JPH09146390A - Cleaning device for transfer roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the saving of space and reduction in cost, to enhance a cleaning property and to secure reliability by providing a means for receiving toner scraped by a blade and a means for dropping the toner received by means of gravity when a transfer paper does not pass. SOLUTION: A toner receiving plate 47 is nearly horizontally arranged at a position just under the contact part of the blade 45 with a transfer roller 14. Since the toner receiving plate 47 receives the scraped residual toner T2, it does not drop on the front surface of the transfer paper P during passage, at the time of transferring. Further, a contact/uncontact turning mechanism 33 for allowing the transfer roller 14 to contact/uncontact with an intermediate transfer belt 10 and simultaneously, turning the toner receiving plate 47, linked with the contact/uncontact and a toner recovering container 21 are provided. The mechanism 33 displaces the toner receiving plate 47 to a retreat position, when the transfer paper dose not pass, to drop the received toner T2 by the gravity. Thus, high image quality is obtained without surface staining and it is unnecessary that a particular recovering container is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer for transferring a toner image on an image carrier onto a transfer paper in an image forming section of an electrophotographic image forming apparatus such as a copying machine, a facsimile machine, a printer or the like. The present invention relates to an improvement of a cleaning device used for removing and cleaning toner adhering to a transfer roller used as a means.

[0002]

2. Description of the Related Art In a color copying machine or the like, an image carrier is formed in order to form a color image of a plurality of colors by using toners of different colors which are respectively supplied onto the image carrier from a plurality of developing devices. Instead of directly transferring the toner on the photoconductor onto the transfer paper, after transferring the toner images of all the colors on the intermediate transfer belt, the toner images of the multiple colors are transferred onto the transfer paper all at once. I am trying to do it. As a means for transferring the toner image on the intermediate transfer belt onto the transfer paper, a transfer roller which is in contact with the surface of the intermediate transfer belt while rolling is used, and when the transfer paper is passed between the transfer roller and the intermediate transfer belt, By applying a bias having a polarity opposite to that of the toner from the transfer roller, the toner on the intermediate transfer belt is transferred onto the transfer paper. By the way, since the transfer roller rotates in contact with the intermediate transfer belt, the toner remaining on the intermediate transfer belt easily adheres to and accumulates on the transfer roller. If the toner adheres to the transfer roller, the transfer performance is deteriorated. Therefore, various cleaning means for removing the toner from the transfer roller have been conventionally proposed. Below, this kind of technology is illustrated. 1. JP-A-58-142366 "Roller cleaning device" Konishi Roku Kogyo Co., Ltd .: Two cleaners to which a bias of the same polarity as that of the residual toner on the image bearing member and a polarity opposite thereto is applied.
A ning roller and an intermediate electrode (charger) are arranged in the circumferential direction of the image carrier, and a scraping blade is brought into sliding contact with the outer peripheral surface of each cleaning roller to remove the toner on the cleaning roller. 2. Japanese Unexamined Patent Publication No. 61-9677 "Transfer device in electrophotographic printing machine" Nippon Signal Co., Ltd .: A bypass resistor for discharging static electricity generated in an insulator around the transfer device is provided, and a bias voltage is applied to the transfer roller. In this technique, the toner attached to the transfer roller is removed by a blade in a technique of stabilizing the potential difference between the photosensitive drum and the transfer roller and increasing the transfer efficiency by turning on and off according to the print timing. 3. Japanese Unexamined Utility Model Publication No. 63-96571 "Transfer device" Fuji Xerox Co., Ltd .: A single metal roll is used as a transfer roller for transferring toner onto a transfer paper which is in contact with a photoconductor drum and passes through a nip between the two. At the same time, the toner adhering to the surface of the transfer roller is removed by a blade. 4. Unexamined-Japanese-Patent No. 1-185572 "Image forming apparatus" Canon Inc .: Toner attached to a transfer roller formed of fine continuous pores is removed by a blade. 5. Japanese Unexamined Patent Publication No. 4-350882 "Transfer device for image forming apparatus" Mita Industry Co., Ltd .: A transfer brush is used by applying a voltage to the fur brush as a cleaning means for the transfer roller in contact with the photoconductor. To clean. 6. Japanese Patent Laid-Open No. 5-11644 “Roller Transfer Device” Fujitsu Ltd .: A roller, which is a member having a lower releasability for a toner than a transfer roller, is pressed against a transfer roller for cleaning. 7. [Image forming apparatus] Minolta Camera Co., Ltd .: A roller for transfer and cleaning is pressed against a photoconductor, and a transfer voltage is applied to the roller at the time of transfer, but after the transfer is completed. Is a technique of applying a voltage having a polarity opposite to that of the residual toner at a predetermined timing, and a technique of removing toner on the roller by a blade. 8. Japanese Laid-Open Patent Publication No. 5-53456 "Cleaning device for transfer roller of electrophotographic device" Toshiba Corp .: Toner on the peripheral surface of a transfer roller is removed by a blade, and toner removed by the blade is directly below the toner. It is received by the receiving member located at. 9. Japanese Patent Laid-Open No. 5-107959 "Image forming apparatus"
Ricoh Co., Ltd .: In the technology of removing the toner on the photosensitive drum by the transfer roller to which a bias having a polarity opposite to the charging polarity of the toner is applied, that is, in the technology in which the transfer roller also serves as the cleaning means, The toner attached to the transfer roller is removed by a blade. 10. JP, 6-186812, A "Transfer device" Mita Industry Co., Ltd .: A recovery roller is brought into contact with the peripheral surface of the transfer roller in contact with the photosensitive member, and a predetermined bias is applied to the recovery roller, whereby a potential difference between the two rollers is generated. In the technique of transferring the toner on the transfer roller to the surface of the collecting roller by using the electric field formed, the toner on the surface of the collecting roller is removed by a blade and received by the toner receiver.

