JPH0252260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an image forming method and apparatus that utilizes an electric field generated in an aperture, and in particular, an image forming method and apparatus that uses an electric signal to directly control the passage of powdered developer (hereinafter referred to as toner) through the aperture. This invention relates to an apparatus for obtaining images.

A conventional direct recording technique of this type has been proposed in US Pat. No. 3,689,935. In this method, two electrodes are provided with an insulating layer interposed between them, and a row of holes are formed in the electrodes (hereinafter referred to as an aperture board).The aperture board controls the passage of charged toner. However, it is intended to obtain an image by the toner that has passed onto a recording member provided on the opposite side of the toner supply source. However, in this conventional method, toner is not supplied uniformly, which tends to cause unevenness in the image on the recording member, making high-speed recording difficult, and problems such as toner clogging on the aperture board, making it practical. has not been standardized.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that eliminates the drawbacks of the above-mentioned conventional examples, and at the same time, enables stable toner supply and long-term stable image formation.

To achieve the above object, the present invention is a recording device that controls the passage of toner using an electric field generated in an aperture, and forms an image on a recording material by the toner that has passed through the aperture, and which carries the toner. a control means having a toner support body to be conveyed, first and second electrodes with an insulating layer sandwiched therebetween, and an opening disposed in the longitudinal direction thereof;
An alternating electric field is created between the recording material, which is disposed on the opposite side of the control means from the toner support and moves relative to the control means, and the developer support and the control means in order to supply developer to the apertures of the control means. a signal power source that applies a signal voltage between the first electrode and the second electrode of the control means to control the passage of the toner; This apparatus includes bias application means for forming an electric field between the control means and the recording material in order to guide the recording material.

With the above configuration, a uniform and even image can be obtained by responding to changes in recording speed, for example by changing the alternating current frequency from low speed to high speed. At the same time, the effect of the alternating electric field causes the toner to reciprocate between the base electrode and the toner transport member, which also has the effect of cleaning the apertures, making it possible to obtain the best images for a long period of time. Furthermore, the combination of magnetic toner and magnetic field makes it possible to reduce toner scattering.

FIG. 1A is a plan view showing the configuration of an avertier board applicable to the present invention, FIG. 1B is a cross-sectional view taken along the line -- in FIG. 1A, and FIG. 2 shows an embodiment of the present invention. Block diagram, FIG. 3 is a block diagram showing another embodiment of the present invention.

In FIG. 1, 1 is a signal electrode that can be applied independently and individually, and 3 is a base electrode that is continuous across all or a plurality of holes.
Reference numeral 2 denotes an insulating member that electrically insulates the signal electrode 1 and the base electrode 3. Reference numeral 4 denotes a hole which penetrates the signal electrode 1, the base electrode 3, and the insulating member 2 with the same area.

The basic operation of the present invention will be explained using FIG. 2. In the figure, 6 is a back electrode, 5 is a recording member, and this member 5 is in close contact with the back electrode 6. Reference numeral 7 denotes a toner conveying section composed of a toner conveying material made of a non-magnetic material, and 11 a monocomponent insulating magnetic toner, which is uniformly applied onto the toner conveying member 7. The avertier board described in FIGS. 1A and 1B is disposed between the back electrode 6 and the toner transport member 7, the back electrode 6 and the signal electrode 1 are opposed to each other, and the toner transport member 7 and the base electrode are arranged to face each other. facing each other. Further, reference numeral 8 connects an AC power source to the base electrode 3 and the toner conveying member 7. 9 is a DC power supply and the back electrode 6
and is connected to the base electrode 3. Reference numeral 10 denotes a signal power source, which is connected to the signal electrode 1 and the base electrode 3.

In the above configuration, when an AC voltage or a DC biased AC voltage is applied between the base electrode 3 and the toner transport member 7 by the AC power supply 8, the toner 11 on the conductive material 7 is transferred between the base electrode 3 and the toner transport member 7.
It moves in between. At this time, when a voltage is applied to the signal electrode 1 and the base electrode 3 from the signal power supply 10, the toner 11 that is moving passes through the aperture 4 and is attracted to the signal electrode 1. Further, since a DC voltage is applied between the back electrode 6 and the base electrode 3 from the DC power source 9, the toner 11 is further accelerated and adheres to the recording member 5.

When there is no signal voltage applied to the signal electrode 1 and the base electrode 3 from the signal power source 10, or when an electric field in the opposite direction is applied, the dynamic toner does not pass through the aperture 4. Further, between the base electrode 3 and the toner conveying member 7, the toner moves back and forth due to the action of the alternating current voltage, and at the same time, a cleaning effect is also achieved. As described above, when a signal is applied to the signal electrode 1 in an imagewise manner, an image of a toner image is formed on the recording member, and then the toner image is fixed on the recording member 5 by heating or pressure.

When the toner particles 11 have a negative (-) polarity, the polarity of the voltage supplied from the signal power source 10 is negative (-) to the base electrode 3, positive (+) to the signal electrode 1, and DC. The polarity of the voltage supplied from the power source 9 is set so that the base electrode is negative (-) and the back electrode 6 is positive (+). Further, although the ground potential may be set anywhere, the base electrode is usually grounded. and,
On the other hand, when the polarity of the toner 11 is positive (+), the above-mentioned polarity is reversed.

FIG. 3 is a block diagram of one embodiment of the present invention, which will be explained below. In addition, in the figure, the same reference numerals as in FIG. 2 mean having the same function. In the figure, recording member 5
is in close contact with the back electrode 6, and is driven by a drive system (not shown) in the direction of the arrow from the roll-shaped recording member source. The gap between the back electrode 6 and the signal electrode 1 can be in the range of 100 microns to 10 mm. In this embodiment, the thickness is about 300μ, and a DC voltage of 300V is applied between the back electrode 6 and the base electrode 3 from the DC power supply 9. The appropriate electric field between the back electrode 6 and the base electrode is 500 to 1500 V per mm. The signal electrode 1 and the base electrode 3 are kept at a gap of 50 μm using an insulating material, and a DC voltage of 50 V can be applied from the signal power source 10 to only the portions necessary for character generation. As described above, the control member is provided with an opening 4 having a diameter of 140 μm so that the insulating magnetic toner 11 can pass through the base electrode 3, the signal electrode 1, and the insulating member 2.

The openings 4 have a center width of 250 μm and are arranged in a staggered manner as shown in FIG. 1, although not shown. For example, when the width of the recording member 5 is 297 mm, this control member is provided with 2376 openings 4 in the width direction of the recording member, and each signal electrode 1 is independently connected to the signal power source 10. . Reference numeral 12 denotes a fixed magnet that is placed inside the hollow cylinder of the toner conveying member 7. 13 is a toner container, and 14 is a magnetic body used to uniformly apply the insulating magnetic toner 11 onto the toner conveying member 7.

On the other hand, the distance between the toner conveying member 7 and the base electrode 3 is suitably 100 to 500 microns, and in order to improve the recording speed, it is better to make it as narrow as possible so that the toner is not pressed and aggregated. In this example, this interval is set to 200
micron, and the AC voltage applied between them was 2KHz with an effective value of 300V.

When the toner conveying member 7 is rotated under the above conditions with a diameter of 32 mm and a rotation speed of 150 rpm, the insulating magnetic toner 11 in the toner container 13 is attracted to the fixed magnet 12 and adheres to the toner conveying member 7, and then the magnetic blade 14, the magnetic toner 11 is applied onto the toner conveying member 7. In this state, when the recording member 5 is moved in the direction of the arrow at 250 mm/sec and a necessary signal pulse is applied to the signal electrode 1 from the signal power supply 10, the magnetic toner 11 adheres well to the recording member 5, and the characters or A figure is formed and visualized. The magnetic toner 11 thus deposited on the recording member 5 is fixed onto the recording member 5 by pressure fixing at step 16.

In the above embodiment, an example in which the toner is directly fixed onto the recording medium 5 has been described, but of course, the toner is further transferred and fixed to another recording medium under an electric field such as a corona discharger, and the recording medium 5 that initially received the toner is reused. Other usages are also possible. This is an effective method when sheet paper is used as the recording medium and the distance between the paper and the recording medium cannot be maintained accurately.

Furthermore, when using non-magnetic toner,
As the toner conveying member, a conductive substrate having a brush or an uneven surface may be used, and the toner may be carried and conveyed by the brush or the uneven surface. When a two-component developer is used, a thin layer of toner is created on the toner transport member by contacting the two-component developer with the toner transport member using a conventional developing device such as a cascade magnetic brush. By using a thin layer of toner, it can be substantially regarded as a one-component toner, and results similar to those of the one-component developer in the embodiment can be obtained.

As explained above, by applying an AC voltage between the toner transport member and a control member such as an averter board, the adhesion force of the toner to the transport member on the toner transport member is weakened, making it possible to record with a low applied voltage. , it is possible to reduce power consumption as much as possible. Furthermore, when the toner moves back and forth between the control means, the toner itself cleans the toner conveying member side of the control means, making it possible to obtain stable images over a long period of time.

[Brief explanation of drawings]

FIGS. 1A and 1B are cross-sectional views of examples of control members, and FIGS. 2 and 3 are cross-sectional views showing one embodiment of the present invention. In the figure, 1 is a signal electrode, 3 is a base electrode,
4 is an opening, 5 is a recording member, 7 is a toner conveying member,
11 is an insulating magnetic toner, 8 is an AC power source, 9 is a DC power source, and 10 is a signal (character generation) power source.

Claims (1)

[Scope of Claims] 1. A recording device that controls the passage of a powder developer using an electric field generated in an aperture and forms an image on a recording material using the developer that has passed through the aperture, comprising: A developer support for carrying and conveying, a control means having first and second electrodes with an insulating layer interposed therebetween and an opening arranged in the longitudinal direction thereof, and a control means on the side opposite to the developer support of the control means. a recording material arranged and moving relative to the control means; an alternating bias applying means for forming an alternating electric field between the developer support and the control means in order to supply the developer to the aperture of the control means; and a developer. a first of the control means for controlling the passage of the
a signal power supply that applies a signal voltage between the electrode and the second electrode; and a bias application means that forms an electric field between the control means and the recording material in order to guide the developer that has passed through the control means to the recording material. An image recording device comprising: