JPH0695458A - Electrostatic image forming method - Google Patents

Abstract

PURPOSE:To eliminate the need for a high voltage not to generate ozone, to make degree of freedom for selecting an image carrier high, further, to easily form the images of a halftone, a large size and high accuracy, simultaneously, to easily increase image forming speed and moreover, to reduce manufacturing cost in a simple constitution. CONSTITUTION:An ionic liquid tank 6 storing an ionic liquid 6a and earthed is provided with respect to a dielectric film 5 over all areas in the breadthwise direction of the dielectric film 5 on the surface side of the dielectric film 5. On the rear surface side of the dielectric film 5, a signal electrode group 7 where plural signal electrodes 7a are arranged at picture element pitches in a main scanning direction is provided opposite to the liquid surface position of the ionic liquid 6a. A picture signal voltage corresponding to the density of each picture element in the main scanning direction in the image to be formed and biased to a negative potential is applied on each signal electrode 7a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image forming method which is applied to an image forming apparatus such as a copying machine, a printer and a display and forms a developable electrostatic image with toner.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine or a display for forming a toner image forms an electrostatic image on an image carrier and transfers the toner image obtained by developing the electrostatic image onto recording paper. Or to display it as it is. Various methods have been conventionally known as the method for forming the electrostatic image, and typical methods include the following. (1) An electrophotographic method of forming an electrostatic image by projecting a light image on a photoconductive layer charged by corona discharge or the like. (2) An electrostatic recording method in which electric charges are applied to a non-photosensitive electrostatic recording layer by an air discharge from an adjacent electrode. Whether or not electric charge is applied is controlled by turning on / off air discharge. (3) Ion flow control for forming an electrostatic image by ionizing molecules in the air by the action of a high electric field to generate gas ions and controlling the amount of the gas ions reaching the electrostatic recording layer by a control electrode. Law.

[0003]

However, in the above electrophotographic method, the image quality depends on the photosensitive characteristics of the photoconductive layer, and it is difficult to obtain a long-life photoconductive layer having good photosensitive characteristics. is there. Moreover, since an optical system for projecting an optical image, means for blocking external light, and the like are required, the structure is complicated, the manufacturing cost is high, and large-scale image formation is difficult.

Further, in the electrostatic recording method, since the presence or absence of charge application to the electrostatic recording layer is determined depending on whether or not the voltage applied to the electrodes exceeds the threshold value of the air discharge, it is possible to form an image having a halftone. Have difficulty. Further, a driver or the like for switching a high voltage is required to control the air discharge based on the image signal, which makes it difficult to reduce the manufacturing cost and downsize the device.

On the other hand, with the ion flow control method, although it is possible to form an image having a halftone, the image forming speed is restricted by the moving time until the gas ions reach the electrostatic recording layer, and the manufacturing cost is increased. Since it is expensive, it is the reality that it has not been put to practical use. In view of the above points, the present invention has a high degree of freedom in selecting an image bearing member by not using a photoconductive layer, and also has an image having a halftone, a large image, and a high-definition image using a small-diameter toner. It is possible to provide an electrostatic image forming method in which the image forming speed can be easily increased, a driver for controlling a high voltage is not required, the configuration is simple, and the manufacturing cost can be reduced. Has an aim.

[0006]

In order to achieve the above object, the present invention provides an ion source on one surface side of an image bearing member made of a dielectric material and at least the above ions on the other surface side. A plurality of counter electrodes in a direction intersecting the boundary line are provided at positions facing the boundary line of the ion supply region by the supply source, and the counter electrodes are moved while relatively moving the boundary line and the image carrier. It is characterized in that a voltage according to an image signal for each pixel is applied to.

[0007]

With the above structure, when the boundary line of the ion supply region moves with respect to the image carrier, the boundary of the image carrier moves away from the ion supply region to a part corresponding to each counter electrode in the part separated from the ion supply region. Ions from the ion source are fixed according to the applied voltage to each electrode at the time.

