JPS61292654A - Automatic electrostatic charger cleaning device - Google Patents

Abstract

PURPOSE:To clean an electrostatic charger line automatically by driving a cleaning member that is in sliding contact with the charger line by a driving wire, and at the same time, detecting the presence of the cleaning member at the home position, making the condition setting of conceivable abnormality of operation of the cleaning member and stopping the operation as the abnormality of operation. CONSTITUTION:Charge cleaners are provided in three chargers; a main electrostatic charger CC, a transfer charger TC and a discharger CL. The cleaning of a discharge wire 18 is made by rotating a driving motor 12 at the first time normally and reversely and reciprocating a cleaner pad 17 holding the discharge wire 18. The control of normal and reverse rotation of the motor 12 and the control of abnormality diagnosis are made by the output (e) of a comparator. The diagnosis of abnormal movement is made in four cases. If abnormality occurred when no constraining signal (e) is generated for more than arbitrary set time, when the signal is generated for more than arbitrary set time and when the difference between time for going and returning is more than the arbitrary set time, the abnormality is displayed on the display part in an operating section, and a copying device is controlled to the state of prohibiting copying.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a charger (
charger) related to automatic cleaning devices.

(Prior Art) A charger of a copying machine is installed in an environment where it is easily contaminated by developer dust. If the charger wire becomes dirty, its discharge characteristics change, degrading the image forming conditions and making it impossible to obtain a proper image.

Therefore, various measures have been taken to prevent chargers from getting dirty.

Conventional techniques for preventing dirt on chargers are mostly related to scattering of developer dust, which is the cause of dirt, but the effectiveness of these techniques is small.
In order to increase the effect, a suction device or the like is necessary, but this requires the device itself to be large and has the disadvantage of being expensive.

In addition, as a means to directly clean the charger line, a charger cleaner pad is installed and the charger is manually inserted and removed.The present invention solves the drawbacks of the conventional example and automatically cleans the charger line. The purpose of this invention is to improve the reliability and image quality of copying devices by providing a device that performs the following functions.

(Structure) To achieve this, the present invention drives the cleaning member that comes into sliding contact with the charger wire using a drive wire, detects that the cleaning member is at the home position, and sets conditions for possible malfunction of the cleaning member. The feature is that when one of the conditions applies, the operation is stopped as an abnormal operation.

The configuration of the present invention will be explained below based on the illustrated embodiments.

In the embodiment, charger cleaners are installed in three chargers: a main charger (CC), a transfer charger (TC), and a static eliminator (CLC).

FIG. 1 is an external view showing a charger having a charger cleaner, including a driving DC motor 12, a passive worm tooth TiL 13, a driving gear 14, and a driving wire boot I.
J-15, pad drive wire 1 charger cleaner is installed.

FIG. 1 is an external view showing a charger having a charger cleaner, including a drive DC motor 12, a passive worm gear 13, a drive gear 14, and a drive wire boot IJ.
-15, a pad drive wire 16, a cleaning pad 17, a discharge wire (charger wire) 18, a passive wire pulley 19, a power receiving terminal 20, and a casing 21.

FIG. 2 is a schematic diagram of the image forming portion of the copying apparatus. FIG. 3 is a block diagram of the copying machine main control section. FIG. 4 is a charger cleaner drive DC motor drive circuit diagram. Fifth
The figure is a drive DC motor control timing diagram. FIG. 6 is a charger cleaner control circulation diagram. FIG. 7 is a charger cleaner control flow diagram. FIG. 8 is an explanatory diagram of flag data used within a control flow.

First, the image forming operation of the copying apparatus will be explained with reference to FIG.

The photosensitive drum 5 charged by the main charger 9 is exposed to document scanning light at the next slit section 10, and an electrostatic latent image is formed on the drum, and the electrostatic latent image is developed by the developing section 11. be converted into On the other hand, the transfer paper 1 is fed by a paper feed roller 2, and is fed to the transfer section by a registration roller 3 in synchronization with the image on the drum. In the transfer section, the transfer charger 4 transfers the image on the drum to the transferred transfer paper. Then, the transfer paper is attracted to the separation belt and conveyed, and then advances to the next fixing device.

Further, the drum 5 is charged with residual charge on the drum by a static eliminator 7, and then the residual toner is collected by a cleaning brush 8, and the drum 5 is rotated again to a position facing the main charger 9, thereby completing the image forming cycle. do.

As described above, toner is scattered and suspended in the atmosphere of these image forming apparatuses, and this adheres to the discharge wires of the respective chargers, changing the image forming conditions and causing image deterioration.

Therefore, in the present invention, a stable image can be obtained by automatically cleaning the discharge wire from the home position using a charger cleaner.

The charger cleaner operation will be explained below.

Cleaning of the discharge wire 18 is performed by rotating the first drive motor 12 forward and backward, and also by reciprocating the cleaner pad 17 holding the discharge wire 18 therebetween.

FIG. 3 is a block diagram of the main control section of the copying machine, and the control board 30 includes a micro CPμ, a ROM section, a RAM section, a non-volatile R
It consists of an AM part, a timer part, and a 110 part, and the charger cleaner is also controlled by the control program in the ROM.

22 (XI-X3) in Fig. 3 is the charger cleaner drive circuit, and the drive DC motor 12 (M,
~ Drive Mri.

Next, the forward and reverse rotational driving of the drive DC motor 12 by the drive circuit 22 will be explained based on FIGS. 4(a) and 4(b).

The drive circuit 22 includes a logic section shown in FIG. 4(a) and a logic section shown in FIG.
The driver shown in b) is divided into parts.

As shown in FIG. 4(b), part of the driver is bipolar driven by a single power source, and forward/reverse control is based on motor lock current detection. In other words, when the DC motor rotates forward (when the cleaner moves forward), the forward rotation signal (a-HIGH,
d=LOW) is output, and the logic section is set to A-HIG.
Four numbers, HSB=LOW, C=LOW, and D-HIGH, are output. As a result, motor (M) 12 has +
A current flows from - to -, and the motor 12 rotates in the normal direction.

Also, when reversing, the main control section sends reverse signals (a-LOW, d
-HIGH) is output, and the logic section consisting of ICI to IC8 outputs A-LOW, B-f(IGH, C-HIGH).
Four numbers SD-LOW are output, and the current of the motor 12 is reversed from - to 10. In addition, the motor drive current rt (reverse rotation current) and ■F (forward rotation current) are detected by the detection resistor R4,
It is converted into a voltage by R11, amplified by IC9 and ICl0, and input to the comparator ICII. Then, forward/reverse control of the motor 12 and abnormality diagnosis control are performed based on the comparator output e.

In other words, the level of the comparator is set as follows.

During forward rotation: RIIIF (1+RIl/R+z) <v
th<R51L(1+R++/R+g)...(1
)IL: When driving motor restricted current reverses: R4IN(1+RIG/Rq)<Vth<
R41L (1+R1°/R9)...(2) Vth-V
oR+ 4/R+n R+s... (3)
Furthermore, regarding detailed control, FIGS. 5, 6, and 7,
This will be explained with reference to FIG.

The flow (OP, CLEANER) in FIG. 7 is a charger cleaner operation subprogram that is called and executed outside the copying operation in the copying machine main control program.

The operation of the charger cleaner is carried out when the power switch of the copying machine is turned on, since the effect is sufficient even if the charger cleaner is cleaned only once a day.

Further, in order to reduce the power supply capacity for driving the cleaner and to reduce the driving noise, each cleaner was driven one by one as shown in FIG. 6. Also, the driving order is OFF of the current SW.
Non-volatile RAM in the main control unit to ensure that it does not go awry even at times.
The drive order DATA is stored in the controller, and the number of times each charger cleaner is cleaned is controlled to be equalized.

When the fixing temperature reaches the copying temperature after the power switch is turned on (reload state), after the reciprocating operation of the charger cleaner in operation is completed, the charger cleaner operation is interrupted and the next charger cleaner operation control is not executed. As a result, the charger cleaner operation is reliably executed without being interrupted during reciprocating movement. Furthermore, the copyable state limited by the charger cleaner cleaning time can be minimized.

The operation timing of each motor 12 is performed as shown in FIG.

First, a reversal signal is issued, and it is checked whether the cleaning pad 17 is at the home position (start position). When the restraint signal e is output, it is determined that the vehicle is at the home position. In order to prevent noise erroneous signals, when the constraint signal e is continuously generated for an arbitrarily set time TC (2 seconds in the example),
The zero-order main control section outputs a normal rotation signal a, which is recognized and processed as a normal signal. When the restraint signal e is output, the main control section outputs the reverse rotation signal d again. Then, when the restraint signal e is output, the reverse rotation signal is set to 0FFL, and the reciprocating operation of the charger cleaner is completed. Similar control is subsequently performed for each charger cleaner in sequence, and when the three charger cleaner operations are completed, the charger cleaner operation cycle is completed.

Abnormal operation diagnosis was performed for four cases.

First, in the initial operation (homing operation), if the restraint signal e is not generated for longer than an arbitrary set time (2 seconds or more in the example) (connector not connected, ! [movement wire broken, etc.), the second .3, the forward rotation signal for the forward motion and the reverse rotation signal for the backward motion are output from the direct error to the restraint signal e.
If this occurs for longer than the arbitrarily set time (2 seconds or more in the example) (drive lock due to overload, etc.), the fourth difference between the forward movement time (T, ) and the backward movement time (T*) is the arbitrarily set time. (4 seconds in the example) or more (driving abnormality due to overload, etc.). When an abnormality occurs, the abnormality is displayed on the display section within the operation section, and the copying apparatus is controlled to be in a copy inhibited state. By being controlled as described above, 2. the charger cleaner can perform its functional state, and the reliability of the copying apparatus and the maintenance and improvement of image quality can be further ensured.

(Effects) The present invention is as described above.According to the present invention, a drive abnormality in the automatic charger cleaning device can be detected before the copying operation of the copying device starts, so it is possible to prevent defective image copies. .

[Brief explanation of drawings]

Fig. 1 is an external view of an automatic charger cleaning device according to an embodiment of the present invention, Fig. 2 is a schematic diagram of the image forming part of the copying machine, Fig. 3 is a block diagram of the main control section of the copying machine, and Fig. 4 (a), (b)
is a drive motor drive circuit diagram, Figure 5 is a drive motor control timing diagram, Figure 6 is a charger cleaner control circulation diagram, Figures 7 (a) to (d) are charger cleaner control flow diagrams, and Figure 8 is a control flow. FIG. 3 is an explanatory diagram of internal use flag data. 12... Drive motor, 16... Drive wire, 1
7 is a cleaning member, 18...charger wire. %2 Figures Guan 4 Figures 5 Figures Children 6 ■

Claims (1)

[Claims] A copying machine comprising a drive wire, a cleaning member fixed to the drive wire and slidably in contact with a charger, a drive motor for reciprocating the cleaning member, and a motor lock detection means for detecting a locked state of the drive motor. In the automatic charger cleaning device, if the above-mentioned restraint signal is not generated within the arbitrarily set time during initial homing, immediately after the forward or backward cleaning operation, or if the restraint signal is generated for longer than the arbitrarily set time, the cleaning At least one of the following when the difference between the forward movement time and backward movement time of the operation is greater than or equal to the arbitrarily set time
An automatic charger cleaning device for a copying machine, characterized in that when the above occurs, the cleaning operation is stopped as an operational abnormality, the copying device is prohibited from operating, and the abnormality is displayed.