JPH11301014A - Method and device for image forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise a speed of image forming by varying a deflection voltage for forming the next image unit by a method wherein controlling is executed such that a trajectory of an image forming particle is not influenced after it passes through a fine opening section even when a value of the deflection voltage applied to a deflection control electrode is varied. SOLUTION: A shield electrode 10 strongly shields a side of a developing roller 1 such that electric variation generated on the developing roller 1 is not transferred to a side of a counter electrode. As a result, a trajectory of toner flying between a flexible print circuit(FPC) 2 and a paper is not deflected even when values of a V active and a V non-act are varied in a range of +25-+225 [V]. Therefore, even when the aggregate of toner is allowed to pass through a portion between the FPC 2 and paper, it is possible to vary the values of the V active and V non-act in order to form the next dot. In this embodiment, it is possible to reduce a time period for forming one dot to be 0.4 mm/sec.

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, a printer, and the like, and an image forming method used in the apparatus, and more particularly, to an improvement in a dot deflection control method.

[0002]

2. Description of the Related Art Conventionally, as an image forming method, an image forming method called direct toning or toner projection has been known. This image forming method (hereinafter, referred to as a direct recording method) forms an image by the following process. That is, a voltage is applied to a flight control electrode provided around a hole or a slit, and an electric field is applied to charged image forming particles, for example, a toner layer or a toner cloud,
An aggregate such as a toner at a specific position corresponding to the hole or the slit is selectively caused to fly. Then, the aggregate is moved through the hole or the slit and adhered to a recording member such as paper, thereby forming a unit image by the aggregate directly on the surface of the recording member. The “unit image” indicates, for example, a dot or the like, and is a concept indicating an image of a minimum unit formed by an aggregate of image forming particles.

FIG. 1 is a schematic diagram showing a flying state of toner by a direct recording method. In the figure, 1 is a particle carrier, 2
Denotes a flexible printed circuit board (hereinafter, referred to as FPC) as an opening holding member made of polyimide resin or the like;
Denotes paper as a recording member, 4 denotes a counter electrode, and 5 denotes toner. The FPC 2 has a dot forming unit as a unit image forming unit including a hole 2c as a minute opening and a ring-shaped flight control electrode 2a arranged around the hole 2c and made of a material such as copper. Have multiple. In addition,
FIG. 1 shows one dot forming portion in an enlarged manner.

In the direct recording method, for example, a negatively charged toner is used, the particle carrier 1 is grounded, a high DC voltage of +900 [V] is applied to the opposing electrode 4, and +325 [V] is applied to the flight control electrode 2a. ] Is applied for 200 [μsec]. By this application, an electric field of 6 × 10 ⁶ [V / m] acts on the toner 5 on the particle carrier 1. As a result of this action, the Coulomb force applied to the toner 5 exceeds the sum of the adhesive force and the mirror image force acting between the toner 5 and the particle carrier 1, and the aggregate of the toner 5 is And fly through the hole of FPC2. The aggregate of the toner 5 that has passed through the hole is further attracted by the flying electric field formed by the voltage applied to the counter electrode 4 and continues to fly, and is transported on the counter electrode 4 in a predetermined direction by a conveying means (not shown). Attach to the paper 3 being conveyed and finish flying. Due to this attachment, dots formed of an aggregate of a plurality of toners 5 are recorded on the paper 3.

In recent years, as an application technique of this direct recording method, a deflection control electrode is provided in addition to the above-mentioned flight control electrode, and a deflection voltage is applied to the deflection control electrode to change the flight path of the toner that has been jetted. A dot deflection control method for deflection (hereinafter, referred to as a DDC method) has been proposed by Array Printers AB of Sweden.

FIGS. 2A, 2B, and 2C are schematic diagrams showing flying states of the toner 5 by the DDC method. In the figure, reference numerals 2b1 and 2b2 denote deflection control electrode pairs that are opposed to each other in the vicinity of the flight control electrode 2a. The flight control electrode 2a shown in black indicates a state where the above-mentioned Vblack is applied. Further, the deflection control electrode 2b1 or 2b2 shown in black is connected to a deflection voltage (Vact
ive) is applied to the flight control electrodes 2b1 or 2b2, which are shown in white, in a state where the deflection voltage is not applied (or a state where Vnonact which is a voltage value closer to zero than Vactive is applied). ) Are shown.

In the DDC method, in addition to the above-described Vblack, for example, a deflection voltage (Vactiv) of +325 [V] is used.
e) is applied to the deflection control electrode to deflect the flight path of the toner 5 in the main scanning direction, so that the toner 5 adheres to the paper 3 from the original adhering position to the left (a) in FIG.
Or shift to the right (c). Then, by shifting the position where the toner 5 is attached to the paper 3 in this manner, three dots corresponding to three pixels on the paper 3 can be formed from one dot forming unit. Specifically, while the paper 3 is moved by one pixel in the sub-scanning direction, the dot Ld (FIG. 2A) by the aggregate of the toner 5 whose flight path is deflected to the left in the main scanning direction in the drawing. Dot Nd by an aggregate of toner 5 that does not deflect the flight path (FIG. 2B)
And a dot Rd (FIG. 2C) formed by an aggregate of the toner 5 whose flight path is deflected rightward in the drawing in the main scanning direction.
Formed on paper 3.

As described above, in the DDC method, three dots can be formed by one dot forming section.
The structure of the PC can be simplified and the manufacturing cost can be reduced. For example, an FPC for 100 [dpi]
[Dpi] image can be formed.

[0009]

However, the DDC method has a problem that an image of good quality cannot be obtained unless the image forming speed is significantly reduced compared to the direct recording method. Then, the present inventors conducted intensive research and found the cause of this problem as follows. That is, DD
In the method C, three dots are formed by one dot forming section, so that in order to form an image at the same speed as the conventional direct recording method, the time required for forming one dot must be reduced to １ ／. Must. However, if the time for forming one dot is reduced to one third of that of the conventional direct recording method, before the second half of the aggregate of the toner 5 flying from the developing roller 1 to form the dot reaches the paper 3, The deflection voltage (Vactive or Vnonac) is used to form the next dot.
The value of t) must be changed. On the other hand, if the value of the deflection voltage is changed before reaching the paper 3 in the latter half, the flight path is deflected. Due to this deflection, the position of adhesion of the latter half to the paper 3 is shifted from the normal position, and this shift has disturbed the shape of the formed image.

Hereinafter, a test performed by the present inventors to clarify the cause will be described.

[Test 1] An image was formed using a conventional direct recording method, that is, a method in which one dot is formed by one dot forming section, in a state in which the following equations 1 to 4 are satisfied.

[Formula 1] Resolution = 300 [dpi]

[Formula 2] Moving speed of recording member = 50 [mm / sec]

[Formula 3] Vblack signal pulse application time = 0.20
0 [msec]

[Formula 4] Vblack signal pulse application interval = 1.69
Every 3 [msec] (Every time the paper 3 passes through one dot forming unit)

[0011]

[Test 2] 300 [dpi] FP for image formation by DDC method
C, ie, 100 [dpi] image forming F of the direct recording method
Using an FPC having the same number of dot forming units as the PC,
An image was formed by the DDC method in a state where the conditions of the above formulas 1 to 3 and the following formulas 5 to 7 were satisfied, and compared with the image formed by the test 1. As a result of this comparison, the quality of the image formed in Test 2 was inferior to the quality of the image formed in Test 1.

