JPH09309221A - Electrostatic recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an electrostatic recording head capable of gaining output characteristics of uniform charge particles. SOLUTION: On a foundation body 9 of an elongated shape, a plurality of line electrodes 1 being extended in its longitudinal direction and a plurality of finger electrodes being extended in the direction intersecting the line electrodes are arranged face to face in a matrix manner via a dielectric layer 3, and openings 4 for producing charge particles are formed at the corresponding part of each matrix intersection at the finger electrodes. Together therewith, a screen electrode 7 is formed in opposition to these finger electrodes 2 via an insulation layer 6. Openings 5, 8 are formed corresponding to each opening of the finger electrodes at the screen electrode and insulation layer, in which the openings of the insulating layer are provided with an electrostatic recording head chip 10 at least permitted to reach the finger electrode position, a matrix with a plurality of the electrostatic head chips arranged and supported in series, and control means for controlling a quantity of charge particle production every electrostatic recording head chip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention modulates charged particles by an ion stream or an electron beam and selectively irradiates the recording member such as a dielectric with a latent image to form an electrostatic image. The present invention relates to an electrostatic recording head.

[0002]

2. Description of the Related Art An image recording apparatus is provided with an electrostatic latent image on a member to be recorded by modulating charged particles by an ion stream or an electron beam and selectively irradiating the member to be recorded such as a dielectric. There is an electrostatic recording apparatus that forms an image and develops the latent image with charged toner particles to form a visible image, thereby performing electrostatic recording. There are two types of latent image developing methods, a dry type and a wet type. In the wet type, a liquid toner in which toner particles are mixed in a volatile liquid is used.

The outline of the wet type is as follows. For example, as shown in FIG. 22, a long sheet-shaped recording member 100 having a dielectric layer formed thereon is fed to a pair of rollers 10.
The rollers 101a, 101a are sandwiched between 1a and 101b.
By the rotation of 101b, the electrostatic recording head 102 is arranged so as to be sent to the downstream side and arranged along the longitudinal direction in the transverse direction of the recording member 100 in the conveyance path of the recording member 100. Liquid developing head 10 which forms an electrostatic latent image and is provided further downstream in the transport path.
3, the liquid toner is applied to the latent image, and the latent image is developed and visualized to obtain a hard copy of the image. This is a typical configuration example of what is called an electrostatic plotter that obtains a print output of a long and large screen.

The dry type has a drum-shaped recording member, which is rotated and an electrostatic latent image is formed by an electrostatic recording head arranged at a fixed position on the recording member. The toner is applied at the developing unit located at a fixed position on the recording member to form a visible image, and the image formed by the toner that appears as a visible image on the recording member is transferred to recording paper, and then heated. It is fixed and obtained as a hard copy. These are all examples of wet and dry devices, but not all, as such, in a general overview.

Conventionally, as the electrostatic recording head for forming the latent image used in such an electrostatic recording apparatus, one disclosed in Japanese Patent Publication No. 2-62862 is known. These known electrostatic recording heads are long rod-shaped, and have a plurality of linear or strip line electrodes extending in the longitudinal direction, and a plurality of linear or strip finger electrodes extending in a direction intersecting with the linear electrode. The electrodes are arranged in a matrix so as to face each other with the dielectric layer in between, and finger openings for generating charged particles are formed at the portions corresponding to the respective matrix intersections of the finger electrodes. Further, a screen electrode having a plurality of screen openings corresponding to the respective openings of the finger electrodes is provided to face the finger electrodes via an insulating layer to form a charged particle control unit, and recording is performed through the openings of the screen electrodes. The surface of the member is irradiated with charged particles.

Each screen opening corresponds to the dot position of the latent image, and the ion or electron beam emitted from this screen opening is incident on the surface of the recording member which is close to the electrostatic recording head. As a result, a dot-shaped electrostatic latent image is formed at each incident position.

In such an electrostatic recording head, a desired latent image can be formed by selecting a screen opening corresponding to a dot position on which a latent image is desired to be formed. An alternating voltage is applied between the line electrodes including the dot positions where a latent image is to be formed and all the finger electrodes. By applying this AC voltage, corona discharge is induced in the vicinity of the openings of all finger electrodes on the same line electrode to generate charged particles, and among these charged particles, the finger electrode corresponding to the dot position where a latent image is to be formed is formed. By a control voltage applied between the screen electrode and the screen electrode, the particles are extracted to the screen electrode side and accelerated, and the accelerated voltage applied to the screen electrode causes the charged particles to be radiated toward the recording member from the opening provided in the screen electrode.

Further, an accelerating voltage for forming an accelerating electric field is applied between the screen electrode and the recording member, and the electric field generated by this causes the charged particles radiated from the opening of the screen electrode to the surface of the recording member. When it reaches, a latent image, that is, an electrostatic charge pattern is formed on the recording member.

By the way, in recent years, the recorded image is required to be dense, and in order to form a latent image (electrostatic charge pattern) having a density of about 300 [DPI] (dot per inch), a thick film technique is used. Is applied to manufacture the electrostatic recording head having the above structure.

The thick film printing technique is, for example,
It shows a technique in which line electrodes and screen electrodes, which are individually patterned, are aligned on a substrate with a dielectric sheet and an insulator sheet interposed therebetween, and then sequentially bonded to assemble an electrostatic recording head. , Shows an electrostatic recording head in contrast to the thin film technology described below.

However, in the case of the thick film technology, even if the position of each electrode at the time of bonding and the coating thickness of the insulating paste used for bonding are the same in the head, there is a strong tendency for the positions to largely vary, so this is emitted. There is a problem that the amount of charged particles varies greatly depending on the opening position of the screen electrode.

This is because the dot density of the recorded image is 600.
[DPI] or 12000 [DPI],
When higher definition is required, the problem of processing accuracy included in thick film technology becomes more apparent, and the variation in density between dots becomes noticeable as density unevenness. The density becomes uneven in a mottled pattern, and the unevenness in the thickness and the blurring occur in the line image portion, which has an influence.

In recent years, in the electrostatic recording head described above, in order to improve the spatial unevenness and line width variation of the output image due to the variation of the charged particle output from the respective openings, Japanese Patent Laid-Open No. Sho 6-96 has been proposed.
A technique for correcting the output from each aperture has been proposed, as disclosed in Japanese Patent Laid-Open No. 1-272558.

In the technique disclosed in this publication, in order to correct the unevenness of the charged particle output caused by the variation of the size of the opening of the finger electrode, the screen electrode is divided into segment electrodes corresponding to the distribution of the charged particle output unevenness. It is intended to be corrected by adjusting the acceleration voltage applied to those segment electrodes.

However, this correction technique has a large problem in application. That is, in this correction technique, among the openings whose output tendencies are relatively similar to each other, a plurality of adjacent ones are set as a group and the accelerating voltage is adjusted for each group. In many cases, the output tendencies of adjacent heads are not similar even between adjacent openings, and in the end, in order to perform more accurate correction, it is necessary to adopt a form close to individual correspondence in dot units. Moreover, since the variation in the output of each aperture differs for each head, the mode of segmenting the screen electrode must be changed for each head, which is not suitable for practical use.

As a technique for correcting the output from each aperture,
In addition, JP-A-61-61868 and JP-B-6-9
There is also a technique disclosed in Japanese Patent No. 8786.

In the technique disclosed in Japanese Patent Laid-Open No. 61-61868, the address information corresponding to the unevenness of the charged particle output is corrected in order to correct the unevenness of the charged particle output caused by the variation in the size of the opening of the finger electrode. The control voltage applied between the finger electrode and the screen electrode is changed in accordance with the above, and the technique disclosed in Japanese Patent Publication No. 6-98786 discloses the accuracy of the mounting distance between the recording head and the recording drum and the head itself. In order to correct the charging potential unevenness due to the characteristic variation, the output of each divided group of the recording head divided into predetermined dot units is measured, the driving condition for keeping the output constant is stored, and the divided driving is performed under that condition. That is. A method of providing a control circuit for each division and a method of sharing a drive circuit and performing time division drive can be applied to the division drive.

However, as described above, in the head formed by using the thick film technique, the output difference for each opening is random, and therefore the correction control is performed in a form close to individual correspondence in dot units. Since control is required and the variation varies from head to head, the above-described address information and head division mode must be changed for each head, which is also the reason why they are not suitable for practical use.

[0019]

As described above, the conventional electrostatic recording head for recording a high-resolution image uses the thick film technology, and the processing accuracy of the thick film manufacturing / manufacturing process is a technique. In view of this, in this case, it is inevitable that variations in the size of the openings of the finger electrodes, variations in the film thickness of the dielectric layer, the insulator layer, and the like, and variations in the shape of the components of the recording head. Moreover, since the distribution of these geometrical variations is determined by uncontrollable factors that occur during the manufacturing process of each of the constituent elements, the pattern of output unevenness of the print head differs for each head, and the pattern of output unevenness is different. It is impossible to predict in advance.

Therefore, it is necessary to increase the number of segments into which the screen electrode is divided in order to maximally correct the output unevenness of the charged particles of all recording heads. Therefore, conventionally, the screen electrode is divided for each opening,
A method of adjusting the control voltage for each divided electrode to perform correction is applied.

However, in such correction for each opening, for example, a resolution of 300 DPI (Dot Per) is used.
Assuming an electrostatic recording head for printing letter size (width of about 8 inch) in Inch, it is necessary to have a structure in which 2400 openings are distributed in an area of 8 inch width in this electrostatic recording head. Therefore, correcting all 2400 openings leads to an increase in the number of connections on the electrostatic recording head and an increase in the correction circuit, and as a result increases the manufacturing cost of the electrostatic recording head and the drive circuit. It will be.

There is also a method of correcting the output by adjusting the control voltage for each finger electrode, but since the variation in the charged particle output for each opening in the head formed by the film thickness technique is random, the recording head It is not possible to deal with the charged particle output unevenness of all the above openings.

Further, in order to correct the charging potential unevenness, the output of each divided group of the recording head divided in a predetermined dot unit is measured, the driving condition for keeping the output constant is stored, and the divided driving is performed under the condition. Even in the correction method of Japanese Patent Publication No. 6-98786, it is necessary to reduce the number of apertures included in one division and increase the total number of division groups in order to deal with the unevenness between all charged particle output apertures. However, if a control circuit is to be provided for each division, the cost of the control circuit increases, and if time-division driving is performed for each division to avoid this, the drive time will increase this time and printing There remains the problem of slowing down.

Therefore, the object of the present invention is to
An object of the present invention is to provide an electrostatic recording head which can obtain a uniform charged particle output characteristic over the entire length even if it is long and can be realized at low cost.

[0025]

In order to achieve the above object, the present invention is configured as follows. That is, a plurality of line electrodes extending in the longitudinal direction and a plurality of finger electrodes extending in a direction intersecting with the plurality of line electrodes are opposed to each other on a slender substrate with a dielectric layer interposed therebetween. Are arranged in a matrix so that openings are formed in the finger electrodes at the intersections of the respective matrix intersections to generate charged particles, and screen electrodes are formed facing these finger electrodes through an insulating layer. An electrostatic recording head chip having openings formed in the screen electrode and the insulating layer at positions corresponding to the openings of the finger electrodes, and a plurality of the electrostatic recording head chips are arranged and supported in series. It is characterized in that a base material and a control means for controlling the amount of charged particles generated are provided for each electrostatic recording head chip.

According to this structure, since a plurality of electrostatic recording head chips are arranged in series to form the electrostatic recording head, it is necessary to prepare a small size electrostatic recording head chip. Therefore, the electrostatic recording head chip can be manufactured by applying the thin film technology which is a semiconductor manufacturing technology capable of maintaining the processing accuracy. Here, the thin film technique refers to a technique of forming a head in the upper surface direction of a substrate through several steps such as vapor deposition, resist film formation, and etching using a wafer substrate as a starting material.
The layer thickness can also be made almost completely uniform in the same head chip by the precision of the precision such as vapor deposition. Therefore,
For each electrostatic recording head chip, the amount of charged particles generated in that head chip is almost balanced,
If the difference in the amount of charged particles generated between adjacent electrostatic recording head chips in the state where a plurality of electrostatic recording head chips are arranged is adjusted for each electrostatic recording head chip by the control means, the electrostatic recording head is obtained. The distribution state of the generated amount of charged particles as a whole can be controlled to be substantially uniform. Therefore, it is possible to obtain a high-quality print in which the distribution state of the generated amount of charged particles is uniform.

Further, the present invention is characterized in that the control means controls the screen voltage applied to the screen electrode. Further, the control means controls the on-state potential of the finger electrodes. Furthermore, the control means, means for measuring the thickness of the insulating layer,
It is characterized in that the finger electrode or the screen electrode is controlled based on the measurement result. Further, the control means controls so that the average amount of charged particles generated in each head chip is the same.

