JPH02297570A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To use plain paper and to achieve direct recording by applying a voltage corresponding to printing information to a control electrode and transferring toner on a toner carrier to the sheet that is carried between the control electrode and a cylindrical electrode. CONSTITUTION:Gaps G having prescribed interval where an electric field with the force sufficient to attract toner T is not be generated depending on the state of the cylindrical electrode (metallic tube) 3 and the magnitude of voltages V1 and V2 applied to a linear electrode 17, and control electrodes 14a and 14b are provided in the gaps G. A printing power source 15 applies a positive pulse voltage to the control electrodes 14a and 14b at the prescribed timing. Consequently, an edge electric field is formed only when a pulse voltage is applied between the metallic tube 3 and the linear electrode 17, and a toner image can be recorded on the sheet P at the timing when the pulse voltage is applied. Thus, an image can be recorded on the plain paper, which can be used as business and official documents.

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 directly prints a toner image on plain paper without using a photoreceptor.

(Prior art and its problems) 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, and in response to image signals, the needle-like electrodes are An electrostatic latent image is formed by applying a voltage and discharging directly onto the paper. After this electrostatic latent image is developed with toner, it is thermally fixed by a fixing device to become a stable visible image.

In a multi-stylus printer with such a configuration, special paper coated with a high electrical resistance agent is used to make it easier for the electric charge generated by the discharge from the needle electrode (stylus head) to be transferred onto the paper. Further, this paper is fed by a transport roll or a transport belt provided on a paper transport path.

However, with the above-mentioned multi-stylus (electrostatic recording device), special paper is used to make it easier to charge the paper, so the resistance agent on the surface of the special paper makes it difficult to write with pencils, inks, etc. It cannot be used as official paper or official documents.

Furthermore, the conveyance rolls and conveyance belts that feed the paper are far away from the position of the needle-shaped electrodes that actually transfer the toner to the paper, and the paper feeding speed at the transfer section that transfers the toner is unstable. Therefore, the recording quality of images formed on paper is extremely poor.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional art, an object of the present invention is to provide an electrostatic recording device that enables direct recording using plain paper and also enables recording of extremely excellent image quality. shall be.

[Key points of the invention]

According to the present invention, the above objects include a toner conveying body that carries toner on its surface and conveys the toner along a predetermined path; It has a helical electrode body provided with a helical electrode, and a rotatable cylindrical electrode arranged on the toner carrying surface side of the toner transporting body opposite to each other with a control electrode interposed therebetween, and a voltage corresponding to the printed information is applied to the control electrode. This is achieved by providing an electrostatic recording device characterized in that the toner on the toner conveying body is transferred to the sheet of paper conveyed between the control electrode and the cylindrical electrode by applying .

[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, a cylindrical electrode (hereinafter referred to as a metal tube) 3, a paper feed cassette 4, a paper feed roller 5, a standby roll 6, a static elimination brush 7, and a conveyance guide plate 8.
, an air suction conveyor belt 9, a fixing roll 10, and a paper discharge tray 11.

First, to briefly explain each member constituting the paper conveyance mechanism, the standby roll 6 has a heater (not shown) inside, and the paper conveyed from the paper feed cassette 4 by the paper feed roller 5 is moved by the arrow at a predetermined timing. This is a roll that transports the paper in the C direction and removes moisture contained in the paper. The static eliminating brush 7 is a brush that removes electrical charges generated on the paper during conveyance.

The conveyance guide plate 8 is a member that guides the conveyance of the paper in the direction of arrow C, and is made of an insulating material. The air suction conveyance belt 9 is a belt that rotates in the direction indicated by the arrow and conveys the sheet having toner attached to its underside while sucking it upward as will be described later. The fixing roll 10 is made up of a heating roll having a built-in heater (not shown) and a pressure roll that is in pressure contact with the heating roll, and is a roll that fixes unfixed toner onto a sheet of paper using heat and pressure.

On the other hand, the developing device 2 has a developing roll (screw ball) 12 provided above the developing container 2'.
A one-component highly magnetic toner T with negative scratchability is housed inside. Further, one end of the developer container 2' forms a blade 2a for regulating the thickness of a layer of toner adhering to the film, which will be described later. The developing roll 12 is composed of a magnet roll 12b fixed to a rotating shaft 12a and a spiral electrode body 12c fixed to the outer periphery of the magnet roll 12b.
It is covered with a film 14 that constitutes a part of.

