JPH11208013A - Toner and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner used in an image forming apparatus forming images with the use of a direct image record method and an image forming apparatus which can eliminate dust. SOLUTION: Images are formed with the use of a toner of a size and a shape whereby an electrostatic force applied to the toner by an electric field formed at a toner fly space between a confronting electrode member 2 and a developing roller 1 by control electrodes of the confronting electrode member 2 and a toner control member 3 and an air resistance force applied to the toner by the air in the fly space when the toner flies are made in the same order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art Conventionally, as a powder image forming method, an image forming method called direct toning or toner projection has been known. In this image forming method, an electric field is applied to a charged toner layer or toner cloud by applying a voltage to a control electrode portion provided around a hole or a slit,
This is to selectively fly toner at a specific position and move the toner through holes or slits to directly form an image on a recording member such as paper.

FIG. 5 is an enlarged schematic diagram of an image recording section of an image forming apparatus employing such an image forming method. The developing roller 1 carrying the toner 7 is grounded, and the toner 7 carried on the developing roller 1 is directed to the opposing electrode member 2 between the developing roller 1 and the opposing electrode member 2 provided opposite thereto. A power supply 8 as a flying electric field forming means for forming a flying electric field for flying is connected. This power supply 8 applies a DC high voltage having a polarity opposite to the average charging polarity of the toner 7 to the counter electrode member 2.

Further, between the developing roller 1 and the counter electrode member 2, a toner flying control having a toner passage hole 31 as a minute opening and a control electrode 32 provided around the toner passage hole 31. An FPC 3 as a member is provided. A power supply (hereinafter, referred to as “image power supply”) 9 for applying a control voltage generated based on image information to each control electrode 32 is connected between the developing roller 1 and each control electrode 32 of the FPC 3. Have been. The image power supply 9 applies a pulse-like control voltage that is ON / OFF controlled based on image information to each control electrode 32. The value of the ON-time control voltage (hereinafter referred to as an image signal voltage) is, for example, +325 V, and the OFF-state voltage (hereinafter, referred to as an image signal voltage).
The value of the non-image signal voltage is set to, for example, -50V.

In the illustrated apparatus, the distance Li between the control electrode 32 of the FPC 3 and the counter electrode member 2 is 0.5 m.
m, the distance Lk between the control electrode 32 and the developing roller 1 is 0.0
5 mm, the peripheral speed of the developing roller 1 is 300 mm / sec, and the transport speed of the paper 6 is 100 mm / sec.

FIG. 6 is a schematic view showing a flying state of the toner. For example, when the developing roller 1 is grounded using a negatively charged toner, a high DC voltage of +1.2 kV is applied to the counter electrode member 2, and an image signal voltage Vblack of +325 V is applied to the control electrode 32 for 200 μsec. field of 3 × 10 ⁶ V / m is applied to the toner 7 on the 1. As a result of the action of the electric field, the Coulomb force applied to the toner 7 exceeds the sum of the adhesive force and the image force acting between the toner 7 and the developing roller 1, and the toner 7 moves toward the counter electrode member 2. It starts to fly, passes through the toner passage hole 31 of the FPC 3, and continues to fly due to the flying electric field formed by the voltage applied to the opposing electrode member 2, and moves in a predetermined direction on the opposing electrode member 2 by a conveying means (not shown). The paper 6 stops when the paper 6 is being conveyed, and an image is recorded on the paper 6. In this apparatus, a non-image signal voltage Vwhite of -50 V is applied to the control electrode 32 corresponding to the non-image portion where the toner on the paper 6 does not adhere.

As described above, an image can be formed on the paper 6 using the image forming apparatus having the above configuration.

