JPH04146159A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To stabilize formation of a high resolution image by disposing an electrode, applied with a surface layer composed of a material having volume resistivity variable with the intensity of working electric field, oppositely to a recording electrode. CONSTITUTION:A tubular electrode 5 has a double layer structure in which a surface layer 5b is laminated on the peripheral surface of a conductive sleeve 5a. The surface layer 5b is composed of such material as the volume resistivity decreases as the intensity of working electric field increases. Developing field for forming black dots has maximum intensity in the center of the width of recording electrode line and the intensity decreases substantially in symmetrical toward the opposite ends over the width of the electrode. Since the surface layer 5b composed of an dielectric is applied on the tubular electrode 5 at a recording position W, volume resistivity is minimized at a part opposing to the lateral center of the recording electrode line when the developing electric field functions on the surface layer 5b of the tubular electrode and the electric lines of force is converged to the central part of dot thus reducing the radiation angle theta. According to the constitution, a recording image having high resolution can be formed stably for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a non-contact electrostatic recording device that forms an electrostatically recorded image without bringing a recording head into contact with a recording medium.

[Prior art and its problems]

Conventionally, a multi-stylus printer is well known as one of electrostatic recording devices. This multi-stylus printer consists of a large number of needle-like electrodes (styli) installed in parallel at close intervals to form a recording device, and a high voltage is selectively applied to each needle-like electrode according to the image signal. , an electrostatic latent image is formed by directly discharging on paper. In such a multi-stylus printer, if the distance between the tip of the needle electrode and the paper surface is wide, the discharge electric field will spread and the formed dots will become large, making it difficult to obtain a high-resolution recorded image. Therefore, a minute gap is secured by providing a gap material on the surface of the paper and bringing the tip of the needle electrode into sliding contact with the gap material. However, this type of electrostatic recording device has the disadvantage that the tip of the needle electrode is worn out.

[Object of the Invention] The present invention has been made in view of the problems of the prior art described above, and is directed to an electrostatic material that does not wear out the recording head and can stably form high-resolution, good recorded images over a long period of time. The purpose is to provide a recording device.

[Key points of the invention]

In order to achieve the above object, the present invention includes a non-magnetic cylindrical body containing a rotatably supported magnet roll, and a plurality of cylindrical bodies arranged in parallel along the axial direction of the cylindrical body on the circumferential surface of the cylindrical body. a recording electrode, a connection means disposed on the surface of the cylindrical body for connecting each of the recording electrodes and a signal generation means for generating a recording voltage according to input recording information; and a connection means disposed substantially below the cylindrical body; and a plurality of conveying means for circulating the developer in the axial direction of the cylindrical body, and a counter electrode disposed with a predetermined gap from the recording electrode, and applying the recording voltage to the recording electrode. In the electrostatic recording device in which the developer conveyed from the conveying means to the cylindrical body in a substantially vertical direction by rotation of the magnet roll is selectively transferred to the counter electrode side, the counter electrode is electrically conductive. The key point is that the surface of the magnetic substrate is coated with a substance whose volume electrical resistance value changes depending on the strength of the applied electric field.

[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 a recording apparatus as an embodiment of the present invention. In the figure, reference numeral 1 denotes a paper feed cassette loaded with plain paper P, which is detachably attached to the side of the machine. A paper feed roller 1a is arranged above the tip of the inserted paper feed cassette 1 so as to be rotatable in the direction of the arrow.

In front of the paper feed roller 1a, upper and lower conveyance guide plates 2a+2b made of insulating members are laid to form a paper transport path. A pair of standby rolls 3 is disposed in this paper feed path, and after temporarily stopping the advance of the paper P fed out by the paper feed roller 1a and adjusting the conveyance posture, the paper P is transferred to the image transfer section T on the downstream side. The image is re-fed in synchronization with the arrival timing of the recorded image, which will be described later. In the image transfer section T on the downstream side of the standby roll pair 3, a transfer charger 4 is arranged opposite to a cylindrical electrode 5 which also serves as an image carrier.

As shown in FIG. 2, the cylindrical electrode 5 has a conductive sleeve 5a.
It has a two-layer structure in which a surface layer 5b is laminated on the circumferential surface of. Here, as shown in FIG. 5, the surface layer 5b is formed of a material having a characteristic that its volume electric resistance value decreases as the strength of the applied electric field increases. Typical materials with such characteristics include dielectric materials, among which polyamide film, anodized aluminum, and the like are suitable as materials for the surface layer 5b of the cylindrical electrode 5. Note that semiconductor materials can also be effectively used as the material for the surface layer 5b.

