JP5796482B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a fax machine, and the like, and a multifunction machine.

  In the development process in the above-described image forming apparatus, the image carrier having finished the transfer of the toner image is scraped off and removed residual toner and other paper dust adhering to the surface with a cleaning blade. In preparation for the next toner image formation.

  Further, in order to satisfactorily clean the surface of the image carrier with the cleaning blade, for example, as shown in Patent Document 1, the surface of the image carrier is immediately after cleaning the surface of the image carrier with the cleaning blade. A lubricant is supplied to maintain the slipperiness, and the surface deposits can be scraped off with a cleaning blade.

Japanese Patent Laid-Open No. 11-065311

  In the disclosed technique of Patent Document 1, the lubricant supply device is configured by a solid lubricant and a brush roller that is rotationally driven in contact with the solid lubricant. Then, the solid lubricant and the brush roller are arranged in non-contact above the surface of the image carrier, and the lubricant scraped off from the solid lubricant by the brush roller onto the surface of the image carrier. It is dropped and supplied.

  However, coarse particles are mixed in the lubricant scraped off to the powder form by the brush roller, and when this is supplied onto the surface of the image carrier, it is transferred in the transfer process by the lubricant having a large particle size. The image may be deteriorated or the surface of the image carrier may be damaged.

  Therefore, the present invention does not supply coarse particles to the surface of the image carrier, even if coarse particles are mixed in the lubricant scraped into a powder form by the lubricant supply device. An image forming apparatus capable of avoiding damage to the surface of a carrier is provided.

  The image forming apparatus of the present invention includes an image carrier, a cleaning blade for cleaning the surface of the image carrier, and the surface of the image carrier at a position downstream of the cleaning blade in the surface movement direction of the image carrier. And a lubricant supply device that supplies lubricant to the surface of the image carrier, and is disposed at a position downstream of the lubricant supply device in the surface movement direction of the image carrier. And a leveling member for uniformly leveling the lubricant supplied to the surface of the image carrier by the lubricant supply device.

  The lubricant supply device is configured such that the solid lubricant and its scraping member rotate relative to each other so that the scraped lubricant can fly in the tangential direction of the contact portion between them.

Then, the solid lubricant and the scraping member are arranged in a direction in which a tangent line passing through the contact portion of the solid lubricant and the scraping member intersects upward with respect to the surface of the image carrier, and the coarse particles of the scraped lubricant is removed by gravity fall, flying toward the lubricant to the surface of the image bearing member, it is mainly characterized in that supply.

  According to the present invention, by the specific arrangement of the solid lubricant and the scraping member constituting the lubricant supply device with respect to the image carrier, the powdered lubricant scraped from the solid lubricant by the scraping member is obtained. When coarse particles are mixed, the coarse particles are dropped by their own weight and removed.

  Therefore, only the particulate lubricant can fly and be supplied toward the surface of the image carrier, and deterioration of the transferred image and damage to the surface of the image carrier can be avoided.

1 is an overall configuration diagram conceptually showing an image forming apparatus as an embodiment of the present invention. Explanatory drawing which expands and shows the arrangement | positioning state of 1st Embodiment of a lubricant supply apparatus. Explanatory drawing which shows 2nd Embodiment of a lubricant supply apparatus. Explanatory drawing which shows 3rd Embodiment of a lubricant supply apparatus. Explanatory drawing which shows 4th Embodiment of a lubricant supply apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the overall configuration of an image forming apparatus according to the present invention.

  The image forming apparatus 1 is a full-color image in which a plurality of photosensitive drums 31Y, 31M, 31C, and 31K as image carriers are arranged in a vertical direction so as to face an intermediate transfer belt 41 as an image carrier in a transfer device. Is called a tandem color image forming apparatus.

  The image forming apparatus 1 includes an automatic document feeder ADF at the top thereof. The documents D placed on the document placement table 15 of the automatic document feeder ADF are separated one by one, sent out to the document conveyance path, and conveyed by the conveyance drum 16.

  The document reading unit 10 reads an image of the document D being conveyed at the document image reading position RP. The first conveyance guide G1 and the document discharge roller 17 discharge the document D that has been read to the document discharge tray 18.

