JP2009098330A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for stably forming images over a long period by appropriately applying a lubricant supplied from a lubricant supply means to the surface of an image holding member by means of a smoothing member. <P>SOLUTION: In the image forming apparatus, a cleaning device 20 for removing residues remaining on the surface of the image holding member, the lubricant supply means 30 for supplying the lubricant to the surface of the image holding member, and the smoothing member 40 whose end part comes in contact with the surface of the image holding member to smoothly apply the lubricant supplied to the surface of the image holding member are disposed on the downstream side of a transfer position to transfer the toner image from the image holding member 10 in the moving direction of the image holding member 10. An elastic blade composed of a material whose hardness (JIS-A) at 25°C is in the range of 35 to 50° is used as the smoothing member. <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, the movement of an image holding member rather than a position where a toner image is transferred from an image holding member that holds and moves a toner image. A cleaning device for removing residues remaining on the surface of the image holding member, a lubricant supply means for supplying a lubricant to the surface of the image holding member, and an end portion on the surface of the image holding member In the image forming apparatus provided with a leveling member for applying the lubricant supplied to the surface of the image holding member by contact to the surface of the image holding member, the above-mentioned lubricant supply means is provided on the surface of the image holding member. It is characterized in that the supplied lubricant is appropriately applied to the surface of the image holding member by a leveling member so that stable image formation can be performed 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 member to which an image is transferred, after a toner image is transferred from such an image holding member to a transfer member such as a recording medium or an intermediate transfer member, a cleaning member such as a cleaning blade is provided on the surface of the image holding member. In order to remove the residue such as toner remaining on the surface of the image holding member.

  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, there are problems such that the cleaning member is worn and the cleaning performance is deteriorated, and the surface of the image holding member is worn and the life of the image holding member is shortened.

  For this reason, conventionally, a lubricant such as metal soap is supplied from a lubricant supply means to the surface of an image holding member on which a toner image is transferred to a recording medium or the like, and the surface of the image holding member and the cleaning member are supplied by this lubricant. The surface of the image holding member is improved, and the toner image formed on the surface of the image holding member is appropriately transferred to the transfer member. Has been done.

  Conventionally, in supplying the lubricant from the lubricant supplying means to the surface of the image holding member having the toner image transferred to the transfer member as described above, as shown in Patent Documents 1 and 2, After scraping off the lubricant from the lubricant with a brush roll, the brush roll is brought into contact with the surface of the image holding member after the toner image is transferred, and the scraped lubricant is applied to the surface of the image holding member. There has been proposed one in which a cleaning member is pressed against the surface of the image holding member.

  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, thereby gradually reducing the ability of the brush roll to scrape off the lubricant from the solid lubricant, thereby maintaining the image. There was a problem that the lubricant could not be properly applied to the surface of the member.

  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 3, the image holding member After removing residues such as toner remaining 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. A technique has been proposed in which the end of the leveling member is pressed against the image holding member in the same direction as the moving direction of the image holding member, and the lubricant supplied to the surface of the image holding member is applied to the surface of the image holding member. ing.

  However, the end portion of the leveling member is pressed in the same direction as the moving direction of the image holding member, and the lubricant supplied to the surface of the image holding member is applied to the surface of the image holding member. Even in this case, depending on the amount of lubricant supplied to the surface of the image holding member and the state of the image to be formed, the state of the lubricant applied to the surface of the image holding member by this leveling member changes, There was a problem that proper image formation could not be performed.

For example, if the amount of lubricant supplied to the surface of the image holding member is reduced, the lubricant is not sufficiently applied to the surface of the image holding member, so that wear of the image holding member and leveling member increases, and image holding is performed. There has been a problem that the transfer performance of the member is deteriorated and the formed image is hollowed out. On the other hand, when the amount of lubricant supplied to the surface of the image holding member increases, a large amount of lubricant accumulates between the wedge-shaped surface of the image holding member and the end of the leveling member. The end of the leveling member is pushed up by the accumulated lubricant, the lubricant passes through the leveling member in the form of particles, and the particles of the lubricant adhere to the charging roller etc. that contacts the surface of the image holding member In addition, excessive lubricant is applied to the surface of the image holding member, the toner image holding force on the surface of the image holding member is reduced, and toner splatters at the time of transfer, and the formed image is blurred. There was a problem such as dripping.
JP 2003-57996 A JP 2006-259661 A JP 2006-251751 A

