Who Is an Inventor—and of What?: Claims, Disclosure, and Inventorship in the United States, Europe, South Korea, China, and Japan

Executive Summary: This article examines how the meaning of “inventor” differs across the United States, Europe, South Korea, China, and Japan, focusing on whether inventorship is determined by the inventions claimed or by everything described in the application. It distinguishes the legally relevant object of the inquiry from the evidence used to identify its creators: claims may define the invention, while the specification, drawings, prior art, and development record reveal what that invention means and who contributed to it. U.S. nonprovisional and Japanese practice are principally claim-centered, although U.S. provisional applications present an important disclosure-based exception. Korean law applies a substantial-creative-contribution standard, with claims serving as a practical reference point under a nonbinding KIPO practice account. China employs a solution-specific inquiry informed by the application and development record, so cancellation of a claim may not eliminate inventorship when the contributor’s work remains foundational to the retained solution. The EPC provides designation rules but no uniform substantive European standard. The article concludes that inventorship must be reassessed as claims evolve and determined separately for each application in a global patent family.

I. Introduction

Patent lawyers routinely speak of “the inventor” as though the term travels intact across borders. It does not. A single multinational research project can produce one technical disclosure, several sets of claims, and different legally correct inventor lists in different applications. The differences are not merely procedural. They reflect distinct answers to two questions: what kind of human contribution counts as invention, and to what legally relevant “invention” must that contribution relate?

Consider a recurring problem. Researcher A conceives the architecture of a new platform. Researcher X later devises an optional module. The patent specification describes both contributions in detail, but the pending claims ultimately cover only A’s architecture. Or perhaps the claims cover the platform in functional terms, and X’s module is one of the structures disclosed for performing that function. Or perhaps a claim directed expressly to X’s work is filed and later canceled, while a narrower claim remains that could not sensibly have been developed without X’s broader concept. Must X be named?

There is no universal answer. The central distinction is between the object of the inventorship inquiry and the evidence used to resolve it. The claims may identify the legally relevant invention, while the specification, drawings, prior art, and development record may show what that invention means and who created it. This article compares how the five systems assign those roles and applies their approaches to the recurring case in which X’s contribution is described but not claimed.

The practical lesson is simple but consequential: inventorship should not be copied mechanically from a laboratory roster, an invention disclosure form, a priority application, or another member of the patent family. It must be analyzed application by application, with the claims, disclosure, and governing jurisdiction each assigned the role local law gives them.

II. Inventorship Is Not Authorship, Employment, or Ownership

Despite their differences, the systems considered here share substantial common ground. Inventorship is a status arising from creative participation in making an invention. It is not a reward for seniority, funding, project management, careful documentation, or the volume of text a person contributed to a patent specification. Nor is it synonymous with ownership. An employer, university, or assignee may own the right to apply for or hold a patent without having invented anything. Conversely, an employee may be an inventor even when local law or contract places the economic rights elsewhere.

U.S. law illustrates the distinction sharply. The “threshold question” is who conceived the invention; a person who merely reduces another’s completed conception to practice ordinarily is not an inventor. Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1376 (Fed. Cir. 1986). Joint inventors need not contribute equally, work together physically, or contribute to every claim, but each must make a legally significant contribution to the conception of at least one claimed invention; reduction to practice alone ordinarily is insufficient. 35 U.S.C. § 116(a) (2024); Pannu v. Iolab Corp., 155 F.3d 1344, 1351 (Fed. Cir. 1998); Hybritech, 802 F.2d at 1376. Mere explanation of a desired result, ordinary skill, or work performed under another’s direction is insufficient. In re VerHoef, 888 F.3d 1362, 1366–67 (Fed. Cir. 2018).

The vocabulary differs elsewhere, but the boundary is recognizable. The Korean Supreme Court requires a substantial contribution to the creative act that produced the technical idea, excluding a person who merely supplied a general research objective, managed researchers, organized data, performed directed experiments, or supplied money and facilities. Daebeobwon [S. Ct.], Dec. 27, 2012, 2011Da67705, 67712 (S. Kor.). China defines an inventor as a person who makes a “creative contribution” to the “substantive features” of the invention-creation and excludes organizers, facilitators of material or technical conditions, and auxiliary workers. Implementing Regulations of the Patent Law of the People’s Republic of China art. 14 (promulgated by the State Council June 15, 2001, amended Dec. 11, 2023, effective Jan. 20, 2024) [hereinafter PRC Implementing Regulations]. Japanese courts ask whether the asserted inventor actually participated in the creative act that formed the invention’s technical idea, especially the characteristic solution to the technical problem. Tōkyō Chihō Saibansho [Tokyo Dist. Ct.], Jan. 22, 2018, 2015 (Wa) No. 25780 & 2017 (Wa) No. 13193, at 26 (Japan).

These tests also preserve the distinction between an inventor and an owner. Article 60(1) EPC provides that the right to a European patent belongs initially to the inventor or successor in title, while Article 60(3) directs the EPO to deem the applicant entitled for purposes of EPO proceedings. EPC art. 60(1), (3). Korean law similarly gives the inventor or successor the right to obtain the patent, and joint makers hold that right jointly. Patent Act, Act No. 950, Dec. 31, 1961, art. 33 (S. Kor.). China gives the inventor a personal right to be named even though the right to apply for and own a service invention may belong to the employer. Patent Law of the People’s Republic of China arts. 6, 16 (promulgated by the Standing Committee of the National People’s Congress Mar. 12, 1984, amended Oct. 17, 2020, effective June 1, 2021) [hereinafter PRC Patent Law].

