Infringement of Utility Model Patent for 'Mosquito Killer Bulb'

Civil Case

Utility Model Patent

–Defining Scope of Protection of Patent

[Headnotes]

To ascertain the reasonable scope of protection, claim terms should not be construed in isolation of the specific technical background but by the purpose of the invention, the technical problems it seeks to solve.

[Synopsis]

First Instance: (2017) Zhe 02 MinChu No. 700

Second Instance: (2018) ZheMinZhong No. 139

Appellants (Defendants in original instance): Wenzhou Sorbo Technology Co., Ltd. (Sorbo); Wenzhou Shengbo Technology Co., Ltd. (Shengbo)

Appellee (Plaintiff in original instance): Ningbo Dayang Industrial & Trade Co., Ltd. (Dayang)

Dayang, the owner of Patent No. ZL201520712890.9 for utility model patent of "Mosquito Killer Bulb", noticed Shengbo crowfunded for the infringing products on Jingdong.com, and Sorbo sold them on Taobao.com and Alibaba.com. It believed the making, selling and offering for sale by Sorbo and Shengbo were an infringement of its patent, and sued therefor, seeking injunction against Sorbo and Shengbo, and damages of 2 million Yuan plus cost for the litigation.

The court of the first instance found that the "USB plug" element in the infringing product was equivalent to the technical feature of claim 1 "the socket to connect with the bulb" and the alleged product therefore fell within the protective range of the patent. The court granted the injunction against Sorbo and Shengbo, and assessed damages of 1.5 million Yuan against Sorbo and 0.5 million Yuan against Shengbo, and dismissed other claims of Dayang.

The court of second instance opined that determination of whether the above element was equivalent should be made on the basis of ascertaining the technical feature of the "socket to connect with the bulb". According to the specification, "this invention seeks to solve a technical problem by providing a mosquito killer bulb with a function of killing mosquito that could be plugged directly into an existing socket in the conventional technology…. Compared with conventional technology, the mosquito killer bulb under this utility model may substitute an existing bulb on the existing power line without having to modify the power line or switch controls." To achieve the purpose of the patent, the technical features of "the socket to connect with the bulb" in claim 1 must be construed to be able to connect to an existing socket to achieve the purpose of replacement of the existing bulb with the mosquito killer bulb without making any modification of the original power line or switches. For this, the protective range of the patent may not include any technical solution that did not accommodate direct replacement of an existing bulb. The accused infringing product connected to outside power lines through USB plug and could not achieve the purposes of the patent at issue since the existing sockets were either Edison screw or bayonet plugs other than USB socket. The two different types of sockets worked in different ways with different functions and effects, and thereby constituted no equivalents. In sum, the accused infringing product did not fall within the protective range of the patent. Therefore, the decision was reversed and all Dayang's claims were dismissed by the second-instance court.

[Typical Significance]

In patent infringement cases, the exact ascertaining of the protective scope is premised on the finding of infringement. Although the inventive purpose delineated in the specification does not form any part of the claim, it plays a vital role in the interpretation of the claim, and may be used as a protective scope limitation. Interpretation of claim must square with the inventive purpose of the specification, and any subject matter that does not fit the inventive purpose of the specification should not be included in the claims; otherwise the patent protective scope would be improperly enlarged.