[0003]

As described above, in the conventional cleaning device for the transfer roller, as a means for preventing the accumulation (protrusion) of the residual toner adhered on the transfer roller. There are many techniques for scraping toner off with blades, but especially in the case of the upper conveyance type where the transfer paper passes over the upper part of the photoconductor / intermediate transfer belt and the image is formed on the lower surface of the transfer paper, cleaning is performed. Means are classified into the following three types. A. A type that scrapes off the toner on the transfer roller with a blade, regardless of the transfer paper passing through the transfer position. The scraped toner drops on the transfer paper. B. A technology that collects toner that has been scraped off from the peripheral surface of the transfer roller by a blade into a collection container. C. No transfer of blades, especially during transfer (when passing through transfer paper)
In addition, a technique to prevent toner from adhering to the transfer roller by applying a reverse polarity voltage to the transfer voltage after a machine is stopped due to a jam during transfer, etc. Of the above three types, first, A. With regard to the type (1), since the toner dropped on the transfer paper is fixed as it is, there is a serious drawback that back stain occurs.
B. With regard to this type, adding a part called a "recovery container" will increase the cost, and it will be necessary to modify the space and mechanism for adding parts, which will increase the size of the machine body. -For the-, a replacement part is required when the collection container is full, which complicates the work, resulting in increased cost and reduced operability.
There is a disadvantage that. C. With respect to the type, since it is a cleaning method that depends only on electrostatic force, the effect is not perfect, and it is not possible to remove the reverse polarity toner (defective toner) that is unavoidably included in the toner. There is a drawback that. Next, the drawbacks of the conventional transfer roller cleaning device will be described by dividing the transfer paper transport system into lower transport and upper transport.

<In the case of a lower-conveyance type image forming apparatus> As a lower-conveyance type apparatus in which transfer is performed on the upper side surface of the transfer paper because the transfer position is on the lower side of the photosensitive member, Japanese Patent Laid-Open No. 5-1
The "image forming apparatus" described in Japanese Patent Publication No. 07959 can be mentioned. In this prior art, the transfer roller also serves as the cleaning means for the photosensitive drum, and the cleaning of the transfer roller is of the blade type. This conventional example aims to reduce the size of the apparatus by providing a cleaning member for cleaning the photosensitive member in the transfer device. From the "scraping method using a blade" to "residual toner on the photoconductor
However, since the transfer roller is transferred to a transfer roller by a transfer roller to which a bias voltage having a polarity opposite to that of the charging polarity is applied (method by electrostatic force) ", the above-mentioned drawback, that is, only electrostatic force is transferred. Since the cleaning is performed, the effect is not perfect, and the reverse polarity toner (defective toner) inevitably contained in the toner cannot be removed.

<Upper Conveying System Image Forming Apparatus> As an upper conveying system device in which transfer is performed on the lower surface of the transfer paper because the transfer position is on the upper side of the photoconductor, Japanese Patent Laid-Open No. 6-1
The transfer device disclosed in Japanese Unexamined Patent Publication No. 86812 can be mentioned. In this system, the toner is transferred onto a recovery roller and recovered by a recovery blade into a recovery container. The purpose of this conventional example is to enable the photosensitive toner adhering to the transfer roller to be efficiently and surely removed. Even if installing a recovery roller is not a problem here, the recovery roller is recovered. Due to the provision of the container, the above-mentioned drawback, that is, a special part called a "recovery container" needs to be added, resulting in an increase in cost, and a space for the addition is required, and the machine body is large. Turn into
For the user, a replacement part is required when the collection container is full, resulting in an increase in cost and a complicated replacement work.

<Object of the Invention> The present invention has been made in view of the above, and in order to solve the above-mentioned drawbacks of the prior arts, the above A. Regarding the back stain, which is a defect of the cleaning device of the type, while the transfer roller is being cleaned (while the transfer paper is passing), the "toner receiving plate" temporarily removes the "remaining toner". The purpose is to realize a system that does not drop onto the transfer paper by adopting the configuration of receiving the paper. The above B. Regarding the drawback of the cleaning device of the type, after the cleaning of the transfer roller (while the transfer paper is not passing), the "toner receiving plate" is rotated by about 90 ° to freely drop the toner, but the recovery is performed. It is an object of the present invention to solve the problem by dropping the container together with the cleaning toner recovery container of the photoconductor or the intermediate transfer belt without providing a special container. C. above. The drawbacks of the cleaning device of the type are intended to be solved by exclusively adopting a blade scraping method (cleaning is reliable and reliability is high).

That is, the invention of claim 1 provides a conventional cleaning device "using a blade" with a means for receiving the toner scraped by the blade and a non-passage of the transfer paper. At times, a means for dropping the toner that has been received by gravity is provided to achieve "high-quality images without stains on the back", eliminating the need for a special "collection container", and saving space and cost. In addition, by adopting the "blade method" which is the conventional technique as it is, the purpose is to ensure high reliability of the cleaning characteristics. In the invention of claim 2, as a means for receiving the toner of claim 1, a mechanism capable of reciprocating the toner receiving plate by approximately 90 ° is provided, and means for dropping the received toner by gravity is provided. The purpose is to prevent back stains, prevent an increase in the number of parts, and ensure high cleaning characteristics, which is an advantage of the blade method. According to a third aspect of the invention, as the mechanism of the second aspect, a gear or a friction pulley is rotatably attached to the fixed shaft of the transfer roller contact / separation member on the driving side.
The transfer roller is fixed to the driven member by fixing a driving member made of a roller or the like, and a driven member made of a gear or a friction pulley for rotating the toner receiving plate on the driven side by about 90 °. The toner receiving plate is configured to open and close approximately 90 ° in synchronization with the rotation of the contacting / separating member (synchronizing with the contacting / separating of the transfer roller) to prevent the back stain and the increase in the number of parts. The purpose is to ensure high cleaning characteristics, which is an advantage of the blade method. According to the invention of claim 4, as the drive / transmission mechanism (contact / separation rotation mechanism) of the device of claim 3, instead of the drive gear / friction pulley, the pulley and the belt / wire / string / chain are used. The purpose of this is to prevent back stains, prevent an increase in the number of parts, and ensure high cleaning characteristics, which is an advantage of the blade method, by using a long transmission means such as a blade. In addition, since the axial distance between the "fixed shaft of the transfer roller contacting / separating member" and the "rotating shaft of the toner receiving plate" is large, the layout should be performed when the drive gear / friction pulley is used. Even if it is difficult to layout, layout is possible.

