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How is evidence collection and trade secret protection managed during litigation?

Takanori Abe of Abe & Partners analyses the different ways of handling evidence collection during patent litigation as well as the management of trade secret protection issues that arise as a result

Litigation procedure and situations where evidence collection and trade secret protection become an issue

Dispositions on the collection of evidence prior to the filing of an action (Code of Civil Procedure, Articles 132-2-132-9) is a tool to collect evidence before filing a lawsuit. However, they are not used in practice because they are not coercive and potential plaintiffs do not want to be known by opponents regarding potential filings. Preservation of evidence (Code of Civil Procedure, Articles 234-242) can be used before and during the lawsuit to collect evidence. After filing a lawsuit, the obligation to clarify specific circumstances (Patent Act, Article 104-2) may urge the accused infringer to disclose their conduct. The submission of documents (Patent Act, Article 105) exists. The court can use in camera inspection (Patent Act, Article 105(2)) to examine whether an obligation to submit exists.

Parties who are urged to disclose trade secrets by these evidence collection procedures can avoid trade secret leakage by confidentiality protective orders (Patent Act, Article 105-4) and restrictions on inspection to preserve confidential information (Code of Civil Procedure, Article 92).


Preservation of evidence

Preservation of evidence is a procedure to examine the evidence in advance and preserve it when it would be difficult to use the evidence if waiting for the official examination of the evidence in the lawsuit. It is used in medical malpractice cases but rarely used in intellectual property cases. According to the Tokyo District Court IP department's statistics, the number of filings of preservation of evidence was nine in 2013, five in 2014 and one in 2015. Preservation of evidence is not coercive, thus a respondent can refuse entry to the factory and submission of inspected evidence if legitimate reason to refuse the submission due to the existence of the trade secret. Trade secret protection is not sufficient as in practice confidentiality protective orders cannot be issued in the preservation of evidence before filing a lawsuit. Bad example exists. This applies when a court does not have an IP department videotaped inside a factory without limitation and recorded it in the inspection minutes.

Submission of documents

Submission of documents is a special rule of obligation to submit documents (Code of Civil Procedure, Article 220) in which the court orders parties to submit documents when they do not voluntarily submit them.

The number of motion for submission of documents was around 50 in 2015 at the Tokyo District Court IP department. As the number of new filings annually is around 330, motion for submission of documents is made in one in around 6.6 cases. The number of motions for submission of documents to prove infringement and to prove damages are almost the same, but the former is a little bit larger than the latter.

For the submission of documents to be issued, both the requirements relating to necessity and legitimate reason to refuse should be satisfied (Patent Act, Article 105(1)).

For the motion for submission of documents to prove infringement, to avoid fishing expeditions the court held petitioner should prove, prima facie, reasonable doubt of infringement and cautiously examined the necessity requirement. Order for the submission of documents are issued many times to prove damages, however, for proving infringement they have only been issued in two cases and generally the necessity requirement is denied. A judge explained the reason why almost no orders for submission of documents were made. As the order compels the party to submit a secret which they definitely do not want their direct competitors to know, the court should carefully examine whether it is necessary evidence for a judgment, and the possibility of a fishing expedition or an abusive application. Judges are facing difficulty controlling the situation. However, recently the judgment of March 28 2016, IP High Court (Presiding Judge Shimizu) held that prima facie proof of infringement itself is not required but prima facie proof of reasonable doubt of existence of infringement to dispel the possibility of a fishing expedition or an abusive application is sufficient, and thereby lowered the threshold of the necessity requirement. Whether the issuance of submission of documents to prove infringement will increase from now on should be paid attention to.

When judging legitimate reason to refuse submission, the court should compare the necessity for trade secret protection and the necessity for evidence. Containing trade secrets is an insufficient reason to refuse submission but disadvantage, which cannot be avoided by confidentiality protective orders, is needed as submission of documents is designed to be used with confidentiality protective orders. Legitimate reason to refuse submission may not exist if infringement is found by in camera inspection.

In camera inspection

In camera inspection allows the person who possesses the document to disclose the document and only the judges to review it to examine whether submission of documents should be granted. In camera procedure is rarely used, but a judgment of March 28 2016, IP High Court (Presiding Judge Shimizu) used it, which attracted attention.

