JPH11348340A - Fly type image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for forming images by flying a toner, particularly a fly type image formation apparatus high in density and print speed. SOLUTION: When a voltage is impressed to an opposite electrode 11, an electric field for flying a toner held at a toner hold body 31 towards the opposite electrode 11 is formed. The electric field is changed by a control electrode 23 in accordance with image signals, thereby controlling passing of the toner through a gate 22. Images are thus formed by the toner to a transfer medium P. A toner feed electrode 28 is also set for transferring and holding the toner from the toner hold body 31 to an opening part before the toner is flown. In this constitution, a quantity of the toner flown to the gate 22 is secured sufficiently, so that uniform images without density irregularities can be formed. Although not shown in the drawing, a projecting part corresponding to the gate 22 may be provided at a front face of the toner hold body 31, to a front face of which transfer the toner of the sufficient quantity is transferred.

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. The toner is caused to fly in accordance with an image signal to form a high-quality toner image on a recording medium. The present invention relates to a flying type image forming apparatus for forming an image.

[0002]

2. Description of the Related Art As a device for forming a visible image on a recording material such as paper based on an electric signal output from an image information output device as an output device such as a digital copying machine, a facsimile, a computer, a word processor, and a printer. Various methods have been proposed, such as a method of flying ink, a method of melting and transferring ink, a method of sublimating ink by heating an ink film, or a method of forming an electrostatic latent image on a photoreceptor and then forming an electrostatic latent image on a photoconductor. An image forming apparatus of an electrophotographic type in which a toner is developed with toner has been put to practical use.

[0003] Of these systems, the so-called ink-jet system for ejecting ink with a relatively simple apparatus configuration has been widely used in accordance with recent demands for higher speed, higher image quality and lower cost. However, in this method, since liquid ink is used, bleeding easily occurs on a recording material, and there is a problem that a good image cannot be obtained with inexpensive general-purpose copy paper. In addition, there is a problem that it is difficult to store a large amount of ink because ink that easily solidifies is used, and it is unsuitable when a large amount of printing is required for business use or the like. Furthermore, in color printing, which has been increasingly demanded in recent years with the advancement of computer performance, it is difficult to produce a vivid color mixture by mixing ink, so when high quality is required and the number of printed sheets is relatively large, electronic Printing using a photographic toner is employed.

[0004] In printing with toner, a visually excellent image having a high color tone without blurring can be obtained, the amount of toner for forming pixels can be controlled, and a mixed color of a plurality of colors is formed in the fixing process. And a good mixed color can be obtained. For this reason, a direct printing method using toner flying has been proposed, which combines a simple process of an ink jet method and a method of an image forming apparatus using toner.

For example, in Japanese Patent Publication No. 1-503221, a charge image is formed in the vicinity of a wire by applying a voltage to a wire formed in a matrix, and a toner image is formed by applying a toner to the charge image. A method of forming is disclosed. Further, Japanese Patent Application Laid-Open No. Hei 5-177865 discloses a method of forming a toner cloud and realizing stable toner flight without clogging. Further, Japanese Patent Application Laid-Open No. 5-330126 discloses a method in which an AC voltage is applied to a toner flow path to vibrate toner particles in the flow path in order to form a stable and dense toner cloud. . Japanese Patent Application Laid-Open No. 6-83109 discloses a method in which a rotating magnet is included in a toner carrier and the toner is stirred by mixing with magnetic particles or by adding a magnetic material to the toner to stir the toner.
No. 6,086,045.

[0006]

In the printing method using toner, printing is performed using fine particles having a size of 10 μm or less, so that the gradation expression is excellent and a visually excellent image can be realized. Because of these advantages, an electrophotographic method has conventionally been used in which an electrostatic latent image is formed on a photoreceptor, developed with toner, and then transferred to a recording material such as paper to form an image. Many schemes have been used. In such a method, since there is a step of once forming an electrostatic latent image,
A photoreceptor for forming a latent image, a charge removing unit, a charging unit, and an exposure unit are required, and there is a problem that the apparatus becomes large. Further, in recent years, from the viewpoint of environmental protection, there has been a problem with post-use processing of a photoconductor or the like having a relatively short life. For these reasons, there is a demand for a method for directly printing using toner.

[0007] In Japanese Patent Publication No. 1-503221, wire-like electrodes are arranged in a grid, and the passage of toner particles is controlled by an electric field near the wire-like electrodes formed by a voltage applied to the electrodes. A method of forming a desired toner image is disclosed. However, in a method of forming an electrode using such a wire, in a printing requiring a resolution of 10 or more per millimeter, an opening serving as a toner passing portion is required. Therefore, it is difficult to ensure the accuracy, and a high-precision control electrode capable of passing a sufficient amount of toner has been demanded.

