DE102008005132A1 - Arrangement for displacement of electrically charged toner to upper surface of toner transporting roller, has electrical graphic printing or photocopying apparatus, and roller lying at electrical potential - Google Patents

Abstract

To remove from a cleaning roller (17) toner, the z. B. originating from a developer roller to remove is seen in the direction of rotation of the cleaning roller (17) laterally adjacent a cup-shaped means (18), for. B. a half-shell (21), provided to form a cleaning zone (20) such a gap (19) to the cup-shaped means (18) that the toner and optionally a developer mixture between cleaning roller (17) and cup-shaped means (18) can pass through without traffic jams. The cup-shaped means (18) is applied to such an electrical potential (P2) that, due to the generated electric field, the toner detaches from the surface of the cleaning roller (17) and moves towards the bowl-shaped means (18) into the cleaning zone (FIG. 20) moves. The toner dissolved from the surface of the cleaning roller (17) can then trickle out at the exit of the cleaning zone (20), e.g. B. due to gravity, and z. B. fall into a developer's store.

Description

Electrographic printing or copying machines are known, see, for. B. US 6,246,856 B1 or DE 10 2004 059 532 A1 , In such a printing or copying machine are on a charge image carrier, for. B. a photoconductor belt, generated by a character generator charge images of the images to be printed. Subsequently, the charge image carrier is moved past developer stations, one per color. These transport toner to the charge image carrier. According to the charge images on the charge image carrier, the toner transfers to the charge image carrier and colors it. In the next step, the toner images are transferred to a substrate and fixed on it. The exact course of the printing process can US 6,246,856 B1 are removed, the contents of which are hereby incorporated into the disclosure.

To develop the charge images, a developer station may be used, as appropriate WO 03/036 393 A2 ( US 2005/0036806 A1 ) is constructed. From a developer mixture of toner and magnetic carrier takes a first magnetic roller assembly, the inking roller, developer in which the toner is triboelectrically charged. The magnetic roller assembly consists of a rotating roller with a magnet roller stator arranged in the interior, in which magnets are provided, which are polarized differently. Adjacent to the first magnetic roller assembly, there is provided a developer roller or applicator roller that takes toner from the magnetic roller assembly due to an electric field existing between the developer roller and the magnet roller assembly and transports it to the charge image carrier. There goes in a developer gap toner for coloring the charge images on the charge image carrier. The residual toner remaining on the developer roller after development is then cleaned by a cleaning roller from the developer roller. The cleaning roller is also realized as a magnetic roller assembly. This is also arranged adjacent to the first magnetic roller assembly and takes over from this developer mixture, forms a mixture carpet and passes this past the developer roller, wherein the residual toner is rubbed off by the mixture carpet from the developer roller. The cleaning process is assisted by an existing between magnetic roller assembly and developer roller electric field. From the cleaning roller, the developer falls into the developer supply due to the polarity of the magnets and using a doctor blade or by using another magnet assembly, which forms a developer mixing brush. A disadvantage of this developer station is the fact that the sleeve of the developer roller is considerably worn by the developer carpet on the cleaning roller sleeve; Likewise, the surface of the sleeve of the cleaning roller is considerably stressed by the mixture brush or a squeegee. To overcome these problems, attempts are made to make the surface properties of the sleeves so that they are resistant to abrasion and the toner does not adhere to them.

Out DE 10 2004 059 532 A1 results in a cleaning arrangement for a developer roller, which is cleaned with an electric field, the residual toner from the developer roller. For this purpose, an electric traveling field is generated. The cleaning arrangement has electrodes for this purpose. The traveling field removes the toner in the direction of the traveling field.

The problem to be solved by the invention is a Specify an arrangement with which the surface of a roller can be cleaned of toner. In particular, this problem should in a cleaning roller for a developer roller, the surface of the cleaning roller being cleaned of toner becomes.

The Problem is solved according to the features of the claim 1 solved.

