JPH0619327A - Excess developer removing device for image recorder - Google Patents

Abstract

PURPOSE:To obtain an image recorder in which excess developer is excellently removed by exerting particulate attracting force on a blade. CONSTITUTION:In the case of excess developer removing operation performed in a state where a developing device is separated from the surface of a rotating drum 13 after developing operation performed with wet developer for electrophotography, the blade T3 is brought into contact with the puddle of the excess developer after development, which flows down at a position near the lowermost part of the drum 13, and voltage is impressed on the blade 73 to generate electric field exerting the attracting force to the developer, so that the excess developer containing the particulates for development is excellently recoverd by the blade 73. The excess developer is collected at the vicinity of the lowermost position of the drum 13 by air pressure from a position nearer to the downstream side of the rotation of the drum than the lowermost position of the drum 13, or the excess developer is collected at the vicinity of the lowermost position of the drum 13 by corona discharge, thereby excellently recovering the excess developer by the blade 73.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing excess developer in an image recording apparatus.

[0002]

2. Description of the Related Art A charge image corresponding to an image is formed on an electrophotographic recording paper, and the charge image is dispersed with developing fine particles containing a colorant and a binder in an electrically insulating liquid. In the image recording apparatus which is made visible by the wet developing solution for electrophotography, in order to prevent fogging of the visualized image, the electrophotographic recording paper of It has been practiced to remove the excess developer remaining on the surface.
As disclosed in Japanese Patent Publication No. 144180, an excess developer removing device using a liquid squeezing roller and a liquid collecting blade,
For example, as disclosed in Japanese Utility Model Publication No. 59-34902, an excess developer removing device using a blade between a developing device and an air knife, for example, Japanese Utility Model Publication No. 54-3731.
As disclosed in Japanese Unexamined Patent Publication No. 3 (1998), various configurations such as an excessive developing solution removing device using an excessive developing solution removing roller and a blade for applying a bias voltage having a reverse polarity to the charges of the electrostatic latent image. Various types of excess developer removing devices have been proposed.

[0003]

However, in the surplus developer removing device disclosed in Japanese Patent Laid-Open No. 62-144180, the liquid removing operation by the liquid squeezing roller and the liquid removing operation by the liquid collecting blade are performed. The removal efficiency is low due to the above-mentioned procedure, and the presence of residual charge causes fogging, and the surface of the rotating drum is also removed by the developing solution. However, in addition to the drawbacks such as causing color mixing, a developer suction device is provided inside the rotating drum, which causes a problem of liquid clogging that complicates the structure. The excess developer removing device disclosed in Japanese Patent Publication No. 59-34902 has a structure in which the blade for removing liquid is close to the image area to perform the liquid removing operation. Can't ignore Not only, cause fogging due to residual charge, the actual Sho 54 over the previously described 37 313
In the excess developer removing device disclosed in Japanese Patent Publication, since the developing particles are attracted to the electrophotographic recording paper by applying an electric field to prevent the developing particles from adhering to the blade. The problem of fogging occurs. Therefore, the emergence of an excess developer removing device that does not cause the above problems has been desired.

[0004]

According to the present invention, a charge image corresponding to an image is formed on an electrophotographic recording paper, and the charge image is contained in an electrically insulating liquid containing a colorant, a binder and the like. A developing device for removing excess developer in an image recording apparatus, which is made visible by a wet developing solution for electrophotography, in which the developed fine particles are dispersed, and is a rotary drum for winding and carrying electrophotographic recording paper. When the developing operation is completed, the blade is brought into contact with the trailing end portion of the recording paper in which the excess developing solution that has flowed near the lowermost position of the In addition, the excess developer removing device in the image recording device, in which the blade is provided with a means for generating an electric field that exerts an attractive force on the electric charge of the developing fine particles, and the electrophotographic recording paper is wound and carried. The excess developer is collected near the lowermost position of the rotating drum by air pressure from the downstream side of the drum rotation than the lowermost position of the rotating drum, and the excess developer flowing down near the lowermost part of the rotating drum is recorded. The blade is brought into contact with the trailing edge of the paper or the accumulated excess developer at the end of the developing operation, and an attraction force is applied to the electric charge of the developing particles on the blade only when the blade is in the contact operation. Excessive developer removing device in an image recording apparatus provided with a means for generating an electric field to exert, and excess developer collected by corona discharge near the lowermost position of the rotating drum and flowing down near the lowermost position of the rotating drum. The blade is brought into contact with the trailing end portion of the recording paper where the liquid is accumulated or the accumulated excess developing liquid at the end of the developing operation, and Providing excess developer liquid removing apparatus in the image recording apparatus only at the time of the contact operation of the blade formed by providing a means for generating an electric field exerting a suction force to the charge possessed by the developing particles to the blade.