The result is an important drafting discipline: do not ask who deserves credit in a colloquial sense. Ask who made the kind of creative contribution that the governing law connects to the invention for which patent rights are sought.

III. The Hidden Question: Inventor of Which “Invention”?

Most hard inventorship disputes contain an unspoken reference-point problem. Patent practice uses the word “invention” to describe at least four different objects.

First is the created invention: what one or more researchers actually conceived or developed. Second is the disclosed invention: the full body of technical teaching placed in the specification and drawings, which may contain alternatives, species, subcombinations, and possible future claim material. Third is the claimed invention: the subject matter for which legal protection is sought in the claims then under consideration. Fourth is the patented invention: the subject matter of the claims that survive to grant.

These objects often overlap at filing and then separate during prosecution. Claims may be added, restricted, divided, narrowed, or canceled. A broad genus may survive while a species claim disappears. An embodiment may remain in the specification solely as support for a later continuation or divisional. A functional limitation may derive its legally operative meaning from structures disclosed only in the description. The inventor list can therefore be correct on filing and wrong after amendment—or correct for a provisional application and wrong for a later nonprovisional.

Three propositions keep the analysis on track.

1.  Disclosure alone is not invariably enough. A person does not automatically become an inventor of every application merely because that person’s work appears somewhere in the specification.

2.  Claim-centered does not mean claim-text-only. Even where claims identify the relevant invention, the specification, drawings, prior art, and development record may reveal what the claims mean, where the inventive concept lies, and who contributed to it.

3.  Cancellation is not always erasure. In a strictly claim-based system, canceling the only claim to which a person contributed ordinarily removes that person from the inventive entity. In a more application-centered system, a canceled contribution may still support inventorship if it remains integral to the retained technical solution.

The distinction between object and evidence is especially useful. The object of the inquiry may be the claimed or patented technical solution; the evidence used to identify that solution and its creators may include the entire application and R&D record. Confusing those two roles produces both under-inventorship and over-inventorship.

IV.            A Comparative Snapshot

System	Primary reference point	If X’s distinct invention is only described and is outside every claim
United States	Each claimed invention in a nonprovisional application or patent; disclosed subject matter for a provisional	Ordinarily do not name X in the nonprovisional; reassess if a claim later reaches X’s contribution
EPC/EPO	Autonomous threshold and formal designation under the EPC; factual and entitlement disputes resolved outside the EPO’s designation review	No uniform claim-versus-disclosure answer; the EPO does not conduct a claim-by-contributor verification
South Korea	Substantial creative contribution under Korean Supreme Court law; claims are the practical reference point in a nonbinding KIPO practice account	Best practical view: ordinarily do not name X solely for a genuinely separate disclosure, although no cited Korean appellate decision squarely decides that hypothetical
China	Substantive features of the relevant patent technical solution, identified principally from the claims, specification, drawings, and development record	Better view: do not name X if truly separate; different result if X’s work remains foundational to retained claims
Japan	Technical idea delineated by the claims; specification used to identify the characteristic portion	Ordinarily do not name X solely because of disclosure

V.  United States: Inventorship Follows the Claims—But the Specification Still Matters

The United States asks a narrower question than who participated in the research project or whose work appears in the patent specification: who conceived the subject matter that the application claims? The Patent Act defines an “inventor” as the individual—or, for a joint invention, the individuals collectively—who invented or discovered “the subject matter of the invention.” 35 U.S.C. § 100(f) (2024). Its operative provisions then sharpen the reference point. An inventor’s oath or declaration concerns the person’s status as an original inventor or joint inventor “of a claimed invention,” and the statute permits joint inventors to apply together even though each did not contribute to every claim. Id. §§ 115(a), 116(a). The implementing rules likewise require every named inventor of a nonprovisional application to have contributed to at least one claim. 37 C.F.R. §§ 1.41(a), 1.45(c) (2025).

The substantive touchstone is conception. Conception is the formation in the inventor’s mind of a definite and permanent idea of the complete and operative invention, including every feature of the subject matter sought to be patented. Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1376 (Fed. Cir. 1986). An inventor need not personally build or test the invention, and carrying out another’s instructions ordinarily does not create inventorship. Burroughs Wellcome Co. v. Barr Laboratories, Inc., 40 F.3d 1223, 1227–28 (Fed. Cir. 1994). For joint inventorship, a person must contribute in a manner that is not insignificant in quality when measured against the full invention and must do more than explain well-known concepts. Pannu, 155 F.3d at 1351. Some collaboration or connection among the contributors is also required. Kimberly-Clark Corp. v. Procter & Gamble Distribution Co., 973 F.2d 911, 916–17 (Fed. Cir. 1992).

These principles make U.S. inventorship claim-by-claim, although the application ultimately carries one composite inventor list. A person need not contribute to every claim; a legally sufficient contribution to one claim is enough. Conversely, each person on the list must have contributed to at least one claim. The USPTO accordingly describes the “inventive entity for a particular application” as consisting of the people who each contributed to at least one claim. U.S. Patent & Trademark Office, Manual of Patent Examining Procedure §§ 2109(IV), 2109.01 (9th ed. rev. 01.2024) [hereinafter MPEP]. Different claims may therefore have different inventive entities even though the face of the application or patent presents their names together.

