JPH10264433A - Image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate whether or not a developer is to pass each group of control electrodes by detecting at a detecting part whether or not gates of the control electrodes adjacent to each other are in a state to allow the developer to pass. SOLUTION: A detecting part where an arrangement pattern of a control electrode 20 is stored beforehand compares the arrangement pattern with image data after the arrangement is converted. Whether or not each gate lets a toner 12 pass is judged from the result, and a gate having an adjacent gate where the toner 12 is to pass is detected. If the gate where the toner 12 is to pass is present adjacent to one gate, the information is sent to a CPU, whereby a voltage to be impressed to the control electrode 20 is varied in accordance with the information, or a voltage to be impressed to a toner carrier body 10 is varied. The detecting part can correctly detect a position of the gate of the control electrode 20 which is required to be corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a printing section of a digital copying machine and a facsimile apparatus, a digital printer, a plotter, and the like, and forms an image on a recording medium by flying a developer. It is about.

[0002]

2. Description of the Related Art As a method for forming a visible image on a recording material such as paper from an electrical signal output from a computer, word processor, facsimile, or the like, an ink jet method using ink, a thermal transfer method for melting and transferring ink, a sublimation method, and the like. There is known an image forming method using an image forming method, an electrophotographic method, or the like.

In recent years, with the increase in speed, image quality, and cost reduction, the use of the ink jet system, which is a relatively simple device configuration in which a print head is integrated in a non-impact system, has been increasing. Since the ink that is liquid is used, bleeding occurs on paper and a good image cannot be obtained.In addition, when performing overprinting in color printing, it is not possible to expect a mixed color due to ink mixing. Therefore, when high quality is required, printing using an electrophotographic toner is employed.

[0004] Printing with toner does not cause bleeding, and a visually excellent image with a dark color tone is obtained. In addition, when a plurality of colors are mixed in colorization, a good mixed color is obtained during the fixing process.

[0005] In view of the above, a direct printing method using a toner, which combines a simple process of an ink jet method and an image using a toner, has been proposed.

For example, Japanese Patent Application Laid-Open No. Hei 6-143664 has a plurality of openings and a plurality of control electrodes provided for each of the openings and to which a toner passing voltage or a toner shielding voltage is selectively applied. In addition, a method of forming an image by providing an aperture electrode for controlling passage or blocking of toner with respect to the opening has been proposed.

[0007]

However, according to the technique disclosed in Japanese Patent Application Laid-Open No. HEI 6-143664, a toner passing voltage is applied to a control electrode corresponding to an opening through which toner is to pass, and an adjacent opening is used. And a control means for controlling the voltage waveform to be different between the case where the toner passing voltage is applied to the control electrode corresponding to and the case where the toner shielding voltage is applied. The details of the discriminating circuit for discriminating whether the control electrode corresponding to the opening to be applied is the case where the toner passing voltage is applied or the case where the toner shielding voltage is applied are not described in detail. It is ambiguous.

Further, merely changing the voltage waveform of the toner passing voltage applied to the control electrode merely increases or decreases the amount of flying toner, and the dot when the flying toner lands on the recording medium has a small amount of flying toner. The area is significantly different between a large number of dots and a small number of dots, and the dots are non-uniform. As a result, an image on a recording medium corresponding to a dot having a small dot area causes image quality defects such as white spots.

[0009]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a supply unit having a carrier for carrying a developer of at least one color; a counter electrode disposed to face the carrier; An insulating substrate disposed between the carrier and the counter electrode, a plurality of gates provided on the insulating substrate to serve as a passage portion of the developer, and at least a plurality of gates provided around the plurality of gates A control electrode having at least one electrode group, the gate and a shield electrode formed so as to electrically expose the electrode group, and a predetermined potential corresponding to at least image data on each of the control electrodes Control circuit means for applying at least a control circuit means, by controlling the passage of the developer through the gate by applying a predetermined potential to the corresponding electrode of the electrode group by the control means, The control electrode In an image forming apparatus for forming an image on the surface of a recording medium conveyed between the opposed electrodes, an image processing unit for binarizing image data to be output, and the binarized data processed by the image processing unit, Based on the arrangement pattern of the control electrodes, a detection unit that detects an electrode to be allowed to pass the developer is provided, and among the gates of the control electrode, gates adjacent to each other are each of the developer. An image forming apparatus, wherein the detection unit detects whether or not the passage is to be permitted, and corrects the flight control of the developer based on the detected information.

