Table of Contents
Broadest reasonable interpretation standard stands (posted 07/09/15)
In a 6-5 decision, In re Cuozzo Speed Technologies, LLC., the full Federal Circuit denied en banc review of its prior panel decision to let stand BRI claim construction by the BPAI during inter partes review. Judge Dyk, joined by Lourie, Chen, and Hughes, authored a concurring opinion finding (1) the PTO has applied BRI standard in proceedings for more than a century, and (2) the AIA does not indicate congressional intent to change the prevailing BRI standard.
Judge Prost, joined by Newman, Moore, O'Malley, and Reyna, dissented, arguing that IPR is a new, court-like proceeding designed to adjudicate validity of issued patent claims and in such proceeidngs claims are given their actual meaning, not BRI. According to Prost, the AIA “is a new statutory regime” and Congress' silence as to the proper claim construction standard does not suggest congressional intent one way or the other on this new proceeding.
Newman wrote a separate dissent, highlighting the outlier nature of the majority opinion, noting that “[a]ll of the amici curiae criticize the panel majority position and urge en banc attention to this “matter of exceptional importance.” Separately she argues that “the legislative purpose [of the AIA] fails if the PTO applies different law than is applied in the courts” and again lists from her panel dissent the reasons BRI is improper in AIA proceedings.
Federal Circuit refines Teva; intrinsic evidence subject to de novo legal analysis (posted 06/19/15)
The Federal Circuit, taking this case on remand from the Supreme Court (see below), in an opinion authored by J. Moore and joined by J. Wallach, again found Teva's patent claims to “molecular weight” invalid as indefinite. Specifically, the court held:
“A party cannot transform into a factual matter the internal coherence and context assessment of the patent simply by having an expert offer an opinion on it. The internal coherence and context assessement of the patent, and whether it conveys claim meaning with reasonable certainty, are questions of law. The meaning one of skill in the art would attribute to the term molecular weight in light of its use in the claims, the disclosure in the specification, and the discussion of this term in the prosecution history is a question of law. The district should not defer to Dr. Grant's ultimate conclusion about claim meaning in the context of this patent nor do we defer to the district court on this legal question. [. . .] Determining the meaning or significance to ascribe to the legal writings which constitute the intrinsic record is legal analysis. The Supreme Court made clear that the factual components include 'the background science or the meaning of a term in the relevant art during the relevant time period.' Teva cannot transform legal analysis about the meaning or significance of the intrinsic evidence into a factual question simply by having an expert testify on it. Determining the significance of disclosures in the specification or prosecution history is also part of the legal analysis. Understandings that lie outside the patent documents about the meaning of terms to one of skill in the art or the science or the state of the knowledge of one of skill in the art are factual issues. Even accepting as correct the district court's factual determinations about SEC and the transfer of chromatogram data to create Figure 1, these facts do not resolve the ambiguity in the Group 1 claim about the intended molecular weight measure.”
Judge Meyer dissented, arguing that key factual findings made by the district court were not clearly erroneous and therefore should be given deference. These findings were ”(1) a person of ordinary skill in the art of polypeptide synthesis would infer from the use of the SEC method disclosed in the specification of the '808 patent that the term 'molecular weight' referred to peak average molecular weight; (2) a skilled artisan would not rely upon a statement Teva made when prosecuting the '847 patent that the expression of molecular weight in kilodalton units 'implie[d] a weight average molecular weight,' because that statement rested on obvious scientific error; and (3) that artisan would instead rely on Teva's affirmative statement, made qhile prosecuting the '539 patent, that 'molecular weight' meant peak average molecular weight.
Fed. Cir. toes line with Alice, invalidates groundbreaking non-invasive fetal diagnostics patent (posted 06/18/15)
Subject matter eligibility test under Mayo 1) :
- Determine whether the claims at issue are directed to a patent-ineligible concept.
- If yes, consider the elements of each claim both individually and “as an ordered combination” to determine whether additional elements “transform the nature of the claim” into a patent-eligible application.
In Ariosa Diagnostics, Inc. v. Sequenom, Inc., the Fed. Cir. held that the application of a discovery that maternal blood plasma contains free copies of fetal DNA is not patentable since the the claims are first held to be drawn to a naturally occurring phenomena, that free fetal DNA is present in maternal plasma or serum, and hence satisfies the first Mayo test that the claim is patent ineligible. Turning then to the second step of the Mayo test, the court determined, “the preparation and amplification of DNA sequences in plasma or serum were well-understood, routine, conventional activities performed by doctors” and hence steps for amplifying and analyzing the fetal DNA “does not result in an inventive concept that transforms the natural phenomenon of cffDNA into a patentable invention.”
En banc Fed. Cir. extends § 112(f) (formerly ¶6); reverses panel decision of validity (posted 06/17/15)
In Williamson v. Citrix, aka Williamson II, the en banc Federal Circuit holds that a claim limitation reading, “distributed control module” invokes 35 U.S.C. § 112(f) (formerly ¶6) means+function analysis.
This ruling reverses the prior panel decision that found the opposite. More specifically, the court reversed previous precedent that held that absence of the word “means” created a strong presumption not to interpret the claim as a means+function claim under 35 U.S.C. § 112(f)/¶6.
The Williamson en banc court held:
- . . . such a “heightened burden” is unjustified . . . [;] we should abandon characterizing as “strong” the presumption that a limitation lacking the word “means” is not subject to § 112, para. 6. That characterization . . . has the inappropriate practical effect of placing a thumb on what should otherwise be a balanced analytical scale. It has . . . resulted in a proliferation of functional claiming untethered to § 112, para. 6 and free of the strictures set forth in the statute. Henceforth we will apply the presumption as we have done prior to Lighting World, without requiring any heightened evidentiary showing and expressly overrule the characterization of that presumption as “strong.”
- We also overrule the strict requirement of “a showing that the limitation essentially is devoid of anything that can be construed as structure.”
- The standard is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.
Analysis of facts
The court construed the claim limitation, distributed learning control module for receiving communications transmitted between the presenter and the audience member computer systems and for relaying the communications to an intended receiving computer system and for coordinating the operation of the streaming data module and held:
- the limitation “is in a format consistent with traditional means-plus-function claim limitations. It replaces the term 'means' with the term 'module' and recites three functions formed by the 'distributed learning control module.'”
- “'Module' is a well-known nonce word that can operate as a substitute for 'means' in context of § 112, para. 6. [. . .] Generic terms such as 'mechanism,' 'element,' 'device,' and other nonce words that reflect nothing more than verbal constructs may be used in a claim in a manner that is tantamount to using the word 'means' because they typically do not connote sufficiently definite structure and therefore may invoke § 112, para. 6” (internal citations and quotes removed).
- The word “module” is a nonce word that “sets for the same black box recitation of structure for providing the same specified function as if the term 'means' had been used.”
- “The prefix 'distributed learning control' does not impart structure into the term 'module.' These words do not describe a sufficiently definite structure. . . . the written description fails to impart any structure significance to the term.”
Letting Newman's words speak for themselves:
I respectfully dissent from the en banc ruling that is inserted into this panel opinion at Section II.C.1. The court en banc changes the law and practice of 35 U.S.C. § 112 paragraph 6, by eliminating the statutory signal of the word “means.” The purpose of this change, the benefit, is obscure. The result, however, is clear: additional uncertainty of the patent grant, confusion in its interpretation, invitation to litigation, and disincentive to patent-based innovation.
Curiously, the court acknowledges that it “has long recognized the importance of the presence or absence of the word 'means.'” Maj. Op. at 13. Nonetheless, the court rejects the meaning and usage of “means” to signal means-plus-function claim construction. The court now overrules dozens of cases referring to a “strong presumption” of means-plus-function usage, and goes to the opposite extreme, holding that this court will create such usage from “[g]eneric terms such as 'mechanism,' 'element,' 'device,' and other nonce words.” Maj. Op. at 17. In the case before us, the so-called “nonce” word is “module.” Thus the court erases the statutory text, and holds that no one will know whether a patentee intended means-plus-function claiming until this court tells us.
I dissent from the majority's reasoning and the majority's holding that “distributed learning control module” falls under paragraph 6. I express no opinion on the ultimate validity of the claim; the claim must stand or fall on its merit, but does not fall under paragraph 6.
Akamai requests new en banc review 06/16/15
See details in Joint Infringement.
S.Ct. reverses Fed. Cir.; holds liability for inducement not dependent on belief as to validity (updated 05/26/15)
May 26, 2015:
In a 6-2 decision written by Justice Kennedy, the Supreme Court reversed the Federal Circuit in Commil v. Cisco. Specifically, the court held that a good-faith belief of invalidity of a patent is not relevant to an inquiry as to whether that party is guilty of inducement to infringe, notwithstanding the legal requirement that the accused have knowledge of the patent and knowledge of infringement to be found guilty of inducement.
