JP4993564B2 - Image forming apparatus - Google Patents

Description

The present invention relates to an image forming apparatus and a process cartridge as an information apparatus copying apparatus capable of forming an image on plain paper of A2 size or higher, and in particular, a mechanism using zinc stearate as a lubricant for a cleaning blade on the surface of an image carrier ( In particular, the present invention relates to an image forming apparatus using a mechanism for applying a wide member.

  A color copying machine using an electrophotographic system is demanded to further improve the image. Image formation with higher resolution and gradation is desired and studied. As improvements on the toner side for visualizing a latent image, in order to provide a high-quality image, the direction of spheroidization and particle size reduction is a major direction, and studies have been made in various directions.

  However, since the toner having a spherical shape and a small particle size is faithfully transferred, it is suitable for obtaining a high-precision image. On the other hand, in blade cleaning, a large load is applied to cleaning. Ensuring performance is a major issue.

  Conventionally, as one of the solutions to the above problem, the solid lubricant is brought into contact with the rotating brush, the lubricant adhering to the rotating brush is attached to the surface of the photoreceptor, and the contact resistance of the cleaning blade to the photoreceptor is reduced. There has been proposed a method for ensuring cleaning performance by reducing the size (see, for example, Patent Document 1).

The method disclosed in Patent Document 1 is a very effective means, and the toner that could not be cleaned on the photoreceptor, which occurs when the cleaning function is lowered, is conveyed to a charging device and charged by a charging roller or the like. It is possible to stain the member and suppress the occurrence of abnormal images such as uneven image density due to uneven charging and ground fog on the image.
Many of these solid lubricants use relatively higher fatty acids.

  However, solid lubricants have properties that are very fragile in strength and have a large expansion as seen in zinc stearate, which is a higher fatty acid.

In consideration of these properties, the present invention takes into consideration that a solid lubricant such as zinc stearate can be used in a machine capable of copying, printing and plotting on plain paper of A2 size or larger.
Japanese Patent No. 3205159

The present invention has been made in consideration of the above-described circumstances. Even when the solid lubricant is divided and staggered and the lubricant is applied to the image carrier, the lubricant is uniformly applied without any unevenness, and the cleaning property is improved. An object of the present invention is to provide an image forming apparatus capable of improving the handling of the entire apparatus at the same time.

In order to solve the above-described problems, the present invention is directed to the application of the lubricant to the surface of the image carrier by a rotatable brush roller that is in contact with the image carrier and the solid lubricant, and the solid lubricant is in the longitudinal direction. In the image forming apparatus, a plurality of overlapping portions in which the solid lubricants are alternately overlapped are arranged in a staggered pattern, and the brush roller has a portion that does not come into contact with each of the plurality of overlapping portions . while a brush diameter portion come in contact with each of the plurality of overlapping portions, and wherein the diameter than the first brush diameter is smaller second brush diameter.

According to the present invention, there is provided an electrophotographic image forming apparatus, wherein the effective width of the image carrier is, for example, 420 mm or more, and the lubricant is applied to the surface of the image carrier in contact with the image carrier and the solid lubricant. An image in which a plurality of solid lubricants are arranged in a zigzag state in the longitudinal direction and the solid lubricants arranged in a staggered pattern are alternately overlapped. In the forming apparatus, the brush diameter of the brush roller having contact with the alternately overlapped portions of the solid lubricant arranged in a staggered manner is different from the diameter of the non-overlapping portion. Even when the solid lubricant is divided and the lubricant is applied in a staggered manner, the lubricant can be uniformly applied to the mating member without application unevenness.
In addition, the lubricant can be used without waste, and the handling of the entire machine can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a color image forming apparatus according to an embodiment of the present invention. As shown in FIG. 1, the color image forming apparatus according to the present embodiment includes an intermediate transfer belt 1 and drum units 30 (photosensitive drum 2, drum lubricant 6, and drum lubricant coating) for each color (cyan, magenta, yellow, black). Brush roller 8), primary transfer roller 3 for each color, secondary transfer roller 4, intermediate transfer driving roller 5, intermediate transfer driven roller 11, intermediate transfer cleaning unit 9 (intermediate transfer belt lubricant 7, intermediate transfer lubricant application roller) 10, an intermediate transfer brush roller 13 and an intermediate transfer cleaning blade 14).