The image forming apparatus according to claim 2, wherein the shape of the equipotential surface acting on the control electrode is corrected based on the information detected by the detection unit. Device.

According to a third aspect of the present invention, in the electrode group of the control electrodes, an electrode to be allowed to pass the developer and an electrode adjacent to the electrode allow the developer to pass. 2. The image forming apparatus according to claim 1, wherein when the electrode is a power electrode, the flying control of the developer is corrected for any one of the two electrodes.

The image forming apparatus according to claim 4, wherein an electric field acting between the carrier and the control electrode is corrected based on the information detected by the detection unit. It is a forming device.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the voltage applied to the control electrode is corrected based on information detected by the detection unit. .

According to a sixth aspect of the present invention, in the image forming apparatus according to the first aspect, a voltage applied to the carrier is corrected based on information detected by the detection unit. .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.

In the following description, an image forming apparatus having a configuration corresponding to a negatively charged toner will be described in detail. However, when a positively charged toner is used, the applied voltage is appropriately adjusted accordingly. What is necessary is just to set the polarity.

FIG. 1 shows a cross section of a printer equipped with an image forming apparatus according to the present embodiment. The outline of each element will be described with reference to FIG.

As shown in FIG. 2, the printing section 102 visualizes an image corresponding to an image signal from the host computer on a sheet 8 as a recording medium using a toner 12 as a developer. It is.

That is, the present image forming apparatus forms an image directly on paper by controlling the flight of the toner 12 based on the image signal.

On the side where paper enters the image forming section 3,
A paper feed unit 101 is provided. The paper supply unit 101 includes a paper cassette 7 that stores paper 8 as a recording medium, a pickup roller 5 that sends out the paper 8 from the paper cassette 7, a paper feed guide (not shown) that guides the supplied paper 8, and a pair of resists. Consists of rollers.

The paper supply unit 101 has a paper supply sensor (not shown) for detecting that the paper 8 has been supplied. The pickup roller 5 is driven by a driving device (not shown).

A fixing section 103 for fixing the toner image formed on the sheet 8 in the image forming section 3 to the sheet 8 by heating and pressurizing the sheet 8 on the sheet output side of the sheet 8 from the image forming section 3. Is provided. The fixing unit 103 includes a heater 40, a heating roller 41, a pressure roller 42, a temperature sensor 4
3 and a temperature control circuit 54. The heating roller 41 is
For example, it is made of an aluminum tube having a thickness of 2 mm.

The heater 40 is composed of, for example, a halogen lamp, and is built in the heating roller 41. The pressure roller 42 is made of, for example, a silicone resin.

The heating roller 41 and the pressure roller 42 provided to face each other have a weight of, for example, 2 kg at both ends of each shaft by a spring or the like (not shown) so that the paper 8 can be pressed. Load is applied.

The temperature sensor 43 measures the temperature of the surface of the heating roller 41. The temperature control circuit 54 is controlled by a main control unit described later, and controls ON / OFF of the heater 40 based on a measurement result of the temperature sensor 43,
The surface temperature of the heating roller 41 is maintained at, for example, 150 ° C. Further, the fixing unit 103 includes a paper discharge sensor (not shown) that detects that the paper 8 has been discharged.

The materials of the heater 40, the heating roller 41, the pressure roller 42 and the like are not particularly limited.

The temperature of the surface of the heating roller 41 is not particularly limited. Further, the fixing unit 103 may be configured to fix the toner image by heating or pressing the sheet 8.

Although not shown, on the paper output side of the paper 8 from the fixing unit 103, a paper discharge roller for discharging the paper 8 processed by the fixing unit 103 onto a paper discharge tray, and a discharged paper 8 A receiving tray is provided. The heating roller 41, the pressure roller 42, and the paper discharge roller are driven by a driving device (not shown).

The toner supply section 4 of the image forming section 3 includes a toner storage tank 1 in which a toner 12 as a developer is stored.
1. A toner carrier 10 serving as a cylindrical carrier (sleeve) for carrying the toner 12 by magnetic force and provided inside the toner storage tank 11 to charge the toner 12 and to be carried on the outer peripheral surface of the toner carrier 10 And a doctor blade 13 for regulating the thickness of the toner layer.

The doctor blade 13 holds the toner carrier 1
It is provided on the upstream side in the rotation direction of 0 so that the distance from the outer peripheral surface of the toner carrier 10 is, for example, 60 μm.

The toner 12 is, for example, a magnetic toner having an average particle diameter of 6 μm, and is charged by the doctor blade 13 such that the charge amount is, for example, −4 μC / g to −5 μC / g.

The distance between the doctor blade 13 and the toner carrier 10 is not particularly limited. Also,
The average particle size and charge amount of the toner 12 are not particularly limited.

The toner carrier 10 is driven by a driving device (not shown) and rotates in the direction of arrow A in the figure at a speed of, for example, 80 mm / sec on its surface.

The toner carrier 10 is grounded, and the doctor blade 1 inside the toner carrier 10 is
A magnet (not shown) is arranged at a position facing the control electrode 3 and a position facing a control electrode 20 described later.

Thus, the toner carrier 10 can carry the toner 12 on its outer peripheral surface. Further, the toner 12 carried on the outer peripheral surface of the toner carrier 10 forms ears at positions corresponding to the positions on the outer peripheral surface.

The rotation speed of the toner carrier 10 is not particularly limited. Further, the toner carrier 10 may be configured to carry the toner 12 by electric force or electric force and magnetic force instead of carrying the toner 12 by magnetic force.

The printing section of the image forming section 3 has a thickness of, for example, 1 m.
m, an opposite electrode 30 facing the outer peripheral surface of the toner carrier 10, an opposite electrode voltage power supply 52 for supplying a high voltage to the opposite electrode 30,
0, the control electrode 20 provided between the control electrode 20 and the neutralizing brush 33.
A charging voltage source 53 for charging the paper 8; a charging voltage power source 51 for charging the charging brush 6; a dielectric belt 32; Support member 3 for supporting belt 32
1a and 31b. The counter electrode 30 is
The distance from the outer peripheral surface of the toner carrier 10 is, for example, 1.1 m.
m.

The dielectric belt 32 is made of PVDF as a base material,
The volume resistivity is 1010 Ω · cm and the thickness is 75 μm. The dielectric belt 32 is driven by a driving device (not shown), and the speed on its surface is, for example, 3 in the direction of the arrow in the figure.
Rotate at 0 mm / sec.

A high voltage of, for example, 2.3 kV is applied to the common electrode 30 by a common electrode voltage power supply 52. That is, an electric field necessary for causing the toner 12 carried on the toner carrier 10 to fly toward the counter electrode 30 by the high pressure is applied between the counter electrode 30 and the toner carrier 10.

The discharging brush 33 includes a dielectric belt 32.
Is provided on the downstream side of the control electrode 20 in the direction of rotation of the piezoelectric element 20 so as to be in pressure contact with the dielectric belt 32.

The neutralizing brush 33 is applied with a neutralizing potential of 2.5 kV by a neutralizing voltage power supply 53 to neutralize unnecessary charges existing on the surface of the dielectric belt 32.

The material of the counter electrode 30 is not particularly limited.

The distance between the counter electrode 30 and the toner carrier 10 is not particularly limited.

Further, the rotation speed of the counter electrode 30 and the applied voltage are not particularly limited.

