JPH0440476A - electrostatic recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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, in the recording section of an electrostatic recording device, the first
As shown in FIG. 5, a number of recording electrodes 102 corresponding to the number of dots for one main scanning line are lined up at minute intervals in the width direction (direction perpendicular to the paper surface: main scanning direction) of the surface of the developer conveying member 101. It is set up. In this case, each recording electrode 102 usually
As shown in FIG. 16, it may be embedded in the electrode holding member 103 or fixedly installed on the developer conveying body 101.

In the electrostatic recording device as described above, in order to appropriately regulate the amount of developer conveyed on the upstream side of the recording/distribution section, the developer d is distributed over the entire surface of the developer conveying body 101 in the recording head section. Same-
It is transported in a state where it is leveled to the same height. Therefore, even on the surface of the holding member +03 on which the recording electrodes 102 are arranged, as shown in FIG. 17, the developer d is supported in a thin layer having a substantially uniform thickness. When a voltage is selectively applied to each recording electrode 102 under such conditions, a voltage leak phenomenon may occur through the developer d existing between each recording electrode 102. As a result, each recording electrode 10
The drawback is that the voltage contrast between the two is reduced, making it difficult to stably obtain clear recorded images.

In addition, in an electrostatic recording device that forms an electrostatic latent image by directly discharging a recording electrode onto a sheet of paper, if the distance between the tip of the recording electrode and the surface of the sheet is wide, the discharge electric field will spread and the dots formed will be This makes it difficult to obtain high-resolution recorded images. For this reason, a gap material is provided on the surface of the paper, and the recording electrode is brought into sliding contact with the gap material to ensure a minute gap. However, this type of electrostatic recording device has the disadvantage that the recording electrode is worn out because the paper is constantly in sliding contact with the tip of the recording electrode.

[Object of the Invention] The present invention has been made in view of the problems of the prior art described above, and it is possible to reliably prevent voltage leakage between recording electrodes, prevent wear of the recording head, and record clear and high-resolution recording. An object of the present invention is to provide an electrostatic recording device that can stably form images.

[Key points of the invention]

In order to achieve the above object, the present invention includes: a developer carrying member made of a non-magnetic material; a developer magnetic conveying means for conveying a magnetic developer containing a magnetic component along the surface of the developer carrying member; A plurality of recording electrodes are arranged in parallel at predetermined intervals on the surface of the developer carrying member, and a counter electrode is arranged with a gap between the recording electrodes, and a voltage is applied to each of the recording electrodes according to recording information. In an electrostatic recording device that selectively transfers the magnetic developer to the counter electrode side by applying an electric current, at least a portion of the developer carrying member that holds the recording electrode is formed of an insulating material, and a surface of the insulating material portion is formed of an insulating material. The key point is that a plurality of recesses are formed in the recess, and the recording electrodes are respectively installed at the bottoms of the recesses.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 14.

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, there is formed a paper transport path defined by upper and lower conveyance guide plates 2a and 2b made of insulating members. 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 disposed opposite to a cylindrical electrode 5 which also serves as an image carrier. In this example, the cylindrical electrode 5 is driven to rotate in the counterclockwise direction indicated by arrow a. This cylindrical electrode 5 is connected to a bias power source 5a capable of applying a bias voltage of -50V since a developer having negative (-) friction charging polarity is used in this example as will be described later. 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. Recorded image forming unit U
The configuration will be explained in detail later.

On the downstream side of the image transfer section T, a separating claw 6 is disposed with its tip pressed against the circumferential surface of the cylindrical electrode. An air suction type conveyor belt 7 is stretched horizontally downstream of the separation claw 6, and the separation claw 6 finishes transferring the recorded image.
The back surface of the sheet separated from the circumferential surface of the cylindrical electrode 5 is sucked and conveyed toward the fixing device 8 provided in front of the sheet. 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. After the fixing, the 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.

