JP2765383B2 - Excess developer removal device in image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A charge image corresponding to an image is formed on a recording paper for electrophotography, and the charge image is dispersed in an electrically insulating liquid by dispersing fine particles for development comprising a colorant, a binder and the like. In an image recording apparatus in which an image is visualized by a wet developer for electrophotography, in order to prevent fogging from occurring in the visualized image, the electrophotographic recording paper is developed after development. It has been practiced to remove excess developer remaining on the surface.
As disclosed in JP-A-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, a surplus 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 Application Publication No. 3-3, various configurations such as a surplus developing solution removing device using a surplus developing solution removing roller and a blade for applying a bias voltage having a reverse polarity to the charge of the electrostatic latent image. A surplus developer removing device of the form has been proposed.

[0003]

However, in the apparatus for removing surplus developer disclosed in Japanese Patent Application Laid-Open No. Sho 62-144180, a liquid removing operation by a liquid squeezing roller and a liquid removing operation by a liquid collecting blade are performed. The removal efficiency is low due to the cleaning process, and fogging occurs due to the presence of the residual charge. Further, since the developer removal work reaches the surface of the rotating drum, the surface of the rotating drum becomes dirty. However, there is a drawback that color mixing is caused, and there is a problem that liquid clogging, which has a complicated structure, occurs because the suction device for the developer is provided inside the rotary drum. The surplus developer removing device disclosed in Japanese Patent Publication No. 59-34902 has a structure in which a blade for removing liquid is in close proximity to an image portion to perform a liquid removing operation. Cannot be ignored Not only, cause fogging due to residual charge, the actual Sho 54 over the previously described 37 313
In the apparatus for removing excess developer disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, since the electric field for preventing the fine particles for development from being attached to the blade is applied, the fine particles for development are attracted to the electrophotographic recording paper. The problem of fogging is a problem. Therefore, an appearance of a surplus developer removing device which does not cause the above-mentioned problem 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 formed by including a colorant, a binder, and the like in an electrically insulating liquid. An excess developer removing device in an image recording apparatus configured to visualize with an electrophotographic wet developer obtained by dispersing developed fine particles, and a rotating drum that winds and carries the electrophotographic recording paper The blade with a variable distance from the rotating drum surface is used for the developing operation against the trailing edge of the recording paper where the excess developer has flowed to the position near the bottom of the recording paper or the excess developer that has accumulated. Removing excess developer in an image recording apparatus provided with means for making contact at the end of the process, and means for generating an electric field which exerts an attractive force on the charge of the developing fine particles on the blade only during the contact operation of the blade. Dress , And the rear end of the recording paper from which the excess developer is to be removed is separated from the peripheral surface of the rotating drum at the portion where the excess developer is removed, so that the rear end of the recording paper or the accumulated excess developer is removed. Provided is an apparatus for removing surplus developer in an image recording apparatus in which a blade is brought into contact.

[0005]

The developing electrode is wound around the rotating drum from the developing electrode in the developing section in which all or most of the developing electrode is located at a position closer to the upstream side of the rotation of the drum than the lowermost portion of the rotating drum. After the developing operation performed by the electrophotographic wet developing solution flowing out toward the surface of the electrophotographic recording paper, the developing device is separated from the rotating drum surface to remove excess developing solution. The blade is brought into contact with the trailing edge of the recording paper or the surplus developing solution in which the surplus developing solution that has flowed down to a position near the lowermost portion of the rotating drum is stored, and only during the contact operation of the blade described above. The blade generates an electric field that exerts an attractive force on the charge of the fine particles for development, and the excess developer containing the fine particles for development is favorably collected by the blade.
The rear end of the recording paper from which the excess developer is to be removed,
The blade is brought into contact with the trailing edge of the recording paper or the accumulated excess developer by separating the blade from the peripheral surface of the rotating drum at the operation of removing the excess developer, and the blade is used only during the contact operation of the blade. Then, an electric field that exerts a suction force on the electric charge of the developing fine particles is generated, and the excess developer containing the developing fine particles is satisfactorily collected by the blade. Also, the 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 rotation of the drum than the lowermost position of the rotating drum, or the excess developer is collected by corona discharge at the lowermost position of the rotating drum. Gather around,
During the operation of removing the excess developer, which is performed by separating the developing device from the rotating drum surface, the trailing edge of the recording paper or the excess developer that has accumulated the excess developer that has flowed to a position near the lowermost portion of the rotating drum. The blade is brought into contact with the blade, and an electric field is applied to the blade so as to exert an attractive force on the charge of the fine particles for development only during the contact operation of the blade. To be collected.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the accompanying drawings, the specific contents of an apparatus for removing excess developer in an image recording apparatus according to the present invention will be described in detail below. FIG. 1 is a side view (partially a cross-sectional view) showing a schematic configuration of an image recording apparatus provided with a surplus developer removing device in the image recording apparatus of the present invention, and FIGS. FIG. 6 is a top view of a developing device, FIG. 7 is a front cross-sectional view of a lifting device, and FIGS. It is a side view for explaining operation of an elevating device. First, a 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 the body of the image recording apparatus. Above the side plate 1 of the body, one end of a rotation shaft 4 of a roll-shaped recording paper 3 for electrophotography is rotatable. Two bearing plates 5 are fixedly supported (the bearing plate for supporting the other end of the rotating shaft 4 is not shown in the figure). An imaginary line 6 in the figure is a covering member for shielding light.

