JPS623965A - Multi-gradation electrostatic recorder - Google Patents

Abstract

PURPOSE:To obtain an electrostatic latent image on an electrostatic recording material through conversion of gradation information into a picture element diameter, by a system wherein a variable bias voltage in a direction for hindering a corona ion flow passing through an opening is impressed between the first and the second controlling electrode, and the bias voltage is regulated based on gradation information of a recording signal. CONSTITUTION:A bias power source 12 is connected to an ion flow recording head 21 so as to maintain a back electrode 9 at a positive potential relative to the first controlling electrode 6, and a negative bias voltage for partially hindering a corona ion flow from passing through the opening 23 is impressed on the second controlling electrode 24. In gradation controlling recording, the bias voltage can be controlled in correspondence with the recording signal. Namely, when a bias power source 28 with a low voltage is selected, an image consisting of picture elements with an appropriate dot diameter corresponding to a picture element density is obtained, whereas when a bias power source 29 with a high voltage is selected, the corona ion flow through the opening 33 is restricted, and an electrostatic latent image with a dot diameter smaller than the picture element pitch is formed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a multi-tone electrostatic recording device, specifically an electrostatic recording member configured by providing a dielectric layer on a conductive support L. The present invention relates to an ion flow recording head that forms an electrostatic latent image by flying a corona ion stream.

[Prior Art] An electrostatic latent image is formed by applying an image-like electrostatic charge directly to a dielectric layer provided on a drum, and this latent image is developed with toner, and the developed toner image is There are various electrostatic recording devices that are well known to create hard copies by transferring images onto recording paper, some examples of which are NIKKEL, ELE, etc.
,CTR,,0NIC81982,7,5 No. 127~
It is also introduced on page 144.

A recording head that forms an electrostatic latent image on a dielectric drum using an ion flow system can form an electrostatic latent image without contacting the dielectric layer, and is also capable of high-speed recording.・It is extremely convenient for configuring a highly reliable recording device.

Next, it was also introduced in the above literature, and USP 4.365
, No. 549, etc., the configuration and recording principle of the ion flow recording head will be explained with reference to FIG. FIG. 7 is a cross-sectional view showing the configuration of a unit recording element 1 of an ion flow recording head, on which a discharge electrode 3 is arranged on one surface of an insulating plate 2 made of Mylar or the like. A discharge electrode 4 having an opening 4a is disposed on the other surface,
This discharge electrode 4 is connected to a control electrode 6 which has an opening 13a through a spacer 5 having an opening 5a made of an insulating phase.
are placed facing each other. The recording head configured in this manner is placed close to and facing the tram-shaped electrostatic recording member. This electrostatic recording member 7 is constructed by providing a dielectric recording layer 8 on the surface of a back electrode 9.

A high voltage high frequency AC power source 10 is provided between the discharge electrodes 3 and 4.
A bias power supply 12 is also connected between the control electrode 6 and the back electrode 9. Recording signal voltage is discharge electrode 4
is applied to the input terminal 11 connected to the control electrode 6 and the discharge electrode 4 to change the potential difference between the control electrode 6 and the discharge electrode 4.

The discharge electrode 4 is notched at the center to form an opening 4a, and when a high-voltage, high-frequency AC voltage is applied between the discharge electrodes 3 and 4, an AC corona discharge occurs around the edge of the notch. Occurs continuously. The control electrode 6 is kept at a negative potential 11'/(for example, -4O0V) with respect to the back electrode 9, and the discharge electrode 4 is always kept at a positive potential (
For example, it is maintained at -500V). The recording signal 14 is applied as a pulsed voltage (for example, -600V) so that it has a negative potential with respect to the potential of the discharge electrode 4 or the potential of the control electrode 6. Therefore, when this recording signal 14 is not applied, an electric field is formed that causes corona ions to flow from the discharge electrode 4 to the control electrode 6.
Since the electric field between the back electrode 9 and the rear electrode 9 is in the direction of stopping the movement of the corona ions (2), no charges reach the dielectric recording layer 8.

