The criteria applicable in the assessment of the novelty of use claims differ from those applied to product/apparatus claims. This is the gist of a recent judgment issued by the German Federal Supreme Court in nullity proceedings (judgment of February 23, 2017, X ZR 99/14 - Cryptosporidium). 

Product/apparatus claims cover the respective tangible goods as such and thus, generally, each and every (commercial) use of them. As a direct consequence of this broad scope of protection, any prior art embodiments showing all of these claims’ features are novelty destroying. 

The legal situation differs when assessing the validity of a use claim. This category of claims is characterized by the inclusion of an additional subjective feature, namely the use of a known or new object for a specific purpose. This “intentional feature” limits the claim’s scope of protection. It does not cover usage of the respective object for other purposes. On the other hand, this feature can also not be ignored when determining the use claim’s validity. For example, prior art can form the basis for a novelty attack only if it shows all of the features defining the patented invention. Consequently, documents revealing use of the respective product or apparatus for other purposes than those specified by the claim are never novelty destroying. 

This particularity of use claims forms the focus of the German Federal Supreme Court’s recent decision. The contested European patent’s (use) claim 1 reads as follows: 

Use of a time-continuous broad band of ultraviolet light of a medium pressure UV mercury lamp in doses of from 10 mJ/cm² to 175 mJ/cm² and with a wavelength range of 200 to 300 nm for treating drinking water to eliminate the potential for Cryptosporidium oocysts infection. 

The prior art introduced by the plaintiff in these nullity proceedings comprised apparatus for the inactivation of bacteria and viruses in drinking water showing all of the contested claim’s objective features. As it did not disclose use of the apparatus specifically for the inactivation of Cryptosporidium, however, the court confirmed novelty of the patented invention over this prior art. The factual inactivation of Cryptosporidium through use of the apparatus before the patent’s priority date did not have any impact on this outcome. The court stressed that the mere factual achievement of the at that time unintended effect did not disclose the patented use. 

Practical Impact: This decision once again highlights the opportunities provided by use claims. Even if the persons skilled in the art already know an apparatus/product showing all of the respective inventions objective features at the priority date, patent protection can still be obtained for use of this object for a new purpose. Such use claims thus present a good fallback position in opposition or nullity proceedings against “pure” apparatus or product claims. It is possible to switch from the product/apparatus claim to the use claim as long as the specific use was sufficiently disclosed in the application and does not change the invention’s nature.