[0005]

The whole or most of the developing electrodes are arranged at a portion closer to the upstream side of the drum rotation than the lowermost portion of the rotating drum, and the developing electrode in the developing portion is wound around the rotating drum. During the operation of removing the excess developing solution by separating the developing device from the surface of the rotating drum after the developing operation performed by the electrophotographic wet developing solution flowing toward the surface of the recording sheet for electrophotography. , The blade is brought into contact with the trailing edge of the recording paper where the excess developing solution that has flowed near the lowermost portion of the rotary drum or the excess developing solution that has accumulated, and only when the blade is in contact operation as described above. An electric field that exerts an attractive force on the electric charge of the developing particles is generated in the blade, and the excess developing solution containing the developing particles is favorably collected by the blade.
Further, excess developer is collected near the lowermost position of the rotating drum by air pressure from a position closer to the downstream side of the drum rotation than the lowermost position of the rotating drum, or the excessive developing solution is corona-discharged to the lowermost position of the rotating drum. The trailing edge of the recording paper where the excess developer that has flowed to the position near the lowermost part of the rotary drum is collected during the operation of removing the excess developer by collecting the developer in the vicinity and separating the developing device from the surface of the rotary drum. Alternatively, the blade is brought into contact with the accumulated excess developer, and an electric field that exerts an attractive force on the electric charge of the developing fine particles is generated in the blade only when the blade is in contact with the developing fine particles. The excess developer is satisfactorily collected by the blade.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concrete contents of the excess developer removing device in the image recording apparatus of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a side view (a part of which is a sectional view) showing a schematic structure of an image recording apparatus provided with an excessive developing solution removing apparatus in the image recording apparatus of the present invention, and FIGS. 2 to 5 are images of the present invention. FIG. 6 is a top view of the developing device, FIG. 7 is a front cross-sectional view of the elevating device part, and FIGS. 8 to 10 are side views of a part of the device used for explaining the operation of the excess developer removing device in the recording device. It is a side view for explaining operation of a lifting device. First, the schematic configuration of the image recording apparatus will be described mainly with reference to FIG. In FIG. 1, reference numerals 1 and 2 denote side plates of a machine body of the image recording apparatus. Above the side plate 1 of the machine body, one end of a rotary shaft 4 of a roll-shaped electrophotographic recording paper 3 is rotatable. Two bearing plates 5 are fixedly attached to support the other end of the rotary shaft 4 (not shown in the figure). An imaginary line 6 in the figure is a covering member 6 for shielding light.

In order to start image recording by the image recording apparatus, when the operator inputs information on the start of image recording to an input section (not shown), the roll-shaped recording paper for electrophotography 3
Is supplied between the guide plates 7 and 8 of the supply unit and supplied to the supply rollers 9 and 10.
The rotating drum 13 is sandwiched by the supply rollers 9 and 10 whose rotation is controlled under the control of the controller 11.
Sent to. Reference numeral 12 denotes a cutting device having a well-known structure, which includes, for example, a rotary blade and a fixed receiving blade. The cutting device 12 cuts the electrophotographic recording paper 3 under the control of the control device 11. . When the supply of the electrophotographic recording paper 3 is started by the supply rollers 9 and 10 as described above, the starting position regulating member 14 provided above the rotating drum 13 operates under the control of the controller 11. A cam (not shown) lowers the tip of the cam to the surface of the rotating drum 13 which is in the stopped state in this state, and moves forward by the rotation of the supply rollers 9 and 10. At the time when the leading end of the electrophotographic recording paper 3 comes into contact with the above-mentioned starting end position regulating member 14,
A signal generated by a sensor (not shown) is given to the control device 11, and the pressing roller 15 is lowered by the operation of a cam (not shown) so that the vicinity of the beginning of the electrophotographic recording paper 3 is transferred to the rotary drum 13. Crimp.

A shallow groove is provided in the generatrix direction of the rotary drum 13 on the surface of the rotary drum 13 in the portion covered by the vicinity of the leading portion of the electrophotographic recording paper 3, and the groove is formed in the groove. Is provided so that a large number of through holes communicate with the suction port 16 of the suction device provided in the internal space of the rotary drum 13, and a vacuum pump (not shown) is connected to the suction port 16. ing. At the time when the leading end of the electrophotographic recording paper 3 comes into contact with the above-mentioned starting end position regulating member 14, the control device 11 sucks with a vacuum pump at a predetermined timing based on a signal generated from a sensor (not shown). The operation is started so that the leading portion of the electrophotographic recording paper 3 is brought into close contact with the peripheral surface of the rotary drum 13.

