Scanner

Scanner Introduction: Scanner is an input device. It reads the graphical images or line art or text from the source and converts it into digital information and send it to the computer. Scanner is electronic device that scans data. Scanners are used to give large volume of data as input to the computer.

Specification of scanner: Scan speed photo color,10*15cm,OCR A4 Optical resolution4800 dpi*9600 dpi Min temperature:50 to 95 degree. Operating humidity range:15-85% OS:windows, MacOS, windows 7/8/XP/2000. Power supply: 15W Port required: hi-speed USB

Types of scanner Flat bed scanners Sheet fed scanners Hand held scanners Drum scanners

Flat bed scanners Sheet fed scanners Hand held scanners

Operation Scanner is operates on the principle of reflection . That is , when a light source falls on an image document , the incident light reflects. The reflection depends upon the color and size of the images in the document.

Structure of Scanner That is black or white spaces reflect more light than colored or inked letters or images.

Cont., The light from the lamp is made to fall on the document through the glass plate. The head receives the reflected light from the document with the help of mirrors (m). The reflected light is filtered with the help of R,G,B filters.

Cont., The filtered light is made to fall on a light sensor having 1024 elements using a mirror and a lens. The sensor converts the analog signals into digital signals and is given as output. The scan head is moved over the document with the help of a motor.

Scan Resolution The number of dots or pixels per inch a scanner can resoluve for a document. In other words resolution relates to the fineness or clarity of the image scanned by the scanner.

Different Resolutions 200 dpi – Dots Per Inch 400 dpi 600 dpi and so on. The more dots per inch a scanner can resolve, the more clarity the resulting image will have.

Flatbed scanner Scan documents, photos, flat object from a PC or laptop. Works like copy or Xerox machine. Flatbed is made up of glass pane and moving CCD array and two mirrors. Most common type of scanner easy to operate, widely used.

Flatbed scanner specification Scanner type: flatbed Size:280*486*52mm Weight :1.7kg Interface:USB1.0 H/W reslution:1200DPI. AC voltage:200-240V 50Hz

Sheet-fed scanner Sheet-fed Scanner smaller and portable Used to scan document and photos Document is fed into horizontal and vertical slot provided with scanner Components of scanner sheet-feeder, scanning module & calibration sheet. Scan single page documents. Not used to scan thicker objects.

Handheld scanner Smaller in size. It is scanning device which is moved over the object that needs to be scanned . To scan the document drag the scanner over document. Used in barcode scanner. Image quality is very poor.

Drum scanner Used in publishing industry. Color drum scanners use three matched photo multiplier tube. High resolution high quality. More Expensive. Drum scanners are slow.

Scan modes Line art Half toning Gray scale True color