DE102009038482A1 - Method for cleaning rotating toner image carrier e.g. transfer belt, from residual toner in electrographic printing device, involves starting cleaning cycle in time intervals, where surface of carrier slides along brush in one direction - Google Patents

Abstract

The method involves cleaning residual toner from a rotating toner image carrier (1) in a cleaning cycle by using a cleaning brush i.e. rotating brush roller, that is located adjacent to the toner image carrier. The cleaning cycle ends and another cleaning cycle is started in adjustable time intervals, where a surface of the toner image carrier slides along the cleaning brush in an opposing direction. The cleaning brush is arranged in a housing. A running direction (PF1) of the toner image carrier is maintained in both cleaning cycles.

Description

• • Der Fotoleiter wird auf ein vorgegebenes Potential aufgeladen.
• • Auf dem geladenen Fotoleiter werden dies Druckbilder mittels Licht von einem optischen Zeichengenerator geschrieben. Das Licht entlädt den Fotoleiter und es entstehen die Ladungsbilder der zu druckenden Bilder.
• • Die Ladungsbilder werden von einer Entwicklungseinheit mittels Toner entwickelt.
• • In einem Umdruckbereich werden die Tonerbilder mit Hilfe eines elektrostatischen Feldes und Kontaktes auf einen Zwischenträger, z. B. ein Transferband, oder das Druckmedium, z. B. Papier, übertragen.
• • Nach dem Umdruck bleibt eine kleine Menge Toner (Resttoner genannt) am Fotoleiter oder dem Transferband hängen. Dieser wird in einer Reinigungseinrichtung abgereinigt und damit der Fotoleiter oder das Transferband für die Aufnahme neuer Bilder sauber gehalten.
• • Der Umdruck kann somit vom Fotoleiter auf den Zwischenträger und von dort auf ein Druckmedium, z. B. eine Papierbahn, oder direkt auf das Druckmedium erfolgen; auf dem Druckmedium werden die Druckbilder anschließend fixiert.
• • Nach dem Umdruck kann dabei eine Restmenge an Resttoner und sonstige Ablagerungen, z. B. aus Tonerbestandteilen, übrig bleiben, die auf dem Fotoleiter oder dem Zwischenträger einen Belag oder einen Film bilden können, der entfernt werden sollte.

Electrographic printing devices are known. These have a photoconductor, z. As a photoconductor drum or a photoconductor belt, are generated on the charge images of the images to be printed. The cyclical process of the print image generation takes place in the following steps:

• • The photoconductor is charged to a predetermined potential.
• • On the loaded photoconductor, printed images are written by light from an optical character generator. The light discharges the photoconductor and creates the charge images of the images to be printed.
• • The charge images are developed by a development unit using toner.
• • In a transfer area, the toner images are printed by means of an electrostatic field and contact with a subcarrier, z. B. a transfer belt, or the printing medium, for. As paper transferred.
• • After transfer printing, a small amount of toner (called residual toner) will remain on the photoconductor or transfer ribbon. This is cleaned in a cleaning device and thus kept clean the photoconductor or the transfer belt for taking new pictures.
• • The transfer can thus from the photoconductor on the intermediate carrier and from there to a printing medium, eg. B. a paper web, or done directly on the print medium; The printed images are then fixed on the print medium.
• • After the transfer printing can be a residual amount of residual toner and other deposits, eg. From toner components left over which may form a coating or film on the photoconductor or subcarrier which should be removed.

In the following, the photoconductor and a possibly used intermediate carrier will be collectively referred to as a toner image carrier.

From the literature, devices are known which remove the loose residual toner from a toner image carrier.

Out US 5,999,791 . EP 0 759 583 It is known to use a cleaning brush with electrically conductive bristles to remove the residual toner from the toner image carrier. The cleaning brush is connected to a power source whose polarity is set opposite to the toner polarity. The residual toner adheres to the bristles and is removed via an extraction or electrostatically from the cleaning brush.

These solutions have in common that they should remove the loosely adhering electrostatic residual toner from the surface of the toner image carrier. However, the other materials that may contaminate the toner image bearing surface and form areas of deposits (hereinafter called film areas) are insufficiently or not removed. These film areas have different physical properties than the toner image carrier and thus lead to changes in the process parameters, with the result that the print quality is degraded

The filming of the surface of the toner image carrier occurs especially when the toner in addition to various polymers and color pigments charge control agents and additives such. As wax or silica, by which the flow behavior of the toner or the fixability of the toner to be influenced. Then, when the toner image carrier and the cleaning brush are running in the same direction or run counter to deposits of toner components, paper components or other ingredients, the film portions may form on the surface of the toner image carrier. A film portion is formed from a seed of toner constituents, paper components or other ingredients, this seed growing in the cleaning direction uniformly on the surface of the toner image carrier to raised points with increasing shape and falls in an edge to the surface of the toner image carrier. The brush hairs of the cleaning brush slide over them due to the shape of the film areas, without being able to sufficiently clean the film areas.

