Laser cartridge devices and its main elements. Troubleshooting charge rollers How to restore the rubber cartridge shaft

In printers that print using laser technology, cartridges are an integral part of the image reproduction system. Almost 70% of all the parts involved in creating the print are concentrated in a replaceable block filled with ink.

Structural elements of the cartridge

IN general view, the replacement unit is a sealed hopper having a compartment with a coloring composition - black, red, yellow or blue and uh electromechanical parts for creating an impression. There are two types of replacement devices for laser printers, with or without a built-in image drum. In the second case, the photosensitive shaft is installed in the printer body and the operating time of the drum increases significantly.

Rice. 1 Main details laser cartridge

Toner Bin Parts and Structures

In this compartment, in addition to the powder itself, there are elements for applying paint to the surface of the photo cylinder. This:

• magnetic roller;
• knife for dispensing the coloring composition;
• a blade that seals the junction of the magnetic shaft and the housing;
• activator for mixing toner and maintaining the recommended density.

MagRoller(magnetic roller). It is made either of an aluminum tube with a protective coating and a magnetic rod inside, or of dense rubber with magnetic properties. The shaft is attached to the walls of the housing using bushings that allow it to rotate freely.

The magnetic field, attracting metallized paint particles, provides the toner with a negative charge. A smooth surface of the shaft is the key to high-quality printing.

Doctor Blade(toner dispenser). A rectangular metal frame, the length of which corresponds to the dimensions of the magnetizing roller, equipped with a flexible plate. The plate material can be metal or polyurethane.

The purpose of the dispensing knife is to leave on the magnetic roller exactly as much toner as is needed for printing at this stage. Wear on the blade affects the quality of the prints, the metal flexible plate can get scratched or chipped, polyurethane lasts longer, but still becomes thinner over time and dispenses worse. Regular cleaning of the dosing plate or its timely replacement in case of severe wear will restore print quality.

Mag Roller Sealing Blade(sealing blade). It is made of flexible materials that do not damage the surface of the magnetic shaft. Most often, it is polyurethane.

After the toner is transferred to the photoreceptor, the part of it that was unclaimed for developing the design remains on the surface of the magnetic roll. The sealing blade removes remaining ink and leaves it in the toner compartment for reuse.

Toner Agitator Bar(activator frame). Metal rotating frame. Prevents coloring powder from sticking and clumping. Optimal density toner is easily and evenly attracted to the magnetic roller.

Toner(toner). Fine powder made from polymers or waxes. Color is given by appropriate pigments, and to obtain magnetic properties it is treated with metal oxides.

Waste toner compartment

This section is where the image is exposed and developed. Essential elements:

• photo drum;
• coronator;
• drum cleaning blade;
• toner pick blade.

OrganicPhoto Conductor (OPC) Dram(photo drum). The main element of image reproduction. It is made in the form of a hollow cylinder coated with an organic photosensitive film or zinc oxide, which has a photoconductive effect.

The negatively charged photoreceptor is irradiated with a laser beam. The image is exposed by a programmer; in the areas that reproduce the image, the laser neutralizes the negative charge. As a result of exposure, toner from the magnetic roller is attracted to these areas.

The lifespan of the photosensitive film is short, so this part has to be changed frequently. Drums with a metal coating are more durable, but are also susceptible to exposure or deformation if not used carefully.

PrimaryCharge Roller ( primary charge shaft). It is made in the form of a shaft with an elastic coating; inside there is a conductor that allows corona discharge to pass through.

The task of the corona meter is to uniformly charge the surface of the photocylinder with a negative charge. Before starting work, the photodrum has no polarity, that is, its surface is a dielectric. The passage of the discharge creates an electric field around the primary charge shaft, which, acting on the photosensitive surface of the photodrum, gives it a negative charge.

It is the work of the coronator that is accompanied by the release of ozone. After transferring the image to paper and cleaning the photodrum from toner residues, the corotron again comes into action to remove the programmed image from the photocylinder.

WiperBlade(cleaning knife, squeegee). The knife is made in the form of a light metal plate with a glued rubber or polyurethane blade.

Not all of the toner ends up on the sheet of paper; some of it remains on the photoconductor. The viper removes the remaining paint composition into the waste compartment.

RecoveryBlade(picking blade). Made from polyurethane. Designed to prevent toner removed by the squeegee from getting onto the paper.