The recording image forming unit) U generally has an agitation roll 12 and a supply roll 3 rotatably disposed at the bottom of a unit container 11 for storing developer d, and integrates an image recording means and a developer conveying means. The recording unit Uw is arranged in such a manner that its recording portion W is exposed through an opening 11a that is open toward the circumferential surface of the cylindrical electrode 5 described above. In this example, the developer d
As a one-component developer containing at least an insulating resin, magnetic fine powder, and colorant particles, an insulating magnetic toner having negative (-) triboelectric charging characteristics is used. 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.

FIG. 2 is a schematic cross-sectional view showing the recording unit Uw and its peripheral members. The recording unit UvJ of this example has an oval cross section and a columnar body extending in the direction perpendicular to the plane of the paper.
Base 1 made of a high magnetic permeability material such as nickel or permalloy
An outer cover member 15 made of a non-magnetic material and whose surface serves as a conveying path for the magnetic toner d covers a region other than a part of the outer circumferential surface of the magnetic toner 4. On the circumferential surface of the base body 14 covered with the outer covering member 15, a large number of concave grooves 14a having a V-shaped cross section are formed in parallel and at equal intervals along the longitudinal axis direction of the base body (direction perpendicular to the plane of the paper). It is. In addition, in FIG. 2, there are a total of 12 recessed grooves 14a.
Although only the recessed groove 1 is shown in the diagram, in reality there are more recessed grooves 1 than that.
4a are densely formed.

The length of each concave groove 14a is set to be longer than the width of the conveyance path defined on the circumferential surface of the outer cover member 15.

A conducting wire 16a is buried in each circuit groove 14a, and
A coil portion 16 as a part of the excitation coil is formed respectively. As shown in FIG. 3(a), this coil portion 16 is
In this example, it is divided into two groups, A and B, and each group's coil portion 16A,
16B are arranged every other piece. In this case, Figure 3 (
As shown in b), a pair of coil parts 16, 18 adjacent to each other with one coil part 16 of the other string in the same group (for example, consecutive odd-numbered and even-numbered coils with the coil part 16B1 placed) Parts 1BAI and 18A2) are the same conductor lea
It is formed by winding it many times in a predetermined direction across every other pair of concave grooves 14a, 14a. Therefore, the running direction of the conducting wires 113a of every other pair of adjacent coil parts 16.16 in the same group (based on the winding direction of the coils)
are in opposite directions.

In addition, when the coil part 16 is divided into m groups of 3 or more, the fill parts of each group are arranged every (m-1) pieces, and the conductor 1
A pair of concave grooves 14a+1 every (m-1) 6a
4a to form a pair of coil parts of the same set.

As shown in FIG. 4, two types (two phases) of alternating current LA+lB LA= I sin (ωt) ・・・・・・
...... (1) i, =IsIncωt+yr/2
)...-(2) are energized, respectively.

By applying an alternating current to each coil portion 16 as described above, a magnetic field corresponding to the applied current as shown in FIG. 5 is excited in each partition portion 14b between each concave groove 14a in the base body 14. . FIG. 5 is a graph showing temporal changes in the excitation magnetic field distribution on the surface of the sleeve 2. FIG. In the graph, the vertical axis represents the sleeve radial component Hr of the excitation magnetic field, and the horizontal axis represents the position on the surface of the sleeve 2. Note that T is the period of the alternating current that is applied. In this example, as described above, the running directions of the conducting wires in the odd-numbered and even-numbered coil portions 16 (for example, 16AI and 16A2) in each set are reversed. Therefore, the coil portions 16 of the same group
If an alternating current with the same phase is passed through the coils, the directions of the magnetic fields excited by the odd-numbered and even-numbered coil portions 16 will be opposite to each other. As a result, the distribution curve of the magnetic field formed on the surface of the sleeve 2 also draws a waveform corresponding to the alternating current as shown in FIG. Since this waveform magnetic field changes with a period T like an alternating current, it results in the formation of a traveling wave magnetic field that travels in a convex direction in the figure.