In the invention of claim 5, a link mechanism is used in place of the mechanism of claims 3 and 4, and in addition to the above effects, it is an object to achieve a more inexpensive mechanism. According to the invention of claim 6, an electromagnetic drive device such as a rotary solenoid is connected to the fixed rotary shaft of the toner receiving plate, and the toner receiving plate is fixed when the transfer paper is not passed based on the control signal of the machine body. By rotating the toner approximately 90 ° and causing the residual toner to fall by gravity, in addition to the above effect, it is possible to cope with the case of the single color mode in which the transfer roller does not come into contact with or separate from the toner. The purpose is to make the layout more flexible. According to the invention of claim 7, a vibrating member is provided at a position where the toner receiving plate is rotated by approximately 90 ° to cause the toner receiving plate to collide with the toner receiving plate so that the residual toner is released from the toner receiving plate by the impact force, and then gravity is applied. It is possible to keep the toner receiving plate in a clean state at all times by making it fall by, and thus prevent various troubles (spills, sticking, etc.) caused by residual toner remaining too much on the toner receiving plate. The purpose is to do. According to the eighth aspect of the present invention, a voltage having an opposite polarity to the voltage applied to the transfer roller and / or an AC voltage is applied to the toner receiving plate to release the residual toner from the toner receiving plate, and then falls by gravity. The purpose is to obtain the same effect as described above.

[0009]

In order to achieve the above object, the invention of claim 1 is an electrophotographic image forming apparatus for transferring a toner image on a transfer belt onto a transfer paper by a bias from a transfer roller. A transfer roller scraped off by the blade, the blade being capable of separating the transfer roller from the transfer belt when the transfer sheet is not passed and removing the toner adhering by sliding contact with the transfer roller. It is characterized by comprising a toner receiving plate for receiving the above toner, and a contact / separation rotating mechanism for displacing the toner receiving plate to the retracted position when the transfer paper does not pass and dropping the received toner by gravity. According to a second aspect of the present invention, in the contact / separation rotation mechanism according to the first aspect, the toner receiving plate is moved to and from the toner receiving position and the toner retreating position by 90 ° between the toner receiving position and the toner retreating position. The toner received by the toner receiving plate is dropped by gravity. According to a third aspect of the present invention, the contacting / separating rotation mechanism includes a continuous member that supports the transfer roller shaft at one end and a drive member such as a gear or a friction pulley at the other end, and the drive member. The transfer roller is provided with a driven member formed of a gear or a friction pulley that is driven to rotate, and a toner receiving plate integrally projecting from the driven member. When the driven member is driven by the driving member, the toner receiving plate is opened and closed by approximately 90 °. According to a fourth aspect of the invention, the contacting / separating rotation mechanism includes a pulley and a transmission medium means. In the invention of claim 5,
The contact / separation rotation mechanism has a link mechanism. According to a sixth aspect of the present invention, there is provided an electrophotographic image forming apparatus for transferring a toner image on a transfer belt onto a transfer sheet by a bias from the transfer roller, wherein the transfer roller is moved from above the transfer belt when the transfer sheet is not fed. In the one provided with a blade capable of separating and separating the toner adhering by sliding contact with the transfer roller, the toner receiving plate for receiving the toner on the transfer roller scraped off by the blade and the toner receiving plate are provided. An electromagnetic drive device for rotational driving is provided, and based on a control signal from the main body of the apparatus, the electromagnetic drive means rotates the toner receiving plate by about 90 ° when the transfer sheet is not passed, and the toner receiving plate on the toner receiving plate is rotated. It is characterized in that the residual toner is configured to be dropped by gravity. Claim 7
In the invention, a vibrating member is provided on the path through which the toner receiving plate rotates approximately 90 °, and the residual toner on the toner receiving plate is released by the impact of the toner receiving plate colliding with the vibrating member. ,
After that, it is characterized in that it can be dropped by gravity. According to an eighth aspect of the present invention, a residual toner on the toner receiving plate is applied to the toner receiving plate by applying a voltage having a polarity opposite to that of the voltage applied to the transfer roller and / or an AC voltage. Is released from the toner receiving plate and then dropped by gravity.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is an overall schematic view of an image forming apparatus to which the present invention is applied, and details of a transfer roller cleaning device, which is an essential part of the present invention, will be described in detail from FIG. 2 onward. This image forming apparatus includes an endless belt-shaped image bearing member (belt-shaped photosensitive member) 1, a charging member 4 as a charging unit, and an electrostatic latent image for each color separated based on color-separated image data. A laser writing system unit 5 as a latent image forming means (image exposing means) for forming an image and a toner of a color corresponding to the color-separated image data visualize the formed electrostatic latent image. Developing means (developing device) 6,
7, 8 and 9, first transfer means (bias roller) 13 for transferring the visualized image on the belt-shaped photoreceptor 1 to the intermediate transfer belt 10, and electrostatic latent image formation to intermediate transfer belt 10 The control means (not shown) that repeats the process of transferring the visible images formed for each of the separated colors by aligning the image positions is superimposed on the intermediate transfer belt 10. A second transfer means (transfer roller) 14 for transferring the toner image onto the transfer paper, and a fixing means 20 for fixing the toner image transferred onto the transfer paper are generally constituted. The belt-shaped photoconductor 1 is installed between the rotating rollers 2 and 3 and is conveyed in the clockwise direction A by the driving of the rotating roller. The laser writing system unit 5 is housed in a holding case having a slit-shaped exposure opening on the upper surface and is incorporated in the apparatus main body. As the laser optical system 5, in addition to the optical system shown in the figure, an optical system in which a light emitting section and a converging photoelectric transmitter are integrated is also used. The charging member 4 and the photoconductor cleaning device 15 are provided close to one roller 2 of the plurality of rollers on which the belt-shaped photoconductor 1 is installed. Each of the developing devices 6, 7, 8 and 9 has a structure for accommodating, for example, a yellow (yellow), magenta, cyan or black developer (toner), and each developing device is connected to the belt-shaped photoreceptor 1 at a predetermined position. The developing sleeves 6A, 7A, 8A and 9A which are in proximity to or in contact with each other are provided, and each developing sleeve is provided with a belt-shaped photoreceptor 1 by a laser beam from a laser optical system 5.
It has a function of visualizing the latent image formed on it by a non-contact developing method or a contact developing method.

Reference numeral 10 denotes an intermediate transfer belt which is a transfer image carrier, and the intermediate transfer belt 10 has rotating rollers 11 and 1.
It is erected endlessly between the two and is conveyed in the counterclockwise direction B by the driving of the rotating roller. The belt-shaped photoconductor 1 and the intermediate transfer belt 10 are in contact with each other at the rotating roller 3, and the first visible image on the belt-shaped photoconductor 1 is a bias roller provided in the intermediate transfer belt. It is transferred onto the intermediate transfer belt 10 by 13. Then, by repeating the same process, the second, third and fourth visible images are not misaligned in the state of being superposed on the intermediate transfer belt 10, respectively. Is transcribed as. A transfer roller 14 is provided at a position on the outer diameter side of the drive roller 11 so as to be able to come into contact with and separate from the intermediate transfer belt 10.
Reference numeral 15 is a cleaning device for removing residual substances such as toner on the belt-shaped photosensitive member, and 16 is a cleaning device for removing residual substances such as toner on the intermediate transfer belt 10. The blade 16A of the internal device 16 is kept at a position separated from the surface of the intermediate transfer belt 10 during image formation, but the surface of the intermediate transfer belt 10 is only shown during cleaning after image transfer as shown in the figure. Is pressed against. 21
Is a toner collection container for receiving the toner scraped by the blade 16A of the cleaning device 16.

<Examples of Embodiments Corresponding to Claims 1, 2, and 3> FIGS. 2, 3, and 4 are configuration diagrams showing an example of an embodiment of a cleaning device corresponding to Claims 1, 2, and 3 of the present invention. , Fig. 2
FIG. 3 is a configuration diagram of the periphery of the cleaning device of the present invention, FIG. 3 is an operation explanatory diagram of a main part thereof, and FIG. 4 is a timing chart of each part when forming a color image. The toner image 32 is carried on the intermediate transfer belt 10, and the driving roller 11
The rotation in the direction of arrow C causes the transfer roller 14 to be transferred to the transfer position. At the transfer position, the transfer roller 14
The toner image 32 on the intermediate transfer belt is transferred onto the transfer paper P by applying a transfer bias from the toner image 32.
a is formed. The residual toner T1 that could not be transferred to the transfer paper P is the intermediate transfer belt cleaning blade 16A.
Thus, the toner is scraped off into the toner collecting container 21. The residual toner T1 scraped off is transferred to the toner transport auger 21.
It is conveyed by A in the direction perpendicular to the paper surface, and is further collected by the waste toner collecting device through a conveying path (not shown).

On the other hand, when the transfer paper does not reach the transfer position due to a jam or the like, the transfer roller 14 directly contacts the intermediate transfer belt 10, or the transfer roller 14 is removed after the jammed paper is removed. To rotate, or transfer to a transfer paper with a large width in the width direction and then transfer it to a transfer paper with a small width in the width direction, or suck toner that is floating in the machine when voltage is applied during transfer. The residual toner T remains on the transfer roller surface due to
As described above, the transfer performance is deteriorated when the toner is attached, and the toner is easily attached. In this embodiment, the residual toner T2 is scraped off by a transfer roller cleaning blade 45 assembled together with the transfer roller 14 to a continuous member (transfer roller contact / separation member) 38 described later. Be done. A toner receiving plate 47, which will be described later, is disposed substantially horizontally just below the contact portion between the blade 45 and the transfer roller, and the toner receiving plate receives the scraped residual toner T2. Transfer paper P in transit
Does not fall on the upper surface (the back surface of the surface on which the toner image 32a is formed).

The transfer roller cleaning device of the present invention comprises a transfer roller 14 and a contact / separation rotation mechanism 33 for contacting / separating the transfer roller 14 with the intermediate transfer belt 10 and simultaneously rotating a toner receiving plate 47, which will be described later. The toner collecting container 21
Etc. The transfer roller 14 is vertically movable by a support bracket 35 extending downward from a casing 34 of the main body of the apparatus located directly above the transfer roller so that the shaft 14a can be moved up and down.
And is constantly urged downward (contact direction) by a pressure spring 36 arranged in the support bracket 35. The shaft 14a of the transfer roller 14 is rotatably supported by a bearing member 37, and moves up and down as the bearing member 37 moves up and down between the positions shown in FIGS. The pressure spring 36 has its upper end supported by the bracket 35 and has its lower end abutted against the shaft 14a to constantly urge the transfer roller including the shaft 14a downward.

