A digital scanner is a scanning device that could trace photos, images, documents etc. It helps to make a standby soft copy of any document that is able to transfer through electronic devices and technologies. It is based on a technology called reprographic.
The basic operation of the scanner is to read the image of the object placed on the scanner pane of optical reading feature which converts the analog code into digitized code. The image scanned is practically measured by dots per inch (dpi).The scanned images are then transferred to PC, where we can edit or modify the object image. The images such scanned can be converted into any reliable format that a PC can support. There are a variety of digital scanners which include hand held, flat bed, film and drum scanners. Each varies by the resolution of the image they could produce. They vary from few DPIs to more than 6000 DPIs. The drum scanners alone are used for business purposes where a high end of scanning and reading of objects takes place.
The main technology remains is Optical Character reading (OCR), which is the brain of all the scanners. This is the principle of all digital scanners. With this optical scanning method, a ray of light scans the object on the glass pane thoroughly from end to end. Similar technique can be seen in the working of TV. But, both make use of different scanning mechanism. The object in the scanner can also be a real time object which some particular scanners allow.
The Hand held scanners are the one which are smaller in size and are used to digitize the images. The problem in them is that they produce a low quality image.
The flat bed scanners are those that have flat bed like body in their structure. The top of the bed is designed by an optical glass pane which has the mechanism to read the object on the pane. This is highly effective for bound documents which give high resolution from 4600 X 9600 dpi to 19600 sq dpi interpolated resolution.
The film scanner is a device, used for scanning photographic films and helps to feed data directly into the computer. This could do more than flat bed scanners to print the photographic images of any custom size. This could be done by specialized software and scratch removal hardware or software.
The drum scanner is used for capturing highest resolution from any images. It uses a drum or cylinder which spins at 1000 RPM, while scanning. A light source from the drum is used to capture the images. A Photo Multiplier Tube (PMT) is used to produce 10000 dpi resolution images. It also uses a three color drum RGB to capture the pictures and this is the first type of image scanner discovered. Because of high cost and rare usage, it is vanishing from the market.
This technology of scanning objects and documents reduces paper work much and increase the standard of reproducing same quality of images for multiple times. The advantages of these digital scanners are, anti-shake factors, fine scanning, speed and accuracy and digital imaging of any hard book without damaging the spine of the book. It is also portable and user friendly to handle and able to scan more documents than an ordinary scanner.
But, still there are some disadvantages at tolerance level in the areas such as distortions, low contrast imaging, reflections, shadowing, etc. Though, it has some tolerable drawbacks, it is highly effective at smaller organizations. It is because of a high resolution image production and sharpness of the image.