Thursday 3 January 2019

Image scanner

Scanner

                           


Scanner is a input device which scans documents and convert them into software files.
Scanner scans any document, photo, letter, and converts it into a digital file (JPG, PDF). It also works for photos. 
Scanner + Printer = Photostat Machine
Scanner now a days is a very important input device mainly in offices.
Scanner is a optical device.

Two Types of Scanners 


  • Sheetfed Scanner 



  • Flatbed Scanner 



SPECIFICATIONS

  • RESOLUTION :   Length * Breadth
No. of Pixels  or  No. of Dots
The more pixels the better the picture,
The picture is not bad at zooming.
200 dpi,  300 dpi,  600 dpi,  1200 dpi,
2400 dpi,  4800 dpi,  9600 dpi  (dots per inch)
Whenever you buy scanner then check the number of pixels (maximum).
  • COLOR DEPTH  ( No. of Colors )
2 bit    =    4 colors
8 bit    =    256 colors
16 bit  =    65,536 colors
24 bit  =    1,67,77,216 colors  = 16 M
32 bit  =    430 crore colors  etc....
  • SPEED OF SCANNER
            Scan Speed
            Preview Speed

The speed of the scanner should be good.
5 - 15 ppm ( page per minute )

  • ADF (Automatic Document Feeder)
This system can scan many papers together. It can scan one post at a time from Paper Dual Side.

  • SIZE OF PAPER 

        Means which size of paper supports (A3,  A4 etc...)

Scanners also come in All-in-One Machine.

They are also cheap and photocopy can also be done.

All-in-One = Print,  Scan,  Copy 



1 comment:

  1. Lots of posts which are regarding service of printers are very useful to people like us who are into service. ADF which is an automatic document feeder can cause problem in picking up the paper if it is damaged or even if it has dirt over it. Sometimes cleaning it can also solve the issue. Being a service person and frequent visit to hp service center has given me the experience. Thanks a lot for the post.

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