587 F.3d 1339, 2009 U.S. App. LEXIS 26338 (Fed. Cir. 2009) (LOURIE, Dyk & Prost)
MAJOR ISSUES: Typographical errors in claims–correction when no reasonable debate about correction–persons skilled in the art
Definiteness–claim construction–dictionary definitions
Laches defense (undue, prejudicial delay in suing for infringement)–fact question on when patent owner first knew of infringement
The suit involved three patents, which concerned rapid-hardening, high-strength cement, and an alleged trade secret misappropriation. uspatno4957556 uspatno6113684 uspatno6406534 A district court granted summary judgment of noninfringment and invalidity and sustained a laches defense. The Federal Circuit reversed.
1. Claim Definiteness and Construction; Typographical Errors. On three issues, the Federal Circuit showed more tolerance than the district court for interpreting and evaluating the asserted patent claims according to what the patent draftsperson clearly intended as opposed to what the bare claim language said.
a. CALCIUM SULFATE ANHYDRIDE MEANS ANHYDROUS CALCIUM SULFATE. First, a claim recited a “soluble CaSO4 anhydride,”also known as “soluble calcium sulfate anhydride.” The district court construed the claim by applying a single dictionary definition, which defined “anhydride” as “a compound formed from an acid by removal of water.” This construction dictated non-infringement because an accused infringer’s cement contained no acid from which water had been removed. From the context in which “anhydride” was used in the claim, it was clear that the patent owner intended to claim anhydrous calcium sulfate, that is, calcium sulfate (not an acid) from which water had been removed. The district court erred by construing “anhydride” in isolation rather than in context and by applying one among multiple dictionary definitions of “anhydride” without consider the specification teaching. The district court’s opinion issued before the Federal Circuit had clarified the role of dictionary definitions in Phillips v. AWH Corp., 415 F.3d 1303, 1314 (Fed. Cir. 2005) (en banc). The patent used “anhydride” as a modifier, not a stand-alone concept. The specification supported construing “soluble calcium sulfate anhydride” to mean “soluble anhydrous calcium sulfate” or, simply, “anhydrite”, which is defined as anhydrous calcium sulfate. The specification never used “anhydride” alone but, rather, only as modifying “calcium sulfate.” The specification did not disclose forming any compound from an acid by removing water. “[I]nterpreting the claim term to mean `soluble anhydrous calcium sulfate’ is not rewriting the claim or correcting a typographical error.”
On definiteness, see Chisum Patent Law Digest § 2420; Chisum on Patents § 8.03; On dictionary definitions in claim construction, see Chisum Patent Law Digest § 5228.40; Chisum on Patents § 18.03[2][b][i].
b. FORMULA WITH A MISSING COMMA; TYPOGRAPHICAL ERROR. Second, the district court held that a second formula was indefinite because it lacked a comma. The claim recited: “C9S3S3Ca(f cl)2.” The symbols “f” and “cl” were for fluorine and chlorine. With a comma, the formula would require the presence of either fluorine or chlorine. Without the comma, it might mean that both must be present. The district court recognized that a person of ordinary skill in the art would recognize that the omission of a comma between “f” and “cl” was a typographical error but held that the law required that the error be clear “on the face of the patent.” HELD: the district court erred “in declining to view the notation in light of the knowledge of one of ordinary skill.” See Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1357 (Fed. Cir. 2003). If a “correction is not subject to reasonable debate to one of ordinary skill in the art, namely, through claim language and the specification, and the prosecution history does not suggest a different interpretation, then a court can correct an obvious typographical error.” The district court “determined that the claimed formula C9S3S3Ca(f cl)2 `corresponds to no known mineral,’ and that one of ordinary skill in the art would know that the formula should contain a comma.”
On correcting errors in claims, see Chisum on Patents § 8.03[3][g].
c. COMPLEX FORMULA COVERING 5000 COMPOUNDS; BREADTH IS NOT INDEFINITENESS. Finally, the district court held that a required compound was defined by a formula that, with all possible substitutions, encompassed more than 5000 possible compounds and, therefore, rendered the claim indefinite. HELD: the district court erred. “[T]he formula for crystal X is obviously complex,” but “it is not necessarily indefinite.” The patent owner argued that that the claim should be construed as limited to a single compound. Because the district court’s broader construction was not indefinite, the Federal Circuit saw no need to decide “whether the term should in fact be construed more narrowly.”
2. Laches. A “laches” defense to a patent infringement suit arises when a patent owner unreasonably delays filing suit and there is prejudice to the accused infringer. The key decision on laches is A.C. Aukerman Co. v. R.L. Chaides Constr. Co., 960 F.2d 1020 (Fed. Cir. 1992) (en banc). On laches, see Chisum Patent Law Digest § 5624; Chisum on Patents § 19.05[2]. A court will presume unreasonable delay and prejudice if the delay period is more than six years. The delay period begins when the patent owner first knows or should have known of the alleged infringement.
In this case, the district court granted summary judgment based on a 12 year delay from when the patent issued (1990) to the filing of suit (2002). This was error. The patent owner filed suit based on other patents and added a complaint for infringement of the 1990 patent only after obtaining litigation discovery from the accused infringer. The patent owner had demonstrated the invention to the accused infringer in 1989. However, the patent claims required as a limitation the presence of anhydrite in the cement product. One could not determine whether a cement maker had used soluble anhydrite merely by testing a finished cement product. The patent could not have sued for infringement of the patent without a reasonable belief in infringement, including the presence of a claim limitation (soluble anhydrite). See Antonious v. Spalding & Evenflo Cos., 275 F.3d 1066 (Fed. Cir. 2002). “In the case of a claim limitation whose presence is undetectable in a finished product, it is reasonable that [the patent owner] might not have known or been able to find out whether [the accused infringer] infringed.”
