JP2008310194A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a lubricant to a surface of an image holding member stably for a long period in an image forming apparatus provided with a lubricant supply means of supplying the lubricant to the surface of the image holding member after a toner image is transferred. <P>SOLUTION: The image forming apparatus which supplies the lubricant from the lubricant supply means 21 to the surface of the image holding member after the toner image is transferred from the image holding member 10 moving while holding the toner image includes as the lubricant supply means a lubricant conveying member 211 scraping a lubricant off a solid lubricant 212 and conveying it and disposed not in contact with the image holding member, and is provided with lubricant electrostatic charging devices 214 and 215 which electrostatically charge the lubricant conveyed by the lubricant conveying member, the lubricant electrostatically charged by the lubricant electrostatic charging devices being supplied from the lubricant conveying member to the image holding member by electrical attraction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine of these, and in particular, after transferring a toner image from an image holding member that holds and moves the toner image, In an image forming apparatus provided with a lubricant supply means for supplying a lubricant to the surface and a cleaning member for removing a residue such as toner remaining on the surface of the image holding member, the image holding from the lubricant supply means This is characterized in that the lubricant is stably supplied to the surface of the member over a long period of time.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these, an image holding member that holds and moves a toner image, for example, a photoconductor on which a toner image is formed, and toner formed on the photoconductor In an intermediate transfer body on which an image is transferred, a toner image is transferred from such an image holding member to a recording medium or the like, and then a cleaning member such as a cleaning blade is pressed against the surface of the image holding member to hold the image. Removal of residual toner and the like remaining on the surface of the member is performed.

  Here, the cleaning member is pressed against the surface of the image holding member after the toner image is transferred as described above, and the operation of removing the residual toner and the like remaining on the surface of the image holding member is lengthened. If it continues, the cleaning member will be worn out and the cleaning performance will be deteriorated, and the surface of the image holding member will be worn out and the life thereof will be shortened.

  For this reason, conventionally, as disclosed in Patent Document 1, the brush roll is scraped from the solid lubricant by a brush roll, and the brush roll is brought into contact with the surface of the image holding member after the toner image is transferred. After the scraped lubricant is applied to the surface of the image holding member, the cleaning member is pressed against the surface of the image holding member to reduce the frictional resistance between the surface of the image holding member and the cleaning member. It has been broken.

  However, when the cleaning member removes residual toner or the like remaining on the surface of the image holding member, the lubricant is applied by bringing the brush roll into contact with the surface of the image holding member. The toner remaining on the surface of the image holding member adheres to the brush roll and gradually accumulates, and as a result, the ability of the brush roll to scrape off the lubricant from the solid lubricant gradually decreases, and the image is held. There was a problem that the lubricant could not be properly applied to the surface of the member.

  In addition, when applying the lubricant by bringing the brush roll into contact with the surface of the image holding member as described above, in order to uniformly apply the lubricant to the surface of the image holding member, the brush density in the brush roll is increased. Further, there is a problem that more residue such as toner adheres to the brush roll and the surface of the image holding member is worn or damaged due to contact with the brush roll.

  Conventionally, in order to prevent the residue such as toner remaining on the surface of the image holding member from adhering to the brush roll as described above, as disclosed in Patent Document 2, After removing residual toner and the like on the surface with a cleaning member, the brush roll is brought into contact with the surface to apply a lubricant to the surface of the image holding member, and then the surface of the image holding member is lubricated. There has been proposed one in which a leveling blade is brought into pressure contact.

  However, even the one disclosed in Patent Document 2 cannot prevent the surface of the image holding member from being worn and damaged due to contact with the brush roll. Further, as described above, lubrication is performed separately from the cleaning member. Since the leveling blade is pressed against the surface of the image holding member, there is a problem that the surface of the image holding member is further worn, the number of parts is increased, the cost is increased, and the apparatus is increased in size.

  Conventionally, as shown in Patent Document 3, image retention after the lubricant is scraped off from the solid lubricant by the brush roll, and the toner image is transferred from the brush lubricant to the brush roll. There has also been proposed one that is dispersed on an intermediate transfer belt as a member.

