KR100433537B1 - Image transfer belt cleaning apparatus for liquid electrophotographic printer - Google Patents

Abstract

The transfer belt cleaning apparatus of the disclosed wet electrophotographic printing machine is for removing contaminants remaining on the transfer belt that is supported by a plurality of support rollers, and is a region other than an image region formed on the transfer belt while being selectively detached from the transfer belt. A cleaning roller for removing contaminants present in the phosphorous non-image area; And a backup roller installed to rotate while facing the cleaning roller with the transfer belt interposed therebetween. According to this configuration, the cleaning roller removes contaminants present in the non-imaging region of the transfer belt, thereby preventing contamination of the transfer roller by the contaminants present in the non-image region, thereby transferring transfer efficiency from the transfer belt to the recording medium. Can improve. In addition, it is possible to reduce the load of the cleaning blade for removing residual images remaining after the images formed on the transfer belt are transferred to the recording medium.

Description

Image transfer belt cleaning apparatus for liquid electrophotographic printer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer belt cleaning apparatus of a wet electrophotographic printing press, and more particularly, to a transfer belt cleaning apparatus for removing a contaminant present in a non-image region, which is a region other than an image region formed on a transfer belt. .

An electrophotographic printing press charges the photosensitive medium, scans the laser beam onto the charged photosensitive medium, and selectively exposes the electrostatic latent image of a predetermined pattern, and then develops the electrostatic latent image into a toner image of a predetermined color using a developer. do. In general, the toner used in the developing machine is cyan, magenta, yellow, and black, and the toners are formed on the transfer belt so that the four colors overlap each other. Each is transferred to form a complete color image. Then, the recording paper stored in the cassette is fed to the transfer roller side in contact with the transfer belt by the pickup roller and rotated so as to transfer the color image. Next, printing is performed by fixing the image under heat and pressure while passing between the heating roller and the pressure roller serving as the fixing unit. The recording paper on which the fixing is completed is discharged to the outside of the printing machine to complete printing on one recording paper.

The electrophotographic printing machine that functions as described above includes a dry type using a powdered toner as a developer, and a wet type using a developer in which a liquid solvent and a powdered toner are mixed. Among these two methods, a wet type that can prevent damage due to excellent print quality and harmful toner dust is mainly employed and used. An example of such a wet electrophotographic printer is shown in FIG.

Referring to FIG. 1, a wet electrophotographic printer includes a plurality of photosensitive drums 160 prepared to correspond to each color as a charged photosensitive medium, and a laser beam is scanned on each of the photosensitive drums 160 so that a predetermined pattern of electrostatic power is applied. An exposure apparatus 170 for forming a latent image, a plurality of developing units 180 for developing the latent electrostatic image with the respective developer for each color, a drive roller 112, a steering roller 113, and a tension roller 114. The transfer belt 100 is supported in a closed curve shape and circulated along the endless track.

Here, the toner images formed on the respective photosensitive drums 160 are moved onto the transfer belt 100 by an electrostatic force acting between the photosensitive drums 160 and the transfer belt 100 to form a first primary transfer. The first toner images thus transferred are sequentially superimposed on the transfer belt 100 to form a complete color image. Next, the color image formed on the transfer belt 100 has a mechanical force acting between the drive roller 112 and the transfer roller 115 and an electrostatic force acting between the transfer belt 100 and the transfer roller 115. Is moved to the recording paper S, whereby the second transfer is made.

However, after the second transfer process from the transfer belt 100 to the recording paper S, the remaining image remains on the transfer belt 100, and when the printing operation is repeated, the transfer belt 100 passes through the transfer belt 100. Since the color image is repeatedly transferred, the surface of the transfer belt 100 gradually becomes contaminated over time. Therefore, in order to maintain a clear printing state, a cleaning device for removing the residual image from the transfer belt 100 is required. Accordingly, the wet electrophotographic printing machine has a first cleaning blade 120 for removing residual images remaining on the transfer belt 100 after the color image is transferred from the transfer belt 100 to the recording paper S. It is provided.

On the other hand, the transfer belt 100 is divided into an image region which is a region where a color image is formed and a non-image region which is an area other than the image region so that the color image can be accurately transferred onto the recording paper S supplied. If the supplied recording paper S is two or more sheets, the area between the image area and the image area becomes a non-image area. In this way, the control of the position at which the image area is formed on the electromagnetic belt 100 in response to the supplied recording paper S is performed by the image control unit 190 adjusting the timing of the exposure start of the exposure apparatus 170.