35 U.S.C. § 271:
(b) Whoever actively induces infringement of a patent shall be liable as an infringer
(c) Whoever offers to sell or sells within the United States or imports into the United States a component of a patented machine, manufacture, combination or composition, or a material or apparatus for use in practicing a patented process, constituting a material part of the invention, knowing the same to be especially made or especially adapted for use in an infringement of such patent, and not a staple article or commodity of commerce suitable for substantial non-infringing use, shall be liable as a contributory infringer.
Stated the Court
- “Global-Tech requires . . . proof [for both contributory infringement and inducement] that the defendant knew the acts were infringing. And the Court's opinion was clear in rejecting any lesser mental state as the standard.”
- The scienter element for induced infringement concerns infringement; that is a different issue from validity. [. . .] . . .because infringement and validity are separate issues under the Act, belief regarding validity cannot negate the scienter required under §271(b).
- To say that an invalid patent cannot be infringed, or that someone cannot be induced to infringe an invalid patent, is in once sense a simple truth, both as a matter of logic and semantics. [. . .] But the questions courts must address when interpreting and implementing the statutory framework requires a determination of the procedures and sequences that the parties must follow to prove the act of wrongful inducement and any related issues of patent validity.“
- ”. . . invalidity is not a defense to infringement, it is a defense to liability. And because of that fact, a belief as to invalidity cannot negate the scienter required for induced infringement.“
Dissent (Scalia, Roberts):
- Saying that infringement cannot exist without a valid patent does not 'conflate the issues of infringement and validity' . . . any more than saying that water cannot exist without oxygen 'conflates' water and oxygen.”
Prior to the the Supreme Court issuing cert., there were two trials between Cisco and Commil. In the first trial, the jury found the Commil patent to be valid and directly infringed; validity has been upheld by the Federal Circuit. However, after Cisco's representatives in the first trial repeatedly used prejudicial and anti-Semitic language (Commil is based in Israel and the inventors of the subject patent are Israeli) the trial judge ordered a new trial on just the issues of induced infringement and damages. In the second trial, the jury returned a $63.7 million verdict against Cisco, which, in 2013, a divided Federal Circuit panel, in Commil USA LLC v. Cisco Systems, Inc., reversed, because “the district court erred in preventing Cisco from presenting evidence during the second trial of its good-faith belief of invalidity to rebut Commil's allegations of induced infringement.” The Federal Circuit panel held:
“It is axiomatic that one cannot infringe an invalid patent. [. . .] Accordingly, one could be aware of a patent and induce another to perform the steps of the patent claim, but have a good-faith belief that the patent is not valid. Under those circumstances, it can hardly be said that the alleged inducer intended to induce infringement. Thus, a good-faith belief of invalidity is evidence that may negate the specific intent to encourage another’s infringement, which is required for induced infringement.”
J. Newman dissented from the panel decision. Newman's dissent was cited in Judges Rayna's dissent to the denial of a request for an en banc. rehearing (which was joined by Rader, Newman, Laurie, and Wallach). Newman argued:
“A defendant's ultimate liability for induced infringement, as for direct infringement, is subject to various defenses including patent invalidity and uneforceability. However, whether there is infringement in fact does not depend on the belief of the accused infringer that it might succeed in invalidating the patent. Such a belief, even if held in good faith, does not negate infringement of a valid and enforceable patent. This rule applies, whether the infringement is direct or indirect. My colleagues err in holding that ‘evidence of an accused inducer's good-faith belief of invalidity may negate the requisite intent for induced infringement.’
[. . .]
“Validity of the Commil patent was sustained by the jury, sustained by the district court, and sustained by this court. Whatever Cisco's ‘belief’ as to invalidity of the patent, this belief is irrelevant to the fact and law of infringement. A belief of invalidity cannot avoid liability for infringement of a patent whose validity is sustained. The panel majority's contrary holding is devoid of support in law and precedent.”
Oral Arguments at Supreme Court:
Supreme Court agrees with Newman!
At the Supreme Court:
The Supreme Court granted Commil's petition for cert. but limited to question 1: “[w]hether the Federal Circuit erred in holding that a defendant's belief that a patent is invalid is a defense to induced infringement under 35 U.S.C. § 271(b).”
