JP2013218209A - Cleaning member, cleaning device, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning member in which increase in a driving torque at the time of driving an image carrier and turn-up of a blade are suppressed, and adjustment of position at the time when the cleaning member is attached to a fixing part is not required, so as to improve productivity.SOLUTION: A cleaning member 11 includes: one end portion 11a1 provided with a blade portion 11c; the other end portion 11a2 having a fixed portion 11a5 to be fixed to a fixing portion 12a; a bent portion 11a3 which is located between the one end portion 11a1 and the other end portion 11a2, and located on a side being separated outward from the surface of a cleaned body 1 with respect to a line segment connecting an abutting portion where the blade portion 11c abuts the cleaned body 1 and the fixed portion; and a supporting part 11a which is provided between the bent portion and the fixed portion and has a fulcrum portion 11a4 serving as a fulcrum at the time when the other end portion distanced from the bent portion by a prescribed distance J is sagged.

Description

  The present invention relates to a cleaning member, a cleaning device, and a process cartridge that remove developer from the surface of an image carrier.

  Here, examples of the image forming apparatus include an electrophotographic copying machine, a laser beam printer, an LED printer, and a facsimile machine. The process cartridge refers to a cartridge in which at least the image carrier and the cleaning device are integrated into a cartridge that can be attached to and detached from the image forming apparatus.

  In an electrophotographic image forming apparatus, after transferring a developer image formed on an image carrier to a recording medium in order to repeatedly use the image carrier, cleaning is performed as a cleaning unit for removing the developer remaining on the image carrier. A blade system is known.

  The cleaning blade method is a method of removing the developer from the surface of the image carrier by bringing an elastic blade into contact with the surface of the image carrier with a predetermined pressure.

  In Patent Document 1, the cleaning member has a structure in which a blade is attached to the tip of a sheet metal as a support portion by molding. Then, the cleaning member is fixed by attaching the sheet metal to the frame body with screws or the like, thereby being brought into contact with the surface of the image carrier at a predetermined pressure.

JP 2002-341721 A

  However, with the widespread use of image forming apparatuses such as printers, there is a tendency for miniaturization, high speed, and high image quality. If the image forming apparatus is downsized, the size of the image carrier is reduced. In addition, the image carrier rotates faster due to the higher speed. That is, the blade that is in contact with the surface of the image carrier causes the image carrier to slide repeatedly on the surface of the image carrier at a high speed. Then, the temperature of the blade itself rises and the hardness of the blade becomes soft. As a result, the frictional force between the image carrier surface and the blade increases. As a result, there may be problems such as an increase in driving torque for driving the image bearing member and blade curl. Furthermore, recently, a developer having a spherical shape may be used to improve image quality. In this case, in order to remove the developer from the surface of the image carrier, it is necessary to increase the contact pressure of the blade against the image carrier, which is one of the factors that promote the above-described problem.

  Therefore, the present invention has been made to solve the above-described problems of the prior art. An object of the present invention is to provide a cleaning member, a cleaning device, a process cartridge, and an image forming apparatus capable of suppressing an increase in driving torque when driving an image carrier and curling of a blade. . It is another object of the present invention to provide a cleaning member, a cleaning device, and a process cartridge that realizes an improvement in productivity, in which the position adjustment is not required when the cleaning member is attached to a fixed portion.

A representative configuration of the present invention for solving the above-described problem is that a cleaning member attached to a fixed portion that removes developer from a cleaning target is the counter member in a counter direction with respect to the moving direction of the image carrier. A blade portion that contacts the object to be cleaned;
A support portion that supports the blade portion and has flexibility, the one end portion provided with the blade portion, the other end portion having a fixed portion fixed to the fixing portion, and the one end portion, The side that is located between the other end and that is away from the surface of the object to be cleaned with respect to the line segment that connects the fixed part and the contact part where the blade part contacts the object to be cleaned And a support portion having a fulcrum portion provided between the bend portion and the fixed portion and serving as a fulcrum when the other end portion at a predetermined distance from the bend portion is bent. It is characterized by having.

  According to the present invention, it is possible to stabilize the contact pressure of the cleaning member to the image carrier, and to suppress an increase in driving torque when the image carrier is driven and to curl the blade portion. Further, when the cleaning member is attached to the fixed portion, the position adjustment is not necessary, and the productivity can be improved.

Sectional drawing of the cleaning member of 1st Example Sectional view of image forming apparatus of embodiment Sectional view of cleaning member of comparative example Sectional drawing of the cleaning member of 2nd Example Sectional drawing of the cleaning member of 3rd Example Sectional view of cleaning member of comparative example Sectional view of cleaning member of comparative example The figure which showed the relationship between the penetration | invasion amount and blade pressure in an Example The figure which showed the relationship between the dynamic friction coefficient and blade pressure in an Example Sectional drawing of the cleaning member of 4th Example Cross-sectional view of the tip of the cleaning member in the comparative example The figure which showed the relationship between a dynamic friction coefficient and contact pressure (blade pressure) in a conventional example and a comparative example

  The image forming apparatus of this embodiment is shown in FIG. FIG. 2 is a longitudinal sectional view of the electrophotographic image forming apparatus 100.

  The apparatus main body M of the image forming apparatus 100 is configured such that a process cartridge 14 having a photosensitive drum 1, a charging roller 2, a developing device 5, and a cleaning device 9 is detachable. When the process cartridge 14 is mounted on the apparatus main body M, the photosensitive drum 1 serving as an image carrier is located at the approximate center of the apparatus main body M. The photosensitive drum 1 has an OPC (organic optical semiconductor) photosensitive layer formed on the outer peripheral surface of a conductive cylinder substrate such as aluminum, and has a predetermined process speed (circumferential rotation) in the direction of an arrow R1 about the axis q. Speed) Rotates at 200mm / s.

  The peripheral surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by a charging roller 2 as a charging unit described later. On the peripheral surface of the photosensitive drum 1 after charging, a laser beam output from a laser beam scanner 3 as an exposure unit is checked to form an electrostatic latent image corresponding to target image information. This electrostatic latent image is developed into a toner image by a developer contained in a developing device 5 as a developing unit. On the other hand, the recording material 6 is fed by a feed roller (not shown), and the toner image formed on the photosensitive drum 1 is conveyed to a transfer nip portion between the photosensitive drum 1 and the transfer roller 8 to transfer the toner image. Is done. A transfer bias for transfer is applied to the transfer roller 8 from a power source provided in the apparatus main body M. The recording material 6 that has received the transfer of the toner image is separated from the surface of the photosensitive drum 1, conveyed to a fixing device 10 as a fixing unit, and heated and pressurized. Then, the toner image is fixed on the recording material 6. On the other hand, after the toner image has been transferred, the toner 7 remaining on the surface without being transferred to the recording material 6 is removed by a cleaning member 11 provided in a cleaning device 9 as a cleaning means.

[Cleaning device]
The cleaning device 9 includes a cleaning member 11, a squeeze sheet 13, and a cleaning container 12. The cleaning member 11 is in contact with the surface of the photosensitive drum 1 as a member to be cleaned in the counter direction with respect to the moving direction R1 of the photosensitive drum 1. The cleaning member 11 is fixed to a fixing portion 12 a provided in the cleaning container 12. A squeeze sheet 13 that contacts the surface of the photosensitive drum 1 for scooping off the toner removed by the cleaning member 11 is provided below the cleaning member 11. Then, the scraped waste toner is stored in a cleaning container 12 which is a toner storage portion constituted by a frame.

[Comparative example]
Next, details of the cleaning member of the comparative example will be described.

  FIG. 3 shows the overall configuration of the cleaning member 111. The cleaning member 111 has a flexible metal thin plate support portion 111a and a blade portion 111c that is integrally formed with one end portion 111a1 of the support portion 111a and abuts against the photosensitive drum 104. And between the one end part 111a1 and the other end part 111a2 of the support part 111a, it has the bending part 111a3. Further, the fixed portion 111a4 provided at the other end 111a2 is fixed to the fixing portion 112 provided at the cleaning container (not shown) with the screw 105. Thereby, the cleaning member 111 is fixed to a cleaning container (not shown). Further, the bent portion 111a3 is located away from the surface of the photosensitive drum 104 with respect to a line segment L1 connecting the abutting portion 111c1 where the blade portion 111c abuts on the photosensitive drum 104 and the fixed portion 111a2. is there.

  Here, as the material of the support portion 111a, SUS having a thickness of 0.2 mm was used. The bent portion 111a3 is bent at approximately 90 ° uniformly in the direction of the photosensitive drum rotation axis. At this time, the distance L2 from the fixed part 111a2 to the bent part 111a3 was 12 mm, and the distance L3 from the bent part 111a3 to the blade part 111c was 12 mm. The blade part 111c is made of urethane rubber and has a JISA hardness of 70 degrees. The shape is as shown in FIG. 11, and evaluation was performed at about k = 3.0 mm, l = 2.0 mm, m = 1.0 mm, and n = 1.0 mm in order to reduce the deformation effect of the tip. As a method of bonding the support portion 111a and the blade portion 111c, a method using a double-sided tape or a hot melt adhesive is used in addition to the integral molding. Further, the contact angle of the blade portion 111c to the photosensitive drum 104 is about 30 degrees, and 1 mm is inserted. The contact pressure at that time was about 40 gf per 1 cm in the axial direction of the photosensitive drum 104. When the contact angle was checked at 20 degrees, the contact pressure was about 35 gf per 1 cm in the axial direction of the 104 axis.

  It confirmed also about the cleaning member which does not have a bending part as a prior art example. As the flexible member of the support portion, the same SUS as in the comparative example and a 0.2 mm thick member was used. The length from the fixed part to the blade part was 21.5 mm. Furthermore, as the material of the blade portion, urethane rubber having a JISA hardness of 70 degrees was used, and the dimensions were the same as those in the above embodiment. When this cleaning member was also allowed to penetrate 1 mm into the photosensitive member at a contact angle of 30 degrees, the contact pressure was about 40 gf per 1 cm in the photosensitive drum rotation axis direction.

  Here, deformation calculation was performed on the cleaning members of the comparative example and the conventional example. As a calculation method, assuming the friction, calculate the relationship between the deformed shape and the force applied when the blade tip is pushed in the downstream direction of rotation of the photoconductor drum, and contact the component perpendicular to the photoconductor surface from the obtained force. The pressure and parallel components were determined as the friction force, and the ratio was determined as the friction coefficient.

The deformation calculation at this time was performed by modeling with a simple two-dimensional cantilever beam by considering the blade support and the neutral axis of the blade.
(Bernoulli-Euler assumption)
In addition, as a parameter used for calculation,
Bending rigidity of SUS plate D = E / (1-ν) = 150 MPa
Longitudinal elastic modulus of urethane rubber E = 6MPa
Was used.

  FIG. 12 shows the result. The horizontal axis represents the dynamic friction coefficient, and the vertical axis represents the contact pressure. Thus, when compared with a conventional cleaning blade having a simple linear structure, it can be seen that the contact pressure of the force in the vertical direction is significantly stable with respect to the increase of the dynamic friction coefficient in the comparative example. Therefore, also in the comparative example, it is possible to sufficiently suppress an increase in driving torque when the photosensitive drum 104 is driven and curl of the blade portion 111c.

  However, in the comparative example, even if the dimensions L2 and L3 of the cleaning member 111 are accurately controlled, the length J of the deformable portion of the other end 111a2 may change due to variations in the mounting position of the cleaning member 111. There is. That is, when the length of J is short, the flexibility of the other end 111a2 of the support 111a is lowered as shown in FIG. 6, so that the contact pressure of the blade 111c to the photosensitive drum 104 increases. Conversely, when J is long, the flexibility of the other end 111a2 of the support 111a is increased as shown in FIG. 7, so that the contact pressure of the blade 111c to the photosensitive drum 104 is reduced. Become.

[Cleaning member]
Therefore, in this embodiment, a configuration for further improving the stabilization of the contact pressure of the cleaning member to the photosensitive drum will be described.

  Next, the cleaning member of Example 1 will be described.

  The cleaning member 11 of Example 1 differs from the cleaning member 111 of the comparative example in that it has a bent portion in addition to the bent portion 11a3 between the one end portion 11a1 having the blade portion 11c and the other end portion 11a2. . Other configurations are the same as in the comparative example. That is, the fixed portion 11a5 is provided on the distal end side of the other end portion 11a2 via the second bent portion 11a4 and the third bent portion 11a6. In the cleaning member 11, a fixed portion 11 a 5 provided on the downstream side of the blade portion 11 c with respect to the moving direction R <b> 1 of the photosensitive drum 1 is fixed to a fixing portion 12 a provided in the cleaning container 9 with screws 15. . Thereby, the cleaning member 11 is attached to the cleaning container 9 (see FIG. 2).

  In the cleaning member 11 of this embodiment, when the photosensitive drum 1 and the blade portion 11c are in contact with each other, the contact pressure is ensured mainly by bending the other end portion 11a2 upward. When the other end portion 11a2 bends upward, the second bent portion 11a4 which is a fulcrum portion serves as a fulcrum. In this configuration, by managing the distance J from the bent portion 11a3 to the second bent portion 11a4 accurately and uniformly, as shown in FIG. 9, the photosensitive drum 1 of the blade portion 11c can be compared with the comparative example. It is possible to further stabilize the contact pressure. FIG. 9 shows the variation in the contact pressure of the blade portion 11c against the photosensitive drum 1 when the dynamic friction coefficient of the blade portion 11c with the photosensitive drum 1 changes. In contrast to the variation range b1 to b2 in the comparative example, the variation range in the configuration of the present example was within the range a1 to a2, and the contact pressure could be stabilized. FIG. 8 shows the relationship between the amount of penetration of the blade portion 11c into the photosensitive drum 1 and the contact pressure of the blade 11c. As can be seen from this graph, the inclination of the contact pressure of the blade 11c with respect to the intrusion amount is small, and in this embodiment, the variation of the contact pressure with respect to the intrusion amount can be suppressed as compared with the comparative example. all right.

  Next, the cleaning member of Example 2 will be described with reference to FIG.

  The cleaning member 21 of the second embodiment also has a bent portion in addition to the bent portion 21a3 between the one end portion 21a1 and the other end portion 21a2 as in the first embodiment. That is, a fixed portion 21a5 fixed to the fixing portion 22a with the screw 25 is provided on the tip end side of the other end portion 21a2 via the V-shaped second bent portion 21a4. The second bent portion 21a4 protrudes toward the fixed portion 22a. The bent portion 21a4 comes into contact with a contact portion 22a2 provided in the fixed portion 22a and recessed from the surface 22a1 to which the fixed portion 21a5 is attached.

  Also in the second embodiment, when the photosensitive drum 1 and the blade portion 21c come into contact with each other, the cleaning pressure of the cleaning member 21 is ensured mainly by bending the other end portion 21a2 upward. . When the other end portion 21a2 bends upward, the second bent portion 21a4, which is a fulcrum portion that is in contact with the contact portion 22a1, serves as a fulcrum. Also in this configuration, by managing the distance J from the bent portion 21a3 to the second bent portion 21a4 with high accuracy and constant, the photosensitive member of the blade portion 21c is compared with the comparative example as shown in FIGS. It is possible to further stabilize the variation in the contact pressure on the drum 1. Other configurations are the same as those in the first embodiment.

  Next, the cleaning member of Example 3 will be described with reference to FIG.