## EQU5 ## Vblack signal pulse application interval = 1.69
3 [msec] /3≒0.564 [msec] (1/3 in order to form three dots with one dot forming unit)

[Formula 6] Vblack signal pulse application time = 0.20
0 [msec]

[Formula 7] Signal pulse application time of Vactive and Vnonact = 0.564 [msec]

[0012]

[Test 3] While forming an image in the same manner as in Test 2, a high-speed camera (Kodak EKTAPRO HS Motion Anal
Using a yzer Model 4540), the flying state of the toner 5 was photographed at a magnification of 140 times as a video image of 27,000 frames per second. Then, when this video image was reproduced at a speed of 25 [frames / sec] and the flying state of the toner 5 was observed, for example, the aggregate of the toner 5 in the left-deflected electric field shown in FIG. If the electric field is switched to the non-deflected electric field shown in FIG. 2B to form the next dot while the latter half is flying, the flying path of the latter half is shifted toward the center, and the shape of the dot Ld is changed. It was confirmed that it would extend in the direction of the center. This extension disturbed the shape of the dot Ld.

[0013]

[Test 4] A dot formation simulation in the DDC method was performed by a simulation system using a dot formation simulation program. In addition, it has been proved by repeated comparison tests that the flying state of the toner observed in this simulation system is very similar to the flying state of the actual toner. FIG. 3 shows a configuration of the FPC and the like assumed in the simulation. In the figure, reference numeral 10 denotes a guard electrode, which shields the voltage applied to the counter electrode 4 from the developing roller 1 so as not to affect the flying of the toner 5 from the developing roller 1. In the drawing, L1 to L12 indicate dimensions [μm], respectively, where L1 = 140, L2 = 30, and L3 =
10, L4 = 50, L5 = 10, L6 = 10, L7 = 2
0, L8 = 30, L9 = 15, L10 = 420, L11
= 80. The formation of the dots Ld, Nd, and Rd was simulated on the assumption that the FPC having the illustrated configuration was used and the conditions of the following Expressions 8 to 18 were satisfied. In this simulation,
It is assumed that the values of Vactive and Vnonact to be applied are not changed (Equation 15).

Formula 8: Particle size of toner 5 = 7 [μm]

[Formula 9] Charge amount of toner 5 = -5 [μC / g]

[Equation 10] Flying toner amount = 150

[Formula 11] Applied voltage to counter electrode 4 = +1600 [V]

[Expression 12] Vactive and Vnonac when not deflected
t = + 125 [V] each

[Expression 13] Vactive at deflection = + 225 [V]

[Formula 14] Vnonact = + 25 [V] at the time of deflection

[Expression 15] Signal pulse application time of Vactive and Vnonact = 0.700 [msec] or more

[Expression 16] Vblack = + 325 [V]

[Formula 17] Vblack signal pulse application time = 0.2
00 [msec]

[Formula 18] Voltage applied to guard electrode 10 = −50 [V]

FIG. 4 is a schematic diagram showing a flying state of the aggregate of the toner 5 observed when the formation of the dot Nd (dot formed by non-deflection) is simulated in Test 4. In addition, in FIG.
Are not shown. (A) is Vblack, Va
(b) to (h) show the state at the moment when active and Vnonact are applied.
The state is shown sequentially for every 0 [msec].

[0015]

[Test 5] The formation of dots was simulated by the above-described simulation system when Vactive and Vnonact were changed. 5 and 6,
FIG. 7 shows each of the electrodes when simulating the formation of the dots Ld (dots formed by left deflection), the dots Nd (dots formed by non-deflection), and the dots Rd (dots formed by right deflection). 3 shows a timing chart of voltage application. As shown in FIG. 5, in the simulation in this test 5, in the formation of the dot Ld, the dot Nd was formed 0.400 [msec] after the start of voltage application to each electrode.
Is assumed to be switched to the non-deflection voltage application condition in order to form. Similarly, it is assumed that the voltage application condition is switched to right deflection in forming the dot Nd and left deflection in forming the dot Rd (FIGS. 6 and 7).

FIG. 8 is a schematic diagram showing the flying state of the aggregate of the toner 5 observed in the test 5 when the formation of the dot Nd was simulated. 4 and 8
When 0.400 [msec] from the start of voltage application to each electrode (from (a) to (e)), that is, until the values of Vactive and Vnonact are switched, the toner 5 in both electrodes is changed. Are exactly the same. However, Vactive and Vnona
When the value of ct is switched, between the FPC 2 and the paper 3, the flight path of the toner 5 in the latter half of the aggregate of the toner 5 that has flew is deflected, and the position at which the toner 5 adheres to the paper 3 is determined. It can be seen that the position deviates greatly from the normal position.
As a result, the dot shape is greatly disturbed. The same disturbance is caused by the dot Ld and the dot Rd
This was also observed when the formation of the dot was simulated. In particular, as shown in FIG. 9, in the formation of the dot Rd, the degree of disorder in the dot shape was large. FIG. 9A shows a case where the values of Vactive and Vnonact are not changed, and FIG. 9B shows a case where both values are changed.
FIG. 9 is a schematic diagram showing a flying state of toner 5 700 [μsec] from the start of voltage application to each electrode when a simulation is performed assuming the following.

In Test 4, the electric lines of force of the simulated electric field used for the simulation of the formation of the dots Ld, Nd, and Rd are shown in FIG.
0, FIG. 11 and FIG. For example, the toner 5 flying at the position of the point P along the line of electric force in FIG.
When the state of the electric field is changed as shown in FIG. 11 by changing the values of active and Vnonact, FIG.
Move to the right along the electric line of force going to the lower right as shown in. That is, the latter half of the aggregate of the toner 5 was deflected in its flight path by changing the state of the electric field formed between the FPC 2 and the counter electrode 4 while flying during this period. Conceivable.

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 method or an image forming apparatus that can form an image at high speed in an image forming method or an image forming apparatus using a DDC method. An object of the present invention is to provide an image forming apparatus.

[0019]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an opening holding member in which a plurality of minute openings are provided independently or in series with each other, and an opening holding member integrated with the opening holding member. Or, provided separately, a plurality of flight control electrodes for controlling the flight of fine image forming particles carried by the particle carrier from the particle carrier, and provided integrally or separately with the opening holding member, A plurality of deflection control electrodes for controlling the deflection of the flight path of the formed particles are disposed between the particle carrier and a counter electrode facing the particle carrier, and an arbitrary flight control is performed based on image information. A flying voltage is applied to the electrodes to selectively fly the image forming particles from the particle carrier, or a flying voltage is applied to an arbitrary flying control electrode and a deflection voltage is applied to the deflection control electrode to carry the particles. Selectively and deflect imaging particles from the body And the transferred image forming particles are transferred to the counter electrode side through an arbitrary minute opening, so that the transferred image forming particles are formed on the counter electrode or on a recording member on the counter electrode. And an image forming method for forming an image by adhering the fine particles, wherein even if the value of the deflection voltage applied to the deflection control electrode is changed, the flight path of the image forming particles after passing through the minute opening is changed. It is characterized in that it is controlled so as not to affect.

According to the first aspect of the present invention, even if the value of the deflection voltage applied to the deflection control electrode is changed, it does not affect the flight path of the image forming particles after passing through the minute opening. Control. With this control, the flying image forming particle aggregate does not affect the flight path even if the value of the deflection voltage is changed after passing through the minute opening. Therefore, the value of the deflection voltage can be changed even if the flying image forming particles do not reach the counter electrode or the recording member by passing through the minute opening. In other words, the deflection voltage is changed to form the next unit image without causing the entire aggregate of image forming particles that have been flown to form a unit image to reach the counter electrode or the recording member. be able to.

According to a second aspect of the present invention, there is provided the image forming method according to the first aspect, wherein the shield electrode is provided on a surface of the opening holding member on the side of the counter electrode or an inner layer near and parallel to the surface. The flying control electrode and the deflection control electrode are provided on the particle carrier side of the shield electrode, and the values of the voltage applied to the counter electrode, the flight control electrode, the deflection control electrode, and the shield electrode are respectively set. By setting a predetermined value or a predetermined range, control is performed so that the above-mentioned influence is not exerted.

In the second aspect of the present invention, by performing the above setting, even if the value of the deflection voltage applied to the deflection control electrode is changed within the predetermined range, the deflection voltage after passing through the minute opening is changed. Control is performed so as not to affect the flight path of the image forming particles. Specifically, in order to prevent an electrical change occurring on the particle carrier side from the shield electrode by the shielding by the shield member from being transmitted to the counter electrode side from the shield electrode, the above values are respectively set to appropriate predetermined values. Set to a value or a predetermined range. With such a setting, the change in the value of the deflection voltage is not transmitted to the space between the shield electrode and the counter electrode. For this reason,
Even before the entire aggregate of image forming particles that have been flown to form a unit image reaches the counter electrode or the recording member, if the entire unit has passed through the minute opening, the next unit image The deflection voltage can be varied to form

According to a third aspect of the invention, there is provided the image forming method according to the second aspect, wherein the voltage applied to the counter electrode is closer to zero and the voltage applied to the flight control electrode or the deflection control electrode is reduced. Also, a voltage close to the voltage applied to the counter electrode is applied to the shield electrode.

According to a third aspect of the present invention, the voltage applied to the shield electrode is set to a value closer to the voltage applied to the counter electrode than the voltage applied to the flight control electrode and the deflection control electrode. Thereby, adhesion and stagnation of the image forming particles in the unit image forming portion are greatly reduced. For example, when charging the image forming particles to a negative polarity,
If the value of the deflection voltage or the flying voltage is larger than the voltage value applied to the shield electrode, the flying image forming particles may be attracted to the flight control electrode or the deflection control electrode and may adhere and stay. is there. On the other hand, if the voltage value applied to the shield electrode is larger than the value of the deflection voltage or the value of the flying voltage, the image forming particles that are flying are attracted to the flight control electrode or the deflection control electrode. It is attracted to the shield electrode and flies toward the counter electrode. That is, adhesion and stagnation of the image forming particles in the unit image forming section are greatly reduced. By this reduction, the passing speed of the image forming particles in the unit image forming unit is increased, and the remaining of the image forming particles in the unit image forming unit is reduced.

According to a fourth aspect of the present invention, there is provided the image forming method according to the second aspect, wherein a voltage closer to zero than a voltage applied to the counter electrode or the deflection control electrode is applied to the shield electrode. It is characterized by the following. (Hereinafter, margin)

According to the fourth aspect of the present invention, the diffusion of the aggregate of the image forming particles which have flown to form the unit image is reduced, and the adhesion area of the aggregate on the counter electrode or the recording member is reduced. Reduce spread. The present inventors have intensively studied and, when a voltage closer to zero than the voltage applied to the counter electrode or the deflection control electrode is applied to the shield electrode, diffusion of the aggregate of the flying image forming particles is reduced. I found what I could do.

According to a fifth aspect of the present invention, there is provided the image forming method according to the fourth aspect, wherein even if an electrostatic repulsive force is generated between the image forming particles, diffusion of the aggregate of the image forming particles due to the repulsive force is prevented. The voltage difference between the voltage applied to the deflection control electrode and the voltage applied to the shield electrode is set to an appropriate value so as not to occur.

According to the fifth aspect of the present invention, even if an electrostatic repulsion is generated between the image forming particles, the aggregate of the image forming particles is not diffused by the repulsion. The present inventors have earnestly studied and by setting the potential difference to an appropriate value,
It has been found that diffusion of the aggregate of image forming particles due to the repulsion can be prevented.

According to a sixth aspect of the present invention, in the image forming method of the fifth aspect, the value of the potential difference is set to 100 [V] or more.

In the sixth aspect of the present invention, by setting the value of the potential difference to 100 [V] or more, even if an electrostatic repulsion is generated between the image forming particles, the image forming particles are not affected by the repulsion. Does not cause aggregation diffusion.

According to a seventh aspect of the present invention, in the image forming method of the fourth, fifth or sixth aspect, the value of the potential difference is set to 100 [V].
It is characterized by being set to 350 V or less.

In the invention according to claim 7, by setting the value of the potential difference between 100 [V] and 350 [V], the image on the surface of the deflection control electrode or the inner wall of the minute opening is formed. Adhesion and retention of formed particles are greatly reduced. The present inventors have made intensive studies and set the value of the potential difference to be not less than 100 [V] and not more than 350 [V].
It has been found that the adhesion and stagnation of image forming particles on the surface of the deflection control electrode and, for example, when the deflection control electrode is provided in the inner layer of the opening holding member, on the inner wall of the minute opening, can be significantly reduced. Was.

The invention according to claim 8 is based on claims 1, 2, 3,
4. The image forming method according to 4, 5, 6 or 7, wherein the aggregate of image forming particles is caused to fly to form a unit image, and immediately after passing through the minute opening for substantially the entire amount of the aggregate. In addition, a value of a voltage applied to the deflection control electrode is changed.

According to the eighth aspect of the present invention, the value of the deflection voltage can be changed at the earliest timing without affecting the flight path of the aggregate of image forming particles that have been flown to form a unit image. it can.

According to a ninth aspect of the present invention, there is provided an opening holding member having a plurality of minute openings formed independently or in series with each other, and formed integrally with or separately from the opening holding member and supported by the particle holding member. A plurality of flight control electrodes for controlling the flight of minute image forming particles from the particle carrier, and formed integrally with or separately from the opening holding member to control the deflection of the flight path of the image forming particles A plurality of deflection control electrodes are provided between the counter electrode facing the particle carrier and the particle carrier, and a flying voltage is applied to any of the flight control electrodes based on image information to apply the flying voltage to the particle carrier. To selectively fly the image forming particles from, or a flying voltage to any flying control electrode,
Applying a deflection voltage to the deflection control electrode to selectively and deflectably fly image forming particles from the particle carrier;
By moving the flying image forming particles to the counter electrode side through an arbitrary minute opening, the transferred image forming particles are attached to the counter electrode or to a recording member on the counter electrode. An image forming apparatus that forms an image, wherein the surface of the opening holding member on the side of the counter electrode, or
An inner layer near and parallel to the surface, a formed shield electrode, the flight control electrode and the deflection control electrode formed closer to the particle carrier than the shield electrode, the counter electrode, the flight control electrode A voltage of a predetermined value or a predetermined range is applied to each of the deflection control electrode and the shield electrode.

