Output Devices

Printer

The printer is an output device that produces a hard copy output on a piece of paper.

Printers are classified into two categories – 

Impact Printers and Non – Impact Printers

The Printing process of a printer depends on the following parameters:-


Speed: The number of pages of text that a printer can print per minute (ppm)

Image Quality: The resolution of the printer refers to how many dots of ink per inch can

be put into a square inch of paper. It is measured in dots per inch (dpi).

A printer can be: -

Character Printers: These printers can print charter by character. Slow speed printing.

Line Printer: The printers that can print line by line at a time, a buffer memory used for temporary storage.

Page Printer: Page printers can print the entire page at a time.

Impact Printers

1. Character Printer: 

The printer that stores individual characters when needed to print. The printer will print one character at a time instead of one line at a time. The speed of character printers is 100-300 characters per second. The various types of character printer as follows:

Dot Matrix Printer: 

The term DOT matrix refers to the process of placing dots to form an image; the quality of the image being determined by the dots per inch. This printer uses print heads to shoot ink or strike an ink ribbon to place hundreds to thousands of little dots to form text and/or images.

Daisy Wheel Printer:

 A type of printer that produces letter-quality type. A daisy –wheel printer works on the same principle as a ball-head typewriter. The daisy wheel is a disk made of plastic or metal on which characters stand out in relief along the outer edge. To print a character, the printer rotates the disk until the desired letter is facing the paper. Then a hammer strikes the disk, forcing the character to hot an ink ribbon, leaving an impression of the character on the paper

      

      
2. Line Printer:

Drum Printer:

     A drum printer is a type of line printer that prints one line at a time in serial order it consists of a solid cylindrical drum that has raised characters in bands on its surface. When the desired character for the selected position rotated around to the hammer line, the hammer hit the paper from behind and pushed it into the ribbon and onto the character. The typical speed of drum printers is in the range of 300-2000 lines per minute.

Chain Printer:

    Chain printer is the type of line printer, Chain printer used type slugs linked together in a chain as its printing mechanism. The chain spins horizontally around a set of hammers. When the desired character is in front of the selected print column, the corresponding hammer hits the paper into the ribbon and onto the character in the chain.

Non-Impact Printers

Non-Impact Printers do not hit or impact a ribbon to print like an impact printer.

Ink-jet printers:

An inkjet printer is any printer that places extremely small droplets of ink on to paper to create an image. The dots are small, about 50-60 microns in diameter which is smaller than the diameter of a human hair (70 microns). The resolution is about 1440x720 dots per inch (dpi). It may have different colors combining together to form a dot, creating photo-quality images. Inkjet printers have a print head with 300 to 600 firing chambers which are tiny nozzles used to spray thousands of droplets of ink per second in a precise pattern to make up the text and images on a page.

Laser Printers:

A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. This is also the way copy machines work.

  
Plotters

A plotter is an output device used with a computer that can be likened to a printer. However, instead of the printing text of images, a plotter is more usually used to draw up technical plans and blueprints, Instead of the print cartridge found in a printer, a plotter commonly uses a pen, and other implements can also be used in place of the pen.

Monitor

The monitor is a very common output device and is provided along with the computer, to view the displayed output.

Speaker

A speaker gives you sound output from your computer. Some speakers are built into the computer and some are separate. A device that converts analog audio signals into the equivalent air vibrations to make an audible sound.

Chain Printer

Daisy wheel

Drum Printer

Inkjet Printer

Laserjet

Monitors

Plotters

Speakers

Pics Source:- Google