[0008]

【Example】

(Basic Principle) First, the basic principle of electrostatic image formation according to the present invention will be described by taking water as an ion supply source as an example. As shown in FIG. 1A, when water 2 is brought into contact with the surface of the electrostatic recording layer 1 made of a dielectric material, an electrode 3 is provided on the back surface, and a voltage is applied between the water 2 and the electrode, Ions contained in the water 2 move to the surface of the electrostatic recording layer 1. The amount of ions that move at this time is determined according to the applied voltage,
The area A to C on the surface of the electrostatic recording layer 1 is uniform.

In this state, as shown in FIG. 1B, when the electrostatic recording layer 1 moves in the direction of the arrow (hereinafter referred to as "scanning direction") and the portion A separates from the water 2, Ions corresponding to the applied voltage at the moment of leaving remain in the A portion, and the A portion is charged. The charge amount of this A part is
After leaving the water 2, it does not change except when spontaneously discharging. Next, when the applied voltage is increased in this state, more ions than in the portion A are in contact with the water 2 B to D.
Move evenly to the part.

Then, as shown in FIG. 1C, when the electrostatic recording layer 1 is further moved and the portion B is separated from the water 2,
More ions are fixed in the portion B than in the portion A, and the portion is charged with a large amount of charge. As described above, if water is brought into contact with the surface of the dielectric layer and the water is removed while applying a voltage, a charged pattern remains on the original boundary of water depending on the applied voltage at the moment the water is removed. By applying a voltage corresponding to the image signal in synchronization with the movement of the dielectric layer, an electrostatic image is formed.

Further, even if the electrode applying a voltage to the water is separated from the water while the voltage is still applied and the water is dried,
It has been confirmed by the study of the present inventor that the charged state is at the same potential as when the electrodes are separated and at the same shape as the contact portion between water and the surface of the dielectric layer at that time. Here, the water 2 is
Although it is necessary to contain water ions for moving to the electrostatic recording layer 1, hydrogen ions H ₃ O ⁺ due to water dissociation, which is contained in what is generally called pure water,
Hydroxide ion OH ⁻ and carbonate ion CO ₃ ⁻ alone have sufficient conductivity in terms of static electricity and are sufficient to obtain a normal image forming speed. Also, other inorganic or organic electrolytes can be added. In this case, the ion density is increased to facilitate faster electrostatic image formation. Not limited to water, if it is an ionic liquid, alcohols such as ethanol and methanol, polar liquids such as ketones and esters,
Alternatively, a mixture thereof can be applied. Further, an electrolyte may be added to these liquids. The ions contained in these liquids are consumed as they move to the electrostatic recording layer 1, but the amount thereof is not a problem at all.

When the ionic liquid is used as the ion supply source as described above, since ions that are naturally ionized in the ionic liquid are used, a high voltage is required as in the case of performing air discharge. In addition, there is an advantage that ozone is not generated with low energy consumption. The ion supply source is not limited to the ionic liquid, and an electrostatic image can be formed by the same action by using various ion generating means such as an ion generating device utilizing corona discharge. Even when this type of ion generator is used, since it is sufficient to continuously generate ions, it is not necessary to provide a driver or the like for controlling a high voltage.

When an ionic liquid is used, the electrostatic recording layer 1 preferably has high water repellency in order to increase the image forming speed. For example, a water repellent polymer layer such as a polyester layer can be applied. In addition, various organic resins and various inorganic ceramics are also applicable. The surface of the electrostatic recording layer 1 may be processed with a water repellent treatment agent such as silicon or fluorine.

