## United States Court of Appeals for the Federal Circuit

2007-1568 E.I. DU PONT DE NEMOURS AND COMPANY, Plaintiff-Appellant,

v. MACDERMID PRINTING SOLUTIONS, L.L.C., Defendant-Appellee.

Lindley J. Brenza , Bartlit Beck Herman Palenchar & Scott LLP, of Denver, Colorado, argued for plaintiff-appell ant. With him on the brief was Allison Freedman , of Chicago, Illinois. Of c ounsel on the brief was John T. Gallagher , Morgan & Finnegan, LLP, of New York, New York. Of counsel was Richard D. Catenacci , Connell Foley LLP, of Roseland, New Jersey. John R. Horvack, Jr. , Carmody & Torrance LLP, of New Haven, Connecticut, argued for defendant-appellee. Wi th him on the brief was Fatima Lahnin

. Appealed from: United States District Court for the District of New Jersey Judge Mary L. Cooper

## United States Court of Appeals for the Federal Circuit

2007-1568

E.I. DU PONT DE NEMOURS AND COMPANY, Plaintiff-Appellant, v.

MACDERMID PRINTING SOLUTIONS, L.L.C., Defendant-Appellee.

Appeal from United States District Cour t for the District of New Jersey in case no. 06-CV-3383, Judge Mary L. Cooper.

__________________________ DECIDED: May 14, 2008

__________________________ Before MICHEL, Chief Judge , PROST, Circuit Judge , and POGUE, ∗ Judge

. MICHEL, Chief Judge

. E.I. du Pont de Nemours & Company (“DuP ont”) appeals from the district court’s denial of its motion for preliminary injunction. Memorandum Opinion, E.I. du Pont de Nemours & Company v. MacDermid, Inc. , Case No. 06-CV-3383 (MLC/TJB) (D.N.J. Aug. 13, 2007) (“Preliminary Injunction Opini on”). We heard oral argument on April 9, 2008. We hold that the distri ct court abused its discretion in finding that a substantial question as to validity existed because of unc ertainty regarding the priority date.

∗ Honorable Donald Pogue, Judge, United States Court of International Trade, sitting by designation.Because the district court did not reach the parties’ remaining arguments as to validity and enforceability as well as the remaining preliminary injuncti on factors, we vacate and remand for the district court to consider these issues in light of the correct priority date.
I. DuPont is the assignee of U.S. Patent No. 6,773,859 B2 (“the ’859 patent”), titled “Process for Making a Flexogra phic Printing Plate and a P hotosensitive Element for Use in the Process.” The applicat ion for this patent was fil ed on February 27, 2002, and the patent issued on August 10, 2004. According to DuPont, its Cyrel FAST digital thermal technology is its commercial embodiment of the invention of the ’859 patent. In prosecuting the ’859 patent, DuPont or iginally filed a provisional application on March 6, 2001, and on February 27, 2002, it f iled a non-provisional application. The Application Data Sheet (“ADS”) filed with the non-provisional application stated: “Continuity Data: This application is a non-p rovisional of provisional 60/273669 2001- 03-06 WHICH IS PENDING.” The patent as issued, however, did not reference the provisional application due to an oversight by the Patent and Trademark Office (“PTO”). After issuance, DuPont sought a certificat e of correction pursuant to 35 U.S.C. § 254 to add a reference to the provisional application on the title p age of the ’859 patent. The PTO issued the Certificate of Correction on July 26, 2005, adding to the title page, “Related U.S. Application Da ta, Provisional appl ication No. 60/273, 669, filed on March 6, 2001.” In April 2006, DuPont sued MacDermi d Inc. and MacDermid Printing Solutions, LLC (“MacDermid”) in the District of Color ado for patent infringement, alleging that MacDermid’s Magma, MLT, and Lava products infringed DuPont’s ’859 patent as well