The cylindrical electrode 5 configured as described above is equipped with a bias power supply 5C capable of applying a bias voltage of -50V, since in this example, a developer with negative (-) triboelectric charging characteristics is used as described later. It is connected. Then, the cylindrical electrode 5 is driven and rotated in the counterclockwise direction shown by arrow A.

On the opposite circumferential surface of the cylindrical electrode 5, a recording image forming unit (U), which will be described later, is arranged to face the cylindrical electrode 5. A toner recorded image is formed on the surface of the cylindrical electrode 5 by this recorded image forming unit (U), and as the cylindrical electrode 5 rotates, the toner recorded image is conveyed to the image transfer section T and transferred onto the paper that is being fed again. . The configuration of the recording image forming unit (U) will be explained in detail later.

In FIG. 1, there is a separation claw 6 on the downstream side of the image transfer section T.
The tip is placed in pressure contact with the circumferential surface of the cylindrical electrode. An air suction conveyor belt 7 is stretched horizontally downstream of the separation claw 6, and the back side of the paper is separated from the circumferential surface of the cylindrical electrode 5 by the separation claw 6 after the recorded image has been transferred. is conveyed toward the fixing device 8 provided in front of it while being sucked. The fixing device 8 consists of a heating roll 8a and a pressure roll 8b, and thermally fixes the toner image when the paper is held between the two rolls and conveyed. The paper that has been fixed is
The paper sheets are discharged from the discharge port 9 and stacked on the paper discharge tray 10 in a face-down state with the image side facing down.

As described above, in the recording apparatus 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 image defects are avoided. Paper feeding defects such as jams are less likely to occur. It also has the advantage that the above-mentioned straight sheet passing path can achieve a face-down sheet discharge state that does not require page alignment, which is preferable for the recording apparatus.

Here, the detailed configuration of the recording image forming unit U will be explained.

Recorded image forming unit) U is approximately as shown in FIG.
a development recording tank 12 equipped with a recording means and a developer conveying means;
The developer storage tank 11 stores developer for replenishment.

In the developer storage tank 11, a stirring blade 11a is rotatably arranged. In this example, an insulating magnetic toner d is used as a developer, which is a one-component developer containing at least an insulating resin, a magnetic fine powder, and colorant particles, and has a negative (-) friction charge polarity. As the developer, a two-component developer in which a magnetic carrier and an insulating toner are mixed in a predetermined ratio can also be used.

At the bottom of the development recording tank 12, a horizontal developer circulation path 13 as shown in FIG. 3 is formed. This horizontal circulation path 1
In the pair of parallel longitudinal paths 13a and 13b in 3, auger rolls l 4 a and 14b are rotatably installed, respectively. Each auger roll 14a, 14b has a fourth
As shown in the perspective view of the figure, each shirt) 14a1.14bl
A plurality of spiral blades 14 a2, 14 b2 are erected on the circumferential surface of the blade, and a reverse feed blade 14 whose spiral direction is opposite is provided at one end of each.
It consists of a3, 14 and b3 standing upright. The auger rolls 14a and 14b are installed in parallel with each other, with the reverse feed blades 14a3 and 14b3 located on opposite sides. As shown in FIG. 3, these pair of auger rolls 14a and 14b are driven and rotated in directions opposite to each other as shown by arrows C and in a direction that transports the developer toward reverse feed blades 14a3 and 14b3. do.

As a result, at a portion of each corner where the reverse feed blades 14a3, 14b3 are provided, conveying forces in opposite directions collide with each other, and the magnetic toner is pushed out in the right angle direction and flows toward the other longitudinal path. In this manner, in this example, the magnetic toner is stirred and circulated in the direction indicated by the broken line arrow 2, and at this time, the magnetic toner can be sufficiently triboelectrically charged. By changing the material and shape of the auger rolls 14a and 14b, it is possible to triboelectrically charge the developer to a sufficient amount.

A central space S is formed in the center of the horizontal circulation path 13 configured as described above, surrounded by a wall Sv to prevent the circulating developer from entering. As shown in FIG. 2, a replenishment port 11b for replenishing magnetic toner dO is provided above the auger roll 14a near the developer storage tank 11 along the axial direction of the auger roll 14a. be.