  The present invention is a cleaning that removes residue remaining on the surface of an image holding member at a position downstream of the image holding member in the moving direction from the position where the toner image is transferred from the image holding member that holds and moves the toner image. An apparatus, lubricant supply means for supplying a lubricant to the surface of the image holding member, and a lubricant supplied to the surface of the image holding member with the end abutting against the surface of the image holding member. It is an object of the present invention to solve the above-described problems in an image forming apparatus provided with a leveling member to be applied to the surface.

  That is, in the present invention, in the image forming apparatus as described above, the lubricant supplied from the lubricant supply unit to the surface of the image holding member is appropriately applied to the surface of the image holding member by the leveling member, It is an object to enable stable image formation over a long period of time.

  In the present invention, in order to solve the above-described problems, the image holding member is located at a position downstream of the moving direction of the image holding member from the position where the toner image is transferred from the image holding member that holds and moves the toner image. A cleaning device for removing residues remaining on the surface of the image holding member, a lubricant supply means for supplying a lubricant to the surface of the image holding member, and an end portion of the surface of the image holding member abutting on the surface of the image holding member. In the image forming apparatus provided with a leveling member that applies the supplied lubricant to the surface of the image holding member, the above-mentioned leveling member has a hardness (JIS-A) at a temperature of 25 ° C. of 35 degrees to 50 degrees. An elastic blade composed of a range of materials was used.

  In the image forming apparatus according to the present invention, when the end portion of the leveling member is brought into contact with the surface of the image holding member, the end direction of the leveling member is opposed to the moving direction of the image holding member. It is preferable to make it contact | abut toward.

  Moreover, as said leveling member, what was comprised with the material selected from urethane rubber, silicon rubber, and fluororubber can be used, for example.

  In the image forming apparatus of the present invention, it is preferable that the cleaning device is provided on the upstream side in the moving direction of the image holding member with respect to the lubricant supplying means.

  In the image forming apparatus of the present invention, the lubricant is supplied to the surface of the image holding member after the toner image is transferred by the lubricant supplying means, and the surface of the image holding member thus supplied with the lubricant is averaged. When the lubricant supplied to the surface of the image holding member is applied to the surface of the image holding member by abutting the end of the fixing member, the above-mentioned leveling member has a hardness (JIS-A) at a temperature of 25 ° C. Since an elastic blade composed of a material in the range of 35 degrees to 50 degrees is used, even when the amount of lubricant supplied to the surface of the image holding member varies, an appropriate amount of lubricant is applied to the image holding member. It is applied to the surface, and stable image formation can be performed over a long period of time.

  That is, when the hardness of the leveling member is lower than the above range, the pressing force on the end of the leveling member with respect to the surface of the holding member becomes weak, and the lubricant supplied to the surface of the image holding member is sufficient. Without forming a film, the lubricant passes through the end of the leveling member in the form of particles and adheres to the charging roller or the like, and the lubricant supplied to the surface of the image holding member in the form of particles cleans the lubricant. The image is removed from the surface of the image holding member by the apparatus, the transfer performance of the image holding member is lowered, and the formed image is likely to be hollow out. On the other hand, if the hardness of the leveling member is higher than the above range, the pressure contact force is too strong on the end of the leveling member with respect to the surface of the image holding member, and the lubricant adheres strongly to the surface of the image holding member. As a result, the holding force of the toner image on the image holding member is reduced, toner scattering occurs during transfer, and bleeding tends to occur in the image.

  On the other hand, when the hardness of the leveling member is within the above range, the pressure contact force of the end of the leveling member to the surface of the image holding member is appropriately maintained, and the lubricant supplied to the surface of the image holding member Is properly coated to prevent the lubricant from passing through the end of the leveling member in the form of particles, and an appropriate amount of lubricant passes through the end of the leveling member to form an image. An appropriate amount of lubricant is applied to the surface of the holding member, and stable image formation can be performed over a long period of time.

