Editing Keystroke sensing (section)

==Overview==
Keyboard [[key]]s can be thought of as a combination of two principles: a method to allow the host device (e.g. computer) to sense that a key was pressed, and a method of operating the switch. These concepts are distinct, although they do overlap. Switch operation covers ways to make the key spring back up when released, and when desired to generate a sound or a change in feel to indicate to the operator that the keystroke was registered.

Fundamentally, a keyboard needs to sense keystrokes. Trade-offs between manufacturing cost and longevity have led to a number of different approaches. Such approaches have been collectively termed "'''contact mechanisms'''", but since many designs do not rely on physical switch contacts this term is a misnomer, and "'''sense method'''" is more appropriate.

Various combinations of the two principles can be combined. For example, rubber domes have been used in conductive, magnetic valve and capacitive switches; in conductive switches they form part of the physical switching mechanism, while in electromagnetic switches they simply serve to return the key and provide [[tactile|tactility]].

The different methods of sensing keystrokes are detailed below.