The amount of charged particles generated in the electrostatic recording head chip can be adjusted by the relationship between the voltage applied to the finger electrodes and the screen voltage applied to the screen electrodes. Since the electrostatic recording head chip is manufactured by using the thin film technology in the present invention, each of the electrostatic recording head chips has a substantially balanced generation amount of charged particles in the head chip. The screen voltage of each electrostatic recording head chip is adjusted by the control means for the difference in the amount of charged particles generated between the adjacent electrostatic recording head chips in the state where a plurality of electrostatic recording head chips are arranged. If adjusted in a form, it is possible to control the distribution state of the generated amount of charged particles in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained. Further, when the control means has a structure having a means for measuring the thickness of the insulating layer, the finger voltage or the screen voltage can be controlled based on the measurement result, so that adjustment corresponding to the thickness of the insulating layer can be performed. The applied finger voltage or screen voltage can be applied to the finger electrodes or screen electrodes. Therefore, it is possible to control the distribution state of the generated amount of charged particles in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

[Technology Underlying the Present Invention] In the present invention, a plurality of linear or strip-shaped line electrodes extending in the longitudinal direction and a plurality of linear or strip-shaped fingers extending in a direction intersecting with the line electrodes. The electrodes are arranged in a matrix so as to face each other with the dielectric layer in between, and openings for generating charged particles are formed at the corresponding portions of the matrix intersections of the finger electrodes, and a plurality of openings corresponding to the openings of the finger electrodes are formed. An electrostatic recording head is provided in which a charged particle control unit is configured by providing a screen electrode having an opening facing a finger electrode through an insulating layer, and irradiating charged particles to the surface of a recording target member through the opening of the screen electrode. Intended. Then, in the present invention, such an electrostatic recording head is formed by a plurality of head chips formed by a thin film technique by a semiconductor manufacturing method.

In the electrostatic recording head, variations in output characteristics of charged particles from a plurality of openings are caused by film forming accuracy of dielectric layers and insulating layers, processing accuracy of line electrodes and finger electrodes, and the like. It depends on how to make it uniform. This can be solved by the following technique.

It applies a thin film technology that can obtain a precise processing accuracy in place of the thick film technology. An insulating substrate (wafer) made of quartz (glass) is used, and a line electrode and a dielectric are formed on the insulating substrate. A plurality of head chips having a body layer, finger electrodes, finger openings, insulating films, screen electrodes, and screen openings are formed by thin film technology.

That is, a line electrode made of metal is formed on an insulating substrate (wafer) made of quartz (glass),
A dielectric layer is formed on it. Here, the dielectric layer has a three-layer structure, and the SOG (Sp) is sandwiched between the first and second insulating films such as a SiO ₂ film and the first and second insulating films.
(In On Glass) film is formed. A finger electrode made of a metal is formed on the dielectric layer, and an organic insulating film made of polyimide or the like is formed on the finger electrode.
Further, a screen electrode made of metal is formed thereon.

The manufacturing process will be specifically described with reference to FIGS. First, as shown in FIG. 2, the line electrode 1 is formed on the insulating substrate 9 made of glass or quartz, and the dielectric layer 3 is formed thereon. The material of the line electrode 1 may be a single-layer metal thin film of Ti, Mo, Cu, Al, W or the like, or a double layer metal film in which Ti or the like is formed on Al. The electrode film is formed by using a manufacturing process such as sputtering, vacuum deposition or plating. The patterning of the line electrode 1 is performed by a well-known photolithography method in the semiconductor manufacturing process, and the metal thin film portion not covered with the resist is wet-etched or R.I. I. E (Reactive Ion
Etching) or the like is used to selectively remove it.

After the line electrode 1 is formed, the dielectric layer 3 formed on the line electrode 1 has a first insulating film 3 as shown in FIG.
-1, a SOG film 3-2, and a second insulating film 3-3 have a three-layer structure. Of these, the first insulating film 3-1 is formed by plasma CVD (Plasma Chemical Vapor).
Deposition method or atmospheric pressure CVD (Atm)
ospheric-Pressure Chemica
The film is formed by a semiconductor manufacturing process such as a vapor deposition method. The film quality of the first insulating film 3-1 is preferably a thin film made of an inorganic material such as a SiO ₂ film or a SiN film, and the film thickness is preferably about 0.2 to 1.5 μm.
Then, S is applied as a coating glass on the first insulating film 3-1.
An OG film (for example, an OCD film manufactured by Tokyo Ohka Co., Ltd.) 3-2 is formed by a spin coating method or the like. After forming the SOG film 3-2, a second insulating film 3-3 made of the same material as the first insulating film 3-1 is formed by the same method as the first insulating film 3-1 to a film thickness of 2.0.
The film is formed to about 3.0 μm.

As described above, the dielectric layer 3 having a three-layer structure is formed. When this dielectric layer is formed of a single layer film such as a SiO ₂ film or the like, an area where the line electrode 2 is formed below, Since a step corresponding to the film thickness of the line electrode 2 is generated between the regions where it is not present, in order to eliminate this step, the SOG film 3-2 is replaced with the first and second insulating films 3-1 and 3 -3.

As a result, the step difference corresponding to the film thickness of the line electrode 2 is reduced and the entire dielectric layer is flattened.
Compared to a single layer film structure such as _{2 and the} like, it is possible to reduce the variation in the generated charge amount between the respective elements and obtain a further image quality improving effect, and at the same time, to form on the line electrode 1 and the dielectric layer 3 upper part. The pressure resistance or durability between the finger electrodes 2 is significantly improved. Further, by sandwiching the SOG film 312 in the middle, the film thickness of the dielectric layer 3 is 3 to 5 μm in terms of pressure resistance.
The thickness is sufficient, and the thickness can be significantly reduced as compared with the conventional film thickness of about 35 μm using the thick film technology.

When the film thickness is about 35 μm, the discharge start voltage needs to be 1500 [Vp-p], but 3 to 5 μm.
By setting the thickness to a degree, it is possible to reduce the minimum discharge start voltage determined by Baschen's law to about 700 [Vp-p].

After the dielectric layer 3 is formed, an alumina film 14 is formed on the dielectric layer 3 as a protective film. In the alumina film forming step, first, as shown in FIG.
About 1 to 1.0 μm, sputtering method, vacuum deposition method,
Alternatively, a film is formed on the second insulating film 3-3 by a plating method or the like. Then, in that state, when immersed in warm water of about 80 ° C., the Al film 14-1 becomes a hydrated Al oxide film 14-3.
Then, a heat treatment is performed in an N ₂ atmosphere at a temperature of about 450 [° C.] to 500 [° C.].
The water contained in −2 is removed to form the alumina film 14. The process shown so far completes the structure shown in FIG.

By the above method, the alumina film 14 is formed on the dielectric layer 3 in the area other than the line electrode pad area. Since the alumina film 14 acts as a protective film for the dielectric layer 3, Further, the pressure resistance and durability are improved.

Next, as shown in FIG. 6, the finger electrodes 2 are formed on the alumina film 14. T as an electrode material
A high melting point metal thin film such as i, Mo, W, or TiN is desirable.
The method for forming this refractory metal thin film is the same as that for line electrodes,
From the durability of the electrode, the film thickness is preferably about 0.5 to 5.0 μm. After the film formation, a resist pattern is formed by a photolithography method, and a wet or R.I. I. Etching is performed by a dry etching method such as E method to form the finger openings 4. The size of the finger opening 4 is set to 15 to 15 in order to drive at the minimum discharge start voltage predicted by Paschen's law.
About 20 μmφ is desirable.

In the conventional method using the thick film technology, the finger openings can be formed only up to 75 μmφ, and the driving voltage for generating charges is much higher than the minimum discharge start voltage predicted by Baschen's law. However, according to the present manufacturing method, it is possible to drive at a lower voltage than that of the conventional element, and it is possible to form a finger opening having a diameter much smaller than the finger opening of the conventional element.
A chip structure of an electrostatic recording head capable of achieving a resolution of 0 [DPI] or higher is obtained.

After forming the finger electrodes 2, an organic insulating film such as polyimide is formed by a spin coating method or a screen printing method to obtain an insulating layer 6. In order to reduce the control voltage, the thickness of the insulator layer 6 is preferably 50 μm or more. Subsequently, after the insulator layer 6 is formed, the screen electrode 7 is formed on the insulator layer 6 by the same manufacturing method as the line electrodes 1 and the finger electrodes 2. As a material for forming the screen electrode 7, a high melting point single-layer metal thin film of Ti, Mo, TiN, W, or the like,
Alternatively, a multi-layered metal thin film that thinly covers Al on top of them may be used. Considering the rigidity and durability of the electrode, the film thickness is 1.
About 0 to 2.0 μm is desirable. After forming the metal thin film for the screen electrode, a resist 11 is formed by the photolithography method which is the same method as the pattern formation of the line electrodes and finger electrodes, and this is used as a mask for wet or R.I. I. E
The screen opening 8 is formed by performing dry etching such as a dry etching method, but the resist 11 may be left until the subsequent etching step of the insulating film 6. The size of the screen opening 8 is preferably about 50 μmφ or less in consideration of the amount of charge extracted from the screen opening 8. The structure as shown in FIG. 6 is formed by the steps up to here.

After the screen electrode 7 is formed, the screen electrode 7 is used as a mask by a dry etching method using plasma or a wet etching method in a chemical solution.
The insulating film 6 other than the lower part of the screen electrode 7 is selectively removed to form a space (hole) 5 below the screen opening 8 shown in FIG. Through the above steps, the chip structure of the electrostatic recording head having the configuration shown in FIG. 1 is completed.

According to such a manufacturing method, a homogeneous thin film structure having a precise and fine structure can be obtained by the process technique used in the semiconductor manufacturing method, and the film thickness of each electrode film and each insulating film can be controlled. Since the uniformity is improved, it is possible to achieve a large increase in resolution and image quality of the electrostatic image forming apparatus. Also,
It enables lower voltage driving than the conventional charge generator using thick film technology, which leads to cost reduction of the drive circuit. Furthermore, by covering the surface of the dielectric layer with an alumina film as a protective film, electrostatic recording is possible. The head chip can also be made highly durable.

Therefore, it is possible to obtain a head chip which has a highly precise structure, is fine, has a uniform thickness of the dielectric layer and the insulating layer, and has a small difference in charged particle output characteristics within the chip.

The head chip used in the electrostatic recording head of the present invention has at least a line electrode, a dielectric layer, and a finger electrode formed in a thin film structure by a semiconductor manufacturing method. A plurality of small-sized head chips of this thin film structure having a small difference in charged particle output characteristics are arranged side by side and connected in order to form one long electrostatic recording head. A feature of the present invention is that an electrostatic recording head having the same overall charged particle output characteristics can be obtained by correcting the voltage or the finger voltage application time.

Further, according to the present invention, the inter-chip correction amount is adjusted on the basis of the correction amount corresponding to the predetermined use time of the recording head, so that the change amount of the output with the use time is changed for each head chip. Even if they are different, the correction is always performed properly between the chips, and the driving is performed so that the output step between the chips does not occur.

In the present invention, the print heads are connected by connecting head chips having different output tendencies in the extending direction of the line electrodes in the head chips so that the corrected output of the print heads becomes uniform over the entire length of the print heads. It is what constitutes.

Further, according to the present invention, an element having a different resistance value depending on the film thickness of at least one of the dielectric layer and the insulating layer in the head chip is provided in the chip, and this resistance element is included in the screen voltage or finger voltage adjusting circuit. It is used as a drive unit.

Further, it is characterized in that the number of fingers per head chip is an integral multiple of the number of channels per finger drive element for controlling the finger voltage of the recording head.

<Basic Operation> The variation of the charged particle output over the entire length of the recording head as seen in the conventional example is due to the shape of the electrode, the insulating layer, and the dielectric layer that form the electrostatic recording head such as the hole diameter and thickness. It is due to such variations.
These shape variations are unavoidable in the conventional thick film forming technology in terms of manufacturing accuracy, but in the present invention, the head chip is manufactured by the thin film manufacturing technology capable of performing fine processing which is a semiconductor manufacturing technology with high accuracy. By manufacturing a plurality of the above, and by connecting a plurality of them to obtain an electrostatic recording head of a required length, it is possible to significantly reduce the geometrical variation of the head constituent elements and to miniaturize each constituent. It enables printing with higher resolution than the conventional recording head using thick film manufacturing technology. Further, it is possible to obtain a long electrostatic recording head capable of obtaining a desired recording length by connecting a plurality of head chips having an arbitrary length.

A manufacturing method for connecting a plurality of head chips formed by a thin film manufacturing technique to obtain an electrostatic recording head of a required length has already been proposed by the present applicant in Japanese Patent Application No. 7-5620.

