What does keyboard mean?

keyboard

##The keyboard is the most commonly used and important input device , through the keyboard, English letters, numbers, punctuation marks, etc. can be input into the computer to issue commands, enter data, etc. to the computer.

Ordinary type (Recommended learning: web front-end video tutorial)

Generally, desktop keyboards can be classified according to the number of keystrokes, Classification of key working principles, keyboard appearance, etc.

There are many types of keyboards, which can generally be divided into three categories: contact type, non-contact type and laser type (laser laser keyboard). The former uses metal to connect or disconnect two contacts. Taking an input signal, the latter generates the input signal with the help of Hall effect switches (using magnetic field changes) and capacitive switches (using current and voltage changes).

By coding

In terms of coding functions, keyboards can be divided into fully coded keyboards and non-coded keyboards.

The fully-encoded keyboard is a keyboard recognition function completed by hardware. It identifies whether a key is pressed and the position of the pressed key, and the fully-encoded circuit generates a corresponding encoding information (such as ASCII code). The non-encoding keyboard uses software to complete the keyboard recognition function. It uses simple hardware and a set of special keyboard encoding programs to identify the position of the keys, and then the CPU converts the position codes into corresponding encoding information through a table lookup program. Non-coding keyboards are slower, but have a simple structure, and can provide great convenience for redefining certain keys through software.

According to application

According to application, it can be divided into desktop keyboard, laptop keyboard, mobile phone keyboard, industrial computer keyboard, speed recorder keyboard, dual control keyboard, Seven categories of ultra-thin keyboards.

According to the nature of the code element, it can be divided into two categories: alphabetical keyboard and numeric keyboard.

According to working principle

1. Mechanical keyboards (Mechanical) use similar metal contact switches. The working principle is to make the contacts conduct or disconnect. It has the characteristics of simple process, high noise, easy maintenance, strong sense of rhythm when typing, and the feel will not change after long-term use. 2. The interior of the plastic membrane keyboard (Membrane) keyboard is divided into four layers to achieve no mechanical wear. It is characterized by low price, low noise and low cost, but the feel will change due to material problems after long-term use. It has occupied the vast majority of the market share.

3. The structure of the conductive rubber keyboard contacts is connected through conductive rubber. There is a layer of conductive rubber with protrusions inside the keyboard. Each key corresponds to a protrusion, and when pressed, the contacts below are connected. This type of keyboard is a transitional product in the market from mechanical keyboards to membrane keyboards.

4. Contactless electrostatic capacitive keyboards (Capacitives) use a principle similar to capacitive switches. By changing the distance between electrodes when pressing the keys, the capacitance changes and the capacitance changes to drive the encoder. It is characterized by no wear and good sealing.

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