JPH07140750A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce a soiled area by developer in an unused area. CONSTITUTION:In this device, a recording sheet (ST) 2 on which an electrostatic latent image (IN) is formed is carried along a carrying path, the developer is allowed to act on the surface of the carried ST 2 by developing head parts (HD) 6a to 6d so as to develop the IN and the image is formed on the ST, and then an image formed part completed on the ST is cut and outputted. The HDs 6a to 6d are plurally disposed around a shaft in parallel with a direction crossing the carrying path, provided with an aperture part on their upper surfaces so as to suck the ST 2 by the suction of the inside of the aperture part by a suction pump, and then the developer is allowed to flow and circulate by negative pressure maintained by the suction. The device is also provided with a control means 40 controlling so that the supply of the developer may be stopped and driving the suction pump may be continued when developing the latent image is finished, and controlling so that recording sheet carrying speed may be lower than the carrying speed at the time of developing operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for reciprocally moving a sheet-like recording medium to sequentially superimpose images of different colors to perform multicolor recording, and more particularly to a paper feed and a developing head (developing apparatus). The present invention relates to an image forming apparatus capable of reducing a waste paper portion which is necessary for wiping off the developing solution but cannot be used for image formation.

[0002]

2. Description of the Related Art As one of image forming apparatuses, an electrostatic recording head forms an electrostatic latent image on a sheet-shaped recording medium such as electrostatic recording paper. There is an electrostatic recording device that can obtain a print output of a large-sized image such as A0 plate by making a developing solution act.

This type of electrostatic recording apparatus includes an electrostatic recording head which is a recording portion for recording an electrostatic latent image on a recording medium, a developing head which develops the electrostatic latent image on the recording medium by applying a developing solution,
It is composed of a developing solution tank containing the developing solution to be supplied to the developing head, a pump for circulating the developing solution to the developing head, and the like.
Color recording is performed by sequentially superimposing images of different colors on a sheet-shaped recording medium, which is a recording paper, while reciprocating through the positions of the electrostatic recording head and the developing head.

FIG. 6 shows an example of a conventional electrostatic color plotter apparatus, which is one of the multicolor recording apparatuses as a wet development type electrostatic recording apparatus, and is a schematic side view of the entire structure thereof. In the figure, reference numeral 1 is an electrostatic recording paper roll, in which a recording paper 2 is wound around the outer circumference of a paper tube. In this electrostatic color plotter device, a guide roller 3 is arranged near the setting position of the recording paper 2, and a recording paper feed roller 11 is arranged downstream of the roller 3. . Further, a guide 14 is provided on the downstream side of the recording paper feed roller 11.
And 23, and a winding roller 31 is further arranged downstream of the guide 14.

A recording system and a developing system are installed between the roller 3 and the recording paper feed roller 11, and a recording paper winding system and a cutting system are arranged downstream of the recording paper feed roller 11. Therefore, the end portion of the recording paper 2 is led out to the recording system, the developing system, the recording paper winding system, and the cutting system via the roller 3. An electrostatic recording head 5 constitutes a recording system, which forms an electrostatic latent image on the recording paper 2 which moves in contact with the end surface thereof.

Reference numeral 4 is an optical mark reading head, and this mark reading head 4 is arranged in the vicinity of the guide roller 3 on the downstream side. The mark reading head 4 reads a recording position control marker, which will be described later, recorded on the recording paper 2 and also reads an edge of the recording paper 2.
A CCD (charge coupled device) linear image sensor (solid-state line image sensor) is used. This image sensor has a one-dimensional position resolution, and therefore, it is possible to identify the position and the width of the mark on the recording paper from the output signal of the image sensor.

In this system, the mark reading head 4
Is sent to a processor (not shown) which is the center of control of the present system, and is used for detection of the absence of recording paper and recording control by the recording system. Therefore, when the recording paper 2 is used in the present system, the recording paper 2 is in the vicinity of one edge (side edge) on the recording surface, in an area outside the recording area, along the edge of the recording paper 2 at predetermined intervals, for example, in a rectangular shape having a predetermined size. The recording position control marker filled in is recorded together with the image of the first color when recording the first color, and is read each time when recording the image of the second color and thereafter, and is used for position correction and scale correction.

Reference numeral 6 denotes a rotary type developing device constituting a developing system. The developing device 6 has four developing heads equiangularly on the peripheral surface of one long shaft and along the axial direction. The structure is such that the portions 6a to 6d are arranged. This developing device 6
Can be rotationally operated about the axis thereof, and these developing heads 6a to 6d can be sequentially moved to the upper surface side by rotating 1/4 rotation. ing.

Each of the developing head portions 6a to 6d is a long prism, and the upper end surface side when the developing head portions 6a to 6d are rotated and come to the upper surface side is configured as shown in FIG. 7A is a perspective view of the developing head portions 6a to 6d, FIG. 7B is a sectional view taken along the line AA, and FIG. 7C is a sectional view taken along the line BB. As shown in FIG.
6d is formed by arranging a plurality of long slits extending in the longitudinal direction in order in the lateral direction.
1 to sn are suction ports h2 near one end on the bottom side thereof.
1 to h2n are provided.

Further, among the slits s1 to sn, the slit sn on the most downstream side as viewed from the paper feeding direction at the time of development is used as a drying groove, and only the inside is sucked by the suction pump.

The remaining slits s1 to sm are developing grooves, and developing solution supply ports h11 to h1m communicating with the other ends of the bottoms of the slits s1 to sm are formed, and a developing solution tank is provided at the developing solution supply port. By connecting a tube that is a pipe line from No. 1 to the suction port h21 to h2n to a tube connected to a suction pump, the suction port is opened with the recording paper covering the slits s1 to sm on the upper surface. When sucked by the suction pump, the inside of the slits s1 to sm becomes negative pressure, the developing solution flows into the developing groove from the developing solution supply port and is discharged from the suction ports h21 to h2m. A developing solution is applied to the recording paper surface for development, and the recording paper surface is sucked by a negative pressure in the drying groove by the slit sn and remains on the recording paper surface by the flow of the air flowing in from the gap between the upper surface of the slit and the paper surface. Main developing solution are to obtain was said that dried by suction function.

Liquid developing agents of different colors are supplied to the developing head portions 6a, 6d of the rotary type developing device 6 to develop the electrostatic latent image on the recording paper with the liquid developing agent. However, the developing head units 6a, 6d
Those which have been rotated and have come to the upper side are subjected to development, and a developer is supplied to those subjected to this development.

Since the developing solution supply system is located below the position of the developing device 6 and circulates the developing solution with a negative pressure, the pump of the developing solution supply system is stopped or the developing solution supply path side with respect to the developing head is opened. By shutting off, the developing solution in the developing head section that has been used for development can be collected in the developing solution supply system to empty the developing head section.

