IO (Input/Output) Devices

IO Devices

1. IO Devices also called as Input/Output devices.
2. Input devices used to send data to a computer.
3. Output devices used to receives data from a computer.

IO Devices

Input Devices
1. Input devices used to send data to a computer.
2. Input devices are keyboard, mouse, webcam, barcode reader, optical pen, joystick and scanner.

Keyboard 
1. Keyboard is used to enter text.
2. The buttons on the keyboard are called keys.
3. The arrangement of keys on a keyboard is called keyboard layout.
4. Most popular keyboard layout is QWERTY.

Keyboard

Mouse

1. Mouse is the most widely used pointer input device on desktop computers.

2. It is used to control the cursor or pointer on the screen.

Mouse

Webcam
1. The term webcam is a combination of  "web" and "video camera".
2. A Simple webcam setup consists of a digital camera attached to your computer, typically through a USB port.
3. Webcams used for video chat with other people.

Webcam

Barcode Reader
1. Barcode reader also called as a price scanner or point-of -sale (POS) scanner.

2. It is a hand-hold or stationary input device used to capture code and read information contained in barcode.

3. It eliminates the possibility of human errors. 

4. Barcode scan fast and reliable, it takes infinitely less time than data entering by hand.

Barcode Reader

Optical Pen

1.  Optical pen is also called as light pen.

2. It is in the form of light sensitive wand used to point displayed object on CRT display.

3. It is also used for draw on the screen in a similar way to touch screen but with greater position accuracy.

Optical Pen

Joystick

Joystick is a cursor control device used in the computer games.

Joystick

Scanner

1. Scanner is connected to the computer using a USB cable.

2. It is used to convert printed picture, drawing or document into digital file which can be edited on a computer. 

Scanner

Output Devices

1. Output devices receives data from a computer.

2. Output devices are speakers, monitors, plotters and printers.

Speakers

1. Speakers are used to play sound.

2. They may be build with system unit or connected with cables.

Speakers

Monitors

1. It displays information in visual form, using text and graphics. 

2. The portion of the monitor that displays the information is called the screen or video display terminal.

3. Computer display monitors are classified into CRT Monitors, LCD Monitor and LED Monitors.

CRT Monitors

1. Cathode ray tubes (CRT) monitors are used for desktop PCs.
2. This type monitors use large vacuum tube, called cathode ray tube.
3. They are relatively big and heavy weight.

CRT Monitors

LCD Monitors

1. LCD (Light Crystal Display) technology is the advanced technology of  CRT.

2. LCDs are very thin but are actually composed of many layers.

3. Those layer include two polarized panels, with a liquid crystal solution between them.

4. Light is projected through the layers of liquid crystal and is colorized, which produce image.

5. Liquid crystal do not produce light themselves, it requires back-light (Florescent lamp).

6. Hence LCD monitors requires more power. 

LCD Monitor

LED Monitors

1. LED (Light Emitting Diode) monitors are also called as "LED backlight LCD monitors".
2. LCD monitor employs LED backlight instead of florescent backlight is called LED monitor.
3. LED monitors takes less power consumption compare to the florescent lamp.

LED Monitors

Plotters 

1. The plotter is a computer printer for printing vector graphics.

2. These printing also called as postscript printing. 

3. Plotters are used to print designs of ships and machines, plans for buildings and so on.

Plotter

Printers

1. Printer is device that accept the text and graphic output from a computer and transfers information to paper.

2. Printers are classified into ink-jet printers, laser printers, thermal printers.

Ink-jet Printers

1. Ink-jet printers use liquid ink sprayed through the microscopic nozzle into the paper.

2. Ink-jet printers are most commonly used type of printers.

3.Ink-jet printers produce high quality text and graphics.

4.Those printers available ranges from small inexpensive models to expensive professional models.

5. It produce black and white documents as well as color documents.

6. Print speed is 6 pages per minute.
7. High maintenance cost.

Ink-jet Printers

Laser Printers

1. Laser printers used toner cartridge (filled with fine powder) and heated fuser.

2. Heated fuser is tonner particles are pulled to the paper to create desired text and images.

3. It produce only black and white documents.

4. Print speed is upto 20 pages per second.

5. Laser printer produce high quality text and images.
6. Low maintenance cost

Laser Printer

Thermal Printer

1. Thermal printers are inexpensive printers mostly used for fax machines, tickets printing, labels printing.

2. Thermal printers use heated pins and ribbons with different color bands.

3. The ribbon passes in front of print head that has series of tiny heated pins.
4. Thermal printers produce low quality and low resolution prints.

5. Whenever thermal ribban heats color bands of thermal ribban to print the  text or image on the empty paper roll. 

Thermal Printers Internal Operation 

Thermal Printers

Dot Matrix Printer

1. Dot matrix printer is the one of the oldest type of printer.
2. The working of the dot matrix printer similar to the traditional typewriter.
3. At the head of the dot matrix printer there are pins which hit the ink ribban and makes various types of patterns.
4. The dot matrix printer print outs dots on the paper to form an image or text.
5. Dot matrix printers are less initial, maintenance and running cost.
6. Dot matrix printers produce less quality print outs.
7. Those printers are commonly used in banks, retail outlets, ATMs and offices.

Dot Matrix Printer