dissenting from the judgment of invalidity of the ’313 patent.
I respectfully dissent from the judgment of my colleagues concerning the ’313 patent, for their separate theories of invalidity are premised on the incorrect position that a continuation-in-part application is not entitled to the parent application’s filing date, even when the claimed invention was enabled and the best mode requirement was met in the parent specification.
The ’313 patent arose from the same parent application as did the ’609 patent discussed supra. It is not disputed that the enablement and best mode requirements were met when the parent application was filed. The district court held that the inventor was required to update the subject matter, including the design details of the commercial reactor, when the continuation-in-part was filed. In the later-overruled district court decision in Transco Products, Inc. v. Performance Contracting, Inc., 821 F.Supp. 537, 28 USPQ2d 1739 (N.D.Ill.1993), a continuation application had been filed in accordance with patent office Rule 60 (permitting expedited refiling when the specification is unchanged), and the court held that the subject matter required full updating upon the refiling. The Federal Circuit reversed, and in a thorough opinion the court explained the principles embodied in the statute. Transco *1582Prods., Inc. v. Performance Contracting, Inc., 38 F.3d 551, 32 USPQ2d 1077 (Fed.Cir.1994), cert. denied, - U.S.-, 115 S.Ct. 1102, 130 L.Edüd 1069 (1995). Judge Mayer in his concurring opinion now applies that reversed decision, distinguishing the Federal Circuit’s discussion as dictum, as I shall discuss.
Chief Judge Archer in his concurring opinion holds that the original filing date was lost because the applicant included in the continuation-in-part claims the additional advantage of single-side heating, viz. reduced crystallographic slip. He would extinguish the parent filing date because an advantage of the pat-entee’s method was not described in the parent specification. Thus there has been added to the patent practice of the Federal Circuit another useless pitfall, now punishing the patentee for disclosing in the continuation-in-part application an advantage of the method that was described and enabled in the parent specification. Both of the concurring opinions divest the continuation-in-part application of the benefit of the parent filing date, holding that it is insufficient that the parent specification enabled the invention that was common to the parent and the continuation-in-part, and that the best mode was described for that common invention as of its filing date. I can not agree.
In Transco the Federal Circuit explained that a rule that removed the benefit of the early filing for subject matter enabled therein would “subvert the patent system’s goal of promoting the useful arts through encouraging early disclosure.” 38 F.3d at 558, 32 USPQ2d at 1082. The court explained that 35 U.S.C. § 120 establishes that when the application as initially filed complies with 35 U.S.C. § 112, that filing date continues to apply to claims to that subject matter.
The court in Transco discussed the relationship of § 120 and § 112 when the subsequent application is a continuation-in-part, that is, when additional subject matter has been added to the specification. The court explained that claims enabled by the original application do not lose their enablement when additional text is added to the specification:
“Any claim in a continuation-in-part application which is directed solely to subject matter adequately disclosed under 35 U.S.C. 112 in the parent application is entitled to the benefit of the filing date of the parent application. However, if a claim in a continuation-in-part application recites a feature which was not disclosed or adequately supported by a proper disclosure under 35 U.S.C. 112 in the parent application, but which was first introduced or adequately supported in the continuation-in-part application such a claim is entitled only to the filing date of the continuation-in-part application.”
Transco, 38 F.3d at 557 n. 6, 32 USPQ2d at 1082 n. 6 (quoting the Manual of Patent Examining Procedure § 201.11).1
Thus this court in Transco explained that when the claims are entitled to the filing date of the parent application, they do not lose that entitlement when carried forward in a refiled application, whether that application is a Rule 60 “continuation” or a continuation-in-part. “The plain and unambiguous meaning of section 120 is that any application fulfilling the requirements therein ‘shall have the same effect’ as if filed on the date of the application upon which it claims priority.” Transco, 38 F.3d at 556, 32 USPQ2d at 1081 (quoting 35 U.S.C. § 120).
However, when claims in the continuation-in-part require the newly added matter for enablement, the best mode is measured as of the filing date governing those claims. See, e.g., In re Chu, 66 F.3d 292, 297, 36 USPQ2d 1089, 1093 (Fed.Cir.1995) (“It is elementary patent law that a patent application is entitled to the benefit of the filing date of an earlier filed application only if the disclosure of the earlier application provides support for the claims of the later application....”); In re Hogan, 559 F.2d 595, 194 USPQ 527 (CCPA 1977) (different claims of continuation-in-part granted benefits of filing dates of different ancestral applications); Wagoner v. Barger, 59 C.C.P.A. 1213, 463 F.2d 1377, *15831380, 175 USPQ 85, 86-87 (1972) (“The question in eases in which the parent application does not contain language contained in the claims of the later application is whether the language which is contained in the parent application is the legal equivalent of the claim language, in the sense that the ‘necessary and only reasonable construction to be given the disclosure [in the parent application] by one skilled in the art,’ Binstead v. Littmann, [44 C.C.P.A. 839, 242 F.2d 766, 113 USPQ 279 (CCPA 1957) ], is the same as the construction which such person would give the claims of the later application.”)
