CHANG TSI
Insights
Over the past couple of years, substantive examination standards for Chinese invention patent applications have tightened considerably, and securing allowance has become harder across the board. The picture is even tougher for applications that have already been rejected and gone on to reexamination: it is widely understood in the profession that once an application is rejected for lack of inventive step, only a modest share of reexamination requests succeed in reversing that decision — and in some technical fields, the odds are lower still.
In other words, once an invention patent application is rejected for “lacking inventive step,” reversing that outcome on reexamination is difficult in the vast majority of cases. The difficulty increases further when the applicant insists on making no amendments to the claims at all during reexamination, relying purely on argument to persuade the examiner or the reexamination panel to change course. It's worth noting that Chang Tsi & Partners' patent team has long maintained a reexamination reversal rate significantly above the industry average — close to 50% — and that track record is part of why we take on these uphill battles with confidence.
Against this backdrop, we're pleased to share good news from a case we handled recently: without amending the claims during reexamination, and relying solely on inventive-step arguments in our request for reexamination, we persuaded the panel to reverse the original rejection. The client is a leading U.S. company in its industry.
After substantive examination — including a second Office Action — the examiner found that the claims lacked inventive step over the cited prior art under Article 22(3) of the Chinese Patent Law, and issued a rejection decision.
Rather than taking the more common route of narrowing the claims to sidestep the examiner's objections, our overseas patent team chose a different path. After thoroughly studying the rejection decision, the original application, and the cited references, we concluded that the examiner had misread both the technical problem the invention actually solves and the technical relationship between the cited reference and the application. We determined that the claimed solution did, in fact, involve an inventive step — and that it was worth fighting for on argument alone.
In the request for reexamination, our team built a complete line of reasoning across several layers:
(1) Reframing the technical problem the invention actually solves.
The rejection decision had defined the technical problem too broadly and too generically. We returned to the specification itself and, grounded in the invention's overall design intent, distilled a technical problem that more accurately captured the substance of the claimed solution — laying the foundation for the inventive-step argument that followed.
(2) Exposing the fundamental architectural difference between the cited reference and the application.
Rather than arguing at the level of whether an isolated feature was disclosed, we focused on a more fundamental point: the cited reference and the application adopt fundamentally different overall architectures. The reference integrates its components into a single, self-contained unit, whereas the application is built around two independent components that must be connected and coordinated with one another. Put simply, the reference's single-piece architecture has nothing to do with the connection-and-coordination issues that arise between the two separate structures in the application's two-piece architecture. Building on this fundamental architectural difference, we argued further that the reference's technical solution and inventive concept are, in fact, incompatible with the application: a person skilled in the art starting from the reference's disclosed concept would not be motivated toward the application's solution — and modifying the reference to arrive at that solution would actually run counter to the reference's own design logic.
(3) A feature-by-feature rebuttal of the examiner's claim-mapping.
Beyond the architecture-level argument, we also challenged the examiner's specific feature-by-feature mapping in detail. The examiner had found that the reference disclosed the features recited in our claims; we went back to the original text of the reference's specification, point by point, and showed that this finding did not hold up factually:
Conflating distinct concepts. For example, the reference described one physical or media-based transfer mechanism, while the claim recited a fundamentally different kind of information transmission. The two are simply not the same in nature, and one cannot be treated as encompassing or equivalent to the other — the examiner's finding of equivalence lacked a factual basis.
"Combining multiple features to match one" is not sound examination practice. The examiner had combined several features described separately across different embodiments in the reference and mapped them collectively onto a single feature in our claim. We showed that this approach doesn't hold up: each embodiment is a relatively independent, self-consistent technical solution, and artificially stitching together content from different embodiments to map onto one claim feature is inconsistent both with the reference's own technical logic and with the “separate comparison” principle set out in the Patent Examination Guidelines.
Combining this high-level architectural argument with granular, feature-by-feature rebuttal, we dismantled the factual basis for the examiner's “already disclosed” findings from two directions at once — leaving the rejection difficult to sustain on either factual or logical grounds.
(4) Emphasizing the integrated, synergistic nature of the claimed features.
We repeatedly stressed that the claimed features do not exist in isolation — they work together, and it is their coordinated interaction that produces the invention's technical effect. The examiner should have considered them as an organic whole, rather than breaking them apart into isolated features, which risks overlooking their combined function. We also demonstrated that the cited reference simply could not achieve the technical effect produced by the application's overall solution.
(5) Rebutting the “common knowledge” finding with evidence.
On the examiner's assertion that certain distinguishing features amounted to common knowledge in the field, we relied on the relevant provisions of the Examination Guidelines to show that these features were not routine technical means, and that there was no evidentiary support for treating them as common knowledge — and we called on the examiner to substantiate that position with evidence if it were to be maintained.
Following this multi-layered argument, the reexamination panel adopted our position and reversed the original rejection — without any amendment to the claims during reexamination. The applicant secured exactly the scope of protection it had originally sought.
This outcome reflects our team's deep technical understanding of the invention, a precise read of the examiner's reasoning, and a strategy that combined big-picture architectural argument with granular, evidence-level rebuttal — challenging the fundamental differences in architecture and technical problem on one hand, while leaving no factual detail unexamined on the other. In a climate where allowance rates are trending downward and reexamination reversals are increasingly hard to secure, a win of this kind — achieved without narrowing the scope of protection — is especially valuable to clients. It's also a reminder that, when facing an inventive-step rejection, a thorough and precise argument can often protect an applicant's core interests more effectively than a forced claim amendment.
Chang Tsi & Partners has been a leading force in China's IP landscape for over two decades, and is recognized as one of the country's premier full-service IP firms for both prosecution and litigation. Our overseas Mechanical & Electrical patent team provides clients around the world with full-cycle support — from filing and Office Action responses through reexamination and invalidation — and has built deep, hands-on experience handling high-difficulty matters such as inventive-step rejections and reexamination arguments, with a success rate that consistently outperforms the industry average. Behind every reexamination win is a team that has dug deep into the technology, read the examiner's reasoning precisely, and stayed firmly focused on protecting the client's core interests. If you're facing a similar challenge at examination or reexamination, we welcome the opportunity to discuss the best strategy for your case.
