Date:9 March 2023

【Volume 105】

In Part I, Part II and Part III, we looked into different perspective on whether an erroneous prior art disclosure may support obviousness in Taiwan, China, and the US.

In the final section of this 4-part series, we look at how the Guidelines for Examination in the European Patent Office offer relevant regulations and a comparison between Taiwan, China, US, and Europe.

Part IV. Europe

1. Guidelines for Examination in the European Patent Office

   In principle, the European Patent Office (EPO) denies the erroneous description in a prior art document to be a valid disclosure. Guidelines for Examination in the European Patent Office indicate different results corresponding to different situations of error in the prior art in judgment.

   Section 9, Chapter IV of Part G stipulates the guidelines for examination when errors exist in prior-art documents:

   “9. Errors in prior-art documents

   Errors may exist in prior-art documents.

   When a potential error is detected, three situations may arise depending on whether the skilled person, using general knowledge,

   (i) can directly and unambiguously derive from the prior art document that it contains an error and what the only possible correction should be;

   (ii) can directly and unambiguously derive from the prior art document that it contains an error, but is able to identify more than one possible correction; or

   (iii) cannot directly and unambiguously derive from the prior art document that an error has occurred.

   When assessing the relevance of a document to patentability,

   in case (i), the disclosure is considered to contain the correction;

   in case (ii), the disclosure of the passage containing the error is not taken into account;

   in case (iii), the literal disclosure is taken into account as is.”

2. Boards of Appeal decisions

   (1)T412/91¹

   The erroneous disclosure in a cited document does not form the state of the art. Specifically, what constitutes the disclosure of a prior art document is governed not merely by the words actually used in its disclosure, but also by what the publication reveals to the skilled reader as a matter of technical reality. If a statement is plainly wrong, whether because of its inherent improbability or because other material shows that it is wrong, then although published it does not form part of the state of the art. Conversely, if he would not recognize that the teaching is wrong, it does belong to the state of the art.

   (2)T230/01²

   A document normally forms part of the state of the art, even if its disclosure is deficient, unless it can unequivocally be proven that the disclosure of the document is not enabling, or that the literal disclosure of the document is manifestly erroneous and does not represent the intended technical reality. Such a non-enabling or erroneous disclosure should then not be considered part of the state of the art.

3. Conclusion

   For erroneous description in prior-art documents, the Guidelines for Examination in the European Patent Office provide the most specific and clear regulations. First, whether to exclude a prior art document to be a valid disclosure is determined based on whether the skilled person can “directly and unambiguously derive from the prior art document that it contains an error”. Then, two levels of results are determined depending on “whether there exists only one possible correction”. In addition, decision T412/91 suggests that the error includes not only noticeable typographical errors or wrong wordings, but also the erroneous statements judging based on technical reality that are scientifically unreasonable or not enabling. Such error shall not be considered part of the state of the art.

Comparison between Taiwan, China, U.S. and Europe Practice

Relevant regulations and court judgements in Taiwan, China, U.S. and Europe practice all deny the erroneous description in a prior art document to be a valid disclosure. Generally, there are two levels of results in practice: (1) the first level is to simply exclude the legal validity of the erroneous part to be a disclosed prior art; and then (2) the second level ,based on the first one, is to further deem the corrected content as the disclosure of the prior art. Disclosure which is not enabling (or not operable) does not constitute probative prior art. This concept is broadly adopted in Europe and US practice. Correspondingly, Patent Examination Guidelines in Taiwan and the judgment of F. Hoffmann-La Roche AG v. Celltrion Healthcare Taiwan also introduced a similar concept. However, erroneous description does not necessarily deprive a prior art disclosure of its operability. For example, in the U.S. Patent No. 5,861,999 ("Tada”) of LG Electronics Inc. v. ImmerVision, Inc., the incorrect values render the Tada’s Embodiment to be non-enabling; in contrast, in (2021) Zui Gao Fa Zhi Xing Zhong No. 83 Judgment of Supreme People's Court of China, the fact that Citation 1 in said judgment mistakenly listed water-insoluble basic bismuth nitrate compound as an example of water-soluble metal nitrate does not mean that the technical means of use of the compound in prints is inoperable. However, in this case, based on the “contradictory description” within the citation, the Supreme People's Court denied the water-insoluble basic bismuth nitrate as a valid disclosure.

In addition, according to the above-mentioned regulations and court judgements in China and U.S. practice, only the erroneous part is denied as a valid disclosure, i.e., the result (1) mentioned in Part I of our series. In China practice, the judgement is based on whether there exists “self-contradictory description” in the prior art document. In U.S. practice, the Yale standard emphasizes “obvious error” which appears to adopt the strictest requirement. However, the decision in LG Electronics Inc. v. ImmerVision, Inc. seems to imply that the so-called “obvious” focuses more on the internal consistency within a prior art reference, rather than the common sense meaning of “immediately recognizable”.

In Europe practice, whether to exclude the prior art document to be a valid disclosure is determined based on whether the skilled person can “directly and unambiguously derive from the prior art document that it contains an error”; then, two levels of results are determined depending on “whether there exists only one possible correction”.

In Taiwan practice, the Patent Examination Guidelines only mention the conclusion that the legal validity of the erroneous part to be a disclosed prior art is excluded (result (1) mentioned in Part I of our series). However, in the judgment of F. Hoffmann-La Roche AG v. Celltrion Healthcare Taiwan, it is concluded that a person ordinarily skilled in the art could easily notice errors, including not only an easily noticeable typographical error in the form, but also the errors found by judging substantively based on scientific reasonability and technical reality with reference to the references cited in the prior art. This judgment concluded by further deeming the corrected content as the disclosure of the prior art (result (2) mentioned in Part I of our series), and its meaning also echoes decision T412/91 of EPO Boards of Appeal.

In conclusion, prior art is the basis for judging patentability, and the regulations for excluding erroneous information play a critical role in determining the legal validity of the prior art. In Taiwan, China, U.S. and Europe practice, the erroneous description does not form the state of the art, and the perspective of a skilled person in the art is introduced in these practices. Based on statutory regulations and court judgements, each practice puts forward different conditions and results for dealing with errors in prior art documents