The district court did not hold that any of the information that it stated should have been added to the specification was needed to enable the claimed invention. The holding was to the contrary, the court stating that (“There is no evidence that, if operated by one skilled in the art to whom elimination of slip was an important consideration, the Figure 6 reactor would not eliminate the slip caused by back side heating.”) Applied Materials, 32 USPQ2d at 1880. Cf. In re Gay, 50 C.C.P.A. 725, 309 F.2d 769, 771, 135 USPQ 311, 314 (1962) (“Since we are of the opinion that as originally filed, appellant’s specification would have indicated to one skilled in the art that all suggested container materials were to be substantially non-porous, we hold that the insertion of this limitation expressly into the specification and claims did not involve ‘new matter.’ ”)
The invention claimed in the ’313 patent is directed to ovens in which the lamps are on the same side of the susceptor as the substrate (called “same side heating” in the district court’s opinion). That configuration was disclosed and enabled in the parent application. The applicant added some general explanatory text, but added neither a new invention nor broadened subject matter nor broadened claims.
There is not asserted to be any deficiency in either enablement or the best mode disclosure of the original application. The district court, like my colleagues on this panel, simply misstated the law in holding that “[a]ll of the features of the AMC-740 [the commercial reactor], whether they contributed to slip free performance or not, should have been disclosed.” The district court did not limit this requirement to features related to same side heating. ASM in its brief, explaining the features that the district court had in mind (such as the oval shape of the reactor), does not mention anything related to same side heating. It appears that the district court had been persuaded that Applied Materials was required to include all subsequently developed aspects of its commercial apparatus, whether or not they were part of the invention claimed in the ’313 patent. That is not the law. See Northern Telecom, Inc. v. Datapoint Corp., 908 F.2d 931, 941, 15 USPQ2d 1321, 1329 (Fed.Cir.1990) (patent document not intended to be a production specification); In re Gay, 50 C.C.P.A. 725, 309 F.2d 769, 773, 135 USPQ 311, 316 (1962) (the Board erred in requiring inclusion of the details of the product “as it is ‘being marketed.’ ”); Engel Indus., Inc. v. Lockformer Co., 946 F.2d 1528, 1532, 20 USPQ2d 1300, 1302 (Fed.Cir.1991) (a patent is not a “production specification”) (quoting In re Gay, 309 F.2d at 774, 135 USPQ at 316).
Prior to the uncertainties now raised by my concurring colleagues, each of whom imposes a different new obligation upon patent applicants, the law was that when the original specification is enabling, the best mode as to claims enabled by the original subject matter is measured as of the original filing date. When an application is refiled with newly added matter, the initial matter does not thereby lose its effective date, and claims that were initially enabled, and a specification that initially met the best mode requirement, do not lose their validity as to the common subject matter.
The district court erred in holding that Applied Materials was required to include in the continuation-in-part application all of the features of its commercial reactor, “whether they contributed to slip free performance or not.” It is hard to imagine any continuation-in-part application that will not fail some judge’s test and, as here, destroy the patent on a successful invention. This is of particular concern because should the United States adopt a first-to-file rule the pressures for early filing will increase, yet now the early filing date is increasingly vulnerable to loss. *1584This simply entraps the inventor. The ultimate loser will be the public, for patent applications will not be refiled, and the innovation incentive will be diminished.
The district court found as fact that the claims of the ’313 patent were entitled to the filing date of the parent application. This finding was made in rejecting ASM’s defense that the patent was invalid because of sales activity after the initial filing date but a year before the continuation-in-part application was filed. No error has been shown in this finding, which resolves the issue on appeal. I dissent, respectfully, from the contrary findings of my colleagues on this panel.
. Judge Mayer observes that in Transco this discussion is dictum. It is simply a statement of existing law, the Transco court citing P.J. Federico, "Commentary on the New Patent Act,” 35 U.S.C.A. § 1 (1954), pp. 31-33, and quoting the Manual of Patent Examining Procedure.