These developing head portions 6a, 6d in the developing device 6 are sequentially synchronized with each reciprocating operation when a color image is formed while reciprocating the recording paper 2 a plurality of times as will be described later. A control operation is performed so that the developing head unit for the color developing solution is rotationally moved to the upper position, and a predetermined color image is performed, and the other developing head units are retracted from the recording paper 2. Development is 1 by this
Each time, one color is used.

10 is a downstream side of the developing device 6, and
A developer sucking roller installed on the upstream side of the recording paper feed roller 11 for sucking and removing the excess developing liquid adhering to the recording paper 2 during development by the developing heads 6a to 6d. Most of the excess developer is removed by the suction groove at the time of development, and the developer suction roller 10 has a function of wiping away moisture.

A pinch roller 12, which is a pressing roller, is arranged in pressure contact with the peripheral surface of the recording paper feed roller 11, and the recording paper feed roller 11 cooperates with the pinch roller 12 to form the recording paper 2. The recording paper feed roller 11
The recording paper 2 can be fed by rotating the. The recording paper feed roller 11 is provided with a guide plate 13 curved in an arc shape. By feeding the leading end of the recording paper 2 between the recording paper feed roller 11 and the guide plate 13, a pinch roller is provided. The recording paper 2 can be held between the recording paper feed roller 12 and the recording paper feed roller 11.

The guide 14 is provided with a guide 23 paired with the guide 14. A sensor 39 for detecting the front end of the recording paper 2 is arranged on the guide 14 located on the exit side of the recording paper feed roller 11, and further downstream thereof, the sensor 39 is fed out from the recording paper feed roller 11 and guided. A branch guide 26 is provided for switching the lead-out direction of the recording paper 2 guided and sent between 14 and 23.

Reference numeral 15 is a Y cutter for cutting the recording paper in a direction orthogonal to the recording paper feeding direction, and 16 is an X cutter for cutting the recording paper in a direction parallel to the recording paper feeding direction. The branch guide 26 for switching the recording paper path is rotatably supported by a pin 27 at its base end side. The branch guide 26 switches the leading end of the recording paper 2 guided and fed by the guides 14 and 23 toward the automatic sheet winding device 30 or the Y cutter 15 and the X cutter 16. It is for.

When the recording paper 2 is guided to the Y cutter 15 and the X cutter 16 by the branch guide 26, the guided recording paper 2 is guided to the Y cutter 15 and the X cutter 16.
Guide rollers 19 and 20 and a guide plate 24 are arranged, and further, a guide plate 25 and a pair of guide rollers 21 and 22 are arranged to send the recording paper 2 cut by the Y cutter 15 and the X cutter 16 to the outside. ing.

The automatic recording paper take-up device 30 takes up the recording paper 2 guided and guided by a take-up roller 31, a pressure contact roller 33 having a peripheral surface in contact with the take-up roller 31, and a branch surface of the take-up roller 31. Guide along the pressure roller 3
3 and a guide plate 32 which is guided between the guide plates 32 and 3. The recording paper 2 guided and guided by the branch guide 26 is automatically wound around the winding roller 31.

Winding roller 31, recording paper feed roller 11
Rotates the recording paper 2 forward when sending it out for recording, etc.
At this time, the electrostatic recording paper roll 1 is slowly rotated forward with an appropriate force in order to apply tension to the recording paper 2.
Gives the moment of reverse rotation. In the case of rewinding, the electrostatic recording paper roll 1 is rotated in the reverse direction so that the winding roller 31,
In order to apply tension to the recording paper 2, the recording paper feed roller 11 slowly rotates in the reverse direction with an appropriate force or applies a forward rotation moment.

FIG. 8 is a schematic configuration diagram of one developing solution supply system, FIG. 9 is a diagram showing the position of the recording paper at each operation, and FIG. 9B shows the state at the time of starting the printing operation, FIG. 9C shows the state at the time of winding multi-color printing, and FIG. 9D shows the state at the time of discharging the recording paper. Further, FIG. 10 is a diagram showing the position of the developing head during each operation. FIG. 10 (a) shows the developing operation, FIG. 10 (b) shows the residual liquid absorption, and FIG. 10 (c) shows the recording paper reverse operation. Show.

FIG. 8 shows the construction of a developing solution supply system for one color. In the drawing, in the developing head portion 6a (to 6d) of the developing head 6, a developing solution supply port is provided on the left side and a developing solution discharge port is provided on the right side, and a piping 652 is provided between the developing solution supply port and the developing solution tank 620. , 651. An electromagnetic valve 660 is connected to a branch point X between the pipe 651 and the pipe 652 via a pipe 653. Also,
The developer discharge port is connected to the suction side of the pump 650 via the pipe 654, and the discharge side of the pump 650 is connected to the developer tank 620 via the pipe 655. The electromagnetic valve 660 is a control means for introducing air from the developing solution supply port of the developing head portion 6a (to 6d), and is in a closed state during development.

In the electrostatic color plotter device having the above construction, first, the recording paper 2 is pulled out from the recording paper roll 1 prior to the start of recording, and the leading end of the recording paper 2 exceeds the detection positions of the feed roller 11, the pressure contact roller 12 and the sensor 39. The guide 24 is set so as to be positioned at the position of the guide 24, and a standby state, which is the state of FIG. In the standby state, not only the setting of the recording paper but also the stage after the print portion is cut and discharged from the recording paper is transferred. Therefore, in this standby state, as shown in FIG. It is arranged so that it is guided not to the winding roller 31 side but to the passage on the cutter side.

When the printing operation is started, the recording paper roll 1 and the feed roller 11 are reversed, and the leading end of the recording paper is moved to the position shown in FIG.
Move from the position A in (a) to the position B in FIG. 9 (b),
It stops when the sensor 39 is off (OFF; detection of no paper state). After that, the branch guide 26 rotates about the shaft 27 and switches from the state of FIG. 9A to the state of FIG. 9B.

Next, the developing device 6 is rotationally driven by a developing device drive motor (not shown), and the developing head 6a for the first color (for example, a black image) is moved to a developing position (a position opposite to the recording paper conveyance path). The state of 9 (b) is set so that the color to be developed for the first color can be developed. This state is shown in Figure 1.
0 (a), the developing head 6a moves to the position in the developing action state as shown in this figure. When the developing system pump 650 of the developing head 6a is operated in this state, the slits s1 to sn of the developing head 6a become negative pressure, and the negative pressure causes the recording paper 2 to be attracted to the upper surface of the developing head 6a. The developing grooves s1 to sm form a closed flow path. And
As a result, the developing solution is sucked up from the developing solution tank 620, circulates to the pump 650 through the slits (developing grooves) s1 to sm of the developing head 6a, and circulates in the route returning to the developing solution tank 620 to record the developing solution. It becomes possible to act on the paper surface of the paper 2.

