JP5446459B2 - Lubricant supply device and image forming apparatus - Google Patents

Description

  The present invention relates to a lubricant supply device and an image forming apparatus.

In an image forming apparatus that forms a toner image by transferring toner to an electrostatic latent image on an image carrier, the toner image formed on the image carrier is directly transferred to a recording medium, or once is an intermediate transfer member And then transferred to a recording medium. At this time, a part of the toner on the image carrier is not transferred but remains as a transfer residual toner on the surface of the image carrier. In order to remove the transfer residual toner, a cleaning device including a cleaning blade or a cleaning brush that contacts the surface of the image carrier is used.
It is known that such a cleaning member that contacts the surface of the image carrier to remove the transfer residual toner wears the surface of the image carrier and shortens the life of the image carrier.

  Patent Document 1, Patent Document 2 or Patent Document 3 describes an image forming apparatus that applies a solid lubricant to the surface of an image carrier in order to suppress wear on the surface of the image carrier due to contact with a cleaning member. Has been.

JP-A-11-212372 JP 2007-298948 A JP 2007-219506 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lubricant supply device and an image forming apparatus that reduce the occurrence of unevenness in the amount of applied lubricant in the width direction of a lubricant supply body.

In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a solid lubricant that contacts a circumferential surface of a lubricant supply body that is a cylindrical member along a width direction, and the solid lubricant is lubricated with the solid lubricant. agent a support member for supporting the entire length in the width direction of the supplying member peripheral surface, by the action of pressing force distribution in the width direction of the peripheral surface of the lubricant supply target body to the back of the support member, the solid lubricant A pressing member that presses the agent against the peripheral surface of the lubricant supply body, and the bending rigidity of the support member is formed to be smaller than the bending rigidity of the pressing member. A lubricant supply device is provided.

  The invention according to claim 2 is the lubricant supply device according to claim 1, wherein the deformable member is deformed by a pressing force transmitted from the pressing member to the supporting member between the supporting member and the pressing member. Is arranged.

  The invention according to claim 3 is the lubricant supply device according to claim 2, wherein the deformable member is formed by superimposing two or more members formed of materials having different relationships between stress and strain. .

  According to a fourth aspect of the present invention, there is provided an image carrier in which a latent image due to a difference in electrostatic potential is formed on an endless peripheral surface, and a toner image is formed by attaching toner to the latent image on the image carrier. A developing device that transfers the toner image to a transported recording medium or intermediate transfer member, and removes toner remaining on the image carrier after the toner image is transferred by the transfer device. A cleaning device; and a lubricant supply device that is provided on the downstream side of the cleaning device in the circumferential movement direction of the peripheral surface of the image carrier, and supplies a lubricant to the peripheral surface of the image carrier, The lubricant supply device is the lubricant supply device according to any one of claims 1 to 3, and provides an image forming apparatus.

  In the lubricant supply device according to the first aspect, it is possible to reduce the occurrence of unevenness in the amount of the solid lubricant applied to the surface of the lubricant supply body, as compared with a device that does not include this configuration.

  In the lubricant supply device according to claim 2, compared to a device that does not have this configuration, the generation of vibration and the generation of vibration noise when the solid lubricant is rubbed against the surface of the lubricant supply body. Can be reduced.

  In the lubricant supply device according to the third aspect, it is possible to suppress vibrations in a wide frequency band as compared with those not provided with this configuration.

  In the image forming apparatus according to the fourth aspect, it is possible to reduce unevenness in the coating amount of the solid lubricant on the surface of the image holding member as compared with the image forming apparatus that does not include this configuration.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a lubricant supply device provided in the image forming apparatus shown in FIG. 1. FIG. 3 is a front view and a partial side view showing a solid lubricant, a support member, and a pressing member of the lubricant supply device shown in FIG. 2. It is a front view which shows the state which combined the solid lubricant, the supporting member, and the press member of the lubricant supply apparatus shown in FIG. It is a schematic perspective view which shows the holding member of the lubricant supply apparatus shown in FIG. It is the schematic which shows the state which the partial wear generate | occur | produced in the solid lubricant, and the state which the partial wear occurred.

