dissenting.
I respectfully dissent. The majority affirms the grant of summary judgment. In so doing, it misapplies the doctrine of laches by imposing on patentees the affirmative burden to police the marketplace.
I
Wanlass tested some General Electric motors between 1977 and 1982 and found no infringement. Wanlass then turned his attention to other potential infringers. General Electric in 1986 changed to an allegedly infringing motor design. Wanlass did not discover the alleged infringement until 1992. He filed suit in 1995. This court upholds, under the strictures of summary judgment, a determination that Wanlass unreasonably delayed bringing suit. To the contrary, Wanlass had no way to detect that General Electric had made infringing changes. Nonetheless, this court imposes on Wan-lass — a small businessman and inventor — the costly.and unreasonable burden of periodically checking and recheeking every product in this crowded market to detect infringement. Because Wanlass did not recheck General Electric’s motors and did not discover the alleged infringement until 1992, this court construes all facts against him and denies him any chance to proceed with his suit.
In affirming the grant of summary judgment, this court determined that there were no genuine disputes of material fact and that General Electric was entitled to judgment as a matter of law. See Fed.R.Civ.P. 56(c). This court bases its holding on a determination that Wanlass should have discovered General Electric’s alleged infringement sometime before April 1989.*
To my eyes, the law does not entitle General Electric to judgment. In 1979, General Electric indicated to Wanlass that it was not interested in licensing his patents. Between 1977 and 1982, Wanlass had tested a number of motors, including some made by General Electric. His tests did not uncover any motors that infringed his patent. In sum, construing disputed facts in Wanlass’s favor as *1342required on summary judgment, these early tests and negotiations lulled him into the belief that General Electric was not interested in his technology, and would not infringe.
In 1986, however, General Electric changed its motor design in a way that allegedly infringes Wanlass’s patent. General Electric did not inform Wanlass' of its changed design. Nonetheless this court determines that Wanlass had a duty to discover the change. The problem with that determination is that the accused motors operate inside air’ conditioners and refrigerators. To discover a change would require Wanlass to disassemble appliances to access the motor and then dismantle the motor to discover the internal changes. Indeed, Wanlass theorizes that ■ alterations in one internal part of the motors altered its magnetic properties and caused the infringement. (In light of this theory, which is consistent with the teachings of Wanlass’s patent, this court’s emphasis on the unchanged circuit diagram is misplaced.) In addition to the complexity of discovering a single instance of infringement, the record of this case shows that General Electric is not the only manufacturer of this type of electric motors in the United States. Many companies make many different models of electric motors for a wide variety of applications. Yet this court requires Wanlass to check and recheck them for infringement, even if he had early indications that a company was not infringing.
Because these undisputed record facts do not establish that Wanlass’s failui’e to discover the alleged infringement before 1989 was unreasonable, this court imposes on Wanlass an affirmative duty to police his patent. This .duty allegedly arises from General Electric’s “pervasive, open and notorious activities” that a reasonable patentee would suspect were infringing. Hall v. Aqua Queen Mfg., Inc., 93 F.3d 1548, 1553, 39 U.S.P.Q.2d 1925, 1928 (Fed.Cir.1996). The Hall case, however, is very different from Wanlass’s case. In Hall, the patentee had knowledge of other open and notorious potential infringements. In Hall, the accused devices were also widely advertised in trade journals and advertised at trade shows. See id. Hall himself, the patentee, was the head of a trade organization. He attended many of these shows and spoke with the management of the accused infringers. Indeed, “Hall [was] a prominent figure in the ... industry throughout the 1970s and 1980s.” Id. at 1552. In light of these facts, this court properly charged Hall with knowledge of the alleged infringing activities.
In contrast, Wanlass had no indications of widespread infringement to raise his suspicions. General Electric’s new motor was not described in any trade publication in sufficient detail to place Wanlass on notice of the possible infringement. Indeed, the record does not indicate when, if ever, General Electric’s change in its electric motor design became known outside of General Electric. Moreover, unlike Hall, Wanlass had checked once for infringement and had unsuccessfully tried to license various manufacturers of single phase motors. For good reason, therefore, Wanlass had turned his attention to larger three-phase motors used in industrial applications. A number of articles in business publications described him as abandoning the single phase motor field. Unlike Hall, Wanlass can hardly be described as a prominent figure in the electric motor industry. This court must stretch Hall far beyond its facts to apply it to Wanlass.
In order to bridge the gap between Hall and the present case, the majority charges Wanlass with constructive knowledge of General Electric’s potential infringement. The majority holds that Wanlass should have discovered the alleged infringing motors within two to three years after General Electric started production. This court explains that General Electric’s “sales, marketing, publication, public use, or other conspicuous activities of potential infringement [were] sufficiently prevalent in the inventor’s field of endeavor.” Again, this standard amounts to a duty on Wanlass to check and recheck large potential infringers.
