How to restore the rubber cartridge shaft. Laser cartridge devices and its main elements. II. toner compartment

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 a coloring composition.

Structural elements of the cartridge

In general, a replaceable unit is a sealed hopper with a compartment containing 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 secured to the housing walls with bushings, allowing 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 exactly as much toner on the magnetic roller 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.

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 blame 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 later 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. WITH reverse side the paper comes into contact with the Transfer Roller, which carries a 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 charge in those places where it was reduced by laser action. Any of the known cartridges includes several different blades, each of which performs an important and the desired 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 the exact dimensions are very important for normal operation 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. The structure of the material, precise and correct dimensions, as well as the quality of the blade tip are important for the normal 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 biggest problems for remanufacturers. The magnetic roller is the basis for the overall print quality and thus has a major impact on the overall performance of the cartridge.

A laser printer cartridge is a rather complex device consisting of many components. In general, it consists of: a compartment with toner, a compartment with waste toner (waste box), housing elements and parts that are involved in transferring the image to a sheet of paper. The toner compartment is a hopper that contains the toner used for printing. It also contains a built-in part (activator) designed to agitate the toner so that it, in turn, is evenly distributed inside the hopper.

All components of the replacement cassette are subject to wear, especially with intensive use. In our article about remanufactured cartridges, we discussed some points regarding the replacement of components that have failed. It is necessary to change not only the photo shaft, but also other spare parts that contribute to image transfer. Let's talk about them in more detail.

Organic Photo Conductor (OPC) Drum
This component is rightfully the most expensive part of a laser cartridge. Since it is precisely this that is the most complex element in its design. The base of the photo roll is an aluminum cylinder on which several layers of special coating are based. The first of which is made of light-conducting material (dielectric), followed by layers that generate and transmit charge. Previously, the photosensitive layer was made from various selenium compounds, but these days this is rare. Amorphous flint is the basis of organic compounds used today. By the way, it is worth noting that one of the main differences between photodrums is their diameter. The larger the volume of the cartridge, the larger the diameter of the photo roller, of course.

The torque of the photoshaft is realized using a gear transmission. Accordingly, different cartridge models use different gears. Thus, the photoconductor is a unique component, despite the fact that they are all very similar.Due to the different structure, the operating principle may differ, but the basic processes remain the same. Let's look at the most common of them.

Using an optical-mechanical system of lenses and mirrors, the laser is directed to the photo shaft and draws (illuminates) the future image on it with a weakly negative charge. Afterwards, toner is transferred from the magnetic roller to the exposed areas, forming a print that will be transferred to paper. It is advisable that the paper be High Quality, since even the smallest particles of dust can damage the drum and it will not last long.

The refilled cartridge should be stored in soft and opaque packaging. As a rule, after every 3-4 refills, the photosensitive layer is already very worn out, and the print becomes pale, even if the removable cassette is refilled. In order to restore the former brightness, replacing the photodrum is simply necessary.

Primary Charge Roller (PCR)

The primary charge shaft is a part that no laser cartridge can do without. This component charges the photo shaft with a negative and uniform charge. The design of the input shaft is very simple - it is a metal core enclosed in a rubber shell. Sometimes, for example in Samsung cartridges, the charging shaft also serves as a cleaner for the photo roller from toner residues, paper dust or other debris. It also removes the residual charge that remains on the photosensitive layer. If this component is damaged, printing errors such as duplicate text may occur. The reason for this is that a damaged charge roller does not completely erase the residual charge from the drum. Failure of this part is a very rare occurrence. But, nevertheless, it is simply necessary to thoroughly clean this roller, since it is subject to constant contamination by paper dust and toner.

Magnetic roller (Mag Roller)

The purpose of the magnetic roller is to transfer the required amount of toner to the photocell. The structure of this component can be very diverse depending on the cartridge manufacturer. Very often, in HP or Canon cassettes, the magnet is a metal shaft, on top of which a special layer is applied. It is worth noting that the magnetic shafts of these manufacturers are very sensitive to mechanical damage. But this component in Samsung replacement cassettes is made of a special rubber material, the service life of which is determined not only by its contamination, but also, of course, by the quality of the toner that is used. Since this part performs a very important function, both the print quality and the operation of the entire cartridge as a whole depend on its operation. Regular maintenance of the magnetic roller will ensure trouble-free operation of the laser cartridge and good print. But only under the following conditions: using high-quality toner, avoiding mechanical damage and performing all refilling and restoration procedures by an experienced specialist who knows the technology for performing these works.

Raquel (Wiper Blade)

A squeegee is a part that is used to remove toner residues from the photodrum. The design of the squeegee consists of two parts: a metal one, with which it is attached to the body of the removable cassette, and a polyurethane blade, which is pressed against the photo shaft and performs the main cleaning function. The polyurethane part is quite elastic, which allows it to be pressed tightly against the photocell without causing any damage to it. The correct operation of all components of the cartridge, especially the photodrum, depends on the condition of the blade itself. Since they are in contact all the time, any damage to the squeegee will immediately affect the state of the photocell. If the laser cartridge is restored, then this component must be replaced with a new one. After all, after the photodrum, it has the second fastest wear rate.
It is also worth noting that there are replaceable cartridges that do not have a compartment with waste toner, and therefore there is no squeegee either. Usually these are models from the brands Brother, Samsung, Xerox, etc. The toner that remains on the photodrum is cleaned off by the charge shaft. And the charge shaft is cleaned with a special brush and dust collector.

