JPH02165169A - Corotron cleaning device - Google Patents

Abstract

PURPOSE:To contrive the improvement of durability of a motor, and also, to reduce current consumption by driving the motor with a constant torque by forward rotation time and reverse rotation time which are set in advance. CONSTITUTION:A constant-current is supplied to a motor driving circuit 73 through a constant-current control circuit 71 from a power source circuit 70, and to its motor driving circuit 73, a forward rotation signal and a reverse rotation signal are outputted alternately from a controller 72 so that a motor 64 can be brought to forward rotation and reverse rotation. That is, by bringing the motor 64 to constant torque control and bringing it to forward rotation by the set time, and thereafter, bringing it to reverse rotation by the set time, a motor current supplied to the motor 64 always becomes the same and an overload does not work on the motor 64. In such a manner, the durability of the motor 64 can be improved, and also, the current consumption can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for cleaning a corotron wire of a corotron used for charging, transfer, etc. in an electrophotographic copying machine.

[Conventional technology]

A corotron is a device in which a corotron wire is stretched around a casing, and a high voltage current is applied to the corotron to cause corona discharge, thereby charging the surface of the photosensitive member.By repeatedly causing corona discharge, the corotron wire Toner and paper dust adhere to the surface of the photosensitive member, making it impossible to uniformly charge the surface of the photosensitive member, making it impossible to obtain good image quality.

In particular, in the case of an image forming apparatus that does not have an independent cleaning device for the photoreceptor, for example, in which a magnetic brush is used as both the developing and cleaning device, toner clouds are likely to occur, and floating toner particles are caused by the electrostatic force of the corotron wire. is attached and looks good.

Therefore, a corotron cleaning device disclosed in Japanese Utility Model Application Publication No. 176854/1983 has been proposed.

In other words, a cleaning member for cleaning the corotron wire is slidable along the casing, a motor for moving the cleaning member, a current detecting means for detecting the current of the motor, and a motor current detected by the current detecting means. This cleaning device is provided with a motor lock detection means for determining whether the motor is rotating or locked based on the motor lock, and when the motor lock detection means detects the motor lock, the motor is reversed to reciprocate the cleaning member.

[Problem to be solved by the invention]

With such a cleaning device, the motor load is increased by moving the cleaning member to the stroke end and making it come into contact with the stopper, and as a result, the remoter current becomes larger than during rotation, and the cleaning member reaches the stroke end. Based on this determination, the cleaning member is moved in the opposite direction by reversing the motor, so it is necessary to provide a stopper on the casing of the corotron to prevent the cleaning member from moving beyond the stroke end.
Moreover, since the stopper needs to be strong, the shape of the casing becomes complicated, and when the cleaning member comes into contact with the stopper, the motor load becomes large and a large current flows. Not only does durability deteriorate, but the current consumption of the motor increases, resulting in increased operating costs.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a corotron cleaning device that can solve the above-mentioned problems.

[Means and effects for solving the problem] A cleaning device that drives a motor that reciprocates a sliding block equipped with a cleaning pad for a preset forward rotation time and reverse rotation time. This prevents the motor from being overloaded or causing the motor current to suddenly increase, improving the durability of the motor and reducing current consumption.

〔Example〕

First, an outline of an electrophotographic copying machine to which the present invention is applied will be explained.

As shown in FIG. 9, a photosensitive member 2,
An exposure optical system 3, a paper feed mechanism 4, a fixing device 5, etc. are provided,
The photosensitive member 2 is provided with a roll-shaped master 7 and a take-up roll 8 in a scroll drum 6 as shown in FIG.
The master 7 is wound around the surface of the scroll drum 6 through the slit-like opening 9 of the scroll drum 6, and then wound around the take-up roll 8 through the slit-like opening 9. The master 7 is unrolled and a new master 7 is wound onto the surface of the scroll drum 6.

