JP2929235B2 - Cleaning device for belt transfer / transport device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cleaning device for a belt transfer / transport device provided in an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

(Prior Art) In general, in an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer, a belt transfer / transport apparatus is employed.

Further, as shown in FIGS. 5 and 6, the above-described belt transfer / transport device is provided with a transfer member transport belt 21 made of a semiconductive rubber material on a lower side of a photoreceptor 20 holding and transporting a toner image.
Are always in contact with each other, and a predetermined charge is imposed on the conveyor belt 21 by a charge applying means.
When a transfer member such as transfer paper conveyed by the printer reaches the photosensitive member 20, the toner image on the photosensitive member 20 is transferred to the transfer member. By the way, since the photoconductor 20 and the conveyor belt 21 are always kept in contact with each other, when a transfer body such as transfer paper is not conveyed and supplied between the two, the toner particles on the photoconductor 20 side are conveyed by the conveyor belt. The transfer belt 21 is transferred to the transfer belt 21 and the transfer belt 21 is contaminated, thereby causing back transfer of the transfer body conveyed by the transfer belt 21. Therefore, it is necessary to clean the transport belt 21. Conventionally, two means are used as a cleaning means for the transport belt 21.

First, as a first cleaning means, as shown in FIG. 5, a cleaning unit 23 having a rubber blade 22 which is always in contact with the transport belt 21 at a lower position on one side of the transport belt 21 is provided. The cleaning is performed by scraping off toner particles adhering to the conveyor belt 21 side by the blade 22.

As a second means, as shown in FIG.
A cleaning fabrush 24 made of nylon, Teflon fiber, etc., which is always in contact with the conveyor belt, and a scraper 25 for toner particles which is always in contact with the fur brush 24, at a lower position in the middle of the conveyor belt 21. A cleaning unit 26 having a
The toner particles adhering to the conveyor belt 21 are transferred to the fur brush 24 by the rotation of the roller 24, and the toner particles are scraped off by the scraping member 25.

(Problems to be Solved by the Invention) However, in the above-described first cleaning unit, since both the transport belt 21 and the blade 22 that is constantly in contact with the transport belt 21 are formed of a rubber material, these transport belts are not used. The frictional resistance between the belt 21 and the blade 2 is large, and both of them wear quickly and have a short life.
There is a problem that the scraping action of the blade 22 is not sufficiently performed due to irregularities on the surface of the transfer member 21 and cleaning failure occurs, thereby causing back transfer dirt on the transfer body.

In the second cleaning means, the transport belt 21
Since the fur brush 24 is constantly in contact with the fur brush 24, there is a problem that the fur brush 24 may fall down and impair the cleaning effect, or the rotation of the fur brush 24 may cause toner particles to scatter and contaminate the surroundings. Was.

The present invention has been made in view of the above-described various problems, and an object of the present invention is to perform long-term stable cleaning of a transport belt without causing scattering of toner particles, and to provide a transfer medium with It is an object of the present invention to provide a cleaning device for a belt transfer / transport device that can reliably prevent the occurrence of back contamination.

(Means for Solving the Problems) In order to achieve the above object, the present invention relates to a belt transfer / conveyance apparatus provided with a transfer body conveyance belt having a charge applying means for transferring a toner image on a photoreceptor side to a transfer body side. In the cleaning device, there is provided a separation / contact mechanism that supports the conveyance belt so as to be able to contact and separate from the photoconductor side, and makes the conveyance belt contact and separate from the photoconductor. And a cleaning unit having a cleaning fur brush that is always in contact with the conveyor belt on the trajectory of the conveyor belt. Even when the conveyance belt is separated from the photoconductor by the end of the image forming operation, the charge imprint on the fur brush of the cleaning unit and the rotation driving are performed. It is characterized in that it is configured to continue for a predetermined time.

(Operation) According to the above configuration, when a toner image is transferred from a photoreceptor to a transfer body such as transfer paper, the transfer belt having the charge applying means is brought into contact with the photoreceptor via the contact mechanism such that the whole of the conveyor belt contacts the photoreceptor. The toner image on the photoreceptor side is transferred to a transfer member supplied between the photoreceptor and the transport belt, and after the image transfer to the transfer member is completed, The entire conveyor belt is separated from the photoreceptor side, so that transfer of toner particles from the photoreceptor to the conveyor belt side during this separation is prevented.

