October Term 2010 · Docket 10-290

What evidence standard proves patent invalidity?

Microsoft seeks a preponderance standard to invalidate patents. i4i defends the clear and convincing evidence rule.

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Microsoft Corp. v. i4i Ltd. Partnership
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Verified source milestones

  1. — An official oral-argument transcript was verified.
  2. — An official oral-argument transcript was verified.

The arguments, in order

This case may have been argued more than once. Each entry below uses that session's official transcript. Later arguments do not erase earlier ones.

  1. Argument 1 ·

    What happened at the argument

    Microsoft argues the current standard enforces invalid patents.

    i4i argues the standard follows broad language from Justice Cardozo.

    questions_asked_by_justices

    Read the official transcript for this argument · Official argument details

    Sources used for this argument breakdown

A citizen's guide to the whole case

What this case is about

The dispute centers on the burden of proof for patent invalidity. Microsoft argues the current standard is too high. i4i argues the standard protects patent rights.

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How the case got here

The Supreme Court heard oral argument in this case on April 18, 2011.

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What each side wants

Microsoft wants a preponderance of the evidence standard to invalidate patents.

i4i wants to keep the clear and convincing evidence standard for invalidity.

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What each side says

Microsoft argues the high standard enforces invalid patents and stifles innovation.

i4i argues the high standard protects patent holders and follows precedent.

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What the justices asked

Justice Sotomayor questioned if cited cases eliminated the burden of proof.

Justice Scalia asked if counsel contradicted Justice Cardozo's prior ruling.

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Why it matters

The standard determines how easily patents face invalidity challenges. It affects the balance between innovation and patent security.

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What happens next

This article currently covers the argument record. Use the official docket link for later case activity.

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Official Court provenance

Official docket and case history · Official Supreme Court oral-argument detail page

Title and summary sources

Revision history

  1. Revision 1 · Official Transcript ·

    Correction: Rewritten to the concise citizen-facing editorial standard.

  2. Revision 2 · Official Transcript ·

    Correction: Migrated to the dated official Court activity contract without model use.

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