KR100346700B1 - Apparatus for prohibiting jam for liquid electrophotographic printer - Google Patents

Abstract

The jam prevention apparatus of the disclosed wet electrophotographic printer includes: a transfer roller which is in close contact with the photosensitive medium and transfers a toner image on the photosensitive medium while being driven by rotation of the photosensitive medium; A feeding roller driven by the transfer roller and the cleaning roller to feed the printing paper passed between the transfer roller and the fusing roller into the discharge passage; And a cleaning roller which is in contact with the transfer roller and the feeding roller at the same time and driven by the transfer roller and the feeding roller. The cleaning roller may flatten the foreign substances on the surface of the transfer roller transferred by the surface energy difference with the feeding roller. Equipped.

Description

Apparatus for prohibiting jam for liquid electrophotographic printer

The present invention relates to a jam prevention apparatus of a wet electrophotographic printing press, and in particular, by contacting the transfer roller and the feeding roller at the same time to clean the foreign material on the surface of the transfer roller and at the same time the foreign material on the surface of the cleaning roller feeding roller The present invention relates to a jam prevention apparatus for a wet electrophotographic printing press having an improved structure to flatten a cleaning roller.

In general, the wet electrophotographic printing machine, as shown in FIG. 1, is adjacent to the circulation path of the photosensitive belt 14 which is circulated by the plurality of rollers 11, 12, and 13 on the endless track. 15), a laser scanning unit 16, a developing unit 17, a drying unit 18, and a transfer unit 20.

Looking at the printing process of the printer having the above configuration, first to form a new electrostatic latent image on the surface of the photosensitive belt 14, the reset device 15 initializes the photosensitive belt 14, the laser scanning unit 17 is to print Light corresponding to the image information is scanned by the photosensitive belt 14 to form an electrostatic latent image. Thereafter, the developing solution is developed in the electrostatic latent image area of the photosensitive belt 14 by the developing unit 17, and only the toner component remains in the developing solution by the drying unit 18, leaving only the toner image on the photosensitive belt 14. . This toner image on the photosensitive belt 14 which is circulated is transferred from the transfer unit 20 to the transfer roller 21. The toner image transferred to the transfer roller 21 is transferred to the printing paper 26 fed between the transfer roller 22 and the fusing roller 24 by the paper feeder 30 so that a desired image is transferred to the paper 23. Is printed. On the other hand, the paper 26 passing between the transfer roller 22 and the fusing roller 24 is separated from the surface of the transfer roller 22 by a claw 29 to feed the feeding roller 27 and the feeding back-up roller ( 29) and exits the press.

However, the surface of the transfer roller 22 is contaminated by foreign matter such as dust in the process of performing a printing operation for a long time. Thus, when the transfer roller 22 is contaminated, the printing paper P is contaminated by the contaminant. There is a risk of foreign matter on the images transferred to the camera.

In addition, since the feeding roller 27 is pressurized by the feeding back-up roller 28 to a value smaller than the pressing force applied between the transfer roller 22 and the fusing roller 24, it is shown in Figs. As described above, the printing paper 26 is scratched by the claw 29 to damage the surface of the printing paper 26, or the printing paper 26 is rolled between the surface of the claw 29 and the transfer roller 22 even during the discharge process of the printing paper 26. There is a fear that a wrap jam phenomenon may occur.

The present invention has been conceived in view of the above problems, the surface of the transfer roller is contaminated by foreign matter jams of the wet electrophotographic printing machine with an improved structure to prevent jams such as image defects, rap jams generated during the printing operation The object is to provide a prevention device.

1 is a view schematically showing the configuration of a wet electrophotographic printing press according to the prior art.

2 and 3 are views for explaining the feeding operation of the transfer unit of the printer shown in FIG.

Figure 4 is a schematic view showing a jam prevention device of a wet electrophotographic printing press according to a preferred embodiment of the present invention.

5 is a cross-sectional view showing a feeding roller portion shown in FIG.

