JPH0792816A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device capable of sufficiently drying a recording medium when it passes through a developing device, making the fixability of toner sure and obtaining an excellent image without the soiling of an image, tailing, etc., in an image forming device obtaining an image by operating a developer for the recording medium on which a latent image is formed. CONSTITUTION:The image forming device forming the image in such a manner that the developer is supplied to an image forming surface by the developing unit 62, while carrying the recording medium 51 whose image forming surface has the formation of the latent image is constituted to provide the developing device 62 for supplying the developer onto the image forming surface of the recording medium 51, a sucking groove 622A placed in the downstream side than a developer supplying position when viewing in the carrying direction of the recording medium 51 at the time of developing and sucking outdoor air with negative pressure and the developer on the recording medium 51 and a drying groove 622B located in the downstream side of the sucking groove and sucking the outdoor air from the gap with the recording medium 51 with the negative pressure to dry the developer on the recording medium 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an electrophotographic image forming apparatus, and in particular, an image forming apparatus for applying a developing solution containing toner to a recording medium on which an electrostatic latent image is formed and developing the image. Developing device.

[0002]

2. Description of the Related Art As an image output device for printing an image, an image is obtained by forming a latent image on an image bearing member such as a photosensitive drum or a dielectric drum or recording paper and developing the latent image with toner to obtain a print output. The forming apparatus is called an electrophotographic method, an electrostatic recording method or the like depending on the latent image forming method and is widely put into practical use. Then, there is one in which a developing solution containing a toner is applied to a recording medium (recording paper) on which an electrostatic latent image is formed to develop the electrostatic latent image. For example, there is a wet electrostatic plotter or the like.

A schematic configuration of this type of image forming apparatus is as shown in FIG. This figure shows an example of a multicolor electrostatic plotter. In the figure, 51 is an electrostatic recording paper, and this electrostatic recording paper 51 is a long sheet, which is wound in a roll 52 shape. , Installed in place. The leading end of the long electrostatic recording paper 51 is pulled out from the roll 52 and is stretched from the roller 72 to the drive roller 71. The drive roller 71 is for conveying the electrostatic recording paper 51, and is rotationally driven by a motor (not shown).
Further, a nip roller (not shown) is arranged to face the drive roller 71, and the nip roller and the drive roller 71 are arranged.
By sandwiching the electrostatic recording paper 51 between and, the electrostatic recording paper 51 is conveyed in the longitudinal direction by the rotational force of the driving roller 71.

Electrostatic recording paper 51 wound into a roll 52
In the installation position, back tension is always applied by a rewinding motor (not shown), and rewinding can be performed in order to print another color on the electrostatic recording paper 51. .

Between the roller 72 and the driving roller 71, an electrostatic recording head 61 for forming an electrostatic latent image on the sheet surface of the electrostatic recording paper 51, and a developing solution on the sheet surface of the electrostatic recording paper 51. The developing devices 62a, 62b, 62c and 62d for imparting the electrostatic recording paper are provided, and the electrostatic recording head 61 is arranged in contact with the sheet surface of the electrostatic recording paper 51. Further, the developing units 62a, 62b, 6
Reference numerals 2c and 62d are provided for applying a developing solution to the sheet surface of the electrostatic recording paper 51 to perform development, and the developing units 62a and 6d.
During development, 2b, 62c, and 62d are moved to positions (developing positions) in which one of them to be developed is in contact with the sheet surface of the electrostatic recording paper 51, and the other are positions apart from the sheet surface of the electrostatic recording paper 51. It is a mechanism to be retracted to (standby position).

Further, the electrostatic recording head 61 and the developing device 62
Each of a, 62b, 62c, and 62d has at least a length corresponding to the width of the sheet surface of the electrostatic recording paper 51, and is arranged in the width direction of the sheet surface of the electrostatic recording paper 51.

The developing device 62a is for black (black; K), the developing device 62b is for cyan (C), the developing device 62c is for magenta (M), and the developing device 62d is for yellow (Y). , 62b, 62c, and 62d are each independently provided with a developing solution supply system for each color, which constitutes a developing device. Each developing solution supply system has a developing solution circulating device, a toner supplying device, and a toner concentration measuring device, and at the time of development, the developing solution circulating system of the developing solution supplying system in the developing device used for the development at that time, The density of the circulating developing solution is measured, and the toner supply control to the developing solution circulating system by the toner supplying device is performed according to the result of the concentration measurement.

The structure of each developing solution supply system in each of the developing devices 62a, 62b, 62c, 62d will be described by taking the developing device 62a for a black image as a representative example.

