When you file a patent application and request examination, you may receive a “Notice of Reasons for Rejection” from an examiner at the Patent Office. To address this, you can file a “Statement of Reasons” or a “Statement of Amendment” to resolve the grounds for rejection. However, particularly when you receive a “Final Notice of Reasons for Rejection,” you must meet the very strict requirements of “limited reduction.”In this article, an intellectual property expert provides a clear explanation of the required timing, the three requirements, specific examples of what is acceptable and what is not, and the benefits of utilizing a patent attorney.
Key Points of This Article
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Some time after filing a patent application and requesting examination, you may receive a document from a Japan Patent Office examiner called a “Notice of Reasons for Rejection.” This notification states that “the application cannot be granted as a patent in its current form,” and it is a common process experienced by many applicants during patent examination. It is by no means rare.
Receiving a Notice of Reasons for Rejection does not mean you have to give up on obtaining a patent. By submitting an “Amendment”—which involves filing a “Statement of Views” to address the examiner’s concerns or a “Statement of Amendment” to modify the content of the claims—you can resolve the grounds for rejection and aim to obtain a patent.
However, you cannot make these amendments freely at any time. As the examination progresses, the rules for amendments become stricter, and particularly at the stage of receiving the “final notice of rejection,” you must meet the very strict requirement known as “limitation by narrowing.”
Critical Risk: If you make an incorrect amendment without knowing this rule, the amendment itself will be “rejected,” leading to the fatal consequence of the patent application being denied.
The strict requirement of limited reduction applies primarily to patent amendments made at the following stages:
When amending in response to the “Initial Notice of Rejection” received from the examiner, amendments can generally be made with relative freedom, provided that no new matters are added (i.e., matters not present in the original specification, etc.). Amendments that broaden the scope of the claims may also be permitted depending on the circumstances.
However, the “Final Notice of Rejection” is issued when new grounds for rejection arise as a result of that initial amendment. Amendments made at this stage are subject to strict restrictions, such as limited reduction.
Even if you submit a written opinion or an amendment in response to the Final Notice of Rejection, the examiner’s decision may not be overturned, and a “final rejection decision” (the final determination not to grant the patent) may be issued. If you disagree with this examination result, you can file a “trial against final rejection decision” with the Japan Patent Office to request a re-examination by three trial judges. Even when amending the claims simultaneously with this trial request, the rules regarding “limited narrowing” are strictly applied.
"Limited narrowing" (Patent Act, Article 17-2, Paragraph 5, Item 2) refers, as the term implies, to an amendment that "narrows (reduces) the scope of the claims (the scope for which rights are claimed under the patent)" in a limited manner.
Four Purposes of Amendments Permitted After the Final Notice of Reasons for Rejection
To avoid prior art and assert the patentability of an invention, the most commonly used method in practice is ② “limiting the scope of the claims.”
Why are such strict limitations imposed in the final stages of examination? The primary reasons are to “expedite patent examination” and to “reduce the examiner’s workload.”
Examiners have already completed their search for relevant prior art from documents worldwide during the initial stage. If an applicant were allowed to add entirely new elements or freely modify the invention into something different, examiners would have to restart the prior art search and examination from scratch, causing delays throughout the entire patent system.
For this reason, only limited amendments—specifically, “slightly narrowing the scope of protection to avoid prior art while maintaining the framework of the invention that has already been examined”—are permitted.
It is not the case that “any narrowing of the scope of protection will be recognized as a limited reduction.” To be recognized as lawful as a limited reduction, all three of the following requirements must be met simultaneously.
It is necessary to objectively narrow (reduce) the scope of protection by narrowing the concept of a claim element described in the pre-amended claim to a more specific, lower-level concept, or by serially adding a new claim element. Deleting part of an element or replacing it with an entirely different element is considered an “expansion of rights” or a “modification of the invention” and is not permitted.
As a result of narrowing the scope of protection through amendment, the “field of industrial application” and the “problem to be solved (objective)” must not change before and after the amendment. For example, an amendment to an invention of an engine part intended to address the problem of “improving automobile fuel efficiency” that, as a result of narrowing the elements, changes the part to one intended to address the problem of “improving the durability of ship propellers” will be rejected because it would require re-examination from a different perspective.Amendments must be limited to the extent that they effectively utilize the results of the examination conducted thus far.
When making amendments involving a limited narrowing, there is an important rule that the invention after the amendment must be capable of being patented on its own (i.e., it must possess novelty and inventive step) (the independent patentability requirement).Even if you “narrow the scope of protection just to follow the rules,” if the invention after narrowing is identical to existing prior art or is something that could be easily conceived, it will ultimately not be patentable. It is necessary to devise an amendment proposal that meets the formal requirements while also possessing substantive patentability.
Since some aspects may be difficult to understand through words alone, we will provide concrete explanations of lawful cases (OK examples) and unlawful cases (NG examples) of limited narrowing from a practical perspective.
[OK Examples] Amendments Recognized as Lawful Limited Narrowing
① Limitation through the sequential addition of components
Before amendment: “A device comprising component A and component B”
After amendment: “A device comprising parts A, B, and C”
→ A new component (Part C) is added to the existing configuration (A+B). Since infringement does not occur unless all elements are present, the scope of the covered products is narrowed (limited), making this a lawful amendment.
