Claim construction: Phillips vs. BRI standards compared

Under Phillips, a claim term gets its 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 whole patent, with the claims, specification and prosecution history weighed before dictionaries or experts. Under broadest reasonable interpretation (BRI), the term gets the broadest reading that is reasonable and consistent with the specification. Courts use Phillips, examiners use BRI, and the PTAB has used Phillips for IPR and PGR petitions filed on or after 13 November 2018.

Where each standard applies

In court, the judge decides. Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996) held that construing patent claims is a matter of law for the court. Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (2015) added a layer: on appeal, a district court's subsidiary findings of fact about extrinsic evidence are reviewed for clear error, while the ultimate construction remains a legal question. Findings about expert testimony the judge credited are therefore harder to disturb on appeal than a construction drawn from the intrinsic record alone.

Outside the US, patent offices and courts apply their own interpretation rules, so a construction built for a US forum does not carry over automatically.

The Phillips framework

Phillips sets both the question and the order in which evidence is consulted. The question is what a person of ordinary skill in the art would have understood the term to mean at the time of the invention, having read the entire patent. The evidence comes in this order.

1. The claims. The term in its own claim, and the way the same term is used in other claims of the patent.
2. The specification. Phillips called it "the single best guide to the meaning of a disputed term." Look for definitions, consistent usage, and passages that describe what the invention includes or excludes.
3. The prosecution history. Amendments, arguments and the examiner's statements show how the applicant and the office understood the term, and can narrow it.
4. Extrinsic evidence. Dictionaries, treatises and expert testimony. Phillips treats them as less significant than the intrinsic record, and they cannot be used to contradict it.

The order is the point. A dictionary definition that fits your case is of little use if the specification uses the term differently.

Broadest reasonable interpretation in examination

During examination, the claims are given their broadest reasonable interpretation consistent with the specification (MPEP 2111). The usual rationale is that an applicant can amend claims while the application is pending, so reading them broadly tests them against the prior art before they issue.

BRI is not the broadest possible reading. It has to be reasonable, and it has to be consistent with the specification. The two standards often produce the same reading in practice. They diverge when the specification describes one form of the invention and the claim language could reach further.

Why the standard can change the outcome

A broader reading cuts both ways. It catches more prior art, which makes a claim easier to reject or invalidate. It also catches more products, which matters to infringement. In litigation, the same construction generally governs both questions, so a patent owner cannot argue for a broad reading against an accused product and a narrow one against the prior art.

Take claim 1 of US 5,960,411 A (the 1-Click patent, issued 28 September 1999, now expired), which requires sending a request "in response to only a single action being performed". Is a press-and-hold a single action? A voice command? A tap followed by a fingerprint confirmation?

• Under BRI, the examiner asks whether reading "single action" to include the alternative is reasonable in light of the specification.
• Under Phillips, the court asks what a skilled person in 1997 would have understood the term to mean after reading the claims, the specification and the prosecution history.

If the specification describes the single action only in one form and the prosecution history relies on that form, a Phillips reading may come out narrower than BRI. If the specification describes it broadly, the two readings may converge. The answer depends on the record, which is why the record has to be built term by term.

The PTAB's 2018 change matters for anyone comparing old and new decisions. A Board decision on a petition filed before 13 November 2018 generally applied BRI, so its constructions may be broader than a court's, and prior-art findings made under them may not transfer to litigation. For later petitions, the Board and the courts apply the same standard.

Building a construction, step by step

1. List the terms

Start with the claim split into labelled limitations (see how to break a patent claim into limitations). Then list the terms likely to be disputed:

• terms that decide whether a key limitation is met or anticipated;
• coined terms and terms with no settled meaning in the field;
• terms of degree such as "substantially" or "approximately";
• terms used differently in different claims or passages;
• functional terms with no structure attached.

2. Build an intrinsic evidence table for each term

3. Write both constructions

Draft your proposed construction and the one the other side is likely to propose. Each should be a short phrase that could replace the term in the claim.

4. Bring in extrinsic evidence last

Use it to confirm what a skilled person would have understood at the time, not to supply a meaning the intrinsic record does not support.

5. Re-run the chart under each construction

Go back to the claim chart and mark every row whose finding flips between the two readings. Those rows are the real dispute. The checks in how to read an element-by-element claim chart apply to each version, and if a gap survives every construction, the doctrine of equivalents is the next question.

6. Record the standard

Note in the chart header which standard and which construction each version of the chart applies. A chart prepared for an IPR petition and one prepared for district court may now use the same standard, but the record each one draws on may differ.

Try it

One Transform's Infringement search parses your patent's claims into individual limitations and charts each candidate product limitation by limitation, with a finding of present, partially present or not found and evidence for every element. Each finding rests on a reading of the claim terms. Before relying on one, test it against the construction you built with the steps above, and mark the rows that would change under the other side's.

Next step: chart a patent with an Infringement search.

This article is general information about patent practice, not legal advice. For advice on a specific matter, consult a registered patent attorney or agent.