JPH0451163A - Electrostatic recording device - Google Patents

Abstract

PURPOSE:To stably form a recorded image with high resolution on a plain paper by opposing recording electrodes juxtaposed on a developer carrying member to a cylindrical electrode which is combined with an intermediate recording medium with a very small gap and setting a cleaning electrode on which the voltage of a reverse polarity to the electrostatically charge polarity of the developer is impressed on the surface part of the developer carrying member on an upstream side. CONSTITUTION:The leading edge part 20al of a recording electrode line 20a positioned in a recording part W is made to rise a little and exposed to the surface of an insulat ing coat 20c, then a recording action is performed. The cleaning electrode 20d made of a non-magnetic conductive material is disposed at a position set at specified length apart from the leading edge exposed part 20al of the recording electrode line to the upstream side, and a cleaning power source 20e capable of outputting the DC voltage of a reverse polarity to the electrostatically charged polarity of developer is interposed between the electrode 20d and a cylindrical electrode 5, and toner d0'' which is not transferred and left on the circumferential surface of the electrode 5 is transferred to the electrode 20d side so as to clean the circumferential surface of the electrode 5. Thus, the plain paper is used and the excellent recorded image with the high resolution is stably formed without causing an after-image.

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 constructs a recording head by arranging a large number of needle-shaped recording electrodes at evenly spaced intervals in the main scanning direction, and selectively applies voltage to each needle-shaped electrode according to the recording signal to print on the paper. An electrostatic latent image is formed by direct discharge. In this case, special paper coated with a high electrical resistance agent is used so that charges can be easily and stably retained on the paper. However, such special paper is difficult to write on with a pencil or pen, and its quality deteriorates depending on environmental conditions such as humidity, so there are problems with its shelf life.
Not suitable for office paper.

Furthermore, if the distance between the tip of the needle electrode and the paper surface is large, 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 gap material is provided on the surface of the paper, and a slight gap of yJs is secured by slidingly contacting the gap material with the tip of the needle-like electrode. However, when using this method, there is a problem that the tip of the needle electrode is worn out.

Therefore, in order to be able to use plain paper and to ensure an accurate minute distance between the image medium and the tip of the recording electrode,
A method is used in which a toner image is formed on a drum-shaped intermediate recording medium and the toner image is transferred onto paper.

In this method, since the intermediate recording medium is used repeatedly, it is necessary to clean the intermediate recording medium each time it is used to prevent afterimages from occurring. However, if the cleaning means is provided around the intermediate recording medium, a problem arises in that the electrostatic recording device becomes larger.

[Object of the Invention] The present invention has been made in view of the problems of the prior art described above. It allows the use of plain paper, eliminates the need for a dedicated installation space for cleaning means, promotes miniaturization, and eliminates the problem of afterimages. It is an object of the present invention to provide an electrostatic recording device that can stably form a good recorded image with high resolution without causing any interference.

[Key points of the invention]

In order to achieve the above object, the present invention includes 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 plurality of recording electrodes. Drive circuits are installed in parallel at predetermined intervals in a width direction perpendicular to the developer transport direction on the surface of the developer carrying member while maintaining electrical insulation from each other, and output a recording voltage according to input information to each of the recording electrodes. The developer has a recording means installed inside the developer conveying means, and a cylindrical electrode arranged opposite to the recording electrode with a predetermined gap therebetween, and the recording electrode is conveyed in a recording section closest to the cylindrical electrode. In an electrostatic recording device that selectively transfers incoming developer to the surface of the cylindrical electrode according to the recording voltage, on the surface of the developer carrying member, upstream with respect to the developer conveyance direction of the recording section, The key point is that a cleaning electrode to which a voltage with a polarity opposite to that of the developer is applied is installed.

[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. A bias power supply 5a capable of applying a bias voltage of -30 to -40V is connected to this cylindrical electrode S, since a developer with negative (-) friction charging polarity is used in this example as will be described later. It is. 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 recorded image forming unit 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. 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 round 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 a stirring roll 12 and a supply roll 13 rotatably disposed at the bottom of a unit container 11 that stores developer, and is a recording unit that integrates an image recording means and a developer conveying means. The unit Uw is arranged in such a manner that its recording head portion is located in an opening 11a of a container 11 that is open toward the circumferential surface of a cylindrical electrode 5. 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 Uw 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, or permalloy.
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 turning groove 14a is set to be longer than the width of the conveying 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 16.16 adjacent to each other with one coil part 16 in the other group in the same group (for example, consecutive odd-numbered and even-numbered coil parts with the coil part 16B1 placed) 1BAI and 16A2) 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 directions (based on the winding direction of the coils) of the conducting wires 16a of every other pair of adjacent coil portions 16, 18 in the same group 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 1
A pair of concave grooves 14a, 14a every (m-1) 6a
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^= whose phases are shifted by π/2 are applied to the A group of coil parts 4A and the eight sets of coil parts 4B configured as described above. I sin (ωt) ・・・・・・・・・
... (1) is: l5ln(ωt+π/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, 16A1 and 16A2) in each set are reversed. Therefore, the coil part 16 of the same grade
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 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 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 divided into two parts so as to be removable, 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. In order to form a flat toner conveyance path, both outer cover members 15A are provided.

