covers, not the abstract. The abstract is useful mainly for quickly scanning patents during a prior art search.

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Anticipation

A legal standard for rejecting a patent claim. If every element of a claim was already disclosed in a single prior art reference — in a patent, article, or product — the claim is "anticipated" and cannot be patented. Anticipation requires a single source to contain every element; if you need two sources, it's an obviousness argument, not anticipation.

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Claim chart

A side-by-side comparison table mapping each element of a patent claim to a specific feature in an accused product or prior art reference. Claim charts are used in infringement analysis, licensing negotiations, and patent litigation. They make it visually clear which claim elements are met (or not met) by the thing being compared.

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Examiner

A USPTO employee trained in a specific technical field who reviews patent applications for compliance with patent law. Examiners search prior art, write office actions rejecting or allowing claims, and conduct interviews with applicants or their attorneys. The examiner assigned to your application has significant discretion in how they interpret your claims and apply prior art.

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