Full opinion text
ORDER ON CROSS-MOTIONS FOR SUMMARY JUDGMENT PATRICK J. SCHILTZ, District Judge. I. BACKGROUND On October 24, 1996, Gary Gustafson filed a patent application covering an apparatus for cutting metal tubing with a laser. The application issued on December 22, 1998 as United States Patent No. 5,852,277 (the '277 patent). The patented apparatus is specifically designed for cutting stents, which are short, thin-walled, perforated sections of metal tubing that are implanted in fluid-carrying tubes in the body — generally arteries, but also veins, ducts, and ureters, among other things — to keep those tubes open. Gustafson assigned his rights in the '277 patent to plaintiff Spectralyties, Inc. Spec-tralytics makes stent-cutting machines, but it has not been very successful in the stent business, either as a supplier of stent-cutting machines or as a manufacturer of stents. Defendant Norman Noble, Inc. (“Noble”), by contrast, has been a very successful manufacturer of stents, which it cuts on machines made by Noble itself. Noble sells stents to defendant Cordis Corporation (“Cordis”). Cordis is one of the country’s leading stent distributors, with annual sales in the hundreds of millions of dollars. Spectralyties believes that Noble has not come by its success honestly. Specifically, Spectralyties contends that at least one model of Noble’s stent-cutting machine infringes the '277 patent. Spectralyties is therefore suing both Noble and Cordis for patent infringement. Spectralyties also contends that Noble stole trade secrets related to the design of stent-cutting machines — -trade secrets that Noble allegedly became aware of in 1995 or 1996 when it was negotiating a possible acquisition of Spectralyties. Spectralyties is therefore suing Noble for theft of trade secrets and unfair competition. All of the parties move for summary judgment. Spectralyties asks the Court to rule that the accused Noble machines literally infringe claim 1 of the '277 patent, that certain disputed references are not part of the prior art, and that claim 1 of the '277 patent is not invalid as either anticipated or obvious. Spectralyties Mot. Partial S.J. [Docket No. 93]; Spectralyties Mem. Supp. Mot. Partial S.J. (“Spectralyt-ics SJ Mem.”) [Docket No. 94], Cordis moves for summary judgment in its favor on some of the same issues — infringement, obviousness, and the status of disputed references — and on the side issue of whether claims based on United States Patent No. 6,114,653 (the '653 patent), which Spectralyties no longer asserts, should be dismissed with or without prejudice. Cordis Mot. S.J. [Docket No. 103]; Cordis Mem. Supp. Mot. S.J. (“Cordis SJ Mem.”) [Docket No. 107]. Noble moves for summary judgment on one patent-law issue raised by Spectralyties — the status of certain disputed references — and on Spec-tralytics’s trade-secrets and unfair-competition claims. Noble Mot. S.J. [Docket No. 88]; Noble Mem. Supp. Mot. S.J. (“Noble SJ Mem.”) [Docket No. 90]. For the reasons given below, the Court grants summary judgment to Spectralyties that the '277 patent is not invalid as anticipated. The Court denies summary judgment to Cordis that the '277 patent is invalid as obvious — -although, as the Court will explain, the Court believes that Cordis will likely prevail on this issue at trial. The Court’s holdings with respect to the subsidiary questions about the content of the prior art are described below. The Court denies both Cordis’s and Spectralyt-ics’s motions for summary judgment with respect to infringement. The Court denies summary judgment to Noble on Spec-tralytics’s trade-secrets and unfair-competition claims- — -although, as also explained below, the Court expects that Noble will prevail on these claims at trial. Finally, the Court grants Cordis’s motion with respect to dismissal of claims related to the no-longer-asserted '653 patent. II. ANALYSIS A. Standard of Review Summary judgment is appropriate “if the pleadings, the discovery and disclosure materials on file, and any affidavits show that there is no genuine issue as to any material fact and that the movant is entitled to judgment as a matter of law.” Fed.R.Civ.P. 56(c). A dispute over a fact is “material” only if its resolution might affect the outcome of the suit under the governing substantive law. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). A dispute over a fact is “genuine” only if the evidence is such that a reasonable jury could return a verdict for either party. Ohio Cas. Ins. Co. v. Union Pac. R.R., 469 F.3d 1158, 1162 (8th Cir.2006). In considering a motion for summary judgment, a court “must view the evidence and the inferences that may be reasonably drawn from the evidence in the light most favorable to the non-moving party.” Winthrop Res. Corp. v. Eaton Hydraulics, Inc., 361 F.3d 465, 468 (8th Cir.2004). B. The '277 Patent 1. Claim Construction In November 2006, the parties filed a joint claim-construction statement in which they set forth agreed-upon constructions for two claim terms in the '277 patent (as well as one claim term in the no-longer-asserted '653 patent). Joint Claim Constr. Stmt. [Docket No. 45]. The parties did not identify any claim language that remained in dispute, and they agreed that a claim-construction hearing was unnecessary. Id. at 5. As it turns out, however, two claim terms are in dispute. Spectralytics’s infringement case turns largely on the meaning of the words “sized to be” in the phrase “the bushing having a central bore which is sized to be slightly greater than an outside diameter of the stock tubing.” '277 Pat. col. 6:20-23. And Cordis’s invalidity case depends in part on the meaning of the words “rigidly carried on” in the phrase “a workpiece fixture rigidly carried on the cutting tool in a fixed spatial arrangement. ...” Id. col. 6:8-9. The parties argue in their summary-judgment briefs for their favored claim constructions. Courts, not juries, construe patent claims. Markman v. Westview Instruments, Inc., 517 U.S. 370, 391, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996). Language in a particular claim must be construed in the context of both that claim and the entire patent, including the specification. Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed.Cir.2005) (en banc). Indeed, the specification, read in light of the prosecution history, is the primary basis for construing patent claims. Id. at 1315. Courts may also rely on “extrinsic evidence” — everything other than the patent and its prosecution history — but that evidence is secondary to the intrinsic evidence. Id. at 1317. In general, claim language means what that language would have meant, ordinarily and customarily, to a person of ordinary skill in the art at the time the patent application was filed. Id. at 1312-13. In some cases, the ordinary and customary meaning of claim language to a person of ordinary skill in the art may be identical to the meaning of that language to a lay person who is not skilled in the art. Id. at 1314. It appears likely that, for purposes of this case, the person of ordinary skill in the art is a mechanical engineer. Spectra-lytics has agreed, for purposes of its affirmative motion, with Cordis’s proposed definition that a person of ordinary skill in the art is “a person with an undergraduate degree in mechanical engineering or equivalent technical training and/or an equivalent amount of industry experience and familiarity with tooling and