Guest Post: The Substantial Identity Requirement of Patent Infringement

Guest Post by Professor Samuel F. Ernst, Golden Gate University School of Law

Every patent litigator knows that if a product or process accused of patent infringement contains every limitation of the asserted patent claim, there is infringement.  “It is fundamental that one cannot avoid infringement merely by adding elements if each element recited in the claims is found in the accused device.”[1]  In fact, this is not the law.  In 1898 the Supreme Court held in Westinghouse v. Boyden Power Brake Co. that two steps are required for a patent holder to prove infringement.[2]  Yes, the patent holder must prove that the accused product falls within the literal language of the patent claims, but this does not end the infringement analysis.  The patent holder must further prove that there is “substantial identity” between the claimed invention and the accused device, “whether that identity be described by the terms, same principle, same modus operandi, or any other.”[3]  Hence, in Westinghouse, the Court held that although George Boyden’s accused air pressure train brake fell within the semantic scope of George Westinghouse’s patent claims, there was no infringement because the accused device “is a novel one and a manifest departure from the principle of the Westinghouse patent . . . because it solved at once in the simplest manner the problem of quick action, whereas the Westinghouse patent did not prove to be a success until certain additional members had been incorporated into it.”[4]  Hence the Court stated the correct rule for patent infringement as follows:

But even if it be conceded that the Boyden device corresponds with the letter of the Westinghouse claims, that does not settle conclusively the question of infringement.  We have repeatedly held that a charge of infringement is sometimes made out, though the letter of the claims be avoided [i.e., the doctrine of equivalents].  The converse is equally true.  The patentee may bring the defendant within the letter of his claims, but if the latter has so far changed the principle of the device that the claims of the patent, literally construed, have ceased to represent his actual invention, he is as little subject to be adjudged an infringer as one who has violated the letter of a statute has to be convicted, when he has done nothing in conflict with its spirit and intent.[5]

The Westinghouse case has never been overruled by the Supreme Court.  In fact, the principle of Westinghouse was reaffirmed by the Supreme Court in dictum in the 1950 Graver Tank case.[6]  The Graver Tank opinion held that infringement may be proven by equivalents, even if there is no literal infringement.  But the Court also noted that infringement may be avoided despite literal infringement, under what has subsequently come to be known as the reverse doctrine of equivalents:

The wholesale realism of this doctrine [of equivalents] is not always applied in favor of a patentee but is sometimes used against him.  Thus, where a device is so far changed in principle from a patented article that it performs the same or a similar function in a substantially different way, but nevertheless falls within the literal words of the claim, the doctrine of equivalents may be used to restrict the claim and defeat the patentee’s action for infringement.[7]

In 1997, the Court declined to “speak the death” of the affirmative doctrine of equivalents, rejecting the petitioner’s argument that the doctrine was overruled by the 1952 Patent Act’s requirement that a patent applicant claim her invention in definite terms.[8]  The Court held that “[i]n the context of infringement, we have already held that pre-1952 precedent survived the passage of the 1952 Act.”[9]  This reasoning applies with equal force to the reverse doctrine of equivalents.  It also survived the passage of the 1952 Act.

Despite this history, since its creation in 1982 the Federal Circuit has all but overruled the reverse doctrine of equivalents.  The Federal Circuit has (accurately) warned litigants and the lower courts that “[n]ot once has this court affirmed a decision finding noninfringement based on the reverse doctrine of equivalents.”[10]  The Federal Circuit refers to the reverse doctrine of equivalents as “one anachronistic exception, long mentioned but rarely applied.”[11]  In the process of vacating findings of infringement under the reverse doctrine of equivalents, the Court has also cabined the doctrine in various ways, making it exceedingly difficult to prove.  Specifically, the court has: (1) held that the plaintiff no longer has the burden of proving substantial identity as part of the affirmative infringement case; rather, reverse equivalency is an affirmative defense with the burden on the accused infringer;[12] (2) overruled a previous case to hold that reverse equivalency is a question of fact, not an equitable determination or a question of law,[13] meaning that an accused infringer cannot readily use the doctrine as a tool to obtain summary judgment; and (3) held that the defense is only available when there is literal infringement, not when any of the claim limitations are infringed merely by equivalents.[14]

In a pair of recent law review articles, I argue that the Federal Circuit is wrong that the reverse doctrine of equivalents was an anachronistic exception, long mentioned but rarely applied.  In The Supreme Court Case that the Federal Circuit Overruled,[15] I dig deeply into the facts and reasoning of the Westinghouse case and several regional circuit court cases relying on the doctrine to argue that the reverse doctrine of equivalents is an essential safety valve in the patent infringement analysis to ensure that substantial innovations are not unduly enjoined or taxed by the patent thicket.  And in The Lost Precedent of the Reverse Doctrine of Equivalents, I review every published case finding or affirming non-infringement under the reverse doctrine of equivalents between 1898 and 1988, to conclude that the doctrine was regularly (even if not routinely) applied to find non-infringement in every decade from the 1900s through the 1980s, when the Federal Circuit effectively killed the doctrine.[16]  Of particular importance, opinions in the Second, Fifth, Sixth, Seventh, and Ninth Circuit courts of appeals hold that both literal and substantial infringement must be proven as part of the plaintiff’s prima facie case.[17]  The Second Circuit stated this fundamental, black letter law of patent infringement poetically: “There is no magic in a name, nor in a claim; that the words preferred by a patentee to define his invention apply literally to another’s device suggests, but does not prove, infringement.”[18]  In 1983, the Sixth Circuit bemoaned the fact that some courts “continue to pay lip service to the doctrine of literal infringement as though it were the rule…. Perhaps we are embarrassed to expose the ‘wholesale realism’ which controls many infringement cases, and we choose instead to present the facade of precision and certainty which attends the doctrine of literal infringement.”[19]