[0007] In order to start image recording by the image recording apparatus, when the operator inputs information of the start of image recording to an input unit (not shown), the roll-shaped recording paper for electrophotography 3 is input.
Supply rollers 9 and 10 pass between guide plates 7 and 8 of the supply section.
The supply rollers 9 and 10 whose rotation is controlled under the control of a control device 11 are
Sent to. Reference numeral 12 denotes a well-known cutting device that includes, for example, a rotary blade and a fixed receiving blade. The cutting device 12 performs an operation of cutting 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 start position control member 14 provided above the rotating drum 13 operates under the control of the control device 11. In this state, the tip of the cam (not shown) descends to the surface of the rotating drum 13 which is in a stopped state while exhibiting a reference rotation phase, and is advanced by the rotation of the supply rollers 9 and 10. When the leading end of the recording paper 3 for electrophotography abuts on the starting end position regulating member 14 described above,
A signal generated by a sensor (not shown) is supplied to the control device 11, and the pressing roller 15 is lowered by the operation of a cam (not shown) to move the vicinity of the leading end of the electrophotographic recording paper 3 to the rotating drum 13. Crimp.

On the surface of the rotating drum 13 at a portion covered by the vicinity of the leading end of the electrophotographic recording paper 3, a shallow groove is provided in the generatrix direction of the rotating drum 13, and the groove is formed in the groove. Is provided so that a large number of through holes communicate with a suction port 16 of a 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-described starting end position regulating member 14, the control device 11 performs suction by 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 rotating drum 13.

As described above, in a state where the leading end position of the leading portion of the electrophotographic recording paper 3 is regulated by the start position regulating member 14, the leading portion of the electrophotographic recording paper 3 is moved to the suction port 16 of the suction device. Immediately after the air is taken into contact with the peripheral surface of the rotating drum 13 immediately after
After the start end position regulating member 14 moves up under the control of the control device 11, the rotating drum 13 starts rotating in the direction of arrow R in the drawing under the control of the control device 11, and the rotating drum 13
The winding operation in a state where the electrophotographic recording paper 3 is in close contact with the outer periphery of the electrophotographic recording paper 3 is started, and the electrophotographic recording paper 3 to be wound on the rotating drum 13 operates under the control of the control device 11 described above. The recording paper 3 for electrophotography is cut to a length necessary for image recording by the cutting operation of the cutting device 12, and the rear end of the electrophotographic recording paper 3 is also suctioned through a number of through holes from the suction port 17 of the suction device. Is brought into close contact with the peripheral surface of the rotating drum 13.

When the rotating drum 13 keeps rotating in a state where the electrophotographic recording paper 3 of a predetermined size is in close contact with the outer peripheral surface as described above, it is wound around the rotating 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 rotary mirror wheel. The rotary mirror wheel 21 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 a laser beam intensity-modulated by predetermined exposure data including halftone image digital data to be recorded, and outputs the laser beam to the lens 2.
3, irradiating the uniformly charged electrophotographic recording paper 3 through an optical system including reflecting mirrors 24 and 25,
The electrophotographic recording paper 3 is exposed by predetermined exposure data including the halftone image digital data to be recorded, and the photoconductor of the electrophotographic recording paper 3 has image information to be recorded. And a corresponding charge image is formed.