As described above, in the state where the leading end position of the leading portion of the electrophotographic recording paper 3 is regulated by the starting end position regulating member 14, the leading portion of the electrophotographic recording paper 3 is sucked by the suction port 16 of the suction device. Immediately after the time when it is brought into close contact with the peripheral surface of the rotary drum 13 by the intake performed from
After the start position regulating member 14 is raised under the control of the controller 11, the rotary drum 13 starts to rotate in the direction of the arrow R in the figure under the control of the controller 11, and the rotary drum 13 is rotated.
The electrophotographic recording paper 3 to be wound around the rotating drum 13 is started under the control of the control device 11 described above. The cutting operation of the cutting device 12 cuts into a length required for image recording, and the rear end portion of the electrophotographic recording paper 3 is also sucked from the suction port 17 of the suction device through the multiple through holes 1. Is brought into close contact with the peripheral surface of the rotary drum 13.

As described above, when the rotary drum 13 in the state where the electrophotographic recording paper 3 of a predetermined size is in close contact with the outer peripheral surface continues to rotate, it is wound around the rotary drum 13. The electrophotographic recording paper 3 is uniformly charged by a charger 18 to which a voltage is supplied from a power supply 19. Reference numeral 21 denotes a rotating mirror wheel, which is rotated at a predetermined rotation speed by a motor 20 to deflect the laser light emitted from the semiconductor laser 22 in a predetermined direction. The semiconductor laser 22 emits laser light whose intensity is modulated by predetermined exposure data including halftone image digital data to be recorded, and the laser light is emitted from the lens 2
3, through the optical system composed of the reflecting mirrors 24, 25, etc., the uniformly charged electrophotographic recording paper 3 is irradiated,
The electrophotographic recording paper 3 is exposed by predetermined exposure data including halftone dot image digital data to be recorded, and the photoconductor of the electrophotographic recording paper 3 is exposed with image information to be recorded. A charge image corresponding to is formed.

A prebath device 26 is mounted on a support plate 27 between the portion where the electrophotographic recording paper 3 is exposed by the laser light and the lowermost portion of the rotary drum 13. The pre-bath device 26 is supplied with the pre-bath liquid from a container 30 of the pre-bath liquid fixed to a bottom plate 29 of the machine body through a pipe 31, and the roller 28 of the pre-bath device 26 uses electrophotographic recording paper. A film of the pre-bath solution is formed on the surface of 3. The excess pre-bath liquid is dropped into the pre-bath device 26 and returned to the pipe 32.
It is collected in the container 30 of the prebath liquid fixed to the bottom plate 29 of the machine body.

The electrophotographic recording paper 3 which has been subjected to the pre-bath treatment in the pre-bath device 26 is then visualized by the developing section. The developing portion (developing device) is provided in the vicinity of the portion immediately below the rotating drum 13 at a portion closer to the upstream side of the drum rotation than the position immediately below the rotating drum 13 described above, and is provided to each of the developing electrodes 33a (developing devices 33 to 37). Developing electrode 33
Among the developing electrodes of the developing devices that are selectively used among a to 37a, the developing device 33 is used in the state shown in the figure, so that all or most of the developing electrodes 33a) are arranged so as to be positioned. . The developing electrode 33a (the same applies to 34a to 37a) of the developing unit 33 (the same applies to 34 to 37).
Has a surface facing the surface of the electrophotographic recording paper 3 wound in close contact with the rotary drum 13 with a small space therebetween, and the surface of the developing electrode 33a can be Is supplied from a container 38 (corresponding to the developing device used in 38 to 42) of the wet developing solution for electrophotography disposed on the bottom plate 29 of the developing device 33 to the developing device 33. The electrophotographic wet developing solution is flowing out or ejected from the through hole 33as (see FIG. 6) formed in the developing electrode 33a, and the electrophotographic wet developing solution is in close contact with the rotating drum 13. By being supplied to the surface of the electrophotographic recording paper 3 which is wound around, the toner corresponding to the charge amount of the charge image of the electrophotographic recording paper 3 is attached to the surface of the electrophotographic recording paper 3. The charge image is visualized.

Since the surface of the above-mentioned developing electrode 33a has an inclination corresponding to the inclination of the surface of the electrophotographic recording paper 3 wound in close contact with the rotary drum 13, the development is performed as described above. Through holes 33as formed in the electrode 33a
The electrophotographic wet developing solution is further discharged or ejected, and the electrophotographic wet developing solution is filled in the gap between the surface of the developing electrode 33a and the surface of the electrophotographic recording paper 3 in the rotating direction of the rotary drum 13. It flows down well and is collected in the developing device 33. The wet developing solution for electrophotography collected in the developing device 33 is collected in a container 38 of the wet developing solution for electrophotography by a pipe 44. In FIG. 1, the containers 38 to 42 of the electrophotographic wet developing solution disposed on the bottom plate 29 of the machine body are different types of electrophotographic wet developing solutions (coloring agent, binder, etc. in the electrically insulating liquid). (Wet developer for electrophotography) in which fine particles for development composed of is dispersed.