  In the image forming apparatus of the present invention, when the end of the leveling member is brought into contact with the surface of the image holding member, the end of the leveling member is directed in a counter direction opposite to the moving direction of the image holding member. If they are brought into contact with each other, the above effects are further improved.

  Further, in the above image forming apparatus, a cleaning device that removes residual toner and the like remaining on the surface of the image holding member after transfer is provided upstream of the lubricant supplying means in the moving direction of the image holding member. To prevent the toner remaining on the surface of the image holding member from adhering to the lubricant supplying means, and the lubricant supplying means can stabilize the lubricant over a long period of time. Will be properly supplied.

  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.

  Residues such as toner remaining on the surface of each photoconductor drum 10 after transfer are respectively guided to the first cleaning device 20, and the cleaning blade 21 provided in the first cleaning device 20 is used as the photoconductor drum 10. The toner is removed from the surface of each photosensitive drum 10 by pressure contact with the surface of the photosensitive drum 10.

  Next, a lubricant is supplied by the lubricant supply means 30 to the surface of each photoconductor drum 10 from which the residue such as toner has been removed in this manner, and the photoconductor drum 10 thus supplied with the lubricant is supplied. The end of the leveling member 40 is brought into contact with the surface, and the lubricant supplied to the surface of each photoconductor drum 10 is uniformly applied to the surface of each photoconductor drum 10.

  On the other hand, 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 fixed on the recording medium S. The fixed recording medium S is discharged.

  Further, the residual toner or the like remaining on the intermediate transfer member 15 without being transferred to the recording medium S is guided to the second cleaning device 50, and the cleaning blade 51 provided in the second cleaning device 50 is used as the intermediate transfer member. The surface of the intermediate transfer member 15 is pressed against the surface of the intermediate transfer member 15 to remove the remaining toner and the like from the intermediate transfer member 15.

  Here, as described above, after the toner and other residues remaining on the surface of the photosensitive drum 10 after the transfer are removed by the first cleaning device 20, the lubricant supply means 30 is applied to the surface of the photosensitive drum 10. In the image forming apparatus according to this embodiment, the brush roller 31 that rotates in contact with the surface of the photosensitive drum 10 is made of a solid lubricant 32 and a spring as shown in FIG. The pressing member 33 is pressed.

  Then, the brush roller 31 is rotated to scrape the lubricant 32a from the solid lubricant 32. The lubricant 32a thus scraped off is supplied to the surface of the photosensitive drum 10, and the lubricant 32a. The scraping member 34 is brought into contact with the brush roller 31 after the toner is supplied to the surface of the photosensitive drum 10, and dust or the like adhering to the brush roller 31 is scraped by the scraping member 34.

  Here, as said lubricant 32a, fatty acid metal salts, such as zinc stearate, magnesium stearate, lithium stearate, can be used, for example.

  Moreover, as a brush of said brush roller 31, the electroconductive or insulating brush comprised by synthetic fibers, such as nylon, rayon, an acryl, can be used, for example.

  Then, the end of the leveling member 40 that is held by the holding member 41 and protrudes is brought into contact with the surface of the photosensitive drum 10 supplied with the lubricant 32a as described above, so that the lubricant 32a is brought into contact with the photosensitive drum. In this embodiment, an elastic blade made of a material having a hardness (JIS-A) at a temperature of 25 ° C. in the range of 35 degrees to 50 degrees is used as the leveling member 40. The end of the leveling member 40 is brought into contact with the surface of the photosensitive drum 10 in the counter direction opposite to the moving direction of the photosensitive drum 10.

  As described above, when an elastic blade made of a material having a hardness (JIS-A) at a temperature of 25 ° C. in the range of 35 degrees to 50 degrees is used as the leveling member 40, the surface of the photosensitive drum 10 as described above is used. The pressure contact force at the end of the leveling member 40 is appropriately maintained, the lubricant 32a supplied to the surface of the photosensitive drum 10 is appropriately coated, and the end of the leveling member is in a state where the lubricant 32a is in the form of particles. And an appropriate amount of lubricant 32a passes through the end of the leveling member 40 so that an appropriate amount of lubricant 32a is applied to the surface of the photosensitive drum 10. become.