The bearing member 37 has an appropriate position, for example, an upper end portion integrated with one end of a plate-like connecting member (transfer roller contacting / separating member) 38, and the other end of the connecting member 38 is ,
The transfer roller 14 is connected to the contact / separation rotation mechanism 33 and moves up and down in conjunction with the operation of the contact / separation rotation mechanism 33. The contact / separation rotation mechanism 33 of this embodiment is fixed to a shaft 41 that is rotatably supported by a support member 40 that is disposed in a proper position of the casing 34 of the device body, that is, at a position downstream of the support bracket 35. Connection member 42, a fan-shaped drive member 43 also fixed to the shaft 41, and a blade 4 protruding from an appropriate position of the connection member 42 toward the outer peripheral surface of the transfer roller 14.
5 to the transfer roller 14 from the shaft portion of the gear (following member) 46 (or friction roller) which is driven and rotationally driven by meshing with the gear portion 43a (or friction portion) of the lower end edge of the fan-shaped driving member 43. Toner receiving plate 4 integrally projecting toward
7 and a connecting member 3 having the other end fixed to the connecting member 42 at an appropriate position.
8 and a transmission shaft 50 integrally formed with the shaft 41 (which may be directly connected at a rear position of the shaft 41 or may be connected in the illustrated positional relationship via a universal joint or the like), An arm 51 fixed to the other end and rotating together with the transmission shaft 50
And a gear 55 that is rotationally driven with a gear mountain on the outside,
It has a half-rotation clutch 56 that is in sliding contact with the inner peripheral surface of the gear 55, and an eccentric cam 57 and the like integrally formed via the half-rotation clutch 56 and a cam shaft 58. The toner receiving plate 47 is connected to the driving member 43.
2 can be rotated between the receiving position of FIG. 2 and the retracted position of FIG. 3, and when it is in the receiving position, it projects directly below the sliding contact portion between the blade 45 and the transfer roller 14,
It is configured to receive the scraped toner T2.

An annular gear 55 having a gear mountain on the outer peripheral surface is constantly rotated by a transmission member from a drive motor (not shown), and is located inside thereof and slides on the outer peripheral surface of the inner peripheral surface of the gear 55. The ring-shaped half-rotation clutch 56 in contact rotates with the frictional force between the half-rotation clutch 56 and the gear 55 when no particular locking force is applied.
Protrusions 56a are provided at intervals of 80 degrees, and when the protrusions 56a are locked by a locking means protruding and inserted by a solenoid (not shown), the half-rotation clutch 56 is prohibited from rotating together with the gear 55 and stops. Each time the solenoid receives a control signal from the control section of the device body, the locking means is projected to lock one of the protrusions 56a, so that the half-rotation clutch 56 is stopped and the locking means is retracted again. Rotate. The locking means again projects at the position of the next protrusion 56a to stop the half-rotation clutch 56. The eccentric cam 57, which is integrated with the half-rotation clutch 56 via the cam shaft 58, rotates the arm 51 in the counterclockwise direction when rotating 180 degrees from the state shown in the drawing, and when rotating 180 degrees further, the arm 51 rotates. Return clockwise to rotate.
In this way, the cam shaft 58 is rotated by half a rotation and the eccentric cam 57 is moved (displaced), thereby pressing the arm 51 to rotate the transmission shaft 50 and the connecting member 38, and the transfer roller 14 is contacted and separated. The movement and the rotation movement of the toner receiving plate 47 are realized.

In the above description, the half rotation clutch is merely an example, and a quarter rotation clutch or a clutch having a cycle other than that may be used.

In FIG. 3, after the transfer operation shown in FIG. 2 is completed, the transfer roller 14 is separated from the intermediate transfer belt 10 by rotating the connecting member 38 by the transmission shaft 50 and the transfer roller cleaning blade. The state in which 45 is separated from the transfer roller 14 is shown. The drive member 43 has a transmission shaft 50.
The gear 46 and the toner receiving plate 47 are rotated about 90 ° in the toner drop direction indicated by the arrow E when the drive member 43 rotates in the direction of the arrow D. Since the toner receiving plate 47 can be directed downward by approximately 90 ° in this manner, the residual toner T2 falls due to gravity and is collected in the toner collecting container 21. The recovered residual toner T2 and the residual toner T1 together with the toner
The transport auger 21A transports the waste toner to a waste toner collecting device (not shown). The drive member 43 and the gear 46 may transmit the drive force by meshing the gears, or may transmit the drive force by contact between the friction transmission members (rubber, resin, etc.). The toner receiving plate 47 is made of a resin such as a stainless thin plate or mylar.

FIG. 4 is a system timing chart in the case where the image forming apparatus is in the color mode. Considering the transfer position where the driving roller 11 and the transfer roller 14 are in contact with each other, on the intermediate transfer belt 10. Color image overlapping state is K → C
When the final Y passes the transfer position, the transfer sheet P is passed, the transfer roller 14 is brought into contact with the intermediate transfer belt 10, and the intermediate transfer belt clear is performed on the intermediate transfer belt 10. The abutting of the blade 16A and the closing of the toner receiving plate 47 are performed substantially at the same time as shown in FIG. Further, thereafter, the above-mentioned members and the like return to the original state all at once with a slight delay.
As described above, according to the above-described embodiment, since the toner T2 does not drop onto the intermediate transfer belt 10, it is possible to realize high image quality without stains on the back of the transfer paper, and it is not necessary to provide a special collecting container. Therefore, space saving and cost reduction are realized.
Further, by directly adopting the "blade method" which is the conventional technique, it is possible to obtain effects such as high reliability of the cleaning characteristics.

