How to assess infringement of patents involving usage environment features

The concept of ‘usage environment feature’ was first introduced by the Supreme People’s Court (SPC) on 11 December 2012, in the retrial decision Min Ti No 1 pertaining to a patent infringement dispute between Shimano INC and Ningbo Sunrun Industry & Trade Co Ltd. The retrial decision defined a usage environment feature as “those technical features included in patent Claims for the purpose of describing the backgrounds or conditions under which the patented solution is used”. The court further elucidated that “the usage environment features having been written into Claims are the essential features of Claims, functioning as the limitation to the protection scope of Claims.”

The concept was later incorporated into the Interpretation (II) of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Cases Involving Patent Infringement Disputes, which became effective on 1 April 2016. Article 9 of this reads: “Where an alleged infringing technical solution cannot be applied in the usage environment as defined by the usage environment features included in the claims, people’s court shall ascertain that the alleged infringing technical solution does not fall within the scope of patent protection.” In other words, the interpretation specifies under what conditions the alleged infringing solution should be held not to fall within the patented scope, without elaborating on the circumstances in which patent infringement could be established.

In Shimano INC v Ningbo Sunrun Industry & Trade Co Ltd, the patent at issue sought to protect a bicycle rear shifter bracket, yet in Claim 1 the feature of the rear shifter and the bicycle frame were not structurally incorporated into the subject matter. Claim 1 reads:

“A bicycle rear shifter bracket for connecting a rear shifter (100) to a bicycle frame (50), wherein, the rear shifter has a bracket member (5), a support member (4) for supporting a chain guide device (3), and a pair of connecting members (6 & 7) for connecting the support member (4) and the bracket member (5), the bicycle frame has a connecting structure (14a) formed on a shifter mounting extension (14) of a rear fork end (51), the rear shifter bracket includes...”.

The feature of the rear shifter and the bicycle frame, which constitutes a use background for the subject matter and connects and works in coordination with the subject matter, amount to a usage environment feature.

In practice, the overly broad nature of the definition made it difficult to arrive at a universally applicable infringement assessment criterion. The Beijing High Court attempted to clarify it in Article 24 of its Guidelines for Patent Infringement Assessment (2017) as: “Different from the subject matter, usage environment features refer to technical features in a claim which are used to describe the background or conditions under which the invention or utility model applies and which are in connection or coordination with the technical solution.”

Still, the infringement assessment criteria remains ambiguous.

With this in mind, this article proposes that patent infringement should be determined on the basis that the accused infringer intends to use the infringing solution in question, in the manner as limited in the usage environment feature. We therefore set out the parameters to be considered as well as a proposed methodology for assessing infringement of patents involving usage environment features.

All Elements Rule still applies

The Supreme People’s Court has made it clear in its retrial decision and in the judicial interpretation that usage environment features limit scope of patent protection. The infringement assessment for usage environment features should follow the All Elements Rule. According to this an allegedly infringing device must be equal to, or equivalent with, each element of a claim in order to establish infringement, which is applicable to all claim features (established in Article 7 of the Interpretation I of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Cases Involving Patent Infringement Disputes (effective as of 1 January 2010)). This is based on the reasoning that usage environment features that have been written into claims, are treated indiscriminately in patent granting and invalidation procedures. In assessing the novelty or non-obviousness of a claim involving usage environment features, consideration must be given to whether such features have been disclosed or taught by prior art.

Actual intention to use matters

Should the infringement assessment be solely based on whether the accused infringing solution is technically applicable to the usage environment feature, it will significantly and unreasonably burden the public with an exorbitant duty of care. The infringement risk clearance, also known as freedom-to-operate (FTO) analysis, is time-consuming and costly.

To alleviate this duty of care, account may be taken of the actual intention to use (ie, the accused infringer must exhibit an actual intention to use the accused infringing solution in the manner stipulated in the usage environment feature). In the absence of an actual intention to use, even if the product of an accused infringer is technically applicable to the usage environment feature, the product would still be excluded from the patent’s scope of protection scope.

Other intention to use not an admissible non-infringement defence

If an accused infringer has other intentions of using this technical solution, this shall not be admitted as a non-infringement defence.

The principle specifically targets an accused infringing product with multiple usages. If an accused product could be used in several ways, and if one of these meets the limitations of the usage environment feature, and the accused infringer intends to employ the product in the same manner as the usage environment feature, infringement should be established. Thus, a practising entity ought to fulfil the risk clearance obligation to make sure that its intention does not conflict with another patent.


When drafting claims, patentees tend to use a smaller unit as the subject matter and include usage environment features for greater enforceability.

If a claim refers to a device or system as the subject matter, it is likely that it will be less enforceable in practice. With the increasing division of labour, a single patented subject matter is less likely to be manufactured or offered for sale by one entity. However, this would lead to the conundrum that, under the All Elements Rule, no infringement could be found if a cohort of entities jointly exploited the patented technology. Even if a patentee claimed that these entities should be held liable for contributory infringement, judicial practice dictates that a contributory infringement finding shall be based on the presence of direct infringement.

In contrast, a smaller unit claim with usage environment features can be easily enforced against a smaller unit such as a component. Once a patentee proves that the component is technically applicable to the usage environment feature and the accused infringer intended to exploit the component under the usage environment, it should be possible to establish infringement.

The remaining issue lies in inferring an accused infringer’s intention. A patentee may produce evidence to demonstrate the context in which the accused infringing product is being used, with the product’s user manual, characteristics and any applicable standards also be deployed to establish intention.

This is an insight article whose content has not been commissioned or written by the IAM editorial team, but which has been proofed and edited to run in accordance with the IAM style guide.

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