JPH0577478A - Image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to easily excite the traveling wave to prevent toner adhesion, and to effectively use the energy input from the excitation source to the aperture electrode to excite the traveling wave. To do. The aperture electrode 1 includes an insulating layer 106 formed in an endless shape, an aperture 11 provided on a flat plate portion of the insulating layer 106 on the counter electrode 112 side, and a control electrode layer 1
08 and a reference electrode layer 107, and a toner clouder section 14 provided on a flat plate portion of the insulating layer 106 facing the modulation control section 13. An excitation device 2 for exciting a traveling wave is attached to the aperture electrode 1. The excitation device 2 includes first and second piezoelectric bodies 21 and 22 attached to the back surface of the insulating layer 106. When an electric signal having a predetermined frequency is applied to the first and second piezoelectric bodies 21 and 22 during image formation, a bending vibration traveling wave is excited in the aperture electrode 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, the present invention relates to an image forming apparatus that directly controls modulation of toner by an aperture electrode to form an image on a recording medium.

[0002]

2. Description of the Related Art An image forming apparatus of this type has been reported in, for example, US Pat. No. 3,689,935. This image forming apparatus includes a toner crowder, an aperture electrode,
It is composed of a counter electrode. The toner clouder is a means for generating a cloud of charged toner and supplying the toner cloud to the vicinity of the aperture electrode. The aperture electrode is a control unit that modulates and controls the flow of toner from the toner cloud, and includes an insulating layer having a large number of apertures or openings, and a first electrode layer provided on one surface of the insulating layer. And a plurality of second electrode layers provided on the other surface of the insulating layer and independently provided for each of the plurality of apertures.
Further, the counter electrode attracts and holds a recording medium such as paper, and is arranged so as to face the aperture electrode. In the image forming apparatus configured as described above, the toner flow supplied by the toner crowder is controlled by an electric signal applied to the aperture electrode and the counter electrode to form an image on a recording medium such as paper. It

However, when an image is formed by this image forming apparatus, there is a problem in that the aperture portion of the aperture electrode is clogged with toner. That is, for example, when it is desired to obtain a recording density of 240 DPI, since the dot size is 100 μm at the maximum, the inner diameter of the aperture of the aperture electrode is up to 50 μm.
It is necessary to reduce the size to about μm, and the toner particles are deposited on the aperture electrode due to the image force, etc. As a result, the aperture electrode is clogged with the toner particles, and it is difficult to always obtain a stable image output. There was a problem.

Therefore, the present applicant has filed Japanese Patent Application No. 2-29111.
As described in the specification and drawings attached to the application of No. 6, it was proposed to excite a traveling wave on the aperture electrode to prevent the deposition of toner particles. This method applies a repulsive force larger than the image force or the like that causes the accumulation to the toner particles to be deposited on the aperture electrode due to the vibration acceleration generated by the traveling wave excited on the aperture electrode, thereby This is a method to prevent the accumulation of particles.

In the image forming apparatus as described above, since the shape of the aperture electrode is generally a rectangular flat plate shape, in order to excite a traveling wave on this aperture electrode, the aperture electrode is arranged in the direction of the aperture row. An exciter is provided at one end, and a reflected wave absorber that absorbs and consumes the energy of the vibration of the traveling wave propagating on the aperture electrode to prevent the generation of the reflected wave is provided at the other end of the traveling electrode. Had to excite.

[0006]

However, when the traveling wave is excited by the above-mentioned method, in order to make the amplitude distribution of the traveling wave in the traveling direction substantially constant, the vibration input from the excitation device is It was necessary to completely consume the energy with the reflected wave absorber, but there was a problem that it was very difficult to completely eliminate the reflected wave.

Further, there is a problem that the characteristic of the image forming apparatus of the present system, which consumes almost no energy in the recording operation, is impaired even when the distribution of the amplitude in the advancing direction can be made almost constant and the distribution of the amplitude can be made almost constant. It was

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to efficiently utilize the vibration energy input from an exciter that excites a traveling wave and to easily make the aperture electrode. Another object of the present invention is to provide an image forming apparatus capable of exciting a traveling wave.

[0009]

In order to achieve this object, an image forming apparatus of the present invention comprises an aperture electrode that modulates and controls charged toner, and an exciter that excites a traveling wave on the aperture electrode. In the image forming apparatus provided with,
The aperture electrode is formed in an endless shape in the traveling direction of the traveling wave propagating on the aperture electrode.

[0010]

In the image forming apparatus of the present invention having the above structure, since the aperture electrode is formed endlessly along the traveling direction of the traveling wave, the traveling direction of the traveling wave on the aperture electrode is As a result of exciting the traveling wave which is the direction of the aperture array provided on the aperture electrode, it is not necessary to absorb the reflected wave by the reflected wave absorber,
As a result, a traveling wave can be easily excited on the aperture electrode without consuming vibration energy.

