Claim Construction (Markman)

Common situations.

• The parties dispute whether "fastener" covers adhesives.
• A defendant argues that statements the patent owner made to the Patent Office narrowed a claim.
• A claim uses a term of degree such as "substantially" or a generic word such as "module."
• After claim construction, one side concludes it cannot win and asks how to appeal.

Who decides.

Claim construction is for the judge, not the jury (Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996)). If the parties actually dispute the scope of a term that matters to infringement or validity, the court must resolve the dispute; leaving it to the jury is error (O2 Micro Int'l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351 (Fed. Cir. 2008)).

How claims are read.

Claim terms carry their ordinary and customary meaning to a person of ordinary skill in the art at the time of the invention, read in the context of the entire patent (Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc)). The sources, in order of weight:

1. The claims themselves. How a term is used in other claims, and differences between independent and dependent claims, are strong evidence.
2. The specification. It is usually the single best guide to the meaning of a disputed term (Phillips). Courts may use it to understand the claims but should not import limitations from a described embodiment into a broader claim.
3. The prosecution history. It shows how the inventor and the examiner understood the patent.
4. Extrinsic evidence. Dictionaries, treatises, and expert testimony can help but are less reliable and cannot contradict the intrinsic record.

When the plain meaning gives way.

The ordinary meaning controls unless the patentee acted as its own lexicographer by clearly defining a term, or clearly disavowed claim scope in the specification or during prosecution (Thorner v. Sony Computer Entm't Am. LLC, 669 F.3d 1362 (Fed. Cir. 2012)).

• Prosecution disclaimer. Clear and unmistakable arguments made to the Patent Office to win allowance can narrow a claim (Omega Eng'g, Inc. v. Raytek Corp., 334 F.3d 1314 (Fed. Cir. 2003)).
• Statements in PTAB proceedings. A patent owner's statements in an inter partes review, including before institution, can also create disclaimer (Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353 (Fed. Cir. 2017)). What a patent owner says to save a claim at the Board can limit it in court.

Means-plus-function and indefinite terms.

A claim element stated as a means or step for performing a function, without reciting structure, covers only the corresponding structure described in the specification and its equivalents (35 U.S.C. § 112(f)). Generic words such as "module" or "mechanism" can trigger this rule (Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015)). If the specification discloses no corresponding structure, or a term lacks reasonable certainty, the claim is invalid as indefinite (Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898 (2014)). Courts often decide indefiniteness at the claim construction stage.

The process.

1. The parties exchange the terms they want construed and their proposed constructions.
2. They file a joint statement listing agreed and disputed terms.
3. They brief the disputes, often with expert declarations and a technology tutorial.
4. The court holds a hearing, usually without live witnesses, and issues a written order.

In Texas federal courts, the local patent rules or standing orders set these steps. See Local Patent Rules in Texas Federal Courts.

After the ruling.

• Amended contentions. The rules in several Texas districts allow amended contentions without leave shortly after the ruling.
• Summary judgment. A ruling often leads to motions for summary judgment of noninfringement or invalidity.
• Appeal. The ruling cannot ordinarily be appealed right away. A party that cannot win under the court's construction may stipulate to a judgment so the construction can be reviewed. The Federal Circuit reviews the construction de novo but defers to factual findings about extrinsic evidence (Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (2015)).
• Consistency with the PTAB. The Patent Trial and Appeal Board applies the same standard in post-grant proceedings (37 C.F.R. § 42.100(b)), so a construction adopted in one forum is often cited in the other.

Texas notes.

• In the Eastern District of Texas, the local patent rules set claim construction deadlines that run from invalidity contentions; the hearing is typically held several months into the case. In Chief Judge Gilstrap's patent cases, Magistrate Judge Roy Payne handles pretrial proceedings, including many claim construction rulings.
• Under the Waco standing order (OGP 4.0), the hearing was set about 23 weeks after the case management conference, with a presumptive limit of 8 to 12 terms depending on the number of patents, and fact discovery opened the next business day.

Sources.

• 35 U.S.C. § 112(b), (f).
• 37 C.F.R. § 42.100(b).
• Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996).
• O2 Micro Int'l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351 (Fed. Cir. 2008).
• Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc).
• Thorner v. Sony Computer Entm't Am. LLC, 669 F.3d 1362 (Fed. Cir. 2012).
• Omega Eng'g, Inc. v. Raytek Corp., 334 F.3d 1314 (Fed. Cir. 2003).
• Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353 (Fed. Cir. 2017).
• Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015).
• Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898 (2014).
• Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (2015).
• E.D. Tex. Patent Rules, P.R. 4-1 to 4-6.
• W.D. Tex. Standing Order Governing Proceedings (OGP) 4.0, Patent Cases (Mar. 7, 2022).

This guide is general information, not legal advice. Law checked through October 20, 2026. See the Disclaimer.