The rotating shaft 12a is rotated at high speed in the direction C shown by an arrow in the figure by a motor (not shown). The magnetic rolls 12b are alternately NI! Since it is made of a magnet in which i and Si are formed and is fixed to the rotating shaft 12a, it rotates at high speed as the rotating shaft 12a rotates. This magnet roll 12b functions to attract the highly magnetic toner T in the developer container 2' to the circumferential surface of the toner conveying member 130 by the magnetic field formed by the magnetic poles. Linear electrodes 17 are embedded in the circumferential surface of the spiral electrode body 12c in a spiral manner at predetermined intervals, and the linear electrodes 17 are connected to a power source 16. In addition, the spiral electrode body 1
Since the magnet roll 2e is fixed to the magnet roll 12b, it rotates at high speed with the rotation of the rotating shaft 12a.

A film 14 disposed to cover the upper part of the developing roll 12
has a thickness of several tens of μm (in this example, it is 40j1 as described later).
It is made of polyethylene terephthalate (PET) with a film 14 having a thickness of m and is attached to the toner conveying body 13 at both ends thereof.

On the other hand, the metal tube 3 provided above the developing device 2 is rotatable at a predetermined speed in the direction of arrow d in accordance with the rotation of a rotating shaft 3a to which rotational force from a motor (not shown) is transmitted. metal tube 3
is composed of an aluminum pipe, etc., and is connected to the power source 3 via the rotating shaft 3a.
A predetermined voltage is applied from b.

FIG. 1 shows a spiral electrode body 12c ('fa-shaped electric scraper 12c) having the above structure.
7), the film 14, and the metal tube 3. FIG. As shown in the figure, control voltages Pi 14a and 14b are formed within the film 14, and both electrodes 14a, 14
There is a predetermined gap between b.

A positive pulse voltage is applied to the control electrodes 14a, 14b from a printing power source 15 at a predetermined timing. The application timing of this printing power source 15 follows image data output from a recording control circuit (not shown).

Further, the distance (gap) G from the circumferential surface of the spiral electrode body 12c (linear electrode 17) to the circumferential surface of the metal tube 3 is set to 250 μm in this implementation. This gap G is the voltage V from the power supply 16 applied to the linear electrode.

is applied to the metal tube 3 from the power supply 3b, and the distance is such that an electric field with a force that attracts the toner T is not formed between the linear electrode 17 and the metal tube 3 even when the voltage (18) is applied to the metal tube 3 from the power source 3b. Furthermore, a sheet of paper (hereinafter referred to as sheet P) is conveyed between the metal tube 3 and the film 14 by the aforementioned sheet conveying mechanism. In this embodiment, the thickness of the paper P is 90 μm, the thickness of the film 14 is 40/jm as described above, and the thickness of the single layer of toner regulated by the blade 2a is approximately 40 μm.
Set to .

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

First, when the main power of the electrostatic recording apparatus 1 is turned on and a motor (not shown) is rotated, the rotation shafts 3a and 12a start rotating as the motor rotates.

The rotation of the rotating shaft 12a also rotates the magnet roll 12b, and the toner T in the developer container 2' is attracted to the outer peripheral surface of the toner conveying member 13 by the magnetic force of the magnet roll 12b. The toner T adsorbed to the circumferential surface of the toner transport body 13 moves in the same direction on the toner transport body 13 as the magnet roll 12b rotates in the direction of arrow C.
The film 14 is regulated to a predetermined height (layer thickness of 40 μm) by the blade 2a on the way, and further moves on the upper surface of the film 14 to the toner transfer portion F.

The toner transfer section F is constructed as described above (metal tube 3 and sleeve 12).
c (, kll-shaped electrodes 17) are opposed to each other with a gap G of 250 μm. Also, during this recording operation, the metal tube 3
A positive voltage VT is applied from the power source 3b to the wire-shaped pole 17, and a negative voltage ``2'' from the power source 16 is applied to the linear pole 17. In this state, as described above, no electric field is formed between the linear electrode 17 and the metal tube 3 that would attract the toner 'r.

Therefore, in this state, the toner T on the film 14 does not transfer to the metal tube 3 side.