That rule supplies the presumptive answer to the article’s X hypothetical. If X conceived a technically complete alternative described in the specification, but X did not contribute to the conception of any pending claim, X ordinarily should not be named as an inventor of that nonprovisional application. Authorship of specification text, ownership of know-how, performance of experiments, and invention of disclosed—but unclaimed—subject matter are not by themselves inventorship of the claimed invention. The Court of Customs and Patent Appeals put the related point crisply: combination claims do not establish that the patentee invented separately unclaimed elements or subcombinations. In re DeBaun, 687 F.2d 459, 463 (C.C.P.A. 1982) (quoting In re Facius, 408 F.2d 1396, 1406 (C.C.P.A. 1969)); see also MPEP § 2109(I).

“Not separately claimed,” however, is not the same as “irrelevant to every claim.” The claims provide the legal reference point, but they are construed in light of the specification, and a claim may encompass a contributor’s technical teaching without reciting a separate dependent claim devoted to it. Ethicon, Inc. v. U.S. Surgical Corp., 135 F.3d 1456, 1460–64 (Fed. Cir. 1998), illustrates the distinction. An electronics technician devised one of two structures disclosed in the specification for performing a function recited in a means-plus-function claim. Because the disclosed structures defined the claimed “means,” the technician was a joint inventor of that claim even though his structure was merely one alternative in the specification. Id. at 1460–64. The USPTO consequently states that a contributor of a disclosed means for a means-plus-function limitation is a joint inventor unless the contribution was only reduction to practice of another person’s broader concept. MPEP § 2109.01.

The broader conception principles can produce the same practical caution outside 35 U.S.C. § 112(f) (2024). A disclosed species, embodiment, experiment, or implementation may help establish who conceived a broader genus, combination, or method claim. But coverage alone is not enough: the fact that a broad claim reads on X’s embodiment does not necessarily prove that X helped conceive the broader claimed invention. The inquiry remains what X contributed to conception, not whether the finished claim can be mapped after the fact onto X’s work. See Pannu, 155 F.3d at 1351; VerHoef, 888 F.3d at 1366–67. Counsel should therefore separate two questions: whether a claim encompasses X’s contribution and whether X’s contribution was part of the creative conception of that claimed subject matter.

A.  Claim Evolution and the Provisional Exception

Because the claims are the reference point, the correct U.S. inventor list can change without any change to the specification or the underlying history. If a newly added claim captures a contribution made by X, X may have to be added. If all claims to which X contributed are canceled, X may have to be removed, even though X’s work remains described. Section 116(c) authorizes correction in a pending application, and the USPTO requires correction when amendments leave a named person with no contribution to any remaining claim. 35 U.S.C. § 116(c) (2024); 37 C.F.R. § 1.48(a) (2025); MPEP § 602.09. After issuance, correction is governed principally by 35 U.S.C. § 256. 35 U.S.C. § 256 (2024).

The same specification may support applications having different inventor lists. A continuation directed to A’s architecture may properly omit X, while a later divisional claiming X’s alternative may have to name X. A continuing application generally needs at least one inventor in common with the earlier application to obtain the benefit of § 120, but the complete inventive entity need not be identical. 35 U.S.C. § 120 (2024); MPEP § 2109(VI). Inventorship should therefore be re-run against the claims of each application rather than copied mechanically across a family.

Provisional applications create an important qualification. A provisional need not contain any claim. 35 U.S.C. § 111(b)(2) (2024). Its inventorship analysis therefore focuses on the subject matter disclosed: each named inventor must have contributed, jointly or individually, to disclosed subject matter. 37 C.F.R. § 1.45(c) (2025). USPTO guidance further states that a provisional must name all inventors. U.S. Pat. & Trademark Off., Provisional Application for Patent, https://www.uspto.gov/patents/basics/apply/provisional-application (last visited July 13, 2026). If X invented a distinct alternative disclosed in a provisional, X ordinarily belongs on that provisional even if the later nonprovisional claims only A’s architecture and properly omits X.

That difference is not cosmetic. A later application obtains the benefit of a provisional only for subject matter adequately disclosed there and only when the statutory relationship between the filings is satisfied. 35 U.S.C. § 119(e)(1) (2024). The later filing must name at least one inventor or joint inventor named in the provisional. 37 C.F.R. § 1.78(a)(2) (2025); MPEP §§ 211, 211.01. The provisional and nonprovisional lists therefore may—and sometimes should—differ, but counsel should document why, confirm the required overlap, and conduct the priority analysis claim by claim.

VI.  The EPC and “Europe”: Formal Designation at the EPO, Substantive Disputes Elsewhere

“Europe” cannot be treated as a single substantive inventorship jurisdiction. The EPC establishes a common filing and grant system, but a granted European patent ordinarily takes effect through national rights, and inventorship and entitlement disputes implicate both the EPC and the law and institutions of the relevant states. The distinction is especially important for the claim-versus-disclosure question because the EPO does not perform the factual inquiry expected in U.S. practice.