As for each of the developing units 33 to 37, one selected from the developing units 33 to 37 is the rotating drum 1 in the vicinity of the portion immediately below the rotating drum 13 as described above.
The developing electrodes are arranged so that all or most of the developing electrodes are located at a portion closer to the upstream side of the drum rotation than the position immediately below 3. In the image recording apparatus shown in FIG. The bottoms of the developing devices 33 to 37 are placed on two transfer bands (for example, chains, belts, etc.) 45 stretched in parallel at a predetermined distance, and the transfer band 45 is indicated by an arrow E in the figure. And move it in the direction of
By the elevating device 49 provided between the book transfer belts 45, one developing unit 33 (34 to 37) on the transfer belt 45 is raised to the above-mentioned predetermined position so that it can be used for the developing processing operation. Of the plurality of developing units 33 to 37 by removing the excess developing solution at a position slightly lowered from the raised position or returning the developing unit to the transfer belt 45. A predetermined one is selected and used. The arrow F in the figure indicates the moving direction of the lifting device. Each of the developing devices 33 to 37 is placed on two transfer belts stretched in parallel at a predetermined interval and in a state where the position is regulated by the interval pieces S, S. Has been done.

The transfer belt 45 (chain) is stretched around the sprockets 46 and 47, and the driving force is transmitted to the driving sprockets under the control of the controller 11.
The supply of driving force may be cut off. Reference numeral 48 is a rail for eliminating the slack of the chain and preventing it from meandering (in the figure, the inside of the two chains stretched in parallel at a predetermined interval). The chained sprocket on the front side is not shown in the figure, and the chain 45 shown in the figure and the sprockets 46 and 47 on which the chain 45 is stretched are
It is the one provided on the back side of the aircraft).

The control device 11 controls the supply state of the driving force to the driving sprocket and transfers one selected one of the developing devices 33 to 37 to the position of the elevating device 49. . The lifting device 49 is the control device 1
Under the control of 1, the cam shaft 5 to which the cam plate 50 is fixed is attached.
When the rotational force is transmitted to the cam plate 5,
With the rotation of 0, the substrate 54 of the elevating member to which the rotation shaft 53 of the roller 52, which is in sliding contact with the cam surface of the cam plate 50, is fixed is moved up or down. 55 is a support. Below the base plate 54 of the elevating member, guide portions 61 and 62 having holes to be fitted into two guide rods 58 and 59 fixed to the mounting plate 56 are fixed, and are also raised and lowered. Above the substrate 54 of the member, the connecting members 62, 6 are provided.
A support base 64 is provided via the unit 3. Lifting device 49
The specific structure of the part is shown in the front sectional view of FIG.

From the state in which the support base 64 of the elevating device is lowered from the height position of the chain 45 on which the developing devices 33 to 37 are placed, the cam plate 50 is raised to rotate. Then, the developing device 33, which was positioned above the support base 64 at that time, is raised to the position of the developing device 33 illustrated in FIG. 1 (and FIGS. 2 and 8), and The predetermined development processing operation as described above can be performed at the position. The developing device 33, which has completed the developing processing operation, supports the support base 64 of the lifting device 49 by the rotation of the cam plate 50 under the control of the control device 11.
3 (or FIG. 5 and FIG. 9) which will be described later, the surplus developer is satisfactorily removed, and then the lifting device 49 is rotated by the rotation of the cam plate 50. The lowering of the support 64 causes the developing device 33 to be placed on the chain 50. In this way, the plurality of developing units 33 to 37 can be selected one by one and used sequentially for the developing processing operation.

When the developing process for the electrophotographic recording paper 3 is completed after the developing process is performed in the developing section, the developing device is lowered by the elevating device 49, but the developing process is performed in the developing section. When an excess developer pool is formed at the trailing edge of the electrophotographic recording paper 3 that has completed the operation, a recorded image with good image quality cannot be obtained, so that a good liquid out state can be obtained. Some means of doing so is required.

