Patent Glossary

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.

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.

Appeal

A request to have a patent examiner's rejection reviewed by a higher authority. After receiving multiple rejections, an applicant can appeal to the Patent Trial and Appeal Board (PTAB) within the USPTO, and from there to federal court. Appeals are expensive and slow, but sometimes necessary when an examiner applies the law incorrectly.

Art unit

A group of patent examiners at the USPTO who specialize in a particular technology area. Each application is assigned to the art unit whose examiners are trained in the relevant field. The art unit assignment matters because examiner expertise — and rejection rates — vary significantly across technology areas.

Assignee

The legal owner of a patent, who may or may not be the inventor. When an employee invents something in the course of their employment, most companies require inventors to assign patent rights to the employer. The assignee appears on the patent document and has the right to license or enforce the patent.

Basis for rejection

The specific legal grounds a patent examiner cites when refusing to allow a claim. Common bases include lack of novelty (35 USC § 102), obviousness (35 USC § 103), failure to fully describe the invention (35 USC § 112), and unpatentable subject matter (35 USC § 101). An office action will state the basis for each rejection, and applicants must address each one in their response.

Broadest reasonable interpretation

A standard the USPTO uses during examination to interpret claim language. Examiners give claim terms the broadest meaning a person skilled in the art would reasonably understand from the specification — not the narrowest. This is intentional: if a claim is too broad it should fail during examination, not slip through and later cause harm. Applicants can argue against an overly broad interpretation by pointing to the specification or adding clarifying language.

Claim

The numbered sentences at the end of a patent that define exactly what is legally protected. Claims are the only part of a patent that determine infringement — if a product or process doesn't fall within the scope of at least one claim, there is no infringement. Every other part of a patent (abstract, drawings, specification) exists to support and illuminate the claims.

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.

Claim construction

The legal process of interpreting what a patent claim means — specifically, the scope of each term in the claim. In litigation, judges perform claim construction in a "Markman hearing" before deciding infringement. Claim construction is often the most consequential step in patent litigation: a narrow construction can defeat infringement, while a broad one can invalidate the claim.

Continuation

A new patent application filed while a parent application is still pending, using the same specification but with different (usually narrower or broader) claims. Continuations allow inventors to pursue multiple rounds of claims from one original disclosure. Many technology companies maintain families of ten or more continuations from a single core invention, each covering a different aspect.

Continuation-in-part (CIP)

A type of continuation that adds new subject matter to the original specification. The original claims keep the parent's priority date; the new material gets a new priority date. CIPs are commonly used when an inventor has improved or expanded an invention after the original filing. The different priority dates within a CIP can create complications during litigation.

Dependent claim

A claim that refers back to and further limits another claim. For example: "The device of claim 1, wherein the housing is made of aluminum." If the claim it depends on is invalid, the dependent claim also falls. Dependent claims provide narrower protection but serve as fallbacks — if broader independent claims are invalidated, narrower dependent claims may survive.

Design patent

A patent covering the ornamental appearance of a functional object — its shape, configuration, or visual design — not how it works. Design patents last 15 years from grant. They are faster and less expensive to obtain than utility patents. Apple's US D618,677 patent on the iPhone's rounded-rectangle shape is a famous example; it was central to over $1 billion in damages against Samsung.

Divisional

A patent application split off from a parent application because the USPTO determined the parent contained claims to more than one distinct invention. When an examiner issues a "restriction requirement," the applicant must elect one group of claims to pursue in the parent; the rest can be filed as a divisional. Divisionals get the parent's original filing date.

Doctrine of equivalents

A legal doctrine that extends patent protection beyond the literal scope of the claims. Even if a competitor's product doesn't literally include every element of a claim, infringement may still exist if each claim element is performed by a substantially similar function in a substantially similar way. Courts apply this doctrine to prevent competitors from making trivial changes to avoid literal infringement.

Enablement

A requirement under 35 USC § 112 that a patent's specification must teach someone skilled in the relevant field how to make and use the invention — without undue experimentation. If the specification fails to enable the full scope of what the claims cover, the patent is invalid for lack of enablement. This is one of the most frequent grounds for invalidating broad software and biotechnology patents.

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.

File wrapper

The complete record of all communications between an applicant and the USPTO during patent prosecution — including the original application, all office actions, all responses, and the notice of allowance. Also called the "prosecution history." The file wrapper is public and permanent; courts use it during litigation to interpret the scope of claims based on statements the applicant made to the examiner.

Freedom to operate (FTO)

A legal opinion assessing whether a product, process, or service can be commercialized without infringing any valid, in-force patents held by others. FTO searches are typically conducted before launching a product. An FTO opinion does not guarantee safety from infringement claims, but a good-faith, well-documented FTO analysis can reduce willfulness damages if litigation occurs.

Independent claim

A claim that stands on its own and does not reference any other claim. An independent claim defines the broadest scope of protection for a particular aspect of an invention. Most patents have one to three independent claims, each capturing the invention from a different angle, with multiple dependent claims narrowing each one.

Infringement

The unauthorized making, using, selling, or importing of a product or process that falls within the scope of a valid patent's claims. Infringement is determined by comparing each element of a patent claim to the accused product or process. If every element is present — literally or under the doctrine of equivalents — infringement exists.

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.

Inter partes review (IPR)

An administrative proceeding at the PTAB that allows any person to challenge the validity of an already-granted patent based on prior art in patents or printed publications. IPR is significantly faster and cheaper than district court litigation. Roughly 60% of patent claims that reach a final decision in IPR are canceled. Large companies frequently use IPR to challenge startup patents without going to court.

