In the PC XT/AT era, the keyboard was mainly based on 83 keys, and it continued for quite a long time, but with the popularity of the Windows system in recent years has been eliminated. Instead, it is a 101-key and 104-key keyboard, and occupy the mainstream of the market, of course, there have been 102-key, 103-key keyboard, but due to poor promotion, all just short-lived. The emergence of the 104-key keyboard in the past half year is emerging multimedia keyboards. It adds a number of commonly used shortcut keys or volume adjustment devices on the basis of the traditional keyboard, which further simplifies the PC operation, sending and receiving emails, and opening browser software. To start a multimedia player, etc., only a special button is needed. At the same time, a major improvement has been made in appearance, emphasizing the personalization of the keyboard. At first, this kind of keyboard was mostly used in brand machines. Brands such as HP and Lenovo were the first to use such keyboards. They were widely acclaimed and once considered to be the characteristics of the brand machine. As time goes on, gradually independent products with various quick functions appear on the market. They are sold separately and have dedicated driver and setting software. Individualized operation can also be implemented on compatible machines.
The conventional keyboard has two kinds of mechanical buttons and capacitive buttons. In the IPC keyboard, there is a keyboard that touches the thin film button. The mechanical keyboard is the earliest adopted structure. Generally, the principle similar to the metal contact switch makes the contacts open or closed. It has the characteristics of simple process, convenient maintenance, general feel, high noise, and easy wear. Most of the cheap machinery The keyboard uses a copper spring as the elastic material, and the copper sheet is easily broken and easily lost its elasticity. The long-term use failure rate has increased. Now it has basically been eliminated and replaced by a capacitive keyboard. It is based on the capacitive switch keyboard, the principle is to change the distance between the electrodes by the key to generate a change in capacitance, temporarily forming the conditions allowed by the oscillating impulse. Theoretically, this kind of switch is non-contact non-contact type. The wear rate is negligibly small and even negligible. There are no hidden dangers of poor contact. It has low noise and easy to control the feel. It can produce a high-quality keyboard, but the process is more mechanical. complex structure. There is also a keyboard for IPC that uses a touch membrane button for complete sealing and is only suitable for special occasions.
The appearance of the keyboard is divided into a standard keyboard and an ergonomic keyboard. On the standard keyboard, the ergonomic keyboard separates the two left and right hand key areas defined by the fingering, and forms a certain angle, so that the operator does not need to be conscious. Clamping both arms to maintain a more natural form, this design of the keyboard is named as Natural Keyboard by Microsoft Corporation. For users who are used to typing blind, they can effectively reduce the missed stroke rate of the left and right hand keypads, such as letters. "G" and "H". Some ergonomic keyboards also intend to increase the area of ​​commonly used keys such as the space bar and the enter key, add hand guard brackets on the lower part of the keyboard, and give support to previous floating wrists to reduce fatigue due to long-term suspension of the wrist. These can all be considered humanized designs.
The shell of the keyboard. At present, the keyboard of the desktop PC computer adopts a movable keyboard. The keyboard functions as an independent input component and has its own shell. The keyboard panel is made of different plastics according to the grade, and some high-quality keyboards use thicker steel plates at the bottom to increase the texture and rigidity of the keyboard. However, this will undoubtedly increase the cost, so many cheap keyboards are designed directly with plastic bases. . In order to adapt to the needs of different users, the bottom of the keyboard is provided with a folding support foot. When the support feet are deployed, the keyboard can maintain a certain degree of inclination. Different keyboards provide single-, double-, or even three-segment angle adjustments.
The interface of the keyboard has AT interface, PS/2 interface and the latest USB interface. Nowadays desktops mostly use PS/2 interface. Most motherboards provide PS/2 keyboard interface. The older motherboards, which often provide AT interfaces, are also known as "big mouths," and are now less common. USB as a new interface, some companies quickly introduced the USB interface of the keyboard, USB interface is only a selling point, there is little effect on the performance improvement, willing to try and USB ports are not yet tense users can choose.