JPH09314888A - Image forming equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming equipment which can always form a high-quality image because its intermediate recording medium does neither shake nor deform. SOLUTION: A toner image formed by adherence on an endless belt-form intermediate recording medium 44 by process units 42Y, 42M, 42C is carried to a position where a pressure roller 54 and a thermal roller 46 are arranged, and transferred to an image recording medium P. After transferred, a residual toner on the intermediate recording medium 44 is removed by a brush roller 56 arranged in opposition to a tension roller 84a between the intermediate recording medium 44.

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 which can be used for a copying machine, a printer, a plotter, a facsimile, and the like.

[0002]

2. Description of the Related Art Conventionally, as one of image forming apparatuses, as disclosed in, for example, Japanese Patent Laid-Open No. 6-155798, a plurality of small holes (hereinafter referred to as apertures) for passing toner are provided. An aperture electrode body having a control electrode for each aperture is provided, and a toner drive aperture signal is applied to each control electrode of the aperture electrode body by applying a drive signal according to an image signal input from the outside. There is known an image forming apparatus of a so-called toner jet system, which controls a toner image and forms a toner image on an image recording medium such as a printing paper by passing the toner. The image recording medium on which the toner image is formed is further heated and pressed by a fixing device including a heated roller, and the toner image formed on the image recording medium by this is fixed on the image recording medium. .

In this image forming apparatus, since the image recording medium is conveyed at a position extremely close to (a distance of 1 mm or less) from the aperture electrode body, the image recording medium comes into contact with the aperture electrode body, and the image recording medium is transferred onto the image recording medium. There is a problem in that the toner image before fixing is disturbed or foreign matter such as paper dust that falls off the image recording medium adheres to the aperture electrode body, which deteriorates the controllability of the toner and deteriorates the image quality. It was In addition, the aperture electrode body is generally extremely thin (25
Therefore, there is also a problem that when the image recording medium comes into contact with the image recording medium, the impact of the contact causes a scratch that causes a defect in the image.

On the other hand, the present applicant has filed Japanese Patent Application No. 6-2
No. 37324, an image configured such that an intermediate recording medium instead of the image recording medium is opposed to an aperture electrode, a toner image is once formed on the intermediate recording medium, and then the toner image is further transferred to the image recording medium. A forming device is proposed.

That is, an intermediate recording medium is formed by stretching a seamless belt or the like of a resin film with a plurality of rollers, and the intermediate recording medium is arranged so as to face the aperture electrode body. There is no risk of contact with the aperture electrode body due to sagging or the like, and paper dust or the like will not fall onto the aperture electrode body, so that the image quality can be reliably improved.

[0006]

However, in the image recording apparatus provided with this intermediate recording medium, a toner image is once formed on the intermediate recording medium, and then the toner image is transferred to the image recording medium by the transfer means. Configured,
When transferring the toner image from the intermediate recording medium to the image recording medium, it is very difficult to transfer all the toner on the intermediate recording medium to the image recording medium. The toner image is conveyed to the position where the toner image is formed by the electrode and the aperture electrode body, and as a result, the toner image newly formed on the intermediate recording medium has a hue shift or color bleeding, and the quality of the output image. There was a problem that was worse. In order to solve this problem, cleaning means for removing the toner remaining on the intermediate recording medium after the transfer may be provided. However, since the intermediate recording medium is a belt formed of a resin film or the like, when the cleaning means is brought into contact with the intermediate recording medium,
There is a problem that the intermediate recording medium is deformed and the toner image formed on the intermediate recording medium is disturbed.

The present invention has been made to solve the above-mentioned problems, and an image forming apparatus capable of always forming an image of excellent quality without vibration or deformation of an intermediate recording medium. It is intended to be provided.

