Basic knowledge of the hottest laser printer II

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Basic knowledge of laser printer (II)

basic knowledge of selenium drum

the core component of laser printer is selenium drum, which directly affects the quality of printing

I. The importance of toner cartridges and toner

what is the relationship between toner cartridges and laser printers? Let's first look at the working principle of laser printer! Take the working principle of black-and-white laser printer as an example: when the computer sends data to the printer through the cable, the printer first stores the received data in the cache temporarily, and then sends it to the printer's processor after receiving a complete piece of data. The processor processes these data into a signal group similar to the data table that can drive the action of the print engine. For laser printers, these signal groups are a group of pulse signals that drive the laser head to work. Next, the laser printer starts working. The core technology of laser printer is electronic imaging technology, which combines the principles of imaging and electronics to generate images. The core component is a photosensitive selenium drum. The laser emitted by the laser transmitter irradiates on a prismatic reflector. With the rotation of the reflector, the light sweeps from one end of the selenium drum to the other end in turn (passing through various focusing lenses halfway, so that the light spots scanned to the surface of the selenium drum are very small). The selenium drum rotates in steps of 1/300 inch or 1/600 inch, and the next line of the scanning part is carried out line by line. In fact, the selenium drum is a cylinder coated with organic material (selenium, a rare element) on the surface, which is charged in advance. When light shines, the exposed part will react with resistance. The data signal sent by the computer controls the emission of the laser. The light scanning on the surface of the selenium drum changes constantly. In this way, some places will be irradiated, the resistance will become smaller, the charge will disappear, and some places will not be irradiated by the light, but still retain the charge. Finally, the surface of the selenium drum will form a latent image composed of charges. As shown in the figure

How does the latent image become a real printed image? Toner plays a key role. In essence, toner is a kind of charged fine resin particles. The charging time and mileage of its lithium battery are important factors to determine whether new energy vehicles are widely used. The polarity of charge is opposite to that on the surface of the toner drum. When the charged surface of the toner drum passes through the inking roller, the charged part adsorbs toner particles, and the latent image becomes a real image. While the toner drum rotates, another group of transmission system sends the printing paper in, and the printing paper belt is charged with a much stronger charge with the same polarity as the surface of the toner drum. Then the paper passes through the toner drum with toner, and the toner on the surface of the toner drum is attracted to the printing paper, and the image is formed on the surface of the paper. At this time, the toner and the printer are only combined by the attraction of electric charge. Before the printing paper is sent out of the printer, the toner is melted after high temperature heating, and solidified on the surface of the paper during cooling

after the toner is attached to the printing paper, the surface of the toner drum continues to rotate and passes through a cleaner to remove the remaining toner in order to enter the next printing cycle. It can be seen that the selenium drum plays a very important role in this process

in fact, selenium drum is the most critical component of laser printer. Because it not only determines the printing quality, but also determines the printing cost. This is because in laser printers, more than 70% of the imaging components are concentrated in the selenium drum, and the printing quality is actually largely determined by the selenium drum. The toner cartridge is also a consumable in the printer. It needs to be replaced after it is used for a period of time and reaches a certain number of sheets. Therefore, there is a lot of knowledge to choose a toner cartridge suitable for laser printers

II. Classification of toner cartridges

toner cartridges are the most important consumables for laser printers. Laser printer toner cartridges can be combined. They also specially invite domestic professional plastic commodity buyers to the meeting, and the procurement is divided into the following three categories:

integrated toner cartridges: photoconductive drums (photosensitive drums), magnetic drums (developing rollers) and toner cartridges. In principle, the design structure of this selenium drum does not allow users to add toner

binary selenium drum: refers to that the selenium drum is divided into two independent parts: one part is the photoconductive drum, and the other part is the magnetic drum and toner box. After the user runs out of toner, he only needs to replace the magnetic drum and toner box parts instead of the optical guide drum

three body selenium drum: refers to that the selenium drum is divided into three independent parts: optical guide drum, magnetic drum and toner box. Users only need to replace the toner box after using up the toner. Usually some manufacturers call it drum powder separation technology

for two or three body selenium drums, it does not mean that users do not need to replace the photoconductive drum during the use of laser printers. In fact, these two types of photoconductive drums, like the first type of integrated selenium drum, have a certain service life, and some even have a longer service life than the integrated selenium drum

photoconductive drums coated with metal selenium alloy photosensitive materials have been recognized by most laser manufacturers in the world because of their superior performance and reliability. Laser printer manufacturers such as HP, Xerox, Lexmark, founder, etc. have selected selenium drums. Some manufacturers also choose ceramic surface photoconductive drums

working principle diagram of selenium drum

III. how to choose selenium drum

at present, there are three kinds of original selenium drum, compatible selenium drum produced by other companies and regenerated selenium drum in the laser printer selenium drum market

