JP2006184766A - Lubricant feeder, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant feeder which prevents lubricant pressurizing force from changing with the lapse of time, without increasing the size of the lubricant feeder, a process cartridge, and an image forming apparatus. <P>SOLUTION: The lubricant feeder 50 comprises a solid lubricant 51, coil springs 52, and a lubricant support plate 53. The lubricant support plate 53 supports the solid lubricant 51. The coil springs 52 are provided respectively at both ends in the long side direction of the lubricant support plate 53, and the solid lubricant 51, supported at the lubricant support plate 53, is pressurized against a photoreceptor and an intermediate transfer member by the restoring force of the coil springs 52. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lubricant supply device, a process cartridge, and an image forming apparatus, and more particularly to a lubricant supply device, a process cartridge, and an image forming apparatus that supply a lubricant to a photosensitive member and an intermediate transfer member of an image forming apparatus.

  In an image forming apparatus using an electrostatic copying method, a toner image is formed by developing an electrostatic latent image formed on the surface of a photoreceptor through a charging process and an exposure process using a developing device, and the toner image is formed on a recording sheet. The image forming process is performed by transferring. The transfer process includes a direct transfer method in which transfer is performed directly from a photoconductor to a recording sheet, and an intermediate transfer method in which transfer is performed indirectly via an intermediate transfer member.

  In this transfer process, the toner that has not been transferred from the photosensitive member to the recording paper or intermediate transfer member remains on the photosensitive member. Further, in the case of the intermediate transfer method, the toner that has not been secondarily transferred to the recording paper remains on the intermediate transfer member.

  When such residual toner is laminated, a filming layer is formed, transfer performance is lowered, and image quality is deteriorated.

  Therefore, a blade cleaning type cleaning device that scrapes off the toner after transfer by pressing the edge of the urethane rubber blade against the surface of the photoconductor or intermediate transfer body, or a bristle brush is brought into contact with the surface of the photoconductor or intermediate transfer body. The residual toner on the photosensitive member and the intermediate transfer member is removed by a fur brush cleaning type cleaning device that scrapes off the toner after transfer.

  However, when a minute amount of toner or toner melted by heat, pressure, or the like remains on the photosensitive member or the intermediate transfer member, it is difficult to completely remove the remaining toner only with the cleaning device.

  Therefore, a lubricant supply device that applies a lubricant to the photosensitive member or the intermediate transfer member is used.

  By applying a lubricant to the photoconductor or intermediate transfer body using a lubricant supply device, the coefficient of friction on the surface of the photoconductor or intermediate transfer body is reduced, so the adsorption force acting on the toner can be reduced. This makes it possible to improve the cleaning efficiency. Further, since a lubricant is applied and scraped off by a cleaning device, an effect that the photosensitive member and the intermediate transfer member are always refreshed can be obtained. Further, since the residual toner is reduced, the transfer performance of the photosensitive member and the intermediate transfer member can be maintained at a high level.

  A conventional lubrication supply apparatus will be described with reference to FIG. FIG. 9 shows a configuration of a process cartridge (image forming unit) provided with a lubricant supply device. The process cartridge includes a photoconductor 10, a charging roller 11, a developing device 20, a cleaning device 30, and a lubricant supply device 40. The developing device 20 includes a developer carrier 21 and a developer container 22. The cleaning device 30 includes a cleaning blade 31 and a space for storing waste toner removed from the photoreceptor 10. The lubricant supply device 40 includes a brush roller 41, a solid lubricant 42, a coil spring 43, and a lubricant support plate 44.

  A desired electrostatic latent image is formed on the photoreceptor 10 uniformly charged by the charging roller 11 by an exposure device. The developing device 20 conveys each color toner accommodated in the developer accommodating container 22 to the photoreceptor 10 by the developer carrier 21, and visualizes the electrostatic latent image on the photoreceptor 10 to form a toner image. The toner image is transferred onto a recording sheet. After the transfer, residual toner remaining on the photoconductor 10 is cleaned by the cleaning device 30. In the lubricant supply device 40, the coil spring 43 pressurizes the solid lubricant 42 on the lubricant support plate 44 in the direction of the brush roller 41, and the lubricant is supplied to the surface of the photoreceptor 10 by the rotation of the brush roller 41. Is done.

  The following technologies have been proposed for such a lubricant supply device.

  In Patent Document 1, in a lubricant supply device that applies a lubricant onto a photoconductor with an application brush, the solid lubricant and the application brush are stabilized by providing a direction regulating member and a direction biasing means for the solid lubricant. A technique has been proposed in which the solid lubricant can be uniformly applied onto the photosensitive member.

  In Patent Document 2, in addition to the application brush (fur brush), a grinding roller that removes the lubricity imparting agent and a bias roller that removes toner adhering to the fur brush are provided in the lubricant supply device. A technique capable of applying a lubricity imparting agent without damaging the surface has been proposed.