The EPC begins with entitlement and attribution. The right to a European patent belongs to the inventor or the inventor’s successor in title, and special choice-of-law rules apply to employee inventions. EPC art. 60(1). The inventor has a right to be mentioned, and every European application must designate the inventor and, where the applicant is not the inventor, state the origin of the applicant’s right. Id. arts. 62, 81. The designation must identify a human inventor: the Legal Board of Appeal has held that a machine is not an inventor within the meaning of the EPC. Case J 0008/20, Designation of Inventor/DABUS, ¶¶ 4.3.1–4.3.9 (EPO Legal Bd. App. Dec. 21, 2021). A 2026 Technical Board decision reaffirmed both the requirement of a legally capable person and the formal nature of the EPO’s review. Case T 0528/25, Designation of Inventor/DABUS, ¶¶ 1.3–1.4 (EPO Tech. Bd. App. Feb. 5, 2026).

But the EPO does not decide whether the named person actually made the legally sufficient creative contribution. Rule 19(2) states that the Office “shall not verify the accuracy of the designation of the inventor.” EPC Implementing Regulations r. 19(2). The Office checks whether the filing identifies a person who can formally be an inventor and, if necessary, states a legally cognizable source of title; it does not weigh laboratory evidence or decide whether the designation is true. Case J 0008/20, Designation of Inventor/DABUS, ¶ 4.2.3. The Board has described “inventor” and “successor in title” as autonomous EPC notions, while recognizing that national law governs matters such as the validity of a transfer and that Article 60 itself directs employee-invention questions to national law. Id. ¶ 4.2.2; EPC art. 60(1).

This division of responsibility means that the EPC contains no EPO-administered, claim-by-claim attribution procedure parallel to U.S. practice. A formally compliant designation is not reexamined whenever claims change. That procedural fact should not be mistaken for a substantive rule that every contributor to the description is an inventor—or that claim amendments can never affect the correct answer. If the identity of the true inventor or the person entitled to the application is disputed, the issue is determined in the competent forum; a final decision recognizing another person’s entitlement can trigger the remedies in Article 61. EPC art. 61(1). The governing standard and remedies must therefore be checked for the relevant European right and forum rather than inferred from the EPO register.

A. The United Kingdom as a National-Law Illustration

United Kingdom law offers a useful, but expressly national, illustration. The Patents Act defines the inventor as the “actual deviser of the invention.” Patents Act 1977, c. 37, § 7(3) (U.K.). In Yeda, the House of Lords held that the first step is to identify the inventor or inventors “of the claimed invention.” The actual deviser is the natural person who came up with the inventive concept, and merely contributing an integer appearing in a claim is insufficient if that integer is not part of the inventive concept. A person seeking recognition as a joint inventor must show a contribution to “the inventive concept underlying the claimed invention.” Yeda Research & Development Co. v. Rhône-Poulenc Rorer International Holdings Inc., [2007] UKHL 43, [19]–[21] (appeal taken from Eng.).

Applied to X, the UK answer is broadly claim-centered but not claim-text-only. If X devised a separate alternative that remains in the description and lies outside the claimed invention, X ordinarily is not an inventor merely because readers can find X’s work in the patent. If, however, X’s disclosed embodiment helped formulate the inventive concept underlying a broad claim, X may be an inventor even without a claim directed exclusively to that embodiment. The specification, prior art, and development evidence are indispensable to identifying that inventive concept and its devisers; they are evidence and interpretive context, not an automatic application-wide roster.

Claim changes can accordingly change the substantive UK analysis even though the EPO will not police the change automatically. Under the Patents Act, unless the context otherwise requires, the relevant “invention” is the invention specified in a claim, interpreted in light of the description and drawings. Patents Act 1977, c. 37, § 125(1) (U.K.). The UKIPO Manual therefore recognizes that the claims may differ between the application and the patent and that a person may be entitled to be named as an inventor in the application but not in the patent. U.K. Intell. Prop. Off., Manual of Patent Practice ¶ 13.02 (Jan. 2026) [hereinafter UKIPO Manual]. Cancellation of the only claims embodying X’s inventive contribution may thus make X irrelevant to the surviving claimed invention. Conversely, a divisional pursuing X’s previously unclaimed alternative may require a different designation.

United Kingdom law supplies its own procedures for correcting inventor information. A person who should have been mentioned may apply to be mentioned under section 13(1) and rule 10(2), while a person who alleges that a named inventor should not have been mentioned may apply under section 13(3). Patents Act 1977, c. 37, § 13(1), (3) (U.K.); Patents Rules 2007, SI 2007/3291, r. 10(2) (U.K.). If a pre-grant amendment makes it no longer fitting for a person properly named in the published application to appear in the granted patent, the UKIPO directs the parties to submit the relevant facts and, where possible, the agreement of those affected; if the matter cannot be agreed, it may be resolved after grant under section 13(3). UKIPO Manual, supra, ¶ 13.18.1. For the European application itself, EPC Rule 21 supplies the EPO procedure for rectifying an incorrect designation, subject to the specified consent requirements. EPC Implementing Regulations r. 21(1).

The careful comparative conclusion is therefore twofold. First, the EPO’s acceptance of a name proves formal compliance, not substantive inventorship. Second, one should not promote the UK’s claimed-inventive-concept test into a universal “European” rule. For the hypothetical, the defensible practice is to analyze X under the law likely to govern entitlement or attribution, preserve evidence of X’s contribution, and revisit the designation whenever amendments or a divisional materially change the invention for which protection is sought. Other EPC contracting states may frame the substantive inventorship or entitlement inquiry differently, so the UK example illustrates rather than defines European practice.

