concurring.
This is a close and difficult case. I generally agree with the majority opinion, but write separately to emphasize three points. First, the majority’s tentative claim construction in response to the indefiniteness argument may or may not be correct. Presumably at trial those of ordinary skill in the art will testify as to whether the specification should be so interpreted by the skilled artisan. At. the preliminary injunction stage the claims enjoy a presumption of validity. Appellants have not shown that a person having ordinary skill in the art could not interpret the language of the claims in a sufficiently definite manner. That skilled artisan would have the details provided in the written description including specific examples. The record before us, in view of the presumption of validity of the claims, is simply insufficient for us to conclude that Oakley has failed to meet its burden of showing a likelihood of success on the merits of the validity of the claims under 35 U.S.C. § 112, ¶ 2, or that appellants have raised a “substantial question” of invalidity. Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343, 1358-59 (Fed.Cir.2001).
Second, in my view, we should not be applying a new claim construction to the facts of this case to uphold a district court’s discretionary preliminary injunction as the majority does, ante at 1344. See Bell & Howell Document Mgmt. *1348Prods. Co. v. Altek Sys., 132 F.3d 701, 708, 45 USPQ2d 1033, 1040 (Fed. Cir.1998) (“Because the district court determined the likelihood of infringement based on an incorrect claim construction, we must remand for a determination whether [plaintiff] has shown that it will likely succeed in proving infringement.”); see also Guttman v. Kopykake Enters., 302 F.3d 1352, 1362, 64 USPQ2d 1302, 1309 (Fed.Cir.2002) (refusing to remand to the district court with instructions to enter a preliminary injunction because “the trial court has not yet passed on whether, under the proper claim construction, [the patentee] is likely to show infringement [and] the resolution of this issue necessarily involves factual determinations that rest within the province of the trial court, not the appellate court”). However, it is sufficient to establish a likelihood of success on infringement at this stage that there was expert testimony that the accused lenses had a vivid colored appearance, and no evidence to the contrary. Oakley Inc. v. Sunglass Hut Int’l, 61 USPQ2d 1658, 1662-63 (N.D.Cal.2001). Appellants offered no claim construction at the preliminary injunction stage. There was no error on the part of the district court in failing to provide an explicit formal claim construction. The district court sufficiently performed its obligation when applying the facts to the claims as presently understood by the district court. See Sofamor Danek Group, Inc. v. DePuy-Motech, Inc., 74 F.3d 1216, 1221, 37 USPQ2d 1529, 1532 (Fed.Cir.1996) (“[T]he trial court has no obligation to interpret [a claim] conclusively and finally during a preliminary injunction proceeding.... A trial court may exercise its discretion to interpret the claims at a time when the parties have presented a full picture of the claimed invention and prior art.”). The appellants’ sole argument against infringement was that it was practicing the prior art, which we have held is not a defense to infringement. Tate Access Floors, Inc. v. Interface Architectural Res., Inc., 279 F.3d 1357, 1366, 61 USPQ2d 1647, 1654 (Fed.Cir.2002).
Finally, the parties at trial are free to offer new claim constructions to the district court and evidence as to why the accused lenses do or do not infringe under those claim constructions. Guttman, 302 F.3d at 1361, 64 USPQ2d at 1308 (“[A]ll findings of fact and conclusions of law at the preliminary injunction stage are subject to change upon the ultimate trial on the merits.”).