First manufacturer to put name on back of synth?

Ok, totaly useless topic. But I was wandering which manufacturer was  
the first to put it's name on the back of a synth?
Totaly brilliant from a marketing point of view. Having your name on  
stage like that.

All of my keyboard synths have their manufacturer's name written on  
them on the back, except for the Solina. So, it must have been an  
analogue synth manufacturer. But which one?

David
http://dvdborn.blogspot.com