A pre-bath device 26 is mounted on a support plate 27 between the portion where the electrophotographic recording paper 3 is exposed by the laser beam and the lowermost portion of the rotating drum 13. The pre-bath liquid is supplied to the pre-bath apparatus 26 from a pre-bath liquid container 30 fixed to a bottom plate 29 of the fuselage through a pipe 31. The rollers 28 of the pre-bath apparatus 26 are connected to the electrophotographic recording paper. A film of the pre-bath solution is formed on the surface of No. 3. The surplus pre-bath is dropped into the pre-bath device 26 and returned to the pipe 32.
Is collected in a container 30 of the pre-bath liquid fixed to the bottom plate 29 of the fuselage.

The electrophotographic recording paper 3 which has been subjected to the prebath treatment in the prebath device 26 is then visualized by a developing unit. The developing unit (developing device) is provided at a developing electrode 33a (developing devices 33 to 37) at a portion near the portion directly below the rotating drum 13 and closer to the upstream side of the drum rotation than the position immediately below the rotating drum 13. Developing electrode 33
The developing electrodes of the developing devices selected and used among the developing electrodes a to 37a are arranged so that all or most of the developing electrodes 33a) are located because the developing device 33 is used in the illustrated state. . Developing electrode 33a of developing device 33 (same for 34 to 37) (same for 34a to 37a)
Is facing the surface of the electrophotographic recording paper 3 whose surface is wound closely to the rotating drum 13 with a slight space therebetween. Is supplied from a container 38 (corresponding to the developing device used among 38 to 42) of the electrophotographic wet developing solution disposed on the bottom plate 29 of the developing device 33 to the developing device 33 through a tube 43. The electrophotographic wet developer flows out or blows out of the through-hole 33as (see FIG. 6) formed in the developing electrode 33a, and the electrophotographic wet developer is in close contact with the rotating drum 13. Is supplied to the surface of the recording paper 3 for electrophotography wound around, the toner corresponding to the charge amount of the charge image of the recording paper 3 for electrophotography adheres to the surface of the recording paper 3 for electrophotography. The visualization of the charge image is performed.

The surface of the developing electrode 33a has an inclination corresponding to the inclination of the surface of the recording paper 3 for electrophotography wound closely on the rotating drum 13, so that the developing A through hole 33as formed in the electrode 33a
The wet developer for electrophotography flows out or gushes out, and the wet developer for electrophotography fills the gap between the surface of the developing electrode 33a and the surface of the recording paper 3 for electrophotography in the rotating direction of the rotating drum 13. It flows down well and is collected in the developing device 33. The electrophotographic wet developer collected in the developing device 33 is collected by a tube 44 into a container 38 for the electrophotographic wet developer. In FIG. 1, containers 38 to 42 for the electrophotographic wet developing solution arranged on the bottom plate 29 of the machine body respectively contain different types of electrophotographic wet developing solutions (colorant, binder, etc. in the electrically insulating liquid). (Wet developer for electrophotography) obtained by dispersing fine particles for development composed of

As described above, one of the developing units 33 to 37 is one of the developing units 33 to 37, and the developing unit 33 to 37 is located near 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 position closer to the upstream side of the rotation of the drum than the position immediately below the position 3. However, 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, a chain, a belt, etc.) 45 stretched in parallel at a predetermined interval. In the direction of
One developing device 33 (34 to 37) on the transport band 45 is raised to the above-described predetermined position by an elevating device 49 provided between the book transport bands 45, so that the developing device 33 is used for the developing operation. Or removing the excess developer at a position slightly lowered from the above-mentioned raised position, or returning the above-mentioned developing device to the transfer zone 45, thereby making the plurality of developing devices 33 to 37 A predetermined one is selectively used. The arrow F in the figure indicates the moving direction of the above-described lifting device. Each of the developing devices 33 to 37 is placed on two transfer belts stretched in parallel at a predetermined interval in a state where the position is controlled by the provided interval pieces S, S. Have been.

The transfer belt 45 (chain) is stretched over sprockets 46 and 47 so that a driving force is transmitted to the driving sprocket under the control of the control device 11,
The supply of driving force is interrupted. Reference numeral 48 denotes a rail for eliminating the slack of the chain or preventing the chain from meandering (in the drawing, two of the two chains stretched in parallel at a predetermined interval). The chained sprocket on the front side is not shown in the drawing, and the chain 45 shown in the figure and the sprockets 46 and 47 on which the chain 45 is stretched are shown in FIG.
Which is located on the far side of the fuselage).

