JPH0443370A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To prevent a recording head from being abraded and to stably form and excellent recorded image whose end is prevented from being contaminated by developer and which has high resolution by setting the width of a dummy electrode so that the width of an electrode juxtaposing area where a recording electrode and the dummy electrode are formed together may be larger than the width of a developer carrying path. CONSTITUTION:The dummy electrode 20c for holding magnetic toner so that it may not be transferred to a cylindrical electrode side is formed at the edge of a recording electrode sheet 20, and the dummy electrode having the same constitution is formed at the other edge of the sheet 20. In such a case, the width DW of the dummy electrode 20c is larger than the width EW of each recording electrode wire 20a and set to satisfy the relation of Ze<Zt<Ze+2.DW, supposing that the width of an area where the recording electrode wire 20a is installed is Ze and the width of a developing area is Zt. Thus, the recorder where the excellent recorded image with end prevented from being contaminated and which has stably formed high resolution is produced in small-size at low cost.

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 a recording head section of an electrostatic recording device, a plurality of recording electrodes are arranged in parallel at minute intervals along the main scanning direction. FIG. 12 shows an example of this, in which a plurality of recording electrodes +02 extending in the circumferential direction are laid out in parallel on the circumferential surface of the developer conveying sleeve 101 with minute intervals maintained in the width direction (main scanning direction). be. In this case, since it is necessary to set the development area larger than the recording area (area where recording electrodes are arranged side by side) Ze, an electrode-free area Z is provided where recording electrodes +02 are not laid at both ends of the circumferential surface of the developer conveying sleeve 101. This is provided. This electrodeless area Z. Since the developer conveyed to the camera is carried in an unstable state where no forced holding force such as an electric field is applied, the developer is transferred to the opposite electrode depending on the operating conditions and environmental conditions, and the developer is deposited at the edge of the image. There is a risk of causing dirt.

In particular, when the end portion of the base film 103 supporting the recording electrode 102 covers the electrode-free area Zo as in the illustrated example, the base film made of an insulating material! 03, and the accumulated charges tend to cause the developer to transfer to the counter electrode side, resulting in noticeable developer stains at the edges of the image.

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 large, the discharge electric field will spread and the dots formed will be distorted. This makes it difficult to obtain high-resolution recorded images. Therefore, a small gap is secured by providing a gap material on the surface of the paper and bringing the tip of the recording electrode into sliding contact with the gap material. However, this type of electrostatic recording device has the disadvantage that the tip of the recording electrode is worn out.

[Purpose of the invention]

The present invention was devised in view of the problems of the prior art described above. The purpose is to provide a recording device.

[Key points of the invention]

In order to achieve the above object, the present invention provides a developer carrying member whose surface serves as a developer carrying path, a developer carrying means for carrying developer along the surface of the developer carrying member, and a developer carrying member. It has a plurality of recording electrodes arranged in parallel at predetermined intervals in a width direction perpendicular to the developer transport direction on the surface while maintaining electrical insulation from each other, and a counter electrode arranged with a gap between the recording electrodes, In an electrostatic recording device in which a voltage is applied to each of the recording electrodes according to recording information to selectively transfer the conveyed developer to the counter electrode side, non-recording information is provided at both ends of the row formed by the recording electrodes. A dummy electrode was provided to which a voltage corresponding to the voltage was applied, and the width of the dummy electrode was set so that the width of the electrode juxtaposed area including the recording electrode and the dummy electrode was larger than the width of the developer transport path. The main point is that.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 11.

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 arranged 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 supply 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. This recording image forming unit/)U allows the cylindrical electrode 5
A toner recorded image is formed on the surface, 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. recording image forming unit)
The configuration of U 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. On the downstream side of the separation claw 6, an air succinct conveyor belt 7 is stretched horizontally, and after transferring the recorded image, the separation claw 6
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 conveyance path from paper feeding to paper ejection is formed in a substantially straight line, so the paper passing operation is generally smooth and there is no problem with image defects. 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 a stirring roll 12 and a supply roll 13 rotatably disposed at the bottom of a unit container 11 for storing developer, and integrates an image recording means and a developer conveying means. The recording unit W is opened from the opening 11a opened toward the circumferential surface of the cylindrical electrode 5 described above.
It is arranged in such a way that it faces the In this example, an insulating magnetic toner is used as the developer, which is a one-component developer containing at least an insulating resin, magnetic fine powder, and colorant particles, and has negative (-) triboelectric charging characteristics. 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 U of this example has a columnar body with an oval cross section and extending in the direction perpendicular to the plane of the paper, and has a base 14 made of a high magnetic permeability material such as iron, nickel, permalloy, etc.
An outer covering member 15 made of a non-magnetic material and whose surface serves as a conveyance path for the magnetic toner d is coated on a region excluding a part of the outer circumferential surface of the magnetic toner d. The peripheral surface of the base body 14 covered with the outer cover member 15 includes
A large number of concave grooves 14a having a V-shaped cross section are formed parallel to each other at equal intervals along the longitudinal axis direction of the base body (direction perpendicular to the plane of the paper). Although FIG. 2 only shows a total of 12 concave grooves 14a, in reality there are more concave grooves 14 than that.
A is formed densely.

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 recessed groove 14a, and
A fill portion 16 is formed as a part of the excitation coil. As shown in FIG. 3(a), this coil portion 16 is
In this example, it is divided into two groups, A and H, and each group's coil portion 16A,
Every other IEiB is arranged. In this case, as shown in FIG. 3(b), a pair of fill sections 16, 16 adjacent to each other with one coil section 16 of another group in the same group (for example, consecutive odd-numbered fill sections with coil sections IEiBI The even-numbered coil parts 16AI and 16A2) are connected to the same conductor I
It is formed by winding E3a many times in a predetermined direction across every other pair of concave grooves 14a, 14a. Therefore,
A pair of coil portions 16 that are adjacent to each other every other coil in the same group.
The running directions of the 16 conducting wires lea (based on the winding direction of the coil) are opposite to each other.

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

As shown in FIG. 4, two types (two phases) of alternating current AllB 1 A with a phase shift of π/2 are applied to the A group of coil portions 4A and the eight groups of coil portions 4B configured as described above. l sin (ωt)...
・・・・・・・・・ (1) i , : r sln (ω
t+π/2)... (2) are respectively energized.

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, 1BAI and 16n) in each set are reversed. Therefore, if an alternating current of the same phase is passed through the coil portions 16 of the same string, 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 the direction C 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 18 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 18 for regulating the toner spikes to an appropriate length to form a toner layer.
It 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 cover member 15B. 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 on the downstream side of the doctor blade 18 is the recording section W, where the magnetic toner d is applied to the cylindrical electrode 5 according to input recording data. The toner is selectively transferred to the surface 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.

On the surface of the outer covering member 15A, a recording electrode sheet 20 is adhered and laid in an area upstream from the recording section W with respect to the toner transport direction opening. The recording electrode/toad 20 of this example is the sixth
As shown in the figure, a plurality of recording electrode wires 20a, which are made of a flexible printed circuit board (FPC) and extend parallel to each other in the longitudinal direction of the sheet, are placed on a base film 2Ob.
1i direction 1i1i1 (toner conveyance path width direction: main scanning direction)
They are formed to extend in parallel at a predetermined fine pitch. The number of recording electrode lines 20a corresponds to the maximum number of data for one main scanning line. In this example, a large number of recording electrode lines 20
a with a pitch of 86 μm (300 μm) with an interval of 40 μm.
It is formed with a density of DPI).

As shown in FIG. 7, a dummy electrode 20c is formed at the end of the recording electrode channel 20 to hold the magnetic toner so as not to transfer it to the cylindrical electrode side. Incidentally, a dummy electrode having the same configuration is also formed at the other end (not shown) of the recording electrode sheet 20. In this case, the dummy electrode 20c
The width DW of is at least the width E of each recording electrode line 20a.
larger than w, and as shown in FIG. 8, the recording electrode line 2
If the laying area width of 0a is Ze and the developing area width is Zt, the settings are made to satisfy the relationship Ze<Zt<Ze+ 2 @Dt. In addition, in relation to the width pv of the maximum size paper to be passed, Pvl=Ze≦
It is desirable to set each dimension so that Pw5Pw2==Ze+20Dv.

When pvl=pw, the non-electrode area is outside the paper and there is no recording prohibited area. Also, when Pψ2=Pw,
The entire dummy electrode width Dw becomes a recording prohibited area.

The dummy electrode 20c of this example is formed on the base film 2Ob on which the recording electrode line 20a is formed. In this example, since a bias voltage of -50V is applied to the cylindrical electrode 5, the dummy electrode 20c is connected to ground.