It is now time for the en banc Federal Circuit or the Supreme Court to overrule the erroneous doctrine of literal infringement and revive the reverse doctrine of equivalents.  As properly applied, the reverse doctrine of equivalents allows for accused innovations to escape infringement when they are substantially superior, practically and commercially, to the invention claimed by an asserted patent. [20]  Opponents of legislative patent litigation reform often argue that prospective legislation could have unforeseen adverse consequences on the incentive to invent.  An invigorated doctrine of equivalents would therefore be a more sensible, cautious, patent law reform than prospective legislation because it is applied by the courts on a case-by-case basis, with the court weighing the value of the patented invention against the value of the allegedly superior accused innovation and only granting relief in unusual cases.  Because the doctrine is not applied prospectively, it does not raise the concerns with unknown consequences that prospective litigation does.  Finally, the doctrine is a proven commodity because it was the law in this country from at least the 1900s through most of the 1980s, a period that saw substantial innovative advances, from the airplane to the rocket ship to the internet.  If a proper litigation vehicle is identified, a petition for certiorari arguing for the revival of the reverse doctrine of equivalents may well attract the attention of the Supreme Court.  The Supreme Court has been inclined to review the work of the Federal Circuit in recent years in cases where the Federal Circuit has applied a rigid rule (like the doctrine of literal infringement), given insufficient deference to district court determinations (as occurs when the district court is not permitted to weigh the principle of the asserted patent against the accused substantial innovation), and disregards or cabins Supreme Court precedent (as has been done with Westinghouse v. Boyden).[21]

= = = = =

[1] Stiftung v. Renishaw PLC, 945 F.2d 1173, 1178 (Fed. Cir. 1991).

[2] Westinghouse v. Boyden Power Brake Co., 170 U.S. 537, 568 (1898).

[3] Id. at 568 (internal citations omitted).

[4] Id. at 572.

[5] Id. at 568 (emphasis added) (internal citations omitted).

[6] Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 608-611 (1950).

[7] Id. at 608-09.  It appears that this fundamental principle of infringement analysis came to be known as “the reverse doctrine of equivalents” due to a 1966 article by Charles F. Pigott, Jr.  See Charles F. Piggott, Jr., Equivalents in Reverse, 48 J. Pat. Off. Soc’y 291 (1966).

[8] Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 21, 26 (1997).

[9] Id.  at 26-27 ((citing Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336, 342 (1961) (new section defining infringement “left intact the entire *27 body of case law on direct infringement”).

[10] Tate Access Floors v. Interface Architectural Res., Inc., 279 F.3d 1357, 1368 (Fed. Cir. 2002).

[11] Id.

[12] SRI Int’l v. Matsushita Elec. Corp. of Am., 775 F.2d 1107, 1123-24 (Fed. Cir. 1985) (en banc).

[13] Id. at 1126 (overruling Kalman v. Kimberly-Clark Corp., 713 F.2d 760 (Fed. Cir. 1983)).

[14] Texas Instruments, Inc. v. United States Int’l Trade Comm’n, 846 F.2d 1369, 1372 (Fed. Cir. 1988).  It should be noted that the Federal Circuit once mercifully vacated a sanctions award of over $10 million and attorney’s fees of over $400,000 that the district court had imposed on a defendant for the offense of merely raising the reverse doctrine of equivalents.  See DePuy Spine, Inc. v. Medtronic Sofamar Danek, Inc., 567 F.3d 1314, 1337-39 (Fed. Cir. 2009).  The Court acknowledged (incorrectly, in this author’s opinion) that “The Supreme Court has recognized it to be a viable defense, even if it is rarely asserted.”  Id. at 1339.  As set forth above, lack of substantial identity is not a defense; proving substantial identity is part of the affirmative infringement case.

[15] Samuel F. Ernst, The Supreme Court Case that the Federal Circuit Overruled: Westinghouse v. Boyden Power Brake Co., 68 Syracuse L. Rev. 53 (2018).

[16] Samuel F. Ernst, The Lost Precedent of the Reverse Doctrine of Equivalents, 18 Vand. J. Ent. & Tech. Law 467 (2016).

[17] See The Supreme Court Case that the Federal Circuit Overruled, 68 Syracuse L. Rev. at 62-66.

[18] Linde Air Prods. Co. v. Morse Dry Dock & Repair Co., 246 F. 834, 838 (2d Cir. 1917).

[19] Mead Digital Sys., Inc. v. A.B. Dick Co., 723 F.2d 455, 462 (6th Cir. 1983) (quoting Graver Tank, 339 U.S. at 608).

[20] By “innovation” I am referring to a practically and commercially functional product or process that has overcome the hurdles of financing, market-testing, regulatory approval, production, and other obstacles to become available for the benefit of the public.  This is distinguished from an “invention,” which is the articulation of an inventor’s idea, but not necessarily a fully realized innovation.  See Robert P. Merges, Commercial Success and Patent Standards: Economic Perspectives on Innovation, 76 Cal. L. Rev. 803, 807 (1988).

