Basic computer questions 2

 

COMPUTER HARDWARE PART  2

::::::::::::::::::::Input devices ::::::::::::::::::::::

1 . Joystick ::-

                 Joystick is used to play game in the computer .

2 . Scanner  ::- 

Scanner is the one of the most usefull input device , which is used to send a copy of photo and document into the computer for further modification.

There are  4 type of Scanner  

                                           

    1. Flat bed scanner . 

           

• It is a multipurpose scanner . 
• It has the capacity to scan color photograph , in multi color document , 3 -dimensional object and also provide preview before scanned.

      2 . Hand held scanner .

          ( it is also known as bar code scanner )

• It is set of light emitting diode ( led ) positioned and move device or to drag it from top to bottom of a picture or text material which has to be scanned.
• The main disadvantages of  scanner is it has accuracy  problem .

 O M R ::- 
       It is stands for Optical mark of reader , Which is used mark which present on the paper or object for further modification . 

• OCR ::-  It is stands for Optical Character Reader  , Which is used for written and compare with the original character .

           OCR  is  plays very important role in the investigation department in order to recolonize the original signs and hand writing.

     3 .  Sheet fed scanner .

A sheet fed scanner (also referred to as an automatic document scanner or ADF scanner) is a digital imaging system specifically designed for scanning loose sheets of paper, widely used by businesses to scan office documents and less frequently used by archives and libraries to scan books that have been dis bound or other .

4 .   Drum  scanner :  

Definition of:  drum scanner. drum scanner. A type of scanner used to capture the highest resolution from an image. Photographs and  transparencies are taped, clamped or fitted  into a clear cylinder (drum) that is spun at speeds exceeding  1,000 RPM during the scanning operation.

5. Web camera  ::- 

• Web camera are used to capture the photos and video  of the required person or object and it can be stored in the computer for further usage and modifications.

• Web camera are classified into various categories based on the quality  of the camera.   
• The quality of camera is measured in the form of pixel .( pixel -Picture element ).
• Hence web camera  are avaliable in 2 , 3 , 5 , 8 , 12 ....etc.
• User can chose the type of camera to the requirement and  the budget.