従来どおりという感もありますが、参考までにCAFC判決です。Marrin v. Griffin
“Preamble language that merely states the purpose or intended use of an invention is generally not treated as limiting the scope of the claim.”
“Clear reliance on a preamble during prosecution can distinguish a claimed invention from the prior art and render the preamble a claim limitation, … “
“[T]he mere fact that a structural term in the preamble is part of the claim does not mean that the preamble’s statement of purpose or other description is also part of the claim.”
“The preamble limits the claimed invention if its is “necessary to give life, meaning, and vitality to the claim.”
タウンゼント知財総合事務所/ 穐場 仁