Printing: Inkjet is to divide a piece of white paper into n small color points according to different figures judged by computer program, then judge the color in each color point, and then spray different colors on different points bit by bit with a very thin needle. Laser printing is realized by using a toner cartridge, which is a cylinder with n tiny electrodes. According to computer control, different electrodes have different charges (+,-), and then the toner in the toner cartridge itself is charged, and then it will stick to an electrode with a charge (either+charge or-charge) because of the charge. But this is just one of them. If there is toner on the+charge, the charged electrode will never be stained with toner. Then a piece of white paper will be pressed by a cylindrical roller covered with toner, and a pattern will appear. Therefore, laser printers can only print one color, mostly black and white, and black is a pattern composed of electrodes and toner pressed on white paper.

Copying: The principle of copying is the same as that of laser printing, except that the work on the computer and the work on the laser printer are integrated into one machine. First, scan the pattern arranged by the original parts, then feed it directly to the electrode of the selenium drum, and then press out the pattern with white paper.

As far as storage time is concerned ... it has nothing to do with the machine, but mainly the quality problems of paper, ink, toner and machine. . Any kind of machine can print materials that have been preserved for a long time, and it can also print things that take several days.