Input devices are the devices that take the data from the outside world and send it to the computer processor for further processing. One major distinction between an output and an input device is that input devices send data to the processor while output devices receive data from the processor.
Types of Input Devices
Input devices can be classified as follows:
1. On the basis of mode of input
Input devices can be distinguished easily on the basis of mode of input. The various modes can be audio, visual, textual, mechanical, etc. The examples include a camera (visual), microphone (audio), touchpad (mechanical), etc.
2. On the basis of nature of the input
The input given to the computer can be either continuous or it can be discontinuous. For example, touchscreen possesses both continuous and discrete form of input, scrolling a touchscreen is continuous while typing on a touch screen is discontinuous.
3. On the basis of the degree of freedom
The number of degrees of freedom can be used to group the input devices. The input on this basis can be 2-dimensional or 3-dimensional. 2D inputs include sound input to the mic, image input to the computer, etc. However, 3D input is usually used in virtual reality-based simulations.
Examples of Input Devices
The keyboard is a prominent example of input devices. When the user presses any key, the circuit present beneath the keypad gets connected, allowing a small fraction of current to flow through it. Therefore, the pressure is converted to an electrical signal which upon further processing fulfils the command given by the user.
The mouse takes the guided motion by the user as an input. It then translates this mechanical movement to a form that is easily understandable to the computer. The shiny red or blue light present underneath a computer mouse is used to calculate its position and locate the coordinates, according to which the cursor moves.
Scanners are everywhere, from the fingerprint scanner on your phone, to the document scanner on your office desk, to the bar code scanner at the mall, and so on. Scanners make use of casting light on a particular pattern to develop a scanned image. Scanners are input devices that take real-life data, mostly pictures or documents, and convert them into much more complicated machine language. This complicated version is then used to make digital copies of the input data.
There are various types of microphones available in the market. For example, condenser mic, carbon granule mic, ribbon mic, etc. All of them have their respective working principles. Typically, a microphone converts the vibrational energy to electrical energy. This electrical energy is fed to a computer which produces output through an output device after necessary processing.
After capturing photos and videos on a digital camera, it can be connected to a computer and the data can be stored for years. When you look at this data in the camera, it is in a human-understandable format. But, when it is present on the computer hard disk, it gets converted to binary or machine language. Hence, a camera is an input device.
6. Magnetic Ink Character Reader (MICR)
Magnetic Ink Character Reader is the code that you generally see at the bottom of a cheque. It consists of the check number, account number and the bank routing code. MICR code is printed with a special type of magnetic ink that is understandable to the reading device. The reading input device extracts the characters and transfers them to the computer which then does the necessary processing.
Gamepad is the chief input device used in almost all video game consoles. These are handheld, compact and multifunctional devices, which are operated mainly by thumbs. Gamepads are similar to joysticks and are designed to provide the user with next-level gaming experience.
8. Touch Screen
A lot of devices are operated by an interactive touch screen. For example, mobile phones, tablets, laptops, televisions, etc. Touch screens, undoubtedly, are input devices as they translate the user-provided commands into a computer-oriented language.
A touchpad serves to be a replacement for a computer mouse. It is usually embedded alongside the keyboard and is operated by a rolling finger over its surface. Two buttons are given adjacent to it that complete the purpose of left and right-click. The touchpad senses the mechanical pressure and motion, conveys the message to the processor which in return generate the command for the cursor to move accordingly.
10. Digital Pen
A digital pen is an input device which converts the analogue data into digital form. In generalized form, analogue data is something that is easily understandable to the user and digital data is very comfortably interpreted by the computer.