fixturing.” Spectralytics SJ Mem. at 33. Meanwhile Cordis has agreed, for purposes of its affirmative motion, with Spectralytics’s proposed definition that a person of ordinary skill in the art is someone with “at least a Bachelor of Science degree in mechanical engineering (including materials science or metallurgy), industrial engineering, or physics, or an equivalent amount of industrial experience and training, and at least one of (a) the use of industrial (cutting) lasers and (b) the practice of cutting stents.” Cordis SJ Mem. at 12. Given these counter-concessions, it seems that — for present purposes — a person of ordinary skill in the art is anyone who meets either party’s definition of such a person. Cordis’s definition may be a little broader than Spectralytics’s, but the parties’ definitions are very close, and nothing seems to turn on the differences between them. The parties have submitted the testimony of a number of witnesses on the claim-construction issues. With one exception, the Court agrees that witnesses whom the parties have characterized as persons of ordinary skill in the art are such persons, and the Court has considered those witnesses’ testimony as evidence of the meaning of the '277 patent’s claims. The exception is Spectralytics’s expert Larry Nixon, who — whatever else his qualifications — is clearly not a person of ordinary skill in the art of mechanical engineering. See Nixon Decl. Ex. 1 at 20-21 [Docket No. 104] (describing Nixon’s educational and professional background). Spectralytics’s argument with respect to the phrase “sized to be” is based mainly on its interpretation of Federal Circuit case law. See Spectralytics SJ Mem. at 15-17. Spectralytics also supports its argument with the testimony of two mechanical engineers, the testimony of Nixon (a lawyer who, as noted, is not a person of ordinary skill in the art), and an analogy based on “[c]ommon sense and real world experience ....” Id. at 19-20. Cordis’s argument about “sized to be” is phrased in terms of the distinction between a “clearance fit” and an “interference fit,” but Cordis’s witnesses explain that distinction in terms that any educated layperson could understand. See Cordis Mem. Resp. Spectralytics Mot. S.J. (“Cor-dis SJ Opp.”) at 13-17 [Docket No. 120], Speaking very roughly, and using the example of an object placed inside a tube: The fit between the object and the tube is a “clearance fit” if there is space or “clearance” between the outer surface of the object and the inner surface of the tube, such that the object can move around inside the tube. Thus, if a one-inch-square sponge is inserted into a two-inch-square tube, the two objects will have a clearance fit. The fit between the object and the tube is an “interference fit” if the outer surface of the object touches the inner surface of the tube, such that there is friction or “interference” between the object and the tube. Thus, if a three-inch-square sponge is compressed into a two-inch-square tube, the two objects will have an interference fit; the object will not move around inside the tube. The parties’ arguments with respect to the phrase “rigidly carried on” are even less technical. The words “carried on” are ordinary English words, and both Spectra-lytics and Cordis base their proposed claim constructions primarily on the language of the '277 patent itself. Spectralytics SJ Mem. at 29-30; Cordis SJ Mem. at 15-17. a. Disputed Tenn 1: “sized to be” The Court construes the term “the bushing having a central bore which is sized to be slightly greater than an outside diameter of the stock tubing” as follows: A bushing has “a central bore which is sized to be slightly greater than an outside diameter of the stock tubing” if, after the stock tubing has been inserted into the bushing’s central bore, the bore’s inner diameter is slightly greater than the stock tubing’s outer diameter. Cordis argues that this term should be construed to refer to a machine designer’s intentions rather than to the machine’s actual operation. Cordis SJ Mem. at 35 (“The claim is addressed to the selection of a bushing that is intended to be larger in diameter than the tubing....”). According to Cordis, any other construction reads the term “sized to be” out of the claim. Id. The Court disagrees. The word “sized,” like the word “painted” (or any other past-participial adjective), can describe an item’s current state. Consider: “Last week, the body shop painted my car. My car is now painted.” Cordis’s proposed construction overlooks this simple fact, and fails to account for the two words after “sized”: “to be.” Although “sized” is a past-participial adjective, “to be” is an infinitive, and raises the question: sized to be slightly greater token? According to Cordis, “sized to be slightly greater” must mean “having been sized to be, before assembly, slightly greater.” But nothing in the claim language or the prosecution history supports this implausible reading. Given that the patent covers a device which, in operation, requires tubing to be inserted inside a bushing, it makes more sense to read “sized to be slightly greater” to mean “having been sized to be (i.e., having a size that is), when assembled, slightly greater.” To support its proposed construction, Cordis asserts that claim 1 “is about a clearance fit, and not an interference fit.” Id. at 36. Cordis may be right — but this is a noninfringement argument, not an argument supporting Cordis’s strained claim construction. Even as construed by the Court, this term of claim 1 requires that the central bore’s inner diameter be “slightly greater than” the stock tubing’s outer diameter. According to Cordis, in the accused machine, after the stock tubing has been inserted into the bushing’s central bore, the bore’s inner diameter is identical in size to — and not slightly greater than — the tubing’s outer diameter. Id. at 31-32. If Cordis is correct (and, as explained below, that will be for the jury to determine), then Cordis’s accused machine does not literally infringe. But infringement must be measured when the device is assembled; it does not depend on subjective, pre-assembly intentions. b. Disputed Term 2: “rigidly carried on” The Court construes the term “workpiece fixture rigidly carried on the cutting tool” as follows: The workpiece fixture is “rigidly carried on the cutting tool” if the workpiece fixture is both rigidly attached to and supported by the cutting tool. Spectralytics contends that the term “rigidly carried on” means “supported by, hanging from, or suspended from.” Spec-tralytics SJ Mem. at 29. The last five words of Spectralytics’s proposed construction are superfluous: to “hang from” or be “suspended from” something is just one way to be “supported by” that thing. (It is to be supported from above.) Because “supported by” is broader than, and entirely encompasses, “hanging from” and “suspended from,” Spectralytics’s proposed construction boils down to this: “rigidly carried on” means “supported by.” The Court agrees with this, as far as it goes, but believes that it is too broad given the actual claim language and the intrinsic evidence. The Court does not, however, adopt Cor-dis’s proposed construction. Cordis argues that “rigidly carried on the cutting tool” means “rigidly mounted or affixed to the laser cutting tool.” Cordis SJ Opp. at 24. That, too, is fine as far as it goes. But Cordis is cagey about the meaning of its proposed construction. On