VII. South Korea: Substantial Creative Contribution to the Invention Being Pursued

Korean patent law begins with a definition familiar throughout East Asia: an “invention” is the highly advanced creation of a technical idea utilizing the laws of nature. The person who makes that invention—or that person’s successor—is entitled to the patent; if two or more persons make it jointly, they are jointly entitled. A Korean application must identify the inventor and ordinarily includes a description and claims, although the claims may now be supplied after the initial filing. Patent Act, Act No. 950, Dec. 31, 1961, as amended by Act No. 21,134, Nov. 11, 2025, arts. 2(1), 33, 42, 42-2 (S. Kor.).

The controlling contribution standard comes from the Korean Supreme Court. It is not enough to supply a general research objective or basic idea; supervise researchers; organize data or perform experiments at another’s direction; provide money or equipment; or otherwise sponsor the work. An inventor must substantially participate in creating the technical idea—for example, by newly proposing, adding to, or supplementing a concrete conception that solves the technical problem; concretizing a new conception through experiments; or supplying concrete means, methods, advice, or direction that make the invention possible. Daebeobwon [S. Ct.], Dec. 27, 2012, 2011Da67705, 67712 (S. Kor.) (Patent Co-Ownership Confirmation & Transfer of Patent Registration). In an unpredictable field such as chemistry, experimental work may itself be inventive when a completed invention could not reasonably exist without experimental data and the person materially helped concretize and complete it. Id.

That test identifies the quality of the contribution, but it does not expressly adopt the U.S. rule that each inventor must contribute to at least one claim. Korean statutory law nevertheless gives the claims a central role in defining the invention for which protection is sought and ultimately conferred. The claims must be supported by the description and must state the structures, methods, functions, materials, or combinations needed to identify the invention; after grant, the scope of protection is determined by the claims. Patent Act arts. 42(4), 42(6), 97 (S. Kor.).

The Korean Supreme Court supplies the substantive contribution standard, and the Patent Act establishes the role of the claims. For the narrower practical question of how the inventor set should be reassessed as claims are added, deleted, amended, or divided, a KIPO-published study provides a useful operational account—not binding law and not the source of Korea’s substantive inventorship standard. The study distinguishes four possible objects of inventorship: every invention actually created, every invention disclosed in the specification, every invention claimed, and every invention ultimately patented. It reasons that the relevant inventor set may change when claims are added, deleted, or amended and when an application is divided. Cha-ho Jeong & Moon-wook Lee, Gongdong Balmyeongja Gyeoljeong Bangbeop Mit Gwanryeon Gwonriui Yeongu [A Study of Methods for Determining Joint Inventors and Related Rights], Jisikjaesan Nondan [Intellectual Property Forum], Jan. 2005, at 52, 54–56 (S. Kor.). The study gives a helpful example: if one person invented claim 1 and another invented claim 2, both may be inventors of the application; if claim 2 is deleted, the second person may cease to be an inventor of the invention still being pursued. Id. at 56. Korean law independently permits claim amendment, including addition and deletion within the originally disclosed matter, and permits an application containing two or more inventions to be divided into new applications. Patent Act arts. 47, 52 (S. Kor.).

Used in that limited operational sense, the study treats claims as the practical reference point, but the legal analysis is not confined to words appearing verbatim in a claim. Under the Supreme Court’s standard, a court may use the specification, drawings, experimental evidence, and development history to determine the technical problem, the claimed solution, when that solution became concrete, and who made the creative contribution. The Supreme Court’s chemical-invention rule makes that especially clear. A scientist whose experiments supplied indispensable data that completed a broadly claimed chemical or pharmaceutical solution may qualify even if the claim does not recite the scientist’s protocol. Conversely, routine execution of an already complete plan does not become inventorship merely because the resulting data appear in an example. See Daebeobwon [S. Ct.], Dec. 27, 2012, 2011Da67705, 67712 (S. Kor.).

No cited Korean Supreme Court decision squarely decides the fully separate, specification-only hypothetical. Applying the Supreme Court’s substantial-contribution standard, and using the KIPO study only as a nonbinding practice account, the better practical view is that X ordinarily need not be named solely because a genuinely separate invention appears in the description, provided X made no substantial creative contribution to the technical idea of any claim being pursued. The answer may change, however, if a broad claim covers both the principal embodiment and X’s alternative; if X’s embodiment supplies the concrete means by which a broadly expressed claimed function was completed; or if X’s experiments were necessary to make the claimed solution concrete. Coverage alone is not dispositive; X still must satisfy the substantial-contribution test. In those circumstances, “not separately claimed” does not mean “not part of the claimed invention.”

Because Korean applications may initially omit claims, the initial inventor designation sometimes must be made before the claim-centered analysis is final. Patent Act art. 42-2 (S. Kor.). The practical response is to identify the inventors of disclosed inventions reasonably expected to be claimed and repeat the analysis when claims are supplied, amended, allowed, or divided. A divisional is a new application and must identify its inventor. Patent Act arts. 42(1)(4), 52 (S. Kor.). If a later divisional claims X’s formerly unclaimed alternative, X should be evaluated—and, if the substantial-contribution test is met, designated—for that divisional. Counsel should not assume that every member of a Korean patent family necessarily has the same inventive entity.