<Description of the symbols for the main parts of the drawings>

32 ... Photosensitive medium 34 ... Transfer roller 36 ... Fusing roller

38.Printing paper 40 ... Feeding roller 42 ... Clow

44 ... cleaning roller 45 ... heat source 46 ... backup roller

48.Feeding Backup Roller

The present invention for achieving the above object is a transfer roller which is in close contact with the photosensitive medium and transfers the toner image on the photosensitive medium while being driven by rotation of the photosensitive medium; A feeding roller driven by the transfer roller and the cleaning roller to feed the printing paper passed between the transfer roller and the fusing roller into the discharge passage; And a cleaning roller which is in contact with the transfer roller and the feeding roller at the same time and driven by the transfer roller. The cleaning roller may flatten the foreign material on the surface of the transfer roller transferred by the difference in surface energy when the contact is made. It includes;

Here, the cleaning roller is formed of an ink coated roll coated with nylon or ink on its outer circumferential surface to have a higher surface energy than the transfer roller, and has a surface energy of 25 dyne / cm to 100 dyne / It has a adsorption layer which is cm.

The cleaning roller has a heat source therein so that its surface temperature is higher than that of the transfer roller.

The feeding roller is rotated at a predetermined rotational speed faster than the transfer roller, and is preferably pressed by a predetermined pressing force by the feeding back-up roller.

And a feeding roller slip means for slipping the feeding roller when a load is generated on the printing paper passed between the transfer roller and the fusing roller by the feeding roller.

And a feeding roller slip means for slipping the feeding roller when a load is generated on the printing paper passed between the transfer roller and the fusing roller.

Here, the feeding roller slip means includes: a gear member coaxially installed on one end shaft of the feeding roller to rotate independently of the feeding roller by gear engagement; coaxial with the shaft to be in close contact with the gear member side by an elastic member. Pressing member installed as; A friction member interposed between the gear member and the pressing member to slip the pressing member with respect to the gear member when a load of the feeding roller is generated; And a stopper member which fixes the gear member on the shaft with respect to the elastic force of the elastic member.

The friction member is characterized by consisting of a felt (felt) material.

The stopper member includes a washer portion installed on the shaft to be in contact with the gear member; And a ring part fixed to the shaft to be in contact with the washer part.

The feeding roller is rotated about 0.05 in / sec faster than the rotational linear velocity of the transfer roller.

On the surface of the feeding roller, a Teflon coating layer is formed to prevent reverse transfer of ink.

Hereinafter, a jam prevention apparatus of a wet electrophotographic printer according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a schematic diagram showing a jam prevention device of a wet electrophotographic printer according to a preferred embodiment of the present invention.

As shown, the jam prevention device is a transfer roller 34 driven by the photosensitive medium 32 which is circulated and the printing paper 38 passed between the transfer roller 34 and the fusing roller 36. Feed roller (40) for feeding to the discharge path not shown, and the transfer roller 34 and the cleaning roller 44 that can be in contact with the feeding roller 40 at the same time. Reference numeral 42 is not shown so that the leading edge of the printing paper 38 does not stick to the surface of the transfer roller 34 when the printing paper 38 passes through the nip formed between the transfer roller 34 and the fusing roller 36. The claw 42 provided with the injection part 41 which injects the air supplied from the predetermined | prescribed predetermined supply source is shown. Reference numeral 46 denotes a backup roller on which the photosensitive medium 32 is supported and circulated.

The transfer roller 34 is in close contact with the photosensitive medium 32, and is transferred to the toner image T on the photosensitive medium 32 by the surface energy difference from the photosensitive medium 32. Transfer roller 34 is heated to about 80 to 95 ℃ by a predetermined heating source not shown. The fusing roller 36 is installed so as to be pressurized to the transfer roller 34 at a predetermined pressure, and the toner image transferred to the transfer roller 34 is fixed to the printing paper 38. The surface of the fusing roller 36 is preferably heated to about 100 ℃ to 115 ℃. In addition, the transfer roller 34 and the fusing roller 36 are each coated with a rubber on the outer periphery of the aluminum core.