② Limitation from a broader concept to a narrower concept
Before amendment: “Apparatus comprising a metal housing”
After amendment: "Apparatus comprising a metal housing"
→ This is a typical limiting narrowing, restricting the scope from the broader concept of “metal” to the narrower concept of “aluminum” (*It is a prerequisite that the added content is described in the original application specifications, etc.).
[NG Example] Amendments Not Recognized as Lawful
① Deletion of a component (expansion of the scope of protection)
Before amendment: "A device comprising component A, component B, and component C"
After amendment: "A device comprising part A and part B" (part C deleted)
→ Since reducing the number of elements results in more products being included within the scope of the patent, this constitutes an “expansion of the scope of protection” and is therefore not permitted.
② Substitution of components (shift amendment)
Before amendment: "A device comprising a spring-based biasing means"
After amendment: "A device comprising a rubber biasing means"
→ Replacing the spring with rubber is not considered a narrowing of the scope of protection but rather a “shift” to a different technical feature, and therefore is not recognized as a limited reduction.
If the examiner determines that the procedural amendment submitted in response to the final notice of rejection does not meet the requirements for a limited narrowing, a severe penalty known as “rejection of the amendment (decision to reject the amendment)” will be imposed under the Patent Act.
If the amendment is rejected, the amendment submitted this time will be treated as if it had never been filed, and the examination will proceed based on the “state prior to the amendment (claims containing the last grounds for refusal).” Since the grounds for refusal that have already been pointed out remain unchanged, the examiner will issue a “notice of refusal” as is.
The chain reaction of amendment rejection: Violating the rule against limited narrowing follows a sequence of “Decision to Reject Amendment → Grounds for Rejection Remain Unresolved → Final Rejection,” which is a very serious risk that effectively leads directly to “failure to obtain a patent.”
Because the rules regarding limited reduction are extremely strict, you may face the dilemma where “attempting to avoid prior art forces you to relinquish the scope of rights you truly wanted for your business, resulting in a patent that is too narrow.”
In such cases, a powerful recovery tool is the “divisional application.” This is a procedure where you extract a portion of the inventions described in the specifications of the original application (parent application) and file it as a new, separate application (divisional application). Since the examination of the new divisional application is reset to the “initial stage,” it is freed from the strict amendment restrictions imposed in the final notice of reasons for rejection.
A multifaceted IP strategy is highly effective: in the original application, you can safely limit the scope to secure rights, while requesting separate examination via a divisional application for the broader scope of rights you truly seek or for rights covering different configurations.
"Limited narrowing" during the final stages of examination is subject to extremely specialized and strict legal rules. There is no end to cases where company representatives attempt to handle this in-house only to face failures such as "misunderstanding the rules and having the amendment rejected" or "unnecessarily narrowing the scope of rights too much to pass examination, resulting in a useless patent that can be easily circumvented by competitors."
① Accurately Interpreting the Examiner’s Intent
We conduct a detailed analysis of the logical structure of the Office Action and the cited references to accurately identify “what is being questioned and how to limit the claims to increase the likelihood of grant.”
② Drafting the Optimal Amendment
We craft a perfect compromise that meets all three criteria: “meeting strict requirements,” “demonstrating inventive step,” and “securing a broad scope of rights that is commercially viable.”
③ Proposing Advanced IP Strategies
We support clients with every possible means to secure a patent grant, including strategic use of “oral examinations” with examiners and “divisional applications.”
To obtain valuable patent rights that contribute to your business, engaging a "patent attorney"—a specialist in patents—is the most reliable choice.
"Limited narrowing" in patent amendments refers to a very strict set of amendment rules required at the time of the final notice of grounds for refusal or when filing a request for trial against a decision of refusal, in order to prevent a re-examination. If all three requirements—"serial narrowing of the scope of rights," "identity of the industrial field of application and the technical problem," and "fulfillment of the requirements for an independent claim"—are not met, there is a significant risk of proceeding from "rejection of the amendment" to a "decision of refusal."
During the intermediate processing stage (the latter half of the examination process), where interactions with the Japan Patent Office become increasingly complex, advanced specialized knowledge and strategic judgment are essential. A single misjudgment could render all the research and development costs and application fees spent up to that point a waste.
“I’ve received the final notice of grounds for refusal but don’t know how to respond,” “I’m unsure whether our proposed amendments are legally valid as a limited reduction,” “I’m dissatisfied with another firm’s approach and want a second opinion”—if you have concerns like these, please consult us before it’s too late.
At EVORIX Intellectual Property Office, we flexibly accept cases transferred from other firms at any stage of the process (including handling from the intermediate stage). Our experienced patent attorneys will propose the optimal amendment strategy to secure a patent grant, based on a thorough understanding of your company’s invention and business model. We are currently offering free initial consultations.
AUTHOR / Writer
Takefumi Sugiura
Representative Patent Attorney, EVORIX Intellectual Property Office
We support clients across a wide range of industries—including IT, manufacturing, startups, fashion, and healthcare—from patent, trademark, design, and copyright applications through to trials and infringement litigation. We are also well-versed in intellectual property strategies for cutting-edge fields such as AI, IoT, Web3, and FinTech. Member of multiple organizations, including the Japan Patent Attorneys Association, the Asian Patent Attorneys Association (APAA), and the Japan Trademark Association (JTA).