Therefore, in the surplus developer removing device in the image recording apparatus of the present invention, the developing device 33 which has completed the developing process for the electrophotographic recording paper 3 and has completed the developing process operation.
However, with the lowering of the support base 64 of the lifting device 49 due to the rotation of the cam plate 50 under the control of the control device 11,
When descending from the position shown in FIG. 1 (and FIG. 2 and FIG. 8), the state of FIG. 3 (and FIG. 9), that is, of the rotary drum for winding and carrying the electrophotographic recording paper is shown. The blade 73 is brought into contact with the excess developer after the development that has flowed to a position near the lowermost portion during the operation of removing the excess developer,
Downstream of drum rotation from the lowermost position of the rotary drum, which is configured to generate an electric field that exerts an attraction force on the charge of the developing fine particles on the blade 73 or which winds and carries the electrophotographic recording paper. From the side, the wind generated in the wind chamber 67 is ejected from the tip 65a of the air guide tube through the air guide tube 65, and the air pressure collects the excess developer near the lowermost position of the rotary drum. The blade 73 is brought into contact with it during the operation of removing excess developer, and the blade 73 is caused to generate an electric field that exerts an attractive force on the electric charges of the developing particles, or the excess developer is removed from the rotating drum by corona discharge. The blade 73 is brought into contact with the excess developer after development collected near the lowest position of the rotary drum and flowing down near the bottom of the rotary drum during the operation of removing the excess developer. Rutotomoni, or by so as to generate an electric field which exerts a suction force to the charge possessed by the developing particles to the blade 73, so that can be satisfactorily remove the excess developer.

FIG. 2 is also shown in FIG. 1 in which the electrophotographic recording paper 3 wound tightly around the outer circumference of the rotary drum 13 is subjected to a developing process by the developing device 33. FIG. 3 is an enlarged side view of the main part near the developing section in the state where the image recording apparatus is performing the developing processing operation as shown in FIG.
Is raised to the uppermost position by the above-mentioned lifting device, and the tip of the developing electrode 33a provided in the developing unit 33 is brought into a state of closely facing the outer peripheral surface of the rotary drum 13. There is. The developing device 33 (34 to 37) described above.
The same applies to the case), which is made of an electrically insulating material (for example, synthetic resin), and 72 in FIGS. 2, 3 and 5 to 10 is a swing shaft. The swing shaft 72 is a bearing 82 provided on one side upper portion of the side plates 80, 81 (see the side plate 81 in FIG. 6) of the casing of the developing unit 33 (the same applies to 34 to 37). 83 (see Figure 6)
Supported by.

Side plates 80 and 81 of the housings of the developing units 33 to 37
The respective ends of the swing shaft 72 protruding from the swing shaft 71 are
After being fitted in the holes provided in the respective side end portions 71a, 71b of the rocking member 71, the respective side end portions 7 of the swing member 71 are screwed by the screws 84, 85.
It is fixed to 1a and 71b. Swing member 71 described above
The vicinity of the tip of each side end 71a, 71b is connected by a blade 73 made of a conductive material. A disk (eccentric disk) 75 is fixed to one side end portion 71b of the rocking member 71 with the center position deviated from the center of the rocking shaft 72. The above-mentioned eccentric disc 75 fixed to the swinging member 71 is shown in FIGS.
When the actuating member 97 shown in FIG. 0 gives a force that is displaced downward in the drawings as described later, the swinging member 71 is as shown in FIGS. 3 and 9. Further, the tip end portion 71c of the swing member is moved upward with the swing shaft 72 as the center of rotation.

Now, as shown in FIGS. 7 to 10, a cam plate 90 is also fixed to the cam shaft 51 to which a cam plate 50 for controlling the lifting operation of the lifting device 49 is fixed. . In FIG. 7, the power from the motor 88 is transmitted to the cam shaft 51 to which the cam plate 90 is fixed via a clutch mechanism and a gear 89 (not shown). The rotation control of the cam shaft 51 described above is performed by the control device 11 to which the control signal generated by the sensor 100 that detects the rotation phase of the cam shaft 51 is applied. Cam shaft 5
A roller 91, which operates as a cam follower, is in contact with the cam surface of the cam plate 90 that is fixed to the No. 1 roller. In other words, the rotation shaft 92 of the roller 91 is the roller support plate 94.
And the roller support plate 94 is urged downward by a spring 93 stretched between the roller support plate 94 and the mounting plate 56.
Is brought into contact with the cam surface of the cam plate 90. A guide portion mounting plate 95 is fixed to the upper end portion of the roller supporting plate 94, and tubular guide portions 98 and 99 fitted to the guide rods 101 and 102 are provided at both ends of the guide portion mounting plate 95.
Is stuck. A lower end portion of a connecting plate 96 is fixed to the guide portion mounting plate 95, and an operating member 97 is fixed to an upper end portion of the connecting plate 96. Therefore, when the cam plates 50 and 90 rotate due to the rotation of the cam shaft 51, the support base 64 of the lifting device 49 moves up and down as described above due to the displacement of the roller 52 that abuts on the cam surface of the cam plate 50. At the same time, the actuating member 97 is moved up and down by the displacement of the roller 91 that contacts the cam surface of the cam plate 90.