The feeding roller 40 has a Teflon coating layer formed on its surface to minimize surface energy. Further, the feeding roller 40 is rotated by a predetermined driving source, not shown, and is pressed by a feeding back up roller 48 at a pressing force of about 5 kg _f . If the rotational linear velocity of the transfer roller 34 is about 3.2 in / sec, the rotational linear velocity of the feeding roller 40 is preferably set to about 3.25 in / sec. This is because the transfer roller 34 and the fusing roller are provided by a feeding roller slip means to be described later instead of making the pressing force pressed by the feeding back-up roller 48 to the feeding roller 40 stronger than the conventional one and increasing the rotation linear speed thereof. This is because the so-called rap jam phenomenon that the printing paper 38 is curled to the surface of the claw 42 and the transfer roller 34 during the high load or the feeding operation at 36 can be prevented.

As shown in FIG. 5, the feeding roller slip means is pressurized toward the gear member 50, the pressing member 52, and the gear member 50 which are coaxially installed at one end of the feeding roller 40 to the shaft 40a. The elastic member 54, the friction member 56 and the gear member 50 interposed between the gear member 50 and the pressing member 52, which are in close contact with the member 52, are not pushed to the end of the shaft 40a. The stopper member 58 which consists of the ring part 60 and the washer part 59 is provided.

The cleaning roller 44 is driven by contacting the transfer roller 34 and the feeding roller 40 at the same time. Therefore, the transfer roller 34 in contact with one side of the rotating cleaning roller 44 can be cleaned by transferring foreign matter present on the surface to the cleaning roller 44 by the surface energy difference, and the cleaning roller 44 The feeding roller 40 in contact with the other side of the feeding roller 40 compacts the surface of the cleaning roller 44 such that foreign matter transferred to the surface of the cleaning roller 44 is flat on the surface of the cleaning roller 44. Therefore, the foreign matter on the surface of the cleaning roller 44 can maintain a smooth gel state, and is in contact with the transfer roller 34 while the surface is flattened. Since the foreign matter is flattened on the surface of the cleaning roller 44 in a gel state, the cleaning efficiency of the cleaning roller may be increased.

To this end, the cleaning roller 44 is preferably moved by a drive source (not shown) such as a cam member to be in contact with the transfer roller 34 and the feeding roller 40 at the same time or spaced apart at the same time. In addition, the cleaning roller 44 has a support layer 44a made of metal and an adsorption layer 44b coated on the outer circumferential surface of the support layer 44a. The adsorption layer 44b has a surface energy higher than that of the transfer roller 34, and preferably has a surface energy of 25 dyne / cm or more and less than 100 dyne / cm. Here, the materials having such surface energy include nylons such as nylon 6 (Nylon-6) and nylon 12 (Nylon-12), and the ink is directly coated and dried at 80 ° C. for about 1 hour. There is an ink coating roll. Therefore, foreign matter present on the surface of the transfer roller 34 having a surface energy of less than 25 dyne / cm may be transferred to the adsorption layer 44b by the difference in surface energy. On the other hand, the cleaning roller 44 is heated by the heat source 45 provided inside the support layer 44a, and its surface temperature is about 15 ° C to 20 ° C higher than that of the transfer roller 34, so that the cleaning roller 44 is cleaned from the transfer roller 34. It is desirable to increase the possibility that the foreign matter can be transferred to the (34) side.

Referring to the operation of the jam prevention device of the wet electrophotographic printer according to a preferred embodiment of the present invention having the above configuration.

First, at the beginning of the printing operation, the cleaning roller 44 is spaced apart from the transfer roller 34 and the feeding roller 40, respectively. However, when the printing operation is repeated for a long time and the surface of the transfer roller 34 is inevitably contaminated by foreign matter such as dust, the cleaning roller 44 is moved to contact the transfer roller 34 and the feeding roller 40, respectively. The cleaning roller 44 is driven by the frictional force of the transfer roller 34. Alternatively, the cleaning roller 44 may be configured to be moved by elapse of a predetermined time so as to periodically clean the surface of the transfer roller 34.