The The invention will be described below in connection with a developer station which has a developer roller, the charge images on a charge image carrier with toner colors and then the one left after coloring Remained toner (hereinafter referred to as residual toner) from a cleaning roller is cleaned. With the help of the invention can now adhering to the cleaning roller Remaining toner will be removed. In this application, the cleaning roller However, the invention is not limited.

at the invention, the cleaning roller is located on a first electrical Potential that the residual toner z. B. from a developer roll to Surface of the cleaning roller pulls on which the residual toner sticks. Seen in the direction of rotation of the cleaning roller, z. B. from the transfer area of the residual toner from the developer roller on the side adjacent is a cup-shaped means arranged to form a cleaning zone a gap to cup-shaped means through which the residual toner through can run. The cup-shaped means is attached to such second electrical potential that due to the in the cleaning zone generated by the residual toner of the surface of the cleaning roller dissolves and towards the bowl-shaped means in the cleaning zone emotional. The dissolved from the surface of the cleaning roller Residual toner can then trickle out at the end of the cleaning zone, z. B. due to gravity, and z. B. fall into a developer's store.

further developments The invention will become apparent from the dependent claims.

Around to achieve a uniform gap, it is appropriate, the cup-shaped means as one adapted to the surface shape of the cleaning roller Tray shell. It is advantageous then a half-shell, the on the side of the cleaning roller is arranged, on which the residual toner is moved down.

The Shell may consist of electrically non-conductive material and inside over its width an electric electrode have, at which rests the second electrical potential. Then their electric field is effective only in the cleaning zone.

Around To prevent deposits of residual toner on the shell, it is expedient the shell at least inside with an anti-adhesive Material, eg. As Teflon to coat.

If in addition to the residual toner through the gap between cleaning roller and shell a developer mixture of toner and magnetic carrier passed then the developer mix can be the one from the surface take the toner removed from the cleaning roller and continue transport. A deposit of residual toner on the shell becomes thereby avoided. The developer mixture can, for. B. from a Einfärbewalze derived, which supplies the toner to the developer roller. Then the gap should be towards the cup-shaped means be chosen that the residual toner and the developer mix between cleaning roller and cup-shaped agent without Jam and thus without bruising can run through

The Effect of the developer mix is further enhanced when in the interior of the cleaning roller, at least in the region of the shell Magnet arrangement is provided, which from alternately poled magnets having. The magnets then become a developer brush formed, which brushes off the residual toner from the shell. The Magnets can be spaced apart, but they can also be right next to each other, whereby the decrease effect is strengthened.

Advantageous is when inside the shell several embedded in the shell insulated electric electrodes are provided where different electrical potentials are applied. Thereby the residual toner is not only released from the cleaning roller, but also a sticking of the residual toner on the shell can be minimized become. The electrical potentials can be chosen that they are alternately active or inactive, d. H. in the active Phase the residual toner from the surface of the cleaning roller do not remove the residual toner in the non-active phase Pull on the shell.

• – eine Einfärbewalze vorsieht, die ein Entwicklergemisch aus Träger und Toner aus einem Entwicklervorrat entnimmt und zu einer Entwicklerwalze transportiert, die zumindest Toner aus dem Entwicklergemisch übernimmt und zu einem Ladungsbildträger transportiert, um Ladungsbilder auf dem Ladungsbildträger mit Toner einzufärben,
• – eine Reinigungswalze benachbart der Entwicklerwalze aufweist, die den nach der Entwicklung auf der Entwicklerwalze verbliebenen Resttoner abreinigt, wobei die Reinigungswalze an einem ersten elektrischen Potential liegt, dessen elektrisches Feld den Resttoner von der Entwicklerwalze zur Oberfläche der Reinigungswalze zieht,
• – in Drehrichtung der Reinigungswalze gesehen seitlich benachbart ein schalenförmiges Mittel aufweist, das einen derartigen Spalt mit der Reinigungswalze bildet, dass der Resttoner und das Entwicklergemisch zwischen Reinigungswalze und schalenförmigen Mittel ungehindert hindurch laufen kann, wobei das schalenförmige Mittel an einem zweiten elektrischen Potential liegt, dessen elektrisches Feld den Resttoner von der Oberfläche der Reinigungswalze löst und in Richtung zum schalenförmigen Mittel bewegt, und wobei der von der Oberfläche der Walze gelöste Resttoner am Ausgang des Spaltes in die Entwicklerstation fällt.