2007-1568 2as another patent not at issue in this appeal. 1 In July 2006, the case was transferred from the District of Colorado to th e District of New Jersey. In October 2006, DuPont moved for a pre liminary injunction, seeking to enjoin MacDermid from continuing to infringe clai m 1 of the ’859 patent. DuPont argued that MacDermid’s MLT and Magma plates infri nge claim 1 and that MacDermid induces infringement of claim 1 by encouraging cu stomers to use its Lava system and MLT and Magma plates in an infringi ng manner. DuPont also argued that its patent is valid, noting the presumption of va lidity, evidence of commercial success, and MacDermid’s offer to take a license. DuPont furt her argued that it had not committed inequitable conduct in prosecuting it s patent. In response, MacDermid raised a num ber of validity an d enforceability challenges. Relevant to this appeal, MacDe rmid argued that the ’ 859 patent was invalid under Section 102(b) because the invention was on sale or in public use before the critical date. According to MacDermid, that date was February 27, 2001, or one year before the filing date of the non-provisional application. In reply, DuPont argued that MacDermi d had not created a s ubstantial question of validity based on the public use or on sale bars of Se ction 102(b). In particular, DuPont argued that MacDermid’s evidence of sales prior to the critical date were actually of prior technology not claimed in the ’859 patent (analog and not digital technology). DuPont also responded to MacDermid’s other invalidity and unenforceability arguments. In support of its reply, DuP ont filed witness declarations

1 The ’859 patent and the perti nent certificate of correction were attached as an exhibit to the complaint.

2007-1568 3that either said that the filing date for the ’859 pat ent was February 27, 2002 or suggested that February 27, 2001 was the critical date. On February 16, 2007, the district c ourt held a hearing on DuPont’s motion for preliminary injunction. At the hearing, Du Pont’s counsel addre ssed a September 2000 trade show at which it “gave a general demons tration of the workflow for a digital thermally developed plate.” DuPont’s counsel stated that the crit ical date was February 27, 2001 and that the September 2000 trade show was before the critical date.

The court then agreed to allow each party to submit a letter brief regarding whether the use at that trade show was a public use. Both MacDermid and DuPont submitted letter briefs that presented subst antive arguments on this point. In its letter brief, DuPont still appeared to accept that th e critical date was one year before the filing date of the non-provisi onal application. Two days later, DuPont submi tted a letter to the court, fo r the first time identifying an earlier critical date. The letter stated: Further investigation has revealed that the ’859 patent was based upon, and claims priority to a provisional patent application, 60/273,669, filed on March 6, 2001. This means that only activities prior to March 6, 200[0] (sic) can invalidate the ’859 patent under 35 U.S.C. [§] 102(b). . . . Accordingly, the demonstr ation at Label Expo in S eptember 2000 is not an invalidating bar under 35 U.S.C. [§] 102(b). J. App’x at 3007. The next day, the parties had a telephon e conference with the court regarding DuPont’s letter. At the hearing, the distri ct court denied MacDermi d’s oral motion to expunge DuPont’s letter. In doing so the court stated: Well, from where my role is posit ioned as opposed to your adversarial roles, what strikes me is that if I we re to rule let’s say adverse to du Pont based upon a set of facts that is on it s face fact-wise in escapable, then the

2007-1568 4Circuit Court could well find plain erro r, and this would be not a service to either party or the Circuit Court. Ha ving been alerted to this problem and simply to judicially exclude any considerat ion of it, it’s true that we’re still in briefing on this supplemental issue. I just . . . don’t see that the positions have hardened to the point where I can ignore the import of this fact. J. App’x at 3252. The court t hen allowed the parties to each fi le a letter brief explaining their positions both on procedural and substantive bases. MacDermid then filed a letter brief opposing DuPont’s argument t hat the critical date should be based on the provis ional rather than the non- provisional application. MacDermid argued that DuPont ’s statements detailed above t hat the critical date was February 27, 2001, were binding judicial admissions and that DuPont was estopped from taking a contrary position. If not j udicial admissions, then MacDermid argued that they were evidentiary admissions which “are more than sufficient to create a substantial question concerning the validity of the ’859 patent.” MacDermid al so argued that the non-provisional application was not entitled to the filing date of the provisional because: (1) the non-provisional appl ication names inventors not named in the provisional application; (2) DuPont did not use the “proper l anguage” in claiming priority to the provisional; (3) the filing receipt, publishe d application, and issued patent did not reference the provisional, showing that t he PTO did not recognize priority to the provisional; (4) DuPont did not alert the PT O that the priority information was missing until the patent issued; and (5) the Certific ate of Correction that added the priority information was wrongly issued. MacDermid also argued that it would be unfairly prejudiced by DuPont’s change of position. DuPont submitted a letter in response, st ating that it had promptly notified the court of its discovery that the ’859 patent wa s entitled to an earlier effective filing date,

