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Claim Differentiation Doctrine Fails To Trump Interpretation Supported By Intrinsic Evidence

Client Alert | 1 min read | 05.23.06

In Inpro II Licensing, S.A.R.L. v. T-Mobile USA, Inc. (No. 05-1233; May 11, 2006), the Federal Circuit affirms a district court's claim construction and holding of non-infringement.  The claims at issue are directed to a digital assistant module, which includes a host interface.  The district court held that both intrinsic and extrinsic evidence limited this interface to a direct parallel bus interface, even though this limitation is not specifically recited in the claims.  The patentee objected, contending that because other, unasserted claims specifically limit the host interface to a direct-access parallel bus the doctrine of claim differentiation requires the recitation of the host interface in the claims at issue to be interpreted more broadly than a direct parallel bus interface.  Like the district court, the Federal Circuit, however, disagrees.  Noting that the patent specification disparages the serial interface that the patentee asserts the claims cover, identifies the direct parallel bus interface as a “very important feature,” fails to describe any other type of bus for the host interface, and describes a serial connection for a different bus, the Federal Circuit holds that employing different words to describe the same element does not necessarily change the scope of the claims where the surrounding evidence fails to support different interpretations.

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Client Alert | 8 min read | 06.30.25

AI Companies Prevail in Path-Breaking Decisions on Fair Use

Last week, artificial intelligence companies won two significant copyright infringement lawsuits brought by copyright holders, marking an important milestone in the development of the law around AI. These decisions – Bartz v. Anthropic and Kadrey v. Meta (decided on June 23 and 25, 2025, respectively), along with a February 2025 decision in Thomson Reuters v. ROSS Intelligence – suggest that AI companies have plausible defenses to the intellectual property claims that have dogged them since generative AI technologies became widely available several years ago. Whether AI companies can, in all cases, successfully assert that their use of copyrighted content is “fair” will depend on their circumstances and further development of the law by the courts and Congress....