Open Decision Ledger · IP, data & telecommunications
Equivalence, the core technical idea, and common general knowledge
Supreme Court, Jan. 14, 2022, 2021Hu10589 (judgment)
No holding summary · checked against points at issue. The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Case name: 권리범위확인(특)
Official text on the National Law Information Center
Question
Where part of the claimed composition of a patented invention has been modified in the target invention, when is the target invention nevertheless equivalent to the claimed composition and within the scope of the patent, and how is it decided whether the two inventions share the same principle of solving the task, and whether their working effect is substantially identical when the core of the patented invention's technical idea was already public when the patent was filed?
Holding
A target invention with a modified element is still equivalent, and within the scope of the patent, unless there are special circumstances, where the two inventions share the same principle of solving the task, the modification still produces a working effect substantially identical to that of the patented invention, and the modification is one that a person with ordinary knowledge in the technical field could easily have conceived. Whether the principle of solving the task is the same is decided by asking, in substance, what the core of the technical idea is on which the means of solution peculiar to the patented invention rests, taking the description of the invention and the state of the art at the time of filing into account. Where that core was already public, or no different from something public, when the patent was filed, working effect is no longer assessed by whether the core is embodied in the target invention; it is assessed by comparing the individual functions or roles of the component at issue.
Points at issue, verbatim
확인대상 발명에서 특허발명의 청구범위에 기재된 구성 중 변경된 부분이 있는 경우, 확인대상 발명이 특허발명의 청구범위에 기재된 구성과 균등한 것으로서 특허발명의 권리범위에 속한다고 보기 위한 요건 및 여기서 ‘양 발명에서 과제의 해결원리가 동일’한지 판단하는 방법
Unofficial English translation
Where there is a changed portion among the constituent elements recited in the claims of the patented invention in the invention subject to confirmation, the requirements for regarding the invention subject to confirmation as being equivalent to the constituent elements recited in the claims of the patented invention and thus falling within the scope of the patented invention, and the method for determining here whether 'the principle of solving the problem in the two inventions is identical'
Disposition
Dismissed Stated in the decision
상고를 기각한다. 상고비용은 피고가 부담한다.
Unofficial English translation
The appeal is dismissed. The costs of the final appeal shall be borne by the defendant.
Form of the test
Elements stated Stated in the decision
양 발명에서 과제의 해결원리가 동일하고, 그러한 변경에 의하더라도 특허발명에서와 실질적으로 동일한 작용효과를 나타내며, 그와 같은 변경이 그 발명이 속하는 기술분야에서 통상의 지식을 가진 사람(이하 ‘통상의 기술자’라고 한다)이라면 누구나 용이하게 생각해 낼 수 있는 정도인 경우에는, 특별한 사정이 없는 한 확인대상 발명은 특허발명의 청구범위에 기재된 구성과 균등한 것으로서 여전히 특허발명의 권리범위에 속한다고 보아야 한다.
Unofficial English translation
Where the principle of solving the problem in the two inventions is identical, and such a change nonetheless exhibits substantially the same operation and effect as in the patented invention, and such a change is of a degree that could readily be conceived by anyone who has ordinary knowledge in the technical field to which the invention pertains (hereinafter referred to as a 'person having ordinary skill in the art'), then, absent special circumstances, the invention subject to confirmation should be regarded as being equivalent to the constituent elements recited in the claims of the patented invention and thus still falling within the scope of the patented invention.
Factors
- 확인대상 발명이 특허발명의 청구범위에 기재된 구성과 균등한 것으로서 특허발명의 권리범위에 속한다고 보기 위한 요건
- 여기서 ‘양 발명에서 과제의 해결원리가 동일’한지 판단하는 방법
- 특허발명에 특유한 해결수단이 기초하고 있는 기술사상의 핵심이 확인대상 발명에서도 구현되어 있는 경우, 작용효과가 실질적으로 동일하다고 보아야 하는지 여부(원칙적 적극)
- 위와 같은 기술사상의 핵심이 특허발명의 출원 당시에 이미 공지되었거나 그와 다름없는 것에 불과한 경우, 작용효과가 실질적으로 동일한지 판단하는 방법
Unofficial English translation
• The requirements for regarding the invention subject to confirmation as being equivalent to the constituent elements recited in the claims of the patented invention and thus falling within the scope of the patented invention
• The method for determining here whether 'the principle of solving the problem in the two inventions is identical'
• Where the core of the technical idea on which the solving means peculiar to the patented invention is based is also embodied in the invention subject to confirmation, whether the operation and effect should be regarded as substantially identical (affirmative as a rule)
• Where the foregoing core of the technical idea had already been publicly known as of the filing date of the patented invention or was nothing more than something equivalent thereto, the method for determining whether the operation and effect is substantially identical
Relation to precedent
Follows earlier decisions Stated in the decision
대법원 2019. 1. 31. 선고 2018다267252 판결(공2019상, 633)
Unofficial English translation
Supreme Court Decision 2018Da267252 decided January 31, 2019 (Gong 2019 Sang, 633)
Decisions referred to
[1][2] 대법원 2019. 1. 31. 선고 2018다267252 판결(공2019상, 633) / [1] 대법원 2014. 7. 24. 선고 2012후1132 판결(공2014하, 1753)
Burden of proof
Not addressed Not in the decision
Open question and revisit condition
Where the core of the technical idea was public at the time of filing, what comparison of the individual functions or roles of the component at issue shows that the working effect is nonetheless substantially identical?