At this time, the branch guide 26 for switching the recording paper path is arranged such that the leading end of the recording paper 2 is fed to the automatic sheet winding device 3.
It is set to the position to guide in the direction of 0. In such a set state, the recording paper 2 is fed in the forward direction, that is, in the direction of the feed roller 11 for forming a marker for recording position control and forming a color image of the first color. Then, when the recording paper 2 is conveyed by a certain amount, the electrostatic recording head 5 first moves the recording paper 2 onto the recording paper 2 in order to form a color image of the first color.
An electrostatic latent image of a color image of a color is formed, and an electrostatic latent image for forming a marker for recording position control is formed on one side of the recording paper 2.

Then, a toner image is obtained by developing these electrostatic latent images by the developing head 6a of the first color corresponding to the developing device 6, and a toner image is obtained with the first color image and the recording position control marker. It is recorded on the recording paper 2.

The solvent of the liquid developer has a high volatility, and the toner attached to the electrostatic latent image has a property of firmly fixing when the solvent volatilizes. This allows printing with the color of the developer.

The leading end of the recording paper 2 which has been developed and sent out is conveyed to the winding portion along the branch guide 26 and the winding guide 32, and is wound around the winding roller 31 and wound until a predetermined image formation is completed. .

When the development is completed, the developing device 6 is driven by the operation of the developing device drive motor as shown in FIG.
A small angle (about 1 °) pivotal movement about the axis 601
The developing head 6a is tilted by the minute angle as shown in FIG.

At the same time, the solenoid valve 660 is switched to "open", and the developing grooves s1 to s from the developing solution supply side of the developing head 6a.
Air is introduced into m. By the introduction of this air, the developer remaining in the developing grooves s1 to sm is instantaneously pumped by the pump 6
It is sucked up by 50 and collected in the developer tank 620.
Further, the developer sucked up to the branch point X where the air is introduced returns to the developer tank 620 by the action of gravity.

At this time, the operation of the pump 650 continues, and the pump 650 is further operated by the control means (not shown).
Rotates at a higher speed than the rotation during printing. Further, by continuing the conveyance of the recording paper 2 in this state, the recording paper 2 shown in FIG.
As indicated by the arrow, a small amount of air flows in from the gap between the recording paper 2 and the developing head 6a, and the developer remaining between the upper surface of the developing head 6a and the recording paper is pumped together with the inflowing air.
The developing head 6a is completely sucked and removed, and the developing head 6a is completely dried.

When the sucking operation is completed, the developing device 6 is further rotated by about 44 ° and the developing head 6a is moved.
Is retracted from the transport path and enters a retracted state as shown in FIG.

The recording paper 2 is further conveyed and is fed until the portion of the recording paper 2 that was in contact with the developing head portion 6a at the end passes through the suction roller 10. As a result, a small amount of the developer remaining in the portion where the developing head 6a is separated from the recording paper 2 is removed.

Next, the recording paper feed roller 11 is reversely rotated to rewind the recording paper 2, and the recording paper 2 is rewound to the print start position as shown in FIG. 9B (reverse operation of the recording paper). .

The same drive control as described above is performed for the second and subsequent colors. Then, the above operation is repeated for each color while sequentially switching the developing heads by the number of colors required for forming the latent image and the image for which development is desired to be recorded, thereby obtaining a color image.

The toner contained in the liquid developer is colored black such as black for the liquid developer for black, magenta for the liquid developer for magenta, and cyan for the liquid developer for cyan. By repeating the above operation for each color, the images of the respective colors are superimposed on the same paper surface of the recording paper 2 with the marker for recording position control as a reference to form a color image.

At the start of printing the final color, the branch guide 26 is switched to the discharge side as shown in FIG. 9D, and the recording paper 2 is guided to the Y cutter 15 and X cutter 16 sides. While printing the final color, the leading edge of the recording paper is the guide 2 on the paper discharge side.
4, the leading edge margin portion is removed by the Y cutter 15 and the X cutter 16, and then discharged to the outside to complete printing.

When the development is completed, the similar sucking operation is performed as described above. Then, the rear end of the obtained color image is conveyed until it reaches the Y cutter 15, and the rear end of the image is cut and discharged.

After the recording paper 2 is discharged, the feed roller 11 is rotated in the reverse direction to rewind the recording paper 2 by a certain amount, and the conveyance is stopped when the margin of the leading end of the recording paper comes to the position of the developing device 6. In this state, the developing device 6 is rotationally moved to return the developing head to the initial position.

When the rotating operation of the developing device 6 is completed, the recording paper 2 is again fed by a fixed amount in the forward direction so that the leading end of the recording paper is positioned at the position shown in FIG. 9 (a). Stop. The flow of such a series of operations is executed under the control of the above-mentioned processor.

[0043]

By the way, in such a rotary type developing head, when a rotating operation is performed for switching the developing head portion, at least a corner portion of the developing head portion comes into contact with the recording paper during rotation. Therefore, even if a small amount of the developer remains on the upper surface of the developing head portion or the recording paper surface, the adhered developing solution is dragged on the recording paper surface and stains the unused area. Increase waste.

Since the developer is a liquid, the liquid remains when the contact portion between the recording paper and the developing head is peeled off, and the developer cannot be completely drained by any means. Therefore, some developer remains on the edge portion of the slit and on the recording paper surface that is in contact therewith.

In order to remove this excess developing solution, in this electrostatic color plotter, after the development of each color is completed, as shown in FIG.
As shown in (b), the developing head is rotated by a small angle (about 1 °) about the axis by a drive motor (not shown), and at the same time, the solenoid valve 660 is open to the atmosphere in the city, and in the developing groove of the developing head. Air is introduced into the developing solution supply port.

By the introduction of the air, first, the developing solution remaining in the developing groove is instantly sucked by the pump 650 and collected in the developing solution tank 620. In addition, the pipe 6 that has been sucked up to the branch point X (see FIG. 8) where the air was introduced
The developer in 51 drops to the developer tank 620 and is collected. At this time, the pump 650 is controlled by a control unit (not shown) so as to rotate at a higher speed than during printing, so that the suction capability is increased.

By the above operation, the developing solution remaining in the developing groove of the developing head is completely removed. However, when the developing head is tilted as shown in FIG. A slight amount of the developing solution still remains on the edge portion of the developing head that comes into contact.

Therefore, in this electrostatic color plotter, even after the development of each color, the recording paper is continuously conveyed at the same speed as that at the time of printing, and a small amount of air is introduced from the gap between the recording paper and the developing head portion. The developer remaining near the contact surface between the upper surface of the developing head and the recording paper (the edge of the developing head) moves toward the inside of the developing head as the recording paper moves, and develops along with the air in the developing groove. I try to remove it by suction.

