JPH0580667A - Image forming device - Google Patents

Abstract

PURPOSE:To save space and energy by energizing conductive toner on a support, to heat and melt the conductive toner, and fix the conductive toner on the support. CONSTITUTION:A flying electric field caused by a rear-surface electrode 11 is shielded by impressing the same potential as a reference electrode or a positive voltage to the control electrode of an aperture corresponding to a non-image part. Alternately, the passing of conductive toner 22 through the aperture is suppressed by forming an electric force line, flowing from the surface to the reference electrode on the back, in the aperture. When the support 10 on which a toner image is formed passes along a fixing roller 13, a sort of capacitor is composed of the fixing roller 13, support 10 and rear-surface electrode 11. An AC current flows in the part of the conductive toner 22 by the potential difference between the rear-surface electrode 11 and the fixing roller 13 connected to an AC power source 15 and the conductive toner 22 melts by joule heat to be fixed on the support 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a printer,
The present invention relates to an image forming apparatus that can be used for plotters, facsimiles, and the like.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus for controlling the passage of an aperture of toner particles by applying an image signal to an electrode having an aperture to obtain an image on a support is proposed in US Pat. No. 3,689,935. Has been done. In this proposal, it is composed of a reference electrode that is continuous on one side with a layer of an insulator interposed between it and a plurality of control electrodes that are insulated from each other on the other side. Each insulated plurality of control electrodes penetrates three layers. An aperture electrode body having at least one row of apertures, means for selectively applying a potential between the control electrode and the reference electrode, and the applied potential modulates the flow of toner particles through the aperture. It is composed of means for projecting electrically charged particles and means for positioning the support in the particle flow path by the relative movement of the support and the aperture electrode body.

[0003]

However, in order to fix the toner having the image formed on the support to the support by controlling the passage of the aperture, a heat roller used in a copying machine or the like is required. However, there is a problem in that it is expensive, requires a large amount of energy, and increases in size.

The present invention has been made to solve the above-mentioned problems, and provides a low-cost, space-saving, and energy-saving image forming apparatus that does not require a heat roller for thermally fixing toner. It is an object.

[0005]

In order to achieve this object, the image forming apparatus of the present invention controls the passage of the charged conductive toner through an aperture by applying an image signal to an electrode having an aperture. And an image forming apparatus for forming an image on a support provided on the opposite side with the toner supply source and the electrode with an aperture interposed therebetween. It has a fixing means for fixing the conductive toner to the body.

[0006]

According to the present invention having the above-mentioned structure, the fixing means applies a current to the conductive toner on the support to melt it, thereby fixing the conductive toner on the support.

[0007]

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

FIG. 1 is a sectional view of an image forming apparatus 100 according to an embodiment of the present invention. As shown in detail in FIG. 2, the aperture electrode body 1 has a reference electrode 3 on the toner supply source side of the insulating layer 2 and a control electrode 4 on the support side.
A large number of apertures 6 penetrating the insulating layer 2 and the control electrode 4 are formed in a row and in the width of the support. In FIG. 1, on the left side of the image forming apparatus 100, a cassette 50 that accommodates the support 10 and a half-moon roller 5 that supplies the support 10 one by one.
1, a support supply roller 52 and a chute 53 that deliver the support 10 to the downstream portion.

On the downstream side, on the control electrode side of the aperture electrode body 1, the support carrier roller 14, the sensor 57, and
A back electrode 11 is disposed in contact with the back surface of the support body 10, and each control electrode 4 is connected to a control voltage drive circuit 8 that generates a voltage according to an image signal. The back electrode 11 is connected to a negative high voltage power supply 12.

A toner transport belt 26 is wound between the drive roller 20 and the backup roller 24 on the reference electrode side of the aperture electrode body 1, and the toner transport belt 2 is provided.
A cam roller 27 having an elliptical cross section is arranged on the back side of the surface of the electrode 6 facing the aperture electrode body, and a charge eliminating brush 37 is arranged on the upstream side thereof. These are in contact with the conductive toner 22 accumulated in the vicinity of the supply roller 23, the supply roller 23, the toner carrying belt 26 and the carrying roller 30 having a clearance of 0.1 to 0.4 mm, and the toner case 21.
It is housed inside. The supply roller 23 is a sponge,
The surface of the carrier roller 30 is made of resin.

The conductive toner 22 contains metal powder and has a resistance value of 10 ⁻⁷ to 10 ⁻⁹ ohm centimeter.

