JPH05257390A - Wet type developing device - Google Patents

Abstract

PURPOSE:To disuse a squeezing device, to miniaturize a wet type developing device and to make it inexpensive by providing a control means which makes the pressure of a developing head negative when development is executed, cuts off the supply of liquid developer while keeping the negative pressure when the development is finished and operates the developing head turning it. CONSTITUTION:When the developing is finished, a developing frame 204 is driven to be turned by a fine angle around a turning shaft 205 as a center and the developing head 203a is inclined by a fine angle. Simultaneously, a solenoid valve 11 is switched and a flowing path between the head 203a and the liquid developer tank of the liquid developer supply system thereof is cut off. Then, the supply of the liquid developer from the developer tank is stopped. At this time, the action of a sucking pump is continued and air flows into a slit-like aperture of the head 203a through a small gap formed on the head 203a inclined by a fine angle with respect to a recording paper 201. Then, the liquid developer in the slit-like aperture is sucked by the sucking pump and recovered to a developing tank. Besides, the excessive liquid developer attached on the surface of the recording paper is recovered together following the suction of the air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet developing device for developing an electrostatic latent image formed on a sheet-shaped recording medium such as electrostatic recording paper by applying a developing solution. In particular, the present invention relates to a wet developing apparatus called a multi-pass color printer, which is suitable for use in an apparatus for recording color images by sequentially superposing images of different colors while reciprocating recording paper.

[0002]

2. Description of the Related Art A wet process in which an electrostatic latent image is formed on a recording sheet such as a recording sheet and is developed by bringing the electrostatic latent image into contact with a developing solution containing toner, thereby recording on the recording sheet. The developing device is, for example, a paper size A0.
It is used as a recording device for recording an image on a large-sized recording sheet such as a plate and an A1 plate.

As such a wet recording apparatus, a recording head which is a recording portion for an electrostatic latent image, a developing head (developing device) for developing the electrostatic latent image, and a developing solution supplied to the developing head are housed. It is composed of a developer container and a suction pump for circulating the developer.

More specifically, for example, the developing head has a box-shaped container in which a developing solution can flow, and the upper surface of a substrate is formed in a flat shape, and the flat portion serves as a developing action area for a recording sheet. A slit-shaped window is provided, and the plane portion serves as a conveyance path for the recording sheet, and the longitudinal direction of the window is a transverse direction of the recording sheet.

The developing head is connected to the developing solution container by a pipe, and when the recording sheet on which the electrostatic latent image is formed is conveyed through the flat portion of the developing head, the inside of the developing head is sucked by a suction pump. Since the recording sheet covers the slit-shaped window of the developing head, the inside of the developing head has a negative pressure, so that the developing solution is sucked up from the developing solution container and circulated, as well as the slit-shaped window of the developing head. In the window, a developing solution is applied to the recording sheet to develop the recording sheet.

Usually, there is only one recording head. In the case of multicolor recording (color printing), one recording head for each color is provided on the upstream side of the recording paper conveyance path, and each color is developed on the downstream side. The heads are arranged in order, and a long recording paper wound in a roll is unwound and fed to the downstream side to form an electrostatic latent image for one color on the paper surface, which corresponds to the electrostatic latent image. The electrostatic latent image is developed using the developing head supplied with the developing solution used for color development to complete the recording of the image of that color, and after recording one color, rewind the recording paper and re-record. While feeding the recording paper, record the next color according to the procedure described above, rewind the recording paper when the recording is finished, and again feed the recording paper to record the next color. Record by printing.

Since the printing recording paper is repeatedly reciprocated in this manner, the paper on which recording for each color is completed is wound up by the winding roller, and the recording paper is returned when recording the next color. It will be. FIG. 5 shows a configuration example of a conventional wet development type color printer.