the one hand, Cordis says that the disputed claim language covers a workpiece fixture that is “rigidly mounted or affixed to the laser cutting tool.” Id. (emphasis added). On the other hand, Cordis apparently believes that under this construction, a workpiece fixture would be “carried on” a laser cutting tool even if the fixture were not attached to the laser cutting tool, but instead the fixture and the tool were each rigidly attached to a third structure, such as the top of a table. Cordis SJ Mem. at 18 (comparing the patented machine to apparatuses in which a cutting tool and a workpiece fixture are “part of a unified tool frame” and explaining that “[t]he connection between these structures [i.e., the workpiece fixture and the cutting tool] is rigid because the tool frame joins them together as a single piece”). Cordis’s apparent interpretation of its own proposed claim construction is thus inconsistent with that construction. If a workpiece fixture and a cutting tool were attached only indirectly — say, by virtue of each being mounted to the top of a table— then the workpiece fixture would not be “mounted or affixed to,” in Cordis’s words, “the laser cutting tool.” Rather, the workpiece fixture would be mounted to the table, as would the cutting tool, and the table would support both the fixture and the cutting tool. While the effect of such an arrangement (so long as both the workpiece fixture and cutting tool were sufficiently rigidly connected to the table) would be to create a rigid linkage between the cutting tool and the workpiece fixture so that if one moved, both would move, the '277 patent claims only a particular method of achieving this result: attaching the workpiece fixture to the cutting tool in such a way that the cutting tool supports the fixture. The Court’s claim construction is supported by the plain language of the claim and the intrinsic evidence. Construing the disputed claim language “involves little more than the application of the widely accepted meaning of commonly understood words,” and therefore “general purpose dictionaries may be helpful.” Phillips, 415 F.3d at 1314. To begin with, the verb “to carry” means “to hold or support while moving; bear.” American Heritage Dictionary of the English Language 285 (4th ed. 2000) (“AHD Fourth ”) (entry 1 for transitive verb “carry”); see also Webster’s Third New International Dictionary 343 (1981) (defining “carry” to mean “to move while supporting (as in a vehicle or in one’s hands or arms)”). “Carry” also means “[t]o support the weight or responsibility of,” as in “a beam that carries the floor.... ” AHD Fourth 285 (entry 7b for transitive verb “carry”). Thus, a workpiece fixture is “carried on” a cutting tool only if the cutting tool supports — i.e., bears the weight of — the fixture. This interpretation is consistent with both uses of the words “carried on” in claim 1 of the '277 patent. Claim 1 covers not just a “workpiece fixture rigidly carried on the cutting tool,” but also “a generally horizontal bushing carried on the fixture body....” '277 Pat. col. 6:8, col. 6:19-20. Figures 2 through 4 of the '277 patent all show a fixture body in which the horizontal bushing is embedded; the fixture body thus necessarily supports the bushing that claim 1 describes as “carried on” the fixture body. Further, the workpiece fixture is “rigidly carried on” the cutting tool only if the fixture and the cutting tool are, according to the Court’s claim construction, “rigidly attached” to each other. This rigid-attachment requirement is evident from the claim language as well as the various descriptions of the patented invention found throughout the '277 patent specification. For instance, the “Background of the Invention” section of the specification ends with this paragraph: The apparatus of this invention comprises a workpiece fixture for holding the tubing beneath the laser cutting tool and for supporting the tubing in a cantilever fashion. The workpiece fixture is rigidly affixed to the laser cutting tool. Thus, bumping either the cutting tool or the fixture does not disturb the accuracy of the cut part as the two move together, again increasing the accuracy and yield of the manufacturing method of this invention. ’277 Pat. col. 2:19-27 (emphasis added). Other passages in the specification, though using different language to describe the invention, are consistent with the quoted paragraph and the Court’s claim construction. In describing the drawings, the specification says that Figure 1 shows “the workpiece fixture attached to the cutting tool,” while Figure 2 shows “the laser cutting tool and conjoined workpiece fixture.... ” '277 Pat. col. 2:36-41 (emphasis added). The specification also says that the “Mixture body 28 is rigidly mounted or fixed to laser cutting tool 2 by a support structure....” Id. col. 3:54-55. The support structure is adjustable, allowing the fixture body to be moved relative to the cutting tool, but once the adjustments are made the “fixture body 28 thereafter is directly carried on laser cutting tool 2 in a fixed, spatial relationship.” Id. col. 3:67 to col. 4:1. Further, the patent contrasts the claimed invention with lathe-type machines found in the prior art, in which the cutting tool and the workpiece support “are not directly coupled to one another.” Id. col. 1:58 (emphasis added). The prosecution history likewise supports the Court’s claim construction. The patent examiner rejected an earlier version of claim 1 as anticipated by Japanese patent 8-187595 to Sato. PTO Office Action (Mar. 4, 1998) at 3. In explaining this rejection, the examiner said that Sato shows “a workpiece fixture ... rigidly carried on the cutting tool in a fixed spatial arrangement....” Id. Sato depicts a downward-facing laser cutting head with a workpiece fixture parallel to the cutting head and attached to the cutting head by a horizontal arm that is attached directly above the cutting head. Rigby Decl. Ex. 8 at SP 51876. The cutting head travels horizontally along a carriage, and when the cutting head moves, the attached workpiece fixture moves with it. The workpiece fixture shown in Sato is therefore, in the words of the Court’s claim construction, “both rigidly attached to and supported by the cutting tool.” The patent examiner also rejected an earlier version of claim 1 as anticipated by United States Patent No. 5,026,965 to Ohe. In doing so, the examiner said that Ohe showed “a workpiece fixture ... rigidly carried on the cutting tool in a fixed spatial arrangement____” PTO Office Action (Mar. 4, 1998) at 4. Ohe depicts a laser cutting head attached directly to a bracket through which tubing travels as the laser cuts holes in the tubing. Merrill Decl. Ex. 39 [Docket No. 108]. Like Sato, Ohe shows a workpiece fixture (the bracket) that is “both rigidly attached to and supported by the cutting tool.” 2. Infringement The parties agree that the accused device meets all of the limitations of claim 1 of the '277 patent save the requirement that the bushing have “a central bore which is sized to be slightly greater than an outside diameter of the stock tubing.” '277 Pat. col. 6:21-23; Cordis SJ Mem. at 33-36; Spectralytics SJ Mem. at 13-20. Under the Court’s construction of claim 1, to meet this limitation, the bushing in the accused device must, after the stock tubing is inserted, have an inner diameter that is slightly greater than the outer diameter of the tubing. Spectralytics argues that