However, since the recording paper is fed at the feeding speed at the time of printing in this operation, the recording paper is rubbed against the surface of the recording head until the developer adhering to the corners of the developing head portion disappears. Staining of recording paper with liquid covers a considerable area.

From the first color to the color immediately before the final color,
Since the recording paper is rewound to the electrostatic recording paper roll side and the developing device is rotated to change to the developing head portion of the next color, the recording paper is wiped off when rewound. Therefore, if you send extra recording paper for the length required for wiping when rewinding during development,
The recording paper is contaminated in the margin of the leading edge, which is the minimum required for conveying the recording paper. Here, the minimum margin of the leading edge for transporting the recording sheet is a section where an image is not formed between the leading edge of the recording sheet and the electrostatic recording head in the print standby state.

However, in the developing process of the final color, the rewinding operation of the recording paper is not performed, and the discharging operation of the recording paper is performed after the image formation is completed, and the conveying speed of the recording paper is kept constant. Therefore, at the end stage of the developing process of the final color, the rear end portion of the above-mentioned front end margin far exceeds the position of the developing head portion and the area corresponding to the next image forming area reaches the developing head position. .

Therefore, at this stage, when the developing device is rotated to prepare for the start of execution of the next print, the excess developing liquid adhering to the edge of the upper surface of the developing head portion of the developing device is recorded at this position. It will be wiped off the paper surface, and the area that should have been used as the next image forming area will be stained.

Therefore, if it is desired to prevent the soiled portion from overlapping the image forming area of the next image, it is necessary to send extra recording paper only to the soiled portion to form an image. The margin of the leading edge is remarkably increased, which causes a problem of increase of waste paper. This leads to waste of resources and also increases running costs.

Therefore, an object of the present invention is to provide an image forming apparatus capable of improving the economical efficiency without increasing the blank portion which is a waste paper at the leading end of the recording paper. It is in.

[0055]

In order to achieve the above object, the present invention is configured as follows. That is, the recording sheet on which the electrostatic latent image is formed is conveyed along a predetermined conveying path, and a developing solution is applied to the sheet surface of the recording sheet to develop the electrostatic latent image,
A wet-developing image forming apparatus in which an image forming portion is cut and discharged, and an opening is formed on the upper surface, and the inside of the opening is sucked by a suction pump to suck a recording sheet and maintain it. Developing means for arranging a developing head portion to circulate the developing solution at a negative pressure, which is arranged in a direction traversing the recording sheet conveying path, and a developing solution supply after the development by the developing means is completed. Is stopped, the driving of the suction pump is continued, and a control means for controlling the conveying speed of the recording sheet to be lower than the conveying speed during the developing operation is provided.

[0056]

According to this structure, the supply of the developing solution is stopped at the end of the development, and the driving of the suction pump is continued. At this time, the conveying speed of the recording sheet should be lower than the conveying speed during the developing operation. Since the control is performed, the negative pressure is maintained by continuing the drive of the suction pump because the circulation of the developing solution is cut off at the stage when the development of the latent image is completed. Drying due to suction is performed rapidly, and at this time, the conveyance speed of the recording sheet is decelerated and slowed down, so the feeding amount of the recording sheet is reduced. Is significantly reduced. Therefore, it is possible to minimize the margin, which is a useless portion that cannot be used for image formation due to stain on the recording sheet.

[0057]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a color electrostatic plotter according to an embodiment of the present invention, and FIG. 2 is a perspective view of the schematic configuration. 3 and 4 are views showing the position of the recording paper and the operating state of the developing device during each operation. FIG. 3 (a) is in the standby state of the device stop, and FIG. 3 (b) is the printing operation start. Time, fig. 3
FIG. 3C is a print operation in progress, FIG. 3D is a residual liquid recovery and drying operation state at the end of printing, FIG. 4A is standby, and FIG. 4B is a final color print operation start. , Fig. 4
FIG. 4C shows a state in which residual liquid is collected and dried at the end of printing the final color, and FIG. 4D shows a standby state.

In FIG. 1, 1 is an electrostatic recording paper roll, and 2 is
Is a recording paper, 3 is a roller, 4 is an optical mark reading head, 5 is an electrostatic recording head which constitutes a recording system, 6 is a rotary type developing device which constitutes a developing system, 10 is a developer absorbing roller, and 11 is A recording paper feed roller, 12 is a pinch roller, 13 is a guide plate, 30 is an automatic sheet winding device, 14 and 23 are guides, 26 is a branch guide, 27 is a pin, 31 is a winding roller, and 39 is a sensor, All of these have basically the same functional configuration operation as that of FIG. 6 described in the conventional example. Therefore, it will not be described again here.

The sensor 39 provided at the position of the guide 14 for guiding the recording paper is turned on when there is the recording paper at the position of the guide 14 and turned off when there is no recording paper.

Similar to the conventional structure, the developing head portions 6a to 6d.
Is formed by sequentially arranging a plurality of long slits extending in the longitudinal direction in the lateral direction, and each slit has a suction port near one end on the bottom side thereof. And of the slits, when viewed from the paper feed direction during development,
The slit on the most downstream side is used as a drying groove, and only the inside is sucked by the suction pump. The remaining slits are developing grooves, and a developing solution supply port communicating with the other end of the bottom of each slit is formed.A tube, which is a conduit from the developing solution tank, is connected to the developing solution supply port and suctioned. By connecting the tube connected to the suction pump to the opening, when the suction port is sucked by the suction pump with each slit on the upper surface covered with the recording paper, the inside of the slit becomes negative pressure and The developer comes in from the developer supply port and is discharged from the suction port. At that time,
The developer is applied to the surface of the recording paper for development, and the surface of the recording paper is sucked with a negative pressure in the dry groove, and unnecessary development that remains on the surface of the recording paper by the flow of the air flowing through the gap between the upper surface of the slit and the paper surface. The function of sucking and drying the liquid is obtained.

Since the developing solution supply system is located below the developing device 6 and the developing solution is circulated with a negative pressure, the pump of the developing solution supply system is stopped or the developing solution supply path side of the developing head section. By introducing the air from the path, the developing solution in the developing head section that has been used for the development is collected in the developing solution supply system to empty the developing head section.

These developing head portions 6a, 6d in the developing device 6 are sequentially synchronized with each reciprocating operation when a color image is formed while reciprocating the recording paper 2 a plurality of times.
Since the control operation is performed so that the developing head unit for the developing solution of another color is rotationally moved to the upper position to perform a predetermined color image, the other developing head units are in a standby state from the recording paper 2. Therefore, the development is performed once for each color.

