JP2008046194A - Lubricant supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant supply device capable of stably supplying a lubricant to an image carrier even with the lapse of time without wastefully using space and lubricant, and an image forming apparatus using the same. <P>SOLUTION: The lubricant supply device includes a rotating brush roller for supplying the solid lubricant to the image carrier while abutting on the surface of the image carrier and the solid lubricant, and holds the solid lubricant by pressuring and energizing the solid lubricant to the surface of the rotating brush roller so that the abutting surface of the solid lubricant may be inclined at a predetermined angle θ toward the upstream side of the rotating brush roller at such a time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubricant supply device, and more specifically, is used in an image forming apparatus such as an electrophotographic system or an electrostatic recording system in a printing apparatus, a printer, a copying machine, etc., and lubricates the surface of an image carrier. The present invention relates to a lubricant supply device for supplying an agent.

Generally, a lubricant supply device to a photoconductive drum of an image forming apparatus includes a rotating brush roller that contacts a solid lubricant and a photoconductor surface, scrapes the lubricant, and supplies the lubricant to the photoconductor surface (for example, , See Patent Document 1).
In the conventional lubricant supply device, the solid lubricant is pressed and brought into contact with the brush roller surface as it is to be rubbed. In this case, the lubricant is consumed only on the upstream side in the rotational direction of the brush roller that comes into contact with it, and the downstream side in the rotational direction is hardly consumed, and most of it remains without being consumed even at the end of the life of the image forming apparatus. In consideration of the amount of lubricant remaining on the downstream side in the rotational direction, it is necessary to set the total amount of lubricant to be greater than the amount of lubricant necessary for performance. Therefore, with regard to the installation method of the solid lubricant from such a problem, the lubricant and the lubricant pressure member are arranged on the upstream side in the rotation direction with respect to the radial direction of the rotation axis of the brush roller so as to be in contact with the brush roller in a plane. The method of installing in is proposed (for example, refer patent document 2).

However, in the configuration as described above, it is difficult to eliminate the remaining shavings, and a space for moving the lubricant and the lubricant pressing member is required on the upstream side of the brush roller, leading to an increase in the size of the process cartridge. There's a problem.
JP 56-142567 A Japanese Patent Laid-Open No. 2002-268397

  In view of the above-described problems, the present invention provides a lubricant supply device that can stably supply a lubricant to an image carrier without using a useless space and useless lubricant and over time, and the same. An image forming apparatus used is provided.

The present inventor simply changes the state in which the solid lubricant is attached while the solid lubricant and the related member are arranged in the radial direction from the central axis of the brush roller, that is, the contact surface of the solid lubricant is changed in advance. By providing the measured predetermined angle θ at an angle, there is no need for useless space for moving each member, lubricant can be consumed evenly on the upstream and downstream sides, and the image can be carried over time. The present inventors have found that a stable lubricant can be supplied to the body and solve the above problems.
That is, the present invention is characterized by the following configuration or structure.

(1) A lubricant supply device comprising a rotating brush roller that contacts the surface of an image carrier and a solid lubricant and supplies the solid lubricant to the image carrier, and the solid lubricant is supplied in the axial direction of the rotating brush roller. The solid lubricant is held so that the contact surface of the solid lubricant is inclined at a predetermined angle θ toward the upstream side of the rotating brush roller. Lubricant supply device.
(2) A holding member that holds the solid lubricant so as to be inclined at the angle θ is provided, the holding member is provided in parallel along the axial direction of the rotating brush roller, and both ends of the holding member are respectively provided with the rotating brush. The lubricant supply device according to (1), wherein the lubricant supply device is supported by a guide member that is reciprocally guided in a radial direction of a roller shaft.
(3) A slide member that slides the guide member is provided, both ends of the holding member are supported by the guide member via the slide member, and the holding member is slid so that the solid lubricant is inclined at an angle θ. The lubricant supply device according to (2), wherein the slide member is attached to the member and the slide member is pressed and urged toward the shaft of the rotating brush roller by the pressure member.

