JPH02155757A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To always stably print an image having a satisfactory high resolution on paper by opposing segment electrodes and a spiral electrode through a toner conveyor, feeding a recording material to an electrode opposing part, and interposing an insulator between signal electrodes. CONSTITUTION:When a screw pole 4b is rotated in a direction of an arrow (b), a linear electrode 4g is moved in parallel from left to right. When a high voltage of + polarity is applied to segment electrodes 4d in response to print information at the time of movement of the electrode 4g, an electric field is formed at an intersection between the voltage applied segment electrodes 4d and the linear electrode 4g, toner t0 charged in - polarity is transferred along the lines of electric force on a sheet surface P1 to print one dot. In this case, since an insulating base 4c is interposed between the end of the segment electrode 4d and a sheet P, flow of charge from the segment electrode 4d to the sheet P is prevented, and a print image having satisfactory high resolution can be always obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrostatic recording device capable of printing on plain paper without forming an electrostatic latent image.

[Prior art]

A multi-stylus printer is known as one of the recording methods that do not use a photoreceptor. A multi-stylus printer forms an electrostatic latent image by arranging a large number of needle-like electrodes at minute intervals and directly discharging them onto a sheet of paper according to an image signal. After the electrostatic latent image is developed with toner, it is fixed by a fixing device.

Also, as shown in Japanese Patent Publication No. 58-54831,
There is also a device in which an electrode provided spirally on the surface of a rotating cylindrical body and a segment electrode are disposed facing each other, a sheet is conveyed between them, and a high voltage is applied between these two electrodes to form an electrostatic latent image. In this case as well, similarly to the multi-stylus printer, an electrostatic latent image is first formed on a sheet of paper, the latent image is developed with toner, and then fixed by a fixing device.

[Problems with conventional technology]

In the case of the above-mentioned multi-stylus printer, the needle electrode is adjusted to the dot density (DPI) of 0.084 Bwn.
(300DP r)~0, 1058mm (240D
They must be arranged in the main scanning direction at intervals of PI), and the structure becomes extremely fine, making the needle electrodes alone expensive.

Furthermore, since the needle electrode has a fine and precise structure, even a small amount of dirt has a large negative effect on image quality.

All of the above-mentioned electrostatic recording devices have a major problem in that they cannot use plain paper. In other words, in order to form an electrostatic latent image directly on the paper, the paper must have high electrical resistance characteristics even in a high humidity environment, and for this reason, it is necessary to use special paper with a high electrical resistance agent coated on the paper surface. There is.

Such special paper is difficult to write on with pencil, ink, etc. due to its surface nature, and is therefore undesirable as paper for office use.

Therefore, as an electrostatic recording device that can use plain paper, a dielectric belt is movably stretched around the dielectric belt, and an electrostatic latent image is formed on the dielectric belt by the above-mentioned multi-stylus recording head, and then developed with toner. A method is known in which the toner image is transferred onto plain paper. This method has the disadvantage that the multi-stylus head has a fine structure and requires a process equivalent to a normal electrophotographic process, making the structure of the entire device extremely complicated.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above, and an object of the present invention is to provide an inexpensive electrostatic recording device that can stably form high-quality images on plain paper with a simple structure. shall be.

[Key points of the invention]

According to the present invention, a toner conveying body that carries toner on its surface and conveys the toner in a predetermined direction, and a recording material that faces the surface of the toner conveying body to which the toner is adhered with a minute distance therebetween. a plurality of segment electrodes disposed on one side of the recording material facing section; an insulating member interposed between the plurality of segment electrodes and the recording material facing section; and a rotating member disposed on the other side of the recording material facing section. and a screw pole in which a spiral electrode is laid on a circumferential surface thereof, and a high voltage is applied between the segment electrode and the spiral electrode according to the printing information to remove the toner on the toner transport body. This can be achieved by providing an electrostatic recording device characterized in that selectively transfers the above to the recording material.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 9.

FIG. 1 is a schematic cross-sectional view showing the overall configuration of an electrostatic recording device as an embodiment of the present invention. In the figure, reference numeral 1 denotes a paper feed cassette, which stores untreated plain paper P and is removably installed at the upper side of the machine body. A paper feed roll 1a is disposed above the leading end of the paper feed cassette 1 in the insertion direction so as to be rotatable in the direction of the arrow.