[21] See also John F. Duffy, Counterproductive Notice in Literalistic Versus Peripheral Claiming, 96 B.U. L. Rev. 1197, 1221 (2016) (opining that the Supreme Court may review the Federal Circuit’s “literalistic claiming approach” in the next five to ten years).

83 thoughts on “Guest Post: The Substantial Identity Requirement of Patent Infringement

  1. 14

    on of several items still captive:

    Your comment is awaiting moderation.
    March 12, 2018 at 3:34 pm

    Notably missing form the author’s viewpoint is the impact from KSR – the oft overlooked aspect that prior patents deserve MORE protection; and the legal requirement of an improvement patent being non-obvious is geared – in part – so that prior patents (the prior shoulders) are stronger.

  2. 13

    There are several countries that have a mechanism of compulsory licenses for patentees who want to exploit “improvement“ patents. These compulsory licenses look like a milder version of the application of the reverse doctrine of equivalents as envisioned in the last paragraph of the post. Is anyone aware of a study showing the impact of such compulsory licenses?

    1. 13.1

      Compulsory licensing is – and should be – anathema to anyone who understand how the sovereign of the United States chose to establish its patent system.


          That subset (“is used or manufactured by or for the United States”) does not cover the gamut of compulsory licensing.

          That section is far more analogous to a Taking.

    1. 12.1

      You had not hit the “don’t have a dialogue” count filter count, Ben.

      Please pay attention to what is actually posted.

    2. 12.2

      One aspect that your “test” misses, Ben, is that the “overflow” from the topic of this thread now appears on adjacent threads.

      When one in the future may wish to revisit the archives, NOT only is any direct dialogue artificially constained (and with insertions mad post-dialogue, twisted), but also, the full (and natural) discussion will not be evident on the very thread of which the dialogue pertains to.

      The ONLY reason why a “don’t have a dialogue” count filter is applied simply FAILS for its purpose on any number of meaningful reasons.

      If people do not like the fact that answers to particular points are not forthcoming, the answer is NOT to stunt the dialogue through artificial means.

      A better answer is to forestall the “drive-by monologue, internet style shoutdown” that occurs when the sAme ones re-post the same comments repeatedly without making any attempt to recognize, acknowledge, accept, understand, and integrate the counter points presented.

      That explicitly will not happen with the current editorial controls and how those controls are meted out.

      Quite in fact – the opposite occurs: the drive-by monologue Internet-style “shout down” is promoted.

  3. 11

    Graver Tank >>>Thus, where a device is so far changed in principle from a patented article that it performs the same or a similar function in a substantially different way,

    Funny, this also strongly supports functional claiming. Also, basically, this is just scope of enablement.

    Westing House>>>The patent holder must further prove that there is “substantial identity” between the claimed invention and the accused device, “whether that identity be described by the terms, same principle, same modus operandi, or any other.”[3]

    So, the author should have put the claims up. Basically, we are talking about reading on a functional element, but performing the function in a different way than is enabled by the patent.

    Of course, Deener said that it didn’t matter how the functions of a method were performed that this would not get you out of infringement.

    There is another modern case on scope of functional claiming. I can’t remember the name off the top of my head.

  4. 10

    Author: “As properly applied, the reverse doctrine of equivalents allows for accused innovations to escape infringement when they are substantially superior, practically and commercially, to the invention claimed by an asserted patent.” “Properly applied”? Who decides in hind sight years later that solutions are “substantially superior” and that they were not made possible by the concepts that were discovered only by the original inventor? Those who propose to resurrect the reverse doctrine of equivalents (RDOE) apparently miss the very notion of invention. They fail to recognize that the invention is a concept – not a particular technological choice for implementing it.

    Proposals to put RDOE on steroids emerged in academia in the 1990’s not only for dealing with literal infringement but also for curtailing the application of the doctrine of equivalents itself when there is no literal infringement. Robert Merges, whom the author cites, used to be one of the key proponents of the reverse doctrine in his 1990 and 1994 papers. These papers presented ostensible historical “evidence” in support of the RDOE proposition: allegations that broadly-interpreted patent claims blocked Glen Curtiss from introducing advances into the fledgling aircraft industry when the Wright patent was asserted against him; that the assertion of the overly broad Selden patent suppressed development in the early automobile industry; that Edison’s assertion of his incandescent lamp patent suddenly rendered competition in the field impossible; and that the Fleming diode patent blocked radio development with triode tubes and that perhaps FM radio would have appeared 10 years earlier.

    For example, under the RDOE, Curtiss would have not been found infringing the Wright patent claims on wing-warping because he used an improved aileron method for causing differential lift on opposite wings for gaining lateral stability. Thus, even though the Wrights have invented the fundamental concept of producing differential lift on opposite wings, Curtiss would have gotten off the hook and the Wrights’ patent would have been made worthless well before its term ended.