Reference numeral 42 is a cutter device having a Y cutter for cutting the recording paper in a direction orthogonal to the recording paper feed direction and an X cutter for cutting the recording paper in a direction parallel to the recording paper feed direction. Whether to guide the leading end of the recording paper 2 which is guided and sent out between the guides 14 and 23 toward the cutter device 42 or the automatic sheet winding device 30 is determined by the branch guide 26. The route is switched and decided.

When the recording paper 2 is guided to the cutter device 42 side by the branch guide 26, the guide plates 43, 44, 45 are arranged so as to guide the guided recording paper 2 to the cutter device 42. Further, guide plates 46 and 47 are arranged to send the printed recording paper cut by the cutter device 42 to the outside.

Reference numeral 40 is a controller which plays a central role in controlling the apparatus. The controller 40 has not only a basic control function required as an electrostatic recording device, but also a detailed description will be given later.
It also takes necessary control from the stage when the image formation for one color of the screen is completed to the preparation stage for the image formation of the next color.

For example, when image formation is completed for each color,
Atmosphere is introduced from the developing solution supply side path of the developing head, and the developing solution in the developing head section is discharged by continuing the suction operation by the negative pressure continuously generated by the continuous pump suction operation. The function of controlling the developing solution in the head unit to dry and then controlling the developing head unit to the standby state, and the rotation of the developing system pump 650 at the stage of performing the drying operation of the developing head unit by this function. In addition to increasing the suction force by increasing the speed, the feeding speed of the recording paper is significantly reduced compared to the printing operation, and the feeding speed of the recording paper is higher than that during the printing operation in the rewinding (reverse) stage of the recording paper. The control function to increase the speed drastically, and when the final color image formation is completed, the developing head section is dried and the recording paper is cut. After cutting them out into 置側, it has a like function of controlling rewinding the recording paper to a predetermined position of the recording sheet tip end comes to the position of the developing device 6.

Reference numeral 48 is a driver and 50 is a motor. The motor 50 is a motor for driving the recording paper feed roller 11, and uses a pulse motor. Driver 48
Is for giving a drive pulse of this pulse motor 50, and the pulse which is the basis of this drive pulse is given from the controller 48.

In order to control the pulse motor 50, the controller 40 is provided with a controller 40a, a clock pulse generator 40b, and a counter 40c. The clock pulse generator 40b generates a clock pulse having a high predetermined frequency, and the counter 40c counts the clock pulse and outputs a pulse every predetermined number.
The output pulse of the counting section 40c is given to the driver 48. The control unit 40a controls the count number set value of the counting unit 40c and the like, and is responsible for various controls for realizing the various functions described above.

Next, details of the vicinity of the rotation drive mechanism portion of the developing device 6 in this apparatus will be described. The developing device 6 is supported so as to rotate about an axis 601 that is parallel to the direction traversing the recording paper conveyance path, and a worm wheel 607 is attached to the axial end of the axis 601 as shown in FIG. 60
Reference numeral 5 denotes a developing device drive motor for rotationally driving the developing device 6, which uses a stepping motor to pulse-control the rotational movement amount of the developing device 6 by a drive pulse. The developing device drive motor 605 transmits a rotational force to the shaft 601 through the worm 606 and the worm wheel 607, and rotates the developing device 6.

Reference numeral 608 denotes a sensor for detecting the rotational position of the developing device 6, which is a detection plate 60 attached to the shaft 601.
A timing mark (not shown) such as a slit or a reflection plate attached to 9 is read to detect the rotational position of the developing device 6.

The developing solution supply system for one color is the same as that described with reference to FIG. 8, and is provided for each developing head section 6a to 6d. The developing head portion 6a (to 6d) in the developing device 6 is provided with a developing solution supply port on the left side and a developing solution discharge port on the right side, and the developing solution supply port and the developing solution tank 620 in FIG. , 651. An electromagnetic valve 660 is connected via a pipe 653 to a branch point X between the pipe 651 and the pipe 652 in FIG. The developer discharge port is connected to the suction side of the pump 650 via the pipe 654, and the discharge side of the pump 650 is connected to the developer tank 620 via the pipe 655. The electromagnetic valve 660 is a control means for introducing air from the developing solution supply port of the developing head portion 6a (to 6d), and is in a closed state during development.

A suction roller 10 is arranged between the developing device 6 and the recording paper feed roller 11. The sucking roller 10 is provided with a developing solution that has been deposited on the recording paper 2 during development by the developing device 6, and a developing head portion 6 a that is used for development in the recording paper 2 and the developing device 6 when development is completed.
The developer that is slightly left on the portion in contact with (~ 6d) is removed.

A gear 52 is attached to the rotary shaft of the recording paper feed roller 11, and the gear 52 meshes with a gear 51 attached to a motor (pulse motor) 50 to rotate the motor 50. Recording paper feed roller 1
It is a mechanism to transmit to 1.

Further, a pinch roller 12 is arranged in pressure contact with the peripheral surface of the recording paper feed roller 11, and the recording paper 2 is formed by the pinch roller 12 and the recording paper feed roller 11.
Hold and transport. A guide plate 13 curved in an arc shape is attached to the recording paper feed roller 11. Guides 14 and 23 are arranged on the exit side of the recording paper feed roller 11 to guide the conveyance of the recording paper 2.

The guide 14 is provided with a sensor 39 for detecting passage of the recording paper 2. 42 is a recording paper 2
The cutter device includes a Y-cutter that cuts in a direction orthogonal to the transport direction and an X-cutter that cuts in a direction parallel to the transport direction.

Reference numeral 26 is a branch guide, which is rotatably supported about a shaft 27. This branch guide 26
Is for guiding the leading edge of the recording paper 2 to the winding device 30 or the cutter device 42, and is operated by a driving device (not shown).

When the recording paper 2 is guided to the cutter device 42 by the branch guide 26, the recording paper 2 is guided to the cutter device 4.
Guides 43, 44, and 45 are provided to guide the sheet to the sheet 2, and a guide 46 and a sheet discharge guide 47 are arranged to discharge the recording paper 2 cut by the cutter device 42 to the outside of the device. .

Next, the rough operation of the electrostatic color plotter device having the above configuration will be described. In the initial state, the leading end of the recording paper 2 from the recording paper roll 1 is set so as to be located between the feed roller 11 and the pressure contact roller 12. A branch guide 26 for switching the recording paper path
Is set to a position that guides the leading edge of the recording paper 2 toward the automatic sheet winding device.

Next, the recording paper 2 is moved in the forward direction, that is, in FIG.
The electrostatic recording head 5 is operated while being fed in the right hand direction at a standard conveying speed to form a recording position control marker and an electrostatic latent image for forming the first color image on the recording paper 2.

