JPS60258882A - Static eleminating and charging method and discharging device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

1. TECHNICAL FIELD The present invention relates to a charging/removing method and a discharging device for charging/removing static electricity in electrostatic recording, electrophotographic devices, etc.

[Kadokyokei Traditionally, in electrostatic recording and electrophotographic equipment, wire diameters of 0
．． Corona discharge devices that perform corona discharge by applying a high voltage to a wire of about 1 mm are widely used. However, such a corona discharge device has the disadvantage that the wire is thin and easily damaged, and furthermore, dirt on the wire causes uneven discharge, resulting in non-uniform charging of the charged object. Furthermore, it is necessary to maintain a certain distance between the wire and the conductive shielding member surrounding the wire, which limits the miniaturization of the corona discharge device. On the other hand, as another discharge device, an alternating current voltage is applied between electrodes that sandwich a dielectric material, thereby generating positive and negative ions at the junction between the end face of one electrode and the dielectric material, and by an external electric field. Extracting ions of desired polarity (U.S. Pat.
155093, Japanese Patent Application Laid-open No. ll1l'154-53537). In such a device, by reducing the thickness of the dielectric material (for example, making the thickness 50011.m or less, preferably about 20 to +200 p-m), compared to a conventional discharge device. As a result, a compact discharge device can be obtained. However, in the discharge device as described in Section 2, it is difficult to uniformly charge or neutralize the surface to be charged. SUMMARY OF THE INVENTION An object of the present invention is to provide a charge removal/charging method and a discharge device that enable substantially uniform charging and removal. Another object of the present invention is to provide a discharge device that is compact and capable of uniform electrification. Another object of the present invention is to provide a discharge device that has a high life-killing charging effect at a relatively low voltage. Another object of the present invention is to provide a charge removal/charging method and a discharge device that are relatively stable against environmental changes (temperature, humidity, etc.) and are capable of satisfactorily uniform charging. Other objects and effects of the present invention will become apparent from the description of the embodiments of the present invention described below. 11 Tate IJ The above-mentioned drawback of this type, which is known to the present inventor, is that the creeping discharge, which extends from the discharge electrode in contact with one surface of the dielectric material along this surface in a direction perpendicular to the discharge electrode, is It was considered that this is because it is difficult to form uniformly in the longitudinal direction. Possible reasons for this non-uniform elongation include non-uniformity of the dielectric material and minute scratches on the electrode surface. According to an embodiment of the present invention, there is provided a charge removal/charging device that applies alternating voltages between a dielectric, an induction electrode and a discharge electrode sandwiching the dielectric, and the induction electrode and the discharge electrode. a power source that causes a creeping discharge on the dielectric surface on the discharge electrode side;
and the alternating voltage is set such that the width of the creeping discharge region almost matches the width of the induction electrode, so that the creeping discharge extends in the direction perpendicular to the discharge electrode. It becomes almost uniform, making it possible to remove and charge uniformly. Practical Examples Examples of the present invention will be described below with reference to the drawings. FIG. 1 explains the basic configuration of the discharge device of the present invention. The discharge member l is arranged facing the charged member 2,
It has a dielectric 3, an induction electrode 4, and a discharge electrode 5. Second
The figure shows a perspective view of the discharge member l. The discharge electrode 5 is a single linear elongated body, and is arranged along the center line of the induction electrode 4 in the width direction. Alternate voltages are applied between the induction electrode 4 and the discharge electrode 5 by an alternate voltage application means 6. On the other hand, the charged member 2 moving in the direction of the arrow A relative to the discharge member 1 is formed of an insulator or a photoconductor on the conductor base 2a. b, and a bias voltage is applied between the conductor base 2a and the discharge electrode 5 by a bias voltage applying means 7. The charging method is to apply alternating voltages between the induction electrode 4 and the discharge electrode 5 to generate a discharge from around the discharge electrode 5, generate sufficient positive and negative ions, and connect the discharge electrode 5 and the conductor. By applying a bias voltage between the bases 2a, -
(h) Selectively extracting positive or negative ions to charge the charged member ・2
The surface of the insulator or photoconductor 2b is charged to a specific polarity and a desired value. Here, dielectric materials include relatively hard inorganic materials such as ceramic, mica, and glass, and flexible organic polymer materials such as polyimide, tetrafluoroethylene, polyester, acrylic, vinyl chloride, and polyethylene. is used. 3A to 3B, alternate voltages are applied between the discharge electrode 5 and the induction electrode 4 of the discharge member 1 shown in FIG. 1 and FIG. The figure shows a state in which a creeping discharge is generated along the surface of the discharge electrode 5 when viewed from the discharge electrode 5 side. What is indicated by a dashed line is the induction electrode 4 in contact with the back surface of the dielectric 3, and its 1] is indicated by L. A shaded area 10 is an area where creeping discharge extends along the surface of the dielectric 3 on both sides of the discharge electrode 5. Figure 3A shows the state of creepage current when the present invention is not used. In FIG. 3A, the creeping discharge area IO is located at the discharge electrode 5.
It extends around the center and its width l is non-uniform in the longitudinal direction. For this reason, when the surface of the insulator or photoconductor 2b is charged by moving the member 2 to be charged as shown in FIG. 1, the surface charge distribution becomes uneven in the longitudinal direction of the discharge member 1. The inventor of the present invention has found that rlltt of the creeping discharge region 10 differs depending on the peak value of the alternating voltage applied between the induction electrode 4 and the discharge electrode 5. This is shown in FIG. 4, where the horizontal axis represents the peak value of the alternating voltage, and the vertical axis represents the width l of the creeping discharge region 10. As the peak φ peak value is increased, creeping discharge starts at the discharge starting voltage B, and the width of the creeping discharge area lO! increases with increasing peak-to-peak value. Then, it eventually becomes saturated, at which time l in the creeping discharge region substantially matches fi]L of the induction electrode 4. Even if the peak-to-peak value is further increased by -1, the creeping discharge area 1 will not increase beyond the width of the induction electrode 4. Here, alumina ceramics with a thickness of 200 gm is used as the dielectric material 3, and the width of the discharge electrode is 500p, m
, the width of the induction electrode was 6.5 mm. The present invention makes use of this phenomenon to make the width of the creeping discharge region 10 uniform over the entire longitudinal direction of the discharge member 1, despite the non-uniformity of the dielectric material 3 and the presence of minute scratches on the electrode surface. It is something. FIG. 3B shows creeping discharge region 10 using the present invention. In this embodiment, the peak-to-peak values of the alternating voltages are set so that the creeping discharge region 10 coincides with l] of the induction electrode 4 over the entire longitudinal direction of the discharge member 1 as shown. As shown in the figure, the creeping discharge region 1 substantially matches the width of the induction electrode 4 over the entire longitudinal direction of the discharge member 1, and is therefore uniform. The applied voltage is an alternating voltage, so if you look at it microscopically, it is in the creeping discharge area! changes with time and expands and contracts repeatedly, but it is in the creeping discharge region when it reaches its maximum expansion! almost matches the width of the induction electrode 4 and is uniform over the entire length of the discharge member l. In this way, when an AC voltage value such that the creeping discharge reaches at least the width of the induction electrode 4 over the entire area is applied between the discharge electrode 5 and the induction electrode 4, the width of the creeping discharge area 10! is constant in the longitudinal direction, and when charged as shown in FIG. 1, uniform charging can be obtained. As mentioned above, even if the above alternating voltage is further increased, the width of the creeping discharge area IO is still the same! does not extend beyond 11 L of the induction electrode 4. Only the charge density in the creeping discharge region 10 increases. Furthermore, the charge density within the creeping discharge region 10 is substantially uniform throughout the longitudinal direction of the discharge member 1. Charging that takes full advantage of this phenomenon allows relatively stable charging against environmental changes (temperature, humidity, etc.), and satisfactorily uniform charging. Actually, we used alumina ceramics with a thickness of 200 gm as the dielectric material 3, and the width of the discharge electrode 5 was 500 gm.
The width of the induction electrode 4 is set to 4.5 mm, and the peak and
When an AC voltage with a peak voltage of 2 kVpp was applied, the elongation of the creeping discharge did not reach the width of the induction electrode 4, and the first
When charging was performed with the output of the bias power supply 7 set to 2 kV, charging unevenness of ±8% occurred. Next, change the AC voltage applied between both electrodes 4 and 5 to 4 kVp.
p, the creeping discharge area lO is sufficiently extended, and the induction electrode 4
When the battery was fully charged to 11, the measured charging unevenness was ±3%. Therefore, in this example, just by changing the peak number and peak value, more than 60% of the charging unevenness was removed. Furthermore, even when the voltage applied between both electrodes 4 and 5 is 4 kVPP, when the width of the induction electrode 4 is changed to 30 mm (other conditions are the same as above), the creeping discharge area lO of the induction electrode 4 is It has not reached the width, and the charging unevenness is 17%.
Met. FIG. 5 and FIG. 6A are perspective views of the basic configuration of a discharge device and a discharge member l according to other embodiments of the present invention, respectively. In this embodiment, a plurality of rows of elongated discharge electrode members constituting the discharge electrode 5 are provided at substantially equal intervals, and the widths of the induction electrode and the dielectric body are accordingly increased. r 'a bt l ttbeforeE'
4 mm ko--ch6(1)T・"9 The detailed explanation is omitted by giving the same reference numerals to the members. FIG. 7A shows the discharge of the present invention shown in FIGS. 5 and 6A. A creeping discharge area in the device is shown. A plurality of discharge electrode members 5
a and 5b are arranged at approximately equal intervals. Then, when the distance between the center line of the discharge electrode member 5a arranged on the outermost side and the widthwise end of the induction electrode 4 is Ll, and the distance between the center lines of adjacent discharge electrodes is L2, L1≧
They are arranged so as to be 1/2×L2. In this embodiment, one inner discharge electrode member 5b is shown, that is, three discharge electrodes in total, but any number of inner discharge electrode members 5b including O may be used. The peak values of the alternating voltages are set so that the creeping discharge region 10a extending from the outermost bipolar electrode member 5a substantially matches the width of the induction electrode 4 over the entire longitudinal direction of the discharge member l, as shown in the figure. There is. In this way, due to the dimensional conditions described in section 2, the creeping discharge regions of the respective discharge electrodes contact or overlap each other, and a uniform creeping discharge region 10b is formed over the entire surface between the discharge electrodes. be done. As shown in the figure, the width of the entire creeping discharge area at each point 1 in the longitudinal direction of the discharge member 1 substantially matches the width of the induction electrode 4 throughout the longitudinal direction, and is therefore uniform. In the case of LL<1/2XL2, in order to form a uniform creeping discharge area IO that almost matches the width of the induction electrode 4, it is necessary to fill the gap between the discharge electrode members (therefore, A voltage may be applied so that a uniform creeping discharge region 10b is formed. Also, the same <Ll<
Under the condition of 1/2 XL2, if the creeping discharge area 10a on the outside of both outermost discharge electrode members 5a is set to the lowest peak-to-peak value that almost matches the width of the induction electrode 4, some of the inside Considerable uniformity can be achieved even if the creeping discharge regions from the discharge electrodes do not contact or overlap with the creeping discharge regions from adjacent discharge electrodes. In this way, when an alternating voltage value is applied between the discharge electrode and the induction electrode 4 such that the creeping discharge reaches at least 11 of the induction electrode 4 over the entire length, 11. Uniform charging can be obtained by charging as shown in FIG. 5, in which the width of the creeping discharge region IO is constant in the longitudinal direction. As described above, even if the alternating voltage is further increased, the width of the creeping discharge region 10 will not increase beyond the width of the induction electrode 4. Only the charge density in the creeping discharge region lO increases. Moreover, the charge density within the creeping discharge region 10 is approximately uniform throughout the longitudinal direction of the discharge member l. If you take full advantage of this phenomenon and charge it, environmental changes (temperature, humidity, etc.)
It is also possible to achieve relatively stable and fully satisfactory uniform charging. These multiple rows of discharge electrodes may be connected in a comb shape electrically connected at one end (Fig. 6B), or may be connected at both ends (Fig. 6C), or may be connected in a zigzag shape. (Figure 6D). If the discharge electrode 5 is formed of one elongated body, the width of the creeping discharge region is limited by the peak-to-peak value of the alternating voltage. Therefore, in order to increase the width of the creeping discharge region, the alternating voltage must be It is necessary to raise the voltage considerably, but if multiple discharge electrodes are used, the voltage can be increased without significantly increasing the TR voltage.
Since the total creeping discharge area width can be increased arbitrarily by changing the number of the electrodes, the charging or neutralizing effect can be significantly improved. FIG. 7B shows a case where there is no creeping discharge as shown in "-". In FIG. 7A, the creeping discharge area 10 extends around each discharge electrode member 5, and each of the regions 11, 2, and 3 is nonuniform in the longitudinal direction. For this reason, when the charged member 2 is moved to charge the surface of the insulator or photoconductor 2b as shown in FIG. 5, the surface of the discharge member 1 is uneven in the longitudinal direction as in FIG. 3A. This results in an undesirable charge distribution. Actually, alumina ceramics with a thickness of 2001 Lm was used as the dielectric 3, three discharge electrodes each having a width of 500 Ii, m were arranged at an interval (L2) of 5 mm, and the width of the induction electrode 4 was 14 mm. When an AC voltage with a peak-to-peak voltage of 2 kVPP was applied between the electrodes, the growth of the creeping discharge was similar to that shown in Figure 7B, and when charged with the output of the bias power supply 7 in Figure 1 set to 2 kV, the increase was ±7. Charging unevenness of 5% occurred. Next, change the AC voltage applied between both electrodes 4 and 5 to 4 kVp.
When the creeping discharge region 10 was extended to fully reach the width of the induction electrode 4 and charged, the charging unevenness was measured to be 2.5% above. Therefore, in this example, just by changing the peak-to-peak value, more than 65% of the charging unevenness was removed. In addition, even when the voltage applied between both electrodes 4 and 5 is 4kVPP, 11 of the induction electrode 4 is changed to 60 mm
When the distance between the discharge electrodes is 20 mm (other conditions are the same as above), the creeping discharge region 10 does not reach the width of the induction electrode 4, resulting in a state similar to that shown in FIG. 3A, and the charging unevenness is It was ±7%. In both embodiments, the width of the creeping discharge region 10 varies depending on the material, dielectric constant, surface electrical resistance, etc. of the dielectric 3, but the width of the creeping discharge region 10 varies depending on the conditions.
All you have to do is determine the peak value. Furthermore, the width of the creeping discharge area 10 is determined based on the usage conditions of the discharge device.
For example, it varies depending on the atmospheric pressure, humidity, temperature, dirt on the surface of the dielectric 3, etc., but depending on the actual usage conditions,
Regardless of these fluctuations, the peak Φ peak value of the alternating voltage can be determined and set so that the width of the creeping discharge region IO almost matches the width of the induction electrode 4. desirable. The alternating voltage applied between the induction electrode 4 and the discharge electrode 5 is not necessarily a so-called AC voltage, but may be a rectangular wave voltage or a pulse voltage. In the above description, the case where the member to be charged 2 is charged has been described, but if the discharge member l is brought close to the member to be charged 2, the charge to be charged member 2 can be neutralized without requiring the charge 1ii7. Even in this case, the above-mentioned present invention can be applied in exactly the same way, and the same effects can be achieved. The power source 7 may be a direct wave or a pulsating current, as long as it can pull the ions generated in the vicinity of the discharge electrode 5 toward the charged member 2. ``Milk-raising force'' As explained below, according to the present invention, the non-uniformity of charge removal and charging can be significantly improved with a small-sized discharge device.

[Brief explanation of the drawing]

FIG. 1 shows the basic configuration of an embodiment of a discharge device using the electrification/charging method according to the present invention, and FIG. 2 is a perspective view of a discharge member used in the discharge device shown in FIG. The figure shows the creeping discharge state when the present invention is not used, FIG. 3B shows the creeping discharge state in the discharge/charging method and discharge device according to the embodiment of the present invention, and FIG. 4 shows the peak and It is a graph which shows the relationship between a peak value and creeping discharge state width. FIG. 5 shows the basic configuration of another embodiment of a discharge device using the electrification/charging method according to the present invention, and FIG. 6A is a perspective view of a discharge member used in the discharge device shown in FIG. Figures 6B, 60, and 6D show examples of connections between multiple rows of discharge electrodes, Figure 7A shows creeping discharge conditions in the discharge devices of Figures 5 and 6, and Figure 7B shows creeping discharge conditions. Indicates insufficient condition. Explanation of symbols 1: Discharge member 2: Charged member 3: Dielectric 4: Inductive electrode 5: Discharge electrodes 5a, 5b: Plural discharge electrode members 6: Alternate voltage application means 1st mouth 2nd figure 9 4th figure 2 4 6 to-7・ 仁'-'yati (k'rl)Figure 7AFigure 78

Claims (4)

[Claims] (1) The discharge electrode side of a discharge member having an induction electrode and a discharge electrode sandwiching a dielectric material is made to face the discharged/charged member, and an alternating voltage is applied between the induction electrode and the discharge electrode. A creeping discharge is generated on the dielectric surface on the discharge electrode side, and the alternating voltage is set so that the width of the creeping discharge region almost matches the width of the induction electrode, and the creeping discharge generated thereby: A method for removing and charging a charged member, which is characterized by removing and charging a charged member. (2) A charge removal/charging device, which applies alternating voltages between a dielectric, an induction electrode and a discharge electrode sandwiching the dielectric, and the induction electrode and the discharge electrode to A power source for generating a creeping discharge on the surface of a dielectric material, and the alternating voltage is applied such that the width of the region of the creeping discharge substantially matches the width of the induction electrode. (3) In the electrification/charging device according to claim 2, the discharge electrode includes a plurality of equally spaced rows of discharge electrode members. (4) In the electrification/charging device according to claim 3, the distance between the outermost discharge electrode member of the plurality of rows of discharge electrode members and the width end of the induction electrode is determined by the discharge The distance between the electrode members is 172 or more.