Computer Keyboard Functions: How does a Keyboard Work
In today's technology driven world, everyone is aware about computing and the usage of computer keyboard. We all know that keyboard is an input device that functions in accordance to the instructions of the user. Computer keyboards are used for preforming various tasks such as typingon a word processor or text editor, accessing menus and playing games. Though pressing a key corresponds to typing a letter, sign or symbol, it may also represent computer commands. For example, pressing the F5 key is a command for refreshing.
For some characters, it is necessary to press and hold more than one key at the same time. Speaking about the history of computer keyboards, it was modeled in the 1940s based on the technology of typewriter keyboard. Similar to typewriter keyboard, a computer keyboard consists of a set of keys engraved with symbols and letters. However, the productivity of working on a computer keyboard is much more than that of a typewriter keyboard.
Functioning of a Computer Keyboard
In general, there are 80-110 keys in a computer keyboard. The keys may vary depending upon the brand and the type of operating system. Nevertheless, the shape, size and spacing of keys are almost same for all keyboards. Also the layout or arrangement of keys that represent letters, signs and symbols is same, which is referred to as QWERTY.
The working of a computer keyboard can be compared to a miniature computer. Inside the keyboard, there are metallic plate, circuit board (key matrix) and processor, which are responsible for transferring information from the keyboard to the computer. Depending upon the working principle, there are two main types of keys, namely, capacitive and hard-contact. Let's discuss in brief about the functioning of capacitive and hard contact key.
Capacitive Key
On the underside of a capacitive key, a metal plunger is fixed, which helps in activating the circuit flow. When a capacitive key is pressed, the metal plunger applies a gentle pressure to the circuit board. The pressure is identified by the computer and the circuit flow is initiated, resulting in the transfer of information from the circuit to the currently installed software.
Hard Contact Key
A hard contact key is attached with a metallic plate that helps in connecting the circuit board. When the hard contact key is pressed, it pushes a metallic plate, which in turn touches the metallic portion of the circuit plate. This overall process of completing a circuit results in a circuit flow, allowing the transfer of the message to the central processing unit (CPU), which is further transmitted to the software.
In both the key types, the circuit signals the processor to read and/or identify the character that has been pressed. For example, in a hard contact key, the processor reads that pressing 'shift' and 'a' keys at the same time corresponds to 'A'. Hence accordingly, the letter, sign or symbol is displayed on the screen. Releasing the pressed key breaks the circuit flow, after which the key retains its original position. The communication between a computer keyboard and main computer is bi-directional, meaning that message or information can be sent within each other.
