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Asetek A/S v. Cooler Master Europe B.V., District Court of The Hague, the Netherlands, 20 September 2017, Case number C/09/515892 / HA ZA 16-906

Asetek is the holder of the European patent EP 1 923 771 B1 (“EP ‘771”) entitled “Cooling system for a computer system”. The patent was filed on 8 November 2004 relying on the priority of US 517924 P dated 7 November 2003 (“US ‘924”). Asetek sued Cooler Master in accelerated proceedings on the merits amongst others claiming an injunction and damages. Cooler Master counterclaimed for invalidity.

EP ‘771 comprises two product claims. Claim 1 of EP ‘771 is directed to a cooling system for a computer system, which system comprises a CPU, a liquid reservoir housing, a heat radiator, a liquid reservoir with certain channels for establishing a certain flow-path for the cooling liquid, a pump provided in the liquid reservoir housing as part of an integrate element and a heat exchanger. Claim 1 further specifies that the pump comprises an impeller which is positioned in a separate recess of the liquid reservoir channels. Claim 2 further limits the system according to claim 1 to a system with a liquid reservoir with a non-smooth inner wall.

Cooler Master argues amongst others that EP ´771 is not entitled to the priority of US ‘924, resulting in Lin, a Chinese utility model which was published on 7 April 2004 (CN 2610125Y), becoming state of the art. According to Cooler Master Lin destroys the novelty of claim 1. Further claim 2 according to Cooler Master is obvious over Lin in light of the common general knowledge of the skilled person.

According to the District Court US ‘924 discloses a centrifugal pump which works with an impeller. US ‘924 however does not provide any information regarding the impeller being placed in a separate recess as claimed in claim 1 of EP ‘771. This according to the District Court means that US ‘924 does not disclose the same invention according to Article 87 EPC. The Court concludes that EP ‘771 cannot rely on the priority date of US ‘924 which results in the filing date of 8 November 2004 becoming the relevant date for considering novelty and inventive step.

After reviewing Lin, the District Court concludes that Lin directly and unambiguously discloses all features of claim 1 of EP ‘771. The District Court therefore finds that claim 1 is not novel over Lin.

In relation to inventive step Cooler Master argued that it is common general knowledge for the skilled person to apply imperfections to a surface in order to increase fluid circulation and hence an improved transfer of heat. The decision does not specify whether Cooler Master relied on any evidence to substantiate the alleged common general knowledge, but it does mention that Asetek has not or at least not sufficiently disputed this common general knowledge.

Further, according to the District Court, this knowledge also follows from PCT application WO 03/098415A1 which was published on 27 November 2003 and is also prior art in light of the fact that the priority of US ‘924 is not validly claimed. The District Court concludes that the skilled person faced with the problem of improving the uptake of heat by the heat exchanging interface would implement non-smooth inner walls according to claim 2 without any inventive step.

As both claims of EP ‘771 are found to be invalid the District Court dismisses Asetek’s infringement claims and invalidates the Dutch part of EP ‘771.

A copy of the judgment (in Dutch) can be read here.

Head note: Mattie de Koning and Rosanne Hoevenaar, Simmons & Simmons LLP