Ten-Year Saga Ended at the SPC — Retrial Win for a U.S.–China Auto JV in a Utility-Model Patent Case

The client is the China joint-venture of a U.S. global automaker, accused by an individual patentee of infringing a utility-model patent covering a high-beam electronic controller through one of its vehicle models. Beginning in 2007, the same plaintiff repeatedly filed and withdrew lawsuits on the same patent and same set of evidence at the Beijing No. 1 Intermediate Court, Beijing High People's Court, and Beijing No. 2 Intermediate Court — four separate filings in all. In two of those prior cases, the court commissioned judicial appraisal of the accused product; both appraisals concluded "neither identical nor equivalent infringement," and the plaintiff withdrew each time.

In 2015, the plaintiff filed a fifth time at the Beijing IP Court on the same facts and the same evidence. After years of being repeatedly drawn into litigation and substantial sunk cost, the client retained Kangrui to handle this case.

First, on the systemic level, we drew a clear procedural distinction between the two prior appraisals: the court-commissioned appraisal in the prior case had been performed on a different vehicle model than the present accused product, and thus could not serve as the basis for technical comparison here. The plaintiff-commissioned appraisal, by contrast, was accepted by both parties and could serve as a reference for technical-solution comparison.

Second, on the accused technical solution's "delay function" and other key features, we showed that the implementation manner involved is general knowledge in the field and is not limited to the specific embodiments disclosed in the asserted patent; that functional features must also be limited by their connection relationships with other components — and these connection relationships did not appear in the accused technical solution.

Finally, we made clear to the court the proper application level of the doctrine of equivalents: it is "feature-level equivalence", not "overall-solution equivalence". The plaintiff's combination of multiple components' functions into a holistic equivalence argument conflated technical solutions with technical features and was contrary to law.

This case set out a tiered, well-reasoned framework for selecting among judicial appraisal opinions in patent litigation (court-commissioned vs. party-commissioned), with implications for the development of adjudicative rules.

It has since been repeatedly cited at multiple court levels as a typical case on rules for using judicial appraisal opinions as evidence, and quoted in judge-training sessions and lectures. It also provides operational guidance on the scope of purely functional features and the proper level for applying the doctrine of equivalents.