Hereinafter, embodiments of the invention according to the present application will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.
This image forming apparatus is a full-color image including four image forming units 30Y, 30M, 30C, and 30K that output images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). Forming device. The image forming unit 30 is disposed so as to face the endless intermediate transfer belt 8 that is stretched so that the circumferential surface of the intermediate transfer belt moves in a circular manner, and sequentially outputs yellow images from the upstream side in the circumferential movement direction of the intermediate transfer belt 8. The first image forming unit 30Y for outputting, the second image forming unit 30M for outputting a magenta image, the third image forming unit 30C for outputting a cyan image, and the fourth image forming unit 30K for outputting a black image are substantially the same. Arranged at intervals.

  On the downstream side of the position where the image forming unit 30 is provided in the direction in which the peripheral surface of the intermediate transfer belt 8 moves, the secondary transfer roll 12 for performing secondary transfer faces the intermediate transfer belt 8. The recording sheet is fed from the sheet tray 21 through the conveyance path 22 to the secondary transfer portion. A fixing device 7 is provided on the downstream side of the secondary transfer portion in the recording sheet conveyance path 22 to heat and press the toner image and press the toner image onto the recording sheet. The paper is discharged to a paper discharge tray (not shown).

  Each of the image forming units 30 has a photosensitive drum 1 that functions as an image holding member on which an electrostatic latent image is formed on the surface, and around each photosensitive drum 1, A charging device 2 that charges the surface almost uniformly; a developing device 4 that selectively transfers toner to a latent image formed on the photosensitive drum to form a toner image; and a toner image on the photosensitive drum 1 A primary transfer roll 5 that primarily transfers the toner onto the intermediate transfer belt, a cleaning device 6 that removes toner remaining on the photosensitive drum after transfer, and a lubricant application device that applies a lubricant to the surface of the photosensitive drum 1. 40. Further, an exposure device 3 for writing an electrostatic latent image by irradiating each uniformly charged photosensitive drum 1 with image light based on an image signal is provided.

  The photoconductor drum 1 is formed by laminating an organic photoconductor layer on the peripheral surface of a cylindrical member made of metal, and the metal portion is electrically grounded. Further, a bias voltage may be applied.

The charging device 2 includes an electrode wire that is stretched at a predetermined interval from the peripheral surface of the photosensitive drum 1 that is a member to be charged, and a voltage is applied between the electrode wire and the photosensitive drum 1. The surface of the photosensitive drum 1 is charged by generating corona discharge.
In the present embodiment, the device for charging by corona discharge is used as described above, but a contact or non-contact charging device such as a solid discharger, a roll shape or a blade shape can also be used.

  The exposure device 3 generates a blinking laser beam based on an image signal, and scans this in the main scanning direction (axial direction) of each photosensitive drum 1 by a polygon mirror. As a result, electrostatic latent images corresponding to the images of the respective colors are formed on the surfaces of the respective photosensitive drums 1.

The developing device 4 uses a two-component developer containing toner and a magnetic carrier, and includes a developing roll 4 a at a position close to the photosensitive drum 1. The developing roll 4 a is formed with a thin layer of a two-component developer formed on a peripheral surface thereof, and rotates to convey the developer to a portion facing the photosensitive drum 1. When the photosensitive drum 1 passes through the developing position facing the developing roll 4a, the toner is electrostatically transferred to the latent image portion on the surface of the photosensitive drum 1, and development is performed.
Note that the toner consumed as a result of image formation is replenished according to the amount consumed.