However, as shown in Patent Document 3, when the scraped lubricant is sprayed from the brush roll onto the surface of the intermediate transfer belt, it is necessary to set the brush roll above the intermediate transfer belt. In addition, the lubricant scraped off as described above is very light, so it does not fall well on the intermediate transfer belt, and the lubricant is evenly distributed on the surface of the intermediate transfer belt. There was a problem that it was difficult to give.
JP 2003-57996 A JP 2006-251751 A JP-A-11-65311

  In the present invention, after a toner image is transferred to a recording medium or the like from an image holding member that holds and moves the toner image, residues such as toner remaining on the surface of the image holding member are removed by a cleaning member. An object of the present invention is to solve the above-described various problems in the image forming apparatus.

  That is, according to the present invention, in the image forming apparatus as described above, the surface of the image holding member and the cleaning member are supplied by supplying the lubricant from the lubricant supplying means to the surface of the image holding member after the toner image is transferred. In order to reduce the frictional resistance between the image holding member, the surface of the image holding member is not worn or damaged, and the size of the apparatus is not increased, and the lubricant is stably supplied to the surface of the image holding member over a long period of time. Therefore, it is an object to stably perform appropriate cleaning over a long period of time.

  In the image forming apparatus according to the present invention, in order to solve the above-described problems, after the toner image is transferred from the image holding member that holds and moves the toner image, a lubricant is applied to the surface of the image holding member. In the image forming apparatus provided with the lubricant supply means to supply and the cleaning member for removing the residue remaining on the surface of the image holding member, the lubricant supply means is in contact with the solid lubricant. A lubricant conveying member that rotates and scrapes and conveys the lubricant from the solid lubricant is disposed in a non-contact state with the image holding member, and the lubricant conveyed by the lubricant conveying member is charged. The lubricant charging device is provided so that the lubricant charged by the lubricant charging device is electrically sucked and supplied from the lubricant conveying member to the image holding member.

  Here, in the image forming apparatus, it is preferable that the cleaning member is provided on the downstream side in the moving direction of the image holding member with respect to the lubricant supplying unit.

  In the image forming apparatus, it is preferable to use a roller for the lubricant conveying member.

  In the above image forming apparatus, when the lubricant scraped off by the lubricant conveying member is charged by the lubricant charging device, the lubricant is charged to a polarity opposite to the charging polarity of the toner. In supplying the lubricant thus charged from the lubricant conveying member to the image holding member, a lubricant supply bias power source for applying a bias voltage for supplying the charged lubricant from the lubricant conveying member to the image holding member. In particular, it is preferable to apply at least an AC bias voltage from the lubricant supply bias power source to the lubricant transport member.

  In the image forming apparatus of the present invention, when the lubricant is supplied from the lubricant supplying means to the surface of the image holding member after the toner image is transferred, the solid lubricant is rotated while being in contact with the solid lubricant. The lubricant conveying member that scrapes and conveys the lubricant from the toner is disposed in a non-contact state with the image holding member, and the lubricant conveyed by the lubricant conveying member is charged by the lubricant charging device, and charged in this way. The lubricant thus supplied is electrically sucked and supplied to the surface of the image holding member after the toner image is transferred from the lubricant conveying member.

  In this case, the residual toner such as toner remaining on the surface of the image holding member adheres to the brush roll as in the conventional case where the lubricant is applied by bringing the brush roll into contact with the surface of the holding member. The lubricant cannot be properly applied to the surface of the image holding member, and the surface of the image holding member is not worn or damaged by contact with the brush roll.

  As a result, in the image forming apparatus of the present invention, the lubricant is supplied from the lubricant supply means to the surface of the image holding member after the toner image is transferred, and the surface between the surface of the image holding member and the cleaning member is supplied. In reducing the frictional resistance, the surface of the image holding member is not worn and damaged, and the lubricant is stably supplied to the surface of the image holding member over a long period of time, so that stable cleaning can be performed over a long period of time. .

  In the above image forming apparatus, when the cleaning member is provided on the downstream side in the moving direction of the image holding member with respect to the lubricant supplying unit, the lubricant supplied to the surface of the image holding member by the lubricant supplying unit. Is uniformly applied to the surface of the image holding member by the above-described cleaning member, and there is no need to press the lubricant leveling blade against the surface of the image holding member as in the prior art, and the surface of the image holding member is worn. In addition, the number of parts is reduced, the cost is reduced, and the apparatus is not enlarged.

