JPH09263001A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of stably forming an image having an excellent quality at a low power consumption with a compact configuration. SOLUTION: A humidifying mechanism 51 for humidifying the surface of an intermediate recording medium 16 is provided between the intermediate recording medium 16 and an aperture 4 in the vicinity of a toner supplying device 10 on the upstream side in the conveyance direction. In the humidifying mechanism 51, a humidifying roller 52 of a hydrophilic rubber is rotatably supported with the lower part thereof partially soaked in the water of a water storage tank 53. Accordingly, owing to the synchronous rotation of the humidifying roller 52 and the intermediate recording medium 16 being conveyed, the water on the surface of the humidifying roller 52 is stuck to the entire surface of the intermediate recording medium 16 so that a toner T supplied from the toner supplying device 10 can adhere on the intermediate recording medium 16 further firmly.

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 transferring a developer, which has jumped out of a passing portion of an aperture electrode body, to an intermediate recording medium, and then transferring the developer to the recording medium, and particularly to the intermediate recording. The present invention relates to a device for improving the adhesion of a developer to a medium.

[0002]

2. Description of the Related Art Conventionally, an aperture electrode having a large number of minute openings formed in rows at minute intervals in the width direction of a recording medium and having electrodes around each of these many openings. A body is provided, and on one side of this aperture electrode body,
A toner supply mechanism that supplies toner to a large number of openings of the aperture electrode body is provided, and a counter electrode to which a high voltage is applied is provided on the other side, and the drive voltage supplied to each electrode of this aperture electrode body is individually provided. The recording medium is conveyed along the counter electrode while being controlled so that the toner supplied from the toner supply mechanism passes through the opening and is applied to the counter electrode by the electrostatic attraction force of the counter electrode. An image forming apparatus has been proposed (see U.S. Pat. No. 3,689,935) in which the image is ejected toward the recording sheet, adhered to a recording sheet, and then fixed by a fixing mechanism to record an image.

However, in this image forming apparatus, the relationship of reliably moving the toner supplied from the toner supply mechanism toward the counter electrode through the opening, and the gap between the aperture electrode body and the counter electrode, Since the thickness is set to about 1 mm or less, the thick recording medium cannot pass through the gap, so that the image cannot be recorded on the thick recording medium.

Therefore, in Japanese Patent Laid-Open No. 4-152154, a transfer drum (corresponding to an intermediate recording medium) that partially contacts the counter electrode is conveyed between the aperture electrode body and the recording medium. The toner that is rotatably driven in synchronism with the recording medium is ejected toward the counter electrode after passing through the opening and once attached to the transfer drum. An image forming apparatus has been proposed which is configured to be transferred to a recording medium and is capable of recording an image on various thick recording media such as resin and metal.

[0005]

By the way, in the image forming apparatus having the transfer drum described in Japanese Patent Laid-Open No. 4-152154, the electrostatic attraction force generated by the high voltage of the counter electrode, that is, The toner attached to the transfer drum (corresponding to the intermediate recording medium) through the opening due to the electrostatic force moves while moving away from the counter electrode due to the rotation of the transfer drum. At this time, the toner attached to the transfer drum is attached mainly due to a relatively large electrostatic force by the counter electrode, but the toner that is gradually not receiving the electrostatic force according to the rotation of the transfer drum is After that, by Van der Waals force or image force, it is transferred to the transfer position while barely adhering.

On the other hand, the toner particles are not neat spheres, but are spheres having a large number of protrusions, such as "Competito". Therefore, the adhesion surface of the transfer drum is the tip of these protrusions. It adheres only on the part, and further in a layered manner collectively over 2 to 3 layers, so when the Van der Waals force and the image force described above become extremely weak, these layers form Since the mass of the adhered toner group is large, the toner group may be partially dropped from the transfer drum during the transfer, which causes a problem that a beautiful image cannot be formed on the recording medium.

An object of the present invention is to provide an image forming apparatus capable of reliably transferring to a recording medium without humidifying the intermediate recording medium by a humidifying means so as to enhance the adhesive force of the developer and prevent the developer from falling off. Is.