[0008]

However, when 1000 sheets were continuously printed using the apparatus having the above structure, the sharp image was initially formed, but the sharpness of the image gradually deteriorated. . The print image is magnified 5
Observation with a magnifying glass of 0x revealed that although little toner was scattered around the characters of the initial print, quite a lot of toner was scattered at the end (hereinafter referred to as dust). This is shown in FIG.
When the toner adheres to the paper 6, the toner randomly rebounds from the paper 6, and some of the rebounded toner 7 a is in a direction parallel to the surface of the paper 6 as indicated by an arrow in the drawing. This occurs when the toner moves at an initial speed to adhere to a position distant from the toner forming the dots 71.

The present inventors have conducted intensive studies to solve such a problem of the generation of dust, and as a result, have found that the particle size and shape of the toner are involved in the generation of dust.

As a method for preventing the generation of dust, the applicant of the present invention has an opening through which the toner that has passed through the opening of the toner flight control member passes. An intermediate electrode for forming an acceleration electric field for accelerating the flying toner and forming a deceleration electric field for decelerating the toner flying between the counter electrode and the toner flying control member and the counter electrode. (Japanese Patent Application No. 9-1).
43376). However, this device has a complicated device configuration.

In the case where the charged toner is caused to fly by being controlled by an electric field and recorded directly on paper, if an adhesive tape is used instead of paper as a recording member, rebound does not occur and image dust can be eliminated. Known (Fred W. Schmi
dlin et.al, "DirectElectrostatic Printing (DEP) -A Si
mple Powder Marking Process ", The SixthInternationa
l Congress On Advances In Non-Impact Printing Tech
nologies, 1990). However, this method cannot directly record on paper.

The present invention has been made in view of the above background, and an object of the present invention is to provide an image forming apparatus capable of eliminating dust.

[0013]

According to one aspect of the present invention, there is provided a toner carrier for supporting a toner, a counter electrode facing the toner carrier, and a counter electrode facing the toner carrier. A toner fly control member disposed between the electrodes and having a plurality of independent or series of minute openings and a plurality of control electrodes controlling the passage of toner through each minute opening; By applying a voltage to the control electrode portion of the member in accordance with an image signal, the toner on the toner carrier is caused to fly selectively, and the flying toner is passed through the minute opening to form the counter electrode. Side, and the toner is used in an image forming apparatus that forms an image by adhering to the counter electrode or a recording member on the counter electrode. And electrostatic force the toner is subjected by the electric field to be formed on the flying space of the toner between the toner carrying member,
The size and the shape are such that the air resistance force received by the air in the flying space during the flight of the toner is of the same order.

According to a second aspect of the present invention, there is provided a toner carrier for carrying a toner, a counter electrode opposed to the toner carrier, and a toner carrier and a counter electrode provided between the toner carrier and the counter electrode. A toner flight control member having a plurality of minute openings and a plurality of control electrodes for controlling the passage of toner through each minute opening, wherein a voltage is applied to the control electrode of the toner flight control member in accordance with an image signal. To selectively fly the toner on the toner carrier,
The toner used in an image forming apparatus for forming an image by transferring the flying toner to the counter electrode side through the minute opening and attaching the toner to the counter electrode or a recording member on the counter electrode. In the method, when the toner collides with the counter electrode or the recording member and rebounds, and moves in the direction with an initial speed in a direction parallel to the surface of the counter electrode, the toner in the direction until the speed in the direction becomes zero becomes zero. It is characterized in that it has a size and a shape such that it receives an air resistance force with a moving distance within 40 μm.

A third aspect of the present invention is the toner according to the first or second aspect, wherein the particle diameter is 8 μm or less.

According to a fourth aspect of the present invention, there is provided the toner according to the first or second aspect, wherein the toner has a size and a shape to receive an air resistance equivalent to that of a spherical toner having a particle diameter of 8 μm or less. .