Now, from the state shown in FIG. 2 (FIG. 8) in which the developing device 33 (34 to 37) is performing the developing processing operation, the control of the control device 11 is performed after the time when the developing processing operation is completed. The lowering of the support base 64 of the elevating device 49 by the rotation of the cam plate 50 performed below causes the developing device 33 (34-
37) when the developing device 33 (34-3
Compared with the descending amount of 7), the downward displacement amount given to the eccentric disc 75 fixed to the swing member 71 by the operating member 97 that is displaced downward according to the cam surface of the cam plate 90 described above. If the cam surface of the cam plate 90 is configured so as to be larger, the developing device 33 (34 to 37)
2 (FIG. 8) in which the developing processing operation is being performed, the support base 64 of the elevating device 49 is provided after the completion of the developing processing operation.
The descending distance of the swing shaft 72 when the developing unit 33 (34 to 37) descends as the developing unit 33 (34 to 37) reaches the position shown in FIG. 3 (FIG. 9), for example. Compared to Lm, the descending distance Lu of the center position of the eccentric disc 75
Has a relationship of Lm <Lu. Therefore, the rocking member 7
1 rotates about the swing shaft 72 as the center of rotation from the state shown in FIG. 2 (FIG. 8) to the state shown in FIG. 3 (FIG. 9).

The developing unit 33 (34 to 37) is shown in FIG.
From the state during the development processing operation illustrated in (FIG. 8),
After the development processing operation is completed, the descent is started, and then, as shown in FIG.
In the swinging member 71 in the state of performing the excessive developing solution removing operation shown in FIG. 3, the tip of the pin 74 implanted in the swinging member is a stopper in which the mounting member 77 of the spring 76 is configured. It is rotated until it comes into contact with 86, and at that time, the tip portion 71c of the swinging member 71 is fixed to the spring 76.
The voltage supplied from a power source (not shown) connected to the spring
→ The tip 71c of the swinging member 71 is applied to the blade 73 by the path of the blade 73. The mounting member 77 of the spring 76 is fixed to the machine frame 103.
In the state of performing the excess developer removing operation shown in FIG. 3 (FIG. 9), the tip portion of the blade 73 fixed to the swing member 71 is wound around the rotary drum 13 near the lowermost portion of the rotary drum 13. Rotating electrophotographic recording paper 3
Of the electrophotographic recording paper 3 wound around the rotary drum 13, the tip of the blade 73 fixed to the swinging member 71 collects on the surface of the end portion of the electrophotographic recording paper 3. To be in contact with the excess developing solution.

FIG. 4 shows that the tip portion of the blade 73 is against the excess developing solution accumulated on the surface of the end portion of the electrophotographic recording paper 3 wound around the rotary drum 13 as described above. In order to make it easily accessible, the developing device 33
2 (FIG. 8) from the state during the developing process operation illustrated in FIG. 2 (FIG. 8), the descent is started after the completion of the developing process operation and the excess developing solution removing operation is performed. To make the end portion of the electrophotographic recording paper 3 wound around the rotary drum 13 separate from the rotary drum 13 so that the end portion of the electrophotographic recording paper 3 floats above the surface of the rotary drum 13. Thus, the case where the tip of the blade 73 is brought into a state where it can easily contact the surplus developing solution accumulated on the surface of the end portion of the electrophotographic recording paper 3 is illustrated.

By the way, there is a surplus developing solution which adheres to the surface of the electrophotographic recording paper 3 and is moved toward the fixing portion by passing through the vicinity of the lowermost portion of the rotating drum 13 as the rotating drum 13 rotates. However, as described above, since the wind blown in the blower chamber 67 is ejected from the tip 65a of the air guide tube 65 to the vicinity of the lowermost portion of the rotary drum 13 as described above, the excess developer is As described above, the excess developer collected near the lowermost portion of the rotating drum 13 is blown up to the position of the blade 73 that is projected near the lowermost portion of the rotating drum 13, After being attracted by the blade 73 of the swinging member 71 to which a voltage is applied as described above, in a state of being in contact with or extremely close to the surface of the electrophotographic recording paper 3 wound on the rotating drum 13. Brae 73 transmitted by returned to the developing device.