Around the photosensitive member 2, a charging corotron 10, a static elimination lamp 11, a flash fixing device 12, a developing device 13, a transfer corotron 14, a paper peeling section 15, etc. are arranged in this order.
The exposure optical system 3 includes a lamp 16, a lens 17, and a mirror 1.
8, the original image on the platen glass 19 is irradiated and exposed onto the photosensitive member 2 to form an electrostatic latent image.
The paper feeding mechanism 4 includes an upper tray 20 and a lower tray 21,
Paper is fed from one of the trays onto the photosensitive member 2 via the paper transport path 22, and the paper is fed onto the photosensitive member 2 from one of the trays.
As shown in FIG. 10, a feed roll 23 is provided, and the paper 24 sent by this feed roll 23 is transferred to an upper chute by a feed roll 27 provided between a first chute 25 and a second chute 26. The photosensitive member 2 is fed between the photosensitive member 2 and the transfer corotron 14 via the transfer corotron 14, is charged by the transfer corotron 14, and is electrostatically attracted to the surface of the photosensitive member 2.

The paper peeling unit 15 includes a peeling belt 15a, which peels off the paper adsorbed on the surface of the photosensitive member 2 and sends it to a paper conveyance belt 29, which transfers the paper to the fixing device 5.
It is intended to be sent to

Next, an outline of the operation of this electrophotographic copying machine will be explained.

(1) Copying operation As in a general electrophotographic copying machine, after the surface of the photosensitive member 2 is charged by the charging corotron 10, the original image is exposed to light by the exposure optical system 3 to form an electrostatic latent image. After this electrostatic latent image is developed into a toner image by a developing device 13, the toner image is transferred to a paper 24 by a transfer corotron 14, and the paper 24 is sent to a fixing device 5 where it is fixed, and then a paper receiver 30
to be discharged.

(2) Printing operation The toner image formed as described above is flash-fixed by the flash fixing device 12 to make the toner image a print master. After this, the print master is charged by the charging corotron 10 and uniformly by the static elimination lamp 11. After being exposed to light, a charge remains only in the toner image portion, and this is developed by a developing device 13 to form an unfixed toner image. After this unfixed toner image is transferred to a paper 24 by a transfer corotron 14, the paper 24 is transferred to a fixing device 5. Send it to and fix it.

Thereafter, by repeating this operation, a large number of copies can be obtained.

Next, an example of the corotron cleaner device according to the present invention will be explained based on FIGS. 3 to 8.

The casing 31 of the charging corotron 10 has a shape having a pair of recesses 36, 36 formed by a bottom plate 32, one side plate 33, an intermediate plate 34, and the other side plate 35, and in the embodiment, the other side plate 35 has an L-shaped plate 37. The erase coroton casing 38 is formed integrally with the bottom plate 3.
An end block 39 at one end and an end block 40 at the other end are provided at both longitudinal ends of 2.
One end of the corotron wire 41 is engaged with the other end, and the corotron wire 41 is disposed along one recess 36, and the other end is wrapped around the support part 42 provided on the end block 40, and then the other end is wrapped around the support part 42 provided on the end block 40. It is arranged along the four parts 36 and the other end is connected to one end block 39, and the one end end block 39 and the other end block 40 are connected to the one end cover 4.
3 and the other end cover 44, and the bottom plate 32
A motor bracket 45 is provided at one end.

A sliding block 46 is slidably provided along the pair of four parts 36 and 36, and the sliding block 46 connects the first block 47 and the second block 48 integrally with a downward U-shaped connecting piece 49. It is connected to the top of the cover 5.
A guide protrusion 51 is integrally formed on the second block 48, and this guide protrusion 51 is attached to the other side plate 35.
The connecting piece 49 is slidably fitted into the guide groove 52 formed in the guide groove 52, and the connecting piece 49 is slidably in contact with the upper part of the intermediate plate 34, so that the sliding block 46 is slidably fitted along the casing 31. It becomes.