Japanese Patent Application Laid-Open No. 5-177865 discloses a method of realizing a highly accurate electrode and passing a sufficient amount of toner.
The publication discloses that an electrode having an aperture (opening) is arranged, and vibration is provided to the toner between the aperture and the toner carrier so as to make the toner cloud-like by vibrating the toner. I have. Also, Japanese Patent Application Laid-Open
Japanese Patent No. 330330 discloses a method in which an alternating voltage is applied to toner between an aperture and a toner carrier to bring the toner into a cloud state. Further, Japanese Unexamined Patent Application Publication No.
Japanese Patent No. 83109 proposes a method of forming a cloud by enclosing a magnet in a toner carrier and agitating the magnetic toner or carrier by rotating the magnet.

In these methods, the electrodes and the aperture can be accurately formed on the insulating electrode support, and the toner passing through the aperture is clouded in advance. Control was realized. However, in the method of forming a cloud as described above, since the toner density is reduced, it is necessary to extend the flight control time in order to obtain a desired print density, that is, a flying amount, and the printing speed is significantly reduced. Was to be invited.

The present invention has been made in view of the above-mentioned circumstances, and is an apparatus for forming an image by flying toner, particularly a high-resolution flying image forming apparatus having a high density and a high printing speed. The purpose is to provide.

[0011]

According to a first aspect of the present invention, there is provided a toner carrier for supporting toner particles charged to a predetermined polarity, and a toner carrier disposed at a predetermined gap from the toner carrier. Control means including a gate through which the flying toner particles can pass and a control electrode capable of applying a voltage for controlling the passage of the gate; and a toner carrier on the opposite side of the toner carrier from the control means. A counter electrode capable of applying a voltage having a polarity opposite to the polarity of the toner, and selectively applying a voltage to the control electrode of the control means in accordance with an image signal to control the passage of toner particles at the gate. In an image forming apparatus that forms an image on a recording medium that moves relatively between a counter electrode and a control electrode, in order to secure a sufficient amount of toner particles, the toner particles are moved in front of the counter electrode on the side opposite to the counter electrode. It is obtained by comprising the conveying means for conveying to the counter electrode direction.

According to a second aspect of the present invention, in the flying type image forming apparatus according to the first aspect, the transporting means has an opening and a transporting electrode arranged on a control electrode side, and is provided on the toner carrier. A substrate provided in close proximity to the carrier electrode, and applying a voltage having a polarity opposite to that of the toner particles on the toner carrier prior to the application of the flying voltage to the control electrode; And transporting the toner particles on the toner carrier.

According to a third aspect of the present invention, in the flying type image forming apparatus according to the first aspect, a convex portion is provided as the transport means at a position corresponding to the gate on the surface of the toner carrier, and the toner carrier is provided. A moving means for moving the toner particles on the body is provided, and the toner particles are moved to convey the toner particles along the shape of the projection in the direction of the counter electrode.

According to a fourth aspect of the present invention, in the flying image forming apparatus according to the third aspect, magnetic toner particles are used as the toner particles, and the toner carrier is formed of a non-magnetic member as the moving means. In addition, a rotatable magnet assembly is provided inside the toner carrier, and the toner particles are moved on the toner carrier with the rotation of the magnet assembly.

According to a fifth aspect of the present invention, in the flying image forming apparatus according to the third aspect, a plurality of electrodes are continuously arranged on the toner carrier in the traveling direction of the recording medium as the moving means. The method is characterized in that toner particles are moved on the toner carrier by sequentially applying voltages to the plurality of electrodes.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a flying image forming apparatus according to the present invention. Note that, in all the drawings for describing the embodiments, portions having similar functions are denoted by the same reference numerals, and repeated description thereof is omitted. First, a cross section of a printer equipped with an image forming apparatus according to the present embodiment is shown in FIG. 1, and an outline of an image forming process in the present apparatus will be described below with reference to FIGS. 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 polarity of each applied voltage is appropriately set accordingly. do it.

