How Does A Scanner Work?

The scanner is an image signal output device. It performs optical scanning on the original, and then transmits the optical image to the photoelectric converter into an artificial electrical signal, converts the artificial electrical signal into a digital electrical signal, and finally sends it to the computer through a computer module.

The steps for the scanner to scan the image are: First, place the original to be scanned face down on the scanner glass. The manuscript can be a text manuscript or a photograph of a drawing. Then, after starting the scanner driver, the movable light source installed inside the scanner starts scanning the original. In order to evenly illuminate the manuscript, the light source of the scanner is a long bar, and the entire original is dropped in the y direction. The light shining on the original passes through a wide gap, forming a light band in the x direction, and then passes through a set of reflecting mirrors, which are discussed by the optical lens and transferred to the beam splitter. The three RGB color light bands obtained through the prism and the red, green and blue color filters are respectively irradiated on the respective CCDs, and the CCD changes the RGB light bands into simulated electronic signals. This signal is changed into a digital electronic signal by the A / D converter.
At this point, the optical signal that reflects the original image is changed to a binary digital electronic signal that the computer needs to reject, and finally sent to the computer through modules such as serial or segmentation. The scanner obtains the image information of one line in the x direction of each original line by scanning the line. With the movement in the y direction, a full image of the original is gradually formed inside the computer.