    But none of the purported “evidence” Merges relied on to promote the RDOE proposition was in fact true – he fell victim to erroneous historical accounts with largely embellished made-up stories and myths from decades ago. By thoroughly studying the real historical facts, we have shown that in every case that Merges cites, the opposite had actually occurred. We have documented not only no suppression, but actual robust industry development surges in the face of these asserted patents in the early aircraft industry (link to, in the incandescent lamp industry when Edison asserted his patent (link to, the Fleming diode and the early radio industry (link to, and the Selden patent in the early automobile industry (link to The RDOE has no evidentiary legs to stand on and I believe that Robert Merges no longer subscribes to such assertions.

    This is important because the proponents of the RDOE not only rely on false facts but apparently gave very little thought to the unintended consequences of RDOE that would frustrate one of Congress’ reasons for enacting Section 112 – ensure that patent disclosures teach and provide clarity as to the invention over the art. Should the RDOE be resurrected, those who prosecute patent applications would readily recognize the substantial risks in providing discussion of the deficiencies of the prior art in the disclosure. Assume the invention I is especially advantageous in the context of new technology N. Suppose further that the disclosure lists disadvantages D1, D2, and D3 of the old technology O. The claims would cover I in the context of either O- or N-based implementations. Now, suppose a competitor introduces an O-based product using invention I, and with improvements to solve disadvantages D1, D2, and D3 – and his product literally infringes the claims. The O infringer is going to argue under RDOE that the claims should not cover O-based implementations because his invention solves D1 through D3 in a “substantially superior” way and is thus “practically and commercially” superior.

    Should RDOE be the law, the inevitable result would be that discussions of the problems inventors sought to solve will disappear from patent disclosures – an outcome which Congress did not intend by enacting Section 112 of the 1952 Patent Act. This is another reason why the CAFC’s jurisprudence on RDOE is the “properly applied” interpretation of Section 112.

  5. 9

    I think we should leave it to the defendant to assert and prove that a literally infringing device is “so far changed in principle from a patented article” that it should escape infringement.

    1. 9.1

      DC, you think that the Supreme Court can be reversed so easily by the Federal Circuit?

      1. 9.1.1

        As confused as the Supreme Court can be on these issues, I am still a stickler for process, so if the Supreme Court puts the burden of proof to negate RDOE on the patentee (Westinghouse is not explicit on this point), that requires the patentee to forecast every crazy argument that a defendant might present and that should be corrected by a proper process.
        In almost every instance, if a device meets the claim language, that is proof enough that it works under the same principles. No more need be said by the patentee.
        Also, Westinghouse seemed technically wrong. The infringer just added a feature to improve the brake. Other than that, it was still an air brake, and air brakes all work on the same principle.
        Also, Westinghouse seemed legally confused. The Supreme Court seemed to apply a means plus function analysis to a claim with no means plus function language. You can read Westinghouse as a MPF case which decided that some element was not equivalent to the claimed MPF element.


          You are correct – this was a mess. Westinghouse is a judge-made law that sought to encode a policy which Congress did not enact – “we will excuse infringement if it is for good innovation cause; and the courts – not Congress – should decide what constitutes good cause.”

          The Court’s confusion in this case on “means-plus-function” is why these types of claims were later specifically provided for in Section 112 of the Patent Act. As I explained above, the enactment of Section 112 put an end to the Westinghouse nonsense; and the Federal Circuit correctly recognized that.


          You are also correct that the application of RDOE “requires the patentee to forecast every crazy argument that a defendant might present.” That is why I predicted that it would inevitably lead to applicants defensively avoiding any description of the deficiencies of the prior art in the disclosure to avoid having to argue later about the defendant’s ” substantially superior” solutions to those deficiencies as a basis for escaping a holding of infringement.

  6. 8

    Interesting article. In a nutshell, after the requirements of 112 have been satisfied, the “reverse doctrine” as a defense shouldn’t be necessary except in bizarre circumstances. A proper claim construction will usually take care of the problem of a “lack of substantial identity” between what is claimed and the accused manufacture, component, or composition.

    I admit I had practically forgotten about the doctrine since it’s been so rarely mentioned here lately. It used to come up semi-regularly but the CAFC appeared to strangle the life out of it. The elephant in the room, as has been noted by Ned and pretty much every other astute observer, is that the CAFC simultaneously (and perhaps not coincidentally) created a massive exception in 112 for the highly dubious purpose of granting patents on data-processing logic.

    As a result of breaking the tether between claim language and any new objective physical structure (or a novel physical transformation of matter), the CAFC created a playground for scrivening and language manipulation which was unprecedented in the history of the patent system. They created an environment in which a company like Intellectr0 ll Ventures could spring up and basically spray the entire system with a toxic waste. When there is nothing underneath the claimed functionality except vapor (e.g., instructions, rules and logic) there are no limits placed on the attorneys who draft the claims. It’s a free-for-all. How many different ways can one come up with to say, e.g., “compare this to that”? Heck, you can make up words on the spot and pretend that they represent a “virtual” “structure” that can literally be anything you want it to be as long as the result is the same as that achieved by the product produced by the accused. This is worse than a “nose of wax”. It’s a nose of pure imagination, bounded only be the limits of one’s greed.

    So of course subject matter eligibility has become a major player to keep the mess under control. And if the reverse doctrine helps do more of that important work or at least gives the CAFC a kick in the kneecaps which causes them to reconsider the disaster they’ve created, that’s all for the better.

    1. 8.1

      created a massive exception in 112 for the highly dubious purpose of granting patents on data-processing logic.

      How goes that effort to copyright “logic”…?

      1. 8.1.1

        How goes that effort to copyright “logic”…

        Meet, “anon”, the resident bl0g tr0ll. Nobody knows what he’s talking about. His mentor and hero is Big Jeans, as everyone is well aware, but “anon” likes to come here because (try to believe it) he thinks there is a lack of “critical thinking” among academics.

        That’s why “anon” spent years here manipulating hundreds of s0 ckp upp ets trying to squelch any discussion of subject matter eligibility … until Dennis outed him. Boo hoo hoo.

        Now “anon” spends his time trying to derail any discussion of the fact that his favorite flavor of patents protect data processing logic and/or information (both of which are ineligible subject matter — oops! let’s just ignore that fact and kick up a mountain of dust).

        Out of the other side of his mealy mouth, “anon” engages in the typical Rep u k k ke whining that “academia” doesn’t spend enough time reciting “anon”s scripts and taking his glibertarian viewpoints seriously. I mean, maybe brown people and women are, in fact, inferior to white men. It should be discussed all the time! And rich entitled people should be paid to come to universities where women and brown people pay tuition and insult them without fear of being shouted down or protested which is, quite plainly, the Worst Thing Ever (“anon” actually believes this and has said so numerous times, by the way — he’s a real piece of work).

  7. 7

    The concern addressed in the reverse doctrine of equivalents echoes the reasoning that many engineers have. Engineers do not understand how their devices could be infringing an umbrella patent when their device has been patented in view of the umbrella patent. Their reasoning is that, because they obtained a patent over the umbrella patent, that proves that their device was not identical or even obvious over the disclosure in the umbrella patent, and therefore their devices cannot fall under the scope of the claims of the umbrella patent. Usually, this reasoning is brushed away by a simple statement that engineers confuse patentability with infringement. Nevertheless, the concern addressed in the reverse doctrine of equivalents seems very much grounded in the common sense of engineers, and some attention should be paid to to this concern.

    1. 7.1

      The words “patentably distinct” suffice for that concern.

      As improvement patents are by far the typical type of patent granted, the “concern” is not anywhere near the klaxon sounding level that the author of this particular blog post wishes to portray.

      1. 7.1.1

        I somewhat agree, the price that was paid to alleviate this concerns has been the courts construing the claims (often after being briefed on the impact of claim construction on infringement).

    2. 7.2

      OMG. If someone invents an automobile and later someone else invents an automobile with a radio in it, should the inventor with the radio be able to sell automobiles with radios in them without getting a license from the guy that invented the automobile?

      1. 7.2.1

        Even worse than that in that improvement patents are what puts a fire under every company to continue to innovate. So, no you should not be able to sell the automobile, but the guy that invented the automobile wants to be able to sell the improved automobile. That is what drives most innovation.

      2. 7.2.2

        Assuming radios already existed, I would say that a car with a radio is substantially identically to a car without one.

        Wouldn’t you?

        [orders humongous bag of popcorn]


          Pika – We are pretty much all engineers here. I for one do not think the way you outlined. If, I’m improving air brakes, I understand that air brakes were invented by someone else and that I see a way to make them faster. I understand, that I am standing on the shoulders of the air brake guy and if his or her patent is still in force, I understand I owe him or her a royalty.


            I like this example of air brakes better than the example of the car with a radio. Thanks Les.
            Now, suppose that you get a patent on your improved faster air brakes, and that your air brakes were accurately not found described in any earlier patent in a way sufficient to enable your improved brakes.
            How do you justify paying a royalty to a patent owner (or even being enjoined not to sell your improved brakes)?
            If your improved brakes fall under the scope of a claim granted in a previous patent, this full scope could not have been enabled. Which is better for the patent system, a finding of non-infringement of your brakes, or a conclusion of invalidity of the claim of the previous patent for insufficient enablement?


              Don’t thank me for the air brakes. That’s what the article is about. Of course the earlier patent doesn’t disclose the improvement. Thats what improvements are. I don’t have to pay royalty on the improvement. I have to pay royalty on the thing that I improved. The original claim is to an airbrake system comprising A, B, C and D. My invention is to A, B, C, D and E or A, B, C’ and D. Clearly A, B, C, D and E includes (comprises) A, B, C and D. According, when I’m making and selling my invention, I am also making and selling the earlier one. There might be some argument when the invention is A, B, C’ and D, but there shouldn’t be. C called for a valve is an orifice and a spring. My invention has an orifice and a spring, but the orifice is bigger than they were using and a stiffer spring. As a result, mine is faster, but the compressor has to have a higher duty cycle and more energy is required to oppose the spring. They may not have disclosed my ideal (for speed purposes) combination of orifice and spring, but the inclusion of an orifice and spring was disclosed.

              I can get a patent on my improvement. We can cross license our patents to each other. Everyone benefits. Progress in the useful arts has been promoted and all is right with the world.

    3. 7.3

      I don’t think it takes an engineering degree to see that being given the right to exclude others to that which you did not provide the public is wrong, absurd, and contrary to promoting the progress in the useful arts. It seems that only those sith a vested interest in overcompensating patentees can’t see it.

      This doctrine sounds like a nice way to police such over-grants. I’m not surprised that the CAFC killed it.

      1. 7.3.1

        may be liberated…:

        Your comment is awaiting moderation.
        March 12, 2018 at 1:50 pm

        With bias displayed like that, Ben, do you really wonder why you are “tagged” with an anti-patent brush?

        You ASSume something “wrong, absurd and contrary to promoting the progress” in order to justify your feeling of “overcompensated.”

        You then ASSume that the CAFC not only “killed it,’ but was wrong in “killing it.”


          Your comments really are devoid of content or value.

          If you invent X to get Z, you shouldn’t be able to claim ‘getting Z’ and be granted the right to exclude others using a Y to get Z. Allowing the inventor of an X to get Z to get the scope of ‘getting Z’ plainly does not promote the progress of the useful arts.


            Your comments really are devoid of content or value.

            Your feelings are noted. Meanwhile in the real world the exact opposite is true.

      2. 7.3.2

        Ben, those who discover new principles have long been trying to claim them as such – not limited to particular means, but to any means that employ the principle to achieve the result. The first example of a patent claiming a principle known to history is the patent of James Watt who invented the condenser. His patent included no drawings and no examples. It just stated the principle without more.

        In the trial of his patent’s validity, the sufficiency of the specification was raised. Watt argued that once the principle was disclosed, any mechanic with ordinary skill could make a steam engine with the adjoined condenser. The opposing view was that he had to disclose at least one working example. The court split two-two. But this was good for Watt because his patent was not proven to be invalid. The preliminary injunctions stood.

        In implementing the American patent laws, Congress required that inventors describe how to make and use the invention, and the best mode for carrying it out. In other words the requirements of the statutes do not permit the patenting of a principle absent examples. Furthermore, it is established American law that one can only exclude others from making and using that which one disclosed or equivalents thereof. However, to the extent that the disclosure is broadly enabling, as it appears to be have been the case with the Watt invention, any means for carrying out the principle would be covered. Claims with such scope are, in effect, a method claims.

        But claims to results alone absent any means or method for achieving the result are not limited to any invention, but simply claim a trade. But this is how most patent attorneys today write claims. They are trained to do it.


          But this is how most patent attorneys today write claims. They are trained to do it.

          Whine some more, the Jepson option-not-option mindset dinosaur.

  8. 6

    >>In a pair of recent law review articles,

    So, if I bother to read your articles and find that you have not been ethical, do I have a recourse? No. That is you should term whatever did as a vanity press publication.

    You “law review articles” are not peer reviewed.

    1. 6.1

      >>>to ensure that substantial innovations are not unduly enjoined or taxed by the patent thicket.

      Let me guess. Lemley got you your job?

      1. 6.1.1

        Yep, once I saw that ‘patent thicket’ language, big turn off. Note to Ernst, using strawmen and weasel words like patent thicket are a big turn off to the knowledgeable reader. Think of it like using net neutrality to a group of FCC lawyers, they know the issues and see right thru the jargon.


          Another indicator was the reliance on Merges – as you indicated, a knowledgeable reader knows the bias therein.

    2. 6.2

      Westinghouse v. Boyden Power Brake Co. good law?

      Again, the SCOTUS is not the one that is supposed to making patent law. The Constitution even says this. It is unethical not to discuss this.


              “Not needed or required 6.”

              Only as long as you have some cultists in the judiciary will it not be needed or required. Cultists cultivated where? lawlschool?


                No “cultists” necessary.

                You rely F A R too much on that “cult” thing as a crutch to any meaningful and critical thinking on your part.

                1. “No “cultists” necessary.”

                  I’m pretty sure judge Giles Rich (chief priest at the time and likely one of the founders of the cult, or acolytes of the founders) played a fairly large role.

                  ” critical thinking”

                  Muh critical thinkin’! Lol. I’ve already conceded that there are benefits to the cultists view(s). There are drawbacks as well. That’s critical thinkin’ bruh.


            More clear? For the most part the ’52 act overturned a large body of 2nd Circuit law – a notorious patent killer circuit – and the SCOTUS law like ‘gist’ or ‘heart of the invention’ law imported from the second circuit. And then you see Ernst citing 2nd circuit law. Yet another tell.


              So does any of the pre-1952 law still stand? How much? It’s of course clear that some of the law was excised. But the extent of that surgery is not clear.


              I quite agree with you that congress did a bit of mucking about in anti-patent lawl so to speak. But they should have been a lot more clear, and a lot more explicit in a lot of the changes they made. Just so that everyone would be clear. Instead they left it to courts to fiddle around with and now there’s a small chance that someone busts up in and the supremes are all like “he he he our lawl stands!” and throws the system a curve, AGAIN. I will lay the blame at the feet of the congress who routinely neglect such things.

    3. 6.3

      Night Writer,

      Your comment of ““law review articles” are not peer reviewed.” only gets you so far.

      The “peers” of a cess pool will not likely notice the stench.

      It is the whole (hole?) of academia that has been infected and infested.


          Brushing aside the mindless ad hominem, academia has been infested with and infected by a “style” of perpetuating a philosophy rather than teaching the skills of critical thinking.

          Thanks for asking (even as you were not asking to engage in any sense of inte11ectual honesty).


            And what they are infested by is a belief that what they are doing is above the law, so that their judicial activism absolves them of the responsibility to follow rules of ethics in journal articles.


            academia has been infested with and infected by a “style” of perpetuating a philosophy rather than teaching the skills of critical thinking


            And your evidence for this?


              Indeed I have to agree with MM here.