The control device 11 controls the supply state of the driving force to the driving sprocket, and transfers a selected one of the developing units 33 to 37 to the position of the elevating device 49. . The lifting device 49 is the control device 1
1 under the control of the camshaft 5 to which the cam plate 50 is fixed.
1 transmits the rotational force to the cam plate 5.
By the rotation of 0, the substrate 54 of the elevating member to which the rotating shaft 53 of the roller 52 which is in sliding contact with the cam surface of the cam plate 50 is raised or lowered. 55 is a support. Below the substrate 54 of the above-described elevating member, guide portions 60 and 61 having holes for fitting into two guide rods 58 and 59 fixed to the mounting plate 56 are fixed. The connecting bodies 62 and 6 are provided above the substrate 54 of the member.
A support base 64 is provided via 3. Lifting device 49
The specific structure of the part is shown in the front sectional view of FIG.

The support table 64 of the elevating device is moved down from the height position of the chain 45 where the developing units 33 to 37 are mounted, and is raised by the rotation of the cam plate 50. Then, the developing device 33 located 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 At the position, the predetermined development processing operation as described above can be performed. The developing device 33, which has completed the developing operation, is mounted on the support 64 of the elevating device 49 by the rotation of the cam plate 50 under the control of the control device 11.
3 (or FIGS. 5 and 9) described later, the excess developer is removed satisfactorily, and then the elevating device 49 is rotated by rotating the cam plate 50. By lowering the support 64, the developing device 33 is placed on the chain 45. In this way, the plurality of developing units 33 to 37 can be selected one by one and used sequentially for the developing operation.

After the developing operation of the electrophotographic recording paper 3 is completed after the developing operation in the developing section, the developing device is lowered by the elevating device 49. If a surplus developer pool is formed at the rear end of the electrophotographic recording paper 3 after the operation is completed, a recorded image of good quality cannot be obtained, so that a good drainage state can be obtained. Some means is needed to achieve this.

Accordingly, in the apparatus for removing excess developer in the image recording apparatus of the present invention, the developing process on the electrophotographic recording paper 3 is completed, and the developing device 33 which has completed the developing operation is completed.
With the lowering of the support 64 of the elevating device 49 by the rotation of the cam plate 50 performed under the control of the control device 11,
When descending from the position shown in FIGS. 1 (and FIGS. 2 and 8), the state shown in FIG. 3 (and FIG. 9), that is, the state of the rotating drum that winds and carries the recording paper for electrophotography. The blade 73 is brought into contact with the surplus developer after development that has flowed to a position near the lowermost portion during the operation of removing the surplus developer,
The blade 73 generates an electric field that exerts an attractive force on the electric charges of the developing fine particles, or is located on the downstream side of the rotation of the drum from the lowermost position of the rotating drum that winds and carries the electrophotographic recording paper. From the side, the wind generated in the draft chamber 67 is blown out from the tip 65a of the air guide tube via the air guide tube 65, and the excess developer is collected near the lowermost position of the rotating drum by the air pressure, At the same time, the blade 73 is brought into contact with the excess developing solution during the removing operation, and an electric field is applied to the blade 73 so as to exert an attractive force on the electric charge of the developing fine particles. The blade 73 is brought into contact with the surplus developer after development collected near the lowermost position and flowed to the vicinity of the lowermost portion of the rotary drum during the operation of removing the surplus 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 around the outer periphery of the rotary drum 13 is subjected to a developing process by the developing device 33. FIG. 3 is an enlarged side view of a main part in the vicinity of the developing unit in a state where the developing unit 33 is in a state where the image recording apparatus is performing a developing processing operation as shown in FIG.
Is raised to the uppermost position by the lifting device described above, and the leading end of the developing electrode 33 a provided in the developing device 33 is brought into a state in which it faces close to the outer peripheral surface of the rotating drum 13. I have. The developing device 33 (34 to 37)
Is also made of an electrically insulating material (for example, synthetic resin), and reference numeral 72 in FIGS. 2, 3 and 5 to 10 denotes a swing shaft. The swing shaft 72 is provided on a bearing 82 provided on an upper portion on one side of side plates 80 and 81 (see FIG. 6 for the side plate 81) of the housing of the developing device 33 (the same applies to the developing devices 33 to 37). 83 (see FIG. 6)
Supported by

