The Incandescent Lamp Patent (159 U.S. 465, 1895 Nov 11)

Decision Parameters

Decisions It Cites Decisions That Cite It
Rules & Quotes
[VAGUE] {1} If the description [of the invention] be so vague and uncertain that no one can tell, except by independent experiments, how to construct the device, the patent is void. ... how would it be possible for a person to know what fibrous or textile material was adapted to the purpose of an incandescent conductor except by the most careful and painstaking experimentation?

Review Articles and Papers

"Experimentation and patent validity: restoring the Supreme Court's Incandescent Lamp Patent precedent", by Kevin Richards, Virgina Law Review, 2015, available at:

Brief Comments and Observations

From [RICHARDS]: The Federal Circuit currently uses "undue experimentation" analysis to determining whether the enablement requirement has been met. That standard is inconsistent with Supreme Court precedent. Incandescent Lamp establishes that a patent must enable the invention to be practiced without experimentation, though some preliminary testing may be allowed. As the "undue experimentation" standard has never been endorsed by the Supreme Court, and Incandescent Lamp has never been overruled or criticized, Incandescent Lamp provides an important tool for patent litigators seeking to invalidate patents which may preempt research into emerging fields.

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