According to a fifth aspect of the present invention, there is provided a toner carrier for carrying a toner, a counter electrode facing the toner carrier, and a toner carrier and a counter electrode provided between the toner carrier and the counter electrode. A toner flight control member having a plurality of minute openings and a plurality of control electrodes for controlling the passage of toner through each minute opening, wherein a voltage is applied to the control electrode of the toner flight control member in accordance with an image signal. To selectively fly the toner on the toner carrier,
In the image forming apparatus for forming an image by transferring the toner that has been jetted to the counter electrode side through the fine opening and attaching the toner to the counter electrode or a recording member on the counter electrode, the toner is used as the toner. The electrostatic force received by the toner due to the electric field formed in the flying space of the toner by the counter electrode and the control electrode unit is the same as the air resistance force received by the air in the flying space during the flight of the toner. It is characterized by using a toner having an appropriate size and shape.

According to a sixth aspect of the present invention, there is provided a toner carrier for carrying a toner, a counter electrode facing the toner carrier, and a plurality of independent electrodes provided between the toner carrier and the counter electrode. A toner flight control member having a plurality of minute openings and a plurality of control electrodes for controlling the passage of toner through each minute opening, wherein a voltage is applied to the control electrode of the toner flight control member in accordance with an image signal. To selectively fly the toner on the toner carrier,
In the image forming apparatus for forming an image by transferring the toner that has been jetted to the counter electrode side through the fine opening and attaching the toner to the counter electrode or a recording member on the counter electrode, the toner is used as the toner. When the toner collides with the counter electrode or the recording member and rebounds, and moves in the direction with an initial velocity in a direction parallel to the counter electrode surface, the moving distance of the toner until the horizontal velocity becomes zero is reduced. It is characterized by using a toner having a size and a shape to receive an air resistance force within 40 μm.

In the first, third, fourth, fifth and sixth aspects of the present invention, the electric field formed by the counter electrode and the control electrode portion in a flying space of the toner between the counter electrode and the toner carrier. Accordingly, the electrostatic force received by the toner and the air resistance received by air in the flying space during the flight of the toner are in the same order. As a result, the flying speed of the toner gradually decreases due to the air resistance, and the speed at which the toner reaches the counter electrode or the recording member becomes relatively small. Therefore, the toner hardly rebounds by colliding with the counter electrode or the recording member. Also, when the toner reaches the counter electrode or the recording member, the toner collides with the counter electrode or the recording member to obtain an initial velocity in a direction parallel to the counter electrode surface and try to move in the direction. When the toner receives the air resistance, it is relatively difficult to move in the direction.
Therefore, even if the toner collides with the counter electrode or the recording member and rebounds, the toner hardly adheres to a position on the counter electrode or the recording member that is away from a desired area where the toner is to be adhered. Further, as compared with the case where the order of the air resistance is larger than the order of the electrostatic force, the time until the toner reaches the recording member is shortened, and the image forming speed can be increased.

According to the present invention, when the toner collides with the counter electrode or the recording member and rebounds, the toner obtains an initial velocity in a direction parallel to the counter electrode surface and moves in the direction. Then, an air drag force is applied so that the moving distance of the toner until the velocity in the direction becomes zero is within 40 μm. Thereby, even when the toner collides with the counter electrode or the recording member and rebounds, the outermost region of the desired region on the counter electrode or the recording member to which the toner is to be adhered is larger than the region of up to 40 μm. It can be prevented from adhering to outside positions.

[0021]

FIG. 1 is a perspective view showing a schematic configuration of a main part of an image forming apparatus according to the present embodiment. The present image forming apparatus includes a developing roller 1 as a toner carrier for carrying toner, a counter electrode member 2 as a counter electrode arranged to face the developing roller 1, and a toner control member as a particle flight control member. An FPC 3 and the like are provided. The developing roller 1 is disposed inside a toner container 4 containing toner. The surface of the developing roller 1 is used when a known electrophotographic image forming apparatus carries toner on a toner carrier. The toner can be supported by a known technique. In the present embodiment, the toner negatively charged by the friction between the doctor blade 5 or a toner supply member (not shown) and the developing roller 1 is carried on the developing roller 1 by electrostatic force and regulated by the doctor blade 5. Thus, a toner layer is formed.