              Anon is inferring that critical thinking is being foregone in the teaching and thus the philosophy is being allowed to be pushed without push back. He is inferring this from the existence of the pushing (itself) of the philosophy, and the success of the pushing. That is not a safe inference to make. Post modernism provides the way to keep critical thinking happening/taught at the same time as pushing x y or z philosophy. This is how other anti-white cis hetero christian capitalist patriarchial philosophies have been entered into academia.

              Though touted as such, Muh Critical Thinking is no absolute barrier against the perpetuating of the philosophy that unis infected with. Indeed, all one needed to do is infect “morals” first (via moral relativism or another method of manipulating morals of which there are many), and then critical thinking will bring those now infected morals, and ultimately the infectious philosophy, into the analysis/thinking/institution for you.

              Thus it is through post-modernist techniques that they need not be forgoing edumacation on critical thinking while still pushing the philosophy into academia and getting it successfully pushed.

              The supposed pinnacle of thought, “muh critial thinking” was undermined long ago, nigh 100 years ago. But I still see people making annoying reference thereto.


                Can anybody translate this sh_tbag’s rant into English?

                Probably sounds better in the original German.

                1. “Probably sounds better in the original German.”

                  It does I’m sure.

                  Though no, there is no translating an explanation of post-modernism and its sub-methods to everyday language. If you could then it wouldn’t have infected academia. It’s literally that bizarro and hoity toity naval gazing intellectualist. And its the foundation of the modern leftist establishment/activism.

                  But here I can try, the basic gist is this:

                  -Muh Critical Thinking is hailed as the be all end all way to think to “improve things/society/everything” since the ancient greeks and is resurrected in the enlightenment continuing on to this very day.

                  -Critical thinking blends ethics, morals, etc. etc. in with objective rational thought along with critique of the way things are to yield things expected to “improve” things, or decide how things “ought to be” (known as a “value determination”, or what “we” or “you” “value”).

                  -Whether things are “improved” or not depends on the underlying x y or z which is valued (social things like social stability, dirty dirty dirty “muh race”, as MM is worried about, dirty “muh gender/gender roles” as MM is a little worried about, patents, or anything including machines, chemicals etc).

                  -In order for critical thinking to provide an intellectual bulwark against non-western/non-enlightenment (derided as white cis hetero christian capitalist patriarchial) philosophies (for example anti-property, commie, or leftist philosophies) being injected into academia there must be an underlying substrate of collective “morals”/”morality”, “values”/things which are valued, etc. among the critical thinkers (professors here). This “protection” is accomplished by critical thinking nigh always yielding the same answers if you input the same data about x y z along with the same morals/ethics/things which are valued etc. Thus an intellectual bulwark is setup against outside philosophies coming into a group of thinkers (say uni profs) by critically thinking professors who all have the same values/morals/ethics and the same data.

                  -When you tamper with the morality of the group (uni profs/law professors or society in general etc.), or “moral substrate” so to speak in hoity toit language, then critical thinking starts outputting different thoughts/answers/ things to do to “improve” things aka different perspectives/policy proposals in law journals.

                  -The moral substrate was tampered with over the last 60 years. Now, with the new morality in place, critical thinking assists in injecting the philosophy that is desired (anti-property, commie, leftist take your pick) to be injected into a given system, specifically one that yields less property.

                  -Patents as a field are no different than the rest of academic fields of studies, muh marxist thought/moral relativism/changed morals in academia has its effects.

                  -anon is above relying on critical thinking as being a bulwark against what he considers bad thinking (say leftist thought, marxism, anti-property thought) but it isn’t anymore. The change in morals among the thinkers (uni profs/intellectuals writing papers) put an end to that. Now critical thinking is what is pushing the philosophy into the scholarship because of the change in morals and also the corresponding change in things which are valued.

                  -thus I agree with MM, evidence would be required as anon cannot just cite a lack of critical thinking and call it a day.

                2. salvaged?:

                  Your comment is awaiting moderation.
                  March 13, 2018 at 7:07 am

                  6, you are beyond “off.”

                  I am not sure where you pulled this “stuff” about critical thinking from, but you are completely wrong as to your little woven idyllic setting.

  9. 5

    Arrghh! Another blown opportunity.

    Scotusblog just posted Security People’s amicus in Oil States provided a convincing argument about the problem of IPR’s until it began to defend, actually defend reexaminations – this after it had relied upon both McCormick Harvesting and Marbury v. Madison for the proposition that only a court could invalidate a patent. The they complained about their jury trial being postponed pending an IPR as if that didn’t happen with reexaminations.

    I can’t get over just how often the rails the defense of reexaminations is. It seems fostered by people who somehow seem under contract from the other side to blow our case.

    1. 5.1

      It seems fostered by people who somehow seem under contract from the other side to blow our case.

      Do you know how many times I have thought this very thing of you , Ned?

      1. 5.1.1

        anon, you have been advancing a weird agenda that makes no sense whatsoever. There are countless people who have said that to your face. Countless. You have no side, as you cannot find even one other person who agrees with you.


          Your post here is false.

          Those who do not like what I have said, say as you do here – such is meaningless in and of itself.

    2. 5.2

      Let us just put it this way. Anyone who argues in favor of reexaminations as being constitutional not only does not understand the constitutional issues, but is a mole for the other side. They are not true friends of the patent system. They are efficient infringers pretending to be in favor of Article III validity trials when they are not.

