Reports are emerging that Nikon has had one of its Z-mount patents invalidated in China, opening the door a little further to third-party access.

Nikon Rumors reports that one of Nikon’s fundamental patents relating to the Z-mount has been invalidated in China, having been challenged by Viltrox’s parent company.

The report, based on AI translations of court documents, suggests that the patent in question is one that sets out the basic physical description and behavior of the mount, constructed in a way that tries to make well-established features, such as the design to prevent incorrect mounting of the lens and a method for preventing damage to the electrical contacts sound original and novel. Patents are only supposed to protect original inventions that would not be obvious to someone working in that field.

Nikon took Viltrox to court in China earlier this year in a separate case, ostensibly to recover license fees but also, we suspect, in the hope that a Chinese court would establish a precedent of its patents being enforceable. As Professor Robert Newman explained in Amateur Photographer magazine at the time, there are at least 13 patents covering various aspects of the Z-mount’s design and operation, including one he described as relating to “a detail of the physical design of the mount, and I would be surprised if that would withstand court scrutiny.”

This description corresponds well with the details being reported by Nikon Rumors, right down to Prof. Newman’s assessment of its likely fate.

The invalidation of this patent doesn’t, in itself, clear the way to third parties being able to produce Z-mount lenses, as there are multiple other patents that describe the communication methods used by the Z-mount. Those would not be affected by this specific patent being invalidated.

It’s notable, though, that Viltrox has added to its range of autofocus Z-mount lenses since the original court case was meant to be heard. Other third-party makers, such as Meike, which briefly removed reference to Z-mount lenses from its website, also have a range of Z-mount options available again.

If, as seems to be the case, non-licensed third-party makers are feeling emboldened to produce AF Z-mount lenses, it puts Nikon in an awkward position with the companies that have been formally licensed to make lenses for the system. Those companies are presumably paying license fees and have to seek approval on a lens-by-lens basis, while their competitors undercut them without any such restrictions.

We have approached Nikon for a statement on this story.

About the Author: Richard graduated as a scientist but had a lot more fun writing and shooting for his university magazine. A number of years spent variously as a reporter, writer and editor on science and engineering titles combined his knowledge of science with his interest in images and words. But it was spotting the connections between emission spectra, white balance and all the nonsense he’d taught himself playing around in Photoshop that helped kindle an interest in digital photography. Searching for a camera led to him discovering DPReview and Richard was recruited by Phil Askey in 2007. He’s been combining his love of photography, communication and attention to detail (pedantry?) ever since.

He has unusually strong opinions about lenses for the APS-C format.