JPH049308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for an electrostatic copying machine, and more specifically, during image formation, a wiping member is brought into sliding contact with a photoreceptor to block residual toner on the photoreceptor and to prevent the cleaning of the photoreceptor from occurring. The present invention relates to a cleaning device for an electrostatic copying machine, in which a wiping member is separated from a photoreceptor during image formation, and the blocked residual toner is brought to a developing device.

Conventionally, when paper dust is mixed into the residual toner on the photoconductor, the paper dust and the residual toner are blocked by a wiping member, resulting in the formation of a lump of paper dust and toner. Such lumps are also brought to the developing device when the wiping member separates from the photoreceptor after the copying operation is completed. On the other hand, in the developing device, in order to prevent the toner from scattering, felt members are provided on both sides of the frame of the developing device to make sliding contact with the photoreceptor, and to prevent the toner from blowing up due to the rotation of the developing roller. In order to prevent this, a rubber blade member is provided at the upstream end of the frame in the direction in which the photoreceptor moves, and is in sliding contact with the photoreceptor. The blade member has sufficient resiliency to allow residual toner from the cleaning device to enter the developer device. However, when a lump of residual toner and paper powder is brought to the developing device as described above, the lump remains between the blade and the photoreceptor, creating a gap between the blade and the photoreceptor. . Therefore, the toner is blown up and scattered from the gap. Note that if the pressure force of the blade against the photoreceptor is reduced to allow the lump to enter the developing device, it becomes difficult to prevent the toner from being blown up from within the developing device.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned technical problem and provide a cleaning device that prevents agglomerates of toner and paper dust from being introduced into a developing device.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a transfer type electrostatic copying machine according to an embodiment of the present invention. The copy sheets in paper feed cassettes 13 and 14 mounted on the body 12 of the electrostatic copying machine 11 are selectively fed into paper feed rollers 15 and 16.
The sheets are fed one by one and transported by a transport device 17 having three pairs of rollers.

A horizontal transparent plate 20 provided at the top of the fuselage 12
A document 21 is placed on top, and the document 21 is tightly attached to the transparent plate 20 by a holding plate 22 . An optical device 24 is provided inside the fuselage 12 at an upper portion partitioned by a partition plate 23 . This optical device 24 includes an exposure lamp 25, a reflecting mirror 26 that efficiently guides light from the exposure lamp 25 to the original 21,
27, reflecting mirrors 29, 30, 31 for forming an optical image of the original 21 on the photosensitive member 28 of the photosensitive drum 18 along the optical path 10, a lens 32, and a reflecting mirror 3.
3. A cooling fan 34 for cooling the optical device 24 is provided near the left end of the body 12 in FIG.

During exposure, the lens 32 and the reflecting mirror 3
The optical devices 24 except 3 move for exposure from the left side to the right side inside the body 12. In this exposure movement,
The moving speeds of the exposure lamp 25 and the reflecting mirrors 26, 27, 29 are set to twice the moving speed of the reflecting mirrors 30, 31. At the end of the exposure, the optical device 24 except the lens 32 and the reflecting mirror 33 moves in the opposite direction to the exposure movement direction and returns to the rest position shown by the solid line. Moreover, the lens 32 moves slightly along the exposure movement direction depending on the copying magnification and is then fixed. In other words, at the time of reduced copying,
The lens 32 is displaced from the position shown by the solid line to the position P shown by the imaginary line. At this time, the reflecting mirrors 30 and 31 are displaced to the positions shown by the imaginary lines. On the other hand, during enlarged copying, the lens 32 is slightly displaced from the position shown by the solid line in the direction opposite to the position P.

The photoreceptor 28 is charged by a corona discharger 37. A document image is formed on the charged photoreceptor 28 from the optical device 24 in the exposure area 38 through the opening 39 of the partition plate 23 and the exposure window 40, thereby forming an electrostatic latent image. . This electrostatic latent image is developed into a toner image by the developing device 41. This toner image is transferred onto the copy paper conveyed by the conveyance device 17 in the transfer area 54 by the action of the corona discharger 42.
The copy paper on which the toner image has been transferred is reliably peeled off from the photoreceptor 28 by the action of the static eliminator 43. This peeled copy paper is wrapped around rollers 44, 4
The image is conveyed to a heat fixing device 47 by an endless conveyor belt 46 that is wound around and driven by a belt 5 .
The heat fixing device 47 includes a heat roller 49 having a built-in heater 48 and a pressure roller 50 that is in pressure contact with the heat roller 49.
Equipped with. When the copy paper passes between the heat roller 49 and the pressure roller 50, the toner on the copy paper is thermally melted and the original image is fixed. The copy paper on which the fixing has been completed is discharged onto a tray 52 by a pair of paper discharge rollers 51.

