Liu Shen has recently obtained the final judgment issued by the Supreme People's Court of China, marking a definitive win for its client, a leading domestic enterprise specializing in textile mechatronic instruments, in defending a patent infringement action.
The dispute revolves around short fiber ratio testers, devices widely used in the cotton textile sector. Test outputs from such testers serve as a critical indicator for quality grading of long staple cotton. A foreign competitor brought a patent infringement suit before the Urumqi Intermediate People's Court of Xinjiang Uygur Autonomous Region, alleging that two models of the client's short fiber ratio testers infringed its invention patent and seeking damages in the tens of millions of RMB.
The central issue throughout the proceedings concerned the proper construction of the claim feature “determining whether fibers are brought into an aligned state”, specifically, whether this feature should be interpreted as a method step feature or a functional limitation.
At an early stage of the matter, the Liu Shen team accurately identified this core controversy and concurrently filed for patent invalidation with the China National Intellectual Property Administration (CNIPA). Upon CNIPA's examination, over broad claims that did not recite this feature or its corresponding apparatus were invalidated. Further, the invalidation decision confirmed that “determining whether fibers are brought into an aligned state” constitutes a method step feature and a distinguishing technical feature over the prior art. This ruling laid a vital factual foundation for the subsequent infringement litigation.
During first instance proceedings, claim to product comparison for the asserted method patent required power on operational testing of the accused products. To fully and accurately demonstrate the technical solution embodied in the accused products, the Liu Shen team guided the client to produce product operation videos. Careful planning covered shooting positions, camera angles and presentation of key procedural steps. Filming was completed in a single unbroken take to truthfully and comprehensively capture product operations. All parties accepted the videos as the basis for infringement comparison. This approach obviated the inconveniences and uncertainties inherent to on site inspection and provided strong evidential support for the non infringement defense.
On second instance appeal, the Supreme People's Court fully adopted our position regarding the legal nature of the disputed technical feature. Based on multiple considerations including the background art, overall context of the claims, corresponding apparatus claims and specific embodiments in the specification, the Court held that “determining whether fibers are brought into an aligned state” is a method step feature rather than a functional limitation. The Supreme People's Court also cited findings from the CNIPA invalidation decision, confirming that the fiber alignment approach under the patent in suit is substantially different from that of the prior art, whose alignment mechanism bears greater resemblance to the technical solution of the accused product.
In the final outcome, the Supreme People's Court dismissed the appeal and upheld the first instance judgment, resulting in a complete victory for our client.
This case illustrates the great strategic value of aligning patent validity confirmation proceedings and infringement proceedings. Through invalidation, the Liu Shen team addressed issues such as overly broad patent scope and ambiguous meaning of key technical features. Factual findings from the invalidation decision were then deployed in the infringement litigation to achieve an effect analogous to a prior art defense, enabling positive interplay between the two sets of proceedings. In addition, the innovative evidence formation strategy resolved well known difficulties in ascertaining technical facts in method patent infringement cases. The ultimate favorable result provides robust protection for the competitive edge of China's signature advantaged industry.
The case was handled by YAO Guanyang and WANG Xiao.
