JPH0422703B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides an electrostatic latent image that forms an electrostatic latent image on the dielectric by providing a pin-shaped electrode facing the dielectric surface and applying a voltage to the pin electrode. This invention relates to an image recording device.

Conventionally, this type of recording device generates a discharge by applying a voltage between a pin electrode and a counter electrode to form an electrostatic latent image on the surface of a dielectric material, and uses methods such as magnetic brush development or liquid development. Visualize the latent image formed using

However, in devices using pin electrodes, as the recording speed increases, the discharge may not occur due to the delay time of the discharge, resulting in missing dots in the information drawn with the pin electrodes, or the quality of the image. If positive (+) polarity is applied to the pin electrode for improvement, the above-mentioned dot dropout is likely to occur even at low speeds.

An object of the present invention is to solve the above-mentioned problems of the prior art in recording devices using pin electrodes, and to make it possible to eliminate dot omissions in recorded images and improve the recording speed, and also to enable electrostatic recording that is not affected by the atmosphere. It provides equipment.

The electrostatic recording device of the present invention that achieves the above object has the following features:
a pin-shaped electrode disposed close to and facing the dielectric surface and moving relative to the dielectric surface; a signal power source for applying a voltage for recording to the pin-shaped electrode;
The device includes high energy applying means that ionizes the atmosphere near the pin-shaped electrode when a voltage for recording is applied to the pin-shaped electrode. The above pin electrodes include those that use a single electrode to scan the dielectric surface, those that move the dielectric surface by arranging multiple electrically independent electrodes in a row, and those that move the dielectric surface by arranging multiple electrically independent electrodes in a row. There are some that move the dielectric surface by arranging the dielectric surface. As a means of applying energy to ionize the atmosphere near these pin electrodes, members that generate ultraviolet rays or radiation, such as various lamps (tubes) or corona light generated during corona discharge, can be used. can.

Therefore, a wire-shaped or needle-shaped corona discharge electrode is placed near the pin electrode, the corona light from this discharge electrode is irradiated to the pin electrode, and at the same time, the ions generated by the corona discharge are directly directed to the pin electrode. To lead is to
This is effective for improving the precision and speed of recording using pin electrodes.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is an explanatory diagram of the configuration of a conventional recording device using pin electrodes. In the figure, 1 is an image receptor, which is constructed by coating a dielectric material 3 on the surface of a conductive material 2, and moves in the direction of the arrow. Reference numeral 4 denotes a pin electrode, which is provided over the entire width of the image receptor 1, and is sandwiched between an insulator support member 5, and its tip is exposed from the support member 5 and faces the recording member 1. Image receptor 1 and pin electrode 4
A signal voltage can be applied from a signal power source 6 between them.

In the above device, if the thickness of the dielectric 3 is made thin, the voltage applied to the pin electrode 4 can be reduced. Therefore, in consideration of mechanical strength, etc., this dielectric layer usually has a thickness of several microns to several tens of microns, and in the experimental device, the thickness was 10 microns. On the other hand, as the minimum unit of the pin electrode 4, a nickel wire with a diameter of 60 microns is used, and the distance between the pin electrode 4 and the image receptor 1 should be as narrow as possible from the viewpoint of improving image quality.
It was set to 20 microns due to mechanical precision constraints. In this case, the voltage applied to the pin electrode 4 must be about 600 ^V , but in this experiment, in order to keep the applied voltage low, the surface of the image receptor 1 was applied in advance using a corona discharger or roller electrode (not shown). Charging was performed so that the potential was uniform, for example, from -400 ^V to -450 ^V , and the voltage applied to the pin electrode 4 was +150 ^V. The application time was 50 μsec per dot.

In addition, when applying a voltage of negative polarity to the pin electrode 4, the polarity is opposite to that described above.

Under the above conditions, the image receptor 1 is moved in the direction of the arrow at a rate of 50 cm per second, a signal voltage corresponding to the image is applied to the pin electrode 4 from the signal power source 6, and the electrostatic potential is deposited on the recording member 1. form an image. Thereafter, the image receptor 1 is visualized using a developing means such as a magnetic brush.

However, in the apparatus having the configuration shown in FIG. 1, the visualized image on the image receptor 1 actually formed in response to the image input signal shown in FIG. This results in a loss of image quality.

The reason for the above dot omission is not yet understood, but when a positive voltage is applied to the pin electrode 4,
Emission of electrons from the pin electrode 4 is not considered, and the empty
Ions of about 100/cm ³ ·sec generated in the image receptor or electrons emitted from the surface of the image receptor increase due to the action of an electric field, and eventually turn into a discharge. However, it is presumed that this is because ions may not actually exist between the pin electrode 4 and the image receptor 1, and electron emission from the surface of the image receptor, which is a dielectric material, is difficult to occur.
On the other hand, when a voltage of negative polarity is applied to the pin electrode 4, the recording speed can be increased more than when applying a voltage of positive polarity. However, if the application time of the signal voltage is shortened as the speed increases, the number of electrons emitted from the pin electrode 4 decreases, resulting in similar dot dropouts. Therefore, even if the applied voltage is set to negative polarity, there is a limit to the recording speed.

FIG. 3 is an explanatory diagram of the configuration of a recording apparatus having a new configuration that solves the problem that occurred in the apparatus shown in FIG. 1, and the same numbers as in FIG. 1 indicate members having the same functions.

In the figure, 7 is a high-voltage power supply, 8 is a wire for corona discharge, and is surrounded by a shield plate 9. This shield plate 9 is partially provided with an opening 10 along the tip of the pin electrode.

When a high voltage is applied between the wire 8 and the shield plate 9 by the high voltage power supply 7, a corona discharge is generated from the wire 8, and the corona light generated by this corona discharge contains a large amount of ultraviolet rays. is applied to the tip of the pin electrode through the aperture 10. As a result, the air near the tip of the pin electrode can be ionized extremely easily as the pin electrode discharges, making it possible to perform electrostatic recording without the above-mentioned dot omission.
Furthermore, a large amount of ions are generated from the wire 8, and even if recording is performed under the same conditions as in FIG. The missing dots as mentioned above do not occur. The reason for this is that, as in the case of the ultraviolet rays, the ions guided to the pin electrode 4 ensure that the electrode 4 is discharged.

By the way, as a specific example of guiding the ions generated by the corona wire 8 in the direction of the opening 10, some high-pressure high air may be introduced into this shield plate 9, or as in the embodiment shown in Fig. 4 below. An air flow toward the opening 10 may be formed within the shield plate 9 using corona wind.

FIG. 4 shows another embodiment of the device of FIG.
5 and open the insulating layer 16 with paint, tape, etc.
Provided on the shield plate near 5. As a result, the corona discharge mainly heads toward the opening 10, and along with the corona wind generated at this time, a wind flow from the opening 15 toward the opening 10 is generated, and the pin electrode Since the amount of ions supplied to the tip of the pin electrode can be increased, the discharge of the pin electrode can be made fast and stable.

FIG. 5 shows an embodiment of a transfer type recording apparatus in which an image receptor is used repeatedly. Here, prior to recording, the charge on the image receptor surface is equalized and reused.
That is, it is necessary to adjust the surface potential of the image receptor 1 to a predetermined constant value before entering the next electrostatic recording process, and in order to make the surface potential of the image receptor 1 constant, a corona discharger provided adjacent to the pin electrode is used. Electric appliance 17 is used. A portion of the shield 9 of the discharger 17 on the pin electrode 4 side is cut out to provide an opening 10 similar to that shown in FIG. 3 above. Furthermore, a grid 18 is provided on the image receptor side of the discharge electrode without providing a shield plate. As a result, the image receptor 1 moving endlessly in the direction of the arrow first moves to the discharger 17
After being charged to a uniform potential, it reaches the pin electrode located downstream. Of course, due to the presence of corona light and ions accompanying the discharge in this pin electrode, recording is possible at a higher speed and more stably than the conventional one, as described above. Note that the image receptor 1 may be belt-shaped or drum-shaped. The latent image on the image receptor 1 is directly transferred to another image receptor, or after development, the developed image is transferred to another image receptor.

FIG. 6 shows an embodiment in which the discharge of the pin electrode is made more stable by taking into account the amount of ions generated at the tip of the pin electrode and the amount of ions actively guided.

In the figure, 11 is a reference discharge electrode, which is a single electrode having the same shape as the pin electrode 4. Reference numeral 13 denotes a DC power supply having an output comparable to the output voltage of the signal power supply 6, which is connected to the reference discharge electrode 11 and measures the current flowing to the reference discharge electrode 11 by the current detection means 12. A feedback circuit line 14 returns the obtained current value to the high voltage power supply 7.

When a DC voltage is applied from the DC power supply 13 to the reference discharge electrode 11 in the above configuration, a discharge is generated between the image receptor 1 and the reference discharge electrode 11, and a current flows. At this time, if the distance between the reference discharge electrode 11 and the image receptor 1 is narrow, a large amount of current will flow, and if it is wide, a small amount of current will flow, and this also depends on the environment, such as humidity and temperature. This current change is detected by the current detection means 12.
By detecting the corona wire 8 by controlling the high voltage power supply 7 by the feedback circuit
By changing the voltage applied to the image receptor 1, the ion concentration between the image receptor 1 and the pin electrode 4 is adjusted, and by keeping the current of the reference discharge electrode 11 constant, the voltage between the pin electrode 4 and the image receptor 1 is adjusted. It is possible to stabilize the discharge for recording. As explained above, the reference discharge electrode 11 is provided in the vicinity of the pin electrode 4, and the current value consumed by the reference discharge electrode is controlled by a feedback circuit so as to be always constant, and the ion beam is controlled so that the current value is always constant. If the density is set, even if there are environmental changes or distance changes, there will be no missing dots like in the past, and good recording will be possible.

In addition, in the explanation of FIG. 6, the reference discharge electrode 11 is provided separately from the pin electrode, but it is also possible to use a part of the pin electrodes 4 arranged in plurality instead. In addition, a reference discharge electrode 11 was provided to measure the current value, but after the recording signal of the pin electrode 4, the image receptor 1
It is also possible to measure the surface potential above and control the high voltage power supply 7 based on the measurement result.

In the embodiment shown in FIG. 6, instead of using a high energy imparting means, it is also effective for a device that simply guides ions.

As described above, according to the present invention, in a recording device using a pin electrode, the polarity of the voltage applied to this electrode can be arbitrarily used, and furthermore, stable recording can be achieved by having ions that are easily ionized or present near the pin electrode. It becomes possible to discharge for Therefore, it is possible to effectively prevent the dot omission described in FIG. 2 above, and also to improve the recording speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional recording device using pin electrodes, FIG. 2A is an explanatory diagram of an image to be recorded, and FIG. 2B is an explanatory diagram showing an image recorded by the device of FIG.
3 to 6 are configuration diagrams of a recording apparatus showing an embodiment of the present invention. In the figure, 1 is an image receptor, 3 is a dielectric, 4 is a pin electrode, 8 is a corona wire, and 11 is a reference discharge electrode.

Claims (1)

[Scope of Claims] 1. An electrostatic recording device that forms an electrostatic latent image on a dielectric surface, comprising: a pin-shaped electrode disposed close to and facing the dielectric surface and movable relative to the dielectric surface; An electrostatic recording device comprising: a signal power supply for applying a recording voltage to the electrode; and a high energy imparting means for ionizing the atmosphere near the pin-shaped electrode when the recording voltage is applied to the pin-shaped electrode. Device. 2. The electrostatic recording device according to claim 1, wherein the high energy imparting means generates ultraviolet rays. 3. The electrostatic recording device according to claim 1, wherein the high energy imparting means generates ions.