知財訴訟の実際―当事者は何を考え、なぜ訴訟に至るのか

2026年8月28日に行われた「【第4回サマリア知財フォーラム】知財訴訟の実際 －当事者は何を考え、訴訟に至るのか？－【講師】河部 康弘 氏： 河部法律事務所 所長／パテント・インテグレーション株式会社 顧問弁護士」のアーカイブ動画（約62分」を視聴しました。
パテント・インテグレーション株式会社の顧問弁護士でもある河部康弘氏が、豊富な訴訟経験を踏まえ、知財紛争における当事者の心理と意思決定を解説しています。河部氏が実質的に関与した、裁判所の事件番号が付された案件は約120件に上るとのことです。
日本では、勝訴者が実際に支払った弁護士費用を、そのまま敗訴者に負担させる制度にはなっていません。裁判には時間も費用もかかるため、権利者も被警告者も、本音では訴訟を避けながら、自らに有利な条件で解決したいと考えます。
権利者は「要求に応じなければ訴える」と圧力をかけ、被警告者は「訴えるならどうぞ」と強気に対応します。双方が相手の譲歩を待ち続け、ブレーキが効かなくなった結果、訴訟に突入する――これが講演でいう「チキンレース」です。
権利者が訴訟を提起するかどうかは、勝訴可能性だけでは決まりません。得られる損害賠償額、回収可能性、無効主張を受けるリスク、訴訟費用、社内負担、顧客やサプライチェーンへの影響、さらに経営者や発明者の感情まで含めて判断されます。
特に重要なのは、知財訴訟も事業活動の一環であるという点です。侵害を放置すれば、「この会社は権利行使をしない」と市場に受け取られ、他社の模倣を誘発するおそれがあります。一方で、相手の事業規模が小さく、自社への影響も限定的であれば、費用を考えて訴えない判断もあり得ます。
被警告者側も、侵害・無効の判断だけでなく、「相手は本当に訴えてくる会社か」を見ています。強力な無効資料を示したり、対象製品がほとんど売れていないことを開示したりして、権利者の訴訟意欲を低下させることも重要な交渉戦略になります。
講演で特に興味深かったのは、特許の実効的な権利範囲は、クレームの文言だけでは決まらないという指摘です。
過去の訴訟実績、訴訟予算の確保、訴訟費用保険への加入、知財訴訟に詳しい弁護士との連携などにより、「この会社は本当に訴えてくる」と相手に認識させれば、訴訟前の交渉力が高まります。強い明細書を作るだけでなく、必要な場合に権利行使できる体制と覚悟を示すことも、特許の牽制力を高める知財戦略といえます。
訴訟開始後は、裁判所の心証が示されることで侵害や無効の見通しが立ちやすくなり、中立的な裁判官が双方の事情を調整するため、和解も成立しやすくなります。
知財戦略は、特許を取得して終わりではありません。権利行使を実行できる組織、予算、社内意思決定、外部専門家との関係まで準備しておくことが、保有特許の価値と企業の交渉力を支える――非常に示唆に富む講演でした。
 
動画はこちらです。
https://www.youtube.com/watch?v=G9OetwbtBRE
 
 
The Reality of IP Litigation—What Do the Parties Think, and Why Do Disputes End Up in Court?
I watched the approximately 62-minute archived video of the seminar held on August 28, 2026, entitled “The 4th Summaria IP Forum: The Reality of IP Litigation—What Do the Parties Think, and Why Do Disputes End Up in Court?” The speaker was Yasuhiro Kawabe, Managing Partner of Kawabe Law Office and Legal Advisor to Patent Integration Co., Ltd.
Drawing on his extensive litigation experience, Mr. Kawabe, who also serves as legal advisor to Patent Integration Co., Ltd., explained the psychology and decision-making processes of parties involved in IP disputes. According to him, he has been substantially involved in approximately 120 cases that were formally assigned court case numbers.
In Japan, the losing party is not generally required to reimburse the prevailing party for the full amount of attorneys’ fees actually incurred. Because litigation is both time-consuming and costly, both rights holders and recipients of infringement warnings would, in truth, prefer to avoid going to court while still resolving the dispute on terms favorable to themselves.
The rights holder applies pressure by saying, “Comply with our demands, or we will sue,” while the accused party responds defiantly, “Go ahead and sue us.” Each side continues waiting for the other to back down, until the brakes cease to function and the dispute proceeds to litigation. This is what Mr. Kawabe described in the seminar as a “game of chicken.”
Whether a rights holder initiates litigation is not determined solely by the likelihood of prevailing. The decision also takes into account the potential amount of damages, the likelihood of actually recovering them, the risk of facing an invalidity challenge, litigation costs, the internal burden on the company, the impact on customers and supply chains, and even the emotions of management and the inventors involved.
One particularly important point is that IP litigation is itself part of business activity. If infringement is left unchallenged, the market may conclude that “this company does not enforce its rights,” potentially encouraging other companies to imitate its products or technology. On the other hand, when the other party’s business is small and the impact on the rights holder is limited, the rights holder may reasonably decide not to sue in view of the costs involved.
The recipient of an infringement warning also considers not only infringement and validity issues, but whether the rights holder is genuinely the kind of company that will bring a lawsuit. Presenting strong prior art that could invalidate the patent, or disclosing that the accused product has generated almost no sales, can reduce the rights holder’s incentive to litigate. This can therefore be an important negotiation strategy.
One of the most interesting observations in the seminar was that the effective scope of patent rights is not determined solely by the wording of the claims.
A company can strengthen its pre-litigation bargaining position by making the other party believe that it is genuinely prepared to sue. Such credibility may be established through a history of prior litigation, the allocation of an adequate litigation budget, the purchase of litigation expense insurance, and close cooperation with attorneys experienced in IP litigation. An effective patent strategy therefore involves not only drafting strong patent specifications, but also demonstrating that the company has both the organizational capability and the determination to enforce its rights when necessary. This can substantially enhance the deterrent effect of its patents.
Once litigation has commenced, the court may indicate its preliminary assessment, making it easier for the parties to evaluate the likely outcomes regarding infringement and validity. In addition, a neutral judge can take both parties’ circumstances into account and help bridge their differences, making settlement more likely.
An IP strategy does not end when a patent is granted. The value of a company’s patent portfolio and its negotiating power depend on advance preparation—including an organization capable of enforcing rights, an appropriate budget, internal decision-making procedures, and established relationships with external specialists.
It was an exceptionally insightful seminar.
 

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