Over the last few weeks there has been an amount of discussion about Nikon taking a case against Viltrox in China’s patent court. One of the interesting aspects of this is the court. There are no international patents, so had Nikon wanted to effectively stop Viltrox selling Z-mount lenses the case would most likely have been taken in the USA and Europe. It might be that the aim is to gain some royalties in the Chinese marketplace, where the Viltrox price advantage is even larger than in other markets.
It’s worthwhile clearing up some of the misapprehensions that have appeared in the photographic press concerning this case. One such is that Nikon has sued Viltrox for infringing the ‘Z-mount patent’. There is no singular ‘Z-mount patent’. Patents (apart from design patents) protect an invention or idea, not a particular product. A patent is a contract between an inventor and a state, whereby a monopoly of use of an invention is given for a period in exchange for making public how it works. The idea is that the common good is served by this disclosure in terms of development of technology, which would not happen were the investor to simply keep the idea secret.
For the inventor to gain the privilege of a monopoly the invention must be original, significant and not an ‘obvious’ development that would occur to any competent practitioner. A patent is granted once an examiner is convinced of this. However, the examiner is not a domain expert and can be bamboozled by obfuscatory language – leading to many patents being anything but clear to read. If sued for patent infringement the defendant can win the case by showing that the patent was wrongly granted, for instance that the invention was not original, significant, or that it was obvious – in which case the patent becomes void and anyone can use this ‘invention’.
A patent consists of three substantive parts.
Firstly, a summary of the invention, which explains the purpose and originality of the invention and the state of the art from which it was developed. Second is a description of some embodiments of the invention, illustrating its usage. Finally are the ‘claims’, the important part, which define precisely what is the novel part of the invention that will be protected.
I have looked at thirteen Nikon patents relating to the design of the Z-mount. One relates to a detail of the physical design of the mount, and I would surprised if that would withstand court scrutiny. The others all relate to the communications between camera and lens, and all but one to an unusual feature of the Z-mount – that it has two serial communication channels. In itself this is not original. It occurred in the Micro Four Thirds mount, where a second channel was added for proprietary lens functions. In the Nikon case the extra channel is dubbed the ‘hot-line’, and is a high-speed channel used for feedback of focus and image stabilisation functions. These were precisely the usages made of the extra channel in the Micro Four Thirds mount, so also not by themselves original.
Reading the Nikon claims, in general they relate to the fact that the second channel is synchronous (whereas the prior art was asynchronous), and the precise order of interplay between the two channels. Whether these differences are significant or obvious will be for the court to decide. That is assuming that Viltrox decides to defend the case. It might be simpler for them to come to an arrangement with Nikon. In the recent case in which RED sued Nikon, using a patent that likely could have been voided, Nikon’s response was to simply to purchase them wholesale!
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