the inner diameter of the bushing in the accused device is necessarily greater than the outer diameter of the inserted tubing; otherwise, says Spectralytics, the tubing would not fit into the bushing. Spectralytics SJ Mem. at 16 (“In the [accused] stent cutting machine, the Teflon core [i.e., the bushing] and the tube cannot occupy the same space.”); id. at 19 (“Defendants have simply taken advantage of the elastic properties of Teflon to create a snug fit between the bushing and the stock tubing. They have not eliminated the engineering requirement that there be clearance between the tube and bushing (footnote omitted). Cordis, however, contends that the bushing’s inner diameter and the tubing’s outer diameter are exactly the same size. Cordis SJ Mem. at 25, 31; Cordis SJ Opp. at 18 (“In practice, because of the properties of Teflon, the Norman Noble bushing is exactly the same size as the tubing when the tubing is being cut.”). The Court finds that the relative sizes of the bushing’s inner diameter and the tubing’s outer diameter are disputed questions of fact. On the one hand, the Court has no reason to reject the testimony of Cordis’s witnesses on the subject. See Merrill Decl. 1 Ex. 27 at 32 (“Miller Dep.”) [Docket No. 108] (“As we got into the Teflon we actually brought the clearance down to zero ....”); id. at 105-07; Merrill Decl. 2 Ex. 64 at 78 (“Przeracki Dep.”) [Docket No. 121] (“You want it [i.e., the bushing] to be the same size as the tubing.”). On the other hand, the Court also has no reason to reject the testimony of Spectralytics’s expert, Patrick Madsen, who is a person of ordinary skill in the art, and who testified that when the accused device is in use, “the central bore of the bushing must necessarily be slightly greater than the diameter of the tubing. Otherwise the tubing could not slide through the bushing.” Rigby Decl. Ex. 96 at 8 (“Suppl. Madsen Report”) [Docket No. 95]. Mad-sen bases this conclusion on his belief that “a basic law of physics” would prevent tubing from sliding through a bushing if the tubing’s outer diameter equaled the tubing’s inner diameter. Id. at 9. The Court is skeptical (but does not decide) that Cordis’s description of the relationship between the tubing and the bushing in the accused device in fact runs contrary to “a basic law of physics.” Spec-tralyties seems to think that because the tubing and the bushing in the accused device are made of separate materials, there must be space between them. This is necessarily true at some molecular level — but at the molecular level, all matter is mostly empty space. See Harald Fritzsch, Elementary PaHicles: Building Blocks of Matter 16 (2005) (“When we touch the surface of a diamond, we gain the impression that it is a very dense bit of matter. And so it actually is — but its very hard appearance is due to a combination of electrical forces acting between the nuclei and the electrons. A diamond ultimately consists of mostly empty space.... ”). Put another way, at a molecular level, nothing touches; space separates everything. But this does not prevent things from being solid, or from touching each other, at the level that matters to mechanical engineers. Accordingly, if the outer surface of the tubing is compressed against the inner surface of the bushing to such an extent that they are touching each other along their entire lengths at the scale that matters to mechanical engineers, then the inner diameter of the bushing could very well equal (as opposed to slightly exceed) the outer diameter of the tubing. In any event, Cordis has admissible evidence that the inner diameter of the bushing is not greater than the outer diameter of the tubing in the accused device. Spec-tralytics has admissible evidence to the contrary. Because the closeness of the fit between tubing and bushing in the accused device is a disputed issue of fact, the Court denies both sides’ motions for summary judgment with respect to literal infringement. 3. Validity Cordis argues that the '277 patent is obvious under the undisputed facts, and that Cordis is therefore entitled to summary judgment that the patent is invalid under § 103 of the Patent Act. 35 U.S.C. § 103. Speetralytics argues that the '277 patent is not obvious under the undisputed facts, and that Speetralytics is therefore entitled to summary judgment that the patent is not invalid under § 103. Spec-tralytics also moves for summary judgment that the '277 patent is not invalid as anticipated under § 102 of the Patent Act. (Cordis has not moved for summary judgment on the question of anticipation.) Whether the '277 patent is invalid as anticipated or invalid as obvious depends on the content of the prior art. Thus, in support of their arguments about validity, the parties ask the Court to determine whether particular references are part of the prior art. The Court first addresses the parties’ arguments about the content of the prior art, and then turns to their arguments about anticipation and obviousness. a. Prior Art (1) Applicable Principles of Law Sections 102(a), (b), (e), and (g) of the Patent Act describe various types of prior art that can render a patent invalid as anticipated under § 102 and that are relevant to whether a patent is obvious under § 103. 35 U.S.C. §§ 102, 103; Riverwood Int’l Corp. v. R.A. Jones & Co., 324 F.3d 1346, 1354 (Fed.Cir.2003) (“The term ‘prior art’ as used in section 103 refers at least to the statutory material named in 35 U.S.C. § 102.”). Although these four subsections of § 102 overlap in many respects, what counts as prior art under one subsection does not necessarily count as prior art under another subsection. Specifically, the temporal and geographic scope of the universe of prior art varies under the different subsections of § 102. Under § 102(b), a reference can count as prior art only if the reference existed before the “critical date” of one year before the filing date of the patent application. Any issued patent or printed publication, from anywhere in the world, that existed before the critical date counts as prior art under § 102(b). Also, any item (or method) that was in public use or on sale in the United States, whether by the patentee or anyone else, before the critical date counts as prior art under § 102(b). Because the date of a patent application is a matter of public record — and because the critical date can be mechanically derived by counting back one year from the date of the patent application — temporal disputes about prior art under § 102(b) are invariably about whether an ostensible prior-art reference existed before the (undisputed) critical date. Under §§ 102(a), (e), and (g), however, the temporal scope of the prior-art universe depends on the date on which the patentee made his invention. And that date often cannot be mechanically derived from the public record. The default rule is mechanical: Under the default rule, the date on which the patentee made his invention is deemed to be the same as the date on which the patentee filed his patent application. 