In the figure, reference numeral 1 is an electrostatic recording paper roll having a recording paper 2 wound around the outer circumference of a paper tube.
In this apparatus, 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. Furthermore, a guide roller 18 is provided on the downstream side of the recording paper feed roller 11.
However, a take-up roller 31 is further arranged on the downstream side, and the end portion of the recording paper 2 is guided to the recording paper feed roller 11 via the roller 3.

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. Reference numeral 5 denotes a multi-stylus electrostatic recording head that constitutes a recording system, and forms an electrostatic latent image on the recording paper 2 that moves in contact with the end surface thereof.

The developing heads 6 to 9 constitute a developing system, and the developing heads 6 to 9 are supplied with liquid developers (developing solutions) of different colors, and the electrostatic charges on the recording paper are discharged. The latent image is developed with the liquid developer. 4 in this example
The developing heads are arranged side by side. These developing heads 6 to 9 are used for the recording paper 2 as described later.
When a color image is formed while reciprocating a plurality of times, the ascending / descending operation is sequentially performed in synchronism with each reciprocating operation to perform a predetermined color image. When it is in contact, the other developing head is retracted from the recording paper 2, and the development is performed once at a time.
It is configured to perform each color.

Reference numeral 10 denotes a developing solution sucking roller which is installed downstream of the developing heads 6 to 9 and upstream of the recording paper feed roller 11, and which is used for developing the recording paper 2 during development by the developing head. It is for absorbing and removing the excess developer adhering to the top.

A pressing roller 12 is arranged in pressure contact with the peripheral surface of the recording paper feed roller 11, and the recording paper feed roller 11 holds the recording paper 2 in cooperation with the pressing roller 12. The recording paper 2 can be fed by rotating the recording paper feed roller 11. 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, the pressing roller is pressed. 12 and recording paper feed roller 11
The recording paper 2 can be held between and.

The guide roller 17 is provided with a guide roller 17 forming a pair with the guide roller 18. A pair of recording paper lead-out guide plates 14 are arranged on the outlet side of the recording paper feed roller 11, and a pair of guide plates are formed on the upstream side of the recording paper feed roller 11 so as to be opened between the guide rollers 18 and 17. 23 is arranged, and the recording paper 2 sent out from the recording paper feed roller 11 is sent out from the recording paper lead-out guide plate 14 to the guide plate 23, and is guided between them and between the guide rollers 18 and 17. It is supposed to be guided. Reference numeral 15 is a Y cutter that cuts the recording paper in a direction orthogonal to the recording paper feed direction, and 16 is an X cutter that cuts the recording paper in a direction parallel to the recording paper feed direction.

Reference numeral 26 is a recording paper path switching guide lever, the base end of which is rotatably supported by a pin 27. The recording paper path switching guide lever 26 guides the leading end of the recording paper 2 pinched and sent by the guide rollers 18 and 17 toward the automatic sheet winding device 30, or in the direction of the Y cutter 15 and the X cutter 16. It is for guiding or switching to.

When the recording paper path switching guide lever 26 guides the recording paper 2 to the Y cutter 15 and the X cutter 16, it guides the guided recording paper 2 to the Y cutter 15 and the X cutter 16. The rollers 19 and 20 and the guide plate 24 are arranged, and further the Y cutter 1
5, a guide plate 25 and a pair of guide rollers 2 for sending the recording paper 2 cut by the X cutter 16 to the outside.
1, 22 are arranged.

In the automatic recording paper winding device 30, a winding roller 31, a pressure contact roller 33 having a peripheral surface in contact with the winding roller 31, and the recording paper 2 guided and fed by the guide lever 26 are provided on the peripheral surface of the winding roller 31. Guide along the pressure contact roller 3
3 and a guide plate 32 which is guided between them. The recording paper 2 guided and guided by the guide lever 26 can be automatically wound around the winding roller 31.