After the transfer process, the photoreceptor 28 is cleaned by a cleaning device 9 according to the present invention. Note that a charge eliminating lamp 53 is provided between the cleaning device 9 and the charging corona discharger 37 to remove residual charges on the photoreceptor. Furthermore, a charge eliminating lamp 96 is provided between the corona discharger 37 and the exposure area 38 for removing the charge on the excess area of the photoreceptor 28 during reduction copying.

FIG. 2 shows the cleaning device 9 and the developing device 41.
FIG. 3 is a cross-sectional view showing the photosensitive drum 18 in detail. The frame 55 of the developing device 41 is connected to the photosensitive drum 18.
is arranged with an opening facing the photoreceptor 28 of
In the opening, a developing roller 58 having a permanent magnet 56 built into a cylindrical body 57 is arranged close to the photoreceptor 28 and having an axis parallel to the photoreceptor drum 18 . Further, a two-component developer storage section 59 is formed in the frame 55, and the two-component developer stored in this storage section 59 is stirred by the stirring means 97 while being moved to the developing roller 58. brought into position. A magnetic brush 98 is formed by the developer on the outer peripheral surface of the developing roller 58, and this magnetic brush 98 rotates in the direction indicated by arrow 99 to rub the photoreceptor 28. As a result, the electrostatic latent image on the photoreceptor 28 is visualized.

Felt members 100 that come into sliding contact with the photoreceptor 28 are attached to the periphery of both sides of the opening of the frame 55 facing the photoreceptor 28.
is fixedly provided. This felt member 100
This prevents the toner inside the frame 55 from scattering outward. Furthermore, a rubber blade member 101 that slides on the photoreceptor 28 is provided at the upstream end of the frame 55 along the moving direction of the photoreceptor 18, that is, at the upper edge of the opening. This blade member 101 prevents toner blown up as the developing roller 58 rotates from scattering above the frame 55 .

A toner replenishing device 102 is provided at the top of the frame 55, and toner is replenished into the storage portion 59 from the toner replenishing device 102 in response to consumption of toner in the developing device 41.

Note that the configurations of the developing device 41 and the toner replenishing device 102 as described above are conventionally known.

The cleaning device 9 according to the present invention is arranged between the transfer area 54 and the charging corona discharger 37 along the moving direction of the photosensitive drum 18. A wiping member 61 is provided in the casing 60 of the cleaning device 9 at a position above the photosensitive drum 18 and at a position close to the corona discharger 37 along the moving direction of the photosensitive drum 18 so as to be movable toward and away from the photosensitive member 28 . is supported. This wiping member 61 is
The swing lever 62 is fixedly provided at one end 62 a in the axial direction of the swing lever 62 , which extends in a horizontal direction substantially perpendicular to the axis of the photosensitive drum 18 . The other end 62b of the swing lever 62 in the axial direction passes through a long hole 64 formed in the rear plate 63 of the casing 60 and extending vertically. In addition, the swing lever 62 is rotatably supported in the middle by a pivot shaft 65 parallel to the axis of the photosensitive drum 18 .

FIG. 3 is a perspective view of the cleaning device 9 seen from behind, and FIG. 4 is a perspective view of the cleaning device 9 cut away from the opposite direction from FIG.
FIG. 5 is a view of the cleaning device 9 seen from the rear from the center. The casing 60 includes a casing body 60a whose cross section perpendicular to the axis is approximately in the shape of an inverted U;
Side plates 6 that close both longitudinal ends of this main body 60a
6, 67, and each one end portion 66a, 67a of the side plates 66, 67 protruding from the main body 60a has a support shaft 6 having an axis parallel to the axis of the photosensitive drum 18.
8, and both ends of this support shaft 68 are connected to both side plates 69, 70 of the fuselage 12 (see FIG. 1).
Supported by. Further, the one end portion 66a, 67a of each side plate 66, 67 of the casing 60 and the other end portion 66 on the opposite side with respect to the casing body 60a.
A shaft 71 having an axis parallel to the axis of the photosensitive drum 18 is inserted through the shafts b and 67b.
Both ends of the fuselage body 12 are received by recesses 72 and 73 which are opened upwardly and cut out at the upper portions of the side plates 69 and 70 of the body 12. Therefore, the casing 60 is
It is rotatable upward around a support shaft 68.