FIG. 2 is a view showing a mechanism for applying a lubricant to the surface of the intermediate transfer belt, and is an enlarged view of the intermediate transfer cleaning unit 9 and the intermediate transfer driven roller 11 shown in FIG.
In FIG. 2, the intermediate transfer belt 1 is driven in the direction of the arrow. The residual toner remaining on the surface of the intermediate transfer belt 1 after the transfer to the plain paper (secondary transfer) is completed, and then the intermediate transfer brush roller 13 which is a cleaning auxiliary means for the surface of the intermediate transfer belt 1 and then the main cleaning means. The intermediate transfer cleaning blade 14 is used for cleaning. By these two means, the surface of the intermediate transfer belt 1 can be kept clean, and the intermediate transfer belt 1 can be used repeatedly.

  After the cleaning, the lubricant is applied to the intermediate transfer belt 1. The lubricant is applied by an intermediate transfer lubricant application roller 10 that is in contact with the intermediate transfer belt 1 and the intermediate transfer belt lubricant 7 and is rotating. The rotating intermediate transfer lubricant applying roller 10 is obtained by winding a shaft made of a thread formed on a surface of a base cloth 21 in a loop shape as shown in FIG. is there. This cloth may be knitted in a loop shape as shown in FIG. 3 (a), or may be one in which a thread is implanted in the base cloth 21 as shown in FIG. 3 (b).

  FIG. 4 is a view showing a mechanism for applying a lubricant to the photosensitive drum 2 used in the image forming apparatus of the present embodiment. Basically, the configuration is the same as that described above for applying the lubricant to the intermediate transfer belt 1. The photosensitive drum 2 and the intermediate transfer belt 1 rotate and move in the directions of arrows, respectively. After the transfer to the intermediate transfer belt 1 is finished, the residual toner remaining on the photosensitive drum 2 is cleaned by a photosensitive brush roller 18 as a cleaning assisting means and then a photosensitive member cleaning blade 17 as a main cleaning means. The As a result, the residual toner after transfer is removed cleanly, and the surface of the photosensitive drum 2 can be kept clean repeatedly. Thereafter, the lubricant is applied by the drum lubricant application brush roller 8 which is rotating in contact with the photosensitive drum 2 and the drum lubricant 6. It is assumed that the brush surface has the configuration shown in FIGS. 3A and 3B, similar to the intermediate transfer lubricant applying brush roller.

  The solid lubricant applied to the respective surfaces of the intermediate transfer belt 1 and the photoreceptor 2 is divided into a plurality of parts in the arrangement longitudinal direction. As the longitudinal arrangement of the lubricant, FIG. 5 shows an arrangement when the lubricant 19 is divided into two in the longitudinal direction, and FIG. 6 shows a case where the lubricant 19 is divided into three in the longitudinal direction. Show. Each of the lubricants 19 is disposed in a staggered manner with an overlapping portion 20. Although the size of the lubricant is not particularly limited, in this embodiment, for example, zinc stearate having a cross section of 8 mm square as shown in FIG. 7 is used.

  As shown in FIG. 8, the lubricant used in the image forming apparatus of the present embodiment preferably has a lubricant holding member 15 for holding a solid lubricant on one surface thereof. If such a configuration is adopted, when the lubricant is fixed to the image forming apparatus, for example, as shown in FIG. 10, a part of the holding member of the lubricant is fixed to the fixing position via the fixing means. Generally, it can be performed by fixing means such as a screw or a stapler, but the fixing means is not limited to this, and is usually used as a fixing means such as an adhesive (pressure-sensitive adhesive). The known fixing means can be used.