This electrostatic latent image is developed by any one of the developing head portions 6a to 6d in the developing device 6,
For example, assuming that the developing head portion 6a has the liquid developer of the corresponding color of the first color, the developing head portion 6a is rotated to the upper position and brought into contact with the recording paper 2.
Then, by being developed with the liquid developer supplied to the developing groove of the developing head portion 6a, the toner contained in the liquid developer adheres to the electrostatic latent image of the first color to be a toner image. The solvent of the liquid developer has a high volatility, and when the solvent volatilizes, the toner attached to the electrostatic latent image is firmly fixed.

During this series of processing, the recording paper 2 is wound around the outer circumference of the winding roller 31 by the action of the winding roller 31, the guide plate 32, and the pressure contact roller 33 of the automatic recording paper winding device 30 and sent. go.

A stage in which the image formation of the first color is completed,
That is, when the rear end position of the latent image forming area on the recording paper 2 has finished passing the developing groove position of the developing head portion, the drying operation is immediately started. The drying operation is carried out for a predetermined time. Then, in this drying operation, the controller 40 rotates the developing head portion by a small angle (about 1 °) and makes the transport speed of the recording paper 2 much slower than the transport speed up to now. As a result, the developing head 6a is tilted by the minute angle, and at the same time, the conveyance of the recording paper 2 is delayed.

At the same time, the solenoid valve 660 is switched to "open",
Air is introduced into the developing groove from the developing solution supply side of the developing head 6a. By the introduction of this air, the developer remaining in the developing groove is instantly sucked up by the pump 650 and collected in the developer tank 620. Further, the developer sucked up to the branch point X where the air is introduced returns to the developer tank 620 by the action of gravity.

At this time, the operation of the pump 650 continues, and moreover, the pump 650 rotates at a higher speed than the rotation during printing (latent image formation and development). Further, by continuing the conveyance of the recording paper 2 in this state, air flows in from the gap between the recording paper 2 and the developing head 6a, and the developing solution remaining between the upper surface of the developing head 6a and the recording paper flows into the inflowing air. And the developing head 6a is completely dried. When the drying operation for a predetermined time is completed, the controller 40 stops the pump 650. This completes the suction operation of the pump 650.

When the sucking and drying operation is completed, the controller 40 further controls the developing head unit 6a.
Is rotated by 44 °, and the developing head portion 6a moves from the recording paper conveyance path position to the standby position.

Even after the drying operation is completed, the recording paper 2 is conveyed at a low speed by the control of the controller 40, and is stopped after being conveyed for some time, but this is the last contact with the developing head portion 6d of the recording paper 2. This is the time required for the broken portion to reach the suction roller 6.

Next, preparation for the formation of the second color image is started. When the preparation is started, the controller 40 reverses the recording paper feed roller 11 at high speed to rewind the recording paper 2, and returns the recording paper 2 to the print start position again (reverse operation of recording paper). This returning is to the position where the front end of the recording paper 2 is separated from the outer circumference of the take-up roller 31 and detected by the sensor 39.

Then, the recording paper 2 is again fed in the forward direction at the standard conveying speed, and at this time, the optical mark reading head 4
The marker for recording position control is detected by the electrostatic recording head 5 while the processor corrects the marker based on the detected marker.
Thus, an electrostatic latent image for forming the second color image is formed on the recording paper 2.

In this way, the electrostatic latent image for forming the color image is formed on the recording paper 2 while using the marker as a reference for the second and subsequent colors. This electrostatic latent image is developed by the developing head section 6b.
Of 6d, the developing head supplied with the liquid developer of the corresponding color of the second color is rotationally moved to the upper part to be brought into close contact with the recording paper 2, and by applying the developing solution, the toner contained in the liquid developer is applied. , Can be converted into a toner image. During this time,
The recording paper 2 whose front end is wound around the winding roller 31 is further wound around the winding roller 31.

Then, when the development is completed, the drying operation is started in the same manner as described above. When the drying operation is completed, the preparation for forming a color image of the next color is started in the same manner as described above. By repeating such an operation, an image is recorded for each color, and a color image is obtained.

The toner contained in the liquid developer is colored black such as black for liquid developer for black, magenta for liquid developer for magenta, and cyan for liquid developer for cyan. By repeating the above operation for each color, the images of the respective colors are superimposed on the same paper surface of the recording paper 2 with the marker for recording position control as a reference, and a color image is formed.

At the preparation stage for recording the last color, the recording paper 2 is rewound until the leading end of the recording paper 2 is separated from the outer circumference of the winding roller 31 and the leading end is detected by the sensor 39. , The recording paper 2 is switched to the direction of discharging it out of the apparatus (state of the dotted line position).

While the recording paper 2 is being sent out again at the standard conveying speed, latent image formation and development are performed, and at the stage of completion of development, the same drying operation as described above is performed. Even after the drying is completed, the conveyance of the recording paper 2 is continued, and when the image forming area of the recording paper 2 reaches the position of the cutter device 42, the controller 40 operates the Y cutter and the X cutter of the cutter device 42, respectively. The recorded recording paper 2 is cut into a desired size and discharged to the outside of the apparatus. When the discharge is completed, the recording paper 2 is returned to the initial state.

In the present invention, by the first control function of the controller 40, when the image formation for each color is completed, the process of drying operation is started, and the atmosphere is introduced from the developing solution supply side path of the developing device 6 to develop the image. The developing solution in the head section is discharged by continuing the suction operation for generating a negative pressure, and the adhering developing solution in the developing head section is controlled to dry by the inflowing atmosphere due to this negative pressure. Then, by this, the developing head portion is dried quickly, and the recording sheet is prevented from being contaminated by the excess developer. Further, in this drying operation process, the conveyance speed of the recording paper is significantly slower than the conveyance speed during printing (latent image formation and development) to suppress the amount of stain on the unused area of the recording paper with the developer. ing.

Further, when the image formation of the final color is completed, the controller 40 performs the drying operation of the developing means by the first control function by the second control function, and after cutting the recording paper, the developing device. The recording paper is rewound and controlled until the predetermined position on the leading edge side of the recording paper reaches the position of 6. After finishing the rewinding control by the second control function,
The third control function controls the rotation operation to return the developing head unit to the initial standby state.

By controlling in this way, the unused area that is contaminated by the developing solution remaining in the developing head portion of the developing device 6 can be extremely reduced, and the margin that is a wasteful portion that cannot be used for image formation can be minimized. As a result, it is possible to minimize the amount of wasted paper that is generated without worrying about soiling the image forming area. Further, after the image formation, the developing head portion is dried by suction of the outside air, so that the excess developer adhering to the developing head portion is minimized and the effect of suppressing the contamination of the recording sheet is enhanced.

