JPS62176854A - Electrostatic recording system - Google Patents

Abstract

PURPOSE:To make it possible to record a stable image having no fog, by connecting a high voltage AC voltage source insulated from earth between a recording electrode and an opposed electrode and connecting a recording signal source between the recording electrode and a rear electrode to form an ionic current. CONSTITUTION:When high AC voltage is applied to between a recording electrode 1 and an opposed electrode 2, an electric field is concentrated to the recording electrode 1 because of the needle shape of said electrode 1 and the electrode 1 performs discharge at every half cycle of AC voltage to generate positive and negative ions. At this time, when signal pulse voltage is applied to between the recording electrode 1 and a rear electrode 4 from signal source 7, the ions generated in the vicinity of the recording electrode 1 advance toward the rear electrode 4 as an ionic current to form an electrostatic latent image on the dielectric 5 arranged on the rear electrode 4. At this time, when positive voltage is applied to the recording electrode 1, a positive ionic current is generated and, when negative voltage is applied, a negative ionic current is generated and, therefore, either positive or negative electrostatic latent image can be formed on the dielectric 5 depending on a purpose.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrostatic recording method capable of obtaining stable images free of white spots and fog.

[Conventional technology]

Conventionally, ions generated in the air by electric discharge are modulated by a control electrode provided with a minute aperture or slit and extracted onto a dielectric material to form an electrostatic latent image, and then the electrostatic latent image is developed. Various electrostatic recording methods for obtaining visible images have been proposed. However, such an electrostatic recording method has the drawback that dust and toner clog the minute openings or slits and cannot be easily removed, and white areas tend to produce images.

As a method to eliminate this drawback, a configuration in which the discharge electrode and the control electrode are arranged on the same plane, for example, a so-called multi-stylus electrode, can be considered. A concrete proposal for such a configuration is made in Japanese Patent Publication No. 40-25953. The electrostatic recording method described in this publication places a recording electrode needle and an ion generation electrode needle close to each other, and applies a signal voltage to the recording electrode needle and an alternating current voltage to the ion generation electrode needle. In this way, an electrostatic latent image is formed by the ion flow on the recording medium placed on the back electrode. According to this electrostatic recording method, the recording head surface consisting of the recording electrode needle and the ion generation electrode needle can be made flat, so that it is difficult for dust to adhere, and even if it does, it can be easily removed. be able to.

[Problem that the invention seeks to solve]

However, studies by the present inventors have revealed that the electrostatic recording method disclosed in the above-mentioned publication has the following drawbacks.

- That is, according to the electrostatic recording method disclosed in the above-mentioned publication, there is a drawback that the background of the recorded image is easily fogged. The cause of this is that one end of the AC power supply connected to the ion generation electrode needle is grounded, which causes corona discharge between the back electrode or recording medium and the ion generation electrode needle. found.

One way to eliminate this fog is to float the back electrode and the recording medium above the ground, but if this configuration is used, charges will accumulate on the back electrode and the recording medium due to frictional charges, etc., so it will not be stable. Records are difficult to obtain. Also, since a conductive layer is usually provided on the back side of the recording medium, the entire path of the recording medium must be insulated from ground.
Therefore, as described above, the method of floating the back electrode and the recording medium above the ground has a problem in that it is extremely difficult to design.

The present invention was made in order to solve the above-mentioned problems in the conventional electrostatic recording method, and it reduces the occurrence of white spots in images due to adhesion of dust, etc., and allows stable image recording without fogging. The purpose of this invention is to provide an electrostatic recording method that can be obtained.

[Means and operations for solving the problems] Next, the principle of the present invention for solving the above problems will be explained. FIG. 1 is a conceptual diagram for explaining the present invention in detail.

In the figure, l is a needle-shaped recording electrode, and 2 is the recording electrode l.
This is a counter electrode with a larger cross-sectional shape. These recording electrodes 1 and counter electrodes 2 are embedded in an insulator 3 such that the end faces of both electrodes 1.2 are exposed on one end plane of the insulator 3. Reference numeral 4 denotes a back electrode disposed facing and spaced from the recording electrode 1 and the counter electrode 2, and 5 is a dielectric material disposed on the back electrode 4. A high-voltage AC power supply 6 isolated from the ground is connected between the recording electrode 1 and the counter electrode 2.
A recording signal source 7 is connected between the recording electrode 1 and the back electrode 4.