In addition, the fur brush of the cleaning unit provided on the transport belt is continuously charged and driven with a predetermined charge for a predetermined time after the transport belt comes into contact with the photosensitive member by the separation / contact mechanism and for a predetermined time after the separation. And therefore,
The toner particles transferred and adhered to the transfer belt side are reliably removed and cleaned by the fur brush, and after the image is transferred to the transfer member, the transfer belt is separated from the photosensitive member side by the separation / contact mechanism. Since the cleaning with the fur brush is performed in a state where the transfer adhesion of the toner particles from the photoconductor to the side of the conveyor belt is prevented, the conveyor belt is maintained in a good cleaning state.

Further, at the time of cleaning by the fur brush, a predetermined charge is applied to the fur brush, and toner particles are electrically attracted from the transport belt, so that toner particles are prevented from scattering around.

That is, in the present invention, the cleaning operation performed during the image forming operation and the application of the predetermined charge to the fur brush are performed for a predetermined time even after the image forming operation is completed and the conveyance belt is separated from the photoconductor. It is characterized in that the cleaning is performed so that a good cleaning state of the transport belt is maintained.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a belt transfer / equipped with the cleaning device of the present invention.
1 shows the overall structure of an image forming apparatus provided with a transport device. In FIG. 1, reference numeral 1 denotes a photosensitive member rotatably supported;
Reference numeral denotes a cleaning device for the photoconductor 1, reference numeral 3 denotes a developing unit, and reference numeral 4 denotes a belt transfer / transport device provided with a cleaning device disposed below the photoconductor 1. Reference numeral 5 denotes a paper feed box containing a transfer body 6 such as transfer paper, and a pair of upper and lower paper feed rollers 7, 7 opposed to each other between the paper feed box 5 and the belt transfer / transport device 4. A sheet feed detection switch RSW for supporting and feeding the transfer body is provided immediately upstream of each of the sheet feed rollers 7, and a downstream side of the belt transfer / conveyance device 4 is provided with: Multiple rollers 81
Is provided, and a discharge detection switch ESW for detecting discharge of the transfer body 6 is provided downstream of the fixing unit 8.

2 and 3, the belt transfer / transport device 4 transports a transfer body 6 such as transfer paper supplied from the paper feed roller 7 and has a semiconductive endless transport belt 41. And upstream and downstream rollers 42 and 43 that support the transport belt 41, and a pair of left and right intermediate wheels 44 and 45 disposed between the rollers 42 and 43. A corona charger 46 connected to a high-voltage power supply E is disposed at an intermediate position between the wheels 44 and 45 as a charge applying means for applying a predetermined charge to the conveyor belt 41. A high-voltage power source E is connected to the roller 42 and the intermediate wheel 44 located on the upstream side, and the conveying belt 41 is
A predetermined charge is imprinted on the upstream side of the transfer belt, and the transfer body 6 supplied from the paper feed roller 7 is conveyed by the imprinted electric charge while being electrically attracted to the conveyance belt 41 side. The sheet is surely conveyed to the photoreceptor 1 side without causing displacement or the like on the belt 41.

Then, the entirety of the transport belt 41 such as the rollers 42 and 43 and the corona charger 46 is integrally assembled via a support frame 47, and the support frame 47 is attached to one side of the rollers 42 and 43 (see FIG. In the example, the transport belt 41 is supported so as to be able to swing up and down around the downstream roller 43) so that the entire transport belt 41 can be brought into contact with and separated from the photoconductor 1 side. A contact / separation mechanism 9 for contact / separation is provided. The detachment mechanism 9 includes, for example, a swing arm that is swingably supported on the fixed member side of the image forming apparatus.
91, a contact 92 such as a roller which is supported on one side in the longitudinal direction of the swing arm 91 and is always in contact with the lower surface side of the support frame 47, and is provided on the longitudinal direction of the swing arm 91. And an arm SOL for swinging the arm. The arm 91 is vertically swung by the operation of the solenoid SOL, and the entire support frame 47, that is, the entire conveyance belt 41 is contacted with the photosensitive member 1 via the contact 92. It is configured to contact and separate from the side.

