How does changing numeric range limits affect patent claim scope?

Changing numeric range limits can significantly affect patent claim scope. The MPEP 2163.05 provides guidance on this:

“A claim that omits an element which applicant describes as an essential or critical feature of the invention originally disclosed does not comply with the written description requirement.”

This principle applies to numeric ranges as well. Modifying range limits can either broaden or narrow the claim scope. For example:

• Expanding a range (e.g., from 5-25% to 1-30%) generally broadens the claim scope.
• Narrowing a range (e.g., from 5-25% to 10-20%) typically narrows the claim scope.

In both cases, the new range must be supported by the original disclosure to comply with the written description requirement.

To learn more:

• numeric ranges
• claim amendments
• written description requirement