  FIG. 9 is a plan view showing a state in which there is no overlap between the lubricants used in the image forming apparatus of the present invention. In other words, the state where there is no overlap is the gap 22 where there is no overlap.

  FIG. 10 is a perspective view of the lubricant used in the image forming apparatus of this embodiment and worn by the brush roller.

  FIG. 11 is a schematic diagram showing an example of a pressing mechanism that is a sliding material used in the image forming apparatus of the present embodiment and that presses the lubricant against the brush roller with an elastic body.

  In this embodiment, in particular, the solid lubricant is arranged in a staggered pattern so that the application region always has an overlapping portion, and the region where application cannot be performed is eliminated. Further, in the present embodiment, the amount of the lubricant that adheres to the brush roller is larger in the overlapping portion than in other portions, which may cause the problem of uneven application of the lubricant. FIG. 12 shows an example in which uneven application occurs. As shown in this example, the friction coefficient of the surface on the applied side may be uneven, and there is a possibility that good cleaning properties may be lost.

For this reason, in the present embodiment, in order to prevent uneven application of the lubricant for the machine having the above-described configuration, the diameter of the application brush roller 23 in the longitudinal direction is not overlapped with the lubricant, and the overlapping region is, it is Ru main feature der whose diameter is different.

Further, in the present embodiment, the relationship between the diameter, as shown in FIG. 13 shall be the brush diameter 26 at which no overlap overlapped portions brush diameter 27 <. This is because the contact force of the application brush roller 25 on the side where the lubricant is applied can be weakened in the region of the overlapping portion 20, and the adhering ability of the region of the overlapping portion 20 can be weakened. As a result, as shown in the unevenness 24 in the amount of lubricant adhering in FIG. 12, the adhering amount was large in the overlapping portion, but as seen in the lubricant application amount 28 in FIG. It becomes possible to adhere to.

Further, in the present embodiment, the lubricant is a square bar, as shown in FIG. 7, that are held by only one side to the lubricant holding member 15 as shown in FIG. As a result, when it is gradually worn by the brush roller as shown in FIG. 10, since it is pressed on one surface, it is a sliding material that causes wear in a form along the brush roller. Can be used up to the end. The lubricant holding member 15 may be a metal or a resin, but is preferably a hard material because the strength of the lubricant itself can be increased. These holding members and the lubricant are bonded with a double-sided tape.

Further, in the present embodiment, the sliding material that is worn is pressed from behind the sliding material holding member by a spring, so that the sliding material can always be pressed against the brush roller with appropriate pressure even if worn. The With this structure, it is possible to use the lubricant efficiently.

Further, in the present embodiment, as a solid lubricant, that is using zinc stearate. Solid lubricants other than zinc stearate include, for example, barium stearate, lead stearate, nickel stearate, cobalt stearate, iron stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, stearic acid Magnesium, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, Relatively higher fatty acids such as lead cabrylate, lead cabronate, zinc linolenate, cobalt linolenate, cadmium linolenate can be used. Colloidal high-temperature silica powder can be used, and natural wax such as carnauba wax can also be used.

Further, the mechanism used in the image forming apparatus of the present embodiment can be mounted in the process cartridge. In other words, the application of the lubricant to the surface of the image carrier has a brush roller that can rotate in contact with the image carrier and the solid lubricant, and has cleaning means in which a plurality of solid lubricants are arranged in a staggered pattern in the longitudinal direction. realize the process cartridge. By making such a process cartridge detachable from the image forming apparatus, the same effects as those of the image forming apparatus of the present embodiment described above can be obtained. That is, even when the solid lubricant is divided and staggered and applied to the image carrier, the lubricant can be uniformly applied without unevenness, improving the cleaning property and the handling of the entire apparatus. . In addition, the lubricant can be uniformly attached to the longitudinal direction. In addition, the lubricant can be used up to the end efficiently. Moreover, it becomes possible to use a lubricating material efficiently.