2007-1568 5and that MacDermid admitted it had been aware of the provisi onal application. DuPont also argued that its non-provisional applicat ion had properly claimed priority to the provisional application, thus ent itling it to a March 6, 2001 effe ctive filing date, and that it did not make binding judici al admissions. On August 13, 2007, the district court entered a memorandum opinion construing various terms and denying DuPont’s motion for a preliminary injunction. Preliminary Injunction Opinion at 1, 3. The district court firs t noted that MacDermid had not disputed infringement in opposing DuPont’s motion for a preliminary injunction, and so the court held that DuPont had shown a reasonable likelih ood of prevailing on infringement. Id. at
47. 2 Next, the court addressed whether MacD ermid had raised a substantial question of validity under Section 102(b). Id. at 48. After laying out t he parties’ arguments as to the various prior uses, the court addressed Du Pont’s argument that the critical date should be based on the filing date of the pr ovisional application rather than the nonprovisional application. Id. at 51. The district court hel d that “DuPont [had] not shown that MacDermid’s asserted defens e that the ’859 patent is inva lid under either the public use or on-sale bars of Section 102( b) lacks substantial merit.” Id. at 55. The court noted that the parties disputed whether DuPont should be al lowed to argue the earlier critical date based on the pr ovisional application. Id. Without explicitly deciding

2 In its brief on appeal and at oral argument, MacDermid stated that it did indeed contest infringement and argued that DuPont failed to show direct infringement by any of MacDermid’s customers. A review of MacDermid’s oppos ition to the motion for preliminary injunction shows that Ma cDermid raised only arguments related to validity and unenforceability below. Because nothing in MacDermid’s briefing below raised non-infringement as an issue, we find no error in the district court’s determination that MacDermid did not dispute infringement.

2007-1568 6whether DuPont’s argument s hould be allowed, the court held that DuPont had failed to prove the earlier critical date in any event and that DuPont’s earlier admissions as to the later critical date raised a subst antial question as to validity: Even if the Court permits DuPont to now argue that March 6, 2000 is the critical date, such statement would r equire evidence that was not proffered in DuPont’s briefs in support of it s motion or during oral argument. Further, the Court agrees with MacD ermid that DuPont’s numerous assertions that the critical date is February 27, 2001 and its subsequent letter stating that the critical date is actually March 6, 2000 raise substantial questions regarding whether the invention of the ’859 patent was in public use or on sale one year prior to the date of the applicable patent application. Id. at 56. The district court f ound that it could not grant a preliminary injunction on the record before it, but reserved judgment as to how it would view the issue on a fully developed record on summary judgment. Id. In a footnote, the court stated: If the Court of Appeals determines that it is preferable that this Court make factual findings on the issue of the co rrect ‘critical date,’ for purposes of deciding this preliminary injunction motion, we will permit both parties to fully brief that issue and we will c onsider any request for an evidentiary hearing limited to that issue. Id. at 56 n.9. The district court declined to address MacDermid’s remaining invalidity and unenforceability arguments. Id. at 56. And because it fou nd that DuPont had not shown a likelihood of success on the merits as to validity, the court did not address the remaining preliminary injunction factors. Id. at 57. DuPont then filed a notice of appeal of the district court’s deni al of a preliminary injunction. The district court sua spon te stayed the case and administratively terminated the case subject to later reopening. We have jurisdiction pursuant to 28 U.S.C. § 1292(c)(1).