Next, focusing on the characteristic operation of the present invention, the details of the control will be specifically described centering on the main operation.
When the printing operation (operation for forming and developing a latent image) is started, first, the recording paper feed roller 11 is reversely rotated, and the leading end of the recording paper is moved from the position A in FIG. 3A to the position shown in FIG. 3B.
To the position B, and stops with the sensor 39 turned off. Then, under the control of the controller 40, the branch guide 26 is rotated around the shaft 27 to switch from the state of FIG. 3A to the state of FIG. 3B.

Next, the developing device drive motor 605 is rotationally driven under the control of the controller 40, and the developing head portion is rotated to the position of the print start state (see FIG. 5B). That is, the developing device 6 is the developing device drive motor 60.
5, the developing head unit for the color for developing the first color (for example, the developing head unit 6a in this embodiment).
Is moved to the position in the print state (developing state) as shown in FIG. In this state, the controller 40 then controls the developing system pump 605 to operate at a normal speed (low speed operation mode; for example, about 1000 rpm) (see FIG. 5A). Then, the recording paper 2 is attracted to the upper surface of the developing head portion 6a, and the developing groove 610
Form a closed channel, the developer is sucked up from the developer tank 620, and the developing groove 610 in the developing head portion 6a is formed.
Circulating to the pump 650 through the inside of the developer tank 62.
Follow the route back to 0.

Next, the controller 40 sets the counter 40c to rotate the motor 50 at a normal speed, outputs a pulse every time the counter 40c counts the clock pulse and counts the set number, and the driver 48. The motor 50 driven by the output of the driver 48 controls the recording paper feed roller 11 to rotate in the carrying direction at a normal carrying speed (for example, about 52 mm / sec). It is transported in the forward direction at the transport speed of. When the recording paper 2 is conveyed at a normal conveyance speed by a certain amount in the forward direction, the electrostatic recording head 5 forms an electrostatic latent image on the recording paper 2. The formed electrostatic latent image is transferred to the developing head section 6a.
Is developed as it passes through.

The leading edge of the recording paper is conveyed to the winding section along the branch guide 26 and the winding guide 32, and the winding roller 3
It is wound around 1 and wound up until the predetermined image formation is completed. When the development of the latent image forming area is completed, the controller 40
Controls to reduce the recording paper conveyance speed. That is,
As shown in FIG. 5A, in order to significantly reduce the transport speed to a predetermined speed, the setting value of the counting unit 40c is changed and the output pulse rate is reduced to a fraction. In this way, the motor 50 is gradually reduced to a predetermined low speed (for example, about 13 mm / sec) in a short time, and when the predetermined low speed is reached, the motor 50 is driven at a pulse rate that maintains the speed (FIG. 5). (See (a)).

Further, the controller 40 drives the developing device drive motor 605 to rotate by a minute angle and controls the recovery of the developer in the developing system to remove and dry the developer. Then, when the recording paper conveyance speed reaches the predetermined low speed, the controller 40 immediately controls the rotation speed of the pump 650 to switch to a high speed rotation (for example, about 3000 rpm) (see FIG. 5B). As a result, the air suction amount of the developing head portion 6a is multiplied, and the developing head portion 6a
Thus, the drying speed of the residual developer on the surface of the recording paper can be increased.

That is, at the stage where the controller 40 controls the developing device drive motor 605 to rotate by a minute angle, the developing device 6 operates by the developing device drive motor 605 to move the developing device drive motor 605 around the shaft 601 at a minute angle (about 1 mm).
) Rotatingly moves, and the developing head portion 6a of the developing device 6 used for the development is tilted by the minute angle as shown in FIG. 3D.

At the same time, the controller 40 switches the electromagnetic valve 660 to "open" to introduce air into the developing groove from the developing solution supply side of the developing head portion 6a. By introducing this air,
The developer remaining in the developing groove of the developing head portion 6a is instantly sucked up by the pump 650, and the developer tank 620
Will be collected. Further, when the atmosphere is introduced, the developer sucked up to the branch point X which is the connection point of the pipe 651 on the developer supply side of the developing head portion 6a and the connection pipe 653 of the solenoid valve 660 has a negative pressure. Is released to the atmospheric pressure, the pipe 651 naturally flows down and returns to the lower developer tank 620.

At this time, the suction operation of the pump 650 continues, and at this time, the pump 650 is rotated at a higher speed than the rotation at the time of printing (at the time of developing the latent image forming area) under the control of the controller 40. Further, in this state, the recording paper 2
By continuing the transport at a slower transport speed,
In the same manner as described in 0 (b), a large amount of air flows in from the gap between the recording paper 2 and the developing head portion 6a that has been used for development, and the air flows between the upper surface of the developing head portion 6a and the recording paper 2. The remaining developing solution is sucked and removed by the pump 650 or dried, so that the developing head portion 6a and the recording paper surface adjacent thereto are completely dried in a short time. Since the recording paper conveyance speed during this period is low, the amount of waste paper that digs into the unused area of the recording paper is significantly reduced as compared with the conventional case. The controller 40 stops the pump 650 (see FIG. 5 (b)) at the stage when the preset amount of time for drying has elapsed, whereby the suction operation of the pump 650 ends.

When the sucking and drying operation is completed, the controller 40 controls the developing head unit 6a.
Is rotated by 44 ° (see FIG. 5C), and the developing head portion 6a shifts from the recording sheet conveyance path position to the standby position as shown in FIG. 4A.

The recording paper 2 is controlled by the controller 40 at a low speed as shown in FIG. 5A, and is further conveyed and then stopped.
This is the time until the part that was last in contact with d reaches the suction roller 6.

At this stage, as shown in FIG. 5 (e), the recording paper conveyance is changed from the low speed to the normal conveyance speed, and the portion of the recording paper 2 which is in final contact with the developing head portion 6d is sucking roller. It is also possible to convey the paper until it reaches 6 and then stop it.

Next, the controller 40 reverses the recording paper feed roller 11 at high speed to rewind the recording paper 2 (high speed reverse; for example, about 208 mm / sec), and again as shown in FIG. 4 (a). Rewind the recording paper 2 to the print start position. Then, as shown in FIG. 3B, the developing device 6 is rotated by 45 ° to move the next second color developing head portion to the print position (developing state position), and the same drive control as described above is performed. .

In this way, for the second and subsequent colors,
The same drive control as described above is performed, and the above operation is repeated for each color while sequentially switching the developing heads by the number of colors required to form the latent image and the image for which development is desired to be recorded, and a color image is obtained. .

At the start of printing the last color, the controller 40
Of the branch guide 26 as shown in FIG.
Is switched, and the recording paper 2 is guided to the cutter device 42. While forming and developing the latent image of the final color, the leading end of the recording paper is discharged along the paper discharge guide 47, and the leading end margin is cut and removed by the cutter device 42.

