A Scanner is a device that optically scans images, print text, and handwriting in to digital image. For i.e. a scanner may uses to convert a printed picture, drawing or document into a digital file. which can be edited on computer. scanner works more like a photocopy machine. It is uses when some information is available on paper. In todays generation some devices have both scanner and printer combine.
Generally, modern scanners uses a charge couple device CCD or a contact image sensor. Drum scanner developed earlier and still uses for highest quality image. The 3D scanners produce information on the 3 dimension structure of solid objects. A digital camera is also uses for a same scanning purpose. A camera of smartphone is also a type of scanner. scans are usually downloads from a computer the unit is attach to.
The first scanner is known as a pantelegraphy. The inventor of this scanner was Giovanni Caselli used commercially in 1860s. It uses electromagnets to drive and synchronize movement to scan and reproduce image. It can produce Handwriting, signatures or drawing in area up to 150*100 mm. Services similar to a wirephoto were calls a Belino in Europe. It was used by news agencies from 1920s to the mid 1990s. They send linear signal through a telephone voice lines to receptors. It synchronously print the proportional on special paper. Color photo were print on separate RGB color print.
This device is a hardware input device, which is optically reads the image and converts it into a digital signal. Foe i.e. a scanner may uses to convert a printed picture, drawing into a digital file. The amount of light that is reflect back tells the computer how the image is light or dark. The light and optical sensor reads information about one line of the image at a time. They must be move down the picture to input whole image.
You place the image on the top of the scanner. The scanner moves the light and sensor itself and scans the full image automatically. Most of the flatbed scanners are available in A4 size. This scanner is also known as a reflective scanner. It works by shining white light on the object and reading the color that reflects from it. This scanner are build for scanning prints and other flat materials but not well for scanning films.
You just manually push the light along the image. Generally, handheld scanners are 5 inches wide. Flatbed scanners are better as they can scan larger images and are more accurate than handheld scanners. Comparatively, handheld scanners are cheaper and more portable. Handheld scanners are rarely sell now.
Barcode reader is a device uses for reading bar code data (data in form of light and dark lines). Bar code data is generally uses in labelling goods, numbering the books, etc. Generally, Bar code reader scans a bar code image, converts it into an alphanumeric value.
A flatbed scanner is usually made up of glass pane, under which there is a bright light. CCD scanners typically contains three rows of sensors with red, green and blue filters.
The second name of this scanner is transparency scanner. It works by narrowly passing light through the film. Films scanners are vary a great deal in price and quality. The specifics are vary by brand and models by optical system and equally important of scanning software. Generally, film scanners contains device like DSLR, and stepper motor etc.
This scanner pulls a flat sheet over the scanning element between rotating roller. They can only handle single sheet at a time. This scanners are very compact, just requiring a pair of narrow rollers where the document passes. some rollers are portable runs with the batteries and some are USB portable or other interface.
In these scanners there are no moving parts are available to scan the object. Document camera captures a full document or object in one step instantly. Generally, this process has benefits of increasing reaction time. The objects which have been gets difficult to scan on other scanners are now able to do with one device. comparatively, This includes particular documents varying shapes, staple in folders which may get jam in the feed scanners.