The electrostatic image forming method as described above has the following features. (1) The electrostatic potential of the electrostatic recording layer is substantially equal to the applied voltage as shown in FIG. 2, and the relationship between the applied voltage and the surface potential of the electrostatic recording layer has a very good linear relationship. is doing. Therefore, uneven charging does not occur and gradation reproducibility is good. Further, the electrostatic recording layer basically needs only to be a dielectric, and high image quality can be obtained regardless of the type. (2) The resolution of the electrostatic image in the scanning direction is extremely high regardless of the size of the ion supply region such as the contact portion between the ionic liquid and the electrostatic recording layer. This is because, in the electrostatic recording layer, only the boundary line portion of the ion supply area has a charge amount according to the applied voltage at that moment when the area is separated from the ion supply area. (3) The charge amount of the electrostatic recording layer is not affected by the charge amount before the ions are supplied. Therefore, it is not necessary to remove the charge before forming the electrostatic image. (4) Since a dielectric such as a water-repellent polymer layer is used as the electrostatic recording layer, the decay rate of the surface potential due to the diffusion of charges is, for example, as shown in FIG. 3 when a polyester film is used. Extremely small. Therefore, since the applied charge is retained for a long time, good development can be performed by a usual electrophotographic developing method or the like. Further, even when the toner image is exposed to light as in the case where it is displayed without being fixed, a high image remaining property can be obtained. (5) Further, by the above (3) and (4), it is possible to easily increase the resolution of the electrostatic image in the direction perpendicular to the scanning direction or form a large size image by overwriting. That is, as shown in FIG. 4, the charging portion 2a formed by the first scanning is slightly displaced from the charging portion 2a by 2
When the charged portion 2a ′ is formed by performing the second scanning, only the width R portion of the charged portion 2a remains in the original charged state without being affected by the second scanning. On the other hand, the charging unit 2a '
Becomes a new charge state without being affected by the original charge state. Therefore, to increase the resolution, water 2,
It is only necessary to set the shift amount of 2'to be small. The resolution in the direction perpendicular to the scanning direction can also be increased by reducing the size of the electrode facing the ion generating means in the direction perpendicular to the scanning direction. (6) Since the movement of the ions to the electrostatic recording layer is substantially instantaneously performed, the image forming speed can be easily increased. (First Embodiment) Next, an example of an image forming apparatus to which the electrostatic image forming method is applied will be described with reference to FIGS. This image forming apparatus has an ionic liquid tank and a multipolar signal electrode set through a dielectric film, and applies an image signal voltage according to the concentration of each pixel between the ionic liquid and each signal electrode. By doing so, the electric field near the liquid surface of the ionic liquid is changed to form an electrostatic image.

The dielectric film 5 has a thickness of about 10 to 80 μm and is driven by a feeding mechanism (not shown),
It is designed to move upward. As the dielectric film 5, various materials can be applied as described above, but those having a large water repellency are preferable so that the ionic liquid does not adhere when the dielectric film 5 moves upward. Ions are formed between the dielectric film 5 and the dielectric film 5 over the entire widthwise direction of the dielectric film 5 (direction perpendicular to the plane of FIG. 5; hereinafter referred to as “main scanning direction”). An ionic liquid tank 6 for storing the ionic liquid 6a is provided. This ionic liquid tank 6 is composed of a grounded conductor. Pure water is suitable as the ionic liquid 6a from the viewpoint of easy handling.

On the rear surface side of the dielectric film 5, facing the liquid surface position of the ionic liquid 6a, as shown in FIG. 6 (shown by the arrow X in FIG. 5), a plurality of signal electrodes 7a are main-scanned. The signal electrode sets 7 are arranged at the pixel pitch in the direction.
Each signal electrode 7a is provided with a signal source (not shown),
An image signal voltage biased to a negative potential according to the density of each pixel in the main scanning direction in the image to be formed is applied.

A static elimination brush electrode 8 and a ground electrode 9 are provided above the signal electrode set 7 and are grounded. The static elimination brush electrode 8 is for giving a counter charge to the back surface of the dielectric film 5 in order to prevent spontaneous discharge of charges on the front surface of the dielectric film 5. A water-containing sponge or the like may be used instead of the static elimination brush electrode 8. Further, the ground electrode 9 is
Between the signal electrode set 7 and the static elimination brush electrode 8, the static elimination brush electrode 8 is provided immediately above the signal electrode set 7 so as to prevent spontaneous discharge from occurring. In some cases, it may not be provided. Further, when toner development or the like is performed in the vicinity immediately above the signal electrode set 7 or the ground electrode 9 and the net charge is sufficiently removed by the adhesion of the oppositely charged toner or the like, the charge removal brush electrode 8 is used.
Need not be provided.

The signal electrode 7a and the ground electrode 9
May be brought close to or in contact with the dielectric film 5, but even if they are brought into contact with each other, the action of giving an electric charge to the back surface of the dielectric film 5 hardly occurs. In the above configuration, when the dielectric film 5 moves upward, the contact line portion P of the dielectric film 5 with which the liquid surface of the ionic liquid 6a comes in contact is gradually separated from the ionic liquid 6a. Therefore, when the image signal voltage of each pixel is applied to each signal electrode 7a, at the moment when the contact line portion P separates from the ionic liquid 6a, in the ionic liquid 6a corresponding to the applied voltage to each signal electrode 7a. Ions of opposite polarity move to the portion of the contact line portion P facing the signal electrodes 7a and are fixed.

Further, when the voltage applied to each signal electrode 7a is changed according to the density of the pixel in the vertical direction as the dielectric film 5 moves upward, an amount corresponding to the density of each pixel in the two-dimensional direction is obtained. Ions are fixed. Here, since ions corresponding to the applied voltage at the moment when this portion separates from the ionic liquid 6a moves to the contact line portion P in the dielectric film 5, regardless of the length of the signal electrode 7a, The directional resolution can be very high.

When the portion of the dielectric film 5 on which ions are fixed on the front surface rises to the position of the brush electrode 8 for static elimination, a counter charge corresponding to the amount of charge by the ions is applied to the rear surface side, and a stable charged state is obtained. It becomes an electrostatic image.
The electrostatic image thus formed is toner-developed by a known dry or wet developing device (not shown), and then the formed toner image is thermally fixed. Here, when wet development is performed, various materials can be applied as the dielectric film 5 as described above. Therefore, the solvent of the developer and the dielectric film 5 which is not easily attacked by the solvent should be selected. Can be done easily. (Modification of First Embodiment) Instead of the ionic liquid tank 6 holding the ionic liquid 6a, a discharge electrode pair 106 having discharge electrodes 106a and 106b as shown in FIG. 7 may be used. A gap 106c of, for example, about 10 to 300 μm is formed between the discharge electrodes 106a and 106b. A predetermined DC voltage with a frequency higher than the highest frequency of the image signal voltage, A, is applied to the discharge electrodes 106a and 106b.
When a C voltage or a DC voltage on which an AC voltage is superimposed is applied, discharge occurs in the gap 106c, and ions in the plasma of the discharge part are generated in a region (ion supply region) near the gap 106c in the dielectric film 5. It is ready to be supplied.

Therefore, when the image signal voltage of each pixel is applied to each signal electrode 7a to form an electric field, an amount of ions corresponding to the image signal voltage moves to the surface of the dielectric film 5, and that portion is The ions are fixed as they move upward and out of the ion supply region. When ions are supplied to the dielectric film 5 by using the air discharge as described above,
It is not necessary to use the dielectric film 5 having water repellency. Further, although it is necessary to apply a high voltage to some extent in order to cause air discharge, the presence or absence of movement of ions to the dielectric film 5 and the amount of movement are relatively low-voltage images applied to the signal electrode 7a. Since the discharge is controlled by the signal voltage, it is sufficient that the discharge is constantly generated, it is not necessary to provide a driver for controlling the high voltage, and the gradation reproducibility can be easily improved.

The gap 106c between the discharge electrodes 106a and 106b may be, for example, 10 to 10 depending on the applied voltage.
You may set in the range of about 1000 micrometers. Also, FIG.
, The corona discharge electrode 206a and the slit 2
Even if an ion generator having a shield 206b on which 06c is formed is used, a high-quality electrostatic image can be similarly formed.