Side plates 80 and 81 of the housing of the developing units 33 to 37
Each end of the swing shaft 72 protruding from the swing member 71
After fitting into the holes provided in the respective side end portions 71a and 71b, the respective side end portions 7 of the swing member 71 are screwed by the screws 84 and 85.
1a and 71b. The swing member 71 described above.
The vicinity of the front end portion of each side end portion 71a, 71b is connected by a conductive material blade 73. A disk (eccentric disk) 75 is fixed to one side end 71b of the swing member 71 in a state where the center of the swing shaft 72 is displaced from the center of the swing shaft 72. The eccentric disk 75 fixed to the swinging member 71 is similar to the eccentric disk 75 shown in FIGS.
When the actuating member 97 shown in FIG. 0 applies a force to be displaced downward in the drawing as described later, the swing member 71 is moved as shown in FIGS. The tip 71c of the swing member is moved upward with the swing shaft 72 as the center of rotation.

As shown in FIGS. 7 to 10, a cam plate 90 is also fixed to the cam shaft 51 to which the cam plate 50 for controlling the elevating operation of the elevating device 49 is fixed. . In FIG. 7, power from a motor 88 is transmitted to a cam shaft 51 to which a cam plate 90 is fixed via a clutch mechanism and a gear 89 (not shown). The rotation control of the cam shaft 51 is performed by the control device 11 to which a control signal generated by the sensor 100 that detects the rotation phase of the cam shaft 51 is given. Camshaft 5
A roller 91 that operates as a cam follower is in contact with the cam surface of the cam plate 90 fixed to 1. That is, the rotation shaft 92 of the roller 91 is
The roller 91 is urged downward by a spring 93 stretched between the roller supporting plate 94 and the mounting plate 56, so that the roller 91
Is brought into contact with the cam surface of the cam plate 90. A guide mounting plate 95 is fixed to the upper end of the roller support plate 94, and cylindrical guides 98 and 99 fitted to the guide rods 101 and 102 are provided at both ends of the guide mounting plate 95.
Is fixed. A lower end of a connecting plate 96 is fixed to the guide mounting plate 95, and an operating member 97 is fixed to an upper end of the connecting plate 96. Then, when the cam plates 50 and 90 are rotated by the rotation of the cam shaft 51, the displacement of the roller 52 abutting on the cam surface of the cam plate 50 causes the support base 64 of the elevating device 49 to perform the elevating operation as described above. At the same time, the displacement of the roller 91 which comes into contact with the cam surface of the cam plate 90 causes the operating member 97 to move up and down.

Now, from the state shown in FIG. 2 (FIG. 8) in which the developing devices 33 (34 to 37) are performing the developing operation, the control of the control device 11 is started after the end of the developing operation. With the lowering of the support 64 of the elevating device 49 due to the rotation of the cam plate 50 performed below, the developing devices 33 (34 to
37) when the developing device 33 (34-3)
Compared with the amount of downward movement of 7), the amount of downward displacement applied to the eccentric disk 75 fixed to the swinging 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 devices 33 (34 to 37)
2 (FIG. 8) in which the developing operation is being performed, the support 64 of the elevating device 49 after the developing operation is completed.
When the developing device 33 (34-37) descends and moves to the position of, for example, FIG. 3 (FIG. 9), the descending distance of the swing shaft 72 described above. Lm, the lowering distance Lu at the center of the eccentric disk 75
Satisfies the relationship of Lm <Lu.
1 rotates from the state shown in FIG. 2 (FIG. 8) to the state shown in FIG. 3 (FIG. 9) with the swing shaft 72 as the center of rotation.

Then, the developing devices 33 (34 to 37) correspond to FIG.
From the state during the developing operation illustrated in FIG.
After the end of the development processing operation, the descent is started, and FIG. 3 (FIG. 9)
When the swinging member 71 is in a state of performing the surplus developing solution removing operation shown in (1), the tip of a pin 74 implanted in the swinging member is configured as a stopper formed by a mounting member 77 of a spring 76. 86, and the distal end portion 71c of the swing member 71 is
, And a voltage supplied from a power supply (not shown) connected via an electric wire 87 is applied to the spring 76.
→ The tip portion 71c of the swing member 71 is applied to the blade 73 through the path of the blade 73. The mounting member 77 of the spring 76 is fixed to the machine frame 103.
In the state where the surplus developer removing operation shown in FIG. 3 (FIG. 9) is performed, the tip of the blade 73 fixed to the swing member 71 is wound around the rotating drum 13 near the lowermost portion of the rotating drum 13. Electrophotographic recording paper 3 being turned
The tip of the blade 73 fixed to the swinging member 71 is accumulated on the surface of the end portion of the electrophotographic recording paper 3 wound around the rotating drum 13 in a state of being in contact with or extremely close to the surface of the electrophotographic recording paper 3. So that it can be brought into contact with the excess developer solution.

FIG. 4 shows the tip of the blade 73 against the excess developer remaining on the surface of the end of the electrophotographic recording paper 3 wound on the rotating drum 13 as described above. In order to make it easily accessible, the developing device 33
When (34 to 37) are changed from the state during the developing operation illustrated in FIG. 2 (FIG. 8) to the state where the descending operation is started after the end of the developing operation and the surplus developing solution removing operation is performed. The end of the electrophotographic recording paper 3 wound around the rotating drum 13 is separated from the rotating drum 13 so that the end of the electrophotographic recording paper 3 floats from the surface of the rotating drum 13. Thus, an example is shown in which the tip of the blade 73 can be easily brought into contact with the surplus developer accumulated on the surface of the end portion of the recording paper 3 for electrophotography.

By the way, there is excess developer which adheres to the surface of the electrophotographic recording paper 3 and moves near the lowermost portion of the rotating drum 13 toward the fixing portion as the rotating drum 13 rotates. However, such a surplus developing solution is used because the wind blown in the blast chamber 67 is jetted from the tip 65a of the air guide tube 65 to the vicinity of the lowermost portion of the rotating drum 13 as described above. The excess developer collected near the lowermost portion of the rotating drum 13 is blown to the position of the blade 73 protruding near the lowermost portion of the rotating drum 13 as shown in FIG. After being attracted to the blade 73 of the rocking 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 Bray 73 transmitted by returned to the developing device.

FIG. 2 in a state where the developing processing operation is being performed.
The developing devices 33 (34 to 37) shown in FIG.
In the course of the descending operation by the elevating device 49 after the end of the developing processing operation, the surplus developing solution on the surface is removed by the surplus developing solution removing operation performed in the state shown in FIG. 3 (FIG. 9). The recording paper 3 for electrophotography is fixed to a fixing unit 66.
After the fixing operation is performed in step (1), the charge is removed by the charge remover 68, and then the sheet is transferred on the guide plate 69 of the sheet discharge section and discharged outside the apparatus. Prior to the paper ejection, the recording paper 3 is provided in the inner space of the rotating drum 13 corresponding to the start end region and the end region of the electrophotographic recording paper 3 wound around the rotating drum 13. Air is ejected from the intake port at a predetermined timing to separate the electrophotographic recording paper 3 from the outer periphery of the rotating drum 13. Drawing reference numerals 70 and 7 in FIG.
Reference numeral 0 denotes a heat fixing unit for a lithographic plate (printing plate).

In the apparatus for removing excess developer in the image recording apparatus of the present invention described with reference to FIGS. 2 to 4 (and FIGS. 8 and 9), the apparatus adheres to the surface of the electrophotographic recording paper 3 and rotates. Excess developer that passes near the lowermost portion of the rotating drum 13 and moves toward the fixing unit as the drum 13 rotates is caused to blow in the blowing chamber 67, and the leading end 65 a of the air guide tube 65 is formed.
Is collected near the lowermost portion of the rotating drum 13 by the wind squirting near the lowermost portion of the rotating drum 13, and excess developer can be satisfactorily removed by the blade 73 projecting near the lowermost portion of the rotating drum 13. I was doing
The excess developer removing device in the image recording apparatus of the present invention shown in FIG. 5 is similar to the excess developer removing device in the image recording apparatus of the present invention described above with reference to FIGS. Instead of blowing the developing solution to the vicinity of the lowermost portion of the rotating drum 13 so that the excess developing solution can be removed by the blade 73 projecting to the vicinity of the lowermost portion of the rotating drum 13, the developing solution of the electrophotographic recording paper 3 is removed. By applying a high pressure to a line 78 in a corona charger 79, the excess developer that has adhered to the surface and passes through the vicinity of the lowermost portion of the rotating drum 13 and is moved toward the fixing unit as the rotating drum 13 rotates. The generated ions are given to the surplus developer, and the surplus developer is contracted by pushing back the surplus developer to the vicinity of the lowermost portion of the rotating drum 13.
This is an embodiment in which the surplus developing solution can be satisfactorily removed by the blade 73 protruding near the lowermost portion of the rotating drum 13.