To remove residual toner is after DE 699 29 501 T2 a cleaning blade or squeegee used. A sharp edge of the cleaning blade scrapes with the residual toner also deposits of toner components.

To DE 102 01 483 A1 For example, a film of residual toner and deposits adhering to a toner image carrier is removed from the toner image carrier with a cleaning roller. For this purpose, the deformable running cleaning roller is pressed against the toner image carrier so that a flattened contact area on the cleaning roller to the toner image carrier is formed, in which there is a relative movement between the toner image carrier and cleaning roller. By this relative movement of the coating is released from the toner image carrier and can pass to the cleaning roller. From there, the deposits are removed via a brush or directly from a pick-up roller and fed to a waste container.

The problem underlying the invention is to provide a cleaning method for a toner image carrier of an electrographic printing device, in addition to the residual toner and deposits of toner components, paper components or other ingredients safely be removed without the toner image carrier is adversely affected.

This problem is solved according to the features of claim 1.

• – Während eines ersten Reinigungszyklus wird durch eine an dem rotierenden Tonerbildträger anliegende Reinigungsbürste kontinuierlich Resttoner von dem Tonerbildträger abgereinigt.
• – Nach einstellbaren Zeitintervallen wird der erste Reinigungszyklus beendet und ein zweiter Reinigungszyklus gestartet, bei dem die Oberfläche des Tonerbildträgers in entgegengesetzter Richtung an der Reinigungsbürste vorbeigleitet.

The process for cleaning a toner image carrier from residual toner remaining on the toner image carrier and film areas adhered thereto from deposits of toner components, paper ingredients or other ingredients using a cleaning brush suggests two cleaning cycles:

• During a first cleaning cycle, residual toner from the toner image carrier is continuously cleaned by a cleaning brush applied to the rotating toner image carrier.
• After adjustable time intervals, the first cleaning cycle is ended and a second cleaning cycle is started, in which the surface of the toner image carrier slides in the opposite direction past the cleaning brush.

Thus, in the first cleaning cycle, the toner image carrier is cleaned of residual toner in a known manner. The remaining on the toner image carrier in the first cleaning cycle film areas from deposits of residual toner, toner components, paper components or other ingredients, however, are not constantly removed, but only in time intervals. For this purpose, no additional element is used, only the cleaning brush. In this case, the toner image carrier is guided past the cleaning brush in the opposite direction, so that the cleaning brush brushes in the opposite direction over the film areas, that is to say initially strikes the edge of a film area and strips it off or strikes off.

When a rotary brush roller is used as the cleaning brush, the rotational direction of the brush roller is changed while maintaining the running direction of the toner image carrier, as compared with the first cleaning cycle in the second cleaning cycle. Thus, the bristles of the brush roll in the opposite direction over the film areas, ie from the edge thereof, with the result that the built-up during the first cleaning cycle edge of the deposition film now forms a resistance and is then stripped or knocked off.

The inventive method has a further advantage when the cleaning roller accordingly DE 102 01 483 A1 is arranged in a housing from which the stripped residual toner, toner ingredients, paper components or other ingredients such. B. are sucked off. Here there is the danger that deposits of these components form on the housing inner wall. These deposits of toner constituents, paper constituents or other constituents on the housing inner wall are also stripped in the second cleaning cycle and can then be easily sucked off. For this purpose, it is expedient that the cleaning brush is arranged in the housing so that their hairs rub against the inner wall.

Further developments of the invention will become apparent from the dependent claims.

With reference to an embodiment, which is illustrated in the figures, the invention will be further explained.

Show it:

1 a schematic representation of a film area of deposits of toner components, paper components or other constituents on a toner image carrier,

2 a schematic diagram of the cleaning of a toner image carrier by a brush roller, in which a film area is formed,

3 a schematic representation of the results of how a film area is removed by a brush roller.

From the cleaning device in the explanation, only the cleaning brush shown, the structure of the entire cleaning device can, for. B. DE 102 01 483 A1 correspond with the difference that the local cleaning roller is replaced by a cleaning brush. The arrangement of the cleaning device to the toner image carrier can also DE 102 01 483 A1 be removed. However, the cleaning device can be provided not only for cleaning a photoconductor member as a toner image carrier, but also for cleaning a transfer ribbon as a toner image carrier on the z. As color separations are collected in color printing to the color image, which is then transferred to a record carrier.

at 1 is as a toner image carrier a rotating photoconductor drum 1 are shown on the charge images of the images to be printed are produced in a known manner, then the charge images are dyed with at least one developer station with toner to toner images, which are transferred in a transfer station to a transfer belt or a recording medium. Behind the transfer station residual toner remains on the photoconductor drum 1 Back, this must be from the photoconductor drum 1 be removed before a new print cycle begins. The removal of the residual toner is carried out by a cleaning device, the photoconductor drum with a cleaning brush 1 cleans. When cleaning through the cleaning brush, the residual toner to the considerable extent of the photoconductive drum 1 away. However, a small portion of residual toner and other components of the toner remain as a deposit on the photoconductive drum 1 back. These deposits can pass through the cleaning brush to film areas on the photoconductor drum 1 weren formed when z. B. on the surface of the photoconductor drum 1 has formed a germ on which the deposits can accumulate. Since the cleaning brush always strokes in the same direction over this germ, forming a film area 2 corresponding 1 on the photoconductor drum 1 , This movie section 2 has an ascending level 3 that in an edge 4 ends, leading to the surface of the toner image carrier 1 drops. In 1 If the cleaning brush is not shown, it can be fixed to the photoconductive drum 1 be arranged, wherein the photoconductor drum 1 rotated in the direction of arrow PF1.

The cleaning brush can be fixed or rotating. 2 shows a rotating brush roller 5 known structure as a cleaning brush, a film area 2 and the photoconductor drum 1 , The brush roller 5 rotates in the direction of the arrow PF2 while the photoconductive drum 1 rotated in the opposite direction PF1. When the brush roller 5 was active on a photoconductive drum for a long period of time 1 usually in several places on the surface film areas 2 corresponding 1 form. These movie areas 2 be through the brush roller 5 not removed because their hair 6 on the rising level 3 can slide along.

To the film areas 2 to be able to eliminate, accordingly 3 proceed. The running direction PF1 of the photoconductive drum 1 is maintained, the rotational direction PF of the brush roller 5 turned around in the direction of PF3. Now the hair is brushing 6 the brush roller 5 in the opposite direction across the film areas 2 So first over the edge 4 , and brush the film area 2 from the edge 4 from the photoconductive drum 1 from.

In the 2 and 3 is the cleaning brush as a rotating brush roller 5 executed, their hair or bristles 6 because of the rotation of photoconductive drum 1 and brush roller 5 the movie section 2 from the photoconductor drum 1 strip. The brush roller 5 can also be performed as a fixed brush on which the photoconductive drum 1 rotates along. With a brush roller 5 As a cleaning brush, however, a cleaning success can be achieved in a shorter time.

In printing operation, thus, a cleaning of the toner image carrier 1 from residual toner constantly performed. Resulting film areas 2 on the other hand, they are only eliminated at intervals. The time interval between the removal of the film areas 2 can be specified, for. B. developed from experience, and then have a constant value. However, it is cheaper to carry out the second cleaning cycle whenever the printing device z. B. due to maintenance, paper change, missing print data, print stop, etc., to be switched to stand-by mode.

LIST OF REFERENCE NUMBERS

1

Toner image carrier = photoconductive drum

2

film industry

3

Ascending level of the movie section

4

Falling edge of the film area

5

Cleaning brush = brush roller

6

Hair of the cleaning brush

PF

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QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5999791 [0004]
• EP 0759583 [0004]
• DE 69929501 T2 [0007]
• DE 10201483 A1 [0008, 0014, 0021, 0021]

Claims (9)

A process for cleaning a toner image carrier of residual toner remaining after the transfer of toner images on the toner image carrier in an electrographic printing apparatus in which in a first cleaning cycle by a on the rotating toner image carrier ( 1 ) fitting cleaning brush ( 5 ) Residual toner from the toner image carrier ( 1 ) is cleaned, in which at adjustable time intervals, the first cleaning cycle is terminated and a second cleaning cycle is started, in which the surface of the toner image carrier ( 1 ) in the opposite direction on the cleaning brush ( 5 ) slides along. Process according to Claim 1, in which a rotating brush roller (FIG. 5 ) is used, in which in the first cleaning cycle, the brush roller ( 5 ) in the one direction (PF2) and in the second cleaning cycle in the opposite direction (PF3) is rotated, wherein the running direction (PF1) of the toner image carrier ( 1 ) is maintained in both cleaning cycles. Method according to Claim 2, in which, in the first cleaning cycle, the direction of rotation of the brush roller ( 5 ) opposite to the running direction of the intermediate carrier ( 1 ) is set. Method according to Claim 3, in which, in the second cleaning cycle, the direction of rotation (PF3) of the brush roller ( 5 ) rectified to the direction of travel (PF1) of the toner image carrier ( 1 ) is set. Method according to one of claims 1 to 4, wherein the second cleaning cycle is then started before the printing device goes into a stand-by mode. Method according to one of claims 1 to 4, wherein the second cleaning cycle is started at predetermined time intervals. Method according to one of the preceding claims, in which the toner image carrier ( 1 ) is a photoconductive element. Method according to one of the preceding claims, in which the toner image carrier ( 1 ) is a transfer belt. Method according to one of the preceding claims, in which the cleaning brush ( 5 ) is arranged in a housing such that the hair ( 6 ) brush the cleaning brush along the inner wall of the housing so that deposits of residual toner, toner constituents, paper components or other constituents on the inner wall of the housing are scraped off.

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