Scanners are widely used in many places, but what are the specific usages and principles of scanners? Let the editor introduce to you what a scanner is, its purpose, and the working principle.
A scanner is an input device of a computer. Its function is to scan the appearance of written materials or physical objects such as pictures, photos, films, and manuscript data, input them into the computer and store them as files. In fact, the scanner has become the third most important computer input device after the keyboard and mouse.
Scanners come in many forms, such as black and white scanners and color scanners according to color. For example, a hand-held scanner, flat-panel scanner, and roller scanner are classified according to scanning mode. The flat-panel scanner has the characteristics of wide application, strong function, and moderate price. It has been widely used in many fields such as graphic image processing, electronic publishing, advertisement making, office automation.
Purpose of scanner
The scanner's duty is to save the photos, images in newspapers and magazines into the computer after scanning. In recent years, the scanner has a new function, which is often called "OCR". With this method, the characters written on paper can be automatically converted into editable files in the computer after scanning, thus greatly reducing the amount of typing. For different purposes, there are different scanners, such as book and document scanner, auto book scanner.
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), light is reflected back from the object and enters the CCD (Charge Coupled Device) through the lens. CCD converts light into analog voltage signals and marks the gray level of each pixel. ADC (analog to digital converter) converts analog voltage signals into digital signals. Each color is represented by 8, 10 or 12 bits. After scanning, it is stored in the computer in Twain (scanning image special format).