In the ninth aspect of the present invention, a predetermined value or a predetermined range of voltage is applied to each of the counter electrode, the flight control electrode, the deflection control electrode, and the shield electrode, so that the voltage is applied to the deflection control electrode. Changing the value of the deflection voltage within the predetermined range does not affect the flight path of the image forming particles after passing through the minute opening. Specifically, by the shield with the shield member, an electric change occurring on the particle carrier side with respect to the shield electrode is set to a value or a range that does not transmit to the counter electrode side with respect to the shield electrode. The applied voltage is applied to each electrode. For this reason, even before the entire aggregate of image forming particles that have flown to form a unit image reaches the counter electrode or the recording member, if the aggregate has passed through the minute opening, the next The deflection voltage can be changed in order to form the unit image.

According to a tenth aspect of the present invention, there is provided the image forming apparatus of the ninth aspect, wherein an image is formed by using the image forming method of the second, third, fourth, fifth, sixth, seventh or eighth aspect. It is assumed that.

According to the tenth aspect of the present invention,
An image is formed by the image forming method of 3, 4, 5, 6, 7 or 8.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of an image forming apparatus using a conventional direct recording method (hereinafter, referred to as a direct recording image forming apparatus) will be described. FIG. 13 is a perspective view showing a schematic configuration of a main part of the direct recording image forming apparatus of the present example.
The direct recording image forming apparatus includes a developing roller 1 as a particle carrier for supporting toner as image forming particles, a counter electrode member 4 as a counter electrode arranged to face the developing roller 1, and a plurality of dot forming members. An FPC 2 having a section is provided. The developing roller 1 is disposed inside a toner container 6 containing toner, and the surface of the developing roller 1 can carry toner by a known technique. In this example, the toner that is negatively charged by friction between the doctor blade 7 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 7. Thus, a toner layer is formed.

The FPC 2 is attached so as to close an opening formed in the lower wall of the toner container 6. As shown in FIG. 14, the FPC 2 has a plurality of toners as a plurality of minute openings so as to control the toner flying from the developing roller 1 to the opposing electrode member 4 between the developing roller 1 and the opposing electrode member 4. It has a through hole (hereinafter, referred to as “hole”) 2c and a ring-shaped electrode 2a formed around each hole as a flying electrode having an inner diameter of 0.160 [mm]. This hole 2c
And the pitch ph between the holes 2c in the direction orthogonal to the paper 3 transport direction (the axial direction of the developing roller 1) are set according to the resolution of the image recorded on the paper 3. In this example, a hole 2c having an inner diameter φ of 0.140 [mm] is formed on a substrate made of polyimide having a thickness of 0.075 [mm] so that an image having a resolution of about 300 [dpi] can be recorded. Are formed at an interval of 0.0845 [mm]. Eight rows (2c-1 to 2c-8) of the holes 2c are formed in a region where the width W of the paper 3 in the transport direction is about 2 [mm], and the total number of the holes 2c is 2,300. Each hole 2
around c are electrically independent from each other and have an inner diameter of 0.16
A ring-shaped electrode 2a of 0 [mm] is formed, and each ring-shaped electrode 2a is connected to a power supply circuit for applying a voltage corresponding to image information.

FIG. 15 is an enlarged schematic view of the image recording section of the present direct recording image forming apparatus. The developing roller 1 carrying the toner 5 is grounded, and the toner 5 carried on the developing roller 1 is directed between the developing roller 1 and the opposing electrode member 4. A high-voltage power supply 8 for generating a flying electric field for flying is connected. The high voltage power supply 8 applies a DC high voltage having a polarity opposite to the average charging polarity of the toner 5 to the counter electrode member 4.

An FPC 2 is provided between the developing roller 1 and the counter electrode member 4. A control voltage generated based on image information is applied between the developing roller 1 and each ring-shaped electrode 2 a of the FPC 2.
A power supply (hereinafter referred to as “image power supply”) 9 applied to a is connected. The image power supply 9 applies a pulse-like control voltage that is ON / OFF controlled based on image information to each ring-shaped electrode 2a. ON of this control voltage
The value of the voltage at the time (hereinafter, referred to as a flight control voltage or Vblack) is set to, for example, +325 [V], and the value of the voltage at the time of OFF (hereinafter, referred to as the non-flying control voltage or Vwhite) is set to, for example, -50 [V]. .

In the illustrated device, the distance Li between the ring-shaped electrode 2a of the FPC 2 and the counter electrode member 4 is 0.5
[Mm], distance L between ring-shaped electrode 2a and developing roller 1
k is 0.05 [mm], and the peripheral speed of the developing roller 1 is 300
[Mm / sec], and the transport speed of the paper 3 is 50 [mm / sec].
c].

FIG. 16 is a schematic diagram showing the flying state of the toner. For example, using a negatively charged toner, the developing roller 1 is grounded, a high DC voltage of +1200 [V] (hereinafter also referred to as Vbe) is applied to the counter electrode 4, and a +325 [V] voltage is applied to the flight control electrode 2a. Flight control voltage (Vbl
ack) is applied for 200 [μsec]. By this application, the toner 5 on the developing roller 1 is 6 × 10 ⁶ [V
/ M]. As a result of this action, the Coulomb force applied to the toner 5 is reduced by the toner 5 and the particle carrier 1.
Exceeds the sum of the adhesive force and the image force acting between
The aggregate of the toner 5 flies toward the counter electrode 4, and the FP
Pass through hole C2. The aggregate of the toner 5 that has passed through the hole is further attracted by the flying electric field formed by the voltage applied to the counter electrode 4 and continues to fly, and is transported on the counter electrode 4 in a predetermined direction by a conveying means (not shown). Paper 3 being transported
Attach to and end flight. Due to this attachment, dots formed of an aggregate of a plurality of toners 5 are recorded on the paper 3. In this apparatus, the ring-shaped electrode 2a corresponding to the non-image portion where the toner on the paper 3 does not adhere is -50
A non-flying control voltage (Vwhite) of [V] is applied.

As described above, an image can be formed on the paper 3 using the conventional direct recording image forming apparatus.

