JPS59126556A - Protecting device of electric field curtain device - Google Patents

Abstract

PURPOSE:To cut off a voltage simultaneously with the breakdown of an electric field curtain and to secure safety by providing a measuring means, etc. which measure the current flowing through each electrode group, a detecting means which detects whether there is a difference between outputs of the measuring means, etc. CONSTITUTION:Current measuring circuits 26a and 26b are interposed respectively in connection lines which connect terminals 17 of two electric field curtain devices 10a and 10b to a power terminal 20, and output terminals of the current measuring circuits 26a and 26b are connected to a control circuit 27. In such a constitution, the voltage is cut off right before or at once an eletric field curtain device breaks down to suppress discharge energy generated at the breakdown point, securing the safety.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an electric field curtain which is used, for example, in a dry-type electrophotographic copying machine and which transports powder particles such as toner along a surface.
/ In the longing, just before the surface breaks down, the G
At the verge of dielectric breakdown, at the same time the electric field force increases σ) The input electric field is automatically cut off.

The free current flowing into the electric field curtain wVc varies widely depending on the temperature and humidity, as shown in Figure 1.

In the case of a TO-electric field curtain device (σ) whose surface is made of an organic material, as the operating time passes, the surface is bombarded with ozone and ions generated near the electrodes, and the surface electrical resistance decreases. As shown in FIGS. 2 and 31, the inflow current increases.

Therefore, in the conventional electric field curtain device 6i, as shown in FIG.
If the output of the same current O2 exceeds a certain value, a breaker 03 is installed to cut off the power supply. and
Breaker-0 is a safety device that cuts off the power supply voltage when the electric field curtain device reaches the end of its life and dielectric breakdown occurs.
3 (Alloy c'L7 YuX) 01, I had to set the operating point taking into consideration the previous gr4 fluctuation.

Therefore, the above operating point must be set at a point that is several times more than the inflow voltage and VC when the new electric field curtain is operated at low temperature and low humidity. Even if a symptom (increase in inflow current) cannot be detected and the electric field curtain is not destroyed, the disturbance, 7-) If there are many so-called malfunctions, resulting in destruction/creation,
At that time, the spark discharge energy generated will inevitably become large, and if the electric field curtain device is used for the purpose of transporting combustible particles, it will become a big problem and pose a safety risk. It was not possible to secure and avoid malfunction θ).

The present invention is a lightning, field curtain sieve that overcomes bright spots such as lightning, sled), protective equipment, and sled) that can prevent malfunctions and ensure safety.7 -1 An electric field curtain device is provided.

The following figures 5 to 91 show the VCl, the misfire μH
[σ] - Fill in the examples.

In the X embodiment, FIG.
Inside the cleaning device (Electric field curtain device 7m, as shown in the example below).

Tube 11: Cleaning device No. (n, not shown, 1 paper, etc.)) Image-bearing photoreceptor held 1, without transferring to transfer material
1) Blacking device for removing toner remaining on the surface.

First, the photoreceptor belt 1 is spanned between a drive roll 2 and a bank-up roll 3, and is driven by the drive roll 2 in the direction of the arrow.

In addition, a cleaner housing 4 is placed in contact with the photoconductor belt h1 at the front station, and within the Uji leg 4, a blank roll 5 is installed along with a pivot 41 and a filter in order to remove residual toner on the photoconductor belt 1. - Knock off the toner adhering to the plan roll 5'f T, - coloring] Flicker bar 6, to prevent the cloud-like toner from blowing out σ) On-face brush full 7, suck the cloud-like toner An exhaust duct 8 is provided for exhaust air.

The displacement from the exhaust duct 8 is roughly 0.2 to 0.4 m.
/min, to prevent toner from forming a layer and accumulating on the inner wall of the housing 4. I'm wearing a bikini.

Here, the general structure and principle of the electric field curtain device will be explained.

Now, as shown in Figure 10, cylindrical electrode groups H are lined up on the same plane, and every other electrode is glued to a single-phase alternating plane. If we have 2n to 5 electric lines of force, an array of alternating and unequal electric fields will be formed. In this case θ), it goes without saying that the electric field, which is a vector quantity, is unequal, and its magnitude and direction vary locally by VC, in other words ¥711. This means that the electric lines of force are curved and their density changes spatially. This twisted light is driven roughly temporally in a sinusoidal manner.

When a charged particle P comes to such an electric field region, the charged particle P
&O Swings on a curved trajectory along the lines of electric force %U+L
, σ) It receives a centrifugal force in the convex direction of the lines of force every half period, and when averaged over time, it receives an average centrifugal force Fc in the convex direction σ] perpendicular to the lines of force. The roughly charged particle P has its vibration σ]
Due to the phase shift 11, places near the electric fence H where the electric field σ is large receive a repulsive force from the square electrode H, and conversely, places far from the electrode H where the electric field σ is small receive an attractive force to the electrode H, and the time If we take a general average, we receive a force Fg in a direction that is tangent to the line of force and moves away from the electrode H. Since Fg is caused by a local change in the width of the electric field, this is called the average gradient force. On the other hand, it goes without saying that Fc is caused by a local change in the direction of the electric field.

In the end, the resultant force Fr of Fc and Fg always acts on the charged particle P in the direction of repelling the particle P from the electrode group H, so if no external force acts, the charged particle P6 vibrates and acts on the electrode group. The charged particles P float up from the row H and are transported in a direction perpendicular to the electrode group H by the inertial force of the charged particles P.

Fig. 10 shows an example of the simplest single-phase electric field car 7269, but the embodiments shown in Figs. It is a single-phase exposed type with high

Next, regarding the academic curtain device 10 in a non-example,
This will be explained with reference to FIGS. 6 to 8.

Using the electric field curtain device 10, a layer with a thickness of 100μσ) is applied to the upper surface of the polyester electrical insulating substrate layer 11.
An internal dielectric layer 12 made of silicone rubber with a thickness of 0 μm is integrally stacked and formed.
The polyester leg surface extensions 13 are integrally stacked and formed.

In addition, Tii, the i-th surface dielectric layer 13゛σ) has a width of 0 on the surface.
．． 3++ o, thickness 35 μα] Copper electrode group 14 is 9 m
0, and between the electrically insulating substrate layer 11 and the internal lightning arrester layer 12, copper@electrode group 15 having the same dimension σ as the electrode group 14 is provided in the electrode group]4. A copper electrode group 1G having the same dimensions as the electrode group 14 should be buried with a spacing of 3 m111.
are biased toward the other side of the electrode group] 5, respectively.
) are buried at intervals.

Each terminal 17 of the copper electrode group 14, 15, and 16 in the glare.
18.19 are connected to 3-phase AC power terminals 20.21.22. )
It is connected to the U-phase secondary winding 23 (a% ground), the ■-phase secondary winding 24, and the W-phase secondary winding 25.

Roughly two terminals σ) Terminals i7a, 17b of electric field curtain devices 10a, 10b and power terminals 20a, 20b
Current measuring circuit 26 a
% 26 b is intermediary '2! Wow, the same current measurement circuit 26
The output terminals of a and 26b are connected to a control circuit 27K.

Further, in the control circuit 27, the current output regulating circuit 26a
126b! , j7) The outputs are compared, and if the difference exceeds the required σ) set value, the switch path inserted in the three-phase power supply circuit is turned off.

Since the structure is as shown in FIGS. 5 to 9, the three-phase AC tonnage pressure (50H2
, SXV・RMS) is connected to the 3-phase AC power supply terminal, 21\22
When marked 71D'f, the unequal intersection of traveling waves in the space corresponding to the electrode groups 14, 15, and 16 @ electric field array has the form YfJzanl,
Toner, which is a charged particle present in the housing 4, is transported in the X direction perpendicular to the longitudinal direction of the electrode group 1.4.15.16.

In addition, since the electric field curtain device 10VC water handling layer 11 and dielectric layer 12 and 13 are organic, they are highly flexible, and as a result, they can be easily attached to the curved cleaner housing 4.
l, and it is inexpensive.

Gira Vcr''lil right @, when lightning dielectric layers 12 and 13 are used under a high electric field, there are abundant ozone, oxygen radicals, and other positive and negative ions generated by the alternating corona on the surface dielectric layer 13. As shown in Figure 2, the surface resistance of the surface inducing layer 130 gradually decreases over time, and as shown in Figure 3. As the current flows into the electric field curtain device γfJo, the current also increases.

Note that when the surface resistance decreases, the intensity of the unequal alternating electric field formed on the surface dielectric layer 13 weakens, and the toner transport ability decreases.

And the subsequent opening 12.13 deteriorated, about 1000 to 2000
After a period of time, the buried electrode 15. as shown in FIG.
Any one of 16 σ) dielectric breakdown occurs directly above C,
The probability that both electric field curtains 1 [J a , 10 b will cause dielectric breakdown at the same time is very small θ),
Current measurement circuit 26a-26bα) A difference occurs in the output,
The control circuit 27 turns switch 4 off g n-, so that no spark discharge occurs between 'tfM14-15 or between electrodes 14-16, and :! Q) Even if a spark discharge occurs, the discharge energy should be suppressed to 0.1 mJ or less.

Therefore, the minimum ignition force for toner is -0.1"-0.2
It is possible to prevent the toner from forming a layer with σ) which can suppress the discharge energy to less than mJ.

In addition, changes in temperature and humidity, changes in input voltage, and changes over time (dielectric layer 12.13) are caused by both electric field curtains.
], Oa%], and ob, so that malfunctions caused by these disturbances can be prevented before they occur.

In the embodiments shown in FIGS. 5 to 9 VC, the 11th X-ray was applied to the two electric field curtain devices 10 h' and 10 b, but as shown in FIG. By installing two sets of electric field curtain equipment W10,
It is also possible to protect the electric field curtain device 1o by applying the invention.

In the embodiments 11j, the switch 28 is disposed on the secondary side of the transformer, but since the secondary 4IilJ is at high voltage, the primary tan is better.

Further, in the embodiment, the electric field curtain device 10a110b
are configured with the same shape and same dimensions, but if these are different, the current measurement circuit 26a%25bθ]
Although the output value is FIS, the control circuit 27 may be constructed taking this into consideration, and the same effects as those of the embodiments described above will be achieved.

In an electric field curtain device in which a large number of electrode groups oriented in a direction perpendicular to the transfer direction are arranged at required intervals in the transfer direction, a current is applied to each electrode group, and a filter current is applied to each electrode group. Measure each measurement method and each measurement method σ]
A detection means for detecting a difference in output and a means for cutting off the Qit electrolytic electrode group source by the output of the detection means σ) are provided. Deterioration over time, lightning, Genrai Ichiden outbreak, F:if
;Mr! 17) Accurately detect the increase in inflow current before spark discharge in the electric field curtain system 17, and automatically shut off the power to the electric field curtain device immediately before or at the same time as dielectric breakdown occurs. .

As shown in σ), the electric field curtain device σ) accurately cuts off the voltage to the electric field curtain before or at the same time as the breakdown surface, and reduces the discharge energy generated from the breakdown point to 0 J.
By suppressing the minimum layer of pyrotechnic powder, gas, etc. to less than the minimum layer of pyrotechnics (f, which can cause bitterness), it is possible to both ensure safety and prevent malfunctions.

[Brief explanation of drawings]

Fig. 11C is a characteristic diagram illustrating the change in the current flowing into the enclosure W depending on temperature and humidity in an electric field curtain device made of organic materials; A characteristic diagram showing a state in which the surface resistivity decreases by 1''A, Figure 3 is a characteristic diagram showing a state in which the flow into the device increases with the passage of operating time, and No. 4 PXJ is an electric field curtain device. Conventional σ] Protection device σ] Outline of 1 sentence
) With maintenance equipment] - Copying machine σ with actual 1iii+' example)
Cross-sectional side view of the main part, 61st night Maso's plane 1 s 1, grass 7 is the transverse direction 1 s 1 cut along the VJI-■11 line of Fig. 6, and Fig. 8 shows the dielectric breakdown of the electric field curtain device. Figure 10 is a cross-sectional explanatory diagram showing the state of 1 zo, 9th is a schematic diagram illustrating an embodiment of the present invention, and 7 is a diagram illustrating the operating principle of the electric field curtain device. FIG. 111 shows another embodiment σ) kanjimata. 10-%, Field Curtain Equipment*, 11... Polyester electric field curtain decoration, 12... Polyester inner dielectric layer, 13... Polyester surface dielectric layer, l
11.1. ;J, ]6...Copper electrode group, +7.18.
19...Copper electrode group terminal, 20,2122...3-phase AC power supply terminal,...U-phase secondary winding, 24...V-phase 2
Secondary winding, stone... W-phase secondary winding, 26, current measurement circuit,
271 control circuit, ah...switch. Agent: Patent attorney Go 13 (L, 1 person, 1st circle, 2nd circle, 3rd figure. Haku9th figure, 11th figure)

Claims (1)

[Claims] In an electric field curtain device in which a large number of electrode groups oriented in a direction perpendicular to the transfer direction are arranged at required intervals in the transfer direction, a measuring means for measuring the current flowing through each electrode group, and A protection device for a Tero electric field curtain device characterized by comprising: a detection means for detecting a difference in the output of each measurement means; and a power cutoff means for cutting off the power to the electrode group based on the output of the detection means. .