In the electrostatic recording device configured as described above, when a high-voltage AC voltage is applied between the recording electrode l and the counter electrode 2, the electric field is concentrated because the recording electrode l is needle-shaped, and the AC voltage is It discharges every half cycle and generates positive or negative ions. At this time, a signal source 7 is placed between the recording electrode l and the back electrode 4.
When a signal pulse voltage is applied from the recording electrode 1 , ions generated near the recording electrode 1 become an ion current and travel toward the back electrode 4 . Then, an electrostatic latent image is formed on the dielectric 5 disposed on the back electrode 4. At this time, the recording electrode l
Applying a positive voltage to the dielectric 5 produces a positive ion flow, while applying a single voltage produces a negative ion flow.
Either a positive or negative electrostatic latent image can be formed thereon depending on the purpose.

Note that in the above conceptual diagram, the recording electrode and the counter electrode are arranged so as to be exposed on one end plane of the insulator, but both electrodes are arranged not only on the mathematical plane of the insulator, but also on A similar effect can be achieved even if the back electrode is exposed on a smooth curved surface with a shape corresponding to the curvature of the dielectric drum constituting the back electrode, and such a configuration is also applicable to the present invention. It is included.

As described above, in the present invention, one end of a needle-shaped recording electrode and a counter electrode are arranged on the same smooth surface to prevent white spots due to adhesion of dust, and furthermore, there is a ground connection between the recording electrode and the counter electrode. An insulated high-voltage AC voltage source is connected, and a recording signal source is connected between the recording electrode and the back electrode to form an ion flow, making it possible to record images stably without fogging. It becomes possible.

〔Example〕

Examples of the present invention will be described below. FIG. 2 shows an electrostatic recording system used for carrying out the electrostatic recording method according to the present invention.
It is a figure which shows the example of a structure of 'fl. In the figure, 10 is a dielectric drum rotating in the direction of the arrow;
The recording head 11 equipped with an ion flow generator is configured to project an ion flow modulated in accordance with an image signal to be recorded in a dot shape to form an electrostatic latent image. This electrostatic latent image on the dielectric drum 10 is developed by a developing device 12 to form a toner image. This toner image is placed below the conveyance path of the recording paper, and is transferred onto the recording paper by the pressure of a pressure transfer roller 13 that rotates in accordance with the rotation of the dielectric drum 10, and is fixed at the same time. The pressure transfer roller 13 is pressed against the dielectric drum IO by a spring and a cam with a large pressure of, for example, about 1 ton.

Toner remaining on the dielectric drum 10 without being transferred to the recording paper by the pressure transfer roller 13 is removed by a toner removing device ff14 equipped with a cleaning blade. The dielectric drum 13 is further freed of static charge by a static eliminator 15, and is prepared for the formation of a new static charge image by the recording head 11.

On the other hand, the recording paper 16 is stacked and stored in a paper feed tray 17, separated one by one by a separation roller 18, conveyed to the transfer section by a paper feed roller 19, and then transferred to a pressure transfer roller 13 as described above. The toner image is transferred and fixed. The recording sheets on which the toner images have been transferred and fixed are sequentially stacked on a paper ejection tray 21 by a paper ejection roller 20.

Note that 1 and negative electrostatic charge images are formed on the dielectric drum,
When developing this with two color toners of different polarities and transferring it to recording paper, if an electrostatic transfer method is used, a charging device is required to make the toner image the same polarity before transfer. When a pressure transfer fixing method is used as in this configuration example, such a means is not required and a simple mechanism can be achieved.

Further, in this configuration example, the recording head 11 is configured to be able to be freely inserted and removed in the axial direction of the dielectric drum 10 along a guide rail (not shown). The electrode surface rubs against the cleaning member, and dust adhering to the electrode surface is easily removed.

FIG. 3 is a plan view showing the structure of the electrode section of the recording head 11 used in the electrostatic recording apparatus shown in FIG.

Two rows of needle-like recording electrodes 31-+ and 3L-x are arranged in a staggered manner on a substrate 30 made of an insulator.

......, 31-bl, 3l-bz, ...
..., 1g 2 rows of recording electrodes 31-□, 31-*,
......, 31-bl, 3l-bz.

Counter electrodes 3 arranged parallel to and on both sides of...
2-a+ 31 are provided so that each electrode end surface is exposed. and each recording electrode 31-+.

3l--t, 3l-bl, 31-
bs, . . . and the counter electrodes 32-, 32-b are made of nickel to prevent deterioration due to discharge.

Each recording electrode 31-1, 31-1. arranged in two rows. ...
. . . and 31b+, 3l-it, . . . are arranged at intervals of t I = 100 μm, respectively,
Spacing between two rows of recording electrodes1. is also set to <100 μm.

