JP3692232B2 - Cleaning device in image forming apparatus, and image forming apparatus provided with the cleaning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer. More specifically, the present invention relates to a first cleaning member and a second cleaning member for performing cleaning while facing the surface of a member to be cleaned in the image forming apparatus. The present invention relates to an improvement of a cleaning device that includes a member in the same casing and collects toner removed from the surface of the member to be cleaned by both cleaning members at the bottom in the casing.
[0002]
[Prior art]
Conventionally, this type of cleaning device is known, for example, in Japanese Patent Laid-Open No. 7-168454. This publication also discloses a cleaning device in which a conveying member that conveys toner from both the cleaning members to the outside of the casing is disposed at the bottom of the casing. An image carrier, toner image forming means for forming a toner image on the image carrier, and a transfer material for transferring the toner formed on the image carrier are held on a transfer belt, and the image carrier An image forming apparatus provided with a transfer belt conveying device that conveys the toner image so as to contact with the transfer belt is also disclosed that uses the cleaning device as a cleaning device for the surface of the transfer belt.
[0003]
Further, the applicant of the present invention is a cleaning device of this type, in a cleaning device for a transfer belt using a cleaning blade as the first cleaning member and a cleaning bias roller as the second cleaning member. An apparatus has also been proposed in which the rotation direction of the bias roller is the same as the direction of travel of the transfer belt (Japanese Patent Application No. 9-93009).
[0004]
FIG. 1 is a schematic configuration diagram of an image forming apparatus including the cleaning device according to the above proposal. In this figure, 1 is a photosensitive drum, 2 is a transfer belt (transfer conveying device), 3 is a drive roller, 4 is a driven roller, 5 is a registration roller, 6 is a push-up lever, 7 is a transfer bias roller, and 10 is a cleaning device. (Cleaning means). The cleaning device 10 includes a cleaning blade 11, a cleaning bias roller 12 (hereinafter referred to as a bias roller), a toner recovery coil 13, and a bias roller cleaning blade 14.
[0005]
The cleaning device according to this proposal cleans the surface of the transfer belt 3 in order to prevent the transfer paper from being stained on the back surface and the edge surface. When the cleaning blade 11 passes through with the toner or the like adhering to the surface of the transfer belt 2, the toner is further adhered to the bias roller 12 on the downstream side in the rotation direction of the transfer belt 2 to remove residual toner and paper dust. can do. In addition, since the rotation direction of the bias roller 10 is the same as the moving direction of the transfer belt 2, the frictional noise between the bias roller 12 and the transfer belt 2 is reduced as compared to the case where the rotation direction is opposite. In addition, it is possible to prevent the surface coating of the transfer belt 2 from being scraped, and it is possible to prevent the cleaning property from being lowered or the cleaning blade 11 from being caught.
[0006]
[Problems to be solved by the invention]
However, when a plurality of cleaning members such as the cleaning blade 11 and the bias roller 12 are used in a common casing, the following problems that did not occur when a single cleaning member is used in the casing occur. Turned out to be.
That is, conventionally, toner removed from the transfer belt 2 to be cleaned by a cleaning member, for example, falls by its own weight and is collected at the bottom of the casing, and is transported to the outside of the casing by a conveying member such as the recovery coil 13 disposed here. Is discharged. In general, the specific location of the collection coil 13 is set at a point where the toner removed by the cleaning member falls.
However, for example, when a plurality of cleaning members are provided as shown in FIG. 1, the toner falls from each of the cleaning members, resulting in a plurality of toner dropping points, and the recovery coil 13 is placed at the toner dropping point. This results in a cleaning member that does not exist. In such a cleaning member, toner accumulates at the dropping point and piles up, and the toner accumulates up to the opposite portion between the cleaning member and the object to be cleaned, which may cause cleaning failure. For example, when the toner pool reaches the contact portion between the cleaning blade 11 and the transfer belt 2, the cleaning performance is remarkably deteriorated.
In the case of an in-device layout located near a cleaning device or a fixing device (not shown) as in the example of FIG. 1, the ambient atmosphere temperature is high due to heat generated by the fixing device, and the stack is piled up in the casing. There is also a possibility that the toner is stuck and the machine is damaged due to, for example, the bias roller 12 being locked.
In order to suppress such a problem caused by the absence of the recovery coil 13 at the toner dropping point, the casing of the toner dropping point with respect to the cleaning blade 11 is adopted for the cleaning blade 11 in the apparatus of FIG. It is desirable to incline the inner surface toward the position where the recovery coil 13 is arranged at the bottom of the casing. However, it has been found that, by this alone, toner that has low fluidity among the dropped toner cannot flow smoothly on the inclined surface, and the above-mentioned problems cannot be solved sufficiently. In particular, as shown in the example of FIG. 1, the bias roller 12 disposed on the downstream side of the transfer belt 2 surface movement direction with respect to the cleaning blade 11 is rotated in such a manner that the surface moves in the same direction at the portion opposite the transfer belt 3 surface. Is set, the contact point of the bias roller cleaning blade 14 to be contacted by the counter method is shifted to the downstream side in the transfer belt surface movement direction as compared with the case where the rotation of the bias roller is set in the reverse direction. Therefore, the horizontal distance between the toner falling point on the cleaning blade 11 and the toner falling point from the bias roller 12 tends to increase.
If the collection coil 13 is arranged at each toner drop point, the above-described problems can be solved. However, this causes the apparatus to be complicated, large, and expensive.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a first cleaning member and a second cleaning member for performing cleaning while facing the surface of a member to be cleaned in the image forming apparatus. And a cleaning device for collecting toner removed from the surface of the member to be cleaned by both cleaning members at the bottom of the casing, the toner being collected well at the bottom of the casing. It is an object to provide an image forming apparatus cleaning apparatus capable of performing the above and an image forming apparatus using the cleaning apparatus.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, a first cleaning member and a second cleaning member for performing cleaning while facing a surface of a member to be cleaned in an image forming apparatus are provided in the same casing. In the cleaning device that is provided inside and collects the toner removed from the surface of the cleaning target member by both cleaning members at the bottom in the casing, at least the cleaning member of both cleaning members is removed from the surface of the cleaning target member and dropped. A plate having a flat plate portion parallel to the inner surface of the casing and a rib portion protruding from the facing surface of the inner surface of the flat plate portion with respect to the relatively poor mobility of the toner moving to the bottom portion in the casing. the bottom of member by parallel swing inner surface, after being removed by the cleaning member In which characterized in that a vibrating means for vibrating the toner to be moved to.
[0011]
According to a second aspect of the present invention, in the cleaning device of the image forming apparatus according to the first aspect, a conveying member for conveying the toner from the two cleaning members to the outside of the casing is disposed at the bottom of the casing. Is.
[0012]
According to a third aspect of the present invention, an image carrier, a toner image forming means for forming a toner image on the image carrier, and a transfer material for transferring the toner formed on the image carrier are held on a transfer belt. An image forming apparatus comprising a transfer belt conveyance device that conveys the image carrier so as to contact the image carrier, wherein the cleaning device according to claim 1 or 2 is used as a cleaning device for the transfer belt surface. Is.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a transfer belt surface cleaning device in an electrophotographic image forming apparatus which is an image forming apparatus having a schematic configuration as shown in FIG. 1 will be described.
First, an outline of the entire image forming apparatus will be described. In FIG. 1, a photosensitive drum 1 is rotatably provided, and although not shown on the outer periphery thereof, a static eliminator that neutralizes the surface of the photosensitive drum 1, a charging device that uniformly charges the surface of the photosensitive drum 1, and a photosensitive member. An optical writing device that forms an electrostatic latent image by scanning an optical signal on a charged portion of the body drum 1, a developing device that develops the electrostatic latent image, a cleaning device that cleans the surface of the photosensitive drum 1 after transfer, and the like. Process units are arranged. Below the photosensitive drum 1, a transfer belt 2 formed of a material having a predetermined resistance is stretched by a driving roller 3 and a driven roller 4.
[0014]
A voltage is applied to the transfer belt 2 on the inner peripheral surface of the transfer belt 2 at a predetermined distance from the transfer nip 9 that is a contact portion between the photosensitive drum 1 and the transfer belt 2 toward the driving roller 3. The bias roller 7 is arranged in contact with the transfer belt 2. Although not shown, the bias roller 7 is connected to a power source.
[0015]
In the image forming apparatus configured as described above, the transfer paper that has been fed to the registration roller 5 and is waiting is sent out by the registration roller 5 in synchronization with the image on the photosensitive drum 1. The transfer belt also comes up to the transfer nip portion 9 at the same time as the leading edge of the transfer paper is pushed up by the push-up lever 6 and contacts the photosensitive drum 1. (Note that FIG. 1 shows a state where the photosensitive drum 1 and the transfer belt 2 are in contact with each other.)
Thereafter, when the transfer sheet enters the transfer nip 9, a transfer bias is applied to the transfer bias roller 7, and a charge having a polarity opposite to the toner polarity on the photosensitive member 1 is applied to the transfer belt 2 to perform transfer. As an example of the above transfer, for example, when a negative / positive reversal development method is adopted as a development method, a negative toner is applied to a portion of the surface of the photoreceptor 1 whose surface is negatively charged and whose potential is lowered by light. Then, the toner is transferred onto the transfer paper by applying a positive voltage to the transfer bias roller. After the transfer of the toner image as described above, the transfer paper is conveyed in the direction of the fixing roller (not shown) as the transfer belt 2 rotates, and is nipped by the fixing roller to fix the toner image.
[0016]
Next, details of the cleaning device according to the present embodiment will be described. FIG. 2 is a partially enlarged view of the cleaning device.
The cleaning device 10 for cleaning the surface of the transfer belt 2 includes a cleaning plate 11 made of polyurethane as a main cleaning unit, and wipes off residual toner and paper dust adhering to the transfer belt 2. Further, as a sub-cleaning means, a bias roller 12 which is a cleaning member by an electric field is provided, and toner or the like that has passed through the cleaning blade 11 is electrostatically removed from the transfer belt 2. The cleaning blade 11 and the bias roller 12 are arranged in contact with the surface of the transfer belt 2. Further, the bias roller 12 is provided with a bias roller cleaning blade 14 so as to wipe off the toner and the like adhering to the surface of the bias roller 12.
At the time of cleaning, for example, in the case of the negative / positive developing system in which the uniform charging polarity of the photosensitive member is negative, the bias roller 10 is supplied with the same positive potential as the applied voltage of the transfer bias roller as shown in the drawing. 12 is applied. As a result, the toner having a negative polarity which is the desired polarity on the transfer belt is removed from the belt 12. In contrast to this, in order to remove the so-called reverse polarity toner charged to a polarity opposite to the desired polarity, a voltage having a polarity opposite to that of the transfer bias roller is applied, or the timing between the desired polarity toner and the opposite polarity toner is changed. The voltage applied to the bias roller 12 may be switched at a predetermined timing so as to be removed from the transfer belt.
The bias roller 10 rotates in the opposite direction to the transfer belt driving roller 3 and rotates in the same direction as the moving direction of the transfer belt 2. The driving method of the bias roller 12 is a method in which the bias roller 12 is connected to the driving roller 3 via a gear and is driven around. The rotational speed is set so that the peripheral speed of the outer peripheral surface of the bias roller 12 and the rotational speed (peripheral speed) of the transfer belt 2 are the same by setting the gear ratio and the outer shape of the bias roller.
[0017]
The material of the bias roller 12 is, for example, stainless steel and is not subjected to surface coating. In this example, the bias roller 12 is not provided with a contact / separation mechanism with respect to the transfer belt 2 and remains in contact with the transfer belt 2. Therefore, when the surface coating is applied, the compatibility between the coating and the surface coating of the transfer belt 2 This is because, depending on the environment or the like, there is a possibility that problems such as fusion of both coatings may occur due to long-time contact.
The surface of the bias roller 12 is finished to about 0.1a. This is because if the surface of the bias roller 12 is too rough, paper dust or the like is easily clogged in the bias roller cleaning blade 14, and there is a possibility of causing a cleaning defect as in the transfer belt 2.
[0018]
As described above, since the rotation direction of the bias roller 10 is the same as the moving direction of the transfer belt 2, the frictional noise between the bias roller 12 and the transfer belt 2 is reduced and the surface coating of the transfer belt 2 is prevented from being scraped. Therefore, it becomes possible to prevent the cleaning property from being lowered or the cleaning blade 11 from being caught.
[0019]
In the cleaning device of the present embodiment, the recovery coil 13 is positioned at the dropping point of the toner that has been removed from the transfer belt 2 by the cleaning blade 11 out of the cleaning blade 11 and the bias roller 12 as two cleaning members. In this configuration, the falling toner directly applies the conveying force by the collection coil 13. On the other hand, with respect to the bias roller 12, the inner surface of the casing at the dropping point of the toner removed from the transfer belt 2 is inclined toward the arrangement position of the collection coil 13, and the arrangement position of the collection coil 13 flows down on the inclined surface. Like to move on. Further, in order to prevent the toner having low fluidity from staying on the inner surface of the inclined casing and being piled up, a vibration plate 15 is provided as means for applying vibration to the toner.
[0020]
FIG. 3 is an explanatory diagram of a configuration for vibrating the diaphragm 15. In FIG. 3, a bias roller driving gear 16 provided with a front cam is attached to the shaft of the bias roller 12, and this front cam has a cam surface inclined from a high part to a low part. The diaphragm is slidable in the longitudinal direction by slide shafts that protrude from both ends in the longitudinal direction and are slidably supported on both end walls of the casing. A spring 17 as an urging means is interposed between the vibration plate and the inner peripheral surface of the casing end wall on the one slide shaft so that the tip of the other slide shaft is always in contact with the cam surface. Energized.
[0021]
When the image forming apparatus starts operation, the cam rotates together with the bias roller 12, and the tip of the slide shaft of the diaphragm 15, which is always in contact with the cam surface by the urging force of the spring 17, The contact position on the cam surface is changed from the high part to the low part. Thereby, the diaphragm 15 swings in the slide axis direction. For example, the bias roller drive gear 16 is swung with an amplitude of 2 mm per rotation. Further, it is swung about 6 times per second.
[0022]
FIG. 4 is a perspective view showing the back surface structure of the diaphragm. A plurality of ribs 15a extending in the inclined direction are formed on the back surface of the diaphragm, that is, the surface facing the inner surface of the casing. With this rib 15a, the toner that has entered the back surface of the diaphragm is scraped off from the inner surface of the casing during the vibration of the diaphragm.
[0023]
As described above, in the cleaning device according to the present embodiment, for the bias roller 12 whose toner drop point is deviated from the recovery coil 13, the toner dropped from the bias roller 12 is received by the vibration plate 15 and flowed down to the recovery coil 13 while improving fluidity by vibration. Therefore, it is possible to prevent the toner having low fluidity from accumulating on the casing surface and being piled up.
[0024]
Various means can be adopted as means for applying vibration to the toner, instead of the vibration plate.
Further, the toner conveyance by the collection coil 13 may be performed on a waste toner bottle outside the casing, or may be performed on a predetermined toner reuse destination unit. Also, without providing such a recovery coil 13, a hole is formed in the bottom of the casing, and the hole is dropped into a waste toner bottle disposed below the apparatus, or the hole is usually closed with a stopper. When the toner accumulation amount in the case sink reaches a predetermined amount, the stopper may be removed and collected in a waste toner bottle set in the apparatus.
[0025]
【The invention's effect】
According to the first to fifth aspects of the present invention, at least one of the two cleaning members is provided for the relatively poor mobility that the toner removed from the surface to be cleaned and dropped is moved to the bottom in the casing. The vibration applying means vibrates the toner that is removed by the cleaning member and then moved to the bottom portion, so that it is possible to prevent the toner having poor fluidity from accumulating on the moving path and being piled up. Yotsute, Ru can collect toner well in the bottom of the casing.
[0026]
Further , since the plate-like member that swings along the inner surface of the casing is used to give vibration to the toner, the vibration means can be made compact.
[0027]
Further , since the plate-like member having a flat plate portion parallel to the inner surface of the casing is used and the plate-like member is swung in parallel to the inner surface, the falling toner is received at the flat portion, The toner can be allowed to flow down on the flat portion, and the toner fluidity can be further improved and the toner can be better collected at the bottom of the casing. In addition, since the rib portion protruding from the inner surface facing surface of the flat plate portion is provided, the toner that goes around between the flat surface portion and the inner surface of the casing and tries to adhere to the inner surface is scraped with the rib as it swings. Can be dropped.
[0028]
In particular, according to the invention 請 Motomeko 2, may either carry a toner collected in the bottom casing, well outside the casing delivery member disposed here.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an image forming apparatus.
FIG. 2 is an enlarged view of a cleaning device according to the present embodiment.
FIG. 3 is an explanatory diagram of a mechanism of the cleaning device.
FIG. 4 is a perspective view of parts of the cleaning device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Transfer belt 3 Transfer belt drive roller 4 Driven roller 5 Registration roller 6 Lever 7 Transfer bias roller 9 Transfer nip part 10 Cleaning device 11 Cleaning plate 12 Cleaning bias roller 13 Collection coil 14 Bias roller cleaning blade 15a Rib 15 Vibration Plate 16 Bias roller drive gear 17 Spring

Claims (3)

A first cleaning member and a second cleaning member for performing cleaning to face the surface of the cleaning target member in the image forming apparatus are provided in the same casing, and both cleaning members remove the cleaning target member from the surface of the cleaning target member. In the cleaning device that collects the removed toner at the bottom of the casing,
At least, among the two cleaning members, a flat plate portion parallel to the inner surface of the casing with respect to the relatively poor mobility that the toner removed from the surface to be cleaned and dropped is moved to the bottom portion in the casing; A plate-like member having a rib portion protruding from the opposite surface of the inner surface of the flat plate portion is swung in parallel with the inner surface, and the toner to be moved to the bottom portion after being removed by the cleaning member is vibrated. A cleaning device in an image forming apparatus, characterized in that vibration imparting means is provided. The cleaning device in the image forming apparatus according to claim 1,
A cleaning device in an image forming apparatus, wherein a conveying member that conveys toner from both of the cleaning members to the outside of the casing is disposed at the bottom of the casing. An image carrier, toner image forming means for forming a toner image on the image carrier, and a transfer material for transferring the toner formed on the image carrier are held on a transfer belt and contacted with the image carrier In an image forming apparatus provided with a transfer belt conveying device for conveying
An image forming apparatus using the cleaning device according to claim 1 or 2 as a cleaning device for the transfer belt surface.

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