The guide roller 3, the take-up roller 31, the recording paper feed roller 11, and the guide rollers 18 and 17 are rotated forward when the recording paper 2 is fed for recording or the like. At this time, the electrostatic recording paper is used. In order to apply tension to the recording paper 2, the roll 1 slowly rotates forward with an appropriate force or applies a moment of reverse rotation. In the case of rewinding, the electrostatic recording paper roll 1 is rotated in the reverse direction, and the guiding roller 3, the winding roller 31, the recording paper feed roller 11, and the guide rollers 18 and 17 apply tension to the recording paper 2. In addition, slowly rotate in the reverse direction with an appropriate force, or give a forward rotation moment.

In such a structure, the operation will be described. 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 is formed by the feed roller 11, the pressure contact roller 12, the guide rollers 17 and 18. It is set so that it is located between. The recording paper path switching guide lever 26 is set to a position that guides the leading end of the recording paper 2 toward the automatic sheet winding device.

In this set state, the recording paper 2 is fed in the right-hand direction in FIG. 6 for forming the first color image. Then, in order to form the color image of the first color, the multi-stylus electrostatic recording head 5 forms an electrostatic latent image of the color image of the first color on the recording paper 2.

Then, a toner image is obtained by developing these electrostatic latent images with the developing head of the corresponding color of the first color,
The image of the first color is recorded on the recording paper 2. When the recording of the image of the first color is finished, the recording of the second color is started,
Next, the electrostatic latent image formation and development for the required color are repeated, such as entering the recording of the third color.

The operation of this system will be described in detail. First, the multi-stylus electrostatic recording head 5 is actuated while feeding the recording paper 2 in the right-hand direction in FIG. 1, and the electrostatic for forming the first color image is formed. A latent image is formed on the recording paper 2.

This electrostatic latent image is developed by the developing heads 6, 7, 8, 9
For example, if it is the developing head 6 that has the liquid developer of the corresponding color of the first color, the developing head 6 is lifted as shown in FIG. Contact 2. Then, the electrostatic latent image of the first color is developed by the liquid developer supplied to the developing head 6, so that the toner contained in the liquid developer adheres to the electrostatic latent image to form a toner image. Can be changed to
The solvent of the liquid developer is highly volatile, and the toner attached to the electrostatic latent image has a property of firmly fixing when the solvent volatilizes.

During this series of processing, the recording paper 2 is wound around the outer periphery 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.

When the formation of the image of the first color is completed, the recording paper 2 is rewound on the recording paper roll 1 and the preparation for the formation of the color image of the second color is started. It is not rewound until it is separated from the outer circumference of the take-up roller 31, and only the tip portion is still wound around the outer circumference of the take-up roller 31. Then, the recording paper 2 is fed again in the right-hand direction, and the second recording paper 2 is transferred from the multi-stylus electrostatic recording head 5.
An electrostatic latent image for forming a color image of a color is formed on the recording paper 2.

This electrostatic latent image is electrostatically developed for the second color by elevating and developing the one of the developing heads 7, 8 and 9 having the liquid developer of the corresponding color of the second color. The latent image is converted into a toner image by the toner contained in the liquid developer adhering to the electrostatic latent image. During this period, the recording paper 2 whose front end is wound around the winding roller 31 is further wound around the winding roller 31.

By repeating the above operation, an image is recorded for each color, and a color image is obtained. The toner contained in the liquid developer is colored such that black is the liquid developer for black, magenta is the liquid developer for magenta, and cyan is the liquid developer for cyan.
By repeating the above operation for each color, the recording paper 2 is superimposed on the same paper surface to form a color image.

At the time of recording the last color, the recording paper 2 is wound around the outer circumference of the take-up roller 31 as in the previous color.
After the image formation is completed, the recording paper 2 is rewound on the recording paper roll 1.