The Supreme Court previously denied Cisco's cross-petition seeking review of Circuit's decision to remand for a retrial only on the issue of induced patent infringement and not also on the “related” question of patent invalidity. Cisco argued that the Seventh Amendment requires that all issues be retried “unless it clearly appears that the issue to be retried is so distinct and separable from the others that a trial of it alone mayh be had without injustice.”
N.D. Illinois upholds GUI claims under Alice (posted 05/07/15)
1. A method of placing a trade order for a commodity on an electronic exchange having an inside market with a highest bid price and a lowest ask price, using a graphical user interface and a user input device, said method comprising:
setting a preset parameter for the trade order displaying market depth of the commodity, through a dynamic display of a plurality of bids and a plurality of asks in the market for the commodity, including at least a portion of the bid and ask quantities of the commodity, the dynamic display being aligned with a static display of prices corresponding thereto, wherein the static display of prices does not move in response to a change in the inside market;
displaying an order entry region aligned with the static display prices comprising a plurality of areas for receiving commands from the user input devices to send trade orders, each area corresponding to a price of the static display of prices; and
selecting a particular area in the order entry region through single action of the user input device with a pointer of the user input device positioned over the particular area to set a plurality of additional parameters for the trade order and send the trade order to the electronic exchange.
In Trading Technologies International, Inc. v. CQG, Inc. and CQGT, LLC, the Northern District of Illinois found that claims drawn to a method of providing a graphical user interface (GUI) were patentable under 35 U.S.C. § 101.
The court rejected CQG's argument that the claims recite an abstract idea for placing orders for a commodity on an electronic exchange based on observed market information. Specifically, CQG argued that the elements recited in the claims, “merely perform basic functions relating to electronic commodity trading and updating market information using unidentified and generic computer components.”
Stated the court:
Neither the claims of the '304 patent nor the claims of the '132 patent are directed to solely “setting, displaying, and selecting” data or information that is visible on the GUI device. Rather, the claims are directed to solving a problem that existed with prior art GUIs, namely, that the best bid and best ask prices would change based on updates received from the market. There was a risk with the prior art GUIs that a trader would miss her intended price as a result of prices changing from under her pointer at the time she clicked on the price cell on the GUI. The patents-in-suit provide a system and method whereby traders mae playce orders at a particular, identified price level, not necessarily the highest bid or the lowest ask price because the invention keeps the prices static in position, and allows the quantities at each price to change.
Fed. Cir.: Claim terms to be consistently construed (posted 04/14/15)
In In re: 55 Brake LLC, the Federal Circuit held that the term, “plurality of sensors,” includes a vehicle motion sensor because claim 7 specifies, “wherein one of said plurality of sensors is a vehicle motion sensor.” The Federal Circuit reasons that:
a broader [than an embodiment described in the specification] reading of “plurality of sensors” to include a vehicle motion sensor, is reasonable in light of the plain language of the claims, the specification, and the overall object of the invention to “enable sensors to detect . . . potentially unsafe conditions in or around the vehicle . . . [and] to automatically control the brakes and/or other equipment” as appropriate.
The court further explained its reasoning in a footnote citing Phillips v. AWH Corp.: “In contrast to claims 7 and 9, claim 13 does not explicitly define a vehicle motion sensor as one of the plurality of sensors. But because claim terms are to be construed consistently throughout a patent, our reasoning above applies equally to claim 13.”
Supreme Court leaves in place CAFC's ruling on inability to compel co-owner to join suit (posted 03/31/15)
The Supreme Court denied certiorari in STC.UNM v. Intel Corp., in which the Federal Circuit upheld the lower court lack of standing dismissal for failure to join a necessary party. The factual background is interesting:
- An initial patent 5,705,321 ('321 patent) resulted from contributions of four people: Brueck, Saidi, and Chu, employed by the University of New Mexico (UNM), and Draper, employed by Sandia. The '321 patent claims technology similar to that of the asserted patent 6,042,998 ('998 patent).
- In mid-1996, the four inventors executed a joint assignment to UNM of the invention that issued as the '321 patent, but in October of 1996, UNM executed an assignment to Sandia to correct Draper's prior assignment to UNM which “was made in error.” This assignment explicitly transferred to Sandia “those rights and interests previously assigned to [UNM] by Bruce Draper . . . and to any and all Patents which may be issued thereon . . . and to any and all divisions, reissues, continuations, and extensions.”
- While '321 was pending Brueck and Saidi continued their research and filed an application leading to the instant '998 patent, which incorporated the '321 patent by reference but did not claim priority to any earlier-filed application.
- During prosecution of the '998 patent the PTO rejected the claims for double patenting over the '321 patent, and the rejection was overcome by UNM filing a terminal disclaimer, which stated that it was “the owner of record of a 100 percent interest in the instant application.”
- In 2002, UNM assigned its own interest in the '321 and '998 patents to STC, a wholly-owned licensing arm of UNM.
- In 2008, STC successfully petitioned the PTO to correct the inventorship of the '998 patent to include two more named inventors, Hersee and Malloy, who were employees of UNM at the time of the invention, and assigned their interests in the '998 patent to UNM. In addition, STC successfully sought a certificate of correction to indicate that the '998 patent is a continuation-in-part of the '321 patent.
- Although Sandia has an ownership interest in the '321 patent since October 1996, Sandia had never claimed any interest in the '998 patent. (In 2009, STC and Sandia entered into a royalty sharing agreement for the '321 patent that does not mention the '998 patent.)
At the district court, Intel argued in a motion for summary judgment that the '998 patent was unenforceable for failing to comply with the common-ownership requirement of the terminal disclaimer. In response, STC contends that Sandia did in fact co-own the '998 patent since it issued by operation of the assignment, or alternatively, that Sandia obtained ownership of the '998 patent when it formally became a continuation-in-part of the '321 patent. Nevertheless, STC confirmed the prior assignment and assigned an undivided interest in each of the '321 and '998 patents to Sandia in 2011. The district court rejected STC's theories and granted partial summary judgment for Intel, reasoning that ownership rights must derive from inventorship and because Draper did not co-invent any claims of the '998 patent, he had no interest in the '998 patent to assign. Thus the court held that Sandia did not co-own the '998 patent with UNM or STC at any point prior to the 2011 assignment. The parties then cross moved on the issue of standing, given Sandia's co-ownership, which was granted by the district court.
STC argued before the Federal Circuit that Rule 19(that requires the court to compel joinder of co-inventor or co-owner of a patent “to bring before the court all persons deemed necessary to the suit.” However, the Federal Circuit held that the holding in Ethicon v. United States Surgical Corp 2) requires co-owners (ordinarily) to consent to the suit, and that this requirement was not dictum, but essential to the disposition of the case. In this case, Sandia did not affirmatively give up its right to refuse to join the suit (e.g., by signing an exclusive license arrangement or otherwise agreeing to join). Unless STC can secure Sandia's voluntary joinder, obtain the '998 and '321 patents outright, or become the exclusive licensee of Sandia's interest, STC cannot enforce the '998 patent in court.
Judge Newman's Dissent:
Judge Newman holds that the present ruling is contrary to Rule 19 as well as precedent. Stating in part:
By statute, “A patentee shall have remedy by civil action for infringement of his patent.” 35 U.S.C. §281. . . . Precedent establishes that all entities with the right to enforce the patent are necessary parties to an action for enforcement; the purpose is to shield the accused infringer from mulitple suits, as well as to resolve all potential claims efficiently and fairly. Entities with enforcement rights who do not voluntarily join in such suit “must” be joined involuntarily, as provided by FRCP 19(a) (“Required Joinder of Parties”).
Departing from this clear and compulsory procedure, the panel majority holds that co-owner Sandia cannot be involuntarily joined with the University in this infringement suit, thus preventing the University from enforcing the patent, for Sandia is a necessary party. That holding is not correct. When a party declines . . . to join . . . involuntary joinder is provided by Federal Rule 19. The panel majority's ruling . . . is contrary to law.
On March 30, 2015, the Supreme Court denied certiorari, leaving the Federal Circuit's panel decision in tact.
Fed. Cir. reverses BPAI's anticipation invalidation (posted 03/16/15)
In Vicor Corp. v. Synqor, Inc., the Federal Circuit reversed the BPAI's reversal of an Examiner's 102 rejection in an Ex parte reexamination. The prior art consisted of U.S. Patent 5,377,090 which incorporates by reference U.S. patent 5,274,539. The two patents issued from separate applications. The earlier '539 patent teaches that an isolation stage can use diodes as rectifiers, but in alternative embodiments, can use controlled rectifiers in place of the diodes. The later patent '090 teaches a single isolation stage having a plurality of regulation stages to produce a plurality of output D.C. voltages. The BPAI reversed the Examiner's rejection, finding that the combined reference did not teach a single embodiment that has an isolation stage that uses controlled rectifiers, followed by multiple regulation stages. The Federal Circuit reversed the BPAI, stating, “The incorporated teachings include Steigerwald '539's alternative embodiment, which teaches a substitution that takes place within the isolation stage.”
