Steven Kirsch invented an optical mouse before he was out of MIT. But he had to start his own business to get it off the ground. His patent, the earliest patent for an optical mouse, explains his intention to make a pointing device with few precision moving parts for more reliable tracking. He intended to use ready made components for ease of manufacture, mass production and affordability.
Patent 4,390,873 filed 18 May 1981
Kirsch founded Mouse Systems in 1982 and shipped the first mice in October, selling a few hundred a month after that for $300 each. The Mouse Systems optical mouse progressed from the Model M-1 through M-4, with design refinements on the inside. The mouse body kept its sleek rectangular shape.
By 1986 Kirsch was ready to focus his creative itch on other ventures. Mouse Systems sold to Kye a few years after he left the main operations behind.