Archived posting to the Leica Users Group, 1997/10/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Under international patent and copyright conventions, the life of intellectual property is controlled by the granting nation. In German law, the life of a patent is 20 years and is non-renewable. (This, incidentally, explains why the initial 3.5/5cm lens on the first Leica was dubbed an 'Anastigmat' and only acquired the Elmax name in '23. The Zeiss patent on the Tessar formula expired at the end of '22: to that point, Zeiss only allowed others to use it if they gave it the Zeiss trademark, 'Anastigmat'. Once the patent expired, Leitz could call it anything they wanted, so they gave it the acronym, ELMAX from "Ernst Leitz Max", the last for Professor Max Berek, head of optical design at Leitz.) I believe Japanese law tracks this as well. In any event, the original LTM patent expired in 1951, and Leitz made no effort to protect it. For that matter, Vivitar made a run of Leica R lenses in the mid-1980's: the patent on the R bayonet would have expired in '83 or so. Thus, I am fairly comfortable in saying that there is no legal protection afforded the M mount anywhere. Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!