A later decision changing the way the same principle of solving the task or working effect is judged, or a change to Article 97 or Article 135 of the Patent Act on which the decision rests, would call for this entry to be read again. So would a decision distinguishing this one from Supreme Court Decision 2018Da267252 or Supreme Court Decision 2012Hu1132.
Cross-family AI independent reading & axis check
8 of 8 axes matched GPT-6 Astra (OpenAI, codex CLI) · 2026-10-25
A reader from another model family (GPT-6 Astra), given the official text but not the primary reading, agreed on all 8 axes.
Raw responses and comparison record: Protocol · Blind readings (JSONL) · Axis comparison (JSONL) · SHA-256 (JSON)
Lower-court contrast & scope of application
Lower-court reading vs. Supreme Court holding
Lower-court context: The Patent Court, in its judgment of 17 June 2021 (2020Heo6316), found that the core of the technical idea of the patented invention, named 'the plate collector transfer device of a plate conveyor system for storage batteries', was not public when the patent was filed, and that the core was embodied as it stood in the target invention. On that footing it held that the two inventions shared the same principle of solving the task, showed a substantially identical working effect despite differences such as the arrangement of the hydraulic cylinders, and that a person with ordinary knowledge could easily have conceived those differences, so the target invention fell within the scope of the patent.
Supreme Court standard: The Supreme Court found no error. Reading the appellate reasons against the applicable law and the record, it held that the court below had not misapprehended the law of equivalence or made any other mistake affecting its judgment, and dismissed the appeal with costs on the losing party.
Distinguishing conditions
- A target invention in which none of the claimed elements has been modified, since the equivalence test applies only where a change has been made to part of the claimed composition.
- A case in which the core of the technical idea on which the means of solution peculiar to the patented invention rests was already public, or no different from something public, at the time of filing, since the working effect must then be judged by comparing the individual functions or roles of the component at issue.
- A modification that a person with ordinary knowledge in the technical field could not easily have conceived, since easy conceivability is one of the requirements the decision states.
Record verification notes
Set the target invention against the claims element by element first, to find where the change was made. Then read the description of the invention and the state of the art at the time of filing to identify the core of the technical idea peculiar to the patented invention, and check whether that core was public when the patent was filed, since that decides which of the two routes the working-effect question takes. Only then weigh easy conceivability and any special circumstances.
From the official text
Points at issue
[1] 확인대상 발명이 특허발명의 권리범위에 속하는지 판단하는 기준 / 확인대상 발명에서 특허발명의 청구범위에 기재된 구성 중 변경된 부분이 있는 경우, 확인대상 발명이 특허발명의 청구범위에 기재된 구성과 균등한 것으로서 특허발명의 권리범위에 속한다고 보기 위한 요건 및 여기서 ‘양 발명에서 과제의 해결원리가 동일’한지 판단하는 방법 [2] 발명의 상세한 설명의 기재와 출원 당시의 공지기술 등을 참작하여 파악되는 특허발명에 특유한 해결수단이 기초하고 있는 기술사상의 핵심이 확인대상 발명에서도 구현되어 있는 경우, 작용효과가 실질적으로 동일하다고 보아야 하는지 여부(원칙적 적극) 및 위와 같은 기술사상의 핵심이 특허발명의 출원 당시에 이미 공지되었거나 그와 다름없는 것에 불과한 경우, 작용효과가 실질적으로 동일한지 판단하는 방법
Unofficial English translation
[1] The criteria for determining whether an invention subject to confirmation falls within the scope of the patented invention / where there is a changed portion among the constituent elements recited in the claims of the patented invention in the invention subject to confirmation, the requirements for regarding the invention subject to confirmation as being equivalent to the constituent elements recited in the claims of the patented invention and thus falling within the scope of the patented invention, and the method for determining here whether 'the principle of solving the problem in the two inventions is identical' [2] Where the core of the technical idea on which the solving means peculiar to the patented invention is based, as ascertained in light of the description of the invention and the publicly known technology as of the filing date, is also embodied in the invention subject to confirmation, whether the operation and effect should be regarded as substantially identical (affirmative as a rule) and, where the foregoing core of the technical idea had already been publicly known as of the filing date of the patented invention or was nothing more than something equivalent thereto, the method for determining whether the operation and effect is substantially identical
Summary of the holding
The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Order
상고를 기각한다. 상고비용은 피고가 부담한다.
Unofficial English translation
The appeal is dismissed. The costs of the final appeal shall be borne by the defendant.
Provisions referred to
[1] 특허법 제97조, 제135조 [2] 특허법 제97조, 제135조
Read 2026-10-25 · Cross-read 2026-10-25. All quotes matched against the official text. The Chinese-character placeholders the court used for anonymised parties are given in their Korean readings, and parenthetical Chinese-character glosses are omitted.
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