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Tao CHEN
Wenhui ZHANG
Chinese Patent Attorney
 

I. Foreword

The scope of protection of a patent is defined by the contents of the claims which recite the technical features of the invention or utility model, including the constituent elements of the technical solution of the invention or utility model or the interrelationship between the elements. Technical features generally include structural features, method features, and the like. In addition, there is another kind of technical feature which is neither a structural feature nor a method feature, but a technical feature expressed in terms of function or effect, i.e., a functional feature. This paper will give a brief introduction to functional features.

II. Related Legal Provisions

What constitutes a functional feature is not clearly stipulated in the Patent Examination Guidelines. Article 8 of the Interpretation of the Supreme People’s Court on Several Issues Concerning the Application of Law in the Trial of Cases Involving Disputes over Infringement of Patent Rights (II) (hereinafter referred to as Judicial Interpretation II), which was published in 2016, defines a functional feature as follows:

“A functional feature refers to a technical feature in which the structures, compositions, steps, conditions or the relations therebetween are defined by their functions or the effects achieved in the invention-creation, except that a specific embodiment for achieving the above functions or effects can be directly and specifically determined by those of ordinary skill in the art only by reading the claims.” In practice, functional features are usually interpreted based on the above definition. However, they are construed differently in grant and confirmation of patents and proceedings concerning patent infringement.

The Patent Examination Guidelines provide in Section 3.2.1, Chapter 2, Part II that:

“Technical feature defined by function in a claim shall be construed as embracing all the implementations that are capable of performing the function.”

Therefore, in substantive examination, reexamination, and invalidation of applications for patents, functional features are broadly construed to cover all the implementations capable of performing the functions. Such construction still prevails in current judicial practice for the administrative litigations concerning the grant and confirmation of patents.

In proceedings concerning patent infringement, on the other hand, functional features are construed differently than in the grant and confirmation of patents.

Article 4 of the Interpretation of the Supreme People’s Court on Several Issues Concerning the Application of Law in the Trial of Cases Involving Disputes over Infringement of Patent Rights (I) (hereinafter referred to as Judicial Interpretation I), which was published in 2009, provides that:

“As for a technical feature defined by function or effect in a claim, when determining the content of such technical feature, the court shall consider the implementation(s) where such function or effect is recited in the specification and drawing(s) and the equivalent implementation(s) thereof.”

According to the above provisions of Judicial Interpretation I, in proceedings concerning infringement, the functional feature would not be construed to cover all implementations capable of performing the function, but rather its scope of protection is limited to the specific implementations of the function or effect depicted in the specification and the drawings and their equivalent.

In the second paragraph of Article 8 of Judicial Interpretation II, the infringement determination involving functional features is further stipulated as follows:

“Where comparing with a technical feature which is recited in the specification or drawings and is indispensable for achieving the function or effect referred to in the preceding paragraph, the corresponding technical feature of an accused infringing technical solution can perform the same function and achieve the same effect in substantially the same way, and that a person of ordinary skill in the art can think of the feature in the accused infringing technical solution without creative work at the time when the accused infringement act occurs, the people's court shall hold that the corresponding technical feature is identical to or is equivalent to the functional feature.”

According to the above provisions of Judicial Interpretation II, in determining whether the corresponding features of the accused infringing technical solution are identical or equal to the functional features, firstly, the technical features indispensable to the achievement of the function should be correctly summarized from the disclosure in the specification and the drawings, and then it is determined whether the corresponding technical features of the accused infringing technical solution, compared with the indispensable technical features, satisfy the requirement of “performing the same function and achieving the same effects with substantially the same means, and that a person of ordinary skill in the art can think of the features in the accused infringing technical solution without creative work at the time when the infringement act occurs”.

III. Case Study

According to the above judicial interpretations, in the infringement determination involving functional features, the following four issues need to be considered: firstly, for a technical feature in a claim that is defined by function or effect, there is often a controversy over whether it is a functional feature; secondly, there are also disagreements on how to properly conclude “technical features indispensable for achieving the function or effect”; thirdly, the “technical features indispensable for achieving the function or effect” are generally a combination of multiple technical features, and therefore, when it comes to the comparison between the corresponding features of the accused infringing technical solution and the “technical features indispensable for achieving the function or effect”, there is a dispute over whether the two types of features should be divided into multiple features for comparison or compared as a whole; and fourthly, in the comparison of the functional features, a determination should be made as to whether “the same function, the same effect” only refer to the effect of the functional features or the function and effect achievable by the “technical features indispensable for achieving the function or effect” should also be taken into consideration.

Regarding the above four issues, the Supreme People’s Court (hereinafter referred to as “SPC”) provides an explicit answer in the case (2018) SPC Civil Shen No. 2345.