A pair of standby rolls 2 is disposed in front of the paper feed roll 1a in the paper feed direction A, and after temporarily stopping the advance of the paper P fed out by the paper feed roll 1a and adjusting the conveyance posture, the image Re-feed in synchronization with the tip. The standby roll pair 2 of this example has a heater 2c built into the upper roll 2a, and heats and dries the paper when it is conveyed while being held between the rolls 2a + 2b that roll into contact with each other. This improves the toner transfer efficiency in the printing process described later. The heater 2c may be built in the lower roll 2b, or may be built in both rolls. Further, a drying roll or a drying heater may be provided separately from the standby roll pair 2.

A static elimination brush 3 is disposed downstream of the pair of standby rolls 2 in the paper conveyance direction. The static elimination brush 3 extends over substantially the entire width direction of the paper conveyance path.
The leading edge is brought into close or sliding contact with the entire area of the paper to remove the electrical charge. Thereby, it is possible to prevent an adverse effect during printing due to the charged charges. In this example, the static eliminating brush 3 is brought into sliding contact with the back surface of the paper (the surface on which no image is printed), but the brush 3 is not limited to this and may be brought into sliding contact with the front surface or both sides of the paper.

A printing section consisting of a print head 4 and a toner supply device 5 is formed downstream of the static elimination brush 3. The printing head 4 is composed of a segment pole 4a and a screw pole 4b, and passes through the circumferential surface of a dielectric drum 6, which has toner uniformly adhered to its surface, through an electrode facing part F in which both poles 4a+4b are opposed to each other. At the same time, toner is selectively transferred onto the paper being conveyed to form an image. The configuration of the print head 4 will be explained in detail later.

In the toner supply device 5, a dielectric drum 6 as a toner conveying member is rotatably supported in a housing 5a in which toner t is stored, and is driven and rotated in the direction of arrow a. Note that in this example, a one-component toner containing no carrier is used. The dielectric drum 6 is arranged so that its circumferential surface passes through the electrode facing portion F described above, and a corona discharger 7 as a toner adhesion means is disposed inside thereof upstream of the screw ball 4b. There is. A scraper 8 serving as a cleaner is disposed near the outer peripheral surface of the dielectric drum 8 on the downstream side of the electrode facing portion F, with its tip slidingly in contact with the outer peripheral surface of the dielectric drum 6, and is used for printing. First, the toner remaining on the circumferential surface of the dielectric drum 6 is scraped off. In this example, two stirring rolls 9, 9 are provided at the bottom of the toner supply device 5.
is arranged, and while stirring the stored toner t, a predetermined amount, for example -
Triboelectrically charges the polarity.

In the toner supply device 5 configured as described above, first, corona ions having a polarity opposite to the frictionally charged polarity of the toner t are discharged toward the back surface of the dielectric drum 6 by the corona discharger 7, and the electrostatic charge is The toner t is uniformly adhered to the circumferential surface of the dielectric drum 6 by the suction force. As the dielectric drum 6 rotates, the toner t is adhered and carried on the circumferential surface of the dielectric drum 6.

is conveyed to the electrode facing section F, where it is selectively transferred onto the paper by the print head 4 according to the image information, and the image is printed. This printing operation will also be explained in detail later.

The toner to' remaining on the circumferential surface of the dielectric drum 6 after the printing process is removed by a scraper 8 that is in sliding contact with the downstream side of the dielectric drum 6.
The toner is scraped off and the stored toner is returned inside. The scraped toner to' is sufficiently stirred and mixed with the stored toner t by a stirring roll 9.9, and then used for printing again. Further, the circumferential surface of the dielectric drum 6 from which the toner to' has been removed is immersed in toner, and then reaches the position where the corona discharger 7 is disposed, where toner is again applied. In this case, the circumferential surface of the dielectric drum 6 is temporarily cleaned of all adhered toner t by the scraper 8. Since the toner is restored to its substantially initial state by removing the . Note that a brush-like cleaner may be provided in place of the scraper 8.

On the downstream side of the head 4, an air saccharging conveyor belt 10 is stretched horizontally, and while it sucks the back side of the paper after printing, a fixing device is installed in front of it. 11.

