JPH1090979A - Automatic cleaning device for corona discharge unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect a cleaning pad position in real time, to easily detect load abnormality and to quickly perform retuging driving. SOLUTION: A variable resistor 8 is connected to a transfer bar 5 for reciprocation-driving a cleaning pad 3a and a signal V0 indicating the position of the cleaning pad is produced. The position and signal V0 levels are linear. Immediately after power input and at the time of closing a copying machine cover, the cleaning pad is driven to a near part, a home position or a return position, by referring to the signal V0 . By reading the signal V0 at a constant cycle, a moving speed Sr is calculated. Driving torque T is calculated from the speed Sr and overloading is detected. Alternatively, overloading is detected by comparing the moving speed Sr with a threshold value Ss. The resistor 8 includes a screw bar 8a connected to the transfer bar 5, a slider 8c screw- connected therewith and a resisting body 8d for contact with the slider, and screw thread pitch of the screw bar 8a is smaller than that of the transfer bar 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically cleaning a corona discharger having a main body casing and a charge wire extending in a longitudinal direction of the main body casing and performing corona discharge. It is used for an electrophotographic image forming apparatus such as a printer and an air purifier.

[0002]

2. Description of the Related Art For example, in an electrophotographic image forming apparatus, a charging charger for charging the surface of a photoreceptor, a transfer charger for transferring a toner image formed on the surface of a photoreceptor to a transfer paper, and the like. A corona discharger in which a discharge wire is stretched in a longitudinal direction in a box-shaped casing is used. The corona discharger performs a corona discharge by applying a high voltage of about a few hundred volts to a few thousand volts to the wire, thereby giving a uniform charge to the surface of the photoreceptor and transfer paper. However, when the corona discharger is used for a long time, the dust of silica or toner adheres to the wire and changes the discharge characteristics, thereby lowering the charging efficiency of the photoreceptor and the transfer paper, and the charging state becomes non-uniform. .

Hitherto, in order to prevent such an adverse effect, a serviceman has regularly performed cleaning and a maintenance part has been regularly replaced. Therefore, the maintenance of the corona discharger required a great deal of labor, cost and resources.

[0004] Therefore, a number of automatic cleaning devices for corona dischargers have been proposed in the past. However, in the conventional apparatus, when the cleaning member is reciprocated, the cleaning member rides on the end block at both ends of the casing, and a load more than the torque of the drive motor is generated, so that the automatic cleaning does not function. Was.

Conventionally, a sensor for detecting that the cleaning member has reached the home position or the offset position is provided (Japanese Patent Application Laid-Open Nos. 61-292655 and 1-284874), (See Japanese Patent Application Laid-Open No. 61-292654).
No.).

However, there is a problem that erroneous detection occurs due to dirt or damage of the sensor, and a method using a drive current has high reliability against troubles due to element damage, but generally uses a low-cost brush motor. Therefore, the characteristics of the torque and the number of revolutions with respect to the drive current change due to the deterioration of the motor, and erroneous detection of the restrained state occurs with the passage of time, resulting in malfunction. Further, the position of the cleaning member cannot be detected while the cleaning member is being driven, so that it takes a lot of time to find an error or the deterioration of the motor is accelerated. In order to improve this, the present inventor detects a constrained current when the cleaning member reaches the end block, and sets a reference value corresponding to the detected value in the traveling region of the cleaning member for overload detection. And developed a technique for preventing an overload detection error due to a change in load over time (Japanese Patent Application No. 7-50831).

[0007]

However, in the aspect in which the end of the cleaning member is detected or an abnormal stop is detected with reference to the motor current, the cleaning member is moved to a traveling area between one end and the other end of the moving range. I don't know where it is. When driving the cleaning member from one end to the other end, by measuring the elapsed time from the start of driving, it is possible to obtain some indication of the position of the cleaning member, but the load changes over time, When the load fluctuation within the moving range is large, the moving distance is not proportional to the elapsed time, and the position cannot be recognized.