[0008]

An image forming apparatus according to a first aspect of the present invention is an aperture electrode body in which a plurality of passing portions are formed in a row in the width direction of a recording medium and each of the plurality of passing portions has an electrode. And a developer supply mechanism that supplies the developer to the passage portion of the aperture electrode body, and the voltage supplied to each electrode of the aperture electrode body are individually controlled to control the developer passing through each passage portion. It is provided on the side opposite to the developer supply mechanism with respect to the agent control means and the aperture electrode body, and is rotationally driven in synchronization with the conveyance of the recording medium to attach the developer passing through the passing portion and transfer it to the transfer position. In the image forming apparatus including the intermediate recording medium, the humidifying means for humidifying the intermediate recording medium is provided in order to increase the adhesive force of the developer adhering to the intermediate recording medium.

At this time, for example, before the developer is supplied,
By previously humidifying the intermediate recording medium with the humidifying means, the adhesive force between the intermediate recording medium and the developer is increased,
When the developer is transferred to the transfer position, the developer does not fall off the intermediate recording medium, and all the developer attached to the intermediate recording medium is reliably transferred to the transfer position, and then transferred to the recording medium at the transfer position. As a result, a beautiful image can be formed on the recording medium.

[0010] The invention described in claim 2 is the same as the claim 1.
In the image forming apparatus described in the item (1), the intermediate recording medium is formed in a belt shape, and the humidifying unit is formed in a roller shape and is in contact with the intermediate recording medium. That is, according to the image forming apparatus of the second aspect, since the intermediate recording medium is formed in the shape of a belt, it can be stored in a smaller space as compared with the case where the intermediate recording medium is formed of a drum, and the humidifying means. Since the arrangement can be performed relatively flexibly, the space can be effectively utilized for the arrangement, and the entire apparatus can be downsized.

Next, a third aspect of the present invention is the first aspect.
Alternatively, in the image forming apparatus according to the second aspect, a plurality of aperture electrode bodies and a plurality of developer supplying means are provided so as to face the intermediate recording medium. Therefore, according to the image forming apparatus of the third aspect, if each developer supplying unit supplies the different color developer to each aperture electrode body, an image having different colors is formed on the intermediate recording medium. By transferring these to an image recording medium, a multi-color or full-color image can be formed on the image recording medium.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a schematic configuration of an image forming apparatus 2 for forming a mono-color image according to the first embodiment.

As shown in FIG. 1, the image forming apparatus 2 of the present embodiment controls the apertures 4 as a plurality of passage portions for passing the toner T as a developer and the passage of the toner T through the aperture 4. In order to do so, an aperture electrode body 8 having a control electrode 6 provided for each aperture 4 and a lower portion of the aperture electrode body 8 for forming an image on an image recording medium P such as recording paper or OHP paper A toner supply device 10 as a developer supply mechanism for storing the toner T and supplying the toner T to the aperture electrode body 8 and a seamless belt-like member are formed on the aperture electrode body 8 at the upper part of the aperture electrode body 8. With respect to the intermediate recording medium 16 disposed at a predetermined interval (for example, 0.5 mm), and the rear electrode roller 12 disposed at a position facing the toner supply device 10 with the aperture 4 interposed therebetween. The intermediate recording medium 16 is provided at a position in contact with the conveyance path of the image recording medium P, and the intermediate recording medium 16 is stretched together with the back electrode roller 12 and has a heater inside to heat the intermediate recording medium 16 to a predetermined temperature. Heat roller 1
4 and the image recording medium P together with the heat roller 14 at a position opposed to the heat roller 14 with the intermediate recording medium 16 interposed therebetween.
To the intermediate recording medium 16 and the pressure roller 18 that conveys the intermediate recording medium 16 while pressing the intermediate recording medium 16 and a predetermined high voltage (for example, 5
00V) to form a predetermined electric field between the back electrode roller 12 and the control electrode 6, and an image forming voltage (for example, + 30V) to the control electrode 6 according to image data input from the outside. , Or a control voltage application circuit 22 as a developer control means for applying an image non-forming voltage (for example, −30 V).

The back electrode roller 12 and the heat roller 14 are rotationally driven in a counterclockwise direction in the drawing (direction of arrow X) at a predetermined speed by a drive circuit (not shown), and the intermediate recording medium 16 is moved at a predetermined speed. It is transferred in.

