Scanner

Scanner function is to read, record and retrieve information of an object either 2D or 3D and compile it for you with the form of images. In contrast to the Printer, Scanner only can take pictures and display information on computer and can be taken in the form of data files. So if you insert a photo it will produce the photograph itself in digital form (a picture in a computer), and if you insert the object it will generate the image itself.

There are several types of scanners rely on usability and how it works, among others:

Among these types of scanners, image scanners are most often referred to as a scanner.

Like the OMR scanner, image scanner can also be used as a scanner Computer Answer Sheet (LJK). For this can be achieved, required software technology with Digital Mark Reader (DMR).

Scanner Types

On Flatbed scanner images, the paper placed on the scanner glass, then the lamp and sensor scanner will move down the paper to get the picture.

In the image scanner Automatic Document Feeder (ADF), the paper is placed on the tray / trays, then one by one paper will be entered by the mechanical scanner with a pad and roller assy. At the time the paper moves over the light detector, the scanner sensor is working to obtain a picture that represents the paper. Advantage scanner Automatic Document Feeder (ADF) is:

This type is the type most often found, because the price is relatively the least expensive, suitable for personal use. This type is characterized by a rectangular shape. Having a cover board, and put a layer of glass where the image. To use it you should put the images one by one for each shooting.

This species is relatively simple to use. You can put the pictures that will be read, then this tool will automatically get their own pictures and read it, for then stored as digital files. The price is certainly more expensive than flat bed type. This type is suitable for offices that have many pictures that will be scanned.

This type requires more skills than its users. Users with these hands will move the scanner over the image to be read. Because the process of reading data by the scanner is very sensitive, then the resulting picture quality is not good, due to the uneven speed of movement. Generally this type is monochrome scanner, or rather can only produce black and white only.

These types are the types of early development. This type of use photomultiplier tubes (PMT) to read image data. This species produces better quality compared to other types. But because the price is relatively expensive, so this type is not widely used. Many people switch to using high-quality flatbed types. But this type still used by the parties who require good quality, like a museum or an artist that will store the work of art.

How scanners work

Here is how to work the scanner:

Digital signal from the CCD sensor is sent to the logical board and sent back to the computer in the form of digital data that show the colors at the points of the reflected image.