Following are some of the important output devices used in a computer.
- Monitors
- Graphic Plotter
- Printer
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
Cathode-Ray Tube (CRT) Monitor
The CRT display is made up of small picture elements called pixels.
The smaller the pixels, the better the image clarity or resolution. It
takes more than one illuminated pixel to form a whole character, such as
the letter ‘e’ in the word help.
A finite number of characters can be displayed on a screen at once.
The screen can be divided into a series of character boxes - fixed
location on the screen where a standard character can be placed. 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
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.
You can hang them on walls or wear them on your wrists. 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).
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
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
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
Dot Matrix Printer
In the market, one of the most popular printers is Dot Matrix
Printer. These printers are popular because of their ease of printing
and economical price. Each character printed is in the form of pattern
of dots and head consists of a Matrix of Pins of size (5*7, 7*9, 9*7 or
9*9) which come out to form a character which is why it is called Dot
Matrix Printer.
Advantages
- Inexpensive
- Widely Used
- Other language characters can be printed
Disadvantages
- Slow Speed
- Poor Quality
Daisy Wheel
Head is lying on a wheel and pins corresponding to characters are
like petals of Daisy (flower) which is why it is called Daisy Wheel
Printer. These printers are generally used for word-processing in
offices that require a few letters to be sent here and there with very
nice quality.
Advantages
- More reliable than DMP
- Better quality
- Fonts of character can be easily changed
Disadvantages
- Slower than DMP
- Noisy
- More expensive than DMP
Line Printers
Line printers are the printers which print one line at a time.
These are of two types −
- Drum Printer
- Chain Printer
Drum Printer
This printer is like a drum in shape hence it is called drum printer.
The surface of the drum is divided into a number of tracks. Total
tracks are equal to the size of the paper, i.e. for a paper width of 132
characters, drum will have 132 tracks. A character set is embossed on
the track. Different character sets available in the market are 48
character set, 64 and 96 characters set. One rotation of drum prints one
line. Drum printers are fast in speed and can print 300 to 2000 lines
per minute.
Advantages
- Very high speed
Disadvantages
- Very expensive
- Characters fonts cannot be changed
Chain Printer
In this printer, a chain of character sets is used, hence it is
called Chain Printer. A standard character set may have 48, 64, or 96
characters.
Advantages
- Character fonts can easily be changed.
- Different languages can be used with the same printer.
Disadvantages
- Noisy
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
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
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.
They make less noise because no hammering is done and these have many
styles of printing modes available. 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
Always check for more updates. . .
If you would like to donate to Ykamazingworld please click here.
Check for more updates on Ykamazingworld Business List.
Check for more updates on Ykamazingworld Business List.
Click to view Director's Profile
To meet your needs with Ykamazingworld click on: http://metyourneeds.blogspot.com/
[Home Page] [Met your needs] [About Ykamazingworld Nigeria Enterprises] [Footwear and Leather Production] [Computer & Businesses] [Media and Communication Studios] [Films and Theatre Production Studios] [Vegetable Oil Dealer] [Home Planning & Building Engineer] Farm Food Production Fashion, Wears and Printing Production Home-made and Cosmetics Ice-block Depot, Drinks, Provision and Business Ventures [Ykamazingworld Search] [Carrier and Opportunity] [Company Overview] [Our Objectives] [Our Vision] [Our Goals] [Our Products] [Our Services] [Networking & Communications] [Consultancy] [Sales of Footwear and Leather Suppliers] [Computer Industrial Training (I.C.T)] [Footwear Industrial Training (F.I.T)] [Payment Rules and Regulation] [Sponsors or Fund Raising] [Ykamazingworld Proposals(for Partnerships)] [Ykamazingworld Banks & Accounts] [Social Media] [Our Address] [Our Contacts] [Ykamazingworld Weblinks] [GOto Blog] [GOto WebChatrooms] [GOto Books and Publishing] [GOto Word of Wisdom] [GOto Answers.com] [Notice for all our Clients]
Together, we rise to the future. . .
No comments:
Post a Comment