That is, in FIG. 3(a), the waveform magnetic field formed on the surface of the sleeve 2 by all the coil portions 16 travels counterclockwise along the surface of the jacket member 15 at a predetermined speed. As a result, the magnetic toner can be conveyed to the port in the clockwise direction opposite to the traveling direction A of the traveling wave magnetic field. In this case, as shown in FIG. 2, the magnetic toner d is conveyed while forming toner spikes corresponding to the lines of magnetic force of the traveling wave magnetic field.

Returning to FIG. 2, in this example, the base body 14 is separably divided into two parts, and the internal space S is formed by joining the divided base bodies 14A and 14B. Each divided base 1
4A and 14B are individually covered with outer cover members 15A and 15B. Both outer covering members 15A are used to form a flat toner conveyance path.

A bridge member 17 is installed at the joint portion of 15B.

On the upstream side of the toner conveyance path, there is a doctor blade 1 for regulating the ears of L-toner to an appropriate length to form a toner layer.
8 is arranged. The doctor blade 18 of this example is fixed to the side wall of the unit container 11 with its tip brought close to the surface of the outer sheath 1J' 158. doctor blade 1
8, the position where the circumferential surface of the jacket member 15A is closest to the circumferential surface of the cylindrical electrode 5 with a small gap therebetween becomes the recording section W, where the magnetic toner d is applied to the surface of the cylindrical electrode 5 according to the input recording data. The toner is selectively transferred to form a toner recorded image. On the downstream side of the recording section W, a scraping plate 19 is disposed with its tip pressed against the surface of the jacket member 15A.

This scraping plate 19 scrapes off the residual magnetic toner d' that has been conveyed without being used in the recording section W.

A recording electrode sheet 20 is provided on the surface of the outer covering member 15A in an area upstream from the recording section W with respect to the opening in the toner transport direction.
It is covered and laid. As shown in FIG. 6, the recording electrode sheet 20 of this example is made of a flexible printed circuit board (FPC), and a plurality of recording electrode lines 20a extending parallel to each other in the longitudinal direction of the sheet are connected to a base film. 2Ob, extending in parallel in the sheet width direction (toner conveyance path width direction: main scanning direction) at a predetermined fine pitch. Recording electrode wire 20a
The number corresponds to the maximum number of data for one main scanning line, which will be described later. In this example, a large number of recording electrode lines 20a are
86μm pitch (300DPI) with 40μm spacing
) with a density of

FIG. 7 is a perspective view showing the leading end of the recording electrode sheet 20. FIG. An insulating coat 20c is provided on the surface of the recording electrode sheet 20.
This ensures insulation between the recording electrode wires 20a and prevents the recording electrode wires 20a from becoming thick due to friction with the magnetic toner. Various electrically insulating materials such as resin can be used as the material for the insulating coat 20c, but the magnetic permeability of the developer used is
1, the magnetic permeability μ2 of the material must satisfy the relationship μm>μ2.

Thus, in a region Z extending over a predetermined range from the tip of the recording electrode sheet 20 located in the recording section W, the recording electrode line 2
The insulating coat part on the top of 0a was removed. That is, a plurality of grooves G extending in the developer transport direction are formed in parallel on the surface of the insulating coat 20c, which serves as the developer carrying surface, and the tip of the recording electrode wire 20a is extended to the bottom surface of the groove, and the recording electrode EL is It consists of:

By configuring the recording electrode EL as described above, the eighth
As shown in the figure, a toner chain of the magnetic toner d to be transported can be collectively formed on the recording electrode EL. That is, the magnetic toner d that has been transported on the surface of the insulating coat 20c by the traveling wave magnetic field described above also enters into the groove G.

