17 thoughts on “Equivalent-of-the-Equivalent

  1. 6

    With respect to Dennis, I think the question was poorly phrased, because it’s not exclusively one or the other, but it is mostly an infringement issue.

    Of course the general scope of an MPF claim element is a claim construction issue. But you cannot determine every possible “equivalent[] thereof” in a vacuum as a claim construction issue, there could be hundreds or even thousands of possible structures that could potentially qualify as literal equivalents under 112(6)/112(f) of the corresponding structure in the specification. The analysis thus always involves the factual assessment, as part of the infringement analysis, of whether the accused structure was after-developed technology and whether it is insubstantially different from the disclosed structure.

    1. 6.1

      Agreed. It’s a chicken-and-egg conundrum, isn’t it?

      In England, the rule is to construe the claim “as if the infringer had never been born”. Trouble is, until you have grasped the details of the accused embodiment, you don’t know which bits of the claim are going to be decisive in the equivalents analysis. Deprived of all knowledge of the infringement, the task of considering all conceivable points of “equivalency” that the claim admits of would require time in geological amounts. Life’s too short for that.

  2. 5

    Without taking any stance on the validity or wisdom of the jurisprudence, the Federal Circuit has answered the equivalent to a structural equivalence question, i.e., when does DOE apply to a means-plus-function limitation by applying a temporal distinction. If the alleged equivalent is after-arising technology, then DOE can apply in the infringement analysis. If the alleged equivalent existed in the prior art, then whether it falls within the scope of “structural equivalents” is a literal infringement analysis looking to the way-result or insubstantial difference.

    Al-Site Corp. is one of the main opinions on this point, where Judge Rader (I think) explained:

    One important difference between § 112, ¶ 6 and the doctrine of equivalents involves the timing of the separate analyses for an “insubstantial change.” As this court has recently clarified, a structural equivalent under § 112 must have been available at the time of the issuance of the claim. An equivalent structure or act under § 112 cannot embrace technology developed after the issuance of the patent because the literal meaning of a claim is fixed upon its issuance. An “after arising equivalent” infringes, if at all, under the doctrine of equivalents. Thus, the temporal difference between patent issuance and infringement distinguish an equivalent under § 112 from an equivalent under the doctrine of equivalents. In other words, an equivalent structure or act under § 112 for literal infringement must have been available at the time of patent issuance while an equivalent under the doctrine of equivalents may arise after patent issuance and before the time of infringement. An “after-arising” technology could thus infringe under the doctrine of equivalents without infringing literally as a § 112, ¶ 6 equivalent.

    Al-Site Corp. v. VSI Int’l, Inc., 174 F.3d 1308, 1320, 50 USPQ2d 1161, 1168-69 (Fed. Cir. 1999) (internal citations omitted – where there was identity of function performed by accused product with the means-plus-function limitation, i.e., fastening eyeglass to hanging member, and the jury found infringement under the doctrine of equivalents, specifically that structure of accused product of two arms containing holes at their ends to receive side members of eyeglass frame was equivalent to a single loop around center part of eyeglass frame, and such technology used in the accused product was not arising after technology, the jury’s finding of infringement under the doctrine of equivalents was also an implicit finding of literal infringement)

    See also

    Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1308, 1310, 46 USPQ2d 1752, 1758 (Fed. Cir. 1998) (“There is an important difference, however, between the doctrine of equivalents and § 112, ¶ 6. The doctrine of equivalents is necessary because one cannot predict the future. Due to technological advances, a variant of an invention may be developed after the patent is granted, and that variant may constitute so insubstantial a change from what is claimed in the patent that it should be held to be an infringement. Such a variant, based on after-developed technology, could not have been disclosed in the patent. Even if such an element is found not to be a § 112, ¶ 6, equivalent because it is not equivalent to the structure disclosed in the patent, this analysis should not foreclose it from being an equivalent under the doctrine of equivalents.” – reversing summary judgment of infringement and directing that summary judgment of no literal infringement and no infringement under the doctrine of equivalents due to the absence of structural equivalents, be entered)

    1. 5.1

      As a further note, DOE can also apply to the function of a mpf limitation.

      Interactive Pictures Corp. v. Infinite Pictures, Inc., 274 F.3d 1371, 1381-82, 61 USPQ2d 1152, 1160 (Fed. Cir. 2002) (“[W]hen a finding of infringement under 35 U.S.C. § 112, paragraph 6 is premised on an absence of identical function, the infringement under the doctrine of equivalents is not thereby automatically precluded. That is because infringement under the doctrine of equivalents may be premised on the accused and the patented component having substantially the same function, whereas structure corresponding to the disclosed limitation in a means-plus-function clause must perform the identical function.” – emphasis in original – substantial evidence supported jury verdict that computer image file in specific format equivalently met means-plus-function claim limitation even though accused structure was not after arising technology – affirming denial of JMOL of noninfringement seeking to overturn jury verdict finding accused device that used a equirectangular panoramic computer file as part of hemispherical imaging system infringed under the doctrine of equivalents and rejecting infringer’s arguments that prosecution history estoppel barred the claim, that a hypothetical claim analysis precluded infringement, and that the function-way-result test was not met)

      For those interested, cases on these issues are collected in the Annotated Patent Digest at § 13:51 Equivalents of the Claimed Function and § 13:52 Equivalents of a Structural Equivalent and After-Arising Technology

  3. 4

    Great question, especially in the aftermath of the recent earthquake in Europe, with a slew of national supreme courts issuing decisions in the world-wide PEMETREXED litigation that amount to a pan-European DoE. Yes, I know, the claim was not expressed in classic M+F language but nevertheless, the claim construction dilemma is front and centre. The claim is explicitly to the disodium salt alone, yet equivalents were found to infringe. When it comes to prior art attacks, what scope does the claim then have? A great deal of ink has been consumed in Europe, these past two years or so, on that very question. The hoary old maxim that what comes after and infringes, if coming before deprives of validity, has fallen off its exalted perch and is as dead as Monty Python’s Blue Portugese parrot.

  4. 3

    I can’t see how it could be anything except claim construction. You have to know the scope of a claim before you can determine possible infringement. It’s not unusual for infringement cases to end right after the Markman hearing because, after claim construction, one or both of the parties realizes that the claims, as construed during the hearing, do not cover the accused product/process/etc.

  5. 2

    Interesting topic.

    I think the Fed. Cir got it wrong. Equivalents thereof was definitely intended to refer to the DOE. It is absurd to think otherwise.

    My theory is that “Equivalents thereof” was included because the DOE function, way, result test does not apply to MPF claims because the “result” part has been generalized as the function of the MPF claim.

    Thus, to preserve the DOE for MPF claims, Congress allowed the DOE to apply to the equivalent of each structure of the specification.

    If interpreted this way, MPF claims would be much broader. Unsurprisingly, the courts screwed it up.

    1. 2.1

      Like maybe I am OCD, but it bothers me to no end that the same word can mean different things in the same body of esoteric law. It cannot be true.

      1. 2.1.1

        But, its not the same. Judicial DOE is a function way result equivalent of a claim element itself, whereas [in the U.S.] a statutory 102(g) equivalent for a means function claim is an equivalent only of the specification enabling example[s] supporting the “means for” claim element [if there is any such enablement].


          Sorry, I meant to type 112(f) of course:
          “(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.”


          Tautological reasoning. I understand they way things are. I don’t agree and the law is not completely settled.

          I am saying the Fed Cir. got it wrong and they are they same. You say that they are not but you do not back up the assertion as to why 112(f) “equivalent” should be interpreted differently.

          Shouldn’t we presume Congress drafted 112(f) with the DOE in mind?


            Bob’s discussion above is great. But the 1952 act was meant to legitimize MPF claims. The fact that MPF claims do not receive the DOE with respect to after arising technologies, is further evidence that the Fed Cir got it wrong.

            IMO, this is a great topic for a law review article.

    2. 2.2

      >If interpreted this way, MPF claims would be much broader.

      OTOH, Festo would apply in full force.

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