the firm's post-grant practitioners are some of the most experienced in the country.


Artificial Intelligence (AI)
Artificial Intelligence (AI)
Digital Health
Digital Health
Energy & Renewables
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Fast Facts

About Our

Law Firm

About Our Law Firm

Headquartered within steps of the USPTO with an affiliate office in Tokyo, Oblon is one of the largest law firms in the United States focused exclusively on intellectual property law.

Get to know our


Get to know our History

Norman Oblon with Stanley Fisher and Marvin Spivak launched what was to become Oblon, McClelland, Maier & Neustadt, LLP, one of the nation's leading full-service intellectual property law firms.

Our Local and

Global Reach

Our Local and Global Reach

Outside the US, we service companies based in Japan, France, Germany, Italy, Saudi Arabia, and farther corners of the world. Our culturally aware attorneys speak many languages, including Japanese, French, German, Mandarin, Korean, Russian, Arabic, Farsi, Chinese.

A few of our


A few of our ACCOLADES

Oblon's professionals provide industry-leading IP legal services to many of the world's most admired innovators and brands.




From the minute you walk through our doors, you'll become a valuable part of a team that fosters a culture of innovation, client service and collegiality.

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GET In Touch

A few ways to GET In Touch
US Office

Telephone: 703-413-3000
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Tokyo Office

Telephone: +81-3-6212-0550
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Patent Forms

Downloadable Patent Forms

The United States Patent and Trademark Office (USPTO) issued final rules implementing the inventor's oath or declaration provisions of the America Invents Act (AIA) on August 14, 2012.

Claim Terms Should Be Defined By Intrinsic Evidence And Not Dictionaries

  • January 23, 2023
  • Article
  • Life Sciences News - January 2023 Newsletter

Associated People

In Grace Inst. Indus., LLC. v. Chandler Inst. Co., LLC, Appeal 2021-2370, January 12, 2023, the Federal Circuit reversed a district court determination the claim term “enlarged chamber” was indefinite. The claimed invention involved a viscometer for measuring the viscosity of a drilling fluid under the pressure in down-hole conditions. The problem with prior art methods was that mixing occurred between the fluid used to create the pressure and drilling fluid which cause errors in the measurement. Alternative methods using a seal introduced errors because of the friction between the seal and the fluid. The claim at issue reads:

1. A pressurized device comprising:

(a) a pressure vessel within which is vertically disposed at least one top section filled with a pressurization fluid of a first density and at least one lower section filled with a test sample of a second density,

(b) an enlarged chamber with reduced openings positioned between the at least one top section and the at least one bottom section for communicating pressure with said top section and said lower section within said pressure vessel,

(c) whereby said pressurization fluid would not mix with said test sample because of the nature of their density difference.

The district court interpreted the term “enlarged chamber” by reference to a dictionary and found it indefinite because the term “enlarged” is a term of “degree’ that calls for a comparison against a baseline. The Court reversed because claim construction requires understanding the term in the context of the entire patent, Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc). If the claim term is clear from the intrinsic evidence, there is no reason to resort to extrinsic evidence. The Court noted that here specification described the enlarged chamber as being large enough such that at maximum pressure the chamber is at least half-filled with the drilling fluid. The viscosity measurement is taken in a smaller chamber disposed below the enlarged chamber and an antimixing fin and is always filled with the drilling fluid. While “enlarged chamber” is not a term of art, the intrinsic record guides a skilled artisan to the meaning of that term as used in the  patent. The Court found the district court erred relying on extrinsic evidence that contradicts the scope and meaning of “enlarged chamber” as described in the intrinsic record.

The key is when using “terms of degree” to provide a description in the specification as to how the term is to be interpreted.  The specification can then provide meaning to the term as sued in the claims.