JPH04251763A - Image formation device - Google Patents

Abstract

PURPOSE:To prolong the life of a cloud generating means of a device with which images are formed on a support body by controlling passage of toner particles through an aperture by a method wherein generation of the toner cloud is suspended in an area where the whole area extending in the breadthwise direction of the support body is found to be nonimage area by an image signal from a memory. CONSTITUTION:Support bodies 10 housed in a cassette 50 are carried one by one, being guided by a chute 53. When the front end of each of the support bodies 10 is detected with a sensor 57, a toner carrying belt 26 travels round a backup roller 24 and a driving roller 20, and the toner 22 is rubbed over a bearing roller 30 and becomes positively charged by rubbing. Then the toner carrying belt 26 is discharged with a discharging brush 31 and when negative voltage is applied to a control electrode 4 in accordance with image signals from a memory, the toner 22 is attracted from the rear side of an aperture 6 to its surface, and an image section is formed over the support body 10. When the whole area extending in the breadthwise direction of the support body 10 is found to be a nonimage area by the image signal, occurrence of toner cloud is suspended.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to copying machines, printers,
The present invention relates to an image forming apparatus that can be used for plotters, facsimile machines, etc.

0002

2. Description of the Related Art Conventionally, an image recording apparatus for controlling the passage of toner particles through an aperture and obtaining an image on a support by applying an image signal to an electrode having an aperture was proposed in US Pat. No. 3,689,935. There is. This proposal consists of a continuous conductor layer (reference electrode) on one side with an insulator layer in between, and multiple conductive layers (control electrodes) insulated from each other on the other side. an aperture electrode body having at least one row of apertures extending through the three layers for each control electrode; means for selectively applying a potential between the control electrode and a reference electrode; and means for selectively applying a potential between the control electrode and the reference electrode; It comprises means for projecting charged particles so as to modulate the flow of toner particles therethrough, and means for moving the support and the aperture electrode relative to each other to position the support in the particle flow path. In this method, as a means for supplying charged toner particles to the vicinity of the aperture, a method has been proposed in which the charged toner is conveyed in a cloud shape using a vibrator.

0003

However, while the image of one document is being output, toner cloud continues to be generated, and the electrodes having the apertures are often contaminated and clogged. Further, it is desired that the cloud generation means be more durable.

The present invention has been made to solve the above-mentioned problems, and is intended to reduce dirt and clogging of electrodes having apertures, and to improve the durability of cloud generation means in image forming apparatuses. is intended to provide.

[0005]

[Means for Solving the Problems] In order to achieve this object, the image forming apparatus of the present invention includes a storage means for storing an image signal, a cloud generation means for generating a toner cloud, and an image signal from the storage means. In the range determined to be a non-image area over the entire width direction, the control means causes the cloud generation means to stop the toner cloud.

[0006]

[Operation] According to the present invention having the above-mentioned configuration, the cloud generation means stops the toner cloud in the range determined to be a blank portion of the document based on the image signal.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying 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 line corresponding to the width of the support. In FIG. 1, on the left side of the image forming apparatus 100, there is a cassette 50 that stores the support 10, and a half-moon roller 5 that supplies the support 10 one by one.
1, a support supply roller 52 for feeding out the support 10, and a chute 53 are disposed downstream.

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

On the reference electrode side of the aperture electrode body 1, a toner conveyance belt 26 is wound between a drive roller 20 and a backup roller 24, and on the back side of the conveyance belt, which faces the aperture electrode body, a cam roller with an elliptical cross section is arranged. 2
7, a static elimination brush 31 is arranged on the upstream side thereof. These are toner 22 stored near the supply roller 23.
, and a supporting roller 30 which is in contact with the supply roller 23 and has a gap of 0.1 to 0.4 mm with the toner conveying belt 26, and is housed in the toner case 21. The surface of the supply roller 23 is made of sponge or the like, and the surface of the support roller 30 is made of resin.

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

The operation of the above-described configuration will be explained in detail below.

The support body 10 housed in the cassette 50 is
The sheets are fed out one by one by the half-moon roller 51 and placed in the chute 5.
3, and is conveyed to the support conveyance roller 14 by the support supply roller 52. When the tip of the support 10 is detected by the sensor 57, the toner conveying belt 26 rotates between the backup roller 24 and the drive roller 20 due to the rotation of the drive roller 20 in the direction of the arrow, and the toner 22 is rotated by the rotation of the supply roller 23 in the direction of the arrow. After being rubbed by the carrier roller 30 and positively charged by friction, the toner is carried on the toner conveying belt 26 by electrostatic coating using a high-voltage power source.

The supported toner is conveyed toward the surface facing the aperture electrode, and at the upstream side of this position, the conveying belt 26 is neutralized by a static eliminating brush 31 from the back side of the conveying belt 26. Since the cam roller is rotating at the position 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 vibrational acceleration of the conveyor belt 26 and is released from adhesion forces such as mirror image force, van der Waals force, and 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 a storage means (not shown), the aperture 6 of the control electrode 4 to which the voltage is applied is directed from the back surface of the aperture 6 to the front surface. The toner 22, which is positively charged with electric lines of force formed therein, is pulled out from the back surface of the aperture 6 to the front surface, and is further blown onto the support by the flying electric field formed by the back electrode 11. is held to form an image portion. By applying the same potential as the reference electrode 3 or a positive voltage to the control electrode 4 of the aperture 6 corresponding to the non-image area, the flying electric field caused by the back electrode 11 can be shielded, or the electric field from the front surface to the back surface inside the aperture 6 can be shielded. By forming electric lines of force directed toward the reference electrode 3, the toner 22 is prevented from passing through the aperture 6. By repeating this process while transporting the support 10, a toner image is formed on the entire surface of the support 10.

However, if it is determined from the image signal from the storage means that the entire widthwise area of the support 10 is a non-image area, the operation of each member in the toner case 21 is stopped;
Stops toner cloud from occurring. When the image area appears again, each member in the toner case 21 starts operating again to generate a toner cloud.The support on which the toner image is formed passes through the fixing device 13, and the image is transferred to the support 10. will be established. Further, it is guided by a chute 54 and discharged onto a tray 56 by a discharge roller 55.

Furthermore, the present invention is not limited to the above embodiments, but can be modified within the scope of the invention.

[0018]

[Effect of the invention] As is clear from the detailed description above,
According to the present invention, dirt and clogging of the electrode having an aperture can be reduced, and the operating time of the cloud generating means can be reduced, so that the life of the cloud generating means can be extended.

[Brief explanation of the drawing]

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 a flowchart of the operation of this embodiment.

[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 device 14 Support conveyance roller 20 Drive roller 21 Toner case 22 Toner 23 Supply roller 24 Backup roller 26 Toner conveyance belt 27 Cam roller 30 Support roller 31 Static elimination brush 51 Half-moon roller 52 Support supply roller 57 Sensor

Claims (1)

[Claims] Claim 1: Controlling the passage of charged toner through the aperture by applying an image signal to an electrode provided with an aperture, and applying an image signal to an electrode provided with an aperture on a support provided on the opposite side of the apertured electrode. In an image forming apparatus that forms an image on a surface, a storage means for storing an image signal, a cloud generation means for generating a toner cloud, and an image signal from the storage means are used to form a non-image area over the entire width direction. , and a control means for stopping the toner cloud by the cloud generation means.