Fed. Cir. construes Octane (posted 02/25/15)
In Biax v. Invidia et al., the Federal Circuit, in a nonprecedential opinion, reversed a lower court's award of attorney's fees under the pre-Octane Fitness, Brooks “objectively baseless” standard. The Fed. Cir. cited Octane stating:
The Supreme Court rejected the Brooks Furniture standard, explaining that “there is no precise rule or formula for making” a determination as to whether a case is exceptional. It is a case-by-case determination based on considering the totality of teh circumstances. Such an exceptional case is “rare.” But, if the case “stands out from others with respect to the substantive strength of a party's litigating position . . . or the unreasonable manner in which the case was litigated,” it is “exceptional” under the meaning of the statute. Thus, objective reasonableness remains a relevant factor. [Emphasis added.]
In applying this construction of the Supreme Court opinion, the Federal Circuit found that the lower court misread expert testimony that was relied upon to conclude that Biax had no reasonable basis to assert infringement.
S.Ct. denies cert. on AIA Consitutionality (posted 02/25/15)
On February 23, 2015, the S.Ct. denied a petition for certiorari alleging that the America Invents Act is unconstitutional because of its first-to-file provisions.
Federal Circuit redefines "exhaustion" (posted 02/18/15)
In Helferich Patent Licensing v. NYTimes and JCPenney (Fed. Cir. 2015), the Federal Circuit found that content providers such as the New York Times must pay a patent royalty to Helfereich, who owns a patent for sending and receiving alerts to mobile phones, despite the fact that the manufacturer of the mobile phones at issue had already licensed the patents.
Supreme Court reverses Circuit's rule for de novo claim construction (posted 01/20/15)
In Teva Pharmaceuticals USA Inc. v. Sandoz, Inc., the Supreme Court held that, when reviewing a district court's resolution of subsidiary factual matters made in the course of its construction of a patent claim, the Federal Circuit must apply a “clear error,” not a de novo, standard of review. Justice Breyer delivered the opinion of the Court.
The case comes to the Supreme Court on appeal by patent holder Teva from a Federal Circuit decision to invalidate a claim due to indefiniteness. Specifically, the Federal Circuit reversed a lower court ruling that the claim term, “molecular weight” referred to “peak average molecular weight” because that is what a skilled artisan would have understood at the time of the patent application. The Federal Circuit reached its invalidity determination based on de novo review of all aspects of the district court's claim construction, including subsidiary facts, in contravention of Federal Rule of Civil Procedure 52(a)(6) which states that a court of appeals “must not . . . set aside” a district court's “[f]indings of fact” unless they are “clearly erroneous.”
The Supreme Court held that:
“In some cases . . . the district court will need to look beyond the patent's intrinsic evidence and to consult extrinsic evidence in order to understand, for example, the background science or the meaning of a term in the relevant art during the relevant time period. In cases where those subsidiary facts are in dispute, courts will need to make subsidiary factual findings about that extrinsic evidence. These are the “evidentiary underpinnings” of claim construction that we discussed in Markman, and this subsidiary factfinding must be reviewed for clear error on appeal”
Justice Thomas, joined by Alito, dissented, arguing:
“Patents are written instruments, so other written instruments supply the logical analogy. [. . .] The classic case of a written instrument whose construction does not involve subsidiary findings of fact is a statute. [. . .] The construction of deeds, by contrast, sometimes involves subsidiary findings of fact. [. . .] The question we must ask, then, is whether the subsidiary findings underlying claim construction more closely resemble the subsidiary findings underlying the construction of statutes or those underlying the construction of contracts and deeds that are treated as findings of fact. [. . .] This, in turn, depends on whether patent claims are more like statutes or more like contracts and deeds. [. . .] For purposes of construction, contracts and deeds are less natural analogies for patents. [. . .] In granting a patent, the Government is acting not as a party to a bilateral contract binding upon itself alone, but instead as a sovereign bestowing upon the inventor a right to exclude the public at large from the invention marked out by his claims. [. . .]
“Because the skilled artisan inquiry in claim construction more closely resembles determinations categorized as 'conclusions of law' than determinations categorized as 'findings of fact,' I would hold that it falls outside the scope of Rule 52(a)(6) and is subject to de novo review.”