The fixing device 11 is composed of a heating roll lfa and a pressure roll 11b, and thermally fixes the paper when the paper is held between the two rolls and conveyed. After fixing, the sheets are discharged from the υ output drawer 12 onto a paper discharge tray 13 in a face-down state with the image side facing down, and are stacked thereon.

As described above, in the electrostatic recording device of this example, the entire paper transport path from paper feeding to paper ejection is formed in a substantially straight shape, so the paper feeding operation is generally smooth, and printing is possible. Paper feeding defects such as defects and jams are less likely to occur. It also has the advantage that page alignment is not required and a face-down paper discharge state, which is preferable for the recording apparatus, can be achieved using the straight paper passage mentioned above.

Here, the configuration of the print head 4 and its electrode facing portion F will be explained using FIGS. 2 to 4.

As shown in FIG. 2, in the print head 4, a segment ball 4a and a screw ball 4b are disposed facing each other with their longitudinal directions extending parallel to each other.
The dielectric drum 6 and the paper P are made to run in the directions of the arrowhead and the arrow a, respectively. The segment ball 4a is
A large number of segment electrodes 4d are embedded in the elongated insulating base 4c at regular intervals along its longitudinal direction at predetermined distances. In this example, a large number of segment electrodes 4d are buried in two rows in a staggered pattern. Each segment electrode 4d is connected to a high voltage power source 4 via a switch 4e.
f is connected. The high-voltage power supply 4f supplies a high voltage with a polarity opposite to that of the toner t, and thus has a polarity in this example.
Each segment electrode 4 corresponds to the opening/closing operation of the 8 switch 4e.
d.

FIG. 3 is a side view showing the detailed structure of the electrode facing part F, and the fourth
The figure is an enlarged side view of the Q section. In FIG. 3, the paper P runs with its back surface P2 in sliding contact with the tip surface of the segment ball 4a so that the paper P can run while maintaining a predetermined minute gap G between the front surface Pt and the dielectric drum peripheral surface 8a. The paper transport path is set accordingly. The minute gap G is between the toner J! supported on the dielectric drum circumferential surface 6a. It is preferable to set lto as small as possible within the limit that lto does not contact the paper surface P1.

Paper P of insulating base 4c in segment pole 4a
The leading end surface that comes into contact with the paper P is formed into a circumferential surface so as to be able to make smooth sliding contact with the paper P. Thickness T1 of the tip of the insulating base 4c
That is, the distance 1iIT between the tip end surface and the tip of the embedded segment electrode 4d formed in a tapered shape prevents the electric charge of the segment electrode 4d from directly flowing into the paper P and is worn out due to sliding contact with the recording material. It is preferable that it be as thin as possible without being exposed. The material of the insulating substrate 4c is preferably a high electrical resistance material with an electrical resistance value of 1012 Ω·01 or more, which has a small coefficient of friction with recording materials such as paper, and
It is preferable to use a hardness that does not damage the recording material even if it is in sliding contact with the recording material for a long period of time.

By configuring the segment pole 4a as described above, a decrease in the resolution of the printed image due to the inflow of charges from the segment electrode 4d to the paper P is prevented. Segment electrode 4
When d directly contacts a recording material such as paper P, charges flow from the segment electrode 4d to paper P, disrupting the state of electric field formation and reducing resolution. In particular, when the paper P is plain paper, the electric resistance value of the plain paper is about 10 9 to 10 I 2 Ω·cm, so charges are more likely to flow in and the resolution is also more likely to decrease.

Therefore, by configuring the segment poles 4a as described above, a high resolution printed image can be stably obtained regardless of the type of recording material.

On the other hand, the screw pole 4b has a plurality of linear electrodes 4g spirally formed on the surface of a cylindrical base 4h! The direction of the arrow opposite to the dielectric drum 6 (clockwise direction)
is rotated at a predetermined speed.

The linear electrodes 4g do not come into contact with each other, and all the linear electrodes 4g are grounded via the base 4h and shaft 41.

FIGS. 5(a) and 5(b) are cross-sectional views showing two types of screw poles 4b and 4b' in which the method of laying the linear electrodes is different, and the screw pole 4b in FIG. 4g of linear electrodes are wound around the electrode. In this case, the electric field can be formed more stably if the tip of the linear electrode 4g is as sharp as possible.