At this time, the leading edge of the recording paper 2 is separated from the outer periphery of the take-up roller 31 and is rewound from the recording paper path switching guide lever 26 to the developing head side. After that, the recording paper path switching guide lever 26 moves the recording paper 2
Is switched to a direction in which the recording paper 2 is discharged to the outside of the apparatus, and the recording paper 2 is fed again, and the recording paper 2 which has been recorded is cut into a desired size by operating the Y cutter 15 and the X cutter 16 in accordance with the feeding positions. Is discharged to the outside of the device. The flow of such a series of operations is executed under the control of a control device (not shown).

[0029]

As described above, the conventional wet type developing device is provided with a plurality of developing heads 6 to 9 so as to supply the toners of a plurality of colors, and is in a roll shape. While the electrographic recording paper is being conveyed by the recording paper feed roller 11, the first recording head 5 for electrostatic latent image recording
An electrostatic latent image of a color is formed, and a developing head for a developer (a liquid developer containing toner of a color corresponding to the color) corresponding to the first color is raised from the standby position on the electrostatic latent image. After the recording paper 2 is slidably contacted and developed, the electrostatic recording paper 2 is rewound to the original roll, and while the recording paper 2 is conveyed again, the electrostatic latent image of the second color is formed by the recording head 5 and developed. This operation is repeated a plurality of times (several colors) to obtain a color image.

At the end of each development, the developing head descends to the standby position and retreats from the recording paper 2, but the recording paper is in contact with the developing head used for development. The developer (developer) adheres to and remains,
If the sheet is conveyed as it is, the developing solution adheres to the conveying rollers, and the image on the recording paper is stained.

Therefore, as shown in FIG. 6, the developing head 9
The squeeze head 103 is provided on the downstream side of the recording medium, and the excess developing solution remaining on the recording paper when the developing heads 6 to 9 used after the development is separated from the recording paper 2 is recorded by operating the vacuum pump 102. Remove from paper, waste liquid tank 10
It was supposed to be collected in 5.

As described above, in the conventional method, the developer adhering to the recording paper is sucked and removed by the squeeze device consisting of the squeeze head and the vacuum pump, but this causes waste liquid to be periodically discarded. There must be. In addition, since it is necessary to secure a space for installing the squeeze head, the transport path for the recording paper is lengthened accordingly, and installation of a squeeze head, a vacuum pump, a waste liquid tank, etc. makes it difficult to downsize the device. Further, there arises a problem that it leads to an increase in cost.

Therefore, the object of the present invention is to
An object of the present invention is to provide a wet developing device which can eliminate the conventionally provided squeeze device, reduce the size of the device, and reduce the cost.

[0034]

In order to achieve the above object, the present invention is configured as follows. That is, the recording paper on which the electrostatic latent image is formed is conveyed along the recording paper conveyance path, and the developer is applied to the surface of the conveyed recording paper to develop the electrostatic latent image. As a developing device used in a recording device, an opening is provided on the upper surface, and by sucking the opening to a negative pressure, the recording paper is sucked and the developing solution is sucked into the opening and circulated. Has a plurality of developing heads and a shaft parallel to the direction traversing the recording paper conveyance path, and the developing heads are arranged and held in parallel around the shaft, and the shaft is used as a center of rotation. By rotating the developing head, one of the developing heads sequentially faces a predetermined position of the recording paper conveyance path, and the developing head holding means for closely adjoining the road surface and the developing head used for the development at the time of negative pressure Negative pressure at the end Supply of Chitsutsu developer blocked, more constituting the developing head and control means for small angle rotating operation.

[0035]

In the above structure, by rotating the developing head holding means, the developing head is rotated about a rotation axis parallel to the recording sheet conveying path surface, and each developing head is sequentially opened on the upper surface. It is possible to switch the part between the developing action state parallel to the recording sheet conveyance path surface and the retracted state in which the section is obliquely separated from the recording sheet conveyance path surface. Then, since the developing head holding means rotates about the rotating shaft, each developing head enters the developing action state at a specific position. Then, for development, suction is applied to the developing head in the developing action state to give a negative pressure, so that the recording paper is attracted to the opening of the developing head and the negative pressure sucks the developing solution into the opening. By applying a developing solution to the surface of the recording paper, the electrostatic latent image formed on the surface of the recording paper is developed. When the development is completed, the developing head in the developing action state is rotated by a small angle to shift to the retracted state, and the supply of the developing solution is cut off. The developing head, which was in the developing action state, is tilted by this minute angle to create a slight gap with the recording paper surface, and air enters the opening through the gap of the developing head with respect to the recording paper surface. The liquid is sucked, and the developer adhering to the recording paper surface is also sucked and collected at the same time.

