JP4486808B2 - Fur brush and image forming apparatus cleaning device using the same - Google Patents

Description

  The present invention relates to a fur brush, and more particularly to a fur brush for cleaning the surface of a photosensitive drum of an image forming apparatus. The present invention also relates to a cleaning device for an image forming apparatus using the fur brush.

  In an image forming apparatus such as a copying machine or a printer, an electrostatic latent image is formed on the surface of a photosensitive drum, and the electrostatic latent image is visualized as a toner image by a developing device and transferred to a sheet. ing. In such an apparatus, toner, additives, compounds thereof, and the like that have not contributed to the transfer remain on the photosensitive drum. In order to clean and remove such deposits, a cleaning device is provided.

The cleaning device includes a cleaning blade disposed so as to contact the surface of the photosensitive drum, a fur brush that rotates while the tip is in contact with the surface of the photosensitive drum, and cleans the drum surface. And the deposit | attachment removed from the drum surface by these members is accommodated in a collection container.
JP-A-11-202711

  The fur brush provided in the cleaning device is configured to rotate together with the photosensitive drum, and is rotated by a common drive system. Since the fur brush is configured by arranging a plurality of piles, depending on the arrangement of the piles, if the rotation speed ratio between the photosensitive drum and the fur brush is an integral multiple, each pile is always on the surface of the photosensitive drum. In this case, uneven wear on the surface of the photosensitive drum is promoted.

  Since the conventional general photosensitive drum has a relatively short life, it is not necessary to consider the surface wear by the fur brush as a problem. However, recently, as disclosed in Japanese Patent Application Laid-Open No. 2003-255569, a photoconductor drum having a long life has been developed, and uneven wear on the surface of the photoconductor drum due to a fur brush cannot be ignored. .

  An object of the present invention is to suppress uneven wear on the surface of the photosensitive drum by suppressing the influence of the fur brush on the surface of the photosensitive drum, particularly in an image forming apparatus using the photosensitive drum having a long lifetime.

  The cleaning device in the image forming apparatus according to claim 1 is a device for cleaning the photosensitive drum of the image forming apparatus, and includes a fur brush, a motor, and a gear mechanism. The fur brush has a rotating shaft and a plurality of piles that are implanted on the surface of the rotating shaft and whose tips are in contact with the surface of the photosensitive drum, and is for cleaning the surface of the photosensitive drum. The motor is for rotating the fur brush together with the photosensitive drum. The gear mechanism is a mechanism for transmitting the rotation of the motor to the photosensitive drum and the fur brush. The piles of the fur brush are configured to suppress contact with the same position on the surface of the photosensitive drum.

  In this apparatus, the photosensitive drum and the fur brush are rotationally driven by a single motor through a gear mechanism. Therefore, depending on the number of teeth of each gear of the gear mechanism, and depending on the number and arrangement of the piles of the fur brush, the respective piles always come into contact with the same position on the surface of the photosensitive drum. It will promote wear.

  Therefore, in the present invention, each pile of the fur brush is prevented from contacting the same position on the surface of the photosensitive drum. In addition, as a structure for this, it implement | achieves by setting the number of teeth of each gear of a gear mechanism to an appropriate number of teeth, or adjusting the arrangement and number of piles. With such a configuration, uneven wear due to contact with the fur brush on the surface of the photosensitive drum can be suppressed.

  According to a second aspect of the present invention, there is provided a cleaning device for an image forming apparatus according to the first aspect, wherein the gear mechanism includes a first gear fixed to the rotating shaft of the photosensitive drum, and rotation transmitted from the first gear to the fur brush. A second gear fixed to the rotation shaft, and the number of teeth of the first gear is a non-integer multiple of the number of teeth of the second gear.

  In this case, the number of times each pile of the fur brush contacts the same position on the surface of the photosensitive drum is reduced, and the photosensitive drum is more uniformly contacted. For this reason, uneven wear of the photosensitive drum can be suppressed.

  According to a third aspect of the present invention, in the image forming apparatus cleaning apparatus according to the first or second aspect, the number of piles in the circumferential direction of the fur brush is a non-integer multiple of the number of teeth of the second gear.

  Here, as described above, the number of times each pile of the fur brush contacts the same position on the surface of the photosensitive drum is reduced, and the photosensitive drum is more uniformly contacted. For this reason, uneven wear of the photosensitive drum can be suppressed.

  According to a fourth aspect of the present invention, there is provided a cleaning device for an image forming apparatus according to any one of the first to third aspects, wherein the plurality of piles of the fur brush are hair-like along the longitudinal direction of the ribbon-like member. A plurality of the fiber bundles are arranged side by side and planted, and the ribbon-like member is wound around the rotation shaft in a spiral shape. In the plurality of pile rows in the ribbon-like member, at least one pile is arranged at a pitch different from the pitch of the piles in the other rows.

  In this case, as compared with the case where all rows of piles are arranged at an equal pitch, the contact positions of the piles on the surface of the photosensitive drum are dispersed, and uneven wear can be suppressed.

  The cleaning device for an image forming apparatus according to claim 5 is the binder resin according to any one of claims 1 to 4, wherein the photosensitive drum contains at least a charge generating agent and a charge transport agent on a conductive substrate. The binder resin contains two types of copolymer polycarbonate resins, and the ratio of the bisphenol ZC type polycarbonate component is specified among the repeating structural units of each copolymer polycarbonate resin. It is a range.

  The photoconductive drum in this case has a longer life than the conventional photoconductive drum. Therefore, in the image forming apparatus having such a photosensitive drum, the influence of the fur brush cannot be ignored during the period in which one photosensitive drum is used. However, in the present invention, since the influence of the fur brush on the surface of the photosensitive drum can be reduced, the effect of extending the life of the photosensitive drum can be enjoyed effectively.

  The cleaning device for an image forming apparatus according to a sixth aspect is the apparatus according to any one of the first to fifth aspects, wherein the fur brush is above the center portion of the photosensitive drum and at least a part of the fur brush in a plan view. It is arranged at a position overlapping with the photosensitive drum.

  When the fur brush is placed at such a position, the deposits removed from the surface of the photosensitive drum by the fur brush or other blades may adhere to the fur brush again or collect in the vicinity of the fur brush. It becomes. Then, the photosensitive drum is rubbed with the fur brush to which the adhering matter adheres, and uneven wear on the surface of the photosensitive drum is promoted.

  However, uneven wear of the photosensitive drum can be suppressed by using the cleaning device configured as described above.

  A fur brush according to a seventh aspect is a brush for cleaning the surface of the photosensitive drum of the image forming apparatus, and includes a rotating shaft and a plurality of piles. The plurality of piles are planted at a predetermined pitch in a plurality of rows on the surface of the rotating shaft. The plurality of piles are formed by arranging a plurality of hair-like fiber bundles arranged along the longitudinal direction of the ribbon-like member on the ribbon-like member, and the ribbon-like member is spirally wound around the rotation shaft. It has been. In the plurality of pile rows in the ribbon-like member, at least one pile is arranged at a pitch different from the pitch of the piles in the other rows.

  In this case, an effect similar to that of the above-described fourth aspect is obtained.

  In the present invention as described above, uneven wear of the photosensitive drum due to sliding contact of the fur brush with the surface of the photosensitive drum can be suppressed. In particular, it is effective for use in an image forming apparatus using a photosensitive drum having a long lifetime.

[First Embodiment]
FIG. 1 shows a cleaning device for an image forming apparatus according to a first embodiment of the present invention. Here, the photoconductive drum used in the image forming apparatus is a photoconductive drum having a long life as disclosed in JP-A-2003-255569. That is, the photosensitive drum 2 includes a single-layer type photosensitive layer made of a binder resin containing at least a charge generating agent and a charge transporting agent on a conductive substrate, and the binder resin is a copolymer polycarbonate resin of two types. And the ratio of the bisphenol ZC type polycarbonate component in the repeating structural unit of each copolymer polycarbonate resin is within a specific range.

  The cleaning device 1 used in the image forming apparatus as described above is a device for cleaning deposits adhering to the surface of the photosensitive drum 2, and is rotatably supported inside the case 5 and the case 5. As with the fur brush 6, the fur brush 6, the cleaning blade 7, and the recovered toner conveying member 8 that is rotatably supported inside the case 5 are provided.

  The case 5 is provided so as to cover the fur brush 6 and the collected toner conveying member 8 so that the side facing the photosensitive drum 2 is opened and the opposite side is not scattered.

  The fur brush 6 includes a rotating shaft 10 rotatably supported by the case 5 and a plurality of piles (hair bundles) 11 provided on the outer periphery of the rotating shaft 10. As shown in FIGS. 2 and 3, the plurality of piles 11 are made by planting hairy nylon fibers (pile 11) in a bundle on a ribbon-like member 11 a (hereinafter simply referred to as a ribbon), and then the ribbon. 11a is formed by spirally winding the rotary shaft 10 around it. With such a configuration, the plurality of piles 11 are arranged on the rotating shaft 10 at a predetermined interval in the circumferential direction and in a plurality of rows along the winding direction of the ribbon. In the example shown in FIG. 3, 17 rows of piles are arranged on a ribbon 11a having a width a, and the ribbons 11a are wound around the rotary shaft 10 so that the number of piles in the circumferential direction is “27”. An angle is set. Further, the density (drive-in density) of the piles 11 in each row of the ribbon 11a is 56 / inch, and the pitch between the piles is equal in all rows.

  Further, the fur brush 6 is disposed above the center portion of the photosensitive drum 2 and at a position where at least a part of the fur brush 6 overlaps with the photosensitive drum 2 in plan view.

  Note that a plate-like toner scraping member 12 is provided at the opening end of the case 5, and the tip of the toner scraping member 12 penetrates into the pile 11 of the fur brush 6.

  The cleaning blade 7 has one end fixed to the opening end of the case 5 and the tip abutting against the surface of the photosensitive drum 2. The tip is configured to scrape off deposits adhering to the surface of the photosensitive drum 2.

  The collected toner conveying member 8 is a member for conveying the collected material collected from the surface of the photosensitive drum by the fur brush 6 and the cleaning blade 7 to the collecting container. The collected toner conveying member 8 has a rotating shaft 8a rotatably supported by the case 5 and And a feed member 8b wound spirally around the outer periphery of the rotary shaft 8a. The rotary shaft 8a and the feed member 8b are integrally formed of resin.

  A charging device 15 for charging the surface of the photosensitive drum 2 is provided adjacent to the cleaning device 1. The charger 15 is supported by a housing 16 formed integrally with the case 5 of the cleaning device 1.

  Although not described here, an exposure device, a developing device, and a transfer device are disposed around the photosensitive drum 2. Then, an electrostatic latent image is formed on the surface of the photosensitive drum 2 by the charger 15 and the exposure device, the electrostatic latent image is visualized as a toner image by the developing device, and the toner image is further formed on the sheet by the transfer device. It is designed to be transcribed.

Next, a gear mechanism for driving the cleaning device 1 will be described.
As schematically shown in FIG. 4, the gear mechanism 20 is a mechanism for transmitting the power from the motor and the speed reducer 21 for driving the photosensitive drum 2 to the fur brush 6 and the collected toner conveying member 8. . The gear mechanism 20 is provided coaxially with the photosensitive drum 2 and rotates in synchronization with the photosensitive drum 2. The gear mechanism 20 is fixed to the end of the rotary shaft 10 of the fur brush 6 and meshes with the first gear 22. A second gear 23 and a third gear 24 that is fixed to the end of the rotating shaft 8 a of the collected toner conveying member 8 and meshes with the second gear 23. Here, the number of teeth of the first gear 22 fixed to the photosensitive drum 2 is 36, and the number of teeth of the second gear 23 fixed to the fur brush 6 is set to 13. That is, the number of teeth of the first gear 22 is set to a non-integer multiple of the second gear 23. Further, as described above, since the number of piles in the circumferential direction of the fur brush 6 is set to 27 bundles, the number of piles in the circumferential direction of the fur brush 6 (27 bundles) is the number of teeth of the second gear 23 (13 sheets). ) Is a non-integer multiple.

Next, the operation will be described.
When the photosensitive drum 2 is rotating during the image forming process, the fur brush 6 and the collected toner conveying member 8 are always rotated by the gear mechanism 20. The fur brush 6 rotates in the forward direction (the rotation direction itself is the reverse direction) with respect to the rotation direction of the photosensitive drum 2.

  In the image forming operation, a toner image is formed on the surface of the photosensitive drum 2, but residual toner, a charged product, or paper dust adheres to the surface of the photosensitive drum 2, or The surface is oxidized and deteriorated to form a deteriorated layer.

  Therefore, in the cleaning device 1, the fur brush 6 is rotated in the forward direction with respect to the rotation direction of the photosensitive drum 2, or the tip of the cleaning blade 7 is pressed against the surface of the photosensitive drum 2. Deposits and deteriorated layers are removed from the surface of the photosensitive drum 2 by the fur brush 6 and the cleaning blade 7. The removed collected material is conveyed to the collection container side by the collected toner conveying member 8.

  Here, the fur brush 6 is driven by a motor that rotationally drives the photosensitive drum 2 via a gear mechanism. Therefore, the number of teeth of the first gear 22 fixed to the photosensitive drum 2 and the number of teeth of the second gear 23 fixed to the fur brush 6 are set to an integral multiple, and the number of teeth of the second gear 23 and the fur brush If the number of piles in the circumferential direction is set to an integer ratio, each pile of the fur brush 6 always comes into contact with the same position of the photosensitive drum 2. When used in such a state for a long period of time, the surface of the photosensitive drum 2 is unevenly worn, resulting in unevenness. When this unevenness progresses, an image defect or the like due to charging failure occurs, and even if the life of the photosensitive drum 2 itself is extended, this is hindered.

  Therefore, in the present embodiment, as described above, the number of teeth of the first gear 22 and the number of teeth of the second gear 23 are set to a non-integer multiple of 36 and 13, respectively. Further, the number of piles in the circumferential direction of the fur brush 6 is set to 27 bundles, and is set to a non-integer multiple of the number of teeth of the second gear 23 (13 sheets).

  With this setting, the number of times the pile 11 of the fur brush 6 contacts the same position on the surface of the photosensitive drum 2 is reduced, and each pile 11 is in sliding contact with the surface of the photosensitive drum 2 uniformly. Become. For this reason, uneven wear of the photosensitive drum 2 is suppressed, and a stable image can be formed even when used for a long time.

  Further, when the fur brush 6 is disposed above the center portion of the photosensitive drum 2 and at least a part of the fur brush 6 overlaps the photosensitive drum 2 in a plan view as in the present embodiment, The deposits removed from the surface of the photosensitive drum 2 by the fur brush 6 and the cleaning blade 7 will adhere to the fur brush 6 again or accumulate in the vicinity of the fur brush 6. Then, the photosensitive drum 2 is rubbed with the fur brush 6 to which the adhered matter is adhered, and uneven wear on the surface of the photosensitive drum 2 is promoted. Note that the contact position between the toner scraping member 12 and the fur brush 6 for removing toner and the like from the fur brush 6 is opposite to the gravitational direction with respect to the contact position between the fur brush 6 and the photosensitive drum 2. When the fur brush 6 is provided on the same side as the contact position between the fur brush 6 and the photosensitive drum 2 with respect to the center of the fur brush 6, the above tendency becomes remarkable. However, uneven wear of the photosensitive drum can be suppressed by using the cleaning device configured as described above.

  Table 1 shows the results of running tests when the photosensitive drum 2 and the fur brush 6 are set under the following conditions.

Photoconductor drum: φ30mm Organic photoconductor Fur brush: φ12.5mm (Nylon fur brush)
210D / 35F 39kF / inch ² (one pile is composed of 35 filaments, and the thickness of each pile is 210 denier)

“80000 sheets” indicates the number of images formed.
In Examples 1-1 and 1-2, no problem occurred up to 300,000 sheets.

  Here, the number of circumferential piles can be changed by changing the winding angle of the ribbon-shaped member around the rotating shaft 10. That is, as described above, the fur brush 6 is formed by spirally winding a ribbon-like member (hereinafter simply referred to as a ribbon) in which a bundle of nylon fibers (pile) is implanted on the rotating shaft 10. However, the number of piles in the circumferential direction can be changed by changing the winding angle (θ in FIG. 2) without changing the number of piles arranged in the width direction of the ribbon. Table 2 below shows the relationship between the winding angle and the number of circumferential piles when the same fur brush is used.

[Second Embodiment]
In the first embodiment, in the fur brush, the axial pitch of the piles in each row is the same pitch, but the axial pitch may be different for each row. The fur brush 6 'in this case and the ribbon 11a' constituting the fur brush 6 'are shown in FIGS. The configuration other than the fur brush 6 'is the same as that of the first embodiment.

  As described above, the fur brush 6 ′ includes a rotating shaft 10 and a ribbon 11 a ′ wound on the rotating shaft 10. The basic configuration of the ribbon 11a 'is the same as that of the first embodiment, but the driving density of each row is different as shown in FIG. That is, the pitch between the piles in each of the rows A, B, C,..., Q (total 17) is not set to be equal.

  In the fur brush 6 ′ configured by winding the ribbon 11 a ′, the piles 11 ′ are dispersed as compared with the first embodiment. For this reason, the position of the pile contacting the surface of the photosensitive drum 2 is wide, and uneven wear can be further suppressed as compared with the first embodiment.

  Table 3 shows the results of running tests when the photosensitive drum 2 and the fur brush 6 ′ are set under the following conditions.

Photoconductor drum: φ30mm Organic photoconductor

Fur brush: 12.5mm (Nylon fur brush)

“80000 sheets” indicates the number of images formed.
In Examples 2-1 and 2-2, no problem occurred up to 300,000 sheets.

Folding density for equal pitch: 56 / inch
Folding density of rows A to Q with irregular pitch (/ inch)
(1) Anomaly 1
A = 56, B = 28, C = 52, D = 15, E = 56, F = 50, G = 48, H = 56, I = 55, J = 32, K = 42, L = 56, M = 24, N = 36, O = 50, P = 48, Q = 64
(2) Anomaly 2
A = 56, B = 52, C = 48, D = 44, E = 40, F = 36, G = 32, H = 28, I = 24, J = 20, K = 16, L = 54, M = 50, N = 46, O = 42, P = 40, Q = 36
Photoconductor drum peripheral speed: 100 mm / sec
Number of teeth of the first gear: 36 Number of teeth of the second gear: 13 Ribbon winding angle: 54.3 °

1 is a longitudinal sectional view of a cleaning device in which an embodiment of the present invention is adopted. The front view of the fur brush used for the said cleaning apparatus. The figure which shows the ribbon which comprises the said fur brush. The schematic diagram of the drive mechanism of the said cleaning apparatus. The front view of the fur brush by other embodiment. The figure which shows the ribbon which comprises the fur brush shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 Photosensitive drum 6, 6 'Fur brush 10 Rotating shaft 11, 11' Pile 11a, 11a 'Ribbon 20 Gear mechanism 21 Motor and reduction gear 22 1st gear 23 2nd gear

Claims (6)

A cleaning device for cleaning a photosensitive drum of an image forming apparatus,
A fur brush for cleaning the surface of the photosensitive drum, comprising: a rotating shaft; and a plurality of piles that are implanted on the surface of the rotating shaft and whose tips contact the surface of the photosensitive drum;
A motor for rotationally driving the fur brush together with the photosensitive drum;
And a gear mechanism for transmitting the rotation of the motor to the photosensitive drum and the fur brush,
The plurality of piles of the fur brush are formed by arranging a plurality of hair-like fiber bundles in a ribbon-like member along the longitudinal direction of the ribbon-like member,
The ribbon-like member is wound spirally around the rotating shaft,
In the plurality of pile rows in the ribbon-shaped member, at least one row of piles is arranged at a pitch different from the pitch of the piles in the other rows,
The fur brush pile is configured to reduce the number of times of contact with the same position on the surface of the photosensitive drum,
A cleaning device for an image forming apparatus. The gear mechanism has a first gear fixed to the rotation shaft of the photosensitive drum, and a second gear fixed to the rotation shaft of the fur brush transmitted from the first gear.
The number of teeth of the first gear is a non-integer multiple of the number of teeth of the second gear,
The image forming apparatus cleaning apparatus according to claim 1. The number of piles in the circumferential direction of the fur brush is a non-integer multiple of the number of teeth of the second gear.
The cleaning device for an image forming apparatus according to claim 1. The photosensitive drum includes a single-layer type photosensitive layer made of a binder resin containing at least a charge generator and a charge transport agent on a conductive substrate, and the binder resin contains two types of copolymer polycarbonate resins. And, the ratio of the bisphenol ZC type polycarbonate component in a specific range among the repeating structural units of each copolymer polycarbonate resin,
The cleaning device of the image forming apparatus according to any one of claims 1 to 3. The fur brush is disposed above a center portion of the photosensitive drum and at a position where at least a part of the fur brush overlaps with the photosensitive drum in a plan view.
The cleaning device of the image forming apparatus according to any one of claims 1 to 4. A fur brush for cleaning the surface of a photosensitive drum of an image forming apparatus,
A rotation axis;
A plurality of piles planted in a plurality of rows at a predetermined pitch on the surface of the rotating shaft,
Wherein the plurality of pile, the ribbon-like member is formed by implanted side by side a plurality of hairy fiber bundle in the longitudinal direction of the ribbon-like member,
The ribbon-like member is wound spirally around the rotating shaft,
In the plurality of pile rows in the ribbon-like member, at least one row of piles is arranged at a pitch different from the pitch of the piles in the other rows.
A fur brush of an image forming apparatus.

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