On the other hand, when a positive pulse voltage 15 is applied to the control electrodes 14a and 14b at a predetermined timing in the above state, the control electrodes 14a and 14
As shown in FIG. 3, an edge electric field E is formed through the gap between b. In this state, since the toner r is of negative polarity as described above, it is attracted to the circumferential surface of the metal tube 3 along this edge electric field E. At this time, the paper P carried out from the paper feed cassette 4 is fed between the metal tube 3 and the film 14 at a predetermined timing by the standby roll 6, and the toner T sucked toward the L metal tube 3 side is absorbed by the paper P. will be transferred to. Therefore, by applying a positive pulse voltage from the printing power supply 15 at a predetermined timing according to the image data and controlling the start of rotation of the standby roll 6, the 1-ner T can be transferred to a desired position on the paper P. .

Moreover, in the transfer section F, the paper P comes into contact with the metal tube 3, and the rotation of the metal tube 3 in the direction of the arrow d makes the conveyance speed extremely stable. Therefore, the toner T transferred to the paper P adheres to a desired position on the paper P accurately. Further, as shown in FIG. 4, since the etching electric field E is formed through the gap between the control electrodes 14a and 14b at the position where the linear electrode 17 and the metal tube 3 face each other, the electric field becomes an electric field with extremely concentrated lines of electric force, and the paper High on P? Store-level toner 'r can be attached.

The toner -T attached to the paper P in this way is sucked upward by the suction conveyor belt 9 and conveyed to the fixing roll 10, and the paper is thermally fixed by the fixing roll 10 and then discharged to the paper output tray 11. be done.

As described above, in this embodiment, depending on the voltage (1) or Vt applied to the metal tube 3 and the linear electrode 17, an electric field having enough force to attract the toner T is generated between the metal tube 3 and the linear electrode 17. A gap G at a predetermined interval that is not formed and this gear 710
Control electrodes 14a, 14b are provided between the control electrodes 14a,
By applying a positive pulse voltage to 14b from the printing power supply 15 at a predetermined timing, an edge electric field E is formed only when a pulse voltage is applied between the metal tube 3 and the linear electrode 17, and the pulse voltage is applied at the timing when the pulse voltage is applied. The resulting toner image is recorded on paper P, which is plain paper.

Further, by conveying the paper P while making it contact with the metal tube 3 located in the transfer section F, the paper P is stably conveyed in the transfer section F, thereby improving the recording quality of the image.

Note that the specific values of the thickness of the paper P, the gap G, etc. used in the previous embodiments do not limit the present invention, and the edge electric field E is Any value is sufficient as long as the edge electric field E is not formed and an edge electric field E is formed when a pulse voltage is applied. That is, this numerical value is set in correlation with the voltage (2) or (1) applied to the power supplies 3b and 16.

(Effects of the Invention) As described above in detail, according to the present invention, images can be recorded on plain paper, and it can also be used as office or official documents.

Furthermore, since the transfer section is constituted by a drum-shaped metal cylinder, conveyance of the paper is extremely stable, and the recording quality of the image is also extremely good.

Furthermore, the configuration is extremely simple, and the recorded image on the paper is of high density, which also makes it possible to improve the recording quality.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the main parts of an electrostatic recording device according to an embodiment, Fig. 2 is a block diagram of the entire electrostatic recording device according to an embodiment, and Fig. 3 is a diagram showing the state of formation of an edge electric field. , FIG. 4 is a diagram illustrating an edge electric field formed in a gap between control electrodes. DESCRIPTION OF SYMBOLS 1... Electrostatic recording device, 2... Developing device, 3... Metal tube, 3b, 16... Power supply, 4... Paper feed cassette 7, 5... Paper feed roller, 6... Standby roll, 7... Static elimination brush, 9... Air suction conveyor belt, 10... Fixing roll, 11... Paper discharge tray, 12... Developing roll, 12b... Magnet roll , 12c... Spiral electrode body, 13... Toner transport body, 14... Film, 14 a, l 4 b... System? II'QtFi
i, 15... Printing power supply, 17... Linear electrode.

Claims (1)

[Claims] A toner conveying body that carries toner on its surface and conveys the toner along a predetermined path, and a spiral that is rotatably disposed on the opposite side of the toner carrying surface of the toner conveying body and has a helical electrode on its peripheral surface. It has an electrode body and a rotatable cylindrical electrode that is disposed opposite to each other on the toner carrying surface side of the toner conveying body with a control electrode interposed therebetween, and the toner conveyance is performed by applying a voltage according to print information to the control electrode. An electrostatic recording device characterized in that toner on the body is transferred to a sheet of paper conveyed between the control electrode and the cylindrical electrode.