1. Literal infringement and equivalents
Patent protection is determined by the claims. Literal infringement occurs when the alleged product or process contains each and every claimed technical feature identically. If one or more features are not literally identical but are equivalent to the corresponding claimed features, infringement may also arise under the doctrine of equivalents.
2. The Supreme People’s Court’s 2001 provisions
Although the Patent Law did not expressly define the doctrine of equivalents, Chinese courts had applied it in judicial practice. Article 17 of the Supreme People’s Court’s 2001 Several Provisions on the Application of Law in the Trial of Patent Dispute Cases expressly addressed equivalents.
It explained the provision in Article 56(1) of the Patent Law that protection is determined by the claims, with the description and drawings used to interpret them. The protected scope included both the essential technical features expressly stated in the claims and their equivalents.
Equivalent features were described as features using substantially the same means, performing substantially the same function and producing substantially the same result as the claimed features, which a person skilled in the art could conceive without inventive effort.
3. The 2009 interpretation: disclosure, estoppel and all technical features
The Supreme People’s Court’s 2009 Interpretation on Several Issues Concerning the Application of Law in the Trial of Patent Infringement Disputes also contains rules affecting equivalents.
Article 5 excludes protection for a technical solution disclosed only in the description or drawings but not included in the claims. Article 6 addresses prosecution-history estoppel, restricting an attempt to recover through infringement litigation technical solutions surrendered by amendment or argument during grant or invalidation proceedings.
Article 7 requires comparison of all technical features of the asserted claim. A product or process falls within the protected scope if it contains technical features identical or equivalent to every claimed feature. If one or more features are missing, or a feature is neither identical nor equivalent, it falls outside that scope.
4. The Beijing High People’s Court’s 2001 opinions and their limits
The Beijing High People’s Court’s 2001 Opinions on Several Issues Concerning Patent Infringement Judgments (Trial Implementation) discussed equivalence in greater detail. Article 35 addressed substitution of specific technical features, including those in the preamble. Article 38 directed courts to compare corresponding features, rather than merely compare the overall technical solutions of the alleged infringement and the claim.
Those 2001 opinions also discussed intentional incomplete implementation, omission and inferior implementations. These discussions must be read subject to the Supreme People’s Court’s later 2009 all-features rule. An omitted feature or inferior implementation cannot be treated as equivalent infringement merely because the overall concept resembles the patented solution. Every claimed feature still requires an identical or equivalent counterpart.
Article 44 of the 2001 opinions gave estoppel priority where its application conflicted with equivalents. Article 37 used the time of infringement as the reference point for assessing equivalence.
The original Japanese-language article also contrasts the Japanese requirement that the differing portion not be an essential part of the patented invention. Chinese analysis does not depend on that classification alone: the corresponding features must satisfy the applicable equivalence requirements, subject to the all-features rule and estoppel.
Source for the 2009 interpretation: https://www.court.gov.cn/fabu/xiangqing/1.html