The in camera procedure was restricted to judging whether legitimate reason to reject submission exist. The 2018 Patent Act amendment allowed in camera procedure to judge whether documents are necessary to prove infringement or calculate damages. According to this amendment, for example, in camera procedure can be used when the structure of the product in question is in dispute and the defendant alleges that they cannot disclose the structure of the product due to it being a trade secret. If the party who submits documents for in camera inspection agrees, the court can disclose documents to technical advisors and seek their expert opinion (Patent Act, Article 105(4)).

Confidentiality protective orders

Confidentiality protective orders prohibit briefs and evidence which contain trade secrets from being used for any purpose other than conducting litigation and from being disclosed to any person other than the one who is subject to the confidentiality protective order. Thereby, confidentiality protective orders help prevent trade secrets being disclosed in the litigation procedure heightening trade secret protection.

The number of issued confidentiality protective orders is small. In the Tokyo District Court, the numbers were one in 2008, three in 2009, one in 2010, three in 2011, five in 2012, four in 2013, two in 2014 and one in 2015. The reason for this small number is a severe criminal sanction against violation of the order. As confidentiality protective orders impose heavy burdens on parties, attorneys, and courts, in practice the court carefully examines whether a non-disclosure agreement and an inspection to preserve confidential information are sufficient, and judges whether confidentiality protective orders are necessary.

The first confidentiality protective orders were issued in a pharmaceutical patent infringement case (judgment of September 15 2006, Tokyo District Court, Presiding Judge Takabe). A generic drug maker filed a motion for confidentiality protective orders regarding the information (test method, standard, etc.) described in the written application for import approval of a generic drug submitted to the Ministry of Health, Labour and Welfare to examine the identity of a brand name drug approved under pharmaceutical affairs law. The court issued confidentiality protective orders.

Confidentiality protective orders can be issued in a preliminary injunction (judgment of January 27 2009, Supreme Court). Explanatory sessions should be held carefully if confidentiality protective orders have been issued. Technical advisors come with a risk of contamination and therefore are not easily selected. The attendance of company personnel is also difficult. Attorneys subject to confidentiality protective orders need to avoid including information about trade secrets subject to the order in briefs submitted after the order and should be cautious not to orally mention trade secrets at the hearing. The effect of a confidentiality protective order remains until vacated, thus companies should keep the contact information of company personnel subject to the order irrespective of their movement and retirement so that companies can ensure that the order is being complied with.

The scope of the people subject to the confidentiality protective order is an issue. If company personnel is subject to the order, contamination risk arises and it is practically impossible for that person to conduct business related to the development of that product. If the documents are subject to attorneys' eyes only under a US protective order, subjecting company personnel to the order will be a violation of the US protective order. Opinions are split about whether experts can be subject to the order. If they are denied, parties cannot conduct activity fully with the aid of experts. Whether the law should be amended to allow third party experts to be subject to the order is under discussion.

It is common to discuss among parties whether a non-disclosure agreement can be formed before a confidentiality protective order is issued. The amount of the penalty, subject of trade secrets, and recipients of trade secrets will usually be disputed.

Inspection to preserve confidential information

Inspection to preserve confidential information limits the inspection of the confidential information in the case record to the parties and prohibits third party inspection. IP judges are fully aware of the importance of trade secret protection, thus compared with usual civil cases inspection to preserve confidential information is more easily granted in IP cases.

Amendment of the Patent Act


Amendment of the law has been discussed as evidence collection methods in patent infringement lawsuits do not function sufficiently under the current legal system. The US discovery system was not referenced as it is too extreme and expensive and may not match the Japanese system. European evidence collection procedure may match and the German inspection system can be a good reference. In the German inspection system, an inspector, who is a technical expert having a confidentiality obligation and appointed by the court, enters the factory of the accused infringer, inspects evidence possessed by the accused infringer, and submits the report to the court. However, introduction was suspended due to strong concern about trade secret leakage from the industry. For example, the concern that there would be a serious problem if someone enters a factory based on alleged evidence collection and urges the factory to disclose a manufacturing method or tries to steal know-how was expressed.

