JPH08207350A - Image-forming apparatus - Google Patents

Abstract

PURPOSE: To make an apparatus compact and cost-saving by constituting a power source part of a power-feeding means of a material of low dielectric strength. CONSTITUTION: When receiving a heat-generating/driving signal from a control unit 70, a heat generation source circuit 65 applies AC100V to a pair of power feed brushes. On the other hand, when a heat generation-stopping signal is received, the heat generation source circuit, 65 stops the outputting of 100V. When a high voltage driving signal is received from the control unit 70, a voltage application circuit 71 applies a high voltage of +1kV to a back electrode roller 51. When a high voltage-stopping signal is received, the circuit 71 stops the outputting of the high voltage. The control unit 70 does not output the heat-generating/driving signal and high voltage driving signal at the same time.

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 applicable to a copying machine, a printer, a facsimile, etc., by controlling the voltage of control electrodes of a plurality of openings formed in an aperture electrode body, The present invention relates to an image forming apparatus that temporarily adheres toner that has passed through an opening to an intermediate recording medium and conveys the toner, and then transfers the toner to the image recording medium, and more particularly to an image forming apparatus that fixes a toner image to the image recording medium at the same time.

[0002]

2. Description of the Related Art Conventionally, as an image recording medium, not only a recording sheet but also a thick one such as cloth can be formed with an insulating sheet arranged in a line in a direction orthogonal to a conveying direction of the image recording medium. And an aperture electrode body formed by forming a plurality of openings and an electrode array composed of a plurality of control electrodes located in the vicinity of these openings, and providing a back electrode between the aperture electrode body and the image recording medium. A transfer drum (corresponding to an intermediate recording medium) that is in partial contact with the image recording medium is rotatably driven in synchronism with the conveyance speed of the image recording medium. The toner once attached to the transfer drum is conveyed to the transfer position, then transferred to the image recording medium by the transfer mechanism including the transfer corona, and then heated and fixed by the fixing mechanism. To configure as proposed imageable image forming apparatus to various thick image recording medium such as a resin or a metallic or fabric (Patent 4─152154
(See the official gazette).

However, in this type of image forming apparatus, a transfer mechanism for transferring the toner adhering to the transfer drum to the image recording medium at a predetermined transfer position is provided, and the toner image transferred to the image recording medium is imaged. Since the fixing mechanism for fixing to the recording medium is separately provided, the image forming apparatus becomes large in size, the number of parts increases, and the assembling work and the adjusting work become complicated. A flexible intermediate recording medium composed of a body,
A pair of energizing electrodes, which are driven to rotate through a rear electrode roller arranged in the vicinity of the electrode array and a driving roller arranged at the transfer position, and which come into contact with the left and right ends of the intermediate recording medium, respectively. It is provided at both left and right ends of the drive roller, and, for example, +1 KV is applied to the back electrode roller, while AC100 V is applied to the intermediate recording medium via these energizing electrodes to contact these energizing electrodes. Since the transfer operation portion of the intermediate recording medium generates heat, the toner that has passed through the opening of the aperture electrode body is attached to the intermediate recording medium by the electrostatic force received from the rear electrode roller, while the toner image attached to the intermediate recording medium is image-recorded. The idea of the image forming apparatus is such that transfer and fixing to a medium can be simultaneously performed.

[0004]

As has been conceived by the inventor of the present application, in an image forming apparatus capable of simultaneously processing transfer and fixing of a toner image attached to an intermediate recording medium to the image recording medium, On the back electrode roller, for example,
When AC 100 V is applied to the intermediate recording medium through the pair of energizing electrodes while applying +1 KV, the intermediate recording medium that is orbitally driven while being in contact with the pair of energizing electrodes and the rear electrode roller has a resistance. + 1K applied to the back electrode roller because it is composed of a semi-conductive heating element
V is AC10 via the intermediate recording medium and the current-carrying electrode.
Since it is applied to the AC power supply unit that applies 0 V, and this AC power supply unit needs to have a withstand voltage of 1 KV or more, there is a problem that the AC power supply unit becomes large and the cost becomes high. .

An object of the present invention is to make the power supply of the energizing means for heating the intermediate recording medium a low withstand voltage so that the size and cost can be reduced and the toner image can be transferred to the image recording medium. An object of the present invention is to provide an image forming apparatus capable of simultaneously performing fixing and fixing.

