PATENT INFRINGEMENT DISPUTE OVER FUNCTIONAL LIMITATIONS

◆ First Instance Docket: (2014) SuZhongZhiMinChuZi No. 00311

◆ Second Instance Docket: (2016) SuMinZhong No. 291

CASE 4 :

Jiangsu Province

[Headnotes]

Plaintiff bears the burden of proof to show that a certain limitation in a claim is not “functional.” All limitations expressed in function or result are not “functional limitations” as described in Supreme People’s Court Judicial Interpretations: if a person having ordinary skill in the art (PHOSITA) may, upon reading the claim, directly and unambiguously derive a specific mode of application achieving the function or result (including by employing any specific mode depicted in a textbook or a reference material), such a limitation should not be considered as a functional limitation. A functional limitation expressed in functions or results should be limited to those modes of application known to a PHOSITA, rather than to be considered as covering all possible modes that can achieve the similar functions or results, unsettling the patent protection scope and the balance of technical contribution.

[Synopsis]

Appellant (Plaintiff below): SMC Corp.

Appellee (Defendant below): Suzhou Shannaisi Pneumatic Co., Ltd. (Shannaisi); SNS Pneumatic Co.,Ltd. (SNS) 

SMC is the patentee of patent No. ZL02130310.X for “Electromagnetic Valve” (the Patent), and of No. ZL02130309.6 for invention patent of “Cylindrical Antennae for Electromagnetic Valve.” It noticed in 2013 that Shannaisi sold several types of electromagnetic valves made and sold by SNS infringed its patents, and therefore filed suit with Suzhou Intermediate People’s Court seeking against Shannaisi and SNS injunction of manufacture and sale of the infringing product, and damages and reasonable fees against SNS in the amount of 1 million Yuan.

The Suzhou Intermediate Court at first instance found: the accused product, compared with claim 1, lacked the fixing iron core, but all the other elements matched the claimed limitations. Claim 1 of the Patent had a limitation of “said solenoid driving said valve core in the near or distant direction from said valve base,” which is expressed in the function to be achieved, and therefore a functional limitation; the accused product does not have the fixed iron core as does the Patent, but instead has the end wall of a magnetic cover as the fixed iron core, which is not a substitute that a PHOSITA may realize without inventive efforts, and therefore a different technical method falling outside the protective range of the Patent. For this, the Suzhou Intermediate Court after first instance trial decided: SMC’s complaint is dismissed.

Dissatisfied with the first instance decision, SMC filed appealed with Jiangsu Province High People’s Court, which vacated the decision below and ruled for injunction against SNS and Shannaisi, and awarded damages and reasonable fees against SNS for the amount of 150 thousand Yuan.

[Judge’s Comment]

Functional limitations have always been the hot and hard point in patent theoretical research and judicial practice. In this case, the court opined:

First and foremost, all limitations defined by function or result are not necessarily functional limitations. If a person having ordinary skill in the art, upon reading the claim alone, may directly and clearly ascertain a specific mode of application to achieve the function or result, the claim limitation should not be considered as a functional limitation.

Secondly, the limitation of “said solenoid driving said valve core in the near or distant direction from said valve base,” in the Patent described the correlative relationship among the valve core, the base and the solenoid, defining the core, under the control of the solenoid, to be close to or distant from the base, to achieve opening or closing of the electromagnetic valve. According to the information revealed in the new evidence introduced by SMC at second instance, the Encyclopedia of Electric Power of China, 2d Ed., regarding electromagnetic valve technology, it can be seen that the “electric coil” corresponds to the solenoid in the Patent, the “middle component” to the cord, and the “electric coil capable of magnetizing or demagnetizing at the command of operator or automatic device; the middle component being powered by magnetic core, in either way

of direct power or guided power” to “said solenoid driving said valve core in the near or distant direction from said valve base.” Since the Encyclopedia, 2d Ed. was a published book, and antedated the application date of the Patent, this information is supposed to be known the PHOSITA for purposes of claim interpretation in this case. Therefore, a person of skill in this art, upon reading the claim, would be clear about how “said solenoid driving said valve core in the near or distant direction from said valve base” was achieved, without further reference to the patent specification for assistance to derive specific modes of application.

Thirdly, in the accused device, the valve core is also driven by the solenoid to be close to or distant from the valve base, which is the same as the limitation of “said solenoid driving said valve core in the near or distant direction from said valve base.” Since all the other elements of the accused device match the claim limitations, under the “all element rule,” the accused device is entirely covered by the Patent. As previously stated, the limitation of “said solenoid driving said valve core in the near or distant direction from said valve base” is not confined to the modes disclosed in the specification, SNS’s argument that the accused device because of the absence of fixing iron core does not fall in the claim may not be sustained.

The second instance court gave detailed and specific instructions under the Judicial Interpretation regarding functional limitation standard, which survives the judicial test, and broadens the thinking and method for handling patent infringement cases, achieving satisfactory legal and social effect.