JPH06266210A - Discharge apparatus - Google Patents

Abstract

PURPOSE:To prevent abrupt stop of a cleaning means at the end part in the transferring direction due to collision, etc., and prevent the cleaning means from being damaged. CONSTITUTION:A slider 7 is attached to a feed screw 6 set in the extended direction of a corona wire 5 and a cleaning pad holding plate 8 at one end of which a projected part 8a is formed is installed in the slider 7 in the way it can rotate. A cleaning pad 9 is so installed in the cleaning pad holding plate 8 as to prevent the cleaning pad 9 from being in contact with the corona wire 5 when cleaning is not carried out. A tilting part 4a and a detecting hole 4b are formed respectively in one end part and the other end part of the shield case 4. When the slider 7 moves to one end while the cleaning pad 9 is brought into contact with the corona wire 5, the pressing force of the cleaning pad 9 to the corona wire 5 increases gradually by bringing the projected part 8a into contact with the tilting part 4a and the driving load which a motor bears increases gradually and due to that transferring speed of the cleaning part composed of the slider 7 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge device used in an image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically, a discharge device for charging or discharging by corona discharge extends in the longitudinal direction of the casing. The cleaning means, which comprises a cleaning member for pressing the discharge wire and a holder for the cleaning member, is appropriately moved in the tension direction of the wire by the driving means while the cleaning member is in pressure contact with the wire. The present invention relates to a discharge device for cleaning a wire.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a facsimile or a printer, for example, a surface of a latent image carrier is charged or discharged, and a latent image formed on the surface of the latent image carrier is charged. A large number of dischargers are provided as a discharge device used for transferring to the image carrier and for separating the image carrier from the latent image carrier and the like. As the discharger, for example, a corona discharger in which a discharge wire is stretched in a longitudinal direction in a box-shaped shield case and a high voltage is applied to the discharge wire to perform corona discharge is used. However, when this corona discharger is used for a long time, a developer such as toner may adhere to the discharge wire. When the developer adheres to the discharge wire in this way, the discharge efficiency at that location is reduced and discharge unevenness occurs, and as a result, it appears as white streaks in regular development and black streaks in reverse development. Have a significant adverse effect on. Particularly, in full-color copying, color unevenness appears, which is a fatal problem.

Therefore, it is necessary to clean the discharge wire of the discharger in a certain cycle. Conventionally, in a discharger of this type, when a traveling member connected to a drive rope and provided with a cleaning member moves along the discharge wire by the drive rope, the cleaning member sandwiches the discharge wire from two directions. There is known one to be cleaned (see, for example, JP-A-2-62565). Also, a cleaning roller as a cleaning member is brought into contact with the discharge wire, a cleaning moving holder provided with the cleaning roller is moved in a direction in which the discharge wire is stretched, and the cleaning roller is rotated to clean the discharge wire. Known (for example, the actual Kaihei 2-8723
No. 8). Also, a cleaner having a pair of elastic pieces having cleaning pads as cleaning members fixed on the surfaces facing each other is moved along with the discharge wires by fitting the elastic pieces into slits formed in the casing of the discharger. It is known that the cleaning pad sandwiches the discharge wire from two directions to clean the discharge wire (see, for example, Japanese Utility Model Laid-Open No. 1-11008).

Further, in the conventional discharger, there is known one using a feed screw for moving the cleaning means, which is provided with a cleaning member which is in pressure contact with the discharge wire, in the tension direction of the discharge wire. In this kind of discharger, the cleaning means can be moved in the tension direction of the discharge wire by engaging the cleaning means with the feed screw and rotating the feed screw. Here, the driving force of the feed screw can be obtained by, for example, decelerating the motor output with a gear or the like. In this type of apparatus, the cleaning means reciprocates in the direction in which the discharge wire is stretched by the forward / reverse rotation of the drive shaft of the motor, that is, the forward / reverse rotation of the feed screw. It becomes a cycle. Now, for example, the home position of the cleaning means is the front end of the discharger, and the forward path (moving process from the front end of the cleaning means to the rear end)
Is set so that the drive shaft of the motor is rotated in the normal direction, and the drive shaft of the motor is rotated in the reverse path (moving process from the rear end to the front end of the cleaning means). Consider the case where the motor starts moving from the position and reaches the rear end of the discharger, the rotation of the motor drive shaft switches from normal rotation to reverse rotation, and then the cleaning means returns to the home position and the motor stops. . In each case, it is necessary to control that the rotation of the drive shaft of the motor is switched from the normal rotation to the reverse rotation or stopped by judging that the cleaning means has reached the rear end portion or the home position. Here, as the means for detecting that the cleaning means has reached the rear end or the home position, for example, sensors may be provided at the front end and the rear end of the discharger. However, if sensors are provided at the front end and the rear end of the discharger to detect that the cleaning means has reached the rear end or the home position, the structure becomes complicated and the design is free. There was a problem that the degree and reliability were lowered, and further the cost was increased.

Therefore, conventionally, a sensor for detecting the position of the cleaning means is not provided, and the lock current is generated when the cleaning means reaches the end portion in the moving direction and the motor is locked (the rotation of the drive shaft is restricted). A method of detecting that the cleaning means has reached the end portion in the moving direction is known. This method utilizes that the current when the motor is locked is larger than the current when the motor is rated.

However, according to this method, since the cleaning means repeats sudden stop at the end portion in the moving direction by colliding with, for example, the side plate of the discharger casing, the load on the motor and the gear is large and the time elapses. There was a problem that it could be damaged. Further, the energy generated when the cleaning means collides with the end side plate in the moving direction is stored as stress in the gear and the feed screw portion and stops while the screw is engaged, so the torque required for restart becomes large, There was a problem that it might not be possible to restart.

Therefore, in order to soften the sudden stop at the end of the cleaning means in the moving direction, it is known to provide a rubber spacer at the end of the feed screw so as to absorb the shock at the time of collision. Has been.

[0008]

However, according to this structure, corona discharge is generated in the vicinity of the spacer made of rubber, and a high concentration of ozone is generated by the corona discharge.
There is a problem in that the reliability cannot be said to be high, such as concern over deterioration of rubber elasticity due to ozone over time.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cleaning means which does not have a shock absorbing member such as a spacer made of rubber, and which is caused by a collision or the like at an end portion in the moving direction. An object of the present invention is to provide a discharge device capable of preventing a sudden stop and preventing damage to a driving means.

[0010]

In order to achieve the above object, the invention of claim 1 is a cleaning method in which a discharge wire stretched in the longitudinal direction of a casing of a discharger for charging or discharging by corona discharge is pressed against the discharge wire. In a discharge device that cleans the wire by appropriately moving a cleaning means including a member and a holder of the cleaning member in a tension direction of the wire by a driving means in a state where the cleaning member is in pressure contact with the wire, Along with the movement of the cleaning means toward the one end side in the longitudinal direction of the casing, the cleaning member is displaced in a direction intersecting with the stretching direction, and the pressing force of the cleaning member against the wire gradually increases. As described above, the contact portion for at least a part of the cleaning means is formed at the end portion in the longitudinal direction of the casing. It is an butterfly. According to a second aspect of the present invention, in the discharger cleaning device according to the first aspect, when the cleaning means comes into contact with the abutting portion, the drive means increases as the cleaning means moves toward the one end side. Drive load detection means for detecting a load, and drive stop means for stopping the drive drive of the cleaning means to the one end side by the drive means based on the output of the drive load detection means. It is a thing. According to a third aspect of the present invention, there is provided a cleaning member including a cleaning member that is in pressure contact with a discharge wire stretched in a casing longitudinal direction of a discharger that performs charging or discharging by corona discharge, and a holder for the cleaning member. In a discharge device which cleans the wire by moving the wire in a tension direction of the wire by a driving means in a state of being pressed against the wire, the cleaning member is formed at an end portion in the longitudinal direction of the casing, and the cleaning member has the longitudinal direction of the casing. With the movement of the end portion of the cleaning member to the one end side, the release portion releases the pressure contact state of the cleaning member with respect to the wire, and the release portion releases the pressure contact state of the cleaning member with respect to the wire. Drive load detection means for detecting the load of the drive means, and based on the output of the drive load detection means In which characterized in that a driving stopping means for stopping the movement drive to the one end side by the driving means.

[0011]

In the first aspect of the invention, the cleaning means is moved in the tensioning direction of the discharge wire by the driving means while the cleaning member is pressed against the discharge wire stretched in the longitudinal direction of the casing of the discharger. The cleaning means comes into contact with the abutting portion during the movement toward one end of the end portion in the longitudinal direction of the casing. When the cleaning means continues to move to the one end side, the pressing force of the cleaning member against the wire gradually increases with the movement.
The cleaning member is displaced in a direction that intersects the discharge wire stretching direction. Then, the pressure contact force of the cleaning member with respect to the wire is gradually increased to increase the driving load of the driving means, and thereby the moving speed of the cleaning member is decelerated. In the invention of claim 2, in the drive load detecting means, the cleaning means makes contact with the contact portion at the end portion in the longitudinal direction of the casing, and the pressure contact force of the cleaning member with respect to the wire gradually increases as the cleaning means moves to one end side. The driving load of the driving means that is increasing due to the increase is detected, and a predetermined signal is output to the driving stopping means. The drive stopping means, which has received the output signal from the drive load detecting means, stops the drive driving of the cleaning means to the one end side by the driving means. In the invention of claim 3, the cleaning means is moved in the tensioning direction of the discharge wire by the driving means in a state where the cleaning member is pressed against the discharge wire stretched in the longitudinal direction of the casing of the discharger. The cleaning unit releases the pressure contact state of the cleaning member with the wire by the release unit during the movement toward the one end side of the end portion in the longitudinal direction of the casing. Then, when the pressure contact state of the cleaning member with respect to the wire is released, the load on the drive unit is reduced. Here, the drive load detection means detects the reduced drive load of the drive means and outputs a predetermined signal to the drive stop means.
The drive stopping means, which has received the output signal from the drive load detecting means, stops the drive driving of the cleaning means to the one end side by the driving means.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a charger used in an electrophotographic copying machine (hereinafter referred to as copying machine) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of the charger according to this embodiment, and FIG. 2 is a cross-sectional view of the charger when it is not cleaned. The charger 1 is a scorotron type charger having a grid electrode 3 (see FIG. 2) provided in an opening 2 facing a latent image carrier (not shown). The charger 1 includes a metallic shield case 4 formed so as to extend in the longitudinal direction of the latent image carrier, and an elastic member (not shown) provided between end blocks (not shown) provided at both ends of the shield case 4 in the longitudinal direction. And two corona wires 5 which are stretched by applying a predetermined tension.

A feed screw 6 is provided above the charger 1 in parallel with the direction in which the corona wire 5 is stretched (hereinafter referred to as the wire stretching direction). The feed screw 6 is connected to, for example, a motor as a drive unit (not shown), and is configured to rotate in the normal direction or reverse direction of the motor drive shaft or to rotate in the normal direction or reverse direction via a gear or the like interposed between the feed screw 6 and the motor. Is configured.

A slider 7 is attached to the feed screw 6 so as to reciprocate in the wire tension direction in accordance with the rotation thereof. The slider 7 is a columnar member, and has a through hole formed from one end surface to the other end surface, and a thread that engages with the thread of the feed screw 6 peripheral surface is cut on the peripheral surface of the through hole. There is. Then, the thread of the slider 7 and the feed screw 6
The slider 7 is attached to the feed screw 6 by engaging with the thread of the peripheral surface and inserting the feed screw 6 into the through hole of the slider 7. The slider 7 is provided with a cylindrical portion 7a protruding toward the opening 2. A cleaning pad holding plate 8 as a holder configured to be rotatable around the cylindrical portion 7a is attached to the cylindrical portion 7a between the slider 7 and the corona wire 5.

The cleaning pad holding plate 8 is set to have a width that is slightly larger than the distance between the two corona wires 5 in the direction perpendicular to the wire tension direction (hereinafter referred to as the wire vertical direction). Further, a cleaning pad 9 as a pair of cleaning members is attached to each corona wire 5 on the surface (lower surface) of the cleaning pad holding plate 8 on the opening 2 side. The length of each of the cleaning pads 9 in the wire tension direction is the cleaning pad holding plate 8 in that direction.
It is set to be about half the length of. Each of the cleaning pads 9 in the pair of cleaning pads 9 is arranged at a predetermined distance from the corona wire 5 in the wire vertical direction, and is arranged so as to be displaced to the left and right in that direction. Further, a protrusion 8a is provided on one end of the cleaning pad holding plate 8 in the wire vertical direction. The protrusion 8a contacts the inner surface of the shield case 4 at the time of cleaning, and is set to a length such that the cleaning pad holding plate 8 is rotated about the cylindrical portion 7a and is inclined by a predetermined amount with respect to the wire tension direction. ing.

The protrusion 8a is brought into contact with one end of the shield case 4 facing the protrusion 8a to increase the inclination of the cleaning pad holding plate 8 with respect to the wire tension direction, thereby cleaning the cleaning pad 9a. An inclined portion 4a is formed as an abutting portion protruding inside the shield case 4 for restricting the posture of No. 1 to the posture in which the corona wire 5 is pressed against the corona wire 5. At the other end, the projection 8a releases the contact state with the inner surface of the shield case 4, and the end of the projection 8a projects outside the shield case 4 so that the cleaning pad holding plate 8 is not tilted. A detection hole 4b is provided as a release portion for the purpose. In the above structure, the slider 7, the cleaning pad holding plate 8 and the cleaning pad 9 form a cleaning means.

In the following description, one reciprocation of the slider 7 is one cleaning cycle. Further, the slider 7 is located at the end portion (hereinafter referred to as the home position) where the detection hole 4b is provided when not cleaning, and as shown in FIG.
The cleaning pad holding plate 8 is not tilted because the end portion a is slightly projected from the detection hole 4b to the outside of the shield case 4, and the cleaning pad 9 is attached to the corona wire 5
Is not in contact with. Further, the slider 7 moves from the home position toward the inclined portion 4a by the normal rotation of the motor drive shaft (normal rotation of the feed screw 6),
It is assumed that the motor drive shaft moves in the home position direction by reverse rotation (reverse rotation of the feed screw 6).

In the above structure, when the driving of the motor is started and the feed screw 6 starts to rotate in the forward direction, the slider 7 starts to move in the direction of the inclined portion 4a and the cleaning pad holding plate 8
The projecting portion 8a comes out of the detecting hole 4b, and its end portion comes into contact with the inner surface of the shield case 4. At that time, the cleaning pad holding plate 8 is tilted by a predetermined amount with respect to the wire tension direction, so that the cleaning pad 9 is pressed against the corona wire 5. In this state, the motor continues to be driven and the slider 7 continues to move, whereby the corona wire 5 is cleaned by the cleaning pad 9. Then, when the slider 7 reaches the vicinity of the end of the shield case 4 where the inclined portion 4a is formed and the protrusion 8a contacts the inclined portion 4a, the inclination of the cleaning pad holding plate 8 gradually increases. Here, when the inclination of the cleaning pad holding plate 8 gradually increases with the movement of the slider 7, the cleaning pad 9 is displaced in the wire vertical direction, whereby the pressure contact force between the cleaning pad 9 and the corona wire 5 gradually increases. Increase. As a result, the stress of the elastic member (not shown) that applies the tension to the corona wire 5 increases, and the moving speed of the slider 7 decreases. After that, the slider 7 abuts on the end block, and the forward movement is completed.

In the return path, the drive of the motor is reversed and the feed screw 6 starts to rotate in reverse, so that the slider 7 starts moving toward the home position. that time,
By moving the protrusion 8a along the inclined portion 4a, the inclination of the cleaning pad holding plate 8 is gradually reduced, contrary to the forward path, and the pressure contact force between the cleaning pad 9 and the corona wire 5 is gradually reduced. To go. And
As the slider 7 continues to move in a state where the end of the protrusion 8a is in contact with the inner surface of the shield case 4, the corona wire 5 is cleaned by the cleaning pad 9 as in the outward path. When the motor continues to be driven after the slider 7 has reached the vicinity of the home position, the protrusion 8a will cause the detection hole 4 to move.
b, the direction of the cleaning pad holding plate 8 is returned by the tension of the corona wire 5 so that its longitudinal direction is parallel to the wire vertical direction, and the pressure contact state between the cleaning pad 9 and the corona wire 5 is released. It Then, after that, the slider 7 collides with the end block, and the movement of the return path is completed.

By the way, one of the above cleaning in the present embodiment
In the cycle, when the protrusion 8a abuts the inclined portion 4a on the outward path and the pressure contact force between the cleaning pad 9 and the corona wire 5 gradually increases, the load on the motor increases, thereby increasing the load on the motor. The flowing current also gradually increases. Further, when the protrusion 8a falls into the detection hole 4b on the return path and the pressure contact state between the cleaning pad 9 and the corona wire 5 is released, the load on the motor sharply decreases, and the current flowing through the motor also sharply decreases. Decrease.

Therefore, in the present embodiment, the drive load detecting means (not shown) detects the magnitude of the current flowing through the motor to detect that the slider 7 has reached the end of the shield case 4, and the motor is detected. The control is performed such that the driving of the motor is reversed and the driving of the motor is stopped by a driving stop means (not shown).

Hereinafter, the slider 7 is used as the shield case 4.
Reverse rotation and stop control of the motor drive shaft when reaching the end will be described. FIG. 3 is a flow chart relating to drive control of the motor, and FIG. 4 is an explanatory diagram showing changes in current flowing through the motor in this embodiment. A constant current (Ic) flows through the motor until the driving of the motor is started and the protrusion 8a comes out of the detection hole 4b. After that, when the protruding portion 8a comes out of the detection hole 4b and the end portion of the protruding portion 8a contacts the inner surface of the shield case 4, if the load applied to the motor increases, the current (Ia) increased according to the load is applied to the motor. Flow (step 1).

Here, the drive load detecting means detects whether or not the current (I) flowing through the motor becomes equal to or higher than a predetermined threshold value (Ib) (step 2). At this time, since the load applied to the motor does not change while the end of the protruding portion 8a is in contact with and slides on the inner surface of the shield case 4, the current (I) flowing through the motor is equal to or greater than the threshold value (Ib). Is not detected (No in step 2), the current (I
a) keeps flowing to the motor.

When the projection 8a contacts the inclined portion 4a and the pressure contact force between the cleaning pad 9 and the corona wire 5 gradually increases, the current flowing through the motor also gradually increases. Here, when the drive load detection means detects that the current flowing through the motor has become equal to or higher than the threshold value (Ib) (Yes in step 2), the drive load detection means sets a predetermined value for the drive stop means. Output a signal. The drive stopping means, which receives the output signal from the drive load detecting means, stops the motor, thereby stopping the cleaning means (step 3).

After a lapse of a predetermined time from the stop of the motor on the outward path, on the return path, a current of the opposite polarity (-) to the outward path flows in the motor to reverse the driving of the motor. At this time, when the protrusion 8a moves in the home position direction along the inclined portion 4a and the pressure contact force between the cleaning pad 9 and the corona wire 5 gradually decreases, the current flowing through the motor also gradually decreases accordingly. Go. Then, when the end of the protruding portion 8a comes into contact with the inner surface of the shield case 4, a current (-Ia ') corresponding to the load at that time flows through the motor (step 4).

Here, the drive load detecting means detects whether or not the current (I) flowing through the motor has reached a predetermined threshold value (-Ic) (step 5). At this time, the protrusion 8
Since the load applied to the motor does not change while the end a is in contact with the inner surface of the shield case 4 and is sliding, it is detected that the current (I) flowing through the motor has reached the threshold value (-Ic). No (No in step 5), the current (-I
a ') continues to flow to the motor. Then, the protrusion 8a falls into the detection hole 4b, and the cleaning pad holding plate 8 is returned by the tension of the corona wire 5 so as to be oriented in the vertical direction,
When the pressure contact state between the cleaning pad 9 and the corona wire 5 is released, the load applied to the motor sharply decreases, and the current flowing through the motor also sharply decreases. Here, when the drive load detection means detects that the current flowing through the motor has reached the threshold value (-Ic) (Yes in step 5), the drive load detection means sets a predetermined value for the drive stop means. Output a signal. The drive stopping means, which has received the output signal from the drive load detecting means, stops the motor, thereby stopping the cleaning means (step 6).

As described above, according to the present embodiment, even when the slider 7 reaches the vicinity of the end portion of the shield case 4 where the inclined portion 4a is formed in the forward path, the protrusion 8a abuts the inclined portion 4a. Since the pressure contact force between the cleaning pad 9 and the corona wire 5 gradually increases and the moving speed of the slider 7 slows down, the cleaning means composed of the slider 7 or the like does not collide with the end block and suddenly stops.
Therefore, a large load is not instantaneously applied to the motor or the like, and the motor or the like is not damaged. In addition, since the control for reversing or stopping the driving of the motor is performed by detecting the magnitude of the current flowing through the motor, the cleaning means constituted by the slider 7 or the like has an end portion. Since it is not necessary to provide a special sensor or the like for detecting the arrival at, the cost can be kept low.
Further, since the inclined portion 4a and the detection hole 4b are formed integrally with the side plate of the shield case 4, the number of parts is increased, the cost is increased, and the number of assembling steps is increased as compared with the case where the inclined part 4a and the detection hole 4b are provided as separate members and assembled to the charger. Can be suppressed. In addition, since the driving of the motor is stopped when the current flowing in the motor is reduced due to the protrusion 8a falling into the detection hole 4b, the cleaning means constituted by the slider 7 or the like collides with the end block and suddenly stops even in the return path. Therefore, a large load is not instantaneously applied to the motor or the like, and the motor or the like is not damaged. Further, when the cleaning means including the slider 7 and the like is at the home position (when not cleaning), the cleaning pad 9 is not in contact with the corona wire 5, so the corona wire 5
The position of can be maintained at a preset position.

In the present embodiment, the corona wire 5 is pressed against the cleaning pad 9 from the vertical direction of the wire, and the protrusion 8a is brought into contact with the inclined part 4a, so that the pressing force between the cleaning pad 9 and the corona wire 5 is increased. Is gradually increased, and the protruding portion 8a falls into the detection hole 4b to release the pressure contact state between the cleaning pad 9 and the corona wire 5. However, instead of this, for example, the corona wire 5 is cleaned from the vertical direction. An opening portion 41c configured to be pressed against each other by the pad 9 and gradually widening toward one end side at the home position side end portion on both side plates of the shield case 4 and one end side portion at the other end portion. A slit 4c having a pressure contact portion 42c that becomes narrower than the above, and a cleaning pad 9 to which a cleaning pad 9 is attached. The slit 4c the end of the de support plate
May be configured to be engaged with. Also with this configuration, the cleaning pad support plate moves to move the pressure contact portion 42c.
Reaching the cleaning pad 9 by the pressure contact portion 42c.
Of the corona wire 5 increases, and the cleaning pad support plate moves to open the opening 41c.
Reach the cleaning pad 9 through the opening 41c.
The pressure contact state between the and corona wire 5 can be released. Therefore,
Even in this configuration, the load applied to the motor changes, and the magnitude of the current flowing through the motor also changes, so
Similar to the present embodiment, the drive control of the motor can be performed based on the magnitude of the current flowing through the motor. Further, in the present embodiment, the scorotron type charger was described as an example, but the present invention is not limited to this, and a corotron type charger, a transfer device having the same configuration, a corona discharger such as a separator, etc. Can also be applied to.

[0029]

According to the first aspect of the invention, since the moving speed of the cleaning means is decelerated at the longitudinal end of the casing of the discharger, the cleaning means may collide with the casing side plate and suddenly stop. Therefore, there is an effect that a large load is not instantaneously applied to the driving means and the driving means is not damaged. According to the second aspect of the present invention, the drive means is driven by the stop signal from the drive stop means based on the signal of the drive load detection means for detecting the drive load of the drive means increased by the contact of the cleaning means with the contact portion. Since the cleaning unit is stopped and the cleaning unit is also stopped accordingly, it is not necessary to provide a special sensor or the like for detecting the stop position of the cleaning unit, and the cost can be kept low. According to the third aspect of the present invention, the drive means is based on the fact that the releasing portion releases the pressure contact state of the cleaning member with the wire at the longitudinal end portion of the casing of the discharger, and the load on the drive means is reduced. Since the cleaning means is stopped and the cleaning means is also stopped accordingly, the cleaning means does not collide with the casing side plate and suddenly stops, so that a large load is not instantaneously applied to the drive means and the drive means is not damaged. effective. Further, there is an effect that the position of the wire can be maintained at a preset position when the cleaning means is not operating. Further, it is not necessary to provide a special sensor or the like for detecting the stop position of the cleaning means,
The effect is that the cost can be kept low.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a charger according to an embodiment.

FIG. 2 is a cross-sectional view of the charger when it is not cleaned.

FIG. 3 is a flowchart relating to motor drive control.

FIG. 4 is an explanatory diagram showing a change in current flowing through a motor.

FIG. 5 is a schematic configuration diagram of a charger side plate according to another embodiment.

[Explanation of symbols]

 1 Charging Device 2 Opening 3 Grid Electrode 4 Shield Case 4a Slope 4b Detection Hole 5 Corona Wire 6 Feed Screw 7 Slider 7a Cylindrical 8 Cleaning Pad Holding Plate 8a Projection 9 Cleaning Pad

Claims (3)

[Claims] 1. A cleaning means comprising: a cleaning member provided with a cleaning member that comes into pressure contact with a discharge wire stretched in the longitudinal direction of a casing of a discharger that charges or removes electricity by corona discharge; and a holder for the cleaning member. In a discharge device which cleans the wire by appropriately moving it in the tension direction of the wire in a state of being pressed against the wire, with the movement of the cleaning means to one end side of the end portion in the longitudinal direction of the casing, So that the cleaning member is displaced in a direction intersecting with the tensioning direction and the pressure contact force of the cleaning member with respect to the wire is gradually increased.
A discharge device, wherein an abutting portion for at least a part of the cleaning means is formed at an end portion in the longitudinal direction of the casing. 2. A drive load detecting means for detecting a load of the drive means, which is increased as the cleaning means is brought into contact with the contact portion, as the cleaning means is moved toward the one end side, and the drive load detecting means. 2. The discharge device according to claim 1, further comprising drive stop means for stopping the drive drive of the cleaning means to the one end side by the drive means based on the output of the load detection means. 3. Cleaning means comprising: a cleaning member, which is in pressure contact with a discharge wire stretched in the longitudinal direction of a casing of a discharger for charging or discharging by corona discharge, and a holder for the cleaning member, wherein the cleaning member In a discharge device which cleans the wire by appropriately moving it in the tension direction of the wire in a state of being pressed against the wire, the discharge member is formed at an end portion in the longitudinal direction of the casing, and an end of the cleaning member in the longitudinal direction of the casing. Release part for releasing the pressure contact state of the cleaning member to the wire with the movement of the cleaning member to one end side, and the drive reduced by releasing the pressure contact state of the cleaning member to the wire by the release part. Drive load detection means for detecting the load of the drive means, and the drive based on the output of the drive load detection means And a drive stopping means for stopping the drive driving to the one end side by the means.