2007-1568 7II. We review the district cour t’s denial of a motion for preliminary injunctive relief for abuse of discretion, the underlying factual determinations for clear error, and legal conclusions de novo. E.g. , Tate Access Floors, Inc. v. In terface Architectural Res., Inc. , 279 F.3d 1357, 1364 (Fed. Cir. 2002). In seeking a pr eliminary injunction, the patentee has the burden to show a likelihood of succe ss regarding the patent’s validity; if the accused infringer raises “a substantial question regarding validity, ” the district court should find that the patentee has not show n a likelihood of success on the merits. See Entegris, Inc. v. Pall Corp. , 490 F.3d 1340, 1351 (Fed. Cir. 2007). On appeal, the sole issue raised by DuPont is whether the distri ct court correctly held that MacDermid raised a substantial ques tion of validity based on the uncertainty as to whether the non-provisio nal application was entitled to claim priority to the provisional application. We find that th is conclusion was an abuse of discretion because based on the undisputed facts contained in the pros ecution history, the nonprovisional application was entitled to the filing date of the provis ional application as a matter of law. 3

3 MacDermid argues that DuPont made a binding judicial or evidentiary admission that preclu des DuPont from argui ng an earlier effectiv e filing date. The district court at least held t hat DuPont made no admissions that would bind it in later proceedings in the case (i.e., summary judgment). Preliminary Injunction Opinion at 56. The district court made no clear ruling, however , as to whether DuPont was bound by its prior statements for the purpose of its motion for preliminary injunction. Because the district court did not explicit ly preclude DuPont’s argument, we see no reason to do so in the first instance. Since MacDermid admittedly was aware of the provisional application, it is difficult to see how MacD ermid would be prejudiced by its consideration in evaluating validity. Additionally, we hav e reviewed the cases ci ted by MacDermid in support of its argument that Du Pont made a bindi ng judicial or evid entiary admission and find that none compel this court to fi nd that a binding admission was made.

2007-1568 835 U.S.C. § 119(e)(1) states in relevant part: An application for patent . . . fo r an invention disclosed in the manner provided by the first paragraph of secti on 112 of this title in a provisional application . . . , by an inventor or inventors named in the provisional application, shall have the same effect, as to such invention, as though filed on the date of the pr ovisional application . . . if the application for patent . . . is filed not later than 12 months after the date on which the provisional application was filed and if it contains or is amended to contain a specific reference to the provisional application. Under this section, four r equirements must be met for a non- provisional application to claim priority to a provisional application: (1) the provisional must comply with the requirements of section 112, first paragraph , and the non-provisional must be for the same invention; (2) the non-provisional mu st be filed within twel ve months of the provisional; (3) there must be an overlap of inventorship; and (4) the non-provisional must include a specific reference to the pr ovisional. It is undisputed that the first two requirements were met in this case. The provisional and non-provisional applications had the same written description and clai ms, and the non-provisio nal application was filed within a year of the pr ovisional application (the provisional was filed on March 6, 2001, and the non-provisional was filed on February 27, 2002). MacDermid argues, however, that the latter two requirements (overlap of inventorship and specific reference) were not met. The facts underlying MacDermid’s argum ents, however, are not disputed (i.e., the extent of the overl ap of inventorship and the language contained in the nonprovisional application referencing the provisio nal application). The only issue is the legal significance of these facts, i.e. whether the non-provisiona l application is entitled to claim the priority date of the provisional app lication. Determination of the priority date (e.g., the effective filing dat e) is purely a question of law if the facts underlying that

2007-1568 9determination ar e undisputed. See Broadcast Innovation, L.L. C. v. Charter Commc’n, Inc. , 420 F.3d 1364, 1366 (Fed. Cir. 2005). Here, the district court gave two reasons why a substantial question of validity was present: (1) DuPont had provided insufficient evidence to show that it was entitled to the priority date of the provisional application and (2 ) the conflict in DuPont’s statements as to the cr itical date (initially conceding the effective f iling date as that of the non-provisional application but then later arguing that the effect ive filing date should be that of the provisional app lication). Neither of these concerns was warranted. First, it is unclear what necessary evi dence the district cour t thought was missing from the preliminary injunction record. In responding to the motion for preliminary injunction, MacDermid provided the district court with the patent’s prosecution history including the ADS containing the reference to the provisional application, and DuPont’s complaint included as an attachment the ce rtificate of correction which corrected the patent to include a reference to the provis ional application. We see no evidentiary deficiency that prevented t he district court from resolving this issue. Additionally, since the facts underlying t he priority determination are undisputed, DuPont’s counsel’s conflicting characterization of those facts is immaterial to the legal analysis and cannot serve to creat e a substantial ques tion of validity. 4 DuPont’s counsel candidly admitted at oral argument in this appeal that the initial concession of a later priority date was based on an oversight, but that the oversight was corrected as soon as it was discovered. Such inconsist ent attorney argument standing alone cannot

