How A Secondhand Ground Brush Wiped Away A Chinese Patent

A Chinese robot vacuum company digs up "hidden evidence" to successfully invalidate a patent owned by its biggest competitor.

Highlights

1. Proof of original sales date of a secondhand product
2. Proof of product launch date

Background

With the growth of online shopping, it is easier than ever to provide evidence of a sale when the product is still being sold on the market. But what if the product is no longer being sold? It's much more challenging to prove the original disclosure date for a secondhand item, especially in a jurisdiction like China, which has very stringent notarization and legalization¹requirements for introducing evidence into a proceeding.

The case below demonstrates an example of how one major Chinese robot company successfully dug up and introduced sufficient evidence to invalidate a patent owned by its biggest competitor. This case was highlighted in the CNIPA's published "Compilation of Key Decisions from Typical Cases of