The control electrode 20 is two-dimensionally spread parallel to the tangential direction of the surface of the counter electrode 30 and opposed to the counter electrode 30.
The structure is such that the toner flow in the direction can pass.

The electric field applied between the toner carrier 10 and the counter electrode 30 changes according to the potential supplied to the control electrode 20, and the toner 12 flies from the toner carrier 10 to the counter electrode 30. Is controlled.

The control electrode 20 is connected to the toner carrier 10
Is provided so that the distance from the outer peripheral surface thereof is, for example, 100 μm, and is fixed by a support member (not shown).

As shown in FIG. 3, the control electrodes 20 correspond to an insulating substrate 21, a high-voltage driver (not shown), independent ring-shaped conductors, that is, ring-shaped electrodes 22, and each ring-shaped electrode 22. The shield electrode 23 has a plate-like shape provided with an opening as described above. The insulating substrate 21 is made of, for example, a polyimide resin and has a thickness of 25 μm.

The insulating substrate 21 has a hole to be a gate 24 to be described later. Ring electrode 22
Are made of, for example, copper foil and are provided around the holes, and are arranged according to a predetermined arrangement. The opening of each hole is formed to have a thickness of, for example, 160 μm, and serves as a passage for the toner 12 flying from the toner carrier 10 to the counter electrode 30. Hereinafter, this passing portion is referred to as a gate 24.

The shield electrode 23 is made of, for example, copper foil, and has an opening corresponding to the gate 24 and the ring-shaped electrode 22 provided therearound.

The distance between the control electrode 20 and the toner carrier 10 is not particularly limited.

Each ring-shaped electrode 22 is provided with an opening having an opening diameter of 220 μm.

The size of the gate 24 and the materials and thicknesses of the insulating substrate 21, the ring-shaped electrode 22, and the shield electrode 23 are not particularly limited.

The gate 24, that is, the ring-shaped electrode 22
For example, 2560 holes are formed,
Each ring-shaped electrode 22 is electrically connected to a control electrode voltage power supply 50 via a power supply line 25 and a high-voltage driver (not shown).

The shield electrode 23 is electrically connected to a control electrode voltage power supply 50 via a power supply line 25.

The number of ring electrodes 22 is not particularly limited.

The surface of the ring-shaped electrode 22, the surface of the shield electrode 23, and the surface of the power supply line 25 are covered with an insulating layer (not shown) having a thickness of 30 μm. Insulation between them and insulation between the ring-shaped electrode 22 and the power supply line 25 that are not connected to each other are ensured, and the surface of the ring-shaped electrode 22, the surface of the shield electrode 23, and the surface of the power supply line 25 are separated from each other. It is protected from short circuit with the member or conductive material.

The material and thickness of the insulator layer are not particularly limited.

A pulse corresponding to an image signal, that is, a voltage is applied to the ring-shaped electrode 22 of the control electrode 20 by the control electrode voltage power supply 50.

That is, the control electrode voltage power supply 50 supplies the toner 1 carried on the toner carrier 10 to the ring-shaped electrode 22.
2 is allowed to pass in the direction of the counter electrode 30, for example, 15
If 0 V is applied and not passed, for example, -200 V
Is applied. To the shield electrode 23, -200 V to be applied when the toner 12 is not allowed to pass is applied. This is to prevent the toner 12 from flying on the control electrode 20.

Here, the image forming process of the present image forming apparatus will be described.

First, upon receiving a signal from a host computer (not shown), the main controller of the printer starts an image forming operation.

That is, image data, which is information of the host computer, is binarized by an image processing unit described later, and the data is collated with an array pattern of the control electrodes 20 by a detection unit described later. / OFF state is detected. The image data for which the detection operation has been completed is temporarily stored in a memory such as a RAM (random access memory). The main control unit of the printer activates a driving device (not shown), and the pickup roller 5 rotated and driven by the driving device feeds the paper 8 in the paper cassette 7 toward the image forming unit 3 and also performs a normal paper feeding state. Is detected by the paper feed sensor.

The paper 8 sent out by the pickup roller 5 is transported between the charging brush 6 and the support member 31a. The support members 31a and 31b have a common electrode voltage power supply 5
2, the same potential as that of the counter electrode 30 is applied.

A charging potential of 1.2 kV is applied to the charging brush 6 by a charging voltage power supply 51. The paper 8 is supplied with electric charge due to the potential difference between the charging brush 6 and the supporting members 31a and 31b, and is conveyed to the surface of the printing section of the image forming section 3 facing the toner carrier 10 of the dielectric belt 32 while being electrostatically attracted. Is done.

Thereafter, a voltage is supplied from the control electrode voltage power supply 50 to the control electrode 20 according to the image data.

The supply of the voltage is performed at a timing synchronized with the supply of the paper 8 to the printing unit by the charging brush 6. The control electrode voltage power supply 50 supplies 150 V or −20 to a predetermined control electrode 20 as appropriate according to the image data signal.
A voltage of 0 V is applied to control the electric field near the control electrode 20. That is, in the gate 24 of the control electrode 20, the prevention of the toner 12 from flying from the toner carrier 10 to the counter electrode 30 and the release thereof are appropriately performed according to the image data.
As a result, a toner image corresponding to the image signal is formed on the sheet 8 moving at a speed of 30 mm / sec toward the sheet output side by the rotation of the support members 31a and 31b.

The paper 8 on which the toner image has been formed is
After being separated from the dielectric belt 32 at the curvature of 1b and conveyed to the fixing unit 103, the toner image is fixed on the sheet 8 by the fixing unit 103. Paper 8 on which toner image is fixed
Is discharged onto a paper tray by a paper discharge roller, and normal discharge is detected by a paper discharge sensor. Based on this detection operation, the main control unit of the printer determines the normal end of the printing operation.

By the above image forming operation, a good image is formed on the sheet 8.

Since the present image forming apparatus forms an image directly on the sheet 8, a visualizing member such as a photosensitive member or a dielectric drum used in the conventional image forming apparatus is not required. Accordingly, the transfer operation for transferring the image from the visualized object to the sheet 8 is omitted, so that the image does not deteriorate.

As a result, the reliability of the device is improved, the configuration of the device is simplified, and the number of parts is reduced, so that the device can be reduced in size and cost.

Subsequently, using the present image forming apparatus, the toner 1
The flight control 2 will be described with reference to FIGS. 4, 5, 6, and 7. FIG.

First, FIG. 4 shows the behavior of the toner 12 when the toner 12 carried on the toner carrier 10 passes through the gate 24 of the control electrode 20. The sheet 8 is conveyed on the counter electrode 30 in the direction of arrow Y in the figure, and the control electrode 20 is applied with a voltage through which the toner 12 passes through the adjacent gates P and Q.

In this case, both gates generate an electric field indicated by a dotted line toward the counter electrode 30. The gates P and Q of the control electrode 20 are controlled so that they fly first in the paper 8 transport direction.

The electric field of the gate P causes the toner 12 carried on the toner carrier 10 to simultaneously pass through the gate P and fly onto the sheet 8 conveyed on the counter electrode 30. Subsequently, at the gate Q, similarly, the toner 12 carried on the toner carrier 10 simultaneously passes through the gate Q by the electric field of the gate Q and flies onto the sheet 8 conveyed on the counter electrode 30. At this time, the toner layer is not formed in a region where the gate P is controlled to fly before the gate Q and is to fly under the influence of the electric field of the gate Q, in the region A in the drawing.

In this case, naturally, A
The toner 12 indicated in the area is insufficient, and the gate Q has a lower toner flying amount than the gate P. Gate P and Gate Q
Since the same electric potential is applied to the sheet 8 and the same electric field is formed, dots of the same size are formed on the sheet 8 conveyed on the counter electrode 30.

This dot becomes a dot of the same size at the gate P and the gate Q, but a difference in the amount of flying toner appears as a deposition amount.

In this case, the paper 8 on which the flight control has been performed is conveyed to the fixing unit 103, and the toner image formed by heating and pressing is fixed on the paper 8. When transported between the pressure roller 41 and the pressure roller 42,
The formed dots are fixed on the sheet 8 by being spread more than the size formed by the pressure of the roller. For this reason, if there is a difference in the amount of toner 12 deposited between the dots, the spread of the dots caused by the pressure will differ.

If the amount of toner 12 deposited is large, the spread of dots becomes large, and if the amount of toner 12 deposited is small, the spread of dots becomes small. If the difference in the amount of flying toner occurs as described above, when the toner 12 is fixed on the sheet 8 in the fixing unit 103, the size of the dots becomes non-uniform and the print quality is reduced.

On the other hand, in the present invention, when the toner 12 flies, the above-mentioned problem is solved by predicting and correcting the flight control in a detection unit described later.

Next, the correction method will be described. FIG. 5 shows the dot formation state when the flight control is not corrected for the gate P.

In the drawing, an equipotential surface as shown by a solid line is formed on the gate P, and an electric field shown by a dotted line in the drawing is generated toward the counter electrode 30. As a result, the flying area of the dots of the toner 12 that has flew is small due to the state of the equipotential surface, and the deposition amount is large.

On the other hand, FIG. 6 shows the dot formation state when the flight control is corrected for the gate Q.

In the figure, an equipotential surface as shown by a solid line is formed on the gate Q, and an electric field shown by a dotted line in the figure is generated toward the counter electrode 30. As a result, the flying area of the dots of the flying toner 12 is reduced due to the state of the equipotential surface, and the amount of the deposited toner is reduced.

In such a state, when the paper 8 passes between the heating roller 41 and the pressure roller 42 of the fixing unit 103, the dots formed by the gate P have a large accumulation amount, and the spread of the dots due to the pressure is large. The dot formed by the gate Q has a small amount of deposition and a small spread of the dot due to pressure, but is formed in a state where the flying area of the dot is widened at the time of dot formation, and the small spread of the dot in this case is compensated for. I have.

When a voltage to pass the toner 12 to the adjacent gates P and Q is applied to one of the adjacent gates P and Q, correction is performed on one of the gates P and Q to change the dot shape to be formed.
The size of each dot fixed above becomes uniform, and it is possible to prevent a decrease in print quality due to a difference in the amount of flying toner.

In this embodiment, when a voltage to pass the toner 12 to each other is applied to the adjacent gates P and Q, the correction is made for the gate Q of both, but the present invention is not limited to this. Not gate, gate P
The same effect can be obtained by performing correction on In this case, the dot area formed with respect to the gate P may be made as small as possible, and the deposition amount may be increased.

Next, a specific correction means for the toner 12 flight control will be described.

There are two electric fields generated between the toner carrier 10 and the counter electrode 30 between the toner carrier 10 and the control electrode 20 and between the control electrode 20 and the counter electrode 30. The electric field acting between the toner 12
The influence on flight is large, and the control electrode 20 and the counter electrode 3
Even if the electric field acting between zeros is corrected, the formed dots have little effect.

Further, if the electric field acting between the control electrode 20 and the counter electrode 30 is corrected, it causes a new problem such as scattering.

Further, as a correction method, a method in which the voltage applied to the counter electrode 30 is variable is considered. However, the voltage applied to the counter electrode 30 is as high as several kilovolts, and it is very difficult to control the voltage. Toner carrier 10 and control electrode 2
As a method of correcting the electric field acting between zero, the control electrode 20
A method of changing the voltage applied to the toner 12 in the direction in which the toner 12 should fly is conceivable.

In this method, the toner flying control can be locally corrected for each gate by changing the voltage value applied to each ring-shaped electrode 22. In this case, a case where the voltage value is varied and a case where the voltage waveform is changed can be considered. However, the present invention is not particularly limited, and the same effect can be obtained in both cases.

As another method, the electric field acting between the toner carrier 10 and the control electrode 20 can be similarly corrected by changing the voltage value applied to the toner carrier 10. In this case, since there is one voltage application unit, the circuit configuration is simplified, and the control is also simplified.

Next, the flow of image data will be described.

As shown in FIG. 7, the image forming apparatus is connected to a host computer, and image data is sent from the host computer via a communication interface. The image forming apparatus includes a main control unit, a memory, a control electrode control unit, and a control electrode voltage power supply unit.

The main control unit includes a CPU for performing image data transfer control, mechanical control in an image forming process, detection of various sensors, and the like, an image processing unit, and a detection unit.

The image processing section converts the image data sent from the host computer into binary data of white or black, and performs array conversion so as to correspond to the array pattern of the control electrodes 20. Here, by binarizing, it is easy to determine whether each gate 24 of the control electrode 20 should pass the toner 12 or not.

The detector stores the arrangement pattern of the control electrodes 20 in advance, and compares the arrangement pattern with the image data after the arrangement conversion. As a result, each gate 24
Determines whether the toner 12 should pass through or not, and detects the gate 24 adjacent to the gate 24 through which the toner 12 should pass.
If there is an adjacent gate 24 through which toner 12 must pass, this information is sent to the CPU and
In the PU, the voltage value applied to the control electrode 20 is varied or the voltage applied to the toner carrier 10 is varied according to the information.

This detection unit can accurately determine the position of the gate 24 of the control electrode 20 that needs to be corrected, so that accurate control can be performed.

The image data for which the detection operation has been completed is
The data is written to an AM (random access memory), sequentially read from the RAM at a predetermined timing, and sent to the control electrode control unit.

The control electrode control section has its output section connected to the control electrode 2.
0, and is also connected to the control electrode voltage power supply. A predetermined applied voltage of the control electrode voltage power supply is switched according to the image data read from the RAM and applied to the ring-shaped electrode 22.

As described above, according to the present invention, it is possible to predict in advance whether or not the toner 12 should pass through each electrode group of the control electrode 20, and based on the prediction result, it is possible to easily perform the image formation at the time of image formation. Since the flight control of the toner 12 can be corrected and dots of a desired size can be formed on each electrode, high-quality printing with a uniform density can be provided.

[0103]

According to the first aspect of the present invention, there is provided a supply means having a carrier for carrying a developer of at least one color;
A counter electrode disposed to face the carrier, an insulating substrate disposed between the carrier and the counter electrode, and a plurality of gates provided on the insulating substrate and serving as passage portions for the developer. And a control electrode having at least one or more electrode groups provided around the plurality of gates, and a shield electrode formed so as to electrically expose the gate and the electrode groups; and Control circuit means for applying at least a predetermined potential corresponding to image data to each electrode, and at least a control circuit means for applying a predetermined potential to a corresponding electrode of the electrode group by the control means. In an image forming apparatus for controlling the passage of a developer through the gate to form an image on the surface of a recording medium conveyed between the control electrode and the counter electrode, an image processing apparatus for binarizing output image data is provided. And a detection unit for detecting an electrode to be allowed to pass the developer based on the binarized data processed by the image processing unit based on the arrangement pattern of the control electrodes, and the control electrode Of each gate of
By detecting whether or not the gates adjacent to each other are in a state in which the passage of the developer is to be permitted by the detection unit, the developer should be passed through each electrode group of the control electrode. Can be predicted in advance,
Based on the prediction result, it is possible to easily correct the flying control of the developer during image formation. Further, by correcting the flight control of the developer based on the information detected by the detection unit, when both adjacent electrodes are electrodes that should allow the developer to pass, Since the flying amount is corrected and dots of a desired size can be formed on each electrode, high-quality printing with uniform density can be provided.

