Means-plus-function

Cross-referenced

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.

Cross-referenced

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.

Markush group

A way of claiming a set of alternatives in a single claim — for example, 'selected from the group consisting of A, B, and C.' It is common in chemistry and pharmaceutical claims to cover several specific options at once.

Markman hearing

A pretrial hearing where the judge decides what the disputed terms of a patent claim mean, as a matter of law. Named after Markman v. Westview Instruments, this claim-construction step often decides the whole case because it sets the yardstick for infringement and validity.

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.

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.