FIG. 2 showing a state in which the development processing operation is being performed.
The developing device 33 (34 to 37) shown in (FIG. 8) is
The surplus developer on the surface is removed by the surplus developer removing operation performed in the state as shown in FIG. 3 (FIG. 9) in the process of the descending operation by the elevating device 49 after the completion of the developing operation. The electrophotographic recording paper 3 is fixed to the fixing unit 66.
After the fixing operation is performed in step S4, the charge is removed by the static eliminator 68, and then the sheet is transported on the guide plate 69 of the sheet discharge unit and discharged to the outside of the machine. Prior to the above-mentioned paper discharge, it is provided in the internal space of the rotary drum 13 which corresponds to the start end region and the end region of the electrophotographic recording paper 3 wound around the rotary drum 13. Air is ejected at a predetermined timing from the intake port to separate the electrophotographic recording paper 3 from the outer periphery of the rotary drum 13. Reference numerals 70 and 7 in FIG.
Reference numeral 0 indicates a heat fixing unit for a planographic printing plate.

In the excess developer removing device in the image recording apparatus of the present invention described above with reference to FIGS. 2 to 4 (and FIGS. 8 and 9), it is attached to the surface of the electrophotographic recording paper 3 and rotated. As the drum 13 rotates, the excess developing solution that has passed through the vicinity of the lowermost portion of the rotating drum 13 and is moved toward the fixing unit is blasted in the blast chamber 67 to generate the tip 65a of the air guide tube 65.
Is collected near the bottom of the rotary drum 13 by the wind blown near the bottom of the rotary drum 13, and the excess developer can be favorably removed by the blade 73 in a state of being projected near the bottom of the rotary drum 13. I was doing
In the excess developer removing device in the image recording apparatus of the present invention shown in FIG. 5, the excess developer is removed by air pressure as in the excess developer removing apparatus in the image recording apparatus of the present invention described above with reference to FIGS. Instead of blowing the developing solution near the bottom of the rotary drum 13 and removing the excess developing solution by the blade 73 protruding near the bottom of the rotating drum 13, the electrophotographic recording paper 3 is By applying a high voltage to the line 78 in the corona charger 79, the excess developer that adheres to the surface and moves toward the fixing section by passing through the vicinity of the lowermost portion of the rotary drum 13 as the rotary drum 13 rotates. The generated ions are applied to the excess developing solution, and the excess developing solution is contracted to push the excess developing solution back to the vicinity of the lowermost portion of the rotary drum 13.
This is an example of a case where the excess developer can be satisfactorily removed by the blade 73 in a state of protruding near the lowermost portion of the rotary drum 13.

As described above, in the excess developing solution removing device in the image recording apparatus of the present invention shown in any of FIG. 3 (FIG. 9) and FIG. 5, the lowermost part of the rotary drum 13 at the time of the excess developing solution removing operation. Since a voltage having a polarity that generates an electric field that exerts a suction force on the excess developer adhering to the surface of the electrophotographic recording paper 3 is applied to the blade 73 protruding at the portion Excessive developer adhering to the surface of the electrophotographic recording paper 3 wound in close contact with the drum 13 can be favorably removed by being sucked by the blade 73 by an electric suction force.

[0030]

As is clear from the above description, the excess developer removing device in the image recording apparatus of the present invention develops in a portion closer to the upstream side of the drum rotation than the lowermost portion of the rotating drum. Wet developing solution for electrophotography, which flows out from the developing electrode in the developing section in which all or most of the electrodes are located toward the surface of the electrophotographic recording paper wound on the rotating drum. After the developing operation performed by the developing device, the blade contacts the excess developing solution that has flowed to the position near the lowermost part of the rotating drum during the removing operation of the excess developing solution that is performed by separating the developing device from the surface of the rotating drum. Then, an electric field that exerts an attractive force on the electric charge of the developing fine particles is generated in the blade so that the excess developing solution containing the developing fine particles is favorably collected by the blade. In addition, the excess developer is collected near the lowermost position of the rotary drum by air pressure from the downstream side of the drum rotation than the lowermost position of the rotary drum, or the excess developer is corona-discharged to the lowest position of the rotary drum. When the excess developer is removed by collecting the developer in the vicinity and separating the developing device from the surface of the rotating drum, the blade is brought into contact with the excess developer after development that has flowed to a position near the lowermost part of the rotating drum. , Generating an electric field that exerts an attractive force on the electric charge of the developing particles on the blade,
Since the excess developer containing the developing fine particles can be favorably recovered by the blade, according to the present invention, the removal of the excess developer, which is likely to remain at the trailing edge of the electrophotographic recording paper, affects the image area. It can be satisfactorily carried out without applying, and fogging that is likely to occur in the step of removing the excess developer can be avoided by applying a voltage to the blade, and further, the voltage supply to the blade is excessive. Since it is performed only during the removal operation of the developing solution, consideration for short circuit of the wiring during the operation of the device is light, and the trailing edge of the electrophotographic recording paper is rotated during the removal operation of the excess developing solution. By making it float above the surface of the drum, the elasticity of the recording paper for electrophotography improves the contact state with the blade, which leads to better drainage and eliminates excess ink. The effect of liquid removal is enhanced, stains and color mixture are reduced, and the excess developer can be removed only on the electrophotographic recording paper, so that the surface of the rotating drum is not soiled and no color mixture occurs. Various effects such as the need for drum cleaning means are obtained, and the above-mentioned conventional problems can be solved well.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of an image recording apparatus provided with an excess developer removing device in the image recording apparatus of the present invention.
(Part is a cross-sectional view).

