In recent days, regarding the case brought by Beijing Xianxing New Mechanical & Electrical Technology Co., Ltd. (“Xianxing” for short) against Guangzhou Zhiguang Electric Holdings Co., Ltd. (“Zhiguang” for short) for infringement on invention patent, Guangdong Higher People’s Court made the second-instance judgment and Zhiguang won in the final instance.
In last July, Xianxing, the patentee of the Chinese invention patent ZL. 95119585.9, filed a lawsuit with Guangzhou Intermediate People’s Court, alleging that Zhiguang manufacturing, selling and offering for sale ZINVERT-series high-voltage infringed upon its invention patent, and demanded compensation up to 15,000,000 Yuan. Guangzhou Intermediate People’s Court heard this case in last November. Two attorneys-at-law of our firm, entrusted by Zhiguang, appeared before the court as representatives and defended for non-infringement.
In the first-instance court session, the controversy between the plaintiff and the defendant focused on how to interpret the protection scope of the claims. The plaintiff alleged that, claim 1 of the patent involved in this case seeks to protect a high-voltage electric power conversion method, which can convert an input alternating current or direct current into a high-voltage direct current, pulsed direct current or alternating current output, and said claim covers in essence six technical solutions; the defendant’s product with alternating current as its input and alternating current as its output is one of the six technical solutions and thus falls into the protection scope of the patent involved in this case. The defendant defended, in the opinion that the technical solution of claim 1 should not be understood as six technical solutions, and alleged that the solution in claim 1 actually indicate that the high-voltage electric power conversion method can process different inputs and outputs and is one overall technical solution in effect; the defendant’s product only processes one input and one output and thus does not fall into the protection scope of the claim. The defendant further showed as evidence the same determination in the examination decision of the request for invalidation regarding the present patent made by Patent Reexamination Board (hereinafter referred to as PRB) in 2006.
Guangzhou Intermediate People’s Court, which had successively heard this case twice, made the first-instance judgment in this April, holding that the protection scope of the patent involved in this case is not the six technical solutions but a multi-functional technical solution for realizing six functions and thus the method used by the defendant’s product does not fall into the protection scope of the patent. The Court rejected all litigious claims by the plaintiff.
Dissatisfied with the first-instance judgment, Xianxing appealed to Guangdong Higher People’s Court. Guangdong Higher People’s Court received the appeal of Xianxing and made a trial. Two attorneys-at-law of our firm resumed to be entrusted by Zhiguang as representatives in the second instance, and stuck to the viewpoints held in the first instance during the trial. Guangdong Higher People’s Court made the second-instance judgment in this July, upheld the previous judgment and rejected the appeal of Xianxing.
The above-identified case is a typical case in which a court makes adjudication by applying the principle of prosecution history estoppel after the Supreme People’s Court promulgated, on December 28, 2009, “Interpretation on Several Issues Concerning the Application of Laws in the Trial of Cases of Patent Infringement Disputes” (hereinafter referred to as Interpretation).
As Rule 6 of the Interpretation prescribed, as for the technical solution which is abandoned by the patent applicant or patentee in the procedures of grant of patent right or in the invalidation procedures through making amendments to the claims or the description or making the observation(s), where the right holder incorporates the said technical solution in the protection scope of the patent right in the cases of patent infringement disputes, the court shall not support it. The above-mentioned provisions are namely the embodiment of the principle of prosecution history estoppel.
In the second-instance judgment made by Guangdong Higher People’s Court, Rule 3 of the Interpretation, which provides making interpretation of the scope of the claims using the description, was applied first, and then the principle of prosecution history estoppel was applied to further strengthen the basis of judgment.
In the court verdict, the collegial panel made the following judgment: “… the above-mentioned interpretation is also supported by PRB in the examination decision No. 9402 of the request for invalidation relating to the present patent. In the decision No. 9402, PRB holds that the method of the present patent should be understood as one overall technical solution, which can process two inputs and may probably obtain three outputs respectively, and it does not generalize six technical solutions, and thus it is different in essence from the single-function technical solution of Reference 1 (U.S. Patent No.4, 674, 024). Claims 1 and 2 of the present patent are thereby upheld in the decision No. 9402. Thus, in the civil infringement litigation, the patentee cannot pull back to interpret claim 1 of the present patent as covering a single-function technical solution with a single input and a single output so as to enlarge its scope of protection”.
It is worth noting that, although the above-mentioned verdict does not directly apply Rule 6 of the Interpretation, the principle of prosecution history estoppel is explicitly applied. In this case, the interpretation of the claims becomes a controversial focus of the whole case, and the application of the principle of prosecution history estoppel decides the ultimate result of this case.
In the determination of patent infringement, the principle of prosecution history estoppel is always a significant principle, but it is a pity that this principle has not been explicitly stipulated in the Patent Law, Implementing Regulations of the Patent Law or judicial interpretations promulgated by the Supreme People’s Court during so many years, but is only mentioned in the document promulgated by Beijing Higher People’s Court in 2001. Thus, in the judicial practice over the years, the principle of prosecution history estoppel can only function as a legal principle but not a legal rule. The legal principle, due to its high generality and abstraction, is applied with a priority lower than that of the legal rule, and its application also falls under many restrictions and dilemmas compared with the application of the legal rule. For example, a judge has a great discretionary power in the practice when applying a legal principle, causing inconsistent standards in its application; for another example, the legality of the legal principle quoted as an effective legal norm is liable to be doubted, etc. Thus, the applicability of the legal principle in the whole judicial practice stands in an awkward position.
The promulgation of the Interpretation by the Supreme People’s Court has just made up the deficiency such that the principle of prosecution history estoppel becomes an explicitly stipulated legal rule from a legal principle, and the Interpretation specifically indicates the condition, subject and object of the application of the principle of prosecution history estoppel, thereby providing more explicit guidance for the future judicial practice. It can be predicted that the promulgation of the Interpretation will exert an in-depth influence on the judgement of patent infringement in the future.