[0011]

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

In FIG. 3, the image forming apparatus 100 comprises a recording section 101 and a heat fixing section 102. An insertion opening 117 and an ejection opening 118 are provided on the side of the image forming apparatus 100. In the recording unit 101, a medium P such as plain paper that has entered through the insertion slot 117.
Then, an image or the like is formed. Then, the image and the like on the medium P are fixed in the heat fixing unit 102. Furthermore,
The medium P passes through the guide 115 and is taken out from the ejection port 118.
Sent to.

The recording unit 101 comprises a conveying roller 103, an aperture electrode 1 and a counter electrode 112.
Around the transport roller 103, a supply roller 104 that is rotatable according to the rotation direction of the transport roller 103 is provided in contact with the transport roller 103. A supply blade 111 is provided in contact with the supply roller 104. The toner T is stored on the supply blade 111. Then, the toner T is forcibly supplied to the supply roller 104 by the supply blade 111. The supply roller 104 and the supply blade 111 are covered with the case K.

Next, the structure of the aperture electrode 1 will be described with reference to FIGS. The aperture electrode 1 is
Insulating layer 106 formed endlessly, and this insulating layer 106
Of a plurality of apertures 11 provided on the flat plate portion of the counter electrode 112 side, a plurality of control electrode layers 108, and a reference electrode layer 107, and the modulation control of the insulating layer 106. The toner cloud portion 14 is provided on the flat plate portion facing the portion 13. Further, the aperture electrode 1 is provided with an exciting device 2 for exciting a traveling wave on the aperture electrode 1. The excitation device 2 is composed of first and second piezoelectric bodies 21 and 22 attached to the back surface of the insulating layer 106, and the first and second piezoelectric bodies 21 and 22 are respectively piezoelectric bodies 21 and 22. Is installed so that the positional phase of the bending vibration excited on the aperture electrode 1 is shifted by a length of ¼ times the wavelength. Further, the first piezoelectric body 21 is electrically connected to the first amplifier 31, and the second piezoelectric body 22 is electrically connected to the second amplifier 32. Further, the first amplifier 31 is connected to the 90-degree phase shifter 41, and the 90-degree phase shifter 41 and the second amplifier 32 are connected to the oscillator 50 that outputs an electric signal of a predetermined frequency.

Next, the apertures 11 are provided in the vicinity of the central portion in the Z direction of the modulation control section 13 so as to open in the insulating layer 106, and are arranged in a row to form the aperture row 12. The reference electrode layer 107 is the insulating layer 106.
Is provided on the surface opposite to the control electrode 108. Further, the control electrode layer 108 is independently provided on the upper surface of the insulating layer 106, around the aperture 11. The reference electrode layer 107 is connected to the ground, and the plurality of control electrode layers 10 are connected.
Each of 8 is connected to a signal source (not shown).

The aperture electrode 1 and the counter electrode 112
Are provided with a predetermined space. The medium P that has entered the space through the insertion opening 117 and has been sent via the guide 115 and the pair of auxiliary rollers 116 passes through this space. The counter electrode 112 is connected to the power source E2 (minus (-)). By applying this voltage, the toner T that has passed through the aperture 11 of the aperture electrode 1 is moved and adsorbed on the medium P.

The heat fixing section 102 is composed of a heat roller 113 having a heat source and a press roller 114.
Then, the heat roller 113 and the press roller 11
4 is arranged so that the medium P can pass therethrough.

Next, the operation of the image forming apparatus will be described with reference to FIG. Medium P inserted from the insertion slot 117
Are conveyed to the recording unit 101. In the recording unit 101, the toner T is pressed against the supply roller 104 by the supply blade 111 and carried. Then, the toner T is supplied by the supply roller 104.
Are supplied to the transport roller 103. At this time, the toner T
Is rubbed while being in contact with the supply roller 104 and the conveyance roller 103, and is, for example, positively (+) charged. The toner T, which is positively (+) charged, is conveyed by the transport roller 1.
03, and is conveyed onto the toner clouder portion 14 of the aperture electrode 1.

At that time, when an electric signal of frequency f is applied from the oscillator 50 to the second piezoelectric body 22, the aperture electrode 1 is

[0020]

[Equation 1]

A bending vibration represented by is excited. Further, when an electric signal of frequency f is applied to the first piezoelectric body 21 from the oscillator 50, as described above, the bending vibration in which the vibration phase is deviated by 90 degrees in terms of position and time, that is,

[0022]

[Equation 2]

A bending vibration represented by is excited. As a result, by combining the two bending vibrations excited on the aperture electrode 1, on the aperture electrode 1,

[0024]

[Equation 3]

A traveling wave as indicated by is excited. Here, in the above equation, k represents the wave number of bending vibration, t represents time, and A represents amplitude of bending vibration.

As described above, since the traveling wave is excited on the toner clouder section 14 by the exciter 2, the traveling wave imparts the vibration acceleration in the + Y direction to the toner T. As a result, The toner T forms a cloud and is supplied to the modulation control unit 13 of the aperture electrode 1.

Then, the flow of the toner T is modulated by the voltage applied from the signal source (not shown) to the control electrode layer 108 of the modulation controller 13.

At this time, even if the charged toner particles try to adhere to the vicinity of the aperture array 12 due to the image force or the like,
Since a large vibration acceleration due to the traveling wave is generated at the position of the aperture array 12, it cannot be attached. As a result, the toner flow is always stably modulated by the signal source S and recorded on the medium P.

The positive (+) charged toner T modulated by the negative (-) power source E2 connected to the counter electrode flies toward the counter electrode. And this toner T
Is sucked by the medium P guided by the guide 115 and the pair of auxiliary rollers 116.

Then, the medium P is conveyed to the heat fixing section 102. Then, at this place, the image on the medium P is
The heat roller 113 and the press roller 114 are pressed against each other to be fixed. Since this fixing method is a general method, detailed description thereof will be omitted. Finally, the image-formed medium P is conveyed to the take-out port 118 via the guide 115, and
Taken out.

Next, the function of preventing clogging of the aperture electrode 1 configured as described above will be described with reference to FIG. At the time of image formation, the first and second piezoelectric bodies 21 and 22 are connected to the first and second amplifiers 31, 32 and 9 from the oscillator 50.
When an electric signal having a predetermined frequency f is applied through the 0-degree phase shifter 41, as described above in detail, the aperture electrode 1
A bending vibration traveling wave is excited at. In the aperture electrode 1 thus configured, a sufficient vibration amplitude can be obtained in the vicinity of the aperture array 12, so that the aperture 11 provided at any position on the aperture electrode 1 can obtain a sufficient vibration amplitude. As a result, the maximum vibration acceleration can be obtained at all the positions of the apertures 11. For this reason, toner does not adhere to the vicinity of the aperture 11 of the aperture electrode 1, and as a result, it is possible to prevent clogging of the aperture 11. The effect of preventing clogging increases as the acceleration of vibration increases. Therefore, in order to effectively prevent clogging, the amplitude and frequency of vibration may be increased. Generally, when trying to excite a high frequency, its amplitude becomes small. Therefore, it is necessary to appropriately determine the excitation frequency according to the material of the aperture electrode.

Therefore, in the image forming apparatus of this embodiment, since the traveling wave is excited on the aperture electrode formed in an endless shape, it is not necessary to absorb and consume the reflected wave, and the toner on the aperture electrode can be easily absorbed. It is possible to prevent the accumulation of particles. Further, the excitation device for preventing toner from adhering to the aperture electrode and the excitation device for toner crowder can be used together, so that the input energy can be used more effectively.

In this embodiment, the vibration excited on the aperture electrode is

[0034]

[Equation 3]

Although the traveling wave represented by (3) has been described as an example, the present invention is not limited to this vibration, and the same effect can be obtained even in other vibration modes as long as the vibration mode can excite the traveling wave. It can also be applied to surface waves propagating on the aperture electrode.

Further, in the present embodiment, the method of exciting the traveling wave on the aperture electrode is exemplified by the method of using the piezoelectric body, but the method is not limited to this, and an element capable of converting electric energy into mechanical energy is used. If so, an electrostrictive element, a magnetostrictive element, or the like can be used.

Further, the method of directly using the piezoelectric body as the excitation device has been described as an example, but the method is not limited to this method, and any method capable of exciting a traveling wave can be used.
Other methods do not impair the effects of the present invention.

Other various modifications are possible without departing from the spirit of the present invention.

[0039]

As is apparent from the above description, in the image forming apparatus of the present invention, since the traveling wave is excited on the aperture electrode formed endlessly, it is necessary to absorb and consume the reflected wave. As a result, it is possible to easily prevent the accumulation of toner particles on the aperture electrode and effectively utilize the input energy without deteriorating the feature of the image forming apparatus of this method that consumes almost no energy in the recording operation. ..

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an aperture electrode.

FIG. 2 is a block diagram of an electric system for exciting a bending traveling wave in an aperture electrode.

FIG. 3 is an explanatory diagram showing a schematic configuration of an image forming apparatus using the aperture electrode shown in FIG.

[Explanation of symbols]

 1 Aperture electrode 2 Excitation device 100 Image forming device

Claims (1)

[Claims] 1. An image forming apparatus comprising: an aperture electrode for modulating and controlling charged toner; and an exciter body for exciting a traveling wave on the aperture electrode, wherein the aperture electrode propagates on the aperture electrode. An image forming apparatus, which is formed in an endless shape in a wave traveling direction.