[0008]

In order to achieve this object, an image forming apparatus according to claim 1 of the present invention is provided with a plurality of passing portions for passing a developing material, and the passing portions of the passing portions are formed. An electrode array having control electrodes at the edges, a developer supply unit that carries a charged developer and supplies it near the passage portion, and between the control electrode and the developer supply unit according to an image signal. The control electrode control means for controlling the applied voltage to control the passage of the developer supplied to the vicinity of the passage portion by the developer supply means and the developer supply means opposite to the passage portion with the passage portion interposed therebetween. A rear electrode which is disposed on the side and which is applied with a predetermined voltage for forming a predetermined electric field between the developer and the developer supplying means, and further causes the developer passing through the passing portion to fly. Between the electrode array and An intermediate recording medium in the form of an endless belt, which forms a developer image by depositing and depositing the developer flying by the back electrode, and transporting the developer image to the conveyance path of the image recording medium, and the endless belt. A plurality of rollers that stretch a sheet-shaped intermediate recording medium, a transfer unit that transfers the developer image formed on the endless belt-shaped intermediate recording medium to the image recording medium, and a developer image by the transfer unit. A cleaning means for removing the developing material remaining on the endless belt-shaped intermediate recording medium after being transferred to the image recording medium, and particularly, the cleaning means is the endless belt-shaped intermediate recording medium. It is arranged so as to face at least one of the plurality of rollers with the medium interposed therebetween.

Therefore, the developer remaining on the intermediate recording medium after the developer image is transferred to the image recording medium is removed by the cleaning means, and the cleaning means is in contact with the roller, so that the cleaning means contacts. This makes it possible to form a high-quality developer image on the intermediate recording medium without vibrating or deforming the intermediate recording medium.

An image forming apparatus according to a second aspect of the invention is
The cleaning means is formed in a roller shape.
Therefore, the residual developer on the intermediate recording medium can be removed without slipping at the contact portion between the cleaning unit and the intermediate recording medium. Therefore, a high-quality developer image can be formed on the intermediate recording medium without vibrating or deforming the intermediate recording medium.

The image forming apparatus according to a third aspect of the present invention provides
The cleaning means is composed of a brush roller. Therefore, since the contact area is large, the residual developer on the intermediate recording medium can be effectively removed.

[0012]

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

FIG. 1 shows an image forming apparatus 40 according to this embodiment.
It is an explanatory view showing a schematic configuration of.

As shown in FIG. 1, the image forming apparatus 40 includes
Three process units 42Y and 4Y that form yellow, magenta, and cyan toner images, respectively, according to the image signal.
2M, 42C and each process unit 42Y, 42M,
The belt-shaped intermediate recording medium 44, which is arranged to face the aperture electrode body 42C of 42C at a predetermined interval (for example, 0.5 mm), and the conveyance path of the image recording medium P, are provided in contact with each other. A heat roller 46 that has a heater and heats the intermediate recording medium 44 to a predetermined temperature, and a pair of a pair of rollers that stretches the intermediate recording medium 44 together with the heat roller 46 and transports the intermediate recording medium 44 in a predetermined direction. Tension roller 4
8a, 48b and back electrodes 50Y, 50 respectively arranged at positions facing the aperture electrode body 8 of each process unit 42Y, 42M, 42C with the intermediate recording medium 44 interposed therebetween.
M, 50C, a DC power source 52 for applying a predetermined high voltage (eg, 500V) 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. The image recording medium P is replaced with the intermediate recording medium 4
The pressure roller 54 that conveys at a predetermined speed while pressing the pressure roller 54.
And is provided to face one roller 48a of the pair of tension rollers with the intermediate recording medium 16 interposed therebetween, and removes the toner remaining on the surface of the intermediate recording medium 44 after the toner image is transferred to the image recording medium P. And a brush roller 56. The toner is the developer of the present invention, the aperture electrode body 8 is the electrode array, and the process units 42Y, 4
2M and 42C are developer supplying means, the heat roller 46 and the pressure roller 54 are transfer means, and the heat roller 46 and the roller 48.
Reference numerals a and 48b constitute a plurality of rollers, and the brush roller 56 constitutes a cleaning means.

The heat roller 46 is electrically grounded, and the intermediate recording medium 44 from the inner surface side of the intermediate recording medium 44.
It also works as a static eliminator that removes the electrostatic charge.

