The input devices are those that fulfill the function of entering or providing data and control signals to the central processing unit of a system. In most cases, we speak of input devices for devices that have a connection to the central unit of a computer, that is, the CPU.
As it was said, the central function of computers is the processing of data, so it can be said that the very history of computing is the history of the improvement of processing methods:
Since 1970, in what is known as the fourth generation of computers, the most important innovation was microprocessors (or chips), which generated a revolution in data processing: the processing speed increases 770000 instructions per second. The computer could be made much smaller, accessible to homes and much less expensive.
Since 1985, computer innovation has focused mainly on the entry of sound waves with wireless systems, as well as the emergence of robotics: cybernetics is progressing faster and faster and interconnections between computers demand the introduction of new methods every time more efficient for data entry and processing.
The fundamental division between the devices, then, is done according to their function with respect to processing:
- Input devices: They provide information to the computer for processing.
- Output devices: They are important for the reproduction and presentation of information to users.
Anyway, there are some cases of mixed or hybrid devices, which at the same time send and receive signals to different parts of the computer: the latest generation of devices such as touch screen, mouse or scanner are examples of this.
1. Optical pen: The stylus is a peripheral that consists of a device in the form of a pen or pen, which has some buttons. The function of this device is for the user to interact with the computer screen. In this way, the user can select elements that are displayed on the screen or create illustrations or drawings by moving the stylus on the surface of the screen. It could be said that it fulfills the functions that a mouse or mouse would have, but with a different form of interaction on the part of the user.
There are two types of optical pencils in general: wire and wireless; similarly, either of them works through the USB port of the computer.
2. Mouse: Functional device to move the cursor around the computer screen.
3. Touch screen: Screen designed to recognize the pressure on the surface. By touching the screen, the user can make a selection or move the cursor, equivalent to the mouse.
4. Scanner: Device that, with a light beam, detects the patterns of light and darkness and thus allows to convert a physical image into a digital signal that reproduces it as it is.
5. Joystick: a pointing device that is used very often in computer games, although it is also common in industrial applications to handle devices.
6. Barcode reader: Using the laser, you can read drawings formed by bars and parallel spaces, coding information.
7. Alphanumeric keyboard: The most frequent, with 62 keys among which are all the numbers and letters, as well as a series of commands.
8. Function keyboard: Useful for computer systems, has 13 configurable letters.
9. Digital photo camera: It connects to the computer and transmits the images it captures. It can be photos or video.
10. Webcam: Like the camera but of small dimensions, not showing the images it takes but simply transmitting them to the computer.
11. Microphone: This input device has the ability to transform acoustic energy into electrical energy. This allows recording, storage, transmission and electronic processing of the audio signals. Thus, the microphone allows users to engage in voice conversations through their computer equipment.
12. Fingerprint sensor or scanner: A fingerprint sensor, also known as a fingerprint reader, is an external device that connects to the computer and serves to read people’s fingerprints and transmit this information to the computer. They can have several uses, one of them is the identification of the fingerprint to be able to have access to a computer. In this way, greater security for the user is guaranteed; since only someone with a certain fingerprint could access the system.
13. CD / DVD disc can be input and output devices. As an input device it can send information from the disc to the computer system .