FIG. 1 shows an example of an image forming apparatus according to the present invention, in which a toner supply electrode is used as means for transporting toner in the direction of a counter electrode. In addition, as a method of transporting the toner in the direction of the counter electrode, a method of applying a traveling wave electric field to the toner particles as shown in FIG. 11 or a method of transporting the toner by using a magnetic toner as shown in FIG. Alternatively, a method of rotating the magnet assembly included in the toner carrier can be used (the operations in FIGS. 9 and 11 will be described later). The image forming apparatus according to the present method controls the passage of the toner T from the toner supply unit 3 in the direction of the counter electrode 11 and then controls the passage of the toner through the gate 22 in accordance with the image signal by the flying control unit 2, so that the recording medium P To form a toner image. A paper feed unit 4 is provided on the upstream side in the transport direction of the recording medium P to the printing unit 1. The paper supply unit 4 includes a recording medium storage unit 41 that stores the recording medium P, and the recording medium storage unit 41.
And a pair of registration rollers 43 for transporting the supplied recording medium P in synchronization with the printing timing.
Is guided to the printing unit 1 along the transport path. The paper supply unit 4 includes a paper supply sensor (not shown) that detects that the recording medium P has been supplied. The pickup roller 42 and the registration roller 43 are rotationally driven by a drive device (not shown) according to a drive signal from the controller unit 7.

A fixing unit that fixes the toner image formed on the recording medium P in the printing unit 1 to the recording medium P by heating and pressing the toner image downstream of the printing unit 1 in the transport direction of the recording medium P. 6 are provided. The fixing unit 6 is shown in FIG.
A heat roller 62 including a heater 61 as shown in FIG.
It comprises a pressure roller 63 and a temperature sensor 64. The heat roller 62 is made of, for example, an aluminum tube having a thickness of 2 mm. The heater 61 is formed of, for example, a halogen lamp, and is included in the heat roller 62. Pressure roller 6
3 is made of, for example, a silicone resin. The heat roller 62 and the pressure roller 63 provided opposite to each other are loaded with, for example, a 2 kg load on both ends of each shaft by a spring or the like (not shown) so that the recording medium P can be pressed therebetween. Has been added.

The temperature sensor 64 measures the temperature of the surface of the heat roller 62. The measured value is controlled by a temperature control unit (not shown) of the controller unit 7, and the ON / OFF of the heater 61 is controlled according to the surface temperature of the heat roller 62 based on the measurement result of the temperature sensor 64. Is kept at, for example, 150 ° C. Further, the fixing unit 6 includes a paper discharge sensor (not shown) for detecting that the recording medium P has been discharged. The materials of the heater 61, the heat roller 62, the pressure roller 63, and the like are not particularly limited. Further, the temperature of the surface of the heat roller 62 is not particularly limited. Further, the fixing unit 6 may be configured to fix the toner image by heating or pressing the recording medium P.

On the discharge side of the recording medium P from the fixing unit 6, a discharge roller (not shown) for discharging the recording medium P processed by the fixing unit 6 out of the machine, and a discharged recording medium P
A discharge tray (not shown) for receiving the image is provided. The above-described heat roller 62, pressure roller 63, and discharge roller are rotationally driven by a driving device (not shown).

As shown in FIG. 2, the toner supply unit 3 agitates the toner T stored in the toner storage tank 35 to prevent the toner T in the toner storage tank 35 from shifting. A cylindrical toner carrier (sleeve) 31 for carrying and transporting the toner T, a supply roller 33 for supplying the toner to the toner carrier 31, and applying a predetermined charge to the toner T and applying the toner T to the outer peripheral surface of the toner carrier 31. A toner layer regulating unit 32 for regulating the amount of toner carried is provided. The toner layer regulating means 32 is provided so as to approach or contact the toner carrier 31 at a predetermined pressure on the upstream side in the toner conveying direction when viewed from the toner acquisition position on the toner carrier 31.

For example, as shown in FIGS. 5 to 7, the toner supply electrode substrate 2
In the configuration in which the toner is temporarily held in the toner supply electrode substrate 27 by a predetermined amount and the flying control is performed, an elastic urethane member is used as the toner layer regulating means 32 shown in FIG. 30 μm to 50 μm
It is possible to form a toner layer having a thickness of the order. At this time, the material of the toner carrier 31 may be any material as long as the material has conductivity. However, it is necessary to secure a toner conveyance amount and rub against the supply roller 33 or the toner layer regulating means 32 to obtain a desired charge amount. For this purpose, it is preferable to form irregularities of about several μm. The toner T used here is, for example, particles of about 10 μm mainly composed of styrene acryl, and a negative charge is given by stirring and transporting in the vicinity of the toner layer regulating means 32 and the supply roller 33. The toner carrier 31, the toner layer regulating means 32, the supply roller 33
Is not particularly limited in the present invention. In this embodiment, the toner carrier 31 is driven by a driving device (not shown), and rotates in a direction indicated by an arrow in FIG. 2, for example, at a speed of 60 mm / sec on the surface thereof.

