Stefan Mileschin

GIGABYTE has introduced its second AORUS-branded keyboard aimed at gamers. The new AORUS K9 Optical, as the name implies, uses optical/infrared switches with all the advantages they can provide. All the keys are black and are backlit using RGB LEDs, but specifically for gamers the manufacturer includes frequently used nine orange keycaps made of PBT.

Harley E. Kelchner from Burroughs Corp. patented optical keyboard technology that used light-emitting diodes and photo sensors to register actuations of keys in 1960. Back then, optical detection of actuated keys was needed to reduce the noise generated by actuation of typewriter or adding machine keys. The technology has never become widespread, but was not forgotten.

https://www.anandtech.com/show/12078...tical-keyboard