The first block 47 and the second block 48 have an upward U-shape, and a U-shaped protrusion 54 is integrally formed in the fourth part 53, and a protrusion piece 54a on one side of the protrusion 54 and a protrusion on the other side The piece 54b has a substantially circular concave portion 55 on one side and a concave portion 5 on the other side.
6 are formed to face each other with their positions shifted in the longitudinal direction, and one side pad 57 and the other side pad 58 are swingable in the longitudinal direction in the negative side opening recess 55 and the other side recess 5B. The negative side and other side pads 57
．． 58 is a substantially circular mounting projection 5 on the back surface of the plate-like body 59a.
A cleaner pad 60 made of felt in the shape of a rectangular plate is adhesively fixed to the front surface of the plastic pad body 59 integrally formed with the pad body 59, and the attachment protrusion 59b is inserted from above so as to have a gap in the recessed part. The negative side pad 57 is fitted so that it can swing freely in the longitudinal direction.
The cleaner pads 60 and 60 of the other pad 58 are spaced apart in the longitudinal direction and slightly overlapped in the width direction.

Pins 61 are provided on the upper surfaces of the first block 47 and the second block 48, respectively, and the cover unit 50 is a rectangular plate-shaped body, and the bins 61 are provided on both sides thereof.
1 are fitted into the bottle fitting holes 62, 62, and an opening 63 into which the connecting piece 49 fits is formed in the middle part, and the cover unit 50 is removable.
The back side 50a of the cover 50 is one side and the other side pad 57
．． The pads 57 and 58 on one side and the other side are held in contact with the upper surface of the pad 58 so that they do not come out.

The motor bracket 45 is provided with a motor 64, a drive pulley 65 is attached to its rotating shaft 64a, and a driven pulley 66 is provided on the other end end block 40. One end of the moving wire 67 wound around the guide projection 51 is connected to one longitudinal end of the guide projection 51 via a spring 68, and the other end is connected to the other longitudinal end of the guide projection 51. The moving wire 67 is disposed in the guide groove 52 of the other side plate 35, and when the motor 64 is driven forward or reverse, the moving wire 67 moves the sliding block 46 along the casing 31 to the other end. Notch 44a of cover 44
It is configured to reciprocate between a standby position located inside and a stroke end position where one end is in contact with the cover 43,
During a copying operation, the cover unit 50 is in a standby position, and the corona discharge range L1 is regulated by the cover 44 at the other end and the cover 43 at one end.

Therefore, when the motor 64 is rotated forward and the sliding block 46 is slid in the direction of the arrow as shown in FIG. 8(a),
The − side pad 57 swings clockwise, the other side pad 58 swings counterclockwise, and the edge portion of the cleaner pad 60 slides while contacting the corotron wire 41.
When the sliding block 46 is slid in the direction of the arrow as shown in FIG. 8(b), the - side pad 57 swings counterclockwise and the other side pad 58 swings clockwise. The edge portion of the cleaner pad 60 on the opposite side slides while contacting the corotron wire 41.

In this way, the negative side pad 57 and the other side pad 58 swing as the sliding block 46 reciprocates, and the edge portions on both sides slide while alternately contacting the corotron wire 41. 57 and the other side pad 58 to squeeze the corotron wire 41.
It can reliably remove stuck toner and paper dust and prevent uneven corona discharge.

In addition, since the - side pad 57 and the other side pad 58 are installed by fitting them into the recessed grooves 55 and 56 on one side and the other side,
- side pad 57, fltl side pad 58 can be easily removed and installed, and one side/other side pad 57.58 can be easily removed and installed if cleaner pad 60 is damaged or dirty.
can be easily converted.

Moreover, the negative side pad 57 and the other side pad 58 are integrated into the cover 50.
Since the cover 50 is held in place, the cover 50 can prevent the one side and the other side pads 57 and 58 from falling when the corotron is mounted facing downward.

Also, when replacing the corotron wire 41,
When replacing the other side pad 57.58, cover 50
However, since the cover 50 can be easily installed and removed without using any tools, the Corotron wire 4
1, one side, and the other side pads 57 and 58 can be easily replaced.

Next, the drive circuit for the motor 64 will be explained.

As shown in FIG. 1, the motor 64 is a DC motor, and a constant current control circuit 71 is connected to a power supply circuit 70.
A constant current is supplied to the starting/forward/reverse controller 72 via the controller 72, and a constant current is output from the controller 72 to the motor drive circuit 73, causing the motor 64 to rotate forward/reverse at a constant torque for a predetermined period of time. The sliding block 46 can be moved at a constant speed.

The controller 72 controls the distance from the standby position to the stroke end position of the sliding block 64, the sliding resistance of the sliding block 64, and the weight of the sliding block 64.
The time for forward rotation and the time for reverse rotation of the motor 64 are determined by the force required to move the motor 64 and the torque of the motor 64, and when the drive signal S1 is input, the motor drive circuit 73 rotates in the forward direction for the time required for forward rotation. In addition to outputting a signal,
Thereafter, a reversal signal is output to the motor drive circuit 73 for the reversal time.

Therefore, by inputting the activation signal S1, the sliding block 46 is moved at a constant speed from the standby position to the stroke end position, and then moved at a constant speed from the stroke end position to the standby position, and the motor 64 is stopped.

In this way, the motor 64 is controlled with constant torque and rotates forward for a set time and then reverses for a set time, so the motor current supplied to the motor 64 is always the same and no overload is applied to the motor 64. Therefore, the durability of the motor 64 can be improved, and current consumption can be reduced to reduce operating costs.

The details of the motor drive circuit are as shown in FIG.

In other words, a constant current is supplied from the power supply circuit 70 to the motor drive circuit 73 via the constant current control circuit 71, and the controller 72 alternately outputs a forward rotation signal and a reverse rotation signal to the motor drive circuit 73 to rotate the motor 64 in the forward direction. , so that it is reversed.

In the above embodiment, the one side pad 57 and the other side pad 58 are provided to be swingable with respect to the sliding block.
As shown in the figure, a pair of cleaning pads 8 are attached to an L-shaped main body 80.
1.81 may be installed vertically or horizontally, and in this way, the circumferential surface of the corotron wire 41 can be cleaned evenly.

Although not shown, a wire is wound along the bottom surface of the casing 31, and a sliding block equipped with a cleaning pad is connected to the negative side and the other side of the wire, and a pair of sliding blocks is connected by rotating the motor in the forward direction. The blocks may be moved in opposite directions.

Although not shown, the pads on one side and the other side that were in contact with the corotron wire when the sliding blower moved to the standby position were separated, and the suction nozzle was placed between the pads on the - side and the other side. It is also possible to suction and remove the toner and paper dust remaining on the surface.

Although not shown in the drawings, a guide rail is provided inside the scroll drum so that it can move in and out through a slit, and the sliding block is movable along this guide rail, so that the sliding block can be moved out of the scroll drum only when cleaning the corotron wire. The pad may be moved along the corotron wire by protruding from the base.

〔Effect of the invention〕

The sliding block 64 can be reciprocated within a predetermined range by driving the motor 64 with a constant torque for a preset forward rotation time and reverse rotation time, so that the cleaning pad can be reciprocated within a predetermined range along the corotron wire 41. You can remove toner and paper dust that has adhered to it.

Therefore, an overload does not act on the motor 64 and the motor current does not suddenly increase, so that the durability of the motor 64 can be improved, and the current consumption can be reduced to make the operation cheaper.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a block diagram of a motor drive circuit, FIG. 2 is a detailed diagram of a motor drive circuit, FIG. 3 is a plan view of a corotron, and FIG. no r
V-IV line sectional view, Figure 5 is a side view of the corotron, Figure 6 is a side view of the corotron.
The figure is an exploded perspective view of the sliding block, Figure 7 is an enlarged plan view of the pad attachment part, Figures 8 (a) and (b) are illustrations of the cleaning operation, and Figure 9 is a schematic illustration of the electrophotographic copying machine. FIG. 10 is an enlarged view of the photosensitive member portion, and FIG. 11 is a front view showing a modified example of the cleaning pad. 31 is a casing, 41 is a corotron wire, 46 is a sliding block, and 64 is a motor. Applicant Fuji Xerox Co., Ltd.

Claims (1)

[Claims] A corotron wire 41 is connected to a motor 6 in a corotron in which a corotron wire 41 is stretched around a casing 31.
In a corotron cleaning device that performs cleaning with a cleaning pad provided on a sliding block 46 that is reciprocated by a sliding block 46, the motor 64 is driven with a constant torque for a preset forward rotation time and reverse rotation time. Characteristic Corotron cleaning device.