Keyboard - the main intermediary between man and many other electronic devices, from personal computers to mobile phones. Despite the honorable age of the keyboard (it was used on the press before the origin of computers) and the development of alternative, "humane" interfaces - coordinate devices and speech recognition technologies, without a keyboard on a computer not to work or in some cases even play games. Reasonable alternative keyboards yet, there is only their various transformations and variations, performing the same basic functions and some more - depending on user requests.
Keyboard design
According to its own keyboard design divided into push and touch.
Touch models do not contain mechanical elements (conductive contacts in these devices are designed as 2-plates separated by a small gap), whereby these keyboards are working quietly and very reliable (because they are protected from dust and other outdoor activities). These devices do not have buttons as such, because the tactile feeling by working with them fundamentally different. Widespread touch keyboard is not received by the need and expense of getting used to.
Most of the users do not have to deal with new-fangled touch, and with the classic - button keypad. On them we'll talk further.
Conventional key pad all types have similar dimensions (about 45.0 x15, 0x1, 5 cm) and placed in rectangular plastic or metal housing of varying levels of strength and integrity. Keys (101 and more) they are placed in a particular order, are (except for the more commonly used) the same size and shape, the stroke, and still at the same distance from each other (all of these features and options are regulated industry standards in particular ISO 9241-4). In non-standard keyboard features may be different, but the fact they are non-standard ...
Pushbutton keyboard in its own sequence separated by the membrane, polumehanicheskie and mechanical.
In models of the first type are closed when you press two membranes (usually they look like wheels on a plastic film, and therefore used the name "membrane keyboard"). Responsible for returning the keys flexible dome (with the shaft in the center). For separation membranes is intermediate plenochka with holes. Due to the fact that the contacts stay on the inner sides of the film, this system is well protected from dust and moisture. Very sealed membrane keypad implementation contains within a single rubber "mat" with under the keys protruding domes. The advantages of membrane keyboards include quiet operation, "softness" (easier to press the keys), the above-mentioned protection from outdoor activities and low cost. Their single drawback is smaller in comparison to the other types of structures durability (20-30 million clicks - about a year of hard use).
In polumehanicheskih keyboards used on longer-term (50-100 million clicks) metal contacts (in expensive models they may be including gold), soldered to the printed circuit board. Otherwise, they are no different from the membrane: the key to the starting position they also returned with an elastic plastic dome. Only those devices are expensive.
In mechanical keyboard after you return spring. Advantages of such devices are considered to be durable and reliable, but also the lack of effect of "fatigue" construction (mechanical keyboard keystrokes resistance is virtually independent of the quantity, which is not the membrane and polumehanicheskih keyboards). Serious negative models provided by type - rather noisy work. In addition, these devices are quite expensive and the device is not protected against external influences. True, there are sealed models, but they are even more expensive.
Interfaces: wired and wireless
To connect a keyboard to a computer using 2-wire interfaces.
Most of the affordable and comparable models focused on old PS / 2 interface. Corresponding round 6-pin ¬ in connector located on most motherboards and traditionally
Connection via USB (the appropriate connector equipped innovative keyboard) have a superior. For example, USB-keyboard can be connected and disconnected in the "hot" mode (an operation with the keyboard PS / 2 may cause a system interrupted or damage to the controller on the motherboard).
There are special adapters as a mini-DIN connector for PS / 2 and back - with USB to PS / 2.
Wireless keyboard instead of the cable interface for interconnection with a computer using a radio channel. To connect to a PC, these devices are equipped with an adapter that is connected to the port USB. The standard radio is a frequent speaker Bluetooth, but quite common and solutions, which use a unique proprietary air interface. Models of the second kind are more spacious range - up to 60 m (the value of this fact is questionable, because the monitor to see at this distance can only binoculars, but manufacturers on this characteristic for unknown reason emphasize).
They feed or from a battery, or the replacement of batteries, a set of which (usually either 2hAA 4hAAA) is enough for 2-3 months of operation. Due to this, to their value added and operating costs of the battery.
So many of the same wireless keyboard can immediately work in the same room, each of them is equipped with a unique identifier. In addition, the transfer of the keyboard commands do these devices is encrypted, which prevents the probability of intercept radio.
Attention
Some USB-keyboard and the highest average price category can be used as a USB-hubs (hubs), so they are equipped with USB-ports to include card readers, flash drives and other storage devices, and even peripheral devices with a similar interface. These solutions are quite comfortable, especially for owners of desktops with minimal USB-ports (which are also considered to be difficult to access), but they are significantly more expensive than conventional models.
Portativnye.Oni less common and traditionally have 83 keys that are installed in almost right next to each other (with a gap between the centers of 13-15 mm instead of ordinary 19mm). The first characteristic of a miniature keyboard for laptops.
K of portable include not only reduced, but also the component model, in which the digital and dial-autonomous units (there are models in which the dial-block consists of 2-parts), and even collapsible keyboard, embedded numeric keypad, which (in order to save place or for other reasons) can be removed. On the expediency of such a decision can be argued, as well as the pros and keyboards later category.
Ergonomic. Concerned about the health of users, a lot of time conducting the computer, more and more manufacturers produce these models of keyboards, hull shape and positioning of buttons that fit the natural position of the hands of man. In fact, all have built-in ergonomic keyboard palm palms (traditionally non-removable, but variations are possible). Rows of alphabetic keys on them separated and deployed to each other, resulting in their placement is V-shaped, and the entire keyboard is S-shaped. However, users who are accustomed to the keyboard of the usual form (especially if it prints "blind") to adapt to the ergonomic model will be difficult.
Multimedia. Recently, almost all manufacturers equip dopklavishami keyboard, supports what may be, for example, to play music or video. Produced even specialized models, "incarcerated" under multimediatsentry. Thanks supplied with the keyboard driver function additional buttons are usually easy to change.
Mobile. They are designed to be paired with a handheld computer, smartphone or an ultraportable laptop (that is, with those devices, a keyboard that is not optimal for typing) and folded for easy transport or even roll up into a tube. These models will be appreciated especially by those who have a lot, and often work in the road - they are not heavy, waterproof, very durable. But are expensive.
Game. For gamers and enthusiasts to issue a special model with a small swing buttons and a rich set of additional keys. In addition, certain keys to primeruÜ on such keyboards can be blocked, because if the gamer in the heat of battle accidentally clicks on it, the game is broken ...
Some manufacturers equip keyboard various additional "features done", such as backlit keys for work or play in the dark or compact display for more information. Originally created for gamers, these options have found application in other areas: for example, displays, keyboards, have learned to use for their purposes monitoring utility sistemy.Klaviatura
Designer. For particularly demanding for the appearance of technology users, there are exclusive design model keyboards. In the era of universal addiction modding and tuning of all and all variety of "refined" keyboards amazing. Metal, silicon, glass, porcelain, fur, skin, rhinestones, and elm tree, painting ... Almost all the companies specialize in creating unusual keyboards, causing the data and computer Soup airbrushing including coloring them "under Khokhloma." Actual use in decorating the keyboard, obviously, no. And treat such delights to critically and carefully - because of the same concerns about their health. And the other - a matter of taste and wealth ...
Laser. Tangible component of such a single keyboard is compact "box" on the projector. It emitted a beam of light "paints" keys on the plane table, and infrared detectors monitor when and which one is "pushing" the user. These devices are not cheap, but the comfort of their use of so far is poor: they do not support printing with high speed.