JPH0725057A - Electrostatic printing device - Google Patents

Abstract

PURPOSE:To restrain the number of drivers and manufacturing cost and prevent damage to pattern and short circuit so as to improve reliability of a device and easily manufacture it by providing high resolution for a direct type electrostatic printing device, preventing a control electrode and a connecting terminal pattern from becoming minute, and reducing the number of connections of the control electrode and the drivers. CONSTITUTION:A control electrode comprises first electrodes 23 formed on a first face of an insulating substrate 21 separately, second electrodes 24 formed on the second face of the insulating substrate 21 separately and in a way traversing the first electrodes 23 obliquely, apertures 22 formed at the crossing parts of the first electrodes 23 and the second electrodes 24, and signal supplying connection terminals 25, 26 connected to each of the first and second electrodes 23, 24 and pulled out in one direction. By using the control electrode, the second electrodes 24 are operated to control electric field by time sharing at every first electrode 23. Thus, in a direct type electrostatic printing device, a toner is flown through the apertures 22 so as to form a toner image on a print medium, fixed, and an image is printed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic printing apparatus which directly attaches a toner image to plain paper or another printing medium, that is, a recording material without using a latent image carrier such as a photosensitive drum.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image carried on a photosensitive drum or other latent image carrier by using modulated light in a dot pattern corresponding to an original image or image information is used as a toner by a developing device. There is known an electrophotographic apparatus in which a visible toner image is transferred onto plain paper after being visualized by a printer, a copying machine or other image forming apparatus. It is used a lot. However, since such an electrophotographic apparatus basically transfers a toner image onto a recording material through a latent image forming means, in addition to a means for converting image information into optical information, a latent image carrier, a transfer means, etc. Needing a means for removing the residual toner adhering to the latent image carrier and a means for recharging, which not only complicates the apparatus configuration, but also makes the above various means function as a latent image carrier. It must be installed in the periphery, resulting in an increase in the size of the device.

In order to solve the above drawbacks, a still image recording paper is used, and needle electrodes arranged in a row are brought into direct contact with the still image recording paper to selectively apply a high voltage to the needle electrodes. , An electrostatic recording device that carries an electrostatic latent image on the static image recording paper and then fixes the toner image on the static image recording paper by a developing device to make it visible, or causes corona discharge in the air A control electrode having a large number of minute holes in the main scanning direction is arranged in the gap between the plasma generation source and the electrostatic recording paper, and the electrostatic recording paper is controlled by controlling the flow of ions by the plasma generation source. There are also ion flow electrostatic recording devices that are configured to form a latent image. However, all of them have to use electrostatic recording paper, and not only lack versatility, but also have the same latent image forming step and developing step as the electrophotographic method in terms of forming an electrostatic latent image. Since it has to be configured separately, there is a limit to downsizing the device.

For this reason, various apparatuses have been developed which can form a toner image directly on a recording paper without forming a latent image using plain paper. Among them, a method called a toner jet shown in FIG. 7 is particularly well known.
This toner jet recording apparatus has a control electrode 1, a toner carrier 2, and a counter electrode 3, and controls the charged toner by a signal given to the control electrode 1,
The toner carrier 2 carries charged toner and supplies charged toner to the vicinity of the control electrode 1, and the counter electrode 3 sandwiches the control electrode 1 and the toner carrier 2
Is located on the opposite side of. Then, in the process of electrostatically attracting the toner toward the counter electrode 3 according to the signal voltage based on the information such as the image supplied to the control electrode 1,
Toner is electrostatically attached to the print medium 10 conveyed immediately before this counter electrode. The control electrode 1
The insulating layer 4, a reference electrode layer 5 to which a reference voltage is applied, and a control electrode layer 6 to which a signal based on information such as an image is supplied are formed on the lower surface of the insulating layer 4. Further, there is provided an opening 7 penetrating both electrode layers 5 and 6 and the insulating layer 4 in at least one row. The reference electrode layer 5 is provided on the toner carrier 2 side of the insulating layer 4,
The control electrode layer 6 is independently provided around the opening 7 on the counter electrode 3 side of the insulating layer 4. The print medium 1 passes through the gap between the control electrode 1 and the counter electrode 3.
A transport roller 8 is provided so that 0 is transported, and a fixing roller 9 that fixes the toner electrostatically attached to the print medium 10 is provided downstream in the transport direction.

