How does the scanner work?
Scanner - a very useful invention of the twentieth century. During the huge circulation of various documentation, the scanner is used very widely in offices and at home. In general, a scanner is a device that allows you to transfer information or images located on the surface into a digital format. The process of converting information is called scanning. This process is quite complex. Probably, it became interesting to many how the scanner works. Let's try to understand this intricate mechanism in this article.
Technical principles of the scanner
Optics scanner consists of mirrors and a lens. The light source sends light rays to the original, which must be obtained on a computer screen. After that, the light, reflected, falls on the very optics. The result is an electrical signal that contains information about the color activity at the point of the scanned image. Next, the color signal comes through the hardware interface to the computer, on which information is decoded by a special program that works with the scanner.
The information is fully displayed on the computer screen. To even better understand how the scanner works, you need to understand the structure of this mechanism. The most important part of the device can be called the read head, which moves along and across the image. On this head is a photodetector. There are two types of photo-receiving matrix.
- One of them is PDS-matrix (charge-coupled device), which consists of a set of sensors that convert the light falling on them
- The other is CDI-matrix (contact image sensor). In CDI scanners, LEDs are used, and in scanning a color image, the presence of three LEDs per pixel is mandatory.
How the scanner transmits information
Now everyone is confronted with scanning. For example, at the checkout of a supermarket scan a bar code printed on a pack of goods, and the name appears on the screen with the price and the amount of the purchase. But it’s still interesting how the barcode scanner works, how it manages to transfer such information to the screen.
Barcode scanners are LED, laser and image scanners. In LED devices, the light-emitting element is an LED.Information is read by a CCD matrix. Also used laser devices that are more convenient.
Image scanners - the peak of fashion. They are the most reliable, fast, high-quality and shock-resistant. They are also able to read any barcode. The barcode lays out product information, and when the light beam is directed, it is read and converted to a computer or other device screen. The principle of operation of such scanners is the same as that of conventional ones. However, the difficulty lies in the fact that it is not the information that is located on the original that is scanned, but the encrypted information into special codes.