According to the second aspect of the present invention, the shape of the equipotential surface acting on the control electrode is corrected based on the information detected by the detection unit, so that the shape of the equipotential surface is related to the flying amount of the developer. Thus, uniform dots can be formed on a recording medium.

According to the third aspect of the present invention, in the electrode group of the control electrodes, the electrodes to be allowed to pass the developer and the electrodes adjacent to the electrodes allow the passage of the developer. In the case of the electrodes to be applied, by correcting the flight control of the developer with respect to any one of the electrodes in both electrodes, the developer that has flown from each electrode forms uniform dots on the recording medium. It can be formed, and high quality printing can be obtained.

According to the configuration of the fourth aspect, the electric field acting between the carrier and the control electrode is corrected based on the information detected by the detection section, so that the equipotential acting on the control electrode is corrected. The shape of the surface can be easily and accurately corrected.

According to the fifth aspect of the present invention, the shape of the equipotential surface acting on the control electrode is corrected by correcting the voltage applied to the control electrode based on the information detected by the detection unit. Correction can be made accurately for each electrode.

According to the sixth aspect of the present invention, the voltage applied to the carrier is corrected based on the information detected by the detection section, so that the voltage applied to the carrier can be controlled with a simple circuit configuration. It is possible to correct the shape of the potential surface.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image forming apparatus according to the present invention.

FIG. 2 is a configuration diagram of a main part of an image forming unit according to the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a control electrode according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a flying region of toner due to an electric field of a gate.

FIG. 5 is a diagram illustrating a state of an equipotential surface when correction of flight control is not performed.

FIG. 6 is a diagram illustrating a state of an equipotential surface when a flight control is corrected.

FIG. 7 is a configuration diagram of a control unit of the image forming apparatus.

[Explanation of symbols]

 3 Image Forming Unit 5 Pickup Roller 7 Paper Cassette 8 Paper 10 Toner Carrier 12 Toner 20 Control Electrode 30 Counter Electrode 40 Heater 41 Heating Roller 42 Pressure Roller 43 Temperature Sensor

Claims (6)

[Claims] 1. A supply means having a carrier for carrying a developer of at least one color, a counter electrode arranged opposite to the carrier, and an insulating member arranged between the carrier and the counter electrode. A substrate, a plurality of gates provided on the insulating substrate and serving as a passage portion of a developer, at least one or more electrode groups provided around the plurality of gates, and the gate and the electrode group At least a control means including a control electrode having a shield electrode formed so as to electrically expose the control electrode, and control circuit means for applying a predetermined potential at least in accordance with image data to each of the control electrodes. The control means controls the passage of the developer through the gate by applying a predetermined potential to the corresponding electrode of the electrode group, and the recording carried between the control electrode and the counter electrode. Image on media surface In an image forming apparatus for forming an image, an image processing unit for binarizing image data to be output, and the developing agent, based on an array pattern of the control electrodes, converting the binarized data processed by the image processing unit into an image. And a detection unit for detecting an electrode to be allowed to pass through, and among the gates of the control electrode, determine whether or not gates adjacent to each other are in a state to allow passage of the developer, respectively. An image forming apparatus, wherein the detection unit detects the correction and corrects the flight control of the developer based on the detected information. 2. The image forming apparatus according to claim 1, wherein a shape of an equipotential surface acting on the control electrode is corrected based on information detected by the detection unit. 3. An electrode group of the control electrodes, wherein an electrode to be allowed to pass the developer and an electrode adjacent to the electrode are electrodes to be allowed to pass the developer. 2. The image forming apparatus according to claim 1, wherein the flying control of the developer is corrected for one of the two electrodes. 4. The image forming apparatus according to claim 1, wherein an electric field acting between said carrier and said control electrode is corrected based on information detected by said detection unit. 5. The image forming apparatus according to claim 1, wherein a voltage applied to the control electrode is corrected based on information detected by the detection unit. 6. The image forming apparatus according to claim 1, wherein a voltage applied to the carrier is corrected based on information detected by the detection unit.