On the other hand, a humidifying mechanism 51 as a humidifying means for humidifying the surface of the intermediate recording medium 16 is provided in the vicinity of the upstream side in the transport direction of the intermediate recording medium 16 with respect to the position where the toner T passes through the aperture 4. . That is, to explain the humidifying mechanism 51, a humidifying roller 52 made of rubber having excellent hydrophilicity is rotatably supported, and a lower end portion of the humidifying roller 52 is partially immersed in water in the water storage tank 53. ing. As a result, the humidifying roller 52 rotates in synchronization with the conveyed intermediate recording medium 16, so that the water adhering to the surface of the humidifying roller 52 adheres to the entire surface of the intermediate recording medium 16 and the toner is supplied. The toner T supplied from the apparatus 10 adheres to the intermediate recording medium 16 more strongly, and the toners T easily adhere to each other. The mechanism of attachment will be described below. That is, when the liquid adheres between the toner particles and another object (here, the intermediate recording medium 16 or the other toner particles) to form an arc-shaped curved surface, both of them are the force due to the negative pressure generated in the water film and the water. It will receive the sum of the surface tensions of the membrane. This force is an adhesive force, and the toner T adheres to the intermediate recording medium 16 more strongly, and the toners T easily adhere to each other.

Next, the intermediate recording medium 16 is made of polyimide,
The resin film is formed of a resin having excellent moisture resistance and releasability such as aramid, Teflon, and silicon, and the resin film is formed in a seamless belt shape.

In order to further improve the releasability of the intermediate recording medium 16, the surface of the resin film may be coated or impregnated with silicone oil or the like. In addition, the intermediate recording medium 16
A coating layer in which carbon particles are dispersed may be formed on the surface of the resin film in order to remove the electrostatic charge and prevent dust and the like from adhering to the intermediate recording medium 16 and deteriorating the image quality. Further, the intermediate recording medium 16 may be configured by using a metal film such as stainless steel or nickel instead of the resin.

The control voltage application circuit 22 is connected to an external computer, an image reading device, an image communication device, etc., and image data is input from these devices.

Here, the toner supply device 10 includes a toner case 24 which also serves as a housing of the toner supply device 10.
A cylindrical toner carrying roller 26 that is rotatably supported in the toner case 24, is also rotatably supported in the toner case 24, and is arranged in parallel while being in contact with the toner carrying roller 26. Cylindrical supply roller 28
And a flat-plate-shaped toner layer regulating blade 30 which is disposed above the supply roller 28 so that one end thereof presses the roller surface of the toner carrying roller 26.

The toner carrying roller 26 and the supply roller 28 are rotationally driven in a clockwise direction (direction of arrow Y) in the drawing at a predetermined speed by a drive circuit (not shown). The surface of the toner carrying roller 26 is covered with an electrode body and is electrically grounded so that the potential thereof becomes 0V.

Toner supply device 10 thus configured
In the above, the toner T accumulated in the toner case 24 is rotated by the rotation of the supply roller 28, and
6 is conveyed. Then, the toner T conveyed to the contact surface between the supply roller 28 and the toner carrying roller 26
Is rubbed against the toner carrying roller 26 to be negatively charged, and also carried by the toner carrying roller 26.
The toner T carried on the toner carrying roller 26 in this manner
Is conveyed toward the aperture electrode body 8 by the rotation of the toner carrying roller 26, and in the middle thereof, is thinned by the toner layer regulating blade 30 so that the toner T is evenly distributed on the roller surface. After the charge amount of each toner T is made uniform, the toner T is supplied to the aperture electrode body 8.

Next, as shown in FIG. 2, the aperture electrode body 8 is composed of an insulating sheet 32 made of polyimide and having a thickness of 25 μm.
A plurality of apertures 4 having a round shape of 00 μm are formed in a line along the longitudinal direction, and a control electrode 6 made of a copper foil having a thickness of 8 μm is formed for each aperture 4 in the passage peripheral portion of the aperture 4. Has been done.

Aperture electrode body 8 constructed in this way
As shown in FIG. 1, with the surface on which the control electrode 6 is formed facing the intermediate recording medium 16, it is disposed so as to press the upper portion of the toner carrying roller 26.

Therefore, the toner T on the toner carrying roller 26 is supplied under the aperture 4 while being rubbed by the insulating sheet 32 constituting the aperture electrode body 8.

Next, the operation of the image forming apparatus 2 configured as described above will be described.

