JPH02297569A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To use plain paper as business or official documents instead of using special paper by recording a toner image on the plain paper after the toner image is temporarily formed on an intermediate transfer medium. CONSTITUTION:The electrostatic recorder is composed of a developing unit 2, the intermediate transfer medium 3 and a paper carrying mechanism 11. The intermediate transfer medium 3 is constituted of a metallic tube 16, a transfer device 17, a separating claw 18 and a cleaner 19. The metallic tube 16 rotates in the direction of the arrow (b) showing a rotary shaft 16a as the shaft 16a rotates in the same direction. The metallic tube 16 is made of an aluminum pipe, etc., a power source 16b applies a prescribed voltage to the tube via the rotary shaft 16a. Toner T is temporarily transferred to the metallic tube 16 composing the essential part of the intermediate transfer medium 3, and further transferred onto the paper by the transfer device 17. Consequently, the toner image can be recorded on the plain paper without using the specialized paper coated with a high electric resistance agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a recording device, and particularly to an electrostatic recording device that prints a toner image on plain paper without using a photoreceptor.

[Prior art]

A multi-stylus printer is known as a recording device that does not use a photoreceptor. This multi-stylus printer arranges needle-like electrodes at minute intervals, applies a high voltage to the needle-like electrodes in accordance with an image signal, and generates a discharge directly on paper to form an electrostatic latent image. After this electrostatic latent image is developed with toner, it is fixed by a fixing device to become a stable visible image. In a multi-stylus printer with this type of configuration, if the distance between the needle-shaped electrode (stylus head) and the paper is wide, the discharge electric field will spread, and the shape of the print 1/2 inch will become larger, making it impossible to achieve high-resolution recording. A gap material is provided on the surface of the paper, and a minute gap is ensured by rubbing this gap material and the needle-shaped electrode.

[Problems with conventional technology]

However, the above-described multi-stylus printer (electrostatic recording device) has the disadvantage that the stylus head is worn out because the paper constantly rubs against the stylus head.

Further, the electrostatic recording device uses special paper coated with a high electrical resistance agent to make it easier to place a load on the paper. However, because of the resistive agent on the surface of such special paper, writing with pencil or ink is poor, and it cannot be used as office paper or official documents.

Further, even if the paper is subjected to the above-described high resistance treatment, the resistance tends to be lowered due to high humidity, and the recording density becomes low because it becomes difficult for electric charges to be transferred to the paper.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide an electrostatic recording device that can perform high-resolution recording using plain paper without abrading the print head.

[Key points of the invention]

According to the present invention, the above object is achieved by: a toner conveying body carrying toner on its surface and conveying the toner along a predetermined path; and a toner conveying body rotatably disposed on the opposite side with respect to the toner carrying surface. a spiral electrode body with a spiral electrode provided on its peripheral surface;
A cylindrical electrode is provided on the toner carrying surface side of the donor transporting body and is placed oppositely across a control electrode, and the toner on the toner transporting body is removed by applying a voltage to the control electrode according to print information. This is achieved by providing an electrostatic recording device characterized in that the toner is transferred to the cylindrical electrode, and the toner transferred to the cylindrical electrode is transferred to paper.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic cross-sectional view of an electrostatic recording device according to an embodiment. In the figure, an electrostatic recording device 1 includes a developing device 2, an intermediate transfer medium 3, a paper feed cassette 4, a paper feed roller 5, a conveyance guide plate 6, a conveyance roll 7, a conveyance guide plate 8, and a fixing roll 9. , and a paper transport mechanism 11 consisting of a paper discharge tray 10. The developing device 2 has a developing roll (screw ball) 13 provided inside the developing container 2'.
A one-component highly magnetic toner T with a negative polarity is housed in the space '. Further, one end of the developing container 2' is provided with a blade 2a that regulates the thickness of a layer of toner attached to the film, which will be described later.
form. The developing roll 13 is composed of a magnet roll 13b fixed to a rotating shaft 13a and a spiral electrode body 13c fixed to the outer periphery of the magnet roll 13b.
It is covered with a film 15 that constitutes a part of 4.

The rotating shaft 13a is rotated at high speed in the direction a (not shown by an arrow) in the figure by a motor (not shown). The magnet roll 13b is made of a magnet in which N and S poles are alternately formed, and since it is fixed to the rotating shaft 13a, it rotates at high speed as the rotating shaft 13a rotates. The magnet roll 13b functions to attract the highly magnetic toner T in the developer container 2' to the circumferential surface of the toner conveying member 140 by the magnetic field formed by the magnetic poles.