Doctor Blade

The metering blade distributes the toner evenly across the magnetic roller. Most often, the dispenser is made of elastic plastic (on HP, Canon cartridges) or metal (Samsung, Xerox). In order for the toner to be distributed evenly, the surface of the dispensing blade must be smooth, without mechanical damage. Those blades that are made of plastic, as a rule, last a very long time, since they do not experience heavy loads. Such parts wear out most often due to low-quality toner. But it is worth noting that these components on Sumsung and Xerox laser cartridges wear out quite quickly, since they are made of metal, which in turn is simply ground off. The process of cleaning the dispensing blade must be timely and, most importantly, of high quality, as this greatly affects the print quality and the condition of other cartridge components.

Felt Shet

Felt seals for the magnetic shaft, squeegee, and other components of the laser cartridge are designed to isolate the working mechanisms of the cartridge from the body parts. One of the main tasks of such seals is to seal the toner compartment and the body as a whole. They are also used in other cartridge assemblies that require sealing. The shape, size and materials from which they are made can be very diverse, depending on the purposes for which they are used. Thanks to their sealing function, toner does not spill out from under various components. If the felt seal is worn out, it may cause toner to spill inside the printer, which may subsequently cause printer failure. It follows from this that monitoring their condition is very important. And it’s even more important to change them on time to increase the service life of all printer components. During the process of restoring cartridges, the seals are, of course, replaced with new ones.

Laser printers (in particular, HP models) are very reliable and easy-to-use devices. Any printing defects on paper, as a rule, arise due to violation of operating rules or wear and tear of cartridge parts, which we easily replace with new ones, giving another life to your cartridge and saving you from spending big on a new cartridge.

The most common defect is damage to the surfaces by a metal clip from a stapler, which was forgotten to be removed from a sheet of paper before printing.

How can you determine, looking at the printed sheet, which element requires immediate replacement? This is quite easy to do.

To begin with, here are sample printouts that indicate a clear lack of toner:

Figure No. 1 shows a sample of the classic end of toner in a cartridge; the print shows that, apart from text spaces, no other defects are visible. This cartridge can only be refilled.

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There are two systems for charging the photoreceptor: using a corotron and using a PCR roller. The advantages of the second option are the high stability of the charging current, the almost complete absence of ozone emission and less dependence on environmental conditions.

The charge roller (PCR - Primary Charge Roller), or primary charge shaft, is a rubber part that is one of the most important elements of a laser cartridge. Its purpose is to charge the surface of the photodrum and erase the residual latent electrostatic image from it. The principle of operation of the roller is to supply it with direct and alternating current at high voltage.

Like the image drum, the charge rollers require periodic maintenance. When disassembling the cartridge from them, using a soft cloth, you need to remove the remains of toner additives (amorphous silicon) and dusty paper particles that the squeegee could not cope with. On average, the service life of these elements is determined by 30,000 printed pages. At the same time, charge rollers, like other parts of printing equipment, periodically fail. In some cases they can be repaired, in others they need to be replaced.

The main problems arise in connection with the charge roller performing its direct functions: insufficient charge of the surface of the photodrum and incomplete erasing of the residual image. This can be caused by several reasons:

Changing the permissible parameters of dielectric constant, electrical conductivity and other electrostatic characteristics of the roller material;

Detachment of the roller material from the metal axis;

Surface wear;

The presence of tears and punctures on the surface;

Detachment of the outer shell of the roller from the porous inner part;

Electrical breakdown of the roller material;

Surface contamination.

You can tell that the charge roller is out of order by regularly appearing spots, dots, stripes and other defects on the prints. For their “early” diagnosis and timely elimination, experts advise periodically printing a test page.

One of the most common defects indicating a malfunction of the PCR is considered image repetition, or ghosting, from the English. ghost (ghost). The repeat interval corresponds to the circumference of the drum and is present on the image that is not yet fixed, that is, before the sheet enters the fuser. In rare cases, this problem is associated with a malfunction of the drum itself.

Unlike ghosting, fusing offset appears due to insufficient fixation of the toner by the fixing unit, and its interval corresponds to the circumference of the shafts of this unit. If the charge of the shaft is unsatisfactory, as well as for a number of other reasons, a background often appears on the sheet, distorting the original image.

The simplest repair is to wipe the roller with a soft cloth soaked in distilled water. There is an opinion that instead of water, you can use “Mr. Muscle”, Platenclene or an acetone solution for these purposes. To clean the roller, press lightly on the surface, carefully removing any adhering toner and whitish areas of paper dust. As a result, the surface should acquire a uniform gray or black color. If this trick does not help, you will have to resort to more serious actions.

If repeats or backgrounds consistently appear on your prints, you need to clean the sliding contact from contaminated conductive grease and apply a fresh layer, and then clean the roller surface using the above method. If the outer “stocking” has peeled off from the porous inner filler, cleaning does not bring a visible result, residues of unremoved toner constantly accumulate on the surface, you will have to completely change the roller along with the squeegee.

It is quite difficult to carry out high-quality surface cleaning, as well as other actions, without damaging the roller coating, so it is better to entrust such work to a specialist. Especially if we're talking about about replacing parts! The charge rollers of some manufacturers are initially designed for one cycle of operation, and therefore, after failure, it is pointless to repair them - it is better to simply replace them.