Development History
With the development of computer applications, users have put forward higher and higher requirements for print output equipment. The mechanical striking structure cannot meet these requirements. The first non-impact printer successfully developed was to draw curves based on electrochemical effects and use them on instruments. In addition, there are devices that use electrocautery recording technology and are used in facsimile machines for communication. Later, thermal printers appeared. In the 1960s, electrostatic printing technology was gradually applied to computer output devices. In the late 1960s, laser technology was combined with xerographic technology to make a laser printer. Shortly thereafter, inkjet printers also came out. Inkjet printers can print Chinese characters and color fonts. Later, various non-impact printers such as magnetic printers and thermal transfer printers appeared.
Product category
Thermal printer
Use thermal paper as the recording medium. Its print head is similar to a stylus printer. The needles selected for dots generate heat by closing the circuit and produce ink dots when they come in contact with the thermal paper. Its font is composed of dot matrix, the advantages are no noise, simple mechanical structure, low cost, and small equipment; the disadvantage is that special paper is required and the printing quality is not high.
Electrostatic printer
The printing principle is to apply a high voltage directly to the dielectric material to obtain an electrostatic latent image. After the electrostatic latent image absorbs the developer, it undergoes a thermal fixing process to complete printing. The advantage of this printer is that the printing speed is extremely high, about 300 to 18,000 lines per minute, but the disadvantage is that it requires special electrostatic printing paper, and the development and fixing process are complicated.
Laser electrostatic printer
It is developed by adding laser scanning on the basis of electrostatic copying technology. The laser scanning system consists of a laser, a modulating deflector, a scanner and an optical path system. The electrophotographic part is composed of a photoconductor drum, a high-voltage generator, a developer, a fuser, and a paper conveying mechanism
The laser beam output by the laser enters the deflector for acousto-optic modulation through a mirror. Multi-frequency diffraction and modulation are performed in the device. The information output by the computer is sent to the font generator through the interface controller to form the pulse information of the character dot matrix. The synchronization signal generated by the synchronizer controls 9 high-frequency oscillators, which are then added to the acousto-optic device through a frequency synthesizer and a power amplifier to diffract the modulated light beams that form characters. The light beam enters the prism polygonal rotating mirror scanner, and the rotating mirror scanner rotates at a constant angular velocity. The light beam reflected by the rotating mirror scanner scans up and down along the axis on the drum surface to form a vertical line of each character dot matrix. If the rotating mirror scanner has 5 reflecting surfaces in one revolution, the beam will be swept up and down 5 times to form 5 vertical dots. The surface of the photoconductor drum is first discharged by the corona of the charging electrode to obtain a high potential. After being exposed to light with information, an electrostatic latent image is formed on the surface of the photoconductor drum, and then developed by a magnetic brush developer, the latent image becomes a visible toner image. In the transfer area, due to the corona electric field of the transfer electrode, the toner is transferred to the plain paper. Afterwards, it will be fixed by the preheating plate and hot roller to fuse the toner on the paper. Laser electrostatic printers have high output speeds, also known as page printers, which are suitable for data processing systems with large output, but they are expensive.
Inkjet printer
The charged inkjet fog dots are deflected by the electrodes to form a font. The advantages of inkjet printers are: no developing and fixing during the printing process, no special paper, high printing speed, good quality, no noise, multiple functions, and can print Chinese characters, graphics and color images.
Thermal transfer printer
Using font dot matrix. When the steel needle on the printing head is energized to generate heat, it is transferred onto ordinary paper by means of a thermal ink ribbon. It is different from a thermal printer in that it does not require thermal paper and can also use color ribbons to print color characters or graphics.