Further, as shown in FIG. 9 or FIG.
A conductive elastic rubber roll 306 or a blade electrode 406 having a conductive coating 406b on the surface of an elastic blade 406a such as rubber may be used. The conductive elastic rubber roll 306 and the conductive coating 406b are, for example, 10 ²
A material having a volume resistance of about 10 ⁹ Ωcm can be applied, and when a DC voltage, an AC voltage, or a DC voltage on which the AC voltage is superimposed is applied, the conductive elastic rubber roll 30 is applied.
Stable minute discharge occurs in a portion where the distance between 6 and the like and the dielectric film 5 is about 5 to 10 μm, and ions necessary for electrostatic image formation are supplied. (Second Embodiment) An example of another image forming apparatus to which the electrostatic image forming method of the present invention is applied will be described with reference to FIGS. 11 to 13. This image forming apparatus moves an aqueous ion applicator that brings water into contact with a dielectric film in the main scanning direction, and moves the dielectric film in the sub-scanning direction for each scanning, as in a dot matrix printer. It is designed to be moved to.

The aqueous ion applicator 11 is composed of a grounded conductor, and as shown in FIG. 11, the water supply slit portion 12 for supplying water to the dielectric film 31 placed on the base plate 21 and the dielectric film 31. And a suction slit portion 13 for sucking the water in contact with the air together with the air. The tip of the water supply slit portion 12 is formed at an acute angle, and the water contacting the dielectric film 31 is sucked by the suction slit portion 13 and separated from the dielectric film 31.
The position of 4 can be accurately stabilized. The aqueous ion applicator 11 is configured to move in the main scanning direction and the returning direction by driving a driving mechanism (not shown).

The insulator 2 is formed on the upper surface of the base plate 21.
As shown in FIG. 12, nine signal electrodes 23 in the main scanning direction are provided via 2 through the moving range of the aqueous ion applicator 11 at a pixel pitch in the sub scanning direction. The signal electrode 23 is connected to a signal source (not shown), and an image signal voltage corresponding to the scanning position of the aqueous ion applicator 11 is applied to each signal electrode 23.

Further, the dielectric film 31 placed on the base plate 21 is intermittently conveyed in the sub-scanning direction shown in FIG. 13 by every one scan of the water-based ion applicator 11 by a not-shown transport mechanism. ing. The pitch of this intermittent conveyance is set to be equal to 9 times the pixel pitch in the sub-scanning direction. Base plate 21
On the side of the sub-scanning direction, a static elimination brush electrode 24 having a length over the moving range of the aqueous ion applicator 11 is provided in the direction perpendicular to the paper surface of FIG. An AC bias voltage is applied to the static elimination brush electrode 24.

In the above structure, the water supplied to the aqueous ion applicator 11 comes into contact with the dielectric film 31 at the tip of the water supply slit portion 12 and leaves the dielectric film 31 at the boundary line 14. Therefore, while the aqueous ion applicator 11 is moving in the main scanning direction, the pixel electrodes corresponding to the position of the signal electrode 23 in the sub-scanning direction and the position of the aqueous ion applicator 11 in the main scanning direction are moved to the respective signal electrodes 23. When the image signal voltage is applied, the dielectric film 3 in the portion of the boundary line 14 facing each signal electrode 23.
Ions in water having a polarity opposite to that of the signal electrode 23 move and are fixed at 1.

When the aqueous ion applicator 11 moves to the end position in the main scanning direction, it returns in the opposite direction, and the dielectric film 31 moves in the sub scanning direction. At that time, a counter charge corresponding to the charge amount of the ions is applied to the back surface of the portion of the dielectric film 31 that passes through the position of the static elimination brush electrode 24, and an electrostatic image in a stable charged state is formed.

