Laser printers are print output devices that combine laser scanning technology with electrophotographic technology. The basic working principle is that the binary data information transmitted by the computer is converted into a video signal by a video controller, and then the video interface / control system converts the video signal into a laser driving signal, and then the laser scanning system generates a character message The laser beam is finally imaged by an electrophotographic system and transferred to the paper. Compared with other printing equipment, laser printers have the advantages of fast printing speed and high imaging quality, but the use cost is relatively high.
Laser printers can be divided into three categories according to their print output speed: low-speed laser printers (output 10 to 30 pages per minute); medium-speed laser printers (output 40-120 pages per minute); high-speed laser printers (output 130-130 per minute) 300 pages).
A laser printer is composed of a laser, an acousto-optic modulator, a high-frequency driver, a scanner, a synchronizer, and a light deflector. Its function is to modulate the binary dot matrix information sent by the interface circuit on the laser beam, and then scan it to the light. Physically. The photoreceptor and the photographic mechanism constitute an electrophotographic transfer system, which transfers the graphic images shot on the photosensitive drum to the printing paper. The principle is the same as that of the copier. Laser printer is a non-hitting output device that combines laser scanning technology and electronic imaging technology. Its different models have different printing functions, but the working principle is basically the same. They have to go through seven processes: charging, exposure, development, transfer, electricity elimination, cleaning, and fixing. Five of these processes are around the photosensitive drum. . When the text or image to be printed is input into a computer, it is pre-processed by computer software. The printer driver then converts the print command (printer language) that the printer can recognize and sends it to the high-frequency drive circuit to control the on and off of the laser transmitter to form a dot matrix laser beam, and then scans the mirror to the electronic imaging system. The photosensitive drum in the center performs axial scanning exposure, and the vertical scanning is realized by the rotation of the photosensitive drum itself.
Compared with dot matrix printers and inkjet printers, laser printers have very obvious advantages. (1) High density. Laser printers have a minimum print resolution of 300dpi, as well as 400dpi, 600dpi, 800dpi, 1200dpi, and 2400dpi and 4800dpi. (2) High speed. Laser printers have a minimum print speed of 4 ppm, typically 12 ppm and 16 ppm, and some laser printers can achieve print speeds of more than 24 ppm. (3) Low noise. Generally below 53dB, very suitable for use in quiet office places. (4) Strong processing capacity. The controller of the laser printer has a CPU and a memory. The controller is equivalent to the computer’s motherboard, so it can perform complex word processing, image processing, and graphics processing. This is not possible with dot matrix printers and inkjet printers. The difference between a page printer and a line printer.