The invention is particularly advantageously applicable to a developer station for an electrographic printing or copying machine, in which the developer station

• Providing a inking roll which removes a developer mixture of carrier and toner from a developer supply and transports it to a developer roller which at least adopts toner from the developer mixture and transports it to a charge image carrier to color toner charge images on the charge image carrier,
• A cleaning roller adjacent to the developer roller which cleans the residual toner remaining on the developer roller after development, the cleaning roller being at a first electrical potential whose electric field draws the residual toner from the developer roller to the surface of the cleaning roller;
• - seen laterally in the direction of rotation of the cleaning roller has a cup-shaped means which forms such a gap with the cleaning roller, that the residual toner and the developer mixture between cleaning roller and cup-shaped means can pass unhindered, wherein the cup-shaped means is at a second electrical potential, the electric field detaches the residual toner from the surface of the cleaning roller and moves toward the cup-shaped means, and wherein the residual toner dissolved from the surface of the roller falls into the developer station at the exit of the nip.

At Hand of embodiments shown in the figures are, the invention will be further explained.

It demonstrate

1 a known developer station showing the flow of the developer mixture;

2 a schematic representation of the invention;

3 a representation of the mixture flow for cleaning the toner from the shell;

4 a first magnet arrangement in the interior of the roller;

5 a second magnet arrangement inside the roller;

6 the arrangement of an electrode inside the shell in side view and front view;

7 the arrangement of a plurality of electrodes in the interior of the shell in side view and front view.

1 shows a developer station ES in principle accordingly WO 03/036 393 A2 ( US 2005/0036806 A1 ) WO 03/036 393 A2 is hereby incorporated into the disclosure. From a supply 1 Developer mixture, which consists of carrier and toner (hereinafter developer 4 called), by a dredger 2 developer 4 taken and a coloring roller 3 fed. The developer 4 is shown schematically, wherein the carrier 5 dashed lines and the toner 6 dotted. The inking roller 3 is realized as a magnetic roller and consists of a rotating roller shell 7 and a stator 8th with magnets 9 , which are poled so that the developer is transported in the direction of rotation. The inking roller 3 transports the developer 4 to a developer roller 10 , which is realized as a jump roller in a development according to the jump principle. The developer roller 10 takes over from the inking roller 3 toner 6 and transports this to a charge image carrier 11 , z. B. a photoconductor belt, over. toner 6 goes according to the charge images on the charge image carrier 11 above. The on the developer roller 10 remaining toner, hereinafter residual toner 12 called, is from a cleaning roller 13 cleaned; this is constructed as a magnetic roller with a stator 14 and magnets 15 internally. Because developers 16 from the inking roller 3 partly to the cleaning roller 13 (the rest of the developer falls into the developer's stock 1 back), forms on the cleaning roller 13 a mixture brush, the rotation of the cleaning roller 13 at the developer roller 10 passes by and the residual toner 12 cleans. From the cleaning roller 13 drops the residual toner 12 into the developer's stock 1 back.

This described sequence is also used in the invention, wherein as a cleaning roller, a roller 17 is used, which does not have to have a magnet arrangement in the interior.

The process of development is supported by electrical potentials P, which in 2 are shown. At the developer roller 10 is a potential P0 of z. B. -600 V and at the cleaning roller 13 a potential P1 of z. B. -100 V on. Assuming that the toner is negatively charged, the potential difference between P0 and P1 will cause the negatively charged residual toner to transfer to the cleaning roller 13 causes.

A problem with the developer station after 1 is the cleaning of the cleaning roller 13 of residual toner from their surface. For this purpose, a squeegee applied to the surface can be used, but also a magnetic roller which wipes off the toner from the cleaning roller with a mixture brush. By this cleaning process, the surface of the cleaning roller is worn considerably. In addition, the squeegee is worn and damaged.

To avoid this, in the embodiment of the 2 adjacent a cleaning roller 17 a cup-shaped means 18 arranged at such a distance that the residual toner through the gap 19 between cleaning roller 17 and cup-shaped means 18 can be passed through. To the cup-shaped agent 18 is applied such an electric potential P2 that the residual toner from the surface of the cleaning roller 17 is dissolved and in a cleaning zone 20 between cleaning roller 17 and cupped means 18 towards the cupped medium 18 is moved. The potential P2 can z. B. 400 V, when the potential P1 at the cleaning roller 17 -100 V is selected.

