How does inequitable conduct in one patent affect related patents or applications?

Inequitable conduct in one patent can have far-reaching consequences for related patents or applications. The MPEP provides insight into this issue:

Clearly, where several patents or applications stem from an original application which contained fraudulent claims ultimately allowed, the doctrine of unclean hands bars allowance or enforcement of any of the claims of any of the applications or patents.

This means that fraud or inequitable conduct in one patent can potentially invalidate or prevent enforcement of related patents or applications. The MPEP cites several cases supporting this principle, including:

• Keystone Driller Co. v. General Excavator Co., 290 U.S. 240, 245, 19 USPQ 228, 230 (1933)
• East Chicago Machine Tool Corp. v. Stone Container Corp., 181 USPQ 744, 748 (N.D. Ill.), modified, 185 USPQ 210 (N.D. Ill. 1974)

These cases establish that fraud or inequitable conduct affecting only certain claims or one of related patents can affect other claims or patents. This underscores the importance of maintaining integrity throughout the patent application process.

AIA Amends Duty to Disclose Errors Without Deceptive Intent MPEP 2000 Informative
Duty of Disclosure Materiality Revised Based on Therasense MPEP 2000 Informative
Duty of Disclosure to Adopt But-For Materiality Standard MPEP 2000 Informative
Guidance on Compliance with Duty of Disclosure Regardless of Materiality Standard MPEP 2000 Informative
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