For example, in the case of a copying machine equipped with a corona discharger, the cleaning member is located at an end position (home position, reverse position).
In the moving range, that is, in the image forming area,
Since it is impossible to uniformly charge the photosensitive member by the corona discharger, immediately after turning on the power or immediately after the copier cover is opened and closed, if the cleaning member is not at the end position, it is driven to the end position ( In this case, it is preferable to drive the cleaning member to the end of the movement area near the current position in order to shorten the driving time. When the cleaning start condition is satisfied, for example, when the integrated copy value becomes equal to or more than the set value, the copy is terminated, and cleaning (driving of the cleaning member) is started when there is no copy instruction. If a copy instruction is issued during this time, it is preferable that the cleaning be stopped, the cleaning member be retracted to the near end, and the cleaning be resumed after the copy corresponding to the copy instruction ends. To achieve these, it is necessary to accurately detect the position of the cleaning member.

An object of the present invention is to greatly improve the reliability of an automatic cleaning apparatus. The first object of the present invention is to detect the position of a cleaning member being driven relatively accurately in real time.
A second object is to relatively easily detect a load abnormality while the cleaning member is being driven, and a third object is to quickly perform charger homing and retreat driving.

[0010]

[Means for Solving the Problems]

(1) A cleaning member (3a) for cleaning a charge wire (2) of a corona discharger having a main body casing (4) and a charge wire (2) for performing corona discharge stretched in a longitudinal direction thereof; Driving means (6, 7a, 5, 3) including a power transmission mechanism (5, 3) for driving the cleaning member (3a) in the direction in which the wire (2) extends, and converting rotational movement into linear movement; A corona comprising: means (7b, 8) for detecting the position of the cleaning member (3a); and means (9) for controlling the driving means with reference to the detected position of the position detecting means (7b, 8). In the automatic discharger cleaning device, the position detecting means (7b, 8) includes the driving means (6, 7).
and a variable resistor (8) coupled to the cleaning member (3a) to generate a resistance value corresponding to the position of the cleaning member (3a). In addition, in order to facilitate understanding, symbols of corresponding elements or corresponding items in the embodiments shown in the drawings and described later are added for reference in parentheses.

According to this, the current position of the cleaning member (3a) can be accurately known in real time from the resistance value of the variable resistor (8).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(2) The variable resistor (8) is a terminal to which the reference potential (0) is given
(A), terminal (C) to which constant voltage (V) is applied, and cleaning member (3
a) a terminal (B) for outputting a voltage (Vo) from the reference potential to a constant voltage corresponding to the position of (a), and a voltage (V
o) is the lowest value (0) when the cleaning member (3a) is located at one end of its movement range, and the highest value when it is located at the other end.
(V), and is proportional to the position of the cleaning member between both ends.

According to this, the voltage (Vo) of the output (B) of the variable resistor (8) is proportional to the position (distance from one end) of the cleaning member (3a) and is based on this voltage (Vo). Recognition of the position of the cleaning member (3a) is simple and accurate.

(3) The control means (9) controls the position detecting means immediately after power-on of the equipment equipped with the corona discharger.
If the detection position (Vo) of (7b, 8) is not one of the one end (0) and the other end (Vo) of the moving range of the cleaning member (3a), the driving means (6, 7a , 5, 3) to drive the cleaning member (3a) to the near end (0 / Vo).

According to this, since the current position of the cleaning member (3a) is clear during the homing drive, the drive time is the shortest, and the homing waiting time is short.

(4) The control means (9) comprises:
When driving the cleaning member (3a) via (6, 7a, 5, 3),
The moving position (Sr) of the cleaning member (3a) is calculated by repeatedly reading the position detected by the position detecting means (7b, 8).

For example, while the cleaning member (3a) is being driven, a fixed period (d
When the position (Vo) of the cleaning member (3a) is read in (t), the value obtained by dividing the difference between the position of the start point and the position of the end point of one cycle (dt) by the cycle (dt) is obtained as the moving speed (Sr). Can be By determining the period (dt) in the time unit expressing the moving speed (Sr), division is unnecessary, and the difference can be regarded as the moving speed (Sr) as it is, and the speed calculation of the cleaning member (3a) is performed. Is easy.

(5) The control means (9) calculates a driving torque (T) of the cleaning member (3a) based on the calculated moving speed (Sr), and the calculated driving torque (T) is set to a set value ( When Ts) or more, the driving by the driving means (6, 7a, 5, 3) is stopped, and this is reported.

FIG. 8 shows the relationship between the rotational speed (Sr) of the driving means (electric motor 6) and the driving torque (T: mechanical load), and the moving speed (Sr) calculated according to this relationship. Can be calculated, and the torque (T) can be detected in real time. Since the load abnormality is determined based on the torque (T), it is possible to prevent the motor life from being shortened due to excessive torque, particularly a relatively long motor energization with excessive torque.

(6) When the calculated moving speed (Sr) is equal to or less than the set value (Ss), the control means (9) controls the driving means.
The drive by (6, 7a, 5, 3) is stopped and this is reported. If the moving speed (Sr) falls below the set value (Ss) due to a load error, the drive will be stopped.
(2) or cleaning member (3a) or driving means (6, 7a, 5, 3)
Is prevented from being damaged or deteriorated.

(7) The position detecting means (7b, 8) includes a rotating shaft (8) coupled to a rotating member (5) of the power transmission mechanism (5, 3).
a) and the sliders (8b, 8c) connected to the rotating shaft body (8a).
including. (8) The rotary shaft body (8a) is a screw rod (8a) to which the sliders (8b, 8c) are screwed.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0023]

【Example】

-First Embodiment- FIG. 1 shows an outline of a mechanism of a first embodiment of the present invention. The corona discharger is constituted by end blocks 1a and 1b, a metal casing 4, and a tungsten wire 2 stretched between the end blocks. The wire 2 and the casing 4 are connected to a high-voltage power supply circuit by a connector (not shown). Have been.

The corona discharger includes a pair of pad holders 3 each having a cleaning pad 3a for automatically cleaning the wire 2, and a spiral (screw rod) for transferring the cleaning member 3 along the wire 2. ) Is provided, and an electric motor 6 for driving the transfer rod 5 is provided. The output shaft of the motor 6 and the transfer rod 5 are connected by a coupling 7a. When the pad holder 3 is transferred, the wire 2 is clamped by the cleaning pad 3a to clean the wire. A variable resistor 8 is connected to the transfer rod 5.

FIG. 2 shows a longitudinal section of the variable resistor 8. A coupling 7b connects the transfer rod 5 to a rotary shaft 8a which is a screw bar, and the female screw 8b of the slider 8c is screwed to the rotary shaft 8a in a relation between a bolt and a nut.
By transmitting the rotation of the transfer rod 5 to the rotation shaft 8a of the position detecting means 8 via the coupling 7, the shaft 8a rotates. A spiral (thread) is formed on the shaft 8a, and the rotation of the shaft causes the slider 8c to move in the same direction as the pad holder 3. Since the spiral pitch of the rotating shaft 8a is smaller than that of the transfer rod 5, the moving amount of the slider 8c is much smaller than the moving amount of the pad holder 3 during one rotation thereof.

At the tip of the slider 8c, there is a conductive sliding contact, which slides on the resistor 8d. The variable resistor 8 has three terminals: an equipment earth potential terminal A, an output terminal B connected to the slider 8c, and a terminal C for applying a constant voltage V.

Rotation of the transfer rod 5, that is, the pad holder 3
Between terminals AB, and between terminals BC
The resistance value between them changes. For example, in FIG. 1, when the pad holder 3 is located at the home position where the left movement is restricted by one end block 1a, the resistance value between the terminals A and B is the lowest, and the pad holder 3 moves right by the other end block 1c. If the resistance value between terminals A and B is set to be the highest when it is located at the return position where is restricted, the position of pad holder 3 can be determined by detecting the resistance value between terminals A and B. In this embodiment, the characteristic of the variable resistor 8 is set so that the resistance value is proportional to the position (distance or movement amount) of the pad holder 3 starting from the home position. It is easy to calculate the position of the pad holder 3 from the above resistance value.

In the actual control, it is easier to detect the voltage value than the resistance value. Therefore, the terminal A is connected to the equipment ground, and the constant voltage V is applied to the terminal C. The voltage Vo at the terminal B was subjected to A / D conversion, and this data was used as position data for the pad holder 3. The relative position between the resistor 8d and the slider 8c is such that the voltage Vo of the terminal B becomes the equipment ground level 0 when the pad holder 3 is at the home position, and the constant voltage V when the pad holder 3 is at the return position. It was set. Here, the position of the pad holder 3 is
Assuming that the distance from the home position D is L, and the distance between the home position and the ritter position is L, then Vo = (D / L) · V (1) Therefore, the position D of the pad holder 3 is , D = (L / V) · Vo (2) Since L and V are fixed values, (L / V) is a constant. When reading the voltage Vo at the terminal B, the setting of the amplification factor of the voltage Vo and the setting of the range of the A / D conversion allow the digitalization of the voltage Vo. The conversion data may immediately represent position D. The resistor 8d of the variable resistor 8 has a uniform resistance distribution, and the position of the slider 8c in the longitudinal direction (AC direction) and the resistance value between the terminals A / B have a linear relationship. . The linearity of the output value of the variable resistor 8 is important because it affects the detection accuracy.

FIG. 3 shows a controller 9 for monitoring and controlling the hardware status of a copying machine equipped with the corona discharger shown in FIG. The controller 9 is mainly composed of a CPU, and the voltage Vo at the terminal B is supplied to an A / D of the CPU via an amplifier (interface) (not shown) for calibrating (amplifying) the voltage. Applied to the conversion input port.

In FIG. 3, reference numeral 10 denotes a ROM storing a control program, and 11 denotes an RA used for data processing and the like.
M and 12 are motor drivers for driving the motor 6, and 13 is a display device of the image forming apparatus. Control
In addition to these, various sensors and switches (including a cover switch) for detecting the state of the hardware of the copying machine are connected to the CPU 6. The CPU reads these state signals at a predetermined timing to read the state signals. Is determined.

FIG. 4 shows an outline of the control operation of the CPU of the controller 6. When the power is turned on, the CPU sets the internal registers, counters, timers, and the like to the values in the standby state,
The signal level at the time of standby is set to the input and output ports for the mechanism unit (step 101). Hereinafter, the word "step" is omitted in parentheses and only the step number is described.

Upon completion of the initialization (101), the CPU reads the state of the mechanism unit and checks for an abnormality (a state in which image formation cannot be started) (102, 103).
If there is an abnormality, it is displayed on the operation board 46 (11).
2). In this state reading, the output voltage Vo of the variable resistor 8 is read, and it is checked whether it is 0 or V. Otherwise (the pad holder 3 is not at the home position,
When the pad holder 3 is not at the return position, the pad holder 3 is driven to the closer one of the home position and the return position (charger homing CH).
C). This content will be described later with reference to FIG. Also, when the copier cover is switched from open to closed,
Execute Jahoming (CHC).

When the copier cover is closed and the pad holder 3 is
When the CPU is in the home position or the return position and there is no other abnormality, the CPU waits for an input of the operation board 46 via a subroutine "Cleaning of Charger" CCC. Processing is performed (104). Here, copy number input, copy magnification input, recording density input, etc.
Write the input to the register. The register is a memory area allocated to the internal memory of the CPU or the RAM 11.

When there is a start input, the fact is displayed on the display 13, and the CPU charges, exposes, erases, feeds, and develops one image (records one image). The start and end timings of transfer, etc. can be set in a timing table corresponding to the copy mode that has already been input (standard mode when there is no input, standard value for parameters without input). It is set (105, 106).

When the timing setting (106) is completed, one copy cycle (one image forming process) is executed, the copy number counter (register) is counted up by one (107), and the contents of the register ECC are set to one in. Clement (CCP). The register ECC is for managing the cleaning timing of the charger. As will be described later, immediately after the data of the register ECC becomes equal to or larger than the set value CCS and the set number of copies (continuous copy) is completed, the charger cleaning (ACC) is executed. Upon completion, the register ECC is cleared there (initialized to the data value 0).

It is checked whether the number of copies (the number of times of image formation) has reached the set number (108). If the number has not reached the set number, another copy cycle (107) is performed.
Execute When the number of sheets reaches the set number, post-processing (end cycle) such as cleaning (continuation time) of the photoreceptor and the transfer belt is set (109), and waiting for input from the operation board 46 (104). . When there is no start input from the operation board 46 and the end cycle is completed, the rotation drive of the photoconductor is stopped and the static elimination lamp is turned off, and the end cycle is stopped there (105, 110, 111). That is, the mechanism unit is set to a standby state (stop).

FIG. 5 shows a "charging home" (CH
The contents of C) are shown. Here, the CPU first converts the output voltage Vo of the variable resistor 8 into a digital signal and reads it (1), and the pad holder 3 is in the home position (position in contact with the end block 1a) or in the return position (end). It is checked whether it is at the position (contact position with the block 1b) (2, 3). If the home position is in either the home position or the return position, this "charger home" (CHC) is terminated, and the routine proceeds to the next step 103 (FIG. 4).

When the pad holder 3 is not in either the home position or the return position, the CPU starts a timer dt having a time limit of dt for determining a cycle for calculating the speed (4). ), Permit the timer interrupt (5).

Then, it is checked whether the pad holder 3 is closer to the home position than the return position (6), and if so, the motor driver 12 is instructed to rotate in the reverse direction (7), and the predetermined period is set. The reading (digital conversion) of the output voltage Vo is repeated at every time, and it is checked whether or not the voltage Vo has reached the home position equivalent value 0 (the pad holder 3 has reached the home position) at each reading ( 8) If so, the motor driver 12 is instructed to stop driving (11), and the timer interrupt is prohibited (12). And "Charger Ja-
"Mumming" (CHC) is finished and the next step 103
Proceed to (FIG. 4).

When the pad holder 3 is closer to the return position than the home position, the motor driver 12 is instructed to rotate forward (9), and the output voltage V
Repeat the reading of o (digital conversion), every time reading,
It is checked whether the voltage Vo has reached the return position equivalent value V (the pad holder 3 has reached the return position) (10), and if so, the motor driver 12 is instructed to stop driving (11). Prohibit timer interrupt (1
2).

As described above, the pad holder 3 is
When the vehicle is deviated from both the return positions, the drive is performed in the closer direction, so that the time required for the homing process is greatly reduced.

While the pad holder 3 is being driven as described above, if the timer dt has timed out, the CPU proceeds to FIG.
(Timer interrupt) (TIN) shown in FIG. This timer interruption is to calculate the load of the motor 6 and stop the driving of the pad holder 3 when the overload exceeds the set value. This "timer interrupt" (TIN)
Will be described later with reference to FIG.

FIG. 6 shows the “charging device cleaning” (CC) shown in FIG.
The contents of C) are shown. Proceeding to this, the CPU registers
It is checked whether the data ECC of CC (the cumulative number of copies after the previous cleaning of the charger) is equal to or greater than the set value CCS (21). If the value is less than the set value CCS, the “charging device cleaning” (CCC) is terminated and the next step 10
4 (FIG. 4), but when the value is equal to or greater than the set value CCS, the output voltage Vo of the variable resistor 8 is read (22), and whether the pad holder 3 is in the home or return position is determined. Check (23).

When the pad holder 3 is at the home position, it is driven to the return position (24-29), and from the return position to the home position.
Return to the normal position (30-36). When it is in the return position, it is driven to the home position (44-49) and returned from the home position to the return position (50-53, 34-36). In any case, when the driving is started, the timer dt is started to permit the timer interruption, and when the driving is stopped, the timer interruption is prohibited. When the one reciprocation is completed, the register ECC is cleared. When the timer dt times out during the operation of the pad holder 3, the CPU executes a "timer interrupt" (TIN) shown in FIG. This timer interrupt
The load on the motor 6 is calculated, and when the load exceeds the set value, the driving of the pad holder 3 is stopped. The contents of this "timer interrupt" (TIN)
It will be described later with reference to FIG.

During driving between the home position and the return position, the CPU reads the voltage Vo at regular intervals and checks whether the voltage Vo matches the destination corresponding value. By monitoring (2
7, 33, 47, 53). When a start signal arrives during this waiting period, the CPU does not show on the flowchart of FIG.
Execute HC (FIG. 5), and when it is finished, go to Step 10
6 (FIG. 4). That is, the process proceeds to the copy process. When the set number of copies have been completed, "Cleaner Cleaning" (CCC) is executed via step 109. This allows
Even when the "charger cleaning" (CCC) is started, it is immediately stopped and the copy waiting time is short.

FIG. 7 shows the contents of the "timer interrupt" (TIN). As described above, this "timer interrupt" (TIN) is performed while the pad holder 3 is being driven in the "charger home" (CHC) or the "charger cleaning" (CCC). Executed when the time is over. When the process proceeds to the "timer interrupt" (TIN), the CPU first starts the timer dt to determine the execution timing of the next "timer interrupt" (61). Next, the output voltage Vo of the variable resistor 8 is read (62), and the register RVo is read.
Is written into the register RVop (63), and the data Vo representing the voltage Vo read this time is written in the register RVop.
(64). Thus, the register RVop contains
There is data RVop indicating the position of the pad holder 3 dt before the present, and there is data RVo indicating the current position of the pad holder 3 in the register RVo. CP
U then moves the pad holder 3 during the distance dt (RV
o-RVop) to calculate the absolute value of the moving speed Sr (65). Sr = A · (RVo−RVop) “A” is a coefficient.

The rotation speed versus torque curve of the DC brush motor 6 is a straight line as shown in FIG. Therefore, the unit time (d
If the motor rotation speed per t) (RVo-RVop) can be calculated, the load torque T at that time can be obtained. The straight line shown in FIG. 8 is represented by T = [(T0−T1) / Sro] · Sr + T1 (3). Therefore, based on the absolute value of the moving speed Sr calculated in step 65, the equation (3) is obtained. Is calculated (66). [(T0-T1) / Sro] is a coefficient.

The CPU checks whether the pad holder 3 is in a narrow area in contact with the home position (the area immediately adjacent to the home) or in a narrow area in contact with the return position (the area immediately adjacent to the return) (67). If it is in a low load region outside of these regions, it is checked whether the calculated load torque T is equal to or greater than the set value Ts (abnormally high load) (70). Is stopped, and the display 13 is notified of the abnormal cleaning of the corona discharger.

When the pad holder 3 is in the area immediately adjacent to the home or the area immediately adjacent to the return (high load area), the count register n is incremented by one (68). If you stay in these areas for a long time,
Is executed in the dt cycle, the count data of the count register n increases sequentially. When the pad holder 3 reaches the home position or the return position immediately after the time in these areas is short and the pad holder 3 immediately reaches the home position or the return position, it is detected by the routine shown in FIG. Is stopped and the timer interrupt is prohibited, so that the timer interrupt is not executed until the value of the count register n reaches the set value Na. However, when the pad holder 3 does not immediately reach the home position or the return position due to some abnormality, the value of the count register n reaches the set value Na. When this is detected in step 69, C
The PU stops driving (energizing) the motor 6 and notifies the display 13 of the abnormal cleaning of the corona discharger (71, 72).

In this embodiment, as described above, the load torque T of the motor 6 can be calculated in real time and used for detecting an abnormal overload.

It is well known that the life of a brush motor is greatly reduced due to an excessive load torque T. Therefore, it is better not to apply an excessive load to the motor. In this embodiment, while the pad holder 3 is driven by the motor 6,
The load torque T of the motor 6 is calculated in real time as described above, and an overload abnormality is monitored.
, The overload energization of the motor 6 is not continued for a relatively long time, and a reduction in the life of the motor 6 is avoided.

Second Embodiment The hardware configuration of the second embodiment is the same as that of the first embodiment, and the content of the overload detection executed by the "timer interrupt" (TIN) of the CPU is different from that of the first embodiment. A little different. FIG. 9 shows the contents of “timer interrupt” (TIN) of the CPU of the second embodiment. In the second embodiment, as in the first embodiment, the absolute value of the moving speed Sr of the pad holder 3 is calculated (65).
Then, it is checked whether the pad holder 3 is located in the home immediate area or the return immediate area (67). If the pad holder 3 is located in a low load area outside these areas, the calculated moving speed Sr is abnormally low. Speed (abnormally high load) judgment threshold value Ss
It is checked whether it is (set value) or less (70). If so, the driving of the motor 6 is stopped and the display 13 is notified of the abnormal cleaning of the corona discharger. Other processes of the CPU of the second embodiment are the same as those of the first embodiment.

In the second embodiment, overload detection ("timer interrupt" TIN) is simplified as compared with the first embodiment.
If the moving speed of the pad holder 3 is abnormally low in a region moving at a relatively high speed, the driving of the motor 6 is stopped there. Although the moving speed of the pad holder 3 is originally low in the region immediately adjacent to the home or the return, in this region, as in the case of the first embodiment, when the time existing in the region is abnormally long, the pad holder 3 is not moved. The driving of the data 6 is stopped.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an outline of a mechanism section of a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of the variable resistor 8 shown in FIG.

FIG. 3 shows a voltage Vo generated by the variable resistor 8 shown in FIG.
FIG. 9 is a block diagram showing a controller 9 for driving the electric motor 6 in the forward and reverse directions and for stopping the electric motor 6 in accordance with FIG.

FIG. 4 is a flowchart showing an outline of a control operation of a CPU of a controller 9 shown in FIG. 3;

FIG. 5 “Charge home” CHC shown in FIG. 4
Is a flowchart showing the contents of the above.

FIG. 6 is a flowchart showing the contents of the “charging device cleaning” CCC shown in FIG. 4;

FIG. 7 is a flowchart showing the contents of a "timer interrupt" TIN executed by the CPU of the controller 9 shown in FIG.

8 is a graph showing a characteristic of a rotation speed versus a load torque of the electric motor 6 shown in FIG.

FIG. 9 shows a CP of a controller 9 according to a second embodiment of the present invention.
A flow showing the contents of the "timer interrupt" TIN executed by U
It is a chart.

[Explanation of symbols]

1a, 1b: End block 2: Tungsten wire 3: Pad holder 3a: Cleaning pad 4: Casing 5: Transfer rod 6: Motor 7a, 7b: Coupling 8: Variable resistor 8a: Rotary shaft 8b: Female screw 8c: Slider 8d: resistor 9: controller 10: ROM 11: RAM 12, motor driver 13: display device

Claims (8)

[Claims] A cleaning member for cleaning a charge wire of a corona discharger having a main body casing and a charge wire for performing corona discharge stretched in a longitudinal direction thereof, and driving the cleaning member in a direction in which the wire extends. Do
A drive unit including a power transmission mechanism for converting a rotary motion into a linear motion; a unit for detecting a position of the cleaning member; and a unit for controlling the drive unit with reference to a detection position of the position detection unit. An automatic cleaning device for a corona discharger, wherein the position detecting means includes a variable resistor coupled to the driving means and generating a resistance value corresponding to a position of the cleaning member. Cleaning device. 2. The variable resistor has a terminal to which a reference potential is applied, a terminal to which a constant voltage is applied, and a terminal for outputting a voltage from the reference potential to a constant voltage corresponding to a position of the cleaning member. When the member is located at one end of the movement range, the voltage of the output terminal indicates the lowest value, when the member is located at the other end, the highest value, and is proportional to the position of the cleaning member between both ends. The apparatus for automatically cleaning a corona discharger according to claim 1. 3. The control means according to claim 1, wherein the position detected by said position detecting means is set within the range of movement of the cleaning member immediately after power-on of the equipment equipped with the corona discharger and immediately after opening and closing of the cover of said equipment. The automatic cleaning apparatus for a corona discharger according to claim 1 or 2, wherein the cleaning member is driven to a closer end via the driving means if neither one of the one end nor the other end is provided. 4. The cleaning device according to claim 1, wherein the control unit calculates the moving speed of the cleaning member by repeatedly reading the detection position of the position detection unit when the cleaning member is being driven via the driving unit. Item 3. An automatic cleaning device for a corona discharger according to Item 2. 5. The control means calculates a driving torque of the cleaning member based on the calculated moving speed, and stops the driving by the driving means when the calculated driving torque is equal to or greater than a set value, and notifies the driving means. The automatic cleaning device for a corona discharger according to claim 4, wherein 6. The automatic cleaning apparatus for a corona discharger according to claim 4, wherein said control means stops driving by said driving means when the calculated moving speed is equal to or lower than a set value, and notifies the driving means. 7. The corona discharger according to claim 1, wherein said position detecting means includes a rotating shaft connected to a rotating member of said power transmission mechanism, and a slider connected to said rotating shaft. Automatic cleaning device for electric appliances. 8. The automatic cleaning device for a corona discharger according to claim 7, wherein the rotating shaft body is a screw rod to which a slider is screwed.