Background
Ron Nystrom owned U.S. Patent No. 5,474,831, which covered a decking board with a convex upper surface designed to shed water and resist the warping and cupping that plagues flat wooden decking. The patent claimed a “board” for use as a wood decking member, with a gently curved top surface that caused water to run off rather than pool. The invention addressed a real practical problem for homeowners and builders: conventional flat deck boards tend to cup and warp after repeated wetting and drying cycles, creating tripping hazards and structural problems.
Trex Company manufactured a competing composite decking product made from a mixture of wood fibers and recycled plastic. Trex’s product had a flat top surface — not a convex one — but Nystrom sued for infringement on the theory that certain aspects of Trex’s product fell within his patent claims. The central dispute was whether the term “board” in Nystrom’s patent encompassed Trex’s composite product made from wood fibers and plastic, or whether it was limited to material sawn from a natural log. The district court construed “board” narrowly to mean material cut from a log, and on that construction found no infringement. Nystrom appealed the claim construction.
The Court’s Holding
The Federal Circuit affirmed the district court’s construction. The court applied the framework established in its landmark 2005 en banc decision in Phillips v. AWH Corp., which had reaffirmed that claim terms must be construed in light of the intrinsic record — the claims, the specification, and the prosecution history — rather than defaulting to the broadest possible dictionary definition.
Examining Nystrom’s specification, the court found that the patent consistently and exclusively described the claimed board as a piece of material sawn or cut from a natural log. Every embodiment described in the patent, every figure, and every piece of explanatory language referred to wood in the sense of material derived from a tree — not wood fibers reconstituted with plastic binders. The patent’s background section described problems specific to solid wood decking; its proposed solution was equally specific to the behavior of natural wood when exposed to moisture. Nothing in the specification suggested that the inventor contemplated composite or engineered wood products as within the scope of the invention.
The court rejected Nystrom’s argument that “board” should be given its broadest ordinary meaning to include any rigid elongated structural member suitable for decking. While ordinary meaning is an important starting point, the court held that a patentee’s consistent use of a term in a narrower sense throughout the specification can confine the claim to that narrower meaning. When the intrinsic record clearly establishes that the inventor used a word in a particular sense, that usage controls — even if the same word might have a broader meaning in a dictionary or in other contexts.
Key Takeaways
- The ordinary meaning of a claim term does not automatically control if the patent’s specification consistently uses the term in a narrower sense — the intrinsic record (claims, specification, prosecution history) defines the meaning the inventor intended.
- When every embodiment, figure, and description in a patent specification refers to a narrower concept, courts will construe the claim term to match that narrower meaning even if the word itself could have a broader ordinary meaning.
- Composite or engineered products that combine natural materials with synthetic binders or matrices are not necessarily within the scope of claims that the specification defines exclusively in terms of natural materials.
- Patent drafters should take care to include embodiments covering alternative materials if they intend their claims to reach product innovations beyond the specific materials used in the described invention.
- The decision is an early application of the Phillips v. AWH framework emphasizing that the specification is the primary guide to claim meaning, not extrinsic dictionaries or the broadest possible interpretation.
Why It Matters
Nystrom v. Trex illustrates one of the most common and consequential issues in patent litigation: how broadly a court will read a claim term that appears simple but turns out to be contested. The term “board” seems straightforward — almost everyone knows what a board is. But the question of whether a composite decking product made partly from wood fibers and partly from recycled plastic counts as a “board” for patent purposes turned on how the inventor himself used the word throughout his patent, not on dictionary definitions alone.
This case matters for innovators and companies in adjacent industries. When a patent uses a term consistently in a narrow sense — focused, for example, on traditional solid wood — a manufacturer of next-generation composite or synthetic materials may escape infringement because those materials were never part of the inventor’s conceptual universe. Conversely, inventors who want their patents to cover future material variations should draft specifications broadly, include diverse embodiments, and avoid language that confines the invention to the specific materials used in the original prototype. The case reinforced that both patent drafters and product developers must pay close attention to how specification language shapes the practical scope of patent protection.