  The image forming apparatus 1 includes a document transfer unit 10, exposure units 20 </ b> Y, 20 </ b> M, 20 </ b> C, and 20 </ b> K, image forming units 30 </ b> Y, 30 </ b> M, 30 </ b> C, and 30 </ b> K, an intermediate transfer unit 40 and a secondary transfer unit 42. 50, a paper discharge reversing unit 70, a paper feeding unit 90, and the like, which are housed in one casing.

  The document reading unit 10 irradiates the image of the document D with the lamp L at the document image reading position RP, guides the reflected light by the first mirror unit 11, the second mirror unit 12, and the lens 13, and An image is formed on the light receiving surface. The imaging device CCD photoelectrically converts incident light and outputs a predetermined image signal. The image reading control unit 14 performs processing such as A / D conversion, shading correction, and compression on the image signal, and converts it into image data in a storage unit of a control unit (not shown). The image data stored in the storage unit is subjected to appropriate image processing according to conditions set by the user, and output image data is generated.

  The exposure units 20Y, 20M, 20C, and 20K are photosensitive drums charged by the main charging units 32Y, 32M, 32C, and 32K in accordance with output information output based on output image data sent from the control unit. The surfaces of 31Y, 31M, 31C, and 31K are scanned and exposed with a laser beam, and electrostatic images for Y, M, C, and BK colors are formed on the photosensitive drums 31Y, 31M, 31C, and 31K.

  The image forming unit 30Y includes a photosensitive drum 31Y, a main charging unit 32Y disposed in the periphery thereof, a developing unit 33Y as a developing device, a first transfer roller 34Y, and a cleaning unit 35Y. The other image forming units 30M, 30C, and 30K have the same configuration as that of the image forming unit 30Y, and the main charging units 32M, 32C, 32K, and the like around the photosensitive drums 31M, 31C, and 31K, respectively. Developing units 33M, 33C, and 33K, first transfer rollers 34M, 34C, and 34K, and cleaning units 35M, 35C, and 35K are disposed.

  The developing units 33Y, 33M, 33C, and 33K are developed with yellow (Y), magenta (M), cyan (C), and black (BK) toners, thereby latent images on the photosensitive drums 31Y, 31M, 31C, and 31K. Visualize the image. As a result, yellow (Y), magenta (M), cyan (C), and black (BK) toner images are formed on the photosensitive drums 31Y, 31M, 31C, and 31K.

  The first transfer rollers 34Y, 34M, 34C, and 34K of the intermediate transfer unit 40 transfer the toner images formed on the photoconductive drums 31Y, 31M, 31C, and 31K on the intermediate transfer belt 41 so as to overlap each other. . A color image is formed on the intermediate transfer belt 41 by superimposing the toner images of the respective colors. The intermediate transfer belt 41 formed of an endless belt moves while rotating in the direction indicated by the arrow in FIG. 1 by the driving force of the belt driving roller 44. The cleaning units 35Y, 35M, 35C, and 35K remove and clean the toner remaining on the surfaces of the photosensitive drums 31Y, 31M, 31C, and 31K after the transfer of the toner images, and the cleaned photosensitive drums 31Y, 31M. , 31C, 31K prepare for the formation of the next toner image.

  On the other hand, the secondary transfer unit 42 transports the color image superimposed and transferred on the intermediate transfer belt 41 from the trays PG1, PG2, and PG3 of the sheet feeding unit 90, and sends out the timing by the registration rollers 91. Then, the image is transferred to a sheet P that is a recorded recording medium. The belt cleaning unit 43 removes and cleans the toner remaining on the surface of the intermediate transfer belt 41 that has finished transferring the color image onto the paper P, and the cleaned intermediate transfer belt 41 prepares for the next image transfer.

  The paper P carrying the toner image is sent to the fixing unit 50, and the fixing unit 50 pressurizes and heats the paper P to fix the toner image on the paper P. In the example shown in FIG. 1, the fixing unit 50 uses a roller nip type fixing device 51 including a heating roller 52 and a pressure roller 53.

