JPH03203687A - Image recording - Google Patents

Abstract

PURPOSE:To make the falling amount of toner constant and to form the toner image corresponding to an image signal by rotating a toner supply roller in the state in contact with a toner control means and applying vibration to the toner control means to appropriately disintegrate a toner lump into individual toner particles. CONSTITUTION:The toner in a toner receiving container 10 is supplied to the first mesh member 23 of a toner control means 20 by the rotation of a toner supply roller 12. Since the toner control means 20 is rotated while the toner supply roller 12 is in contact with the toner control means 20 under pressure, vibration is generated and the toner lump is appropriately disintegrated on the first mesh member 23 to efficiently pass through the mesh parts of the mesh member. The toner particles pass through the first mesh member 23 and an electric field is generated in the toner passing holes 22 of a conductive substrate 21 by the electric signal applied to the second mesh member 25. The toner particles preliminarily charged negatively are attracted to the positive electric field applied to the second mesh member 25 as an image signal and pass through the second mesh member 25 to fall on the recording paper 60 placed on a base electrode 50 and the toner image faithful to the image signal can be always formed.

Description

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

(Prior Art) Inkjet printers have been developed and put into practical use as recording means for word processors, facsimile machines, computers, and the like.

An inkjet printer is a typical so-called non-impact printer, in which pressure is applied to a predetermined ink while applying ultrasonic vibrations using a piezoelectric element, etc., and the ink is supplied through an ink nozzle. Particles fly in a predetermined electric field and adhere to recording paper to form a recorded image. An inkjet printer using this method has the advantage that it does not generate noise during printing and can form clear images.

However, in this image recording method using the inkjet printer method, it is necessary to control the speed at which the ink penetrates onto the recording paper, so it is necessary to use special paper that has been surface-treated as the recording paper. Furthermore, since the ink is supplied through a nozzle, there is a problem in that the nozzle is clogged due to foreign matter generated in the ink.

In order to solve this problem, by using powder toner as the image recording medium, it is possible to use plain paper without surface treatment as the recording paper, and furthermore, it is possible to create an image that prevents troubles such as nozzle clogging. The present applicant has proposed a recording method in Japanese Patent Laid-Open No. 62176873. This method uses ultrasonic vibration to cause powder toner particles to fly onto recording paper via a mensch member using magnetic or electrostatic attraction generated in response to an image output signal, thereby creating a predetermined recorded image. As a result, image formation using powder toner can be effectively performed, plain paper can be used as recording paper, and nozzle clogging can be prevented.

(Problem to be Solved by the Invention) However, in image recording using the above method, the image information generating means that generates the image signal is located on the opposite side of the insulating recording paper from the mesh member that holds the toner. Therefore, the following problems may occur.

■Since the electric field is formed through insulating recording paper, the electric field efficiency is not sufficient.

■The image density is not constant because the resistance varies depending on the type of paper.

■The moisture content of the paper varies depending on the environment such as humidity, so the image density is not constant.

■ Even if the paper is the same, the density on the paper will vary due to the difference in moisture content, making it impossible to obtain a uniform image.

Furthermore, it is necessary to apply ultrasonic vibration to the mesh member to loosen the toner supplied onto the mesh, making the device complicated.

(Objective of the Invention) The present invention has been made to solve the above-mentioned problems of the prior art.The purpose of the present invention is to use powder toner to make it possible to use plain paper as recording paper, and to prevent toner clogging. An object of the present invention is to provide an image recording method that prevents such troubles.

Another object of the present invention is to provide an image recording method that allows formation of images with high density, uniform and clear images with suppressed density unevenness.

Still another object of the present invention is to provide an image recording method that prevents differences in image density from occurring depending on the type of paper, environment, etc., and always provides uniform and clear images.

Still another object of the present invention is to provide an image recording method that does not require an ultrasonic vibration oscillator for dissolving toner and has a simple tank bottom.

