Patent bar Written description, enablement and claims (35 U.S.C. 112) question: delivery route in a computer-implemented system

Patent barWritten description, enablement and claims (35 U.S.C. 112)

A claim recites 'means for calculating a delivery route' in a computer-implemented system. The specification says only that 'a general-purpose processor calculates the route' and discloses no algorithm. What is the most appropriate rejection?

A Under 112(d), because the means limitation fails to further limit the claim
B Under 101, because routes are abstract ideas, with no 112 issue
C No rejection, as a general-purpose processor is sufficient structure
D Under 102, as general-purpose processors are known
E Under 112(b), for lack of a disclosed algorithm

Show the answer and explanation

Answer: E. Under 112(b), for lack of a disclosed algorithm

Answer: Under 112(b), for lack of a disclosed algorithm. For a 112(f) limitation implemented by a computer, the corresponding structure is the general-purpose computer programmed to perform a disclosed algorithm. Without an algorithm, the claim lacks corresponding structure and is indefinite under 112(b); it may also lack written description under 112(a) (MPEP 2181(II)(B), 2185). Why not the others: - 102: known processors do not address the missing algorithm. - A processor is enough: a bare general-purpose computer is not adequate structure for a specialized function. - 112(d): that concerns dependent claims failing to further limit. - Only 101: eligibility may also be analysed, but it does not cure the missing structure under 112. Rule: Computer-implemented 112(f) limitations require a disclosed algorithm, or the claim is indefinite. Source: MPEP § 2181, § 2185 (9th ed., Rev. 01.2024); 35 U.S.C. 112(b), 112(f); as at Oct 2026

Common mistake

Accepting 'a processor' as the structure for any computer function.

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Original study material written from the MPEP; not a question from the current exam.Independent. Not affiliated with or endorsed by the USPTO. Verify figures and rules against current guidance before relying on them.