Also, a downstream roller on the revolving locus of the transport belt 41 is used.
The cleaning unit 10 is assembled integrally with the cleaning unit 10 via the support frame 47 at the lower position of 43. Specifically, as the cleaning unit 10, a unit case 10a
A cleaning fur brush 10b made of nylon, Teflon fiber, etc., which is always in contact with the conveyor belt 41, is rotatably supported on the inner upper side, and the fur brush 10b is mounted on a lower side of the fur brush 10b. The cleaning roller 10c that is always in contact with the cleaning roller 10c is rotatably supported, and a cleaning blade 10d that is in contact with a part of the outer periphery of the cleaning roller 10c is provided. Also,
A high-voltage power supply E is connected to the fur brush 10b and the cleaning roller 10c, respectively, and a predetermined charge is applied to the fur brush 10b and the cleaning roller 10c by the high-voltage power supply E. The cleaning unit 10
Is not limited to the lower position of the downstream roller 43 on the trajectory of the transport belt 41, but may be provided on an appropriate trajectory of the transport belt 41. In addition, the fourth
As is apparent from the timing chart of FIG. 2, the fur brush 10b and the cleaning roller 10c of the cleaning unit 10 are not only contacted by the separation / contact mechanism 9 with the photosensitive member 1 but also by the separation mechanism 9. Conveyor belt
Even after the entire 41 is separated from the photoreceptor 1, the charging of a predetermined charge and the rotation driving are performed for a predetermined time. Next, the operation of the above configuration will be described with reference to the timing chart shown in FIG. First, when the print key switch KSW is turned on, the drive motor DM is driven to start the rotation drive of the photoconductor 1, and the solenoid SOL of the separation / contact mechanism 9 is operated, so that the entirety of the transport belt 41 is moved. 2 is swung upward from the state shown in FIG. 2 to the state shown in FIG. 3, and a predetermined charge BHVT is applied to the fur brush 10b of the cleaning unit 10 and a predetermined charge CHVT is applied to the cleaning roller 10c. With the load, the remaining toner particles on the side of the transport belt 41 are transferred and adhered to the side of the fur brush 10b by the rotational drive of the fur brush 10b, and the transport belt 41 is cleaned.
Further, the toner particles on the fur brush 10b side are transferred to the cleaning roller 10c side and removed by the cleaning blade 10d.

Then, when the transfer body 6 is supplied and conveyed from the paper feed box 5 side and the paper feed detection switch RSW is turned on, the corona charger 46 moves to the conveyor belt 41 side at a predetermined timing after the on operation. A predetermined charge THVT is imprinted, and the toner image on the photoconductor 1 side is transferred to the transfer body 6 conveyed between the conveyance belt 41 and the photoconductor 1,
The feed detection switch RSW is turned off after passing through the transfer body 6. Further, the transfer body 6 on which the image transfer has been performed.
Is transported to the fixing unit 8 side via the transport belt 41,
When the image is fixed and discharged to the outside by the fixing unit 8, the discharge detection switch ESW is turned on, and at a predetermined timing after the on operation, the charge THVT imprinted on the transport belt 41 is lost. You. The above operation is similarly performed when the next transfer body 6 is conveyed and supplied after the transfer body 6.

Further, when the image transfer to all the transfer bodies 6 is completed,
After a lapse of a predetermined time since the discharge detection switch ESW is turned off in the final transfer body 6, the solenoid SOL of the separation / contact mechanism 9 is turned off so that the entire conveyance belt 41 is separated from the photoreceptor 1. The discharge detection switch ESW is turned off, and the solenoid S is turned off.
After a predetermined time has passed since the OL was turned off, the drive of the drive motor DM was stopped, and the fur brush 10 was stopped.
Both the charge BHVT of b and the charge CHVT of the cleaning roller 10c disappear. In other words, the transport belt 41 is not always in contact with the photoconductor 1 side, but after a predetermined time has passed since the discharge detection switch ESW was turned off in the final transfer body 6, the transfer mechanism 41 The toner particles are separated from the photoconductor 1 side by the operation, so that the transfer and adhesion of the toner particles from the photoconductor 1 to the conveyance belt 41 side when the conveyance belt 41 is separated is prevented.