Ironically, Wanlass had- checked General Electric. This fact adds to the confusion of this court’s summary judgment result. This court imposes on the patentee the burden to conduct a reasonable scheme of product testing designed to enforce his patent. But what is a reasonable testing program? In this *1343case, Wanlass conducted initial tests 'on motors that were manufactured by General Electric and others. Having discovered no infringement, he turned to other activities until his discovery in 1992. As noted above, electric motors are commonly used in a wide variety of applications. Some devices with motors that might use the Wanlass technology are relatively inexpensive. Others are very expensive. Rather than consider these facts (and others that might have been in the record had the parties known that this court would impose this duty on Wanlass), this court pronounces Wanlass’s failure to recheck per se unreasonable. At the very least, this case should be vacated and remanded so the district court could consider whether Wanlass should be charged with constructive knowledge under the majority’s new standard and whether his decision to cease testing was reasonable in light of all of the circumstances.
II
Because the majority announces new legal rules and offers so little guidance, patentees can only look to the facts of this ease. What they will see will be disheartening, as it represents a substantial new burden. Wan-lass’s patent claimed an improvement to a component used in a wide variety of applications. The component was not the focus of the advertising campaigns for these products, nor would it have been a feature sought by purchasers of the equipment. Indeed, this court does not say why Wanlass, who had tested General Electric products in the past, should have suspected that General Electric had made changes that resulted in infringement of his patent. Instead this court assumed that, because. General Electric is a large company with widely distributed products, Wanlass should have known what it was doing. Therefore, this case places, upon pat-entees the duty to test any product that might contain the claimed invention. For inventions, such as Wanlass’s, that have broad potential application, this new requirement is a significant burden.
The rule created by this ease is unnecessary. Patentees already have an incentive to enforce their patents. By placing an extra incentive on the patentee, this decision will prompt patentees to over-invest in patent enforcement. This court’s per se rule requiring testing and retesting also overlooks the public notice furiction of claims. See Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 117 S.Ct. 1040, 1051, 137 L.Ed.2d 146 (1997) (noting that the “role of claims [is to] defin[e] an invention and pro-vid[e] public notice.”). The requirement that patentees mark patented articles before they can collect damages, see 35 U.S.C. § 287(a), is further designed to provide notice of the patent. Public notice alerts other parties to avoid making use of patented subject matter. In allocating too much of the burden of policing the patent to the patentee, this court undervalues the fundamental principle that the public has a duty to avoid infringement.
Ill
Because this decision announces new rules of law that place substantial burdens on pat-entees and improperly affirms summary judgment in the face of genuine disputes of material facts, I must dissent.
As an alternative basis for its result, this court suggests that Wanlass had actual knowledge of General Electric's infringement in 1987. This court reaches this conclusion due to its interpretation of the Potempa memo. However, the meaning of this memo is not clear enough for resolution on summary judgment. This decision interprets the key word in the memo — "then”— as meaning "soon after that.” With this interpretation, the delay — "about 8 years” — between the start of General Electric's infringement and Wanlass's discovery would suggest that Wanlass had actual knowledge of General Electric’s infringement in 1987.
However, Webster's also defines "then” as "being next in a series,” without defining a more precise temporal connection between the events. This second meaning is a common usage. Given that Wanlass is describing a series of events, this meaning is as consistent with the context as that chosen by the majority. This definition does not fix the time between the tests and the start of infringement. Thus, if Wanlass was using "then” in this second sense, as he himself has suggested, it would be inappropriate to infer actual knowledge from this memo.
Furthermore, the memo does not identify which General Electric products Wanlass believed to infringe. Because laches is a claim specific defense, cf. Gasser Chair Co. v. Infanti Chair Mfg. Corp., 60 F.3d 770, 773, 34 U.S.P.Q.2d 1822, 1824 (Fed.Cir.1995); Aukerman, 960 F.2d at 1029-30 (referring to laches as a defense to a claim of infringement), the presumption of laches would not be triggered unless it were shown that the memo was referring to the products accused in this suit. If Wanlass suspected that some other General Electric product was infringing in 1987, this would be evidence of the unreasonableness of his delay and his failure to discover the alleged infringement. The application of laches with respect to one product would not, however, act as a bar to the assertion of a claim against a different product produced by the same manufacturer.
Moreover, if the memo does refer to the motors that are the subject of this suit, summary judgment would still be inappropriate. Wan-lass testified that he did not discover the infringement until 1992. Therefore, even if the majority's interpretation of the memo is correct, the most that the Potempa memo can do is create a genuine dispute over a material fact — when Wanlass discovered General Electric's alleged infringement.