A bridge member F is installed at the joint 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 and forming toner scales.
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 sheet 20 of this example has the sixth
As shown in the figure, a plurality of recording electrode lines 20a, which are made of a visible printed circuit board (FPC) and extend parallel to each other in the sheet longitudinal direction, are placed on the base film 2Ob in the sheet width direction (toner transport path width direction). : are formed extending in parallel at a predetermined fine pitch in the main scanning direction). This recording electrode wire 20
The number a corresponds to the maximum number of data for one main scanning line. In this example, a large number of recording electrode lines 20a are
The pattern was formed by etching at a density of 86 μm pitch (300 DPI) with a spacing of m.

FIG. 7 is a schematic cross-sectional view showing the detailed configuration of the recording section W and its vicinity. An insulating coat 20c is applied to the surface of the recording electrode sheet 2o, so that each recording electrode wire 2
This configuration ensures electrical insulation between Oa and prevents abrasion of the recording electrode wire 20a due to the original oscillation with the magnetic toner d.

Tip portion 20a of the recording electrode wire 20a located in the recording portion W
As shown in the enlarged explanatory view of FIG. 8, + is slightly raised and exposed on the surface of the insulating coat 200. The exposed end portion 20al of the recording electrode line 20a becomes a recording electrode portion that substantially performs a recording operation.

A cleaning electrode 20d made of a non-magnetic conductive material is provided at a position a suitable distance away from the recording electrode wire tip exposed portion 20al toward the upstream side.

As shown in FIG. 6, the cleaning electrode 20d is embedded in the insulating coat 20c with its upper surface exposed and extending over the entire width of the developer transport path (the surface of the insulating coat 200). It is.

In this case, the recording electrode wire 20a is coated with an insulating coat 2.
The structure is such that the picture electrodes 20a and 2Od are insulated by intervening the picture electrodes 20a and 2Od.

As shown in FIG. 7, a cleaning power supply 20e is interposed between the cleaning electrode 20d and the cylindrical electrode 5, and is capable of outputting a DC voltage having a polarity opposite to that of the developer. In this example, since magnetic toner d with negative charging polarity is used,
A leaning power supply 20e capable of outputting a voltage of +50V is installed and connected. As a result, the cleaning electrode 20
A voltage of +50 V is applied to the cylindrical electrode 5 from d to form a cleaning electric field that attracts negative magnetic toner toward the cleaning electrode 2Od. Due to this cleaning electric field, untransferred toner do'' remaining on the circumferential surface of the cylindrical electrode 5 is transferred to the cleaning electrode 2Od side as described later, and the circumferential surface of the cylindrical electrode 5 is cleaned. Also, the cleaning electrode 20d as a cleaning means Since it is embedded in the recording electrode sheet 20, a dedicated installation space for the cleaning means is not required, which greatly contributes to promoting miniaturization of the electrostatic recording device.

Immediately downstream of the recording section W, in this example, a step G equal to the thickness of the recording electrode sheet 20 is formed. By providing this step G, the magnetic toner d'' that transfers to the circumferential surface of the cylindrical electrode 5 and forms a recorded image and the magnetic toner d' that remains on the surface of the outer covering member 15A are sufficiently separated after image formation, and both magnetic It is possible to reliably prevent the inconvenience of the toners d'd'' interfering with each other and disturbing the formed image. In this case, the height of the step G is preferably about 10 times the electrode facing interval Lw in the recording section W, and in this example, a height of about 500 μm is ensured. In addition, in FIG. 7, for convenience of explanation, the electrode facing interval LW is illustrated to be larger than the step G, unlike the actual configuration.

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 filter of the recording unit UW is arranged, 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 the ears are cut to a predetermined thickness by the doctor blade 18, they are conveyed to the recording section W. At this time, magnetic toner d
is triboelectrically charged to negative polarity.

