Computer Fundamentals- Output Devices | Output Device In Computer Fundamental | Computer Fundamentals- Output Devices In Hindi

 

Computer Fundamentals- Output Devices

Following are some of the important output devices used in a computer.

• Monitors
• Graphic Plotter
• Printer

 

1.   Monitors

 

Monitors, commonly called as Visual Display Unit (VDU), are the main output device of a computer. It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels.

There are two kinds of viewing screen used for monitors.

• Cathode-Ray Tube (CRT)
• Flat-Panel Display

 

1.   Cathode-Ray Tube (CRT) Monitor

 

The CRT display is made up of small picture elements called pixels. It takes more than one illuminated pixel to form a whole character, such as the letter ‘e’ in the word help.

Most screens are capable of displaying 80 characters of data horizontally and 25 lines vertically.

There are some disadvantages of CRT −

• Large in Size
• High power consumption

Fig: CRT-Monitor 

2.   Flat-Panel Display Monitor

 

The flat-panel display refers to a class of video devices that have reduced volume, weight and power requirement in comparison to the CRT. Current uses of flat-panel displays include calculators, video games, monitors, laptop computer, and graphics display.

 

  The flat-panel display is divided into two categories –

 

·        Emissive Displays 

 

Emissive displays are devices that convert electrical energy into light. For example, plasma panel and LED (Light-Emitting Diodes).

 

·        Non-Emissive Displays 

 

Non-emissive displays use optical effects to convert sunlight or light from some other source into graphics patterns. For example, LCD (Liquid-Crystal Device).

 

Fig: Flat- Monitor 

2.   Printers

 

Printer is an output device, which is used to print information on paper.

 

There are two types of printers −

• Impact Printers
• Non-Impact Printers

 

     I.            Impact Printers

Impact printers print the characters by striking them on the ribbon, which is then pressed on the paper.

 

Characteristics of Impact Printers are the following −

• Very low consumable costs
• Very noisy
• Useful for bulk printing due to low cost
• There is physical contact with the paper to produce an image

 

These printers are of two types −

• Character printers
• Line printers

 

Ø Character Printers

 

Character printers are the printers which print one character at a time.

These are further divided into two types:

• Dot Matrix Printer(DMP)
• Daisy Wheel

  

   Ø Dot Matrix Printer

 

Advantages

• Inexpensive
• Widely Used
• Other language characters can be printed

 

Disadvantages

• Slow Speed
• Poor Quality

 

Fig: Dot-Matrix Printer 

  Ø Daisy Wheel

 

Advantages

• More reliable than DMP
• Better quality
• Fonts of character can be easily changed

 

Disadvantages

• Slower than DMP
• Noisy
• More expensive than DMP

 

Fig: Daisy-Wheel-Printer 

 

Ø Line Printers

 

Line printers are the printers which print one line at a time.

 

These are of two types −

• Drum Printer
• Chain Printer

Fig: Line-Printer 

 

  Ø Drum Printer

 

Advantages

• Very high speed

 

Disadvantages

• Very expensive
• Characters fonts cannot be changed

 

  

  Ø Chain Printer

 

Advantages

• Character fonts can easily be changed.
• Different languages can be used with the same printer.

 

Disadvantages

• Noisy

 

2.Non-impact Printers

 

Non-impact printers print the characters without using the ribbon. These printers print a complete page at a time, thus they are also called as Page Printers.

 

These printers are of two types −

• Laser Printers
• Inkjet Printers

 

Characteristics of Non-impact Printers

• Faster than impact printers
• They are not noisy
• High quality
• Supports many fonts and different character size

 

  Ø Laser Printers

 

These are non-impact page printers. They use laser lights to produce the dots needed to form the characters to be printed on a page.

 

Advantages

• Very high speed
• Very high quality output
• Good graphics quality
• Supports many fonts and different character size

 

Disadvantages

• Expensive
• Cannot be used to produce multiple copies of a document in a single printing

Fig: Laser Printer 

 

Ø Inkjet Printers

 

Inkjet printers are non-impact character printers based on a relatively new technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high quality output with presentable features.

 Color printing is also possible. Some models of Inkjet printers can produce multiple copies of printing also.

 

Advantages

• High quality printing
• More reliable

 

Disadvantages

• Expensive as the cost per page is high
• Slow as compared to laser printer

 

Fig: Inkjet Printer