Viltrox filed another patent in China that involves the Nikon Z-mount – here is the interpretation I got from AI translation:
This new Chinese design patent CN 309984573 S from Viltrox protects the ornamental/appearance design (not the mechanical function or electronics) of a bayonet-mount/lens-mount ring that appears very similar to the Nikon Z-mount. The purpose of the patent is to connect camera lenses or camera adapter rings (Viltrox teleconverter or lens adapter).
This Viltrox design patent appears to be for Nikon Z-mount lenses/adapters. It is not an official Nikon patent, nor does it invent a brand-new proprietary mount. It is Viltrox protecting the visual appearance of the specific bayonet ring they use on their Z-mount products.
Viltrox has been producing autofocus lenses and adapters for the Nikon Z-mount for years (alongside Sony E, Fuji X, and, more recently, L-mount). The timing of the patent (application in late 2025, granted on May 15th, 2026) directly ties it to the high-profile Nikon vs. Viltrox legal dispute from early 2026. Nikon sued Viltrox in the Shanghai Intellectual Property Court over Z-mount-related intellectual property, specifically royalties and alleged infringement during the provisional protection period of Nikon’s invention patents (covering the Z-mount interface, electronics/communication protocols, etc.).
Chinese blogs, forums, and photography communities discussing the lawsuit explicitly reference this exact patent number (CN309984573S) in the context of Nikon Z-mount third-party products.
The mechanical bayonet in the patent is engineered to match the Nikon Z-mount standard (large ~55 mm inner diameter, short flange distance, specific lug/tab geometry for full compatibility with Nikon Z cameras). Viltrox patented the look of their implementation (the precise contours, proportions, and details visible in the patent drawings) as part of their IP strategy while making Z-mount lenses.
This fits the pattern of third-party manufacturers reverse-engineering or closely replicating mirrorless mounts (Sony E, Nikon Z, etc.) while sometimes filing their own design patents on cosmetic or minor variant details.
The ongoing Nikon lawsuit is about licensing/royalties for Nikon’s underlying Z-mount technology, not this specific Viltrox design patent:
Stores and distributors in China are removing all Sirui Z-mount lenses
Detailed report on the Nikon and third-party Chinese Z-mount lens manufacturers
Additional information on the patent:
- Patent Number: CN 309984573
- Application Date: October 31, 2025
- Publication/Grant Date: May 15, 2026