print quality is the first thing customers need to consider. There is no doubt that the original selenium drum is obviously the best choice. Original selenium drum 4. Please make sure that the grounding mark of the mortar tensile testing machine is grounded. Because the integration with other parts of the printer is carefully considered in the design process, the production process is meticulous, so it can also create an ideal printing effect, which is much better than other compatible products. The text printed on the printer with the original selenium drum has clear edges, uniform black and vivid pictures, but the effect will be far worse when replaced by other products. This is because the engineers of the original toner cartridge have carried out a lot of experiments and improvements in the laboratory in order to achieve the best printing effect, and even the smallest defects must be eliminated. Therefore, users who pay attention to print quality usually choose the original toner cartridge without hesitation

the compatible toner cartridge can basically meet the output requirements of the printer in terms of print quality, but it may be different in some special cases, such as some ambiguity when printing 2-pound small words. However, due to the manual method used in the manufacturing process, the printing quality of the recycled toner drum is uneven, and the printing effect is difficult to be guaranteed. Of course, when we consider print quality, print cost is also a very important consideration, especially for price sensitive individual users

due to its long service life, the original selenium drum saves users more money than the price of the printer itself. Therefore, it is recommended to use the original selenium drum. The combination of low-cost utilization and intelligent monitoring and early warning functions with compatible toner cartridges can basically meet the output requirements of laser printers from its print quality, but it may be different in some special cases

compatible toner cartridges are also produced by famous brands, and the product quality is guaranteed. Although the price is slightly lower than the original toner cartridge, the number of printed sheets is lower than the original toner cartridge, so the overall printing cost is similar to the original toner cartridge

although the price of the recycled toner cartridge is very attractive, its total printing cost is not lower than that of the original toner cartridge and compatible toner cartridge because the number of printed sheets is too few or even less than half of that of the original toner cartridge$ Page break $

IV. daily maintenance of selenium drum

1. Installation and storage

selenium drum is an important part of laser printer, which directly affects the quality of printing. The installation of selenium drum is actually very simple. Just take the selenium drum out of the packaging bag, take out the sealing strip, and then rotate it with the axis of the selenium drum as the axis, so that the drum powder is evenly distributed in the selenium drum, and then install it on the printer

as for the storage of toner cartridges, it is actually very simple. As long as the toner cartridge is stored in the original packaging bag at room temperature. Avoid direct exposure to sunlight, otherwise it will affect the service life of the selenium drum, and even cause the selenium drum to be scrapped

2. Maintenance matters

because the imaging of the laser printer depends on the exposure of the photoconductive drum. When the toner drum encounters strong light, the inner and outer layers of the toner drum are connected, so that the voltage at this place is different from that at the unexposed place. The exposed place can attract toner for imaging during the fixing process. However, the exposure time and times of a certain point of the selenium drum are limited, especially in the case of long-time continuous exposure, the damage to the selenium drum is more serious. Therefore, you should pay attention to the maintenance of selenium drum when using it at ordinary times

1) do not expose the toner cartridge directly to sunlight or other strong light sources

2) do not replace the toner cartridge under strong light, but complete the installation process as soon as possible

3) when the toner cartridge is removed from the printer, please immediately put it back in the packaging box or wrap it with a thick soft linen cloth

4) if the toner cartridge comes from a cold place, move it to a warm place and leave it for an hour or more before using

5) the selenium drum light barrier shields the external light source to protect the photosensitive selenium drum. Do not open the selenium drum light barrier

6) do not touch the surface of the photosensitive drum with your hands, and prevent the surface of the selenium drum from being scratched by hard objects

7) do not place the selenium drum in a place with high temperature and humidity

8) make sure that the selenium drum is away from the display, hard disk drive, floppy disk drive or any other magnetic substance

v. tips for toner drum maintenance

1. Extend the service life of toner drum

after a long period of use, the printed text and image will appear blurred, the bottom ash will increase and other phenomena. Even if a new toner box is replaced, it will not solve the problem, so we should consider that it may be the problem of the toner cartridge. We know that the selenium drum of laser printer has a service life: generally more than 10000 pages, such as HP, Lenovo, etc

when the service life of the selenium drum is up, the above phenomenon will appear. This is mainly due to the aging of photosensitive characteristics on the surface of the drum, the decline of surface potential and the increase of residual voltage, which affect the imaging of the drum

is there any way to bring the selenium drum back to life

the specific method is as follows: take 5g of chromium trioxide, dip it directly with lens paper, and carefully wipe it along one direction of the selenium drum (do not wipe it back and forth!) Once, wipe the surface of the selenium drum completely without omission. Special care should be taken when wiping! After the above processing, the photosensitive toner drum can generally reprint thousands to thousands of pages

2. Make full use of selenium drum of laser printer


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