Next, an example of a conventional image forming apparatus for forming an image using the DDC method (hereinafter referred to as a DDC image forming apparatus) will be described. In the DDC image forming apparatus according to this example, in addition to the configuration of the direct recording image forming apparatus,
The PC 2 has a deflection control electrode pair 2b for deflecting the toner flying from the developing roller 1. FIG. 17 is an enlarged view of a hole 2c of the FPC 2 in the present DDC image forming apparatus.
(A) is a plan view and (b) is a cross-sectional view. This FPC2
Has deflection control electrodes 2b-1 and 2b-2, which are deflection control electrode pairs, on the counter electrode member 4 side of the ring electrode 2a in addition to the ring electrode 2a. Deflection control electrode 2b
-1 and the second deflection control electrode 2b-2 are each a banana-shaped, specifically, the ring-shaped flight control electrode 2a.
It has a shape corresponding to an angle smaller than 0 degrees, and is formed directly below the flight control electrode 2a with the above-described hole 2c interposed therebetween. In the figure, reference numeral 10 denotes a guard electrode, which shields the voltage applied to the counter electrode 4 from the developing roller 1 so as not to affect the flying of the toner 5 from the developing roller 1.

When the potential difference between the deflection control electrode 2b-1 and the deflection control electrode 2b-2 is changed in the apparatus having the above configuration, the electric field formed by the potential difference (hereinafter, referred to as deflection electric field) changes. 2, the landing point of the toner 5 changes. When the voltage applied to the deflection control electrode 2b-2 is 0
[V] Assuming a state in which the voltage applied to the deflection control electrode 2b-1 is kept constant and the simulation system performs the simulation, the voltage applied to the deflection control electrode 2b-1 and the paper 3 FIG. 1 shows the relationship with the shift amount of the toner landing point from the position corresponding to the above central portion.
FIG. As shown in the figure, the shift amount from the position corresponding to the central portion increases in direct proportion to the potential difference between the left and right deflection control electrodes. Also in the actual measurement, the positions of the dots changed according to the deflection potential difference.

As described above, according to the DDC method, the number of dot forming portions can be reduced. For example, 300
In the case of dividing into three by [dpi], the toner stream is divided into three from one hole in time and the toner stream is passed, and the leading toner stream is shifted to the left by about 84 [dpi] corresponding to about 84 [dpi].
[Μm], the next toner stream goes straight without applying a deflection voltage, and the third toner stream is deflected to the right by about 84 [μm] to form an image. In this way, the number of dot formation units for 100 [dpi] is 30.
An image of 0 [dpi] can be obtained.

Next, an embodiment of an image forming apparatus to which the present invention is applied will be described. FIG. 19 is an enlarged sectional view of the image forming unit of the image forming apparatus according to the present embodiment. As illustrated, the FPC 2 of the image forming apparatus includes a shield electrode 11 having a thickness L12 (20 [μm]) on the surface on the side of the counter electrode 4. Distance L13 between shield electrode 11 and paper 3
Is 400 [μm], and the arrangement distances other than L12 and L13 are the same as those of the image forming unit shown in FIG.

Each of the flight control electrode 2a, left deflection control electrode 2b-1, right deflection control electrode 2b-2, counter electrode 4, guard electrode 10 and shield electrode 11 of the FPC 2 is provided by an electric circuit (not shown). , A voltage of an individual value is applied. For example, in this embodiment,
A V325 of +325 [V] or a Vwhite of -50 [V] is applied to each of the flight control electrodes 2a and the left deflection control electrode 2b.
Vactive of +125 to +525 [V] or Vnon of +25 to +425 [V] is applied to −1 or the right deflection control electrode.
When act is applied to the opposite electrode 4 +1100 to +1600 [V]
, A guard voltage of −50 [V] is applied to the guard electrode 10, and +100 to +600 [V] is applied to the shield electrode 11.
Is applied. In addition, Vactive,
The values of Vnonact, the counter voltage, and the shield voltage are appropriately set by the operator within the aforementioned ranges. On the other hand, the control circuit (not shown) controls each electrode to apply a voltage of a value set by the operator from a power supply (not shown). Other than the above configuration, the DD
Since the configuration is the same as that of the C image forming apparatus, the description is omitted.

Next, a description will be given of a first embodiment in which the constructions of claims 1, 2, 3 and 8 are applied to the image forming apparatus of the above embodiment. The image forming apparatus of the first embodiment is set so that a shield voltage of +600 [V] is applied to the shield electrode 11. Each voltage value applied to each electrode other than the shield electrode 11 is the same as each voltage value in the DDC image forming apparatus of Test 5 described above. That is, +
A counter voltage of 1600 [V] is applied to the flight control electrode 2a by +3.
Vblack of 25 [V] is applied to the guard electrode 10 by -50.
A guard voltage of [V] is applied. Further, when forming the dot Ld (left deflection dot), the Vac of +225 [V] is applied to the left deflection control electrode 2b-1.
active is +125 [V] when forming the dot Nd (non-deflection dot), and +25 when forming the dot Rd (right deflection dot).
Vnonact of [V] is applied. For the right deflection control electrode 2b-2, when forming the dot Ld (left deflection dot), Vno of +25 [V] is used.
Nact is set to Vactive of +125 [V] when the dot Nd (non-deflection dot) is formed, and +225 to form the dot Rd (right deflection dot).
[V] Vactive is applied. The timing of applying a voltage to each electrode in the image forming apparatus of the first embodiment is the same as that of the image forming apparatus of Test 5, and is as shown in FIG. 5, FIG. 6, and FIG. That is,
0.400 [msec] after starting voltage application to each electrode
c] Then, the values of Vactive and Vnonact are changed to form the next dot. However, as described above, the image forming apparatus of the first embodiment includes the shield electrode 11 in addition to the electrodes shown in these drawings, and the shield electrode 11 has a shield voltage of +600 [V]. Are continuously applied at the same timing as that of the guard electrode 10.

By setting each voltage value as described above, the shield voltage (+600 [V]) is always set to the opposite voltage (+16 [V]).
00 [V]), and Vblack (+
325 [V]) and deflection voltage (+25, +125 or +2)
25 [V]), which is closer to the counter voltage.

FIG. 20 schematically shows the flying state of the toner 5 when the formation of the dot Nd (non-deflection dot) is simulated by the simulation system assuming the use of the image forming apparatus of the first embodiment. This is shown in FIG. Comparing FIG. 8 with FIG. 20, in the image forming apparatus of the first embodiment, after 0.400 [msec] from the start of voltage application to each electrode ((e) in each drawing), the next Vactive and Vnona to form dot Rd
It can be seen that even if the value of ct is switched, the flight path of the aggregate of the toner 5 between the FPC 2 and the paper 3 is not deflected. Similarly, even when the formation of the dots Ld (left deflection dots) and the dots Rd (right deflection dots) is simulated, the flight path of the aggregate of the toner 5 between the FPC 2 and the paper 3 is not deflected. confirmed. In particular, as shown in FIG. 21, it can be seen from the comparison with FIG. 9 that in the formation of the dot Rd in which the degree of the dot shape disorder was large in Test 5, a significant improvement in the dot shape was observed.