  Further, in the above image forming apparatus, when a roller is used for the lubricant conveying member, the lubricant conveying member and the image holding member are arranged in a state in which the lubricant conveying member is disposed in a non-contact state with the image holding member. The interval can be appropriately maintained, and the lubricant charged as described above can be appropriately supplied by being electrically attracted from the lubricant conveying member to the surface of the image holding member.

  Further, in the image forming apparatus, the lubricant scraped from the solid lubricant by the lubricant conveying member is charged to the opposite polarity to the charging polarity of the toner by the lubricant charging device, and is charged in this way. When supplying the lubricant to the image holding member from the lubricant conveying member, a lubricant supply bias power source for applying a bias voltage for supplying the charged lubricant from the lubricant conveying member to the image holding member is provided. When at least an AC bias voltage is applied from the lubricant supply bias power source to the lubricant conveying member, the lubricant in the lubricant conveying member is appropriately supplied to the surface of the image holding member while flying between the image holding member and the lubricant conveying member. Will come to be.

  Next, an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the image forming apparatus according to the present invention is not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist thereof.

  In the image forming apparatus according to this embodiment, four photosensitive drums serving as image holding members corresponding to the four developing devices 11 containing toners of different colors of yellow, magenta, cyan, and black. 10 is provided.

  Here, in this image forming apparatus, when full-color image formation is performed, the respective photosensitive drums 10 are rotated, and the surface of each photosensitive drum 10 is charged by the charging device 12, respectively. Each of the photosensitive drums 10 is exposed according to image data by the exposure device 13 to form an electrostatic latent image on the surface of each of the photosensitive drums 10.

  Then, toner of a predetermined color is supplied from each developing device 11 corresponding to each photosensitive drum 10 on which the electrostatic latent image is formed in this manner to the electrostatic latent image on each photosensitive drum 10 and developed. The toner images of the respective colors are formed on the surface of each photosensitive drum 10.

  Next, the toner images of the respective colors formed on the respective photosensitive drums 10 are respectively transferred to the intermediate transfer body 15 in the form of an endless belt that is driven around the roller 14 and transferred in the form of a roller. A primary transfer is sequentially performed by the device 16 to form a full-color toner image on the intermediate transfer member 15.

  Then, the residual toner and the like remaining on the surface of each photoconductor drum 10 after the transfer is guided to the first cleaning device 20 to remove the residual toner and the like from the surface of each photoconductor drum 10. .

  Further, the full-color toner image formed on the intermediate transfer member 15 as described above is guided to a position facing the secondary transfer device 17 formed into a roller shape by the intermediate transfer member 15, and the image forming apparatus. The sheet-like recording medium S accommodated in the lower part of the sheet is guided between the intermediate transfer member 15 and the secondary transfer device 17 by the feed roller 18 and formed on the intermediate transfer member 15 by the secondary transfer device 17. The resulting full-color toner image is secondarily transferred to the recording medium S.

  After that, the recording medium S to which the full-color toner image is transferred in this way is guided to the fixing device 19, and the transferred full-color toner image is heated and fixed on the recording medium S, and then the full-color toner image is thus obtained. Is discharged.

  On the other hand, the residual toner such as toner remaining on the intermediate transfer member 15 without being transferred to the recording medium S is guided to the second cleaning device 30, and the cleaning blade 31 provided in the second cleaning device 30 is moved to the intermediate transfer member 15. Residue such as toner remaining on the intermediate transfer member 15 is removed from the intermediate transfer member 15 by being brought into pressure contact with the surface.

  Here, in the image forming apparatus according to this embodiment, in the first cleaning device 20 that removes residual toner and the like remaining on the surface of each photoconductor drum 10 after transfer, Lubricant supply means 21 for supplying a lubricant to the surface and a cleaning member 22 for removing residues such as toner remaining on the surface of the photosensitive drum 10 are provided. The lubricant supply means 21 is provided by the cleaning member 22. Also, the photosensitive drum 10 is positioned upstream in the moving direction.

  Here, in the lubricant supply means 21, as shown in FIG. 2, there is provided a lubricant transport member 211 that is in the form of a roller so as to face the photosensitive drum 10 with a required interval, The solid lubricant 212 is pressed against the outer peripheral surface of the lubricant conveying member 211 by a pressing member 213 made of a spring.

  Then, the lubricant conveying member 211 is rotated so as to move in the same direction as the photosensitive drum 10 at a position facing the photosensitive drum 10, and the outer periphery of the lubricant conveying member 211 is moved from the solid lubricant 212. The surface is scraped off with lubricant.

  The lubricant thus scraped off is charged by a lubricant charging device that charges the scraped lubricant while being guided to a position facing the photosensitive drum 10 by the lubricant transport member 211.

  Here, when the scraped lubricant is charged by the lubricant charging device, in this embodiment, the conductive brush 214 is brought into contact with the outer peripheral surface of the lubricant conveying member 211, and the conductive brush 214 is contacted with the conductive brush 214. A voltage is applied from the charging power source 215 to charge the lubricant on the outer peripheral surface of the lubricant transport member 211.

  Then, the lubricant conveying member 211 is grounded, the lubricant charged by the lubricant conveying member 21 is guided to a position facing the photosensitive drum 10, and the charged lubricant is grounded. The lubricant conveying member 21 is electrically sucked and supplied to the surface of the photosensitive drum 10.

  After supplying the lubricant to the surface of the photosensitive drum 10 in this way, the cleaning member 22 is pressed against the surface of the photosensitive drum 10 and supplied to the surface of the photosensitive drum 10 by the cleaning member 22. The lubricant is uniformly applied to the surface of the photoconductor drum 10, and residues such as toner remaining on the surface of the photoconductor drum 10 are removed.

  Here, in the above embodiment, negatively chargeable toner is used, and reversal development is performed on the photosensitive drum 10, and a toner image formed on the surface of the photosensitive drum 10 is transferred. A specific example in which the lubricant is supplied to the surface of the photosensitive drum 10 by the lubricant supply means 21 will be described.

Here, in this example, as the solid lubricant 212, a material obtained by melting and molding various metal soap powders such as zinc stearate is used, and as the roller-shaped lubricant transport member 211 described above. The outer periphery of the metal core bar is provided with a coating layer such as conductive urethane rubber, the interval between the lubricant conveying member 211 and the photosensitive drum 10 is set to about 100 μm, and the conductive brush 214 is used as the conductive brush 214 described above. Using a conductive nylon brush having a fiber thickness of 2 dtex and a fiber density of 150,000 / inch ² , the amount of biting into the lubricant conveying member 211 of this brush is about 0.5 mm. A DC voltage of +3 to 6 kV is applied to 214 from the charging power source 215 so that the lubricant on the outer peripheral surface of the lubricant transport member 211 is positively charged.

  When the positively charged lubricant is guided to the position facing the photosensitive drum 10 by the lubricant conveying member 211, the photosensitive drum 10 is exposed as shown in FIG. On the other hand, the negative potential of the surface is low in the image portion, while the negative potential of the surface is kept high in the non-exposed non-image portion. The intensity of the electric field between them is larger in the non-image part than in the image part.

  Therefore, the lubricant 212 a positively charged as described above is strongly electrically attracted to the non-image portion of the photosensitive drum 10 and supplied from the lubricant transport member 211. . Note that, in the image portion of the photoconductive drum 10, since the electric potential between the − and the lubricant transport member 211 is weak, the positively charged lubricant is supplied to the image portion of the photoconductive drum 10. However, the negatively charged toner t remaining in the image portion is prevented from being guided to the lubricant transport member 211, and the lubricant transport member 211 is prevented from being contaminated with toner.