Each process unit 42Y, 42M, 42
C is composed of a toner supply device, an aperture electrode body, and a control voltage application circuit having exactly the same configuration, and the configurations and operations are exactly the same. Therefore, here, the process unit 42Y will be exemplified to describe the configuration and operations. explain. The process unit 42Y for forming a yellow toner image has a yellow toner, the process unit 42M for forming a magenta toner image has a process unit 42M for forming a magenta toner image, and the process unit 42C for forming a cyan toner image has a process unit 42C. And cyan toner are stored respectively.

FIG. 2 is an explanatory diagram showing a schematic structure of the process unit 42Y.

As shown in FIG. 2, the process unit 42
Y is a plurality of apertures 4 for passing the toner T.
And an aperture electrode body 8 having a control electrode 6 provided for each aperture 4 in order to control the passage of the toner T through the aperture 4, and an image recording such as recording paper or OHP paper provided below the aperture electrode body 8. A process unit 42Y that stores toner T for forming an image on the medium P and supplies the toner T to the aperture electrode body 8 is formed in a seamless belt shape, and the aperture electrode is formed above the aperture electrode body 8. The intermediate recording medium 44 disposed at a predetermined distance (for example, 0.5 mm) from the body 8, the back electrode 50Y disposed at a position facing the process unit 42Y with the aperture 4 in between, and the back electrode 50Y. A DC power source 52 that applies a predetermined high voltage (for example, 500 V) to the back electrode 50Y and the control electrode 6 to form a predetermined electric field, and an image input from the outside. It is constituted by a control voltage applying circuit 22 for applying an image forming voltage to the control electrode 6 according to the data (e.g. + 30 V), or non-imaging voltage (e.g. -30 V). The aperture 4 constitutes the passage portion of the present invention, and the control voltage application circuit 22 constitutes the control electrode control means.

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 process unit 42Y includes a toner case 24 which also serves as a housing of the process unit 42Y, a cylindrical toner carrying roller 26 rotatably supported in the toner case 24, and the toner case 2 as well.
4, a cylindrical supply roller 28 that is rotatably supported inside and is disposed in parallel with the toner carrying roller 26, and one end of the cylindrical supply roller 28 is above the supply roller 28. It is configured by a flat-plate-shaped toner layer regulating blade 30 arranged so as to press the surface.

The toner carrying roller 26 and the supply roller 28 are rotationally driven at a predetermined speed in the clockwise direction (arrow direction) in the figure 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.

The process unit 4 configured in this way
In 2Y, the toner T stored in the toner case 24 is conveyed toward the toner carrying roller 26 by the rotation of the supply roller 28. Then, the toner T conveyed to the contact surface between the supply roller 28 and the toner carrying roller 26 is rubbed by the toner carrying roller 26 and negatively charged, and is 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 on the way thereof, on the roller surface by the toner layer regulating blade 30. The toner is thinned so that the toner is evenly distributed, and the charge amount of each toner T is made uniform, and then the toner is supplied to the aperture electrode body 8.

Next, as shown in FIG. 3, 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 formed in a round shape of 00 μm are formed in a line along the longitudinal direction, and a control electrode 6 made of copper foil with a thickness of 8 μm is provided for each aperture 4 at the peripheral edge of the opening of the aperture 4. Is formed in.

Aperture electrode body 8 constructed in this way
As shown in FIG. 2, with the surface on which the control electrode 6 is formed facing the intermediate recording medium 44, the upper part of the toner carrying roller 26 is pressed against the intermediate recording medium 44.

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 intermediate recording medium 44 is made of polyimide,
The resin film is made of a resin having excellent heat resistance and releasability such as aramid, Teflon, and silicon, and the resin film is formed in a seamless belt shape.

Next, the operation of the process unit 42Y configured as described above will be described.

That is, in the process unit 42Y, when an image signal is input from the outside, the control voltage application circuit 22 applies + 30V to the control electrode 6 of the aperture 4 through which the toner T should pass in accordance with the image signal. , Toner T
A voltage of -30 V is applied to the control electrode 6 of the aperture 4 which does not pass through.

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, the DC power source 5 is connected to the back electrode 50Y.
The voltage of + 500V is applied by the toner 2 and the toner T pulled out to the control electrode 6 side receives an electrostatic force due to the electric field formed by the potential difference between the back electrode 50Y and the control electrode 6 to further increase the potential. It flies toward the high back electrode 50Y, and adheres and deposits on the intermediate recording medium 44 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, in the intermediate recording medium 44, a pixel is formed in a portion facing the aperture 4 to which + 30V is applied to the control electrode 6, and the pixel is opposed to the aperture 4 to which −30V is applied to the control electrode 6. No pixel is formed in the part,
A toner image for one row is formed.

In this way, 1 is recorded on the intermediate recording medium 44.
When the toner images for the rows are formed, the intermediate recording medium 44 is
One pixel is transferred in the vertical direction with respect to the four columns of apertures. Then, the toner image for one screen is formed on the intermediate recording medium 44 by repeating the process for forming the toner image for one column.

Next, the operation of the 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 flies toward 50 C, and the intermediate recording medium 44
A toner image is formed by adhering to and depositing on the toner image.

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 way, 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 54 and the heat roller 46. Is transferred to the position where is provided.

The pressure roller 54 is connected to the image recording medium P.
The full-color toner image formed on the intermediate recording medium 44 is transferred to the image recording medium P by transporting the image recording medium P at the transfer speed of the intermediate recording medium 44 while pressing the intermediate recording medium 44. Also, the heat roller 4
The intermediate recording medium 44 heated by 6 heats 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 brush roller 56 from toner remaining on the toner image forming surface and adhering dust, and then again, the process units 42Y, 42M, 42C and the rear electrodes. 50Y, 5
It is supplied between 0M and 50C, and a new toner image is formed.

Since the brush roller 56 is provided so as to face the tension roller 48a with the intermediate recording medium 44 interposed therebetween, the intermediate recording medium 44 is deformed, loosened, vibrated, etc. due to the contact of the brush roller 56. Therefore, the toner image of high image quality can always be formed on the intermediate recording medium 44.

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

For example, in the above-mentioned embodiment, the brush roller 56 is exemplified as the cleaning means, but it is also possible to use a sponge roller.

It is also possible to further enhance the toner removing effect by applying a predetermined bias to the cleaning means, that is, the brush roller 56.

Further, in the above embodiment, three process units 42Y, 42M and 42C are provided as process units for forming a color image. However, for forming a single color image, for example, a black toner image is formed. It is also possible to provide only one process unit to be formed.

Further, in the above-mentioned embodiment, the brush roller 56 is provided at a position facing the tension roller 48a. However, for example, the intermediate recording medium 44 is 180 degrees with respect to the heat roller 46.
The brush roller 56 may be provided at a position opposed to the heat roller 46 when the brush roller 56 is wound so as to come into contact with the heat roller 46 at a degree. That is, when the starting point in the direction in which the intermediate recording medium 44 is conveyed is 0 degree at the portion where the intermediate recording medium 44 contacts the heat roller 46, 90
When the transfer to the image recording medium P is performed at the 180 degree position, the brush roller 56 can be disposed at the 180 degree position.

The brush roller 5 is provided at both the position facing the heat roller 46 and the position facing the tension roller 48a.
By providing 6, it is possible to further enhance the toner removing effect.

Further, in the above embodiment, the plurality of rollers for tensioning the intermediate recording medium 44 are constituted by the three rollers of the heat roller 46 and the tension rollers 48a and 48b.
For example, the heat roller 46 and the tension roller 48a may be used. In this case, the process unit is arranged so as to face the intermediate recording medium 44 in the path from the tension roller 48a to the heat roller 46. On the contrary, it is also possible to provide more rollers to stretch the intermediate recording medium 44, and it is also possible to provide the brush roller 56 so as to face these rollers.