In the first embodiment, the dots Ld,
The electric lines of force of the simulated electric field used for the simulation of the formation of the dots Nd and the dots Rd are shown in FIG.
2, shown in FIG. 23 and FIG. Comparing these three figures, the directions of the electric lines of force in the hole 2c differ greatly, but surprisingly, the directions of the lines of electric force between the FPC 2 and the paper 3 (and thus the counter electrode 4) are exactly the same. It turns out that. That is, the shield electrode 10 strongly shields an electrical change occurring on the developing roller 1 side from the shield electrode 10 so as not to be transmitted from the shield electrode 10 to the counter electrode 4 side. For this reason, the flight path of the toner 5 flying between the FPC 2 and the paper 3 is Vactive and Vnon.
Even if the value of act is changed within the range of +25 to +225 [V], it is not deflected. Therefore, as long as the aggregate of the toner 5 is allowed to pass through the hole 2c, even if the aggregate is flying between the FPC 2 and the paper 3, V is set to form the next dot.
The values of active and Vnonact can be changed. In the first embodiment, the one-dot forming time required for the conventional DDC image forming apparatus of 0.800 [mm / sec] or more can be reduced to 0.4 [mm / sec]. That is, the image forming speed can be doubled or more than the conventional one.

As described above, according to the image forming apparatus of the first embodiment, the FPC 2 and the paper 3 only need to be passed through the hole 2c through substantially the entire aggregate of the toner 5 that has been flying to form dots.
Even if the aggregate is flying during the period, the values of Vactive and Vnonact can be changed to form the next dot, so that the speed of image formation can be increased.

Next, a first comparative example in which the configuration of claim 3 is not applied to the image forming apparatus of the above embodiment will be described.
The shield electrode 11 of the image forming apparatus of the first comparative example includes:
A shield electrode of +100 [V] is applied. That is, a shield voltage having a value closer to zero than the flying voltage (+325 [V]) or the deflection voltage Vactive (+125 or +225) is applied to the shield electrode 11.

Other than the above configuration, the image forming apparatus of the first embodiment is the same as the first embodiment, and the description is omitted.

Assuming that the image forming apparatus of the first comparative example is used, the flight state of the toner 5 when the formation of the dots Nd (non-deflection dots) is simulated by the simulation system is a schematic diagram. 25. 20 and FIG. 25, a large amount of toner 5 adheres to the deflection control electrode 2b in the image forming apparatus of this embodiment.
It can be seen that it stayed and did not pass through the hole 2c. That is, in the image forming apparatus of the present comparative example, as a result of applying a shield voltage of a small value (a value close to zero) to the shield electrode 11, the toner 5 charged negatively and caused to fly is caused to fly by the flight control electrode 2a and the deflection control electrode 2b. And attracts and stays. When such adhesion / retention occurs, not only does the image formation speed decrease, but also the flight control electrodes 2a,
This causes clogging of the dot forming portion composed of the deflection control electrode 2b and the hole 2c, and lowers the density of the formed image.

On the other hand, if the voltage value applied to the shield electrode 11 is larger than the values of Vactive and Vblack (as opposed to the value of the opposing voltage), as in the first embodiment, the toner 5 that has been fly by being negatively charged is used. If they are close to each other, even if they are attracted to the flight control electrode 2a or the deflection control electrode 2b, they are further attracted to the shield electrode 11 and thus fly toward the counter electrode 4.

That is, according to the image forming apparatus of the first embodiment, since the adhesion and stagnation of the toner 5 in the dot forming section is reduced, the speed of image formation is further increased, and clogging of the dot forming section, The decrease in the density of the formed image can be reduced. (Hereinafter, margin)

Next, claim 4 implemented by the present inventors,
Test 6 according to configurations 5, 6, and 7 will be described. The formation of the dots Nd (non-deflection dots) was simulated by the simulation system assuming the application of each of the five voltage values as shown in Table 1 below.
The timing of applying a voltage to each electrode in this simulation is the same as in Test 5 and the first embodiment. The units of the numerical values shown in Table 1 are all [V]. "Left 2b-1" is the left deflection control electrode 2b-1.
And "right 2b-2" is the right deflection control electrode 2b-2. Numerical values shown in parentheses indicate potential differences from the shield voltage.

[Table 1]

As shown in Table 1, in Test 6, the potential difference between the shield voltage and the counter voltage was 1000
Assuming the condition set to [V], the value of the shield voltage in each simulation was changed by +100 [V].

In each of the simulations of the dot Nd, +500, +400, +300, +
FIGS. 26, 27, 28, 29 and 30 are schematic diagrams showing flying states of the toner 5 assuming the application of a shield voltage of 200 and +100 [V], respectively. These 5
From the comparison between the two figures and FIG. 20, the following five items were found. 1. As the potential difference between the deflection voltage (Vactive or Vnonact) and the shield voltage is set smaller, the flying path of the aggregate of toner 5 is diffused laterally to disturb the dot shape, but as the potential difference is set larger, the flying path becomes larger. To form dots of regular shape. 2. If the potential difference between the deflection voltage and the shield voltage is set to 25 [V], the dot shape will be disturbed by the above diffusion, but if it is set to 125 [V], a dot having a satisfactory shape can be obtained. 3. The smaller the potential difference between the deflection voltage and the shield voltage is set, the smaller the adhesion / retention of the toner 5 to the deflection control electrode is, while the larger the potential difference is, the more the adhesion / retention is promoted. 4. The potential difference between the deflection voltage and the shield voltage is 425 [V]
If the setting is made, problems such as a decrease in the passing speed of the toner 5 through the hole 2c, a decrease in the density of formed dots, and a clogging of the hole 2c occur due to the adhesion / retention.
When set to [V], the problem does not occur. 5. The potential difference between the deflection voltage and the shield voltage is 225 [V]
, The toner 5 adheres to the deflection control electrode 2b.
Stagnation can be reduced, and the aggregate of the toner 5 can be made to fly without being diffused laterally as compared with the image forming apparatus of the first embodiment (from a comparison between FIG. 20 and FIG. 28).

FIG. 31 shows the electric field lines of the simulated electric field in the simulation in which the potential difference between the deflection voltage and the shield voltage was set to 225 [V] in Test 6. As shown in the figure, the lines of electric force extend from the exit of the hole 2c to the hole 2c.
Are narrowed down toward the central axis. On the other hand, FIG.
As shown in (1), the lines of electric force at the time of forming the dots Nd in the first embodiment extend laterally from the exit of the hole 2c. For this reason, when the potential difference between the deflection voltage and the shield voltage is set to 225 [V] in Test 6, the aggregate of the toner 5 flies without being diffused more laterally than the image forming apparatus of the first embodiment. I was letting it. In FIG. 30, slight diffusion is observed in the flight path of the aggregate of the toner 5, and it is considered that the electrostatic repulsion between the negatively charged toners 5 is involved in this diffusion. That is, when the potential difference between the deflection voltage and the shield voltage is set too small, it is considered that the flying path of the flying toner slightly diffuses due to the electrostatic repulsion between the toners 5.

Next, a description will be given of a second embodiment in which the configurations of claims 4, 5, 6 and 7 are applied to the image forming apparatus of the above embodiment. Voltage values shown in the following Table 2 are applied to each electrode of the image forming apparatus of the second embodiment. In Table 2, the numerical values shown in parentheses, "Left 2b-1" and "Right 2b-2" have the same concept as in Table 1.

[Table 2]

As shown in Table 2, the deflection voltage (Vactive or Vno) in the image forming apparatus of the second embodiment is shown.
nact) and the shield voltage are 125 to 32
It is set in the range of 5 [V]. The above Test 6 has revealed that this range is a range in which the adhesion of the toner 5 to the deflection control electrode 2b is reduced and the flying path of the aggregate of the flying toner 5 is not diffused. Other than the above configuration, the configuration is the same as that of the image forming apparatus according to the first embodiment, and thus the description is omitted.

With the above arrangement, in the image forming apparatus of the second embodiment, the diffusion of the aggregate of the toner 5 flying to form the dots is reduced, and the adhesion area of the aggregate on the paper 3 is reduced. Reduce the spread of Therefore, even if an electrostatic repulsion is generated between the negatively charged toners 5, diffusion of the aggregate of the toner 5 due to the repulsion is prevented. Further, the adhesion and stagnation of the toner 5 on the surface of the deflection control electrode 2b and the inner wall of the hole 2c are greatly reduced.

As described above, according to the image forming apparatus of the second embodiment, the diffusion of the adhesion area on the paper 3 of the aggregate of the toner 5 flying to form the dots is reduced. Disturbance can be reduced. Further, even if an electrostatic repulsion is generated between the negatively charged toners 5, the aggregate of the toner 5 is not diffused by the repulsion, so that the disturbance of the shape of the dots to be formed can be further reduced. Further, since the adhesion and stagnation of the toner 5 on the surface of the deflection control electrode 2b and the inner wall of the hole 2c is greatly reduced,
The image forming speed can be further increased, and clogging of the dot forming portion and a decrease in the density of the formed image can be reduced.

In the embodiments and examples of the present specification, the flying control electrode 2a is provided on the developing roller 1 side of the FPC 2.
And the image forming apparatus in which the deflection control electrode 2b is provided on the counter electrode 4 side. However, as shown in FIG. 2, the deflection control electrode is provided on the same plane as the flight control electrode 2a and outside the flight control electrode 2a. 2b may be provided. Further, the structure of each electrode is not limited to a ring shape or a banana shape, and various modifications are possible. Further, the present invention is not limited to the powder image forming method and the powder image forming apparatus using the charged toner particles, but may use an ion modulation for controlling ions, a load-deflection type ink jet for deflecting a charged ink droplet by an electric field, or the like. The present invention is applicable to an image forming method or an image forming apparatus.

Also, a recording material such as paper is used as a recording member to form an image by adhering toner onto the recording material, but the recording member may be an insulating material such as paper, or the like.
An electrode layer (for example, an aluminum foil layer) functioning as the counter electrode may be formed on the back surface of the paper. Further, the counter electrode may be made of a rotating endless belt-shaped metal thin film, and may be configured to transfer the attached toner to a recording member such as paper.

Further, although the description is omitted in the above Test 6, the minimum value of the above potential difference (the potential difference between the deflection voltage and the shield voltage) that can form a dot having a satisfactory shape is determined by the detailed tests of the present inventors. It was about 100 [V]. In addition, the maximum value of the potential difference capable of reducing the adhesion and stagnation of the toner 5 on the deflection control electrode 2b was about 350 [V].

[0072]

According to the present invention, claims 1, 2, 3, 4, 5, 6, 7,
According to the invention of 8, 9 or 10, the next unit image can be formed without making the entire aggregate of the image forming particles that have been flown to form the unit image reach the counter electrode or the recording member. Since the deflection voltage can be changed for forming, there is an excellent effect that the speed of image formation can be increased.

In particular, according to the third aspect of the present invention, since the passing speed of the image forming particles in the unit image forming portion is increased, there is an excellent effect that the image forming speed can be further increased. Further, since the residual image forming particles in the unit image forming section are reduced, it is possible to reduce clogging of the minute opening, the deflection control electrode, or the deflection control electrode, and reduction in density of a formed image. Has an excellent effect.

According to the fourth aspect of the present invention, the diffusion of the adhesion area of the aggregate of the image forming particles flying to form the unit image on the counter electrode or the recording member is reduced. There is an excellent effect that the disturbance of the shape of the unit image can be reduced.

According to the fifth aspect of the present invention, even when an electrostatic repulsion is generated between the image forming particles, the aggregate of the image forming particles is not diffused by the repulsion, so that the unit image to be formed is formed. There is an excellent effect that the disturbance of the shape of can be further reduced.

According to the invention of claim 6, even if an electrostatic repulsion is generated between the image forming particles, the aggregate of the image forming particles is not diffused by the repulsion, so that the unit image to be formed is formed. There is an excellent effect that the disorder of the shape can be prevented.

According to the seventh aspect of the present invention, the adhesion and stagnation of image forming particles on the surface of the deflection control electrode or the inner wall of the minute opening is greatly reduced. The effect of (1) is an excellent effect that the speed of image formation can be further increased, and clogging of the minute openings or the deflection control electrodes and reduction in the density of the formed image can be reduced.

According to the eighth aspect of the present invention, the value of the deflection voltage is changed at the earliest timing without affecting the flight path of the aggregate of image forming particles which have been flown to form a unit image. Therefore, there is an excellent effect that the image forming speed can be maximized within a range where the influence is not affected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a flying state of toner by a direct recording method.

FIG. 2A is a schematic diagram illustrating a flying state of toner when dots Ld are formed by a DDC method. FIG. 4B is a schematic diagram illustrating a flying state of the toner when forming the dots Nd by the DDC method. FIG. 3C is a schematic diagram illustrating a flying state of the toner when the dots Rd are formed by the DDC method.

FIG. 3 is a configuration diagram of an image forming unit assumed in a simulation of Test 4;

FIGS. 4A to 4H are schematic diagrams showing flying states of toner 5 in the same simulation assuming formation of dots Nd.

FIG. 5 shows a dot Ld in the simulation of Test 5;
4 is a timing chart of voltage application during formation.

FIG. 6 is a timing chart of voltage application when forming a dot Nd in the simulation.

FIG. 7 is a timing chart of voltage application when forming a dot Rd in the simulation.

FIGS. 8A to 8H are schematic diagrams showing flying states of toner 5 in the same simulation assuming formation of dots Nd.

FIG. 9A is a schematic diagram illustrating a flying state of toner 5 in a simulation of Test 4 assuming formation of a dot Rd. (B) is a schematic diagram of a flying state of the toner 5 in a simulation of a test 5 assuming formation of a dot Rd.

FIG. 10 is a schematic diagram of a simulated electric field used in a simulation of Test 4 assuming formation of dots Ld.

FIG. 11 is a schematic diagram of a simulated electric field used in the simulation assuming formation of dots Nd.

FIG. 12 is a schematic diagram of a simulated electric field used in the simulation assuming formation of dots Rd.

FIG. 13 is a perspective view showing a schematic configuration of a conventional direct recording image forming apparatus.

FIG. 14 is an enlarged plan view showing an FPC of the direct recording image forming apparatus.

FIG. 15 is an enlarged schematic diagram of an image recording unit of the direct recording image forming apparatus.

FIG. 16 is a schematic diagram illustrating a flying state of toner in the direct recording image forming apparatus.

FIG. 17A illustrates an FPC in a DDC image forming apparatus.
2 is an enlarged plan view of a second hole 2c. FIG. (B) is an enlarged sectional view of the same hole 2.

FIG. 18 shows the voltage applied to the deflection control electrode 2b-1 and the paper 3
FIG. 6 is a diagram illustrating a relationship between the upper part and a shift amount of a toner landing point.

FIG. 19 is an enlarged cross-sectional view of an image forming unit of the image forming apparatus according to the embodiment.

FIGS. 20A to 20H are schematic diagrams illustrating flying states of toner 5 in a simulation of the first embodiment assuming formation of dots Nd.

FIG. 21 is a schematic diagram of a flying state of toner 5 in the same simulation assuming formation of a dot Rd.

FIG. 22 is a schematic diagram of a simulated electric field used in the simulation assuming formation of dots Ld.

FIG. 23 is a schematic diagram of a simulated electric field used in the simulation assuming formation of dots Nd.

FIG. 24 is a schematic view of a simulated electric field used in the simulation assuming formation of dots Rd.

FIGS. 25A to 25H are schematic diagrams illustrating flying states of toner 5 in a simulation of a first comparative example assuming formation of dots Nd.

FIGS. 26A to 26H are each +500.
FIG. 11 is a schematic diagram of a flying state of toner 5 in a simulation of a second comparative example assuming formation of a dot Nd by application of a shield voltage [V].

FIGS. 27A to 27H are schematic diagrams of the flying state of the toner 5 on the assumption that a shield voltage of +400 [V] is applied in the same simulation.

FIGS. 28A to 28H are schematic diagrams of the flying state of the toner 5 when it is assumed that a shield voltage of +300 [V] is applied in the same simulation.

FIGS. 29A to 29H are schematic diagrams of the flying state of the toner 5 on the assumption that a shield voltage of +200 [V] is applied in the same simulation.

FIGS. 30A to 30H are schematic diagrams of the flying state of the toner 5 when it is assumed that a shield voltage of +100 [V] is applied in the same simulation.

FIG. 31 shows that the potential difference between the deflection voltage and the shield voltage is 225
The schematic diagram of the simulation electric field in the simulation of the test 6 set to [V].

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing roller 2 FPC 2a Ring electrode 2b Deflection control electrode 2c Toner passage hole 3 Paper 4 Counter electrode member 5 Toner 6 Toner container 7 Doctor blade 8 High voltage power supply 9 Image power supply 10 Guard electrode 11 Shield electrode

 ────────────────────────────────────────────────── ─── Continued on the front page (71) Applicant 597063831 Owneds Brygga 13 421 57 Vestro Fround a Sweden (72) Inventor Masafumi Kamonaga 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Invention Person Takahiko Tokumasu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Daniel Nilsson Birgel Jarlsgatan 20 i-414 69 Gothenburg Sweden

Claims (10)

[Claims] An opening holding member provided with a plurality of minute openings independently or in series with each other, and a fine image forming particle provided integrally with or separately from the opening holding member and carried by a particle carrier. A plurality of flight control electrodes for controlling the flight from the particle carrier, and a plurality of deflection control electrodes provided integrally with or separately from the opening holding member to control the deflection of the flight path of the image forming particles. It is disposed between the carrier and a counter electrode opposed to the particle carrier, and based on image information, a flying voltage is applied to an arbitrary flight control electrode to selectively form image-forming particles from the particle carrier. Or the flying voltage is applied to an arbitrary flying control electrode, and the deflection voltage is applied to the deflection control electrode to selectively and deflectably fly the image forming particles from the particle carrier. Pass the image forming particles through any minute openings Transferring the image forming particles onto the counter electrode or a recording member on the counter electrode to form an image by transferring the image forming particles onto the counter electrode or the recording member on the counter electrode. An image forming method, characterized in that even if the value of the deflection voltage applied to the control electrode is changed, control is performed so as not to affect the flight path of the image forming particles after passing through the minute opening. 2. The image forming method according to claim 1, wherein a shield electrode is provided on a surface of the opening holding member facing the counter electrode or an inner layer near and parallel to the surface. The flight control electrode and the deflection control electrode are provided on the particle carrier side, and the values of the voltage applied to the counter electrode, the flight control electrode, the deflection control electrode, and the shield electrode are set to predetermined values or predetermined ranges, respectively. The image forming method is characterized in that control is performed so that the above-mentioned influence is not exerted by setting the image forming apparatus to (1). 3. The image forming method according to claim 2, wherein the voltage applied to the opposing electrode is closer to zero than the voltage applied to the opposing electrode, and the voltage applied to the opposing electrode is more than the voltage applied to the flight control electrode or the deflection control electrode. An image forming method, wherein a voltage having a value close to the applied voltage is applied to the shield electrode. 4. An image forming method according to claim 2, wherein a voltage having a value closer to zero than a voltage applied to said counter electrode or said deflection control electrode is applied to said shield electrode. Forming method. 5. The image forming method according to claim 4, wherein even if an electrostatic repulsion is generated between the image forming particles, the aggregate of the image forming particles is not diffused by the repulsion. An image forming method, wherein a potential difference between a voltage applied to the deflection control electrode and a voltage applied to the shield electrode is set to an appropriate value. 6. The image forming method according to claim 5, wherein the value of the potential difference is set to 100 [V] or more. 7. The image forming method according to claim 4, wherein the value of the potential difference is set to be not less than 100 [V] and not more than 350 [V]. 8. An image forming method according to claim 1, wherein the aggregate of image forming particles is caused to fly to form a unit image, and the aggregate is formed. An image forming method, wherein a value of a voltage applied to the deflection control electrode is changed immediately after passing the entire amount through the minute opening. 9. An opening holding member having a plurality of minute openings formed independently or in series with each other, and a minute image formed integrally with or separately from the opening holding member and carried by the particle carrier. A plurality of flight control electrodes for controlling the flight of formed particles from the particle carrier; and a plurality of deflection control electrodes formed integrally with or separately from the opening holding member to control the deflection of the flight path of the image forming particles. Is provided between the counter electrode facing the particle carrier and the particle carrier, and based on image information, a flying voltage is applied to an arbitrary flight control electrode to form image forming particles from the particle carrier. Selectively fly, or
A flying voltage is applied to an arbitrary flight control electrode, and a deflection voltage is applied to the deflection control electrode to cause the image forming particles to fly selectively and deflectively from the particle carrier. An image forming apparatus for forming an image by causing the transferred image forming particles to adhere to the counter electrode or to a recording member on the counter electrode by transferring the image forming particles to the counter electrode side through the minute opening. A surface on the counter electrode side or an inner layer near and parallel to the surface of the opening holding member, a shield electrode formed, and the flight control electrode formed on the particle carrier side of the shield electrode. And the deflection control electrode, wherein a voltage of a predetermined value or a predetermined range is applied to the counter electrode, the flight control electrode, the deflection control electrode, and the shield electrode, respectively. 10. An image forming apparatus according to claim 9, wherein an image is formed by using the image forming method according to claim 2, 3, 4, 5, 6, 7, or 8. .