1 Donald S. Chisum, Chisum on Patents § 3.08 (2008) (“A general rule in patent law is that the date of invention of the applicant or patentee for purposes of novelty and anticipation is presumed to be the date he files a complete patent application in the Patent and Trademark Office disclosing the invention.”). But a patentee can attempt to avoid the default rule and establish an earlier invention date in two ways. First, if the patentee can establish that he in fact reduced his invention to practice as of a particular date, then that date (and not the patent-application date) will be treated as the invention date. Second, if the patentee can establish that he conceived his invention as of a particular date, then that date (and not the patent-application date) will be treated as the invention date, but only if the patentee can also establish that, after conceiving his invention, he worked diligently to reduce it to practice. See Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1169 (Fed.Cir.2006) (“We have held that priority of invention goes to the first party to reduce an invention to practice unless the other party can show that it was the first to conceive of the invention and that it exercised reasonable diligence in later reducing that invention to practice.”) (quotation omitted); Loral Fairchild Corp. v. Matsushita Elec. Indus. Co., 266 F.3d 1358, 1361 (Fed.Cir.2001) (in infringement suit, discussing same two ways to prove an invention date). Because patents are presumed to be valid, challengers bear the burden of proving a patent’s invalidity by clear and convincing evidence. 35 U.S.C. § 282 (“A patent shall be presumed valid.”); TypeRight Keyboard Corp. v. Microsoft Corp., 374 F.3d 1151, 1157 (Fed.Cir.2004) (“The party seeking to invalidate the patent must do so by clear and convincing evidence.”). This allocation of the burden of proof makes sense when an alleged infringer attempts to prove invalidity under § 102(b) by establishing that a particular reference is prior art — i.e., that it existed before the critical date — and that the reference anticipates the claimed invention. But this allocation of the burden of proof makes less sense when an alleged infringer attempts to prove anticipation under §§ 102(a), (e), or (g) and invalidity turns on whether an ostensible prior-art reference whose date is undisputed predates the patentee’s invention date. When a patentee’s invention date is in dispute, common sense dictates that the patentee' — the person who knows when he conceived the invention and what he did to reduce it to practice — should bear the burden of proving an invention date that predates the patent-application date. In addition, because the PTO does not generally make any findings about a patentee’s invention date in the course of examining a patent application, the mere fact that the PTO has granted a patent provides no reason for a court or a jury to defer to the patentee’s contentions about his invention date. Such contentions should be treated like any other argument about a disputed issue of fact and evaluated in light of the relevant evidence. Typically, the PTO does not look at evidence about a patentee’s invention date. It has no reason to do so in many cases. But sometimes during the prosecution of a patent, the PTO will assert that a particular reference invalidates the claimed invention. If that reference is not § 102(b) art — that is, if it is dated in the year between the critical date and the patent-application date — the patent applicant may antedate the reference (“swear behind” it, in patent-lawyer jargon) by filing an affidavit under PTO Rule 131 asserting an earlier invention date. 37 C.F.R. § 1.131; Manual of Patent Examining Procedure (“MPEP”) § 715. Rule 131(b) prescribes what the applicant must show to establish the earlier invention date: The showing of facts shall be such, in character and weight, as to establish reduction to practice prior to the effective date of the reference, or conception of the invention prior to the effective date of the reference coupled with due diligence from prior to said date to a subsequent reduction to practice or to the filing of the application. Original exhibits of drawings or records, or photocopies thereof, must accompany and form part of the affidavit or declaration or their absence must be satisfactorily explained. 37 C.F.R. § 1.131(b). The PTO examines an applicant’s affidavit for compliance with this rule, but the PTO does not otherwise investigate the applicant’s assertions about his invention date. See MPEP § 715; Loral Fairchild, 266 F.3d at 1366 (Newman, J., concurring) (“Inventors’ affidavits have always been admissible to antedate a reference. The regulations are explicit that evidence to antedate a reference may be provided by the inventor....”). Given the limited nature of the PTO’s scrutiny of an inventor’s Rule 131 affidavit, there is little reason for courts to defer to findings about invention dates made by the PTO during patent prosecution. Requiring a patentee to bear the burden, when litigating his patent’s validity, of establishing an invention date preceding his patent-application date would also be consistent with the Federal Circuit’s recent decision in PowerOasis, Inc. v. T-Mobile USA, Inc., 522 F.3d 1299 (Fed.Cir.2008). In PowerOasis, the accused in-fringer (T-Mobile) argued that the patents in suit were anticipated by a reference (the MobileStar Network) that was prior art under § 102(b) because it existed more than one year before June 15, 2000 — the date on which the patentee (PowerOasis) had filed the continuation-in-part (CIP) application that resulted in the patents in suit. Id. at 1302-03. But the patents in suit were part of a family of patents and patent applications that grew out of an application filed in February 1997, well before the MobileStar Network existed. Id. at 1301. PowerOa-sis contended that the patents in suit, though resulting from the CIP application filed in June 2000, should be treated as if they had been applied for in February 1997. Id. at 1303. (In patent-law jargon, PowerOasis argued that “its asserted claims should have the benefit of priority going all the way back to the filing date” of the first application in the patent family. Id.) If PowerOasis had prevailed on its argument, the MobileStar Network would not have been prior art and thus could not have anticipated the patents in suit. The district court rejected Power Oasis’s argument, holding that the priority date— that is, the effective patent-application date — of the patents in suit was June 15, 2000 (the date of the CIP application). Id. On appeal, PowerOasis argued that the district court should have required T-Mobile (as the party asserting invalidity) to prove that PowerOasis was not entitled to the February 1997 priority date, instead of placing on PowerOasis the burden of proving that the patents in suit were entitled to the February 1997 priority date. Id. at 1304. In affirming the district court’s judgment and rejecting PowerOasis’s argument, the Federal Circuit said: [I]n this case, the PTO did not, at any point, make any determination with regard to the priority date of the various claims of the asserted patents.... The Mobile Star Network prior art was never considered by the examiner. In fact, in this case the PTO did not make a determination regarding the priority date for the asserted claims with respect to any reference.... When neither the PTO nor the Board has previously considered priority, there is simply no reason to presume that claims in a CIP application are entitled to the effective filing date of an earlier filed application. Since the PTO did not make a determination regarding priority, there is no finding for the district court to defer to. Id. at 1304-05. The court noted that T-Mobile (the accused infringer) bore the burden of proving invalidity