JPH0673046B2 - Control system for automatic charger cleaning device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic cleaning device for a charger that is applied to an image forming process of a copying machine or the like.

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

Therefore, various measures have been taken to prevent stains on the charger.

As a conventional technique for preventing the stain on the charger, there are many measures for scattering the developer dust that causes the stain, but the effect is small. In scattering prevention technology, in order to increase its effect, a suction device or the like is absolutely necessary, but for that purpose, the device itself becomes large,
Further, there is a drawback that the cost is high.

In addition, as a means for directly cleaning the charger wire, a charger cleaner pad is installed, and the charger pad is manually inserted and removed, and the cleaner pad and the charger wire are rubbed. However, this method has a drawback in that service maintenance must be performed regularly and maintenance cost is high.

(Purpose) The present invention aims to solve the above-mentioned drawbacks of the conventional example and to provide an apparatus for automatically cleaning a charging line, thereby improving the reliability and image quality of a copying apparatus. is there.

(Structure) Therefore, according to the present invention, the cleaning member that slides in contact with the charger wire is driven by the drive wire, the cleaning member is detected to be in the home position, and the operating time of each cleaning device does not overlap. The feature is that the noise is suppressed by controlling so that they are individually driven in order.

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

In the embodiment, three chargers, a main charger (CC), a transfer charger (TC) and a static eliminator (CLC) are equipped with a charger cleaner.

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

FIG. 2 is a schematic diagram around the image forming of the copying apparatus. FIG. 3 is a block diagram of the copying machine main controller. FIG. 4 is a circuit diagram of a DC motor driving circuit for driving a charger cleaner. FIG. 5 is a drive DC motor control timing chart. FIG. 6 is a charge cleaner control circulation diagram. FIG. 7 is a flow chart of the charge cleaner control. FIG. 8 is an explanatory diagram of use flag data in the control flow.

First, the image forming operation of the copying machine will be described with reference to FIG.

The photosensitive drum 5 charged by the main charger 9 is exposed by the original scanning light at the next slit portion 10 to form an electrostatic latent image on the drum, and the electrostatic latent image is visualized by the developing portion 11. Be converted. On the other hand, the transfer paper 1 is fed by the paper feed roller 2 and is fed by the registration roller 3 to the transfer portion in synchronization with the image on the drum. Transfer charger 4 at the transfer section
As a result, the image on the drum is transferred to the transferred transfer paper. Then, the transfer paper is attracted to the separation belt and conveyed, and advances to the next fixing device.

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

As described above, the toner is scattered and suspended in the atmosphere of these image forming apparatuses, and the toner adheres to the discharge wire of the charger to change the image forming conditions and cause image deterioration.

Therefore, in the present invention, a stable cleaner is used to automatically clean the discharge wire from the home position to obtain a stable image.

The operation of the charger cleaner will be described below.

The discharge wire 18 is cleaned by rotating the drive motor 12 in the forward and reverse directions and reciprocating the cleaner pad 17 with the discharge wire 18 sandwiched therebetween.

FIG. 3 is a block diagram of the main control unit of the copying machine.
30 is composed of a micro cpμ, a ROM section, a RAM section, a non-volatile RAM section, a timer section, and an I / O section, and the charger cleaner is also controlled by the control program in the ROM.

Reference numeral 22 (X _{1 to} X ₃ ) in FIG. ₃ denotes a charger cleaner drive circuit unit, which drives the drive DC motor 12 (M _{1 to} M ₃ ).

Next, forward / reverse rotation drive of the drive DC motor 12 by the drive circuit 22 will be described with reference to FIGS. 4 (a) and 4 (b).

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

As shown in FIG. 4 (b), the driver unit is a bipolar drive with a single power source V _D , and the forward / reverse control is based on detection of a motor restraint current. In other words, the forward rotation signal (a = HIGH, d = LO) from the main control during DC motor forward rotation (cleaner forward movement).
W) is output, and in the logic section, A = HIGH, B = LOW,
Four signals of C = LOW and D = HIGH are output. As a result, a current flows from + to-in the motor (M) 12, and the motor 12 rotates normally.

Also, at the time of reverse rotation, the main controller outputs a reverse rotation signal (a = LOW, d = H
IGH) is output, and the logic part composed of IC1 to IC8 is A
= LOW, B = HIGH, C = HIGH, D = LOW, four signals are output, and the motor 12 has a current flowing from + to + and reverses.
Also, motor drive current I _R (reverse rotation current), I _F (forward rotation current)
Is converted into a voltage by the detection resistors R ₄ and R ₈ , amplified by IC9 and IC10, and input to the comparator IC11. Then, forward / reverse rotation control and abnormality diagnosis control of the motor 12 are performed by the comparator output e.

That is, the level V _{th of the} comparator is set as follows.

Forward _{rotation: R 8 I F (1 +} R 11 / R 12) <V th <R 8 I L (1 + R 11 /
R ₁₂ )… (1) I _L : Drive motor restraint current Reverse rotation: R ₄ I _R (1 + R ₁₀ / R ₉ ) <V _th <R ₄ I _L (1 + R ₁₀ / R ₉ )
(2) V _th = V _D R ₁₄ / R ₁₄ -R ₁₃ (3) Further, the detailed control is shown in FIGS. 5, 6, and 7.
This will be described with reference to FIG.

The flow (OP.CLEANER) of FIG. 7 is a charge cleaner operation sub-program, which is called and executed outside the copy operation in the copying machine main control program.

The operation of the charger cleaner is performed when the copying machine power switch is turned on because the effect is sufficient if it is cleaned once a day.

Further, in order to reduce the cleaner driving power source capacity and reduce the driving noise, the automatic charger cleaning devices are sequentially driven one by one as shown in FIG. 6 so as not to overlap in operation time. Further, the driving order DATA is stored in the main control member non-volatile RAM so that the driving order does not change even when the current SW is turned off, and control is performed so that the number of times of cleaning of each charger cleaner is made uniform.

When the fixing temperature reaches the copyable temperature after the power switch is turned on (reload state) After the reciprocating operation of the running charger cleaner is completed, the charger cleaner operation is interrupted.
The operation control of the next charge cleaner is not executed.
As a result, the cleaning operation is reliably performed without interruption during the reciprocating movement. Also, the copyable state, which is limited by the cleaning time of the charger cleaner, can be minimized.

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

First, a reverse rotation signal is output and it is confirmed 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 a noise erroneous signal, the restraint signal e is recognized and processed as a normal signal when continuously generated for an arbitrary set time T _c (2 seconds in the embodiment). Next, the main control unit outputs the normal rotation signal a. When the restraint signal e is output, the main control unit outputs the reverse rotation signal d again. When the restraint signal e is output, the reverse rotation signal is turned off, and the reciprocating operation of the charger cleaner is completed. Thereafter, similar control is sequentially performed for each of the charge cleaners, and when the operation of the three charge cleaners is completed, the operation of the charge cleaner is completed.

The abnormal operation diagnosis is performed for four cases.

First, in the initial operation (homing operation), when the restraint signal e is not generated for an arbitrary set time or more (two seconds or more in the embodiment) (connector not connected, drive wire broken, etc.), second, third When the restraint signal e is generated for more than an arbitrary set time (2 seconds or more in the embodiment) immediately after the forward rotation signal for the forward movement and the reverse rotation signal for the backward movement are output (drive lock due to overload, etc.) Fourthly, when the difference between the forward movement time (T _F ) and the backward movement time (T _R ) is an arbitrary set time (4 seconds in the embodiment) or more (drive abnormality due to overload or the like). Then, when an abnormality occurs, the abnormality is displayed on the display section in the operation section, and the copying machine is controlled to the copy prohibited state. By controlling as described above, the charger cleaner can execute its functional state, and the reliability and image quality of the copying apparatus can be maintained and improved more reliably.

(Effects) The present invention is as described above. Generally, since this type of cleaning device is operated when the copying apparatus is stopped, the operation noise causes noise to the user, but according to the present invention, a plurality of operation noises are generated. Noise can be suppressed by operating each of the drive motors independently. Further, since the drive current may have a capacity of one piece, a low capacity power source can be used.

[Brief description 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 around the image forming of a copying machine, FIG. 3 is a block diagram of a copying machine main controller, and FIG. (A), (b)
Is a drive motor drive circuit diagram, FIG. 5 is a drive motor control timing diagram, FIG. 6 is a charge cleaner control circulation diagram, and FIGS. 7 (a) and (b) are charge cleaner control flow diagrams, 8 The figure is an illustration of use flag data in the control flow. 12 ... Drive motor, 16 ... Drive wire, 17 is cleaning member,
18 ... Charge line.

Claims (1)

[Claims] 1. A home for detecting at least a drive wire, a cleaning member fixed to the drive wire and in sliding contact with a charger wire, a drive motor for reciprocating the cleaning member, and a home position of the cleaning member. What is claimed is: 1. A plurality of automatic charger cleaning devices comprising position detecting means, wherein automatic control is performed such that each of the automatic charger cleaning devices is independently driven in order so that the operating times of the automatic charger cleaning devices do not overlap. Control system for the charger cleaning device.