Definition: computer keyboard. What is a computer keyboard? Detailed description of keyboard keys
We continue to get acquainted with the structure of a computer, and today we’ll talk about peripherals, more specifically, about keyboards. Any person who has at least once seen a PC or laptop has an idea of what a keyboard is and how to use it. But this article is for those who want to get more information about how these devices work and what they are like.
What is a keyboard
Computer keyboard - an element of a personal computer or laptop, consisting of buttons, the main function of which is to enter data. Consists of alphabetic, numeric and additional function keys arranged in a certain order.
In simple words, a keyboard is something with which you can enter data into a computer: type text, trigger some actions using keyboard shortcuts (for example, changing the printing language), etc.
The role of the keyboard in a personal computer is extremely important, both for the average user who uses it only for entertainment, and for those who work at the machine all day long. At the same time, it cannot be said that without a physical keyboard you cannot use a PC. You can, of course, but it will be quite tedious, difficult and time-consuming. You will need a mouse with which you can press keys on the on-screen keyboard.
As for spending time in computer games, you can’t do without a keyboard: the controls in most games are based on the response from it, that is, a computer without this input device will be useless for a child, for example (we don’t take into account various joysticks and gamepads).
The keyboard in a laptop plays exactly the same role. Only, unlike a regular desktop PC, it is built into the case. This means that the keyboard that is in the laptop cannot be connected to the PC, but vice versa - yes, please. To be fair, it should be said that today there are quite a lot of laptops with a touch screen, which makes working with a virtual keyboard much more enjoyable.
What does the keyboard consist of?
In the definition, we said that the keyboard consists of keys, which are divided into several subtypes:
- Keys for typing. Their functionality is simple - one key is responsible for entering one character. These include keys that are designed to enter numbers, letters, and punctuation marks. Often, they are drawn on the keys;
- Function keys - are responsible for performing a certain action when pressed (almost all laptops have an Fn key - a function that, in combination with F1, F2, F3, etc., performs a certain action in the system, such as increasing or decreasing the volume, brightness, etc.);
- Keys for comfortable reading of pages and documents. These are the keys: Page Up, Page Down, Home, End;
- Auxiliary numeric keypad. Most often located on the right side of the main one and resembles a calculator keyboard;
- Buttons whose functionality corresponds to their name. So, the “Space” button creates this same “Space” - space, etc.
Also, many keyboards have additional buttons with completely different functionality, from playing music to turning off the computer.
Types of keyboards
There are many ways to divide keyboards by type; let’s look at the most common ones.
Based on the type of key mechanism design, keyboards are divided into:
- Membrane - built on the basis of an elastic membrane, which is pressed when a key is pressed, thereby causing the contact to close on the printed circuit board. The only advantage of this type of keyboard can be considered the price, since they work significantly less than the other two types, and their tactile sensations do not “click” as pleasantly.
- Scissor — have a number of advantages over membrane ones, such as: increased response, work approximately twice as long, the keys do not wobble, but are securely attached to their place. They are most often found in laptops, but some manufacturers also make regular keyboards using this technology. The device is ideal for those who like to type quickly, because the tactile sensations from the buttons are very positive.
- Mechanical – standard of quality. Each key is a switch with metal contacts and a spring, due to which the service life of such a keyboard is 5 times longer than a scissor keyboard. Other advantages include stability in pressing (that is, just as you confidently pressed a button on a new keyboard, you will also press it after 3 years), a pleasant feeling after work;
Depending on the method of connecting to a computer, keyboards are:
- Wired — connected using a cable with a USB or PS/2 connector;
- Wireless — do not have unnecessary wires, but connect to a PC or laptop via a radio channel (Bluetooth). The biggest advantage is the absence of a wire, which allows you to use the keyboard at a great distance from the PC.