The toner carrier 31 is electrically connected between the toner supply electrode 28 and the counter electrode 11 so as to generate an electric field required for toner conveyance and flight control. In the following description, FIGS. 1 to 7 will be referred to as appropriate.
The printing unit 1 includes a flight control unit 2 facing the outer peripheral surface of the toner carrier 31 and the counter electrode 11. The printing unit 1 applies a voltage to the ring-shaped control electrode 23 in accordance with an image signal to thereby form a toner supply electrode 28. And the passage of the toner through the opening of the toner supply electrode substrate 27 and the gate 22 on the toner carrier 31 are selectively controlled. On the other hand, the recording medium P is accommodated in the recording medium accommodating section 41, and is picked up by a pickup roller 42 in response to a print start signal from the controller section 7.
And is conveyed by the registration rollers 43. Recording medium P conveyed by registration roller 43
Is transported in close contact with the counter electrode 11 by being sandwiched between the paper feed guide plate 44 and the paper pressing plate 45.

The counter electrode 11 is set so that the distance from the outer peripheral surface of the toner carrier 31 is, for example, 1 mm. Further, a voltage of 2 kV is applied to the counter electrode 11 by a counter electrode power supply 71 during, for example, a printing operation. That is, by applying a voltage to the counter electrode 11 by the counter electrode power supply 71, the toner supply electrode substrate 27 and the toner carried on the toner support 31 are placed between the counter electrode 11 and the toner carrier 31 and the toner supply electrode 28. An electric field necessary for causing T to fly in the direction of the counter electrode 11 is formed. The distance between the counter electrode 11 and the toner carrier 31 is not particularly limited.

As shown in FIG. 6, the controller unit 7 includes a counter electrode power supply 71, a control electrode driver 72 (an ON potential power supply 72a for applying a flying electric field to the control electrode 23 for permitting the gate 22 to pass the toner, and a gate unit 22). OFF potential power supply 72b that forms an electric field that inhibits toner from passing through, a toner supply electrode driver 73 (toner supply electrode power supply 73a) that applies an electric field to the toner supply electrode 28 so as to convey toner on the toner carrier, and an image signal. The operation is controlled by a CP in the controller unit 7.
U (not shown) controls the driving means for transporting the recording medium and controls the entire image forming apparatus such as temperature control in the fixing unit 6.

The flight control unit 2 is parallel to the counter electrode 11 and extends two-dimensionally in opposition to the counter electrode 11.
The passage of toner from 1 to the counter electrode 11
Is possible. And this gate 2
The electric field acting on the toner supply electrode substrate 27 and the toner T carried on the toner carrier 31 is changed by the potential applied to the control electrode 23 provided so as to surround
The flying of the toner T from the toner carrier 31 to the counter electrode 11 is controlled.

As shown in FIG. 3, the base substrate 25
The control electrode 23 and the power supply line 24 for supplying power to the control electrode 23 are arranged at a predetermined interval so as to keep insulation from each other. The base substrate 25 is made of, for example, a polyimide resin and is molded to a thickness of 25 μm. These base substrates 25
In the flight control unit 2 composed of the laminated substrate of the control electrode 23 and the cover layer 26, a hole to be the gate 22 is formed. For example, if the electrode diameter of the control electrode 23 is 2
The hole diameter is set to 160 μm with respect to 00 μm, and the electrode is completely covered at the opening of the gate 22 to keep the insulation. The control electrode 23 and the gate 22
Of the opening, the arrangement of the gates, and the layer configurations of the base electrode 25, the control electrode 23, the cover layer 26, etc. of the flight control unit 2 are appropriately determined according to conditions such as printing resolution, applied voltage, and type of toner. As described above, the potential applied to the flight control unit 2 is controlled according to the image signal, and when the recording medium P is disposed on the side of the opposing electrode 11 facing the toner carrier 31, the image signal is applied to the surface of the recording medium P. Is formed in accordance with.

The above image forming apparatus can be used not only as a printer for outputting from a computer or a word processor but also as a printing unit for digital copying. An example will be described.