(Means for Solving the Problems) The image recording method of the present invention includes a toner storage means, a toner supply roller provided at an opening of the toner storage means, and a toner supply roller disposed in pressure contact with the toner supply roller. and a base electrode located below the toner control means and facing the toner control means. By applying vibration and a bias voltage between the toner control means and the base electrode, a toner image corresponding to image information given to the toner control means is created between the toner control means and the base electrode. It is characterized in that it is formed on intervening recording paper, thereby achieving the above object.

(Function) In the present invention, the toner supply roller supplies toner from the toner storage means to the toner control means, and since the toner supply roller rotates in pressure contact with the toner control means, vibrations are applied to the toner control means. Give. Due to this vibration, the toner mass supplied to the toner control means is appropriately broken down into individual toner particles. As a result, a constant amount of toner falls from the toner flJ't8 means, making it possible to form a toner image according to the image signal.

By applying a bias voltage between the toner control means and the base electrode, the toner is controlled to fall to a predetermined position on the recording paper, and the toner is applied to the image information area on the recording paper interposed between the toner control means and the base electrode. It is possible to drop the toner only on the corresponding portions.

The toner control means, to which the image signal is applied from the image information generation means, is placed in pressure contact with the toner supply means without using the recording paper, so it is not affected by the type of recording paper, environment, etc. A uniform and clear toner image can be formed on recording paper.

Because of the above-mentioned features, the method of the present invention allows the use of plain paper and prevention of toner clogging, and also provides a uniform image with high image density and suppressed density unevenness.

Further, it is not necessary to apply ultrasonic vibration to the toner control means in order to loosen the toner, and the apparatus for carrying out the present invention becomes inexpensive and has a simple configuration.

(Preferred Embodiment of the Invention) In FIG. 1 showing an apparatus for preferably carrying out the recording method of the present invention, this image recording apparatus includes a toner container 1
0, a toner supply roller 12 provided in the opening 11 of the toner storage container 10, a toner control means 2o provided in pressure contact with the toner supply roller 12, a toner control means 2o located below the toner control means 20, The base electrode 50 facing the base electrode 50 and the opposite base electrode 50 are separated from each other.

The upper part of the toner storage container 10 communicates with a toner hopper, etc., so that the storage container 10 is replenished with toner. A recording paper 60 on which a toner image is formed is placed on the base electrode 50 and moves in the direction of arrow A following the movement of the base electrode 50. Alternatively, the base electrode 50 may be fixed, and a separate recording paper transport means may be provided to move only the recording paper 60.

The toner control means 20 is supplied with an image signal from the image information generation means 40 . The image information generating means 40 is operated by a controller in response to a signal from a main body of a device such as a word processor, facsimile, computer, etc., and generates image information as an electrical signal. Accordingly, the powder toner passes through the toner control means 20 and falls downward, forming a predetermined toner image on the recording paper 60. The recording paper 60 on which the toner image has been formed is then transferred to a predetermined fixing mechanism (
(not shown), and fixing is performed by heat or pressure.

The present invention is characterized in that the toner supply roller 12 rotates in pressure contact with the toner control means 20, thereby imparting vibration to the toner control means 20. However, the material, shape, etc. of the toner supply roller 12, etc. The pressure welding force differs depending on the For example, when using a roller (shown in Figure 1) whose surface is made of a relatively soft material such as a sponge roller,
The pressure applied to the toner control member 20 is preferably set to be strong enough to partially dent the sponge roller.

Further, as shown in FIG. 2, when a roller made of relatively hard resin or the like having protrusions 13 on the surface is used, the pressing force to the toner control means 20 is set weak, and only the protrusions 13 are used to prevent toner from being applied. Press it into contact with the control means. In either case, since the toner supply roller 12 is in contact with the toner control means 20, at least its surface needs to be made of an insulating material.

Although the rotation speed of the toner supply roller 12 varies depending on the shape and material of the roller, it is generally desirable that the rotation speed is 50 mm/sec or more. If the peripheral speed of the toner supply roller is slower than 50 m/sec, the density of the formed image will be insufficient.

In the present invention, the toner control means 20 is vibrated by the rotation of the toner supply roller 12, and is also given an image signal from the image information generation means 40, and has a function of controlling toner fall in accordance with this signal.