Further, the fur brush 10 of the cleaning unit 10
The b and the cleaning roller 10c continue to be driven until a predetermined time elapses after the discharge detection switch ESW is turned off in the final transfer body 6 and the solenoid SOL is turned off, and the fur brush 10b The charges BHVT and CHVT of the cleaning roller 10c and the cleaning roller 10c continue to be charged until a predetermined time elapses after the discharge detection switch ESW is turned off and the solenoid SOL is turned off, similarly to the drive thereof. Therefore, when the transfer member 6 is not supplied between the photosensitive member 1 and the transport belt 41, the residual toner particles transferred and adhered from the photosensitive member 1 to the transport belt 41 side receive the fur brush 10b and the cleaning roller 10c.
The transfer belt 41 is removed from the photoreceptor 1 by the separating mechanism 9 after the image transfer to the transfer body 6 is completed. The cleaning is performed by the fur brush 10b and the cleaning roller 10c in a state where the transfer and adhesion of the toner particles from the photoreceptor 1 to the transport belt 41 at the time of the separation are prevented. It is maintained in a proper cleaning state.

Further, at the time of the above cleaning, the fur brush 10
Since a predetermined charge is applied to b and the cleaning roller 10c, the toner particles are reliably prevented from scattering around. In the above-described embodiment, the entirety of the conveyor belt 41 is supported in a cantilever manner so as to swing up and down with respect to the photoreceptor 1. However, for example, the entire conveyor belt 41 is moved in the horizontal direction. It may be.

(Effect of the Invention) As described above, according to the cleaning device of the belt transfer / transport device according to the present invention, the transport belt is supported so as to be able to contact and separate from the photoconductor side, and the transport belt is attached to the photoconductor. A separation / contact mechanism for contacting and separating the image forming apparatus is provided. The image forming apparatus is configured to be in contact with the photoconductor when the image forming operation is started and to be separated when the image forming operation is completed. A cleaning unit having a cleaning fur brush that is always in contact with the transport belt, and even if the transport belt is separated from the photoconductor by the end of the image forming operation, Since the charge imprinting and the rotation drive of the above are configured to continue for a predetermined time, that is,
The cleaning operation performed during the image forming operation and the application of the predetermined charge to the fur brush are performed for a predetermined time even after the image forming operation is completed and the conveyance belt is separated from the photoconductor. By
Since the good cleaning state of the transport belt is maintained, the transport belt can be stably cleaned for a long time without causing toner particles to be scattered at the time of cleaning. Can be reliably prevented.

[Brief description of the drawings]

FIG. 1 shows a belt transfer / equipped with the cleaning device of the present invention.
FIG. 2 and FIG. 3 are side views showing the main part of the belt transfer / conveyance apparatus, and FIG. 2 is a side view showing the main structure of the image forming apparatus provided with the conveyance apparatus. FIG. 3 shows a state in which the conveyor belt is in contact with the photosensitive member, FIG. 4 shows a timing chart, and FIGS. 5 and 6 show conventional examples. It is a schematic diagram. DESCRIPTION OF SYMBOLS 1 ... Photoreceptor, 41 ... Conveyer belt, 46 ... Charge provision means (corona charger), 9 ... Separation mechanism, 10 ... Cleaning unit, 10b ... Fur brush.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65H 5/00 G03G 15/00 G03G 21/00

Claims (1)

(57) [Claims] A cleaning device for transferring and transferring the toner image on the photosensitive member to the transfer member; And a separation / contact mechanism for contacting and separating the conveyor belt from / to the photoconductor, so that the conveyance belt contacts the photoconductor when the image forming operation is started, and is separated when the image forming operation is completed. And a cleaning unit having a cleaning fur brush that is constantly in contact with the conveyor belt is disposed on the revolving locus of the conveyor belt, and the conveyor belt is separated from the photoconductor by the end of the image forming operation. Wherein the charging of the electric charge to the fur brush and the rotational driving of the cleaning unit are continued for a predetermined period of time. The cleaning device of transferring and conveying device.