Table. Operating resources of cartridge components (in cycles)

Cartridge	Primary charge shaft	Image drum		Magnetic shaft

Principles of interaction of cartridge elements during printing

The cartridge is the first to start working when the “print” signal is given. The following actions occur.

Rice. 2 Scheme of operation of a cartridge in a laser printer

1. Treatment of the photodrum with a corona treatment (PCR) to impart negative polarity to the surface of the cylinder.
2. Turning on the laser unit located in the printer body. The laser, controlled by the programmer, removes part of the charge from those points of the photoreagent surface of the cylinder where the image is programmed. This process is called exposure. The result is a complex of point charges with different levels of polarity. More strongly negatively charged points on the surface will repel similarly charged toner. Accordingly, the exposed parts of the surface will attract paint and the desired image will appear.
3. In parallel with the operation of the laser, the magnetic shaft is turned on. It attracts toner from the hopper and gives it negative polarity. The interaction of the fields of the magnetic shaft and the photodrum promotes the transfer of ink powder to the photosensitive surface. Turning off the device at this point in operation will allow you to examine the pattern printed on the photo cylinder. This method is used to diagnose wear on the surface of the photodrum.
4. From the photoconductor, the image is transferred to the supplied sheet of paper. The sheet is first pulled through rollers that give it a positive polarity. The image formed by the negatively charged toner on the surface of the drum is deposited on the paper. To fix text and pictures, a sheet of paper is pulled through heated rollers that melt the toner.
5. The next step is to clean the photo cylinder from any remaining paint. The procedure is performed with a cleaning knife.
6. Next, the coronator removes the previous exposed image and prepares the photoconductor for the next printing step.

After restoring the original data, the process is repeated. Printing one sheet of A4 format may include several sequential text transfer processes.

Equipping laser cartridges with chips

Currently, all manufacturers equip replacement units for printers with programmable modules - CHIPs. The presence of such accessories in cartridges has both positive and negative sides.

What's good about CHIPs?

1. The amount of unused toner is recorded.
2. The volume of used paint returned to the waste compartment is determined.
3. Interact with the automatic calibration system of the device. The system monitors color purity and print quality.
4. An optical system located in the cartridge writes data to the module.

Rice. 3 Color laser cartridges

What's wrong with CHIPs?

1. Can be programmed for a certain number of printed sheets or even drum rotations.
2. After the message about the end of the toner, the connection with the calibration system is broken. An accompanying background appears on the prints and color rendering in color printers decreases.
3. Some modules can only work with certain printer models and cartridges. For example, in a color laser printer you cannot change the chips on the cartridges from a red to a green or black block.
4. Contactless radio chips are difficult to detect and replace.
5. After the ink runs out, the CHIP may block the printer.
6. Non-reprogrammable CHIPs are quite expensive.

Customers should not be guilty of the greed of the company that refills cartridges. In addition to the cost of toner, it is necessary to replace some parts that have undergone significant wear or deformation during extreme use. But, the most significant part of the cost of refilling is programmable modules.

There are two main compartments in the cartridge - the waste compartment and the toner compartment.

The main components of the mining compartment:

1 - Organic Photo Conductor(OPC) Drum, Drum (OPC, Drum, Photoreceptor). It is an aluminum cylinder coated with an organic photosensitive and photoconductive material that is capable of preserving the image created by the laser beam.

2 - Primary Charge Roller PCR (charging roller, primary charge roller). Provides a uniform negative charge to the drum.

3 - Wiper Blade Viper (Cleaning Blade, squeegee, cleaning blade). Clears the drum of any remaining toner that has not been transferred to the paper. Structurally, it is made in the form of a metal frame (Stamping) with a polyurethane plate (Blade) at the end.

4 - Recovery Blade. Covers the area between the drum and the mining hopper. The Recovery Blade passes toner remaining on the drum into the hopper, preventing toner from leaking in the opposite direction (from the hopper onto the paper).

TONER COMPARTMENT

Main components of the toner compartment:

1 - Magnetic Developer Roller Magnetic roller (Mag Roller, Developer Roller). It is made in the form of a rotating metal tube, inside of which there is a stationary magnetic core. The toner is attracted to the magnetic roller and, before being supplied to the drum, acquires a negative charge under the influence of direct/alternating voltage.