Above the other auger roll 14b, a developing sleeve 15 for conveying the developer in the vertical direction is installed extending parallel to the auger roll 14b. The developing sleeve 15 has a magnet roll 16 rotatably built therein, and is arranged to face the cylindrical electrode 5 described above. Different magnetic poles are alternately magnetized on the circumferential surface of the magnet roll 16, and the magnet roll 16 is driven and rotated in the counterclockwise direction shown by the arrow H to spread the magnetic toner d along the circumferential surface of the developing sleeve 15 along the broken line. Convey in the clockwise direction indicated by the arrow.

A doctor blade 12a is disposed on the peripheral surface of the developing sleeve 15, which serves as a developer conveyance path, on the upstream side in the developer conveyance direction to regulate the layer thickness of the magnetic toner d to an appropriate thickness. On the downstream side of the doctor blade 12a, the developing sleeve 15
The position W where the circumferential surface of the cylindrical electrode 5 is closest to the circumferential surface of the cylindrical electrode 5 with a small gap is the recording position, and as described later, the magnetic toner d is selectively applied to the circumferential surface of the cylindrical electrode 5 according to the recorded information. The toner is transferred to form a toner recorded image. The minute gap at this recording position W is desirably set to 100 μm or less in order to transfer the toner efficiently.

On the downstream side of the recording position W, a wall SWI on the developer storage layer 11 side of the wall that surrounds the central space S of the horizontal circulation path described above is extended, and its tip is brought into contact with the circumferential surface of the developing sleeve 15. It's a shame. As a result, it is not transferred at the recording position W and remains on the circumferential surface of the developing sleeve 15, and the magnet roll 16
The magnetic toner d' conveyed by the rotation of is scraped onto the replenishment tank length measuring path 13a of the horizontal circulation path, thereby preventing the magnetic toner d' from entering the central space S or passing through the horizontal circulation path. The inconvenience of being directly returned to the upstream side along the circumferential surface of the developing sleeve 15 is prevented. Note that residual magnetic toner d adheres to the developing sleeve 15 separately from the peripheral wall of the central space S.
A special scraper may be provided to scrape off the . In this case, the scraper may be supported in the vertical direction, its tip abutted on the circumferential surface of the developing sleeve 15, and its other end extended to the bottom of the central space S. Furthermore, if the scraper is made of a magnetic material, the magnetic force of the magnet roll 16 can be blocked, and a smoother scraping and return effect can be obtained.

A recording electrode sheet 17 is disposed on the circumferential surface of the developing sleeve 15 in an area upstream from the recording position W in the toner transport direction. The recording electrode sheet 17 of this example is made of a flexible printed circuit board (FPC), and as shown in FIG. They are formed to extend in parallel at a predetermined fine pitch in the sheet width direction (toner conveyance path width direction: main scanning direction). The number of recording signal lines 17a corresponds to the maximum number of data for one main scanning line. In this example, a large number of recording electrode lines 17a are patterned at a density of 84.6 μm pitch (300 DPI) with a gap of 40 μm maintained. Although not shown, an insulating film is coated on the surface of the recording electrode sheet 17, thereby ensuring insulation between each recording electrode line 17a.

In FIG. 2, the recording electrode sheet 17 is laid over about half of the circumferential surface of the developing sleeve 15, pulled out horizontally and then lowered vertically, extending into the central space S of the horizontal circulation path described above. It is.

A plurality of drive circuit elements 18 are mounted on the vertically extending portion of the recording electrode sheet 17 to apply a recording voltage to each recording electrode line according to recording data. Then, as shown in FIG. 4, an appropriate number of recording electrode wires 17a of the recording electrode sheet 17 are connected to each drive circuit element 18. In this manner, by accommodating and installing the driving circuit element 18 mounting portion of the recording electrode sheet 17 in the central space S, the driving circuit element 18 can be protected from dust such as developer, and the structure inside the developing recording tank 12 can be protected. Extremely compact.

Next, a recorded image forming operation in the electrostatic recording apparatus of this example will be explained.

In FIG. 2, when the magnet roll 16 is driven and rotated in the direction of the small arrow, a rotating magnetic field is formed on the circumferential surface of the developing sleeve 15 that causes the particles of the magnetic toner d to rotate, and the magnetic toner d forms spikes. The magnet roll 16 is transported in the direction indicated by the dashed arrow, which is opposite to the rotation direction of the magnet roll 16. The conveyed magnetic toner d reaches the recording position W after being cut to a predetermined thickness by the doctor blade 12a. At this time, the magnetic toner d used in this example is sufficiently charged to a negative polarity due to friction between the toners and the peripheral surface of the developing sleeve 15.

On the upstream side of the recording position W, recording electrode lines 17a are laid in parallel as shown in FIG. Each recording electrode line f7a
, the drive circuit element 18 selectively applies a recording voltage according to recording information.

In this case, when one bit of recording information is "H", a voltage of -200V is applied to the corresponding recording electrode line 17a. This state is defined as the electrode-on state. In FIG. 2, a bias power source 5c is applied to the cylindrical electrode 5 facing the recording electrode line at -50V17)! Since a voltage is applied, a developing electric field based on a potential difference of 150 V is formed from the cylindrical electrode 5 toward the recording electrode line to which a voltage of -200 V is applied.

Since the negatively charged magnetic toner d moves toward the higher potential, a voltage of -200V is applied at the recording position W where the interval is the narrowest and the developing electric field is maximum (the input recording information is "H"). ) Only the magnetic toner d on the recording electrode line is selectively transferred to the circumferential surface of the cylindrical electrode 5, forming a black dot.

On the other hand, when the 1-bit recording information is "L", the drive circuit element 18 connects the recording electrode line to the ground circuit and sets it to the ground potential. This state is defined as an electrode-off state. As a result, the potential difference seen from one cylindrical electrode 5 to its corresponding recording electrode line becomes -50V, and an electric field is formed in the opposite direction to the above-mentioned developing electric field. Therefore, the negatively charged magnetic toner d remains held on the recording electrode line (recording electrode sheet 17) side and does not transfer.

In the above recorded image forming operation, in this example, the cylindrical electrode 5
dielectric surface! Since the i5b is provided, a high resolution image can be stably formed in the following manner.

As shown in Figure 6, the developing electric field that forms black dots is maximum at the center of the recording electrode line width (length in the main scanning direction).
It has an intensity distribution characteristic that decreases almost symmetrically toward both ends and spreads beyond the electrode width.

The magnetic toner that has been conveyed to the recording position is transferred and adheres to the cylindrical electrode side according to this electric field intensity distribution, forming a single black dot.

FIG. 7(a) shows a comparative example to this example.
FIG. 2 is a schematic explanatory diagram showing the state of development electric field formation when a cylindrical electrode 5' without a dielectric surface layer is used, with the recording position cut along the main scanning direction. In this case, since no surface layer is provided on the cylindrical electrode 5', the lines of electric force of the developing electric field are not focused at the center of the dot, and the radiation angle of the lines of electric force is θ,
The angle is quite large, about 45 degrees for boat fishing. As a result, as shown in the figure, the size of one dot is enlarged, the resolution is lowered, and there is a possibility that black dots that should be separated by one white dot may be connected. In this case, a method of reducing the distance between the electrodes may be considered in order to increase the resolution, but since magnetic toner is transported between the electrodes, there is a limit to reducing the distance.

On the other hand, at the recording position W of this example shown in FIG. 7(b), since the cylindrical electrode 5 is provided with the surface layer 5b made of a dielectric material, the developing electric field having the intensity distribution characteristic shown in FIG. acts on the cylindrical electrode surface layer 5b, based on the characteristics shown in FIG. The volume electrical resistance value of part) is the minimum. As a result, the lines of electric force forming the developing electric field are focused at the center of the dot, and the radiation angle θ2 of the lines of electric force becomes considerably smaller than the above-mentioned radiation angle θ1. Therefore, even at the recording position W where a sufficient distance between the electrodes is secured, the radiation angle of the electric lines of force is θ1.
Due to the development electric field with a small and sharp intensity distribution,
A high-resolution toner recording image consisting of dots with a clear outline and an appropriate size can be stably formed on the surface of the cylindrical electrode 5.

In FIG. 1, the high-resolution toner recorded image formed as described above is conveyed to the image transfer section T with the rotation of the cylindrical electrode 5 in the counterclockwise direction A, and here the timing is controlled by the standby roll pair 3. The image is measured and transferred onto the paper that is re-fed. In addition, in order to adjust the density of the above-mentioned toner recorded image, it is sufficient to change the bias voltage of the bias power supply 5c.

In that case, the appropriate adjustment range is about 0 to -50V,
The closer to Ov, the higher the image density.

In FIG. 2, the residual magnetic toner d' that was not transferred to the cylindrical electrode 5 side at the recording position W but was transported downstream is removed from the scraping wall S.
It is scraped off from the surface of the developing sleeve 15 by wl and falls onto the supply side auger roll 14a of the horizontal circulation path.

As the auger roll 14a rotates, the residual magnetic toner d' that has fallen back and the magnetic toner dO that is replenished from the replenishment port 11b of the developer storage layer 11 are mixed and stirred, and as shown in FIG. In cooperation with the rolls 14b, the material is circulated and conveyed within the horizontal circulation path 13 in the two directions indicated by the broken line arrows. In FIG. 2, when the magnetic toner d that is being circulated is transported along the longitudinal path 13b on the anti-replenishment side, it is again transported in the vertical direction by the rotating magnetic field of the magnet roll 16 extending above it.

As described above, the residual magnetic toner d' that has not been transferred to the cylindrical electrode 5 side at the recording position W but has been conveyed downstream passes through the horizontal circulation path to the replenishment magnetic toner d.

The toner is smoothly returned to the upstream side while being stirred and mixed with the toner, and is used again to form a toner recorded image. In this case, the magnetic l/ner d before being conveyed in the vertical direction is
Since the toner is conveyed while being stirred along the axial direction of the developing sleeve 15 (width direction of the toner vertical conveyance path: main scanning direction), it is always uniformly supplied over the entire widthwise area of the circumferential surface of the developing sleeve 15. . Therefore, the magnetic toner d is always uniformly supported on the circumferential surface of the developing sleeve 15 over the entire width direction and is conveyed to the recording position W, making it possible to stably obtain a good recorded image with uniform image density. It becomes possible. Further, when the magnetic toner d is circulated and conveyed while being stirred in the horizontal circulation path, the magnetic toner particles rub against each other, and the magnetic toner is sufficiently triboelectrically charged.

It should be noted that the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention.

For example, as shown in FIG. 8, a coil roll 19 that utilizes a traveling wave magnetic field generated by an excitation coil may be employed as a means for vertically conveying the developer. coil roll 19
A large number of grooves 20a are formed in parallel to the width direction on the outer circumferential surface of a base body 20 made of a magnetic material and having a cross section that is an omitted circle, excluding a part of the circle.
The excitation coil 21 is formed by winding a conducting wire between each of the grooves 2Oa. This excitation coil 2
When the coil roll 19 is divided into n appropriate groups and an alternating current with a phase shift of π/n is applied to each group V, a traveling wave magnetic field is generated that travels along the circumferential surface of the coil roll 19 in the direction indicated by the dashed arrow. do. A recording electrode sheet 22 constructed in the same manner as the recording electrode sheet 17 shown in FIG. 5 is laid on the outer peripheral surface of this coil roll 19. In addition, residual magnetic toner d is placed on the flat surface downstream from the recording position W (the leading end of the recording electrode sheet 22).
' A scraping plate 23 is provided.

The coil roll 19 configured as described above also allows the magnetic toner to be vertically conveyed smoothly in the same way as in the embodiments described above, making it possible to stably obtain a clear recorded image with high resolution. In addition, in the case of the coil roll 19 of this example, since no rotating member is used, the durability of the device is improved, and the developer conveyance path can be freely set, making it possible to significantly promote downsizing of the device. becomes.

Further, as shown in FIG. 9, the developer circulation conveying means may be constructed using a spring belt 24. In this case, pulleys 25.25 are provided at both ends of the developer circulation path 13 having the same configuration as the embodiment shown in FIG.
The spring belt 24 is wound between the holes 5 and 5. Boo IJ25,25
When the spring belt 24 is rotated in the direction of the arrow and the spring belt 24 is rotated in the direction of the arrow N, the magnetic toner also follows and flows in the same direction. Note that instead of the spring belt 24, a normal band belt may be wound around. The belt-type circulation conveyance means of this example can be configured to be smaller than the auger-roll type described above.
This is extremely useful for downsizing the device.

Further, in the embodiment shown in FIG. 2, a negatively (-) chargeable toner is used as the toner, but a positively (+) chargeable toner may also be used. In that case, each bias voltage applied to the cylindrical electrode 5 and the recording electrode line may have positive (+) polarity.

〔Effect of the invention〕

As described above in detail, according to the present invention, the developer is conveyed vertically upward from the bottom circulation path using magnetic force, and then dropped back to the circulation path to be recycled. A plurality of recording electrodes are installed in parallel in the width direction, and a counter electrode coated with a surface layer made of a substance whose volume electric resistance value changes depending on the strength of the applied electric field is placed opposite to the recording electrode. The lines of electric force of the developing electric field that transfers can be focused at the center of the width of the recording electrode. As a result, it is possible to reliably form a developing electric field with a small radiation angle of electric lines of force, and it is possible to secure a sufficient distance between the counter electrode and the recording electrode to stably form sharp recorded images with high resolution. can.

In addition, by configuring the recording electrode drive circuit in the central space of the bottom circulation path, a recording means in which a large number of recording electrodes are densely mounted is incorporated into the developer conveying means, and development recording that performs development and recording at the same time is possible. The structure of the section can be greatly simplified. Therefore, it is possible to manufacture an electrostatic recording device that is small and inexpensive and can stably form high-resolution, good recorded images on plain paper.

Furthermore, since the developer can be agitated and transported along the bottom circulation path and uniformly supplied in the width direction of the vertical transport path, it is possible to prevent variations in image density due to unevenness of the developer.

In addition, since it is a non-contact recording method, the durability of the electrostatic recording device is improved, and good images with high resolution and uniform image density can be stably formed over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing the overall configuration of an electrostatic recording device as an embodiment of the present invention, FIG. 2 is a sectional view showing a recorded image forming unit and its peripheral configuration in the electrostatic recording device, and FIG. FIG. 3 is a plan sectional view showing the horizontal circulation path of the recorded image forming unit, FIG. 4 is a perspective view showing the recorded image forming unit, and FIG. 5 is a graph showing the volume electric resistance value characteristics of the dielectric with respect to the applied electric field. 6 is a graph showing the electric field strength distribution characteristics of the developing electric field in the recording image forming unit, and FIGS. 7(a) and 7(b) are a comparative example and the formation of the developing electric field in the recording image forming unit. Each schematic explanatory drawing showing the state, FIG. 8 and FIG. 9 are each a schematic sectional view showing other embodiments of the present invention. 4... Transfer charger 5.5'... Cylindrical electrode 5a... Conductive sleeve 5b... Surface layer 5c... Bias power supply 11... Developer storage tank 12... Development recording tank 13...Horizontal circulation path 14a, 14b...Auger roll 15...
・Developing sleeve 16... Magnet roll 17.22... Recording electrode sheet 17a... Recording electrode wire 17b... Base film 18... Drive circuit element 19... Coil roll 21... Excitation coil 24...Spring belt S...Central space U...Recording image forming unit W...Recording position

Claims (6)

[Claims] (1) A non-magnetic cylindrical body containing a rotatably supported magnet roll, a plurality of recording electrodes arranged in parallel along the axial direction of the cylindrical body on the circumferential surface of the cylindrical body, and each of the recording electrodes. and a signal generating means for generating a recording voltage according to input recording information, the connecting means being disposed on the surface of the cylindrical body, and the connecting means being disposed substantially below the cylindrical body, and a connecting means disposed substantially below the cylindrical body, and a connecting means disposed on the surface of the cylindrical body, and a connecting means disposed substantially below the cylindrical body, and a signal generating means for generating a recording voltage according to input recording information. a plurality of conveying means for circularly conveying in the axial direction of the magnet roll, and a counter electrode arranged with a predetermined gap maintained between the recording electrode and the recording electrode, and by applying the recording voltage to the recording electrode, the magnet roll is In an electrostatic recording device that selectively transfers the developer conveyed from the conveyance means onto the cylindrical body in a substantially vertical direction to the counter electrode side by rotation, the counter electrode is connected to the surface of the conductive substrate by applying an applied electric field to the surface of the conductive substrate. An electrostatic recording device characterized in that it is formed by coating a substance whose volume electrical resistance value changes depending on its strength. (2) The electrostatic recording device according to claim 1, wherein the signal generating means is provided in a space between the cylindrical body and the conveying means. (3) The electrostatic recording device according to claim 1, wherein the conveying means has a stirring function. (4) The electrostatic recording device according to claim 1, further comprising a scraper that comes into sliding contact with the cylindrical body and peels off the developer conveyed onto the cylindrical body. (5) The electrostatic recording device according to claim 4, wherein the scraper is made of a magnetic material. (6) The electrostatic recording device according to claim 1, further comprising a developer replenishing means for replenishing developer downstream of the opposing portion of the opposing electrode and the recording electrode.