A patent infringement procedure in Germany follows a structured legal process that includes several key stages, potential defenses, and legal remedies. Below is an overview, including relevant case law and examples.

1. Legal Basis for Patent Infringement in Germany

Patent infringement proceedings in Germany are primarily governed by the German Patent Act (Patentgesetz, PatG) and the Code of Civil Procedure (Zivilprozessordnung, ZPO). The European Patent Convention (EPC) also plays a role when dealing with European patents.

Types of Patent Infringement

• Direct Infringement (§ 9 PatG) – Unauthorized manufacturing, using, offering, or selling of a patented product/process.
• Indirect Infringement (§ 10 PatG) – Supplying or offering essential means for using a patented invention without authorization.

2. Procedure for Patent Infringement Litigation

Step 1: Cease-and-Desist Letter (Abmahnung)

Before initiating court proceedings, the patent holder often sends a cease-and-desist letter to the alleged infringer. This letter demands that the infringer stop the infringing activities, provide information about past infringements, and pay damages.

Step 2: Filing a Lawsuit (Patent Litigation)

If the infringer does not comply, the patent owner may file a lawsuit before one of the three specialized patent litigation courts in Germany:

• Düsseldorf Regional Court (LG Düsseldorf)
• Mannheim Regional Court (LG Mannheim)
• Munich Regional Court (LG München I)

These courts have jurisdiction over civil patent infringement cases.

Step 3: Proceedings in the First Instance

• Written Pleadings & Exchange of Arguments – The plaintiff (patent holder) submits claims, and the defendant can respond with defenses.
• Evidence & Expert Opinions – The court examines whether the patent is infringed based on claim interpretation. Expert witnesses and technical reports may be considered.
• Oral Hearing & Judgment – The court issues a ruling on the infringement and possible remedies.

3. Defenses Against Patent Infringement Claims

A defendant may argue:

1. Non-Infringement – The allegedly infringing product does not fall under the patent claims.
2. Patent Invalidity – The defendant can initiate a parallel nullity action before the Federal Patent Court (Bundespatentgericht, BPatG) to challenge the validity of the patent.
3. Exhaustion Doctrine – Once a patented product is sold in the EEA by the patent owner or with their consent, further sales cannot be restricted.
4. License Defense – The defendant argues that they have a valid license to use the patented invention.

4. Legal Remedies for Patent Infringement

If a patent infringement is found, the court may order:

1. Injunction (§ 139(1) PatG) – Prohibition of further use or sale of the infringing product.
2. Damages (§ 139(2) PatG) – Compensation based on:
   • Lost profits
   • Reasonable royalties
   • Unjust enrichment of the infringer
3. Destruction of Infringing Products (§ 140a PatG) – Removal of infringing goods from the market.
4. Information & Accounting (§ 140b PatG) – Disclosure of supply chains and sales data.

5. Appeals & Legal Remedies

• Appeal (Berufung, §§ 511 ff. ZPO)
  The losing party can appeal to the Higher Regional Court (Oberlandesgericht, OLG).
• Further Appeal (Revision, § 543 ZPO)
  If a fundamental legal question is at stake, an appeal to the Federal Court of Justice (Bundesgerichtshof, BGH) is possible.
• Nullity Proceedings at the BPatG (§ 81 PatG)
  Defendants often challenge the validity of the patent in separate proceedings.
• Parallel EPO Proceedings
  If the disputed patent is a European Patent (EP), opposition proceedings before the European Patent Office (EPO) may be initiated.

6. Key Case Law in Germany

1. BGH “Formstein” (1986) – Established the Formstein defense, which limits the doctrine of equivalents by preventing infringement claims if the allegedly infringing device would itself be unpatentable due to prior art.
2. LG Düsseldorf “Heat Exchanger” (2019) – Reinforced the need for precise claim interpretation in complex technical fields.
3. BGH “Okklusionsvorrichtung” (2019) – Confirmed that equivalents can infringe a patent, but only if they achieve the same technical effect in an obvious manner.

7. Example: Apple v. Samsung (Patent Dispute in Germany)

In the long-running global patent war, Apple sued Samsung in Germany over smartphone patents, including touchscreen functionalities. The LG Düsseldorf and the OLG Düsseldorf ruled in different instances, demonstrating the complexity of claim interpretation in software patents.

Conclusion

Patent infringement proceedings in Germany involve specialized courts, technical complexity, and multiple legal remedies. Companies often rely on strategic litigation, including parallel nullity actions and EPO opposition proceedings, to defend their market position.