I don't think Canon ever licensed the EF mount.
It's been posted several times here but is perhaps being lost as there are so may duplicate threads with so many replies. Canon could have indeed patented the RF protocols but it is perfectly legal to reverse engineer them. However, if a competitor had obtained the code by deception, theft etc, then it would be illegal to use it. It has been reported several times but I cannot vouch for it that Canon has licensed to Sigma and Tamron but would not license to a non-Japanese company.
You keep referencing "obtained the code by deception, theft etc." but that's not how patents work. Stealing something is a criminal offense, so obtaining corporate secrets through theft or deception would be a matter to take to criminal court. Protecting a patent is a property right. A patent case does not need to prove that the information was obtained illegally. It just has to prove that someone is using your patented design. How they came up with that design is irrelevant. Even if you come up with the design all on our own, without any knowledge of the patent, if it duplicates one that is patented then you are infringing on the patent.
Where has that been reported? My understanding is that @entoman is correct that Canon never licensed the EF designs to anyone, but that Sigma and other third party manufacturers had designs that did not violate the patents. Most people assume they came up with those designs through reverse engineering, which certainly sounds plausible.
I would not be at all surprised if there was some patent infringement going on.
It is far more complicated than you think. Read this from beginning to end, especially the end, https://en.wikipedia.org/wiki/Reverse_engineering where it is explained. Some court cases about reverse engineering are also summarised in wiki https://en.wikipedia.org/wiki/Atari_Games_Corp._v._Nintendo_of_America_Inc. https://en.wikipedia.org/wiki/Bowers_v._Baystate_Technologies,_Inc.
I wrote: "It has been reported several times but I cannot vouch for it that Canon has licensed to Sigma and Tamron but would not license to a non-Japanese company." The meaning should be clear: I have seen it reported many times but have never seen the evidence that supports the assertions. I don't keep records of gossip.
First, I was agreeing with your main points.
Well the above is true and quite relevant to a discussion on a forum dedicated to camera gear, I don’t believe any of that really applies to the ‘typical consumer’.
It is correct that, per se, reverse engineering does not expose you to legal liability. The point is, though, that relates specifically to the reverse engineering process, ie pulling something apart to learn how it works. To make a product based on what you have learned is a separate step, and if your product infringes another person's intellectual property, you have a problem even if there was nothing illegal about you reverse engineering the other product to learn how it works. If what you learned was simply something which was previously a trade secret, it is unlikely you will be infringing IP by using what you learned in your product (unless, as you have already noted, you have breached an end user agreement, been deceptive, etc). However, with other forms of IP (ie other than confidential information) such as patents, copyright, registered designs, integrated circuit layout rights, etc, the situation is different. So, for example, reverse engineering the RF mount is one thing, developing a lens which can use the RF mount is another. In particular, what we seem to be seeing is that developing a lens which makes use of the electronics in an RF mount must be difficult or perhaps even impossible to do without infringing Canon's IP (in particular, it seems, infringing one or more Canon patents).
First of all, I'm not a lawyer. That said, I think you are comparing Apples to Oranges in this case. Yes, Motorola enforces their patents. And good for them. Either Canon did not patent the EF protocols ( according to one poster here ) OR Canon did not enforce their EF patents for about 35 years ( from 1987 onwards ) OR Sigma legitimately reverse engineered the EF mount communications protocols. So my understanding of patent law is that you have to enforce your patents or essentially, you lose them. They may have to enforce the current RF physical mount patent, as used on the EF to RF adapters, assuming they have one and send a Cease and Desist letters to the various makers of these adapters to retain that patent but it would appear to me that the EF focus / stabilization protocols could be used based on Canon's previous behaviors. Like I said previously, make a Sigma Sport 150-600 DN with Canon RF physical mount using Sigma's EF communications protocols with the promise that once they work things out with Canon, that mount can be upgraded either through firmware or by sending the lens back to Sigma to replace the original RF style mount with a new, true RF Mount.
Thanks for this thoughtful post.
Not at all... patent infringement is patent infringement. There is either only apples or there are only oranges.
Canon has one of the largest patent portfolio's in the world and are also one of the most successful litigators of patent infringement. If Sigma infringed on there IP they would have been sued. That said Sigma is a true 3rd party brand and have a reputation to uphold. So there is no way they would release a product that Canon can buy in any store, take apart and find firmware\hardware that is a direct copy of there design. Pro Tip: Reverse Engineering is not cloning.
Not really that simple... But in this case it is completely irrelevant since Canon was still filing patents on the EF mount in 2020 - https://petapixel.com/2020/01/23/new-patents-show-canon-hasnt-given-up-on-the-ef-mount-just-yet/
Yes, I would agree with that regarding patents. The situation isn't necessarily the same for all types of IP though. For example, for copyright infringment, essentially there needs to be some relevant dealing with the copyright work. So, if I come up with something which is identical to your copyright work but I didn't copy your work (eg I didn't even know you had ever even created your copyright work so I couldn't have copied it), that isn't copyright infringement. Obviously, that would be an unusual situation though!
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