Inventor

The person (or persons) who conceived the claimed invention. Inventorship is a legal concept distinct from contribution to a project — someone who merely built what was designed, or who had a general idea that was made more specific by someone else, may not qualify as an inventor. Incorrectly listing inventors can invalidate a patent.

License

Permission granted by a patent owner to another party to make, use, sell, or import a patented invention, typically in exchange for payment. Licenses can be exclusive (only one licensee) or non-exclusive (multiple licensees allowed). They can cover specific geographies, time periods, or fields of use. Unlike an assignment, a license does not transfer ownership of the patent.

Maintenance fees

Periodic fees that must be paid to the USPTO to keep a granted utility patent in force. For US utility patents, fees are due at 3.5 years, 7.5 years, and 11.5 years after grant. If a fee is missed, the patent expires. Many patents go abandoned not because the invention was worthless, but because the owner decided the cost of maintenance wasn't justified by the remaining commercial value.

Non-obviousness

One of the three core requirements for a utility patent. An invention is non-obvious if someone with ordinary skill in the relevant field could not have easily combined existing knowledge to arrive at the invention. Non-obviousness (35 USC § 103) is the most frequently litigated and most difficult requirement to satisfy — the line between "obvious" and "not obvious" is contested in almost every patent case.

Non-provisional application

The "full" patent application examined by the USPTO — as opposed to a provisional application, which is a placeholder. A non-provisional application must include a complete specification, drawings (if necessary), at least one claim, and payment of the filing fee. The non-provisional is what gets examined and, if allowed, issues as a patent.

Notice of allowance

A document the USPTO sends when an examiner has determined that the claims in a patent application are allowable and a patent will be issued — once the applicant pays the issue fee. Receiving a notice of allowance means prosecution is essentially over. The applicant typically has three months to pay the issue fee.

Novelty

The requirement that an invention must be new — not previously known, used, or disclosed publicly anywhere in the world before the filing date. Under the America Invents Act (2013), the US uses a first-to-file system: the applicant who files first gets priority, regardless of who invented first. Even the inventor can destroy novelty by publicly disclosing the invention more than a year before filing.

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.

Office action

A written communication from a USPTO examiner to a patent applicant, typically containing rejections, objections, or requirements for the application. A "final office action" signals that the examiner has given the applicant one more chance to respond before the application is abandoned. Applicants generally have three months to respond (extendable to six months for a fee).

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.

Prior art

All publicly available information that existed before a patent's priority date that is relevant to the novelty and non-obviousness of the claimed invention. Prior art 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 inventor can take.

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.

Provisional application

A simplified, lower-cost patent application that establishes a priority date and allows an inventor to claim "patent pending" status for 12 months. A provisional is never examined and never becomes a patent on its own. The inventor must file a non-provisional application within 12 months or lose the priority date entirely. Provisionals are commonly used to lock in a date while refining the invention or seeking funding.

Public domain

The status of an invention (or creative work) that is no longer — or never was — protected by any intellectual property rights, meaning anyone can use it freely. Patents enter the public domain after expiration (typically 20 years from filing for utility patents). Expired patents represent a vast, free library of technology available to all. Many foundational technologies — aspirin, the original CRISPR patents — have entered or are approaching the public domain.

Response

A written reply from a patent applicant to an office action. A response must address every rejection and objection raised by the examiner — arguing why the rejection is wrong, amending the claims to overcome the rejection, or both. Failing to respond within the deadline causes the application to go abandoned. A well-crafted response is often the difference between getting a patent and getting a final rejection.

Specification

The written description portion of a patent application — everything except the claims. The specification must describe the invention in enough detail that someone skilled in the field could make and use it. It typically includes background of the invention, a summary, a description of the drawings, and a detailed description of at least one embodiment. Courts use the specification to interpret what claim terms mean.

Terminal disclaimer

A document filed with the USPTO in which a patent applicant agrees that the term of a patent will end no later than the expiration of an earlier related patent. Terminal disclaimers are commonly required to overcome an "obviousness-type double patenting" rejection — which occurs when two related patents claim inventions that aren't patentably distinct from each other.

Trade secret

Confidential business information that provides a competitive advantage and is subject to reasonable efforts to keep it secret. Unlike patents, trade secrets have no registration requirement and can last indefinitely — but only as long as the secret is maintained. The formula for Coca-Cola and the Google search algorithm are famous examples. Trade secrets and patents are often compared: patents give stronger rights but require disclosure; trade secrets keep information hidden but can be lost if independently discovered.

Trademark

A word, phrase, logo, symbol, or trade dress that identifies the source of goods or services and distinguishes them from those of competitors. Trademarks protect brand identity, not inventions. Unlike patents, trademarks can theoretically last forever as long as the mark is used in commerce and renewals are filed. Federal registration at the USPTO provides nationwide rights and the right to use the ® symbol.

Utility patent

The most common type of US patent, covering inventions that have a useful function — how something works, how it is made, or how it is used. Utility patents account for roughly 90% of all US patents issued. They last 20 years from the filing date of the non-provisional application, subject to payment of maintenance fees. Software, medical devices, chemical processes, and mechanical inventions are all protectable as utility patents.

Written description

A requirement under 35 USC § 112 that an inventor must demonstrate, through the specification, that they actually possessed the claimed invention at the time of filing — not just that they had a vague idea. Written description is separate from enablement: enablement asks whether the reader can make the invention; written description asks whether the inventor had already conceived it. Failing the written description requirement is common when inventors try to add new matter to a continuation.