Accordingly, the squeeze device, which is a device dedicated to collecting the developer adhering to the recording paper surface, which has been conventionally provided, can be eliminated, whereby the length of the recording paper conveying path can be shortened and the device can be downsized. In addition, it is possible to reduce the cost because parts such as a squeeze head and a vacuum pump that are components of the squeeze device can be reduced, and a plurality of developing heads can be integrally attached to the developing head holding means. Since the developing head holding means is held and supported by the rotating shaft and is rotated together with the developing head holding means, the operation of tilting the developing head is easy, and the developing head has a simpler structure than the conventional one. It becomes possible to operate.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a wet developing apparatus showing one embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of one developing system. FIG. 3 shows the structure of the developing head and the state of the recording sheet. (A) is a partial plan view, (b) is a side sectional view of the recording sheet in close contact, and (c) is the recording sheet. It is a side surface sectional view in the state inclined by a minute angle. FIG. 4 is a state transition diagram for explaining the positional relationship of the developing head with respect to the recording paper in each state from the developing operation to the developing ending operation. FIG. At the time of sucking, (c) shows the time of reverse of the recording paper. In FIG. 1, 201 is a recording sheet, 202 is an electrostatic head (recording head), 203a and 203d are developing heads, respectively.
Reference numeral 204 is a developing frame.

Further, 3 and 10 and 12 are rollers,
Reference numeral 11 denotes a recording paper feed roller (driving roller), which constitute a recording paper conveyance system. The developing head 20
3a to 203d are added with subscripts a to d only when it is necessary to distinguish them from each other.
The subscript will be omitted in the general description of item 3. The same applies to other components described below.

The recording paper 201 is in the form of a roll, is wound around the recording paper feed roller 11 via the rollers 3 and 10, and is conveyed in the forward and reverse directions along a predetermined recording paper conveyance path. The developing heads 203a to 203d are of a developing solution suction type and are independently provided for each developing solution of one color, and are attached around the developing frame 204 at predetermined intervals.

That is, as shown in FIG. 1, the developing frame 204 is of a fan type, and a rotary shaft 205 is provided at a position corresponding to the main part of the fan, and the rotary shaft 205 is located below the recording paper conveying path. By arranging the rotary shaft 205 at a predetermined position in the area in parallel with the recording paper conveyance path, a desired point on the peripheral surface of the developing frame 204 can be opposed to the recording paper conveyance path.

By disposing and fixing the developing heads 203a, 203d at predetermined intervals in sequence on the peripheral surface of the developing frame 204, the developing frame 204 can be rotated about the rotating shaft 205. , Developing head 20
A desired one of 3a to 203d can be opposed to the recording paper conveyance path. The position of the developing head facing the recording paper transport path is the position in the developing action state, and the other positions are in the standby state (retracted position).

The rotating operation of the developing frame 204 is performed by a pulse motor (not shown), and the developing heads 203 of the respective colors are rotated.
a to 203d face the recording paper on the recording paper conveyance path at a predetermined position, and the operation amount required to rotate to the predetermined position is set in advance as a pulse number to a control device (not shown). Remembered The rotation operation amount is 90 ° to 1
All the developing heads 203a to 203d can face the recording paper 201 by rotating in this range over about 00 °.

The developing heads 203a to 203d are connected to independent developing solution supply systems, and are supplied with developing solutions of different colors. Developing head 203
a, ~ 203d generate a negative pressure by sucking with a pump, suck the recording paper to make a negative pressure inside, and use the negative pressure to suck up and circulate the developing solution. There is.

