Prosecution History Disclaimer 1880 – 2019

Technology Properties Limited LLC v. Huawei Technologies Co., Ltd. (Supreme Court 2019)

In its new petition for writ of certiorari, Tech. Properties focuses on claim construction and the Federal Circuit’s application of prosecution history disclaimer.

Whether the United States Court of Appeals for the Federal Circuit’s development and application of the doctrine of “prosecution history disclaimer” is consistent with fundamental principles of separation of powers, the Patent Act, and long-established Supreme Court precedent.


The patent at issue here (5,809,336) stems from a 1989 application and a divisional filed just before the 1995 change-over to the 20-year-from-filing patent term. The microprocessor system claims require an “oscillator.”  In interpreting that limitation, the court added some additional negative limitations that (1) the oscillator “does not require a command input to change the clock frequency” and (2) the oscillator’s frequency “is not fixed by any external crystal.” The addition was based upon arguments that the patentee made during prosecution.  That narrowing, the patentee argues “runs afoul of the separation of powers among Congress, the USPTO, and the federal courts embodied in the Patent Act.”

The most interesting aspect of the petition here is reliance on so many 19th century decisions by the Supreme Court:

  • Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274 (1877) (The Patent Act of 1836 “relieving the courts from the duty of ascertaining the exact invention of the patentee by inference and conjecture. . . . This duty is now cast upon the Patent Office. There his claim is, or is supposed to be, examined, scrutinized,
    limited, and made to conform to what he is entitled to.”)
  • Merrill v. Yeomans, 94 U.S. 568 (1876) (claims are of primary importance).
  • Goodyear Dental Vulcanite Co. v. Davis, 102 U.S. 222 (1880) (prosecution history cannot “enlarge, diminish, or vary” the claim limitations).
  • White v. Dunbar, 119 U.S. 47 (1886) (“unjust to the public, as well as an evasion of the law, to construe it in a manner different from the plain import of its terms”).
  • McCarty v. Lehigh Val. R. Co., 160 U.S. 110 (1895) (“[I]f we once begin to include elements not mentioned in the claim, in order to limit such claim, . . . we should never know where to stop.”).

Of course, the petition also includes the mystery statement: “While the prosecution history can play some role in claim construction, it should not be used to diminish or enlarge the scope of the claims.” What is this mystery role?

33 thoughts on “Prosecution History Disclaimer 1880 – 2019

  1. 10

    The basic premise of the Petition is that, as a matter of separation of powers, a federal court lacks the power to use the prosecution history to narrow the scope of issued claims. You have to wonder about the echo chamber, among those who own the asserted patent, that that would commission and pay for such an ill-conceived petition.

    I suppose you can forgive the Petition for ignoring Supreme Court precedent from the first half of the 20th century explicitly acknowledging the role of the file wrapper in construing (and narrowing) issued claims. The bigger problem is that the argument is irremediably flawed; the separation of powers argument they make really has nothing to do with the prosecution history at all. The real argument here is that an Article III court simply does not have the power to narrow the claims of a patent beyond what the claims facially say.

    Under the Petition’s rationale, the entire judicial claim construction process under Markman would be unconstitutional, at least to the extent it results in a court order narrowing issued claims from what they facially say. After all, if the prosecution history cannot be used to narrow the claims, as the Petition asserts, then why should a court be allowed to rely on the specification to do the same thing? Or dictionaries? Or expert testimony? Or for that matter, even the language of other claims (e.g. under the doctrine of claim differentiation)? The judicial claim construction process, regardless of what evidence the court relies upon, can result in an order that narrows the scope of the claims from what their plain words would otherwise convey.

    If that result is unconstitutional, as the Petition seems to assert, there really is no role left for Article III courts in claim construction. So no, the Supreme Court is not going to invalidate the entire judicial claim construction process based on the half-baked arguments in this Petition. You can almost sense that the Petitioner at the last minute realized how unsupportable their argument was by adding in a line that Dennis calls the “mystery role,” of permissible use of prosecution history in claim construction.

    In the end, the patent holder lost the infringement suits because it sued a swath of companies for using the very same microprocessor design the applicants repeatedly told the Patent Office fell outside the scope of their claims.

    Pretty easy prediction here: cert denied.

  2. 8

    I was curious as to whether or not those 19th century cases said waht they were asserted for. So, I read the Goodyear v. Davis case, and it says the exact opposite.

    The Justice states verbatim: “[I]t is reasonable to hold that such a construction may be confirmed by what the patentee said when he was making his application.”

    Here is a more quote of the entire cited paragraph:

    “This construction of the patent is confirmed by the avowed understanding of the patentee, expressed by him or on his half, when his application for the original patent was pending. We do not mean to be understood as asserting that any correspondence between the applicant for a patent and the Commissioner of Patents can be allowed to enlarge, diminish, or vary the language of a patent afterwards issued. Undoubtedly a patent, like any other written instrument, is to be interpreted by its own terms. But when a patent bears on its face a particular construction, inasmuch as the specification and claim are in the words of the patentee, it is reasonable to hold that such a construction may be confirmed by what the patentee said when he was making his application. The understanding of a party to a contract has always been regarded as of some importance in its interpretation.”

