Prior Art and Public Availability: Key Decisions in German Patent Litigation
In Short
The Situation: Even after the introduction of the European Unitary Patent Court, Germany remains a key battleground in major patent litigations. In the bifurcated German litigation system, nullity cases are heard before the German Federal Patent Court. Its decisions often have a signal effect for the outcome of litigation in Europe and beyond. In a number of recent decisions, the German Federal Patent Court has made critical rulings regarding prior art and public availability in nullity proceedings.
The Details: These decisions highlight the importance of thorough documentation of competitor products and the meticulous search for prior art, underlining the courts' rigorous standards in determining patent validity. They emphasize the need for patent holders and challengers alike to pay close attention to the nuances of public disclosure.
Looking Ahead: Whether through ensuring comprehensive records of product features or understanding the full scope of prior art, the nuances of public disclosure remain a cornerstone of patent law in Germany.
Motorized Wheelchair
The first case (Federal Patent Court Judgment dated 03/29/2023—6 Ni 1/22 (EP)) revolved around a patent for a wheelchair featuring mid-wheel drive and rear stability systems, designed to prevent tipping while maintaining obstacle-climbing ability. The nullity plaintiff presented compelling evidence of prior public use showcasing a used 20-year-old wheelchair identical to the patented design. This wheelchair had been sold by the patentee before the priority date and was later bought by the plaintiff secondhand on eBay. When the patentee denied that the wheelchair had been delivered before the priority date of the patent, the nullity plaintiff managed to prove the delivery to the buyer by means of the patentee's own warranty database.
The court examined sales records, invoices, and the used chair carefully. It determined that through the model sold, the wheelchair's features were accessible to the public before the patent was filed, leading to the conclusion that the patent lacked novelty and was thus invalid.
Diaphragm Pressure Sensor
In this case (Federal Patent Court Judgment dated 11/24/2022—19 W (pat) 10/22), the nullity plaintiff claimed prior public use, providing detailed delivery notes, technical drawings, and witness testimony to demonstrate that the patented features were known and available to the public before the priority date. The evidence showed that the sensors had been delivered to the patentee, who was also a competitor, thus ensuring that the technical details were accessible for inspection and measurement. The court agreed that these features were publicly disclosed, making the patent invalid due to lack of novelty.
Diver Propulsion Vehicle
In contrast, despite the nullity plaintiff's allegations regarding public prior use, citing public exhibitions and a loan agreement, the patent in this case (Federal Patent Court Judgment dated 03/22/2023—8 Ni 8/23 (EP)) was upheld. The court found that the public displays at events like the "Red Dot Design Award 2011" and the trade fair "Boot 2012" did not provide sufficient evidence that the vehicle's internal features were accessible to the public. Furthermore, the loan agreement for testing purposes included a confidentiality clause, which protected the disclosure of the vehicle's details. The lack of clear, public accessibility of the critical features led the court to uphold the patent's validity.
Three Key Takeaways
- Meticulously document competitor products. This is crucial, as thorough collection of evidence of prior public use can significantly impact the outcome of possible future patent litigation.
- Dig deep to find prior art. This can be the key to invalidating patents based on public availability. The decisions show that German courts take disclosure of patented features in products on the market very seriously and are willing to undertake in-depth investigations in litigation. Patentees may well have tripped themselves up by prematurely releasing their own patented product. Hence, it is worth the effort to carry out an investigation of products on the market around the priority date.
- Confidentiality Matters. Non-disclosure agreements play a vital role in protecting patent validity by preventing public disclosure of critical features.