4 We recognize that the district cour t was initially reasonably misled by DuPont’s counsel’s incorrect stat ements as to the priority date.

2007-1568 10create a substantial question as to a pur ely legal issue when the undisputed facts necessary to resolve the legal issue are before the court. We thus conclude that the district court’s reliance on la ck of evidence and conflicting attorney argument to find a subst antial question of validity was an abuse of discretion. Because the fact s that DuPont contends entitle the ’859 patent to the effective filing date of the prov isional application are not di sputed, we can resolve this question in the first instance.
A. Overlap of Inventorship MacDermid argues that the ’859 patent ca nnot claim priority to the provisional application because the provis ional application named only one inventor, whereas the issued patent names five in ventors. Because the prov isional and non-provisional applications were identical, the argument goes, they should have named the same inventors, or DuPont should have at least amended the provis ional application to name additional inventors. 37 C.F. R. § 1.48(d) (“If the name or names of an inventor or inventors were omitted in a provisional application thr ough error without any deceptive intention on the part of the omitted inventor or inventors, the prov isional application may be amended to add the name or names of t he omitted inventor or inventors.”). According to MacDermid, over lap of at least one inventor is insufficient because “all patent applications, including pr ovisional applications, need to be made in the names of the true inventors.” We disagree. This court has held that “for [a] non-prov isional utility applicat ion to be afforded the priority date of the provis ional application, the two applic ations must share at least one common inventor.” New Railhead Mfg., L.L.C. v. Vermeer Mfg. Co. , 298 F.3d 1290,

2007-1568 111294 (Fed. Cir. 2002). While an applicant can corre ct the inventorship of a provisional application under 37 C.F.R. § 1.48(d), both comments in final rulemaking on this regulation and the Manual of Patent Examining Procedure state that correction of inventorship of a provisional application is normally not necessary unless the correction is needed to establish an overlap of inv entorship. Manual of Patent Examining Procedure § 201.03 (8th ed., Re v. 6, 2007) (“MPEP”) (“For pr ovisional applications, it may not be necessary to correct the inventorship under 37 CFR 1.48 (d) and (e) unless there would be no overlap of inventors upon the filing of the nonprovisional application with the correct inventorship.”); Changes to Patent Practice and Procedure, 62 Fed. Reg. 53132, 53139 (Oct. 10, 1997) (“Section 1.48(d)(1) is also clarified to specify that the error to be addressed is the inventorship e rror. It is not expected that the party filing a provisional application will normally need to correct an error in inventorship under this paragraph by adding an inve ntor therein except when necessary under § 1.78 to establish an overlap of inventorsh ip with a continui ng application.”). The MPEP further states: An error in not naming or in naming a person as an inventor in a provisional application woul d not require correction under either 37 C.F.R. 1.48(d) (to add an inventor) or 37 C.F.R. 1.48(e) (t o delete an inventor) in the provisional application so long as the nonprovisional application naming the correct inventorship would contain an overlap of at least one inventor with the provisional application. The existe nce of inventorship overlap would prevent t he original inventorship error from having any effect upon the ability of the provisiona l application to serve as a basis for a benefit claim under 35 U.S.C. 119( e) with the U.S. Patent and Trademark Office. MPEP § 201.03 (emphasis added). In this case, the provisional applicati on named Roxy Ni Fan as an inventor, and the non-provisional also named Fan as an invent or. Thus, there is at least one common