by clear and convincing evidence. But the court applied the elear- and-convincing-evidence requirement to what it called T-Mobile’s “prima facie case”: T-Mobile, the party asserting invalidity, must still show by clear and convincing evidence that the asserted patent is invalid. Once it has established a prima facie case of invalidity and its burden is met, the party relying on validity is then obligated to come forward with evidence to the contrary. Id. at 1305 (quotation marks omitted). The court found that T-Mobile “established its prima facie case of invalidity” based on undisputed evidence that the Mo-bileStar Network existed more than a year before the filing date of the CIP application. Id. With respect to the parties’ burdens of proof, the court held: Once T-Mobile established by clear and convincing evidence that the Mo-bileStar Network was § 102(b) prior art to the asserted claims of the '658 and '400 patents, the burden was on PowerOasis to come forward with evidence to the contrary. The district court therefore correctly placed the burden on PowerOasis to come forward with evidence to prove entitlement to claim priority to an earlier filing date. Id. at 1305-06. Just as the burden was properly on PowerOasis to establish a priority date earlier than the default priority date (in that case, the date of the CIP application), so too in this case would it make sense to place the burden on Spectralytics to establish an invention date earlier than the default invention date (the date of the '277 patent application). The PTO made no findings about when Gustafson invented the apparatus claimed in the '277 patent, just as the PTO made no findings about the priority date of the patents at issue in PowerOasis. But Federal Circuit case law about proof of invention dates, and dates of prior art, is not so simple or logical. When a paten-tee seeks to avoid a reference offered by a defendant as prior art under §§ 102(a), (e), or (g) by establishing an invention date earlier than the date of the reference, the patentee bears only a burden of production, not of persuasion. Mahurkar v. C.R. Bard, Inc., 79 F.3d 1572, 1577 (Fed.Cir.1996) (“Dr. Mahurkar offered evidence at trial to show that he invented the subject matter of the patent before publication of the Cook reference. He met his burden of production.”); see also Loral Fairchild, 266 F.3d at 1361 (applying Mahurkar). As long as the patentee produces evidence supporting his claim of an invention date earlier than the ostensible prior-art reference, the patentee need not persuade the factfinder of that invention date. Instead, the defendant must establish, by clear and convincing evidence, that the patentee’s invention date does not precede the date of the ostensible prior-art reference. Mahurkar, 79 F.3d at 1578. This would be confusing enough: How can the defendant affirmatively prove a negative proposition (the invention was not made by a certain date)' — -and do so by clear and convincing evidence — when all of the proof of the affirmative proposition (when the invention was made) is likely to be in the opposing party’s hands? But it gets even more confusing, because the pat-entee, when attempting to avoid a defendant’s ostensible prior-art reference that predates the patent-application date but arguably postdates the patentee’s invention date, bears not an ordinary burden of production, but a heightened one. The patentee must do more than offer some evidence (such as an affidavit) supporting his pre-patent-application invention date; the patentee must offer corroboration of that invention date. See Loral Fairchild, 266 F.3d at 1363 (“[B]ecause the Amelio [Le., the inventor’s] affidavit asserts reduction to practice prior to publication of the Erb reference [i.e., an allegedly invalidating reference], the issue then becomes whether Loral [the patentee] submitted independent evidence sufficient to corroborate this assertion.”). If the patentee fails to offer corroboration — or offers legally insufficient corroboration — as part of its burden of production, then the patentee’s invention date remains the default date (the date of the patent application). To apply this set of rules in determining whether a potentially invalidating reference offered by a defendant as prior art under §§ 102(a), (e), or (g) is in fact prior art, a court or a factfinder would have to ask a series of questions. (The Court defers for the moment consideration of which of these questions are for the judge and which are for the jury.) For simplicity’s sake, assume that the date of the reference is undisputed and predates the patent-application date. The first question would then be: Did the patentee produce some evidence of an invention date earlier than the date of the reference? The next question might be: Was the patentee’s evidence corroborated at all? The third question might be: How well was the pat-entee’s evidence corroborated — was it “sufficiently” corroborated? If the paten-tee’s evidence was “sufficiently” corroborated, the next question would be: Did the defendant prove by clear and convincing evidence that the patentee’s invention date did not precede the date of the purported prior-art reference? If so, the reference would be prior art. Only then would the factfinder turn to the substantive question whether the reference invalidated the patent. The analysis becomes even more rococo when the date or the existence of the purported prior-art reference is in dispute. To establish that a purported prior-art reference existed on a certain date, a defendant must provide evidence that corroborates the reference’s existence at the relevant time. Adenta GmbH v. OrthoArm, Inc., 501 F.3d 1364, 1371 (Fed.Cir.2007) (“[A] patent cannot be invalidated based on one person’s testimony alone without corroborating evidence, particularly documentary evidence.”); Checkpoint Sys., Inc. v. All-Tag Sec. S.A., 412 F.3d 1331, 1337 (Fed.Cir.2005) (“[T]he corroboration rule ... is available in appropriate cases to protect patentees from invalidation of their patent based solely upon uncorroborated, testimonial evidence.”) Without such corroboration, the ostensible prior-art reference cannot be used to invalidate a patent. Thus, if both the patentee’s invention date and the date and existence of an ostensibly invalidating prior-art reference are in dispute, the necessary inquiry goes something like this: Did the patentee provide sufficiently corroborated evidence of an invention date earlier than his patent-application date, and did the defendant provide sufficiently corroborated evidence that the proffered prior-art reference existed (and met the relevant criteria, such as being public, being in the right country, etc.) before the (sufficiently corroborated) invention date? If the answer is yes on both counts, does the reference invalidate the patent? A further crucial issue is whether (and to what extent) questions about corroboration are legal questions for the judge or factual questions for the jury. Federal Circuit case law on the subject is not clear. In TypeRight Keyboard Corp. v. Microsoft Corp., the Federal Circuit seemed to say that the district court must independently determine whether the existence of a pri- or-art reference was corroborated. 374 F.3d 1151, 1159 (Fed.Cir.2004). But the meaning of TypeRight is uncertain in light of a more recent case, Adenta GmbH v. OrthoArm, Inc., 501 F.3d 1364 (Fed.Cir.2007). In TypeRight, the district court granted summary judgment that a patent was invalid as obvious in light of a prior-art reference (the “Marquardt document”) whose status as prior art was disputed by TypeRight (the patentee). 