That is, in the image forming apparatus 2, when an image signal is input from the outside, the control voltage applying circuit 22
In accordance with this image signal, a voltage of + 30V is applied to the control electrode 6 of the aperture 4 that should pass the toner T, and a voltage of -30V is applied to the control electrode 6 of the aperture 4 that should not pass the toner T.

Then, the control electrode 6 to which a predetermined voltage is applied and the toner carrying roller 26 which is grounded and set to 0V.
An electric field corresponding to the voltage applied to the control electrode 6 is formed in each aperture 4 due to the potential difference between and, and the negatively charged toner T is subjected to an electrostatic force toward the higher potential side.

That is, in the aperture 4 to which the voltage of +30 V is applied to the control electrode 6, the potential on the control electrode 6 side becomes high, so that the toner T receives the electrostatic force toward the control electrode 6. As a result, the toner T carried on the toner carrying roller 26 flies from the surface of the toner carrying roller 26, passes through the aperture 4, and is drawn out to the control electrode 6 side of the aperture electrode body 8. Here, a voltage of +500 V is applied to the back electrode roller 12 by the DC power source 20, and the toner T drawn to the control electrode 6 side is not included in the back electrode roller 1.
2 and the control electrode 6, an electric field formed by the electric potential difference between the control electrode 6 and the control electrode 6 receives an electrostatic force to further increase the potential of the back electrode roller 1.
It flies toward 2, and adheres and deposits on the intermediate recording medium 16 disposed between the aperture electrode body 8 and the back electrode roller 12.

In the aperture 4 to which the voltage of -30 V is applied to the control electrode 6, the potential on the toner carrying roller 26 side becomes high, and the toner T receives the electrostatic force toward the toner carrying roller 26. Therefore, the toner T is held on the toner carrying roller 26 without flying from the surface of the toner carrying roller 26.

As a result, on the intermediate recording medium 16,
A pixel is formed in a portion facing the aperture 4 to which + 30V is applied to the control electrode 6, and a pixel is not formed in a portion facing the aperture 4 to which -30V is applied to the control electrode 6, and one column is formed. A toner image is formed.

In this way, the intermediate recording medium 16 is
When the toner images for the columns are formed, the back electrode roller 12 and the heat roller 14 are driven to rotate, and the intermediate recording medium 16
Are moved by one pixel in the vertical direction with respect to the four columns of apertures. Then, by repeating the above-described process of forming the toner image for one line, the intermediate recording medium 16 is
A toner image for one screen is formed.

On the other hand, the humidifying mechanism 5 for humidifying the intermediate recording medium 16 and the surface of the intermediate recording medium 16 in the vicinity of the upstream side in the transport direction with respect to the toner supply device 10 with the aperture 4 interposed therebetween.
1 is provided. That is, the humidifying mechanism 51 will be described. The humidifying roller 52 made of rubber having excellent hydrophilicity.
Is rotatably supported, and the lower end of the humidifying roller 52 is partially immersed in the water in the water storage tank 53. As a result, the humidifying roller 52 rotates in synchronization with the conveyed intermediate recording medium 16, so that the water adhering to the surface of the humidifying roller 52 adheres to the entire surface of the intermediate recording medium 16 and the toner is supplied. The toner T supplied from the device 10 adheres more strongly to the intermediate recording medium 16.

After that, the intermediate recording medium 16 is transported, so that the portion where the toner image is formed is moved to the pressure roller 1.
8 and the position of the heat roller 14 are reached.

The pressure roller 18 presses the image forming medium P against the intermediate recording medium 16 while conveying the image forming medium P in a predetermined direction in accordance with the transport speed of the intermediate recording medium 16 to press the intermediate recording medium 16. The upper toner image is transferred to the image forming medium P. At the same time, the intermediate recording medium 16 heated to a predetermined temperature by the heat roller 14 applies heat to the image forming medium P to fix the transferred toner image on the image forming medium P, whereby the image recording medium is fixed. A series of operations for forming an image on P is completed. In this case, the heat roller 14
The intermediate recording medium 16 heated by is simultaneously dehumidified, and the toner image can be fixed without wetting the image forming medium P.

As described above, according to the image forming apparatus 2 of the present embodiment, by moistening the surface of the intermediate recording medium 16, the toner T supplied from the toner supplying device 10 is further discharged. Will adhere strongly to. When the attached toner image is fixed, the image quality is further improved and stable image formation can be performed.