The rear plate 63 of the casing 60 includes the photosensitive drum 1.
A solenoid 74 having an axis extending parallel to the solenoid 8 is supported, and one end of a spring 76 is connected to a plunger 75 that is driven to expand and contract by the solenoid 74 . The other end of the spring 76 is connected to the lower end of the cam 78. This cam 78 is connected to the swing lever 6
It is rotatably supported on the rear plate 63 by a pin 79 having an axis perpendicular to the axis of the solenoid 74 below the other end portion 62b protruding from the rear plate 63 of the solenoid 74 . A cam surface 80 is formed on the upper edge of the cam 78, and the other end 62b of the swing lever 62 always comes into contact with this cam surface 80.

In FIG. 5, the plunger 75 shown by a solid line,
The positions of the cam 78 and the swing lever 62 are shown when no image is being formed. The swing lever 62 is rotated counterclockwise around the rotation shaft 65 as shown by the imaginary line in FIG. 2, so that the wiping member 61 is separated from the photoreceptor 28. In this state, when forming an image, the solenoid 74 is excited, and the plunger 75 is thereby drawn into the solenoid 74. In response to this contraction movement of the plunger 75, the cam 78 moves the pin 7 as shown by the imaginary line in FIG.
9 in the clockwise direction, and the swing lever 6
The other end portion 62b of No. 2 is pushed upward.
As a result, the swing lever 62 rotates clockwise in FIG. 2 around the rotation shaft 65, and the wiping member 61
comes into sliding contact with the photoreceptor 28. When the image forming operation is completed, the solenoid 74 is demagnetized, and the plunger 75 and cam 78 return to the positions indicated by solid lines in FIG. 5 accordingly. Note that the other end 62b of the swing lever 62 is connected to the rear plate 63 of the casing 60.
The swing lever 62 is urged downward by a leaf spring 105 fixed to the cam 78, and the swing lever 62 returns to the position shown by the imaginary line in FIG. 2 following the rotational movement of the cam 78.

Referring again to FIG. 2, on the upstream side of the wiping member 61 along the moving direction of the photosensitive drum 18, the casing 60 has an axis parallel to the photosensitive drum 18 and comes into sliding contact with the photosensitive drum 28. A fur brush 81 is supported. The rotating shaft 82 of this fur brush 81 is connected to the side plates 66, 6 of the casing 60.
7, and a gear 83 is fixedly provided at the end of the rotating shaft 82 protruding from the side plate 67, as shown in FIG. On the other hand, a gear 85 is attached to the end of the rotating shaft 65 protruding from the side plate 67 via a one-way clutch 84, and this gear 85 meshes with the gear 83.

FIG. 7 is a simplified cross-sectional view for explaining the function of the one-way clutch 84. This one-way clutch 84 transmits only the rotational power in the arrow direction 86 from the rotation shaft 65 to the gear 85. That is, gear 8
Yafu 8 is attached to the inner circumferential surface of the support 87 fixed to
Recesses 88 having inner circumferential surfaces close to the rotation shaft 65 in six directions are formed at intervals in the circumferential direction. A cylindrical roller 89 is provided between each recess 88 and the outer peripheral surface of the rotating shaft 65, and each roller 89 is elastically biased in the arrow direction 86 by a spring 90.

When the rotation shaft 65 rotates in the direction of arrow 86, the rollers 89 move between the recess 88 and the rotation shaft 6 as shown in FIG. 7a.
Caught between 5 and 5. Thereby, the rotational power of the rotation shaft 65 is transmitted to the support body 87 and the gear 85 via the rollers 89.

When the rotation shaft 65 rotates in the direction indicated by the arrow 91 opposite to the arrow 86, the roller 89 is displaced in the arrow 91 direction against the spring force of the spring 90, as shown in FIG. 7b. . As a result, the rotational power of the rotation shaft 65 is not transmitted to the support body 87 and the gear 85.

In this way, the one-way clutch 84 transmits only the rotational power of the rotation shaft 65 in the arrow direction 86 to the gear 85, and from the gear 85 via the gear 83 to the rotation shaft 86.
2. Moreover, the rotation direction indicated by the arrow 86 is selected as the rotation direction when the swing lever 62 rotates clockwise in FIG. 2 to bring the wiping member 61 into sliding contact with the photoreceptor 28. Therefore, the fur brush 81 rotates in the direction indicated by arrow 92 in FIG. 2 as the wiping member 61 comes into sliding contact with the photoreceptor during image formation. Furthermore, the amount of angular displacement of the fur brush 81 due to a single rotational movement is preset to such an extent that it will be displaced 360 degrees by 1000 rotational movements, for example, and the gear 83, 85 shapes are determined.