Keyboards are also divided into types based on functionality and number of keys. The most common ones today are:
- 101-104 keyboards - standard, simplest keyboards that have a basic set of keys: printed, functional and additional digital. The 104 keyboard has two additional Win buttons (with the Windows logo), as well as an Application key;
- Multimedia - got their name due to the fact that they have additional keys for controlling various PC functions: volume, player (play, pause, switching tracks), network connection, some programs, and even turning the computer itself on and off;
- Gaming — for the most part, they are not much different from standard keyboards, but may have additional programmable keys for more convenient play;
And another way to divide keyboards into types is the type of case:
- Standard - classic rectangular input devices, also called PC/AT or simply AT;
- Ergonomic — have a curved shape, often also a hump in the central part, a non-standardly placed block of printed keys (as a rule, they are divided into two separate blocks for each hand), and may have a special wrist rest. All this was done in order to make working at the computer as comfortable as possible;
- Flexible - yes, there are keyboards that can be easily rolled up and transported in this form in a backpack. In addition, they also have moisture and dust protection.
Regarding the question of types of keyboards, I think everything is clear, let's move on.
Characteristics of computer keyboards
So, the main characteristics of the keyboards:
- Key mechanism - membrane or mechanical. Affects cost and service line;
- Type of shell - also written above - standard, ergonomic or flexible;
- Connection method - wire or wireless. The latter allows you to use the keyboard from a distance. A wired keyboard can be connected via PS/2 or USB. The second option is more universal, since the user will not have problems connecting the keys to the laptop; the PS/2 connector is very rare on them;
- Number of keys - ultimately affects the convenience of working at the computer;
- Materials — keyboards can be made of plastic or using various metals. The price and strength of the input device will depend on this.
In addition to the above, many manufacturers make computer keyboards with backlighting, the ability to change keys, etc. This point also requires attention, since the same functions have little effect on ease of use, but significantly increase the cost of the peripherals.
conclusions
To summarize, it is worth saying that a computer keyboard is a necessary part of a PC, without which comfortable and fruitful work on it will be impossible. Today, there are many types and models of these peripherals.
You can find a simple membrane keyboard for the office, or you can buy a real work of art with multi-colored backlighting that responds to every press of the mechanical keys. Such models can have fantastic, futuristic shapes and delight the owner not only with high-quality work, but also with their appearance, perfectly complementing the interior of the room.
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The first computers did not have a keyboard: data was entered into the computer either by installing mechanical switches and wires, or using punched cards (for example, ENIAC). As computer performance increased, and especially with the advent of time-sharing mode, it became necessary to enter commands without interrupting the operation of the machine. Initially, electromechanical teletypes were used for this purpose, later they were replaced by specialized video terminals. In such a terminal, the keyboard was part of it, even if it was housed in a separate housing. There were no standards either for the electrical part or for the composition and location of the buttons. Such terminals could have separate keys for controlling the cursor, scrolling text on the screen, or sending control signals.
The Common Keyboard Standard, like many other computer hardware standards, is associated with the IBM PC computer. The first version of the keyboard for the IBM PC, the so-called “XT-keyboard,” was noticeably different from subsequent ones both in the layout and in the communication protocol with the computer: it had 83 keys (of which 10 were functional), and there were no input mode indicators. In 1984, along with the IBM PC/AT computer, a new keyboard standard appeared, which later became widespread - the exchange protocol became two-way, which made it possible to place three LED input mode indicators above the digital block. However, the layout changed slightly: the SysRq key was added, the numeric block was separated from the main alphanumeric one, and some keys were moved to other places. Despite the external similarity and the use of the same DIN connector, the new keyboard was incompatible with previous models of IBM PC and IBM PC/XT computers - some keyboards had a special switch to connect to them. The next generation of keyboards began with the introduction in 1986 of the " Model M", which had, depending on localization, from 101 (in the American layout) to 106 (in the Japanese layout) keys, and became the standard. Further development of keyboards came from the Model M: the connection port was replaced with PS/2 and USB, Windows and menu keys were added, and on some, multimedia keys. On laptops and compact keyboards, the layout of the keys may differ; Some keys can be accessed using a modifier, but most computers use keyboards derived from IBM PCs, with the exception of keyboards from Apple and keyboards from specialized workstations like Bloomberg terminals.
| 105-key layout keyboards IBM/Windows | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Esc | F10 | F11 | F12 | PrtSc SysRq |
Scroll Lock |
Pause Break |
||||||||||||||||||
| Ins | Home | PgUp | NumLk | − | ||||||||||||||||||||
| Del | End | PgDn | ||||||||||||||||||||||
| Ent | ||||||||||||||||||||||||
| ← | ↓ | → | ||||||||||||||||||||||
Device
In most computer keyboards, the key contacts are connected in a matrix. The keyboard controller sequentially applies potential to the rows of keys and, when a signal appears on the output loop, recognizes which key is pressed. Pressing three keys, one of which is at the intersection of tracks leading to two other keys, results in the registration of a phantom press of the fourth. In inexpensive keyboards, the layout is optimized to prevent such cases for the most common combinations, and in ambiguous cases, pressing the third key is ignored. More expensive keyboards may have a diode on each key.