Next, when the recording signal 14 is applied and the potential of the discharge electrode 4 becomes more negative than the potential of the control electrode 6, the corona ions of ○ move toward the control electrode, and further from the control electrode 6 to the back electrode 9.
Dielectric recording layer 8-1=
Negative corona ions fly away.

The charges reaching the dielectric recording layer 8 form an electrostatic latent image having a diameter approximately equal to the size of the opening 13 of the control electrode 6.

In order to perform high-speed, high-pixel-density recording, an ion flow recording head is constructed by assembling a large number of unit recording elements whose cross-sectional structure is shown in Figure 7 above, but the recording head is processed. In order to simplify the process, it is preferable to adopt a configuration in which the elements are arranged two-dimensionally as shown in FIG. ．． 3
No. 65,549, Pig 5.

That is, the electrode groups Yl, Y2, . . . constitute the discharge electrode 3, and the electrode groups X1, . X2... constitutes the discharge electrode 4, and the intersection of both addressed electrodes becomes the recording position. Another advantage of this two-dimensional array is that the drive circuit can be greatly simplified by dividing the elements into groups indicated by X and Y in a matrix and performing matrix drive for the X and Y groups. There is also.

However, despite these improvements, it is not easy to manufacture a recording head with a sufficiently high-density element array, and the element density that can be achieved with realistic processing accuracy is about 300 (dots/inch). 'The size of the recording head constituting one pixel is as large as 150 microns, for example.

For example, when the pixel arrangement pitch is 300 (dots/inch), the pixel size is about 85 microns, for example, 15
If it is too large, such as 0 microns, various problems will occur. One of these is that because the pixels are large, the pixels overlap each other multiple times, and the level of resolution expected from the pixel density cannot usually be obtained. Another drawback is that there is a large difference in image density between an image formed by a single pixel and an image formed by a group of pixels, and as a result, good recording cannot be performed using a single pixel. Figure 9 is a diagram illustrating the latter problem. Figure 9 (A) shows an image area where pixels are clustered, and pixels are doubled to quadruple in the same area. They overlap. Therefore, the electric potential of the electrostatic latent image in the area where the images overlap is on average several times higher than that in the independent pixel area formed by a single pixel as shown in FIG. 9(C). . In addition, the electric field of the electrostatic latent image formed by the ion flow is distorted as the latent image potential increases, and an electric field is formed that diffuses the ion flow that flows later, causing the recorded dot to expand. The image expands where the dots overlap. FIG. 9(B) shows a line-shaped image with −pixel width, but in this case, compared to the image in FIG. 9(C)! The average charge amount per 11th area is about 1.5 to 1.8 times.

Normally, when recording character images, etc., the area of the first part of the image is formed by grouped pixels as shown in FIG. The amount of ion flight is set to prevent abnormal weight gain. Then, in areas where the pixel overlap effect is small or where there is no effect as shown in Figures 9(B) and (C), the potential of the electrostatic latent image is as shown in Figure 9(A). As a result, the potential is reduced to a fraction of the appropriate potential range, and the image is not developed to a normal density, resulting in an image with extremely low density, or in a state where it is not developed as an image.

Therefore, the opening 1 of the control electrode 6 of the ion flow recording head
3 could be made even smaller, but it would be difficult to process the head, and if foreign matter adhered to the area around the aperture or there was a shape defect in the aperture, the recording would be more affected by this. This is difficult to realize because it will easily cause unevenness.

[Problems to be Solved by the Invention] Incidentally, in an electrostatic recording device using an ion flow recording head as described above, there is a demand for forming a multi-tone image by adjusting the image density. There is a way to respond to this demand by changing the latent image potential, but in that case, the characteristics of the charge retention member and the developer must be highly stable, and this is not sufficient for practical use. The problem is that it is not possible to obtain sufficient stability. For this reason, methods have been put into practical use to express gradations by assembling multiple pixels to form a matrix and changing the number of black pixels in a unit area, but this method complicates signal processing and also increases the complexity of gradation expression. This method has the disadvantage that high-definition recording cannot be performed because the matrix size becomes large.