  Further, when the end portion 41 of the leveling member 40 formed of the elastic blade as described above is brought into contact with the surface of the photosensitive drum 10 in the counter direction opposite to the moving direction of the photosensitive drum 10, As shown in FIG. 3, in a state where the lubricant 32a is sufficiently applied to the surface of the photosensitive drum 10, the frictional resistance between the surface of the photosensitive drum 10 and the end of the leveling member 40 is weak. The deformation of the end portion of the leveling member 40 is reduced, the leveling force of the lubricant by the leveling member 40 is increased, and the lubricant 32a is prevented from being excessively supplied and applied to the surface of the photosensitive drum 10. Is done.

  As a result, the toner image holding force on the surface of the photoconductor drum 10 is prevented from being reduced, the toner is prevented from scattering during transfer, and bleeding is prevented from occurring in the image.

  On the other hand, as shown in FIG. 4, when the amount of the lubricant 32a applied to the surface of the photosensitive drum 10 is small, the frictional resistance between the surface of the photosensitive drum 10 and the end of the leveling member 40 is low. As a result, the end of the leveling member 40 is greatly deformed, the damming force of the lubricant 32a by the leveling member 40 is reduced, and the lubricant 32a passes through the end of the leveling member 40, so that the photosensitive drum An appropriate amount of lubricant 32 a is applied to the surface of 10.

  As a result, the frictional resistance between the surface of the photoconductive drum 10 and the end of the leveling member 40 is reduced, and the surface of the photoconductive drum 10 and the end of the leveling member 40 are prevented from being worn. In addition, the transfer performance of the photosensitive drum 10 is also prevented from being deteriorated, and the occurrence of voids in the formed image is prevented.

  In the image forming apparatus according to this embodiment, as described above, the end of the leveling member 40 is brought into contact with the surface of the photosensitive drum 10 in the counter direction opposite to the moving direction of the photosensitive drum 10. However, the end of the leveling member 40 can be brought into contact with the surface of the photosensitive drum 10 in the same direction as the movement direction of the photosensitive drum 10. Even when the end portion of the leveling member 40 is brought into contact with the surface of the photoconductive drum 10 in the same direction as the movement direction of the photoconductive drum 10, the leveling member 40 has a temperature of 25 ° C. When an elastic blade made of a material having a hardness (JIS-A) of 35 degrees to 50 degrees is used, the above effects can be obtained.

  Next, in the image forming apparatus according to the above-described embodiment, as the above-described leveling member, five types of leveling at a temperature of 25 ° C. (JIS-A) of 27 degrees, 36 degrees, 42 degrees, 55 degrees, and 59 degrees are used. It is clear that an excellent effect can be obtained when using a smoothing member made of a material having a hardness (JIS-A) at a temperature of 25 ° C. in the range of 35 degrees to 50 degrees. To.

  First, when 5000 images are formed by each image forming apparatus using the above five types of leveling members, the middle portion of the fine line in each formed image is visually evaluated, Table 1 below shows ◯ when no omission occurred, Δ when omissions occurred slightly, and x when more omissions occurred.

  In addition, when each of the image forming apparatuses using the above five types of leveling members formed 100,000 images, the occurrence of image noise due to poor cleaning in each formed image was visually evaluated. Table 1 below shows ◯ when no image noise occurred, Δ when a little image noise occurred, and x when a lot of image noise occurred.

  As a result, when a leveling member composed of a material having a hardness of 25 ° C. (JIS-A) of 27 degrees was used, or a material having a hardness of 25 degrees C. (JIS-A) of 59 degrees. When a leveling member is used, image noise occurs due to voids or poor cleaning, but the leveling member is made of a material having a hardness (JIS-A) at a temperature of 25 ° C. in the range of 35 degrees to 55 degrees. When using, image noise due to voids or poor cleaning did not occur.

  Further, when 5000 images are formed by each image forming apparatus using the above five types of leveling members, environmental conditions of a temperature of 10 ° C. and a humidity of 15%, and a temperature of 30 ° C. and a humidity of 85%, respectively. Under the above environmental conditions, the pure water contact angle on the surface of the photosensitive drum was measured, and the results are shown in FIG.