(Embodiment 1) First, for example, an image signal from a host computer (not shown)
The controller separates the image signal into a print start signal and a control signal such as a recording medium size and image data. First, the pickup roller 42 is rotated by the print start signal, and is stored in the recording medium housing 41. The recording medium P is sent out until it comes into contact with the registration rollers 43. At this time, the operation of the pickup roller 42 is confirmed after the presence of the recording medium P is confirmed by a recording medium detection sensor (not shown) for detecting the presence or absence of the recording medium provided in the recording medium accommodation part 41. Begins. Next, constant speed rotation of the registration roller 43 starts and the recording medium P
Is transported at a constant speed along the counter electrode 11 while being sandwiched between the paper feed guide plate 44 and the paper pressing plate 45. Processing of an image signal is started by the image forming control unit of the controller unit 7 in synchronization with the start of the rotation operation of the registration roller 43. However, since the recording medium P is conveyed from a state of being in contact with the registration roller 43, recording is performed. The image forming position on the leading end side of the medium P can be a predetermined position calculated in the image forming control unit.

Here, for example, as shown in FIG. 2, in the toner supply section 3, the toner carrier 31 and the supply roller 33 are provided.
The toner T charged to a predetermined polarity is carried on the toner carrier 31 by sliding with the toner layer regulating means 32, and is conveyed to a position facing the flight control unit 2 with its rotation. The flight control unit 2 controls the power supply line 2 according to the image signal.
A voltage is applied so as to control the control electrode 23 through 4 and form an electric field that allows the gate 22 to pass the toner. At this time, the thickness of the toner layer on the toner carrier 31
The amount of toner flying from above the toner layer is determined by the range of the electric field. Here, if the range in which the toner flies is too large, the toner in the range that should be used for forming adjacent pixels is used, and it is impossible to obtain a uniform image density.

According to the present invention, the toner carrier 31 is conveyed in the direction of the counter electrode 11 of the flight control unit 2 at a position where the toner carrier 31 faces the gate 22 by providing means described later. Thus, it is possible to obtain a sufficient amount of toner from the sandwiched area on the toner carrier 31 to obtain a sufficient amount of image density, and to realize a solid image with sufficient density and uniformity in full-page printing, so-called solid printing. Was completed.

In the above-mentioned flight control unit 2, as shown in FIG. 6, the distance from the outer peripheral surface of the toner carrier 31 is 40 μm.
m, a 50 μm-thick toner supply electrode substrate 27 having a 25 μm-thick toner supply electrode 28 disposed on the control electrode side is provided at a position where the distance from the outer peripheral surface of the toner carrier 31 is 120 μm. The base substrate 25 was fixed and held by the electrode mount 21. A control electrode driver 72 is connected to the control electrode 23 so that a voltage can be independently applied to each gate 22.
A potential (ON potential, +200 V in this embodiment) that allows the passage of two toners or a potential (OFF potential, -100 V in this embodiment) that inhibits the passage of toner is applied. Further, the toner supply electrodes 28 are provided corresponding to the respective gates 22, the respective toner supply electrodes 28 are electrically connected, and a common potential is applied by a toner supply electrode driver 73 at a predetermined cycle to each of the toner supply electrodes 28. Is applied to

In this embodiment, as shown in FIG. 8, when a voltage (+150 V) b is applied to the toner supply electrode 28 prior to the image signal a applied to the control electrode 23, a toner image having a high density is formed. We were able to. The voltage application time is determined by the application speed, the toner charge amount, and the toner conveyance speed of the toner carrier 31. In this embodiment, the voltage of 500 μsec or more is applied to the toner supply electrode 28 (FIG. 8, t2- A good image could be obtained when t3) was applied.

The image forming operation in the above configuration will be described with reference to FIG. In the present embodiment, a toner supply electrode 28 having an opening diameter smaller than the opening diameter of the control electrode 23 is disposed between the toner carrier 31 and the control means, facing the gate 22 of the control means. The toner supply electrode substrate 27 disposed on the side surface is provided. When a voltage is applied to the toner supply electrode, as shown in FIG.
7 and the toner supply electrode 28, the toner is conveyed so as to be held, and when the control electrode is turned to the ON potential, as shown in FIG. The toner T held in the opening formed by the toner supply electrode 28 and the toner on the toner carrier 31 fly toward the counter electrode. When the control electrode is at the OFF potential, an electric field that attracts toner from the counter electrode 11 is completely cut off by the control electrode 23, and the control electrode 23 controls the toner T held on the toner supply electrode 28. Irrespective of the potential of the toner supply electrode 28 (ON potential, +100 V, OF
(F potential, 0 V) The toner does not overflow from the toner supply electrode. Further, the toner T on the toner carrier 31
Is transported with the rotation of the toner carrier 31 in a state of being in contact with or in proximity to the toner supply electrode substrate 27, so that the toner T enters the opening of the toner supply electrode substrate 27. In operation (FIG. 7A), the retained toner does not return to the toner carrier 31 even when the toner supply electrode is at the OFF potential (0 V).

According to the above configuration, the toner used for flying has the bottom of the opening formed by the toner supply electrode substrate 27 and the toner electrode 28 and the toner carrier 31.
Is used for flying, and a sufficient flying amount can be obtained. Further, since the area for obtaining the toner T on the toner carrier 31 is determined by the opening diameter of the toner supply electrode substrate 27, the toner for printing is obtained without affecting the toner used for forming the adjacent pixels. be able to. Note that the toner carrier may be rotated in the toner conveyance direction generated by the rotation of the magnet assembly, so that the flying electric field acts at a timing corresponding to the gate of the flight control unit and the projection of the toner carrier. . In this case, more toner can be conveyed, and high-speed printing can be handled.

(Embodiment 2) As shown in FIGS. 9 and 10, a projection is formed on the surface of the toner carrier 31 facing the gate 22 of the flight control unit 2, and the toner is transferred at a position facing the gate 22. When the transport direction was set to be in the direction of the counter electrode 11, the density of the image was improved, and the shading unevenness during solid printing was reduced. Note that the shape of the projection is the same as that of the control electrode 2.
3 and the opening diameter of the gate 22, and the thickness of the toner layer carried on the toner carrier 31. In this embodiment, when the thickness of the toner layer is about 40 μm, the bottom of the protrusion is It is desirable that the height of the projection is about 100 μm and the height of the projection is about 50 μm.

In this embodiment, the toner carrier 31 is
An alumite toner carrier 31 having a base of 100 μm and a height of 50 μm with projections and depressions is fixed at a position where each projection faces the gate 22 of the flight control unit 2. The enclosed magnet assembly 37 was rotated in the arrow direction M shown in FIGS. As the toner, powder particles having an average particle diameter of 10 μm obtained by kneading 30 parts by weight of a fine powder of magnetite into a resin mainly composed of styrene acrylic and subjecting them to pulverization and classification are used. Here, the magnet assembly 37 included in the toner carrier 31 is:
An N-pole magnet 37a having an outer peripheral direction of 800 Gauss and an S-pole magnet 37b having an outer peripheral direction of 800 Gauss are alternately arranged. The toner carrier 31 is rotated with the rotation of the magnet assembly 37. The upper toner T is sequentially conveyed in a direction opposite to the rotation direction of the magnet assembly 37 so as to be attracted to the approaching magnetic pole.

When the control electrode 23 is at the flying potential (ON potential), the flying electric field acts on all of the toner carried on the convex portions of the toner carrying member 31, so that the toner carrying member 31 is made flat. More toner was able to fly than at times.

(Embodiment 3) As shown in FIG. 11, the reference surface (bottom surface of the convex portion) of the toner carrier 31 2 was arranged so as to have a gap of 100 μm. The surface of the toner carrier 31 is molded so as to form a projection at a position facing the gate 22 of the flight control unit 2. Here, the convex portion had a bottom surface of 100 μm and a height of 80 μm. Further, on the surface of the toner carrier 31, as shown in FIGS. 12 and 13, a toner transfer electrode 36 having a width of 25 μm and extending in a direction perpendicular to the moving direction of the recording medium P is formed to a thickness of 50 μm.
, And a three-phase alternating current having a phase shift of 120 degrees for every three recording mediums P in the transport direction of the recording medium P is applied to the toner transport electrode 36 by the toner transport electrode driver 75. At this time, the voltage a shown in FIG. 15 is applied to the toner transport electrodes 36 indicated by a1, a2... An in FIG. 14, and the toner transport electrodes 36 indicated by b1, b2.
In FIG. 14, the voltage b shown in FIG.
A voltage c shown in FIG. 15 was applied to the toner transport electrode 36 indicated by c2... cn. In addition, a, b, in FIG.
Each of the voltages c is a sine wave having a maximum value of 150 V, a minimum value of 0 V, and a frequency of 10 kHz, and each phase is applied with a delay of 120 degrees.

As a result, the toner T charged in advance to a predetermined charge amount (−5 μC / g in this embodiment) is sequentially drawn to the next electrode and transported in the direction of the arrow in FIG. The toner used in the present embodiment is a kneaded and pulverized resin mainly composed of styrene acryl, and particles having an average particle diameter of 8 μm obtained by classification are used. As shown in FIG. Was given.

