JPH04278366A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device capable of obtaining an ideal toner could and easily controlling the toner cloud passing through an aperture. CONSTITUTION:An aperture electrode body 1 is disposed so that an aperture 6 is opposed to a position of a loop 31 of a first vibration wave from a position at which a toner 22 is held on a toner transport belt 26 hung between a back-up roller 24 and a drive roller 20. The toner transport belt 26 vibrates at 20kHz by an ultrasonic vibrator 27. A toner cloud which is easy to control in passing through the aperture is efficiently generated below the aperture 6.

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 as a plotter, facsimile machine, etc.

0002

2. Description of the Related Art Conventionally, US Pat. No. 3,689,935 discloses an image recording apparatus that controls the passage of toner particles through an aperture by applying an image signal to an electrode having an aperture to form an image on a support. There is.

This image recording device has a continuous conductive layer (hereinafter referred to as a reference electrode) on one side with an insulating layer in between, and a plurality of conductive layers (hereinafter referred to as reference electrode) that are insulated from each other on the other side. , control electrodes) are formed, and 3 for each control electrode.
an aperture electrode body having at least one row of apertures through the layer, means for selectively applying an electrical potential between the control electrode and the reference electrode, and flow of toner particles through the apertures by the applied electrical potential. and means for moving the support and the aperture electrode relative to each other to position the support in the particle flow path.

In the above-mentioned image recording apparatus, a method has been proposed in which charged toner particles are conveyed in a cloud shape using a vibrator as means for supplying charged toner particles to the vicinity of an aperture.

[0005]

[Problems to be Solved by the Invention] However, as described above, in order to supply toner particles near the aperture, the toner conveying belt is vibrated by a vibrator below the aperture, and the charged toner is conveyed in the form of a cloud. However, the entire toner conveying belt vibrates and the toner scatters before it reaches the aperture, making it impossible to obtain a good toner cloud.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus that can obtain a good toner cloud and that can easily control passage through an aperture.

[0007]

[Means for Solving the Problems] In order to achieve this object, the image forming apparatus of the present invention controls the passage of charged toner through an aperture by applying an image signal to an electrode provided with an aperture. In an image forming apparatus that forms an image on a support provided on opposite sides of a supply source and an electrode with an aperture, a toner conveying belt is disposed so that one side faces the aperture, and a toner conveying belt is arranged to face the aperture of the toner conveying belt. A supply means for supplying toner onto the surface, and a vibration means for vibrating the toner conveying belt in a higher order mode, from the position where the toner is supplied to the toner conveying belt by the supply means to the position of the first antinode of the vibration wave. The apertured electrodes are arranged so that the apertures face each other.

[0008]

According to the present invention having the above structure, the charged toner is carried on the toner conveying belt and conveyed to the surface facing the aperture. The surface of the toner conveying belt is vibrated in a higher order mode by the vibrating means. Therefore, the toner carried on the surface of the toner conveying belt is freed from adhesion forces such as van der Waals forces generated between the toner and the belt due to the vibrational acceleration of the belt surface, and moves on the belt.

On the other hand, the electrode with an aperture is arranged so that the aperture faces the position where the toner is carried on the toner conveying belt and the position where the antinode of the first vibration wave is generated. A relatively small electric field controls toner passage through the aperture.

0010

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

As shown in detail in FIG. 2, the aperture electrode body 1 constituting the apertured electrode of the present invention has a reference electrode 3 formed on one surface of an insulating layer 2, and a reference electrode 3 and an insulating layer 2. A large number of penetrating apertures 6 are formed in a line, and are lined up by the width of a support 10, which will be described later.

The control electrodes 4 are provided around the apertures on the other surface of the insulating layer 2, one for each aperture, so that a control voltage can be individually applied to each of the many apertures 6. ing. Each of the control electrodes 4 is
It is connected to a control voltage drive circuit 8 that generates a voltage according to the image signal. Note that the reference electrode 3 is grounded.

As shown in FIG. 1, a support conveyance roller 14 for conveying a support 10 is disposed on the control electrode 4 side of the aperture electrode body 1, and the surface of the support 10 facing the aperture electrode body 1 is disposed on the control electrode 4 side of the aperture electrode body 1. A back electrode 11 is disposed so as to be in contact with the back side of the back electrode 11 , and the back electrode 11 is connected to a negative high voltage power source 12 . Furthermore, a fixing device 13 is arranged at the destination where the support body 10 is transported.

An aperture electrode body 1 is provided at the upper end of the case 21.
is fixed, and a driving roller 2 is provided inside the case 21 so as to face the reference electrode 3 of the aperture electrode body 1.
0 and a backup roller 24 connected to a negative high-voltage power source 12. On the opposite side of the aperture electrode body 1 with the toner conveying belt 26 in between, an ultrasonic vibrator 27 constituting the vibrating means of the present invention is arranged. The gap between the toner conveying belt 26 and the ultrasonic vibrator 27 is 10 mm or less.

Toner 22 is stored inside the case 21 to the lower left of the backup roller 24 . A supply roller 23 is disposed near the accumulated toner 22, and a carrier roller 30 is disposed at a position in pressure contact with the supply roller 23. A gap of 0.1 to 0.4 mm is formed between the carrying roller 30 and the toner conveying belt 26 wound around the backup roller 24. The surface of the supply roller 23 is made of sponge or the like, and the surface of the carrier roller 30 is made of resin. The supply roller 23 and the carrier roller 30 constitute the supply means of the present invention.

The aperture electrode body 1 is located at the antinode 31 of the first vibration wave caused by the ultrasonic vibrator 27 when viewed from a position facing the carrying roller 30 of the toner conveying belt 26.
An aperture 6 is disposed to face the position.