The present invention was made with attention to these points, and it is possible to reduce the size of recording pixel dots without reducing the electrode aperture diameter of the ion flow recording head, and to achieve a size commensurate with the pixel density. It is possible to obtain recording pixel dots of 1,000 pixels, and record independent pixel dots, thin lines, etc. in a good and stable manner.
It is an object of the present invention to provide a multi-gradation electrostatic recording device having an ion flow recording head having a function of controlling the pixel dot diameter.

[Means for Solving the Problems] In this device, as the concept of the present invention is shown in FIG. 1, an insulating plate 2 has a discharge electrode 3 on one surface and an opening 4a on the other surface. Discharge electrodes 4 are respectively provided, and a control electrode 6 having an opening 13 is placed between the discharge electrode 4 having the opening 4a and a spacer 5 made of an insulating material having an opening 5a. In an electrostatic recording device having an ion flow recording head that is integrally connected to the ion flow recording head, the ion flow recording head further includes an insulating material spacer 25 having an opening 25a and a second control electrode 24 having an opening 23. , each opening 25a is formed on the first control electrode 6.
, 23. The recording head is constructed by arranging the recording heads such that the first and second recording heads coincide with each other. A variable bias voltage in the direction of blocking the flow of corona ions passing through the aperture was applied between the second control electrodes 6 and 24, and the bias voltage was adjusted based on the gradation information of the recorded image signal. Therefore, the diameter of the corona ion flow passing through the aperture of the recording head changes according to the gradation information of the recording signal. You can get the image.

[Function] FIG. 1 is a cross-sectional view of the basic structure of the single recording element 21 of the ion flow recording head in the multi-gradation electrostatic recording apparatus of the present invention, and its basic operation is explained below. To explain, the bias voltage applied between the control electrodes 6 and 24 by the bias power supply 26 is applied such that an electric field is formed at the periphery of the aperture in a direction that partially stops the ion flow attempting to pass through the aperture. be done. Furthermore, a voltage of opposite polarity to the bias voltage applied to the back electrode 9 by the bias power supply 12 based on the control electrode 6 is applied to the second control electrode 24 . The bias voltage applied to the back electrode 9 serves to form an electric field 11 that causes a flow of corona ions from the opening to the electrostatic recording member. In the configuration shown in FIG. 1, corona ions marked with ○ are used for image formation, so the bias power supply 12 is connected to maintain the back electrode 9 at a positive potential when viewed from the first control electrode 6. A negative bias voltage is applied to the second control electrode 24 from a power source 26 so as to partially prevent the corona ion flow from passing through the opening 23. Incidentally, when the corona ions (2) are used for recording, the connection polarities of the bias power supplies 12 and 26 are reversed.

The state of the electric field formed around the openings 13.25a and 23 when the control electrode 6.24 and each bias power supply are connected is shown by thin lines.

Thin lines a, b, c, and d mainly indicate the equipotential surfaces of the electric field formed by connecting the bias power supply 26 to the control electrodes 6 and 24, and the equipotential surfaces are the openings 13.25.
a, it protrudes into the inside of 23 in a ring shape so as to narrow the opening diameter. As you get closer to the center of the opening, the influence of the electric field created by the bias power supply 26 decreases, and the discharge electrode 3,
4. The specific gravity of the electric field formed by the space charge generated by the voltage applied to the back electrode 9 etc. and the distribution of corona ions in the space surrounded by the spacer 5 or near the opening increases. Therefore, although the electric field situation is complex and changes over time, at least when a recording signal pulse is applied from the recording signal circuit 27 and recording is being performed, the direction in which the corona ions are moved from the discharge electrode toward the back electrode is 1
A directional potential gradient state is created. The electric field at the center of the aperture becomes a concave lens-shaped electric field as the voltage value of the bias power supply 26 increases, and the ion flow at the inner periphery of the corona ion flow from the discharge electrode toward the control electrode is affected by the bias power supply as shown by the thin line j. 26, it is attracted by lines of electric force created around the opening of the control electrode 6 and flows into the control electrode 6. On the other hand, openings 13', '25'a'
, In the center of 2'3, the electric lines of force perpendicular to the concave lens-shaped isoelectric lines are barrel-shaped, as shown by the thin line, and the ion flow can pass through the aperture, but as the amount decreases, At the same time, the ion flow diameter remains narrowed and reaches the surface of the electrostatic recording member. Note that the electric lines of force i are at the opening 1'3. '25
a'.

The lines of electric force formed at the periphery of the inside of 23 are formed in a direction that pushes the corona ion flow in the opposite direction, indicating that the effect of narrowing the corona ion flow also occurs in this part. ing. As the voltage value of the bias power supply 26' is increased, the effect of the electric field to stop the passage of the corona ion flow is increased by the opening 13.25a.

23, the effect of confining the corona ion flow becomes even stronger, and the dot diameter of the formed electrostatic latent image becomes smaller, but the charge density per unit area does not decrease.

Figures 2 (A), (B), and (C) schematically explain the situation in which various types of image recording are performed by forming an electrostatic latent image with a dot diameter that matches the pixel density and density using the recording head. This is a diagram. FIG. 2(A) shows the case where an image with a wide area is formed, and as is clear from the above-mentioned FIG. 9(A), the overlapping portion of pixels is significantly reduced. Compared to the case of single pixel recording shown in ('C), the charge density per unit area is suppressed to a low increase rate of about 1.2 to 1.3 times. Therefore, since the conditions suitable for developing the independent pixels in FIG. 2(C) and the conditions suitable for developing the aggregated pixels in FIG. 2(A) are almost the same, the aggregated pixel image (
When the electrostatic latent image potential and development conditions are set such that the image shown in FIG. 2(A) is well formed, a single pixel (see FIG. 2(C)) is also developed well and a stable recording is obtained. It is obvious that a line-shaped image with a width of one pixel (Fig. 2 (B)) is formed under conditions intermediate between the two, and a sufficiently good image can be obtained as well.In this way, the electrostatic latent image By narrowing down and optimizing the pixel diameter, the latent image potential of the medium pixel and the latent image potential of the aggregated pixel can be made substantially equal. The effect of being able to form high-definition images by simultaneously eliminating the negative effects of lower resolution depending on the system is an added bonus.Moreover, in order to achieve this effect, the processing accuracy of the recording head must be increased to achieve high definition. Instead, the structure of the head has been improved so that it can be easily realized using practical processing methods.

The ion flow recording head according to the present invention basically has a function of narrowing down the ion flow diameter so that an image with a pixel diameter appropriate for the pixel arrangement density can be formed. As described above, by using this function of narrowing down the diameter of the ion flow, it can be used as a gradation control means for performing more diverse image expressions.

[Embodiment] FIG. 3 shows an embodiment in which gradation control recording is performed using the ion flow recording head according to the present invention. In this embodiment, the differences from the recording head structure shown in FIG. 1 above are as follows. Second control electrode6.
The bias voltage applied between 24 and 24 is configured to be adjustable in accordance with the recording signal. In the figure, the bias voltage adjustment circuit is shown as a schematic circuit using a DC power supply 28, 29 having two different voltage values and a changeover switch 30, but in reality it is a variable voltage circuit using a semiconductor. It is now configured. This recording head has two signal receiving ends. One of them is an input terminal that accepts image pattern information, ie, the recording signal circuit 27, and the other is an input terminal that accepts image density information, ie, the switch 30. Therefore, the recorded image information is divided into pattern information and density information and input to the recording head. The means for manually inputting the recorded image information is configured as shown in a block circuit diagram, for example. This circuit diagram shows an example of a circuit that generates a signal to be applied to a recording head from a recording original signal such as a character signal.