The electrostatic recording head manufactured by this semiconductor manufacturing technology has a line electrode width, a finger electrode opening diameter and its shape, a screen electrode opening diameter and its shape, which are different from those of the conventional thick film manufacturing technology. It is possible to dramatically improve the uniformity of the shapes of the constituent elements such as the thickness of the dielectric layer and the thickness of the insulating layer.

However, in order to form a head chip by the thin film semiconductor manufacturing technique, a wafer is used, and this wafer is subjected to film formation by vacuum vapor deposition, sputtering, CVD, ion plating or the like, and then photolithography or the like is applied thereto. Since the required structure is obtained by patterning, etc., it is possible to obtain high-precision uniformity in the adjacent regions in the wafer, but it is possible to form in the central region and edge region of the wafer, or between different wafers. It is inevitable that a slight difference occurs in the film thickness and the shape of the fine structure. Certainly, the difference in the film thickness and the shape of the fine structure is so small that it cannot be compared with that of the thick film technology. .

Therefore, when only the head chips in the central portion of a single wafer are selected and they are interconnected to form a recording head, the charged particle output difference due to the film thickness difference in this wafer or between wafers is In principle, it does not matter. However, since an electrostatic recording head is obtained by using a plurality of head chips, it is actually impossible to select and use only head chips with uniform characteristics from the viewpoint of cost. A head chip will be used.

The difference in the film thickness and the shape of the recording head constituting members is, though slightly smaller than that of the thick film technology.
Since the difference is directly reflected in the charged particle output difference from the recording head, it cannot be ignored in order to improve the image quality.

Further, even when the head chips are arranged, if it is not possible to mount the head chips so that the screen surfaces of the head chips are located on the same plane without a step, even if the head chips having the same output characteristics are used. However, due to the difference in the distance between the screen surface and the recording medium that receives the charged particles, the charged particle accelerating electric field formed by the recording medium and the screen due to the difference in level between the screen surfaces of the head chips. Deviation occurs, resulting in a difference in output between the head chips. In the present invention, this is corrected for each head chip.

If the correction can be performed for each head chip, the circuit for correction can be simple, and the difficulty of correction in the case of a thick film can be solved. In the present invention, when viewed on a chip-by-chip basis, attention is paid to the fact that the head chip created by the thin film manufacturing technique has a small variation in the charged particle output characteristics from each opening in the chip itself. If the correction is performed, the scale of the circuit for correction can be reduced, and a long electrostatic recording head capable of high-resolution image formation can be realized, and further, it can be realized at low cost. Become.

That is, since the charged particle output can be kept substantially uniform in the head chip, when a plurality of the head chips are connected to form one electrostatic recording head, the charged particle output becomes a problem. The non-uniformity factor is specified by the output deviation between the head chips.

Therefore, in the present invention, the output deviation between the head chips is corrected by controlling either the screen voltage or the finger voltage or the finger voltage application time to make the charged particle output in the recording head uniform. In this case, since the correction unit can be made the same as the head chip unit, the number of correction units can be greatly reduced compared to the case of correcting the internal output deviation of the recording head by the conventional thick film forming technique, so that the drive required for the correction The correction circuit associated with the circuit can also be simplified and the cost of the drive circuit can be reduced. Since there are several correction methods, they will be described individually.

(Two Methods of Correction between Chips) Regarding the method of correcting the output deviation between the head chips, the present invention proposes two different correction methods.

According to the thin film manufacturing process, the output of charged particles in the head chip can be made substantially uniform, but the dielectric of the head chip from the center to the end in one wafer that is the source of the head chip. There is a gradual change in the film formation of the body layer and the insulating layer, and a slight output deviation remains in each head chip cut out from the corresponding wafer. However, the deviation within the original wafer is small, and the output deviation within each head chip is often in the form of an output gradient in which the output is inclined in the direction in which the line electrode extends.

FIG. 7 schematically shows an example of charged particle output of a recording head having a plurality of head chips arranged in series. In the figure, the vertical axis represents the magnitude of the charged particle output, and the horizontal axis represents the position in the extending direction of the line electrode on the recording head. The five solid lines in the figure represent the outputs of five different head chips, and since these head chips were taken out from different wafers or from widely separated places on the same wafer, their average output values were However, the output deviation within the chip is only a small output gradient.

Here, in the case of correcting the output deviation between these head chips, as shown in FIG. 8A, a method of correcting so that the average value (broken line in the figure) of each head chip is the same (hereinafter referred to as chip) An average correction method) and a method (hereinafter referred to as a chip boundary correction method) in which the outputs of the head chip ends are the same at the boundaries between the head chips as shown in FIG. 8B.

In the chip average correction method, since the same output is obtained for the average value of the head chips over the entire recording head, it is possible to obtain an extremely uniform recording head output in the long-term cycle. An output step due to the output gradient in each head chip is generated at the boundary between them, and uniformity in a short-term cycle is deteriorated.
However, in the chip average correction method, the maximum value of the charged particle output gradient in the chip of the head chip forming the recording head matches the maximum value of the chip boundary output step of the recording head, so the charged particle output gradient in the head chip is constant. By controlling the value within the value of, it is possible to suppress the boundary output step to a level that does not cause a problem.

In particular, in the case of a head chip manufactured by a thin film manufacturing process, the uniformity in the wafer and between wafers varies depending on the size of the substrate wafer used to manufacture the head chip and various conditions related to the manufacturing, but depending on the degree of the uniformity. It is easy to control the charged particle output gradient within the head chip within a fixed value by appropriately adjusting the size of the head chip cut.

On the other hand, in the chip boundary correction method, the long-term charged particle output displacement of the entire recording head is larger than the internal charged particle output deviation of each head chip constituting the recording head.
The direction of the internal charged particle output gradient of each head chip is greatly influenced.

FIG. 9 is a diagram for explaining the influence of the output gradient of the charged particles inside the head chip. The head chips in the figure all have the same output gradient amount. Here, FIG. 9A is a model assuming that the output gradient directions in the chips are all the same, and when the output in chip units is corrected so that the chip boundary of the head chip before correction (wavy line) is eliminated, a solid line is obtained. Although there is no output step at the chip boundary as shown, the output of the recording head is greatly different at both ends.

Even if the displacement amount of each chip is small, when chips having the same displacement tendency are gathered and chip boundary correction is performed as in this example, the total displacement amount is the product of the in-chip displacement amount and the number of connected chips. Therefore, when a long print head is constructed by connecting a large number of head chips, the deviation amount between both ends of the print head becomes large.

Next, FIG. 9 (b) is a model assuming a case in which head chips having different in-chip output gradients coexist. In this case, the long-term charged particle output displacement of the entire recording head is corrected (solid line). What is much smaller than the case of FIG. 9A is obtained. FIG. 9C is a model assuming a case where head chips having different in-chip output gradients are adjacent to each other. In this case, the long-term charged particle output displacement of the entire recording head after correction (solid line) is the smallest. Has been obtained.

As described above, in the chip boundary correction method, it is possible to reduce the long-term output displacement of the recording head after the inter-chip output correction by appropriately arranging the head chips in different output gradient directions of the internal charged particles. Become.

The premise and concept of the present invention have been described above. Next, a specific example of the present invention will be described.

[Specific Example of the Present Invention] (Basic Head Chip Configuration Common to First and Second Specific Examples)
First, the basic structure of the head chip used in the first and second specific examples of the present invention will be described.

FIG. 10 shows the structure of the head chip used in the first and second specific examples of the present invention. In order to make the structure easy to understand, a perspective view in which a part of each member of the head chip is cut away is shown. It is shown. In the figure, 10 is a head chip, 1 is a line electrode, 2 is a finger electrode, 3 is a dielectric layer, 4 is a finger opening, 5 is a hole,
Reference numeral 6 is an insulator layer, 7 is a screen electrode, 8 is a screen opening, and 9 is a head chip base material.

The head chip 10 has a rectangular plate shape and has a laminated structure composed of the screen electrode 7, the insulator layer 6, the dielectric layer 3, and the head chip base material 9, and the insulator in the dielectric layer 3 is formed. The finger electrodes 2 are arranged on the layer 6 side, and the line electrodes 1 are arranged on the head chip base material 9 side in the dielectric layer 3.

That is, although there are a plurality of line electrodes 1 and finger electrodes 2 respectively, a plurality of line electrodes 1
Are arranged in parallel on the dielectric layer 3 on the side of the head chip base material 9 and so as to extend in the longitudinal direction of the head chip 10, and the plurality of finger electrodes 2 are arranged opposite to the dielectric layer 3. On the surface, they are arranged in parallel so as to extend in the lateral direction of the head chip 10 so as to intersect these line electrodes 1. As a result, the plurality of finger electrodes 2 and the line electrodes 1 face each other with the dielectric layer 3 in between, and are arranged so as to form a matrix arrangement configuration.

Further, the finger electrode 2 is provided with a fine hole at a position corresponding to each matrix intersection corresponding portion, each of which serves as a finger opening 4 for generating charged particles. As a result, finger openings 4 corresponding to the number of matrix intersections are arranged in the finger electrodes 2 in an orderly manner.

Holes 5 having a diameter larger than that of the finger openings 4 are formed in the insulator layer 6 at positions corresponding to the finger openings 4. The Z direction in the drawing, which is the central axis direction of the holes 5, is the charged particle emitting direction on the finger electrode 2, and the hole 5 is provided in the charged particle emitting direction on the finger electrode 2 to thereby provide the empty space. The holes 5 function as holes through which charged particles pass.

A screen electrode 7 is arranged on the surface of the insulator layer 6 opposite to the side surface of the finger electrode 2. The screen electrode 7 has a position corresponding to the finger opening 4 for emitting charged particles. A plurality of screen openings 8 are formed, and charged particles generated by the finger electrodes 2 and the line electrodes 1 intersecting with the finger electrodes 2 pass through the holes 5 and pass through the screen openings 8 on the screen electrodes 7 to the outside. It is the composition to be released.

The electrodes 1, 2 constituting the head chip 10, the dielectric layer 3, and the insulator layer 6 are the head chip base material 9
They are laminated and integrally formed by a thin film manufacturing process to which a semiconductor forming process is applied.

Next, this head chip 10 shown in FIG.
The specific structure and manufacturing method will be described with reference to the sectional view of the finger electrode 2 in the extending direction. The line electrode 1 is formed on the head chip substrate 9. The head chip substrate 9 is a strip-shaped plate made of quartz glass having a thickness of about 1 mm. The head chip substrate 9 is provided with a plurality of head chips 10 at one time from a wafer, and a semiconductor forming process is applied. Since the thin film manufacturing process described above is used, a disk-shaped wafer is used as in the case of semiconductors. The wafer used here is a disc-shaped one made of quartz glass having a thickness of about 1 millimeter, and has a standard size in a semiconductor process such as a 4-inch wafer or an 8-inch wafer.

The line electrode 1 is formed by forming an aluminum thin film having a thickness of about 2 μm on a quartz glass wafer serving as the head chip substrate 9 by a sputtering method, and then forming a resist pattern of the arrangement shape of the line electrode 1 on the aluminum thin film surface. The aluminum thin film surface is wet-etched using this resist pattern as a mask to obtain a desired pattern shape.

Next, a flat layer 3a made of coating glass is formed on the side surface of the line electrode 1 of the head chip substrate 9 by a spin coating method so as to cover the line electrode 1 thus formed. Further, a silicon oxide film 3b having a thickness of about 2 μm is formed thereon, and aluminum oxide (A
The l ₂ O ₃ ) film 3c is formed to a thickness of 0.5 micron. Thus, the dielectric layer 3 having a three-layer structure including the flat layer 3a, the silicon oxide film 3b, and the aluminum oxide film 3c is formed.

For the finger electrode 2, a titanium (Ti) thin film having a thickness of 5 μm is formed on the dielectric layer 3 by a sputtering method, and then a mask pattern of the finger electrode is formed on the titanium thin film, and this mask pattern is used as a mask. By etching, a desired pattern shape including the finger electrode openings 4 is obtained and created.

When the formation of the finger electrodes 2 is completed,
Next, the insulator layer 6 is formed. This is a mask pattern in which a polyimide layer having a thickness of 50 μm is formed on the entire surface of the dielectric layer 3 on which the finger electrodes 2 are formed by spin coating, and then a portion for forming holes 5 for passing charged particles is removed on the polyimide layer. Is formed and is etched using this mask pattern to form an insulator layer 6 in which holes 5 for passing charged particles are formed corresponding to the positions of the finger openings 4.

Next, after filling the opening (hole 5 forming region) of the insulator layer 3 with a liquid resist material, an aluminum thin film having a thickness of 2 μm is formed by a sputtering method, and then this is used as a mask. By etching using the pattern, the screen electrode 7 having a desired pattern shape including the radiation opening 8 for the charged particles is formed.

After the screen electrode 7 is formed, the head chip 10 is separated from the quartz glass wafer by dicing, and the liquid resist material is removed at the end to complete the process.

The liquid resist material may be removed before the cutting of the head chip, but in order to prevent the intrusion of cutting water and fine powder generated by the cutting at the time of cutting, the dicing saw and the glass substrate at the time of cutting are also used. It is removed after the head chip is cut in order to prevent the internal structure destruction caused by the triboelectric charging and the electric discharge.

FIG. 12 shows 4 inch wafers 50 through 24.
This is an example in which one head chip 10 is obtained.
Each head chip 10 has a resolution of 600 [DPI] and has 384 charged particle output apertures formed of a matrix of 12 line electrodes 1 and 32 finger electrodes 2, and the head chip in the direction in which the line electrode 1 extends. The length (size in the longitudinal direction of the head chip 10) is about 16 mm. It should be noted that the numbers attached to the head chips 10 in FIG. 12 are numbers indicating the order given for convenience to distinguish the 24 head chips formed on the wafer 50.

FIG. 13 shows the charged particle output of each head chip corresponding to the position of the wafer 50. Each head chip from No. 1 (chip number # 1) to No. 24 (chip number # 24) is shown. 10 shows the results of measuring the charged particle output of each screen opening 8 when each of the 10 is driven under a constant condition by the amount of current flowing into the counter electrodes facing each other with a constant distance.

In each graph in the figure, the vertical axis represents the average charged particle output amount with the finger electrode 1 as one unit, and the horizontal axis represents the position in the direction in which the line electrode 1 extends on the wafer 50. The numbers in each graph correspond to the head chip numbers (#n, n = 1, 2, 3, ...) In FIG. Also,
The unit of the vertical axis is the chip in the center of the wafer (chip number # 1
In the output graph of each head chip 10, the broken line is “100”, the upper end is “110”, and the lower end is “90” in the output graph of each head chip 10. I am trying.

As is clear from the figure, the head chip 10 located at the center of the wafer 50 has a uniform output, but the output gradually decreases as it approaches the edge of the wafer 50.
The maximum output difference from the center is about 5%.

When the geometrical dimensions of the respective constituent elements in the head chip 10 were measured, this output difference was found to be that the thickness of the polyimide layer formed as an insulating layer at the wafer end was 0. It is known that this is due to the fact that it is formed with a thickness of about 8 microns.

With respect to the output deviation inside each head chip 10, the length of the head chip 10 in the extending direction of the line electrode 1 is set to 16 mm, so that the head located near the end of the wafer 50 is positioned. With the chip 10 as well, it was possible to suppress the amount to within 2% at maximum.

(First Specific Example) <Basic Configuration (Screen Correction, etc.)> FIG. 14 shows a first specific example according to the present invention, in which the head chip 10 having a length of 16 mm is It is a perspective view showing a part of recording head formed by connecting 13 in series.
Note that, for convenience of description, the head chips 10 will be referred to as head chips 10A, 10B, and 10C with subscripts A, B, C, ... Further, when it is necessary to distinguish the screen electrode 7 of each head chip 10, the subscripts a, b, c ...
It will be indicated as a, 7b, 7c.

In the recording head having the structure shown in FIG. 14, head chips 10A to 10C are arranged in series on a rod-shaped recording head base material 60, and each head chip 10A is arranged.
-10C of the screen electrodes 7a to 7c are arranged so that the surfaces thereof are arranged on the same plane. A line electrode connection pad 11, a finger electrode connection pad 13, and a screen electrode connection pad 12 are arranged on each of the head chips 10A to 10C, and the line electrode connection pad is 10
The same line electrodes 1 of adjacent head chips of A to 10C are connected to each other by wire bonding 14 to electrically connect the line electrodes 1 between all chip heads.

That is, each of the head chips 10A to 10C has a finger electrode pad 13 individually drawn from each finger electrode 2 to the longitudinal side edge of each head chip 10A to 10C, and the screen electrodes 7 and Connected to each head chip 10A-1
Screen electrode pad connection pad 12 drawn out to the edge portion on the longitudinal side of 0C and the respective head chips 10A to 10A.
Line electrode pads 11 are formed corresponding to each line electrode 1 at both edge portions on the shorter side of 10C.

Further, on the peripheral surface of the recording head base material 60 side,
Finger electrode pads 13b for connecting the finger electrode pads 13 drawn out to the respective longitudinal side edge portions of the head chips 10A to 10C to guide the wiring, and finger electrodes for drawing the wiring from the finger electrode pads 13b to a required position. Lead wire 13a and head chips 10A-10
A flexible substrate 15 having an electrode pad 12b for connecting the screen electrodes 7 of C and for guiding the wiring and a screen electrode lead wire 12a for guiding the wiring from the electrode pad 12b to a required position is arranged. The pads to be connected are connected by wire bonding.
The electrode pads 11 of the line electrodes are connected to the electrode pads on the flexible substrate 15 from the line electrode connecting chips located at both ends of the recording head (not shown).

The screen electrode pad 12 is provided through the screen electrode lead wire 12a on the flexible substrate 15.
b is a variable resistor 1 whose resistance value is variable in the range of 0 to 200 kΩ
It is connected to the middle point (connection point between the variable resistor 16 and the base resistor 17) of the resistance voltage dividing circuit including the base resistors 17 of 6 and 10 [MΩ]. The other end of the variable resistor 16 is connected to a -600 [V] screen power supply line 18 common to all head chips, and the other end of the base resistor 17 is connected to a zero volt GND line 19.

Therefore, the voltage supplied to the screen electrode 7 of each head chip 10 can be supplied to a different screen voltage for each head chip by adjusting the resistance value of the variable resistor 16 provided for each head chip. It becomes a composition. In this specific example, the screen electrode 7 of each head chip 10 can independently have its voltage arbitrarily set within the range of -590 [V] to -600 [V].

FIG. 15 schematically shows the structure of the power supply voltage applied to each electrode of the recording head in this example, and the element parts surrounded by broken lines are the parts mounted on the recording head. . The screen electrode 7, which is one of the parts mounted on the recording head, is connected to the screen power supply 20 via the variable resistor 16 and the base resistor 17, as described above. Finger electrode 2 is MOS-F
The voltage is −580 which is applied to the drain of the finger switching element 21 made of ET and is in the OFF state of the finger electrode 2 via the current limiting resistor 23.
The Vbb potential power supply 24 of [V] is connected.

Further, the source of the finger switching element 21 is connected to the Vf potential power source 22 of -610 [V] which is the applied voltage of the finger electrode 2 in the ON state, and the gate of the finger electrode 2 is turned on / off. It is connected to a control signal line 25 which is a supply line of a control signal for controlling the state. 1 [MHz] 1500 for generating a discharge between the line electrode 1 and the Vbb potential power supply 24
A line power supply 26 that generates a line voltage Vrf of [Vp-p] (pp indicates peak-to-peak) is connected.

Next, the voltage applied to the finger electrode 2 and its action, and the charged particle output control action by the screen voltage will be described with reference to FIG. The vertical axis of FIG. 16 represents the potential of each electrode. In the example of FIG. 16, Vsc is a standard screen voltage and is −600 [V]. Also, Vbb
Is a potential for turning off, −580 [V],
Vf is a potential for turning on, which is −610 [V] in this example.

Voltage Vsc supplied to screen electrode 7
Can be varied independently in the range of −590 [V] to −600 [V] for each head chip 10 by adjusting the resistance value of the variable resistor 16 provided for each head chip 10.

When the finger switching element 21 is turned on by the control signal, the Vf potential power source 22 is applied to the finger electrode 2, and when the finger switching element 21 is turned off by the control signal, the Vbb potential power source 24 is supplied.
(Vbb is −580 [V] in the example of FIG. 16) is applied to the finger electrode 2.

That is, by applying an AC voltage between the line electrode 1 and the finger electrode 2, a charge generated by inducing a corona discharge near the opening of the finger electrode corresponding to the matrix intersection of both electrodes. The particles are blocked by a control voltage applied between the finger electrode 2 and the screen electrode 7, or are extracted to the screen electrode 7 side and accelerated to be discharged, but the finger electrode 2 has a voltage of −580 [V]. When the Vbb potential power supply 24 is applied, the finger electrode 2 is turned off, that is, the charged particles are prevented from being emitted. That is, in the off state, the finger electrode 2 is more than the screen electrode 7 by 20.
Since the [V] positive side potential is applied, the negatively charged particles used in this example are generated by the reverse electric field between the finger and the screen (between the finger electrode 2 and the screen electrode 7). It is pulled back to the finger electrode 2 side without passing through 7. Therefore, the emission of the charged particles is blocked.

On the other hand, Vf potential power source 2 is applied to finger electrode 2.
When 2 (Vf is -610 [V] in the example of FIG. 16) is applied, the finger electrode 2 is turned on, that is, the charged particles are emitted. In the ON state, the finger electrode 2 is applied with a potential of 10 [V] on the negative side of the screen electrode 7, so that the negative charged particles generated by the discharge generate a potential difference Vd between the finger and the screen.
Can be passed through the screen electrode 7 by the forward electric field.

Here, by adjusting the voltage dividing ratio by adjusting the resistance voltage dividing circuit consisting of the variable resistor 16 and the base resistor 17 described above, the absolute value of -595 [V] which is slightly smaller than the standard screen voltage Vsc. ] Naru screen voltage V
It is assumed that sc ′ is created and applied to the screen electrode 7.

In this case, since this Vsc 'is independent of the voltage Vf for turning on, the finger-
The potential difference Vd 'between the screens is the standard screen voltage V
Finger when sc is applied to the screen electrode 7
It becomes larger than the potential difference Vd between the screens. As a result, the forward electric field between the finger and screen also increases,
Finally, the amount of charged particles emitted from the screen electrode opening 8 also increases.

At this time, since the screen voltage Vsc 'is smaller than the standard screen voltage Vsc, the electric field for accelerating the charged particles after passing through the screen electrode opening 8 is slightly reduced, but the effect of changing the amount of charged particles is small. Since the potential difference Vd between the finger and the screen when the standard screen voltage Vsc is applied to the screen electrode 7 is much larger, the influence of the acceleration electric field decrease is almost negligible.

Table 1 below shows the result of measurement of the charged particle output of this recording head by the same method as the charged particle output measurement for each head chip on the wafer shown in FIG. The total deviation of the recording head is the ratio of the difference between the maximum and minimum charged particle outputs in the recording head to the average charged particle output of the recording head. In addition, the recording head boundary deviation in the table is the amount of step difference at the boundary of the head chip 10 having the largest charged particle output step,
It is the ratio to the average charged particle output of the recording head.

[0113] The uncorrected term in the item symbol A is the result of measurement with the variable resistance of each head chip set to 0Ω.
Here, since the chip heads 10 are selected from the wafer and arranged in a completely random manner, there is a boundary where the chip at the edge of the wafer and the chip at the center of the wafer are adjacent to each other in the print head. Along with the deviation, the recording head boundary deviation is also relatively large.

The term of the chip average correction in the item symbol B is the value of the variable resistance arranged for each chip head based on the result of the measurement of the charged particle output of each uncorrected head chip of A, It shows the result of adjustment so that the average charged particle output of the chip head becomes equal (chip average correction method). The deviation of the recording head boundary along with the deviation of the entire recording head was reduced, and a uniform recording head output could be obtained.

However, since the correction is performed by the chip average correction method, a slight difference in charged particle output occurs at the head-chip boundary, which causes a step difference in the latent image level, and the level difference is recorded. It became about 1.3% of the head output.

Therefore, in order to verify to what extent such a latent image level difference of about 1.3% becomes a problem,
The charged particle outputs of all the holes of the recording head are radiated onto an electrostatic recording sheet having a conductive layer used for a so-called electrostatic plotter and a charge holding layer on the conductive layer to form an electrostatic latent image of an image of uniform density. After forming, the image developed with the liquid developer was measured by an optical reflection densitometer and examined.

As a result of scanning the developed image of uniform density with an optical reflection densitometer, the overall density uniformity was good, and the step difference (level difference) between the head chips observed in the charged particle output measurement of the recording head was observed. ), The optical density difference was less than 0.02 in terms of image density, which was a density difference that could not be detected by the naked eye.

The term C is the value of the variable resistance of the voltage dividing resistor circuit for adjusting the screen voltage arranged for each head chip based on the result of the measurement of the charged particle output of the uncorrected recording head of A. Shows the result of adjusting so that the charged particle outputs of the head chip ends are equal at the head chip boundary (chip boundary correction method).

As is clear from the numerical values in the table, the screen voltage adjustment for each head chip by this adjustment eliminates the step difference (level difference) in the charged particle output at the boundary between the adjacent head chips, resulting in a more uniform output. The characteristics can be obtained. Further, in the present invention, a plurality of head chips having similar characteristics or different characteristics, such as those obtained from the same wafer and those obtained from different wafers, are mixed in series without any selection. Electrostatic recording heads are arranged side by side in this case. In this case, although the output gradient directions inside the head chips are different from each other, the difference in characteristics is so large due to the application of thin film technology that can obtain precise processing accuracy. Not the thing, especially when looking at the charged particle output of each screen opening in one head chip,
The property is flat with no undulating fine changes. Therefore, although head chips with different characteristics are mixed, if the screen voltage is adjusted by applying the chip boundary correction method, the charged particle output level can be adjusted for each head chip, and other head chips can be easily adjusted. It can be aligned with the charged particle output level.

Therefore, when the chip boundary correction method is applied to the electrostatic recording head using a plurality of head chips to which the thin film technique is applied as in this example, the heads having different output gradient directions inside the head chips are applied. It can be seen that, by mixing the chips, the output deviation of the charged particles in the entire recording head can be greatly reduced and a long electrostatic recording head with uniform characteristics can be obtained.

The item D in Table 1 means that the head chips on the wafer shown in FIG. 13 are selectively arranged so that the internal charged particle output gradient directions of the adjacent head chips are different from each other. The value of the variable resistance of the voltage dividing resistance circuit for adjusting the screen voltage arranged for each
It shows the result of adjusting so that the charged particle outputs at the ends of the head chips become equal at the boundary of the head chips.

In this case, it is understood that not only the step (level difference) of the charged particle output amount at the boundary between the head chips is eliminated but also the charged particle output deviation of the entire recording head is reduced.

In this example, a voltage dividing resistance circuit using a variable resistor 16 and a fixed resistor (base resistor 17) is used as a structure for adjusting the voltage applied to the screen electrode 7 of each head chip. Although it was realized by adjusting the resistance value of the variable resistor 16 and changing the voltage division ratio, the resistor formed by screen printing or the like in place of the variable resistor 16 is trimmed by laser light and the resistance value is changed. It is also possible to use a so-called laser trimming resistor that changes In this case, calculate the resistance value after laser trimming from the deviation of the charged particle output amount of each head chip in the resistance value before laser trimming,
It is also possible to automatically correct the output.

As described above, in this example, a plurality of line electrodes and finger electrodes having a plurality of finger openings serving as passage holes for charged particles are arranged so as to intersect with each other through the dielectric layer, and charged particles are generated. In addition, by providing a screen electrode on the finger electrode side that controls the emission of the generated charged particles, and controlling the potential between the screen electrode and the finger electrode, the emission of the charged particles from each finger opening to the outside. The electrostatic recording element (electrostatic recording head) for controlling the insulating substrate wafer is manufactured by a thin film manufacturing process that can be processed with precision to reduce variations in the output characteristics of charged particles from each finger opening. It is formed as a small-sized head chip on the top, and a plurality of head chips are connected in series to form an electrostatic recording element having a required length. Together, each head chip has a configuration in which a screen voltage adjustment means for adjusting the screen voltage in the head chip unit, respectively.

By configuring a plurality of head chips each having a small chip size in series so as to have a required length, it becomes possible to apply the thin film technology to the production of each head chip. With the head chip using, it is possible to form a plurality of head chips at a time on an insulating substrate wafer in an appropriate head chip size unit so that the internal deviation becomes a constant value. After arranging a plurality of them in series and connecting them, the charged particle output deviation between each head chip is adjusted by adjusting the applied screen voltage in each head chip. In addition, the number of correction units is small because the adjustment is performed for each head chip, and therefore the cost of the correction circuit can be reduced. Both can correction circuit to obtain a recording head to be uniform even though the charged particle output quantity and low cost.

Further, by disposing the correction adjusting circuit on the recording head as in this example, a uniform charged particle output can be obtained without providing any additional circuit on the recording apparatus side using the recording head. Even if the recording head is worn or damaged, even if the recording head is replaced, it is possible to immediately obtain a uniform charged particle output without making any adjustment on the apparatus side.

In the above, the screen voltage can be adjusted for each head chip so that the level of the charged particle output can be made uniform for each head chip constituting the recording head. This is a technology for homogenizing properties. When the recording head is used, the level of the charged particle output tends to change depending on the position of the screen opening due to the deposition of products due to the influence of the discharge over time. The second technique to correct this is
Will be described as a specific example.

(Second Specific Example) <Correction by Finger Voltage and Time and Limitation of Finger Drive Chip> FIG. 17 shows a second specific example according to the present invention, which is similar to the first specific example shown in FIG. It also shows a part of a recording head formed by connecting 13 head chips 10 each having a width of 16 mm in series and a part of a drive circuit thereof. In the figure, the same parts as those of the first specific example are designated by the same reference numerals, and screen electrodes 7a to 7c are provided on the head chips 10A to 10C, respectively.
32 corresponding to the finger electrode 2 in the first specific example
Finger electrodes AF1, AF2, AF3, AF3
2, BF1 to BF32, CF1 to CF32 are arranged.

AF1, AF2, AF3, ... AF3
Reference numeral 2 denotes 32 finger electrodes formed on the head chip 10A, and BF1 to BF32 are head chips 10B.
32 finger electrodes formed on the
CF32 are 32 finger electrodes formed on the head chip 10C.

The screen electrodes 7a to 7c of the head chips 10A to 10C are connected to a common screen power supply line 30, and the finger electrodes are respectively connected to the head chips 10A to 10C.
Finger drive chips FDA arranged every 10 C, ~
Connected to FDC. The FDA is the head chip 10
A, FDB is for the head chip 10B, FDC is for the head chip 10C, and a shift register IC (integrated circuit element) for driving a so-called liquid crystal panel is provided for the finger drive chips FDA, to FDC. Diverted.

31 is each finger drive chip FDA, ...
This is an input that defines the on-timing of the FDC, and this input 31 has a finger enable signal 32 that is common to the head chips 10A to 10C, that is, a finger that defines the on-timing of a finger electrode that is common to the head chips 10A to 10C. The enable signal 32 is given, and the finger electrodes can be turned on / off at a timing common to all head chips.

33 is each finger drive chip FDA, ...
An input line for a signal that defines the off-state potential of the output channel of the FDC, and 34 is a V that supplies a DC Vbb voltage.
bb power supply line, 35 is each finger drive chip FDA,
The output channel of ~ FDC is an input that defines the potential of the ON state, and the Vbb power supply line 34 is connected to the input line 33 in common to each of the head chips 10A to 10C.

The input 35 is connected to the connection point between the variable resistor 36 and the base resistor 37. The variable resistor 36 and the base resistor 37 constitute a resistance voltage dividing circuit. This resistance voltage dividing circuit has the other end of the variable resistor 36 connected to the Vf power supply line 38 common to all head chips, The other end of 37 is connected to a zero volt GND line 39. Therefore, the on-state voltage of the finger electrode of each head chip can be supplied with a different on-voltage for each head chip 10A to 10C by adjusting the resistance value of the variable resistor 36 provided for each head chip 10A to 10C. Is.

The resistance value of the variable resistor 36 provided for each finger driving chip is adjusted according to the output of each chip based on the chip average correction method or the chip boundary correction method as in the first specific example. It is possible to obtain a uniform charged particle output over the entire recording head.

In this specific example, since the number of finger electrodes on the head chip and the number of output channels on the finger driving chip are the same, a finger driving chip is provided for each head chip. If the number of finger electrodes of the chip is an integral multiple of the number of output channels of the finger driving chip, V is set for each chip head unit.
It is possible to obtain a similar correction effect by providing a resistance voltage dividing circuit for the f power supply voltage and sharing the corrected voltage obtained by this circuit between the finger drive chips that drive the same chip head.

Also, by partially modifying this example, a common Vf power supply line is connected to the input for defining the on-state potential of the output channel of each finger driving chip, and the finger enable applied commonly to each finger driving chip is connected. If the ON time of the finger electrode can be adjusted between each head chip by providing a different timing generation source for each finger drive chip for each signal, the output deviation between the head chips can be corrected by the ON time of the finger electrode. Is also possible.

Further, in this case, it is possible to arbitrarily set the output deviation correction amount between the head chips according to the time when the print head is used and the environment where the print head is used.

In the head chip 10 having the structure shown in FIG. 11, the discharge product and the surrounding structural composition are sputtered on the dielectric layer 3 and the finger electrodes 2 by the discharge with the lapse of the use time. The resulting metamorphic deposits cause a gradual change in their charged particle output.

Since the change characteristic of the charged particle output changes depending on the film thickness of the dielectric layer 3 and the electrode thickness of the finger electrode 2, the output deviation of the head chip 10 is caused by the film thickness of the dielectric layer 3 and the finger electrode 2. In the case of the difference in the electrode thickness, it becomes necessary to adjust the correction amount with the lapse of the use time of the head chip 10.

FIG. 18 shows changes in the output of charged particles with the lapse of usage time in each of two types of head chips having different thicknesses of the dielectric layer 3 as the head chip 10. 3, the head chip having a film thickness of 4.5 μm and the head chip having a film thickness of 4.7 μm were connected and driven, and the output amount of the charged particles was measured. As is clear from the figure, since the head chip having the dielectric layer 3 having a thickness of 4.5 μm has a larger change amount of the charged particle output with the lapse of use time, the charged particle output deviation between the two head chips with the lapse of use time. The quantity is increasing.

In such a case, the timing source provided for each finger driving chip described above is provided with the correction amount data which changes with the use time of the print head, so that the print head has a uniform charged particle output regardless of the use time. It is possible to obtain

The correction amount data, which changes with the time of use of the recording head, is detected by the charged particle output detector provided in the image recording apparatus having the recording head of the present invention at regular intervals. However, the characteristic feature of the head chip formed by the thin film manufacturing process is that the characteristics of the charged particle output change over time are also uniform due to its uniform internal structure.

Therefore, when the difference in charged particle output of each head chip is caused by the difference in film thickness of the dielectric layer 3 or the difference in thickness of the finger electrodes 2, the amount of charged particle output for each use time can be predicted. Yes, and therefore
It is also possible to mount a storage unit that stores predicted data in advance on the recording head and perform a correction based on the data. In this case, it is possible to avoid an increase in the size and cost of the device, which is caused by providing the charged particle output detection unit in the image output device equipped with the recording head.

When the recording head of this example is used in a recording apparatus of a gradation recording system in which charged particle outputs which are different in stages for each screen opening are outputted and the dot diameter of the output image is changed stepwise. It is possible to change the charged particle output depending on the finger voltage and the finger voltage application time. In this case, assuming that the output of the charged particles is changed in a required step on the output image, for example, 32 gradations, the drive circuit sets the finger voltage or the finger voltage application time to the required step, that is, 32 gradations. In addition, a plurality of stages, for example, a stage number obtained by adding 16 stages, that is, in this example, a configuration in which a multistage change of 48 stages can be switched, and the dot diameter is changed for 32 stages of the 48 stages. This is especially used to correct the output deviation between the head chips by using the remaining 16 stages of change not used for changing the dot diameter.

As described above, when the output of the charged particles is changed in 32 steps on the output image, the drive circuit sets the finger voltage or the finger voltage application time so that it can be changed in 48 steps, and is not used for changing the dot diameter. The output deviation between the head chips is corrected by using the 16-step variation, but such a correction method can also be applied to the correction of the output nonuniformity of the recording head created by the conventional thick film manufacturing technique. It is possible.

However, in that case, since the output correction is performed for each finger electrode or each screen opening, a huge amount of correction data and a complicated correction circuit for processing the data are required. However, in the present invention, a chip head created by a thin film manufacturing technique is used,
In the case of a chip head created by this thin film manufacturing technology, there is little variation in the charged particle output characteristics from chip to chip. Therefore, if correction is performed for each chip head, the correction data and its processing circuit will be greatly simplified. It is possible to expect significant effects in cost reduction, space saving, and yield improvement.

Although the screen electrode of each head chip is connected to the common screen power supply line in this example, a screen current detection circuit is provided between the screen electrode of the head chip and the common screen power supply line. , This screen current detection circuit detects the current flowing in or out of the screen electrode of each head chip to detect the output difference between the head chips, and based on this, apply the finger voltage or finger voltage to the output between each head chip. It is also possible to correct according to time.

The screen current is generated when some of the charged particles that try to pass through the screen electrode opening are adsorbed to the screen electrode when the finger electrode is in the ON state. Therefore, the magnitude of the current value passes through the screen opening. It has a close relationship with the amount of charged particles. Therefore, a current detection circuit is provided for each head chip to detect the screen current of each head chip, or a current detection circuit common to each head chip is provided in the source part of the screen power supply line, and each head chip is sequentially driven. If the screen current is detected, it is possible to estimate the charged particle output amount of each head chip.

Therefore, it is possible to determine the correction amount of the finger voltage or the finger voltage application time by performing the required arithmetic processing using the load current output estimated value for each head chip. In this case, the chip-to-chip correction amount can be adjusted at any time simply by providing a simple circuit for detecting the screen current value, so that a uniform output can always be obtained.

The difference in the charged particle output level of each head chip is also caused by the difference in the insulating layer film thickness of each head chip. This is because the insulating layer is formed on the wafer by the spin coating method, and thus it is unavoidable that the film thickness difference occurs depending on the position on the wafer, and therefore the head chip is held in the manufacturing process and cannot be avoided. This is one of the problems. However, this problem cannot be ignored in terms of ensuring image quality, so the technique for dealing with this problem will be described next.

(Third Specific Example) A film thickness detection function is provided to correct the charged particle output level difference of each head chip caused by the difference in the insulating layer film thickness to make the charged particle output level uniform. An example will be described in which the screen voltage is automatically adjusted according to the film thickness detected thereby, so that the level difference of the charged particle output of each head chip becomes inconspicuous.

<Chip correction amount automatic setting structure 1> FIG.
9A is a plan view showing a third specific example based on the present invention, and FIG. 19B is a cross-sectional view showing a head chip constituting a recording head, and a head chip thereof. It represents a part of the drive circuit. The cross-sectional view of FIG. 19B shows the chip cross section along the broken line M on the plan view of FIG. Further, in the drawing, the same parts as those of the head chip structure shown in FIG. 11 which is used in common in the first and second specific examples will be denoted by the same reference numerals.

The head chip base material 9 made of quartz glass, which is a substrate for forming the head chip 10, the line electrode 1, the dielectric layer 3, and the finger electrode 2 are made of the same material as the example shown in FIG. 11 by the same manufacturing method. It was formed.
These line electrode 1, dielectric layer 3, finger electrode 2
In the same manner as in the example shown in FIG. 11, a large number of head chips 10 are formed by thin film technology on a disk-shaped wafer made of quartz glass having a thickness of about 1 mm, which becomes the head chip base material 9.
Will be formed at the same time.

Reference numeral 40 denotes an insulator layer, which is formed on the side surface of the dielectric layer 3 on which the finger electrodes 2 are formed so as to cover the finger electrodes 2, like the insulator layer 6 in FIG.
The holes 41 formed at the positions corresponding to the finger openings 4 are shown in FIG.
1 has a columnar shape having a diameter larger than that of the finger opening 4, whereas the hole 41 in this specific example has a mortar shape, and as it approaches the screen opening 8 side. This is a configuration in which holes having a shape such that the opening is enlarged are provided.

This insulator layer 40 is obtained by forming a 50 μm polyimide layer by spin coating. And
In this insulator layer 40, an opening for passing charged particles is formed by dry etching after forming a polyimide layer to form a hole 41, and at the same time, a film thickness detection is made in a portion near the center of the head chip where the finger electrode 2 does not exist. Hole 4
2 is provided. The film thickness detection hole 42 also has a mortar shape with an inner peripheral surface having an inclined portion 43, and has a structure in which the mouth is widened to the screen electrode 7 side like the hole 41, and is larger than the hole 41. .

At the time of dry etching of the polyimide layer, isotropic etching is performed by setting a high gas pressure in the dry etching conditions in order to form the inclined portion 43 in the film thickness detection hole 42. After filling and filling the charged particle passage opening (hole 41) and the film thickness detection hole 42 with liquid resist materials having different removal conditions, an aluminum thin film having a thickness of 2 μm is formed on the insulator layer 40 by a sputtering method. Then, a desired pattern shape including a radiation opening 8 for charged particles is formed on the aluminum thin film by etching to form a screen electrode 7.

Next, after removing the liquid resist material of the film thickness detection hole while leaving the liquid resist of the charged particle opening (hole 41), a titanium nitride (TiN) thin film having a thickness of 1 micron is formed by the sputtering method. Then, as shown in the plan view of FIG. 19A, the film thickness detection resistor 44 of the arrangement pattern reaching the screen electrode 7 portion through the inner peripheral surface of the film thickness detection hole 42 is formed by the titanium nitride thin film. It is formed by etching into a linear pattern shape.

A large number of head chips are formed on the wafer through such a process. In order to separate the head chips, dicing between the head chips is carried out, and then charged particle openings (holes) are formed. Individual head chips are completed through the liquid resist removal process of 41).

A plurality of completed head chips are connected in series to form a long recording head. When operated under the same driving conditions, a level difference in charged particle output is recognized between the head chips. . In this specific example, it has been confirmed that such a level difference in charged particle output between the head chips is caused by a difference in insulating layer film thickness between the head chips. This is because when forming the insulator layer, the wafer is rotated at high speed by spin coating,
A polyimide layer is formed and used as an insulator layer, but the speed of rotation of a disk-shaped wafer varies depending on the position on the wafer.

That is, since the peripheral speed of the disk-shaped wafer is higher in the peripheral part than in the central part and slower in the central part, the spread state of the polyimide is different between the central part and the peripheral part, which is the difference in the film thickness. The situation is different for each wafer, and by using head chips that are affected by these in a random arrangement, it is possible to avoid mixing head chips with different insulation layer thicknesses. Therefore, the charged particle output level difference cannot be avoided as it is.

Therefore, a film thickness detecting function is provided in order to correct the charged particle output level difference of each head chip caused by the difference in the insulating layer film thickness and to make the charged particle output level uniform. The screen voltage is automatically adjusted according to the film thickness.

This function is performed by the film thickness detecting hole 42, the film thickness detecting resistor 44 having a linear pattern of a titanium nitride thin film formed on the inner peripheral surface of the film thickness detecting hole 42, and each head chip. It is obtained from the base resistor 45 provided in the. The depth of the film thickness detection hole 42 is closely related to the film thickness of the insulator layer 40 in which the film thickness detection hole 42 is formed.

The film thickness detecting holes 42 are mortar-shaped so that the film thickness detecting resistors 44 in the form of a linear pattern can be easily formed on the inner surface, but all the film thickness detecting holes 42 have the same slope angle. Then, the resistance value of the film thickness detecting resistor 44 having a linear pattern shape laid on the slope reflects the film thickness of the insulating layer 40.

Further, each head chip is provided with a base resistor 45 whose one end is connected to the screen electrode 7 of the head chip, and the other end of the base resistor 45 is connected to a Vsc power supply supplying a standard screen voltage Vsc common to all chip heads. By connecting the other end of the film thickness detecting resistor 44 to the ground line GND common to all chip heads, a resistance component for the standard screen voltage Vsc by the base resistor 45 and the film thickness detecting resistor 44 is provided for each head chip. Since a voltage circuit is formed and the standard screen voltage Vsc is divided through this resistance voltage dividing circuit and is supplied to the screen electrode 7 as a film thickness corresponding corrected screen voltage Vsc ′, the insulator layer The corrected screen voltage Vsc ′ can be supplied to the screen electrode 7 in such a manner that the correction corresponding to the film thickness of 40 is automatically performed. A configuration that can be.

That is, in this specific example, the film thickness detecting resistor 44 of each head chip forms a resistance voltage dividing circuit together with the base resistor 45 provided for each head chip, and contacts the screen electrode of the film thickness detecting resistor. One end of the base electrode is connected to a power supply that supplies a standard screen voltage Vsc common to all chip heads, and one end of the base electrode is connected to a zero volt GND common to all chip heads. In the configuration described above, Vsc is divided by the resistance voltage dividing circuit according to (4) and applied to the screen electrode, and when the thickness of the insulating layer of the head chip is large, the inclined portion 4 of the film thickness detection unit is used.
3 is extended, and the value of the film thickness detection resistance is correspondingly increased.
When the value of the film thickness detection resistance is large, the value of the corrected screen voltage Vsc 'generated by being divided by the resistance voltage dividing circuit decreases and the charged particle output increases.

Originally, when the film thickness of the insulating layer is large, the electric field formed between the screen electrode 7 and the finger electrode 2 when the finger electrode 2 is turned on is reduced, so that the charged particle output output from the screen opening is also reduced. Although it decreases, the charged particle output is corrected in the direction in which the film thickness detection resistance increases as described above, and as a result, the charged particle output of each head chip is corrected by the chip average correction method. It is possible to automatically correct the thickness.

As described above, in this example, the level difference of the charged particle output is related to the film thickness of the insulating layer 40 that determines the distance between the finger electrode 2 for extracting / accelerating the charged particles and the screen electrode 7. Based on this, the film thickness detection hole 42 is provided outside the finger opening arrangement area of the insulator layer 40 so that the screen voltage applied to the screen electrode 7 is automatically corrected in accordance with the film thickness of the insulator layer 40. Thickness detection hole 4
A resistance wire (film thickness detection resistance) is formed in a linear pattern, one end of which passes through the inner peripheral surface of 2 to the screen electrode, and this is grounded, and the screen electrode is connected via a base resistance having a predetermined resistance value. A base resistance reaching the screen voltage source was formed, and a screen voltage was applied by a resistance voltage dividing circuit composed of a linear pattern resistance wire (film thickness detection resistance) and the base resistance.

The film-thickness detection resistor has a structure in which it reaches the screen electrode through the inner peripheral surface of the film-thickness detection hole 42, the resistance value thereof is related to the wiring distance, and the wiring distance is the thickness of the insulating layer 40. Since this is reflected, the screen voltage divided by the resistance voltage dividing circuit line by the film thickness detection resistance and the base resistance and applied to the screen electrode is a voltage adjusted corresponding to the film thickness of the insulator layer. Therefore, the level difference of the charged particle output due to the different thickness of the insulator layer is eliminated as a result of the screen voltage being automatically corrected corresponding to the thickness.

In this example, since the insulator film thickness in the central portion of the head chip is almost equal to the average insulator film thickness of the entire head chip, the film thickness detecting section is installed in the center of each head chip and the chip average correction method is used. Although the output deviation between chips was corrected by the above, the film thickness detection unit was placed near both ends of the head chip, and the film thickness of the insulating layer at each end of each head chip was detected and calculated to calculate the screen voltage and finger-on for each head chip. Correction by the chip boundary correction method can also be performed by adjusting the voltage, the finger-on time, and the like.

Further, in this example, since the output deviation between head chips is caused by the deviation of the insulating layer film thickness, the film thickness detecting portion is arranged in the insulating layer. However, the output deviation of the head chip is the dielectric layer film. In the case of the thickness deviation, by arranging a film thickness detection unit of the same form in the dielectric layer, it becomes possible to automatically correct the output deviation between the head chips.

As described above, according to this example, the correction amount can be automatically determined by the film thickness detection unit without performing the measurement of the charged particle output of the head chip and the adjustment of the correction amount based on the measurement result. The steps required for measurement, adjustment of the correction amount, etc. are not required, and the cost of the recording head and the output device using the recording head can be reduced.

Next, another example will be described.

(Fourth Concrete Example) <Chip Correction Amount Automatic Setting Structure (2)> FIG. 20 shows a fourth concrete example according to the present invention, which shows the film thickness detecting portion of the third concrete example. It is a figure for demonstrating a different form.
The steps up to the step of forming the finger electrodes 2 are formed in the same manner as the third specific example. Then, in the opening 50 for passing charged particles,
Filled and filled with polyimide resin using the printing method,
A resin containing carbon is linearly printed on the film thickness detection unit 51 so as to traverse through the film thickness detection unit 51 and is fired to form the resistance element 52. A silicon oxide film is formed.

Next, after the entire surface of the wafer is flattened by chemical mechanical polishing, an aluminum thin film having a thickness of 2 μm is formed by the sputtering method, and a desired pattern shape including the radiation opening 8 for charged particles is formed by etching. To form the screen electrode 7. The resistance element 52
The lead wire 53 patterned at the time of forming the finger electrode 2 is connected to the finger electrode surface side, and the lead wire 54 patterned at the time of forming the screen electrode 2 is connected to the screen electrode surface side of the resistance element 52. A film thickness detecting portion having a current passage path equal to the film thickness is formed. The polyimide resin filled in the openings 50 is removed by ashing after forming the openings 8 on the screen electrode.

The resistance element 52 thus formed has a current passing path length equal to the film thickness of the insulator layer.
The resistance value increases and decreases as the thickness of the insulator layer increases and decreases. Therefore, the resistance element 52 is arranged at the center or both ends of each head chip, and is used as a part of a circuit for correcting the charged particle output deviation between the head chips by the chip average correction method or the chip boundary correction method. Alternatively, it is used as substitute data for the charged particle output of the head chip (that is, correction data for the time for outputting the charged particles).

In this example, since the resistance element having the same current passage as the thickness of the insulator layer can be formed, it is possible to obtain the resistance element output that more accurately reflects the thickness of the insulator layer. . Therefore, it was confirmed that automatic correction is possible even in a long recording head formed by connecting head chips obtained from two or more wafers.

If a dielectric is used instead of the resistance element 52 of this example, it is possible to form a capacitance element whose capacitance value changes according to the thickness of the insulator layer. .
In this case, in particular, if a capacitance element using the dielectric layer itself as a dielectric is formed in a dielectric layer having a smaller thickness than the insulating layer, the capacitance increases and the difference in the film thickness can be detected more. Easier to do.

As described above, according to this example, the correction amount can be automatically determined by the film thickness detection unit without performing the charged particle output measurement of the head chip and the adjustment of the correction amount based on the measurement result. The steps required for output measurement and adjustment of the correction amount are unnecessary, and the cost of the print head and the output device using the print head can be reduced.

In the above, the correction of the charged particle output, which changes depending on the film thickness of the insulator film, is carried out by using the structure capable of directly reflecting the film thickness of the insulator film on the resistance value or the like. However, a configuration in which correction is performed by monitoring the charged particle output is also conceivable. An example will be described below.

(Fifth Specific Example) <Monitoring of Charged Particle Output by In-Chip Charged Particle Strength Detection Unit> In this specific example, a dummy line electrode, a dummy finger electrode for monitoring the charged particle output on the head chip,
A dummy charged particle output unit consisting of a dummy screen electrode and a detection unit for detecting charged particles output from this dummy charged particle output unit are formed, and the screen voltage or finger of each head chip is determined according to this detection output. The voltage and finger voltage application time are adjusted to correct the output level variation.

FIG. 21A shows a fifth specific example of the present invention. FIG. 21A is a plan view showing a part of a head chip constituting a recording head, and FIG. 21B is a sectional view thereof. is there. Here, the head chip 10 is divided into a charged particle output portion P and a charged particle output detection portion Q by a broken line O, and the configuration and forming method of the charged particle output portion P are the same as those in the third specific example.

The structure and method of forming the charged particle output detector Q will be described below. After the dummy line electrode 60 is formed simultaneously with the line electrode of the charged particle output unit, the dielectric layer 3 is formed.
Are formed in common for the charged particle output unit and the charged particle detection unit. The dummy finger electrode 61 is simultaneously formed so as to have the same opening shape as the finger electrode 2 of the charged particle output portion, and then an insulator layer is formed so as to have the charged particle passage opening 62 of the same shape as the charged particle output portion.

Furthermore, when forming the screen electrode 7 of the charged particle output portion P, the minute opening 64 and the charged particle detection electrode 6 are formed.
A dummy screen electrode 66 having 5 is formed. In addition,
Charged particle passage opening 6 in the insulator layer before forming the screen electrode
The liquid resist material filled in 2 is removed from the minute openings 64 after each head chip is separated from the wafer by dicing.

Here, the dummy line electrode 60 and the dummy finger electrode 61 are applied with a voltage having the same potential and frequency as those of the line electrode 1 and the finger electrode 7 of the charged particle output portion P, and the dummy screen electrode 66 is not shown. A charged particle output detection circuit is connected.

The charged particle output detection unit Q has exactly the same structure, material and forming process as the charged particle output unit P except for the dummy screen electrode 66. Therefore, the amount of charges generated around the dummy finger electrode 61 is the same. Is the same as the generated charge amount of the charged particle output portion P.

Therefore, the charged particle output current obtained by the charges generated around the dummy finger electrode 61 flowing into the dummy screen electrode 66 through the opening of the insulating layer having a constant thickness is the charged particle output detection unit. The output amount of the charged particle output portion P around Q is reflected.

Therefore, by adjusting the screen voltage, the finger voltage, and the finger voltage application time of each head chip based on the detection data obtained from the charged particle output detection circuit, it is possible to correct the output between the head chips. Even if the balance of the charged particle output deviation between the head chips changes due to changes over time or usage conditions, it is possible to correct this at any time and always obtain a uniform charged particle output characteristic. .

Further, when the present recording head is used for an output printer of a printing proofing system or the like, it is necessary to keep the amount of charged particle output from the recording head constant at all times. It is also possible to make the output amount of charged particles of the head chip uniform to a constant value.

Although the location of the charged particle output detector Q on the head chip is not specified in this example, it is arranged near the center of the chip head to perform the correction by the chip average correction method. Alternatively, it is also possible to arrange them at both ends of the chip head and perform the correction by the chip boundary correction method.

The dummy line electrode 60 and the dummy finger electrode 61 of the charged particle output detection unit Q are connected to any line electrode 1 and finger electrode 2 of the charged particle output unit P in the head chip to drive them simultaneously. For example, the drive circuit can be simplified.

Although various specific examples have been described above, the present invention includes the following configurations.

[1] A plurality of line electrodes 1 extending in the longitudinal direction and a plurality of finger electrodes 2 extending in a direction intersecting with the plurality of line electrodes 1 are formed on the elongated base 9. , Are arranged in a matrix so as to face each other with the dielectric layer 3 interposed therebetween, and the finger electrodes 2 are provided with openings 4 for generating charged particles at corresponding portions of the matrix intersections, and with an insulating layer 6 interposed therebetween. A screen electrode 7 is formed facing these finger electrodes 2, and openings 5 and 8 are formed in the screen electrode 7 and the insulating layers 6 and 40 at positions corresponding to the respective openings of the finger electrodes. Electrostatic recording head chip 10 in which openings 5 and 6 and 40 reach at least finger electrode positions
A base material 60 for arraying and supporting a plurality of the electrostatic recording head chips 10 in series; and a control means for controlling the amount of charged particles generated for each electrostatic recording head chip. To do.

According to this structure, since a plurality of electrostatic recording head chips 10 are arranged in series to form an electrostatic recording head, it is necessary to prepare a small size electrostatic recording head chip. Therefore, the electrostatic recording head chip can be manufactured by applying the thin film technology, which is a semiconductor manufacturing technology capable of maintaining the processing accuracy. Therefore, each electrostatic recording head chip is The generated amount of charged particles of the electrostatic recording head chips is almost balanced, and the difference in the generated amount of charged particles between the adjacent electrostatic recording head chips in a state where a plurality of electrostatic recording head chips are arranged is controlled by the control means. By adjusting each electrostatic recording head chip, it is possible to control the distribution state of the amount of generated charged particles in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high quality print can be obtained.

[2] In the structure of the above item [1], the control means controls the screen voltage applied to the screen electrode. Further, the control means controls the on-state potential of the finger electrodes. Further, it is characterized in that the control means controls the thickness of the insulating layers 6 and 40 and controls the finger electrodes or screen electrodes based on the measurement result. Further, the control means controls so that the average amount of charged particles generated in each head chip is the same.

The amount of charged particles generated in the electrostatic recording head chip can be adjusted by the relationship between the voltage applied to the finger electrodes and the screen voltage applied to the screen electrodes. Since the electrostatic recording head chip is manufactured by using the thin film technology in the present invention, each of the electrostatic recording head chips has a substantially balanced generation amount of charged particles in the head chip. The screen voltage of each electrostatic recording head chip is adjusted by the control means for the difference in the amount of charged particles generated between the adjacent electrostatic recording head chips in the state where a plurality of electrostatic recording head chips are arranged. If adjusted in a form, it is possible to control the distribution state of the generated amount of charged particles in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained. Further, the control means has means for measuring the thickness of the insulating layers 6 and 40, and the finger voltage or screen voltage is controlled based on the measurement result, so that adjustment corresponding to the thickness of the insulating layer is performed. A finger voltage or screen voltage can be applied to the finger electrodes or screen electrodes. Therefore, it is possible to control the distribution state of the generated amount of charged particles in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained. Further, since the control means controls so that the average amount of generated charged particles in each head chip is the same, the distribution state of the amount of generated charged particles in the entire electrostatic recording head can be controlled to be substantially uniform. . Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained.

[3] A plurality of line electrodes, a plurality of finger electrodes arranged in a direction intersecting with the line electrodes, and charged particles emitted from the line electrodes and the finger electrodes which are arranged on the charged particle output side. An electrostatic recording head chip 10 having a screen electrode to be controlled, a base material 60 for holding a plurality of the electrostatic recording head chips 10 arranged in series, and the electrostatic recording head chip in the base material 60. A line 1 of a screen power supply which is provided in the vicinity of the holding position, forms a lead line for each finger electrode, and extends in a direction parallel to the head chip arrangement direction.
8 and the ground line 19, and each electrostatic recording head chip for dividing the voltage of the screen power supply line 18 and the ground line 19 in the flexible board and applying it as a screen voltage to the screen electrode lead line. It is characterized in that corresponding voltage dividing means 16 and 17 are provided. This configuration corresponds to the configuration shown in FIG.

According to this structure, the voltage between the screen power supply line 18 and the ground line 19 causes the screen electrode of the corresponding electrostatic recording head chip to pass through the voltage dividing means 16 and 17 corresponding to each electrostatic recording head chip. And the charged particle output at the electrostatic recording head chip is adjusted to correspond to the screen voltage. Since the screen voltage of the electrostatic recording head chip can be adjusted appropriately by adjusting the voltage division ratio of the voltage dividing means 16 and 17 corresponding to the electrostatic recording head chip, the screen voltage of each electrostatic recording head chip is appropriately adjusted. The distribution state of the generated amount of charged particles in the entire electrostatic recording head can be controlled to be substantially uniform by adjusting Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high-quality print can be obtained.

[4] The electrostatic recording head has a plurality of linear or strip line electrodes 1 extending in the longitudinal direction and a plurality of lines extending in a direction intersecting with the linear electrodes 9 on the elongated substrate 9. -Shaped or strip-shaped finger electrodes 2 are arranged in a matrix so as to face each other with a dielectric layer 3 in between, and openings 4 for generating charged particles are formed at the corresponding points of the matrix intersections of the finger electrodes. A screen electrode 7 having a plurality of openings 8 corresponding to the respective openings is provided so as to face the finger electrodes through the insulating layer 6 to form a charged particle control unit, and the surface of the recording member is provided through the openings of the screen electrodes. Electrostatic recording head chip that irradiates charged particles to
A plurality of units are connected in series to form an electrostatic recording head arranged on one base material 10, and ion amount control means for controlling the amount of generated ions (generated amount of charged particles) is individually provided for each head chip. It has a different configuration. Then, the average value of the charged particle output of each head chip is corrected to be equal to each other (chip average correction method).

[5] Further, in the configuration of the item [4], the correction is performed so that the charged particle outputs at the connection boundaries between the head chips become equal to each other (chip boundary correction method).

[6] In addition, in the configuration of the item [4],
The electrostatic recording head is configured by mixing head chips having different in-chip output inclination directions in the direction in which the line electrodes of the electrostatic recording head chip extend (in-chip output gradient).

[7] Also, in the configuration of the item [4],
The in-chip output inclination directions in the extending directions of the line electrodes of the adjacent head chips on the recording head are different from each other.

According to the configurations of the above items [4] to [7], a plurality of electrostatic recording head chips 10 are arranged in series to constitute an electrostatic recording head. It suffices to prepare a head chip having a small size. Therefore, the electrostatic recording head chip can be manufactured by applying a thin film technology which is a semiconductor manufacturing technology capable of maintaining processing accuracy. One by one, the generated amount of charged particles in the head chip is almost balanced, and the generated amount of charged particles between adjacent electrostatic recording head chips when a plurality of electrostatic recording head chips are arranged side by side. If the difference is adjusted for each electrostatic recording head chip by the control means, it is possible to control the distribution state of the charged particle generation amount in the entire electrostatic recording head to be substantially uniform. Therefore, it is possible to provide the electrostatic recording head in which the distribution state of the generated amount of charged particles is uniform and the high quality print can be obtained. Then, by the control means,
Since it is possible to adjust the amount of charged particles generated for each electrostatic recording head chip, it is possible to mix head chips having different in-chip output inclination directions in the direction in which the line electrodes of the electrostatic recording head chip extend, and electrostatically mix them. It is now possible to configure the recording head, and to avoid the problem when using electrostatic thin film technology to fabricate a plurality of electrostatic recording head chips on a wafer and to separate them into chip units. The difference in charged particle output characteristics for each chip, which cannot be achieved, is adjusted by the control means so that they can be used in parallel, and even if multiple chips are connected in series, the total charge It is possible to provide an electrostatic recording head having a uniform particle generation amount distribution and capable of obtaining a high-quality print.

[8] In the configuration of the above item [4], whether the number of fingers per one chip of the electrostatic recording head chip is equal to the number of channels per one finger drive element for controlling the finger voltage of the recording head, Alternatively, it is characterized by being an integral multiple of the number of channels (finger voltage correction circuit structure). With this configuration, it is possible to reduce the number of finger drive elements that perform finger voltage control, reduce the system cost, and save space.

[9] In the configuration of the above item [4], when adjusting the charged particle output of the electrostatic recording head chip, correction is performed so as to reduce the output deviation between the electrostatic recording head chips, and the correction amount. Is changed with the use time of the recording head (time correction of chip correction amount).

The electrostatic recording head chip may deteriorate and the charged particle output may change with the lapse of use time. However, in this case, the output deviation between the electrostatic recording head chips gradually changes. It is possible to provide an electrostatic recording head which can be controlled so as to be small, and in which the distribution state of the entire generated amount of charged particles is always uniform and high quality prints can be obtained.

[10] In the configuration of the above item [4],
A drive control circuit that gradually changes the output amount of charged particles from each screen hole (opening of the screen electrode) of the recording head by a predetermined number of steps, and an electrostatic discharge using a part of the predetermined number of output change steps. The feature is that the correction between the recording head chips is performed. When this electrostatic recording head is used for recording in the gradation recording method in which the charged particle output is changed stepwise for each screen opening and the dot diameter of the output image is changed stepwise, the charged particle output is used as the finger voltage. Or the finger voltage application time, the drive circuit changes the finger voltage or the finger voltage application time to the required step when the output of the charged particles is changed by the required step (required gradation) on the output image. In addition, a multi-step change switching configuration for the number of steps is added to this, and the output deviation between head chips is corrected using the change for the number of steps not used for changing the dot diameter. For example, the output of charged particles is 32 on the output image.
When changing in stages, the driving circuit sets the finger voltage or finger voltage application time so that it can be changed in 48 stages. Then, out of the 48 steps, the output deviation between the head chips is corrected by using an extra 12 steps of change not used for changing the dot diameter. Such a correction method can also be applied to the correction of the output nonuniformity of the recording head created by the conventional thick film manufacturing technique, but in that case, the output correction is performed for each finger electrode or each screen opening. Therefore, a huge amount of correction data and a complicated correction circuit for processing the data are required. However, as in the present invention, a chip head made by a thin film manufacturing technique is used and each chip head is used. If correction is performed for each, correction data and its processing circuit can be greatly simplified, and significant effects can be expected in cost reduction, space saving, and yield improvement.

[11] In the configuration of the above [4],
By a resistance element or a capacitance element formed in the dielectric layer or the insulating layer so as to have a resistance value or a capacitance value depending on at least one of the dielectric layer and the insulating layer in the electrostatic recording head chip. It is characterized in that it has a film thickness detection element and is used for correction of the screen voltage or finger voltage or finger voltage application time (correction amount automatic setting structure). According to this structure, the dielectric layer or the insulating layer is formed to have a resistance value or a capacitance value according to at least one of the dielectric layer and the insulating layer in the electrostatic recording head chip. There is a film thickness detection element including a resistance element or a capacitance element. Since this element provides a resistance value or electrostatic capacitance value that reflects the film thickness, by adopting a configuration that corrects the screen voltage or finger voltage or finger voltage application time corresponding to this value, each electrostatic recording It becomes possible to correct the difference in the charged particle output between the individual electrostatic recording head chips due to the variation in the thickness of the dielectric layer or the insulating layer between the head chips.

[12] In the structure of the above [11], the film thickness detecting element is provided in the dielectric film or the insulating layer of the head chip, at least a part of which has a through hole having an inclined surface, and on the inclined surface. It is characterized in that it is composed of a resistor arranged.

[13] In the structure of the above [11], the film thickness detecting element is constituted by a through hole provided in the dielectric film or the insulating layer of the head chip and a resistor arranged in the through hole. (Specific structure 2 of the resistance element).

[14] In the structure of the above [11], the film thickness detecting element is composed of a through hole provided in the dielectric film or the insulating layer of the head chip and a dielectric material arranged in the through hole. (Specific structure of the capacitance element).

According to the above-mentioned constitutions [12] to [14], when the angle of the inclined surface is constant, the length of the resistor arranged on the inclined surface is the dielectric film or the insulation of the head chip. It is closely related to the layer thickness. Therefore, the dielectric film or insulating layer of the head chip is formed with a through hole having an inclined surface at least at a part thereof, and the line of the resistor is formed on the inclined surface to reduce the film thickness of the dielectric film or insulating layer. A reflected film thickness detecting element can be built in, and a head chip having a film thickness detecting element can be easily manufactured.

[15] In the configuration of the above item [4],
A line particle in the head chip, a dielectric layer, a finger electrode, the same material as the insulating layer, respectively, the electrode formed by the manufacturing method and a charged particle output detection unit consisting of a film layer and holes are arranged on each head chip, Either the voltage applied to the screen electrode or the voltage applied to the finger electrode or the application time of the voltage applied to the finger electrode, which is the charged particle output deviation between the head chips based on the amount of charged particles output from the charged particle output detection unit. It is characterized by the correction (a chip with a built-in charged particle output detection unit).

According to this structure, the charged particle output detection unit including the same material as the line electrode, the dielectric layer, the finger electrode, and the insulating layer in the head chip, the electrode formed by the same manufacturing method, the film layer, and the hole is formed. It is included in the head chip. Therefore, the charged particles generated in the charged particle output detection unit have the same generation conditions as the charged particles generated by the line electrode and the finger electrode in the head chip, and the charged particle output monitor is used for the charged particle output detection unit. It can be done with output. Therefore, the applied time of the voltage applied to the screen electrode or the voltage applied to the finger electrode or the voltage applied to the finger electrode is based on the amount of charged particles output from the charged particle output detection unit. Can be controlled so as to reduce the output deviation between the electrostatic recording head chips, and the output between the electrostatic recording head chips that gradually deteriorates with the progress of use time. It is possible to provide an electrostatic recording head in which the deviation can be controlled so as to be small, the distribution state of the entire amount of charged particles generated is always uniform, and high-quality prints can be obtained.

[16] In the configuration of the above item [4],
A screen current detection unit that detects a current flowing through a screen electrode of the electrostatic recording head chip; and a correction between electrostatic recording head chips based on a current value detected by the screen current detection unit. Yes (correction by screen current detection).

Part of the charged particles generated in each opening by the line electrode and the finger electrode flow into the screen electrode. Therefore, if the current flowing through the screen electrode is detected, the situation of the generated charged particles can be grasped,
If the current flowing through the screen electrode is detected by the screen current detection unit and the correction between the electrostatic recording head chips is performed based on the detected current value, the output deviation between the electrostatic recording head chips will be reduced. Can be controlled to reduce
Also, it is possible to control to reduce the output deviation between the electrostatic recording head chips, which gradually deteriorates with the lapse of usage time, and the distribution state of the entire charged particle generation is uniform at all times. It is possible to provide an electrostatic recording head capable of obtaining a print of.

The present invention is not limited to the above-mentioned specific examples, but can be implemented in various modified forms.

[0219]

As described above, according to the present invention, the following effects can be obtained.

(1) A plurality of head chips formed in a thin film structure by a semiconductor manufacturing method are connected to form one recording head, and the output deviation between the head chips is determined by either screen voltage or finger voltage or finger voltage application time. By making the correction by the above, it is possible to provide an electrostatic recording head which can simplify the circuit structure required for the correction and can obtain a uniform charged particle output over the entire length of the recording head.

(2) By arranging and correcting the in-chip output inclination directions in the extending direction of the line electrodes of the adjacent head chips on the recording head so as to be different from each other, both long-term and short-term cycles are made uniform. It is possible to provide an electrostatic recording head that provides a charged particle output.

(3) An element having a resistance value which differs depending on the film thickness of at least a dielectric layer or an insulating layer in the head chip is provided in the chip, and this resistance element is part of a screen voltage or finger voltage adjusting circuit. It is possible to perform the correction automatically without measuring the charged particle deviation amount between the head chips and adjusting the correction amount.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the present invention and is a partial cross-sectional view showing an example of a chip structure of an electrostatic recording head of the present invention.

FIG. 2 is a diagram for explaining the present invention and a diagram for explaining a manufacturing process as a technique which is a basis of the present invention.

FIG. 3 is a diagram for explaining the present invention and a diagram for explaining a manufacturing process as a technique which is a basis of the present invention.

FIG. 4 is a diagram for explaining the present invention and a diagram for explaining a manufacturing process as a technique which is a basis of the present invention.

FIG. 5 is a diagram for explaining the present invention and a diagram for explaining a manufacturing process as a technique which is a basis of the present invention.

FIG. 6 is a diagram for explaining the present invention and a diagram for explaining a manufacturing process as a technique which is a basis of the present invention.

FIG. 7 is a diagram for explaining the present invention, and schematically shows an example of charged particle output of a recording head in which a plurality of head chips of the present invention are arranged in series.

FIG. 8 is a diagram for explaining the present invention and a diagram for explaining an example of output deviation correction between head chips applied to the present invention.

FIG. 9 is a diagram for explaining the present invention, which is a diagram for explaining the influence of the internal charged particle output gradient of the head chip.

FIG. 10 is a diagram showing a configuration of a head chip used in the first and second specific examples of the present invention, and is a perspective view showing a part of each member of the head chip by cutting away.

FIG. 11 is a diagram for explaining the present invention, which is a cross-sectional view in the direction in which the finger electrodes 2 of the head chip 10 of the present invention extend.

FIG. 12 is a view for explaining the present invention and is a plan view showing an example of the arrangement of head chips on a wafer when 24 electrostatic recording head chips are obtained from a 4-inch wafer.

13 is a diagram for explaining the present invention, and FIG.
5 is a diagram showing an example of charged particle output characteristics depending on the position of each head chip on the wafer shown in FIG.

FIG. 14 is a diagram for explaining the present invention and is a perspective view showing a configuration example of a first specific example of the present invention.

FIG. 15 is a diagram for explaining the present invention, which is a diagram schematically illustrating a configuration of a power supply voltage applied to each electrode of the recording head.

16 is a diagram for explaining the present invention, which is a diagram for explaining a voltage applied to the finger electrodes 2 and its action, and a charged particle output control action by a screen voltage. FIG.

FIG. 17 is a diagram for explaining the present invention, showing a part of the recording head and a part of its drive circuit in the second example of the present invention.

FIG. 18 is a diagram for explaining the present invention, which is a change in charged particle output with the passage of use time in each of two types of head chips having different dielectric layer 3 thicknesses as head chips 10. The figure showing the situation.

FIG. 19 is a diagram for explaining the present invention, which is a plan view and a cross-sectional view showing a third specific example of the present invention, and is a diagram showing a part of a head chip and its drive circuit.

FIG. 20 shows a fourth specific example of the present invention, and is a diagram for explaining a different form of the film thickness detection section shown in the third specific example.

FIG. 21 is a diagram for explaining a fifth specific example of the present invention, and is a plan view and a cross-sectional view showing a part of a head chip.

FIG. 22 is a diagram showing a configuration example of a wet image recording apparatus using an electrostatic recording head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Line electrode 2 ... Finger electrode 3 ... Dielectric layer 4 ... Finger opening 5 ... Hole 6 ... Insulator layer 7, 7a, -7c ... Screen electrode 8 ... Screen opening 9 ... Head chip base material 10, 10A,- 10C ... Head chip 11 ... Line electrode connection pad 12 ... Finger electrode connection pad 13 ... Screen electrode connection pad 14 ... Wire bonding 16 ... Variable resistor 17 ... Base resistance 19 ... GND line 20 ... Screen power supply 21 ... Finger switching element 22 ... Vf potential power supply 23 ... Current limiting resistance 24 ... Vbb potential power supply 25 ... Control signal line 26 ... Line power supply 50 ... Wafer 60 ... Base material 60 ... Dummy line electrode 61 ... Dummy finger electrode 66 ... Dummy screen electrode P ... Charged particle output unit Q ... Charged particle output detector.

Claims (3)

[Claims] 1. A dielectric layer comprising a plurality of line electrodes extending in the longitudinal direction and a plurality of finger electrodes extending in a direction intersecting with the plurality of line electrodes on an elongated substrate. The electrodes are arranged in a matrix so as to face each other, and the finger electrodes are provided with openings for generating charged particles at the corresponding portions of the matrix intersections,
An electrostatic recording head chip in which a screen electrode is formed to face these finger electrodes via an insulating layer, and openings are formed in the screen electrode and the insulating layer at positions corresponding to the openings of the finger electrodes. A base material for arraying and supporting a plurality of the electrostatic recording head chips in series, and a control means for controlling the amount of charged particles generated for each electrostatic recording head chip. Electrostatic recording head. 2. The electrostatic recording head according to claim 1, wherein the control means controls a screen voltage applied to the screen electrode. 3. An electrostatic recording head chip having a plurality of line electrodes, a plurality of finger electrodes arranged in a direction intersecting with the line electrodes, and a uniform screen electrode arranged on the charged particle output side of these finger electrodes. A base material for holding a plurality of the electrostatic recording head chips arranged in series, and a lead wire for each of the finger electrodes provided near the holding position of the electrostatic recording head chip on the base material. And a flexible board on which a screen power supply line and a ground line extending in a direction parallel to the head chip arrangement direction are formed, and a voltage of the screen power supply line and the ground line of the flexible board is divided to extract the screen electrode. Provided corresponding to each electrostatic recording head chip to apply as screen voltage to the line An electrostatic recording head characterized by comprising: