Article 23 of the Taiwan Patent Act prescribes “lack of novelty based on legal fiction,” as “A person shall not be entitled to a patent if the claimed invention was described in the specification, claim(s) or drawing(s) of a patent issued or an application for invention or utility model patent laid open or published after the filing of the claimed invention concerned, in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.” The Taiwan Patent Examination Guidelines provides that the examination of lack of novelty based on legal fiction is conducted by comparing the technical contents recited in each claim of the application with those of the earlier-filed application to determine whether the contents are identical. “Identical contents” refers to the following criteria: (1) totally identical; (2) the difference only lies in the literal descriptions or in technical features which can be directly and unambiguously deduced; (3) the difference resides in the generic and specific concepts of corresponding technical features; or (4) the difference lies only in technical features which can be directly replaced based on common general knowledge. Criteria (1) to (3) are consistent with those considered in determining whether contents are identical for purposes of novelty, whereas criterion (4) is unique to lack of novelty based on legal fiction. In past practice, there has been debate over how to apply this “direct replacement” standard and how to distinguish it from the determination of inventive step. In this regard, the Supreme Administrative Court’s 2025 Shang Zi No. 577 judgment, rendered on March 12, 2026, concerning lack of novelty based on legal fiction, provides useful guidance.
The patent-in-suit in the judgment (TW M567542, the “’542 Patent”), is directed to a cover for closing the opening of a mushroom cultivation bag. The cover includes components such as an air-permeable sheet, a body, and a bottom wall. The ‘542 Patent describes that the air-permeable sheet is bonded to the upper side of the body to close a through-hole at the center of the cover, and that openings connected to the bottom wall are provided on the side wall at the bottom of the body, thereby forming a moisture passage extending from the air-permeable sheet, through the through-hole, and to the side-wall openings. This configuration is intended to maintain the moisture of the culture medium inside the cultivation bag and prevent the side-wall openings from being blocked by the culture medium. The invalidation petitioner asserted that the ’542 Patent lacked novelty based on legal fiction in view of an earlier-filed application (TW M562560). The patentee primarily argued that there were differences in technical features between the earlier-filed application and the ’542 Patent. For example, said earlier-filed application showed that the side-wall openings of the cover were not connected to the bottom wall, and the air-permeable pad merely covered the upper side of the cover bottom rather than being bonded thereto. The patentee further argued that these differences were not technical features that a person ordinarily skilled in the art could directly replace.
However, both Taiwan Intellectual Property Office (the “TIPO”) and the Petitions and Appeals Committee, Ministry of Economic Affairs (the “Appeals Committee”) determined that the above technical differences could be directly replaced based on common general knowledge, so that the ‘542 patent lacked novelty based on legal fiction. Dissatisfied with the decisions of TIPO and Appeals Committee, the patentee filed an administrative lawsuit with the Intellectual Property and Commercial Court (the “IPC Court”). In its 2025 Xing Zhuan Su Zi No. 1 judgment, the IPC Court held that, based on the specification and claims, a person ordinarily skilled in the art would understand that the functions of the two technical features of the ’542 Patent were to “maintain air permeability of the openings” and to “join the air-permeable pad to the cover,” and that the differing technical features in the earlier-filed application had the same functions. The IPC Court therefore determined that these technical features could be directly replaced based on common general knowledge. The patentee appealed to the Supreme Administrative Court, arguing that the IPC Court’s reasoning regarding “direct replacement based on common general knowledge” was in substance an inventive step analysis, and that the IPC Court’s judgment was unlawful due to misapplication of the law.
In its 2025 Shang Zi No. 577 judgment, the Supreme Administrative Court stated that the provision of Taiwan Patent Act regarding lack of novelty based on legal fiction adopts an expanded approach to determining novelty. That is, in addition to the principles for determining normal novelty, if the differences in technical features between a later-filed patent application and an earlier-filed application can be directly replaced by a person ordinarily skilled in the art using general knowledge and ordinary skill, the later-filed application may be further determined to lack novelty based on legal fiction. In determining whether differing technical features can be “directly replaced,” it is necessary to consider whether the technical features before and after replacement have the “same function” based on common general knowledge. The Supreme Administrative Court further emphasized that the determination of “direct replacement” focuses on whether the individual technical features before and after replacement have the same or different effects. This differs from the determination of inventive step, which requires consideration of whether the overall technical means before and after replacement of the technical feature produce the same effect. Accordingly, there was no concern, as alleged by the patentee, that the criteria for determining inventive step had been improperly introduced into the determination of lack of novelty based on legal fiction. Based on the above, the Supreme Administrative Court found no error in the IPC Court’s reasoning that a person ordinarily skilled in the art would understand that the differing technical features of the ’542 Patent and the earlier-filed application had the same functions and could be directly replaced based on common general knowledge. The Supreme Administrative Court therefore upheld the finding that the ’542 Patent lacked novelty based on legal fiction.
This Supreme Administrative Court judgment indicates that, in determining whether the differing technical features between a patent and an earlier-filed application can be directly replaced based on common general knowledge, the relevant consideration is whether the differing individual technical features before and after replacement have the same function, rather than whether the overall technical means before and after replacement of the technical features produce the same function. The IPC Court had also expressed similar views in other prior civil litigation (2022 Min Zhuan Shang Zi No. 19 judgment), and in other prior administrative litigation (2024 Xing Zhuan Su Zi No. 17 judgment). Particularly for invalidation requesters or defendants in civil litigation seeking to assert lack of novelty based on legal fiction, the Supreme Administrative Court’s view in this judgment may serve as useful guidance when searching for suitable earlier-filed applications and preparing related arguments.