In this case, the focus of dispute lies in whether the feature of the asserted patent, namely, “a rotation mechanism fixed between the first inner cover and the second inner cover, through which the first inner cover and the second inner cover are rotatably connected”, is a functional feature, and whether the accused infringing product possesses the same or equivalent feature as the said functional feature. The SPC’s views of whether the feature of the rotation mechanism is a functional feature are as follows:

“The Court is of the opinion that the determination of a functional feature, in addition to the specific manner in which the disputed feature is defined in the claims, should also focus on the function and effect it serves in the technical solution defined by the claims. On the basis of such function and effect, it should be determined whether a person of ordinary skill in the art can directly and clearly determine the specific implementation of such function and effect merely by reading the claims. If only the way in which the disputed feature is usually implemented in the art is taken into account, while ignoring the adaptive relationship between the feature and other technical features in the claim, and its consequent impact on the specific implementation for achieving the function and effect defined in the claim, it will be difficult to accurately determine whether the technical feature is a functional feature.

In the present case, with respect to the feature of the rotation mechanism, Claim 1 limits its position to ‘fixed between the first inner cover and the second inner cover,’ and its function to ‘the first inner cover and the second inner cover are rotationally connected by means of this rotation mechanism.’ However, Claim 1 does not further describe how the rotational connection between the two inner covers is realized by the rotation mechanism.

The section of ‘Background Technology’ in the specification of the patent in question states that: ‘The existing design of the foot platform on the balance bike is typically a board-like flat plate that always remains horizontal during use. This design does not allow for any relative rotation between the plates, making it impossible for users to control the balance bike solely with their feet.’

The asserted patent makes an improvement by providing different left and right inner cover structures and rotatably connecting the left and right inner covers through a rotation mechanism, thus realizing the relative rotation of the left and right sides of the electric balance vehicle. But it is not feasible for a person skilled in the art to directly and clearly conclude, merely by reading the claims, that the existing connection method could collaborate with the left and right inner cover structures in the asserted patent to realize the rotational connection of the left and right inner covers in Claim 1.

In this regard, the Decision on Examination of Request for Invalidation No. 36457 concerning the patent in question has made the following finding: ‘The inner cover structure in the present patent and the configuration that the left and right inner covers are relatively rotatable are closely interconnected and act in close coordination. Even if certain features exist in the prior art, it requires creative work to organically integrate them in a specific way to obtain a specific structure.’

In summary, the feature of the rotation mechanism of claim 1 of the asserted patent is a functional feature.”

As to whether the accused infringing product has the identical or equivalent technical features as those of the rotation mechanism, the SPC made the following statements:

“The Court is of the view that in determining whether the accused infringing product has a corresponding technical feature that is ‘identical or equivalent to’ the functional feature, attention should be given to the following issues:

Firstly, the specific content defined by the functional feature should be clarified. If multiple technical features are contained in the corresponding specific implementation of a functional feature recited in the specification and drawings, on the premise of satisfying the statutory conditions for grant of patents, such as 'sufficient disclosure' as stipulated in Article 26(3) of the Chinese Patent Law, the patentee usually would choose to recite only the technical features that are indispensable for the achievement of the function or effect of the functional feature in the specification and drawings, so as to obtain a broader scope of protection. Therefore, unless there are circumstances in which technical features are obviously not indispensable for the achievement of the function or effect defined by the claim, the specific content defined by the functional feature shall generally be determined in accordance with the specific implementation corresponding to the functional feature as depicted in the specification and the drawings.

Secondly, in determining whether ‘identical or equivalent’ feature is constituted, it is inappropriate to split the functional feature for comparison. In a technical solution of a claim, a functional feature may constitute the smallest technical unit for achieving a specific function and effect. In the comparison carried out for infringement evaluation, the specific implementation corresponding to the functional feature should be compared as a whole with the corresponding technical feature of the accused infringing technical solution. It is inappropriate to split the indispensable technical features in the specific implementation and individually compare them with the corresponding technical features of the accused infringing products.

Thirdly, regarding the basis for comparison of 'function' and 'effect', for the comparison involving a functional feature in infringement evaluation, in determining whether the corresponding technical feature of the accused infringing product can ‘perform the identical function’ and ‘achieve the identical effect’, the basis should be the function and effect defined by the functional feature recited in the claim, rather than the function and effect achieved by the technical features that are indispensable for achieving such function and effect as recited in the specification and the drawings.

In the present case, with regard to the feature of the rotation mechanism, according to paragraph 43 of the specification of the asserted patent, the content defined by the feature of the rotation mechanism in Claim 1 should recite as follows: ‘The rotation mechanism comprises a sleeve, two bearings and two circlips, wherein said sleeve is an axial hollow structure that allows a connecting line between the first inner cover and the second inner cover to pass through, and both the first inner cover and the second inner cover are rotatable relative to said sleeve. The bearings are fixed in the two sleeves and fixed to the inner covers by means of the circlips.’

In the accused infringing product, one end of the sleeve and the inner cover are fixed relative to each other by means of interference fit and pin riveting, while the other end is connected to the inner cover on the other side by means of fitting with the bearings and the circlips.

The Court held that Claim 1 of the asserted patent defines that the function of the feature of the rotation mechanism is to achieve ‘the rotational connection between the first inner cover and the second inner cover’, and the rotation mechanism in the accused infringing product also performs the same function. Whether both the inner covers are rotationally connected to the shaft is irrelevant to the function and effect of the rotation mechanism as defined in Claim 1, and does not prejudice the determination of ‘performing the same function’. The technical means employed by both of them as a whole are also not substantially different, thus constituting ‘equivalent’ technical features as stipulated in Article 8(2) of the Judicial Interpretation II of Patent Infringement. Company BOSUER claimed that the inner covers on both sides of the accused infringing product are both rotatably connected to the shaft, while in the asserted patent only the inner cover on one side is rotatably connected to the shaft. This difference is concluded by splitting the feature of the rotation mechanism and comparing it with the corresponding technical feature of the accused infringing product, which does not have a substantial impact on the overall equivalence between the feature of the rotation mechanism and the corresponding feature of the accused infringing product. Similarly, the differences in the quantity of circlips and the installation position are also concluded after further splitting the feature of the rotation mechanism and then making the comparison, which have no substantive impact on the equivalence determination of the functional feature of “rotation mechanism”.

This case is of great reference value for the drafting of patent application documents and the comparison involving function features in infringement evaluation.

Firstly, when drafting claims, it is important to be fully aware of the risk that features serving as an improvement might be identified as functional features. In the aforementioned case, as for the feature “a rotation mechanism fixed between the first inner cover and the second inner cover, through which the first inner cover and the second inner cover are rotatably connected” in Claim 1, generally speaking, most people would think that the rotation mechanism itself is very common, and it is the common knowledge in the art, and a person skilled in the art can directly and clearly determine the specific implementation for realizing the configuration that “the first inner cover and the second inner cover are rotatably connected by the rotation mechanism” by merely reading the claims, and therefore, the risk of the above feature being identified as a functional feature will likely be overlooked. From this case, it is evident that while the rotation mechanism is indeed common knowledge in the art, since this feature is one of the improvements of the patent over the prior art, the specific structure defined by this feature as a whole is not common knowledge in the art, and a person skilled in the art may not be able to directly and clearly determine the specific implementation by merely reading the claims.

Secondly, when drafting the application documents, it is important to provide more specific implementations in the specification for a feature that is likely to be identified as a functional feature. Additionally, it is recommended to briefly describe at least one of the implementations related to the feature. For example, in the aforementioned case, according to the textual disclosure in the specific implementations in the specification, the content of the feature of the rotation mechanism is determined as “The rotating mechanism comprises a sleeve, two bearings and two circlips, wherein said sleeve is an axial hollow structure that allows a connecting line between the first inner cover and the second inner cover to pass through, and both the first inner cover and the second inner cover are rotatable relative to said sleeve. The bearings are fixed in the two sleeves and fixed to the inner covers by means of the circlips”. If the specific implementations in the specification give a simpler description of the structure of the rotation mechanism by employing more examples, the finally-determined technical content of the functional feature will cover a broader scope.
Thirdly, in the comparison involving a functional feature, the aforementioned case explicitly reveals that the specific implementation corresponding to the functional feature should be seen as a whole to be compared with the corresponding feature of the accused infringing technical solution. It is inappropriate to split the indispensable technical features in the specific implementation and individually compare them with the corresponding technical features of the accused infringing product.

Fourthly, for the comparison involving a functional feature in infringement evaluation, in determining whether the corresponding technical feature of the accused infringing product can “perform the same function” and “achieve the same effect”, the determination should be based on the function and effect defined by the functional feature recited in the claim, rather than the function and effect achieved by the technical feature that is indispensable for achieving such function and effect as recited in the specification and the drawings. This shows that, for a functional feature, if the accused infringing product can perform the same function, then it is supposed to be able to achieve the same effect. The focus of the comparison carried for infringement evaluation lies in whether the technical means are substantially different and whether they are readily conceivable.

IV. Conclusion

Functional features are crucial for the scope of protection of patents, so a good grasp of the rules of comparison involving functional features for infringement evaluation is of great significance for innovators as well as patent attorneys. This paper briefly introduces the rules of comparison involving functional features for infringement evaluation based on the case ruled by the SPC. Should there be any comments or questions, please do not hesitate to let us know.