2 - Doctor Blade Doctor (Metering Blade). Provides uniform distribution of a thin layer of toner on the magnetic roller. Structurally, it is made in the form of a metal frame (Stamping) with a flexible plate (Blade) at the end.

3 - Mag Roller Sealing Blade A thin plate similar in function to the Recovery Blade. Covers the area between the magnetic roller and the toner supply compartment. The Mag Roller Sealing Blade allows toner remaining on the magnetic roller to flow into the compartment, preventing toner from leaking in the opposite direction (from the compartment to the outside).

4 - Toner Reservoir Toner bin. Inside this hopper is the “working” toner, that is, the one that will be transferred to the paper during the printing process. In addition, the Toner Agitator Bar is built into the hopper - a wire frame designed for mixing toner.

5 - Seal Seal. In the new cartridge, the toner hopper is covered with a special seal, which prevents toner from spilling during transportation of the cartridge. This seal is removed before use.

Laser printing principle

The figure below shows a cross-section of the cartridge. When you turn on the printer, all components of the cartridge begin to move - the cartridge is prepared for printing. This process is similar to the printing process, but the laser beam is not sent to the drum and the image is not formed. The cartridge components then stop and the printer enters the Ready state.

When you send an image to print, the following processes occur in the cartridge:

1. Charging the drum

PCR uniformly coats the surface of the rotating drum with a negative charge.

2. Overexposure

The negatively charged surface of the drum passes under the laser beam. The beam is focused on the drum and is activated only in those places where toner will subsequently be applied. Under the action of the laser, the photosensitive surface of the drum partially loses its negative charge. Thus, the laser deposits a prototype image on the drum in the form of a weakened negative charge.

3. Applying toner

At this stage, the prototype image on the drum is converted into a visible toner image, which will then be transferred to paper. The toner located near the magnetic roller is attracted to its surface under the action of a permanent magnet from which the core of the roller is made. When the magnetic shaft rotates, the toner located on its surface passes through a narrow gap formed by the doctor and the shaft. As a result, the toner on the magnetic roller becomes electrified, acquiring a negative charge. Negatively charged toner sticks to areas of the drum that have been exposed to light. The doctor also ensures the uniformity of the toner layer on the magnetic roller.

4. Transferring toner to paper

Continuing to rotate, the drum, on which the toner image has already been applied, comes into contact with the paper. On the reverse side, the paper is in contact with the Transfer Roller, which carries positive charge. As a result, negatively charged toner particles are attracted to the paper. The result is an image “sprinkled” with toner on paper.

5. Pin an image

The paper with the toner image “spread” moves further to the fixing mechanism. This mechanism consists of two contacting shafts, between which paper passes. The Lower Pressure Roller presses the paper against the Upper Fuser Roller. The top roller is heated, and upon contact with it, the toner particles melt and bake to the paper.

6. Cleaning the drum

Some toner does not transfer to the paper and remains on the drum. The drum needs to be cleaned of any remaining toner. This function is performed by the viper. All toner remaining on the drum is cleaned by a wiper into the waste bin. In this case, Recovery closes the area between the drum and the waste hopper, preventing toner from spilling onto the paper.

7. "Erasing" an image

At this stage, the prototype image applied by the laser beam is “erased” from the surface of the drum. PCR uniformly coats the surface of the drum with a negative charge, restoring the charge in those places where it was reduced by the laser. Any of the known cartridges includes several different blades, each of which performs an important and necessary function. Cleaning the photodrum, dispensing toner, and sealing the cartridge hoppers depend on the blades. During operation, any defect in any of the blades, be it the drum cleaning blade, the toner dispensing blade, or the magnetic roller sealing blade, can damage the cartridge.

Drum cleaning blade (Wiper blade)

The cleaning blade is used to clean the drum of any residual toner that was not transferred to the paper during the image transfer process. The quality of the cleaning blade surface, the sharpness of the edges and exact dimensions, are very important for the normal operation of the cartridge.

Toner dispensing blade (Doctor blade)

The polyurethane metering blade regulates the amount of toner delivered to the magnetic roller and triboelectrically charges the toner to ensure accurate image transfer to the drum. The surface finish of the dispensing blade, its rigidity and dimensional accuracy are important for the normal operation of the cartridge.