The recording original signal 40 is a signal in the form of a code that does not directly indicate the shape of an image, such as a character signal, but it also has information regarding density. From this original signal, a signal specifying the density is extracted by a density command circuit 41, and is also input to a pattern generator circuit 42 such as a photo generator, which extracts a specified pattern signal, and edits them to generate a time-series image signal. generated by the circuit 43. Since the recording head of this embodiment has a configuration in which the recording elements are two-dimensionally arranged in a 7-trix shape as shown in FIG. 8, the pattern signal is converted by the matrix conversion circuit 44. Then apply it to the recording head. At this time, since the image density information is also subjected to matrix conversion, the image density information is converted in a matrix conversion circuit and extracted separately from the pattern recording signal. The pattern signal and density signal are converted into a signal state that can be applied to the recording head by corresponding output circuits 45 and 46, and are applied to the recording head.

In this embodiment, two bias power supplies 28 and 29 are prepared to selectively apply a low bias voltage and a high bias voltage between the control electrodes 6 and 24. 13.25a, 23 (Hereinafter, these three openings 13°25a, 23 will be collectively referred to as 3.
The smaller the voltage value, the weaker the effect is. Furthermore, when the bias power supply 28 with a low voltage value is selected, as explained in FIG. The setting is such that a pixel-based image of about 100% is obtained.

On the other hand, when the bias power supply 29 with a high voltage value is selected,
The corona ion flow system passing through the aperture 33 is further narrowed down to form an electrostatic latent image with a diameter smaller than the pixel pitch.

The state of image formation using small diameter dots is shown in FIG.

As shown in FIG. 4(A), in the solid portion, the image becomes a collection of discontinuous small-diameter dots, and the average density decreases significantly due to the reflection of the white portions interposed between the black dots, resulting in a gray image. A line image consisting of a series of single pixels is recorded as a thin line as shown in FIG. 4(B), and is recorded as a thin line as shown in FIG.
This is a record that can be distinguished from the line with the thickness of a marker shown in .

Conventionally, with laser beam printers, etc., in order to make characters and information in a specific area of a recorded page stand out, characters are printed in a manner that overlaps with a halftone band, and halftone is used for graphic recording. There was a need to be able to express images with different densities than normal character prints, such as filling in text or printing regular format parts with thin lines or halftones. In contrast, conventional laser beam printers, etc.
For printers that can only change the pixel dot diameter, black dots are thinned out to form a pattern matrix in which white and black pixels repeat in a specific combination.
I was trying to express the sound of a futone. Therefore, it is necessary to prepare a specific pattern in the pattern generator in advance, and when expressing low density, the minimum pixel expression is performed in units of 7 trix sizes,
It has been difficult to express low-density images of complex structures such as characters.

However, according to the present invention, as is clear from FIG. 4, it is possible to form a low-density image without reducing the pixel density. It is possible to increase the power of the city and increase the means of image expression. In addition, when expressing low density, it is possible to lower the potential of the electrostatic latent image by keeping the dot diameter the same (for example, by shortening the printing pulse width), but in that case, it is possible to Since it utilizes analog characteristics of density changes, it is susceptible to various fluctuations and the recording characteristics are unstable.In contrast, in the present invention, the recording dot diameter mainly changes, and the latent image potential changes little. Therefore, stable gradation expression can be achieved by utilizing the saturated region of development characteristics.

Also, is it appropriate for the switch 30 that changes the pixel dot diameter in the embodiment shown in FIG. 3 to configure a switching circuit using a semiconductor element to increase speed?
If the capacitance between the control electrodes 6 and 24 becomes large, it becomes difficult to obtain a high-speed response. Therefore, especially the bias power supply 28
．． 29, switching elements, etc. must have low internal impedance, which has the disadvantage of increasing the size of the circuit. To eliminate this problem, the control electrode 6
, 24 is appropriate, and for this purpose, it is preferable to divide one of the electrodes into small areas and use the small area divided electrodes for scanning during recording. FIG. 5 shows a specific example of a recording head constructed of segmented electrodes. In this specific example, the control electrode 24 in FIG. 3 is replaced with a plurality of electrodes 34a, 34b,
...-20 = 34n, and lead wires 35a, :35b, .

37b...37n, respectively. Note that the reference numeral 33 indicates an opening for corona ions to pass through. A scan switching circuit (not shown) is connected to the electrodes 37a to 37n via connectors, and the electrodes 37a to 37n are connected to the bias voltage changeover switch 30 via the circuit. Furthermore, the unit of division of the divided electrodes 34a to 34n is made to match the unit of division by Xl, X2, . . . , Xo of the matrix circuit shown in FIG. When addressing, it is necessary to select and drive the electrodes 34b in accordance with each other.

In addition, in the specific example of FIG. 5, for convenience of explanation, the electrodes 34a to
The portion 34n is shown significantly enlarged from its actual size, and the lead wires 35a to 35n and the connector terminal 36 are not enlarged much. Further, in the above embodiment, the selection of gradations is made into two stages, which corresponds to the multi-stage adjustment level of the bias voltage, and allows a large number of gradations to be expressed in 11 functions.

Furthermore, in the manual embodiment, in order to arbitrarily perform recording at different gradations, the ion flow recording head is operated by separately providing a pattern recording signal input terminal and a density control wholesale signal input terminal. It was made into a head'+M composition. However, separating recorded image information into pattern information and density information and handling them separately is called signal processing. It is not necessarily advantageous to make u>It. Usually, an image signal having gradation information often has density information together with a pattern signal, such as corresponding to the image density (e.g., a peak value or pulse width).

In the ion flow recording head according to the present invention, the voltage applied between the two control electrodes is devised, and by adding the recording image signal to the bias voltage, it is possible to stabilize the signal with density information in the peak value and to obtain a multilevel signal. This makes it possible to record images in different colors.

FIG. 6 shows a second embodiment of the present invention which performs the above multi-tone image recording.
This shows an example. In this embodiment as well, the mechanical structure of the single recording element in the ion flow recording head is similar to that of the embodiment shown in FIG. This second embodiment differs from the first embodiment (see FIG. 3) in the way the bias voltage is applied and the recording signal application means.

That is, in the figure, a fixed bias power supply 47 is connected between the discharge electrode 4 and the first control electrode 6, and a bias power supply 48 and a recording signal are connected between the first control electrode 6 and the second control electrode 24. The circuit 49 is connected in series. When assembling recording elements to form a recording head with a 7-trix configuration,
Electrode 1 in FIG. 8 above! Equivalent to ¥Y,,Y2...! The configuration of iY is constructed by dividing the discharge electrodes 3 or 4 into an electrode group Xl.

The structure of the prince corresponding to to perform matrix drive.

Similarly to FIG. 7, AC corona discharge is generated by the high-voltage, high-frequency AC power source 10 in the discharge electrode portions corresponding to the Y group selected by the matrix drive circuit. The bias power supply 47 serves to move polar ions applied to the recording of generated AC corona ions, such as ○ ions, in the direction of the aperture 33, and this action is similar to that shown in FIGS. 1, 3, and 7. In the sixth example, the process is configured to be performed selectively in accordance with the image signal for each pixel, or in this embodiment, the process is performed non-selectively and fixedly. control electrode 6,
24 is either XI shown in FIG.

The groups flt (r7) corresponding to X2 are sequentially addressed by the switching scanning circuit.

Between the first and second control electrodes 6.24, an electric field is normally formed in the aperture 33 by the bias power supply 48 to completely block the passage of the corona ion flow used for recording. , bias voltage is applied. ○
When corona ions are used for recording, the second control electrode 24 is kept at a negative and sufficiently high potential with respect to the first control electrode 6 to completely block the passage of the ion flow. The recording signal circuit 49 generates a signal voltage having a polarity opposite to that of the bias power supply 48, thereby canceling out the effect of blocking the ion flow due to the bias voltage. If the voltage generated at this time is sufficiently high, the ion path opens wide and an electrostatic latent image with a large diameter is formed. Also, when a low voltage signal is generated from the signal circuit 49, the power supply 48
The effect of the bias voltage is partially canceled out, and a narrow ion flow path is formed in the center of the aperture 33, forming a small-diameter electrostatic latent image. Therefore, as the voltage value generated from the signal circuit 49 changes continuously, the diameter of the electrostatic latent image formed also changes continuously, making it possible to perform gradation recording.

In this way, the gradation recording of this embodiment is similar to halftone dot expression in printing in that the dot diameter changes to express gradation, and it is not easily affected by development conditions or changes in latent image potential. It has the feature of realizing stable gradation recording.

In this embodiment, the recording signal circuit 49 generates a gradation signal, but it is extremely easy to generate an on-off binary signal and operate it as a binary recording head.

[Effects of the Invention] As detailed above, the present invention changes the diameter of the corona ion flow in the ion flow recording head according to the gradation information, and expresses the gradation by changing the latent image pixel diameter. Gradation expression can be performed without reducing density, and stable gradation recording can be performed without being affected much by fluctuations in various parameters of image formation. Therefore, it is possible to provide a multi-gradation electrostatic recording device having an ion flow recording head that smoothly controls the gradation.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of the configuration of an ion flow recording head showing the concept of the present invention, and FIGS. 2 (A), (B), and (C) are diagrams showing the relationship between pixel arrangement pitch and pixel size. Fig. 2(A) shows an image formed by a set of pixels, Fig. 2(B) shows a line-shaped image with -pixel width, and Fig. 2(C) shows an image formed by a single pixel. are shown respectively. FIG. 3 is an enlarged sectional view of an ion flow recording head in a multi-gradation electrostatic recording device showing the first embodiment of the present invention, and FIG. FIG. 5 is a diagram showing the relationship with the pixel size; FIG. 5 is a plan view showing an example of the structure of the divided electrodes in the ion flow recording head; FIG. FIG. 7 is an enlarged sectional view of an ion flow recording head in an electrographic recording device. FIG. 7 is an enlarged sectional view showing an example of a conventional ion flow recording head. FIG. 8 is an enlarged sectional view of an ion flow recording head in which electrodes are arranged two-dimensionally. Diagram showing an example of the arrangement of cases, FIG. 9 (A)
(B) and (C) are diagrams showing the relationship between the pixel arrangement pitch and the pixel size. 1.21...Ion flow recording head (unit recording element)

Claims (1)

[Scope of Claims] A discharge electrode provided on one surface of an insulating layer, a discharge electrode provided on the other surface and having an opening, a spacer made of an insulating material and having an opening, and a control electrode having an opening. An ion flow recording head constructed by integrating the apertures in this order so as to overlap each other in this order is placed facing an electrostatic recording member comprising a dielectric layer on a conductive support, and a high voltage is applied between the two discharge electrodes. A high-frequency AC voltage is applied to generate AC corona ions, and based on the potential difference formed between the discharge electrode, control electrode, and conductive support, the corona ion flow is caused to fly on the dielectric layer to form an electrostatic latent image. In an electrostatic recording device, the above-mentioned ion flow recording head is added to the same head, and a spacer having an opening made of an insulating material and a second spacer having an opening are provided.
control electrodes are arranged over the first control electrode so that each opening coincides with the control electrode, and a corona ion flow passing through the opening between the first and second control electrodes is blocked. 1. A multi-gradation electrostatic recording device, characterized in that a variable direction bias voltage source is connected, and the bias voltage is adjusted based on gradation information of a recording image signal.