  The primary transfer roll 5 is obtained by coating the outer peripheral surface of a metal core material with a conductive rubber material, and a position where the photosensitive drum 1 provided in each image forming unit 30 and the intermediate transfer belt 8 face each other. The intermediate transfer belt 8 is disposed behind the intermediate transfer belt 8. A transfer bias voltage is applied between the primary transfer roll 5 and the photosensitive drum 1 from a bias power source (not shown), and the intermediate transfer belt 8 passes through a position where the primary transfer roll 5 and the photosensitive drum 1 face each other. The toner image on the photosensitive drum is electrostatically transferred to the surface.

  The cleaning device 6 includes a cleaning member such as a cleaning brush and a cleaning blade disposed in contact with the peripheral surface of the photosensitive drum 1 and removes toner remaining on the photosensitive drum after the toner image is transferred. Is.

  The lubricant application device 40 is configured to apply a lubricant directly by bringing a solid lubricant into contact with the surface of the photosensitive drum. The lubricant application device 40 will be described in detail later.

For example, the intermediate transfer belt 8 has a surface resistivity of 10 ¹⁰ by dispersing a material for imparting conductivity such as carbon or an ion conductive material in a resin material such as polyimide, polyamideimide, polycarbonate, or fluorine resin. It is formed by adjusting to about 10 ¹² Ω / □ (measurement voltage: 100 V). And it is stretched around the drive roll 9 that is rotationally driven, the tension roll 10 that adjusts the tension, and the backup roll 11, and moves around in the direction of the arrow A shown in FIG.

The secondary transfer roll 12 is disposed so as to face the backup roll 11 with the intermediate transfer belt 8 interposed therebetween, and a secondary transfer bias voltage is applied between the secondary transfer roll 12 and the backup roll 11. The recording sheet conveyed from the sheet tray 21 is sandwiched between the secondary transfer roll 12 and the intermediate transfer belt 8, and the toner on the intermediate transfer belt 8 is placed on the recording sheet within an electric field formed by the secondary transfer bias voltage. The image is to be transferred.
A toner removing device 13 that removes toner remaining on the intermediate transfer belt 8 is provided on the downstream side of the position facing the secondary transfer roll 12.

  The fixing device 7 includes a heating roll 7a having a built-in heating source and a pressure roll 7b pressed against the heating roll 7a. These are arranged in parallel and contact each other to form a nip portion. ing. The recording sheet to which the toner image has been transferred is fed into the nip portion, and is heated and pressurized between the heating roll 7a and the pressure roll 7b that are rotationally driven, so that the toner is pressed onto the recording sheet. It has become a thing.

Next, the lubricant application device 40 will be described in detail.
As shown in FIG. 2, the lubricant application device 40 includes a zinc stearate bar 41 in which zinc stearate, which is a lubricant, is formed into a rod shape, a support member 42 that supports the zinc stearate bar 41, and a support member. 42, a pressing member 43 that contacts the back surface of 42 and presses the zinc stearate bar 41 against the surface of the photosensitive drum 1, and the zinc stearate bar 41, the support member 42, and the pressing member 43 at both ends in the axial direction. The main part is comprised by the holding member 44 to hold | maintain. Further, between the support member 42 and the pressing member 43, interposition materials 50 and 51 which are deformation members are interposed.

  The zinc stearate bar 41 is formed in a bar shape in which the powder of zinc stearate is aggregated to have a substantially rectangular cross-sectional shape, and has a length that makes contact with the image area on the photosensitive drum 1 over the entire width. Is formed. Further, as shown in FIG. 3B, the corner portions 41a on the upstream side and the downstream side of the surface that contacts the surface of the rotating photosensitive drum 1 are rounded and are easy to slide. .

The support member 42 is formed by bending a steel plate, and has a groove shape having a bottom portion 42a and side portions 42b raised from both side portions thereof. The bottom 42a is flat, and the zinc stearate bar 41 is bonded to the bottom surface of the bottom so as to be continuous in the axial direction.
The length of the support member 42 in the axial direction is slightly longer than the length of the zinc stearate bar 41 in the axial direction, and both ends of the support member 42 are stearin as shown in FIG. It protrudes from the zinc oxide bar 41.

The pressing member 43 is a solid rod-shaped member made of steel, and the cross-sectional shape is a rectangle having a long side in the vertical direction. As shown in FIG. 3A, at the end portion, a lower portion of the cross section is longer than the upper portion and becomes a protruding portion 43a protruding in the axial direction.
As shown in FIG. 4, the pressing member 43 has a lower portion fitted into a recess formed in a groove shape from above the supporting member 42, and the supporting member 42 is interposed via insertion members 50 and 51. It is arranged in contact with the bottom 42a of the. At this time, the protruding portion 43 a slightly protrudes upward from the top of the support member 42.

As shown in FIG. 2, the holding member 44 is fixedly supported by the housing of the cleaning device 6, and holds these at both ends in the axial direction of the support member 42 and the pressing member 43.
As shown in FIGS. 2 and 5, the holding member 44 includes a double box-shaped inner frame 45 and an outer frame 46, and the inner frame 45 is fitted with the press member 43 and the support member 42 fitted together. It is intended to hold the end. The outer frame 46 can move in a direction that advances and retreats with respect to the surface of the photosensitive drum 1. A spring 47 is inserted between the outer frame 46 and the inner frame 45, and the inner frame 45 and the pressing member 43 held by the spring 47 are moved by the elastic repulsive force of the spring 47 to the surface of the photosensitive drum 1. It is to be pushed to the side. As a result, the pressing force from the pressing member 43 to the supporting member 42 and the zinc stearate bar 41 bonded to the supporting member is transmitted toward the surface of the photosensitive drum 1. Therefore, regardless of the remaining amount of the zinc stearate bar 41, the zinc stearate bar 41 follows the surface of the photosensitive drum 1 and is rubbed against the surface of the photosensitive drum 1.

The insertion members 50 and 51 are interposed between the support member 42 and the pressing member 43 over almost the entire length in the axial direction. When the pressing member 43 is pressed by the spring 49 and a pressing force distributed in the axial direction acts between the pressing member 43 and the support member 42, the insertion materials 50 and 51 are moved by this pressing force. It is to be deformed.
Such insertion materials 50 and 51 are formed by laminating two kinds of materials having different relations between stress and strain, and preferably include materials made of a material exhibiting viscoelastic behavior.

In the present embodiment, the zinc stearate bar 41 is disposed in direct contact with the surface of the photosensitive drum 1 and vibrates and vibrates with the surface of the photosensitive drum 1 to generate a so-called “squeal” noise. Easy to do. In addition, vibrations having a lower frequency than the vibrations that generate abnormal noise are transmitted to the photosensitive drum 1, which may cause rotation unevenness in the photosensitive drum 1.
On the other hand, the insertion materials 50 and 51 are disposed near the position where the zinc stearate bar 41, which is a vibration generation source, comes into contact with the photosensitive drum 1, and absorbs the propagation vibration and attenuates the vibration. It has become. In addition, by interposing two types of insertion materials 50 and 51 having different characteristics between the support member 42 and the pressing member 43, it is possible to cope with a wide range of frequencies, noise, and noise of the photosensitive drum 1. Rotational unevenness is reduced efficiently.
In the present embodiment, for example, a thermosetting foam, a thermoplastic non-woven fabric, a thermoplastic foam, a natural non-woven fabric, or the like can be used. Has been.

On the other hand, the support member 42 is formed so that the bending rigidity is smaller than the bending rigidity of the pressing member 43. Further, the pressing force distributed in the axial direction from the pressing member 43 through the insertion member acts, so that the support member 42 is deformed even when the wear amount of the zinc stearate bar 41 is not uniform in the axial direction. Thus, the zinc stearate bar is brought into contact and rubbed without leaving the photosensitive drum.
The bending rigidity can be expressed by the sectional secondary moment (I) × the elastic coefficient (E) of the member. In this embodiment, the pressing member 43 is formed to have a sectional secondary moment larger than that of the support member 42. Has been.

Such an image forming apparatus operates as follows.
The surface of the rotating photosensitive drum 1 is charged by the charging device 2. Thereafter, a flashing laser beam based on the image data is output from the exposure device 3 and scanned on the surface of the photosensitive drum 1. The charged potential is attenuated at the position where the photosensitive layer is irradiated with laser light, and an electrostatic latent image due to the potential difference is formed on the surface of the photosensitive drum 1.

  The electrostatic latent image formed on the photosensitive drum 1 is conveyed to a position facing the developing roll 4a, that is, a developing position by the rotation of the photosensitive drum 1. Then, the toner adhering to the developing roll 4a is electrostatically transferred to the latent image portion where the potential is attenuated when the surface of the photosensitive drum 1 passes through the developing position, and a toner image is formed.

  The toner image developed on the surface of the photosensitive drum 1 is conveyed to a primary transfer position facing the intermediate transfer belt 8 by the rotation of the photosensitive drum 1. At the primary transfer position, a transfer bias voltage is applied between the primary transfer roll 5 and the photosensitive drum 1, and the toner image on the surface of the photosensitive drum is transferred to the surface of the intermediate transfer belt 8. At this time, the transfer bias voltage applied to the primary transfer roll 5 has the polarity (−) opposite to the polarity (+) of the toner. For example, in the first image forming unit 30Y, constant current control is performed to about +20 to 30 μA.

  The intermediate transfer belt 8 is driven to rotate and is sequentially conveyed to a position facing the image forming units 30M, 30C, and 30K, and the toner images of the respective colors are superimposed and transferred. The intermediate transfer belt 8 on which the toner images of all colors are transferred in multiple directions moves in the direction of arrow A shown in FIG. 1, and the toner image is transferred between the backup roll 11 and the secondary transfer roll 12 via the intermediate transfer belt 8. To the opposing secondary transfer position.

Accordingly, the recording sheet conveyed from the sheet tray 21 via the conveyance path 22 is fed at a predetermined timing between the secondary transfer roll 12 and the intermediate transfer belt 8, and the surface of the intermediate transfer belt 8 is The toner image is transferred to the recording sheet.
Thereafter, the recording sheet is fed into the fixing device 7 and the toner image is heated and pressurized. As a result, the color-superposed toner images are fixed on the surface of the recording sheet, and the recording sheet is carried out toward the discharge unit.

  On the other hand, the toner remaining on the surface of the photosensitive drum 1 after the toner image is transferred is removed by the cleaning device 6. On the downstream side of the position where the cleaning device is provided, the surface of the photosensitive drum 1 is in contact with a zinc stearate bar 41 as a lubricant, and the zinc stearate is applied as the photosensitive drum 1 rotates. The

  The zinc stearate bar 41 is pressed against the surface of the photosensitive drum 1 and rubbed by the elastic repulsion force of the spring 47 transmitted through the pressing member 43, the interposing materials 50 and 51, and the support member 42. At this time, as shown in FIG. 6A, the sliding resistance between the zinc stearate bar 41 and the photosensitive drum 1 may vary depending on the position in the axial direction. Further, rattling may occur in the held portion due to manufacturing errors of members, contamination of foreign matters, and the like, and the posture in which the zinc stearate bar 41 contacts the photosensitive drum 1 may change. Thus, when there is a change in posture and a difference in sliding resistance, the amount of lubricant applied to the photosensitive drum 1 in the axial direction of the zinc stearate bar 41 changes. And as shown in FIG.6 (b), uneven wear arises and the residual amount of the zinc stearate bar 41 becomes non-uniform | heterogenous in an axial direction.

  In the present embodiment, since the pressing member 43 and the supporting member 42 are supported at both ends in the axial direction via the springs 49, the zinc stearate bar is used even in a portion with a large amount of wear as shown in FIG. 41 contacts the surface of the photosensitive drum. In addition, the portion where the wear amount is small has a greater pressing force than the portion where the wear amount is large, and the amount of coating on the surface of the photosensitive drum 1 increases. This promotes wear and acts to eliminate uneven wear.

  Further, even if the contact surface of the zinc stearate bar 41 with the photosensitive drum is slightly curved due to uneven wear on the zinc stearate bar 41, the bending rigidity of the support member 42 is reduced by bending the pressing member 43. Since it is formed to be smaller than the rigidity, the support member 42 and the zinc stearate bar 41 are deformed and contact the photosensitive drum 1 continuously in the axial direction. As a result, it is possible to supply zinc stearate as a lubricant to almost the entire width of the photosensitive drum 1.

Further, vibration is generated by friction when the zinc stearate bar 41 comes into contact with the surface of the photosensitive drum 1. This vibration is from a high frequency that generates an abnormal sound called so-called squeal, and a low frequency vibration that repeatedly causes bending deformation in the circumferential direction of the photosensitive drum 1 on the support member 42 and the zinc stearate bar 41. included.
In the present embodiment, the interposing materials 50 and 51 are arranged near the portion where the zinc stearate bar 41 that is a vibration source contacts the photosensitive drum 1, and absorbs vibration or attenuates vibration. This suppresses the propagation of vibration and attenuates the vibration with respect to the vibration of a wide frequency band, thereby suppressing abnormal noise and suppressing the occurrence of rotation unevenness of the photosensitive drum 1.

In the image forming apparatus described above, a two-component developer is used, but a one-component developer can also be used.
In the present embodiment, two types of insertion materials are stacked, but one type may be used, or two or more types may be used. However, in order to efficiently suppress abnormal noise caused by vibration of the zinc stearate bar and rotation unevenness of the photosensitive drum, it is desirable to reduce vibration of a wide frequency band, and it is made of a plurality of materials having different properties. It is preferable to interpose the insertion material between the support member 42 and the pressing member 43.

1: Photosensitive drum, 2: Charging device, 3: Exposure device, 4: Developing device, 5: Primary transfer roll, 6: Cleaning device, 7: Fixing device, 8: Intermediate transfer belt, 9: Drive roll, 10: Tension roll, 11: backup roll, 12: secondary transfer roll, 13: toner removing device,
21: Sheet tray, 22: Transport path,
30: Image forming unit,
40: Lubricant coating device, 41: Zinc stearate bar, 42: Support member, 43: Press member, 44: Holding member, 45: Inner frame, 46: Outer frame, 47: Spring,
50, 51: Insertion material

Claims (4)

A solid lubricant that contacts the circumferential surface of the lubricant supply body, which is a cylindrical member, along the width direction;
A support member for supporting the solid lubricant over the entire length of the circumferential surface of the lubricant supply body;
A pressing member that applies a pressing force distributed in the width direction of the peripheral surface of the lubricant supply body to the back surface of the support member, and presses the solid lubricant against the peripheral surface of the lubricant supply body; and Have
The lubricant supply device is characterized in that the bending rigidity of the support member is formed to be smaller than the bending rigidity of the pressing member.   The lubricant supply device according to claim 1, wherein a deformation member that is deformed by a pressing force transmitted from the pressing member to the supporting member is disposed between the supporting member and the pressing member. .   The lubricant supply device according to claim 2, wherein the deformable member is formed by superposing two or more members formed of materials having different relationships between stress and strain. An image carrier in which a latent image due to a difference in electrostatic potential is formed on an endless peripheral surface;
A developing device for forming a toner image by attaching toner to the latent image on the image carrier;
A transfer device for transferring the toner image to a transported recording medium or intermediate transfer member;
A cleaning device for removing toner remaining on the image carrier after the toner image is transferred by the transfer device;
A lubricant supply device provided on the downstream side of the cleaning device in the circumferential movement direction of the peripheral surface of the image carrier, and supplying a lubricant to the peripheral surface of the image carrier;
Have
The image forming apparatus according to claim 1, wherein the lubricant supply device is the lubricant supply device according to claim 1.

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