FIG. 2 shows a developing solution supply system for one system. The developing solution supply system will be described with reference to FIG. 2. The developing solution suction type developing head 203 using negative pressure has a developing solution supply port IN and a developing solution discharge port OUT of the developing head 203.
Is located in the lower part, and the developer tank 212 is arranged below the developing head 203, and the developer supply port IN and the developer tank 21 are provided.
2 are connected to each other via pipes 301 and 302 via a solenoid valve 211. The developer outlet OUT is connected to the suction side of the suction pump 210 via a pipe 303, and the discharge side of the suction pump 210 is connected to the developer tank 21 via a pipe 304.
Connected to 2. The electromagnetic valve 211 controls the opening and closing of the flow path from the developing solution tank 212 to the developing head 203, and is in an open state during development.

The developing head 203 has a recording paper 20 on its upper surface.
In order to attract 1 to cause the developing solution to act on the electrostatic latent image on the recording paper surface, a plurality of slit-shaped openings 64a to
64n are provided, and these slit-shaped openings 6 are provided.
4a to 64n each have a developer supply port IN at one end thereof.
Further, the other end is connected to the developing solution outlet OUT.

FIG. 3 shows the developing head 203 (203a to 20a).
3D) shows an example of the configuration, wherein FIG. 3A is a plan view of the developing head, FIG. 3B is a sectional view of the developing head and a posture at the time of development, and FIG. ing. In FIG. 3, reference numeral 203 is a developing head, 62 is a rod-shaped substrate, 63 is a flat peripheral flat surface portion, 64a to 64n are slit-shaped openings, IN is a developing solution supply port, OUT is a developing solution discharge port, and 65 is a developing solution inflow. A passage, 66 is a developing solution outflow passage in the head, an arrow Y is a recording paper feed direction at the time of development, and P is a recording paper.

The base 62 is in the shape of an elongated rod box,
Slit-shaped openings 64a to 64n are formed on the upper surface thereof. The slit-shaped openings 64a to 64n are arranged so as to extend along the longitudinal direction of the base body 62, and a plurality of slit-shaped openings 64a to 64n are provided in parallel on the upper surface of the base body 62. The peripheral flat surface 63 is formed.

The lengths of the slit-shaped openings 64a to 64n are set to be slightly shorter than the width of the recording paper P. A developing solution supply port IN is provided at the bottom near the one end of the rod-shaped base 62, and a developing solution outlet OUT is provided at the bottom near the other end of the rod-shaped base 62. .. The developing solution supply port IN is connected to the head inflow passage 6
5 is communicated with the bottoms of the slit-shaped openings 64a to 64n on one end side, and the developer outlet OUT is provided in the head outflow passage 6
The slit-shaped openings 64a to 64n are communicated with the bottoms of the slit-shaped openings 64a to 64n on the other end side. Next, the operation of the present apparatus having such a configuration will be described. Although not shown, the following operation is performed under the control of the control device provided with the control device.

In the initial state, the developing frame 204 is rotated to move the developing head 203 having the supply system of the developing solution for the color to be developed first to the position in the developing action state. In this state, the developing head 2 in the position of the developing action state
03 (for example, 203a) is the state as shown in FIG. 4A, and the others are in the standby state.

Now, assume that the recording paper 201 (P) is unwound from the roll and set in the recording paper conveyance path, and the electromagnetic valve 211 of the developing solution supply system of the developing head 203 is opened to open the developing solution supply system. When the suction pump 210 is operated, the slit-shaped openings 64a to 64 of the developing head 203a.
n is exhausted, and the inside of these is made negative pressure. As a result, the recording paper 201 (P) is attracted to the upper peripheral flat surface portion 63 of the developing head 203a. When the recording paper 201 (P) is adsorbed by the developing head 203a, the slit-shaped openings 64a to 64n, which are developing grooves, form a closed flow path for the developing solution. Therefore, the developing solution flows from the developing solution tank 212 into the developing head 203a through the electromagnetic valve 211, fills the slit-shaped openings 64a to 64n, and further circulates from the developing head 203a to the suction pump 210 to the developing solution tank 212. Form a return channel.