The most common type of keyboards is membrane ones with rubber pushers, which simultaneously serve to create a pressing force on the membrane and return it after releasing the key. More expensive models may use spring-loaded metal contacts, reed switches, or capacitive sensors.
Responsible for polling the key matrix, generating scan codes and transferring them to the computer via PS/2 or USB protocol, as well as for indicating input modes keyboard controller. Many microcomputers of the 1970s and 80s did not have a separate keyboard controller: the keyboard was polled by the central processor. In IBM PC/AT standard keyboards, the keyboard is polled by a microcontroller similar to the Intel 8042. Keyboards connected to a computer via a PS/2 port generate an interrupt when you press, hold, or release keys. Keyboards connected to a computer via a USB port report the keyboard status after each polling cycle.
Key groups
According to their purpose, the keys on the keyboard are divided into main groups:
Additional groups:
A certain number (twelve in a PC/AT keyboard) of function keys are located in the top row of the keyboard. Below is a block of alphanumeric keys. To the right of this block are the cursor control keys, and at the very right edge of the keyboard is a numeric pad, which can be removable.
Alphanumeric block
Alphanumeric keys are also called alphanumeric keys, data keys, data keys. The basis of this block is a set of characters similar to the character set of a typewriter. Typically, a single data key has multiple letters, numbers, punctuation marks, and symbols associated with it. Which letter will be entered is determined by the specified keyboard case - the keyboard operating mode set by the control keys or case switching keys.
The alphanumeric block includes keys for entering letters, numbers, punctuation, and symbols main arithmetic operations, as well as special characters. On a standard keyboard PC/AT this block includes 47 keys. For some languages, where the number of letters in the alphabet is more than 26, keyboard manufacturers produce keyboards with additional keys in the alphanumeric block - for example, on keyboards for the Ukrainian language (33 letters) there are already 48 of them (see: Ukrainian keyboard layout). There are no special keyboards produced for the Russian alphabet with its 33 letters - all letters of the Russian alphabet are placed on the keys of a standard keyboard PC/AT.
The alphanumeric block keys are divided into rows and zones. [ ] The bottom row of the block is above the spacebar and the modifier keys Ctrl, Alt, AltGr. He is considered the first. Above is the second one, in the ten-finger touch typing method also called "home" row [ ] . Even higher is the third. The top row of block keys - the fourth - in the Latin QWERTY layout does not contain keys for entering letters, but includes all keys for entering numbers. For this reason it often called digital series [ ] .
For greater convenience of typing, the surface of the keys can be located not in one plane, but along an arc. Some keyboards, such as IBM Model M", or some keyboards with separate left- and right-hand zones, use a curved board, but it is more common to use keys of different heights. The most common type of key profile is also known as the OEM profile. The disadvantage of this approach is that keys from different rows are not interchangeable. In addition, both technologies cannot be used in laptops and low-profile scissor keyboards.
A zone is a set of keys assigned in the ten-finger touch typing method to the fingers of each hand. The zones are numbered from left to right. [ ]
The effect of alphanumeric keys depends on the case (lower or upper) and level (first or second) in which these keys are pressed.
Control keys
Modifier keysModifier keys are designed to change (modify) the actions of other keys and include the following keys: ⇧ Shift, Ctrl, ⇪ Caps Lock, Alt, AltGr (right Alt) and ⊞ Win. Enabling uppercase keys (with ⇪ Caps Lock disabled) is done by pressing and holding the ⇧ Shift key. Pressing and holding the AltGr key is used to move to the second level of the keyboard. The Fn key is of particular importance: it does not generate a scan code, but changes the scan code of other keys.