As shown in FIG.
a first mesh member 23 provided on the upper surface of the conductive substrate 21 and a second mesh member 25 provided on the lower surface of the conductive substrate 21 with an insulating member 24 in between. It is positioned so as to come into pressure contact with the supply roller 12. The conductive substrate 21 is grounded, and the first mesh member 23 is grounded through it.

The second mesh member 25 is given an electrical signal from the image information generating means 40 . This electrical signal is given a positive potential and a negative potential depending on the presence or absence of an image, and is controlled so that, for example, a voltage of +100V is applied in the case of image information, and -100V is applied in the case of non-image information. With the above configuration, the toner control means 20 functions as a pinhole electrode centered on the toner passage hole 22.

The thickness of the conductive substrate 21 is preferably set in the range of 0.01 to 1 mm, and the thickness of the toner passage hole 22 formed in the conductive substrate 21 is set in the range of 0.1 to IIIIIIl. Further, the opening of the first mesh member 23 is preferably 20 to 100 μm, the opening of the second mesh member 25 is preferably 50 to 300 μm, and the opening of the second mesh member 25 is the same as the opening of the first mesh member 23. It is set to be larger.

The toner image formation process when such a toner control means 20 is used will be described.

Due to the rotation of the toner supply roller 12, the toner storage container 1
The toner in 0 is supplied to the first mesh member 23 of the toner control means 20. Since the toner control means 20 rotates while the toner supply roller 12 is in pressure contact with the toner supply roller 12, vibrations are generated, and the toner lumps are appropriately disintegrated on the first mesh member 23.
Efficiently passes through the mesh section. First mesh member 23
Depending on the image signal applied to the second mesh member 25, it is determined whether the toner particles that have passed through the second mesh member 25 fall through the second mesh member 25 or return onto the first mesh member 23. That is, the toner passing hole 2 of the conductive substrate 21 is opened by the electric signal applied to the second mesh member 25.
An electric field is generated within 2. The toner particles, which are negatively charged in advance, are attracted by the positive electric field applied as an image signal to the second mesh member 25, pass through the second mesh member 25, and are deposited on the recording paper 60 on the base electrode 50. It will fall. Since a positive bias voltage is applied to the base electrode 50 with respect to the first mesh member 23,
Falling of the toner from the toner control means 20 is promoted.

The bias voltage applied to the base electrode 50 is sufficiently higher than the electrical signal applied to the second mesh member 25, and is preferably in the range of 300 to 1000 V in the case of negatively charged toner. If the bias voltage applied to the base electrode 50 is less than 300 V, there is a risk that the toner falling position will vary and the image will be distorted. 1000 again
If it is larger than V, there is a risk that discharge will occur.

On the other hand, when no image signal is applied, a negative electric field is formed in the second mesh member 25, so that the toner is returned onto the first mesh member 23. Instead of being grounded, the first mesh member 23 is applied with a bias voltage (in this case, a voltage) of the opposite polarity to the toner, so that the toner is actively held on the first mesh member 23 and suppressed from falling by itself. You can also do this.

As described above, since the toner control means of the present invention directly applies an image signal to the toner, there is no difference in density in the formed image due to differences in the resistance of the recording paper, environment, etc.
A toner image faithful to the image signal can always be formed.

For the first and second mesh members, a tile mesh, an etched mesh, or the like made of metal such as nickel, stainless steel, aluminum, copper, silver, or conductive resin is used.

In the above description, the image forming process was performed with the first mesh member 23 grounded and the image signal applied to the second mesh member 25; however, the toner supply roller 12
A first mesh member that is in close or pressure contact with the conductive substrate 21 is disposed on the upper surface of the conductive substrate 21 via an insulating member to give an image signal, and a second mesh member is grounded on the lower surface of the conductive substrate 21. It is also possible to have a configuration where it is arranged. Even with this configuration, when an image signal (positive electric field) is applied, toner passes through the first mesh member, is accelerated by the bias difference between the second mesh member and the base electrode, and is transferred to the base electrode. Fall into place above. When a non-image signal (negative electric field) is applied, the toner does not pass through the mesh portion of the first mesh member, so the toner does not fall. As a result, a toner image corresponding to the image information is formed on the recording paper 60, similarly to the above-described configuration.