<Example of Embodiment Corresponding to Claim 4> FIG. 5 is an explanatory view of a main part configuration of an example of an embodiment corresponding to claim 4 of the present invention. The drive pulley 60 is replaced by the gear 46 instead of the drive member 43 of the second embodiment.
A driven pulley (driven member) 61 is used instead of
As the transmission medium means 62, a toothed timing belt / flat belt / round belt / chain / string / wire / etc. (These are collectively referred to as a long transmission means) are used. That is, the contact / separation rotation mechanism 33 of this embodiment rotatably supports the shaft 60a of the drive pulley 60 by the bracket 70 positioned upstream of the support bracket 35, and the shaft 60a has one end of the connecting member 71. Is fixed, the intermediate portion of the connecting member 71 is fixed to the bearing member 37, and the other end of the connecting member 71 is bent downward to support the transfer roller cleaning blade 72 at its tip 71a. A transmission medium means 62 is wound around a driven pulley 61 having a toner receiving plate 47 integrally projecting therefrom and a drive pulley 60, and the toner receiving plate 47 is indicated by a dotted line by the forward and reverse rotation of the drive pulley 60. It rotates between the receiving position shown and the retracted position shown by the solid line. The configurations and operations of the other members indicated by the same reference numerals as those in the above-described embodiment are the same as above. Since the state is the non-transfer state in the state shown in FIG. 5, the transfer roller 14 is separated from the intermediate transfer belt 10, and the toner receiving plate 47 is in the retracted position. On the other hand, when the pulley 60 is rotated by a predetermined angle in the counterclockwise direction by a driving unit (not shown) such as the gear 55 shown in FIG. 2, the driven pulley 61 is rotated by 90 ° in the same direction.
Due to the rotation, the toner receiving plate 47 moves to the toner receiving position shown by the dotted line. This form example corresponds to the transmission shaft 5 shown in FIG.
0 and the axis of rotation of the toner receiving plate 47 are distant from each other, and therefore, when it is difficult to lay out using the drive gear / friction pulley in the other embodiment, the present embodiment According to the example, layout is possible.

<Example of Embodiment Corresponding to Claim 5> FIG. 6 is a configuration diagram of an example of an embodiment corresponding to claim 5 of the present invention. In this embodiment, a driving member 43 of the embodiment of FIG. 1 is driven. The wire-75 uses a driven link 76 instead of the gear 46, and the driven link 76 is constantly subjected to a rotation return force in the arrow F direction by a return (coil) spring 77. When the transfer timing comes, a stopper 78 is provided so that the toner receiving plate 47 integrated with the driven link 76 receives the rotation return force and comes to the position of the broken line. That is, the contact / separation rotation mechanism 33 of this embodiment rotatably supports the shaft 81a of the connecting member 81 by the bracket 80 located on the upstream side of the support bracket 35, and at the same time, supports the shaft 81a.
Has one end of the connecting member 81 fixed, the middle portion of the connecting member 81 fixed to the bearing member 37, and the other end of the connecting member 81 is bent downward and the transfer roller cleaning blade at its tip 81a. Supports 82. Toner receiving plate 47
A drive wire 75 is connected between a driven link 76 integrally projecting the above-mentioned member and a tip portion 81a of the connecting member 81, and the toner receiving member is moved by the vertical movement of the connecting member 81 around the shaft 81a. The plate 47 rotates between the receiving position shown by the dotted line and the retracted position shown by the solid line. As the drive means of the connecting member 81, the drive means of FIG. 1 can be used as it is. As a result, it is possible to provide a device that is less expensive than the above-described embodiments.

<Example of Embodiment Corresponding to Claim 6> FIG. 7 is a configuration diagram of a main part of an example of the embodiment corresponding to claim 6 of the present invention. Unlike the moving mechanism, when the connecting members 38, 71, 81 are not used, or even when the connecting members 38, 71, 81 are used, in the monochrome mode (the transfer roller remains in contact with the intermediate transfer belt). Is also suitable for an image forming apparatus that requires cleaning of the transfer roller 14. The toner receiving plate drive mechanism 90 is fixed to a proper position of the device so that the shaft 14a of the toner receiving plate drive mechanism 90 is slidably contacted with the transfer roller 14 supported by the support bracket 35 in a vertically movable and rotatable manner.
And an output shaft 93 of the electromagnetic drive device 92, which is integrated with and projects in the outer diameter direction, and is rotatable between the toner receiving position shown by the dotted line and the retracted position shown by the solid line by the rotation of the output shaft 93. The toner receiving plate 47 is provided, and the toner collecting container 21 and the like located directly below the toner receiving plate 47 are provided. In this embodiment, the toner receiving plate 47 is directly driven by the electromagnetic drive device 92, and the toner T2 scraped off the transfer roller surface by the blade 91.
Receive or drop. Examples of the electromagnetic drive device 92 include a rotary solenoid and a stepping motor.
Data is used. A system timing chart in this form example is shown in FIG. In this figure, the opening / closing timing of the toner receiving plate 47 is set for each transfer, but in general, the amount of residual toner on the transfer roller 14 is set in the case of the intermediate transfer belt 10 or the photoconductor. Since it is not much compared with the above, it is possible to further reduce the frequency of the opening / closing operation. By driving the toner receiving plate 47 by using the electromagnetic drive device 92 as in the present embodiment, it is possible to deal with the case of a single color mode (while the transfer roller is in contact), and a simple structure is obtained. The layout becomes more flexible.

<Example of Embodiment Corresponding to Claim 7> An example of the embodiment corresponding to claim 7 of the present invention relates to a vibrating member indicated by reference numeral 95 in FIG. 5, and the toner receiving plate 47 is indicated by a dotted line. A vibrating member 95 is provided at a position rotated by approximately 90 ° from the receiving position shown to the retracted position shown by the solid line, and the vibrating member 95 is made to collide with the vibrating member 95, whereby the residual toner accumulated on the toner receiving plate 47 by the impact force. T2 is surely released from the toner receiving plate 47, and thereafter, it is intended to be freely dropped by gravity. The vibrating member 95 may be made of metal or resin, and further may be an electrostrictive element that vibrates when an AC voltage is applied, an exciting vibration element, or the like. Thereby, the toner receiving plate 47 can be always kept in a clean state.
Therefore, it is possible to prevent various troubles (such as dropping onto the transfer paper and sticking due to spillage) caused by the residual toner T2 being excessively accumulated on the toner receiving plate 47. Also, by using such a vibrating member,
Since it is possible to enhance the dropability of toner and the prevention of sticking, the toner receiving plate 4 at the toner receiving position, for example, can be used.
By making the shape of the upper surface of 7 concave, it is possible to improve the trapping property and the holding property of the toner. The embodiment using the vibrating member according to claim 7 can be applied to all the above-mentioned embodiments.

<Example of Embodiment Corresponding to Claim 8> In an example of embodiment corresponding to claim 8, a bias (not shown) is applied to the toner receiving plate 47 shown in FIGS. 2, 5, 6 and 7. The residual toner T2 is released from the toner receiving plate 47 by applying a voltage having an opposite polarity to the voltage applied to the transfer roller 14 and / or an AC voltage from the means, and then the toner is dropped by gravity. As the material of the receiving plate 47, "stainless steel thin plate" or "conductive resin" is used. In addition,
The polarity of the voltage applied to the toner receiving plate 47 is the transfer roller 1
Needless to say, it has the opposite polarity to the toner on No. 4. Therefore, various troubles (spillage, sticking, etc.) caused by the residual toner T2 remaining too much on the toner receiving plate 47
Can be prevented beforehand. The toner dropping method by bias application according to claim 8 can be applied to all the above-described embodiments. The cleaning device of the present invention described above is applied to a cleaning device for a transfer roller of an electrophotographic image forming apparatus such as a copying machine, a facsimile machine, a printer or the like. In addition to the above, the present invention is also applicable to a device for temporarily storing a falling cleaning toner and re-falling it at a timing (delayed).

[0025]

As described above, according to the invention of claim 1,
A cleaning device for a transfer roller using a blade is provided with a means for receiving the toner scraped by the blade and a means for dropping the received toner by gravity when the transfer paper does not pass, Furthermore, by utilizing the existing toner collection container as a means for receiving the dropped toner, it is possible to improve the image quality without back stains, eliminate the need to install a special collection container, and save space and cost. Further, by adopting the "blade method" which is the conventional technique as it is, it is possible to secure high reliability of the cleaning characteristics. In the invention of claim 2, the toner of claim 1
As a means for receiving the toner, a contact / separation rotation mechanism capable of reciprocating the toner receiving plate by about 90 ° from the toner receiving position to the dropping position is provided in association with the operation of the transfer roller contacting and separating from the intermediate transfer belt. The toner that has been once received is rotated so that it will fall due to gravity when the transfer roller separates, so it prevents back stains, prevents an increase in the number of parts, and ensures high cleaning characteristics, which is an advantage of the blade method. Can be achieved.

According to a third aspect of the invention, as a contact / separation rotation mechanism for rotating the toner receiving plate and contacting / separating the transfer roller of the second aspect, the drive roller is rotated about the shaft of the transfer roller contact / separation member. A drive member including a gear or a friction pulley is freely fixed, and a driven member including a gear or a friction pulley is also rotatably fixed to rotate the toner receiving plate on the driven side by about 90 °. Then, in synchronization with the rotation of the transfer roller contact / separation member (transfer roller).
(To synchronize with the contact and separation of the rack), the toner receiving plate is opened and closed by approximately 90 ° to prevent back stains, increase in the number of parts, and secure high cleaning characteristics, which is an advantage of the blade method. Can be planned. According to a fourth aspect of the invention, as the contact / separation rotation mechanism of the device of the third aspect, a pulley and a belt / wire are used instead of the drive gear / friction pulley.
By using a / string / chain, etc., it is possible to prevent back stains, prevent an increase in the number of parts, and ensure high cleaning characteristics, which is an advantage of the blade method. In addition, since the axial distance between the "transfer roller contact / separation member shaft" and the "toner receiving plate rotation shaft" is large, the layout is a contact / separation rotation mechanism consisting of a drive gear / friction pulley. Even when it is difficult to perform the layout, the layout is possible according to this embodiment.

According to the invention of claim 5, in addition to the above effect, a link mechanism which operates in conjunction with the connecting member is used in place of the contact / separation rotation mechanism of claims 3 and 4, in addition to the above effects. An inexpensive mechanism can be achieved. Claim 6
In this invention, an electromagnetic drive device such as a rotary solenoid is connected to the rotary shaft of the toner receiving plate to control the machine body.
The toner receiving plate is set to approximately 90
By rotating and causing the residual toner to fall by gravity, in addition to the above effects, it is possible to deal with the case of the single color mode in which the transfer roller does not come into contact with or separate from it. You can be more free.

