How to distinguish computer Input And Output Device?
What Is An Input Device?
An input device is essentially a piece of hardware component used to provide data and control signals to an information processing system such as computer or information device. Common inputs devices on modern computers include keyboards, mouse and touch screen which are used to enter commands and data directly. Other examples of input devices include scanners, digital cameras, joysticks and microphones.
Keyboard
- The management mechanism of keyboard input is closely related to the design of the window system, and the focus window is the destination of keyboard input.
- Functionally, the keyboard has two capabilities: one is to enter text, and the other is to trigger commands
- To enter text, you need to enter the cursor to indicate the target window, and the target window must be the focus window.
- Trigger commands are not necessarily in the focus window, such as hotkeys, trigger screenshots, get QQ messages, etc.
Mouse
1.The management mechanism of mouse input is the same as that of the keyboard, and is closely related to the design of the window system
2.Mouse events are always handled by the window to which the mouse position belongs, but there are exceptions, such as drag and drop
3.In the mobile era, the mouse completely disappeared, and the combination of touch screen + finger completely replaced the mouse
Microphone
1.Microphones are very promising next-generation input devices, such as smart cars, smart speakers
2. In the IoT field, voice interaction is still dominated by trigger commands, and there are more and more usage scenarios for inputting text, but the advantages are still in everyday language and long texts, and the input effect in special fields and personalized scenarios is not good.
Camera
1.In addition to introducing voice, the camera also adds gestures, expressions, and actions
2.In terms of expressive ability, this is the richest and most natural way of expressing
3.This kind of interaction is still in its develop.
What Is An Output Device?
An output device is any hardware component that use received data from a computer to perform a task. The data received by the output device can be text, graphic, tactile, audio or video. Three most commonly used output devices are a printer, a monitor and speakers. A printer is used to generate a hard copy or graphics on a physical medium such as paper. Speakers are used for communicating with the user by voice or for playing music or the soundtrack to a movie whereas a monitor displays visual output such as text, graphics and videos on a screen.
Monitor
1.The display has undergone multiple generations of updates from CRT to LCD, supporting more colors and higher resolution, but no substantial changes have occurred
2.The window system is for the operating system to allow different software to be presented on the same monitor screen, each software has one or more windows
3.Because the screen of mobile devices is too small, the operating system allows the top-level window to occupy the entire screen in full screen, so screen management is relatively simple
4.Another major challenge in display device management is the rendering subsystem, and the software needs rendering capabilities to render the contents of the window.
5. GDI in the operating system is responsible for drawing, mainly involving 2D graphics (paths, brushes, brushes), 3D graphics (models, materials, lighting), text related (fonts), image processing (bitmaps, image format codecs)
6.The operating system provides common interface elements, usually called controls, such as static text, buttons, radio selection, check box, input box, progress bar, etc.
Speaker
1.The management of speaker equipment is very simple, and it is easy to do multiple software to operate the equipment at the same time and have reasonable results
2.Under certain circumstances, a software is allowed to prohibit the sound played by other software, such as answering a phone call
Printer
1.The process by which software uses the printer is basically mutually exclusive. When a software prints a document, other software can only print it after it has finished printing.
2.The use of printers is based on documents as mutually exclusive units. In order to avoid long-term mutual waiting between software, the operating system often introduces a large print buffer into the management program of the printer.
3.When the software operates the printer, it does not wait for the printer to actually print the content, but prints the document into the print buffer to complete the printing.
Summary
Output and input devices are two types of hardware devices. The main difference between them is that input devices are used to send data into the computer while output devices are used to take data out of the computer.
Most devices are either input devices or output devices, as they can only accept data input from a user or output data generated by a computer. However, some devices can accept input and display output and are referred to as I/O devices (Input /Output devices). For example a touch screen displays visual output and takes input from a user. Other devices like printers also function as document scanners.