In addition to the above-mentioned toner control means 20 in the present invention, a structure as shown in FIG. 4 can also be used. This corresponds to the toner control means 2 in FIG.
0, the second mesh member 25 is connected to the ring-shaped electrode 26.
It has been replaced with . The cavity 27 formed by the ring-shaped electrode corresponds to the toner passage hole 22 of the conductive substrate 21. As a result, the toner particles that have passed through the mesh member 23' provided on the upper surface of the conductive substrate 21 are attracted by the electric field formed by the image signal applied to the ring-shaped electrode 26, and are prevented from falling onto the recording paper 60. It is determined.

When the ring-shaped electrode 26 is used, the applied electric field acts uniformly on the toner particles, making it possible to efficiently and accurately attract the toner corresponding to the image signal. The ring-shaped electrode 26 is preferably made of metal such as copper or aluminum, and has a ring diameter of 50 to 500 μm.

Even when this ring-shaped electrode is used, the mesh member 23' is provided on the conductive substrate 21 via the wA edge member to give an image signal, and the ring-shaped electrode 26 It may be arranged in a grounded state under the conductive substrate 21.

The toner control means 20 according to the present invention may also have the configuration shown in FIG. 5.

The toner control means 20 includes an insulating substrate 31 in which a toner passage hole 32 is formed, an upper electrode 33 provided on the upper surface of the insulating substrate 31 and in close or pressure contact with the toner supplying means 12, and an insulating substrate 31 and to which the image signal from the image information generating means 30 is applied. In this case, the toner passage hole 32 formed in the insulating substrate 31 is a small hole of about 5 to 300 μm. (However, the particle size is set to be larger than the particle size of the toner particles.) In the toner control means 20 having such a configuration, the toner supply roller 12 rotates while being in pressure contact with at least the upper electrode 33, so that the inside of the toner storage container 10 is toner is supplied to the upper electrode 33, and vibration is applied to the upper electrode 33, thereby breaking up the toner lumps and causing the toner particles to pass through the toner passing holes 32. The toner particles are charged with a certain polarity (for example, negative) in advance, and are attracted by the positive electric field generated by the image signal applied to the lower electrode 34 to pass through the toner passage hole 32.
The toner particles fall further and form a toner image on the recording paper 60. When no image signal is applied, a negative electric field is exerted and the toner is returned onto the upper electrode 33.

Instead of grounding the upper electrode 33, a bias voltage (in this case, negative) of the opposite polarity to the toner is applied to the upper electrode 33, and the upper electrode 33 is actively grounded.
Alternatively, the toner may be held on top of the toner to prevent it from falling naturally.

As the upper electrode 33 and the lower electrode 34, patterns of copper foil, silver foil, aluminum, or the like are preferably used. The same effect can also be obtained by applying an image signal to the upper electrode 33 and performing the image forming process with the lower electrode 34 grounded.

When the toner control means 20 having such a configuration is used, the sixth
As shown in the figure, since a large number of electrodes can be arranged along the longitudinal direction of the toner supply roller 12, high-speed printing is possible. That is, toner passage holes 32a, 32b, .

32b, . . , the lower electrodes 34a, 34b+”・
to be placed. Since the upper electrode 33 is grounded, it is sufficient that the upper electrode 33 has holes corresponding to the toner passage holes 32a, 32b, . . . , and may be integrally formed. With this configuration, an image signal for each toner passage hole (corresponding to each pixel) is transmitted from the image information generating means 30 to each lower electrode 34a, 34b.
, . . , and images in the longitudinal direction of the toner supply roller 12 (in the direction perpendicular to the conveying direction of the recording paper 60) can be simultaneously formed, thereby enabling high-speed printing processing. Moreover, the image signal given to the lower electrode 34a is transmitted through the toner passage hole 32.
Since the electric field is applied only to the electrodes a and does not affect the electrodes adjacent to each other, it is possible to accurately form a toner image at a predetermined position according to image information.

In the above-mentioned apparatus, the toner control means 20 has been described in such a manner that the electrode on either the upper or lower surface of the conductive substrate or the insulating substrate is grounded and an image signal is applied to the other. As shown, the mesh member may be disposed only on the upper surface of the conductive substrate, and the conductive substrate itself may serve as the electrode opposite to the base electrode.

In this configuration, a mesh member 23' is disposed above the conductive substrate 21 via an insulating member 24''. Image information is given to the mesh member 23° from an image information generating means 40, and Vibration is applied by the rotation of the toner supply roller.This causes the mesh member 23
The toner supplied from the toner supply roller 12 is appropriately distributed and allowed to fall downward in accordance with the image signal. The toner that has passed through the mesh member 23'' is accelerated by the potential difference between the conductive substrate 21 and the base electrode 50, and falls onto a predetermined position on the recording paper 60.

In the present invention, it is desirable to use a toner having a relatively small average particle size of 5 to 25 μm, and the small-diameter toner makes it possible to form a recorded image with excellent resolution.

The distance between the toner control means 20 and the recording paper 60 varies depending on the magnitude of the applied voltage applied from the image information generation means 40, but is generally preferably in the range of 0.3 to 2.5 mm.

(Experimental Example) Actual length 11 - The following conditions were set in an apparatus for carrying out the method of the present invention.

・Toner supply roller...Sponge roller diameter: φ15
++s, Peripheral speed: 200/sec Toner control means Conductive substrate Aluminum thickness: 0.5M Toner passage hole: φ0.5mm First electrode member: 350 tieer and mesh No. 2 Electrode member...150 tyre-mesh insulating member...
・Polyethylene sheet thickness: 100μm ・Bias voltage...+800■ ・Toner 0.・Distance between the center of the non-magnetic toner toner supply roller and the toner control means ・・
...6 cabinets: Distance between toner control means and recording paper...0.5 t
m Under the above conditions, plain paper with a thickness of 100 μm without surface treatment is conveyed as recording paper on the base electrode 50, the toner control means 20 is grounded, and the second electrode member 26
When a voltage of ±100 V was modulated according to the image signal and applied to the image sensor, a clear image with excellent resolution was obtained, and no fogging occurred.

Further, when similar experiments were conducted with the thickness of the recording paper changed to 70 μm and 150 μm, exactly the same clear and uniform images were obtained.

Next, when the above experiment was conducted in an environment of (1) temperature 10°C and humidity 30% (ii) temperature 20°C and humidity 45% (ij) temperature 35°C and humidity 80%, both The same clear and uniform images were obtained even under different conditions.

(Effects of the Invention) As described above, according to the present invention, image recording using powder toner is effectively performed, plain paper can be used as recording paper, and there is no fear of toner clogging. Furthermore, it has become possible to obtain a uniform image with high density and suppressed density unevenness.

Furthermore, the image quality does not vary depending on the type of recording paper or the environment, making it possible to always obtain clear and uniform images.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of an apparatus for implementing the recording method of the present invention, FIG. 2 is a diagram showing another example of an apparatus for implementing the recording method of the present invention, and FIGS. FIG. 2 is a diagram illustrating a toner control means in the recording method of the present invention. DESCRIPTION OF SYMBOLS 10... Toner storage container, 12... Toner supply roller, 20... Toner control means, 40... Image information generation means, 50... Base electrode.

Claims (1)

[Claims] (1) A toner storage means, a toner supply roller provided at the opening of the toner storage means, and a toner control means disposed in pressure contact with the toner supply roller to drop the toner according to image information. , a base electrode located below the toner control means and facing the toner control means, and the toner control means is vibrated by rotation of the toner supply roller, and the toner control means and the base electrode are connected to each other. By applying a bias voltage between the
1. A method for recording an image, comprising forming an image on a recording paper interposed between a toner control means and a base electrode.