In the recording section W, a drive circuit element 21 selectively applies a recording voltage to each recording electrode line 20a according to recording data,
An electric field is formed between the exposed tip 20a+ (hereinafter referred to as recording electrode section 20a+) of the recording electrode wire 20a and the circumferential surface of the cylindrical electrode 5, and the magnetic toner d is selectively transferred to the circumferential surface of the cylindrical electrode 5. In this example, when one bit of recording data is "H9+", a voltage of -180V is applied to the corresponding recording electrode section 20al.As a result, a voltage of -30V is applied to the cylindrical electrode 5, so that A potential difference of 150 V is formed from the cylindrical electrode 5 to the recording electrode section 20a1.The negatively charged magnetic toner d moves toward the higher potential, so in the recording section W where the interval is the narrowest and the electric field is maximum. , -1sov voltage is applied to the recording electrode section 2Oa.
Only the magnetic toner d on l 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 portion 20al is at the ground potential. As a result, the potential difference seen from the cylindrical electrode 5 to its corresponding recording electrode section 20a1 is -30V.
Therefore, the negative polarity magnetic toner d remains held on the recording electrode portion 2Oal side and does not transfer.

As described above, the recording electrode section 20a is adjusted according to the input recording data.
The potential of 1 is selectively controlled to 1180V and ground potential,
A toner recorded image corresponding to recorded data is formed on the opposing portion of the circumferential surface of the cylindrical electrode 5. The density of this toner recorded image is
It can be adjusted by changing the bias voltage of the bias power supply 5a.

In that case, the appropriate adjustment range is about 0 to -40V,
The closer to OV, the higher the image density.

Since the step G is formed immediately downstream of the recording section W,
The magnetic toner d' remaining on the recording electrode sheet 20 side without being used for image formation immediately moves away from the circumferential surface of the cylindrical electrode 5 after passing through the recording section W. Therefore, the toner recorded image formed on the circumferential surface of the cylindrical electrode 5 in the recording section W is the residual magnetic toner d'
The inconvenience caused by mutual interference between the two is reliably avoided.

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.

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. The untransferred toner remaining on the circumferential surface of the cylindrical electrode 5 without being transferred is conveyed to the recording section W again as the cylindrical electrode 5 rotates. In FIG. 7, on the upstream side of the recording section W, a voltage of +50 V is applied from the cylindrical electrode 5 to the cleaning electrode 20d at the opposing portion of the cleaning electrode 20d and the circumferential surface of the cylindrical electrode 5.
voltage is applied to form a cleaning electric field. Due to this cleaning electric field, untransferred toner d remains on the circumferential surface of the cylindrical electrode 5. ' is transferred to the cleaning electrode 2Od side. Furthermore, in this cleaning electric field formation area, magnetic toner d is transported along the toner transport path on the recording unit Uw side and untransferred toner d is collected from the cylindrical electrode 5 side. # is temporarily retained, forming a toner pool Rt. Due to the scraping effect of the toner chain grown in this toner pool Rt, untransferred toner do
# is removed from the circumferential surface of the cylindrical electrode 5. After the untransferred toner do# is cleaned and removed from the circumferential surface of the cylindrical electrode 5 in this way, the recording operation is performed again in the recording section W, so there is no image defect such as afterimage due to poor cleaning, and a high-resolution recorded image is obtained. is stably formed.

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. 8 uses a pair of magnet rolls 23 and 24 as a developer conveying means in the recording unit U of the image forming unit U. FIG. 10 is a schematic cross-sectional view showing in detail the image forming process section consisting of the recording unit Uw and the cylindrical electrode 5. As shown in FIG. 10, the recording unit Uw of this example includes a pair of magnetic transport rolls 25 each containing magnet rolls 23 and 24.
A developer carrying member 27 made of a non-magnetic material is installed between the remagnetic transport rolls 25 and 28, and a recording electrode body 28 as a recording means is arranged between the remagnetic transport rolls 25 and 26. When both the magnet rolls 23 and 24 are rotated at the same speed in the same direction indicated by the arrows, a composite rotating magnetic field is generated on the surface of the developer carrying member 27 due to the resultant force of the magnetic forces of the magnets and sotrols 23 and 24. It is formed. This combined rotating magnetic field transports the magnetic toner d along the surface of the developer carrying member 27 in the direction of arrow C.

In the developer transport path along the surface of the developer carrying member 27, the leading end surface of the recording electrode body 28 is made to protrude from the recording portion W closest to the circumferential surface of the cylindrical electrode 5 rotating in the direction of arrow a. As a result, a step G is formed immediately downstream of the recording section W. As shown in FIG. 11, the recording electrode body 28 has the recording electrode sheet 20 of the above embodiment on the surface of a plate-shaped electrode support member 28a.
It is made by covering a material with the same structure as that of Recording electrode sheet 20
ζ The drive circuit element 29 is directly mounted thereon.

A cleaning electrode 30 is embedded on the surface of the developer carrying member 27 on the upstream side of the recording section W with one side exposed. Between the cleaning electrode 30 and the cylindrical electrode 5,
Similar to the above embodiment, a cleaning power source 31 is provided to output a DC voltage having a polarity opposite to the charged polarity of the developer, thereby forming a cleaning electric field.

In this example, as in the above embodiment, the untransferred toner do'' remaining on the circumferential surface of the cylindrical electrode 5 is reliably removed by the scraping effect of the cleaning electric field and the toner pool Rt. The occurrence of image disturbance is avoided.As a result, a high-resolution recorded image is stably formed without an afterimage.

Furthermore, since the cleaning electrode 30 is embedded in the surface of the developer carrying member, a dedicated installation space for the cleaning means can be omitted. Furthermore, since the recording electrode body 28 serving as a recording means is built into the recording unit Uw, the recording unit Uw in which recording electrodes are densely mounted can be constructed small and compact. Therefore, the size of the image forming process section consisting of the UW (around the cylindrical electrode 5 and the recording unit) is promoted, and the size of the non-contact electrostatic recording device using the intermediate recording medium (cylindrical electrode 5) is greatly promoted. becomes possible.

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, the present invention is applicable even when a non-magnetic developer is used instead of a magnetic developer.

〔Effect of the invention〕

As described above in detail, according to the present invention, the recording section is constructed by making recording electrodes arranged in parallel on a developer carrying member and a cylindrical electrode that also serves as an intermediate recording medium face each other with a minute gap, and the recording section By installing a cleaning electrode to which a voltage with a polarity opposite to that of the developer is applied to the surface of the developer carrying member on the upstream side of the developer, the minute gaps necessary to form a high-resolution image in the recording section can be created. This can be stably ensured, and by forming a cleaning electric field on the upstream side of the recording section, untransferred developer can be reliably removed from the peripheral surface of the cylindrical electrode. As a result, it is possible to stably form a high-resolution recorded image on plain paper without image defects such as afterimages due to poor cleaning.

Furthermore, since the cleaning electrode is installed in the developer carrying member and the recording electrode drive circuit is installed in the developer conveying means,
Not only is there no need for dedicated installation spaces for the cleaning means and the recording drive circuit, but also the recording means and the developer conveying means, in which a large number of recording electrodes and their drive circuits are densely mounted, can be compactly integrated. Therefore, it is possible to manufacture a non-contact type electrostatic recording device in a small size and at low cost, which is free from image defects due to poor cleaning and can stably form high-resolution recorded images on plain paper.

[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 the excitation magnetic field distribution curve due to the excitation coil, FIG. 6 is a partially cutaway perspective view showing the recording unit in the recording image forming unit, and FIG. 7 shows the recording section in the recording image forming unit and its FIG. 8 is an enlarged explanatory view showing the detailed structure of the tip end of the recording electrode sheet in the recording section; FIG. 9 is a schematic sectional view showing the detailed structure of the vicinity;
The figure is a schematic sectional view showing another embodiment of the present invention, FIG. 10 is a schematic sectional view showing an image forming process section in the above other embodiment, and FIG. 11 is a recording electrode body of the above image forming process 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...Base film 20c...Insulating coat 20d, 30...Cleaning electrode 20e, 31...Cleaning power supply 21.29...Drive circuit element 22. ... Input wiring circuit 23, 24 ... Magnet roll 27 ... Developer carrying member 28 ... Recording electrode body T ... Image transfer section U ... Recording image forming unit Uw ... Recording unit W ...recording department

Claims (1)

[Claims] A developer carrying member whose surface serves as a developer carrying path, a developer carrying means which carries the developer along the surface of the developer carrying member, and a plurality of recording electrodes arranged along the developer carrying member surface in the developer carrying direction. and a drive circuit that outputs a recording voltage according to input information to each of the recording electrodes is installed in the inside of the developer conveying means. and a cylindrical electrode disposed opposite to the recording electrode with a predetermined gap therebetween, the recording electrode controls the developer conveyed in the recording section closest to the cylindrical electrode according to the recording voltage. In the electrostatic recording device, a voltage having a polarity opposite to the charging polarity of the developer is applied on the surface of the developer carrying member on the upstream side with respect to the developer transport direction of the recording section. An electrostatic recording device characterized in that a cleaning electrode to which is applied is installed.