  The embodiment of the present invention has been described above, but the present invention is not limited to the description of the embodiment, and various modifications can be made without departing from the scope of the invention.

1 is a cross-sectional view illustrating a configuration of a color image forming apparatus that is an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a lubricant application mechanism to an intermediate transfer belt used in the image forming apparatus that is an embodiment of the present invention. It is sectional drawing which shows the base fabric for lubricant coating rollers used for the image forming apparatus which is one Embodiment of this invention. 1 is a cross-sectional view showing a mechanism for applying a lubricant to a photosensitive drum used in an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing the arrangement of the lubricant used in the image forming apparatus according to the embodiment of the present invention and divided into two in the longitudinal direction. FIG. 3 is a schematic diagram illustrating an arrangement of a lubricant used in an image forming apparatus according to an embodiment of the present invention and divided into three in the longitudinal direction. 1 is a perspective view showing a lubricant using zinc stearate as a lubricant used in an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view showing a lubricant used in the image forming apparatus according to the embodiment of the present invention, the lubricant being held on one surface of the lubricant by a lubricant holding member. FIG. 3 is a plan view showing a state in which there is no overlap between the lubricants used in the image forming apparatus according to the embodiment of the present invention. 1 is a perspective view showing a lubricant used in an image forming apparatus according to an embodiment of the present invention and worn by a brush roller. FIG. 5 is a schematic diagram illustrating a state in which the lubricant is used in the image forming apparatus according to the embodiment of the present invention and the elastic body pushes the lubricant against the brush roller. It is explanatory drawing which shows generation | occurrence | production of the coating unevenness of a lubricating material. It is a side view which shows the sliding material overlapping part brush diameter used for the image forming apparatus which is one Embodiment of this invention. FIG. 5 is an explanatory diagram illustrating an example in which the lubricant is used in the image forming apparatus according to the embodiment of the present invention and the lubricant coating amount is uniformly attached in the longitudinal direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate transfer belt 2 Photosensitive drum 3 Primary transfer roller 4 Secondary transfer roller 5 Intermediate transfer drive roller 6 Drum lubricant 7 Intermediate transfer belt lubricant 8 Drum lubricant application brush roller 9 Intermediate transfer cleaning unit 10 Intermediate transfer lubricant Application roller 11 Intermediate transfer driven roller 12 Intermediate transfer unit 13 Intermediate transfer brush roller 14 Intermediate transfer cleaning blade 15 Lubricant holding member 16 Pressure spring (pressing means)
DESCRIPTION OF SYMBOLS 17 Photoconductor cleaning blade 18 Photoconductor brush roller 19 Lubricant 20 Overlapping part 21 Base cloth 22 Gap 23 Applicable brush roller 24 Unevenness of the amount of lubricant adhering 25 Application brush roller 26 Brush diameter of non-overlapping part 27 Overlapping part brush Diameter 28 Lubricant application amount 30 Drum unit

Claims (4)

Application of the lubricant to the surface of the image carrier is performed by a brush roller that is in contact with the image carrier and the solid lubricant and is rotatable, and a plurality of the solid lubricants are arranged in a staggered pattern in the longitudinal direction. An image forming apparatus having a plurality of overlapping portions in which the solid lubricants are alternately overlapped,
The brush roller is
Portion not in contact with each of the plurality of overlapping portions, while a first brush diameter portion come in contact with each of the plurality of overlapping portions, the second the diameter than the first brush diameter is small An image forming apparatus having a brush diameter.   The image forming apparatus according to claim 1, wherein the solid lubricant has a holding member that holds the solid lubricant on one surface thereof.   The image forming apparatus according to claim 2, wherein the holding member has a pressing mechanism against the brush roller by an elastic member.   The image forming apparatus according to claim 1, wherein the solid lubricant is zinc stearate.

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