Keyboard - what is it?

A computer keyboard is a device for inputting or outputting information. The input is carried out through a call to the operations carried out in the processor and displayed on the screen. Conclusion occurs, as a rule, on additionally connected devices, such as printers, copiers, scanners, flash drives. The keyboard has a standard 101 or 102 button. Depending on the model and manufacturer, additional ones that perform certain functions may be included.

All available buttons can be distributed on:

• including alphabet and numbers;
• performing certain functional actions depending on the software used;
• special;
• cursor controls;
• keys of the digital panel - they duplicate the digital keys, but are located on the right side panel of the keyboard;
• modifiers that can change the functionality of other keys.

All variety of keyboards can be classified from three points of view.

1. The first is usability and purpose. Here we can distinguish - office, ergonomic, multimedia, gaming, for multimedia centers.
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2. The second is the type of construction - standard, compact, customizable, folding, rubber, waterproof.
3. The third is the type of construction of the key and the principle of its operation - mechanical, membrane, scissor, capacitive sensor.

Principle of operation

Inside there is a mini-computer, or rather, a microcircuit that provides all the functions inherent in this part of the computer or laptop. The main functional purpose of the microcircuit is tracking the signal from one button or another. Next, the chip sends this signal for processing to the central processor of the computer. In order for the signal to arrive on the microcircuit, certain sensors are used that track the pressure. When the pressure reaches a certain level, the electrical circuit closes.

Software support

Any hardware, including the one in question, requires software support, which is responsible for processing all the information. For a keyboard, software is called a driver, which in the vast majority of cases comes with hardware and an operating system. It is this type of driver that allows the user to select the layout of the language and buttons.

Varieties

Today, in the development of computer technology, two types of keyboards can be distinguished:

• mechanical;
• sensory.

In mechanical data transmission, directly from the keyboard, is carried out by physically closing the contact between the key and the receiving device. The principle of operation of the sensor is to use special materials and semiconductors with certain properties. The definition of such a boundary between mechanical and touch keyboards is rather arbitrary.

Mechanical keyboards

The principle of mechanical operation is quite simple. It consists in such a button mechanism that allows reciprocating movements in the vertical direction. When the key is lowered, the contacts are closed. At the same time, a signal is transmitted to the processing nodes. After the logical signal is transmitted, the operator releases the key. Return to the starting position is carried out by a special spring mechanism. This is the principle of operation of most keyboards on personal computers and laptops.

This type of device has the following advantages:

1. Durability when using. The standard keyboard withstands the number of clicks on each button in the region of 50 million times.
2. Ease of maintenance.
3. Ease of use, as there is a quick and accurate response to pressing.
4. This type of keyboard is in an affordable price category, therefore, if the product breaks down and if it is not maintainable, it is possible to replace it with a new one.

Despite the presence of a large number of positive characteristics, there are also negative points:

1. Failure to completely seal the inner filling, which can lead to the ingress of debris and various liquids. The result is a breakdown of the product.
2. Enough impressive dimensions that do not allow to reduce the size of the accompanying product.

Membrane

The principle of operation of the membrane keyboard is very close to mechanical. But in this type of work it turns out to reduce the overall dimensions of the product.

The membrane as such has no buttons. Instead of them, elastic membranes are located, pressing which transmits the required signal, when compressing the membrane, it is necessary to carry out to such a level that it touches the conductive contact. In turn, the conductive contact is mounted in one of the layers of the multilayer structure directly to the stationary contact. And the stationary contact itself is attached to the device board.

Pros of membrane keyboards:

1. Low noise.
2. Low cost.
3. The ability to completely seal the inner part from external influences.
4. An opportunity to reduce overall dimensions.

Despite the presence of significant advantages, nevertheless, they also have disadvantages, which, by the way, made their use in computer technology a rather rare occurrence. The main ones include:

1. Low level of tactility at work.
2. Rapid wear of the component parts of the product, which leads to its breakdown and not maintainability.
3. During operation, after a certain service life, membrane wear occurs. This leads to a decrease in sensitivity when pressed, and sometimes to a complete non-response of the key to external influences.

REFERENCE. At the moment, membrane buttons are rarely used in the manufacture of computer keyboards. Most often, these are buttons located on the front panels of household appliances, such as stoves, microwave ovens, washing machines, remotes from the TV, etc.

Scissor keyboards

For many who hear this name for the first time, the question arises - scissor keyboard what is it? It is also a computer device for input-output data, in this case is a combination of the two above examples. That is, it is a hybrid of mechanical and membrane.

This is due to the appearance of the scissor structure. The buttons resemble a standard mechanical. But nevertheless, contact and impact in this case is carried out on a special stock. In order for the rod to reciprocate in the vertical plane, two special plates are used. They cross among themselves, which resembles the design of scissors. By the way, It is precisely because of this that the keyboard got its name. At the attachment point there is a hinge that allows the plates to move down and returns them to the upper position - in this way a signal is transmitted.

The advantages of this design include:

1. Affordable price category.
2. The noise is low, although there is still sound when typing on the keys.
3. Good tactile feedback and key response to keystrokes. This allows the operator to make quick typing without spaces or dashes.
4. The service life of such a product is high and differs little from the mechanical type.

But scissor keyboards still have drawbacks:

1. Despite the fact that such a structure is more or less well protected from dust, it can fail from moisture ingress.
2. Its overall dimensions are quite large, as well as the mechanical one. Therefore, talking about minimizing size is hard.

IMPORTANT. It is the scissor keyboard that will allow for fast typing with minimal negative impact on the hands.

Capacitive sensors

The desire of technology to constantly reduce the size of the device used has led to the emergence of capacitive sensor technology. This type of key is used on most tablets, smartphones, laptops and all-in-ones. A thickness of several millimeters can significantly save space, ergonomics and ease of use of the device, and, consequently, the dimensions of the product.

The principle of operation of a capacitive sensor is as follows: the surface is divided into segments, and on a small area of ​​such segments can be from several thousand to millions. The larger the number, the higher the tactile sensitivity of the sensor. Each segment is equipped with a microcapacitor. The dimensions of such a capacitor are very small, which allows them to be used in a significant amount. When pressed, tactile pressure is applied to the capacitor. He, in turn, changes his capacity from this effect, that is, his main parameter. Changing the capacity leads to a response from the processor, which captures this as a signal, with subsequent processing and transmission to the central processor of the product.

If we talk about the whole variety of keyboards, then, in principle, it is quite limited. In any case, this applies directly to the operation of the product keys. So, capacitive sensors are indispensable companions of all new-fangled gadgets, including smartphones. Membrane keys and buttons are used in household appliances. Then so scissor keyboards are the perfect choice for computer purposes.