The electrostatic image thus formed is the first
After toner development as in the image forming apparatus of the embodiment, the formed toner image is thermally fixed. The signal electrode 23 may not be fixedly provided as described above, but may be configured to scan and move together with the aqueous ion applicator 11. In this case, the length and the position of the signal electrode 23 in the main scanning direction should be at least in the portion facing the boundary line 14.
It suffices if it is set so that 3 exists. Further, in this case, the static elimination brush electrode 24 may be similarly scanned and moved so that the rear surface side of the portion of the dielectric film 31 immediately after the ions are moved and fixed is neutralized. (Third Embodiment) As an example of still another image forming apparatus to which the electrostatic image forming method of the present invention is applied, an image forming apparatus for forming a multicolor image will be described with reference to FIGS. 14 and 15.

In this image forming apparatus, pure water is used as the ionic liquid 42 supplied by the aqueous ion applicator 41, and an electrostatic image forming and developing unit is provided for each color of the formed image. There is. In this device, the point where the dielectric film 51 is conveyed, the signal electrode set 6
1 is provided across the width of the dielectric film 51, and the ionic liquid 42 is the dielectric film 51.
Similar to the first embodiment, the relative position of the boundary line 43 away from the signal electrode set 61 does not move, and the second embodiment is that the ionic liquid 42 is removed from the surface of the dielectric film 51 by suction. Similar to the example.

The ionic liquid 42 has a water supply slit portion 44.
Is supplied to the dielectric film 51 and comes into contact with the dielectric film 51, and is recovered by the water repellency of the dielectric film 51 and the suction action by the pressure reduction from the suction slit portion 45. The signal electrode set 61 is provided at a position facing the boundary line 43, and is configured by arranging a plurality of signal electrodes 61a at a pixel pitch in a direction perpendicular to the transport direction of the dielectric film 51. Each signal electrode 61a has a maximum of 200 depending on the density of the pixel at the corresponding position by a signal source (not shown).
An image signal voltage of 800 V is applied. A static elimination brush electrode 62 is provided on the downstream side of the signal electrode set 61 in the transport direction of the dielectric film 51.

A liquid developing device 72 having a developing roll 71 is provided on the downstream side of the aqueous ion applicator 41, and a charge eliminating brush 73 is provided above the developing roll 71. Aqueous ion applicator 41 and signal electrode set 6
In the electrostatic image formed by 1 in the same manner as in the first and second embodiments according to the signal applied voltage, the liquid developing device 72 forms a first color image. This image is dried to the extent that the image is not disturbed by the contact with the ionic liquid 42 before reaching the aqueous ion applicator 41 for the second color. A second-color electrostatic image is formed on the first-color image so as to be developed, and thereafter, the same processing is performed the required number of times, and then the image is dried and fixed. When the dielectric film 51 on which the multicolor image is formed in this way is transparent, it is laminated on, for example, paper or a white sheet to form a completed image.

Here, when the electrostatic images of the second and subsequent colors are formed, there is no need to carry out the residual image erasing because it is not affected by the previous charging state as described above. Further, since the relationship between the image signal voltage and the surface potential of the dielectric film 51 has a good linear relationship, it is possible to easily improve the color reproducibility of a full-color image which requires high gradation reproducibility. .

Furthermore, since the resolution in the direction crossing the boundary line 43 is high, image processing relating to the high frequency components of the image signal and improvement in image quality by adding a modulation power source and superimposing a triangular wave can be performed. It is possible. Instead of the liquid development described above, development may be performed using dry toner. In this case, for example, after the toner image of the first color is assumedly attached by flash or the like, the electrostatic image of the second color may be formed. (Modification of Third Embodiment) The aqueous ion applicator 4 described above.
Instead of 1, the discharge electrode pair 141 in which a gap 141c is formed between the discharge electrodes 141a and 141b as shown in FIG. 16 may be used as in the modification of the first embodiment (FIG. 7). Also in this case, an electrostatic image is similarly formed and developed for each color to obtain a color image.

In each of the above embodiments, an example in which an image is directly formed on the dielectric film has been shown. However, as in an electrophotographic image forming apparatus using a photosensitive conductor, recording is performed by electrostatic transfer or the like. It may be transferred to a sheet.
In this case, since it is easy to select a material having high heat resistance as the dielectric film, it is not limited to electrostatic transfer, but is once adsorbed to a silicon-coated heat roller and then transferred onto a recording sheet and simultaneously heat-fixed. It is also easy to use the thermal transfer method. Polyimide, liquid crystal polymer, or the like is suitable as the material described above.

Further, a display capable of repeatedly forming an image without fixing the toner image may be constructed. Also,
The signal electrode provided on the back surface side of the dielectric film 5 is not limited to the solid electrode as described above, and for example, as shown in FIGS. 17 and 18, a plurality of nozzles 107a for ejecting pure water into a fine jet shape and the like. May be used. The pure water thus ejected is sucked together with air by the suction nozzle 107b.

[0037]

As described above, according to the present invention,
With relatively simple components, it is possible to form a high-definition, high-density electrostatic image with extremely low efficiency using a low voltage, continuous tone reproduction, and good color reproducibility. Produce an effect. Moreover, since the degree of freedom in selecting the dielectric is high, it is possible to directly form an image using, for example, a strong and thin dielectric film.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the basic principle of electrostatic image formation according to the present invention.

FIG. 2 is a graph showing the relationship between the applied voltage and the surface potential of the electrostatic recording layer in the present invention.

FIG. 3 is a graph showing the decay rate of the surface potential of the polyester film applicable to the present invention.

FIG. 4 is an explanatory diagram showing an example of a charged state when the resolution in the direction perpendicular to the scanning direction is increased.

FIG. 5 is a sectional front view showing the configuration of the image forming apparatus in the first embodiment.

6 is an X arrow view of the signal electrode set in FIG.

FIG. 7 is a sectional front view showing a modified example of the first embodiment.

FIG. 8 is a sectional front view showing a modified example of the first embodiment.

FIG. 9 is a sectional front view showing a modified example of the first embodiment.

FIG. 10 is a sectional front view showing a modified example of the first embodiment.

FIG. 11 is a sectional front view showing the configuration of the image forming apparatus in the second embodiment.

FIG. 12 is a plan view of the same.

FIG. 13 is a side view of the same.

FIG. 14 is a sectional front view showing a configuration of a multicolor image forming apparatus according to a third embodiment.

FIG. 15 is a bottom view of the signal electrode set.

FIG. 16 is a sectional front view showing a modified example of the third embodiment.

FIG. 17 is a sectional front view showing another example of the signal electrode.

FIG. 18 is a partial sectional view taken along the arrow Y in FIG.

[Explanation of symbols]

 1 Electrostatic Recording Layer 2 Water 3 Electrode 5 Dielectric Film 6 Ionic Liquid Tank 6a Ionic Liquid 7 Signal Electrode Set 7a Signal Electrode 11 Aqueous Ion Applicator 12 Water Supply Slit 13 Suction Slit 14 Boundary 23 Signal Electrode 31 Dielectric Body film 41 Aqueous ion applicator 42 Ionic liquid 43 Boundary line 44 Water supply slit part 45 Suction slit part 51 Dielectric film 61 Signal electrode set 61a Signal electrode 106 Discharge electrode pair 106a Discharge electrode 106b Discharge electrode 106c Gap 107a Nozzle 107b Suction nozzle 141 Discharge Electrode Pair 141a Discharge Electrode 141b Discharge Electrode 141c Gap 206a Corona Discharge Electrode 206b Shield 206c Slit 306 Conductive Elastic Rubber Roll 406 Blade Electrode 406a Elastic Blade 40 6b Conductive film

Claims (2)

[Claims] 1. An ion supply source is arranged on one surface side of an image carrier made of a dielectric material, and at a position facing the boundary line of at least the ion supply area of the ion supply source on the other surface side. Providing a plurality of counter electrodes in a direction intersecting with the boundary line, and applying a voltage corresponding to an image signal for each pixel to each counter electrode while moving the boundary line and the image carrier relatively. Characteristic electrostatic image forming method. 2. The electrostatic image forming method according to claim 1, wherein the ion supply source is an ionic liquid in contact with the image carrier.