A timeline published by Logitech states that in 1982, "Logitech introduced its first *mouse*, the P-4. The P-4 used opto-mechanical technology, featuring optical encoders connected to the rollers to deliver greater tracking precision while providing the tactile response of a rolling ball." As usual, every mouse has a tale much more interesting than the bare facts.
In 1977 André Guignard and Professor Jean-Daniel Nicoud designed the computer mouse produced by the watchmaking company Dubois Depraz SA. Another Swiss company, Logitech, purchased and marketed it in 1980-83 [Wikipedia]. The opto-mechanical encoders improved on Doug Engelbart's invention that was developed at Stanford. The Dépraz mouse was also sold for Smaky personal computers.
14 Oct 2009 - World Radio Switzerland reports the passing of René Sommer, who added the micro-processor to the design of the Logitech mouse in 1985.