As a result, a potential difference of -50V is formed from the cylindrical electrode 5 to the dummy electrode 20c, and the negatively charged magnetic toner transported onto the dummy electrode 2Oc is held on the dummy electrode 2Oc side by the electric field force based on the potential difference. do.

In addition to grounding the dummy electrode 20c,
0c may be held at a potential equal to the ground potential, or a dedicated voltage (non-recording voltage) for holding magnetic toner may be applied to the dummy electrode 20c by a drive circuit element 21, which will be described later.

To manufacture the recording electrode sheet 20 described above, a base film 20b made of a flexible insulating material coated with copper foil is etched to pattern a large number of recording electrode lines 20a and a pair of dummy electrodes 20c at the same time. Just form it.

Note that instead of forming the dummy electrodes on the same base film 20b as the recording electrode lines 20a, a unique dummy electrode sheet may be formed and fixedly provided at both ends of the row of recording electrode lines 20a.

The recording electrode sheet 20 configured as described above is submerged below the bridge member 17, as shown in FIG.
It passes through the joint surfaces of 4A and 14B and extends to the internal space S. 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. The recording electrode wires 20a of the recording electrode sheet 20 described above are divided into appropriate numbers and connected to these drive circuit elements 21, respectively. From each drive circuit element 21,
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. The magnetic 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. On the upstream side of the recording section W, a recording electrode line 20a and a dummy electrode 20C (see FIG. 7) are laid in parallel. As described above, the drive circuit element 21 selectively applies a recording voltage to each recording electrode line 20a according to recording data.

In this case, when one bit of recording data is "H" and a voltage of -200V is applied to the corresponding recording electrode line 20a, a voltage of -50V is applied to the cylindrical electrode 5 facing the recording electrode line 20a. Therefore, from the cylindrical electrode 5 to the recording electrode line 2
A potential difference of 150V is formed toward 0a. Because the negatively charged magnetic toner d moves toward the higher potential,
In the recording section W where the interval is the narrowest and the electric field is maximum, -
Only the magnetic toner d on the recording electrode line 2Oa to which a voltage of 200V is applied is selectively transferred to the surface of the cylindrical electrode 5,
Form a black dot.

On the other hand, when the 1-bit recording data is "L", the recording electrode line 20a becomes the ground potential. As a result, the potential difference seen from the cylindrical electrode 5 to its corresponding recording electrode line 20a is -50V!
: The negative magnetic toner d remains held on the recording electrode line 2Oa side and does not transfer.

As mentioned above, the corresponding recording electrode line 2 is
The potential of 0a is selectively controlled to 1200 V 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. At this time, as described above, the dummy electrodes 20c are grounded to both ends of the row of recording electrode lines 20a.
Therefore, the magnetic toner conveyed onto the dummy electrode 2Oc is conveyed directly to the downstream side without being transferred to the cylindrical electrode 5 side. That is, an electric field based on a potential difference of -50 V is formed from the cylindrical electrode 5 to the dummy electrode 20c, and the negatively charged magnetic toner is held on the side of the dummy electrode 2Oa, which has a higher potential. This prevents magnetic toner from adhering to both ends in the width direction of the image, which are non-image areas (record-prohibited areas), and it is possible to stably form a good, clean toner recorded image.

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' remaining in the recording section W without being transferred to the cylindrical electrode 5 side 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 screw 19, and the stored magnetic toner d' Stirred and mixed with toner.

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

Note that the same components as those in the above embodiment are given the same reference numerals, and the explanation thereof will be omitted.

The embodiment shown in FIG. 9 uses a pair of magnet rolls 23 and 24 as developer conveying means in the recording unit U of the image forming unit U. A developer carrying member 27 is installed between a pair of magnetic conveyance rolls 25.26 containing magnet rolls 23 and 24, respectively, and a recording electrode body 28 as a recording means is placed between both magnetic conveyance rolls 25.2E.
H1 of both magnetic rolls 23 and 24.
The structure is such that the magnetic toner d is conveyed in a predetermined direction along the surface of the developer carrying member 27 by the combined action of the force (D).

In the developer transport path along the surface of the developer carrying member 27, the recording portion W closest to the circumferential surface of the circular electrode 5 has the recording electrode body 2
The tip surface of No. 8 is made to protrude. This recording electrode body 28 is
As shown in FIG. 10, a sheet having the same structure as the recording electrode sheet 20 of the above embodiment is adhered to the surface of the board-shaped electrode support member 28a. A drive circuit element 29 is integrally mounted on the recording electrode body 28, and on the tip end surface which projects into the recording section W, as shown in FIG. Electrodes 20c are laid respectively.