374 F.3d at 1155. The Federal Circuit reversed, holding that TypeRight was entitled to a jury determination of whether the Marquardt document was prior art, because a finding that the document was prior art depended on an assessment of the credibility of witnesses who testified on behalf of the defendant (Microsoft Corporation) about the document’s publication date. Id. at 1158 (“[Sjummary judgment was improper because genuine issues remain as to the credibility of Microsoft's] witnesses[’] testimony that the Marquardt document was publicly distributed in 1986.”). The Federal Circuit also held, however, that even if at trial the jury found Microsoft’s witnesses credible and concluded that the Marquardt document was indeed prior art, “the district court will still have to address whether the legal requirement of corroboration has been met.” Id. at 1159 (emphasis added). More recently, however, the Federal Circuit held in Adenta that “[assessing the sufficiency of evidence which corroborates a witness’s testimony concerning invalidating activities has been analyzed under the ‘rule of reason’ test, and it is a jury question.” 501 F.3d at 1372 (emphasis added). As best this Court can tell, the Federal Circuit means to establish two seemingly separate, but logically sequential, corroboration requirements. The first requirement is to be considered by the judge alone, and the second is to be considered by the jury, subject to the normal constraints on jury factfinding embodied in rules on judgment as a matter of law. The question for the judge is: Is there any corroborating evidence at all — setting aside the quality and quantity of that evidence — on the issue in question (the status of a prior-art reference; a patentee’s invention date)? If not, then the jury has no business considering the issue. If there is some corroborating evidence on the issue in question, then — at least when the question is the status of a prior-art reference — the issue must be submitted to a jury. In most areas of the law, one simply lets the jury decide whether a fact has been proven to the requisite standard of proof. If patent law were like other areas of the law, this would mean that the jury would have to decide whether a defendant proved by clear and convincing evidence that an ostensible prior-art reference existed at a certain time and met other applicable statutory requirements (e.g., it was sufficiently public in the relevant geographic area). The Federal Circuit, however, said in Adenta that “assessing the sufficiency” of corroborating evidence “is a jury question” that “has been analyzed under the ‘rule of reason’ test....” 501 F.3d at 1372. It is difficult to know what the Federal Circuit meant, for two reasons. First, if the jury must decide whether clear and convincing evidence shows that a particular reference qualifies as prior art, why separate out the subsidiary issue of whether the corroborating evidence was “sufficient” under some “rule of reason”? Second, the “rule of reason” test for corroboration was originally a tool for the PTO and reviewing courts — -not juries — and it has been applied more in patent-interference proceedings (in which the PTO is the factfinder) than in infringement cases. Moreover, Adenta seems internally inconsistent. The Federal Circuit described the question of the sufficiency of corroboration as one for the judge, and then described the question as one for the jury. Adenta held, “[w]e cannot say that the [district] court erred in concluding that there was sufficient evidence corroborating [the witnesses’] testimony to enable the jury to find” that the purported prior-art reference was, in fact, prior art. 501 F.3d at 1372. How can the sufficiency of corroborating evidence be both a question for the judge and a question for the jury? The answer, in this Court’s view, is that district judges do not, in fact, need to police jury findings about what counts as prior art by assessing the sufficiency of corroborating evidence; nor do district judges need to instruct juries to assess the sufficiency of corroborating evidence. Rather, provided that some corroborating evidence exists, if a party moves for summary judgment or judgment as a matter of law on the status of a prior-art reference, the district judge must determine whether a reasonable jury could find by clear and convincing evidence that the reference is in fact prior art. Courts routinely assess whether evidence is sufficient for a reasonable jury to find that a party has borne its burden of proof. If a court holds, despite the existence of some corroborating evidence, that a reasonable jury could not find that an ostensible prior-art reference was in fact prior art, one could describe the court’s action as “finding the corroboration insufficient” — but this description only muddles the analysis. In all cases, if the evidence (including corroborating evidence) is insufficient for a reasonable jury to find in favor of a party on an issue, a court will grant summary judgment or judgment as a matter of law against the party on that issue. There is no reason to put this in terms of whether “corroboration” is “sufficient.” The Federal Circuit’s corroboration requirement thus has independent significance in only one situation: when uncorroborated witness testimony on an issue (the status of a prior-art reference; an invention date) would be sufficient, in the absence of the corroboration requirement, for a reasonable jury to find that the testimony proves the issue to the requisite standard of proof. In such a situation, if a judge finds that there is no evidence that independently corroborates the testimony, then the judge must find as a matter of law that the issue is not established, even though a reasonable jury could find the issue established by the requisite standard of proof. To summarize, then, with reference to this case: If there is no evidence to corroborate the testimony of Spectralytics’s witnesses that, before the '277 patent-application date, Gustafson either (1) reduced the claimed invention to practice or (2) conceived of it and worked diligently to reduce it to practice, then the Court must find as a matter of law that Spectralytics has not met its burden of production with respect to establishing an invention date that predates the application date. But if there is such corroborating evidence, then Gustafson’s invention date is a question of fact for the jury, unless no reasonable jury could find, by clear and convincing evidence, that his invention date came after the date of the particular disputed reference. With respect to prior-art references offered by Cordis, if there is no evidence to corroborate the testimony of Cordis’s witnesses about the existence or status of the ostensible prior art, then the Court must find as a matter of law that Cordis has not met its burden of production with respect to that prior art. But if there is corroborating evidence, then the existence or status of the ostensible prior art is a question of fact for the jury — again, unless no reasonable jury could find that Gustafson’s invention date came after the date of the particular disputed reference. The Court applies these principles below. Before doing so, however, the Court takes this occasion to