JPH04189554A - Image formation device - Google Patents

Abstract

PURPOSE:To improve resolution of recording image without constraint in processing technique by providing a pair of electrodes arranged on both faces of a substrate for forming an electric field to make a toner pass through a toner passing hole, image information generating means for setting a predetermined electric potential between the pair of electrodes in accordance with image information, and deflecting means arranged in an output side of the toner passing hole for deflecting the toner in a predetermined direction. CONSTITUTION:A deflecting means 70 is provided with a pair of deflecting plates 71 arranged in an opposed manner in right and left directions at a lower part of a control electrode 25 and a feed means 72 for applying pulse voltage and pulse voltage having a polarity opposite thereto between the deflecting plates. In such a deflecting means 70, when the feed means 72 supplies pulse voltage having positive and negative polarities between the deflecting plates 71, a toner came out from a toner passing hole 22 in response to the polarity of the pulse voltage is deflected in two directions at left side or right side. Thus, the toner can be stuck on a recording paper 60 in a specific direction convergently. Accordingly, resolution of recording image can be improved.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an image forming apparatus using powder toner.

(Prior Art) Image forming methods using inkjet printers are known for word processors, facsimile machines, computers, and the like.

An inkjet printer is a typical so-called non-impact printer, which applies pressure to a predetermined liquid ink while applying ultrasonic vibrations using a piezoelectric element, etc.
A recorded image is formed on the recording paper by ejecting the liquid ink from an ink nozzle within a predetermined electric field, and controlling the ink particles by the electric field so that they adhere to the recording paper. Such an inkjet printer method has the advantage that it does not generate noise when forming an image and can form a clear image. On the other hand, in order to control the speed at which the ink soaks into the recording paper, it is necessary to use special paper with a surface treatment, etc., and since the ink is supplied from a nozzle, the nozzle can detect foreign particles in the ink. There is a problem that it is easy to get clogged due to such things.

In order to solve these problems with inkjet printers, an image forming apparatus using powder toner as an image recording medium is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-263962. This image forming apparatus uses powder toner particles to
A toner control means is provided in the pinhole-shaped toner passage hole to control the passage of the toner by an electrostatic attraction force generated in response to an image output signal, and the toner control means selects toner particles onto the recording paper. A predetermined recorded image is formed on the recording paper. In such devices, plain paper without surface treatment can be used as the recording paper, and furthermore, since fine particle powder toner is used, toner clogging in each toner passage hole is suppressed. .

A toner control means for controlling powder toner includes an insulating substrate provided with a large number of pinhole-shaped toner passage holes, and a toner control means provided between the insulating substrate so as to form an electric field in each toner passage hole. It has a pair of electrodes. Each pair of electrodes is provided with a through hole similar to each toner passage hole, and is attached to one surface of each insulating substrate with each through hole aligned with each toner passage hole. ing.

Then, by applying a predetermined voltage between both electrodes to form an electric field in a predetermined direction within the toner passage hole, toner particles pass through the toner passage hole.

When preventing toner particles from passing through the toner passage hole, a predetermined voltage is applied between each electrode so that an electric field is formed in the toner passage hole in the opposite direction to that when toner particles are allowed to pass through. be done.

(Problems to be Solved by the Invention) Incidentally, the resolution of a recorded image in an image recording apparatus using powder toner as an image recording medium is determined by the formation density of pinhole-shaped toner passage holes. Therefore,
In order to improve resolution, it is necessary to form toner passage holes through micromachining and achieve a high integration of toner passage holes, so there was a limit to the ability to improve resolution due to limitations in processing technology. . Another drawback is that the manufacturing cost is high.

The present invention is intended to solve the problems of the prior art, and it is an object of the present invention to provide an image forming apparatus that can improve the resolution of recorded images without any restrictions on processing technology.

(Means for Solving the Problems) An image forming apparatus of the present invention is an image forming apparatus that supplies toner to paper through toner passage holes provided in a substrate, thereby forming an image. , a pair of electrodes forming an electric field for passing the toner through the toner passage hole; image information generating means for setting a predetermined potential between the pair of electrodes in accordance with image information; A deflecting means is provided on the exit side and deflects the toner in a predetermined direction, thereby achieving the above object.

The image forming apparatus of the present invention is an image forming apparatus that supplies toner to a sheet of paper through toner passing holes provided in a substrate, thereby forming an image. In addition to providing a pair of electrodes that form an electric field for passing the toner, the electrode located on the exit side of the toner passage hole is divided, and the electrode located on the entrance side of the toner passage hole is selectively connected between the divided electrode and the electrode located on the entrance side of the toner passage hole. is set to a predetermined potential, thereby achieving the above object.

(Operation) When the toner exiting the toner passage hole is deflected by the deflecting means, the toner flies in a specific direction (deflection direction) in a high-density state and adheres to the paper. Therefore, resolution can be improved.

Furthermore, if the electrode on the exit side of the toner passage hole is divided and a voltage is selectively applied to the divided electrode, the axis of the toner passage hole is An electric field oblique to the heart is formed.

Therefore, the toner that has exited the toner passage hole flies while being deflected according to the direction of the electric field and adheres to the paper. Therefore, in this case as well, the resolution can be increased in the same manner as above.

(Example) Examples of the present invention will be described below.

As shown in FIG. 1, the image forming apparatus of the present invention includes a toner container 10 to which toner is sequentially replenished from a toner hopper or the like. An opening 11 is provided at the bottom of the toner storage container 10, and an upper portion of a toner supply roller 12, which is toner supply means, is fitted into the opening 11. The toner supply roller 12 is a sponge roller configured by attaching a sponge layer 14, which is an elastic insulator, to the outer peripheral surface of a roller portion 13.

Below the toner supply roller 12, a toner control means 2 is provided.
0 is disposed horizontally close to the toner supply roller 12. The toner control means 20 is supplied with an image signal from the image information generation means 40 .

The image information generating means 40 operates in response to a signal from a main body of a device such as a word processor, a facsimile machine, a combination roller, etc., and generates a pulse-like voltage signal corresponding to image information. According to this voltage signal, powder toner charged to a predetermined polarity supplied from the toner supply roller 12 is transferred by the toner control means 20 onto the recording paper 60 disposed below the toner control means 20. Supply and non-supply are controlled. As a result, a predetermined toner image is formed on the recording paper 60. The toner control means 2o may be in pressure contact with the toner supply roller 12. A base electrode 50 is provided below the toner control means 20 and facing the toner control means 20 .

A recording paper 60 on which a toner image is formed on the base electrode 50
is placed. The base electrode 50 is connected to the recording paper 6 on which it is placed.
You can also make it move in the direction shown by arrow A together with 0 (
Alternatively, the base electrode 50 may be fixed and only the recording paper 60 may be moved by a predetermined recording paper transport means. When a predetermined toner image is formed on the recording paper 60 by the toner control means 2°, the recording paper 60 is conveyed to a predetermined fixing device (not shown), and the toner image is transferred to the recording paper by the fixing device. It is fixed at 60.

In addition, the toner control means 20 includes an ultrasonic vibration generating means 3.
0 is set. The ultrasonic vibration generating means 30 applies ultrasonic vibration to the toner control means 20, thereby causing the pinhole-shaped toner passage hole 22 formed in the toner control means 20 to
(See FIG. 2) The toner supplied to the pump is crushed, and the toner is broken down into particles and passed through. As the ultrasonic vibration generating means 30, a piezoelectric element such as PZT is used, for example.

Next, details of the toner control means 20 and the biasing means 70 disposed below the toner control means 20 will be described with reference to FIG.

