Flatbed Input Devices Scanner What is a Scanner?A Scanner is adevice which converts any physical paper to a digital one (which computers canunderstand). What are different types ofScanners?· Drum Scanner:Drum Scanner is acylindrical scanner which is used to scan colour images more accurately and ina better resolution.· CCD Scanner:CCD is an abbreviation ofCharged Coupled Device .This is thetype of Scanner which we use in our daily life.
There is an opening and a flatsurface where we have to keep the document which we want to scan. The surfaceis covered and a ray of light passes through it and the document is scanned. · CIS ScannerCIS Scanner or ContactImage Sensor Scanner use an array of LEDs to shine light on the document sothe image sensor can essentially take a snapshot of it like we do by takingimages of the document, but this method is more accurate than taking imagesthrough mobile phones and less accurate than CCD Scanner. CIS is cheaper, morelightweight and more efficient technology to scan images. So it used in smallportable scanners which can be powered from solely USB port instead of requiringa wall outlet.· Roller Scanner:This type of scanner canscan only a limited width of a paper. The paper is rolled around a rod which isto be scanned and then rollers are rotated. This is very small and compactscanner which can store in its memory or could be transferred to a computerthrough USB port.
How does a Scanner work? Scanneruses something called as Charged-Coupled device (CCD) to scan a page. The CCDcan convert light into an electrical charge which then sends data to thecomputer as digital data. A rayof light is released from the scanner which is due to a xenon lamp or a coldcathode hits the paper and is reflected back underneath a glass surface thenfocused by a lens onto an array of CCD sensors.
The dark parts containing inkon paper reflects less light then white portion. The CCD Arrays will analyze thesedifferences and will show up as an accurate image in the computer. The more thesensors in the array the more pixels we get in the final image.
How does a Colour scannerwork? ColourScanner uses different lenses to detect different versions of Red, Green andBlue colour to scan any colour. What is the future ofScanners? Nowadaysphone has a scanner which converts the document to an image format or a PDFformat using some machine learning algorithms which eliminates the uselessparts of background (like user’s hands while capturing image). Apart fromthat nowadays 3D Scanner technology is developing. They scan athree-dimentional object.