  Here, the pure water contact angle on the surface of the photosensitive drum increases as the amount of the lubricant film formed on the surface of the photosensitive drum increases, and the pure water contact angle exceeds 120 °. The amount of the lubricant film formed on the surface of the photoconductive drum becomes too large, the toner image holding force on the surface of the photoconductive drum is reduced, the toner scatters during transfer, and the image becomes It blurs. On the other hand, when the pure water contact angle is less than 80 °, the amount of the lubricant film formed on the surface of the photosensitive drum becomes too small, and the gap between the surface of the photosensitive drum and the end of the leveling member is reduced. The frictional resistance of the photosensitive drum increases and the surface of the photosensitive drum and the end of the leveling member are easily worn, and the transfer performance of the photosensitive drum is deteriorated.

  As shown in FIG. 5, when using a leveling member made of a material having a hardness (JIS-A) at a temperature of 25 ° C. of 35 ° to 50 °, the environment at a temperature of 10 ° C. and a humidity of 15%. The pure water contact angle on the surface of the photosensitive drum is maintained in the range of about 80 ° to 120 ° under both the conditions and the environmental conditions of temperature 30 ° C. and humidity 85%, and at the time of transfer In this case, toner scattering and voids are prevented.

1 is a schematic explanatory view showing an image forming apparatus according to an embodiment of the present invention. In the image forming apparatus according to the embodiment, the first cleaning device removes the residue remaining on the surface of the photosensitive drum at a position downstream of the position where the toner image is transferred from the photosensitive drum in the moving direction of the photosensitive drum. And a lubricant supply means for supplying a lubricant to the surface of the photosensitive drum, and a lubricant supplied to the surface of the image holding member with the end abutting against the surface of the photosensitive drum on the surface of the image holding member. It is the schematic explanatory drawing which showed the state which provided the leveling member to apply | coat. In the image forming apparatus of the embodiment, when the end of the leveling member is brought into contact with the surface of the photosensitive drum to which the lubricant is sufficiently applied toward the counter direction opposite to the moving direction of the photosensitive drum, It is the partial explanatory view which showed the deformation | transformation state of the edge part of a leveling member. In the image forming apparatus of the embodiment, when the end of the leveling member is brought into contact with the surface of the photosensitive drum to which almost no lubricant is applied in the counter direction opposite to the moving direction of the photosensitive drum. It is the partial explanatory view which showed the deformation | transformation state of the edge part of a leveling member. In an experiment using an image forming apparatus using five types of leveling members having a hardness (JIS-A) of 27 °, 36 °, 42 °, 55 °, and 59 ° at a temperature of 25 ° C., the surface of each photosensitive drum It is the figure which showed the measurement result of the pure water contact angle in.

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 Cleaning blade 30 Lubricant supply means 31 Brush roller 32 Solid lubricant 32a Lubricant 33 Pressing member 34 Scraping member 40 Leveling member 41 Holding member 50 Second cleaning device 51 Cleaning blade S Recording medium

Claims (4)

  A cleaning device that removes residue remaining on the surface of the image holding member at a position downstream of the image holding member in the moving direction from the position at which the toner image is transferred from the image holding member that holds and moves the toner image; Lubricant supply means for supplying a lubricant to the surface of the holding member, and an average for applying the lubricant supplied to the surface of the image holding member with the end abutting against the surface of the image holding member applied to the surface of the image holding member. In the image forming apparatus provided with the shim member, an elastic blade made of a material whose hardness (JIS-A) at a temperature of 25 ° C. is in the range of 35 degrees to 50 degrees is used as the leveling member. An image forming apparatus.   2. The image forming apparatus according to claim 1, wherein an end of the leveling member is in contact with a counter direction opposite to a moving direction of the image holding member.   3. The image forming apparatus according to claim 1, wherein the leveling member is made of a material selected from urethane rubber, silicon rubber, and fluorine rubber.   4. The image forming apparatus according to claim 1, wherein the cleaning device is provided at a position upstream of the lubricant supplying unit in the moving direction of the image holding member. 5. An image forming apparatus.

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