Utility and functionality of scanners

Scanners are widely used in many places, but what are the specific uses and principles of scanners? Below, I will introduce you to what is a scanner, as well as the purpose and working principle of the scanner.

The purpose and principle of the scanner

A scanner is an input device for a computer, and its role is to scan the written materials or physical appearance of pictures, photos, films, and document materials into the computer, and save them as files. In fact, the scanner has become the third most important computer input device after the keyboard and mouse.


There are many types of scanners, such as black and white scanners and color scanners. In terms of scanning methods, there are handheld scanners, flatbed scanners, and roller scanners. Flatbed scanners are versatile, powerful, and affordable. It has been widely used in many fields such as graphic image processing, electronic publishing, advertising production, office automation and so on.


The purpose of the scanner

Scanners are inherently responsible for scanning photos and images or images from newspapers and magazines and saving them to a computer. In recent years, the scanner has played a new trick, which is often called "OCR". With this method, the text written on the paper can be scanned and automatically converted into editable text on the computer. This can greatly reduce the amount of text input when typing.

The principle of the scanner is actually very simple, just like we usually look in the mirror. When it scans an image (only one line at a time), the light is reflected back from the object and shot through a lens into a CCD (Charge Coupled Device). The CCD converts the light into an analog voltage signal, and marks the gray level of each pixel. Then the ADC (analog-to-digital converter) converts the analog voltage signal into a digital signal. Each color uses 8, 10, or 12 bits. It means that after scanning, it is saved in the computer in Twain (Special Format for Scanned Images) format.