(4) The lubricant supply device according to (1), wherein a contact surface between the rotating brush roller and the solid lubricant is a curved surface having a predetermined width in the rotation direction of the brush roller.
(5) The lubricant supply device according to (1), further comprising a toner intrusion prevention member that prevents toner from entering the roller surface upstream of the contact surface between the brush roller and the solid lubricant.
(6) The lubricant supply according to (1), further comprising a toner discharge member that is disposed on a roller upstream of a contact surface between the brush roller and the solid lubricant and discharges clogged toner in the brush roller. apparatus.
(7) An image forming apparatus having an intermediate transfer member, comprising the lubricant supply device described in (1) to (6) above.

According to the lubricant supply device according to the configurations of (1) to (3) of the present invention, the solid lubricant tends to flow in the rotation direction and tilt when the brush roller rotates. In this case, due to the inclination of the angle θ of the solid lubricant, the substantially central portion of the contact surface of the solid lubricant is positioned on the normal line of the brush roller. For this reason, it becomes possible to consume solid lubricant equally upstream and downstream. The solid lubricant can also be reduced to the minimum size required for performance without waste, and the cleaner unit including the lubricant supply device and the process cartridge can be expected to be miniaturized.
Further, when the solid lubricant is tilted to the upstream side with respect to the rotation direction of the brush roller, the slide member that slides in the radial direction of the shaft of the rotary brush roller is given a tilt of the solid lubricant. There is no need to install it on the upstream side, and the space required for it can be omitted, and the process cartridge can be reduced in size.

In addition, according to the lubricant supply device according to the configuration of (4) of the present invention, when the contact surface of the solid lubricant is a curved surface in advance, it is possible to suppress the initial peak consumption of the lubricant. Thus, it is possible to eliminate the excessive supply to the image carrier and to supply the lubricant stably throughout.
According to the lubricant supply device according to the configuration of (5) of the present invention, the inside of the device is prevented from being filled with toner. It is possible to stabilize the contact pressure to the brush roller and to stabilize the lubricant supply amount.
According to the lubricant supply device according to the configuration (6) of the present invention, the brush roller rubs the solid lubricant in a constantly refreshed state, so that the lubricant supply amount can be stabilized.
According to the image forming apparatus according to the configuration of (7) of the present invention, since the lubricant supply device as described above, the cleaner unit including the lubricant supply device, and the process cartridge are used, the surface of the image carrier is removed. Improves releasability from toner. Thereby, the transfer property to the intermediate transfer member in the image forming apparatus is improved, and a good image quality can be obtained.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows an example of an embodiment of an image forming apparatus according to the present invention. FIGS. 2 and 3 show an example of an embodiment of a lubricant supply apparatus according to the present invention used in an image forming apparatus.

As shown in FIG. 1, the image forming apparatus A forms multicolor and single color images on a predetermined sheet (recording paper) in accordance with image data transmitted from the outside. The image forming apparatus A includes an exposure unit 1, a developing unit 2, a photosensitive drum 3, a charger 5, a cleaner unit 4, a transfer conveyance belt unit 8, a secondary transfer roller 11, a fixing unit 12, a sheet conveyance path S, a supply unit. The paper tray 10 and the paper discharge tray 15 are configured.
Note that image data handled in the image forming apparatus A corresponds to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y). Accordingly, the exposure unit 1, the developing device 2 (2a, 2b, 2c, 2d), the photosensitive drum 3 (3a, 3b, 3c, 3d), the charger 5 (5a, 5b, 5c, 5d), the cleaner unit 4 ( 4a, 4b, 4c, and 4d) are provided in each of four types so as to form four types of latent images corresponding to the respective colors, a being black, b being cyan, c being magenta, and d being yellow. Four image stations are configured.

