JPH0239080B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an ion supply device for supplying ions to a charged object and creating a charged state of uniform charge density on the charged object. Various problems arise when the charge density of a charged object is non-uniform. For example, when transferring toner by electrodeposition, as in a dry copying machine, if the electrical charge state of the paper surface is uneven, the transferred lines will not appear sharply, and each color will not appear as desired, especially in the case of color copying. It is not electrodeposited and the desired hue cannot be obtained. As a countermeasure to this problem, there is a conventional method of eliminating static electricity from a charged object and making the potential uniform by reducing it to zero, and for this reason, AC corona discharge type static electricity removal devices are widely used. This type of corona discharge type static eliminator generally uses single-phase alternating current, which eliminates static electricity, and even if the measured value is zero V when measured with a conventional charged potential measuring device, the above problem will not occur. There were cases where it could not be resolved. As a result of considering this point, we found that, for example, when measuring with a precision charged potential measuring device on the order of a few volts to several tens of volts, charges of 20 to 30 volts or less actually remain scattered as positive or negative charged areas. There was found. Therefore, in the conventional corona discharge type static eliminator using single-phase alternating current, it has not been possible to avoid the adverse effects caused by non-uniformity by reducing the potential to zero or approaching zero. On the other hand, as a method of making the charge density of a charged object uniform, it is possible to actively supply ions to the charged object to make it in a charged state with a uniform charge density. For this purpose, attempts were made to use a corona discharge electrode to supply ions to a charged object to create a charged state with a uniform charge density, but it was difficult to achieve a charged state with a uniform charge density. That's the first
This is because there are limits to static elimination or charging using the corona discharge electrode shown in the figure due to the mechanism of ion supply. That is, discharge needle a
A corona discharge occurs between the earth electrode b and the air, which ionizes the air and supplies ions c to the charged object A, which are repelled by the discharge needle.
Neutralization is performed by this, and charging is performed by the supplied ions c. In this case, more ions c are supplied to the charged object A in the area closest to the tip of the discharge needle a, and the amount of ions c supplied decreases as the area moves away from the tip, and the ions are uniformly distributed over the entire surface of the charged object A. cannot be supplied. For this reason, a linear discharge electrode is used as a corona discharge electrode to expand the discharge area, but even if the linear discharge electrode is made smaller in diameter and a large number of them are used to uniformly supply ions. There is a limit to the diameter of the linear discharge electrode due to the applied voltage, and there is also a limit to the distance between the discharge electrodes in order to avoid spark discharge, so it is difficult to uniformly supply ions to the charged object. There are limits to what you can do. An object of the present invention is to provide an ion supply device for supplying ions to a charged object to create a charged state with a uniform charge density on the charged object by neutralization or charging. discovered that the above object could be achieved by moving ions along the surface of a charged object, and completed the ion supply device of the present invention. The first invention includes an ion generator and a plurality of ion transport electrodes arranged in parallel to the ion generator, and the plurality of ion transport electrodes are connected to terminals of a multiphase AC power source. The ion generator is a plurality of sets of electrodes arranged in order of smallest or largest phase delay, arranged in a row facing a traveling charged object, It is characterized in that it is disposed at the entrance of the object to the row of ion transport electrodes, and supplies ions while moving the ions generated by the ion generator along the running direction of the charged object. Further, a second invention is an ion supply device with a simple structure that serves both as an ion generator and an ion transport electrode in the first invention, and is composed of a plurality of discharge electrodes that serve as an ion generator and an ion transport electrode. , the plurality of discharge electrodes are a plurality of electrode groups in which the electrodes of each phase connected to the terminals of the multiphase AC power source are arranged in order of smallest or largest phase delay, and the plurality of discharge electrodes are a set of electrodes connected to the terminals of a multiphase AC power source, and are arranged in order of decreasing phase delay or increasing phase delay. It is characterized in that it is arranged in a row facing the object and supplies ions while moving the ions generated by the discharge electrode along the running direction of the charged object. To explain in more detail with reference to FIG. 2 which shows an example of the implementation of static elimination according to the present invention, 1 is an ion generator, 2 is an ion transport electrode, and 3 is a counter electrode. The ion generator 1 is appropriately selected from a conventional corona discharge electrode, an ion generator using radiation, etc. depending on the purpose of static elimination or charging. The ion transport electrode 2 is close to the ion generator 1, and three linear electrodes 2 are arranged horizontally at intervals to form a set.
Each electrode 2 was connected to a secondary terminal of a multi-phase alternating current, for example, a three-phase alternating current, so that U, V, and W were arranged in the order of decreasing phase delay. In the case shown in the figure, two more sets of two groups of electrodes were arranged in the same order, and a U-phase electrode 2 was added to prepare the two electrode surfaces. The counter electrode 3 is arranged to face the ion transport electrode group 2, and forms a running space for the charged object A between the electrodes 2 and 3. The illustrated counter electrode 3 is a linear electrode similar to the ion transport electrode 2, and is opposed to each ion transport electrode 2, and both electrodes are at ground potential. Further, this counter electrode 3 may be configured to conduct multiphase alternating current similarly to the ion transport electrode 2, and in this case, the phase thereof is different from that of the opposing ion transport electrode.
Then, the charged object A is caused to travel between the electrodes 2 and 3 from the ion generator 1 side to supply ions. Therefore, for example, in the case of static elimination, the ion generator 1
A conventional single-phase AC corona discharge electrode is used to generate positive and negative ions alternately. Ions generated from this ion generator 1 are attracted to the charged object A side by the counter electrode 3, and the electric field generated at the ion transport electrode 2 moves as a positive and negative sine wave electric field, so that the ions are attracted along the moving direction of the charged object A. The ions are attracted and forcibly moved, and ions are uniformly supplied to the entire surface of the charged object A, resulting in neutralization and uniform static elimination. In addition, in the case of charging, ions are transferred to the ion transport electrode 2 and the counter electrode 3 using an ion generator of a corona discharge electrode connected to a DC power source that generates positive or negative ions depending on the charge to be charged to the charged object A. The ions are supplied to the space between the electrodes 2 and 3, and the counter electrode 3 attracts ions to the charged object A side, while the ion transport electrode 2 attracts ions along the charged object A. By attracting, transporting, and supplying ions to the charged object A, a charged state having a uniform charge density can be obtained. In the above embodiment, an example in which a counter electrode was provided was shown, but the object of the present invention may not be impeded depending on the purpose of ion supply, the type of ion generator, etc. FIG. 3 shows another embodiment of the present invention, in which the ion generator 1 described above is used.
It also serves as the ion transport electrode 2. Three linear discharge electrodes 4a, 4b, 4c are arranged at intervals to form a set, and each discharge electrode 4a, 4b, 4c is connected to a three-phase AC They were connected to the secondary side terminals of U, V, and W so that they were arranged in order of decreasing phase delay.
In addition, as in the above embodiment, two more sets of the four discharge electrodes in one set are arranged in the same order, and in order to arrange the four surfaces of the discharge electrodes, a gap is left between the four discharge electrodes in each set, and the V phase is arranged. A discharge electrode 4 was added. For example, in the case of static elimination, the charged object A is moved along the above-mentioned arrangement direction of the 4 groups of discharge electrodes to supply ions and perform static elimination. More specifically, as described above, each discharge electrode 4 is an electrode for each phase in the order of U, V, and W with the smallest phase delay, so for example, when the potential of the V-phase discharge electrode 4b is zero, the U-phase The discharge electrode 4a is at a positive high potential and generates positive ions, at which time V
Since the phase discharge electrode 4b has zero potential, no ions are generated, and the W phase discharge electrode 4c has a negative high potential, so it generates negative ions, which causes the phase difference (120°) between each phase. It moves to each discharge electrode 4 with the following. The positive and negative ions generated simultaneously in this way are emitted to the opposing charged object A, and the electric field of the adjacent discharge electrode 4 moves as a positive and negative sine wave electric field and acts to attract each ion. ions move in a mixed state. In this case, since the charged object A is moved along the moving direction of each phase of each of the 4 groups of discharge electrodes, positive and negative ions are uniformly supplied to the charged object A at the same time, resulting in a positively charged area α dispersed in the charged object A. The negative band region β is simultaneously neutralized over the entire area, and each unneutralized ion is forcibly moved by each discharge electrode 4, so that the proportion of ions that are neutralized in the air on the way is smaller. Contributes to neutralizing the charged object A. Therefore, since the positively charged area α and the negatively charged area β distributed on the charged object A are simultaneously neutralized, the area where the charge is zero is expanded, so the charge is reduced in absolute value, and the residual potential is also small. The impact will be extremely small. Next, the test results are as follows.

[Table] As is clear from the above results, with the conventional single-phase AC corona discharge method, the static elimination effect is small at several 100V.
Even at an applied voltage of , static electricity could be removed until the residual potential approached zero in the above example. In the embodiment shown in the third figure, unlike the embodiment shown in the second figure, a counter electrode is not provided, but it may be provided if necessary. In the above two embodiments, linear electrodes were used as the ion transport electrode and the discharge electrode, but in the present invention, ions are moved uniformly, so even if a large number of needle-shaped electrodes are arranged. has the same effect. As is clear from the above explanation, the first aspect of the present invention
According to the invention, the ions generated from the ion generator are forcibly moved along the surface of the charged object by the ion transport electrode, so that the ions can be uniformly supplied. Since the ion generator and the ion transport electrode are separate, the voltage applied to the ion transport electrode can be kept low, thereby reducing the distance between each electrode. This has the effect of providing an ion supply device suitable for downsizing the device. Further, according to the second aspect of the present invention, there is an effect of providing an ion supply device by using a discharge electrode that has the same purpose as the first invention and serves both as an ion supply device and an ion transport electrode.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional single-phase AC type ion supply apparatus, FIG. 2 is a schematic diagram of an apparatus for implementing the present invention, and FIG. 3 is a schematic diagram of another apparatus for implementing the present invention. 1... Ion generator, 2... Ion transport electrode, 4... Discharge electrode.

Claims (1)

[Claims] 1. Consisting of an ion generator and a plurality of ion transport electrodes arranged in parallel with the ion generator, the plurality of ion transport electrodes are connected to terminals of a multiphase AC power source. The ion generator comprises a plurality of electrode groups in which connected electrodes of each phase are arranged in ascending order of phase delay or in ascending order of phase delay, and are arranged in a row facing a traveling charged object. The ion is disposed at the entrance of the charged object to the row of ion transport electrodes, and is configured to supply ions while moving the ions generated by the ion generator along the traveling direction of the charged object. Feeding device. 2 Consists of a plurality of discharge electrodes that serve both as an ion generator and an ion transport electrode, and the plurality of discharge electrodes are arranged in the order of the smallest or largest phase delay between the electrodes of each phase connected to the terminals of the multiphase AC power supply. A group of multiple electrodes arranged in a row facing a moving charged object, which discharge ions while moving the ions generated by the discharge electrodes along the running direction of the charged object. An ion supply device characterized by supplying.