  The paper discharge reversing unit 70 conveys the paper P after the fixing process by the fixing unit 50 and discharges the paper P to the paper discharge tray 75. When the paper P is reversed and discharged, the paper discharge guide 72 once guides the paper P downward, holds the rear end of the paper P between the paper discharge reverse rollers 73, and reversely conveys the paper P. 72 guides the paper P to the paper discharge roller 74 and discharges it.

  When image formation is performed also on the back side of the paper P, the paper discharge guide 72 conveys the paper P, which has been subjected to the fixing process of the toner image on the front surface, to the re-feed unit 80 below, and is fed by the re-feed reverse roller 81 After pinching the rear end, the paper P is reversed by reverse feeding and sent to the refeed conveyance path 82 for image formation on the back surface.

  A cleaning blade 60 made of an elastic material such as urethane rubber is used for the cleaning units 35Y, 35M, 35C, and 35K in the image forming units 30Y, 30M, 30C, and 30K and the belt cleaning unit 43 in the intermediate transfer unit 40, for example. .

  Immediately after cleaning the surface of the image carrier by the cleaning blade 60, a lubricant is supplied to maintain the slipperiness of the surface of the image carrier.

  An example of the arrangement of the lubricant supply device 100 is shown in FIG. 2 taking the photosensitive drum 31 of the image forming unit 30 as an example of the image carrier. In FIG. 1, symbols Y, M, C, and K representing colors formed after the symbols common to the four sets of image forming units are attached, but in FIG. 2, these symbols are not attached. ing.

  The lubricant supply device 100 is arranged on the photosensitive drum 31 at a position downstream of the cleaning unit 35 shown in FIG. 1 in the surface movement direction of the photosensitive drum 31 and between the cleaning unit 35 and the main charging unit 32. It is arranged in non-contact with the surface of 31.

  In the example shown in FIG. 2, the lubricant supply device 100 is disposed below the photosensitive drum 31 on the downstream side of the cleaning blade 60, and further on the downstream side of the lubricant supply device 100. A leveling member 110 for uniformly leveling the lubricant supplied to the surface of the drum 31 is provided.

  As the leveling member 110, a rubber blade similar to the cleaning blade 60 can be used.

  The lubricant supply device 100 includes, for example, a solid lubricant 101 made of zinc stearate and a scraping member 102 that comes into contact with the solid lubricant 101 and scrapes it off. The solid lubricant 101 and the scraping member 102 are configured to rotate relative to each other so that the lubricant scraped by the scraping member 102 can fly toward the tangential direction of the contact portion between the both 101 and 102.

  In the example shown in FIG. 2, a brush roller 102 </ b> A is used as the scraping member 102, which comes into contact with a stationary solid lubricant 101 and is rotationally driven by driving means (not shown).

  Then, the solid lubricant 101 and the brush roller 102A can remove coarse particles of the scraped lubricant by falling under their own weight so that the lubricant can fly and be supplied toward the surface of the photosensitive drum 31. It is arranged.

  Specifically, in the example shown in FIG. 2, the solid lubricant 101 and the brush roller 102 </ b> A are arranged in such a direction that the tangent line a passing through the contact portions intersects the surface of the photosensitive drum 31 upward. is there.

The arrangement relationship between the cleaning blade 60, the lubricant supply device 100, and the leveling member 110 is determined from the primary transfer portion (first transfer roller 34) side with respect to a horizontal line H passing through the center of the photosensitive drum 31. The angle relationship is ₁ <θ ₂ <θ ₃ . However, θ ₁ = the arrangement angle of the contact point between the cleaning blade 60 and the surface of the photosensitive drum 31, θ ₂ = the arrangement angle at which the tangent line a of the lubricant supply device 100 and the surface of the photosensitive drum 31 intersect, θ ₃ = the average An arrangement angle of the contact point between the solder member 110 and the surface of the photosensitive drum 31.

  The solid lubricant 101 and the brush roller 102A are brought into contact with each other with a required pressure contact force by a pressing spring 111. In the example shown in FIG. 2, the pressing spring 111 is provided on the solid lubricant 101 side.

  The brush roller 102A, the leveling member 110, and the pressing spring 111 described above can have the following specifications, for example.

Brush roller 102A: nylon brush, outer diameter 14 mm, fiber 6d, density 100K (100,000) filaments / in ² , distance to photoconductor drum 31 = 1 mm at the nearest point of contact.

  Leveling member 110: rubber blade, thickness t = 2 mm, free length 6 mm.

  Press spring 111: compression coil spring, two in the depth direction of the paper surface of FIG. 2, one force = 1.6N.

  According to the image forming apparatus of the present embodiment configured as described above, when the toner image is transferred from the photosensitive drum 31 to the intermediate transfer belt 41 by the primary transfer unit 34 in FIG. The remaining toner reaches the cleaning unit 35 and is scraped off by the cleaning blade 60 to prepare for the next toner image formation.

  Immediately after cleaning the surface of the photosensitive drum 31 by the cleaning blade 60, the lubricant is supplied to the surface of the photosensitive drum 31 by the lubricant supply device 100 in the form of powder.

  The powdery lubricant supplied to the surface of the photosensitive drum 31 reaches the leveling member 110 and is uniformly leveled by the leveling member 110, and the distribution of the lubricant on the surface of the photosensitive drum 31 is uniform. Maintained.

  As a result, the slipperiness of the surface of the photosensitive drum 31 is maintained satisfactorily, and the residual toner is scraped and cleaned by the cleaning blade 60 after the next transfer.

  Here, in the lubricant supply device 100, the lubricant is scraped off in powder form by the sliding rotation of the brush roller 102 </ b> A against the solid lubricant 101. The powdery lubricant scraped off by the brush roller 102A flies and is supplied upward toward the surface of the photosensitive drum 31 in the tangential a direction.

  When coarse particles are mixed in the powdery lubricant scraped off by the brush roller 102A, the coarse particles are dropped by their own weight and removed in the process of the lubricant flying upward in the tangential a direction.

  As a result, only the particulate lubricant can fly and be supplied toward the surface of the photosensitive drum 31. As a result, it is possible to avoid deterioration of the transferred image and damage to the surface of the photosensitive drum 31 due to biting of coarse particles in the primary transfer portion 34.

  In the present embodiment, the lubricant supply device 100 is composed of a stationary solid lubricant 101 and a brush roller 102A that is rotationally driven in contact with the solid lubricant 101, so that the lubricant is scraped and generated. The rotation of the brush roller 102A makes it easy to fly the generated powdery lubricant upward in the tangential line a direction.

  Here, the lubricant supply device 100 may be disposed so that the tangent line a passing through the contact portion between the solid lubricant 101 and the brush roller 102A intersects the surface of the photosensitive drum 31 upward. It is not limited to the lower arrangement of the photoconductive drum 31 illustrated in FIG. 2, and it is also possible to arrange the photoconductive drum 31 laterally due to the layout.

  FIG. 3 shows a second embodiment of the lubricant supply device. In this embodiment, the solid lubricant 101 is a roller (hereinafter referred to as a “lubricant roller”) 101 </ b> A that is rotationally driven by driving means (not shown). It is composed.

  On the other hand, the scraping member 102 is a flat brush 102B that comes into contact with the lubricant roller 101A in a stationary manner.

  The lubricant roller 101A and the flat brush 102B are arranged in such a direction that a tangent line a passing through the contact portion intersects the surface of the photosensitive drum 31 upward.

  As a result, when coarse particles are mixed in the lubricant scraped into the powder form by the brush 102B by the rotation of the lubricant roller 101A, the powdery lubricant is moved in the tangential direction a by the rotation of the lubricant roller 101A. In the process of flying and supplying toward the surface of the drum 31, the coarse particles are dropped and removed by their own weight.

  Therefore, even in the second embodiment, the same effect as that of the first embodiment can be obtained.

  FIG. 4 shows a third embodiment of the lubricant supply device. In this embodiment, instead of the flat brush 102B as the scraping member 102 in the second embodiment, the edge is the surface of the lubricant roller 101A. The blade 102C is rubbed. As the scraping blade 102C, a rubber blade similar to the cleaning blade 60 or the leveling blade 110 can be used.