Magnetic shaft sealing blade

The magnetic roller sealing blade seals the toner hopper and prevents toner from spilling onto the paper. The sealing blade of the magnetic shaft is easily damaged during cartridge reconditioning and must be replaced in this case.

Drum sealing blade

The drum seal blade is used as a seal between the OPC drum and the waste toner bin to prevent toner from spilling onto the paper, causing a "splashing" effect when printing. Material structure, precise and correct sizes, as well as the quality of the blade tip are important for the proper operation of the cartridge.

Primary Charge Roller (PCR)

The primary charge roller charges the drum with a uniform negative charge, wiping out the old charge.

Magnetic roller (MagRoll)

The roller, together with the toner dispensing blade, charges the toner with a negative charge and transfers it to the drum unit, thus playing a significant role in the image formation process. If the toner is not uniformly charged or applied uniformly to the surface of the magnetic roller, the result will be light printing and a change in print density. Constant wear of the magnetic shaft is one of the most big problems for restorers. The magnetic roller is the basis for the overall print quality and thus has a major impact on the overall performance of the cartridge.

The photoreceptor charging system using a roller has noticeable advantages over a system using a corotron for this purpose: almost complete absence of ozone generation, less dependence on environmental conditions, and fairly high stability of the charging current. However, nothing in this world is perfect, so you have to deal with problems caused by these videos quite often in life.
The article discusses typical faults in monochrome laser printers HP/Canon, which are caused by charge rollers, recommendations are given for cleaning them and determining the need for replacement, problems that may arise when using compatible PCRs are described, and ways to solve them.

Charge roller, aka Primary Charge Roller (PCR) , aka primary charge shaft, aka “cartridge rubber shaft”, aka “cartridge corotron” (the author really doesn’t like the last term when applied to PCR, but people use it so often that you can turn a blind eye to the fact that the corotron, by definition, must have a corona discharge) performs two functions in the cartridge - charging the surface of the drum and erasing the residual latent electrostatic image. For this purpose, PCR is submitted high voltage, which has constant and variable components. This leads to two main problems that can be caused by a faulty PCR - insufficient charge of the drum surface and insufficient erasure of the afterimage. The main reasons for this are usually the following:

• Contamination of the roller surface.
• Electrical breakdown of the roller material.
• Detachment of the outer shell (“stocking”) of the roller from the porous inner part.
• Punctures and tears on the surface.
• Surface wear.
• Detachment of the roller material from the metal axis.
• Change in electrostatic characteristics (dielectric constant, electrical conductivity) of the roller material.

Apart from dots and spots on the surface of the roller, repeated on the print at intervals equal to the circumference of the charge roller, then the most common manifestation of a faulty PCR is repeat image . IN English language this defect is called " "(from the word "ghost" - ghost). To distinguish this defect from the very similar fusing offset, which is caused by insufficient fixation of the toner by the fixing unit, two main methods are used. The first is the measurement of the interval from the main image to the repeat - it should correspond to the circumference of the drum, and not the circumference of the fixation block shafts. The second is when printing stops at the moment when a sheet of paper is between the drum and the oven - if the repetition is already present on the unfixed image, then the reason is not in the oven.

At the initial stage of the roller failure, many people do not see the image repeat, because it is noticeable only in areas with a solid gray fill (and appears at an interval equal to the circumference of the charge roller or drum). This feature can be used for “early diagnostics” by printing a special test page similar to the one shown in the figure (for correct diagnostics, there should be several more pages in the job before this page with more uniform filling).

Here, in the gray areas, you can see a faint repetition of the letter "G" located at the top of the page. One or two faint repetitions on this page are normal, large quantity Clearly visible repeats at intervals of the charge roller or drum indicate problems with the charge roller.
If the charge roller performs the function of erasing the afterimage very poorly, then the repetition becomes noticeable in the white areas. An example is shown in the figure. In very rare cases, the cause of this problem is a drum failure.

Elimination method– make sure there is stable contact on the charge roller, to do this, clean the PCR sliding contact from dirty grease and apply a thin layer of fresh conductive lubricant (for example, OIL---SC-CONLUBE), clean the charge roller (on how to properly clean, described below), did not help - replace the roller.

Other common problem – background caused by insufficient charge on the drum surface. Since this problem has many other causes, its localization should be carried out using the “halving method”, i.e. by substituting a known good half of another cartridge into the phonating cartridge, etc. After we have found out that the reason is PCR, we do the same as in the previous case.