The intermediate recording medium 16 is made of a resin film formed in a belt shape and stretched by the back electrode roller 12 and the heat roller 14. The distance between the intermediate recording medium 16 and the aperture electrode body 8 is always constant. Since it is kept constant, there is no risk of foreign matter coming into contact with the aperture electrode body 8, and damage to the aperture electrode body 8 can be prevented.

Further, since the intermediate recording medium 16 allows the image recording medium P to be arranged at a position distant from the aperture electrode body 8, even if foreign matter is detached from the image recording medium P, it adheres to the aperture electrode body 8. There is nothing to do. Therefore,
Since the controllability of the toner T is not deteriorated, the image quality is excellent and stable image formation can be performed.

Further, according to the image forming apparatus 2 of this embodiment, the intermediate recording medium 16 is dehumidified, the intermediate recording medium 16 is transferred to the image recording medium P, and the toner image is fixed on the image recording medium P. Is performed at once by pressing the image recording medium P onto the heated intermediate recording medium 16, so that the power consumption can be reduced as compared with the conventional apparatus in which the transfer and the fixing are performed separately. Moreover, since the intermediate recording medium 16 made of a resin film has a small heat capacity, it can be quickly heated to a predetermined temperature with a small amount of heat energy. Therefore, according to the present embodiment, power consumption can be significantly reduced.

Since the intermediate recording medium 16 is formed in a belt shape and is stretched by the back electrode roller 12 and the heat roller 14, the arrangement of the heat roller 14 can be changed relatively freely. Compared to the case where the intermediate recording medium is composed of a drum, the intermediate recording medium can be stored in a small space, and the humidification mechanism 51 can be arranged relatively flexibly, so that the space can be effectively used for arrangement. As a result, the entire device can be downsized. Therefore, since the space can be effectively used for the arrangement, the device can be downsized.

In the first embodiment, an example in which the present invention is applied to an image forming apparatus for forming a mono-curler image has been shown, but the present invention is not limited to this, and a multi-color or full-color image is formed. It can also be applied to an image forming apparatus.

A second embodiment in which the present invention is applied to a full-color image forming apparatus will be described. Note that FIG. 3 is an explanatory diagram showing a schematic configuration of the full-color image forming apparatus 40 according to the second embodiment.

As shown in FIG. 3, the full-color image forming apparatus 40 of the present embodiment has three process units 42Y which form yellow, magenta, and cyan toner images, respectively, according to an image signal input from the outside. , 42M, 4
2C and a predetermined distance (for example, 0.5 mm) from the aperture electrode body of each process unit 42Y, 42M, 42C
Belt-shaped intermediate recording medium 44, which is arranged to face each other
A heat roller 46 which is provided at a position in contact with the conveyance path of the image recording medium P and has a heater therein to generate heat to heat the intermediate recording medium 44 to a predetermined temperature; and the intermediate roller 44 together with the heat roller 46. The intermediate recording medium 4 is stretched
4 of a pair of tension rollers 48a, 4 for transporting 4 in a predetermined direction
8b and back electrodes 50Y, 50M, 50C respectively arranged at positions facing the aperture electrode bodies of the process units 42Y, 42M, 42C with the intermediate recording medium 44 interposed therebetween.
A DC power source 54 for applying a predetermined high voltage (500 V, for example) to each of the back electrodes 50Y, 50M, 50C, and a position facing the heat roller 46 with the intermediate recording medium 44 interposed therebetween. Between the heat roller 46 and the tension roller 48a and the pressure roller 55 that conveys P at a predetermined speed while pressing P on the intermediate recording medium 44,
Roller-shaped remover 56, which is provided so as to contact the surface on which the toner image is formed and removes the toner T remaining on the surface of the intermediate recording medium 44 after the toner image is transferred to the image recording medium P, and the remover 56. Similarly to the intermediate recording medium 44
Roller-shaped static eliminator 58 which is provided so as to contact the surface of the intermediate recording medium 44 on which the toner image is formed.
It is composed of

On the other hand, with respect to the position of the tension roller 48a, in the vicinity of the upstream side of the intermediate recording medium 44 in the conveying direction,
A humidifying mechanism 61 for humidifying the surface of the intermediate recording medium 44 is provided. That is, the humidifying mechanism 61 will be described. A humidifying roller 62 made of rubber having excellent hydrophilicity is rotatably supported, and a lower end portion of the humidifying roller 62 is partially immersed in water in the water storage tank 63. ing. As a result, the humidifying roller 62 rotates in synchronization with the conveyed intermediate recording medium 44, so that the water adhering to the surface of the humidifying roller 62 adheres to the entire surface of the intermediate recording medium 44, and the toner is supplied. The toner T supplied from the device 10 adheres more strongly to the intermediate recording medium 44. The configuration of the intermediate recording medium 44 is similar to that of the intermediate recording medium 16 in the first embodiment.

The heat roller 46 is electrically grounded, and the intermediate recording medium 4 is exposed from the inner surface side of the intermediate recording medium 44.
It also functions as a static eliminator for removing the charge of No. 4.

Each process unit 42Y, 42M, 42
Each of C is composed of a toner supply device, an aperture electrode body, and a control voltage application circuit which have exactly the same configurations as those described in the first embodiment, and the operation is exactly the same as in the first embodiment. Therefore, the description thereof is omitted. The process unit 42Y that forms a yellow toner image has a yellow toner T, and the process unit 42M that forms a magenta toner image has a magenta toner T.
Process unit 42 for forming a cyan toner image
In C, cyan toner T is stored.

Next, the operation of the full-color image forming apparatus 40 will be described.

The color image signal input from the outside is 3
The color signals are separated and input to the respective control voltage application circuits of the corresponding process units 42Y, 42M, 42C. Accordingly, each process unit 42Y, 4Y
From 2M, 42C, each process unit 42Y, 42
Back electrodes 50Y, 50M, which are arranged opposite to M, 42C,
The toner T flies toward 50C, and the intermediate recording medium 4 is ejected.
A toner image is formed by depositing and depositing on toner particles 4.

Therefore, a yellow toner image is first formed on the intermediate recording medium 44 when passing through the process unit 42Y, and then a magenta toner image is formed when passing through the process unit 42M. When passing through the unit 42C, a cyan toner image is formed. In this way, the intermediate recording medium 44 passes through the three process units 42Y, 42M, and 42C, so that a full-color toner image is formed on the intermediate recording medium 4.
4 is formed.

In the intermediate recording medium 44 on which the full-color toner image is formed in this manner, the heat roller 46 and the tension rollers 48a and 48b are rotationally driven by a drive circuit (not shown), so that the pressure roller 55 and the heat roller 46. Is transferred to the position where is provided.

The pressure roller 55 presses the image recording medium P against the intermediate recording medium 44, and conveys the image recording medium P at the transfer speed of the intermediate recording medium 44, whereby the image recording medium P is formed on the intermediate recording medium 44. The full-color toner image is transferred to the image recording medium P, and the heat roller 4
The intermediate recording medium 44 humidified by 6 humidifies the image recording medium P, so that the transferred toner image is thermally fixed on the image recording medium P, and a full-color image recorded on the image recording medium P is obtained. .

After the transfer, the intermediate recording medium 44 is removed by the remover 56 to remove the toner T remaining on the toner image forming surface and adhering dust and the like, and the static eliminator 58 removes static electricity. Process units 42Y, 42M, 42C and back electrodes 50Y, 50M, 5
0C, and a new toner image is formed.

As described above, according to the full-color image forming apparatus 40 of the present embodiment, the toner T, dust, and the like that remain on the intermediate recording medium 44 are removed every time transfer is performed, so that the quality of the image is always maintained. You can get a good image.

Of course, the same effects as those of the image forming apparatus 2 of the first embodiment can be obtained.

In this embodiment, the full-color toner image is formed on the intermediate recording medium 44 and then transferred to the image recording medium P. However, one color toner image is formed on the intermediate recording medium 44. It is also possible to form a full-color image on the image recording medium P by sequentially switching the process units and repeating three times the process of transferring to the image recording medium P after that.

Further, in the present embodiment, three process units for yellow, magenta, and cyan are used, but a process unit for forming a black toner image may be mounted. According to this, a brighter black color can be expressed in the formed image.

Although the respective embodiments of the present invention have been described above in detail, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention. Is.

Here, the configuration may be modified in the following manner.

For example, the humidifying mechanisms 51 and 61 may be configured by using a simple humidifier or may be configured to spray.

The intermediate recording medium 1 used for image formation
The amount of humidification by the humidifying mechanisms 51, 61 may be adjustable according to the types of 6, 44.

Next, as in the case of a steam iron which blows out steam, a plurality of minute spray holes are formed in the humidification mechanisms 51 and 61, and even if the humidification mechanisms 51 and 61 perform humidification while spraying from these spray holes. Good.

Further, for example, ethanol or other organic or inorganic solvent may be used in order to increase the adhesion and evaporation of the moistening liquid.

In each of the above embodiments, the control voltage applied to the control electrode 6 when the toner image is not formed is -3.
Although it is set to 0V, it may be set to the same potential (0V) or less as the potential of the toner carrying roller 26. When the control voltage is 0V, the structure of the control voltage applying circuit can be simplified.

Further, in the above embodiment, the aperture electrode body 8 having the apertures 4 formed in a line is used for controlling the toner T when forming the toner images on the intermediate recording media 16 and 44. As described in the specification of US Pat. No. 5,036,341, it is also possible to use an aperture electrode body in which apertures are two-dimensionally formed.

[0065]

As is apparent from the above description, according to the image forming apparatus of the first aspect, the adhesive force between the intermediate recording medium and the developer is obtained by previously humidifying the intermediate recording medium by the humidifying means. When the developer is transferred to the transfer position, the developer does not fall off from the intermediate recording medium, and all the developer attached to the intermediate recording medium is reliably transferred to the transfer position, and then recorded at the transfer position. It can be transferred to a medium to form a beautiful image on a recording medium.

According to the second aspect of the present invention, the intermediate recording medium is formed in the shape of a belt, and the humidifying means is formed in the shape of a roller so as to contact the intermediate recording medium. Compared with the case where it is done, the humidifying means can be placed in a small space, and the humidifying means can be arranged relatively flexibly, so that the space can be effectively used and the humidifying means can be arranged effectively, and the entire device can be downsized. can do.

Next, according to the third aspect of the invention, since a plurality of aperture electrode bodies and a plurality of developer supplying means are provided so as to face the intermediate recording medium, each developer supplying means has a different color developer. By supplying to each aperture electrode body, images of different colors can be formed on the intermediate recording medium, and by transferring these to the image recording medium, a multi-color or full-color image can be formed on the image recording medium. Can be formed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is a perspective view showing a configuration of an aperture electrode body used in the image forming apparatus 2.

FIG. 3 is an explanatory diagram showing a schematic configuration of a full-color image forming apparatus according to a second embodiment.

[Explanation of symbols]

 2,40 Image forming apparatus 4 Aperture 6 Control electrode 8 Aperture electrode body 10 Toner supply device 12 Back electrode roller 14,46 Heat roller 16,44 Intermediate recording medium 51,61 Humidification mechanism 52,62 Humidification roller 53,63 Water storage tank 22 control voltage application circuit 26 toner carrying roller 32 insulating sheet 42Y, 42M, 42C process unit 48a, 48b tension roller 50Y, 50M, 50C rear electrode

Claims (3)

[Claims] 1. An aperture electrode body having a plurality of passing portions formed in a row in a width direction of a recording medium, and an electrode having an electrode in each of the plurality of passing portions, and a developing agent applied to the passing portion of the aperture electrode body. A developer supply mechanism that supplies the developer, a developer control unit that individually controls the voltage supplied to each electrode of the aperture electrode body to control the developer that passes through each passage portion, and the aperture electrode body. In an image forming apparatus provided with an intermediate recording medium, which is provided on the opposite side of a developer supply mechanism, is rotationally driven in synchronization with the conveyance of a recording medium, and adheres the developer that has passed through a passing portion to transfer it to a transfer position. An image forming apparatus comprising: a humidifying unit for humidifying the intermediate recording medium in order to enhance the adhesive force of the developer adhering to the intermediate recording medium. 2. The image forming apparatus according to claim 1, wherein the intermediate recording medium is formed in a belt shape, and the humidifying means is formed in a roller shape and is in contact with the intermediate recording medium. 3. The image forming apparatus according to claim 1, wherein a plurality of the aperture electrode bodies and the developer supplying means are provided so as to face the intermediate recording medium.