Linear electrodes are embedded around the spiral electrode body 13c at predetermined intervals. FIG. 3 is a perspective view of the developing roll 13 and the metal tube 16 that constitutes the main part of the intermediate transfer medium 3 provided above the developing roll 13. As shown in the figure, the spiral electrode body 1
The linear electrodes 12 embedded in the circumferential surface of the electrode 3c are arranged in a spiral shape with predetermined intervals.

This linear electrode 12 is connected to a power source 21 as shown in FIG. Further, the film 15 disposed to cover the upper part of the developing roll 13 is a Bolie film with a thickness of several μm.

It is made of ethylene terephthalate (PET) and is attached to the toner conveying body 14 at both ends thereof.

On the other hand, the intermediate transfer medium 3 is composed of a metal tube 16, a transfer device 17, a separation piece 18, and a cleaner 19, and the metal tube 16 rotates in the same direction as the rotating shaft 16a rotates in the direction indicated by the arrow. The metal tube 16 is made of an aluminum pipe or the like, and the rotating shaft 16
A predetermined voltage is applied from a power supply 16b via a. Further, a high voltage power source 17a is connected to the transfer device 17, and a high voltage is applied to the transfer device 17 from the high voltage source 17a. The separation member 18 is a member for separating the paper from the metal tube 16, and the cleaner 19 removes toner adhering to the circumferential surface of the metal tube 16 with a blade 19a. The toner T removed by this cleaner 19 is transferred to the recycling pipe 2
0 to the developer container 2'.

FIG. 1 shows a helical electrode body 13C (NIA-like electric rod 1) having the above-mentioned configuration.
2), a film 15, and a metal tube 16. FIG. As shown in the figure, control electrodes 15a and 15b are formed within the film 15, and there is a predetermined gap between the two electrodes 15a and 15b. These control electrodes 15a, 15
A positive pulse voltage 22 is applied to b at a predetermined timing. The timing at which this pulse voltage 22 is output follows image data output from a recording control circuit (not shown).

Furthermore, the distance (gap) G from the linear electrode 12 embedded in the spiral electrode body 13c to the circumferential surface of the metal tube 16 is set to 150 μm in this implementation. This gear G generates an electric field (toner T) between the linear electrode 12 and the metal tube 16 even when the voltage V1 from the power source 21 is applied to the linear electrode 12 and the voltage 2 from the power source 16b is applied to the metal tube 16. This is the interval at which no electric field (such as an attractive electric field) is formed.

In this embodiment, the thickness of the film 15 disposed in the gap G is specifically about 40 μm, and the thickness of the film 15 disposed in the gap G is approximately 40 μm.
The thickness of a single layer of toner regulated by is approximately 40 μm.

The above-mentioned fixing roll 9 includes a heating roll 9a having a built-in heater 9a' and a pressure roll 9 that comes into pressure contact with the heating roll 9a.
This is a roll that fixes unfixed toner onto paper using heat and pressure.

The operation of recording an image on paper in the electrostatic recording apparatus 1 having the above configuration will be described below.

First, when the main 1t# of the electrostatic recording apparatus 1 is turned on and a motor (not shown) is rotated, the rotating shafts 13a and 16a start rotating as the motor rotates.

The rotation of the rotating shaft 13a also rotates the magnet roll 13b, and the toner T in the developer container 2' is attracted to the outer circumferential surface of the toner transport body 14 by the magnetic force of the magnet roll 13b. Then, the toner T adsorbed on the circumferential surface of the toner conveying body 14 moves on the toner conveying body 14 in the direction of arrow a according to the rotation of the magnet roll 13b in the direction a, and is moved to a predetermined ear height (layer thickness of 40 μm) by the blade 2a. The film 15 is further moved on the upper surface to the toner transfer portion F.

As described above, the toner transfer portion F faces the sleeve 13C (linear electrode 12) and the metal tube 16 with the gear G having a diameter of 150 μm. Also, during the recording operation, a positive voltage 2 is applied to the metal tube 16 from the power source 16b, and the linear electrode 1
2 is applied with a negative voltage (2) from the power supply 21. However, in this state, as described above, the linear electrode 12 and the metal tube 1
6, no electric field is formed to attract the toner T. Therefore, in this state, the toner T on the film 15 does not transfer to the metal tube 16.