The FPC 3 is attached so as to close an opening formed in the lower wall of the toner container 4. As shown in FIG. 2, the FPC 3 is provided between the developing roller 1 and the counter electrode member 2 between the developing roller 1 and the counter electrode member 2.
In order to control the toner flying, a plurality of toner passage holes (hereinafter, referred to as “holes”) 31 as minute openings and a ring-shaped control electrode 32 having an inner diameter φ of 0.160 mm formed around each hole. have. The diameter φh of the hole 31 and
The pitch Ph between the holes 31 in a direction (axial direction of the developing roller 1) orthogonal to the transport direction of the paper 6 as a recording medium is set according to the resolution of an image recorded on the paper 6.
In this embodiment, holes 31 having a diameter φh of 0.140 mm are formed in a substrate made of polyimide having a thickness of 0.075 mm at intervals of the pitch Ph of 0.0845 mm so that an image having a resolution of about 300 dpi can be recorded. Has formed. The hole 31 has a width W of about 2 in the conveyance direction of the paper 6.
Eight rows (31-1 to 31-8) are formed in a mm area, and the total number of holes 31 is 2,300. A ring-shaped control electrode 32 having an inner diameter φ of 0.160 mm, which is electrically independent from each other, is formed around each hole 31.
Are connected to a power supply circuit for applying a voltage corresponding to image information.

The basic configuration, dimensions, voltage conditions, and toner flying principle of the image recording unit of the image forming apparatus shown in FIG. 1 are the same as those described with reference to FIGS. Therefore, the description is omitted.

The inventors of the present invention first examined the initial toner and the last toner, specifically 1 The toner on the developing roller 1 immediately before the image forming of the first sheet and the toner on the developing roller 1 immediately after the continuous printing of 1,000 sheets are performed are collected, and the charge amount and the distribution, the particle size and the The distribution was measured with a particle analyzer (E-spart: trade name) manufactured by Hosokawa Micron Corporation. As a result, it was found that the average charge amount and the charge amount distribution did not change, and the ratio of toner having a particle size of 9 μm or more increased even though the average particle size hardly changed. This result suggests that the toner having a large particle diameter is involved in generation of image dust. The reason why the ratio of the toner having a relatively large particle size increases as described above is that when the toner on the developing roller 1 is regulated by the doctor blade 5, the toner having a relatively large particle size has a relatively small particle size. This is considered to be because it is harder to pass through the restricting portion of the doctor blade 5 than the toner.

Next, in order to confirm the presumption that the toner having a large particle diameter is involved in the generation of image dust, a high-speed camera (Kodak EKTAPR) manufactured by Kodak Corporation was used.
OHS Motion Analyzer Model
4540: trade name), the flying and landing state of the toner was photographed at a magnification of 140 times and 27000 frames / sec.
It was reproduced at 25 frames / sec and observed. As a result, it was difficult to perform quantitative measurement because the resolution was not high, but the toner that rebounded greatly upon landing appeared to have a large particle size.

Further, in order to investigate in detail the relationship between the toner particle size and the generation of dust, the toner particle size was set to 3.0 μm, and 6.
0 μm, 7.0 μm, 8.0 μm, 9.0 μm, 12.
The flying and landing states of the toner were simulated by changing to 0 μm, 15.0 μm, and 18.0 μm. It has been confirmed many times in advance that the results of this simulation agree well with the results of high-speed camera photography. In this simulation, the charge amount of the toner was set to -10
μC / g, and the applied voltage to the counter electrode member 2 was increased to +1000.
V, the voltage applied to the control electrode 32 was set to +250 V, the developing roller 1 was grounded, and a total of 150 to 75 toners were stacked on the developing roller 1. As a result of these simulations, when the particle size is 3.0 μm, the toner does not rebound at all when the toner lands on the paper 6, and when the particle size is 6.0 μm, it hardly rebounds.
It was found that the bounce gradually increased when the particle size was 7.0 μm or more. In the case of forming an image of 300 dpi, the ideal dot diameter is about 120 to 140 μm. Therefore, if the maximum allowable dot diameter is 1.5 times that, it becomes 180 to 210 μm. Therefore, the allowable horizontal movement distance is about 40 μm. However, especially the particle size is 9.
Above 0 μm, the rebound becomes considerably large,
The value exceeded the allowable limit of 40 μm at the time of image formation at 0 dpi, and further jumped as far as 500 μm or more with 18 μm toner.