[0048]

As is apparent from the above description, in the image forming apparatus according to the first aspect of the present invention, a plurality of passage portions for passing the developing material are formed, and the edges of the passage portions are formed. Is an electrode array each having a control electrode, a developer supplying means for carrying a charged developer and supplying it near the passing portion, and applying it between the control electrode and the developer supplying means according to an image signal. Control electrode control means for controlling the voltage to control the passage of the developer supplied to the vicinity of the passage portion by the developer supply means, and the opposite side of the developer supply means with the passage portion interposed therebetween. A back electrode, which is provided and is applied with a predetermined voltage for forming a predetermined electric field between the developer supply means and the developer and further flies the developer having passed through the passage portion, and the back electrode and the back electrode. Placed between the electrode arrays To form a developing material image a developer material which is caused to fly by attaching deposited by the back electrode,
An endless belt-shaped intermediate recording medium that conveys the developer image to the conveyance path of the image recording medium, a plurality of rollers that stretches the endless belt-shaped intermediate recording medium, and is formed on the endless belt-shaped intermediate recording medium. Transfer means for transferring the developed developer image to the image recording medium, and removing the developer remaining on the endless belt-shaped intermediate recording medium after the developer image is transferred to the image recording medium by the transfer means. In particular, the cleaning means is provided so as to face at least one of the plurality of rollers with the endless belt-shaped intermediate recording medium interposed therebetween.

Therefore, the developer remaining on the intermediate recording medium after the developer image is transferred to the image recording medium is removed by the cleaning means, and further, the cleaning means faces the roller, so that the cleaning means contacts. This makes it possible to form a high-quality developer image on the intermediate recording medium without vibrating or deforming the intermediate recording medium.

The image forming apparatus according to claim 2 is
The cleaning means is formed in a roller shape.
Therefore, the residual developer on the intermediate recording medium can be removed without slipping at the contact portion between the cleaning unit and the intermediate recording medium. Therefore, a high-quality developer image can be formed on the intermediate recording medium without vibrating or deforming the intermediate recording medium.

The image forming apparatus according to the third aspect of the invention is
The cleaning means is composed of a brush roller. Therefore, since the contact area is large, the residual developer on the intermediate recording medium can be effectively removed.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram of a process unit used in the image forming apparatus.

FIG. 3 is a perspective view showing a configuration of an aperture electrode body.

[Explanation of symbols]

 8 Aperture electrode body 22 Control voltage application circuit 42Y, 42M, 42C Process unit 44 Intermediate recording medium 46 Heat roller 48a, 48b Tension roller 50Y, 50M, 50C Back electrode 54 Pressure roller 56 Brush roller

Claims (3)

[Claims] 1. A plurality of passing portions for passing a developing material are formed, an electrode array having control electrodes at the edges of the passing portion, and a charged developing material being carried in the vicinity of the passing portion. The developer supply means for supplying the developer and the voltage applied between the control electrode and the developer supply means in accordance with the image signal are controlled so that the developer supplied to the vicinity of the passing portion by the developer supply means is controlled. A control electrode control unit that controls passage and a predetermined electrode for forming a predetermined electric field between the control electrode control unit and the developer supply unit, which is disposed on the opposite side of the developer supply unit with the passage portion interposed therebetween. A back electrode to which a voltage is applied to further fly the developing material that has passed through the passing portion, and a developing material that is arranged between the back electrode and the electrode array and is made to fly by the back electrode are deposited and deposited. Form developer image In addition, an endless belt-shaped intermediate recording medium that transfers the developer image to the conveyance path of the image recording medium, a plurality of rollers that stretches the endless belt-shaped intermediate recording medium, and the endless belt-shaped intermediate recording medium. A transfer unit for transferring the developer image formed on the image recording medium to the image recording medium, and a developer remaining on the endless belt-shaped intermediate recording medium after the developer image is transferred to the image recording medium by the transfer unit. An image forming apparatus comprising: a cleaning unit that removes the cleaning unit; the cleaning unit is disposed so as to face at least one of the plurality of rollers with the endless belt-shaped intermediate recording medium interposed therebetween. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the cleaning unit is formed in a roller shape. 3. The image forming apparatus according to claim 2, wherein the cleaning unit includes a brush roller.