The "Broadest Reasonable Interpretation Rule" in China's Patent Invalidation Proceedings: What is "Calculating"?
China recently released the Judgment Digests of the Intellectual Property Court of the Supreme People's Court (2021), wherein the first decision, i.e., (2019) SPC IP Admin. Final 61, deals with how to implement the broadest reasonable interpretation rule for claim terms during the patent invalidation proceedings. In the decision, the Supreme Court pointed out: the People’s Court shall interpretate claim terms with the meanings as generally understood by a person skilled in the art after reading the claims, specification, and drawings. If the terms in the claims are clearly defined or described in the specification and drawings, they shall be so interpretated accordingly. Even when the so-called broadest reasonable interpretation rule is applied to the claims, “reasonable” interpretation should be used as the starting and concluding points within the broadest scope of the meaning of the claim terms.
The patent-in-issue is an invention patent (CN 201310072198.X) owned by Shanghai United Imaging Healthcare Co., Ltd., and relates to an image reconstruction method for echo-planar imaging sequence. The independent claim 1 is recited as follows:
1. An image reconstruction method for echo-planar imaging sequence, comprising:
obtaining echo-planar imaging data Si, and simultaneously acquiring three reference echo signals R1, R2 and R3 which are not phase encoded, said three reference echo signals are an even signal, an odd signal and an even signal respectively;
calculating, from said reference echo signals, parameters for correcting said echo-planar imaging data;
performing an one-dimensional Fourier transform on said echo-planar imaging data along a readout direction to obtain a transformed result FSi, and correcting FSi with said correction parameters to calculate corrected echo-planar imaging data;
performing an one-dimensional Fourier transform on the corrected echo-planar imaging data along a phase-encoding direction to obtain an image.
On November 30, 2016, Siemens (Shenzhen) Magnetic Resonance Co., Ltd. (“Siemens”) filed a request for invalidation against the patent-in-issue before the Patent Reexamination Board (hereinafter referred to as “the Board”). One of the reasons for invalidity was independent claim 1 of the patent-in-issue involved is not novel over D1 (DE19715113A1). The difference between the technical solutions of claim 1 and D1 is that the former calculates the parameters needed for correcting the echo-planar imaging data from three reference echo signals, whereas D1 uses an interpolated echo S2+ obtained from two reference echoes S1+ and S3+ of the same polarity for the subsequent correction. Therefore, whether the “calculating” in independent claim 1 covers the specific calculation method disclosed in D1, i.e., how to interpret “calculating,” directly determines whether independent claim 1 possesses novelty over D1.
In this regard, the Board interpreted the “calculating” in claim 1 in a restrictive manner as “directly calculating” based on the specification, and further found that the technical solution of claim 1 is different from the one of D1, and therefore claim 1 is novel.
However, during the appellate judicial review, the court of first instance did not support the finding of the Board. Firstly, the court of first instance pointed out that the “calculating” in claim 1 of the patent-in-issue had a clear meaning to a person skilled in the art, i.e., calculating an unknown quantity from a known quantity. Secondly, the court of first instance held that, under the “broadest reasonable interpretation rule,” as the present specification neither specifically defines “calculating” in claim 1 nor contains any expression related to “directly calculating,” “calculating” should be interpreted in the broadest sense, and such broadest interpretation should not go beyond a reasonable scope. Finally, the court of first instance held that the protection scope of claim 1 of the patent-in-issue covers all the methods of acquiring three reference echo signals of different polarities and using them to calculate the correction parameters. Since D1 also acquires three reference echo signals of different polarities and used them to calculate the correction data, D1 already discloses the aforesaid technical feature of claim 1. As a result, claim 1 does not possess novelty.
Nevertheless, in the second instance, the Supreme People’s Court reversed the finding of the court of first instance. The Supreme People’s Court first pointed out: the interpretation of the term “calculating” in this case should not simply be based on its literal meaning, but should be based on the understanding of a person skilled in the art after reading the claims, the specification, and the drawings; that is, the word “calculating” should be interpreted and explained in the light of the purpose of the invention, the specification, and the drawings of the patent-in-issue. The Supreme People’s Court held that since the patent-in-issue clearly states in the specification that the purpose of the invention is to overcome the defect of the prior art of losing phase information when calculating phase difference via two echo signals, the “calculating” in claim 1 of the patent-in-issue refers to direct calculation without losing phase information and other information. The Supreme People’s Court eventually determined that claim 1 possesses novelty on the ground that D1 does not disclose the “method of direct calculation without losing phase information and other information.”
When interpreting the scope of patent, whether the specific technical information that is not explicitly disclosed in the claims should be considered, or whether it should just make a narrower interpretation of the claim terms is one of the most controversial issues in patent invalidation cases.
As early as 2015, the Supreme People’s Court, in its decision (2014) Admin. Retrial No. 17, clearly put forward for the first time what is commonly regarded as the “broadest reasonable interpretation rule” in China’s patent invalidation proceedings. The decision involves a dispute over the invalidation of Patent No. 03123304.X. In this case, regarding the issue that whether claim 1 of the patent-in-issue possesses novelty, the dispute between the parties focused on how to interpret the term “current transformer prepared from full optical fiber” in claim 1.
The Board’s view was as follows: the specification of the patent shows that the patent-in-issue is an improvement to overcome the defect existing in the technical solution of the prior art which uses a speculum bonded to an end face of an optical fiber as a reflector. Therefore, the technical solution of the patent-in-issue should be deemed to have clearly excluded the use of a speculum as the reflector. Accordingly, the “full optical fiber” in claim 1 should be directed toward a full optical fiber structure in the optical fiber current sensing unit, which structure comprises a reflective film on the end face of the optical fiber as the reflector. On this basis, the Board found that since Exhibit 1 uses a mirror at the end of the optical fiber as the reflector, which has a different structure from the “full optical fiber” of the patent-in-issue, claim 1 possesses novelty.
The Board’s finding was upheld by the court of first instance and the court of appeal but was overturned by the Supreme People’s Court in the retrial proceeding. The Supreme People’s Court indicated:
“The specification does not describe the technical solution with ‘reflective film’ as background art, nor does it use the technical feature of ‘reflective film’ to specifically define the “current transformer prepared from full optical fiber” in claim 1. The relevant content in the specification can only explain that the present patent uses a method of coating the end face of the optical fiber with a reflective film in a further preferable embodiment corresponding to dependent claim 10, and it does not mean that the ‘current transformer prepared from full optical fiber’ in claim 1 has the specific meaning as described in the preferable embodiment. When Decision No. 14794 defines the ‘current transformer prepared from full optical fiber’ in claim 1, it adopts a restrictive interpretation by introducing additional technical features of its dependent claim and the content of the specification, which is an erroneous application of the law that shall be corrected by this Court.”
As it can be seen, in the 2014 decision, the Supreme People’s Court still refused to exclude a particular solution from the scope of the claim even when the specification explicitly states the particular solution is defective and believed that this practice is required under the “broadest reasonable interpretation rule” for claim interpretation in patent invalidation cases. However, in its 2019 decision, the Supreme People’s Court interpreted the scope of a claim by excluding the technical solution deemed defective in the specification, mainly based on the analysis about the defect of the prior art in the background section of the specification. As for how to apply the “broadest reasonable interpretation rule” in patent invalidation proceedings, we may only try to interpretate the changing rationality of the Supreme People’s Court according to the following statement in its 2019 decision: even when the so-called broadest reasonable interpretation is applied, “reasonable” interpretation should be used as the starting and concluding points within the broadest scope of the meaning of the claim terms.