Modifier keys are the most frequently used and therefore have a larger size. And frequently used keys ⇧ Shift and Ctrl are duplicated on both sides of the block of alphanumeric keys.
System command keys
The system command keys include the following keys: SysRq, Esc, PrtSc, Pause, Break, ≣ Menu.
Function keys
Top of the keyboard standard PC/AT there is a block of so-called function keys - keys from F1 to F12. PC/XT computer keyboards had 10 function keys (F1 through F10) arranged in two columns on the left side of the keyboard. The purpose (function) of the function keys is determined depending on the system or application software: after turning on the computer - by the motherboard configuration program (Setup BIOS), and subsequently - by the running operating system.
The purpose (function) of individual function keys, combinations of function keys with the ⇧ Shift, Ctrl and Alt keys and “regular” keys form part of the user interface and, as a rule, are constant for a particular type of software. There are a number of universal assignments that are most widely used: often pressing the F1 key will display the program's built-in reference manual (often already open on the page corresponding to the program mode in which it is located), and pressing the ESC key will interrupt the current operation.
Numeric keypad
The keyboard's number pad contains 17 keys, similar to those used in calculators, cash registers, and the like. The main purpose of the keys of the numeric keyboard block is to duplicate the functions of the keys of the alphanumeric block in terms of entering numbers and symbols of basic arithmetic operations. It is believed that the numeric keys are more convenient for entering numbers and arithmetic symbols than the alphanumeric keys. When Num Lock is disabled, the numeric keys duplicate the cursor keys.
The range of keyboards varies. Keyboards for the fingers are available for such instruments as the piano, organ, harpsichord, celesta, synthesizer, as well as the button accordion, accordion and some other instruments.
Musical instruments that have a keyboard are classified as keyboard instruments.
Alphanumeric keyboards
Alphanumeric keyboards are used to control technical and mechanical devices (typewriter, computer, calculator, cash register, push-button telephone). Each key corresponds to one or more specific characters. It is possible to increase the number of actions performed from the keyboard using keyboard shortcuts. In this type of keyboard, the keys are accompanied by stickers depicting the symbols or actions corresponding to the press.
Entering data into an electronic device using a keyboard is called set, in the case of a mechanical or electric typewriter we speak of printing. There is a certain typing technique that allows you to avoid occupational disease [[K:Wikipedia:Articles without sources (country: Lua error: callParserFunction: function "#property" was not found. )]][[K:Wikipedia:Articles without sources (country: Lua error: callParserFunction: function "#property" was not found. )]] . There are also techniques that allow you to type text without looking at the keyboard, the so-called touch typing method.
Numeric keypads
A numeric keypad is a collection of closely spaced number keys designed to enter numbers (for example, numbers). There are two different options for the arrangement of numbers on such keyboards.
Calculators use a keyboard in which the numerical values of the keys increase from left to right and from bottom to top. Many computer keyboards have a key block on the right that includes a calculator-type keyboard.
Computer keyboard
Computer keyboard is a keyboard designed for entering information into a computer (input device). Keyboards - copies of keyboards supplied with IBM PC/AT series computers - have become widespread. Such keyboards are called “PC/AT keyboards” or “AT keyboards” and have 101 or 102 keys. The keyboards shipped with the IBM PC and IBM PC/XT series had 83 or 84 keys. The layout of the keys on the AT keyboard follows a single generally accepted pattern, designed for ease of typing letters of the English alphabet. A programmable keyboard (and, in particular, a POS keyboard) may include a different number of keys; keys can be combined using special overlays
Monuments
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Notes
Literature
- Voroisky F. S. Computer science. New systematic explanatory dictionary-reference book. - 3rd ed. - M.: FIZMATLIT, 2003. - 760 p. - (Introduction to modern information and telecommunication technologies in terms and facts). - ISBN 5-9221-0426-8.
Links
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Excerpt characterizing the Keyboard
And putting his hand into his bosom, he pulled it out... a miracle!His thin long fingers were shone through with a bright pulsating emerald light!.. The light poured more and more, as if alive, filling the dark night space...
Radomir opened his palm - an amazingly beautiful green crystal rested on it...