Here, the cleaning roller 44 is in contact with the transfer roller 34 and at the same time operate the heat source 45 so that the temperature of the adsorption layer 44a is about 15 to 20 ℃ higher than the transfer roller. For this purpose, a thermistor not shown may be installed around the cleaning roller. Then, foreign matter on the surface of the transfer roller 34 is cleaned while being transferred to the adsorption layer 44b of the cleaning roller 44 by the difference in the surface energy between the transfer roller 34 and the cleaning roller 44. The foreign matter is compacted on the surface of the cleaning roller 44 by the feeding roller 40 in contact with the rotating cleaning roller 44 and flattened by the heat source 45. Therefore, even if the foreign matter thus smoothed is continuously rotated in contact with the transfer roller 34, the cleaning roller 44 can increase the cleaning efficiency because the surface of the cleaning roller 44 is kept flat.

The jam prevention lip device of the wet electrophotographic printing machine having the above configuration is attached to the transfer roller and the feeding roller at the same time to clean the surface of the transfer roller and at the same time to flatten the cleaned foreign material and transfer it back to the transfer roller. Preventing damage to the surface of the transfer roller to increase the cleaning efficiency, there is an advantage that can prevent the occurrence of jams caused by the contamination of the transfer roller surface.

In addition, by rotating the feeding roller of the slip structure faster than the conventional one so that the rotational speed can be adjusted according to the load variation, the printing paper discharged to the feed passage by the feeding roller and the feeding back-up roller is scratched on the surface of the claw or the claw and transfer roller. You can prevent rap jams from rolling in.

Claims (10)

A transfer roller that is in close contact with the photosensitive medium and transfers a toner image on the photosensitive medium while being driven by rotation of the photosensitive medium; A feeding roller driven by the transfer roller and the cleaning roller to feed the printing paper passed between the transfer roller and the fusing roller into a discharge passage; And Contact with the transfer roller and the feeding roller at the same time can be driven by the transfer roller and the feeding roller, the foreign matter on the surface of the transfer roller transferred by the surface energy difference at the time of contact can be flattened by the feeding roller And a cleaning roller having a jam preventing device of the wet electrophotographic printing machine. The method of claim 1, The cleaning roller is formed of nylons or ink coated rolls on its outer circumferential surface to have a higher surface energy than the transfer roller, and has an adsorption layer having a surface energy of 25 dyne / cm to 100 dyne / cm. An anti-jamming device for a wet electrophotographic printing press. The method of claim 1, And the cleaning roller has a heat source therein so that the surface temperature thereof is higher than that of the transfer roller. The method of claim 1, The feeding roller has a rotational linear speed that is rotated faster by a predetermined rotation speed than the transfer roller, and the jam prevention apparatus of the wet electrophotographic printing machine, characterized in that is pressed by a predetermined pressing force by the feeding back-up roller. And a feeding roller slip means for slipping the feeding roller when a load is generated in the printing paper passed between the transfer roller and the fusing roller by the feeding roller. Device. The method of claim 1, And a feeding roller slip means for slipping the feeding roller when a load is generated on the printing paper passed between the transfer roller and the fusing roller. The method of claim 5, wherein the feeding roller slip means: A gear member installed coaxially with one end shaft of the feeding roller to rotate independently of the feeding roller by gear engagement; A pressing member coaxially mounted to the shaft to be in close contact with the gear member by an elastic member; A friction member interposed between the gear member and the pressing member to slip the pressing member with respect to the gear member when a load of the feeding roller is generated; And And a stopper member for fixing the gear member on the shaft with respect to the elastic force of the elastic member. The method of claim 6, The friction member is a jam prevention device of a wet electrophotographic printing machine, characterized in that the felt (felt) material. The method of claim 6, The stopper member includes a washer portion installed on the shaft to be in contact with the gear member; And And a ring portion fixed to the shaft to be in contact with the washer portion. The method of claim 1, And the feeding roller is rotated about 0.05 in / sec faster than the rotational linear speed of the transfer roller by a nip (roller contacting portion). The method of claim 1, The jam prevention apparatus of the wet electrophotographic printing machine, characterized in that the Teflon coating layer is formed on the surface of the feeding roller.