As described above, in the surplus developer removing device in the image recording apparatus of the present invention shown in either FIG. 3 (FIG. 9) or FIG. Is applied to the blade 73 protruding from the portion of the electrophotographic recording paper 3 so as to generate an electric field that exerts a suction force on the surplus developer adhering to the surface of the electrophotographic recording paper 3. Excess developer adhering to the surface of the electrophotographic recording paper 3 wound closely on the drum 13 can be satisfactorily removed by being sucked by the blade 73 by an electric suction force.

[0030]

As is apparent from the above description, the surplus developing solution removing device in the image recording apparatus of the present invention develops a portion closer to the upstream side of the rotation of the rotating drum than the lowermost portion of the rotating drum. Wet developer for electrophotography which is discharged 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 in which the toner image is formed on the recording paper for electrophotography by the developing operation, the developing device is separated from the surface of the rotating drum, and during the removing operation of the excess developer, the lowermost portion of the rotating drum is removed. The blade is brought into contact with the excess developer after development that has flowed down to a nearby position, and an electric field that exerts an attractive force on the electric charge of the developing fine particles on the blade is generated.
Since the excess developer containing fine particles for development is sucked and collected by the blade, the blade is not in contact with the image area and damages the image. In addition, the excess developer of the electrophotographic recording paper can be effectively removed and recovered. In addition, it is possible to satisfactorily remove the surplus developing solution remaining on the trailing end portion of the electrophotographic recording paper without affecting the image area. This can be avoided by applying a voltage to the blade. Further, since the supply of the voltage to the blade is performed only during the operation of removing the excess developer, the wiring is not connected during the operation of the apparatus. The short-circuit consideration is light, and the trailing edge of the recording paper for electrophotography is lifted off the surface of the rotating drum during the operation of removing the excess developer. The contact condition has improved,
The drainage becomes better, the effect of removing excess developer increases,
Dirt and color mixing are reduced, and the surplus developer can be removed only on the electrophotographic recording paper, so that the surface of the rotating drum is not stained, so that color mixing does not occur and drum cleaning means is unnecessary. And the like, and the above-mentioned conventional problems can be satisfactorily solved.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of an image recording apparatus including an excess developer removing device in the image recording apparatus of the present invention.
(A part is a sectional view).

FIG. 2 is a side view of a part of the apparatus used for explaining the operation of the excess developer removing device 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 excess developer removing device 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 excess developer removing device in the image recording apparatus of the present invention.

FIG. 5 is a side view of a part of the apparatus used for explaining the operation of the excess developer removing device 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 the 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 the body of the image recording apparatus, 3 ... recording paper for electrophotography, 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 ... Support of elevating device 49, 65 ... Wind guide tube, 67 ... Wind room, 71 ... Swing member, 7
2 ... swing shaft, 73 ... blade, 75 ... disk (eccentric disk), 97 ... operating member,

Claims (2)

(57) [Claims] 1. A charge image corresponding to an image is formed on a recording paper for electrophotography, and the charge image is dispersed in an electrically insulating liquid by dispersing fine particles for development comprising a colorant, a binder and the like. An excess developer removing device in an image recording apparatus which is made to be visible by an electrophotographic wet developing solution formed at a position near a lowermost position of a rotating drum for winding and supporting an electrophotographic recording paper. With respect to the trailing edge of the recording paper where the excess developer that has flowed down or the excess developer that has accumulated, a blade configured such that the distance from the rotating drum surface is variable,
A surplus in an image recording apparatus comprising: means for making contact at the end of a developing operation; and means for generating an electric field which exerts an attractive force on the electric charge of the developing fine particles on the blade only during the contact operation of the blade. Developer removing device. 2. A rear end portion of the recording paper from which the excess developer is to be removed is separated from a peripheral surface of the rotary drum at a portion where the excess developer is removed, so that the rear end portion of the recording paper or the accumulated excess developer is removed. The blade is brought into contact with the blade.
The surplus developer removing device in the image recording apparatus.