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China IP Magaziine




◆ First Instance Docket: (2015) ShenZhongFaZhiMinChuZi No. 1043

CASE 8 :

City of Shenzhen


Patent law imposes estoppel whereby a patentee is estopped from asserting protective range in litigation that has been excluded from the protective range during patent prosecution or invalidation through amendments or statements, and on top of that, an exception is added for clear denial to the estoppel. A functional limitation defined by mode of application or equivalents thereof in the specification or accompanying drawings should be narrowly interpreted, on a different footing from the Doctrine of Equivalents in patent infringement comparison of structural limitations.


Plaintiff: Philips Quality Life Co., Ltd. (Philips)

Defendants: Yuyao WeiFeng Electronics Co., Ltd. (WeiFeng); Cixi ZhaoFeng Appliance Co., Ltd. (ZhaoFeng); Shenzhen YiRan Home Applicances Co., Ltd. (YiRan)

Plaintiff Philips obtained an exclusive license for the patent at issue, and is authorized by the patentee to take legal actions against patent infringement for compensation, for which the patentee relinquishes all rights to sue. Philips purchased from JingDong internet e-platform, Shanben Specialty Store, a “Shanben Air Frying Pan (Model S B-001)” on which it has the registered trademark “ 山本SHANBEN.” Plaintiff contends that the accused device has a round circular projection at the bottom, which constitutes an equivalent of the patent claims 1, 9 and the limitations of F and G of claim 10 in combination of drawing Fig. 1 for “Air Conduction Component” in the patent specification, falling thereby in the protective range of the patent. Thus, it sued in Shenzhen Intermediate People’s Court for infringement of its patent.

The court at first instance found: the accused device lacks at least one or more elements for the claim limitations, and therefore cannot constitute infringement by equivalency. The court dismissed Philips complaint.

[Judge’s Comment]

The two defendants contended that the patentee made a statement in the invalidation proceedings further defining the location of heat radiation device, leading to a subject matter without placing heat radiation above the food chamber, and is therefore estopped from claiming so. The court clarified at first instance that the patentee made further limitation in response to challenges in prosecution proceedings, once accepted, shall result in estoppel. According to Supreme People’s Court Interpretation of Several Issues of Law Applicable in Patent Infringement Disputes (II)(“Interpretation (II)”), Article 13, estoppel does not apply to patentee due to above statement.

Interpretation of functional limitations and the estoppel (relinquishment of subject matter) are the tough spot in the trial of patent infringement. In the present case, useful exploration was made on how to determine functional limitation and the protection range therefor:

1. The judicial opinion of this case accurately understood and applied laws of civil proceedings and the judicial interpretations. The estoppel set up by the Patent Law mandates that by setting up the estoppel from asserting as protective range whatis abandoned by amendment or statement in the patent prosecution or invalidation proceedings, and on top of which, adds an exception to the estoppel for “clear denial.” In this case, Interpretation (II), Article 13, is further defined from legislative history and purpose, and analysis is made on “denial of limiting amendment or statement,” enhancing operability of the Article.

2. As to interpretation of functional limitations, this opinion following Interpretation (II) no longer uses the doctrine of “secondary equivalency,” i.e., the equivalents of a functional limitation are defined by the specific modes set forth in the specification and drawings, rather than all possible modes of application, to wit, once equivalency is “primarily” applied to the specific modes, the protective range of the functional limitation is defined. There is no second bite for further equivalency. 

This dispute over patent between Philips and Chinese small appliance enterprises is properly handled, with careful analysis and accurate determination of technical problems, achieving satisfactory social effect, providing practical guidance for similar future cases.