      1. 5.2.1

        Sounds like the same types of mole of those who disfavor a form of innovation that they feel should not have patent protection…

        Forms of innovation like software…
        Forms of innovation like business methods…

        Sounds like the same type of mole of those who shade the law, who do not give full credit to the reaction of Congress against the Court, the anti-patent Court of the 30’s and 40’s….

        Sounds like you Ned.

      2. 5.2.3

        True that. Reexamination, since 35 USC 145 has been repealed, is a case of first impression IMHO. You could make an argument that Sect 145, could have saved reexamination from Constitutional infirmity, and that was the posture of the matter when Patlex was decided. But not anymore. It’s just as unsound at IPR’s now and for the same reasons.

  10. 4

    As we already have serious ambiguities with subsequent Sup. Ct. 101 “abstraction” exceptions, do we really want to re-introduce another dubious ambiguity like “I made an improvement in your generic-claimed basic invention, so I’m not equivalent, so I don’t infringe?”* Especially since we have a 112 defense for over-claiming, a claim ambiguity defense, and a serious limitation on the scope of “means-function” claims, even if they do not use the words “means”?
    Cases in which a claim in a patent on one technology might accidentally read on a product in a completely different technology, so that reverse-DOE might logically apply, are rare.

    1. 4.1

      Paul, there is no “defense.” Proof of infringement requires a showing that the claims are met and that the infringing device is an equivalent of the disclosed apparatus, etc. Simply improving something is


      It has to accomplish the result in a way that is not substantially the same as the invention. Look at Westinghouse for more. I gave more of the relevant quotes.

  11. 3

    Footnote 20 and the (implicit – or otherwise) notion of “must make” by the author’s unfounded distinction between invention and innovation is a pure fallacy, and sounds in the Efficient Infringer’s mantra.

  12. 2

    Might I add that I have long argued that one is entitled to claim no more than what one has disclosed and equivalents. This necessarily excludes non-equivalents.

    Not only did the Supreme Court declared this to be a principal of infringement in Graver Tank, they expressed this very same concern in Halliburton in connection with functional claiming and why it is wrong. (Westinghouse involved a functional claim.) A functional claim would literally reads on the accused device because it operated in the same way or achieved the same result. But, in many cases, the accused device may not be an equivalent of what is disclosed, or but may in fact be an independent inventions of others.

    The Supreme Court in Halliburton held that claims functional at the point of novelty were invalid as indefinite. Halliburton was addressed in the fifty-two legislation with what we now know as §112(f). But the command of that statute is that functional claims be limited to the corresponding structure and equivalents. Arguably, all claims should be subject to the standard because if a claim literally reads on an accused device that is not the equivalent of the disclosed invention it is because of functional claiming.

    1. 2.1

      The author omits from the quote from Westinghouse the following:

      “An infringement,” says Mr. Justice Grier in Burr v. Duryee, 1 Wall. 531, 572, “involves substantial identity, whether that identity be described by the terms, `same principle,’ same `modus operandi,’ or any other… . The argument used to show infringement assumes that every combination of devices in a machine which is used to produce the same effect, is necessarily an equivalent for any other combination used for the same purpose. This is a flagrant abuse of the term `equivalent.'”


          No, 112(f) commands that functional claims adopt the construction of Westinghouse rather than be declared invalid.


            No, Ned.

            You continue to misunderstand claims using some terms sounding in function and FULLY (truly – purely) functional claiming.

            Vast Middle Ground

            Try to understand what that means.

            Try to understand that 112(f) is an option – and one that does NOT capture all claim forms that may use terms that sound in function.

    2. 2.2

      The Supreme Court continued:

      We have no desire to qualify the repeated expressions of this court to the effect that, where the invention is functional, and the defendant’s device differs from that of the patentee 569*569 only in form, or in a rearrangement of the same elements of a combination, he would be adjudged an infringer, even if, in certain particulars, his device be an improvement upon that of the patentee. But, after all, even if the patent for a machine be a pioneer, the alleged infringer must have done something more than reach the same result. He must have reached it by substantially the same or similar means, or the rule that the function of a machine cannot be patented is of no practical value. To say that the patentee of a pioneer invention for a new mechanism is entitled to every mechanical device which produces the same result is to hold, in other language, that he is entitled to patent his function. Mere variations of form may be disregarded, but the substance of the invention must be there.

  13. 1

    “Despite this history, since its creation in 1982 the Federal Circuit has all but overruled the reverse doctrine of equivalents. ”

    You have the cult of the claim to thank for that.

    “essential safety valve in the patent infringement analysis to ensure that substantial innovations are not unduly enjoined or taxed by the patent thicket.”

    It was. And it was also an essential check on the imperative that drafters would have to expand the scope of their submitted claims in patent applications well beyond the invention described in the patent. That last part is essential for the cultists in the cult of the claim to get rid of. So they did. And nobody with any real power/balls has risen to reinstate it.

    To be clear, there are many positives to the patent-world view of the cultists. Administrative etc. But there is also the rare occasion where you might have someone that invented a bike and is suing someone that made a motorcycle or similar situation. Such situations are of course rare in the useful arts of yore, but now that the patent system has expanded into the not so useful arts these sorts of issues grow in magnitude.

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