Further downstream, a fixing roller 13, a chute 54, a discharge roller 55 and a tray 56 are arranged. The fixing roller 13 is made of metal and is disposed at a slight distance from the back electrode 11, and the AC power supply 15 is provided between the fixing roller 13 and the back electrode 11.
Connected to.

The operation of the above structure will be described in detail below.

The support 10 housed in the cassette 50 is
The half-moon roller 51 feeds the sheets one by one, the chute 53 guides them, and the support-feeding roller 52 conveys them to the support-conveying roller 14. When the tip of the support 10 is detected by the sensor 57, the toner transport belt 26 rotates between the backup roller 24 and the drive roller 20 by the rotation of the drive roller 20 in the direction of the arrow, and the toner transport belt 26 becomes conductive by the rotation of the supply roller 23 in the direction of the arrow. The toner 22 is rubbed by the carrying roller 30 to be positively triboelectrically charged, and then carried on the toner carrying belt 26 by electrostatic coating using a high voltage power source.

The carried conductive toner 22 is conveyed toward the surface facing the aperture electrode, and the conveying belt 26 is discharged from the back side of the conveying belt 26 on the upstream side of this position by the discharging brush 37. Since the cam roller 27 is rotating at the position facing the aperture electrode, the conveyor belt 26
Surface vibrates. Therefore, the conductive toner 22 carried on the conveyor belt 26 receives a force due to the vibration acceleration of the conveyor belt 26, and is released from the image force, the van der Waals force, and the adhesion force such as the electrostatic force with the conveyor belt 26.

On the other hand, at this time, when a negative voltage is applied to the control electrode 4 in accordance with an image signal from the storage means (not shown), the aperture 6 of the applied control electrode 4 changes from the back surface to the front surface of the aperture 6. The positively charged conductive toner 22 in which a line of electric force is formed and which is positively charged is extracted from the back surface of the aperture 6 to the front surface, and is further spread on the support by the flying electric field formed by the back electrode 11. The gauze is retained and forms the image area.

By applying the same potential or a positive voltage as that of the reference electrode 3 to the control electrode 4 of the aperture 6 corresponding to the non-image portion, the flying electric field by the back electrode 11 is shielded or the inside of the aperture 6 is covered. By forming a line of electric force from the surface to the reference electrode 3 on the back surface, the passage of the conductive toner 22 through the aperture 6 is suppressed. By repeating this process while transporting the support 10, the support 10
A toner image is formed on the entire surface.

When the support having the toner image formed thereon passes through the fixing roller 13, the fixing roller 13, the support 10 and the back electrode 11 constitute a kind of capacitor and are connected to the back electrode 11 and the AC power supply 15. Due to the potential difference between the conductive toner 22 and the fixing roller 13, an AC current flows through the conductive toner 22 and is melted by Joule heat, so that the conductive toner 22 is fixed to the support 10.

Since a current flows only in the toner portion of the support 10 on which the toner image is formed, thermal fixing can be performed with good energy efficiency.

Further, it is guided by the chute 54 and discharged onto the tray 56 by the discharge roller 55.

Further, the present invention is not limited to the above-mentioned embodiment and can be modified within a range not departing from the gist thereof.

[0022]

As is clear from the above description,
According to the toner thermal fixing apparatus of the present invention, current flows only in the toner portion of the support on which the toner image is formed, so that the energy efficiency is good, the structure is simple, and the volume occupied in the apparatus is small. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment embodying the present invention.

FIG. 2 is a perspective view showing details of an aperture electrode body.

[Explanation of symbols]

 1 Aperture electrode body 2 Insulating layer 3 Reference electrode 4 Control electrode 6 Aperture 8 Control voltage drive circuit 10 Support 11 Back electrode 12 High voltage power supply 13 Fixing roller 15 AC power supply 20 Drive roller 22 Conductive toner 23 Supply roller 24 Backup roller 26 Toner Conveyor belt 27 Cam roller 30 Support roller

Claims (1)

[Claims] 1. A support provided on the opposite side of an electrode with an aperture from the toner supply source to control the passage of the charged conductive toner through the aperture by applying an image signal to the electrode provided with the aperture. An image forming apparatus for forming an image on a substrate is provided with a fixing unit for fixing the conductive toner on the support by causing an electric current to flow through the conductive toner on the support to melt the heat. apparatus.