Then, a slit-shaped opening 64 which is a developing groove.
The developer flowing in a to 64 n acts on the surface of the recording paper 201 (P), and the recording head 202 causes the recording paper 201 (P) to move.
The electrostatic latent image formed on (P) is developed.

When the development is completed, the developing frame 204 is driven to rotate about the rotating shaft 205 by a small angle (about 1 degree) by the driving device (not shown), and the developing head 203a is moved to the above-mentioned position as shown in FIG. 4B. Tilt only a small angle.

At the same time, the electromagnetic valve 11 is switched to the closed state, and the developing head 203a and the developing solution tank 21 of the developing solution supply system thereof.
The flow path to 2 is shut off, and the supply of the developing solution from the developing solution tank 212 is stopped.

At this time, the operation of the suction pump 210 is continued, and as shown by the arrow in FIG.
1 to the slit-shaped opening 6 of the developing head 203a from a slight gap generated in the developing head 203a inclined by a minute angle.
Air AIR flows into 4a to 64n, and the developer in the slit-shaped openings 64a to 64n is sucked by the suction pump 210 and collected in the developer tank 212. Further, with the suction of the air AIR, the excess developer adhering to the recording paper surface is also collected.

Further, in this state, the recording paper feed roller 11
When the recording paper surface is separated from the developing head 203a, the adhering developer on the recording paper 201 is sucked and removed into the slit-shaped openings 64a to 64n by moving the recording paper 201 in the forward direction by an appropriate amount. Completely dried.

When the removal of the adhering developer on the recording paper 201 is completed, the developing frame 204 is further rotated about the rotating shaft 205 by a driving device (not shown), whereby the developing head 203a used for the development. Moves from the recording paper conveyance path to the standby state position, and FIG.
The state of (c) is obtained. The developing head 203a is the recording paper 20.
When retracted from 1, the recording paper 201 is rewound, and the recording paper 201 is returned to the start position.

When the developing frame 204 rotates and the developing head 203 (for example, 203b) of the next color reaches the developing action position, the developing frame 204 is stopped, and this time, the above-described developing solution supply system of the developing head 203b. Drive control is performed. Then, thereafter, similarly, the above operation is repeated for each color while sequentially switching the developing heads by the number of colors necessary for forming the electrostatic latent image and the image for which development is to be recorded.
Get a color image.

Although not shown, the developing head is rotated by using a DC motor, a pulse motor or the like, and the positioning of each position can be performed by detection by a sensor or pulse counting of the pulse motor. it can.

As described above, this apparatus has the opening on the upper surface, and by making this opening a negative pressure, the negative pressure is utilized to suck the recording paper, and at the same time, the developing solution is introduced into the opening. A plurality of developing heads sucked and circulated and supplied are rotatable about an axis parallel to a direction traversing the recording paper conveyance path, and one of the desired ones is sequentially specified by the rotation operation. The developing head is arranged in a positional relationship of being close to the road surface facing the position, the developing head used for development is made negative pressure at the time of development, and at the end of development, the supply of the developing solution is cut off while maintaining the negative pressure. Is configured to be rotated by a small angle.

The developing head is rotated about a rotation axis parallel to the recording paper conveyance path surface, so that the opening on the upper surface is in a developing operation state parallel to the recording paper conveyance path surface and the recording paper conveyance path surface. It is possible to switch to a retracted state in which the recording paper is attracted to the opening by negative pressure in the developing action state, and the developing solution is sucked into the opening by this negative pressure and the developing solution acts on the recording paper surface. By doing so, the electrostatic latent image formed on the recording paper surface is developed,
At the end of development, the developing head that was in this developing action state is moved to a retracted state by rotating it by a small angle,
Air is sucked in by utilizing the gap of the developing head with respect to the recording paper surface generated by this slight angle inclination,
By shutting off the supply of the developing solution, the developing solution in the opening of the developing head and the adhering developing solution on the surface of the recording paper are collected.