However, even if the residual image remaining on the transfer belt 100 after the color image is secondarily transferred onto the recording paper S is removed by the first cleaning blade 120, it is difficult to completely remove the portion, and a part thereof is still intact. It remains and acts as a pollution source of the transfer belt (100). Due to such a pollution source, the remaining image remains in the non-image region as well as the image region newly formed on the transfer belt 100 in accordance with the continuous printing operation.

In addition, the charging voltage of the photosensitive drum 160 and the developing voltage of the developing roller 181 are slightly changed according to the change of the printing environment such as temperature or humidity, and due to this change, the non-image area on the transfer belt 100 is also changed. Fine toner particles are present, and the fine toner particles present in the non-image area serve as a contamination source of the transfer belt 100.

As described above, since the pollutants existing in the non-image area on the transfer belt 100 are not transferred to the recording paper S, they directly contaminate the transfer roller 115, and the contamination of the transfer roller 115 causes the transfer belt 100 to be contaminated. ), The transfer efficiency of the color image transferred to the recording paper S is reduced. In addition, there is a problem that excessive load is applied to the first cleaning blade 120 to remove not only an image area on the transfer belt 100 but also a source of contamination present in the non-image area.

SUMMARY OF THE INVENTION The present invention has been made in view of the above necessity, and the transfer belt cleaning of a wet electrophotographic printing machine having an improved structure to remove contaminants present in a non-image area, which is an area other than the image area formed on the transfer belt. The purpose is to provide a device.

1 is a configuration diagram schematically showing a wet electrophotographic printing machine employing a conventional transfer belt cleaning apparatus;

Figure 2 is a schematic view showing a wet electrophotographic printing machine employing a transfer belt cleaning apparatus according to an embodiment of the present invention,

3 is a view showing a cleaning roller detachment apparatus for attaching and detaching the cleaning roller shown in FIG. 2 to the transfer belt.

<Description of Symbols for Major Parts of Drawings>

100 ... Transfer belt 111 ... Transfer backup roller

112 ... Drive Roller 113 ... Steering Roller

114 ... tension roller 115 ... transfer roller

120 ... 1st cleaning blade 130 ... cleaning roller

140.Backup roller 150 ... 2nd cleaning blade

160 ... photosensitive drum 170 ... exposure

180 ... developing 190 ... image control unit

200 ... Cleaning roller removal device 201 ... Rotary support member

202..Guide member 203 ... Cam member

S ... Recording paper M ... Motor

The transfer belt cleaning apparatus of the wet electrophotographic printing machine of the present invention for achieving the above object is to remove the contamination source remaining on the transfer belt which is supported by a plurality of support rollers, and selectively detachable from the transfer belt. A cleaning roller for removing contaminants present in a non-image area, which is an area other than the image area formed on the transfer belt; And a backup roller installed to be rotatable facing the cleaning roller with the transfer belt interposed therebetween.

The transfer belt cleaning apparatus may further include a cleaning blade installed to be in contact with the cleaning roller to remove the pollutant present in the cleaning roller.

In addition, the cleaning rollers are preferably provided at the rear of the plurality of developers for developing the electrostatic latent image formed on the surface of the photosensitive medium into a predetermined toner image.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic diagram illustrating a wet electrophotographic printing machine employing a transfer belt cleaning device according to an exemplary embodiment of the present invention. Here, the same reference numerals as those shown in Fig. 1 represent the same components having the same function.

Referring to the drawings, the transfer belt cleaning apparatus of the wet electrophotographic printing press according to an embodiment of the present invention, the first cleaning blade for removing the residual image remaining on the transfer belt 100 after being transferred to the recording paper (S) 120 and the rear of the developing unit 180 for developing the electrostatic latent images formed on the respective photosensitive drums 160 with the respective developer for each color, are selectively detached from the transfer belt 100 and the transfer belt 100. And a plurality of cleaning rollers 130 for removing contaminants present in non-image areas, which are areas other than the image area formed on the front side, and facing the plurality of cleaning rollers 130 with the transfer belt 100 interposed therebetween. A plurality of backup rollers 140 are installed so as to be possible, and a plurality of second cleaning blades 150 are installed to be in contact with each of the plurality of cleaning rollers 130 to remove contaminants on the cleaning rollers 130.

On the other hand, Figure 3 shows an example of a cleaning roller detachment device for selectively detaching the cleaning roller to the transfer belt.

Referring to the drawings, the cleaning roller detachable device 200 is a rotation support member 201 for rotatably supporting both ends of the cleaning roller 130, and the rotation support member 201 is guided to slide up and down A guide member 202 and a cam member 203 which rotates according to the driving of the motor M and support the lower surface of the rotation supporting member 201 are provided. In this case, the motor M is driven according to the control signal of the image controller 190.

Therefore, when the cam member 203 rotates by the motor M driven according to the control signal of the image control unit, the rotation support member 201 in which the lower surface is closely supported by the cam member 203 is a guide member ( Guided by the 202 to move up and down, the cleaning roller 130, the both ends of which are rotatably supported in accordance with the up and down movement of the rotary support member 201 is selectively detachable to the transfer belt (100).

The operation of the transfer belt cleaning apparatus of the wet electrophotographic printer according to the present invention configured as described above will be described in detail with reference to FIGS. 2 and 3.

As shown, an electrostatic latent image is formed on each of the selectively exposed photosensitive drums 160 according to a control signal of the image controller 190 controlling the start point of exposure for each color, and the electrostatic latent image is developed by the developer 180. By developing the toner image for each color is formed on the photosensitive drum 160. The color toner images formed as described above are sequentially transferred to the transfer belt 100 circulating in one direction. Then, the transfer belt 100 is divided into an image region which is a region where the toner images for each color are sequentially transferred and a non-image region which is a region other than the image region. If the recording paper S supplied is two or more sheets, the non-image area becomes an area between the image area and the image area.

In this case, when the non-image area of the transfer belt 100 passes between the cleaning roller 130 and the backup roller 140 respectively installed at the rear of the developing unit 180, an image control unit for controlling the start point of exposure for each color ( The cleaning roller 130 is in close contact with the backup roller 140 facing the transfer belt 100 with the cleaning roller detachable device 200 controlled according to the control signal of 190. Then, the contamination source existing in the non-image area of the transfer belt 100 is transferred to the cleaning roller 130 by the electrostatic force acting between the cleaning roller 130 and the transfer belt 100 to which a predetermined voltage is applied. In this way, the pollutant transferred to the cleaning roller 130 is removed by the second cleaning blade 150.

According to the transfer belt cleaning apparatus according to the embodiment of the present invention as described above, the residual image remaining on the transfer belt 100 after being transferred to the recording paper (S) is not removed by the first cleaning blade 120 as it is. The remaining toner or the fine toner particles existing in the non-image area on the transfer belt 100 are previously removed by the cleaning roller 130, thereby preventing contamination of the transfer roller 115 in advance. In addition, after the image is transferred onto the recording paper S, the load of the first cleaning blade 120 for cleaning the non-image area on the transfer belt 100 can be reduced.

As described above, the transfer belt cleaning apparatus of the wet electrophotographic printing machine according to the present invention removes the contaminant present in the non-image area of the transfer belt by the cleaning roller, thereby removing the transfer roller by the contamination source present in the non-image area. By preventing contamination, the transfer efficiency from the transfer belt to the recording medium can be improved. In addition, it is possible to reduce the load of the cleaning blade for removing residual images remaining after the images formed on the transfer belt are transferred to the recording medium.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

Claims (4)

It is for removing the contamination source remaining on the transfer belt that is supported by a plurality of support rollers, A cleaning roller which is selectively attached to and detached from the transfer belt and removes a contaminant present in a non-image area of the transfer belt; A backup roller installed to be rotatable facing the cleaning roller with the transfer belt interposed therebetween; And a cleaning roller detaching apparatus for supporting the cleaning roller and detaching the detaching roller from the transfer belt. The method of claim 1, And a cleaning blade installed in contact with the cleaning roller to remove contaminants present in the cleaning roller. The method of claim 1, And the cleaning rollers are respectively installed behind a plurality of developing apparatuses for developing a peak latent image formed on the surface of the photosensitive medium to a predetermined toner image. The method of claim 1, The cleaning roller detachable device is A rotation support member rotatably supporting both ends of the cleaning roller; A guide member for slidably guiding the rotating support member up and down; The transfer belt cleaning apparatus of the wet electrophotographic printer, characterized by comprising a cam member installed below the rotary support member to slide the rotary support member up and down.