Purpose
The skill structures the patent infringement action according to the Düsseldorf model: existence of the IP right → feature breakdown of the main claim → infringement (literal wording / equivalence) → catalogue of claims §§ 139 et seq. PatG. It simultaneously addresses the strategic choice of forum (Regional Court with patent dispute chamber vs. Unified Patent Court UPC for European bundle patents without opt-out) and the limitation period § 141 PatG.
Inputs
- IP right (DE patent / EP-validated / unitary patent / utility model) with publication/grant dates
- Patent claim (main claim + relevant dependent claims)
- challenged embodiment (technical description of the infringing act)
- Infringement period (first knowledge, ongoing acts, territorial scope)
- known prior art / nullity attacks
- UPC opt-out status (for European bundle patent)
- for SEPs: FRAND correspondence with defendant (cross-reference antitrust law)
Sub-agent architecture
Researcher supplies PatG and EPC statutes, BGH X-senate case law (in particular on scope of protection and equivalence), the OLG Düsseldorf series as well as commentary passages from Benkard, Kühnen, Mes. Drafter prepares the statement of claim framework incl. feature breakdown, statement of infringement and catalogue of claims with threefold calculation of damages. Reviewer checks limitation period § 141 PatG, choice of forum, UPC opt-out status and expert representation § 143 PatG.
Procedure
1. Existence of the IP right
- Grant in force? Lapsed § 20 PatG (surrender, non-payment of annual fees), invalid § 22 in conjunction with §§ 81 et seq. PatG, revoked in opposition proceedings § 59 PatG?
- For European bundle patent: validation in DE carried out (§ 65 PatG)? Translation filed with the DPMA?
- For unitary patent: entry in the Register for unitary patents?
- For utility model: pending cancellation proceedings (§ 13 GebrMG)?
2. Feature breakdown
The main claim is divided into features (M1, M2, M3 …) . Each feature is compared with a point of the challenged embodiment. This is the central procedural working technique and the basis of subsumption.
3. Scope of protection § 14 PatG / Art. 69 EPC
Patent claims determine the scope of protection; the description and drawings are interpretation aids, not an independent extension of the scope of protection (Art. 69 EPC + Protocol on Interpretation).
Interpretation methodology (BGH line):
- meaning of the patent claims from the perspective of the person skilled in the art on the priority date
- consult the description and drawings insofar as necessary for clarification
- function of the feature within the patent structure
- "What the patent achieves" — no narrowly grammatical understanding
4. Infringement
4.1 Literal infringement (Sec. 9 Patent Act)
All features of the main claim are realized literally — if necessary with interpretation — by the challenged product / process. Infringing acts Sec. 9 sentence 2 Patent Act: manufacturing, offering, placing on the market, using, importing, possessing (product patent); using or offering for use (process patent).
4.2 Equivalent infringement
If a feature is realized not literally but by a modified means , the Federal Court of Justice triad is applied ("Schneidmesser I", X ZR 168/00; "Schneidmesser II", X ZR 135/01; "Schneidmesser III" [unverifiziert – prüfen]):
- Same effect — modified means objectively solves the same technical problem with essentially the same effect
- Findability — the person skilled in the art could find the modified means without inventive effort
- Equivalence oriented to the patent claim — the person skilled in the art considers the modification as an equivalent solution, oriented to the wording of the claims
Additionally: no patent limitation due to selection decision during grant (waiver by the applicant; cf. Federal Court of Justice "Okklusionsvorrichtung", X ZR 16/09).
4.3 Indirect infringement Sec. 10 Patent Act
Supply of means relating to an essential element of the invention to persons not authorized to use it, if the supplier knows / it is obvious that these means are suitable and intended for use of the invention in Germany.