From these simulation results, the distance from the center of the toner that rebounded farthest to the left and right for each particle size (hereinafter referred to as the rebound distance) was read, and the relationship between the toner particle size and the rebound distance was determined. The result is shown in FIG. From this result, it is clear that there is a strong correlation between the toner particle size and the rebound distance, such that the larger the toner particle size, the larger the rebound distance.

In the above simulation, the charge amount Q / m is set equal to each other even if the toner particle diameters are different from each other. Further, the electric fields E formed in the toner flying space between the developing roller 1 and the counter electrode member 2 by applying a voltage to each of the electrodes are also equal to each other.
The acceleration a due to the electrostatic force F = QE received by the toner in the toner flying space is a = F / m = QE / m = (Q / m) × E
And becomes constant regardless of the toner particle size. As a result, the collision speed of the toner should be equal. Further, in the above simulation, the collision coefficient was also set to 0.1 regardless of the particle size.
Since it is set at 71, the rebound distance should be constant regardless of the particle size.

Therefore, the present inventors further studied the simulation results in order to obtain the reason why the relation obtained that the rebound distance increases as the toner particle diameter increases, based on the results obtained from the above simulation. Then, it was found that although the speed based on the electrostatic force should be constant irrespective of the particle size, the smaller the particle size, the longer it takes to land. Here, the present inventors paid attention to air resistance, simulated flying and rebounding similarly for toner having a particle diameter of 6.0 μm under the condition that there is no air resistance, and performed comparative study. As a result, it hardly bounced off when there was air resistance, but when air resistance was not present, 50% like 18 μm toner.
The result was a large rebound of 0 μm or more. Therefore, when there is no air resistance, it is clear that the toner having a small particle diameter rebounds as much as the toner having a large particle diameter.

Next, in order to investigate the influence of air resistance, a flying speed and a collision speed (hereinafter referred to as a landing speed) at the time of collision are obtained for each toner particle size from the above simulation results. The relationship with the landing speed was determined. The result is shown in FIG. The flying speed when similarly simulated with the same particle diameter of 6.0 μm as the actual toner and the charge amount of −10 μC / g is 1.2 m / sec, which is 1.3 m obtained from the photographing result of the high-speed camera. / sec
Therefore, it is considered that the result of this simulation is similar to that obtained by actual measurement.
From FIG. 4, it can be seen that the flying and landing speeds vary greatly depending on the particle size, and the smaller the particle size, the lower the flying speed and landing speed. In particular, it can be seen that the speed is greatly reduced below 10 μm. This is because the smaller the particle size, the greater the effect of air resistance and the lower the flight speed and landing speed. In other words, the larger the particle size, the smaller the effect of air resistance and the higher the flying speed and landing speed. It is. According to Stokes' law, since the air resistance is proportional to the particle size, it seems contradictory that the larger the particle size, the smaller the effect of the air resistance and the higher the speed. However, as the particle size increases, the charge amount of the toner increases as the cube of the particle size, and the electrostatic force acting on the toner also increases as the cube of the particle size. Therefore, the air resistance acting on the first power of the particle diameter becomes relatively small, and the flying speed approaches the state without air resistance without limit.