The magnetic permeability of the magnetic toner d that has entered the groove G is
Since the magnetic permeability is thicker than that of the insulating coat 20c forming both side walls of the groove G, the lines of magnetic force of the traveling wave magnetic field are shown by the dashed line.
Focus within. As a result, the magnetic toner d continues along the lines of focused magnetic force, forming a toner chain on each recording electrode EL that extends toward the cylindrical electrode 5 side. In this case, since almost no magnetic toner d exists between the adjacent recording electrodes EL, it is possible to reliably prevent voltage leakage between them. Therefore, the voltage contrast is sufficiently maintained, and a clear, high-resolution toner recorded image can be stably formed on the circumferential surface of the cylindrical electrode 5. Furthermore, since no unnecessary toner chain is formed between the adjacent recording electrodes EL, the amount of toner transported to the recording section W can be reduced. Therefore, a toner recorded image can be efficiently formed with less transport energy and the minimum necessary amount of magnetic toner.

If a magnetic material is coated on the surface of the recording electrode EL facing the cylindrical electrode 5, or if the entire recording electrode EL is made of a conductive magnetic material, the focusing effect of the magnetic lines of force will be promoted, and a sharp image with improved resolution can be obtained. You can get the image.

As shown in FIG. 6, the recording electrode sheet 20 constructed as described above is submerged below the bridge member 17, and is laid down to the internal space S through the joint surfaces of the divided bases 14A and 14B. A plurality of drive circuit elements 21 are arranged within the internal space S to drive the recording electrode lines 20a according to recording data.

These drive circuit elements 21 are connected to the recording electrode sheet 2 described above.
The number of recording electrode lines 20a is divided into appropriate numbers and connected to each other. From each drive circuit element 2, the input wiring circuit 22 is drawn out from the recording unit Uw from the other joint surface of the divided bases 14A and 14B. The input wiring circuit 22 is connected to a recording control section (not shown).

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

In FIG. 2, when the above-mentioned alternating current is applied to the excitation coil, a traveling wave magnetic field moving in the direction of arrow A is formed on the outer peripheral surface of the area where the excitation coil of the recording unit Uw is disposed, and the magnetic The toner d is conveyed in the opposite direction of the arrow while forming ears. The magnetic toner d being conveyed is
After being cut to a predetermined thickness by the doctor blade 18, it reaches the recording section W. At this time, the magnetic toner d is triboelectrically charged to a negative polarity. Recording electrodes EL (see FIG. 7) are arranged in parallel on the upstream side of the recording section W, and the drive circuit element 21 applies a recording voltage to each recording electrode EL according to recording data as described above. Apply selectively. In this case, when 1 bit of recording data is "H" and a voltage of 1200V is applied to the corresponding recording electrode EL, the recording electrode EL
Since a voltage of -50V is applied to the cylindrical electrode 5 facing the
A potential difference of V is formed. Since the negatively charged magnetic toner d moves toward the higher potential, only the magnetic toner d on the recording electrode EL to which a voltage of -200V is applied is present in the recording section W where the interval is the narrowest and the electric field is the largest. is selectively transferred to the surface of the cylindrical electrode 5, forming a black dot.

On the other hand, when the 1-bit recording data is "L", the recording electrode EL becomes the ground potential. As a result, the potential difference seen from the cylindrical electrode 5 to its corresponding recording electrode EL becomes 50 V, and the negative magnetic toner d remains held on the recording electrode EL side and does not transfer.

As mentioned above, depending on the input recording data, the corresponding recording electrode EL
The potential of is selectively controlled to 1200V and the ground potential, and a toner recorded image is formed on the circumferential surface of the opposing cylindrical electrode 5 in accordance with recorded data. In this case, as mentioned above, the recording electrode E
Since recording electrode ELJ is placed at the bottom of groove G:
can be focused to form a toner chain of sufficient length.

Therefore, the voltage leak phenomenon between the recording electrodes EL is prevented,
High resolution and clear toner recorded images can be stably formed.

The toner recorded image formed on the circumferential surface of the cylindrical electrode 5 is
As shown in the figure, as the cylindrical electrode 5 rotates in the counterclockwise direction a, the image is conveyed to the image transfer section T, where it is transferred onto a sheet of paper that is re-fed at a timing measured by a pair of standby rolls 3. Incidentally, 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 5a. In that case, the appropriate adjustment range is about 0 to -50V, and the closer it is to OV, the higher the image density becomes.

The magnetic toner d' that remains without being transferred to the cylindrical electrode 5 side in the recording section W moves downstream with the progress of the traveling wave magnetic field and is scraped off from the surface of the jacket member 15A by the scraping plate 19, and the stored magnetic toner d' Stirred and mixed with toner.

Next, other embodiments of the present invention will be described.

Components that are the same as those in the first embodiment are designated by the same reference numerals and their explanations will be omitted.

In the embodiment shown in FIG. 9, a plurality of magnet rolls 23 and 24 are used as developer conveying means in the recording unit Uw of the image forming unit U. A developer carrying member 27 is installed between a pair of magnetic transport rolls 25 and 26 each containing magnet rolls 23 and 24, and a recording electrode body 28 serving as a recording means is placed between both magnetic transport rolls 25 and 28.
The magnetic toner d is conveyed in a predetermined direction along the surface of the developer carrying member 27 by the cooperative action of the magnetic forces of both the magnet rolls 23 and 24.

Thus, the leading end surface of the recording electrode body 28 is made to protrude into the recording portion W closest to the circumferential surface of the cylindrical electrode 5 in the developer transport path along the surface of the developer carrying member 27. This recording electrode body 2
Reference numeral 8 is formed by adhering a sheet having the same structure as the recording electrode sheet 20 of Example 1 to the surface of a plate-shaped substrate. Recording electrode body 28
The drive circuit element 29 is integrally mounted on the drive circuit element 29, and a recording electrode having the same structure as the recording electrode EL shown in FIG.

The image forming unit (U) of this example can also stably form a clear image with high resolution, as in the first embodiment. Furthermore, since the recording electrode body 28 of the recording means is built into the recording unit 0w, the recording unit UW in which the recording electrodes are densely mounted can be made small and compact.

The embodiment shown in FIG. 10 uses a single magnet roll 30 as the developer conveying means. A magnet roll 30 is rotatably disposed within a sleeve 31 as a developer carrying member made of a non-magnetic material.
Cylindrical electrodes 5 are arranged to face each other in the sleeve 31, and a large number of recording electrodes EL' are arranged in parallel in the width direction (main scanning direction) of the sleeve 31 in the recording part W where the circumferential surfaces of both sides are closest to each other.

As shown in FIG. 11, the recording electrodes EL' are embedded in the bottoms of recesses R formed at minute intervals on the tip surface of the electrode holding member 32 made of an insulating material. Similarly to the recording electrode EL in the above embodiment, the recording electrode EL' of this example also has the following features:
It is made of a material whose magnetic permeability is higher than that of the magnetic developer used.

In FIG. 10, as the magnet roll 30 rotates in the direction indicated by the arrow A, magnetic toner is conveyed on the circumferential surface of the sleeve 31 in the direction indicated by the arrow C, which is opposite to the direction in which the magnet roll 30 rotates. As shown in FIG. 12, the magnetic toner d that has been conveyed while forming a toner chain in the recording portion W advances along the surface of the electrode holding member 32 and enters the recess R.

Here, due to the same magnetic force line focusing effect as in the above embodiment, the toner chain is formed on the recording electrode EL' (
(inside the recess R) to prevent voltage leakage between the recording electrodes EL'.

The embodiment shown in FIG. 14 is a combination of the developer conveying means used in the embodiment shown in FIG. 10 and the recording means shown in FIG. That is, the recording electrode sheet 33 is laid on the circumferential surface of the sleeve 31 from the recording portion W to the upstream side. This recording electrode sheet 33 has a recording electrode EL formed at its tip end and is equipped with a drive circuit element 22, similarly to the recording electrode sheet 20 of FIG.