2007-1568 12inventor in the provisional and non-provisional, and the requirement for overlap of inventorship was met. B. Specific Reference MacDermid argues that the reference in the non-provisional application was insufficient to claim priority to the provisi onal application. It is undisputed that the Application Data Sheet submitted with the non- provisional applicati on stated: “Continuity Data: This application is a non-provisio nal of provisional 60/273669 2001-03-06 WHICH IS PENDING.” 35 U.S.C. § 119(e)(1) requires, for a clai m of priority, that the non-provisional application contain “a specific reference to the provisional applic ation.” Under MPEP § 201.11, the specific reference can be either in the first sent ence of the specification or in the application data sheet. “If the specific reference is only contained in the application data sheet, then the benefit claim information will be included on the front page of any patent or pat ent application public ation, but will not be included in the first sentence(s) of the specification.” Id. ; see also 37 C.F.R. § 1.76(b)(5) (“Providing [domestic priority information] in the applic ation data sheet constitutes the specific reference required by 35 U.S.C. 119(e) . . . , and need not otherwise be made part of the specification.”); 37 C.F. R. § 1.76(d)(4) (“The Office will capture bi bliographic information from the applicat ion data sheet . . .”). In this case, it is undisputed that the ADS contained a reference to the provisional application. But MacDermid ar gues that the refer ence in the ADS was insufficient because DuPont did not use the la nguage that is “autho rized by the MPEP to claim the benefit of a provisional appl ication.” Under MPEP § 201.11, “[w]hen the

2007-1568 13nonprovisional application is entitled to an earlie r U.S. effective filing date of one or more provisional applications un der 35 U.S.C. 119(e), a statement such as ‘This application claims the benefit of U.S. Provisional Application No. 60/ ---, filed ---, and U.S. Provisional Applic ation No. 60/ ---, filed ---.’ should appear as the first sentence(s) of the description or in an applicati on data sheet.” (emphasis added). Here, rather than the precise language su ggested in the MPEP, the ADS in the non-provisional applicati on stated: “Continuity Data: This application is a non-provisional of provisional 60/273669 2001-03- 06 WHICH IS PENDING.” C ontrary to MacDermid’s argument, this reference did not run afoul of the MPEP by failing to use magic words. The MPEP provision requires only that t he applicant use a statement “such as” the one provided in Section 201.11. A reasonable person r eading the language in the ADS would have concluded that the applicant was claiming priority to an earlier provisional application. Thus, we find no defect in t he language used to reference the provisional application here. C. Certificate of Correction Despite the language in the ADS, the ’ 859 patent issued without any reference to the provisional applicat ion. DuPont sought a certificate of correction pursuant to 35 U.S.C. § 254, which aut horizes certificates of correcti on for mistakes made through the fault of the PTO, to add the specific referenc e to the provisional application on the title page of the ’859 patent. The PTO issued the Ce rtificate of Correction on July 26, 2005, adding to the title page, “Related U.S. App lication Data, Provisional application No. 60/273,669, filed on March 6, 2001.”

2007-1568 14MacDermid argues that the Certificate of Correction is invalid because the error was DuPont’s and not the PTO’s. According to MacDermid, the failure to include the continuity data on the title page of the patent was due to numerous errors by DuPont, including failure to correct t he filing receipt and the publis hed application, both of which made no mention of the priority claim. 5 By putting the continuity data in the AD S, DuPont expected that the PTO would capture the information and place it on the title pa ge of its patent. As MacDermid notes, however, there were some indications during prosecution that the PTO had failed to capture the information. MPEP § 201.11. We hold that a lack of diligence during prosecution, at least under the facts of this case, does not convert a PTO error into an applicant error for the purpose of seeking a post-issuance certificate of correction. It is, of course, desirable to have applic ants correct the PT O’s mistakes in pending applications as soon as possible so that the correct information is reflected in published applications and issued patents. Nevertheless, nothing in the statute conditions eligibility for a cert ificate to correct PTO error on the applicant’s diligence in correcting the mistake, and the statute does not set any time limit for seeking such corrections. 35 U.S.C. § 254 (“Whenever a mistake in a patent, incurred through the fault of the Patent and Trademark Office, is clearly disclosed by the records of the Office, the Director may issue a certificate of correction stating t he fact and nature of such mistake, under seal, without charge, to be recorded in the records of patents.”). Additionally, because there is a requirement that such certificates issue only if the

5 MacDermid argues that DuPont also made an error by failing to use the precise language given in the MPEP for claiming priority to a provisional application. However, as discussed above, we have conc luded that the language used by DuPont was a sufficient, specific referenc e to the provisional application.