The discussion resumed and the inspection system was introduced in the Patent Act in the 2019 amendment (amended Patent Act, Article 105-2). When there is a possibility of patent infringement, a neutral technical expert (inspector) enters the factory of the accused infringer, conducts the necessary investigation regarding infringement proof, and submits a report to the court. Inspection is allowed only after filing a lawsuit. Inspection will be granted when there is i) a necessity to prove infringement; ii) a probability of infringement; iii) no other means of adequate evidence collection; and iv) to avoid an excessive burden on the alleged infringer. The inspector will enter the opponent's factory, conduct an inquiry, ask for submission of documents and conduct machine operation, measurements, experiments, and other conduct permitted by the court. No entry to third parties' factories will be made. The opponent has an obligation to cooperate to collect materials. If the opponent refuses the requests of the inspector which is permitted by the court, the court has discretion to find the petitioner's allegation to be true. The inspector submits an inspection report to the court. A copy of the inspection report will be served to the inspected party. The inspected party can ask the court within two weeks after the service not to disclose all or part of the inspection report to the petitioner. The court can grant such a motion if legitimate reason exists. Inspection will start to be used in practice within one and half years from May 17 2019. We should pay attention to how the court will run this new system.


1 訴訟手続きの流れと、証拠収集手続きおよび営業秘密保護



2 各論

2-1 証拠保全




2-2 書類提出命令






2-3 インカメラ手続




2-4 秘密保持命令





秘密保持命令の名宛人の範囲についても問題となる。企業の担当者を名宛人とする場合、情報のコンタミネーションのリスクが生じ、その後に当該製品開発部門で業務に従事することが事実上困難となる。対象文書が米国の訴訟手続きにおけるProtective Orderの対象としてAttorneys' Eyes Onlyになっている場合に、当事者を名宛人に含めてしまうとProtective Order違反となる。外部の専門家を名宛人として営業秘密の開示ができるかについては見解が分かれているが、否定的に解すると専門家の助力を得た十分な立証活動ができなくなってしまう。この点、立法論として、第三者の専門家を名宛人とできる制度を導入するかが検討されている。


2-5 閲覧制限



3 法改正

3-1 査証


その後、再度議論され、令和元年改正において、査証制度として導入された(改正特許法105条の2)。査証制度とは、特許権侵害の可能性がある場合、中立な技術専門家(査証人)が被疑侵害者の工場等に立ち入り、特許権の侵害立証に必要な調査を行い、裁判所に報告書を提出する制度である。査証は提訴後のみ認められ、①必要性(対象が立証に必要なものであること)、②蓋然性(特許権侵害訴訟の相手方が侵害したことを疑うに足りる相当な理由)、③補充性(他の手段では当該証拠の収集ができないこと)、④相当性(「当該証拠の収集に要すべき時間又は査証を受けるべき当事者の負担が不相当なものとなることその他の事情により、相当でないと認めるとき」に該当しないこと)の発令要件を満たした場合に認められる。査証人は、相手方の工場等への立入り、相手方に対する質問、書類等の提示、装置の作動、計測、実験その他裁判所の許可を受けた行為を実施する。相手方当事者以外の第三者の工場等への立入りは想定していない。相手方に対しては、資料収集への協力義務を課し、裁判所が認めた範囲内における査証人の要求を拒んだ場合については、裁判所の裁量により真実擬制が行われる。査証人は、査証報告書を作成して裁判所に提出する。査証報告書の写しは、査証を受けた当事者に送達される。査証を受けた当事者は、送達の日から2週間以内に、査証報告書の全部又は一部を申立人に開示しないことを申し立てることができる。裁判所は、正当な理由があると認めるときは、査証報告書の全部又は一部を申立人に開示しないとすることができる。査証制度は、公布の日である令和元年 5 月 17 日から1年6月を超えない範囲内において政令で定める日に施行される。査証制度に関する裁判所の運用が注目される。

Takanori ABE 阿部隆徳



Mr Abe is a lawyer, admitted in both Japan and New York. He is currently a guest professor at Osaka University Graduate School of Medicine and was formerly a lecturer at the University of Tokyo Graduate School of Medicine and Faculty of Medicine. He is an arbitrator in Japan.

Mr Abe works on a wide range of international and corporate matters with a focus on intellectual property law and international commerce. The patent litigations that he has participated in cover the fields of pharmaceuticals, chemistry, electronics and machinery. These often involve advanced technology such as biotechnology and semiconductors, etc. They are also frequently cross-border matters.




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