From the above results, the reason why the rebound distance of the small particle size toner is significantly shorter than that of the large particle size toner is that the air resistance is relatively large and the landing speed is low, specifically, 2 m / sec. It is concluded that:

Next, even if the landing speed is reduced to 2 m / sec or less by another method irrespective of the air resistance, the toner particle size is set to 18 to check whether the rebound distance becomes short.
Similar simulations were performed for the μm toner by lowering the landing speed by weakening the electric field formed in the toner flight space as compared to the above simulation. The voltage conditions in this case were as follows: the applied voltage to the counter electrode was reduced from 1000 V to 250 V, and the applied voltage to the control electrode 32 was reduced from 250 V to 63 V, respectively, to 1/4. It was made to be 1/4 of that of the simulation. As a result, the landing speed decreased to approximately the same as the landing speed (2 m / sec) obtained by the simulation of the toner having a toner particle diameter of 9 μm when the electric field was not weakened, but the rebound distance was 9 μm. Much larger than the rebound distance of the toner,
It rebounded almost 500 μm.

When the electric field is weakened, the time required for the toner 7 after collision to reach the paper 6 again becomes longer, and the distance in which the toner 7 moves in the horizontal direction during that time also becomes longer. The rebound distance is very large. From this result, not only does the small particle size toner reduce the landing speed due to the air resistance, but also obtains the initial velocity in the horizontal direction by colliding with the paper 6 and the air resistance is reduced when the toner moves laterally, that is, horizontally. It is probable that the brakes were applied and the horizontal movement distance was shortened. From this analysis result, in order to reduce the rebound and prevent the image dust, the flying force and the landing speed of the toner 7 until the toner reaches the paper 6 can be suppressed within the allowable range. Obviously, it is sufficient to use a toner that receives an air resistance that resists or an air resistance that can stop the toner moving at the initial speed within an allowable distance.

Therefore, in the image forming apparatus according to the present embodiment, the counter electrode member 2 and the control electrode 32
Is the toner 7 between the counter electrode member 2 and the developing roller 1.
An image is formed using a toner having a size and a shape such that an electrostatic force received by the toner due to an electric field formed in the flight space of the air and an air resistance force received by air in the flight space during the flight of the toner are in the same order. Perform formation. In the present image forming apparatus, the rebound distance is 300 dpi.
An image is formed using a toner that falls within the allowable limit of 40 μm when forming the image. Specifically, the flying toner 7 collides with the paper 6 and rebounds,
When an initial velocity in a direction parallel to the counter electrode surface (hereinafter, referred to as a horizontal direction) is obtained and the toner is moved in the horizontal direction, the moving distance of the toner until the velocity in the horizontal direction becomes zero is 40 μm.
An image is formed using a toner having a size and a shape capable of receiving an air resistance within the range.

Here, the air resistance is determined by the particle size and shape of the toner. In the illustrated apparatus, an image is formed using a spherical toner of 8 μm or less as a toner satisfying the above conditions. If the toner having such a particle size and shape is used, as is clear from the above-described simulation results, the landing speed when the toner 7 collides with the paper 6 due to the air resistance is suppressed, and the horizontal direction after the collision is reduced. When the toner is moved with the initial speed to the horizontal speed, the moving distance of the toner until the horizontal speed becomes zero is 40 μm.
Within. As a result, dust can be eliminated, and an image with good image quality can be obtained.

The toner need not always be a spherical toner. For example, even when the irregular toner is used, the same effect can be obtained as long as the toner has a size and a shape capable of receiving air resistance equal to or higher than that of the spherical toner of 8 μm or less.

[0037]

According to the first to sixth aspects of the present invention, there is an excellent effect that dust can be eliminated and a high quality image can be obtained. In addition, there is also an excellent effect that the apparatus configuration is simple and that recording can be performed directly on paper.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a main part of an image forming apparatus according to an embodiment.

FIG. 2 is an explanatory diagram showing a pattern of a control electrode in a toner control member of the image forming apparatus.

FIG. 3 is an explanatory diagram illustrating a relationship between a toner particle diameter and a rebound distance.

FIG. 4 is an explanatory diagram showing a relationship between a toner particle size, a flying speed, and a landing speed.

FIG. 5 is an enlarged schematic diagram of an image recording unit of a conventional image forming apparatus.