Also, the screw pole 4b' in the same figure (b) is attached to the base 4h.
A linear electrode 4g' is embedded in the surface of the electrode 4g', and has the advantage that there is little wear even after long-term use. Similar to the screw pole 4b described above, the narrower the width of the linear electrode 4g' is, the more stable the electric field formation state will be.

FIG. 6 is a perspective view of the segment electrode 4d and the linear electrode 4g viewed from above the segment pole 4a in a state where the linear electrode 4g is expanded. In the figure, when the screw pole 4b is now rotated in the direction indicated by the arrow (sub-scanning direction), the linear electrode 4g is translated from the left to the right in FIG. During this movement, when a polar high voltage is selectively applied to each segment electrode 4d according to the printed information, as shown in FIG. An electric field is formed at the intersection of the two, and the monopolarly charged toner to is transferred onto the paper surface P1 along the lines of electric force (indicated by broken lines), thereby printing one dot. In this case, since the insulating substrate 4c is interposed between the tip of the segment electrode 4d and the paper 2, electric charges are prevented from flowing into the paper P from the segment electrode 4d, and a good printed image with high resolution can always be obtained.

In addition, since the voltage is applied via the dielectric drum 6, unlike conventional multi-stylus printers, the degree of change in the electric field strength depending on the electrical resistance value of the paper P is small, and it is always good even in a high humidity environment. Print quality can be stably obtained. Furthermore, since unnecessary charges on the paper P are also removed by the static eliminating brush 3, the print quality becomes more stable.

In the print head 4 described above, the moving speed of the linear electrode 4g (rotation speed of the screw ball 4b), the segment electrode 4
By appropriately setting the period of high voltage application to d, the relative position of the linear electrode 4g and the segment electrode 4d, etc., it is possible to print separated into dots of a desired size. These numerical relationships will be explained below using FIG.

First, the running speed V of the dielectric drum circumferential surface 6a and the paper P
ppc is the energization time Tw of the high voltage power supply 4t to form one dot.
o is Two= 7w* DUTY Cs :l...
・・・・・・・・・・・・・・・(5) The rotational speed T”sp of the screw ball 4b is the same as that of the adjacent linear electrode 4g.
If the interval in the sub-scanning direction between ) (sp) is (PPM: number of sheets printed per minute), the effective length Lgi of the segment electrode 4d is L8H=DS・
N(,,) ・・・・・・・・・・・・・・・・・・
...(2) CDB: Size of 1 dot) (N: Number of dots supported by 1 segment electrode) Linear electrode 4g
The main scanning direction interval Lap is Lsp=DsX(1/DU
TY) (mm) ”” ... (3
) (DUTY: Printing duty) The printing time Tw for one line in the main scanning direction is (CYCLE
: Number of linear electrodes 4g) Here, screw ball 4b
The relationship between the circumferential speed Hip/Tw and the paper running speed V PPC must be Hsp/T>>V ppc. In FIG. 6, θ8p represents the angle formed by the linear electrode 4g with the main scanning direction.

For example, a) Arrangement of segment electrodes 4d in 22 rows staggered arrangement b) Number of linear electrodes 4g: CYCLE = 10C) Printing duty: DUTY = 1/128d) θsp" 45 degrees e) Number of sheets printed per minute: PPM = 4 (A4 vertical feed) r
) Paper spacing = 50 Sankag) Ds"0.0846mm (300DP I) If you try to realize a printer with specifications like (300DP I), the above (1)
The numerical values in equations (8) to (8) are as follows.

Paper running speed: Vppc:” 23.13 (as/
s) Effective length of segment electrode 4d: Lsg=8.0
37 (April (when set to N=95) Linear electrode main scanning direction interval: L sp” 10.828
8 C-1] Printing time: '['w=3.88 (m
s) 1 dot energization time: T wo” 28.59
Cμs] Rotation speed: T sp= lG39 (r
pm).

With these numerical values, a printer having the specifications a) to g) above can be realized.

Next, print timing in the sub-scanning direction will be explained with reference to FIG. In addition, in the figure, the broken line A' represents the position of the first linear electrode 4gs when the second linear electrode 4g2 moves from B to the position B', and the -dotted chain line B# represents the position of the first linear electrode 4gs. , 1st
This shows the position of the second linear electrode 4gz when the linear electrode 4g+ moves from the position A to the position A#.

The distance of the first linear electrode 4g+ from the position A to the position B in Fig. 6! I! The time it takes to move by Lsp is Tw, and 128 dots are printed during this time. At this time, the first printing position and the final printing position of the 128th dot are as follows:
This results in a shift in the sub-scanning direction by D8, which is the size of one dot. Here, the distance from the left end of the first segment electrode 4d to the intersection with the first segment electrode 4dt when the first linear electrode 4g□ comes to the position A# is defined as Y, and is defined as X:Lsa-Y. Also, let E be the locus followed by the printed dots. The first dot F printed by the second segment electrode 4da ultimately becomes the first segment electrode 4d on the paper.

It must be adjacent to the last drum (printed in )H on the trajectory E. For this purpose, the distance Hs between the first segment electrode 4d and the second segment electrode 4d2 in the sub-scanning direction is
i must not be an integer multiple of Ds and must be in the interval shown below. That is, in order to make the final print H by the first segment electrode 4d and the first print F by the second segment electrode 4d2 adjacent on the locus E, the interval between the second segment electrode 4d2 and the final print H is , MD, (M is an integer). Therefore, the interval) 1sB is ND
It must be set narrower by X·tanθ1 than an integral multiple of 8. Here, θ1 is the angle between the main scanning direction and the trajectory E, and in this example, janθW=1/128. Therefore, the interval) (sg is Hsa= M @D s
It can be expressed as X ・tanθ, (7). Here, M is an integer and is the number of delay stages between the print data by the first segment electrode 4d+ and the print data by the second segment electrode 4d2.

As can be seen from FIG. 6, X is as follows: X=HsB @cotθ8°. Therefore, the interval H8E is as follows. Now, if we set M=35, H8E=2
, 938 (m-).

Next, the printing timing of each segment electrode 4d will be explained. As can be seen from FIG. 6, the first linear electrode 4g
When □ moves from position A to position A#, that is, the distance [
It is only necessary to start printing by the second segment electrode 4d2 when the second segment electrode 4d2 has moved by Y. Here, the distance Y is calculated from the above formula as Y'' L 5EI−Hse・cotθ,,=
5.099 (,,). Lsp's 10.8288
■■The time required to move is 3.66m5, so 5.
The time required to travel 099m+* is 1.72m5.

FIG. 7 is a time chart showing the timing of printing, and shows the timing from the start of printing by the first segment electrode 4d to the start of printing by the second segment electrode 4da.
1 of the time required to move the above-mentioned distance Y indicated by D2
．． This means that it is only necessary to delay by 72+ms. In addition, T
The period indicated by wnX 95 is the actual printing period. Also, a third segment electrode 4d.

Considering the printing start timing of , the left end of the first segment electrode 4d and the third segment electrode 4da
The distance from the left end of Electrode 4
g+ is L, p=io, and 82881 letters are on the left. Therefore, when calculating its position by the distance from the left end of the first segment electrode 4d, 2・LSR−LSP=
5, 2452■■. When calculated in the same manner as above, 5.2452+sw becomes 1.77m5, which is T shown in FIG. 0 is this delay time.

The above delay time Tos can be expressed in a general formula as follows.

First, odd-numbered segment electrodes 4d, 4d,.

4d! Regarding S..., it can be expressed as follows. However, n" L 3+ 5...
The value in 11 of equation (9) is defined as the value obtained by truncating the calculated value below the decimal point.

Next, even numbered segment electrodes 4d2, 4d4°4d
,... can be expressed as. However, n=2.4.8...
The value in 11 in formula (10) is defined as the calculated value rounded down to the decimal point.

Next, considering the synchronization difference between the drive clocks of the odd-numbered segment electrodes and the drive clocks of the even-numbered segment electrodes, as can be seen from FIG. 6, the distance between the odd-numbered segment electrodes and the even-numbered segment electrodes is v! The printing timing is shifted by a time corresponding to nY. When this is converted into time, t = (Y/L sp) ΦTw. Here, if we define Y:L・Ds+β (where, is a natural number), t is t:(t,-p s/L
5p)T w”(β/L 5p)T w”・(11
). Here, the first term on the right side of the above equation is D for both the numerator and denominator.
Since it is an integral multiple of s, it has no relation to synchronization deviation. Therefore, the time of the second term on the right side of the above equation becomes the synchronization shift time. If the synchronization deviation time is t, then t, = (β/Lsp)・Tw・
・・・・・・・・・・・・・・・・・・・・・(12), and since Y in the above example is 5.099■■, L=GO, β=0.023m■ becomes. Therefore, the synchronization shift time t1 is t,=7.77 μs. FIG. 8 is a clock time chart showing the synchronization shift relationship when the drive clock for the odd segment electrodes is ckl and the drive clock for the even segment electrodes is ck2.