- What is this??? – as if afraid to frighten away, Magdalena also quietly whispered.
“The Key of the Gods,” Radomir answered calmly. - Look, I'll show you...
(I am talking about the Key of the Gods with the permission of the Wanderers, whom I was lucky enough to meet twice in June and August 2009, in the Valley of the Magicians. Before that, the Key of the Gods had never been spoken of openly anywhere).
The crystal was material. And at the same time truly magical. It was carved from a very beautiful stone, like an amazingly transparent emerald. But Magdalena felt that it was something much more complex than a simple gem, even the purest one. It was diamond-shaped and elongated, the size of Radomir’s palm. Each cut of the crystal was completely covered with unfamiliar runes, apparently even more ancient than those that Magdalene knew...
– What is he “talking about,” my joy?.. And why aren’t these runes familiar to me? They are a little different than those that the Magi taught us. And where did you get it from?!
“It was once brought to Earth by our wise Ancestors, our Gods, to create here the Temple of Eternal Knowledge,” Radomir began, looking thoughtfully at the crystal. – So that he helps worthy Children of the Earth find Light and Truth. It was HE who gave birth on earth to the caste of Magi, Veduns, Sages, Darins and other enlightened ones. And it was from him that they drew their KNOWLEDGE and UNDERSTANDING, and from it they once created Meteora. Later, leaving forever, the Gods left this Temple to people, bequeathing to keep and take care of it, as they would take care of the Earth itself. And the Key to the Temple was given to the Magi, so that it would not accidentally fall into the hands of the “dark-minded” and the Earth would not perish from their evil hand. So since then, this miracle has been kept for centuries by the Magi, and they pass it on from time to time to a worthy person, so that a random “guardian” does not betray the order and faith abandoned by our Gods.
– Is this really the Grail, Sever? – I couldn’t resist, I asked.
- No, Isidora. The Grail was never what this amazing Smart Crystal is. People simply “attributed” what they wanted to Radomir... like everything else, “alien.” Radomir, all his adult life, was the Guardian of the Key of the Gods. But people, naturally, could not know this, and therefore did not calm down. First, they were looking for the Chalice that supposedly “belonged” to Radomir. And sometimes his children or Magdalene herself were called the Grail. And all this happened only because the “true believers” really wanted to have some kind of proof of the veracity of what they believe in... Something material, something “holy” that could be touched... (which, Unfortunately, this is happening even now, after many hundreds of years). So the “dark ones” came up with a beautiful story for them at that time in order to ignite sensitive “believing” hearts with it... Unfortunately, people always needed relics, Isidora, and if they didn’t exist, someone simply made them up. Radomir never had such a cup, because he did not have the “Last Supper” itself... at which he allegedly drank from it. The cup of the “Last Supper” was with the prophet Joshua, but not with Radomir.
And Joseph of Arimathea actually once collected a few drops of the prophet’s blood there. But this famous “Grail Cup” was really just a simple clay cup, which all Jews usually drank from at that time, and which was not so easy to find later. A golden or silver bowl, completely strewn with precious stones (as the priests like to portray it) never existed in reality, neither in the time of the Jewish prophet Joshua, nor even more so in the time of Radomir.
But this is another, albeit most interesting, story.
You don't have much time, Isidora. And I think you will want to know something completely different, something that is close to your heart, and that perhaps will help you find more strength within yourself to endure. Well, in any case, this tangled tangle of two lives that are alien to each other (Radomir and Joshua), too closely tied by “dark” forces, cannot be unraveled so soon. Like I said, you simply don't have enough time for this, my friend. Forgive me...
I just nodded in response, trying not to show how much I was interested in this whole real true Story! And how I wanted to know, even if I was dying, all the incredible amount of lies brought down by the church on our gullible earthly heads... But I left it to the North to decide what exactly he wanted to tell me. It was his free will to tell me or not tell me this or that. I was already incredibly grateful to him for his precious time, and for his sincere desire to brighten up our sad remaining days.
We again found ourselves in the dark night garden, “eavesdropping” on the last hours of Radomir and Magdalena...
– Where is this Great Temple, Radomir? – Magdalena asked in surprise.
- This device (set of keys), designed to control the information input device.
History of the origin of the keyboard
The prototype of almost all modern keyboards is the "IBM Enhanced 101 Key Keyboard", which became a standard in 1987. This type of keyboard was most suitable for users. What models were used previously? IBM's first model was the XT keyboard, which had 83 buttons. On the left side there were 10 function keys, and on the right there were keypads with pointers and numbers. The Shift, Alt and Ctrl buttons were located next to the function keys. In the main row, to the left of the numbers, was Escape. Between the Z key and the left Shift key was the Backslash. To the right of Shift there was a key that allowed you to type the * symbol. The Enter key was vertical and narrow, and not everyone could find it right away. This initial draft of the IBM standard had both reasonable and absurd keyboard layouts, but some clever parts made the shortcomings less noticeable.
IBM's next project was the AT keyboard, which was incompatible with the earlier XT project. It also had 10 function keys on the left, but Esc and asterisk moved to the numeric keypad. The Enter key had an L-shape, and the Backsplash (/) key shared space with the period. When an upgrade was needed, IBM created an extended keyboard that was compatible with the original AT model, but the key layout was completely different. The 12 function keys and Esc were located at the top, and the numeric keypad moved to the right. The index keypad was located between the number pad and the letter keys. It was T-shaped and consisted of 4 indicators.
Del (Delete);
Ins (Insert);
End And Home;
PgDn (Page Down) And PgUp (Page Up).
But then a serious flaw was revealed - users often mistakenly pressed Delete instead of End. This was a disaster at the time because without today's software capabilities it meant many hours of work was wasted. Soon complaints from users began to flow into the IBM office. As a result, the Backspace key became wide again, the backslash had its own key, Ctrl and Alt were located on either side of the spacebar, and Caps lock moved to the place of Ctrl. The Del key remains in its old place, but on some keyboards it has doubled in size. Today this keyboard layout is the international standard.
Who came up with the keyboard layout?
Naturally, the letters are arranged in a certain order. If you compare the keyboard of a computer and a typewriter, you will find that the letters on them are arranged in the same way. Surprisingly, this layout was invented to slow down typing speed! The first commercial typewriter was invented by the American Christopher Scholes about 150 years ago. This machine was not very convenient, because the person typing did not have the opportunity to monitor the result - the hammers were located under the paper sheet. However, people quickly mastered these machines, but soon another problem appeared - the letter hammers interlocked with each other, which led to the machine breaking down. And since the keys were arranged in alphabetical order, often two adjacent keys were pressed almost simultaneously.
The solution was obvious - to space the frequently repeated letters apart, which was done. The number of breakdowns has decreased, but printing has also become inconvenient. And in 1874, Remington 1 appeared, the first typewriter with a QWERTY letter arrangement, which has survived to this day. In the middle of the last century, Arthur Dvorak proposed a more convenient arrangement that ensured a balanced load on the hands. However, by that time there were already millions of machines with the old layout, and people simply did not want to completely change the usual layout. In Russia, typewriters appeared later than America, and therefore the Cyrillic layout is more rational - frequently used letters are in the center of the keyboard. Thus, our layout turned out to be much more ergonomic than the English one, because the most popular letters are located under the strongest fingers - the index fingers. But still, there is one significant drawback. When Russifying the keyboard, I did not pay much attention to the placement of the comma, and it was assigned to one key with a period, in upper case. But we use a period much less often than a comma, but in order to put a period, you need to press one key, and a comma - two. Isn't it rational? Yes, but Dvorak already tried to fix a much more inconvenient layout, and it didn’t work out. And all because most people type not as it is more convenient, but as they are accustomed to, and do not want to change anything.
A keyboard is a device for entering data into a computer: letters, numbers and symbols. It is also used to control the system, that is, it is analogous to a computer mouse. Depending on the type of connection, it can be wired or wireless.
Wired connects to a computer via a USB port or PS/2 connector.
Wireless can be connected via a radio transmitter (USB receiver) or Bluetooth. The range is usually about 10 meters.
Since wireless devices do not have stationary power, they must be recharged separately. To do this, a special battery can be built into the keyboard itself, which needs to be charged from time to time. Or it can run on batteries.
