What are Pointing Devices? Explain
What are Pointing Devices? Explain
Pointing Devices :
An input devices used to control a pointer on the screen is called pointing device. A pointer is small symbol that appears on the screen in graphical user interface.
Some Important Pointing Devices are as follows:
- Mouse
- Trackball
- Pointing Stick
- Touch pad
- Touch screen
- Light pen
- Digitizer/ Graphic Tablet
- Joy stick
- Pen-based System
What is Mouse ?
Mouse is the widely used pointing device. It is a small and lightweight input device. It is used to input instructions with a pointer on the screen. Mouse is moved on a flat surface to control the movement of the cursor or the pointer. It is attached to the computer by a cable or wireless connection. Mouse is very easy to use. It is mostly used in graphics application.
A mouse usually has two or three buttons. These buttons are used to perform different tasks such as selecting an object or opening a program etc. It may also include a scroll wheel to scroll through long documents. The mouse contains a small ball at the bottom. The movement of the cursor depends on the movement of ball.
What is Track Ball ?
A trackball can be used as an alternative to mouse. This device has buttons similar to those on mouse. It has a large rotating ball on the top. The body of the trackball is not moved. The ball is rolled with fingers. The position of the cursor on the screen is controlled by rotating the ball.
An advantage of the trackball is that it takes less space to move than mouse. Trackball is often included in laptop computers. It can also be used as separate input devices with standard desktop computers.
What is the purpose of touch-pad / track-pad ?
A touch-pad is a small, flat surface over which the user moves his finger. The movement of the finger moves the cursor on the screen. It is also known as track-pad.
A touch-pad also has one or more buttons near it. These buttons work like mouse buttons. Touch-pad are commonly used with notebook computers.
Describe touch screen?
Touch screen is a display screen that receives input form the touch of finger. The screen is covered with a plastic layer. There are invisible beams of infrared light behind the screen.
The user enters data by touching icons or menus on the screen. Most touch screen computers use sensors to detect touch of a finger. Touch screen is commonly used in ATM, departmental stores and supermarkets.
Briefly explain pointing stick?
Pointing stick is a pressure-sensitive device. It is similar to a pencil eraser and exists between keys on the keyboard.
The pointer on the screen moves when the user pushes the pointing pointing stick is normally used with notebook computers.
What is digitizer/graphics tablet?
A graphics tablet consists of a flat pad connected to a stylus or puck by wire. A stylus is a pen-like device used to create sketches and images. A puck is a copying device used to copy an image. A puck looks like a mouse. The puck is specially used to trace a drawing ad store it in the computer in digital form.
A designer can produce very accurate drawings using graphics tablet. Graphic tablets are often used to make maps and engineering drawings.
Briefly describe light pen?
A light pen is a hand held pointing device. It looks like a pen. It is connected by a wire to the computer. The pen sends information to the computer when user touches the pen on specific areas of a specially designed screen. Light pen is usually used by engineers and graphic designers etc.
Explain the purpose of joystick.
A joystick consists of a base and a stick. The stick can be moved in any direction to move an object around the computer screen. A joystick can perform a similar function to a mouse or trackball. But it is often considered less comfortable and efficient. The most common use of a joystick is for playing computer games.
Describe the pen-based computer systems?
Pen-based system is used to enter handwriting and marks in computer using pen-like stylus. The user writes words and symbols on the screen. This system uses handwriting recognition software. The software translates processed by computer. Many handheld computers have pen input. Pen-based systems are commonly used to input signatures, graphics that are stored as images.
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