VIII. Japan: The Claims Delimit the Technical Idea

Japanese law likewise defines an invention as a highly advanced creation of technical ideas utilizing the laws of nature. A person who makes an industrially applicable invention may obtain a patent for it, and the application must state the inventor’s name. Tokkyo-hō [Patent Act], Law No. 121 of 1959, arts. 2(1), 29(1), 36(1)(ii) (Japan). The statutory architecture is explicitly claim-centered: each claim must state all matters the applicant considers necessary to define the invention for which protection is sought, and the technical scope of a patented invention is determined from the claims. Id. arts. 36(5), 70(1).

Japan’s claim-centered approach is not claim-text-only. Article 70 directs that claim terms be interpreted in light of the description and drawings. Id. art. 70(2). Inventorship decisions follow the same structure. The claims delimit the technical idea under examination, while the specification and evidentiary record disclose the problem addressed, the means adopted, the invention’s effects, and the people responsible for conceiving and concretizing those means.

The Intellectual Property High Court stated the point directly in the Plastic Food Conveying Device case. An inventor is a person who completed the concrete technical means of the invention stated in the claims. Where several people participated, an inventor is one who creatively contributed to completing the invention’s “characteristic part”: the portion of the claimed combination not found in the prior art and underlying the invention’s distinctive means of solving its problem. Chizai Kōtō Saibansho [Intell. Prop. High Ct.], July 30, 2007, 2006 (Gyō-Ke) No. 10048, at 14–15 (Japan) (Plastic Food Conveying Device Case). The court did not isolate that characteristic part by reading the claims mechanically. It examined the specification’s account of the prior art, problem, solution, and effects and compared that account with drawings, communications, prototypes, and testing evidence. Id.

A later Tokyo District Court decision used an even more precise formulation. To be an inventor, a person must actually participate in the creative activity that renders concrete and objective—at a level a skilled person can practice—the portion of the technical idea that provides the invention’s distinctive solution. The court said that the relevant technical idea is bounded by the claims, then used the specification to identify the technical problem and the claimed structures that solved it. Tōkyō Chihō Saibansho [Tokyo Dist. Ct.], Jan. 22, 2018, 2015 (Wa) No. 25780 & 2017 (Wa) No. 13193, at 26–29 (Japan) (Ground-Improvement Device Case). It found joint inventorship where one group supplied the basic conception and another creatively transformed it into a workable structure; merely stating the goal would not have been enough. Id.

The Cancer Treatment Agent case demonstrates the converse and is particularly instructive for research-intensive inventions. The patent emerged from a chain of divisional applications and claimed cancer therapy using antibodies that blocked the PD-1/PD-L1 immunosuppressive signal. The claimant had performed experiments corresponding to examples in the specification and had proposed a combination of cells that became a starting point for one experiment. The Intellectual Property High Court nevertheless held that those activities did not make the claimant an inventor. The relevant technical idea was the discovery that blocking the PD-1/PD-L1 interaction with an anti-PD-L1 antibody activated antitumor immunity. Inventorship required creative participation in conceiving that idea or making it concrete; conducting individual experiments under direction, making ordinary adjustments, or suggesting a starting point without designing the inventive experimental program was insufficient. Chizai Kōtō Saibansho [Intell. Prop. High Ct.], Mar. 17, 2021, 2020 (Ne) No. 10052, at 35–38 (Japan) (Cancer Treatment Agent Case).

Although these decisions do not pose the specification-only hypothetical in precisely these terms, their claim-delimited formulation supplies a relatively clear answer for X. If X created an alternative device, compound, method, or use that is described but genuinely outside every pending or issued claim, X ordinarily is not an inventor of that application or patent merely because the alternative was disclosed. Authorship of the description and inventorship of the claimed technical idea are different inquiries. Nor is a person necessarily an inventor simply because that person performed the experiment reported as an example. See id.

Two cautions keep the answer from becoming mechanical. First, X need not have supplied language that appears literally in the claim. A broad claim may encompass X’s embodiment, and X’s work may have supplied or concretized the characteristic solution underlying that claim. Second, the characteristic part is identified by reading the claims with the description, drawings, prior art, and development evidence. A feature presented as one “embodiment” may therefore establish who completed the technical idea of a broader claim, even though no dependent claim singles out that embodiment. See Chizai Kōtō Saibansho [Intell. Prop. High Ct.], July 30, 2007, 2006 (Gyō-Ke) No. 10048, at 14–15 (Japan) (Plastic Food Conveying Device Case).

Claim evolution consequently matters. Japan permits amendment of the description, claims, and drawings within prescribed limits. Patent Act art. 17-2 (Japan). Because Article 44 treats a divisional as a new patent application and Article 36 requires an application to state the inventor, the substantive inventorship analysis should be performed for each divisional. Patent Act arts. 36(1)(ii), 44 (Japan). Parent and divisional applications may therefore properly have different inventor designations. If claims directed to X’s subject matter are removed from the parent but pursued in a divisional, the applications should be analyzed independently. Similarly, cancellation or narrowing of the only claim to which a person creatively contributed should trigger a renewed inventorship analysis. Neither claim cancellation nor narrowing automatically removes an inventor; the question remains whether that person creatively contributed to the technical idea of any surviving claim. The formal availability and timing of a correction should be addressed with Japanese prosecution counsel, but the substantive audit should occur whenever the legally relevant claimed technical idea changes.