Therefore, the squeeze device, which is a device dedicated to collecting the developer adhering to the recording paper surface, which has been conventionally provided, can be eliminated, whereby the length of the recording paper conveying path can be shortened and the device can be miniaturized. In addition to this, it is possible to reduce the cost because parts such as a squeeze head and a vacuum pump that are components of the squeeze device can be reduced, and the developing head can be integrally attached to a structure holding a plurality of developing heads. Since the structure (unit) is supported by the rotating shaft and is rotated together with the structure, the operation of tilting the developing head is easy, and the operation of the developing head is simpler than the conventional one. It will be possible.

The present invention is not limited to the above-mentioned embodiments, and can be carried out by appropriately modifying it within the scope not changing the gist thereof. For example, in the above-mentioned embodiments, the present invention is color electrostatic recording. Although it is applied to the apparatus, it is needless to say that the present invention is not limited to this and can be applied to a wet developing apparatus using another slit developing device.

[0064]

As described above, according to the present invention, a small amount of air flows in through the gap between the inclined developing head and the recording paper, and the developer in the developing groove can be efficiently removed.
Further, by feeding the recording paper with the developing head tilted, it is possible to suck and remove the adhesion of the developing solution to the recording paper when the recording paper is separated from the developing head. Therefore,
The squeeze device that has been conventionally provided can be eliminated, so that the transport path can be shortened and the device can be downsized. Moreover, since the related components of the squeeze device can be reduced, the cost can be reduced. Further, since the plurality of developing heads are rotated together with the unit as a unit, the operation of tilting the developing head is easy, and this can be performed with a simpler configuration than in the past.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a wet developing apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of one developing system used in the developing device of FIG.

3 is a diagram showing a configuration of a developing head used in the apparatus of FIG. 1 and a state of recording paper.

FIG. 4 is a view for explaining the positional relationship of the developing head with respect to the recording paper in each state from the developing operation to the developing end operation.

FIG. 5 is a schematic configuration diagram of a conventional wet developing device.

FIG. 6 is a schematic configuration diagram of a conventional wet developing device.

[Explanation of symbols]

2a, 3, 10, 12 ... Roller, 11 ... Recording paper feed roller (driving roller), 62 ... Substrate, 64a to 64d ... Slit-shaped opening (developing groove), 201, P ... Recording paper, 202 ...
Electrostatic head (recording head), 203a to 203d ... Developing head, 204 ... Developing frame, 205 ... Rotating shaft, 2
10 ... Suction pump, 211 ... Electromagnetic valve, 212 ... Developer tank.

Claims (1)

[Claims] 1. A recording paper on which an electrostatic latent image is formed is conveyed along a recording paper conveyance path, and a developing solution is caused to act on the surface of the conveyed recording paper, whereby the electrostatic latent image is formed. As a developing device used in a recording device for developing a sheet, an opening is formed on the upper surface, and by sucking the opening to a negative pressure, the recording paper is sucked and the developing solution is sucked in the opening. It has a plurality of developing heads that are circulated and an axis that is parallel to the direction that traverses the recording paper conveyance path. Around this axis, the developing heads are arranged and held in parallel, and the axis is rotated. One of the developing heads sequentially faces a predetermined position of the recording paper conveyance path by rotating around the moving center, and a developing head holding means for closely adjoining the road surface, and a negative pressure for the developing head used for development during development. And at the end of development A wet developing device, comprising: a control unit that shuts off the supply of a developing solution while maintaining a negative pressure and rotates the developing head by a small angle.