In the above printing operation of the print head 4, the printed dots are shifted by an angle θ from the main scanning direction. In the case of A4 size, this amount is 210Xjanθw:1. l
It becomes 114mm. In order to correct this amount of deviation, the printing timing of each dot can be delayed in the sub-scanning direction by a delay means, or the print head 4 can be arranged in advance at an angle of 90+θW with respect to the sub-scanning direction. good.

It should be noted that the present invention is not limited to the preferred embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention. For example, segment electrode 4d
is not buried in the insulating base 4c, and each segment electrode 4d
An insulating member may simply be interposed between the leading edge and the paper 2.

Further, as shown in FIG. 9, a plate-shaped toner adhesion plate 14 may be provided as the toner adhesion means of the toner supply device 5, and its abdomen may be brought into pressure contact with the circumferential surface of the dielectric drum 6. This results in
The toner t is sandwiched between the toner adhering plate 14 and the circumferential surface of the dielectric drum 6, is charged by friction, and is forcibly adhered to the circumferential surface of the dielectric drum 6. According to this method, toner can be uniformly adhered to the circumferential surface of the dielectric drum 6 by simple mechanical means.

Furthermore, each linear electrode 4g is connected to toner t instead of being grounded.
A bias voltage having the same polarity as the charged polarity may be applied.

As a result, an electrostatic repulsive force acts on the toner on the dielectric drum surface 6a, and the toner is more quickly transferred onto the paper P, making it possible to obtain a clear image.

〔Effect of the invention〕

As described above in detail, according to the present invention, a segment electrode as a signal electrode and a spiral electrode as a common electrode are made to face each other via a toner transporting body, and a recording material is caused to run on this electrode facing portion, and recording is performed. By interposing an insulating material between the material and the signal electrode, it is easy to create an electrostatic recording device that can consistently and stably print high-resolution images on plain paper through a simple image forming process that does not form electrostatic latent images. can be realized. In this case, an electrostatic recording device can be provided at low cost because a print head with a complicated structure such as a multi-stylus is not required, and individual image forming process members such as a developer and a cleaner are not required. Additionally, since only the minimum amount of toner required is transferred to the paper, toner consumption efficiency is improved and running costs are reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the overall structure of an electrostatic recording device as an embodiment of the present invention, FIG. 2 is a perspective view showing the printing section of the electrostatic recording device, FIG. 4 is a schematic side view and an enlarged side view respectively showing the electrode facing part F and its essential parts, and FIGS. 5(a) and 5(b) are longitudinal sections showing different configurations of the screw pole, respectively. FIG. 6 is a plan view showing the arrangement relationship between segment electrodes and linear electrodes, and FIG.
9 is a printing time chart of each segment electrode, FIG. 8 is a time chart of a driving clock, and FIG. 9 is an explanatory diagram showing a modified embodiment of the present invention. 1... Paper feed cassette 2... Standby roll pair 3... Static elimination brush 4... Print head 4a... Segment ball 4b... Screw pole 4c... Insulating base 4d... Segment Electrode 4f... High voltage power source 4g... Linear electrode 5... Toner supply device 6... Dielectric drum 7... Corona discharger 8... Scraper 9... Stirring roll 14... Toner adhesion plate

Claims (1)

[Claims] A toner conveying body that carries toner on its surface and conveys the toner in a predetermined direction, and a recording material facing section where a recording material faces with a minute distance maintained from the surface of the toner conveying body to which the toner is attached. a plurality of segment electrodes, an insulating member interposed between the plurality of segment electrodes and the recording material facing portion, and a spiral electrode rotatably disposed on the other side of the recording material facing portion; a screw pole installed in the toner carrier, and selectively transfers the toner on the toner conveying body to the recording material by applying a high voltage between the segment electrode and the spiral electrode according to print information. An electrostatic recording device characterized by: