China Invalidates Nikon Z-Mount Patent in Viltrox Dispute

China's patent office ruled Nikon's Z-mount 'Accessories' patent invalid on July 13, finding it lacks an inventive step — a direct win for Viltrox, which challenged the patent in December 2025. The patent covered the bayonet lug geometry and electrical contact placement on the Z-mount. Nikon can appeal through Chinese courts, and the ruling covers this one patent only, not the Z-mount system broadly.