JPS6292971A - Method and device for preventing variance of electrification due to corona discharge - Google Patents

Abstract

PURPOSE:To suppress the stain of a discharging wire and to prevent the occurrence of electrification unevenness due to corona discharge by starting an ozone treatment when a certain time elapses after the corona discharge is started and terminating the ozone treatment within the corona discharge time in a corona discharge device provided with an ozone treating device. CONSTITUTION:A suction fan 9 is started to suck ozone a certain time Q after the start of discharge of a discharging wire 2 of a discharging device 1. The suction fan 9 is stopped at a certain time R before the discharge of the discharging with 2 is stopped. The time difference R between the stop of discharge of the discharging wire 2 and that of operation of the suction fan 9 is set to a time when the suction fan 9 is operated by inertia. Ozone is sucked in only the discharge time to reduce the quantity of dust to the discharging wire 2 which causes the variance of electrification, thus preventing the unevenness of electrification.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ozone treatment device for a corona discharge device in an electrophotographic apparatus, which discharges ozone from each discharge device to the outside of the corona discharge device.

[Prior art]

In electrophotographic apparatuses, corona discharge devices have conventionally been used in processes such as charging a photoreceptor and transferring a toner powder image on the photoreceptor to an entire sheet of paper. Ozone generation is unavoidable during corona discharge. Inhaling large amounts of ozone has a negative effect on the human body, so high-floor copying machines, etc., which generate a large amount of ozone, are equipped with ozone suction processing equipment to keep the amount of ozone emitted outside the machine below a certain level. .

The ozone suction treatment methods used in these devices include a method in which a large fan is installed inside the machine and the entire air inside the machine is exhausted through an ozone filter, and a method in which all the ozone is sucked out from the back of each discharge device. Ru. In other words, there are two types: one type in which the entire air inside the aircraft is processed by passing it through an ozone filter (the discharge device is treated with air blowing), and the other type is in which each discharge device is treated with ozone individually (the discharge device is treated with suction). Ru. For the former, use an appropriate ventilation fan/
Dust can be removed using simple equipment. Since O ozone can be processed in one place, it can be easily processed and the processing capacity is excellent. 0 It has the advantage of being suitable for machines with a sealed interior.However, Q is likely to cause uneven charging because it sucks in dust from the air. There is a large variation in the degree of occurrence of zero charging unevenness.

There are disadvantages such as the change in the zero charge position and the fact that the assistant is a dog, and
In the latter case, the capacity of the zero ozone suction fan can be small. 0 It is possible to downsize the machine and reduce costs. Q: Can save power. It has advantages such as being suitable for machines where the inside of the IB is closed, but since it sucks in dust from the air, it tends to adhere to the wire and cause uneven charging. Since the inside of the charger is not ionized, charging unevenness tends to occur easily.
The choice of whether to install it depends on the characteristics of the machine1. However, even in the case of Izutaku, it was not possible to suppress the occurrence of charging unevenness due to corona discharge.

〔the purpose〕

SUMMARY OF THE INVENTION The present invention provides a method and an apparatus for preventing uneven charging due to corona discharge that occurs when ozone, dust, etc. are treated from within a casing in a charger of an electrophotographic apparatus.

〔composition〕

The present invention provides a method for suppressing troubles such as charging unevenness by setting the ozone treatment operation time of the corona discharge device within the discharge time of the corona discharge device and performing ozone treatment within the corona discharge device, and implementing method 7. The gist of this article is the equipment that is used.

The present invention will be explained below with reference to embodiments shown in the drawings. Figure 1 is an explanatory diagram of the corona discharge device when the ozone treatment inside the corona discharge device is performed by blowing air, an explanatory diagram of the corona discharge device when the ozone treatment is performed by a fan, and Figure 4 is an explanation of the operating time in the case of suction ozone treatment. It is a diagram.

(1) When ozone treatment is performed using a blower fan (first
(see Figures and Figure 2).

A discharge wire 2 is installed in the discharge device 1, and a hole 4 for blowing air is provided in the casing 3.

The hole 4 of the casing 3 is connected to a duct 5, and a blower fan 6 is installed at the end of the duct 5 to blow air into the duct, and an air filtration filter 7 is installed at the duct opening to prevent discharge. The inside of the device is designed to prevent dust and other particles from entering. In addition, the code|symbol 8 is a charging surface.

To explain the operation of the discharge device 1 configured as above, ozone generated due to the discharge of the discharge wire 2 is caused by the air blown through the duct 5 and all the holes 4 of the casing 3 when the blower fan 6 starts rotating. It is discharged outside the device 1 in the direction of arrow A. At this time, the outside air sucked in from the duct opening is full of dust that adheres to the discharge wire 2 and causes uneven charging or leaks, but the dust adheres to the air filtration filter 7 and discharges. It is designed not to enter the device 1. Next, the timing of starting/stopping the fan and discharging will be explained with reference to FIG. 2.

In the present invention, after discharge is started (ON) and the inside of the discharge device 1 is ionized, the blower fan is started (ON) L at an interval of S time after the inside of the discharge device 1 is ionized, and the ozone inside the device 1 is discharged.

This is because the inventors of the present invention have long noticed that the charging potential of the blower type is lower than that of the suction type, but there is no unevenness in charging, but it has been confirmed that this state is gradually becoming more rapid.

For example, there was a considerable difference in the charging potential and charging unevenness between the initial copying of each sheet, the initial stage of repeat copying, and the initial continuous copying. As a result of focusing on this point and verifying it, we found that the charged potential
It has been found that it is better to completely ionize the discharge device 1 in order to prevent variations in charging unevenness. In particular, by ionizing the space between the discharge wire 2 and the charging surface 8, it is possible to create a condition in which it is difficult for discharge from the discharge wire 2 to the charging surface 8, which is suitable for preventing the occurrence of uneven charging, etc. I discovered that

In this method and apparatus, the start of air blowing is delayed from the start of discharge for an amount of time S, so that a constant amount of ions is always maintained in the discharge device 1, and a stable copy can be obtained at all times regardless of the copy operation mode.

There is no specific time limit for the end of the first discharge, but in order to avoid unnecessarily blowing all the air, the air blowing should be stopped at the end of the discharge.
The blower fan 6 is set to be stopped (OFF) after a time T when the discharge wire 2 is stopped (OFF).

(2) When ozone treatment is performed by suction (Figures 3 and 4)
(see figure).

The discharge device 1 and the duct 5 connected thereto are the same as those used in the ozone treatment using air blowing described above. A suction fan 9 is provided at the end of the duct 5, and the duct opening is covered with an ozone removal filter IO. In the case of the suction fan 9, the ozone generated due to the discharge of the discharge wire 2 is sucked into the duct 5 by the suction fan 9 in the direction of arrow B, and most of it is adsorbed by the filter 10 while passing through the ozone removal filter. and the exhaust gas is discharged to the outside air.

At this time, if the suction fan is constantly rotating, the charging device 1
External dust is unnecessarily sucked into the device, and the sucked dust adheres to the discharge wire 2, causing uneven charging or leakage.

Therefore, the timing of the operation of the suction fan 9 and the discharge of the discharge wire 2 in order to minimize the amount of dust sucked in and prevent the discharge wire 2 from getting dirty is shown in FIG.

The suction fan 9 is started (ON) with a delay of Q time from the discharge start (ON) of the discharge wire 2. Then, the suction fan 9 is stopped (OFF) at a time R before the discharge of the discharge wire 2 is stopped (OFF). The time lag (R) between the stop of discharge of the discharge wire 2 and the stop of operation of the suction fan 9 should be approximately the time required for the suction fan to move due to inertia, and the suction fan 9 must be completely stopped when the discharge is stopped. is desirable.

In this way, by sucking ozone only during the discharge time, the amount of dust adhering to the discharge wire, which causes uneven charging, is significantly reduced, which was avoided when the suction fan was constantly rotating. No charging unevenness occurs.

Furthermore, from the other point of view, which has been explained in detail in the case where ozone treatment is performed by blowing air, it is also possible to start discharging from the viewpoint that charging unevenness is less likely to occur if the inside of the discharge device 1 is ionized. (ON), a certain period of time (Q) is left, and during that time, the space between the discharge wire 2 and the charged surface 8 is ionized to create a state in which it is difficult to discharge from the discharge wire 2 to the charged surface 8, and then the suction fan/ 9 is started, this method also satisfies the condition for preventing uneven charging.

〔Effect of the invention〕

The present invention prevents dust such as dust that adheres to the discharge wire and causes uneven charging or causes leakage from entering the device, so it is possible to suppress dirt on the discharge wire, and Since all ozone treatment is performed after ionizing the space between the discharge wire and the charged surface to make it difficult for discharge from the discharge wire to the charged surface, uneven charging can be suppressed and uniform charging can be achieved over a long period of time. , it is possible to provide stable images regardless of the copy mode.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the corona discharge device when ozone treatment inside the corona discharge device is performed by blowing air, Fig. 2 is an explanatory diagram of the operating time in the case of air ozone treatment, and Fig. 3 is an illustration of the inside of the corona discharge device. FIG. 4 is an explanatory diagram of the corona discharge device when the ozone treatment is performed using a suction fan, and FIG. 4 is an explanatory diagram of the operating time in the case of the suction ozone treatment. 1... Discharge device, 2... Corona discharge wire, 6...
- 1st match fan, 9... suction fan.

Claims (2)

[Claims] (1) In a corona discharge device having an ozone treatment device, a method for preventing charging unevenness due to corona discharge, characterized in that ozone treatment is started after a certain period of time has elapsed after the start of corona discharge, and the ozone treatment is completed within the corona discharge time. . (2) In a corona discharge device having an ozone treatment device, the ozone treatment device is started after a certain period of time has elapsed after the discharge of the corona discharge device has started, and the ozone treatment device is stopped within the corona discharge time. Device to prevent uneven charging due to discharge.