In the invention of claim 7, the toner receiving plate is substantially 9
By providing a vibrating member at a position rotated by 0 ° and causing the collision, the residual toner is released from the toner receiving plate by the impact force, and then the toner is dropped by gravity, so that the toner receiving plate is always clean. Therefore, it is possible to prevent various troubles (spill, sticking, etc.) caused by the residual toner remaining too much on the toner receiving plate. According to the eighth aspect of the invention, the residual toner is applied to the toner receiving plate by applying a voltage having an opposite polarity to the voltage applied to the transfer roller and / or an alternating voltage.
Is released from the toner receiving plate and then dropped by gravity, the same effect as described above can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration explanatory diagram of an example of an image forming apparatus to which the present invention is applied.

FIG. 2 is a schematic diagram showing an overall configuration of a first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a main part of FIG.

FIG. 4 is an operation timing chart of each unit of the color image forming apparatus.

FIG. 5 is an enlarged view of a main part of a second embodiment of the present invention.

FIG. 6 is an enlarged view of a main part of a third embodiment of the present invention.

FIG. 7 is an enlarged view of an essential part of a fourth example of the present invention.

FIG. 8 is an operation timing chart of each part of the fourth embodiment.

[Explanation of symbols]

1 belt-shaped image bearing member (belt-shaped photosensitive member), 2 and 3 rotating roller, 4 charging member, 5 laser writing system unit, 6, 7, 8 and 9 developing means (developing device), 10 intermediate transfer belt , 13 first transfer means (bias roller),
14 second transfer means (transfer roller), 14a shaft, 1
5 cleaning device, 16 cleaning device, 16
A blade, 20 fixing means, 21 toner collecting container, 21A toner conveying auger, 32 toner image, 32
a toner image, 33 contact / separation rotation mechanism, 34 casing, 35 support bracket, 36 pressure spring, 3
7 bearing members, 38 continuous members (transfer roller contacting / separating member),
40 support member, 41 shaft, 42 connecting member, 43 driving member, 45 transfer roller cleaning blade, 46
Gear (friction roller), 47 toner receiving plate, 50 transmission shaft, 51 arm, 55 gear, 56 half-rotation clutch, 57 eccentric cam, 58 cam shaft, 60 drive drive
Reference numeral 61, driven pulley, 62 transmission medium means, 70 bracket, 71 continuous member, 75 drive wire, 76
Driven link, 77 Return (coil) spring, 7
8 stoppers, 80 brackets, 81 continuous members,
81a axis, 82 transfer roller cleaning blade,
90 toner receiving plate drive mechanism, 91 blade, 92 electromagnetic drive device, 93 output shaft, 95 vibrating member,

Claims (8)

[Claims] 1. An electrophotographic image forming apparatus for transferring a toner image on a transfer belt onto a transfer sheet by a bias from the transfer roller, wherein the transfer roller is separated from the transfer belt when the transfer sheet is not fed. In addition, in a device equipped with a blade capable of slidingly contacting the transfer roller and removing the adhered toner, a toner receiving plate for receiving the toner on the transfer roller scraped off by the blade, and the toner receiving plate when the transfer paper does not pass through A cleaning device for a transfer roller, comprising a contact / separation rotation mechanism for displacing the plate to a retracted position and causing the received toner to drop by gravity. 2. The contact / separation rotation mechanism according to claim 1 is the toner.
Set the receiving plate 90 ° between the toner receiving position and the toner retracting position.
A transfer roller cleaning device characterized in that the toner received by the toner receiving plate is dropped by gravity at the toner retracting position by reciprocating the rotation. 3. The contact / separation rotation mechanism includes a continuous member that supports a transfer roller shaft at one end and a drive member such as a gear or a friction pulley at the other end, and is driven to rotate by the drive member. A driven member composed of a gear or a friction pulley, and a toner receiving plate integrally projecting from the driven member, and interlocked with the contacting / separating operation of the transfer roller by the rotation of the connecting member. The cleaning device for a transfer roller according to claim 1, wherein the toner receiving plate is opened and closed by approximately 90 ° when the driven member is driven by the driving member. 4. The cleaning device for a transfer roller according to claim 1, wherein the contacting / separating rotation mechanism includes a pulley and a transmission medium means. 5. The transfer roller cleaner according to claim 1, wherein the contact / separation rotation mechanism has a link mechanism.
Equipment. 6. An electrophotographic image forming apparatus for transferring a toner image on a transfer belt onto a transfer sheet by a bias from the transfer roller, wherein the transfer roller is separated from the transfer belt when the transfer sheet is not fed. In addition, in the case where a blade capable of slidingly contacting the transfer roller and removing the adhered toner is provided, the toner receiving plate for receiving the toner on the transfer roller scraped by the blade and the toner receiving plate are rotationally driven. An electromagnetic drive device for rotating the toner receiving plate on the toner receiving plate by rotating the toner receiving plate by approximately 90 ° when the transfer sheet is not passed by the electromagnetic driving means based on a control signal from the main body of the apparatus. A cleaning device for a transfer roller, wherein the cleaning device is configured so as to fall by gravity. 7. A vibrating member is provided on a path of rotation of the toner receiving plate by about 90 °, and a residual toner on the toner receiving plate is released by an impact of the toner receiving plate colliding with the vibrating member. The cleaning device for a transfer roller according to claim 1, 2, 3, 4, 5, 6, or 7, wherein the cleaning device is made to fall by gravity. 8. The residual toner on the toner receiving plate is applied to the toner receiving plate by applying a voltage having a polarity opposite to that of the voltage applied to the transfer roller and / or an alternating voltage to the toner receiving plate. -The device is detached from the receiving plate and then dropped by gravity.
A cleaning device for a transfer roller as described in 5, 6, 7 or 8.