In the 2023 Summary of Intellectual Property Court Judgments by the Supreme People’s Court, a range of cases were carefully chosen to shed light on the assessment of "further limitation" amendments in patent enforcement proceedings. While these summaries offer valuable insights, some areas still remain unclear. "Further limitation" refers to the act of narrowing a patent's scope by introducing additional technical features from other claims. This article aims to explore the legal framework surrounding such amendments, drawing from trial precedents dating back to 2017.

Ⅰ. Acceptance of "Further Limitation" Amendments Across Independent Claims

The practice of limiting technical features across independent claims, known as "further limitation" amendments, leads to the formation of new solutions. However, challenges arise during invalidation proceedings, such as incorporating one or more technical features from one independent claim into another independent claim. Despite this, authorities tend to support this approach. Invalidation decision No. 37563 reinforces that added features can come from any part of the patent, provided they meet Patent Law requirements.

Ⅱ. Independent Claims Prevail in Assessing Scope of Patent Protection Post-Amendment

In patent invalidation proceedings, the comparison between the scope of protection before and after amendment plays a pivotal role, often centering on whether to base it on independent or dependent claims. The Supreme People’s Court provided critical clarification through judgments (2019) Zui Gao Fa Zhi Xing Zhong No. 19  and (2020) Zui Gao Fa Zhi Xing Zhong No. 246 , stipulating that the comparison should rely on the independent claim, not the dependent claim. Once a patent is granted, it has a significant impact on the public, and their trust typically relies on the independent claims, which offer the broadest scope of protection. This legal precedent ensures consistency and precision in assessing the extent of protection granted by the original patent. The court's rulings underscore the importance of adhering to established legal principles and maintaining moderation when introducing new legal standards that could restrict certain types of amendments.

Ⅲ. Legal Interpretation of Amending Dependent Claims Alone in Patent Enforcement

The recent Supreme People’s Court decision (2021）Zui Gao Fa Zhi Xing Zhong No. 548 clarified the acceptance of amendments solely to dependent claims in patent enforcement procedures in some situation. This ruling departs from previous understandings, indicating that such amendments should be allowed even without modifications to independent claims as long as the scope of protection is narrowed, and the public can assume new scope based on the original scope.

Before this clarification, uncertainties persisted regarding the rules for further amendments, leading to ambiguity in enforcement. The Patent Reexamination Board attempted to address this with guidelines such as "Understanding and Application of 'Further Limitation of Claims." However, concerns lingered, particularly regarding whether solely amending dependent claims would narrow the scope of protection as required.

The court's decision brings clarity, emphasizing that the aim of further limitation amendments is to enhance flexibility for patentees without compromising public trust. While patentees aren't mandated to amend independent claims when further limiting claims, such amendments still contribute to narrowing the scope of protection.

Ⅳ. Legal Interpretation of Claim Amendments as a Whole

The question of whether claim amendments should be evaluated as a whole is not explicitly addressed in the Guidelines of Patent Examination. However, discussions by Reexamination Board members shed light on this issue. They emphasize considering the claims collectively, assessing compliance based on the entirety of the claim document. If any part of the amendments fails to meet regulations, the entire set of claims may be rejected.

This approach underscores the interconnectedness of claims, advocating for a comprehensive evaluation rather than isolated scrutiny. Failing to adopt this holistic perspective risks overlooking crucial contextual factors and may lead to missed deadlines.

In practice, ambiguity surrounding amendments like "further limitation" and "obvious error correction" poses challenges. Minor amendments within the claim text can jeopardize the acceptance of the entire amended claims. Patentees resort to preparing multiple versions, but their effectiveness remains uncertain due to the reason that collegial panels may only examine the final version.

For instance, in the case (2018) Jing 73 Xing Chu No. 7914, amendments resulted in new claims, with the court deeming them non-compliant. Despite attempts to rectify during the oral hearing, the acceptance of revised claims remained rejected.

Ultimately, the interpretation of whether amendments should be accepted or rejected as a whole involves balancing legal requirements with practical considerations, highlighting the complexities inherent in patent examination procedures.

In conclusion, recent Supreme Court decisions bring clarity to patent enforcement procedures. They confirm acceptance of "further limitation" amendments across independent claims and emphasize assessing scope based on independent, not dependent, claims. These rulings promote fairness and predictability. However, challenges remain in evaluating claim amendments as a whole, highlighting complexities in patent examination. We will discuss the other issues on patent amendments in Part II.

Author

Helen ZHANG

With over 10 years of experience in intellectual property, Helen is familiar with domestic intellectual property laws and regulations, particularly in patent litigation and invalidation. She handled over a hundred patent invalidation cases in mechanical engineering, optoelectronics, and chemistry. Helen has also been involved in nearly a hundred cases of patent administrative litigation and patent infringement litigation. Her clients included ZF Friedrichshafen AG, Swarovski, Taiwan Wonderland Group, Mitsubishi, Bose, and Norma. Before joining Peiwei Law, Helen was a senior lawyer in a well-known intellectual property agency in China and a law firm. She also served as an intellectual property manager in a photovoltaic group company. Contact Helen at helen.zhang@peiweilaw.com.

Suyuan WANG

Suyuan has over 8 years of experience in the intellectual property industry, specializing in patent search, investigation, and analysis, patent portfolio management, patent invalidation, handling international intellectual property and competition law litigation disputes, and other related work. He previously led various patent analysis reports and completed nearly a hundred cases of patent invalidation and administrative litigation. Before joining Peiwei Law, Suyuan worked at China Aviation Industry Corporation, Beijing IP Sunshine, and Hylands Law Firm. He holds a Bachelor's degree in Engineering and a Master's in Law. Contact Suyuan at suyuan.wang@peiweilaw.com.

* The article is prepared by the lawyers at Peiwei Law, a strategic alliance of PurpleVine IP in China. The article is authorized by Peiwei Law to publish on PurpleVine IP Group’s platform.