The photosensitive drum 3 is disposed (attached) at substantially the center of the image forming apparatus A. The charger 5 is a charging unit for uniformly charging the surface of the photosensitive drum 3 to a predetermined potential. As the charging means, in addition to a charger-type or brush-type charger, a contact-type roller-type charger as shown in FIG. 1 is used. The exposure unit 1 uses a laser scanning unit (LSU) in which light emitting elements are arranged in an array, for example, an EL or LED writing head, a laser irradiation unit, and a reflection mirror.
By exposing the charged photosensitive drum 3 according to the input image data, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 3. The developing device 2 visualizes the electrostatic latent images formed on the respective photosensitive drums 3 with toner (K, C, M, Y). The cleaner unit 4 scrapes and removes / recovers toner remaining on the surface of the photosensitive drum after development / image transfer using a cleaning blade 46. Further, the lubricant which is one of the embodiments for supplying the lubricant to the surface of the photosensitive drum 3 using the solid lubricant 41 (41a, 41b, 41c, 41d) disposed in the cleaner unit 4 is provided. It also serves as the supply device 40.

Next, the cleaner unit 4 including the lubricant supply device 40 will be described in detail with reference to FIGS. 2 and 3.
The toner remaining on the surface of the photosensitive drum 3 is removed and collected by a cleaning blade 46 and is discharged out of the unit by a toner conveying screw 48.
The lubricant supply device 40 includes a rotating brush roller 42 that contacts the surface of the photosensitive drum 3 and the solid lubricant 41 and supplies the solid lubricant 41 to the photosensitive drum 3. The lubricant supply device 40 presses and urges the solid lubricant 41 in the axial direction of the brush roller 42. At that time, the solid lubricant 41 is so solid that the contact surface of the solid lubricant 41 is inclined at a predetermined angle θ toward the upstream side direction (direction a in FIG. 2) of the brush roller 42 (direction b in FIG. 2). The lubricant 41 is held.

  Specifically, a holder (holding member) 45 that holds the solid lubricant 41 so as to be inclined at the angle θ is provided. The holder 45 is provided in parallel along the axial direction of the brush roller 42 (the front-rear direction of the paper surface of FIG. 2). Each end of the holder 45 is supported by a guide member (guide member) 43 that guides the brush roller 42 so that it can reciprocate in the radial direction of the shaft.

Further, in this case, the guide member 43 may directly support the holder 45. However, in order to facilitate assembly and the like, the guide member 43 has a slider (sliding member) 44 as shown in FIGS. It is preferable to support the holder 45 via.
For example, a slider (sliding member) 44 that slides the guide member 43 is provided, both ends of the holder 45 are supported by the guide member 43 via the slider 44, and the solid lubricant 41 is inclined at an angle θ. The holder 45 is attached to the slider 44, and the slider 44 is pressed and urged toward the shaft of the rotating brush roller 42 by a compression coil spring (pressure member) 47.
In order to incline the solid lubricant 41 at an angle θ, the surface of the slider 44 may be inclined as shown in FIG. 3, or the surface of the holder 45 may be inclined, although not shown. .

More specifically, the lubricant supply device 40 includes a brush roller 42 adjacent to the photosensitive drum 3. The brush roller 42 is a roll brush having a diameter of 16 mm, in which polyester fibers formed in a loop shape having a bristle length of 5 mm are laid on the outer periphery of a stainless steel core bar having a diameter of 6 mm. Then, both end shafts of the brush roller 42 are appropriately rotatably supported and arranged parallel to the shaft of the photosensitive drum 3, and the brush roller 42 is rotatable with the front end of the polyester fiber contacting the surface of the photosensitive drum 3. Provided. The brush roller 42 is always in contact with the photosensitive drum 3 and itself removes and collects toner remaining on the surface of the photosensitive drum 3. In addition, it has a role to promote toner separation so that the cleaning blade 46 can be easily scraped off.
A solid lubricant 41 is disposed on the outer periphery in the radial direction of the brush roller 42. As the solid lubricant 41, one formed by melting a material containing zinc stearate as a main component and then cooling and solidifying it to form a horizontally long plate is used.

  The guide member 43 guides the solid lubricant 41 from the radial direction of the brush roller 42 toward the central axis. The solid lubricant 41 is fixed to the holder 45. Sliders 44 are provided at both ends of the holder 45, and the slider 44 is movable on the guide member 43 in a direction in which the solid lubricant 41 is in contact with the brush roller 42. Further, the slider 44 is provided with an angle θ so that the solid lubricant 41 is inclined upstream with respect to the rotation direction of the brush roller 41. The angle θ is preferably at least 5 degrees or more, more preferably in the range of 5 to 15 degrees, although it depends on the properties of the solid lubricant 41 in order to obtain a substantial effect. The solid lubricant 41 is pressed and urged against the surface of the brush roller 42 with a constant load by the compression spring 47 disposed on the back surface of the holder 45.