A toner control means 20 to which negatively charged toner is supplied from the toner supply roller 12 includes a horizontal insulating substrate 21 having a pinhole-shaped toner passage hole 22 and a top surface of the insulating substrate 21. A common electrode 23 is provided. In addition, a control electrode 25 is provided on the lower surface of the insulating substrate 21 for each toner passage hole 22 . The common electrode 23 covers the upper opening of the toner passage hole 22, and is in close proximity to or in pressure contact with the toner supply roller 12.

The common electrode 23 and the control electrode 25 are supplied with the above-mentioned pulsed voltage signal from the image information generating means 40. The image information generating means 40 generates the voltage signal based on the image information, and applies, for example, a voltage of +100 V to the control electrode 25 for a predetermined time corresponding to the pulse width as an image forming signal to form an image. Set the potential between .25 and 100■. Therefore, at this time, an electric field is formed in the toner passage hole 22 from the control electrode 25 toward the common electrode 23, and the negatively charged toner falls through the toner passage hole 22 due to the electric field and flies toward the recording paper 60. ·adhere to.

Note that it is preferable to apply a positive bias voltage to the base electrode 50 with respect to the common electrode 23. That is, by doing this, the toner passage hole 22
This is because the toner that has passed through the base electrode 50 is attracted to the base electrode 50 and its fall is promoted.

On the other hand, when not forming an image, the control electrode 2S is
A voltage of 00■ is applied, which causes the toner passage hole 22
An electric field in the opposite direction to that described above is formed inside, and the toner returns to the common electrode 23 side.

Below the control electrode 25, that is, if the toner
[I] A deflection means 70 is arranged between the means 20 and the base electrode 50 to deflect the toner that has passed through the toner passage hole 22 in the direction shown by the broken line in the figure. The deflecting means 70 includes a pair of deflecting plates 71.71 arranged below the control electrode 25 and facing each other in the left-right direction in the figure, and the deflecting plates 71.7.
1 and a power feeding means 72 for applying a pulsed voltage of opposite polarity to the pulsed voltage shown in the figure.

In such a deflection means 70, positive and negative pulsed voltages are applied from the power supply means 72 to the deflection plates 71 and 71.
When applied between the two directions, the toner exiting the toner passage hole 22 is deflected in two directions, either to the left or to the right, depending on the polarity of the /f pulse-like voltage, thereby concentrating the toner in a specific direction on the recording paper 60. It can be attached. Therefore, the resolution of recorded images can be improved.

FIG. 3 shows a modification of the deflection means 70. In this modification, a stepped voltage as shown in the diagram is applied between the deflection plates 71 and 71, thereby directing the toner exiting the toner passage hole 22 in multiple directions. A configuration is adopted that deflects the image and improves resolution.

Furthermore, an analog voltage may be applied between the deflection plates 71 and 71. By applying the analog voltage, toner can fly and adhere to any position on the recording paper 60. By appropriately setting the analog voltage, toner adhesion in the main scanning direction of the paper can be controlled. The amount can be made uniform. Therefore, straight lines can be recorded with respect to the main scanning direction, and problems such as the appearance of jagged lines oblique with respect to the main scanning direction can be reliably prevented.

4 and 5 show another embodiment of the present invention. In this embodiment, the control electrode 25 is divided into two as shown in FIG. ．． A pulse-like voltage is selectively applied to 250 from the image information generating means 40, and the electric field generated thereby deflects the toner exiting the toner passage hole 22 in two directions, to the left and right, and performs recording in the same manner as in the above embodiment. Ditto image resolution.

Selective application to the control electrodes 250, 250 takes place via a switching circuit 90 shown in FIG. That is, a control means (not shown) issues a switch changeover signal 91 to the switching circuit 90, switches the switch position, and selectively applies a voltage corresponding to the image signal to the control voltage [J50.250].