When the development of the latent image forming portion is completed, the developing device 6 is controlled to the state shown in FIG. 4C, and the above-mentioned sucking and drying operation is performed. Then, the recording paper 2 is conveyed until the rear end of the obtained color image area reaches the cutter device 42, and when the rear end of the color image forming area on the recording paper surface reaches the cutter device 42, the cutter device 42 Cut the trailing edge of the image and discharge it to the outside.

After ejecting the recording paper (print) on which the image has been formed, the controller 40 reverses the recording paper feed roller 11 at a high speed to rewind the recording paper 2 by a predetermined amount (the leading end of the recording paper is the recording paper feed roller 11). Rewind until it reaches the nip point by the pinch roller 12 or a position near this point). In this state, the margin portion on the leading end side of the recording paper is located at the position of the developing device 6, but the rewinding of the recording paper 2 is held in a state where the conveyance required for the next image formation can be automatically performed. To the limit, and the margin of the front edge of the recording paper in this state is the minimum necessary length. In addition, since the front end margin of the recording paper is transported at a low speed and the above-described sucking and drying operation is performed by sucking a large amount of air, the stain area due to the developing solution is significantly smaller than the conventional area.

The controller 40 in this state is shown in FIG.
As shown in, the recording paper is further conveyed at a low speed and then stopped. This is the distance until the portion of the recording paper 2 that was in contact with the developing head portion 6d at the end reaches the suction roller 6, and the conveyance at this stage is performed by conveying the recording paper as shown in FIG. 5 (e). By shifting from low speed to normal transport speed,
The recording paper 2 may be conveyed until the portion of the recording paper 2 that is in final contact with the developing head portion 6d reaches the suction roller 6 and then stopped. Stop the recording paper conveyance.
Prior to this, the developing device 6 is rotated and returned to the initial standby position at the stage when the above-described sucking and drying operation is completed (state (d) of FIG. 4).

Therefore, it becomes a standby state, and it is possible to immediately shift to the sequence of printing the second sheet.
As described above in detail, in the apparatus described in the embodiment of the present invention, the conveying speed of the recording paper is set to be low during the sucking and drying operation which is the developing solution collecting and drying process of the developing device,
The developing system is released to atmospheric pressure, and the negative pressure is increased to increase the amount of air sucked into the developing device, dry the developing device and recording paper at high speed, and reduce the stain area of the developing solution outside the print area. It was done.

Therefore, since the unused recording paper has a small amount of the developer stain area outside the print area, the waste area that cannot be used for image formation (the waste area that cannot be used for printing) is minimized and the reverse speed of the recording paper is increased. As a result, the time required until the end of printing can be shortened, waste paper can be suppressed, and high-speed operation can be achieved.

In this embodiment, the pulse motor is used as the rotating operation means of the developing head. However, the rotational position of each developing head can be controlled by a sensor using a DC motor. .

Further, the above-mentioned embodiment is a case where the present invention is applied to an electrostatic recording device such as a color electrostatic plotter, but the present invention is not limited to this, and a wet developing system using another slit developing head is used. The present invention can be applied not only to an electrostatic recording device but also to a monochromatic electrostatic recording device. Further, the developing device is not limited to the rotary type developing device, and the developing heads for the respective colors are arranged side by side in the recording paper conveyance path in order, the developing heads to be used are raised to a position in the recording paper conveyance path, and the others are retracted. The present invention can also be applied to a wet developing type electrostatic recording device using. Furthermore, the conveyance speed control pattern when the recording paper is absorbed and dried (during absorption) and the conveyance speed control pattern when the recording paper is reversed are shown in FIG.
The pattern is not limited to that shown in (a), and an optimum pattern can be adopted as needed.

[0118]

As described in detail above, according to the present invention, it is possible to provide an economical image forming apparatus in which there is no fear of contaminating the image forming area and the waste paper generated can be minimized.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention,
The figure which shows the outline of a principal part structure.

FIG. 2 is a diagram for explaining an embodiment of the present invention,
The schematic perspective view of the principal part.

FIG. 3 is a diagram for explaining an embodiment of the present invention,
The figure explaining the state at the time of operation of this device.

FIG. 4 is a diagram for explaining an embodiment of the present invention,
The figure explaining the state at the time of operation of this device.

FIG. 5 is a diagram for explaining an embodiment of the present invention,
The timing chart which shows the operation example of this device.

FIG. 6 is a diagram for explaining a conventional example.

FIG. 7 is a diagram for explaining a conventional example.

FIG. 8 is a view showing a schematic configuration of a developing solution supply system for the developing head unit.

FIG. 9 is a diagram for explaining a conventional example.

FIG. 10 is a diagram for explaining a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Recording paper roll 2 ... Recording paper 5 ... Electrostatic recording head 6 ... Developing head 6a-6d ... Developing head part 10 ... Suction roller 11 ... Recording paper feed roller 26 ... Branch guide 30 ... Winding device 39 ... Sensor 40 ... Controller 42 ... Cutter device 50 ... Motor 620 ... Developer tank 650 ... Pump 660 ... Solenoid valve.

Claims (2)

[Claims] 1. A recording sheet on which an electrostatic latent image is formed is conveyed along a predetermined conveying path, and a developing solution is applied to the sheet surface of the recording sheet to develop the electrostatic latent image. After that, the image forming apparatus is a wet development type image forming apparatus that cuts and discharges the image forming portion, and has an opening on the upper surface, and the inside of this opening is sucked by a suction pump to suck the recording sheet, A developing head portion, in which a developing solution is circulated by a negative pressure maintained by this, is arranged in a direction traversing the recording sheet conveying path, and after completion of development by the developing means, Stop the developer supply,
An image forming apparatus comprising: a control unit that controls the suction speed of the suction pump so that the speed of transporting the recording sheet is kept lower than the speed of transport during the developing operation. 2. A recording sheet on which an electrostatic latent image is formed is conveyed along a predetermined conveying path, and a developing solution is applied to the sheet surface of the recording sheet to develop the electrostatic latent image. After that, the image forming apparatus is a wet development type image forming apparatus that cuts and discharges the image forming portion, and has an opening on the upper surface, and the inside of this opening is sucked by a suction pump to suck the recording sheet, A plurality of developing head portions, which are made to circulate the developing solution at a negative pressure maintained by this, are arranged and held around an axis parallel to the direction traversing the recording sheet conveying path, and A developing unit configured to expose one of the developing head units to a predetermined position of the recording sheet conveying path in order to develop the electrostatic latent image by rotating the center, and after completion of the developing by the developing unit, Supply developer Sealed,
An image forming apparatus comprising: a control unit that controls the suction speed of the suction pump so that the speed of transporting the recording sheet is kept lower than the speed of transport during the developing operation.