[0006]

According to another aspect of the present invention, there is provided an image forming apparatus, wherein a plurality of openings are provided in an insulating sheet in a direction orthogonal to a conveying direction of an image recording medium, and a plurality of openings are provided near the openings. Of the control electrode, an aperture electrode body formed with an electrode array, a toner supply mechanism for supplying toner to the electrode array of the aperture electrode body, and a plurality of openings of the aperture electrode body facing from the side opposite to the toner supply mechanism. An image including a back electrode, a voltage applying unit that applies a predetermined voltage to the back electrode, and an electrode control unit that individually controls the drive voltage applied to the plurality of control electrodes of the electrode array based on the image signal. In the forming apparatus, a flexible intermediate recording medium having a resistance heating element, a back electrode roller as a back electrode, and at least one roller member parallel to the back electrode roller are interposed. And a transfer driving mechanism that drives the intermediate recording medium to rotate in a predetermined direction, and a transfer mechanism that transfers the toner that has passed through the opening to the intermediate recording medium, conveys it, and transfers it to the image recording medium at a predetermined transfer position. Of the intermediate recording medium, at least a predetermined transfer position and a transfer operation portion located in the vicinity thereof are energized via a roller member, and an energizing means and a voltage applying means and an energizing means are switched so that they are not simultaneously operated. And a switching control means for controlling the switching.

According to a second aspect of the present invention, in the first aspect of the invention, the intermediate recording medium is an endless belt member having a width equal to or larger than the maximum width of the image recording medium, and the energization is performed. The means includes a pair of energizing electrodes which are provided at both ends of the roller member and are in contact with both ends of the resistance heating element of the intermediate recording medium in the width direction. According to a third aspect of the present invention, in the first or second aspect of the invention, the intermediate recording medium is entirely constituted by a resistance heating element. An image forming apparatus according to a fourth aspect is the image forming apparatus according to the first or second aspect, wherein the intermediate recording medium comprises a resistance heating element and an insulating coating formed on an outer surface of the resistance heating element.

An image forming apparatus according to a fifth aspect of the present invention is an electrode comprising a plurality of openings arranged in an insulating sheet in a direction orthogonal to the conveying direction of the image recording medium and a plurality of control electrodes located in the vicinity of these openings. An aperture electrode body forming an array,
A toner supply mechanism that supplies toner to the electrode array of the aperture electrode body, a back electrode that faces the toner supply mechanism from the side opposite to the toner supply mechanism with a plurality of openings in the aperture electrode body, with a conveyance gap for the image recording medium. In an image forming apparatus including a voltage applying unit that applies a predetermined voltage to electrodes and an electrode control unit that individually controls drive voltages applied to a plurality of control electrodes of an electrode array based on an image signal, a resistance heating element is provided. A flexible intermediate recording medium, and a transfer driving mechanism that drives the intermediate recording medium to rotate in a predetermined direction via a back electrode roller as a back electrode and at least one roller member parallel to the back electrode roller. The toner passing through the opening is attached to the intermediate recording medium and conveyed.
A transfer mechanism for transferring to an image recording medium at a predetermined transfer position, an energizing means for energizing at least a predetermined transfer position of the intermediate recording medium and a transfer operation portion located in the vicinity thereof via a roller member, and a rear surface. And an insulating coating formed on the outer peripheral surface of a back electrode roller as an electrode.

[0009]

In the image forming apparatus according to the present invention, the aperture electrode body is formed by forming a plurality of openings in the insulating sheet and an electrode array consisting of a plurality of control electrodes located in the vicinity of these openings. Toner is supplied to the electrode array by the toner supply mechanism, and the intermediate recording medium has a rear electrode roller as a rear electrode facing the plurality of openings of the aperture electrode body from the side opposite to the toner supply mechanism and a parallel surface of the rear electrode roller. When the transfer drive mechanism is orbitally driven in a predetermined direction via at least one roller member, the switching control means first activates the voltage applying means and the energizing means so that the image formation is switched. A predetermined voltage is applied to the back electrode from the voltage applying means. Then, the electrode control means individually controls the driving voltage applied to the plurality of control electrodes of the electrode array based on the image signal, so that the electric field between the control electrode and the toner supply mechanism and the control electrode and the back electrode are controlled. The toner that has flown through the plurality of openings via the electric field is sequentially attached to the intermediate recording medium having the resistance heating element.

After the toner image for one page is attached to the intermediate recording medium, the switching control means switches the toner image so that the energizing means is activated and the voltage applying means is not activated. By the energizing means, at least a predetermined transfer position of the intermediate recording medium and a transfer operation part located in the vicinity thereof are energized via the roller member, and the resistance heating element of the transfer operation part generates heat, The toner image attached to the intermediate recording medium is conveyed to a predetermined transfer position and then transferred to and fixed on the image recording medium by the heat generated by the resistance heating element.

That is, regardless of whether the image is formed on the intermediate recording medium or the toner image attached to the intermediate recording medium is transferred, the voltage applying means and the energizing means are switched so as not to operate at the same time. Therefore, the predetermined voltage of the voltage applying means does not affect the power supply section of the energizing means. Therefore, the power supply unit of the energizing unit can be configured to have a low withstand voltage, so that the size and cost can be reduced, and the transfer and the fixing of the toner image onto the image recording medium can be simultaneously processed.

In the image forming apparatus of the second aspect, the same operation as in the first aspect is achieved, but the intermediate recording medium is composed of an endless belt body having a width equal to or larger than the maximum width of the image recording medium, The energizing means is provided at both ends of the roller member, and is provided with a pair of energizing electrodes that come into contact with both ends of the resistance heating element of the intermediate recording medium in the width direction. Only the transfer operation portion can heat efficiently and easily over the entire width of the intermediate recording medium.

In the image forming apparatus of claim 3, the same operation as that of claim 1 or 2 is achieved, but since the intermediate recording medium is entirely constituted by a resistance heating element, a polyimide resin or the like is used. By including a heat-generating material such as carbon particles or fine powder of metal in the heat-resistant base material of
The intermediate recording medium as the resistance heating element can be easily manufactured, and the heating value can be easily adjusted depending on the content of the heating material.

According to the image forming apparatus of claim 4, the same operation as that of claim 1 or 2 is achieved, but the intermediate recording medium comprises a resistance heating element and an insulating coating formed on the outer surface thereof. As a result, the resistance heating element can generate heat by being energized through the pair of energizing electrodes, and further, the toner charged to a predetermined polarity can be conveyed while being surely attached by the insulating coating.

An image forming apparatus according to a fifth aspect operates in substantially the same manner as the first aspect, but differs in the following points. That is, since the insulating coating is formed on the outer peripheral surface of the back electrode roller as the back electrode, the intermediate recording medium can be electrically secured to the back electrode roller even when the voltage applying means and the energizing means operate simultaneously. Since it can be insulated, the predetermined voltage of the voltage applying unit does not affect the power supply unit of the energizing unit. Therefore, the power supply unit of the energizing unit can be configured to have a low withstand voltage, so that the size and cost can be reduced, and the image forming process for attaching the toner to the intermediate recording medium can be performed while performing the image recording of the toner image. Transfer to the medium and fixing can be processed simultaneously.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the image forming apparatus 1 is an image recording apparatus applicable to a copying machine, a printer, a facsimile, a plotter, and the like. The image forming apparatus 1 has a sheet P (image A paper transport mechanism 10 for transporting a recording medium, a predetermined amount of toner 3, a toner supply mechanism 30, and a toner case 3 of the toner supply mechanism 30.
1 and the toner 3 that has passed through the opening 42 of the aperture electrode body 40 are attached to the intermediate recording medium 53 and conveyed, and the paper P is transferred at a predetermined transfer position.
And a transfer mechanism 50 for transferring to.

The paper transport mechanism 10 includes a plurality of guide plates 12 to 15 for supporting the transported paper P, a plurality of transport rollers 16 to 19, a transport roller 16,
A conveyance roller (not shown) that supports and conveys a portion of the paper P at both ends in the width direction between the paper 17 and the conveyance rollers 18 and 19, and the paper P in the paper cassette 11 is fed one by one. A sheet feeding roller (not shown), a roller driving mechanism (not shown) for driving the sheet conveying mechanism 10, etc., and a sheet cassette 11 storing a large number of sheets P is provided on the front side of the main body frame 2. On the rear side of the main body frame 2, there is provided a paper discharge tray 20 for receiving the recorded and discharged paper P.

Next, the toner supply mechanism 30 will be explained. In the toner case 31 having a width wider than the maximum width of the paper P in the direction orthogonal to the paper conveyance direction (from front to back), toner having electric insulation is provided. 3 is stored. Further, inside the toner case 31, a toner conveying roller 32 and a toner supplying roller 33 for supplying the toner 3 to the toner conveying roller 32 are horizontally arranged in the left-right direction. Each is rotatably supported.

Here, the toner supply roller 33 is composed of a silicon foam, and the toner supply roller 33 transfers the toner 3 toward the toner conveying roller 32 and is in frictional contact with the toner 3. The toner 3 is charged on the negative electrode. The toner carrying roller 32 is a roller body 32a made of a synthetic resin foam made of an insulating material.
A toner sleeve 32b made of nickel is externally fitted to the outer circumference of the toner carrier roller 32, and the toner 3 attached to the surface of the toner carrier roller 32 by electrostatic force is carried in the direction of arrow A. The toner supply roller 33 and the toner transport roller 32 are rotationally driven in the arrow B direction and the arrow A direction by a roller driving mechanism (not shown). Incidentally, a synthetic resin insulating coating or semi-conductive coating may be formed on the entire circumferential surface of the toner transport roller 32.

Inside the toner case 31, a toner layer restriction blade 34 made of an insulating material having a thin plate-like elasticity is attached, and its curved portion is in pressing contact with the toner conveying roller 32, and the toner conveying roller 32 is conveyed. The layer thickness of the toner 3 adhered to the surface of the roller 32 in layers is regulated by the toner layer regulation blade 34 to a predetermined thickness (about 40 to 50 μm).

The upper end of the toner case 31 is substantially covered with a roof so as to cover the opening at the upper end of the toner case 31 and contact the upper end of the toner transport roller 32 from above with the layered toner 3 interposed therebetween. An aperture electrode body 40 inclined to the mold is attached. This aperture electrode body 4
0 will be described. As shown in FIGS. 2 and 3, the aperture electrode body 40 includes an insulating sheet 41 made of a synthetic resin (for example, polyimide) and having a thickness of about 25 μm, and a large number of minute openings 42. On the surface of the insulating sheet 41, an electrode array 44 composed of a large number of annular control electrodes 43 respectively formed on the outer peripheral portions of a large number of openings 42, and a large number of conducting wires 45 extending from the large number of control electrodes 43 in predetermined directions. Etc.

A large number of openings 42 are formed in a row in the horizontal direction orthogonal to the conveyance direction of the paper P at predetermined minute intervals at a position approximately in the center of the insulating sheet 41 in the front-rear direction. On the surface of the insulating sheet 41, an annular control electrode 43 made of a copper film and surrounding the outer circumference of each opening 42 and a conductive wire 45 made of a copper film integrally extending from the control electrode 43 are formed. . The diameter of the opening 42 is, for example, about 65 μm.
The pitch between the openings 42 is about 127 μm. For example, in the case of A4 size paper, the number of openings 42 (that is, the number of control electrodes 43) is about 1700.

By the way, the toner 3 provided directly above the aperture electrode body 40 and having passed through the opening 42 is attached to the intermediate recording medium 53 and conveyed, while the toner 3 of the intermediate recording medium 53 is transferred onto the paper P. The transfer mechanism 50 will be described with reference to FIGS. 1 and 3 to 5. Immediately above the aperture electrode body 40, a metal rear electrode roller 5 is provided.
1 is disposed horizontally in the left-right direction, and a drive roller (corresponding to a roller member) 52 made of synthetic resin having excellent heat resistance is horizontally disposed in the left-right direction above the back electrode roller 51. These rollers 51,
Each 52 is rotatably supported. Then, the endless intermediate recording medium 53 causes the two rollers 51, 52 to
It is stretched over. This endless intermediate recording medium 5
The peripheral length of 3 is longer than the maximum length of the paper P.

Further, the pressing roller 5 which comes into pressure contact with the driving roller 52 from above via the intermediate recording medium 53.
4 is arranged parallel to the drive roller 52 and is rotatably supported. The intermediate recording medium 53 has a width dimension equal to or larger than the maximum width of the paper P and is excellent in flexibility and heat resistance. For example, a resistance heat generation having a thickness of about 25 to 100 μm made of polyimide resin containing carbon particles. The outer surface of the body 53a is made of a polyimide resin having excellent heat resistance and has a thickness of about 25 to 1
It is an endless belt body configured by adhering a flexible insulating coating 53b of 00 μm.

That is, the toner 3 flying from the surface of the toner conveying roller 32 and passing through the opening 42 adheres to the insulating coating 53b on the outer peripheral portion of the intermediate recording medium 53 according to the drive voltage applied to the control electrode 43. By cooperating with the driving roller 52 and the pressing roller 54, the paper P and the intermediate recording medium 53 are pressed, so that the toner 3 attached to the intermediate recording medium 53 can be transferred to the paper P. .
Then, by a transfer driving mechanism (not shown), the driving roller 5
By rotating 2 in the counterclockwise direction in FIG. 4, the intermediate recording medium 53 is driven in the counterclockwise direction, and at the same time, the back electrode roller 51 and the pressing roller 5 are rotated.
4 is driven by the intermediate recording medium 53 which is rotated by the rotation of the driving roller 52. Here, the drive roller 52 is elastically biased upward so that a predetermined tension can always be applied to the intermediate recording medium 53.

Next, the resistance heating element 53 of the intermediate recording medium 53.
The energization mechanism 60 that heats a will be described with reference to FIGS. 4 and 5. A pair of cylindrical energizing electrodes 61 and 62 are externally fitted and fixed to the left and right ends of the drive roller 52, and energizing brushes 63 and 64 correspond to the energizing electrodes 61 and 62, respectively. Then, the heating brushes 63, 64 are brought into contact with each other in a pressing manner, and a heating power supply circuit 65 for outputting AC 100 V is connected to each of the energizing brushes 63, 64.
The left and right ends of the resistance heating element 53a contact the energizing electrodes 61 and 62 from the outside.

Then, the AC1 from the heating power supply circuit 65
When 00V is applied to both energizing brushes 63 and 64, it is applied to the resistance heating element 53a via the pair of energizing electrodes 61 and 62 which contact these energizing brushes 63 and 64, and the resistance heating element 53a Of these, these energizing electrodes 61,
The transfer operation portion in contact with 62 generates heat at a predetermined fixing temperature (for example, about 130 ° C.).

Next, the control system of the image forming apparatus 1 will be briefly described with reference to FIG. 3. In the back electrode roller 51, a voltage applying circuit (corresponding to voltage applying means) 7 is provided.
1, a high voltage of about +1 KV is applied, and the negatively charged toner 3 is attracted to the back electrode roller 51 by a large electrostatic force. On the other hand, a control unit 70 that receives an image signal from the outside and a power supply circuit 72
And an electrode drive circuit 73, and the control unit 70
Thus, the drive voltage applied to the large number of control electrodes 43 via the electrode drive circuit 73 is controlled based on the image signal. Further, the toner carrying roller 32 is always grounded.

That is, a large number of conductive wires 4 of the aperture electrode body 40.
5 is connected to an electrode drive circuit 73 via a control line 74 composed of a large number of signal lines.
Two kinds of drive voltages of + 30V and -30V are supplied from the power supply circuit 72. The control unit 70 sends a control signal corresponding to the image signal for the multiple control electrodes 43 to the electrode drive circuit 7.
3 simultaneously, and the electrode drive circuit 73 applies a drive voltage of +30 V to the control line 7 for each control electrode 43 for recording pixels.
Each control electrode 4 which outputs through 4 and does not record pixels
A drive voltage of -30 V is output to the control line 3 via the control line 74.

Further, the heat generation power circuit 65 is connected to the control unit 70, and when a heat generation drive signal is received from the control unit 70, AC 100 V is applied to the pair of energizing brushes 63 and 64, while heat generation is stopped. When receiving the signal, the output of AC100V is stopped. Also,
Similarly, the voltage application circuit 71 applies a high voltage of about +1 KV to the back electrode roller 51 when receiving a high voltage drive signal from the control unit 70, and outputs the high voltage when receiving a high voltage stop signal. Discontinue. Here, the control unit 70 does not output the heat generation drive signal and the high voltage drive signal at the same time. That is, the control unit 70 is configured to include electrode control means and switching control means.

Next, the image forming operation of the image forming apparatus 1 described above and the operation of the image forming apparatus 1 will be described. First, when the image forming process is started, as shown in FIG. 6, the control unit 70 outputs a high voltage drive signal to the voltage applying circuit 71 and outputs a heat generation stop signal to the heat generation power supply circuit 65. While a high voltage of about +1 KV is applied to the back electrode roller 51 by the voltage application circuit 71, the resistance heating element 53a of the intermediate recording medium 53 does not generate heat. At this time, the high voltage applied to the back electrode roller 51 is applied not only to the entire intermediate recording medium 53 that contacts the back electrode roller 51, but also to the pair of energizations that contact the intermediate recording medium 53. The same applies to the electrodes 61 and 62 and the energizing brushes 63 and 64.

Then, as shown in FIGS. 2, 3, and 6,
The toner 3 charged on the negative electrode is transported to the electrode array 44 while being attached to the peripheral surface of the toner transport roller 32, and when + 30V is applied to the control electrode 43, the toner 3 is discharged from the control electrode 43. The rear surface electrode receives electrostatic force from the electric field toward the transport roller 32, flies toward the control electrode 43 through the opening 42, and further receives electrostatic force from the strong electric field toward the control electrode 43 from the rear electrode roller 51 to receive the rear electrode. Flying toward the roller 51, the intermediate recording medium 5
3 collides with and adheres.

However, when −30 V is applied to the control electrode 43, the toner 3 receives an electrostatic force from the electric field from the toner carrying roller 32 toward the control electrode 43, and does not pass through the opening 42. Then, the intermediate recording medium 53 is circularly driven by the transfer mechanism 50, so that the toner image for one page based on the image signal is sequentially attached to the intermediate recording medium 53 and conveyed. That is, during the image forming process, the heat-generating power supply circuit 65 is configured so that the pair of energizing brushes 63,
Since it is in the state of being electrically disconnected with respect to 64, the high voltage of about +1 KV applied to the energizing brushes 63 and 64 is not applied to the heat generating power supply circuit 65.

When the toner image for one page is completely attached to the intermediate recording medium 53, the control unit 70
Since -30V is output to all the control electrodes 43 and a high voltage stop signal is output to the voltage applying circuit 71 and a heat generation drive signal is output to the heat generation power supply circuit 65 at the end of the image forming process, the resistance is reduced. The energizing electrode 61 of the heating element 53a,
The transfer operation portion in contact with 62 heats up to a predetermined fixing temperature over the entire width, while the application of the high voltage to the back electrode roller 51 is stopped. Here, the intermediate recording medium 53
Even if the application of the high voltage to the intermediate recording medium 53 is stopped, the toner 3 on the intermediate recording medium 53 falls off from the adhesion surface due to the Van der Waals force or the image force that interacts with the intermediate recording medium 53 and the toner particles. There is nothing to do.

As shown in FIGS. 4 and 7, the toner 3 attached to the intermediate recording medium 53 and conveyed is gradually softened as it approaches the transfer position due to heat generation over the entire width of the transfer operation portion. Then, the toner 3 is changed to a fixable state, and the softened toner 3 is reliably transferred to the sheet P and fixed at the same time by being pressed by the pressing roller 54. Then, the fixing-processed paper P is conveyed in the paper conveyance direction and stored in the paper discharge tray 20.

In this way, by controlling the drive voltage applied to the electrode array 44, the toner 3 passing through the opening 42 is attached to the intermediate recording medium 43 to form an image, and the toner is attached to the intermediate recording medium 53. In any case when the toner image is transferred to the paper P, the voltage application circuit 71 and the heat generation power supply circuit 65 are switched so as not to operate at the same time, so that +1 KV of the voltage application circuit 71 is the heat generation power supply. It does not affect the circuit 65. Therefore, the heat generation power supply circuit 65 can be configured to have a low withstand voltage, so that the size and cost can be reduced, and the transfer and fixing of the toner image onto the paper P can be simultaneously processed.

By the way, as shown in FIG. 8, an insulating coating 80 made of polyimide resin having an insulating property and having a thickness of about 25 to 50 .mu.m is formed on the outer peripheral surface of the metallic back electrode roller 51A to form an intermediate layer. The transfer mechanism 50A may be configured such that the resistance heating element 53a of the recording medium 53A is electrically and reliably insulated from the back electrode roller 51A.
In this case, the voltage of +1 KV applied to the back electrode roller 51A by the voltage application circuit 71A is equivalent to the insulation coating 8
0 does not affect the resistance heating element 53a,
The control unit 70A outputs a high voltage drive signal to the voltage application circuit 71A and also outputs a heat generation drive signal to the heat generation power supply circuit 65A so that the transfer and fixing processes can be executed while executing the image forming process. Also in this case, the heat generating power supply circuit 65A can be configured with a low withstand voltage to reduce the size and cost, and can simultaneously transfer and fix the toner image to the image recording medium.

The entire intermediate recording medium 53, 53A is composed of a resistance heating element, yellow, cyan, magenta,
Various modifications may be made based on existing technology or technology obvious to those skilled in the art within the scope of the technical idea of the present invention, such as a structure capable of recording a color image provided with each black toner supply mechanism. possible. The present invention can be applied to various image forming apparatuses configured to convey the paper P in the vertical direction and control the image recording of the toner image on the image recording medium by the aperture electrode body 40. Of course.

[0039]

According to the image forming apparatus of the first aspect, the transfer mechanism having the intermediate recording medium and the transfer driving mechanism, the energizing means, and the switching control means are provided, so that the image is formed on the intermediate recording medium. Regardless of whether the toner image attached to the intermediate recording medium is transferred or formed, the voltage application unit and the energization unit can be switched so as not to operate at the same time. The voltage does not affect the power supply section of the energizing means. Therefore, the power supply unit of the energizing unit can be configured to have a low withstand voltage, so that the size and cost can be reduced, and the transfer and the fixing of the toner image onto the image recording medium can be simultaneously processed.

According to the image forming apparatus of the second aspect, the same effect as that of the first aspect is obtained, but the intermediate recording medium is composed of an endless belt having a width equal to or larger than the maximum width of the image recording medium. The energizing means is provided at both ends of the roller member and is provided with a pair of energizing electrodes that come into contact with both ends of the resistance heating element of the intermediate recording medium in the width direction. Only the transfer operation portion of the medium can efficiently and easily generate heat over the entire width of the intermediate recording medium.

According to the image forming apparatus of claim 3, the same effect as that of claim 1 or 2 can be obtained, but since the intermediate recording medium is entirely constituted by a resistance heating element,
An intermediate recording medium as a resistance heating element can be easily manufactured by including a heat-generating material such as carbon particles or fine powder of metal in a heat-resistant substrate such as a polyimide resin. Thus, the heat generation amount can be easily adjusted.

According to the image forming apparatus of claim 4, the same effect as that of claim 1 or 2 is obtained, but the intermediate recording medium includes a resistance heating element and an insulating coating formed on the outer surface thereof. Therefore, the resistance heating element can generate heat by being energized through the pair of energizing electrodes, and further, the toner charged to a predetermined polarity can be reliably adhered by the insulating coating and conveyed.

According to the image forming apparatus of the fifth aspect, the transfer mechanism including the intermediate recording medium and the transfer driving mechanism, the energizing means, and the back electrode roller as the back electrode are provided with the insulating film, so that the voltage is applied. Even if the applying means and the energizing means operate simultaneously, the predetermined voltage of the voltage applying means affects the power supply section of the energizing means because the intermediate recording medium can be electrically and reliably insulated from the back electrode roller. There is no. Therefore, the power supply unit of the energizing unit can be configured to have a low withstand voltage, so that the size and cost can be reduced, and the image forming process for attaching the toner to the intermediate recording medium can be performed while performing the image recording of the toner image. Transfer to the medium and fixing can be processed simultaneously.

[Brief description of drawings]

FIG. 1 is a partial vertical schematic side view of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a partial perspective view of an aperture electrode body of the image forming apparatus as viewed from a control electrode side.

FIG. 3 is a diagram showing an aperture electrode body and a rear electrode roller.
FIG. 3 is an enlarged partial side view of a main part of FIG.

FIG. 4 is an enlarged partial side view of a main part of FIG. 1, showing a driving roller and a pressing roller.

5 is a vertical sectional front view taken along the line EE of FIG.

FIG. 6 is an enlarged partial side view of an essential part of FIG. 1 for explaining an image forming operation.

FIG. 7 is a diagram corresponding to FIG. 6 for explaining transfer and fixing.

FIG. 8 is a view corresponding to FIG. 6 in which an insulating coating is formed on the outer peripheral surface of the back electrode roller according to the modification.

[Explanation of symbols]

 1 Image Forming Apparatus 2 Body Frame 3 Toner 30 Toner Supply Mechanism 32 Toner Conveying Roller 33 Toner Supply Roller 40 Aperture Electrode Body 42 Opening 43 Control Electrode 44 Electrode Array 50 Transfer Mechanism 51 Rear Electrode Roller 52 Drive Roller 53 Intermediate Recording Medium 60 Energization Mechanism 61/62 Current-carrying electrode 63/64 Current-carrying brush 65 Heat-generating power supply circuit 70 Control unit 71 High-voltage power supply circuit 80 Insulating film P Paper

Claims (5)

[Claims] 1. An aperture electrode in which a plurality of openings arranged in a line in a direction orthogonal to a conveyance direction of an image recording medium and an electrode array formed of a plurality of control electrodes near the openings are formed on an insulating sheet. Body, a toner supply mechanism for supplying toner to the electrode array of the aperture electrode body, a back electrode facing the plurality of openings of the aperture electrode body from the side opposite to the toner supply mechanism, and a predetermined voltage applied to the back electrode. In an image forming apparatus provided with a voltage applying means for applying and an electrode controlling means for individually controlling a driving voltage applied to a plurality of control electrodes of an electrode array based on an image signal, a flexible heating device having a resistance heating element is provided. The intermediate recording medium is orbitally driven in a predetermined direction through the intermediate recording medium, the back electrode roller as the back electrode, and at least one roller member parallel to the back electrode roller. A transfer driving mechanism that allows the toner that has passed through the opening to adhere to the intermediate recording medium and is conveyed, and transfer the toner to the image recording medium at a predetermined transfer position; and at least the intermediate recording medium, An energizing means for energizing the transfer operation portion located at a predetermined transfer position and its vicinity through the roller member, and a switching control means for switching and operating the voltage applying means and the energizing means so as not to operate simultaneously, An image forming apparatus comprising: 2. The intermediate recording medium is composed of an endless belt having a width equal to or larger than the maximum width of the image recording medium, and the energizing means is provided at both ends of the roller member.
The image forming apparatus according to claim 1, further comprising a pair of energizing electrodes that are in contact with both ends of the resistance heating element of the intermediate recording medium in the width direction. 3. The image forming apparatus according to claim 1, wherein the intermediate recording medium is entirely composed of a resistance heating element. 4. The image forming apparatus according to claim 1, wherein the intermediate recording medium comprises a resistance heating element and an insulating coating formed on an outer surface of the resistance heating element. 5. An aperture electrode in which a plurality of openings arranged in a line in a direction orthogonal to a conveyance direction of an image recording medium and an electrode array consisting of a plurality of control electrodes located in the vicinity of these openings are formed on an insulating sheet. Body, a toner supply mechanism that supplies toner to the electrode array of the aperture electrode body, and a plurality of openings of the aperture electrode body, and a back electrode that opposes the toner supply mechanism from the side opposite to the toner supply mechanism with a conveyance gap for the image recording medium. An image forming apparatus comprising: a voltage applying unit that applies a predetermined voltage to the back electrode, and an electrode control unit that individually controls a drive voltage applied to a plurality of control electrodes of the electrode array based on an image signal, A flexible intermediate recording medium having a resistance heating element, a back electrode roller as the back electrode, and at least one roller member parallel to the back electrode roller A transfer driving mechanism that drives the recording medium to rotate in a predetermined direction, attaches the toner that has passed through the opening to the intermediate recording medium, conveys the toner, and transfers the toner to the image recording medium at a predetermined transfer position; An energization unit that energizes at least the transfer operation portion located in the vicinity of the predetermined transfer position of the recording medium via the roller member, and formed on the outer peripheral surface of the back electrode roller as the back electrode. An image forming apparatus comprising: an insulating film.