Similarly to the above embodiment, the image forming unit (U) of this example also reliably prevents the adhesion of magnetic toner to both sides of the image in the width direction, thereby stabilizing a good image without developer stains on the width edges. It can be formed by Further, since the recording electrode body 28 of the recording means is built into the recording unit Uw, the recording unit U in which the recording electrodes are mounted at high density can be configured to be small and compact.

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.
When A is formed of an insulating material such as resin, the recording electrode and the dummy electrode may be laid directly on the outer cover member 15A.

Furthermore, the present invention is applicable not only to the case where linear recording electrodes are used as in the above-mentioned embodiments, but also to the case where recording electrodes are arranged side by side in a dotted manner, such as needle-like electrodes in a so-called multi-stylus printer. can do.

Furthermore, the present invention is also applicable to the case where a non-magnetic developer is used instead of a magnetic developer.

〔Effect of the invention〕

As described in detail above, according to the present invention, the recording electrodes are arranged at both ends of the array of recording electrodes arranged in parallel in the width direction perpendicular to the developer conveying direction on the surface of the developer carrying member, and the opposite electrode side of the developer By providing a dummy electrode that prevents the transfer of the developer, it is possible to reliably prevent stains caused by adhesion of the developer to the edges of the recorded image. Furthermore, if the recording electrode drive circuit is installed within the developer transport means, the recording means in which a large number of recording electrodes and their drive circuits are mounted in high density and the developer transport means can be compactly integrated. Therefore, it is possible to manufacture a small and inexpensive recording apparatus that can stably form a good recorded image with high resolution and no stains on the edges. Furthermore, since the electrostatic recording apparatus of the present invention uses a non-contact recording method, the durability of the recording head section is also excellent.

[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 to the excitation coil. Figure 5 is A graph showing a temporal change in the excitation magnetic field distribution curve by the excitation coil, FIG. 6 is a partially cutaway perspective view showing the recording unit in the recording image forming unit, and FIG. 7 is a recording electrode section in the recording image forming unit. FIG. 8 is an explanatory diagram showing the relationship between the configuration of the recording electrode section and the developing area and paper size. FIG. 9 is a schematic cross-sectional view showing another embodiment of the present invention. FIG. 10 is a perspective view showing the recording electrode body in the above other embodiment, FIG. 11 is a perspective view showing the configuration of the recording electrode section in the above other embodiment, and FIG. 12 shows the structure of the conventional recording electrode section. FIG. 1... Paper feed cassette 3... Standby roll pair 4... Transfer charger 5... Cylindrical electrode 5a... Bias power supply (cylindrical electrode side) 8... Fixing device 11... Unit container 12... Stirring roll 14... Base bodies 14A, 14B... Divided base bodies 15. 15A, 15B... Outer covering member 16... Coil portion 18... Doctor blade 19... Scraping plate 20 Recording electrode sheet 20a Recording electrode wire 20b Fist base film 20c Dummy electrode 21.29 Drive circuit element 22 Input wiring circuit 23.24 Magnet roll 27 ...Developer carrying member 28...Recording electrode body [)w...Dummy electrode width EW...Recording electrode width T...Image transfer section U...Recording image forming unit Ul...Recording Unit W... Recording section Ze... Electrode laying area width (of recording electrode) 21... Development area width

Claims (2)

[Claims] (1) A developer carrying member whose surface serves as a developer carrying path, a developer carrying means for carrying the developer along the surface of the developer carrying member, and a surface perpendicular to the developer carrying direction of the developer carrying member surface. has a plurality of recording electrodes arranged in parallel with each other at a predetermined interval in the width direction, and a counter electrode arranged with a gap between the recording electrodes, and each recording electrode is provided with recording information. In an electrostatic recording device that selectively transfers the developer conveyed to the counter electrode side by applying a voltage according to the recording electrode, a dummy is applied to both ends of the row formed by the recording electrodes according to the non-recording information. Electrostatic recording, characterized in that an electrode is provided, and the width of the dummy electrode is set so that the width of the electrode juxtaposed area including the recording electrode and the dummy electrode is larger than the width of the developer transport path. Device. (2) The electrostatic recording device according to claim 1, wherein the recording electrode and the dummy electrode are formed on the same insulating substrate, and the insulating substrate is attached to the surface of the developer carrying member.