FIG. 6 is a schematic diagram illustrating a flying state of toner in the image recording unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 toner carrier 2 counter electrode member 3 toner control member 31 hole 32 control electrode 4 toner container 5 doctor blade 6 paper (recording medium) 7 toner 8 power supply 9 image power supply

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Shinichi Kuramoto 1-3-6 Nakamagome, Ota-ku Tokyo Torslanda

Claims (6)

[Claims] 1. A toner carrier for carrying a toner, a counter electrode facing the toner carrier, and a plurality of minute openings independent of each other or arranged in series between the toner carrier and the counter electrode. And a plurality of control electrode units for controlling the passage of toner through each minute opening, and a toner flight control member having a plurality of control electrode units. By applying a voltage according to an image signal to the control electrode unit of the toner flight control member, Selectively flying the toner on the toner carrier, passing the flying toner through the fine opening to the counter electrode side,
The toner used in an image forming apparatus that forms an image by adhering to the counter electrode or a recording member on the counter electrode, wherein the counter electrode and the control electrode unit are formed by the counter electrode and the toner carrier. The size and shape are such that the electrostatic force received by the toner due to the electric field formed in the flying space of the toner and the air resistance received by the air in the flying space during the flight of the toner are the same. Characterized toner. 2. A toner carrying member for carrying a toner, a counter electrode facing the toner carrying member, and a plurality of minute openings which are provided between the toner carrying member and the counter electrode and are independent of each other or a series of minute openings. And a plurality of control electrode units for controlling the passage of toner through each minute opening, and a toner flight control member having a plurality of control electrode units. By applying a voltage according to an image signal to the control electrode unit of the toner flight control member, Selectively flying the toner on the toner carrier, passing the flying toner through the fine opening to the counter electrode side,
In the toner used in an image forming apparatus that forms an image by adhering to the counter electrode or a recording member on the counter electrode, the toner bounces off by colliding with the counter electrode or the recording member and is parallel to the counter electrode surface. The size and the shape are such that, when an initial velocity in a certain direction is obtained and the toner is moved in the direction, the toner travel distance of the toner until the velocity in the direction becomes zero is within 40 μm. Characterized toner. 3. The spherical toner according to claim 1, wherein the particle diameter is 8 μm or less. 4. The toner according to claim 1, wherein the toner has a size and a shape such that the toner receives an air resistance equivalent to that of a spherical toner having a particle size of 8 μm or less. 5. A toner carrying member for carrying a toner, a counter electrode facing the toner carrying member, and a plurality of minute openings which are provided between the toner carrying member and the counter electrode and are independent from each other or a series of minute openings. And a plurality of control electrode units for controlling the passage of toner through each minute opening, and a toner flight control member having a plurality of control electrode units. By applying a voltage according to an image signal to the control electrode unit of the toner flight control member, Selectively flying the toner on the toner carrier, passing the flying toner through the fine opening to the counter electrode side,
An image forming apparatus for forming an image by adhering to the counter electrode or a recording member on the counter electrode, wherein the toner is generated by an electric field formed in a flying space of the toner by the counter electrode and the control electrode unit. An image forming apparatus using a toner having a size and a shape such that the electrostatic force received by the toner and the air resistance received by air in the flying space during the flight of the toner are the same. 6. A toner carrier for carrying a toner, a counter electrode facing the toner carrier, and a plurality of micro-openings provided between the toner carrier and the counter electrode, independent of each other or in series. And a plurality of control electrode units for controlling the passage of toner through each minute opening, and a toner flight control member having a plurality of control electrode units. By applying a voltage according to an image signal to the control electrode unit of the toner flight control member, Selectively flying the toner on the toner carrier, passing the flying toner through the fine opening to the counter electrode side,
In the image forming apparatus for forming an image by adhering to the counter electrode or the recording member on the counter electrode, the toner may collide with the counter electrode or the recording member and bounce off, and may be parallel to the counter electrode surface. A toner having a size and a shape such that when it is moved in the direction with the initial velocity in the direction, the moving distance of the toner until the horizontal velocity becomes zero is within 40 μm, which is an air resistance force; An image forming apparatus comprising: