JPS61292656A - Automatic electrostatic charger cleaning device - Google Patents

Abstract

PURPOSE:To make the cleaning of a device sure by detecting the presence of a cleaning member at home position and continuing the order of starting operation after the interruption of action of the cleaning member according to the information in a non-volatile memory. CONSTITUTION:Since the effect of a charger cleaner is sufficient by cleaning once a day, the operation of the cleaner is made at the time applying the power source SW of the copying device. The cleaner is driven by turns one by one to reduce the capacity of power source of the cleaner and to lower the noise of driving. To prevent the upsetting of order of driving even when a current SW is off, driving order data are stored in a non-volatile RAM in a main controlling section, and controlled to make the number of times of cleaning uniform. When the temperature of fixing arrives at a temperature that allows copying after applying the power source SW, the operation of the charger cleaner is suspended after the completion of reciprocal movement of operating charger cleaner, and the control of operation of the next charger cleaner is not executed. Thus, the operation of the charger cleaner is not interrupted during the reciprocation, and the cleaning operation is executed surely.

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.

Many of the conventional techniques for preventing dirt on chargers are related to scattering of developer dust, which is the cause of dirt, but their effectiveness is small. In scattering prevention technology,
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.

Also, as a means of directly cleaning the charger wire, there is a method of installing a charger cleaner pad and cleaning it by manually inserting and removing the charger and causing friction between the cleaner pad and the charger wire, but this method does not work. There were drawbacks such as the need for periodic service maintenance and high maintenance costs.

(Objective) The present invention eliminates the drawbacks of the conventional example and provides a device that automatically cleans the charger line.The present invention eliminates the drawbacks of the conventional example and provides a device that 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 tasks.

(Structure) To achieve this, the present invention uses a drive wire to drive the cleaning member that comes into sliding contact with the charger wire, detects that the cleaning member is at the home position, and stores the order of operation start after the interruption of the operation of the cleaning member in a non-volatile memory. The apparatus is characterized in that the information on the apparatus is used to ensure that the apparatus is cleaned properly.

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 drive DC motor 12, a passive worm gear 13, a drive gear 14, and a drive wire pulley 1.
5, Pad drive wire 1 Power receiving terminal 20, Casing 2
1.

FIG. 2 is a schematic diagram of the image forming portion of the copying apparatus. FIG. 3 is a block diagram of the main control section of the copying machine. 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 the 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 bud 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 section, a timer section, and an I10 section, and the charger cleaner is also controlled by the control program in the ROM.

Reference numeral 22 (XI to Xs) in FIG.
M s ).

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.

Part of the driver is powered by a single power supply vn, as shown in Figure 4(b).
The motor is bipolar driven, 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 main control sends a forward rotation signal (a = HIGH,
d=LOW) is output, and in the logic section, A=HIG
H, B-LOWSC-LOIIISD-) (4 signals called 10H are output. This causes the motor (M) 12
A current flows from + to -, and the motor 12 rotates in the normal direction.

Also, when reversing, the main control unit sends a reversal signal (aw LOWS).
d-HIGH) is output, and the logic section consisting of ICI to IC8 outputs A-LOW, B-HIGH, and C-HIG.
Four signals H, D-LOW are output, and motor 1
2, the current is reversed from - to +. Also, the motor drive current II (reverse rotation current) and IF (forward rotation current) are detected by the detection resistor R.
4, is converted into a voltage by Rs, amplified by IC9 and ICl0, and input to the comparator ICI1. Then, forward/reverse control of the motor 12 and abnormality diagnosis control are performed based on the comparator output e.

That is, the level V of the comparator is set as follows.

During normal rotation: Rg I y (1+ R++/Raz)
<Vth<Rs I t(1+ R++/Raz
)...(1) ■L: When drive motor lock current reverses: Ra I * (1+ RIG/Rq)
<Vth〈Ra I L(1+R+o/Ra)
...(2) Vth-VnR+4/R+a R,,+
+ (3) Furthermore, detailed control is shown in Figures 5 and 6.
This will be explained with reference to FIGS. 7 and 8.

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 drive 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),
It is recognized and processed as a regular signal. Next, the main control section outputs a normal rotation signal a. 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, drive wire broken, etc.), 2.3. If the restraint signal e occurs for longer than an arbitrary set time (2 seconds or more in the example) from the direct conversation in which the forward rotation signal for forward motion and the reverse rotation signal for backward motion are output as
drive lock due to overload, etc.), and the fourth is forward movement time (T
This is a case where the difference between the return movement time (TR) and the return movement time (TR) is greater than or equal to an arbitrarily set time (4 seconds in the embodiment) (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, 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, and according to the present invention, the operation of the automatic charger cleaning device is controlled by the OF of the copying machine power SW.
Even if it is interrupted by F etc., when restarting,
Since the operating order of the cleaning devices is maintained, each device is reliably cleaned, and the number of cleanings between the devices does not vary greatly.

[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. Figure 2 Helmet Figure 4 (G)

Claims (1)

[Claims] In a device that independently drives a plurality of automatic charger cleaning devices that automatically clean the charger one by one according to a preset order based on data stored in a nonvolatile storage unit, the cleaning device 1. A control method for an automatic charger cleaning device, characterized in that an operation start order after an operation is interrupted is continued based on information in the nonvolatile storage section.