JPH05185640A - Powder feeder - Google Patents

Abstract

PURPOSE:To provide a powder feeder capable of efficiently supplying a powder by simple constitution without requiring a vibration means. CONSTITUTION:Supported toner 22 is fed to the opposed surface of an aperture electrode but, since the curvature of a toner feed belt 26 at the time of the electrostatic coating with the toner is R being the radius of a backup roller 24 but changes from R to infinity at the time of the transfer to a straight line part, the surface of the toner feed belt 26 receives compression stress and the toner 22 is blown off forwardly and can be supplied to an aperture in a cloud form.

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 a powder supply device 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 interposed between it and a plurality of control electrodes that are insulated from each other on the other side, and three layers are provided for each insulated control electrode. An aperture electrode body having at least one row of apertures penetrating through it, 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. And a means for projecting the charged particles as described above and a 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, as a means for supplying charged toner particles to the vicinity of the aperture, a system in which charged toner is carried on a belt and the belt is vibrated by a vibrator to convey the toner in a cloud shape is disclosed in Japanese Patent Application No. Hei. 29458
It is proposed in the specification and drawings attached to the application for No. 7.

[0004]

However, in order to vibrate the belt, a large amount of energy is required because the mass of the belt is larger than that of the toner.

Further, since the entire belt vibrates, there is a problem that the toner is scattered on the entire belt and the dense toner cloud cannot be efficiently supplied to the aperture.

The present invention has been made to solve the above-mentioned problems, and does not require a vibrating means,
It is an object of the present invention to provide a powder supply device capable of efficiently supplying powder with a simple structure.

[0007]

In order to achieve this object, a powder supply device of the present invention supports a powder, and a powder carrier having a variable curvature, and a powder carrier. And a supply means for supplying.

[0008]

According to the present invention having the above structure, the supply means supplies the powder to the powder carrier, and the powder carrier forms the powder into a cloud shape at the portion where the curvature changes. Supply powder.

[0009]

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 equipped with the powder supply apparatus 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.

The insulating layer 2 is made of a resin film or the like, and has a high rigidity on the side of the reference electrode 3 near the aperture 6.
A book support rod 61 is adhered to the aperture electrode body 1. A plurality of piezo elements 6 are provided on the back surface of the two support bars 61.
6 is glued. A compression spring 62 is provided between the two support bars 61. Tension is applied to the aperture electrode body 1 by the support rod 61 and the compression spring 62. A connector 63 is soldered to the control electrode 4 side.

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.

At 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 via a connector 63. The back electrode 11 is connected to a negative high voltage power supply 12.

A toner transport belt 26 is wound around the drive electrode 20 and the backup roller 24 on the reference electrode side of the aperture electrode body 1. These are the toner 22 and the supply roller 2 accumulated near the supply roller 23.
3, and 0.1 to the toner conveying belt 26.
Carrier roller 30 having a clearance of 0.4 mm
It is also stored in the toner case 21. The supply roller 23 has a sponge or the like, and the supporting roller 30 has a resin surface. The aperture electrode body 1 is arranged so that the aperture 6 is located above the backup roller 24.

Further downstream, the fixing device 13 and the chute 5 are provided.
The operation will be described in detail below in the above-described configuration in which the 4, the discharge roller 55 and the tray 56 are arranged.

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. After being rubbed by the carrying roller 30 to be positively triboelectrically charged, the toner is carried on the toner carrying belt 26 by electrostatic coating with a high voltage power source.

The carried toner 22 is conveyed toward the surface facing the aperture electrode, and the curvature of the toner conveying belt 26 when electrostatically applied is R which is the radius of the backup roller 24. At the time of transfer, since the curvature changes from R to infinity, the toner transport belt 26
The surface of the toner is subjected to compressive stress, the toner 22 is pushed off and becomes a cloud, and the toner 22 is supplied to the aperture 6.

Therefore, it is possible to efficiently supply the toner 22 in the form of a cloud to the aperture 6 with a simple structure without requiring a vibrating means.

On the other hand, at this time, when a negative voltage is applied to the control electrode 4 via the connector 63 in accordance with an image signal from a storage means (not shown), the aperture 6 is held in the aperture 6 of the applied control electrode 4. Lines of electric force are formed from the back surface of the aperture 6 to the front surface, and the positively charged toner 22 is drawn from the back surface of the aperture 6 to the front surface, and is further supported by the flying electric field formed by the back electrode 11. It flies over the body and is retained to form the image area.

By applying the same potential or a positive voltage as 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 control electrode 4 is placed inside the aperture 6. The passage of the toner 22 through the aperture 6 is suppressed by forming a line of electric force from the front surface to the reference electrode 3 on the back surface. By repeating this process while conveying the support 10, the support 1
A toner image is formed on the entire surface.

By applying a voltage of frequency S to the piezo element 66 and vibrating it to vibrate the support rod 61, the aperture 6 vibrates at the vibration frequency S, and the toner 22 attached to the aperture 6 is shaken off. Prevents hole clogging.

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, the tray 5 is guided by the chute 54 and is discharged by the discharge roller 55.
It is discharged to 6.

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.

[0024]

As is clear from the above description,
According to the present invention, it is possible to efficiently supply powder in the form of a cloud with a simple structure without the need for a vibrating means.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a powder supply device of 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 22 Toner 23 Supply roller 26 Toner transport belt 30 Support roller

Claims (1)

[Claims] 1. A powder supply apparatus comprising: a powder support that supports powder and has a variable curvature; and a supply unit that supplies the powder to the powder support.