2007-1568 15mistake is “clearly disclosed by the record s of the [PTO],” the chance that competitors will be harmed by any delay is minimal. In th is case, the continuity data was included in the ADS, a document contained in the prosecution history. Further, DuPont could have corrected its published applicati on under 37 C.F.R. § 1.221 and MPEP § 1130. While failure to make such a correction may have potential
consequences, 6 we see no reason why failure to correct a published application should prevent the patentee from later correcting hi s issued patent under 35 U.S.C. § 254. Finally, MacDermid argues that even if the ce rtificate of correction is valid, it has no effect in this case because it was issued “after the cause of action arose.” This argument is based on a misreading of Southwest Software, Inc. v. Harlequin Inc. , 226 F.3d 1280, 1295 (Fed. Cir. 2000) (hol ding that a certificate of correction is not effective for causes of action arising before its issuance ). MacDermid argues that the certificate of correction in this case issued after DuPont’s cause of action arose because MacDermid was already engaged in the allegedl y infringing conduct when the patent issued. As DuPont correctly notes, however, we have held that each act of infringement gives rise to a separate cause of action. Hazelquist v. Guchi Moochie Tackle Co., Inc. , 437 F.3d 1178, 1180 (Fed. Cir. 2006) (“Our case law clearly states that each act of patent infringement gives rise to a separate cause of action.”). In Southwest Software , the court stated “it strikes us as an illogica l result to allow the patent holder, once the certificate of correction has issued, to sue an alleged infringer for activities that occurred

6 For example, failure to correct a published application could affect a patentee’s ability to collect a reasonable royalt y during the time peri od from publication until issuance under 35 U.S.C. § 154(d) if the errors in the published application resulted in the issued claims not being “substantially identical” to those in the published application.

2007-1568 16before the issuance of the ce rtificate of correction.” Southwest Software , 226 F.3d at 1295-96. In contrast here, only MacDe rmid’s future conduct (i.e., prospective infringement occurring after the issuance of the certificate of correction) is at issue for the purposes of the preliminary in junction motion. Further, unlike Southwest Software , the Certificate of Correction issued pr ior to DuPont filing suit. In sum, the undisputed facts in this case show that the ’859 patent is entitled to claim priority to the provisio nal application as a matter of law: the provisional and nonprovisional applications are iden tical; the non-provisional ap plication was filed within 12 months of the filing of the provisional application; the two appl ications share a common inventor; and the non-provisiona l application included a specific reference to the provisional application in the application data sheet. Thus, we vacate and remand for the district court to consider MacDermid’ s remaining invalidity and unenforceability challenges in light of the corre ct priority date, as well as the remaining preliminary injunction factors. 7

7 MacDermid argues that even if the crit ical date is March 6, 2000, claim 1 would still be invali d under Section 102(b) because Du Pont publicly used an analog version of Cyrel FAST at a trade show in Ap ril 1999. But the dist rict court expressly declined to decide whether analog and digital or only digital technol ogy were within the scope of the claim. In any event, MacDermi d cites no record evidence to support this assertion, and we decline to reach this issue fo r the first time in this appeal. Evidence concerning the 1999 trade show s hould be raised in the first in stance with the district court on remand. Additionally, MacDermid raises numer ous other alternative grounds for affirmance, including anticipation, obvious ness, failure to disclose best mode, and inequitable conduct. None of t hese grounds were reached by the district court, and all would require fact finding that is unnecessary for this court to undertake in the first instance. Thus, we decline to reach these issues.

2007-1568 172007-1568 18 III. For these reasons, the dist rict court’s order denying the motion for preliminary injunction is VACATED AND REMANDED

.