respectfully urge the Federal Circuit to revisit the extraordinarily complex set of rules that this Court has spent the past fifteen-plus pages trying (perhaps unsuccessfully) to decipher. Rules assigning burdens of production and proof — and dividing responsibilities between judges and jurors — have to be understood and applied by the ordinary mor-tais who sit on district-court benches and in jury boxes. Moreover, at some point distinctions become so fine that they become lost on typical jurors (or even typical judges) and thus have little practical impact. Simplification and clarification of these rules would be most welcome. (2) Published Patents that Predate the '277 Application Date The parties dispute whether the prior art includes two United States patents (to Kash and Muhlniekel) and one Japanese patent (to Sato). The patents do not qualify as prior art under § 102(b) because their effective dates fall in the year preceding Gustafson’s application for the '277 patent — that is, after § 102(b)’s critical date. To qualify as prior art under § 102(a), (e), or (g), these patents must have predated Gustafson’s invention date. Of these three patents, the one with the earliest effective date is Kash, which was applied for on April 2, 1996. The basic issue, then, is whether Gustafson’s invention date precedes April 2, 1996. The first question for the Court is whether Spectralyties has met its burden of production with respect to Gustafson’s invention date. Specifically, has Spectra-lytics produced some corroborated evidence that, before April 2, 1996, Gustafson either (1) actually reduced his invention to practice, or (2) conceived his invention and worked diligently until his application date to reduce it to practice? Although it is a close question, the Court finds that Spec-tralyties has met its burden of production. There is corroborating evidence, in the form of a drawing, that Gustafson conceived of the invention no later than January 16,1996. Rigby Decl. Ex. 45. But the evidence of his actual reduction of the invention to practice, or his diligence in attempting to reduce it to practice, is more equivocal. Cordis, in its summary-judgment reply brief, has abandoned its argument for summary judgment with respect to Gustaf-son’s invention date. Cordis Reply Mem. at 14 [Docket No. 139]. Instead, Cordis concedes that evidence presented by Spec-tralyties creates a fact question as to Gus-tafson’s invention date. Id. Spectralyties, however, continues to press its argument for summary judgment that Kash and Sato are not prior art. Given that Spectralyties has met its burden of production with respect to an invention date earlier than April 2, 1996, the question for the Court is this: Could a reasonable jury find, by clear and convincing evidence, that Gustafson’s invention date did not come before April 2, 1996? Only if a reasonable jury could not possibly find, by clear and convincing evidence, that Gustafson’s invention date came after April 2, 1996 would Spectralyties be entitled to summary judgment that Kash and Sato are not prior art. The Court finds that Spectralytics is not entitled to summary judgment. The evidence with respect to Gustafson’s invention date is exceedingly unclear, making it impossible for the Court to hold that a reasonable jury must find that Gustafson’s invention date precedes April 2,1996. Spectralytics cites testimony of two of its employees (but not Gustafson) that the invention was working before the end of January 1996. Spectralytics Mem. Opp. Noble Mot. S.J. (“Spectralytics Opp. Noble SJ Mot.”) at 38/20 [Docket No. 124]. Spectralytics also cites testimony of a third employee, Bruce Allen, that he saw the invention working in late March 1996. Id.; Allen Decl. ¶¶3-4 [Docket No. 126]. Spectralytics also argues that by March 1996, Gustafson was working diligently to reduce the invention to practice. Spectra-lytics Opp. Noble SJ Mot. at 34/16 to 35/17. To the extent that Spectralytics argues that Gustafson actually reduced his invention to practice, there is a fact question as to whether the invention ever worked for its intended purpose. That purpose is not, as Spectralytics puts it, “to have the workpiece fixture (and bushing) carried on the laser head so that they were maintained in ‘a fixed spatial relationship’ and movement of one would also move the other.” Id. at 36/18; id. at 40/22 (characterizing the invention’s intended purpose as “keeping the workpiece fixture (and bushing) and laser head in ‘a fixed spatial relationship’ so that movement of one would also move the other”). If that was the invention’s purpose, the device would have been reduced to practice even if it never cut a single stent. The '277 patent itself, however, tells us that the invention “is useful in manufacturing small, thin-walled', tubular devices known as stents....” '277 Pat. col. 1:7-8 (emphasis added). Further, the patent tells us that “[t]his invention relates to a method of and apparatus for cutting a pattern along the length of a thin walled, hollow workpiece, such as a stent, which is much more reliable and has much less scrap than known methods.” Id. col. 1:66— 67 to col. 2:1-2. An invention’s “purpose” is the thing for which it is useful; it is not the means by which it accomplishes that useful thing. Directly attaching the workpiece fixture to the cutting tool and maintaining them in “a fixed spatial relationship” is therefore not the purpose of Gustafson’s invention. Rather, it is a means by which the invention achieves its purpose of cutting metal tubing more reliably, and with less scrap, than existing methods and devices. And because Spectralytics focuses in its briefs on establishing that the invention worked for the wrong intended purpose, Spectra-lytics has not established that Gustafson’s invention worked for its true intended purpose before he filed his patent application. To the extent that Spectralytics argues for an invention date based on conception and diligence in reducing the invention to practice (as opposed to actual reduction to practice), there is a fact question as to Gustafson’s diligence. It is unclear from the record what Gustafson did to reduce his invention to practice after conceiving of the invention in January 2006. Given the state of the record, the Court cannot decide on summary judgment whether Kash, Sato, and Muhlnickel are prior art to the '277 patent. To establish that these patents are prior art, Cordis will have to convince the jury to find, by clear and convincing evidence, that the patents predate Gustafson’s invention date. Because the status of these patents as prior art is in dispute, the Court will not consider them in connection with Cordis’s invalidity arguments. (3) The Accused Device Spectralytics moves for summary judgment that the accused device is not prior art under § 102 because it was not public. Noble concedes the point. Noble Mem. Opp. Spectralytics Mot. S.J. (“Noble SJ Opp.”) at 3 [Docket No. 117] (“[Defendants agree that the Follower Assembly [i.e., the accused device] is not prior art under Section 102 because Noble maintained it as a trade secret.”). The Court therefore grants summary judgment to Spectralytics on this issue. Noble further contends, however, that the accused device, although not prior art, is nevertheless relevant to the validity of the '277 patent. Id. at 36. Specifically, Noble argues that its development of the accused device “is relevant to the level of ordinary skill