JPH0531947A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To obviate the connection between recording electrodes and a circuit board by transmitting signal voltage from a first recording electrode to a second recording electrode through a conductive developer and further bonding the conductive developer to a recording medium from the second recording electrode in the peripheral part of the recording medium to form an image. CONSTITUTION:The signal voltage from the driving IC 3 on a circuit board 2 is applied to a second recording electrode 9 through the first electrode 1 formed on the circuit board 2 so as to provide a wiring pattern. At this time, the position of the first electrode 1 is held so as to provide a distance of a degree receiving compression obtaining a resistance value wherein the resistance of conductive magnetic toner 6 is sufficiently low to transmit a signal with respect to the second recording electrode 9 on a sleeve 4. By this constitution, the applied signal voltage is transmitted to the second recording electrode 9 through the toner 6 and almost simultaneously applied to the second recording electrode 9 positioned at the shortest distance from the conductive layer 7b of a recording sheet 7 and the toner 6 is electrostatically bonded to the surface of the recording sheet 7 corresponding to an image signal to form an image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer or a display device for electrostatically attaching a developer to a recording medium to form an image.

[0002]

2. Description of the Related Art Conventionally, in this type of device, a Japanese Patent Publication
It is known that an image is formed by the method described in Japanese Patent Publication No. 51-46707. An example of an actual product produced by using such a method is an image forming apparatus as shown in FIGS. 8 and 9. FIG. 8 is a sectional view around the developing portion of the apparatus, and FIG. 9 is a perspective view thereof.

In FIGS. 8 and 9, a conductive magnetic toner 51 having an outer periphery of a non-magnetic cylindrical sleeve (hereinafter simply referred to as “sleeve”) 50 is provided with a rotating magnet (hereinafter referred to as “magnet”) provided coaxially with the sleeve 50. A magnetic field of a roller 52) is applied to the outer peripheral surface of the sleeve 50 for conveyance. Then, the toner 51 is passed through the recording electrode 53 having a conductor portion provided on the outer peripheral surface of the sleeve 50, and the conductive layer 54b, from the inner side provided adjacent to the sleeve 50,
A voltage is applied to the recording electrode 53 by the driving IC 56 provided on the circuit board 55 while being in physical contact with the recording medium 54 formed by laminating the insulating layer (or dielectric layer) 54a. At this time, by applying a voltage according to image information between the recording electrode 53 and the conductive layer 54b of the recording medium 54, the toner 51 is attached to the insulating layer 54a of the recording medium 54 to form an image. is there.

The recording electrode 53 is formed by forming an electrode cable 53b on a flexible printed circuit board 53a, and a conductor portion which contributes to recording is exposed at the tip of the electrode cable 53b. Further, a hole 53 for passing the toner 51 is provided between the connection portion of the recording electrode 53 with the driving IC 56 and the conductor portion.
c is partially provided.

[0005]

However, in the above-mentioned conventional example, the vicinity of the tip of the recording electrode 53 is fixed on the peripheral surface of the sleeve 50, and the electrode cable 53b is connected to the driving IC 56, which will be described below. It was causing challenges. First, a step of connecting the circuit board 55 and the electrode cable 53b is required in the assembly process. In addition, due to restrictions such as soldering and other connection means used for the above-mentioned connecting portion and the processing accuracy of the electrode cable 53b, and local densification of the wiring pattern pitch by the holes 53c for passing the toner 51, the recording electrodes 53 can be made finer. It is difficult to convert (200 dpi or less). Further magnet roller
In the development method using 52, in order to increase the display speed, it is necessary to increase the rotation speed of the magnet roller 52 or to make the magnet multi-pole, and accordingly, the developing device becomes large, the weight also increases, and the motor However, there is a problem in that the driving force must be increased, which further increases the manufacturing cost.

The present invention has been made to solve the above-mentioned problems of the prior art. The purpose of the present invention is to save the trouble of connecting the recording electrode and the circuit board, and to improve the recording density, high-speed recording, The purpose is to reduce size, weight, and cost.