Still referring to FIG. 2 again, the casing 60
A scraping plate 93 is provided at the lower part of the photosensitive drum 18 and extends upwardly, facing the photoreceptor 28 of the photosensitive drum 18, and the upper end of the scraping plate 93 contacts the fur brush 81. In addition, the scraping plate 93 and the rear plate 63
A storage section 94 is formed between the two. Further, a permanent magnet piece 95 is fixed to the surface of the scraping plate 93 facing the photoreceptor 28.

In the cleaning device 9 configured as described above, during image formation, the fur brush 81 blocks the lumps of paper dust and toner adhering to the photoreceptor 28 . Therefore, no lumps of paper dust and toner are brought to the wiping member 61, and only the residual toner is blocked at the wiping member 61. Note that, if a carrier is attached to the photoreceptor 28, the attached carrier is removed by the permanent magnet piece 95.

When image formation is completed, the wiping member 61 is separated from the photoreceptor 28 as described above, and the remaining toner that has been blocked is removed from the developing device 41 as the photoreceptor 28 moves. brought about. At this time, since the mass consisting of toner and paper powder is blocked by the fur brush 81, the developing device 4
1 and therefore, as before, the said mass is not brought to the blade member 10 of the developing device 41.
1 and the photoreceptor 28, and as a result, the occurrence of toner blow-up development in the developing device 41 is prevented.

During the next image formation, when the wiping member 61 moves close to the photoreceptor 28, the fur brush 81 is slightly rotated in the direction of the arrow 92 (see FIG. 2). Accordingly, the lump consisting of toner and paper powder adhering to the fur brush 81 at the portion reaching the position of the scraping plate 93 is scraped off by the scraping plate 93 and brought to the storage portion 94. Therefore, the contact portion of the fur brush 81 with the photoreceptor 28 is a clean portion free from the above-mentioned lumps. Incidentally, along with the scraping operation by the scraping plate 93, the fur brush 81 is rotated slowly so that the toner and paper powder do not scatter within the casing 60.

The toner and paper powder stored in the storage section 94 are
At the time of maintenance, the casing 60 may be opened around the support shaft 68 and removed.

As another embodiment of the present invention, a fur brush 81
may be rotated in the opposite direction to the arrow 92 in FIG. Moreover, the permanent magnet piece 95 may be omitted. Further, although the above-mentioned embodiments were explained in relation to an electrostatic copying machine using a two-component developer, the present invention
It can also be practiced in conjunction with electrostatic copying machines that use component-based developers.

As described above, according to the present invention, the mass consisting of toner and paper powder is blocked by the fur brush, so that it does not reach the developing device, and therefore, the mass consisting of toner and paper dust is blocked between the blade and the photoreceptor in the developing device. This prevents the toner from being bitten, and the toner is reliably prevented from blowing up due to the biting. Moreover, since the fur brush rotates by a set angle as the wiping member approaches the photoreceptor, large amounts of lumps of toner and paper powder do not adhere to the fur brush. The lumps can be easily removed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a transfer type electrostatic copying machine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing details of a cleaning device 9, a developing device 41, and a photosensitive drum 18, and FIG. 3 is a cleaning FIG. 4 is a perspective view of the cleaning device 9 seen from behind, FIG. 4 is a cutaway perspective view of the cleaning device 9 taken from the opposite direction to FIG. 3, and FIG.
FIG. 6 is a cross-sectional view showing the connected state of the rotating shaft 65 and the rotating shaft 82, and FIG. 7 is a simplified cross-sectional view for explaining the function of the one-way clutch 84. 9...Cleaning device, 18...Photosensitive drum, 28...Photoconductor, 37...Corona discharger, 4
1... Developing device, 61... Wiping member, 62... Rocking lever, 65... Rotating shaft, 74... Solenoid, 78... Cam, 81... Fur brush, 82
... Rotating shaft, 84 ... One-way clutch.

Claims (1)

[Claims] 1. A wiping member disposed upstream of a charging corona discharger along the moving direction of the photoreceptor is brought into sliding contact with the photoreceptor during image formation to remove residual toner on the photoreceptor. In the cleaning device for an electrostatic copying machine, the cleaning device for an electrostatic copying machine is configured to block the photoconductor and move the wiping member away from the photoconductor during non-image formation to bring the blocked residual toner to a developing device, a fur brush that slides into contact with the photoreceptor further upstream than the wiping member and downstream of the transfer area along the wiping member; 1. A cleaning device for an electrostatic copying machine, comprising means for driving an angular displacement by a predetermined angle. 2. A patent characterized in that the wiping member is provided at one end of a swinging lever, and a rotating shaft that pivotally supports the swinging lever is connected to a rotating shaft of the fur brush via a one-way clutch. A cleaning device for an electrostatic copying machine according to claim 1.