Incidentally, the common electrode 23 and the left control electrode 250
When a voltage is applied between them, an electric field is formed that is inclined toward the stone side with respect to the axis of the toner passage hole 22.
As a result, the toner that has exited the toner 2 flies in a state where it is deflected to the left and adheres to the recording paper 60.

Note that the number of divisions of the control electrode is not limited to two.

In the present invention described above, it is preferable to use a toner having a relatively small average particle diameter of 5 to 20 μm, and an image with excellent resolution can be formed using a toner having a small diameter.

The distance between the toner control means 20 and the recording paper 6o varies depending on the magnitude of the applied voltage applied from the image information generation means 40, and is usually in the range of 0.3 to 2.5.

In this embodiment, a sponge roller is used as the toner supply roller 12. As the sponge roller rotates, it effectively crushes the aggregated toner in the toner storage container 1o, and the toner is held almost uniformly in the joints on the surface. amount of toner is supplied.

In each of the above embodiments, the common electrode 23 and the control electrode 25 were provided on both sides of the insulating substrate 21 to form the toner control means 20, but an insulating member was provided on one side of the conductive substrate. It is also possible to use a toner control means in which a common electrode and a control electrode are disposed on both the front and back surfaces formed by the insulating member and the conductive substrate.

(Effects of the Invention) According to the image forming apparatus according to the first aspect, the toner exiting the toner passage hole is deflected by the deflecting means, flies in a specific direction at high density, and adheres to the paper.

Therefore, by microfabrication, resolution can be easily improved without increasing the integration of toner passage holes.

According to the image forming apparatus according to the second aspect, the electrode on the outlet side of the toner passage hole among the pair of electrodes provided on both sides of the substrate is divided, and a voltage is selectively applied to the divided electrode. , an electric field oblique to the axis of the toner passage hole is formed between the selected electrode and the electrode on the entrance side of the toner passage hole, so that the toner exiting the toner passage hole is affected by the electric field. Deflected according to direction. Therefore, claim 1
Similar to the image forming apparatus described above, the resolution can be easily increased.

Further, in particular, according to the image forming apparatus according to claim 1, when an analog voltage is applied to the deflecting means, the toner can be caused to fly to an arbitrary position. This makes it possible to equalize the amount of toner adhering to the paper in the main scanning direction.Therefore, it is possible to record straight lines in the main scanning direction, which prevents problems such as jagged lines that are diagonal to the main scanning direction. There's nothing to do.

[Brief explanation of drawings]

FIG. 1 is a drawing showing an embodiment of the image forming apparatus of the present invention, FIG. 2 is a drawing showing an enlarged view of the main part thereof, FIG. 3 is a drawing showing a modification of the deflecting means, and FIG. 4 is a drawing showing an embodiment of the image forming apparatus of the present invention. Drawings showing another embodiment, FIG. 5 is an abbreviated plan view showing the core troll electrode. 20... Toner control means, 21... Insulating substrate, 2
2... Toner passage hole, 23... Common electrode, 25...
... control electrode, 40 ... image information generating means,
70... Deflection means, 71. 71... Deflection plate, 72...
...Power supply means, 250.250...Control electrode. that's all

Claims (1)

[Scope of Claims] 1. In an image forming apparatus that supplies toner to paper through toner passage holes provided in a substrate to thereby form an image, the toner is provided on both sides of the substrate and the toner is supplied to the toner passage holes. a pair of electrodes that form an electric field for passing the toner; an image information generating means that sets a predetermined potential between the pair of electrodes according to image information; An image forming apparatus including a deflecting means for deflecting in a predetermined direction. 2. In an image forming apparatus that supplies toner to paper through a toner passage hole provided in a substrate and thereby forms an image, an electric field is formed on both sides of the substrate to cause the toner to pass through the toner passage hole. A pair of electrodes is provided, the electrode located on the exit side of the toner passage hole is divided, and a predetermined potential is selectively set between the divided electrode and the electrode located on the entrance side of the toner passage hole. image forming device.