The toner T on the toner carrier 31 is shown in FIG.
As shown in (1), the toner is conveyed to the position opposite to the gate 22 of the flight control unit 2. Since the convex portion is formed on the toner carrier 31 here, the toner is conveyed so as to climb up the convex portion. Here, the control electrode 23 of the flight control unit 2
When a potential (ON potential, +200 V in this embodiment) that allows toner to pass through the gate 22 is applied to the toner carrier 3, the flying electric field in the direction of the counter electrode 11
Most of the toner carried on the convex portion flies over the entire convex portion. Further, the control electrode 23 of the flight control unit 2
Potential (O) that prohibits toner from passing through the gate 22
When an FF potential (−100 V in this embodiment) is applied, the electric field from the counter electrode 11 is completely shut off, and a repulsive force acts on the control electrode 23.
Unnecessary toner passage (toner leakage) through the control electrode 2
3 can also be prevented.

As described above, according to the present embodiment, a toner image having a sufficient density and a uniform image without density unevenness even in a solid state could be obtained. The image forming apparatus according to the present invention can be suitably applied to, for example, a printing unit of a digital copying machine and a facsimile machine, and an apparatus for forming a particularly high-resolution or color image such as a digital printer and a plotter.

[0043]

According to the first aspect of the present invention, a means for conveying the toner on the toner carrier in the direction of the counter electrode is provided at a position facing the gate of the control means, so that the amount of toner during flight control is ensured. Therefore, even when the toner layer is thin, or when the printing speed is high and the flying voltage application time is short, a toner image having a sufficient density can be obtained.

According to a second aspect of the present invention, a columnar toner whose diameter is defined by the opening formed by the toner electrode substrate and the toner supply electrode and whose height is from the toner carrier to the upper surface of the toner supply electrode is used for image formation. And a sufficient amount of flight can be obtained. further,
Since the toner acquisition area on the toner carrier is determined by the opening diameter of the supply electrode substrate, the toner can be acquired without affecting the toner used for forming the adjacent pixels.

According to the third aspect of the present invention, the toner is conveyed along the convex portion of the toner carrier provided opposite to the gate of the flight control section, so that the amount of toner in the range where the flying electric field acts can be increased. As a result, a sufficient amount of toner can be secured during the flight control.

According to the fourth aspect of the present invention, the magnetic toner is transported by the rotating magnet assembly, and the toner is transported along the convex portion of the toner carrier provided opposite to the gate of the flight control unit. Thus, the amount of toner in a range where the flying electric field acts can be increased. In addition, since the toner particles are conveyed on the convex portion so as to rise in the direction of the counter electrode due to the rotation of the magnet assembly, a sufficient amount of flying toner can be obtained even with a small electric field. Further, when the toner carrier is rotated in the toner conveyance direction generated by the rotation of the magnet assembly, and the gate of the flight control unit and the convex portion of the toner carrier act at a timing corresponding to the flying electric field, the above-described configuration is more preferable. A large amount of toner can be transported, and high-speed printing can be handled.

According to a fifth aspect of the present invention, the toner carrier is arranged so as to be two-dimensionally spread opposite to the control means, and a convex portion is formed on the surface of the toner carrier opposed to the gate of the control means. When the electrode reaches the flying potential (ON potential),
The substantial area of the flying electric field that reaches the toner carrier can be increased, and more flying toner can be obtained at each gate. Further, since the toner particles are conveyed by the action of an electric field generated by a voltage applied to an electrode disposed on the toner carrying surface, ordinary non-magnetic toner can be used, and a high-definition color image is realized. You can also. In addition, since a mechanical drive unit is not required in the control unit and the toner carrier that directly affect the print quality, extremely high-definition print quality can be realized. In addition, the toner particles on the toner carrier are transported in the direction above the convex portion by the transport electric field formed by the toner transport electrode disposed on the toner carrier surface, and the voltage applied to the low control electrode is sufficient. Flying characteristics can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration diagram illustrating a configuration example of a toner supply unit of the flying image forming apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram illustrating an outline of a printing unit for describing a printing process of the flying image forming apparatus according to the present invention.

FIG. 4 is a top view (toner carrier side) of a configuration example of a toner flight control electrode of the flight type image forming apparatus according to the present invention.

FIG. 5 is a perspective view showing a cross section of a part of a configuration example of a toner flight control electrode of the flight type image forming apparatus according to the present invention.

FIG. 6 is a diagram illustrating a configuration example of a toner control mechanism including a flight control circuit of the flying image forming apparatus according to the present invention and an operation thereof.

FIG. 7 is a conceptual diagram illustrating the behavior of toner in the flying image forming apparatus according to the present invention.

FIG. 8 is a diagram illustrating an example of a timing chart of control in the flying image forming apparatus according to the present invention.

FIG. 9 is a schematic configuration diagram illustrating another configuration example of the toner supply unit in the flying image forming apparatus according to the present invention.

FIG. 10 is a view for explaining a configuration of the toner carrier shown in FIG. 9;

FIG. 11 is a diagram illustrating another example of the toner control mechanism in the flying image forming apparatus according to the present invention.

FIG. 12 is a schematic diagram illustrating a main part of another configuration example of the toner supply unit in the flying image forming apparatus according to the present invention.

FIG. 13 is a view for explaining another configuration example of the toner flying control mechanism in the flying image forming apparatus according to the present invention.

FIG. 14 is a view for explaining a toner conveying mechanism in the embodiment shown in FIGS. 12 and 13;

FIG. 15 is a diagram illustrating an example of a timing chart of control in the toner transport mechanism illustrated in FIG. 14;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printing part, 2 ... Flight control part, 3 ... Toner supply part, 4 ...
Paper feed unit, 6 fixing unit, 7 controller unit, 11 counter electrode, 21 electrode mounting base, 22 gate, 23 control electrode, 24 power supply line, 25 base board, 26 cover layer, 27 ... toner supply electrode substrate, 28 ... toner supply electrode, 31 ... toner carrier, 32 ... toner layer regulating means, 3
3 supply roller, 34 stirring roller, 35 toner storage tank, 36 toner transport electrode, 37 magnet assembly, 37a
... N pole magnet, 37b S pole magnet, 41 recording medium storage section, 42 pickup roller, 43 registration roller, 44 feed guide plate, 45 paper press plate, 51 conveyance guide plate, 61 heater , 62 ... heat roller, 63
... pressure roller, 64 ... temperature sensor, 71 ... counter electrode power supply, 72 ... control electrode driver, 72a ... ON potential power supply,
72b: OFF potential power supply, 73: toner supply electrode driver, 73a: toner supply electrode power supply, 74: image signal processing unit, 75: toner transport electrode driver, F: toner flying direction, M: magnet assembly rotating direction, P ... Recording medium, S: moving direction of recording medium, T: toner.

Claims (5)

[Claims] 1. A toner carrier carrying toner particles charged to a predetermined polarity, and a gate disposed at a predetermined gap from the toner carrier and capable of passing toner particles flying from above the toner carrier. A control means including a control electrode capable of applying a voltage for controlling passage of the gate, and a voltage application having a polarity opposite to the polarity of the toner on the toner carrier is applied between the control means and the opposite side to the toner carrier. With a possible counter electrode,
An image for forming an image on a recording medium that relatively moves between a counter electrode and a control electrode by selectively applying a voltage to a control electrode of the control means according to an image signal and controlling the passage of toner particles at a gate. In the forming apparatus, in order to secure a sufficient amount of toner particles, a flying type image is provided, which has a transporting unit that transports the toner particles in the direction of the counter electrode on a side opposite to the counter electrode between the gates. Forming equipment. 2. The flying image forming apparatus according to claim 1, wherein said transport means has an opening and a transport electrode disposed on a control electrode side, and is provided close to said toner carrier. A substrate having a polarity opposite to that of the toner particles on the toner carrier before the flying voltage is applied to the control electrode. A flying type image forming apparatus, which transports toner particles. 3. The flying-type image forming apparatus according to claim 1, wherein a convex portion is provided as a portion of the toner carrier at a position corresponding to the gate on the surface of the toner carrier, and toner particles are formed on the toner carrier. A moving means for moving the toner particles, and transporting the toner particles in the direction of the counter electrode along the shape of the projection by moving the toner particles. 4. The flying image forming apparatus according to claim 3, wherein the toner particles are magnetic toner particles, and the moving means is constituted by a non-magnetic member and the toner carrier is a non-magnetic member. A flying image forming apparatus, wherein a rotatable magnet assembly is provided inside a body, and toner particles are moved on the toner carrier with the rotation of the magnet assembly. 5. The flying image forming apparatus according to claim 3, wherein a plurality of electrodes are continuously arranged on the toner carrier in the traveling direction of the recording medium as the moving means, and the plurality of electrodes are provided on the plurality of electrodes. A flying image forming apparatus, wherein toner particles are moved on the toner carrier by sequentially applying a voltage.