The cup-shaped agent 18 is in the direction of rotation of the cleaning roller 17 seen laterally arranged. It can have a shape that matches the shape of the cleaning roller 17 is adapted and z. B. the shape of a shell, preferably a half-shell 21 , shorter shells are of course possible, with the width of the gap 19 can also be designed differently, for. B. at the output or input wider than in the remaining area can be selected. In the following, but of half shell 21 be spoken without limiting the invention thereto. The half shell 21 extends over the width of the cleaning roller 17 ,

For negatively charged toner can z. For example, the potential P0 at the developer roller 10 -600 V and the potential P1 at the cleaning roller 17 -100V. At these potential ratios, the residual toner from the developer roller 10 to the cleaning roller 17 drawn. If the potential P2 on the half shell z. B. 400 V, the residual toner from the surface of the cleaning roller 17 in the gap 19 pulled in and then at the end of the cleaning zone 20 fall back into the developer station ES.

• a) Bei einer ersten Lösung wird entsprechend 3 ein Entwicklergemisch 22 aus Toner und magnetischen Träger z. B. von der Einfärbewalze durch die Drehbewegung der Entwicklerwalze 10 und der Reinigungswalze 17 zwischen Entwicklerwalze 10 und Reinigungswalze 17 hindurchgeführt und von dort durch die Drehbewegung der Reinigungswalze 17 durch die Reinigungszone 20 geführt. Das Entwicklergemisch 22 nimmt zumindest einen Teil des Resttoners 12 auf, zudem streift es an der Halbschale 21 entlang und streift durch den mechanischen Kontakt den Resttoner 12 von der Halbschale 21 ab. Dieser Vorgang wird noch unterstützt, wenn im Inneren der Reinigungswalze 17 eine Magnetanordnung 23 vorgesehen wird, 4 oder 5, die eine Gemischbürste erzeugt, die an der Halbschale 21 entlang streift. Bei der Magnetanordnung 23 nach 4 sind dazu Magnete 24 vorgesehen, die abwechselnd gepolt sind und bis zu der Stelle der Reinigungswalze 17, an der das Entwicklergemisch abfallen soll, angeordnet sind. Bei der Magnetanordnung 25 der 5 sind die Magnete 26 unmittelbar nebeneinander angeordnet, wodurch eine verbesserte Wirkung erzeugt wird.

If no further measures are taken, such a cleaning of the cleaning roller 17 in the worst case, residual toner on the half shell 21 settle with the result that in the cleaning zone 20 the electric field is weakened and field collapses would be possible, whereby the cleaning function would be weakened. To deposit residual toner on the half shell 21 Several solutions are proposed below:

• a) At a first solution will be appropriate 3 a developer mix 22 made of toner and magnetic carrier z. B. from the inking roller by the rotational movement of the developer roller 10 and the cleaning roller 17 between developer roller 10 and cleaning roller 17 passed through and from there by the rotational movement of the cleaning roller 17 through the cleaning zone 20 guided. The developer mix 22 takes at least part of the residual toner 12 on, also it touches on the half shell 21 along and rubs through the mechanical contact the residual toner 12 from the half shell 21 from. This process is still supported when inside the cleaning roller 17 a magnet arrangement 23 is provided 4 or 5 which produces a mixture brush attached to the half shell 21 along stretches. In the magnet arrangement 23 to 4 are magnets to it 24 provided, which are alternately poled and up to the point of the cleaning roller 17 where the developer mix should drop off. In the magnet arrangement 25 of the 5 are the magnets 26 placed directly next to each other, creating an improved effect.

• b) Bei einer zweiten Lösung kann eine Ablagerung von Resttoner 12 an der Halbschale 21 minimiert werden, wenn die Halbschale 21 zumindest an der Innenseite mit einem antiadhäsiven Material, z. B. von Teflon, überzogen ist, womit verhindert wird, dass der Resttoner an der Innenfläche der Halbschale 21 haften bleibt.
• c) Als dritte Lösung kann das zur Funktion der Halbschale 21 erforderliche Potential P2 herangezogen werden. Wie aus 6 ersichtlich ist, kann an der Innenfläche 27 der elektrisch nicht leitenden Halbschale 21 eine Elektrode 28 angebracht werden, an die das Potential P2 angelegt wird. 6a zeigt die Seitenansicht der Halbschale 21, 6b die Vorderansicht der Halbschale 21. Die Wirkung wird verbessert, wenn entsprechend 7 mehrere Elektroden 29 an der Innenfläche 27 der Halbschale 21 angeordnet werden. Z. B. sind bei der Ausführungsform der 7 sechs Elektroden 29 an der Innenfläche 27 der Halbschale 21 vorgesehen. Wenn an diese Elektroden 29 abwechselnd unterschiedliche Potentiale angelegt werden, kann durch die unterschiedlich erzeugten elektrischen Feldkräfte verhindert werden, dass sich Resttoner an der Innerseite der Halbschale 21 absetzt. Z. B. kann an die Hälfte der Elektroden 29 0 V angelegt werden, an die andere Hälfte 400 V. 7a zeigt dabei die Halbschale 21 in Seitenansicht, 7b in Vorderansicht. Die Ausführungsform der 7 kann mit den Ausführungsformen 4 oder 5 kombiniert werden, da die Bereiche der Halbschale 21, an der der Resttoner nicht in Richtung zur Halbschale 21 gezogen wird, von dort haftendem Resttoner durch die Gemischbürste leichter gereinigt werden kann.

By choosing the number of magnets and their polarity can be achieved that a deposit of residual toner on the half shell 21 is avoided.

• b) In a second solution may be a deposit of residual toner 12 on the half shell 21 be minimized when the half shell 21 at least on the inside with an anti-adhesive material, eg. B. Teflon coated, which prevents the residual toner on the inner surface of the half-shell 21 sticks.
• c) As a third solution, this may affect the function of the half shell 21 required potential P2 are used. How out 6 It can be seen on the inner surface 27 the electrically non-conductive half shell 21 an electrode 28 are attached, to which the potential P2 is applied. 6a shows the side view of the half-shell 21 . 6b the front view of the half shell 21 , The effect is improved, if appropriate 7 several electrodes 29 on the inner surface 27 the half shell 21 to be ordered. For example, in the embodiment of the 7 six electrodes 29 on the inner surface 27 the half shell 21 intended. When to these electrodes 29 alternately different potentials are applied, can be prevented by the differently generated electric field forces that residual toner on the inside of the half-shell 21 settles. For example, you can connect to half of the electrodes 29 0 V are applied, to the other half 400 V. 7a shows the half shell 21 in side view, 7b in front view. The embodiment of the 7 can with the embodiments 4 or 5 combined because the areas of the half shell 21 where the residual toner is not going towards the half shell 21 is drawn from there adhering residual toner through the mixture brush easier to clean.

To optimize the cleaning of the cleaning roller 17 several parameters can be set: length of the cleaning zone 20 ; Depth of the cleaning zone 20 ; Number of electrodes; Potentials P at the electrodes; Design of the magnet arrangement.

IT

developer station

P

electrical potential

1

Developers stock

2

Developers excavators

3

inking

4

developer

5

carrier

6

toner

7

rolling shell

8th

stator

9

magnet

10

developer roller

11

Charge image carrier

12

Waste toner

13

cleaning roller

14

stator

15

magnet

16

developer

17

cleaning roller

18

shell-like medium

19

gap

20

cleaning zone

21

half shell

22

developer mixture

23

magnet assembly

24

magnets

25

magnet assembly

26

magnets

27

palm the Bowl

28

electrode

29

electrodes

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6246856 B1 [0001, 0001]
• DE 102004059532 A1 [0001, 0003]
• WO 03/036393 A2 [0002, 0025, 0025]
• US 2005/0036806 A1 [0002, 0025]

Claims (14)

Arrangement for removing electrically charged toner from the surface of a toner-transporting roller in an electrographic printer or copier, in which the roller ( 17 ) is at a first electrical potential (P1), the toner to the surface of the roller ( 17 ) pulls, in the direction of rotation of the roller ( 17 ) seen laterally adjacent a cup-shaped means ( 18 ), - as the cleaning zone ( 20 ) such a gap ( 19 ) to the roller ( 17 ) has the toner through the cleaning zone ( 20 ) between roller ( 17 ) and bowl-shaped means ( 18 ) is running without jamming, which is due to such a second electrical potential (P2), that the toner from the surface of the roller ( 17 ) and towards the bowl-shaped means ( 18 ), in which the surface of the roller ( 17 ) dissolved toner at the exit of the purification zone ( 20 ) between roller ( 17 ) and bowl-shaped means ( 18 ) from the purification zone ( 20 ) falls out. Arrangement according to claim 1, wherein the cup-shaped means ( 18 ) one to the surface shape of the roller ( 17 ) adapted shell ( 21 ). Arrangement according to Claim 2, in which the shell ( 21 ) is a half-shell. Arrangement according to Claim 2 or 3, in which the shell ( 21 ) consists of electrically non-conductive material, the inside over the width of an electrode ( 28 ), at which the second electrical potential (P2) is applied. Arrangement according to one of claims 1 to 4, wherein the shell ( 21 ) is coated at least in the interior with an anti-adhesive material. Arrangement according to one of claims 1 to 5, - in which by the cleaning zone ( 29 ) between roller ( 17 ) and shell ( 21 ) a developer mix ( 22 ) is conducted from toner and magnetic carrier, which from the surface of the roller ( 17 ) removes detached toner, - in which the gap between shell ( 21 ) and roller ( 17 ) is selected such that the residual toner and the developer mixture ( 22 ) between roller ( 17 ) and shell ( 21 ) can run without congestion and without pinching. Arrangement according to Claim 6, in which, inside the roller ( 17 ) at least in the area opposite the shell ( 21 ) a magnet arrangement ( 23 ) is provided, the alternately poled magnets ( 24 ) having. Arrangement according to Claim 7, in which the magnets ( 24 ) are spaced apart. Arrangement according to Claim 7, in which the magnets ( 26 ) lie next to each other. Arrangement according to one of Claims 5 to 8, in which the shell ( 21 ) consists of electrically non-conductive material, the inside of several isolated from each other electrodes ( 29 ), at which different electrical potentials (P3) are applied. Arrangement according to one of the preceding claims, in which the roller ( 17 ) is a cleaning roller that cleans residual toner from another roller. Method of removing toner from the surface a toner-transporting roller in which an arrangement according to one of claims 1 to 11 is used. Developer station for an electrographic printer or copier, - in which a inking roller ( 3 ), which is a developer mix ( 4 ) of carrier ( 5 ) and toner ( 6 ) to a developer roller ( 10 ) transported by the inking roller ( 3 ) at least toner ( 6 ) and moves it past a charge image carrier to charge images on the charge image carrier ( 11 ) with toner ( 6 ), - in which a cleaning roller ( 17 ) adjacent the developer roller ( 10 ), which after development on the developer roller ( 10 ) remaining residual toner ( 12 ), wherein the cleaning roller ( 17 ) is at a first electrical potential (P1), the toner from the developer roller ( 10 ) to the surface of the cleaning roller ( 17 ), - in the direction of rotation of the cleaning roller ( 17 ) seen laterally adjacent a cup-shaped means ( 18 ) arranged to produce a cleaning zone ( 20 ) such a gap ( 19 ) with the cleaning roller ( 17 ) forms the residual toner through the purification zone ( 20 ) between cleaning roller ( 17 ) and bowl-shaped means ( 18 ) passes unhindered through, - in which the cup-shaped means ( 18 ) is at such a second electrical potential (P2) that the residual toner from the surface of the cleaning roller ( 17 ) and towards the bowl-shaped means ( 18 ), - in which the surface of the cleaning roller ( 17 ) dissolved toner at the exit of the purification zone ( 20 ) between cleaning roller ( 17 ) and bowl-shaped means ( 18 ) from the purification zone ( 20 ) falls out. Developer station according to Claim 13, in which the cup-shaped means ( 18 ) a half-shell ( 21 ) is.