    1. 8.1

      It is amazing that attorneys do not seem to get actually financially sanctioned for citing cases that hold the opposite of what they are being cited for, even if it is to the Sup. Ct. But motions for such sanctions seem to rarely ever get filed?

    2. 8.2

      If that’s how you read that case, you should try again. That is in no way “the exact opposite.” Rephrasing the quotation we get:
      The construction can be confirmed by what the patentee said.
      The construction cannot be enlarged, diminished or varied by what the patentee said.
      Both can be true and both are paraphrases of what the Court said. Ability to confirm is not equal or opposite to the ability to change, as they very explicitly clarified (“We do not mean to be understood as [what you’re trying to imply them to have said]”). The quote cited (at least that in the article above) the same paragraph you do, just the clarifying second sentence instead of your claimed “opposite” first sentence.

  3. 7

    “What is this mystery role.”

    Well, it can provide definitions for terms used in the claims.

    “Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.”

    1. 7.1

      The term and its definition are not separable. The point is that words in claims either narrow the claim scope or enlarge it, unless the terms are ignored which used to be The Worst Thing Ever but now we are told by Greg DeL it’s okay because you have to keep copyright and patent law separate. Or something, but definitely not related to 101.

  4. 6

    IMHO, the petition has merit. Since I was a tadpole at patents, I’ve often wondered why the examiner doesn’t just say: “Fine, good argument, put it into the claims and I’ll consider it.” Negative limitation? Great. Put it in the claims. The whole notion of having to pull a file wrapper and divine what was going on in order to figure out claim scope opens a can of worms.

    1. 6.1

      Often wondered? You don’t lack company. Examiners at the EPO, fully backed up by the Boards of Appeal, and motivated in part by the “can of worms” they see on the other side of the pond, have been saying exactly that, as one, for the last 40 years.

      But then, the EPO is free, isn’t it? Free to find a sensible way forward, rather than being told what to do by a patent-ignorant national Supreme Court.

      Nevertheless, for me the Petition is absurd. For any established stable representative democracy, the Separation of Powers is an inviolable principle.

    2. 6.2

      The other about PHE is that it is at the discretion of the district court judge.

      They pretty much do what they want with PHE at the Markman hearing. It just adds another point where the judge can do whatever they feel like doing.

  5. 5

    Functionally claimed cr @p of the worst kind. Good grief just read the summary, and then read the g@ rbage claims.

    Probably still a zillion times better than anything Hyatt has pending. Did he die yet and pass his interest on to even more disgusting people?

    1. 5.1

      Did you notice that that the lead lawyer on the petition is Ken Star from the Whitewater and Vince Foster investigations? In other words, with enough money thrown at him, he’ll probably represent anyone or any position you want.

      1. 5.1.1


        Also a notorious sexual assault enabler and a well-documented l-i-a-r. The best people! Patent law swirls further down the cessp 00l. Look for more Rep u k k les to get more involved in the gritting, as if that’s even possible at this stage.

  6. 4

    Maybe they should have thrown into the petition that they were not properly Mirandized. “You have the right to remain silent. Anything you say can and will be used against you in a court of law…”

    1. 4.1

      Terrific, I wonder if any Examiner has the chutzpah to Mirandize an obnoxious interviewer as a joke?

      1. 4.1.1

        I did hear about one who told the interviewer he could leave through the door or out the window. Management was not kind to the examiner.

  7. 3

    Re: “..(1880) (prosecution history cannot “enlarge, diminish, or vary” the claim limitations)” I wonder how many decisions can one could find since 1880 in which prosecution history DID “diminish” [narrow] the literal scope of some claims? Not even to mention the hundreds of D.C.s and IPRs in which prosecution history claim narrowing is regularly argued by the patent owners themselves to avoid prior art?

    1. 3.2

      The citation of White v. Dunbar is particularly ironic, since it is famous for saying that patent claims cannot be “twisted like a nose of wax” between validity and infringement.

  8. 2

    What’s really mysterious is how/why do attorneys as awful as these people find themselves pretending to “do patent law”?

    Golly, I wonder what happened. It’s a real mystery. It’d be irresponsible to speculate…

    1. 2.1

      It really is a question of “How d-mb do you think everyone else is?” Sure, let’s let the claim be broad. Then what? Then it goes down as obvious. Oh but wait! That’s going to cost a lot of money because of the Separation-violating “judicial activist” doctrine of having to consider post-filing “evidence” like commercial success.

      Like nobody can see this transparently hypocritical game these attorneys are playing?

      I’m sure Mossoff is getting out his sharpie right now to add a new item his wish list: “No use of patent proesecution derp to limit patent scope derp take that infringers derp!”


            “meme” does not mean what he thinks it means. He got the definition from Wikipedia. Not his fault.

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