Keyboards play an important role in the function of computers and other electronic devices with a user interface. As you probably already know, they allow users to control a computer by typing. Keyboards have an array of keys, consisting of letters, numbers, special characters, quick access buttons, etc. And while all keyboards feature this same general design, there are different technologies that power them. Here are four keyboard technologies that you’ve probably never heard of.

#1) Buckling Spring

Developed in the early-1990s by IBM, buckling-spring keyboards are characterized by a unique design in which a spring is installed over a switch. When a key is pressed, the switch closes the circuit, thereby telling the computer or device to which it was connected that the key was pressed. Buckling-spring keyboards were originally manufactured by IBM. Now, however, Unicomp manufactures most of them.

#2) Hall Effect

Another type of keyboard that you’ve probably never heard of is hall effect. Featuring Hall effect sensors in place of traditional switches, they work by using magnets to identify keypresses. When you press a key on a hall-effect keyboard, a magnet  moves closer to the Hall effect sensor, allowing it to determine which key you pressed. When compared to other keyboard technologies, hall effect is among the most reliable. This is due to the fact that no direct contact is required. Rather, the magnet only needs to move next to the sensor for it to register the user’s keypress.

#3) Laser Projection

Laser projection keyboards are smaller keyboard that use lasers to identify keypresses. Although effective, these keyboards rely specifically on one or more lasers to function. If the laser stops working, none of the keys will register.

#4) Optical

Finally, there are optical keyboards, which are still relatively new but gaining momentum in the computer peripheral market. Also referred to as photo-optical keyboards, optical keyboards feature a combination of photo sensors and light-emitting diodes (LEDs) to register keypresses. The LEDs project light across the surface of the keyboard. When you press a key, lock is blocked in the specific area of that key. This allows the keyboard to determine which key you pressed, and it relays this information to the computer or device to which it’s connected.

These are just a few alternative keyboard technologies. Of course, mechanical switch and membrane remain the most popular choices, and for good reason: They offer the perfect combination of ergonomics, versatility, reliability and customization.