35 U.S.C. § 112 (f) Element in Claim for a Combination:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
講完了對於手段功能用語的基本介紹,回頭說說本案經過。專利權人MTD Products Inc.擁有關於割草機驅動和轉向系統的美國專利US8011458,訴願人The Toro Company對此專利提起IPR (Inter Partes Review) 專利無效挑戰,最終PTAB認定此專利不具備進步性/創造性,而在此無效決定中,最為關鍵的是權利範圍中對於技術特徵「mechanical control assembly…configured to…(機械控制總成…配置以用於…)」的表述被PTAB認定並非手段功能用語。專利權人隨後對此決定提起上訴。
訴爭技術特徵寫法分析
於本案獨立項中,對於主要爭點技術特徵「mechanical control assembly」是這麼表述的:
…
a mechanical control assembly coupled to the left and right drive units that is configured to actuate the left and right drive units based on a steering input received from the steering device and a speed input received from the speed control member;
…
透過上面的權利範圍文字可以觀察到,在權利範圍中沒有明確提出「mechanical control assembly」的詳細結構,僅有透過連接詞「configured to」來描述其作用。而透過上文的介紹我們可以知道,這應該是屬於手段功能用語的表現方式。
為何PTAB認定並非手段功能用語?
PTAB的認定主要根據禁反言原則,即專利權人已經於專利申請過程中聲明此特徵是結構上的限制 (structural limitation),因此日後主張權利的過程中,就不能再回頭主張這特徵是手段功能用語。更詳細的說,在專利申請答覆OA (Office Action, 審查意見) 的過程中,專利權人為了要讓此特徵可以與引證資料中的結構直接比對且主張具有區別,專利權人曾於意見回復書中寫道:「此特徵涉及的是機械控制總成的配置 (the claim language at issue concerns the configuration of the claimed mechanical control assembly)」、以及「這配置確實是結構性的限制 (the claimed configuration is indeed structural)」,PTAB認定這些聲明為訴爭特徵並非手段功能用語的強力證據[2]。另外作為輔助觀點,PTAB還認為說明書內容足以明確說明此特徵的結構、故可以回避不成為手段功能用語。
上訴法院CAFC反駁觀點
CAFC對於PTAB的上述兩理由都加以反駁,對於禁反言理由,CAFC說明根據Williamson v. Citrix Online, LLC(Fed. Cir. 2015,全院聯席審理en banc)的判例,這種權利範圍寫法就是手段功能用語,且專利權人於申請過程中只是提出應考慮到權利範圍中其他實質結構特徵的權重、並沒有明確表達此特徵並非手段功能用語。另外,關於PTAB提到的「說明書內容足以明確說明此特徵的結構,故可回避不成為手段功能用語」之說法,CAFC則認為是否為手段功能用語判斷仍應依據權利要求內容而非說明書、否則若只要說明書有揭露實施細節就能規避的話,那天底下就不存在手段功能用語了[3]。因此,最終CAFC認定訴爭技術特徵「mechanical control assembly」仍為手段功能用語。
是否被認定為手段功能用語為何如此重要?
因為如同本文一開始的介紹,手段功能用語的保護範圍解釋必須限縮至說明書的實施方式及等同的實施方式中,若僅具有相同功能、但是實施方式上差別較大的,就將會被排除在權利範圍的解釋之外,因此可以看到本案中專利權人於申請過程中、以及日後無效程序中對於手段功能用語認定態度180度大轉變的現象。即如前所述、本案專利權人於申請專利時主張訴爭技術特徵「mechanical control assembly」不是手段功能用語,為的就是擴大權利保護範圍、而不至於日後授權範圍被限縮至說明書的實施方式中;但等到了無效程序階段,因為對方提出的無效證據中、對應的其他結構也擁有相同功能效果,因此專利權人趕緊轉而聲稱此特徵是手段功能用語,限縮其解釋範圍以避免整篇專利被無效,這樣的轉變剛好的說明了手段功能用語對於專利不同階段有著截然不同的影響。
Larry M.Goldstein (2014). Litigation-proof patents: Avoiding the most common patent mistakes, P.53 (“This is considered to be a narrow form of structure claim”).
本案判決書原文:「The most persuasive piece of evidence to the Board, however, was the prosecution history...The Board emphasized MTD’s statements that “the claim language at issue concerns the configuration of the claimed mechanical control assembly” and “the claimed configuration is indeed structural.”...The Board concluded that these statements “present strong evidence that the disputed phrase should be understood as a structural limitation rather than a means-plus-function limitation under § 112 ¶6."」
本案判決書原文:「The Board’s analysis implies that so long as a claim term has corresponding structure in the specification, it is not a means-plus-function limitation. This is not consistent with our prior decisions. Indeed, this view would seem to leave § 112, ¶ 6 without any application: any means-plus-function limitation that met the statutory requirements, i.e., which includes having corresponding structure in the specification, would end up not being a means-plus-function limitation at all」