5. Catalog of claims Sec. 139 et seq. Patent Act
| Claim | Provision | Requirement |
|---|---|---|
| Injunction | Sec. 139 I Patent Act | Infringement; no fault required |
| Removal | Sec. 139 I Patent Act | as for injunction |
| Damages | Sec. 139 II Patent Act | fault (intent / negligence; as a rule negligent due to market monitoring duty) |
| Disgorgement of profits (residual damages) | Sec. 812 et seq. German Civil Code in conjunction with Sec. 141 Patent Act | still possible for 10 years after the limitation period of the damages claim |
| Information | Sec. 140b Patent Act | infringement; third-party information |
| Destruction | Sec. 140a I Patent Act | products in the possession / ownership of the infringer |
| Recall | Sec. 140a III Patent Act | from distribution channels |
| Inspection | Sec. 140c Patent Act | sufficient likelihood; Düsseldorf inspection proceedings |
| Publication of judgment | Sec. 140e Patent Act | in the relevant trade circle |
6. Threefold damages calculation (Sec. 139 II Patent Act)
Claimant's right to choose:
- Concrete own loss / lost profit (§ 252 BGB; often difficult to prove)
- Disgorgement of the infringer's profits — the entire profit achieved through the infringement; share causally attributable to the infringement; crediting of general business overheads disputed (German Federal Court of Justice "share of overheads", I ZR 246/98)
- Licence analogy — reasonable royalty that reasonable contracting parties would have agreed; customary royalty rates depend on the industry and the type of product
Choice at the latest by the end of the oral hearing; combination generally inadmissible (German Federal Court of Justice [unverifiziert]), staged action § 254 ZPO with information claim § 140b PatG is customary.
7. Choice of forum and jurisdiction
7.1 National Regional Court patent litigation divisions (§§ 143–145 PatG)
Concentration ordinances assign patent disputes to certain Regional Courts (in particular Düsseldorf Regional Court, Mannheim Regional Court, Munich I Regional Court, Hamburg Regional Court, Braunschweig Regional Court). Appeal: the respective Higher Regional Court (e.g. Düsseldorf Higher Regional Court). Dual representation (lawyer + patent attorney) pursuant to § 143 III PatG is permissible and customary.
7.2 UPC (Unified Patent Court)
Since 01.06.2023 competent for:
- Unitary patents (mandatory)
- European bundle patents (validated European patents) during the transitional period (7 years + extension) only if no opt-out has been declared
Strategic consideration for the claimant: the UPC offers proceedings with effect in all UPC member states in one forum, with accelerated duration of proceedings (12–14 months at first instance). Risk: in the event of an invalidity attack, the patent may be lost centrally. For bundle patents without opt-out, choice of forum of the patent proprietor (UPC or national court).
7.3 For SEPs
FRAND objection (ECJ "Huawei/ZTE", C-170/13): the SEP proprietor must follow a specific negotiation path, otherwise an antitrust objection to the injunction claim applies. Cross-reference Plugin kartellrecht.
8. Limitation period § 141 PatG
- 3 years from the end of the year in which the claim arose and the holder of the claim has knowledge of the infringement and of the person of the infringer (§§ 195, 199 BGB by analogy)
- 10 years maximum period independent of knowledge
- Residual damages claim up to 30 years under the law of unjust enrichment (§ 852 BGB by analogy, German Federal Court of Justice "voltage supply device", X ZR 109/16)
- Continuing infringement: each individual act of infringement starts its own limitation period
Sources and citation style
Binding: ../../../references/zitierweise.md.
Statute
- § 9 PatG (effects — direct)
- § 10 PatG (indirect use)
- § 14 PatG (scope of protection)
- § 139 PatG (injunction, damages)
- § 140a PatG (Destruction, recall)
- § 140b PatG (Information)
- § 140c PatG (Inspection)
- § 141 PatG (Statute of limitations)
- § 143 PatG, § 145 PatG (Patent litigation matters)
- Art. 64 EPC (Effects of the EPC); Art. 69 EPC + Protocol on Interpretation
- UPC Agreement, Art. 32 ff. (jurisdiction), Art. 83 (transitional period / opt-out)
Commentaries
- Scharen, in: Benkard, PatG, 12th ed. 2023, § 14 para. 1 ff., § 139 para. 1 ff.
- Kühnen, Handbuch der Patentverletzung, 16th ed. 2024, Ch. A–E (Düsseldorf practice)
- Voß, in: Schulte, PatG, 11th ed. 2022, § 139 para. 1 ff.
- Rinken, in: Mes, PatG, 5th ed. 2020, § 139 para. 1 ff.