The operation of the image forming apparatus configured as described above will be described in detail below.

As the drive roller 20 rotates clockwise (in the direction of the arrow) in FIG. 1, the toner conveying belt 26 rotates between the backup roller 24 and the drive roller 20. On the other hand, as the supply roller 23 rotates clockwise (arrow direction) in FIG. 1 and the carrier roller 30 rotates clockwise (arrow direction) in the figure, the toner 22 is distributed between the supply roller 23 and the carrier roller 30. It is rubbed and triboelectrically charged.

Since a negative high voltage from the high voltage power supply 12 is applied to the backup roller 24, an electric field is generated between the support roller 30 and the backup roller 24 due to this voltage. The toner 22 positively charged by the electric field flies onto the toner conveying belt 26 that is stretched around the backup roller 24, and the toner 22 is carried by electrostatic coating on the surface of the toner conveying belt 26 facing the aperture electrode 1. .

The supported toner 22 is conveyed downward of the aperture electrode 1 as the toner conveying belt 26 rotates.

On the other hand, the surface of the toner conveying belt 26 located between the backup roller 24 and the drive roller 20 is the same as that of the ultrasonic vibrator 27 through the air due to the vibration of 20 kilohertz or more of the ultrasonic vibrator 27. It vibrates in a higher mode at a higher frequency. Therefore, at the first vibration wave antinode 31 after the toner 22 is carried on the toner conveying belt 26, the toner 22 receives a force due to the vibration acceleration of the toner conveying belt 26, and is subjected to mirror image force, van der Waals force, and conveyance force. It is released from the adhesion force such as electrostatic force with the belt 26, and a toner cloud is generated.

At this time, a negative voltage is applied to the control electrode 4 in accordance with the image signal. Lines of electric force are formed in the aperture 6 corresponding to the control electrode 4 to which a negative voltage is applied, going from the reference electrode 3 side to the control electrode 4 side. The positively charged toner 22 generating a toner cloud is drawn out from the reference electrode 3 side to the control electrode 4 side through the aperture 6, and further onto the support 10 by the flying electric field formed by the back electrode 11. The toner particles fly and adhere to the support 10 to form a toner image.

By applying the same potential as the reference electrode 3 or a positive voltage to the control electrode 4 corresponding to the aperture 6 that is not related to the image, it is possible to shield the flying electric field from the back electrode 11 or to protect the aperture from the aperture. By forming lines of electric force in the aperture 6 from the control electrode 4 side toward the reference electrode 3 side, passage of the toner 22 through the aperture 6 is suppressed.

By repeating the above operations while transporting the support 10, a toner image is formed on the entire surface of the support 10. The support 10 on which the toner image is formed is transferred to a fixing device 13
The toner image is fixed on the support 10 by passing through the toner image.

In the experiment, the thickness of the toner conveying belt 26 was 0.1 mm, the tension of the toner conveying belt 26 was 340 grams, the gap between the toner conveying belt 26 and the ultrasonic vibrator 27 was 0.5 mm, and ultrasonic vibration was applied. Child 2
When the frequency of 7 is 20 kilohertz and the amplitude of the ultrasonic vibrator 27 is 5 micrometers, the maximum amplitude of the vibration wave of the toner transport belt 26 from the position where the toner 22 is carried on the toner transport belt is 18 micrometers. However, the backup roller 24 and the ultrasonic transducer 2
7, the maximum amplitude of the toner conveying belt 26 is 6 micrometers, and the ultrasonic vibrator 2
The toner conveying belt 2 is located at a position opposite to the center position of 7.
The maximum amplitude of No. 6 was also comparable. Note that the vibration frequency of the toner conveying belt 26 was 20 kilohertz in all cases.

[0026] The vibration acceleration is proportional to the amplitude, and the larger the amplitude, the larger the vibration acceleration, and the more likely it is to generate a toner cloud. Therefore, the aperture electrode body 1 is arranged so that the aperture 6 faces the first antinode 31 of the vibration wave of the toner conveying belt 26 from the position where the toner 22 is carried, where the amplitude is larger than other positions. By doing so, a toner cloud is extremely easily generated.

Furthermore, due to the vibration at the position of the antinode 31, most of the toner 22 carried on the toner conveying belt 26 flies from the toner conveying belt 26 in the form of a cloud. Toner 22 is placed on the toner conveying belt 26 located near the drive roller 20.
is hardly carried. Therefore, even if the aperture electrode body 1 is arranged so that the aperture 6 faces a position other than the position of the antinode 31, a toner cloud is not generated at that position, so a toner image is formed on the support 10. Not done.

[0028]

[Effect of the invention] As is clear from the detailed description above,
According to the present invention, it is possible to efficiently generate a toner cloud directly under an aperture without toner scattering elsewhere, and to provide an image forming apparatus that can easily control passage through the aperture.

[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.

[Explanation of symbols]

1 Aperture electrode body (electrode with aperture) 6
Aperture 10 Support 22 Toner 23 Supply roller (supply means) 26 Toner transport belt 27 Ultrasonic vibrator (vibration means) 30 Carrying roller (supply means)

Claims (1)

[Claims] [Claim 1] Controlling the passage of charged toner through the aperture by applying an image signal to an electrode with an aperture, and printing an image on a support provided on the opposite side of the toner supply source and the electrode with an aperture. In an image forming apparatus for forming an image, a toner conveying belt disposed with one side facing an aperture, a supply means for supplying toner to a surface of the toner conveying belt facing the aperture, and a toner conveying belt placed in a high-order mode. and a vibrating means for vibrating, and the electrode with the aperture is arranged so that the aperture faces the first antinode of the vibration wave from the position where the toner is supplied to the toner conveying belt by the supply means. image forming apparatus.