JPH0524249A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device wherein remaining toner in a toner supply source does not influence images adversely. CONSTITUTION:When a toner 22 having a small quantity of electrification on a toner conveying belt 26, which is remainder occurred at previous image forming operation, is to be dispersed, the toner 22 does not stain a support body 10 passing through an aperture 6 since a rear face of the aperture 6 is covered with a cover 60.

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 obtaining an image on a support by controlling the passage of toner particles through an aperture by applying an image signal to an electrode having an aperture has been proposed in US Pat. No. 3,689,935. Has been done. In this proposal, a reference electrode that is continuous on one side with a layer of an insulator sandwiched between it and a plurality of control electrodes that are insulated from each other on the other side are provided. Also, an aperture electrode body having a row of apertures, a means for selectively applying a potential between the control electrode and the reference electrode, and a potential applied to modulate the flow of toner particles through the aperture. It comprises means for projecting 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.

In this system, a system has been proposed in which toner particles charged by frictional charging are applied onto a belt, and the vibrator vibrates the belt to supply the toner particles in the vicinity of the aperture.

[0004]

However, the toner remains on the belt after the image is output on the support or when the operation is interrupted due to an error. The toner remaining on the belt adversely affects the image during the next image output operation because the flow of toner particles through the aperture cannot be modulated by the potential applied to the aperture electrode body.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an image forming apparatus in which the toner remaining in the toner supply source does not adversely affect the image.

[0006]

In order to achieve this object, the image forming apparatus of the present invention controls the passage of the charged toner through the aperture by applying an image signal to an electrode having an aperture, and the image forming apparatus controls the passage of the toner. An image forming apparatus for forming an image on a support provided on the opposite side with a toner supply source by a cloud and an electrode with an aperture interposed therebetween, wherein toner is supplied to the electrode with an aperture from the toner supply source. It has a shielding means to prevent it.

[0007]

According to the present invention having the above structure, the shielding means prevents the toner remaining in the toner supply source from being supplied to the aperture electrode body by the toner supply source.

[0008]

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. Aperture electrode body 1
2 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 of the insulating layer 2, and an aperture 6 penetrating the reference electrode 3, the insulating layer 2 and the control electrode 4 as shown in FIG. Are formed in a single row in the width of the support.

In FIG. 1, on the left side of the image forming apparatus 100, a cassette 50 for accommodating the support 10 and a support 1 are provided.
Half-moon roller 51 that supplies 0 one by one, support supply roller 52 that sends support 10 downstream, and chute 5
3 are provided.

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

On the reference electrode side of the aperture electrode body 1, a toner conveying belt 26 is wound between the driving roller 20 and the backup roller 24, and a cam having an elliptical cross section is provided on the back side of the conveying belt facing surface of the aperture electrode body. The roller 27 is provided with the static elimination brush 31 on the upstream side thereof. These are in contact with the toner 22 accumulated in the vicinity of the supply roller 23 and the supply roller 23, and the toner transport belt 2
6 and the carrying roller 30 having a clearance of 0.1 to 0.4 mm are housed in the toner case 21. The supply roller 23 is a support roller 3 such as a sponge.
The surface 0 is made of resin.

Aperture electrode body 1 and toner transport belt 2
A cover 60 is provided between the cover 6 and the cover 6.

As shown in FIGS. 3 and 4, the lid 60 is supported by a frame (not shown) so as to be movable in the left and right directions.
A rack 61 is provided at one end of 0. A gear 62 meshes with the rack 61, and the gear 62 is rotated by a well-known motor (not shown).

Further downstream, the fixing device 13 and the chute 5 are provided.
4, a discharge roller 55, and a tray 56 are arranged.

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

The support 10 housed in the cassette 50 is
Half moon roller 51 feeds out one by one and shoots 5
3 is guided by the supporting member feeding roller 52 and is conveyed to the supporting member 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 arrow direction, and the toner 22 is rotated by the rotation of the supply roller 23 in the arrow direction. Is rubbed against the carrying roller 30 to be positively triboelectrically charged, and then carried on the toner carrying belt 26 by electrostatic coating with a high voltage power source.

The carried toner is conveyed toward the surface facing the aperture electrode, and on the upstream side of this position, the conveying belt 26 is removed from the back side of the conveying belt 26 by the static elimination brush 31.
Is discharged. Since the cam roller 27 is rotating at the position of the surface facing the aperture electrode, the surface of the conveyor belt 26 vibrates. Therefore, the toner 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, if a negative voltage is applied to the control electrode 4 in accordance with an image signal from the storage means (not shown),
Electric force lines from the back surface of the aperture 6 to the front surface are formed in the aperture 6 of the applied control electrode 4, and the positively charged toner 22 is extracted from the back surface of the aperture 6 to the front surface. Flies on the support by the flying electric field formed by the back electrode 11 and is held, forming an image portion.

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. The passage of the toner 22 through the aperture 6 is suppressed by forming a line of electric force from the surface to the reference electrode 3 on the back surface. This process is applied to the support 10
A toner image is formed on the entire surface of the support 10 by repeating the above-described process while being conveyed.

The support on which the toner image is formed is the fixing device 1.
After passing through 3, the image is fixed on the support 10. Further, it is guided by the chute 54 and discharged onto the tray 56 by the discharge roller 55.

Next, before restarting the image forming operation,
As shown in FIG. 3, the lid 60 is
The gear 62 rotates to the right by the motor and moves to the left by the rack 61 to the state shown in FIG. 4, which covers the back surface of the aperture 6 portion of the aperture electrode body 1 (S1).

Then, the supply roller 23 and the carrying roller 3
0, the toner transport belt 26, and the cam roller 27 are driven, and the toner 22 having a small amount of charge remaining on the toner transport belt 26 due to the previous image forming operation is scattered (S).
2).

At this time, since the back surface of the aperture 6 is covered with the lid 60, the residual toner having a small charge amount adheres to the aperture 6 or the back surface of the aperture electrode body 1, or the toner 22 passing through the aperture is the toner 22. In order to prevent the toner from clinging to the surface of the aperture electrode 1, clogging of holes in the aperture electrode body 1 and the toner 22 clinging to the surface of the aperture electrode body 1
Therefore, the support is not soiled.

When the remaining toner 22 on the toner conveying belt 26 has been scattered for a certain period of time, the gear 62 rotates counterclockwise by a drive system (not shown), and the rack 61 causes the lid 6 to rotate.
0 moves to the right (S3) and returns to the retracted state shown in FIG.
The newly charged toner 22 is supplied to the aperture 6,
The image forming operation is started.

Further, the present invention can be modified without departing from the scope of the invention without being limited to the above-mentioned embodiments.

[0027]

As is clear from the above description,
According to the present invention, the shielding means prevents the residual toner having a small charge amount from adhering to the aperture or the back surface of the aperture electrode body, or the toner passing through the aperture from flowing around to the surface of the aperture electrode body. There is no clogging of the holes and the contamination of the toner on the surface of the aperture electrode body does not stain the support.

[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.

FIG. 3 is an explanatory diagram of a drive unit of a lid that covers the back surface of the aperture.

FIG. 4 is an explanatory diagram of a drive unit of a lid that covers the back surface of the aperture.

FIG. 5 is a flowchart showing an operation.

[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 22 Toner 26 Toner 26 Belt Conveyor 27 Cam Roller 60 Lid

Claims (1)

Claim: What is claimed is: 1. An image signal is applied to an electrode having an aperture to control the passage of the charged toner through the aperture, and the opposite side of the toner supply source by the toner cloud and the electrode with the aperture are sandwiched. An image forming apparatus for forming an image on a support provided in the image forming apparatus, wherein the electrode with aperture has a shielding means for preventing toner from being supplied from the toner supply source. ..