JP2002006679A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a lubricant coating applicator and to obstruct the occurrence of the coating application unevenness of a lubricant to the surface of an image carrying member of an image forming device having the lubricant coating applicator for applying a lubricant on the image carrying member formed with a toner image. SOLUTION: The solid lubricant 36 is brought into contact with pressurized contact directly with the surface of the image carrying member 2Y and this solid lubricant 36 is oscillated in the axial direction of the image carrying member 2Y, by which the lubricant is uniformly applied to the surface of the image carrying member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming a toner image on an image carrier and transferring the toner image to a transfer material by a transfer device.

[0002]

2. Description of the Related Art An image forming apparatus of the above-mentioned type configured as an electronic copying machine, a printer, a facsimile or a multifunction machine having at least two functions thereof has been conventionally known. When a lubricant is applied to the surface of the image carrier of the image forming apparatus by a lubricant applying device, the friction coefficient of the surface can be reduced. Also, the amount of wear on the surface of the image carrier can be reduced, and the life of the image carrier can be prolonged (see, for example, JP-A-11-174664).

A conventional lubricant application device has an application brush that is driven to rotate while being in contact with the surface of an image carrier, and a solid lubricant that is pressed against the application brush. From the surface of the image carrier, and the powdered lubricant is applied to the surface of the image bearing member. As described above, since the lubricant is applied to the surface of the image carrier via the application brush, the lubricant can be uniformly supplied to the surface of the image carrier, and the occurrence of uneven application can be prevented.

However, when the application brush is provided as described above, the size of the lubricant application device is correspondingly increased, and the structure thereof is complicated. Therefore, the solid lubricant is directly pressed into contact with the surface of the image carrier, and while the lubricant is scraped off from the solid lubricant as the surface of the image carrier moves, the powdered lubricant that has been scraped off is transferred to the image carrier. It can be applied to the body surface. With this configuration, the application brush can be omitted, and the structure of the lubricant application device can be simplified and its size can be prevented.

However, if the solid lubricant is brought into direct contact with the surface of the image bearing member, it is difficult to uniformly press the entire solid lubricant against the surface of the image bearing member. Uneven coating of the supplied powdery lubricant occurs. As a result, the image carrier surface portion where the amount of the applied lubricant is too small and the image carrier surface portion where the amount of the applied lubricant is excessive are formed, and the effect of applying the lubricant cannot be sufficiently obtained. Failure to consume lubricant more than necessary is unavoidable.

Further, a plurality of image carriers are arranged along the direction of movement of the transfer material, toner images of different colors are formed on the respective image carriers, and the toner images are superimposed on the transfer material. Although an image forming apparatus that performs transfer by transfer is also well known, the same problem as described above occurs when the image forming apparatus is configured to apply a lubricant to the surface of each image carrier by a lubricant applying apparatus. I do.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus which eliminates the above-mentioned conventional disadvantages.

[0008]

In order to achieve the above object, the present invention provides an image carrier on which a toner image is formed, a transfer device for transferring the toner image on the image carrier to a transfer material, An image forming apparatus comprising: a lubricant application device for applying a lubricant to a surface of an image carrier; wherein the lubricant application device comprises: a solid lubricant directly in contact with the surface of the image carrier; An image forming apparatus comprising a driving unit for oscillating the agent is provided (claim 1).

Further, in order to achieve the above object, the present invention provides a plurality of image carriers arranged along a moving direction of a transfer material, and a lubricant coating for applying a lubricant to the surface of each image carrier. And an image forming apparatus for forming toner images of different colors on each of the image carriers, and transferring each of the toner images to a transfer material by a transfer device. A solid lubricant directly pressed into contact with the surface of the carrier; and a drive unit for oscillating each solid lubricant, wherein the drive unit applies the solid lubricants at substantially the same amplitude, and moreover, At the same phase, and at substantially the same period, the rocking member is oscillated, and the time required for the transfer material to move between the toner image transfer portions of the image carriers adjacent to each other is set to T and n, respectively.
An image forming apparatus is proposed in which each solid lubricant is oscillated at a cycle of approximately T / n when the above integer is set (claim 2).

Further, in the image forming apparatus according to the present invention, the driving means may move each solid lubricant in a longitudinal direction of the solid lubricant and other than the moving direction of the surface of the image carrier. (Claim 3).

The image forming apparatus according to any one of claims 1 to 3, wherein the driving means is configured to move the solid lubricant in a longitudinal direction of the solid lubricant, and Advantageously, it is configured to swing in a direction substantially perpendicular to the direction of movement of the surface (claim 4).

Further, in the image forming apparatus according to any one of claims 1 to 4, a cleaning brush for removing transfer residual toner adhering to the surface of the image carrier after transferring the toner image, and applying a voltage to the cleaning brush. Means for applying, the cleaning brush, conductive fibers,
It is particularly advantageous to include a large-diameter fiber having a higher volume resistivity than the conductive fiber and a larger diameter than the conductive fiber (claim 5).

At this time, the polarity of the voltage applied to the cleaning brush is set to a polarity opposite to the polarity of the voltage applied to the transfer device, and the cleaning brush is pressed against the surface of the image bearing member, and It is advantageous that a cleaning blade is provided for removing the adhered residual toner.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic vertical sectional view showing an example of an image forming apparatus comprising a color printer. In the image forming apparatus main body 1, a plurality of drum-shaped photosensitive members, in the illustrated example, are provided. Four image carriers 2Y, 2M, 2
C and 2BK are arranged along the moving direction of a transfer material S (see FIG. 2) described later, that is, along the transport direction A thereof.
In the example shown here, a yellow toner image is formed on the surface of the image carrier 2Y on the most upstream side in the transport direction A of the transfer material, a magenta toner image is formed on the surface of the next image carrier 2M, and the next A cyan toner image is formed on the surface of the image carrier 2C, and a black toner image is formed on the surface of the next image carrier 2BK.
Each of 2M, 2C, and 2BK is driven to rotate in the direction of arrow B. In the following description, each of these image carriers is referred to as an image carrier 2Y for yellow, an image carrier 2M for magenta, an image carrier 2C for cyan, and an image carrier 2BK for black as needed. I will call it.

A transfer material transporting device 3 is disposed to face the image carriers 2Y, 2M, 2C, and 2BK. The transfer material transporting device 3 of this embodiment includes a plurality of support rollers 4, 5, 6, and 7, And a transfer belt 8 composed of an endless belt wound around the support rollers 4, 5, 6, and 7. One of the support rollers 4 is driven to rotate counterclockwise in FIG. Then, the transfer belt 8 is driven to rotate in the transfer direction A of the transfer material. Each of the image carriers 2Y, 2M, 2C, and 2BK abuts on the surface of the transfer belt 8, and the toner image on the image carrier is provided at a position substantially opposed to each image carrier with the transfer belt 8 interposed therebetween. Transfer brushes 9Y, 9M, 9C, and 9BK, which are examples of a transfer device for transferring onto a transfer material, are arranged.

On the other hand, in the lower part of the image forming apparatus main body 1,
A cassette 11 of the sheet feeding device 10 is arranged, and a transfer material S is stacked on a bottom plate 12 arranged in the cassette 11. As the transfer material, for example, a flexible piece such as a transfer paper, a resin film, a resin sheet, or a cloth is used. When the feed roller 13 abutting on the upper surface of the uppermost transfer material S is driven to rotate counterclockwise,
The uppermost transfer material S is fed in the direction of arrow C. The fed transfer material S is sent out at a predetermined timing by the rotation of the pair of registration rollers 14, and is carried on the transfer belt while being transported.
The toner image passes through toner image transfer portions T1, T2, T3, and T4 between M, 2C, and 2BK and the transfer belt 8 sequentially.

Here, as described above, a yellow toner image is formed on the surface of the image carrier 2Y for yellow.
When the transfer material S passes through the toner image transfer portion T1 between the image carrier 2Y and the transfer belt 8, the operation of the transfer brush 9Y to which a transfer voltage having a polarity opposite to the charge polarity of the toner on the surface of the image carrier is applied. Accordingly, the yellow toner image formed on the surface of the image carrier 2Y is transferred to the surface of the transfer material S. The transfer material S successively passes through the toner image transfer portions T2, T3, and T4 between the transfer belt 8 and the image carrier 2M for magenta, the image carrier 3C for cyan, and the image carrier BK for black. At this time, the toner images of the respective colors on the image carriers 2M, 2C, and 2BK are transferred to the yellow toner already transferred onto the transfer material S by the action of the transfer brushes 9M, 9C, and 9BK to which the transfer voltages are respectively applied. The images are sequentially transferred while being superimposed on the image.

The transfer material S, on which the superimposed toner images of four colors have been transferred on the surface as described above, passes through a fixing device 34. The fixing device 34 has a fixing roller 15 and a pressure roller 16 which are each driven to rotate in the direction of the arrow, and the transfer material passes between these rollers 15 and 16. The toner image is fixed on the surface of the transfer material S. The transfer material S having the full-color toner image formed on the surface in this manner is discharged out of the image forming apparatus main body as shown by an arrow E, and the paper discharge tray 17 formed by the upper wall of the image forming apparatus main body. Stacked on top.

Each of the image carriers 2Y, 2M, 2C, 2BK,
Each element for forming a toner image on its surface is configured as an integrated image forming unit 18Y, 18M, 18C, 18BK detachably attached to the image forming apparatus main body 1, respectively. Each of the image forming units 18Y, 18M,
Since the basic configurations of 18C and 18BK are substantially the same, only the configuration and operation of an image forming unit 18Y having one yellow image carrier 2Y will be described below with reference to FIG.

As shown in FIG. 2, this image forming unit 18
The Y image carrier 2Y is rotatably assembled to the unit case 19, and is driven by an unillustrated driving device by an arrow B.
It is driven to rotate in the direction. A charging roller 20, which is an example of a charging device rotatably supported by a unit case 19, comes into contact with the surface of the image carrier 2Y while rotating, and the surface of the image carrier 2Y has a predetermined polarity by the charging roller 20. Is charged. In this example, it is assumed that the image carrier 2Y is negatively charged.

On the other hand, as shown in FIG. 1, a laser writing unit 21 which is an example of an exposure device is arranged in the image forming apparatus main body 1 separately from each image forming unit. The charged laser beam L exposes the charged surface of the image carrier 2Y as shown in FIG. 2, thereby forming an electrostatic latent image for yellow image on the surface of the image carrier. In this example, the laser beam L
Is irradiated, the portion where the absolute value of the surface potential of the image carrier is reduced becomes an electrostatic latent image, and the surface portion of the image carrier not irradiated with the laser beam becomes a background portion.

The electrostatic latent image is stored in the developing device 2 shown in FIG.
2 makes the image visible as a yellow toner image. The developing device 22 includes a developing case 23 formed by a part of the unit case 19, a developing roller 24 rotatably supported by the developing case 23, and driven to rotate in a counterclockwise direction. The developing case 23 includes a rotatable stirring roller 25, and the developing case 23 contains a powdery two-component developer D having a yellow toner and a carrier. A one-component developer having no carrier can also be used.

The developer D is agitated by the agitating roller 25, and the toner and the carrier are frictionally charged to polarities opposite to each other. In this example, the toner is negatively charged and the carrier is positively charged. Such developer D
Is carried on the developing roller 24 to which a negative bias voltage is applied, and is conveyed. The developer whose amount is regulated by the regulating blade 26 is transferred to the developing roller 24 and the image carrier 2.
And the toner in the developer is electrostatically transferred to the electrostatic latent image formed on the surface of the image carrier, and the electrostatic latent image is converted to a visible toner image as a yellow toner image. Be transformed into

The yellow toner image is transferred to the surface of the transfer material S as described above, and the transfer residual toner adhering to the surface of the image carrier after transferring the toner image is removed by the cleaning device 27. This cleaning device 27
Is a cleaning case 28 constituted by a part of the unit case 19, a cleaning brush 29 rotatably supported by the cleaning case 28 and driven to rotate in the direction of the arrow, and a base end fixed to the cleaning case 28. The cleaning brush 29 and the cleaning blade 30 come into contact with the surface of the image carrier 2Y to scrape off and remove transfer residual toner on the surface.

The image carrier 2Y is cleaned by the cleaning device 27.
Is transported in the toner return screw 31, and is conveyed in the toner container 33 of the developing device 22 by a toner conveying screw 32 that is rotated and driven in the toner return duct 31. When the toner concentration sensor 35 detects a decrease in the toner concentration of the developer D accommodated in the developing case 23, the toner supply roller 36 rotates, and the toner in the toner container 33 is supplied into the developing case 23.

Another image forming unit 18M, 1 shown in FIG.
The developing cases of the developing devices 8C and 18BK contain a powdery two-component developer having magenta toner and carrier, cyan toner and carrier, and black toner and carrier, respectively. , 2BK,
A magenta toner image, a cyan toner image and a black toner image are respectively formed. This is the only difference between the image forming units.

As described above, the image forming apparatus of this embodiment has an image carrier on which a toner image is formed and a transfer device for transferring the toner image on the image carrier to a transfer material. As the image carrier, a belt-shaped photoconductor which is wound around and driven by a plurality of rollers, or an image carrier made of a drum-shaped or belt-shaped dielectric can be used. Further, a transfer blade to which a voltage is applied, a transfer roller, a corona discharger, or the like can also be used as the transfer device.

Here, in the image forming apparatus of the present embodiment, each image carrier 2Y, 2Y, 18M, 18C, 18BK is used for the purpose of reducing the friction coefficient of the image carrier surface.
A lubricant applying device for applying a lubricant to the surfaces of 2M, 2C, and 2BK is provided. This lubricant application device is shown in FIG.
As shown in FIG. 3 to FIG. 3, each image carrier 2Y, 2M, 2C,
Solid lubricant 36 directly pressed against the surface of 2BK
have. FIG. 4 shows the solid lubricant 36 pressed against the yellow image carrier 2Y. As can be seen from FIG. 4 and FIG. 3, each solid lubricant 36 is attached to each image carrier 2Y.
Y, 2M, 2C, and 2BK are formed in a substantially rectangular shape extending in the axial direction, and one long side of the rectangular shape is in contact with the surface of the image carrier. Also, a rod-shaped holder 3 is provided on the other long side.
The holder 37 is fixed, and the holder 37 is pressed by a pressing member including a compression spring 38, whereby each solid lubricant 36 is pressed against the surface of each image carrier. Solid lubricant 36
Is made of, for example, a fluororesin, preferably PTFE (polytetrafluoroethylene).

When each of the image carriers 2Y, 2M, 2C, and 2BK rotates in the direction indicated by arrow B in FIG. 1, each solid lubricant 36 is scraped by an appropriate amount, and the scraped powdery lubricant is removed. The agent is applied to the surface of each image carrier 2Y, 2M, 2C, 2BK. As a result, the friction coefficient of the surface of each image bearing member is reduced, and a longer life can be achieved. Further, since each solid lubricant 36 is in direct contact with the surface of each image carrier without passing through the application brush, the size and structure of the lubricant application device can be reduced. Moreover,
As will be described below, the lubricant applying apparatus of the present embodiment has a driving means for swinging each solid lubricant 36 in the direction of arrow F, and thereby the uneven application of the lubricant to the image carrier. Can be prevented from occurring.

As shown in FIG. 3 and FIG.
Is pressurized by an urging member comprising a compression spring 39, and the other end in the longitudinal direction is in pressure contact with the cam surface of the cam 40. A gear 41 is concentrically fixed to each cam 40, and each gear 41 is rotatably supported by the unit case 19 (FIG. 2) of each image forming unit. As shown in FIG. 3, drive gears 42 mesh with each gear 41, and each drive gear 42 is rotationally driven by a motor 43, and the rotation is transmitted to the gear 41 and the cam 40, and 40 is driven to rotate. Accordingly, each holder 37 swings in the axial direction of each image carrier, that is, in the direction of arrow F, together with each solid lubricant 36. As a result, an appropriate amount of powdery lubricant scraped off from the solid lubricant 36 is uniformly applied to the surface of the image carrier. In this way, it is possible to enhance the effect of applying the lubricant to the surface of the image carrier, and to prevent the lubricant from being wasted.

As described above, the driving means of the lubricant applying apparatus of this embodiment applies each solid lubricant 36 in the moving direction B of the surface of the image carrier 2Y, 2M, 2C, 2BK as shown in FIG. It is configured to swing in a direction perpendicular to the direction, that is, in a direction indicated by an arrow F which is also an axial direction of each image carrier. However, as shown in FIG. Thus, an angle α (α) with respect to a direction F orthogonal to the moving direction B of the surfaces of the image carriers 2Y, 2M, 2C, and 2BK.
<90 °), the solid lubricant 36 may be swung in the direction indicated by the arrow F1. Alternatively, the solid lubricant 36
To the image carriers 2Y and 2Y, as indicated by reference numeral B1 in FIG.
M, 2C, and 2BK can be swung in a direction parallel to the moving direction B of the surface.

However, as shown in FIG.
When the solid lubricant 36 is configured to swing in the longitudinal direction of the solid lubricant 36 and in a direction F substantially perpendicular to the moving direction B of the image carrier surface,
Compared to the case where the solid lubricant 36 is oscillated in the direction shown in FIG. 6, the lubricant is applied over a wide range in the axial direction of the image carrier only by oscillating the solid lubricant 36 with a small amplitude. The solid lubricant 36 can be oscillated by the driving means having a simpler configuration than when the solid lubricant 36 is oscillated in the direction shown in FIG.

The configuration of the lubricant applying apparatus described above is not limited to an image forming apparatus provided with a plurality of image carriers, but can be applied to an image forming apparatus provided with only one image carrier. . Further, for example, a toner image is formed on an image carrier made of a photoreceptor, the toner image is primarily transferred to a transfer material made of an intermediate transfer body, and the toner image is transferred to a final transfer material such as transfer paper. The above-described lubricant applying device can be applied to an image forming apparatus without any trouble. Also in this case, the solid lubricant is pressed against the image carrier composed of the photoreceptor, the solid lubricant is oscillated by the driving means, and the lubricant is applied to the surface of the image carrier. Further, the above-described intermediate transfer member also constitutes an image carrier on which a toner image is formed, and the above-described lubricant applying device may be employed to apply a lubricant onto the image carrier. it can. In this case, a solid lubricant is brought into pressure contact with the surface of the intermediate transfer member, the solid lubricant is oscillated by driving means, and the lubricant is applied onto the intermediate transfer member.

Incidentally, the image forming apparatus shown in FIG.
It has a plurality of image carriers arranged along the moving direction of the transfer material, forms toner images of different colors on each image carrier, and transfers each toner image to the transfer material by a transfer device. Each image carrier is supported by its support (the unit case 19 in the image forming apparatus of this embodiment).
Since it is difficult to assemble the image carrier without play at all, each image carrier is assembled so that a very small amount within the range of the tolerance can be loosened in the axial direction of the image carrier. Have been. For this reason, when the solid lubricant 36 is pressed against each image carrier as described above and the solid lubricant 36 is oscillated, each image carrier is subjected to frictional force received from the solid lubricant 36, It will rock with the solid lubricant 36 in a very small stroke, for example, a stroke of 1/10 mm.

In particular, as shown in FIGS. 5 and 6, when the driving means is configured to swing the solid lubricant 36 in a direction other than the moving direction B of the surface of the image carrier,
Each image carrier 2 is moved by the swing of the solid lubricant 36.
Since an external force in the axial direction is applied to Y, 2M, 2C, and 2BK, the image carrier easily swings in the axial direction.

When each image carrier swings as described above, a color shift may occur in the toner image formed on the transfer material. FIG. 10 is an explanatory view showing one example, and reference numeral YL in FIG. 10 indicates a linear toner image transferred from the yellow image carrier 2Y to the transfer material S. The linear toner image YL is to be formed linearly on the transfer material S along the transport direction A, but the image carrier 2Y for yellow is pressed against the solid Since the image carrier 2Y is swung in the axial direction by the swing of the lubricant 36, the actual toner image is a sine-curve toner image having an extremely small amplitude indicated by δ as indicated by YL. Is transferred onto the transfer material S. The value of 2 × δ is the stroke at which the image carrier 2Y can rattle in the axial direction as described above, and the value is, for example, about 1/10 mm.

The toner image indicated by the broken line in FIG. 10 and indicated by the symbol ML is transferred from the image carrier 2M for magenta to the transfer material S.
It is a toner image transferred on the top. The magenta image carrier 2M is also swung in the axial direction of the image carrier 2M by the solid lubricant 36 which is pressed against and swings, so that the toner image ML also has a sinusoidal curve having an amplitude δ. Is transferred onto the transfer material S.

Here, both toner images YL and ML are originally
Although it is to be transferred by being superimposed on the transfer material S, as shown in FIG. 10, both toner images do not overlap as a result of the image carriers 2Y and 2M swinging in their axial directions, respectively. As a result, color shift occurs, and the image quality of the completed toner image is degraded.

In the illustrated image forming apparatus, in order to prevent the above-mentioned problem, the above-mentioned driving means causes the solid lubricants 36 to have substantially the same amplitude, to have substantially the same phase, and to have substantially the same phase. The toner image transfer portions T of two image carriers adjacent to each other while being swung in a cycle.
When the time for the transfer material S to move between 1, T2, T3 and T4 is T and n is an integer of 1 or more, each solid lubricant 36 is oscillated at a cycle of substantially T / n. Have been. The amplitude, phase and period of each solid lubricant 36 completely match, and the oscillation period of the solid lubricant 36 is T /
Most preferably, it is set to be completely equal to n.

More specifically, as shown in FIG.
When each of the image carriers 2Y, 2M, 2C, and 2BK comes into contact with the transfer material S with a predetermined nip width N in the transport direction A, the distance P between the center of each nip width in the transfer material transport direction. Are set equal, T is the time required for the transfer material S to move the distance P, and n is an integer including 1, and the oscillation cycle of each solid lubricant 36 is T
/ N, and the swing of all the solid lubricants 36 is synchronized as described above. Accordingly, it is possible to prevent or effectively suppress the occurrence of color shift of the toner image transferred from each image carrier to the transfer material S.

FIG. 9 is an explanatory view similar to FIG. 10 showing one example. As can be seen from FIG. 9, the linear toner image YL transferred from the yellow image carrier 2Y to the transfer material S
Coincides with the linear toner image ML transferred from the magenta image carrier 2M, thereby preventing the occurrence of color misregistration. The toner images YL and ML are transferred onto the transfer material S in a state of waving in a sine curve with an amplitude of δ. However, since the actual value of δ is extremely small, the toner images Even if the image is transferred in such a wavy state, it can be visually ignored, and the image quality of the toner image does not substantially deteriorate.

As described above with reference to FIG. 2, the image forming apparatus of this embodiment has the cleaning brush 29 for removing the transfer residual toner attached to the surface of the image carrier after the transfer of the toner image. ing. At this time, the cleaning brush 29 scrapes off the transfer residual toner on the surface of the image carrier, and a voltage is applied to the cleaning brush 29 by the power supply 44, thereby causing the transfer residual toner on the image carrier to be electrostatically charged. The transfer to the cleaning brush 29 is performed so that the transfer residual toner on the image carrier can be efficiently removed. The transfer residual toner attached to the cleaning brush 29 is knocked down by the flicker 45. The power supply 44 constitutes an example of a unit for applying a voltage to the cleaning brush.

As described above, to apply a voltage to the cleaning brush 29 to electrostatically transfer the transfer residual toner on the image carrier to the cleaning brush 29, the fibers constituting the cleaning brush 29 are electrically conductive. It is necessary to have nature. For example, the fibers of the cleaning brush 29 are made of polyester or acrylic resin mixed with carbon, and the fibers are used as conductive fibers.

On the other hand, if filming in which the toner adheres in a thin film on the surface of the image carrier is formed, the image quality of the toner image formed on the image carrier deteriorates. Therefore,
It is preferable that the above-described cleaning brush 29 gives a scraping action to the surface of the image carrier, thereby removing filming formed on the surface of the image carrier to prevent occurrence of filming.

In order to remove the filming on the image carrier by the cleaning brush 29, it is necessary to increase the diameter of the fiber, strengthen the stiffness, and bring the fiber into contact with the surface of the image carrier. There is. However, conductive fibers made of, for example, carbon-containing resin are expensive, and if the diameter of such fibers is increased, the material cost increases, and the cost of the cleaning brush 29 is inevitable from the above-described disadvantage.

Therefore, the cleaning brush 29 of this embodiment is
Is configured to include a conductive fiber and a nonconductive large-diameter fiber having a higher volume resistivity than the conductive fiber and a larger diameter than the conductive fiber. The flocking density is, for example, 12,000 fibers per square inch. The non-conductive large-diameter fiber is made of, for example, polyester into which carbon is not mixed, and the cleaning brush 29 is formed in a state where the non-conductive large-diameter fiber and the conductive fiber are uniformly mixed. .

As described above, since the cleaning brush 29 contains conductive fibers, by applying a bias voltage to the cleaning brush 29, the transfer residual toner on the image carrier is electrostatically removed. Cleaning brush 2
9 can be shifted. At that time, since the diameter of the conductive fiber is set relatively small, the amount of expensive conductive material used can be reduced, thereby avoiding the disadvantage of increasing the cost of the cleaning brush 29. Further, since the cleaning brush 29 contains non-conductive large-diameter fibers, the large-diameter fibers can effectively remove filmig on the surface of the image carrier.
This can prevent filming from occurring on the image carrier, and can form a high-quality toner image on the image carrier for a long period of time. At this time, since the material cost of the non-conductive fiber is originally low, the diameter of the fiber is large, and therefore, even if the amount of the material constituting the fiber is large, the cost of the cleaning brush 29 increases. Can be suppressed. In this manner, the cleaning brush 29 having both the efficiency of removing the transfer residual toner and the effect of removing the filming can be formed at low cost.

The transfer residual toner adhering to the surface of the image carrier after passing through the toner image transfer position T1 shown in FIG. 1 and FIG.
Under the influence of the transfer voltage applied to Y, the polarity is reversed to the same polarity as the transfer voltage, that is, to the plus polarity in the example of FIG. Therefore, in the image forming apparatus of the present embodiment, the polarity of the voltage applied to the cleaning brush 29 is opposite to the polarity of the voltage applied to the transfer device (the transfer brush in the example in the figure), and is negative in the example in the figure. Is set. As a result, the transfer residual toner having the polarity reversed to the plus direction can be effectively electrostatically transferred to the cleaning brush 29 side.

The transfer residual toner that has not been completely removed by the cleaning brush 29 is scraped off by the cleaning blade 30 pressed against the surface of the image carrier downstream of the cleaning brush 29 in the moving direction of the surface of the image carrier. Removed. When the transfer residual toner that has passed through the transfer position T1 includes a toner of negative polarity whose charge polarity has not been inverted, the toner is
9 makes it difficult to remove. After passing through the cleaning brush 29, the toner is scraped off by the cleaning blade 30.

In this case, when the image carrier itself passes through the toner image transfer position T1, the charge polarity of the surface of the image carrier may be reversed to a positive polarity under the influence of the voltage applied to the transfer device. However, when the image carrier portion passes through the cleaning brush 29, since a negative polarity voltage is applied to the cleaning brush 29, the charging polarity of the image carrier surface portion is returned to the normal negative polarity. Therefore, the transfer residual toner charged to the negative polarity can be efficiently scraped and removed by the cleaning blade 30. If the surface portion of the image carrier to which the transfer residual toner of the negative polarity adheres remains charged to the positive polarity, the transfer residual toner of the negative polarity strongly adheres electrostatically to the surface of the image carrier. 30 makes it difficult to remove the transfer residual toner, but in the example shown in the figure, such a problem can be prevented.

As described above, in addition to the cleaning brush 20 that removes the transfer residual toner by contacting the surface of the image carrier, the cleaning brush that presses against the surface of the image carrier to remove the transfer residual toner adhered to the surface. By providing the blade 30, transfer residual toner can be efficiently removed. The cleaning blade 30 is preferably in pressure contact with the surface of the image carrier downstream of the cleaning brush 29 in the moving direction of the surface of the image carrier. The cleaning blade 30 is made of an elastic material such as rubber or resin, as is well known per se.

The above-described cleaning brush 29 and cleaning blade 30 are connected to the other image forming units 18M and 1M.
8C and 18BK are also provided. Further, the configuration of the cleaning brush 29 and the cleaning blade 30 is not limited to an image forming apparatus having a plurality of image carriers,
The present invention is also applicable to an image forming apparatus having two image carriers. Further, the present invention can be applied to the case where the image carrier is formed of the above-mentioned intermediate transfer member without any trouble. Further, the present invention can be applied to an image forming apparatus which does not have the above-mentioned lubricant applying device. Further, the present invention can be widely applied to image forming apparatuses other than printers.

[0054]

According to the first aspect of the present invention, it is possible to reduce the size and the structure of the lubricant applying device and to suppress uneven application of the lubricant to the surface of the image carrier. Can be.

According to the second aspect of the invention, in addition to the above effects, it is possible to effectively suppress the occurrence of color misregistration of the toner image formed on the transfer material.

According to the third aspect of the present invention, the image carrier is easily oscillated in the direction perpendicular to the moving direction of the surface of the image carrier due to the oscillation of the solid lubricant. The occurrence of color misregistration in the toner image formed on the material can be effectively suppressed.

According to the fourth aspect of the invention, the structure of the driving means can be simplified.

According to the fifth aspect of the present invention, the efficiency of removing the transfer residual toner on the image carrier and the efficiency of removing the filming can be increased, and the cost of the cleaning brush can be reduced.

According to the present invention, the efficiency of removing the transfer residual toner on the image carrier can be further improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view illustrating an example of an image forming apparatus.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a schematic plan view illustrating an example of a plurality of image carriers, a solid lubricant pressed against the surface of each image carrier, and a driving unit that swings the solid lubricant.

FIG. 4 is a perspective view showing a solid lubricant pressed against an image carrier for yellow and a part of a driving means for swinging the solid lubricant.

FIG. 5 is an explanatory diagram showing a relationship between an image carrier and a solid lubricant in a swing direction.

FIG. 6 is an explanatory diagram showing another example of the relationship between the image carrier and the solid lubricant in the swing direction.

FIG. 7 is an explanatory view showing still another example of the relationship between the image carrier and the solid lubricant in the swing direction.

FIG. 8 is an explanatory diagram showing a positional relationship between a plurality of image carriers.

FIG. 9 is a diagram illustrating that a color shift does not occur in a toner image formed on a transfer material.

FIG. 10 is a diagram illustrating a problem that a color shift occurs in a toner image formed on a transfer material.

[Explanation of symbols]

 2Y image carrier 2M image carrier 2C image carrier 2BK image carrier 29 cleaning brush 30 cleaning blade 36 solid lubricant A moving direction B moving direction F direction F1 direction

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuto Yokokawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Takaya Muraishi 1-3-6 Nakamagome, Ota-ku, Tokyo Share F-term in Ricoh Company (reference) 2H030 AA06 AB02 AD03 AD16 2H034 AA07 BD03 BD04 BD09 BF00

Claims (6)

[Claims] 1. An image carrier on which a toner image is formed, a transfer device for transferring the toner image on the image carrier to a transfer material, and a lubricant coating device for applying a lubricant to the surface of the image carrier An image forming apparatus comprising: a lubricant applying device comprising: a solid lubricant that is in direct pressure contact with the surface of an image carrier; and a driving unit that swings the solid lubricant. Image forming apparatus. 2. The image carrier according to claim 1, further comprising: a plurality of image carriers arranged along a moving direction of the transfer material; and a lubricant applying device for applying a lubricant to a surface of each image carrier. An image forming apparatus that forms toner images of different colors on the upper surface thereof and transfers the toner images to a transfer material by a transfer device, wherein the lubricant applying device is a solid state directly pressed against each image carrier surface. A lubricant, and a driving means for oscillating each solid lubricant, wherein the driving means drives each solid lubricant at substantially the same amplitude, at substantially the same phase, and at substantially the same period. And the time required for the transfer material to move between the toner image transfer portions of the image carriers adjacent to each other.
When n is an integer of 1 or more, each solid lubricant is oscillated at a cycle of approximately T / n. 3. The image forming apparatus according to claim 2, wherein the driving unit swings each solid lubricant in a direction other than the moving direction of the surface of the image carrier.
An image forming apparatus according to claim 1. 4. The driving means comprises:
4. The image forming apparatus according to claim 1, wherein the solid lubricant is swung in a longitudinal direction of the solid lubricant and in a direction substantially perpendicular to a moving direction of the surface of the image carrier. 5. A cleaning brush for removing transfer residual toner adhering to the surface of an image carrier after transfer of a toner image, and a means for applying a voltage to the cleaning brush, wherein the cleaning brush comprises conductive fibers 5. The image forming apparatus according to claim 1, further comprising a large-diameter fiber having a higher volume resistivity than the conductive fiber and a larger diameter than the conductive fiber. 6. The polarity of the voltage applied to the cleaning brush is set to a polarity opposite to the polarity of the voltage applied to the transfer device, and the cleaning brush is pressed against the surface of the image carrier and adheres to the surface. The image forming apparatus according to claim 5, further comprising a cleaning blade that removes the transfer residual toner.