IX. China: An Application-Wide Evidentiary Lens, but a Solution-Specific Inquiry

Chinese patent law does not reduce inventorship to a mechanical comparison between a person's contribution and the final claim language. Its statutory inquiry is whether a natural person made a creative contribution to the invention-creation's “substantive features.” The current Implementing Regulations state that an inventor or designer is a person who makes a creative contribution to the substantive features of the invention-creation; a person who merely organizes the work, facilitates the use of material or technical conditions, or performs other auxiliary work is not an inventor. PRC Implementing Regulations art. 14. The Patent Law separately gives an inventor the right to be identified as such in the patent documents and requires the request to state the inventor's name. PRC Patent Law arts. 16, 26.

Both Supreme People's Court judgments discussed below applied Article 13 of the 2010 Implementing Regulations because the applications predated the 2023 revision; the operative inventorship definition was carried forward without material change as current Article 14. In this section, “patent technical solution” means the technical solution reflected in a patent application or granted patent; it does not imply that grant is required.

That formulation leaves an important question: what is the “invention-creation” against which the contribution is measured? The Patent Law distinguishes between the specification and the claims. The specification must clearly and completely describe the invention, while the claims—supported by the specification—define the protection sought. PRC Patent Law art. 26. For infringement purposes, the claims define the patent's scope, with the specification and drawings available to interpret them. Id. art. 64. Neither provision, however, says that inventorship is established solely by finding a contributed limitation in a claim. Recent Supreme People's Court decisions instead point to a two-part approach: the object of the inquiry is the patent technical solution at issue, while the evidence used to identify that solution and its creators extends across the application documents and development history.

A.                 “Substantive Features” Are Not Merely the Patentable Delta

The Supreme People's Court's companion COVID-19 drug-use cases are the clearest illustration. Two university researchers proposed using an androgen-receptor antagonist, proxalutamide, to treat COVID-19 and participated in the ensuing research. The company later sought a patent on medical uses of the compound but did not name the researchers. During prosecution, after an examiner cited prior art, the company deleted claims covering treatment of COVID-19 generally and retained narrower claims directed to diseases caused by identified viral variants. (2023) Zui Gao Fa Zhi Min Zhong No. 2911 (Sup. People's Ct. Apr. 24, 2024) (China); companion case (2023) Zui Gao Fa Zhi Min Zhong No. 2912 (Sup. People's Ct. 2024) (China).

The court rejected that claim-deletion theory. It held that the “substantive features” relevant to inventorship are not necessarily identical to the features that distinguish a claim from cited prior art in the novelty or inventive-step analysis. Inventorship instead asks whether a particular natural person substantively participated in creating the relevant patent technical solution—how and to what extent that person participated, what role the person performed, and what technical contribution the person made. The determination should principally examine the relevant technical content of the patent application documents, especially the background technology, technical problem, purpose, beneficial effects, and specific embodiments, together with the other evidence concerning the invention's formation. Case No. 2911, (2023) Zui Gao Fa Zhi Min Zhong.

On the facts, the broader use of proxalutamide to treat COVID-19 was the premise and foundation for its use against particular variants; the two ideas were continuous and related. The specification and the applicant's prosecution submissions supported that relationship, and the researchers had also participated in related development work. Their contribution therefore remained part of the patent's substantive features even though the claims expressly directed to the broader use had been deleted. Id. The Patent Law's good-faith obligation reinforced the result: patent applications and the exercise of patent rights must conform to good faith, and applicants should identify inventors truthfully and completely. PRC Patent Law art. 20; Case No. 2911, (2023) Zui Gao Fa Zhi Min Zhong.

The case does not establish that every contributor to anything appearing in a specification is an inventor. It establishes a narrower—and more useful—rule: deletion of a claim does not erase a contribution when the contributed concept remains a foundation of, or has sufficient continuity and substantive connection with, the retained patent technical solution. Nor does an examiner's conclusion that a contributed feature is known in the prior art automatically defeat inventorship. Patentability and inventorship serve different purposes and pose different questions.

B.                 The 2025 Chip-Architecture Decision Confirms the Broader Evidentiary Inquiry

The Supreme People's Court reinforced that distinction in a judgment issued in October 2025 and published in June 2026. An engineer alleged that four chip-architecture patents had been derived from an architecture specification he created and uploaded to his employer's internal system. The patent documents and technical disclosure materials reproduced or closely tracked substantial parts of that earlier work, including diagrams and descriptions of the relevant problems and solutions. The listed first inventor claimed that some features were known and that the patents reflected independent improvements. (2025) Zui Gao Fa Zhi Min Zhong No. 491 (Sup. People's Ct. Oct. 27, 2025) (China).

The court began with the burden of proof: a person claiming inventorship must prove a creative contribution to the invention-creation's substantive features. It then reiterated that the principal reference materials are not the claims alone but the claims, specification, and drawings, with particular attention to the background, technical problem, purpose, beneficial effects, and specific embodiments. Comparing those materials with the engineer's timestamped architecture document, the court found the technical solutions overall highly consistent. It also held that inventorship is not coextensive with the inventive-step inquiry; the presence of known or conventional features in the source document or patents did not by itself resolve who had participated creatively in forming the patent technical solutions. Id. The court recognized the engineer as an inventor, rejected inventorship for a person who could not substantiate any creative contribution, and treated the misattribution as a serious violation of good faith. Id.

The decision matters for both doctrine and proof. Doctrinally, it confirms that Chinese courts identify the relevant patent technical solution from the claims, specification, drawings, and development evidence rather than isolating only the claim language that survived examination. Evidentially, it shows the importance of dated drafts, version-control records, internal submissions, technical disclosure forms, email, drawings, and testimony connecting an individual's work to the application. But the court repeatedly described the object of analysis as the patents' or applications' “technical solutions.” The relevant application materials provide the principal evidentiary lens; they do not convert every disclosed but unrelated idea into part of every patent technical solution.

C.                 What If X's Invention Is Described but Not Claimed?

Suppose X created an alternative technology described in the specification, but no pending or issued claim covers it. The answer should turn on the relationship between X's contribution and the technical solution for which inventorship is being determined.

If X's work is wholly collateral—a self-contained alternative that neither forms part of nor provides the problem, organizing concept, technical premise, or necessary foundation for the claimed solution—mere inclusion in the specification should not make X an inventor of that patent. Article 14 still demands a creative contribution to the substantive features of the relevant invention-creation; authorship of text, routine experiments, or assistance in preparing the application is insufficient. Neither Supreme People's Court decision discussed here holds that a person must be named solely because an unrelated invention appears somewhere in the specification.

The result may differ when X's exact embodiment is not claimed but X supplied the key problem, broader concept, architecture, or enabling technical path from which the claimed solution developed. The COVID-19 cases show that a contribution need not survive as a separately recited claim limitation if it remains foundational, continuous, and substantively related to the retained solution. The better shorthand is therefore neither “claims only” nor “disclosure as a whole.” Chinese doctrine applies an application-wide evidentiary inquiry to a solution-specific substantive question.

D.                 Claim Amendments and Divisionals

Inventorship should be reassessed when prosecution materially changes the technical solution being pursued, but deletion of claims should not trigger automatic deletion of inventors. Counsel should ask whether a person's contribution has truly become a separate, abandoned disclosure or remains part of the problem-solution chain underlying the surviving claims. The same analysis should be repeated when claims are added from the original disclosure. New matter cannot be introduced by amendment: amendments to an invention or utility-model application may not exceed the scope recorded in the original specification and claims. PRC Patent Law art. 33.

A divisional presents the converse problem. Chinese law permits division when an original application contains two or more inventions; a qualifying divisional retains the original filing date and, where applicable, the priority date, but cannot exceed the original disclosure. PRC Patent Law art. 31; PRC Implementing Regulations arts. 48–49. Because a divisional may pursue a different technical solution drawn from the common disclosure, its inventor list should be assessed independently rather than copied reflexively from the parent. If the divisional pursues X's previously unclaimed alternative and X creatively contributed to that alternative's substantive features, X ordinarily should be named for that divisional; contributors with no substantive relationship to the divisional's solution should not be carried over merely because they were named in the parent.

For multinational applicants, the practical lesson is straightforward. Maintain both a claim-contribution chart and a broader problem-solution development record. Revisit inventorship after significant amendments and before filing a divisional. Most importantly, do not import a rigid U.S.-style claim-by-claim deletion rule into the Chinese analysis. The Chinese cases require attention to what the relevant patent technical solution is, how it emerged, and whose creative work remains embodied in it—even when prosecution has changed the words and scope of the claims.

X. Testing the Rules Against the Recurring Variations

The comparative rules produce four practical checkpoints. A genuinely separate unclaimed embodiment ordinarily does not create inventorship in claim-centered systems and, on the better Chinese reading, does not do so merely by appearing in the specification. A disclosed embodiment may nonetheless establish inventorship when it defines or helps complete a broader claimed concept. Cancellation of the only relevant claim normally requires reassessment, but China’s COVID-19 cases show that cancellation does not necessarily extinguish a foundational contribution. A continuation or divisional directed to previously unclaimed subject matter requires its own inventor analysis. These are not exceptions to the jurisdictional rules; they are the recurring fact patterns in which the distinction between the legal object and the evidence becomes decisive.

XI. Conclusion

“Who is the inventor?” is an incomplete question. The complete inquiry is: who made the legally sufficient creative contribution, and what is the legally relevant invention to which that contribution must relate?

The United States expressly anchors nonprovisional inventorship to claimed inventions and treats provisional inventorship according to disclosed subject matter. Japan is claim-centered; Korean law, though not expressly claim-by-claim, supports a similar practical analysis of the technical idea being pursued. China uses the relevant technical content of the application and the development record to identify contributors to the patent technical solution and does not equate inventorship with the novelty-bearing residue of the final claims. The EPC requires a human-inventor designation but does not provide an EPO-administered merits determination; the governing national law must be consulted for substantive disputes.

For X, disclosure is neither automatically sufficient nor automatically irrelevant. In the United States and Japan—and, on the best reading, Korea—a genuinely separate embodiment outside every claim ordinarily does not support naming X. Under Chinese law, the same is likely true where X’s subject matter is genuinely unrelated to the relevant patent technical solution, but X may still qualify if the contribution remains foundational, continuous, and substantively connected to that solution. The EPC itself supplies no uniform claim-versus-disclosure answer. Whenever claims change, inventorship should be reassessed; the result need not change if the contribution remains legally connected to the surviving invention.

That is why inventorship is not a one-time formality. In a global portfolio, it is a living legal conclusion.