Even in the two embodiments in which the developer is transported by the single magnet roll 30 described above, voltage leakage between the recording electrodes is reliably prevented, and clear recorded images with high resolution can be stably obtained.

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, in the embodiment shown in FIG. 10, the sleeve 31 as a developer carrying member is formed of a non-magnetic insulating material,
A plurality of grooves may be formed in the surface of the sleeve 31 located in the recording section W, and a recording electrode EL' may be installed at the bottom of each groove. In this case, the electrode holding member 32 becomes unnecessary, and the structure becomes simpler.

〔Effect of the invention〕

As described in detail below, according to the present invention, the magnetic developer is transported along the surface of the developer carrying member by the magnetic transporting means, and the portion of the developer carrying member that holds the recording 7B pole is insulated. By forming a plurality of recesses on the surface of the insulating material and installing recording electrodes on the bottoms of these recesses, the lines of magnetic force of the magnetic transport means can be focused on the recording electrodes. . As a result, ears of magnetic developer can be collectively formed on the recording electrode,
Voltage leakage via the magnetic developer between the recording electrodes can be reliably prevented. As a result, a clear recorded image with high resolution can be stably formed.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the overall configuration of a recording apparatus as an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a recorded image forming unit and its peripheral configuration in the recording apparatus, and FIG.
Figures (a) and 3(b) are explanatory diagrams showing the configuration of the excitation coil in the recording device, respectively, Figure 4 is a graph diagram showing the waveform of the current flowing through the excitation coil, and Figure 5 is the A graph showing a temporal change in an excitation magnetic field distribution curve due to an excitation coil, FIG. 6 is a partially cutaway perspective view showing a recording unit in the recording image forming unit, and FIG. 7 shows a recording electrode in the recording image forming unit. A perspective view, FIG. 8 is an explanatory diagram showing the recording operation by the recording electrode, and FIG. 9 is a perspective view.
The figures are a schematic sectional view showing another embodiment of the present invention, FIG. 10 is a schematic sectional view showing still another embodiment of the invention, and FIG.
13 are perspective views showing the structure of recording electrodes and respective explanatory views showing the recording operation thereof in the other embodiments described above, and FIG. 14 is a schematic cross-sectional view showing still another embodiment of the present invention, FIGS. 15 to 17 are explanatory diagrams showing the configuration of a conventional recording electrode and the recording operation thereof, respectively. 1... Paper feed cassette 3... Standby roll pair 4... Transfer charger 5... Cylindrical electrode 5a... Bias power supply (cylindrical electrode side) 8... Fixing device 10... Paper discharge Tray 11... Unit container 12... Stirring roll 14... Base 14A, 14B... Divided base 15. 15A, 15B... Outer cover member 16... Coil portion 18... Doctor blade 19 ...Scraping plate 20.33...Recording electrode sheet 20a...Recording electrode wire 20b...Base film 20c...Insulating coat 21.29...Drive circuit element 22...Input wiring circuit 23.24.30... Magnet roll 27... Developer carrying member 28... Recording electrode body 31... Sleeve 32... Electrode holding member G... Groove R... Recess T...・Image transfer section U...recorded image forming unit Uw...recording unit W...recording section

Claims (2)

[Claims] (1) A developer carrying member made of a non-magnetic material, a developer magnetic conveyance means for conveying a magnetic developer containing a magnetic component along the surface of the developer carrying member, and a developer magnetic conveying means arranged on the surface of the developer carrying member. It has a plurality of recording electrodes arranged in parallel at intervals of In an electrostatic recording device that selectively transfers to a counter electrode side, at least a portion of the developer carrying member that holds the recording electrode is formed of an insulating material, and a plurality of recesses are formed on the surface of the insulating material portion; An electrostatic recording device characterized in that the recording electrodes are respectively installed at the bottoms of the recesses. (2) The electrostatic recording device according to claim 1, wherein at least a surface portion of the recording electrode facing the counter electrode is formed of a magnetic material.