Working principle of keyboard

Answer 1

the keboard work as:

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.

Answer 2

Keyboards use a variety of switch technologies. Capacitive switches are considered to be non-mechanical because they do not physically complete a circuit like most other keyboard technologies. Instead, current constantly flows through all parts of the key matrix. Each key is spring-loaded and has a tiny plate attached to the bottom of it. When you press a key, it moves this plate closer to the plate below it. As the two plates move closer together, the amount of current flowing through the matrix changes. The processor detects the change and interprets it as a key press for that location. Capacitive switch keyboards are expensive, but they have a longer life than any other keyboard. Also, they do not have problems with bounce since the two surfaces never come into actual contact.

All of the other types of switches used in keyboards are mechanical in nature. Each provides a different level of audible and tactile response -- the sounds and sensations that typing creates. Mechanical key switches include:

• Rubber dome
• Membrane
• Metal contact
• Foam element

Rubber dome switches are very common. They use small, flexible rubber domes, each with a hard carbon center. When you press a key, a plunger on the bottom of the key pushes down against the dome, and the carbon center presses against a hard, flat surface beneath the key matrix. As long as the key is held, the carbon center completes the circuit. When the key is released, the rubber dome springs back to its original shape, forcing the key back up to its at-rest position. Rubber dome switch keyboards are inexpensive, have pretty good tactile response and are fairly resistant to spills and corrosion because of the rubber layer covering the key matrix.

Rather than having a switch for each key, membranekeyboards use a continuous membrane that stretches from one end to another. A pattern printed in the membrane completes the circuit when you press a key. Some membrane keyboards use a flat surface printed with representations of each key rather than keycaps. Membrane keyboards don't have good tactile response, and without additional mechanical components they don't make the clicking sound that some people like to hear when they're typing. However, they're generally inexpensive to make.

Metal contact and foam element keyboards are increasingly less common. Metal contact switches simply have a spring-loaded key with a strip of metal on the bottom of the plunger. When the key is pressed, the metal strip connects the two parts of the circuit. The foam element switch is basically the same design but with a small piece of spongy foam between the bottom of the plunger and the metal strip, providing a better tactile response. Both technologies have good tactile response, make satisfyingly audible "clicks," and are inexpensive to produce. The problem is that the contacts tend to wear out or corrode faster than on keyboards that use other technologies. Also, there is no barrier that prevents dust or liquids from coming in direct contact with the circuitry of the key matrix.

Different manufacturers have used these standard technologies, and a few others, to create a wide range of non-traditional keyboards. We'll take a look at some of these non-traditional keyboards in the next section.

Answer 3

there is a circuit board inside the keyboard that is wired up to the power that comes from the computer

on top of that there is a thin membrane that is lined up to the keys on the outside

the keys have a Poker on the other side that press on the membrane and then this action is recorded by the keyboard to be sent to the computer

it in a way completes the circuit on the board to produce a result that can then be displayed on screen

Answer 4

A keyboard is a input device primarily used on computing devices. The parts inside a keyboard are basically a computer. There is a circuit running under the keys and when the key is pressed it cuts the circuit in that area and the chip on the keyboard translate it as which key.

Answer 5

The keyboard has five major components.

1. The frame or case
2. The keys
3. The contact membrane
4. The printed Circuit board
5. The electronics

When a user presses on a key he flattens a cup under that key. Under the silicon rubber cup it a small disc of conductive rubber. This is pressed against the surface of the printed circuit board which completes an electrical circuit.

The signal from the circuit is then feed to an CDP1871A chip which decodes the matrix location of the key and turns this into a numeric serial signal which is passed through the case by the coiled wire to the computer.

Answer 6

by sending electrical impulses in the the i/o controller and the controller deciphers it as binary or HEX, and the changes that in to regular alphabet

Answer 7

The computer keyboard works as the main hardware used to key in information into a computer. Laptops usually have an internal keyboard while desktops use external keyboards.

Answer 8

Keyboard is used for typing whereas with mouse you cant

Answer 9

with electronic stuff and some wires