FIG. 2 is a side view of a part of the apparatus used for explaining the operation of the excessive developing solution removing apparatus in the image recording apparatus of the present invention.

FIG. 3 is a side view of a part of the apparatus used for explaining the operation of the excessive developing solution removing apparatus in the image recording apparatus of the present invention.

FIG. 4 is a side view of a part of the apparatus used for explaining the operation of the excessive developing solution removing apparatus in the image recording apparatus of the present invention.

FIG. 5 is a side view of a part of an apparatus used for explaining the operation of the excessive developing solution removing apparatus in the image recording apparatus of the present invention.

FIG. 6 is a top view of the developing device.

FIG. 7 is a front sectional view of a lifting device.

FIG. 8 is a side view for explaining the operation of the lifting device.

FIG. 9 is a side view for explaining the operation of the lifting device.

FIG. 10 is a side view for explaining the operation of the lifting device.

[Explanation of symbols]

1, 2 ... Side plate of machine body of image recording device, 3 ... Electrophotographic recording paper, 9, 10 ... Supply roller, 11 ... Control device, 12 ...
Cutting device, 13 ... Rotating drum, 14 ... Starting end position regulating member, 15 ... Pressing roller, 16, 17 ... Suction port, 33-3
7 ... Developing device, 49 ... Lifting device, 50, 90 ... Cam plate, 5
DESCRIPTION OF SYMBOLS 1 ... Cam shaft, 52 ... Roller, 64 ... Elevating device 49 support stand, 65 ... Baffle tube, 67 ... Winding chamber, 71 ... Oscillating member, 7
2 ... Swing shaft, 73 ... Blade, 75 ... Disc (eccentric disc), 97 ... Actuating member,

Claims (4)

[Claims] 1. An electrophotographic recording paper on which a charge image corresponding to an image is formed, and the charge image is dispersed with development fine particles containing a colorant and a binder in an electrically insulating liquid. A device for removing excess developer in an image recording device, which is made visible by a wet developer for electrophotography, which is provided at a position near the lowermost portion of a rotary drum that winds and carries electrophotographic recording paper. With respect to the trailing edge of the recording paper in which the excess developer that has flowed down or the excess developer that has accumulated, the blade is contacted at the end of the developing operation, and only when the contact operation of the blade described above is performed. A device for removing excess developer in an image recording apparatus, which is provided with a means for generating an electric field that exerts an attractive force on the electric charges of the developing particles. 2. A charge image corresponding to an image is formed on an electrophotographic recording paper, and the charge image is dispersed with developing fine particles containing a colorant, a binder and the like in an electrically insulating liquid. A surplus developing solution removing device in an image recording device which is made to be visualized by a wet developing solution for electrophotography, the position being lower than a lowermost position of a rotary drum that winds and carries electrophotographic recording paper. The excess developer is collected near the lowermost position of the rotating drum by air pressure from the downstream side of the drum rotation, and the excess developer flowing down near the lowermost part of the rotating drum is accumulated at the trailing end of the recording paper or the accumulated excess. A means for bringing a blade into contact with the developer at the end of the developing operation, and for generating an electric field that exerts an attractive force on the electric charge of the developing particles on the blade only when the blade makes a contact operation. A device for removing excess developer in an image recording apparatus provided with. 3. A charge image corresponding to an image is formed on a recording paper for electrophotography, and the charge image is dispersed with a developing fine particle containing a colorant, a binder and the like in an electrically insulating liquid. A device for removing excess developer in an image recording apparatus, which is made visible by a wet developer for electrophotography, wherein the excess developer is collected near the lowermost position of the rotating drum by corona discharge, The excess developer that has flowed near the lowermost part of the recording paper is retained at the trailing edge of the recording paper or the excess developer that has accumulated at the end of the development operation, and only during the contact operation of the blade described above. An apparatus for removing excess developer in an image recording apparatus, wherein the blade is provided with means for generating an electric field that exerts an attractive force on the electric charge of the developing particles. 4. The rear end portion of the recording paper, from which the excess developing solution should be removed, is separated from the peripheral surface of the rotary drum at the operation portion for removing the excess developing solution so that the rear end portion of the recording paper or the accumulated excess developing solution is collected. The excess developer removing device in the image recording apparatus according to claim 1, wherein the blade is brought into contact with the blade.