Case law
- BGH, "Schneidmesser I", X ZR 168/00 — equivalence triad same effect
- BGH, "Schneidmesser II", X ZR 135/01 — discoverability
- BGH, "Schneidmesser III"
[unverifiziert – prüfen in juris/epo.org]— equivalence oriented to the patent claim - BGH, "Okklusionsvorrichtung", X ZR 16/09 — selection decision of the applicant
- BGH, "Diglycidverbindung", X ZR 69/10 — interpretation methodology
- BGH, "Spannungsversorgungsvorrichtung", X ZR 109/16 — residual damages § 852 BGB by analogy
- CJEU, judgment of 16.07.2015 – C-170/13, Huawei/ZTE — FRAND
- Düsseldorf Higher Regional Court series on information and inspection practice
[unverifiziert – prüfen in juris/epo.org]
Output format
KLAGESCHRIFT (Entwurf) — Patentverletzung
LG <…>, Patentstreitkammer / UPC <Lokalkammer/Zentralkammer>
Klägerin: <…>
Beklagte: <…>
Aktenzeichen Patent: <DE / EP / EP(UE)-Nr.>
A. Klageanträge
1. Unterlassung (§ 139 I PatG)
2. Auskunft (§ 140b PatG)
3. Schadensersatz dem Grunde nach (§ 139 II PatG) — Wahl der
Berechnungsmethode nach Auskunft
4. Vernichtung (§ 140a I PatG)
5. Rückruf (§ 140a III PatG)
6. ggf. Urteilsveröffentlichung (§ 140e PatG)
B. Tatbestand
I. Parteien
II. Klagepatent (Rechtsstand, Veröffentlichung, Erteilung,
Einspruchsstatus, ggf. Nichtigkeitsverfahren)
III. Angegriffene Ausführungsform (technische Beschreibung)
IV. Verletzungshandlungen (erste Kenntnis, Zeitraum)
C. Rechtliche Würdigung
I. Schutzrechtsbestand
II. Schutzbereich § 14 PatG
Merkmalsgliederung Hauptanspruch
M1 …
M2 …
M3 …
III. Verletzungstatbestand
1. Wortlautverletzung § 9 PatG
Subsumtion M1 — M2 — M3 — …
2. Hilfsweise: äquivalente Verletzung
(Gleichwirkung — Auffindbarkeit — Gleichwertigkeit)
3. Ggf. mittelbare Verletzung § 10 PatG
IV. Anspruchskatalog § 139 ff. PatG
– Unterlassung (verschuldensunabhängig)
– Schadensersatz § 139 II
• dreifache Berechnung (entgangener Gewinn /
Verletzergewinn / Lizenzanalogie)
• Wahl nach Auskunft
– Auskunft § 140b
– Vernichtung / Rückruf § 140a
V. Verjährung § 141 PatG — drei-Jahres-Frist (gewahrt) /
Höchstfrist / Restschadensersatzanspruch
VI. Forumwahl
– LG <…> Patentstreitkammer (§§ 143–145 PatG)
– ggf. UPC: Opt-out-Status geprüft
VII. Bei SEPs: FRAND-Compliance
D. Beweismittel
– Patentschrift, Registerauszug
– angegriffene Ausführungsform (Produktfotos, Datenblätter)
– Zeugen, Sachverständigengutachten
E. Risiken / offene Punkte
🟢 / 🟡 / 🔴 mit Begründung
– Nichtigkeitsangriff erwartbar?
– Aussetzungsantrag § 148 ZPO?
– Streitwertfestsetzung
F. Quellenverzeichnis
Examples
Scenario: Plaintiff holds a granted European bundle patent without UPC opt-out, validated in DE. Defendant has been distributing a literally identical competing product for 14 months. Question: action before the Düsseldorf Regional Court or the UPC?
Short answer (🟡): literal infringement appears unproblematically provable. Choice of forum strategic: the UPC offers a pan-European injunction in one proceeding, but carries a central invalidity risk; the Düsseldorf Regional Court provides only DE protection, but has well-established infringement doctrine and separation of infringement / invalidity (stay practice § 148 ZPO). Limitation § 141 PatG is observed for 14 months; Information § 140b PatG via staged action § 254 ZPO, choice of damages calculation only after information. Before filing the action: Opt-out status check in the UPC register.
Risks / typical mistakes
- Feature breakdown missing or imprecise — subsumption collapses.
- Equivalence assessed in a blanket manner without checking the BGH triad — action fails on appeal.
- Selection decision during grant overlooked (applicant deleted a variant) — equivalence corridor blocked.
- Overlooked statute of limitations § 141 Patent Act — for continuing infringement, observe installment-based limitation; use residual damages claim.
- UPC opt-out status not checked — action filed in the wrong forum, dismissal for lack of international jurisdiction.
- FRAND requirements not complied with for SEPs — injunction claim ceases under CJEU "Huawei/ZTE", C-170/13.
- Expert representation under § 143(3) Patent Act not arranged — patent attorney required in addition to the lawyer.
- Choice of damages calculation determined too early — exercise the right of choice until the end of the oral hearing.