  Therefore, even in the third embodiment, the same operational effects as in the second embodiment can be obtained.

  FIG. 5 shows a fourth embodiment of the lubricant supply device. In the present embodiment, the lubricant roller 101A in the second and third embodiments is used as the solid lubricant 101, while the brush roller 102A in the first embodiment is used as the scraping member 102.

  The lubricant roller 101A and the brush roller 102A are arranged in contact with each other and are both driven to rotate in the driven direction indicated by the arrow in FIG. 5 by driving means (not shown), but the lubricant roller 101A rotates at a lower speed than the brush roller 102A. It is designed to be driven by rotation.

  The lubricant roller 101 </ b> A and the brush roller 102 </ b> A are arranged in such a direction that a tangent line “a” passing through the contact portion intersects the surface of the photosensitive drum 31 upward.

  Therefore, according to the structure of this 4th Embodiment, there can exist an effect similar to the said 1st Embodiment. Further, since the lubricant roller 101A rotates with a rotational delay in the driven direction with respect to the brush roller 102A, the frictional impact on the lubricant surface can be reduced and coarse particles can be suppressed. Moreover, since the rubbing position between the lubricant roller 101A and the brush roller 102A is not constant, the ability to evenly scrape the surface of the lubricant roller 101A contributes to the suppression of coarse particles.

  In the above-described second to fourth embodiments, although not shown in the drawings, a pressing spring 111 is attached as in the first embodiment. This is the same as the solid lubricant 101 and the scraping member 102. What is necessary is just to attach to either.

  In each of the above embodiments, the lubricant supply device 100 is arranged around the photosensitive drum 31. However, the same effect as described above can be obtained by arranging the lubricant supply device 100 around the intermediate transfer belt 41. Can do.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 31 ... Photosensitive drum (image carrier)
41. Intermediate transfer belt (image carrier)
35 ... cleaning unit 43 ... belt cleaning unit 60 ... cleaning blade 100 ... lubricant supply device 101 ... solid lubricant 101A ... lubricant roller 102 ... scraping member 102A ... brush roller 102B ... flat brush 102C ... scraping blade 110 ... Leveling member

Claims (6)

An image carrier;
A cleaning blade for cleaning the surface of the image carrier;
A lubricant supply device that is disposed in contact with the surface of the image carrier at a position downstream of the cleaning blade in the surface movement direction of the image carrier, and that supplies the lubricant to the surface of the image carrier; ,
It is disposed at a position downstream of the lubricant supply device in the surface movement direction of the image carrier, and uniformly distributes the lubricant supplied to the surface of the image carrier by the lubricant supply device. A member, and
The lubricant supply device is configured to rotate the solid lubricant and its scraping member relative to each other so that the scraped lubricant can fly toward the tangential direction of the contact portion between the two,
The solid lubricant and the scraping member are arranged in such a direction that a tangent line passing through the contact portion of the solid lubricant and the surface of the image bearing member crosses upward, and coarse particles of the scraped lubricant are self-weighted. It was removed by falling, flying toward the lubricant to the surface of the image bearing member, an image forming apparatus and supplying. The image forming apparatus according to claim 1, wherein the image bearing member characterized in that it is a photosensitive drum.   The image forming apparatus according to claim 1, wherein the scraping member is a brush roller that is driven to rotate in contact with a stationary solid lubricant. The solid lubricant is configured as a roller that is rotationally driven,
The image forming apparatus according to claim 1, wherein the scraping member is a flat brush that comes into contact with a roller made of the solid lubricant in a stationary manner. The solid lubricant is configured as a roller that is rotationally driven,
The image forming apparatus according to claim 1, wherein the scraping member is a blade whose edge rubs against a surface of the roller made of the solid lubricant. The scraping member is a brush roller driven to rotate;
The image forming apparatus according to claim 1, wherein the solid lubricant is configured as a roller that contacts the brush roller and can rotate in a driven direction at a low rotation with respect to the brush roller.

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