Here, in such a direct electrostatic printing apparatus, toner is transferred from the toner carrier 2 to the printing medium 10.
For the mechanism of flying to, for example, Japanese Patent Laid-Open No. 59-1
This mechanism is described by applying it to FIG. 7, but a voltage opposite to that of the toner is applied to the counter electrode 3 and a signal based on the image signal is supplied to the control electrode 1. The control is performed by controlling the passage of the toner through the opening 7 to control the adhesion of the toner to the print medium 10. The toner charged here is preferably JP-A-59-
No. 181370 or Japanese Examined Patent Publication No. 2-52260, it is preferable that the toner carrier is present near the surface of the toner carrier in a smoked state by means of applying an AC voltage between the toner carrier and the lower surface base electrode of the control electrode. . Other proposals for such a toner jet recording apparatus are disclosed in JP-A-04-128062 and JP-A-04-28062.
Many have been proposed as seen in Japanese Patent No. 131255.

Further, regarding the structure of the control electrode of such a direct type electrostatic printing apparatus, the Japanese Patent Publication No. 2-52260, the Japanese Patent Laid-Open No. 59-181370, and the academic paper (Proceeding THE MIXTH INT)
ERNATIONAL CONGRESS ON AD
VANCES IN NON-IMPACT PRIN
TING TECHNOLOGIES P. P. 710
~ P. P. 722).

In each of the control electrode structures shown in these drawings, the signal electrode is separated by each opening and formed in a pattern on the insulating substrate, and the connection terminals with the triber are drawn out to both sides of the insulating substrate, resulting in each It has a structure having one connecting portion for each opening (corresponding to a dot). In addition, the reference electrode is formed on the entire surface of the insulating substrate or in a pattern similar to the signal electrode in which each hole is separated. In any case, the number of drivers for driving the control electrode is at least the hole. Only the number, that is, the number of dots in the column direction is necessary.

[0008]

The present inventor has studied the above-described control electrode structure in a direct type electrostatic printing apparatus, but when a control electrode having a resolution of 300 dpi is actually obtained, at least 4 holes are formed. It has been found that rows are needed, preferably 6-8 rows. The largest reason for this is that the size of the dot to be formed cannot be printed unless the size of the opening is several times larger than the maximum dot diameter to be formed on the recording medium. Even if the holes are arranged in four rows, a connection terminal for connecting the control electrode and the driver is required for every signal electrode. Therefore, the wiring pattern for connecting the signal electrode and the driver formed in the central two rows is Since the wiring pattern is formed between the signal electrodes formed on both sides of the central two rows, the wiring pattern becomes very fine, which causes a large increase in the manufacturing cost of the control electrodes. If the row of holes is 6 or 8, the finer pattern is formed and the cost is further increased.

Further, even if the control electrode can be manufactured regardless of the opening, the number of connecting terminals with the drive circuit board is required to be the number of dots in the column direction, and if the connecting terminals are wired on one side. Then, if it is a control electrode of 300 dpi,
The connection must be made with a fineness of 300 dpi, and the connection must be made with a fineness of 150 dpi even if distributed on both sides. In either case, it is difficult to connect over a long length corresponding to a print medium such as A4 size. When connecting to both sides, the connection pitch will be wider and connection will be easier than on one side.
Two connection wirings (FPC, etc.) are required, and it is troublesome to divide the drive circuit board into two or connect the wirings to one circuit board due to the configuration of the printing apparatus, which is costly. Cause rise in. Further, considering a control electrode for a high-resolution printing apparatus such as 600 dpi, which will become the mainstream in the future, the number of aperture rows will further increase (approximately 8 to 16).
Column), resulting in further miniaturization of the electrode pattern, and even if pulled out from both sides, 300 each on both sides.
Connection at a pitch of dpi is required, and the number of drive circuits becomes twice as large as 300 dpi, resulting in an increase in cost.

Further, in a general direct type electrostatic printing apparatus, the voltage applied between the first and second electrodes of the control electrode is as high as several hundreds of volts, which is not only expensive for the driver but also A4 size. If the resolution is 300 dpi, the number of drivers required is approximately 2560. In addition, the control electrode needs to have the same number of holes for flying the toner, that is, 2560 holes (when each dot is an independent hole), and the size of the holes is different on the recording medium. Maximum required dot diameter (80 to 100 at 300 dpi)
μmφ), which is several times larger (differs under various conditions, but was about 2 to 5 times in our experiments), which means that when the apertures are associated with individual dots, It is physically impossible to form the holes in a single row (each opening has a pitch of about 85 μmφ when the rows are arranged at 300 dpi). Therefore, it is necessary to disperse the openings in a plurality of rows and provide the openings.

Even if a plurality of rows of holes are provided, the number of connecting portions with the driving circuit is equal to the number of dots, and the number is 2560, which is huge. Further, it is difficult to dispose the connection terminal with the drive circuit on one side of the insulating substrate because the wiring pattern becomes fine.
Even if it could be realized, it would be very difficult to make very fine connections of 300 dpi (pitch of 85 μm). Therefore, the wiring pattern must be arranged on both sides of the control electrode in the longitudinal direction. This means that the drive circuit board
There is an inconvenience such as dividing into individual pieces or drawing connection lines from both sides to connect to the circuit board. Further, two wires (FPC or the like) for connecting the control electrode and the drive circuit are required. If the number of connection terminals is large, the number of failure occurrence factors increases and the reliability is poor, and a fine pattern is required for the connection wiring, which causes an increase in cost. In addition, pulling out the connecting wires from both sides allows the driver to be installed on the recording surface side of the upstream side (toner does not adhere) and the downstream side (toner adheres) of the recording medium with the row of apertures as a boundary. Protrusion of the connection part (connection part and seal part) occurs,
In particular, the presence of a protrusion on the downstream side of recording medium conveyance
Since the gap between the control electrode and the counter electrode, and further between the control electrode and the print medium, is extremely small, there is a problem that the toner adhering surface of the recording medium is rubbed and the print quality is deteriorated.

That is, in the conventionally known technique, the number of drivers and the number of connecting portions between the control electrodes and the driving circuits become enormous, and the complexity of routing the connection wiring between the control electrode and the driver and the miniaturization of the wiring. Not only causes an increase in manufacturing cost but also causes a failure due to pattern damage, pattern short-circuiting, etc., which is a problem from the viewpoint of reliability. In addition, the structure of the control electrode has a fine pattern. There is a problem in that the formation of the printing apparatus is required and the cost of the printing apparatus is increased.

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a toner carrier, a counter electrode opposed to the toner carrier and kept at a relatively constant potential, and the counter electrode. A control electrode having an array of apertures placed in the gap between the toner carrier and the toner carrier; an electric field control means for applying a variable electric field to the control electrode; and a gap between the counter electrode and the control electrode in a print medium. The control electrode is composed of a transport unit for transporting the toner, and a fixing unit for fixing the toner electrostatically attached to the print medium from the toner carrier through the opening of the control electrode by the electric field control unit. A substrate, a plurality of first electrodes formed on the first surface of the insulating substrate so as to be separated from each other in the row direction, and a plurality of first electrodes formed on the second surface of the insulating substrate in the column direction and intersecting with the first electrode. The second formed A pole and a first electrode, an insulating substrate, and a second electrode are formed at intersections of the first electrode and the second electrode, respectively, and are arranged so as to be oblique to the traveling direction of the print medium. An aperture and a signal supply connection terminal connected to each of the first electrode and the second electrode and connected to the electric field control means, and the electric field control means,
An electrostatic printing device characterized in that the first electrode is driven in a time-division manner in which each electrode is circulated at regular intervals, and a signal according to an image signal is supplied to each of the second electrodes. did. Further, the connection terminal of the control electrode of this electrostatic printing apparatus was pulled out in one direction, and this was arranged on the upstream side in the transport direction of the recording medium.

[0014]

By configuring the electrostatic printing apparatus as described above, it is possible to reduce the number of drivers and the number of connecting portions that connect both the control electrode and the driver. Further, miniaturization of the wiring pattern of the control electrode can be prevented, the manufacturing yield of the control electrode can be improved, and the wiring for connecting the control electrode and the driver can be simplified, thereby achieving a large cost reduction. Further, since the number of connecting parts is reduced, reliability can be improved.
Also, connect the control electrode and driver from one side,
By arranging this connection part on the upstream side of the recording medium conveyance with reference to the opening of the control electrode, the protrusion of the connection part of the control electrode with the triber and the toner adhering surface of the recording medium on the downstream side of the recording medium conveyance. It is possible to prevent the print quality from deteriorating due to abrasion.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, 11 is a perspective view showing an outline of a recording unit of the electrostatic printing apparatus, and 12 is a toner storage container 12a.
A toner supply roller, which is provided inside and serves as a toner carrier for supplying toner to the image recording unit 11, is rotatably driven by a drive motor (not shown) and is maintained at the ground potential. Reference numeral 13 denotes a counter electrode which is arranged so as to face the toner supply roller 12 and is kept at a constant voltage difference from the toner supply roller 12 by a power source E. 14 is the toner supply roller 1
2 is a control electrode arranged in a gap between the counter electrode 13 and the counter electrode 13 and having a structure described in detail later. The connection terminal of the control electrode 14 is wired by a flexible wiring board (FPC) 15 to the electric field control means 16. It is connected. 17
Is a cut sheet as a printing medium, and is conveyed in the direction of (a) while the gap between the counter electrode 13 and the control electrode 14 is in contact with the counter electrode 13 by a transport roller (not shown) as a transport means. Further, a fixing roller (not shown) as a fixing unit is disposed behind the control electrode 14 in the conveying direction. The entire device has the same structure as the conventional one.

FIG. 2 shows the control electrode 14 of the electrostatic printing apparatus described above.
FIG. 3 is a plan view of FIG. 3, and FIG. To explain based on this, first, the insulating substrate 21 is provided with a plurality of rows (four rows in this embodiment) of openings 22 for flying toner.
Is provided, and each of the rows of holes formed in the column direction of the control electrodes (left-right direction in FIG. 2) is connected to one surface of the insulating substrate 21, and the Y rows separated from each other are arranged in rows.
Four columns of first electrodes 23 of 1 to Y4 are formed, and the other side of the insulating substrate 21 has the control electrodes in the row direction (see FIG. 2).
In the column direction, the plurality of openings (four in this embodiment) formed in the vertical direction) are separated from each other in the column direction.
The second electrodes 24 of n columns of 1 to Xn are formed. Then, the first electrode 23 (Y1 to Y4) and the second electrode 24 (X1 to X4) are provided on one side (lower side in FIG. 2) of the insulating substrate 21.
n) and the control electrode drive circuit (not shown) for electrically connecting terminals 25 (n) and 26 (4).
Are formed.

Such a control electrode 14 is provided on the insulating substrate 21.
As an inorganic material, for example, alumina, glass, zirconia, etc., an organic material, for example, a film of polyimide, polyethylene terephthalate, etc. is used, and a material to be electrodes on both sides thereof, for example, copper, aluminum, gold or the like is formed as a thin film, a thick film, Alternatively, the first electrode 23 and the second electrode 2 are formed by adhering foils and the like, and are formed by a technique such as photolithography.
4 is patterned. The openings 22 may be formed either before or after forming the electrode material. It may also be performed after patterning. As a method for forming the openings, it is desirable to use a processing method suitable for the insulating substrate to be used, such as laser processing, sandblast processing, ultrasonic processing, drilling (mechanical) processing or etching processing. Although an insulating film or a protective film for insulating the first electrode 23 and the second electrode 24 or improving the environment resistance is not shown, it is preferable to form these films.

Next, the principle of driving the control electrode of the present invention will be described with reference to FIG. For example, considering the case where 100V, Y2, Y3, and Y4 of the first electrode 23 are applied to ground, X1 is applied to the ground, and X2 is applied to 150V, toner can fly in the opening 22-1, that is, the reference electrode. Since the electric potential of Y1 becomes higher than the electric potential of X1 which becomes the signal electrode, an upward electric field is formed on the inner peripheral wall of the opening and the toner flies, but at the openings 22-2 to 22-4, the same electric potential, In 22-5 to 22-8, an electric field in the direction opposite to the toner flight, that is, from the signal electrode X1 to the reference electrode Y
The electric field polarity from 2 to Y4 is downward, and an electric field that prevents the toner from flying to the counter electrode 13 is formed.
Toner cannot fly in these openings.

That is, in the toner flying control, if the voltages applied to the control electrodes X1 to Xn and the reference electrodes Y1 to Y4 of the respective holes are Vb and Vc, respectively, the relationship between Vb and Vc is Vc when the toner is flying. > Vb, and when not flying, it is sufficient to apply the voltage so that Vc <Vb. If it is a theoretical interpretation of the toner non-flying that the electric field is not generated in the inner peripheral wall of each opening 22 in the substrate thickness direction, theoretically, the toner does not fly even if Vc = Vb.
Therefore, in the hole 22-1, Vc (100V)> Vb
(Ground), Vc (ground) = Vb (ground) in the openings 22-2 to 22-4, and Vc (1 in the opening 22-5.
00V) <Vb (150V), openings 22-6 to 22-8
Then, the relationship of Vc (ground) <Vb (150V) is established, and the toner flying occurs only in the opening 22-1. These drive voltages are optimally set according to the printing conditions in the final printing apparatus, and differ depending on various conditions.

Here, the first electrode 2 formed on the control electrode
No matter which of the third and second electrodes 24 is the signal electrode or the reference electrode, the reference electrode and the signal electrode are not discriminated. The problem is whether to generate an electric field that causes the toner to fly, or an electric field that is opposite to the toner fly, in the thickness direction of the substrate of the opening where the toner should fly. X1 to X of the second electrode 24
n is formed to be inclined at a predetermined angle with respect to Y1 to Y4 of the first electrode 23.

Next, the first electrode 23 and the second electrode 2 of the control electrode
The time division driving of No. 4 will be described based on the timing chart of FIG. The first electrode 23 makes the Y electrode within the time required to print the four reference electrode lines of Y1 to Y4 within the predetermined time.
A certain voltage is sequentially applied as 1, Y2, Y3, and Y4. The second electrode 24 is applied with a certain voltage for n electrodes at the same time according to each timing of the first electrode 23. Here, for example, the first electrodes Y1 to Y4 are used as reference electrodes (on the toner carrier side),
When the second electrodes X1 to Xn are signal electrodes (on the back electrode side), for example, 100V or ground is applied according to the voltage application timing of the signal electrodes X1 to Xn, and the reference electrodes Y1 to Y4 are the reference electrodes. For example, ground, 150 V is applied according to the application timing.

FIG. 6 uses the control electrode 14 of this embodiment,
FIG. 9 is a diagram schematically showing a state in which a line with a predetermined resolution is printed when toner is ejected onto a print medium under a predetermined driving condition. The openings 22 are linearly formed in four rows in the row direction of the control electrodes 14, but the openings 22 in each row are arranged so as to be offset by a predetermined distance. That is, it corresponds to that the above-mentioned second electrode 24 is formed at a certain angle. 22-in the figure at the position where the print medium is
The toner is ejected from the opening 22 of FIG. 1, and then the toner is ejected from the opening 22-2 when the print medium is conveyed by the conveying means for a predetermined distance to the position of the opening 22-2. In this manner, by sequentially ejecting the toner from the openings 22-3 and 22-4, even if the openings 22-1 to 22-4 are formed to have a coarser resolution than a predetermined resolution, the toner may not be formed on the print medium. It is possible to print at a desired resolution.

By using the control electrode according to the present invention as described above with reference to the embodiments, it is easy to set the number of control electrode aperture rows to 8 or 16 rows.
It is possible to form a control electrode of i, 1200 dpi with a simple rough electrode pattern. However, the increase in the number of time-division driving means that the printing speed is simply slowed down.Therefore, when the printing speed is required, the first electrode is arranged in each opening row as described above. The structure is such that the second electrodes are separated in the row direction for each half of the aperture row, and the second electrodes are arranged on both sides of the control electrode to reduce the number of time-division driving. It is possible to improve the printing speed.

However, when the connection terminals are provided on both sides, a through hole is opened in the insulating substrate and the connection terminal with the FPC for connecting with the drive circuit must be wired on either one side of the insulating substrate. The connection terminals will be arranged on both sides.
Therefore, if an FPC or an anisotropic conductive film is used, a protrusion of at least about 0.1 mm will be formed on both sides of the substrate due to its thickness. Further, particularly in the case of connection using an anisotropic conductive film, the amount of protrusion of the protrusion becomes larger because the connection portion is covered with a thin film layer of epoxy resin or the like for improving the environment resistance characteristics. Even if the connection is performed by another method, at least the thickness of the connection wiring is projected. Since the print medium is conveyed between the signal electrode and the counter electrode as shown in FIG. 1, when the connection between the signal electrode connection terminal and the FPC is provided on both sides of the control electrode, the print medium protrudes toward the print medium side. That is, a portion exists, and the recording medium of the print medium protrudes on both the upstream side (a toner image is not formed) and the downstream side (a toner image is formed) in the conveying direction.

The gap between the signal electrode and the counter electrode of the control electrodes is about 0.1 to 0.5 mm, and the print medium (about 0.06 mm) is arranged in this gap so as to come into contact with the counter electrode. Therefore, the distance from the signal electrode to the print medium side is about 0.1.
A protrusion of up to 0.3 mm hinders the running of the recording medium. If the gap between the signal electrode and the counter electrode is 0.
If the thickness of the printing medium is 5 mm, the thickness of the printing medium is 0.06 mm, and the projecting amount of the projecting portion of the connection portion of the signal electrode and the connecting wiring is 0.3 mm, the gap between the printing medium and the projecting portion is 0.14 mm.
It is very difficult for the print medium to run in this gap without coming into contact with the signal electrodes, and a toner image has not yet been formed on the upstream side in the transport direction with respect to the recording portion of the print medium. Although there is no major problem with the print quality even if they contact with each other, contact of the print medium with the signal electrode on the downstream side disturbs the toner image formed on the print medium, resulting in great damage to the print quality. turn into. In other words, it is clear that a larger gap, particularly on the downstream side in the transport direction of the print medium, reduces the possibility of contact between the recording medium and the signal electrode, which means that the protrusion of the control electrode, that is, the signal electrode and the FPC. It is desirable that the connection part of is provided only on the upstream side in the transport direction of the print medium.

Furthermore, it is desirable that the reference electrode, which is the other electrode, is connected only from one side and is drawn out from the same side as the signal electrode. Because all the connection wiring (signal electrode, reference electrode) is drawn out from one side of the control electrode, it is possible to connect to the control electrode drive circuit at almost the same distance, which simplifies connection wiring processing and routing. This is because it leads to cost reduction. If the signal electrode and the reference electrode are drawn out from one side in the longitudinal direction of the substrate, if one drive circuit board (including the signal electrode and the reference electrode drive circuit) is provided and provided on the signal electrode lead-out side, Although the connection wiring can be easily connected, the reference electrode connection wiring is routed from the opposite side to the signal electrode side, which complicates the device configuration.

It should be noted that it is not desirable to form a protruding portion of the connecting portion on the downstream side of the print medium conveyance direction because it may cause deterioration of print quality, but on the upstream side, the print medium may be slidably contacted with the counter electrode side. When it is deviated, wrinkles and the like generated on the print medium are corrected during transfer and become flat, so that the toner flying from the openings can be adhered to the print medium well. In addition, it is desirable to use it as a guide that is disposed on the counter electrode side and that uses the protruding portion generated at the connection portion to shift the print medium to the counter electrode side. Although not shown, this guide may be formed not only in the connecting portion but also in the vicinity of the opening of the control electrode. Regarding this formation, it may be formed simultaneously with the sealing of an epoxy resin or the like for improving the environmental resistance, or may be formed by another member after the sealing. Further, the thickness of the protruding portion is preferably substantially equal to or smaller than the value obtained by subtracting the thickness of the recording medium from the gap between the counter electrode and the control electrode (signal electrode). However, if the member to be used has elasticity, it does not matter even if it is large.

There is no problem in forming such a guide as long as the thickness of the print medium is substantially constant, but in the case of a printing apparatus in which various thicknesses of the print medium can be used, etc. It is desirable to provide a mechanism that adjusts the gap between the control electrode and the counter electrode according to the thickness variation of the print medium. To achieve this, the counter electrode is supported by a spring or the like to adjust the gap. Good to do.

[0029]

According to the first aspect of the present invention, even if the resolution is increased as described above, the number of connection terminals between the control electrode and the drive circuit is not increased. Can be prevented and reliability can be improved. Further, according to the invention of claim 2, since the connecting portion between the control electrode and the drive circuit board is provided only on the upstream side in the transport direction of the print medium with respect to the recording portion, the protrusion formed at the connecting portion of the control electrode. The portion does not disturb the toner image formed on the print medium, and more stable print quality can be secured.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a recording unit according to an embodiment of the invention.

FIG. 2 is a plan view of a control electrode according to an embodiment of the present invention.

FIG. 3 is a diagram showing a part of an AA cross section of a control electrode according to an example of the present invention.

FIG. 4 is a diagram illustrating a time division driving principle of the embodiment of the present invention.

FIG. 5 is a timing diagram illustrating time division driving according to the embodiment of this invention.

FIG. 6 is a diagram showing how to print with the control electrode according to the embodiment of the present invention.

FIG. 7 is a diagram showing a conventional toner jet recording apparatus.

[Explanation of symbols]

 12 Toner Carrier 13 Counter Electrode 15 Flexible Wiring Board 16 Electric Field Controlling Means 21 Insulating Substrate 22 Opening 23 First Electrode 24 Second Electrode 25 Connection Terminal 26 Connection Terminal

Claims (2)

[Claims] 1. A toner carrier, a counter electrode facing the toner carrier and having a relatively constant potential, and a row of holes arranged in a gap between the counter electrode and the toner carrier. From the toner carrier by the electric field control means, the electric field control means for giving a variable electric field to the control electrode, the conveying means for conveying the print medium through the gap between the counter electrode and the control electrode, A fixing means for fixing toner electrostatically adhered to the print medium through the opening of the control electrode, wherein a plurality of the control electrodes are arranged on a first surface of the insulating substrate in a row direction. A first electrode formed separately, a plurality of second electrodes formed on the second surface of the insulating substrate so as to be separated from each other in the column direction and intersecting the first electrode, the first electrode and the second electrode. The first electrode at the intersection with the two electrodes An opening formed through the insulating substrate and the second electrode and obliquely arranged with respect to the traveling direction of the print medium, and the electric field connected to each of the first electrode and the second electrode. And a signal supply connection terminal connected to the control means, the electric field control means,
An electrostatic printing apparatus, characterized in that the first electrode is driven in a time-division manner in which each electrode is circulated at regular intervals, and a signal according to an image signal is supplied to each of the second electrodes. 2. The electrostatic printing apparatus according to claim 1, wherein the connection terminal of the control electrode is drawn out in one direction, and the connection terminal is arranged on the upstream side in the transport direction of the recording medium.