[0007]

A typical means for solving the above-mentioned problems of the prior art and applied to the embodiments described below is a first recording for applying a voltage to a developer according to image information. An electrode, a driving unit for applying a signal voltage corresponding to image information to the first recording electrode, a recording medium for forming the image by adhering the developer, and the recording electrode and the recording medium. It is characterized by having a developer supply means for supplying a developer between them and a second recording electrode for adhering the developer to a recording medium provided on the peripheral surface of the developer supply means.

[0008]

According to the above construction, the first developer is introduced through the conductive developer.
By transmitting a signal voltage according to image information from the recording electrode to the second recording electrode and further injecting a charge from the second recording electrode to the conductive developer in the peripheral portion of the recording medium, the conductive developer is formed on the recording medium. Can be attached to form an image. As a result, there is no need to connect the circuit board that constitutes the driving means and the flexible cable that constitutes the recording electrode, and there is a restriction due to the processing accuracy of the connection portion and the flexible cable and the wiring pattern pitch due to the holes for passing the developer. It is easy to miniaturize the recording electrode because there is no restriction such as local high density. In addition, it is possible to record at high speed and stable image quality without increasing the rotation speed of the motor that is the drive source of the developer supply unit and without making the magnet multipolar.
At the same time, it is possible to reduce the size and weight of the developing device and reduce the cost.

[0009]

【Example】

(Embodiment 1) Hereinafter, Embodiment 1 of an image forming apparatus to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a sectional view showing a main part of the image forming apparatus, FIG. 2 is a perspective explanatory view of a recording electrode, and FIG. 3 is a sectional explanatory view of a recording medium.

In FIG. 1, reference numeral 1 is a first recording electrode for applying a voltage to a developer in accordance with image information, and an image is driven by a driving IC 3 which is a driving means provided on the circuit board 2. A signal voltage corresponding to information is applied. The first recording electrode 1 and the driving IC 3 are connected by wire bonding.

Reference numeral 4 denotes a non-magnetic cylinder (hereinafter referred to as a "sleeve") which constitutes a developer carrying means, and a rotary magnet 5 is rotatably provided therein. The number of magnetic poles of the rotating magnet 5 in this embodiment is 16 and the number of rotations is 1500 rpm, and the toner 6 as the developer is not transferred to the sleeve by the alternating magnetic field formed by rotating the rotating magnet 5 in the clockwise direction (the arrow direction in the drawing). 4 is conveyed in the counterclockwise direction on the peripheral surface.

The toner 6 is made of a conductive magnetic toner, and is manufactured by internally adding magnetic powder to a plastic resin and then externally adding carbon.
The volume resistance value in the connecting direction of the toner when the toner is formed into a chain by the magnetic brush method is 10 ³ to 10 ⁸ Ωcm.

Reference numeral 7 denotes an endless belt-shaped recording sheet which is a recording medium and is composed of a dielectric layer 7a and a conductive layer 7b. More specifically, as shown in FIG. 3, the dielectric layer 7a is a surface layer 7a ₁
And a resistance layer 7a ₂ . The surface layer 7a
₁ has a volume resistance value of 10 ⁷ to 10 ¹⁶ Ωcm, and 1 to 20 μm.
It is made of a plastic resin having a thickness of m such as butyral resin, acrylic resin, nylon resin, polyester resin, urethane resin, and phenol resin. Further, the resistance layer 7a ₂ has a volume resistance value of 10 ⁰ to 10 ⁷ Ωcm,
It has a thickness of 30 μm and has titanium oxide, aluminum oxide, tin oxide, indium oxide, or the like dispersed in a plastic resin.

The conductive layer 7b has a volume resistance value of 10 ⁰ to 10 ² Ωcm and is 0.8 on the support layer 7b ₁ made of a plastic resin such as polyethylene terephthalate resin or polyimide resin having a thickness of 70 to 300 μm. nm to 1.0 n
Conductive vapor deposition film 7b ₂ of aluminum or the like having a thickness of m
It consists of what formed Reference numeral 8 denotes a conveyance roller for conveying the recording sheet 7 which is a recording medium,
The conveyance speed is set to 129.4 mm / sec, and the recording sheet 7 is conveyed in the direction of the arrow in the figure.