Below is an example of printing in the case of detachment of the outer “stocking” of the charge roller from the internal porous filler. No amount of cleaning or restoring contacts will help in this case - the PCR needs to be changed.

The charge rollers inevitably become dirty during operation. One source of contamination is very small particles of toner additives (for example, amorphous silicon, often used as an additive that regulates the charge and fluidity of toner) that cannot be completely removed with a squeegee. These particles, together with paper and other dust, create a whitish coating on the PCR, which prevents the roller from performing its functions normally. Accordingly, it needs to be cleaned before reuse, but it is important not to damage the roller by cleaning, which, as practice shows, is very easy to do.

For cleaning original charge rollers in HP/Canon monochrome cartridges(except 35A, 36A and similar Canon) We do not recommend the use of any cleaner other than a lint-free cloth dampened generously with distilled water.. Alternative opinions on this matter related to the use of “Platenclene”, “Mr. Muscle”, etc. exist, but we cannot clearly confirm their effectiveness or harmfulness, so we simply DO NOT RECOMMEND it.

When cleaning, ensure that the roller surface is uniformly gray or black, free of whitish areas and toner adhesion. In this case, you should not put too much pressure on the roller, so as not to cause peeling of the outer shell. If after such cleaning there are indelible toner build-ups left on the roller, then you should think about the reasons for their appearance. Does the squeegee clean well? Is the toner collecting dust in the developing area? Something else? In our opinion, it is better to replace such a roller and eliminate the cause of its excessive contamination. For a comment on an alternative point of view, see just above.

Another point worth paying attention to is that in modern HP/Canon cartridges there are several types of charge rollers. Rollers of one of these varieties (let's call them “lipped”) are potentially prone to rapid failure. Their feature, which is clearly visible visually, is that the outer shell at the ends protrudes several millimeters beyond the internal porous filler. If you squeeze the edge of such a roller, you can see that the shell is easily separated from the central part.

"Lipped" PCR

The shell of the “lipped” PCR moves away from the inner part when compressed

Our recommendation for these types of rollers is to replace them immediately after the original cycle., because there is no guarantee that they will survive the next cycle to the end (even their own ones do not always survive). If you risk leaving such a roller in the cartridge, then it should be cleaned very gently, since even a small force can damage it.

Not all original charge rollers are so prone to failure. There are varieties that can work several cycles without problems, but, unfortunately, they are becoming less and less common. Below is what a “normal” original PCR looks like.

The shell of a "normal" PCR is cut flush with the inside

The shell of a “normal” PCR does not move away from the inside when compressed

Closed-end PCR is also "normal"

"

Once the decision is made to replace the charge roller with a compatible one, there is a chance to encounter problems caused by differences in the production technology of compatible PCRs from the original ones.

Many manufacturers' rollers have an outer shell that is significantly thinner than the original. In addition, they have the same problem as the “lipped” original PCRs - the “stocking” easily peels off from the inner filler. Shown below appearance such videos. Usually these rollers work fine for one cycle, then depending on your luck.

The next type of compatible PCR is the so-called "hard" rollers. They are manufactured by SCC. Their peculiarity is that they are made of a more rigid material than the original ones. On the one hand, this is good, because... The service life of these rollers is high and they can be cleaned without thinking too much about the force with which we press on the surface of the roller.

"Hard" PCR produced by SCC

But they also have a negative point. When using “hard” PCR printers with print speeds of more than 10 ppm. the transformer in the high-voltage power supply begins to emit a clearly audible squeak. This squeak does not affect the performance of the printer in any way, but many users do not like it. In order to minimize this problem, SCC suggests using special rollers in conjunction with these rollers. drums with “noise-reducing insert” inside. The insert is a heavy plastic tube glued inside the drum.

“Noise-reducing” insert

This solution does not eliminate the squeak completely, but makes it noticeably quieter, which is acceptable for most users.
Such drums can also be used in conjunction with “soft” charge rollers without any negative consequences.

The latest solution to replace PCR, devoid of the disadvantages described above, appeared not so long ago. “Soft” SCC Odyssey® charge rollers do not cause unnecessary noise and at the same time have a fairly long service life.

"Soft" PCR SCC Odyssey®

In conclusion, here are the order codes for the most popular items mentioned in the article.