With such a configuration, the fine particles of the solid lubricant 41 scraped off by rubbing with the brush roller 42 are conveyed by the brush roller 42. 25 to 40 μg of lubricant per sheet (recording paper) is supplied to the photosensitive drum 3.
Here, in the conventional case, when the solid lubricant 41 is scraped off by the rubbing of the brush roller 42, the solid lubricant is inclined unintentionally in the rotation direction of the brush roller 42. For this reason, only the upstream side of the brush roller 42 with which the solid lubricant 41 abuts is consumed, and the downstream side in the rotational direction is hardly consumed, and most of it remains without being consumed even at the end of life of the image forming apparatus A.
On the other hand, in the lubricant supply device 40, the solid lubricant 41 is tilted upstream in the rotation direction of the brush roller 42 in advance, so that the center of the solid lubricant 41 is the center of the brush roller 42 during rotation. It matches the axis and can be contacted and consumed evenly over the entire width of the contact surface.

  In addition, since the solid lubricant 41 is inclined with respect to the slider 44, the solid lubricant 41 can be tilted while the guide member 43 is disposed in the radial direction of the central axis of the brush roller 42. Thereby, there is no need for an extra space for moving the guide 43 upstream, and the cleaner unit can be downsized, that is, the process cartridge can be downsized.

  As shown in FIG. 2, a toner shield 49 is disposed on the upstream side of the contact surface of the brush roller 42 with the lubricant 41. Without the toner shield, the toner enters the periphery of the member related to the lubricant supply such as the solid lubricant 41 and the holder 45. For this reason, the solid lubricant 41 is prevented from being pressed against the brush roller 42, and a large amount of toner is present on the sliding contact surface of the lubricant 41. As shown in the wavy line graph of FIG. 4, the lubricant supply amount decreases and becomes unstable. In such a case, as shown in the solid line graph of FIG. 4, the toner shield 49 prevents the intrusion of the toner and stabilizes the lubricant supply amount.

Further, a flicker (toner discharging member) 50 is disposed on the upstream side of the contact surface of the brush roller 42 with the solid lubricant 41.
As described above, the brush roller 42 itself removes and collects the toner remaining on the surface of the photosensitive drum 3. Further, it has a role of facilitating scraping on the cleaning blade 46 side or promoting toner peeling. For this reason, it is placed in an environment where it is always in contact with the toner, and toner clogging tends to occur in the brush roller 42 over time. For this reason, the toner removal / recovery ability on the surface of the photosensitive drum 3 is lowered, causing the toner to slip through and the supply amount of the lubricant to be lowered as shown in the one-dot chain line graph of FIG.
In such a case, in the embodiment, the flicker 50 is always provided at a position in contact with the brush roller 42 and scrapes and discharges the toner accumulated in the brush roller 42. For this reason, as shown in the solid line graph of FIG. 4, the brush roller 42 always maintains the same function as the initial stage.

As described above, the solid lubricant 41 is formed in a horizontally long plate shape extending in the front-rear direction of the paper surface of FIG. Usually, 25 to 40 μg of fine particles of lubricant per sheet (recording paper) is supplied to the photosensitive drum 3.
In this case, if the sliding contact surface of the solid lubricant 41 is a flat surface, the contact area with the brush roller 42 is small and the surface pressure is high. Therefore, the lubricant 41 is excessively consumed and supplied until the shape of the solid lubricant 41 conforms to the outer peripheral shape of the brush roller 42, that is, at a relatively early stage (see the wavy line graph in FIG. 5). . This causes a reduction in image quality due to toner scattering during transfer, which is a subsequent process. On the other hand, in the embodiment, the contact surface of the solid lubricant 41 with the brush roller 42 is formed on a curved surface that matches the shape of the outer periphery of the brush roller 42, so that the solid line graph of FIG. As described above, it is possible to suppress the initial excessive consumption and supply, and to provide a stable supply throughout.

  As the solid lubricant 41, in addition to the zinc stearate, barium stearate, lead stearate, nickel stearate, cobalt stearate, iron stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, stearin Magnesium oxide, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate Relatively higher fatty acids such as lead cabrylate, lead cabronate, zinc linolenate, cobalt linolenate, cadmium linolenate can be used. Also, natural wax such as colloidal high-temperature silica powder or carnauba wax can be used.

As shown in FIG. 1, the image forming apparatus A may include an intermediate transfer member.
The transfer conveyance belt unit 8 disposed below the photosensitive drum 3 includes a transfer belt 7, a transfer belt driving roller 71, a transfer belt tension roller 73, a transfer belt driven roller 72, and a transfer roller 6 (6a, 6b, 6c, 6d) and a transfer belt cleaning unit 9.
The transfer belt driving roller 71, the transfer belt tension roller 73, the transfer roller 6, the transfer belt driven rollers 72, 74, and the like stretch the transfer belt 7 and rotate the transfer belt 7 in the direction of arrow B.

  The transfer roller 6 provides a transfer bias for transferring the toner image on the photosensitive drum 3 onto the transfer belt 7. The transfer belt 7 is provided so as to be in contact with each photosensitive drum 3. Each color toner image formed on the photosensitive drum 3 has a function of forming a color toner image (multicolor toner image) by sequentially superimposing and transferring the toner image on the transfer belt 7. This transfer belt is formed endlessly using a film having a thickness of about 100 μm to 150 μm.

  The transfer of the toner image from the photosensitive drum 3 to the transfer belt 7 is performed by the transfer roller 6 in contact with the back side of the transfer belt 7. A high voltage transfer bias (a high voltage having a polarity (+) opposite to the toner charging polarity (−)) is applied to the transfer roller 6 in order to transfer the toner image. At this time, the transfer efficiency when no lubricant was supplied was 94%, and the phenomenon of missing characters was also observed. On the other hand, when the lubricant was supplied, the transfer efficiency was improved up to 98%, and the character omission was improved.

The transfer roller is a roller whose base is a metal (for example, stainless steel) shaft having a diameter of 8 to 10 mm and whose surface is covered with a conductive elastic material (for example, EPDM, urethane foam, or the like). With this conductive elastic material, a high voltage can be uniformly applied to the transfer belt 7. In this embodiment, the transfer roller 6 is used as the transfer electrode, but a brush or the like is also used.
Further, the toner adhering to the transfer belt 7 due to contact with the photosensitive drum 3 is set to be removed and collected by the transfer belt cleaning unit 9 in order to cause the back surface of the recording paper to become dirty. In the transfer belt cleaning unit 9, for example, a cleaning blade is used as a cleaning member that contacts the transfer belt 7.

That is, the color toner image (multi-color toner image) transferred onto the transfer belt 7 is conveyed by the transfer belt 7 and is transferred between the transfer belt driving roller 71 and the secondary transfer roller 11 together with the conveyed sheet (recording paper). Pass through. The secondary transfer roller 11 is for transferring the toner image transferred onto the transfer belt 7 to a sheet (recording paper).
The paper feed tray 10 and the manual paper feed tray 20 are trays for storing sheets (recording paper) used for image formation, and are provided below the image forming unit of the image forming apparatus A. The paper discharge tray 15 provided on the upper part of the image forming apparatus A is a tray for placing printed sheets face down.

  The image forming apparatus A is provided with a paper transport path S for sending the sheets in the paper feed tray 10 to the paper discharge tray 15 via the transfer transport unit 8 and the fixing unit 12. In the vicinity of the paper transport path S from the paper feed tray 10 and the manual paper feed tray 20 to the paper discharge tray 15, a pickup roller 16, a registration roller 14, a fixing unit 12, a transport roller 25 for transporting a sheet, and the like are arranged. .

  A plurality of conveyance rollers 25 are provided along the sheet conveyance path S, and promote and assist the conveyance of the sheet. The pickup roller 16 is a draw-in roller that is disposed at the end of the paper feed tray 10 and supplies sheets from the paper feed tray 10 to the paper transport path S one by one. The registration roller 14 temporarily holds the sheet being conveyed on the sheet conveyance path S. The registration roller 14 has a function of conveying the sheet in a timely manner in accordance with the rotation of the transfer belt 7 so that the toner image on the transfer belt 7 can be satisfactorily transferred onto the sheet. That is, the registration roller 14 conveys the sheet so that the leading edge of the toner image on the transfer belt 7 is aligned with the leading edge of the image forming range on the sheet based on a detection signal output from a pre-registration detection switch (not shown). Is set.

The fixing unit 12 includes a heat roller 31, a pressure roller 32, and the like. The heat roller 31 and the pressure roller 32 rotate with the sheet interposed therebetween. The heat roller 31 is set to a predetermined fixing temperature by the control unit based on a signal from a temperature detector (not shown). The heat roller 31 thermocompresses the sheet together with the pressure roller 32. The sheet on which the multicolor toner image has been fixed is conveyed to the reverse paper discharge path of the paper conveyance path S by the conveyance roller 25, and in a reversed state (with the multicolor toner image facing downward), the paper discharge tray 15 Discharged to the top.
It should be noted that the image forming apparatus A and the lubricant supply device 40 of the present invention are not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention. .

  INDUSTRIAL APPLICABILITY The lubricant supply device and the image forming apparatus according to the present invention can be used in an industrial manner capable of stably supplying a lubricant to an image carrier without using a useless space and useless lubricant and over time. It is highly possible.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows the structure of the cleaner unit (lubricant supply apparatus) which concerns on embodiment of this invention. It is a disassembled perspective view of the principal part of the lubricant supply apparatus shown in FIG. FIG. 6 is a line graph showing the amount of lubricant consumed per page with respect to the number of printed sheets in the image forming apparatus with and without toner shield and flicker. FIG. 5 is a line graph showing the amount of lubricant consumed per page with respect to the number of printed sheets in the image forming apparatus in the shape change of the contact surface of the solid lubricant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Photosensitive drum 4 Cleaner unit 40 Lubricant supply apparatus 41 Solid lubricant 42 Rotary brush roller 43 Guide member 44 Slider 45 Holder 47 Compression coil spring 49 Toner shield 50 Flicker

Claims (7)

  A lubricant supply device including a rotating brush roller that contacts a surface of an image carrier and a solid lubricant and supplies the solid lubricant to the image carrier, and directs the solid lubricant in an axial direction of the rotating brush roller. Lubricant characterized by holding the solid lubricant so that the contact surface of the solid lubricant is inclined at a predetermined angle θ toward the upstream side of the rotating brush roller. Feeding device.   A holding member that holds the solid lubricant so as to be inclined at the angle θ, the holding member is provided in parallel along the axial direction of the rotating brush roller, and both ends of the holding member are provided on the shaft of the rotating brush roller; The lubricant supply device according to claim 1, wherein the lubricant supply device is supported by a guide member that is reciprocally guided in a radial direction.   A slide member that slides the guide member is provided, and both ends of the holding member are supported by the guide member via the slide member, and the holding member is attached to the slide member so that the solid lubricant is inclined at an angle θ. The lubricant supply device according to claim 2, wherein the slide member is pressed and urged toward the shaft of the rotating brush roller by the pressure member.   2. The lubricant supply device according to claim 1, wherein a contact surface between the rotating brush roller and the solid lubricant is a curved surface having a predetermined width in the rotation direction of the brush roller.   The lubricant supply device according to claim 1, further comprising a toner intrusion prevention member that prevents toner from entering a roller surface upstream of a contact surface between the brush roller and the solid lubricant.   2. The lubricant supply device according to claim 1, further comprising a toner discharge member that is disposed on a roller upstream of a contact surface between the brush roller and the solid lubricant and discharges clogged toner in the brush roller. An image forming apparatus having an intermediate transfer member, comprising the lubricant supply device according to claim 1.

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