Key layout
The button layout follows the same generally accepted pattern. Twelve function keys from F1 to F12 (located in the top row). Below them are alphanumeric keys. On the right are the cursor control buttons.
The far right part is the so-called number pad. It duplicates the alphanumeric block (more precisely, only numbers and arithmetic signs). Enabled using the Num Lock button.
On many keyboards, in addition to this standard set, there are also additional buttons of a different shape and size (sometimes of a different color). Their task is to simplify the management of certain computer functions.
So, among others, there may be buttons that control the volume, launch some programs (browser, Word, Excel), and keys for controlling the player (pause, rewind).
Keyboard device
Membrane. The most popular and most inexpensive type. Inside each key there is a special membrane. When pressed, it is pressed and closes the contact. The service life of each key is about 5 million presses.
Scissor. Such keyboards are installed in all laptops. The principle of operation of the keys is similar to scissors - that’s where the name comes from. The pressure is soft and clear, which is very convenient when typing. But it costs more. Service life is about 10 million clicks.
Mechanical. The best, but also the most expensive type. Under each key there is a switch with a metal spring and metal contacts. Thanks to him, the button is triggered even before it is lowered all the way. Using such a keyboard is easy and pleasant - a completely different tactile sensation. But the sound when pressing the keys is louder. Service life is about 50 million clicks.
They have different types of keys depending on your needs: gaming, for working with text, universal and all sorts of others.
Semi-mechanical. Something between membrane and mechanical. In fact, these are the same membrane ones, but with an increased service life.
Design
The classic keyboard looks simple and unpretentious - a plastic rectangular thing. It comes in different colors, but it is better to choose the standard one: white, black or metallic (gray).
But now you can find other types on sale, for example, rubber keyboards. They look interesting, but in reality they are very inconvenient - the keys are too tight.
There are also all sorts of design options: wooden and even glass. And there are also “virtual” ones, where the keys are simply drawn with a laser.
By the way, they are very inconvenient to use: even on a perfectly flat surface, the device constantly “glitches”.
But among the truly useful ones, I would single out two types: ergonomic and gaming.
Ergonomic. They have a non-standard curved shape, and some models even consist of two separate parts (which, by the way, is worse). Thus, the keyboard follows the natural position of the hands and helps to avoid carpal tunnel syndrome.
Such a device is simply necessary for those who type a lot of text touch-sensitively (with all fingers, without looking at the keys).
Gaming. They have a more convenient key layout for gamers. Plus they usually have backlighting and additional keys.
What else to look for when choosing
Purpose. Despite the fact that the keyboard is a universal thing, there are now special ones on sale - for laptops, TVs and media players. Actually, they are not much different from the classic ones, but they are still more convenient for these devices.
Type of printing on keys. This is how the letters and numbers are printed on the buttons. Most often, two types of application are used: conventional printing (90%), laser burning.
In normal printing, the letters appear to be on stickers.
With laser, every symbol is burned out. They do not wear off for a long time, but the inscription is less visible.
In general, there are no problems with the keys now - in almost any computer store you can find special stickers for them. And those for whom this option is not suitable can order engraving - this service is also now provided and is not that expensive. This is especially true for laptops purchased abroad (they do not have Russian letters).
Water protection. Such protection is only available on membrane keyboards, and even then not on all of them. Whether it is or not can be found out from the description of a specific model.
Backlight. Relevant for gaming keyboards. It is in almost every one of them.
Price issue
The price of a standard “tailed” keyboard starts from $3, wireless - from $10. Scissor ones are more expensive (from $15), and mechanical ones are difficult to find for less than $25. Ergonomic ones are even more expensive.
How to clean your keyboard
It would be a good idea to do this at least once every couple of months. After all, not only do we usually not wash our hands before working at the computer, but also various dirt and dust get in through the cracks between the keys.
Cleaning it is easy:
1 . Blow out the dirt with a vacuum cleaner (in blowing mode). You can also do this with a hairdryer, but only with cold air. If you don't have either, just turn the keyboard over and shake it.
2. Wipe the top of the keys themselves with a cloth slightly moistened with an alcohol-containing solution (can be bought at a pharmacy). Just don’t overdo it: using alcohol can accidentally erase the inscriptions on the buttons.