It adopts line-by-line scanning and samples the input graphics at a certain density. The main input data form is an image, that is, a pixel matrix composed of brightness values. This kind of equipment often adopts automatic scanning input mode, so the input is fast and convenient. However, the image data it obtains must be converted into graphic data before it can be used by CAD processes and subsystems. This transformation is a process of pattern recognition. In recent years, the research in this field is gradually entering the practical stage. Commonly used raster scanning graphic input devices are scanners and cameras.

Working principle: In this display, the trajectory of the electron beam is fixed. That is, scan the screen from left to right and from top to bottom to generate a grating. Features: Because graphics are stored in the frame buffer in the form of dot matrix. Therefore, the electron beam of the raster scanning display scans the screen from top to bottom and from left to right, so as to establish a pattern. Advantages and disadvantages: it can display rich and colorful static and dynamic images, and the production cost is low, but the line quality is not high.

Functionally, it can be divided into six categories:

1) point coordinate positioning;

2) The coordinates of a series of points are strokes;

3) numerical value;

4) choose;

5) pattern recognition;

6) character string;