PCR-HP-LJ1200-SC-OS-SOFT– “Soft” SCC Odyssey® charge roller for Q2612A, C4092A, Q2624A/X, C7115A/X, Q2613A/X, C3906A and similar cartridges Canon cartridges. This roller is not yet qualified for use in Q5949A/X and Q7553A/X cartridges in low humidity environments.
PCR-HP-LJ2100-SC-OS-SOFT– “Soft” SCC Odyssey® charge roller for C4096A, Q2610A, Q6511A/X, C4127A/X, C8061A/X, Q1338A, Q1339A, Q5942A/X, Q5945A, Q7551A/X cartridges.
PCR-HP-LJ5L-SC– “Hard” SCC charge roller for Q2612A, C4092A, Q2624A/X, C7115A/X, Q2613A/X, C3906A, Q5949A/X, Q7553A/X and similar Canon cartridges. When installing these rollers, do not forget about the need to use drums with a noise-reducing insert.
DRUM-HP-LJ1010-SC-V3-INSERT– drum with noise-reducing insert for Q2612A cartridges.
DRUM-HP-LJ1200-SC-V3-INSERT– drum with noise-reducing insert for cartridges 2624A/X, C7115A/X, Q2613A/X.
DRUM-HP-LJP2015-SC-INSERT– drum with noise-reducing insert for cartridges Q5949A/X, Q7553A/X.

In contact with

Classmates

The laser cartridge consists of a waste toner compartment and a toner compartment. The waste toner compartment includes the drum unit, primary charge roller, cleaning blade, and drum sealing blade. The toner compartment includes a magnetic roller, a toner dispensing blade, a magnetic roller sealing blade, a toner hopper and a sealing pin.

Since in Russia there are no uniform federal standards that would fix the names Supplies for printers and copiers, these names are not unambiguous and have many synonyms.

Names of working compartments and parts of the laser cartridge mechanism

Part name	Common synonyms
I. Waste toner compartment
Image drum	Organic Photo Conductor, OPC, Drum, Drum unit, Photoreceptor, drum, photoreceptor drum, photosensitive drum
Primary charge shaft	Primary Charge Roller, PCR, charging roller, charging roller, primary charge roller
Blade cleaning	Wiper Blade, Cleaning Blade, squeegee, wiper, cleaning blade
	Recovery Blade, OPC Sealing Blade, Drum Sealing Blade
II. Toner compartment
Magnetic shaft	Magnetic developer Roller, Mag Roller, Developer Roller, development roller, image transfer roller, developer roller
Toner dispensing blade	Doctor Blade, Metering Blade
	Mag Roller Sealing Blade, mylarka
Toner Hopper	Toner Reservoir
Sealing pin	Seal, seal

I. WASTE TONER COMPARTMENT

Laser Toner Waste Box Parts

(1) Image drum- this is the photosensitive “heart” of the laser cartridge, consisting of a hollow aluminum cylinder coated with a layer of dielectric.

The photodrum can be located either in a cartridge (drum) or directly in a printer or copier (drum unit). In the first case, the photodrum is serviced together with the cartridge, in the second case – independently from the other components of the printer or copier.

The functions of the photodrum are as follows. After sending the document for printing, the primary charge shaft, pressing against the photodrum, transfers to it a negative charge and the ability to repel toner microparticles.

The laser beam transfers a document print invisible to the eye to the surface of the photodrum. The areas of the photodrum marked by the laser beam change their charge to positive and attract toner. Thanks to the attracted toner particles, a visible imprint of the document sent for printing is formed on the photodrum.

The photodrum, rolling over a sheet of paper, transfers the document print to its surface. After this, the paper medium enters the printer oven, in which it is heated. Under the influence of high temperature, the toner is fused into the paper and fixed to it.

The photodrum is the most expensive and at the same time the most capricious part of a laser printer. He's afraid of anyone mechanical damage, from direct sunlight it can light up and produce black prints; you should not touch it with bare hands, since toner sticks to the sweat and grease marks remaining on its glossy surface, which leads to printing defects.

Over time, the glossy layer of the image drum wears off, resulting in poor print quality. The first sign of the end of the drum's life is black stripes along the edges of the printed document. When such stripes appear, it is necessary to diagnose the photodrum, and then either clean its surface with a special solution, or replace the photodrum with a new one.

(2) Primary charge shaft- this is a part of a laser cartridge that, evenly pressing against the surface of the photodrum, transfers a uniform negative charge to it. After the paper passes through the photodrum, the primary charge shaft neutralizes the residual effects of the previous charge on the photodrum.

The primary charge shaft consists of a metal shaft on which a layer of conductive foam or rubber is applied. This part of the laser cartridge is quite heavily contaminated with paper dust, so it needs to be cleaned regularly and thoroughly.

(3) Blade cleaning is a flat metal scraper with a polyurethane tip designed to clean the photodrum of a laser printer from microparticles of toner and paper adhering to it. In Russia, the cleaning blade is better known as a “squeegee” (from the German Rakel - scraper). In color laser printing, a squeegee removes color toner stuck to the transfer belts.

It should be noted that not all laser printers are equipped with a squeegee. In some models of Xerox and Samsung laser printers, excess toner adhering to the photodrum is removed from its surface using the primary charge shaft, and from there it is shaken off with a special brush into the waste toner bin.

(4) Drum Sealing Blade closes the gap between the image drum and the waste toner bin. The sealing blade, while not preventing waste toner from entering the hopper, does not allow it to spill back onto the paper.

II. TONER COMPARTMENT

(1) Magnetic shaft is a structural element of a laser cartridge that charges toner microbeads with a negative charge and transfers them to the surface of the photodrum.

The magnetic shaft is made in the form of a hollow tube; manufacturers use various materials for its manufacture. Samsung magnetic shafts are made of high-quality rubber, Canon and HP magnetic shafts are made of metal coated with a rubberized layer. The materials used in Samsung mag rollers are more durable than the materials used in Canon and HP mag rollers, resulting in less wear and tear and longer life.

Laser cartridge toner compartment parts

(2) Toner dispensing blade is a metal frame with a flexible plate at the end, designed to evenly distribute toner over the surface of the magnetic roller.

Metal toner dispensing blades are most often found in laser Samsung printers and Brother, but HP and Canon make them from polyurethane materials.

To perform its function, the toner dispensing blade must have a high-quality, smooth surface without defects, nicks, or protrusions. Curvature of the toner dispensing blade degrades print quality, causing light or dark longitudinal stripes to appear on the document.

HP and Canon dispensing blades are more durable than Samsung and Brother blades and therefore less prone to wear and tear. Their breakdowns usually occur due to the use of low-quality toner.

Toner particles stick to the toner dispensing blade, so it needs to be cleaned periodically to prolong its performance.

(3) Magnetic shaft sealing blade- This is a thin plate, similar in function to the sealing blade of a photodrum. The blade closes the gap between the magnetic roller and the toner supply compartment. It allows toner remaining on the surface of the magnetic roller to pass into the compartment and prevents it from spilling out.

(4) Toner Hopper Designed to store unused toner. The hopper is equipped with a special wire frame (Toner Agitator Bar), which mixes the toner, keeping it in working condition, preventing it from clumping and drying out.

(5) Sealing pin– this is a seal that covers the toner hopper, protecting the toner from spilling when transporting the cartridge. The sealing pin is removed before using the cartridge.

In contact with

Often the cause of cartridge malfunction is wear of its main components - the photoreceptor drum, cleaning blade, magnetic shaft, dispensing blade and primary charge shaft. Malfunctions can also be caused by the repair blade, contacts, pins, drum curtains, and even the housing itself, in general terms. And now, a little more about each of the problems.

Photoreceptor drum

Most often, the photo roller is responsible for cartridge failure. The toner is removed from it with a cleaning blade, and paper also comes into contact with it during the printing process, which greatly affects the condition of the protective layer. Typically, if the photoreceptor drum is damaged during printing, the following symptoms appear:

1) A straight, very thin line means the drum is scratched.

2) Groups of dots repeated throughout the entire page indicate a chip on the drum. The distance between the points corresponds to the circumference of the drum.

3) Gray toner marks on the page. The reason is an overexposed drum. The distance between spots depends on the circumference of the drum.

4) Gray "tire tracks" on either the left or right edge of the page. This is sometimes called "wind-blown sand." This defect is caused by wear of the drum.

In all of the above cases, the drum should be replaced. There is no reliable way repair the damaged surface of the photo roll.

Cleaning blade (squeegee)

The cleaning blade removes any remaining toner from the surface of the photoreceptor drum.

The following signs of breakdowns are usually encountered:

1) A 3.2mm thick gray line along the entire page is caused by a cut or worn blade.

2) Gray page, toner build-up on the drum - caused by a very old, dull blade. Such blades cannot be reused.

3) The cleaning blade "jumps" and therefore damages the drum. This means that not enough lubrication has been applied to the blade. If such a defect is found, the cleaning blade should be replaced. A poorly lubricated squeegee can also “stick” to the drum if not used for a while.

Magnetic roller (HP/Canon cartridges)

The magnetic roller is a specially coated aluminum roller that transfers toner from the toner supply compartment to the drum unit. The main problems occur due to scratches or wear.

1) Light print. The main cause of this defect is wear of the magnetic shaft, because Over time, the black conductive coating on the shaft will wear off. If, during a visual inspection of the shaft, you notice a silver core, it means the shaft is worn out and requires replacement. This problem mainly occurs when printing solid black areas. Simple text will be printed without noticeable defects.

2) White spots on the page may appear if there are scratches on the coating. Usually one or two scratches do not cause problems, but if there are more, white spots will appear when printing. This is especially noticeable if the scratches are concentrated in one specific place.

3) Intermittent printing - this defect in image transmission occurs when the magnetic shaft contact is faulty. This results in light-colored or blank pages.

4) Large gray spots that repeat with each revolution of the shaft - the cause of the problem is a static discharge on the shell of the magnetic shaft. Static discharge can be caused by using a vacuum cleaner, for example, while refilling a cartridge when the humidity is below 40%. The only way to get rid of the charge is to wipe the shaft with a special cleaning agent.

Development roller (Samsung/Xerox cartridges)

The development roller is a roller consisting of a metal core covered with molded rubber with a conductive coating. The toner is held on the developing roller by constant voltage from a high-voltage power source. In this case, no magnets are used to attract toner. The main problems occur due to scratches or wear of the conductive coating. All toner is abrasive, and as the pressure of the metering blade forces it against the surface of the developer roller, it can cause wear on the developer roller.

Magnetic shaft - problems usually occur
similar to problems with the magnetic shaft of HP/Canon cartridges (see point above).

Primary charge shaft
The primary charge shaft performs two functions. First, it places a permanent charge on the surface of the drum, which allows the laser beam to create an image on it. Second, it places an alternating charge on the photoroll, which helps wipe away any residual charges remaining on the surface. Because of this dual role, many serious problems occur with the primary charge shaft.

The following problems usually occur:
1) “Blurring” of the image - this defect manifests itself in the fact that an image printed, for example, at the top of the page will be less clearly repeated below. This occurs when the outer cover of the primary charge shaft is worn or dirty.

2) Vertical stripes - caused by wear on the outer coating of the primary charge shaft.

3) Background - the reasons are similar to the previous two.

4) Horizontal stripes - this defect is caused by contamination of the contacts of the primary charge shaft.

5) Black spots on the sheet - This problem is caused by scratches on the primary charge shaft. Spots appear over distance equal to length shaft circumference.

6) Random dots on the page are a problem caused by too much powder on the primary charge roller. There may be black spots on white areas and white spots on black areas.

Feed roller (Samsung/Xerox cartridges)
The toner, mixed in the hopper using a stirrer and receiving a triboelectric charge, is transferred to the toner supply shaft, which is energized. Further, due to the potential difference, the toner is transferred to the development shaft.

Measuring blade (HP/Canon cartridges)
The metering blade controls the amount of toner on the magnetic roller. A worn blade will result in light-colored printing, and the blade will create grooves on the surface of the roller, causing streaks (white voids) to appear along the entire page.

Dispensing blade (Samsung/Xerox cartridges)
The metering blade controls the amount of toner on the development roller. A worn blade will lead to the same consequences as in the case of HP/Canon.

Recovery Blade
The recovery blade directs the toner removed from the drum into the waste toner hopper. A damaged blade will cause dots to appear all over the page, and this defect will only get worse over time. This phenomenon is caused by toner spillage. Most often, the cleaning blade becomes damaged (crumpled) during recovery, and toner begins to accumulate on the surface of the blade and fall off from there. The longer a cartridge prints with a bent blade, the more toner accumulates on it and spills into the cartridge. If a cartridge is returned to you with this problem, you should carefully disassemble it and examine the recovery blade.