On the other hand, if ten pulse voltages 22 are applied to the control electrodes 15a and 15b at predetermined timing in the above state, the metal tube 1
As shown in FIG. 4, an edge electric field E is formed between the control electrodes 6 and the linear electrode 12 through the gap between the control electrodes 15a and 15b. Therefore, the toner T moves along this edge electric field and is transferred to the circumferential surface of the metal tube 16. Therefore, by applying the pulse voltage 22 at a predetermined timing according to the image data, the desired toner of the metal tube 16 is transferred. Furthermore, as shown in FIG. 5, the edge electric field E is formed at the position where the linear electrode 12 and the metal tube 16 face each other through the gap between the control electrodes 15a and 15b. Therefore, the electric field becomes extremely dense, and the toner T of high concentration can be attracted to the metal tube 16.

The toner T transferred to the metal tube 16 in this manner moves to a position facing the transfer device 17 as the metal tube 16 rotates in the b direction. At this time, the paper carried out from the paper feed cassette 4 by the paper feed roller 5 is being fed between the metal tube 16 and the transfer device 17 by the transport roll 7 at a predetermined timing, and a high voltage applied from the high voltage power source 17a is applied. As a result, a potential difference is generated between the transfer device 17 and the metal tube 16. That is,
Since the high voltage applied to the transfer device 17 is higher than the voltage V2 applied to the metal tube 16, the toner T on the circumferential surface of the metal tube 16 is attracted toward the transfer device 17. For this purpose, the metal tube 16 and the transfer device 1
The toner T is transferred to the paper that is conveyed between 7 and 7, and then
The sheets onto which the toner T has been transferred are thermally fixed by a fixing roll 9, and then discharged onto a paper discharge tray 10, where they are sequentially stacked.

As described above, in this embodiment, the -H toner T is transferred to the metal tube 16 constituting the main part of the intermediate transfer medium 3, and the high electrical resistance agent is transferred to the paper by the transfer device 17. It is possible to record toner images on plain paper without using special coated paper.

In the above embodiment, the transfer device 17 was used to transfer the toner image from the metal tube 16 to the paper (plain paper), but the transfer may be performed using a bias roller to which a predetermined bias voltage is applied.

〔Effect of the invention〕

As explained in detail above, according to the present invention, a toner image is once formed on an intermediate transfer medium and then recorded on plain paper, so there is no need to use special paper as in the past.
It can also be used for office or official documents.

In addition, high-density toner transfer to the intermediate transfer medium can be performed, and therefore, the recorded image on the paper transferred from the intermediate transfer medium also becomes an image of high resolution and recording quality.

Furthermore, since a needle electrode such as a stylus spatula is not used, the electrostatic recording device of the present invention does not require consideration of head wear and the like.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a power supply of an electrostatic recording device according to an embodiment, and Fig. 2
The figure is an overall configuration diagram of an electrostatic recording device according to an embodiment, FIG. 3 is a perspective view of a developing roll and a metal tube, FIG. 4 is a diagram showing the state of formation of an edge electric field, and FIG. 5 is a diagram showing the state of formation of an edge electric field. FIG. 3 is a diagram illustrating an edge electric field formed in a gap. DESCRIPTION OF SYMBOLS 1... Electrostatic recording device, 2... Developing device, 3... Intermediate transfer medium, 4... Paper feeding power center, 5... Paper feeding roller, 7... Conveyance roll, 9. ... Fixing roll, 10... Paper discharge tray, 11... Paper transport mechanism, 12... Linear electrode, 13... Developing roll, 13b... Magnet roll, 13c... Spiral electrode body , 14... Toner transport body, J5... Film, 15a, 15b---Control electrode, 16... Metal tube, 16b, 21... Power source, 17... Transfer device, 17a... High voltage power supply, 19...Cleaner, 22...Pulse voltage.

Claims (1)

[Claims] A toner conveying body that carries toner on its surface and conveys the toner along a predetermined path, and a spiral electrode that is rotatably disposed on the opposite side to the toner carrying surface of the toner conveying body and provided on the peripheral surface. a spiral electrode body, and a cylindrical electrode disposed on the toner carrying surface side of the toner conveying body to face each other with a control electrode in between; An electrostatic recording device characterized in that toner on the body is transferred to the cylindrical electrode, and the toner transferred to the cylindrical electrode is transferred to paper.