  In Patent Document 3, a lubricant film forming means for forming a film made of a lubricant on the surface of the photoreceptor is provided, and the lubricant film forming means is provided on the surface of the photoreceptor through an application roller and the cleaning brush. There has been proposed a technique for extending the life of the lubricant by providing a moving mechanism that is configured to be applied to the surface and capable of contacting and separating the lubricant and the application roller.

  Further, in Patent Document 4, in an intermediate transfer type image forming apparatus, the solid lubricant is pressed onto the surface of the transfer roller by a solid lubricant pressurizing unit that pressurizes the solid lubricant at a plurality of locations. Techniques that enable uniform application have been proposed.

Further, in Patent Document 5, an appropriate value of the lubricant application amount is achieved by rotating the cam based on the result of detecting the photoreceptor surface temperature by the thermistor and changing the pressure of the lubricant by the compression spring. Techniques have been proposed to increase the margin for poor cleaning at high temperatures.
JP 2000-172118 A JP 09-81005 A Japanese Patent No. 3342613 JP 2002-174960 A JP 09-138622 A

  However, the above-described invention has the following problems.

  The technique described in Patent Document 4 is a technique for applying a lubricant to the intermediate transfer roller, and the conditions and shape when using the technique are limited.

  Further, in the techniques of Patent Documents 1, 2, 3, and 5, a coil spring is used as a spring that supports the lubricant and applies an applied force. However, when the lubricant is pressed by the coil spring, the lubricant is worn. The spring length changes and the lubricant pressure decreases with time. If the applied pressure decreases, the proper amount of lubricant applied will be affected. If the lubricant is not properly applied, it will be difficult to improve the cleaning efficiency, and the transfer performance of the photoreceptor and intermediate transfer member will be high. Can no longer be kept.

  Here, as a technique for preventing the lubricant pressure from being changed in the lubricant supply device using the coil spring, there is one that reduces the spring constant by making the spring length as long as possible. Will become larger.

  The present invention has been proposed in view of the above problems, and provides a lubricant supply device, a process cartridge, and an image forming apparatus in which the lubricant pressure does not change over time without increasing the size of the lubricant supply device. The purpose is to do.

  The invention according to claim 1 is a lubricant supply device for applying the solid lubricant to the image carrier by press-contacting the solid lubricant to the rotationally driven image carrier, and supporting the solid lubricant. A lubricant supply device comprising: a support member; and a mainspring spring provided at both ends of the lubricant support member, wherein the solid lubricant is brought into pressure contact with the image carrier by a restoring force of the mainspring spring. is there.

  According to a second aspect of the present invention, there is provided a lubricant supply device for applying a solid lubricant to an image carrier via an application member that is driven to rotate, a lubricant support member that supports the solid lubricant, and the lubricant support member. A mainspring provided at both ends of the mainspring spring, the solid lubricant is pressed against the application member by the restoring force of the mainspring spring, the solid lubricant is supplied to the application member, and the application member The lubricant supply device is characterized in that the solid lubricant is applied to the image carrier which is in contact with the application member and is rotationally driven.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the lubricant support member is rectangular, and the mainspring springs are provided at both ends in the longitudinal direction of the lubricant support member.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the mainspring spring is a constant load mainspring spring.

  According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, the image carrier is a photoconductor.

  A sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fourth aspects, the image carrier is an intermediate transfer member.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the solid lubricant support surface of the image lubricant support member is parallel to a vertical direction, and A restoring force acts on the mainspring spring in the horizontal direction.

  According to an eighth aspect of the present invention, there is provided an image carrier and a process that includes at least one of a developing unit, a charging unit, a cleaning unit, and a transfer unit in the vicinity of the image carrier and is detachable from the image forming apparatus. A process cartridge comprising the lubricant application device according to any one of claims 1 to 7.

  A ninth aspect of the present invention is an image forming apparatus comprising the lubricant supply device according to any one of the first to seventh aspects.

  A tenth aspect of the present invention is an image forming apparatus having the process cartridge according to the eighth aspect.

  According to the present invention, since the mainspring spring is used as the lubricant pressurizing means when supplying the lubricant to the photosensitive member or the intermediate transfer member, the lubricant pressing force that changes with time is small without increasing the size of the supply device. A lubricant supply device can be realized. In addition, the adsorption force acting between the photoconductor and the toner can be reduced without being influenced by the passage of time, so that the cleaning efficiency can be maintained at a high level, and transfer of the photoconductor and the intermediate transfer body can be performed. The performance can be maintained at a high level.

  A lubricant supply device according to the present embodiment will be described with reference to the drawings. FIG. 1 shows a view of the lubricant supply device 50 of the present embodiment as viewed from the side, and FIG. 2 shows a view of the lubricant supply device 50 of the present embodiment as seen from above.

  The lubricant supply device 50 includes a solid lubricant 51, a mainspring spring 52, a lubricant support plate 53, and a fixed shaft 54. The lubricant support plate 53 is a rectangular plate and supports the solid lubricant 51. The mainspring springs 52 are respectively provided at both ends in the longitudinal direction of the lubricant support plate 53, and the solid lubricant 51 supported by the lubricant support plate 53 is the direction in which the mainspring spring 52 is restored (the direction in which it is wound), that is, Pressure is applied in the direction of action of the mainspring spring 52. Further, one end of the spiral spring 52 is fixed by a fixed shaft 54 of the lubricant supply device 50.

  Next, the mainspring spring will be described. The mainspring spring is obtained by processing one end or both ends of a belt-shaped material into a spiral shape, and stores energy by rotating and winding up an inner end or an outer end, and uses this as a power source. The mainspring spring has characteristics such that relatively large energy can be obtained in a small space, it is relatively inexpensive, and the mechanism is simple.

  There are various types of mainspring springs such as non-contact type mainspring springs and constant torque mainspring springs, which have different characteristics. However, the mainspring spring 52 used in this embodiment is preferably a constant load mainspring spring. A constant load mainspring is shown in FIG.

  The constant load mainspring is a spring that linearly pulls out the outer end of a thin plate tightly wound with a constant curvature and uses the restoring force (winding force) of the outer end, and the load P depends on the amount of pull-out. However, it has a characteristic of being almost constant.

  In order to show the above characteristics, a calculation formula for the load P of the constant load spring is shown below. The load P of the constant load mainspring is calculated by the following formula.

Each parameter is as follows.
E: Young's modulus b: plate width t: sheet thickness R _n: coiling radius R _1: a driven shaft radius

  As described above, the constant load spring can apply a substantially constant load in a small space. Therefore, by using a constant load mainspring for the lubricant supply device 50, it is possible to realize a lubricant supply device with a substantially constant lubricant pressure over time without increasing the size of the supply device at a low cost. Become.

  In addition, as the solid lubricant 51 used in the present embodiment, a zinc stearate solid bar, carnauba wax, or the like is used.

  Next, the lubricant application method of the lubricant supply device of this embodiment will be described with reference to the drawings. The lubricant supply device 50 according to the present embodiment applies the lubricant to the toner carrier 60. As an application method, the application brush 55 is provided in the lubricant supply device 50 as shown in FIG. FIG. 5 shows an indirect application method in which a lubricant is supplied to the application brush 55 by pressurizing the agent 51 against the application brush 55, and the solid lubricant 51 is indirectly applied to the toner carrier 60 by the application brush 55. There is a direct application method in which a lubricant is applied by directly pressing such a solid lubricant 51 to the toner carrier 60. The toner carrier 60 is a photosensitive member or an intermediate transfer member.

  As shown in FIG. 6, the lubricant supply device 50 includes a spring spring 52 that pressurizes the lubricant support plate 53 so that the surface of the lubricant support plate 53 that supports the solid lubricant 51 is parallel to the vertical direction. It is desirable that the restoring force acts in the horizontal direction so that the solid lubricant 51 is pressed in the horizontal direction against the direct application target 61 of the solid lubricant 51. Here, the direct application target 61 is the application brush 55 in the indirect application type lubricant supply device 50, and the toner carrier 60 in the direct application type lubricant supply device 50. By comprising in this way, the fluctuation | variation of the applied pressure when the solid lubricant 51 is worn and its own weight is changed can be reduced, and the change of the applied pressure with time can be made more constant.

  According to the present embodiment, it is possible to realize a lubricant supply device having a substantially constant lubricant pressure with time without increasing the size of the supply device. In addition, since the coefficient of friction of the photosensitive member can be reduced and the attractive force acting between the toner and the toner can be reduced regardless of the time, the cleaning efficiency can be maintained at a high level. It becomes possible to maintain a high level of transfer performance.

  The lubricant supply device 50 may be formed as a process cartridge. FIG. 7 is an example of the process cartridge 62. In FIG. 7, the photosensitive roller 10, the lubricant supply device 50, the charging roller 11, the developing device 20, and the cleaning device 30 are integrated to form a process cartridge 62. The configuration of the image forming apparatus is not limited to this, and at least one of a developing device, a charging device, a cleaning device, and a transfer device is provided near the periphery of an image carrier (photosensitive member, intermediate transfer member) that includes a lubricant supply device. It is sufficient if one is deployed and integrated. By using the process cartridge in this way, the replacement work can be facilitated.

  A second embodiment will be described with reference to FIG. FIG. 8 shows the configuration of the image forming apparatus. The image forming apparatus 70 includes a document table 71, a document reading unit 72, a document writing unit 73, a developing device 74, a photosensitive member 10, a lubricant supply device 50, a cleaning device 30, a transfer roller 75, A fixing roller 76, a paper discharge roller 77, a paper discharge tray 78, a paper feed tray 79, and a paper feed roller 80 are provided.

  The document reading unit 72 reads the image data of the document placed on the document table 71 and transmits the read image data to the image writing unit 73. The image writing unit 73 irradiates a writing laser to form an electrostatic latent image on the photoconductor 10. The developing device 74 develops the electrostatic latent image on the photoconductor 105 to form a toner image. The toner image is transferred onto a sheet conveyed from the sheet feeding tray 79 by the sheet feeding roller 80. The cleaning device 30 removes residual toner remaining on the photoconductor 10. The fixing roller 76 thermally fixes the toner image transferred onto the paper. The sheet on which the toner image is thermally fixed is discharged onto a discharge tray 79 via a discharge roller 78.

  The lubricant supply device 50 applies a lubricant to the photoconductor 10 in order to prevent the transfer performance from being deteriorated and the image quality from being deteriorated by the filming layer formed by laminating the residual toner. As a result, the coefficient of friction of the photoconductor can be reduced to reduce the attractive force acting with the toner, and the cleaning efficiency of the cleaning device 75 can be improved, and the transfer performance of the photoconductor 10 can be improved. It becomes possible to keep it.

  However, if the lubricant pressure of the lubricant supply device 50 changes (decreases) over time, the proper amount of lubricant applied will be affected. If the proper application is not performed, it is difficult to improve the cleaning efficiency, and the transfer performance of the photoconductor 10 cannot be maintained at a high level.

  Therefore, the image forming apparatus 70 of the present embodiment includes the lubricant supply device described in the first embodiment as the lubricant supply device 50. According to this embodiment, since the lubricant pressure of the lubricant supply device 50 hardly changes with time, the cleaning efficiency of the cleaning device 75 can be improved, and the transfer performance of the photoconductor 10 is kept at a high level. It becomes possible.

It is a figure which shows the state which looked at the lubricant supply apparatus of one Embodiment of this invention from the side. It is a figure which shows the state which looked at the lubricant supply apparatus of one Embodiment of this invention from the top. It is a figure which shows a constant load mainspring spring. It is a figure which shows the lubricant supply apparatus of an indirect application system. It is a figure which shows the lubricant supply apparatus of a direct application system. It is a figure which shows the lubricant supply apparatus pressurized to a horizontal direction. It is a figure which shows a process cartridge. 1 is a diagram illustrating an image forming apparatus. It is a figure which shows the image forming unit containing the conventional lubricant supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photosensitive body 50 Lubricant supply apparatus 51 Solid lubricant 52 Mainspring spring 53 Lubricant support plate 55 Application brush 60 Toner carrier 62 Process cartridge

Claims (10)

In the lubricant supply device for applying the solid lubricant to the image carrier by pressing the solid lubricant on the image carrier to be rotationally driven,
A lubricant support member for supporting the solid lubricant;
A mainspring provided at both ends of the lubricant support member,
A lubricant supply apparatus, wherein the solid lubricant is brought into pressure contact with the image carrier by a restoring force of the mainspring spring. In a lubricant supply device for applying a solid lubricant to an image carrier via a rotary driving application member,
A lubricant support member for supporting the solid lubricant;
A mainspring provided at both ends of the lubricant support member,
By pressing the solid lubricant against the application member by the restoring force of the mainspring spring, the solid lubricant is supplied to the application member,
The lubricant supply device according to claim 1, wherein the solid lubricant is applied to the image carrier which is in contact with the application member and rotationally driven by the application member. The lubricant support member is rectangular,
The lubricant supply device according to claim 1, wherein the mainspring springs are provided at both ends in the longitudinal direction of the lubricant support member.   The lubricant supply device according to any one of claims 1 to 3, wherein the mainspring spring is a constant load mainspring spring.   The lubricant supply device according to claim 1, wherein the image carrier is a photosensitive member.   The lubricant supply device according to any one of claims 1 to 4, wherein the image carrier is an intermediate transfer member. The support surface of the solid lubricant of the lubricant support member is parallel to the vertical direction,
And,
The lubricant supply device according to any one of claims 1 to 6, wherein a restoring force acts on the mainspring spring in a horizontal direction. An image carrier and a process cartridge that has at least one of a developing unit, a charging unit, a cleaning unit, and a transfer unit in the vicinity of the image carrier, and is detachable from the image forming apparatus,
A process cartridge comprising the lubricant application device according to claim 1.   An image forming apparatus comprising the lubricant supply device according to claim 1.   An image forming apparatus comprising the process cartridge according to claim 8.

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