In addition, each recording electrode 31-7.31-g arranged in two rows,
...and 31-0.3l-bx, ...
. . and each counter electrode 32-. .

The distance t with respect to 32-5 is set to 200 μm.

FIG. 4 is a diagram showing a high-voltage AC voltage waveform and a recording signal waveform applied to the recording head shown in FIG. 3. 33-
, are recording electrodes 31-a++ 31-t, 31-s,...
...31-1 and the counter electrode 32-, a high-voltage AC voltage waveform applied between, for example, a peak-to-peak value of 2
600V.

The configuration is such that an AC voltage having a frequency of IMllz is applied for 6 ps at intervals of 1 m.

34-1.34-z, 34-s, 34
−, , are the dielectric drum serving as the back electrode and each recording electrode 3
1-□, 3l-az+3l--s,・・・・・・・・・
31-, . This is a recording signal waveform in which a recording signal pulse voltage is generated in synchronization with the pulse voltage of the high-voltage AC voltage waveform 33-1.

A pulse voltage of 400 VDC is applied to the image portion, and no recording signal voltage is applied to the non-image portion.

331 are recording electrodes 31-bl, 31-! , 3l-bz,
. . . 31-t, - is a high-voltage AC voltage waveform applied between - and the counter electrode 32-1, and the high-voltage AC voltage waveform 33-
The AC pulse voltage is shifted by 500 from the AC pulse voltage of 1, and is configured to generate an AC pulse voltage of a similar value. 34-
,,.

34-bz-34-bs, 34-1.
The dielectric drum and each recording electrode 31-b+, 31-L
□, 31-bz, 31-,.

This is a recording signal waveform in which a recording No. 13 pulse voltage is generated in synchronization with the pulse voltage of the high-voltage AC voltage waveform 33-5.

The quality of each dot image formed by applying the No. 13 recording pulse voltage to each recording electrode of the recording head is determined not only by the voltage value of the recording signal pulse voltage but also by the distance between the recording head and the dielectric drum serving as the back electrode. It also varies greatly.

Table 1 Table 1 shows data showing changes in the diameter of the dot image obtained on the recording paper when the recording signal pulse voltage and the distance between the recording head and the dielectric drum were changed.

As can be seen from this table, the dot diameter increases as the recording signal pulse voltage increases. On the other hand, if the distance between the head and the drum is increased, the dot diameter becomes smaller and the image density becomes lower. If the distance is made even smaller than 200μm, will it be an image? It is believed that a high-quality dot image with a high yield and a small dot diameter can be obtained, but due to mechanical precision, the distance between the recording head and the dielectric drum is limited to 200 um. In the above configuration example, the head-drum distance is set to 200 μm, and the recording signal pulse voltage is set to 400V.

(Effects of the Invention) As explained above in the conceptual diagram of the present invention and the electrostatic recording device used for implementing the present invention, according to the present invention, the needle-shaped recording electrode and the counter electrode are formed on the smooth surface of the insulator. Since there are no openings or slits, there is less risk of dust adhesion, and it is possible to prevent white spots in the recorded image.In addition, the high-voltage alternating current connected between the recording electrode and the counter electrode is Since the power supply is not grounded and the recording signal source is connected between the recording electrode and the back electrode to form an ion flow, stable image recording can be performed without fogging.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram for explaining the present invention in detail, and FIG.
The figure shows an example of the configuration of an electrostatic recording device used to carry out the electrostatic recording method according to the present invention, FIG. 3 is a plan view showing the electrode section of the recording head, and FIG. It is a figure which shows the high-voltage AC voltage waveform and recording signal waveform to apply. In the figure, l is a needle-shaped recording electrode, 2 is a counter electrode, 3 is an insulator, 4 is a back electrode, 5 is a dielectric, 6 is a high voltage AC power supply,
7 indicates a recording signal source. Patent applicant Olympus Optical Industry Co., Ltd. 1: Acicular recording electrode 2: Counter electrode 3: Insulator 4: Back electrode 5: Dielectric 6: High voltage AC power source 7: Recording signal source 4 Figure 33-b-111 →−−−

Claims (1)

[Claims] A needle-shaped recording electrode and a counter electrode are placed apart from each other so that one end of each is exposed on the smooth surface of an insulator, and an AC power supply insulated from earth is connected between the recording electrode and the counter electrode. , characterized in that a recording signal voltage is applied between the recording electrode and a back electrode disposed close to the recording electrode to generate an ion flow between the recording electrode and the back electrode. Electrostatic recording method.