On the outer peripheral surface of the sleeve 4, as shown in FIG. 2, a good conductor such as copper or gold is used, more preferably, a ferromagnetic material such as iron or permalloy is used. The annular second recording electrode 9 is provided by a method such as winding along a direction or winding an electrode pattern sheet formed by etching a thin film.

By rotating the rotary magnet 5,
The conductive magnetic toner 6 is conveyed on the sleeve 4 and supplied onto the second recording electrode 9, and a signal voltage corresponding to the image information generated by the driving IC 3 on the circuit board 2 is applied by the first recording electrode 1. And charge toner 6 (10 ^-8 to 10 ^-7 c)
Recording sheet 7 (1000 to 10,000 p
The toner 6 existing between the conductive layer 7b (F / cm ² ) and the second recording electrode 9 is electrostatically attached to the recording sheet 7 to form an image. Further, the toner 6 used for forming an image once is collected on the second recording electrode 9 immediately below by rotating the endless belt-shaped recording sheet 7 once and passing it through a cleaning brush (not shown). , Can be reused.

An image forming process of the image forming apparatus configured as described above will be described with reference to the drawings. Figure 3
First, the signal voltage output from the driving IC 3 on the circuit board 2 is applied to the second recording electrode 9 via the first recording electrode 1 having a wiring pattern formed on the circuit board 2. At this time, the position of the first recording electrode 1 has a sufficiently low resistance value with respect to the second recording electrode 9 on the sleeve 4 so that the resistance of the conductive magnetic toner 6 that has entered the gap between them can transmit a signal. The distance (0.
4 mm or less). As a result, the signal voltage applied to the first recording electrode 1 is transferred to the second recording electrode 9 via the conductive magnetic toner 6 and the shortest path immediately above the electrode. This signal voltage is applied to the area of the second recording electrode 9 located at the shortest distance (0.4 mm or less) from the conductive layer 7b of the recording sheet 7 almost at the same time along the circumferential direction, and the conductive magnetic field passing through the gap between the two is applied. An electric charge is injected into the toner 6, and the toner 6 electrostatically adheres to the surface of the recording sheet 7 in accordance with the image signal to form an image.

In this embodiment, as a method of transporting the conductive magnetic toner 6 on the surface of the sleeve 4 in the above steps, a method of rotating the rotary magnet 5 inside the sleeve 4 is used. The recording speed is the same as that of the conventional example, but with such a configuration, the circuit board 2 can be provided at any position around the sleeve 4 other than the recording area, and the degree of freedom in design is increased. In addition, the number of parts such as flexible cables can be reduced, the manufacturing cost can be reduced by omitting the connection process between the flexible cable and the circuit board, and the connection such as soldering that reduces the processing accuracy as in the conventional example High-density recording is possible without using any means or flexible cable (200
dpi or more).

(Second Embodiment) FIG. 4 shows a second embodiment of the image forming apparatus according to the present invention. The schematic configuration of the entire apparatus is almost the same as that of the first exemplary embodiment, but the method of transporting toner is configured to rotate the sleeve 4 instead of rotating the rotating magnet 5. According to the above configuration, the toner 6 can be conveyed even if the number of magnetic poles is about four.
It is possible to reduce the size and weight of the developing device. In addition, since the load required for driving the sleeve 4 is lighter than that of the normal rotating magnet 5, it is possible to use a motor with a smaller output, and speedup (1500 rpm or more) is facilitated. Further, since the magnetic field right under the recording electrode is fixed, it is not necessary to synchronize the rotation cycle of the magnet with the timing of applying a signal as in the conventional example.

(Third Embodiment) FIG. 5 shows a third embodiment of the image forming apparatus according to the present invention. The schematic configuration of the entire apparatus is almost the same as that of the first embodiment, but as a toner conveying method, both the rotating magnet 5 and the sleeve 4 are rotated. That is, the rotating magnet 5 is rotated in the clockwise direction to convey the toner 6 in the counterclockwise direction, and the sleeve 4 is rotated in the counterclockwise direction. According to the above configuration, in addition to the effect of the first embodiment, the conveying force of the toner 6 is a combination of the forces in the circumferential direction by both the rotating magnet 5 and the sleeve 4, so that the recording speed can be further increased. (15
00 rpm).

(Embodiment 4) FIGS. 6 and 7 show Embodiment 4 of the image forming apparatus according to the present invention. The schematic structure of the entire apparatus is almost the same as that of Embodiment 1, but in this embodiment, An arc-shaped second recording electrode 9 is provided on the surface of the sleeve 4 at a position facing the recording sheet 7. The second recording electrode 9 is formed of a good conductor such as copper or gold, more preferably a ferromagnetic material such as iron or permalloy, and arranges them in a wire shape or forms a thin film in the same manner as described above. It is configured by a method such as adhering an electrode pattern sheet created by etching.

In FIG. 6, the means for transporting the conductive magnetic toner 6 uses a method of rotating the rotary magnet 5 inside the sleeve 4. In the case of this method, the recording speed is the same as that of the conventional example, but it is not necessary to form the second recording electrode 9 in an annular shape along the circumference as in the first embodiment, and only a part facing the recording sheet 7 It is only necessary to form the electrodes in the regions.
According to the above configuration, the second recording electrode 9 on the peripheral surface of the sleeve 4 and the circuit board 2 can be changed without significantly changing the conventional device.
The number of parts can be reduced, the manufacturing process can be simplified, and high-density recording can be performed only by changing the fixed position of.

[0023]

As described above, according to the present invention, the signal voltage corresponding to the image information is transmitted from the first recording electrode to the second recording electrode via the conductive developer, and the second recording is performed in the peripheral portion of the recording medium. By injecting charges from the electrodes into the conductive developer, the conductive developer can be attached onto the recording medium to form an image. As a result, there is no need to connect the circuit board that constitutes the driving means and the flexible cable that constitutes the recording electrode, and there is a restriction due to the processing accuracy of the connection portion and the flexible cable and the wiring pattern pitch due to the holes for passing the developer. There is no restriction such as local densification, and it becomes easy to miniaturize the recording electrode to achieve high definition of the image. In addition, it is possible to record at high speed and stable image quality without increasing the rotation speed of the motor, which is the drive source of the developer supply means, and without making the magnet multi-polarized. At the same time, it is possible to reduce the size and weight of the developing device and reduce the cost. Becomes

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of an image forming apparatus according to a first embodiment.

FIG. 2 is a perspective explanatory view of a recording electrode.

FIG. 3 is a cross-sectional explanatory diagram of a recording medium.

FIG. 4 is a sectional view showing a second embodiment of the image forming apparatus.

FIG. 5 is a sectional view showing a third embodiment of the image forming apparatus.

FIG. 6 is a sectional view showing a fourth embodiment of the image forming apparatus.

FIG. 7 is a perspective view showing a fourth embodiment of the image forming apparatus.

FIG. 8 is a sectional view showing a conventional image forming apparatus.

FIG. 9 is a perspective view showing a conventional image forming apparatus.

[Explanation of symbols]

1 is a first recording electrode, 2 is a circuit board, 3 is a driving IC, 4
Is a sleeve, 5 is a rotating magnet, 6 is toner, 7 is a recording sheet, 7a is a dielectric layer, 7a ₁ is a surface layer, 7a ₂ is a resistance layer,
7b the conductive layer, 7b ₁ the support layer, 7b ₂ is conductive evaporated film, the transport rollers 8, 9 is a second recording electrode.

Claims (5)

[Claims] 1. A first recording electrode for applying a voltage to a developer according to image information, a driving unit for applying a signal voltage according to image information to the first recording electrode, and the developer. A recording medium for forming an image by adhering toner, a developer supplying unit for supplying a developer between the recording electrode and the recording medium, and a recording medium provided on the peripheral surface of the developer supplying unit. An image forming apparatus having a second recording electrode for adhering a developer to the. 2. The image forming apparatus according to claim 1, wherein the second recording electrode has an annular conductive pattern formed on the peripheral surface of the developer supplying unit. 3. The image forming apparatus according to claim 1, wherein the second recording electrode has an arc-shaped conductive pattern formed on the peripheral surface of the developer supply unit so as to face the recording medium. 4. The image forming apparatus according to claim 1, wherein the recording medium is formed by laminating a dielectric layer and a conductive layer. 5. The image forming apparatus according to claim 4, wherein the image formed on the recording medium is a display device which is used by being displayed on a display unit.