  In this embodiment, when the lubricant charged from the lubricant transport member 211 is electrically attracted to the surface of the photosensitive drum 10 and supplied, the lubricant transport member 211 is grounded and the photosensitive drum 10 is photosensitive. Only an electric field for electrically attracting the charged lubricant to the surface of the photosensitive drum 10 is applied between the body drum 10 and particularly the non-image portion. As shown, a lubricant supply bias power source 216 for applying a bias voltage to the lubricant transport member 211 is provided, and an AC bias voltage is applied to the lubricant transport member 211 from the lubricant supply bias power source 216 to lubricate the lubricant transport member 211. The lubricant in the agent transporting member 211 is caused to fly between the lubricant transporting member 211 and the photosensitive drum 10, so that the lubricant can be more efficiently applied to the surface of the photosensitive drum 10. It is also possible to be supplied to. Further, the lubricant supply bias power source 216 applies a DC bias voltage for supplying the lubricant to the surface of the photosensitive drum 10 in combination with the AC bias voltage to the lubricant transport member 211, and more. It is also possible to supply the lubricant to the surface of the photosensitive drum 10.

  In this embodiment, the roller-shaped lubricant conveying member 211 is a metal core having an outer periphery provided with a coating layer such as conductive urethane rubber. However, a metal roller or brush roller is used. The conductive brush 214 is not limited to the conductive nylon brush as described above, and various conductive brushes using rayon, acrylic, or the like can be used.

  Further, in the image forming apparatus of this embodiment, in the first cleaning device 20 that removes residual toner and the like remaining on the surface of each photoconductor drum 10 after transfer, the surface of the photoconductor drum 10 is removed. However, the second cleaning device 30 for removing the residual toner and the like remaining on the intermediate transfer body 15 after the transfer is also illustrated. However, as in the case of the first cleaning device 20 described above, a lubricant supply means for supplying a lubricant to the surface of the intermediate transfer body 15 can be provided.

1 is a schematic explanatory view showing an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a schematic explanatory diagram illustrating details of a lubricant supply unit provided in a first cleaning device that removes a residue such as toner remaining on the surface of the photosensitive drum in the image forming apparatus of the embodiment. FIG. 6 is a schematic explanatory view showing a state in which the lubricant is supplied from the lubricant transport member in the lubricant supply means provided in the first cleaning device to the surface of the photosensitive drum in the image forming apparatus of the embodiment. FIG. 6 is a schematic explanatory view showing a modification example in which a lubricant supply bias power source for applying a bias voltage to a lubricant transport member in a lubricant supply unit provided in the first cleaning device is connected in the image forming apparatus of the embodiment. .

Explanation of symbols

10 Photosensitive drum (image holding member)
DESCRIPTION OF SYMBOLS 11 Developing device 12 Charging device 13 Exposure device 14 Roller 15 Intermediate transfer body 16 Primary transfer device 17 Secondary transfer device 18 Feeding roller 19 Fixing device 20 First cleaning device 21 Lubricant supply means 211 Lubricant transport member 212 Solid lubricant 212a Lubricant 213 Pressing member 214 Conductive brush 215 Charging power supply 216 Lubricant supply bias power supply 22 Cleaning member 30 Second cleaning device 31 Cleaning member t Toner S Recording medium

Claims (6)

  After transferring the toner image from the image holding member that holds and moves the toner image, the lubricant supplying means for supplying the lubricant to the surface of the image holding member and the residue remaining on the surface of the image holding member are removed. In the image forming apparatus provided with the cleaning member to perform, as the above-mentioned lubricant supply means, the lubricant supply means that rotates in contact with the solid lubricant and scrapes and conveys the lubricant from the above-mentioned solid lubricant The member is disposed in a non-contact state with the image holding member, and a lubricant charging device for charging the lubricant transported by the lubricant transporting member is provided and charged by the lubricant charging device. An image forming apparatus, wherein the lubricant is electrically sucked and supplied from the lubricant conveying member to the image holding member.   The image forming apparatus according to claim 1, wherein the cleaning member is provided downstream of the lubricant supply unit in the moving direction of the image holding member.   3. The image forming apparatus according to claim 1, wherein the lubricant conveying member is a roller.   4. The image forming apparatus according to claim 1, wherein the lubricant is charged to a polarity opposite to a charging polarity of the toner by the lubricant charging device. 5.   5. The image forming apparatus according to claim 1, wherein the lubricant charged by the lubricant charging device is electrically sucked and supplied from the lubricant conveying member to the image holding member. An image forming apparatus comprising a lubricant supply bias power source for applying a bias voltage to the lubricant conveying member.   6. The image forming apparatus according to claim 5, wherein at least an AC bias voltage is applied from the lubricant supply bias power source to the lubricant transport member.

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