The developing unit 62a has an elongated box-like structure.
An opening slit is provided in the upper part, and an inlet and an outlet for the developing solution are provided at the bottom of the developing device 62a. The developing solution is supplied from the inlet of the developing solution and discharged from the outlet to create a new developing solution inside the developing device 62a. And the developing solution is applied to the sheet surface of the recording paper 51 at the upper opening slit.

The developing device 62a is connected to one end of a developing solution supply passage 63a by a tube at the developing solution inlet and one end of a developing solution discharge passage 64a by a tube at the developing solution outlet. Further, in the middle of the developing solution supply passage 63a,
The toner concentration measuring device 65a is provided, and the developer supply path 6 is provided.
The other end of 3a is connected to the developer tank 53a. Further, the other end side of the developer discharge path 64a is connected to the developer tank 53a.

The black developer 5 is placed in the developer tank 53a.
4a is contained therein, and the other end of the developer supply path 63a is immersed in the developer 54a. A circulation pump 66a using a vacuum pump is provided in the middle of the developer discharge path 64a.

As described above, the black developing system is constructed around the developing unit 62a. Similarly, the developing device 62b as the center, a cyan developing system (not shown), and the developing device 6
2c as a center, a magenta developing system not shown, and a developing device 6
A yellow developing system (not shown) is constructed around 2d. The developing devices 62a to 62d can be selectively brought into contact with and separated from the lower surface of the electrostatic recording paper 51 by a driving mechanism (not shown).

Next, the operation of the recording apparatus having the above configuration will be described. Assuming that a black image is recorded first, first, a drive mechanism (not shown) brings the developing device 62a into contact with the electrostatic recording paper 51 under the control of the control device, and causes the pump 66a to be driven by suction. Due to the suction force of this pump, the inside of the developing device 62a is sucked to a negative pressure, and the electrostatic recording paper 5
One surface is attracted to the opening slit of the developing device 62b. Due to this adsorption, the negative pressure inside the developing device 62b becomes high, and the other end of the developing solution tank 53a is immersed in the developing solution supply passage 63a.
Then, the developing solution in the developing solution tank 53a is sucked. Then, from the one end side of the developing solution supply passage 63a to the developing device 62b.
The developer is sucked into the inside of the container and fills the inside of the developing device 62b. As a result, the developing solution in the developing unit 62b is stored in the recording paper 51.
It is applied to the surface and exerts a developing action.

The developing solution in the developing device 62b is circulated by a circulation pump 66.
The negative pressure a causes the developer to be discharged into the developer tank 53a through the developer discharge passage 64a. As a result, the developer tank 53
The developing solution in a is circulated to maintain the developing action.

In this way, the developer 54a, which is a liquid developer, can be circulated in the developing unit 62b by the circulation pump 66a. Next, the recording paper 51 is moved to the driving roller 7
The sheet is sent out from the roll 52 by 1 and conveyed (forward conveyance). At the same time, a latent image corresponding to a black image is formed on the electrostatic recording paper 51 by the electrostatic recording head 61. The electrostatic recording paper 51 on which the latent image for the black image is formed is conveyed onto the developing device 62a, where the latent image for the black image is developed with the black developer supplied to the developing device 62a. The black image is completed.

After the black image is formed, the developing device 62a descends to the standby position under the control of the control section, and the electrostatic recording paper 51 is discharged.
The developer remaining on the top is removed by a suction device (not shown).

Since the developing device 62a is lowered to the standby position, the upper opening slit is opened to the atmospheric pressure, the internal negative pressure is released, and the circulation of the developing solution is stopped. On the other hand, the electrostatic recording paper 51 on which the black image is formed is conveyed in the opposite direction by the reverse rotation of the roll 52 and the drive roller 71, and is rewound on the roll 52.

When rewound, for example, the cyan developing device 62b is moved upward from the standby position to the developing position, and the developing device 62b is circulated in the same manner as in the case of black. It

Then, the electrostatic recording paper 51 is started to be conveyed in the forward direction, and the electrostatic recording paper 51 is moved from the electrostatic recording head 61.
A latent image for a cyan image is formed on the developing device 6 and the latent image is developed.
By 2b, a cyan developer is applied and developed. When the development of the cyan image is completed, the developing unit 62b is lowered to the standby position, the electrostatic recording paper 51 is conveyed in the reverse direction, and the roll 5 is rolled.
Rewind to 2.

The same operation is performed for the developing units 62c and 62d, and the magenta and yellow images are sequentially recorded on the cyan image and the black image, and a final color image is obtained. When the color image is completed, the recorded area of the electrostatic recording paper 51 passes through the position of the driving roller 71, is cut to a required size by an X cutter and a Y cutter (not shown) located downstream of the forward transport path, and is discharged from the discharge port to the outside. The print is completed.

Here, a conventional example of each developing device of such an image forming apparatus is shown in a perspective view in FIG. 9, and sectional views of a developing device portion of the developing device are shown in FIGS. 10, 11 and 12, respectively. . 10 is a view showing a cross section taken along the line AA of the developing unit 62 in FIG. 9, and FIG. 11 is a cross section taken along the line BB of the developing unit 62 in FIG. 12 is a schematic diagram of FIG. 9, and FIG.
It is the figure which showed the arrow cross section. Here, the developing units 62a, 62
b, 62c, and 62d have the same structure, and a, which is attached to each of the general descriptions, is a.
The subscripts of ~ d are omitted and the subscripts are added only when necessary.

As shown in the figure, the developing device 62 has an elongated box-shaped structure, and a plurality of opening slits 621 extending in the longitudinal direction are arranged on the upper part of the elongated box-shaped developing device main body 620 in order in the lateral direction. ing. In the figure, the developing device main body 62
This is a configuration in which three opening slits 621 are provided in the upper part of 0. Further, the opening slit 6 is provided on the upper part of the developing device main body 620.
The slit 62 is located in the downstream side of the electrostatic recording paper 51 when the electrostatic recording paper 51 is transported in the forward direction as viewed from 21, and is parallel to the opening slit 621.
2 is formed, and this slit 622 is used as a suction groove. The slit 622 that serves as a suction groove is longer than the opening slit 621.

At the bottom of the developing device main body 620, a developing solution supply port (developing solution inlet) 623 and a developing solution discharge port (developing solution outlet) 624 are provided which communicate with each of the plurality of opening slits 621. Then, the developing solution is supplied from the developing solution supply port 623 and discharged from the developing solution discharge port 624 to fill each opening slit 621 in the developing device 62 with a new developing solution, and the upper opening portion of the opening slit 621 is electrostatically charged. A developing solution is applied to the sheet surface of the recording paper 51.

Each developing solution supply port 623 has a corresponding opening slit 6
21 is located near one end side, and each developer discharge port 624 is located near the other end side of each opening slit 621. In addition, the slit 622 which is a suction groove has a suction port 625 communicating with the bottom of the developing device main body 620 on the other end side, and the suction port 625 of this slit 622 is a suction pump together with the developer discharge port 624. It is connected to the suction side conduit 64 of a circulation pump 66.

A developing solution tank 53 is arranged below the developing device main body 620, and each developing solution supply port 6 is provided.
Reference numeral 23 denotes a pipe line 63 having a lower end inserted in the developer tank 53.
Is connected to the upper end portion of the circulation pump 66, and the discharge side of the circulation pump 66 is connected to the inside of the developer tank 53 via a pipe line. By driving the circulation pump 66, each opening slit 621 and the slit 622 are sucked. can do.
Then, the electrostatic recording paper 51 is covered with the upper surface of each opening slit 621.
, The electrostatic recording paper 51 is attracted to the upper surface of each opening slit 621, the inside of the slit becomes a negative pressure, the developing solution in the developing solution tank 53 is sucked into each opening slit 621, and the developing solution discharge port is formed. 624 through the circulation pump 66 to the developer tank 53, and each opening slit 6
The developing solution filled in 21 is applied to the electrostatic recording paper 51 to continue the developing action.

Therefore, by the electrostatic recording head 61, development is carried out in the development groove (each opening slit 621) in the upper surface portion of the developing device 62 covered with the recording medium (electrostatic recording paper 51) on which the latent image is formed. By suctioning from the liquid discharge 624 by the circulation pump 66, a negative pressure is generated in the developing groove, and the developing solution in the developing solution tank 53 is made to flow from the developing solution supply port 623.
Development can be performed while circulating the developing solution. Since the slit 622, which is a suction groove, is also connected to the discharge side of the circulation pump 66, the inside of the groove of the slit 622 becomes negative due to the negative pressure of the circulation pump 66, and the inside of the groove is sucked.

During the development, the recording medium (electrostatic recording paper 51) is conveyed in the direction D, which is the forward conveying direction, and the developer excessively attached to the recording medium is covered with the recording medium. Is sucked in vacuum by the suction groove (slit 622) in and the developer is removed by suction.

[0028]

As described above, in the wet type developing device of the image forming apparatus, the developing solution is sucked and circulated by the negative pressure obtained by the pump suction in the slit on the upper surface of the developing device. Recording medium under development (electrostatic recording paper 51)
The developer is applied to the latent image forming surface at the stage of being conveyed in the direction A, which is the forward conveying direction, and is developed, and the developer excessively attached to the recording medium is covered by the recording medium being conveyed. The developer is removed by vacuum suction in the suction groove (slit 622) on the upper surface of the developing device 62.

The developing solution is a mixture of a highly volatile solvent and toner, and when the solvent evaporates and dries, the toner is stably fixed on the surface of the recording medium. Therefore, there is no special fixing step.

However, in such a developing operation, the developing solution on the recording medium immediately after passing the developing device is not completely dry and is in an unstable state, and as a result, the internal conveyance path of the image forming apparatus is formed. Peeling of an image due to contact between the recording medium that is conveyed with the path component in
The peeled developer pigment may adhere to the recording medium again to cause image smearing or an image tailing phenomenon, impairing the quality of the formed image.

Therefore, an object of the present invention is to provide an image forming apparatus using a developing type developing device for developing a recording medium on which a latent image is formed by causing a developing solution to act on the recording medium. Provided is an image forming apparatus capable of being sufficiently dried when passing through a sheet, ensuring a fixing property of toner, and capable of obtaining a good image without image stains or tailing. To do.

[0032]

In order to solve the above-mentioned problems and achieve the above object, the present invention is configured as follows. That is, in an image forming apparatus that conveys a recording medium having a latent image formed on the image forming surface and forms an image by applying a developing solution to the image forming surface by a developing device, the image forming surface of the recording medium is developed. A suction device for sucking the developing solution on the recording medium by sucking the outside air by a negative pressure by arranging the developing device for applying the liquid on the downstream side of the developing solution applying position when viewed from the conveying direction of the recording medium during development. A groove and a drying groove which is located on the downstream side of the suction groove and sucks the outside air from the gap between the recording medium and the negative pressure to dry the developing solution on the recording medium are provided.

[0033]

In the present apparatus having such a structure, the developing solution applied to the recording medium by the developing device is sucked and removed by the suction groove, and air is taken in from the space between the recording medium and the drying groove. An air flow is applied to the image forming surface to dry it.

As described above, the excess amount of the developer applied to the recording medium is sucked and removed by the suction groove, and further air is sucked through the gap between the recording medium and the drying groove, and the drying effect of the ventilation causes the drying effect. Since the more complete drying of the developing solution on the recording medium is promoted, the image on the recording medium which has been developed and visualized has a high degree of fixing, and is rubbed and smeared at the recording paper conveying stage, There is no fear of causing tailing or peeling and it becomes possible to form a high quality image.

Therefore, by applying a developing solution to the recording medium, in an image forming apparatus using a developing type developing device for developing, the recording medium can be brought into a sufficiently dry state when passing through the developing device. In addition, it is possible to provide an image forming apparatus in which the fixing property of the toner is ensured and a good image can be obtained in which the image is free from stains and tailing.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) Since the basic structure of the image forming apparatus according to the present invention is the same as that of the conventional example, only the main part will be described below. When the developing device of the present invention is applied to an image forming apparatus, FIG. 1 is a perspective view showing the configuration of essential parts, and FIG. 2, FIG. 3 and FIG. 4 are sectional views of the developing device portion of the developing device.
2 is a view showing a cross section taken along the line AA of the developing unit in FIG. 1, which is a cross section taken along the line AA, and FIG. 3 is a view showing a cross section taken along the line BB of the developing unit in FIG. And FIG.
FIG. 2 is a view showing a cross section taken along the line CC of the developing device in FIG. 1.

In the case of a multicolor image forming apparatus, the developing device 62 is for black, cyan, magenta, and yellow developing devices 62a, 62b, 62c, 62 as described above.
Although there is d, the structure is the same in the present embodiment as well, and when giving general explanations, the subscripts of a to d added when individually explaining are omitted, and only when necessary,
I will add a subscript.

As shown in the figure, the developing device 62 has an elongated box-shaped structure, and a plurality of opening slits 621 extending in the longitudinal direction are arranged in order in the lateral direction on the upper part of the elongated box-shaped developing device main body 620A. Has been done. In the figure, three developing unit main bodies 620A are provided with three opening slits 621. Further, two slits 622A and 622B are formed in parallel with the opening slit 621 at the upper part of the developing device main body 620A so as to be positioned downstream from the opening slit 621 when the electrostatic recording paper 51 is conveyed in the forward direction. The slits 622A and 622B are used as suction grooves for sucking and removing the excess developer by using the former and as drying grooves for completely drying the latter. The slits 622A and 622B are longer than the opening slit 621.

At the bottom of the developing device main body 620A, there are provided a developing solution supply port (developing solution inlet) 623 and a developing solution discharge port (developing solution outlet) 624 which communicate with each of the plurality of opening slits 621. Then, the developing solution is supplied from the developing solution supply port 623 and discharged from the developing solution discharge port 624 to fill each opening slit 621 in the developing device 62 with a new developing solution, and the upper opening portion of the opening slit 621 is electrostatically charged. A developing solution is applied to the sheet surface of the recording paper 51.

Each developing solution supply port 623 has each opening slit 6
21 is located near one end side, and each developer discharge port 624 is located near the other end side of each opening slit 621. Further, the slits 622A which are suction grooves and the drying groove 622B are respectively formed with suction ports 625 which communicate with the bottom portion of the developing device main body 620A on the other end side.
Each of the suction ports 625 of 22A and 622B has a developer discharge port 62.
4 is connected to the suction side conduit 64 of the circulation pump 66 which is a suction pump.

A developing solution tank 53 is arranged below the developing device main body 620A, and each developing solution supply port 623 has a conduit 6 whose lower end is inserted into the developing solution tank 53.
3 is connected, and the discharge side of the circulation pump 66 is connected to the inside of the developer tank 53 via a pipe line.
By driving the circulation pump 66, the opening slits 621 and the slits 622A and 622B can be sucked. When the upper surface of each opening slit 621 is covered with the electrostatic recording paper 51, the electrostatic recording paper 51 is attracted to the upper surface of each opening slit 621, the inside of the slit becomes negative pressure, and the developing solution in the developing solution tank 53 is developed. Is each opening slit 62
1, and the circulation pump 6 from the developer discharge port 624.
The developer that has been circulated in the path through the developer tank 53 to the developer tank 53 and is filled in the opening slits 621 is stored in the electrostatic recording paper 5.
1 to maintain the developing action.

Accordingly, in the apparatus having such a structure, the electrostatic recording head 61 covers the developing groove (in the upper surface of the developing device 62 covered with the recording medium (electrostatic recording paper 51) on which the latent image is formed). The developer discharge 62 is provided in each opening slit 621).
By performing a suction operation from 4 through the circulation pump 66, the inside of the developing groove is made a negative pressure, the developing solution in the developing solution tank 53 is made to flow in from the developing solution supply port 623, and the developing solution can be circulated for development. Since the slit 622A which is a suction groove and the slit 622B which is a drying groove are also connected to the discharge side of the circulation pump 66, the negative pressure of the circulation pump 66 also causes a negative pressure in the groove of the slit 622 to suck the inside of the groove. It will be in the state of being.

During development, the recording medium (electrostatic recording paper 51; hereinafter referred to as recording medium) is conveyed in the direction of arrow A, which is the forward conveying direction, and the developer excessively attached to the recording medium is covered with the recording medium. Vacuum suction is performed by the suction groove (slit 622A; hereinafter referred to as suction groove) on the upper surface of the developing device 62, and the developer is removed by suction. Further, when passing through a drying groove (slit 622B; hereinafter referred to as a drying groove) located downstream of the suction groove (slit 622A), this drying groove (slit 622B; hereinafter referred to as a drying groove) has an internal negative pressure. By sucking the outside air through the gap between the upper opening side and the recording medium (electrostatic recording paper 51), the surface of the recording medium 51 is further dried by the sucked outside air flow.

The operation will be specifically described. The recording medium 51 is a long one made of a paper or polymer film having a surface coated with a dielectric film, and when the recording medium 2 passes over the recording head 61, an electrostatic latent image is formed. It The recording medium on which the latent image is formed is conveyed to the developing device 62 side.
When the image forming apparatus is a multi-color recordable apparatus, the latent image is formed for each color, and the developing apparatus for the developing solution of the corresponding color is used depending on the color of the formed latent image. Then, the developing device of the developing device is moved from the standby position to the developing position and provided for development.

The developing device 62 includes a developing groove 621 and a suction groove 6.
22A and a drying groove 622B are provided. Development groove 62
1 is connected to the developer tank 53 via the developer supply port 623. Further, the developing groove 621, the suction groove 622A, and the drying groove 622B are connected to the developer discharge port 624, the vacuum suction port, and the suction port 625 which is an air outlet, respectively, and the pump 66 is connected to the developer tank 53. It is connected.

Therefore, when the pump 66 is in operation, the upper surface side of each slit groove of the developing groove 621, the suction groove 622A, and the drying groove 622B is covered with the recording medium 51.
A negative pressure is applied, and the developing solution is introduced into the developing groove 621 through the developing solution supply port 623.
The latent image on the recording medium 51 is developed while circulating along the path of the developing groove 621, the pump 66, and the developing solution tank 66.
The developer that excessively adheres to the recording medium 51 reaches the suction groove 622A while being conveyed in the forward direction, and is sucked due to the negative pressure inside the suction groove 622A, so that the recording medium (electrostatic recording It is sucked together with air into the suction groove 622A from above the paper 51). Then, it is collected in the developer tank 53 via the pump 66.

The recording medium (electrostatic recording paper 51) has a suction groove 62.
After passing 2A, it further reaches the drying groove 622B.
The recording medium (electrostatic recording paper 51) is sucked due to the negative pressure inside the drying groove 622B, and at this time, air is dried from the slight gap between the developing device 62 and the recording medium due to the unevenness of the surface of the recording medium. It flows into the groove 622B, and the developer on the recording medium is forcibly dried by ventilation by the flow of air.

By adopting such a structure, the drying groove 622B has the effect of drying the developing solution on the recording medium 51, and when the suction groove 622A cannot completely suck the developing solution,
It also has the effect of removing the developer that could not be completely sucked. In order to further enhance such an effect, the developing groove 62
1 and the suction groove 622A may be structured such that the circulation pump 66 sucks, but it is better to provide another suction pump for sucking the drying groove 622B. This is because it takes a large load to suck even the developing groove 621, the suction groove 622A and the drying groove 622B with one circulation pump 66, and the developing groove 621, the suction groove 622A and the drying groove 622B have respective roles. This is because it is more convenient to separate the developer system and the drying system in which only air flows in order to fulfill the respective roles.

As described above, the developing groove, the suction groove, and the drying groove are provided in the developing device, the developing solution is circulated in the developing groove, and the suction groove and the drying groove are provided with a negative pressure to perform only the suction operation. The excess amount of the developer applied to the recording medium in the groove is sucked and removed in the suction groove, and air is sucked through the gap between the recording medium and the drying groove, and the drying effect by the ventilation causes the development on the recording medium. It is designed to promote more complete drying of the liquid.

Therefore, the image developed and visualized on the recording medium has a good degree of fixing, and there is no fear of rubbing and smearing, tailing of the image, or peeling when the recording paper is conveyed. , It becomes possible to form high quality images.

In the above embodiments, the drying groove has the same shape as the suction groove, but it may have the same shape as the suction groove, or it does not necessarily have to have the same shape. In short, the present invention is to provide a groove on the upper surface of the developing device, the main purpose of which is to dry the developing solution on the recording medium, and the suction for the purpose of removing the excessive developing solution adhering to the recording medium. Even when the groove and the shape are the same, the function is clearly distinguished.

In order to further enhance the function of the drying groove, it is preferable that the sucked air is in a good circulation state and that the recording medium is not adsorbed to the developing device more than necessary. Another embodiment of the drying groove capable of obtaining such an effect will be described below.

(Second Embodiment) Another embodiment of the drying groove 622B will be described with reference to FIG. The example shown in FIG. 5 is a perspective view of the developing device 62, and 620B is a developing device main body and 621.
Is a developing groove, 622A is a suction groove, and 622B is a drying groove. In this example, in order to prevent the recording medium 51 from being attracted to the developing device more than necessary and to allow the dry airflow to flow through the gap between the recording medium 51 and the recording medium 51 as much as possible, the developing device main body 620B has the recording medium order. U connected to the drying groove 622B at the upper end surface on the downstream side when viewed from the transport direction
A plurality of V-shaped air circulation grooves 700 are arranged.

When the length of the developing device 62 is about 1 m, the air circulation groove 700 has a width of about 2 mm, which is close to the width of the developing groove 621, a depth of about 0.5 to 1 mm, and an array number of 10
It is enough if it is about a book.

In the case of the structure in which the air circulation groove 700 extending in the recording medium conveying direction is formed, a plurality of air circulation grooves 700 are formed even when the recording medium 51 covers the upper surface of the developing device main body 620B. Thus, the drying groove 622B communicates with the outside, and air can be sucked into the drying groove 622B through the air circulation groove 700.

Therefore, when the image forming surface of the recording medium 51 reaches the drying groove 622B, it is exposed to a large amount of flowing air and dried. Moreover, since the air circulation groove 700 is provided so that the circulation airflow can be easily flowed, the recording medium 51 is not sucked by the developing device main body 620B more than necessary.

(Third Embodiment) Still another embodiment will be described with reference to FIG. The example shown in FIG. 6 is a perspective view of the developing device 62b. 620C is a developing device main body, 621 is a developing groove, 622A is a suction groove, and 622B is a drying groove. In this example, the recording medium 51 is not adsorbed to the developing device more than necessary, and moreover, the dry airflow is circulated as much as possible through the gap between the recording medium 51 and the wider area of the recording medium 51 is exposed to the dry airflow. In order to make it possible, a plurality of U-shaped air circulation grooves 700 connected to the drying grooves 622B are obliquely arranged on the upper end surface of the developing device main body 620C on the downstream side when viewed from the recording medium forward transport direction. It is set up.

In the case of this structure, even when the recording medium 51 covers the upper surface of the developing device main body 620C, the drying grooves 622B are communicated with the outside by the plurality of air circulation grooves 700, and the drying is performed through the air circulation grooves 700. Air can be sucked into the groove 622B. Therefore, the image forming surface of the recording medium 51 is exposed to a large amount of airflow when it reaches the drying groove 622B and is dried.

Moreover, in order to allow the air flow to flow in a wider area of the recording medium 51, the air flow grooves 700 are obliquely arranged. Therefore, the airflow flowing through the air flow groove 700 acts on a wider area of the recording medium 51 to dry the developer. Further, since the large number of air circulation grooves 700 are provided, the recording medium 51 is not sucked into the developing device main body 620C more than necessary.

(Fourth Embodiment) Still another embodiment will be described with reference to FIG. The example shown in FIG. 7 is a perspective view of the developing device 62D. 620D is a developing device main body, 621 is a developing groove, 622A is a suction groove, and 622B is a drying groove. In this example, the recording medium 51 is not adsorbed to the developing device more than necessary, and moreover, the dry airflow is circulated as much as possible through the gap between the recording medium 51 and the wider area of the recording medium 51 is exposed to the dry airflow. In order to enable this, the developing device main body 620D has a drying groove 622 in the vicinity of the upper end surface on the downstream side when viewed from the recording medium forward transport direction.
A large number of hemispherical projections 701, for example, are formed and arranged in the region between B and B. This protrusion 701 is an air circulation groove 700.
The gap between the protrusion 701 and the recording medium 51 serves as a flow path for the dry air flow.

The region where the protrusion 701 is formed is the protrusion 701.
The gap portion 702 is formed by lowering the height (about 0.5 to 1 mm). In the case of this configuration, the recording medium 51
Since the plurality of protrusions 701 support the recording medium 51 even when the upper surface of the developing device main body 620D is covered,
Many gaps are secured between the protrusion 701 and the recording medium 51. Air is sucked into the drying groove 622B through this gap, and this becomes a dry air flow.

Therefore, the image forming surface of the recording medium 51 is exposed to a large amount of airflow when it reaches the drying groove 622B and dried. Moreover, a plurality of protrusions 701 are provided in order to allow the circulation airflow to flow in a wider area of the recording medium 51.

Therefore, the dry air flow acts on a wider area of the recording medium 51 to dry the developing solution. Further, since the many projections 701 are provided, the recording medium 51 is not sucked into the developing device main body 620D more than necessary.

The various embodiments have been described above. In short, the present invention is not limited to the developing device for applying the developing solution to the image forming surface of the recording medium on which the latent image is formed. As viewed from the developer application position, a suction groove for sucking the outside air by negative pressure to suck the developer on the recording medium is provided downstream of the developer applying position, and an outside air is sucked downstream from the gap between the recording medium and the negative pressure by the negative pressure. A drying groove for drying the developing solution on the recording medium is provided. Then, the developer applied to the recording medium by the developing device is sucked and removed by the suction groove,
Air is taken in from the space between the recording medium and the drying groove, and an air stream is caused to flow on the image forming surface of the recording medium to dry the recording medium.

As described above, the excess amount of the developing solution applied to the recording medium is sucked and removed by the suction groove, and air is sucked through the gap between the recording medium and the drying groove, so that the ventilation effect allows the drying effect. Since the more complete drying of the developing solution on the recording medium is promoted, the image on the recording medium which has been developed and visualized has a high degree of fixing, and is rubbed and smeared at the recording paper conveying stage, There is no fear of causing tailing or peeling and it becomes possible to form a high quality image.

The present invention is not limited to the above-described embodiments, but can be modified and implemented as appropriate without departing from the scope of the invention. For example, although the above-described embodiments have been described as the developing device of the image forming apparatus of the electrostatic recording type, the developing device of the present invention is also applicable to the image forming apparatus of the other type image recording method using the same developing device. Applicable.
For example, a method using magnetic force instead of static electricity, or a method of forming a latent image by light or heat can be applied.

[0067]

As described above, the drying groove of the developing device of the present invention can have the same structure as the developing groove and the suction groove, and can be easily processed. Therefore, the developing device of the present invention has a simple structure, whereby image peeling due to contact between the device and the recording medium inside the image recording device, and image peeling of the peeled developer pigment onto the recording medium again can be achieved. It effectively prevents stains and image tailing, and gives excellent images.

Therefore, according to the present invention, in the image forming apparatus using the developing type developing device for developing by circulating the developing liquid and causing the developing liquid to act on the recording medium, the recording medium is the developing device. When it passes, it can be kept in a sufficiently dry state, so that the fixing property of the toner is ensured,
It is possible to provide an image forming apparatus capable of obtaining a good image without causing image stains or tailing.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention,
FIG. 3 is a perspective view showing a configuration of a main part of the present invention when the present invention is applied to an image forming apparatus.

FIG. 2 is a diagram for explaining an embodiment of the present invention,
FIG. 3 is a cross-sectional view of a developing device to which the present invention is applied, taken in a longitudinal direction of a drying groove.

FIG. 3 is a diagram for explaining an embodiment of the present invention,
FIG. 4 is a diagram showing a cross section on the developer supply port side (developer solution inlet side) of the developing device to which the present invention is applied.

FIG. 4 is a diagram for explaining an embodiment of the present invention,
FIG. 3 is a diagram showing a cross section of a developing device to which the present invention is applied, on the side of a developing solution outlet (developer outlet side).

FIG. 5 is a diagram for explaining an embodiment of the present invention,
FIG. 6 is a perspective view showing another embodiment of the developing device to which the present invention is applied.

FIG. 6 is a diagram for explaining an embodiment of the present invention,
FIG. 6 is a perspective view showing still another embodiment of the developing device to which the present invention is applied.

FIG. 7 is a diagram for explaining an embodiment of the present invention,
FIG. 6 is a perspective view showing still another embodiment of the developing device to which the present invention is applied.

FIG. 8 is a diagram for explaining a conventional example and is a diagram showing a schematic configuration of a conventional image forming apparatus.

FIG. 9 is a diagram for explaining a conventional example, which is a perspective view showing a main configuration of a developing device in a conventional image forming apparatus.

FIG. 10 is a view for explaining a conventional example, showing a longitudinal cross section at a developing groove portion of a developing device in a conventional developing device.

FIG. 11 is a diagram for explaining a conventional example, showing a cross section of a developing device in a conventional developing device at a developer supply port side (developer solution inlet side).

FIG. 12 is a view for explaining a conventional example, showing a cross section of a developing device in a conventional developing device at a developing solution discharge port side (developing solution outlet side).

[Explanation of symbols]

 51 ... Electrostatic recording paper (recording medium) 53 ... Developer tank 61 ... Recording head 66 ... Circulation pump 62, 62a-62d ... Developing device 620A-620D ... Developing device main body 621 ... Developing groove (opening slit) 622A ... Suction groove (Slit) 622B ... Drying groove (slit) 623 ... Developer supply port (developer inlet) 624 ... Developer discharge port (developer outlet) 625 ... Suction port 700 ... Air circulation groove 701 ... Projection

Claims (1)

[Claims] 1. An image forming apparatus for forming an image by conveying a recording medium having a latent image formed on the image forming surface and applying a developing solution to the image forming surface by a developing device. The developing device for applying the developing solution to the surface is positioned on the downstream side of the developing solution applying position when viewed from the recording medium conveying direction at the time of development, and the outside air is sucked by the negative pressure to remove the developing solution on the recording medium. A suction groove for sucking and a drying groove for drying the developing solution on the recording medium by sucking outside air from a gap between the recording medium and the recording medium by a negative pressure are provided on the downstream side of the suction groove. Image forming apparatus.