  In the cleaning member 31 of the third embodiment, the fixed portion 31a5 is fixed to the fixing portion 32a with the screw 35, and the other end portion 31a2 is bent 180 degrees in the direction of the fixing portion 32a. And end part 31a5a of fixed part 31a5 which is a return part contacts the 3rd contact part 31a2a in the middle of other end 31a2. Also in the third embodiment, when the photosensitive drum 1 and the blade portion 31c come into contact with each other, the cleaning pressure of the cleaning member 31 is ensured mainly by bending the other end portion 31a2 upward. . When the other end portion 31a2 bends upward, the third contact portion 31a2a serves as a fulcrum. Also in this configuration, by controlling the distance J from the bent portion 31a3 to the third contact portion 31a2a with high accuracy and constant, the photosensitive portion of the blade portion 31c is compared with the comparative example as shown in FIGS. It is possible to further stabilize the variation in the contact pressure on the body drum 1.

  In the cleaning member 31 of Example 3, the fulcrum portion was formed using the end portion of the fixed portion 31a5 that is the folded portion.

  In the cleaning member 41 of the fourth embodiment, the other end 41a2 is not folded back, but a spacer 42e, which is a spacing member, is attached between the other end 31a2 and the fixing portion 42a. The spacer 42 is provided with a through hole 42a through which the screw 45 passes. The through hole 45 a is a hole having a larger diameter than the screw portion 45 a of the screw 45. Therefore, the spacer 42 is configured to be movable so that the distance from the bent portion 31a3 to the fourth contact portion 41a2a can be adjusted. The screw portion 45a of the screw 45 is engaged with a screw hole provided in the fixing portion 43a, so that the cleaning member 41 is attached to the fixing portion 43a.

  And the corner | angular part 42b of the spacer 42 is made to come to the position of the distance J from the bending part 41a3. By doing so, the contact part 41a2a of the other end part 41a2 with which the corner part 42b comes into contact becomes a fulcrum part, and the other end part 41a2 bends upward. Also in this configuration, by managing the distance J from the bent portion 41a3 to the fourth contact portion 41a2a with high accuracy and constant, the photosensitive portion of the blade portion 41c is compared with the comparative example as shown in FIGS. It is possible to further stabilize the variation in the contact pressure on the body drum 1.

  As described above, in this embodiment, the cleaning member that removes the toner from the photosensitive drum as the member to be cleaned has been described. However, the member to be cleaned may be a transfer belt as a transfer member to which the developed image is transferred from the photosensitive drum.

  As described above, the contact pressure of the cleaning member to the image carrier can be stabilized as described in the present embodiment. Therefore, it is possible to suppress an increase in driving torque when driving the image bearing member and to prevent the blade portion from curling. Further, when the cleaning member is attached to the fixed portion, the position adjustment is not necessary, and the productivity can be improved.

11 cleaning member 11a support part 11a1 one end part 11a2 other end part 11a3 bending part 11a4 fulcrum part 11a5 fixed part

Claims (12)

In the cleaning member that is attached to the fixed part and removes the developer from the object to be cleaned,
A blade portion that contacts the object to be cleaned in a counter direction with respect to the moving direction of the object to be cleaned;
A support portion that supports the blade portion and has flexibility, the one end portion provided with the blade portion, the other end portion having a fixed portion fixed to the fixing portion, and the one end portion, The side that is located between the other end and that is away from the surface of the object to be cleaned with respect to the line segment that connects the fixed part and the contact part where the blade part contacts the object to be cleaned And a support portion having a fulcrum portion provided between the bend portion and the fixed portion and serving as a fulcrum when the other end portion at a predetermined distance from the bend portion is bent. When,
A cleaning member.   The cleaning member according to claim 1, wherein the fulcrum portion is a second bent portion.   The cleaning member according to claim 1, wherein the fulcrum part is a second contact part that contacts the fixed part.   The cleaning member according to claim 1, wherein the fulcrum portion is a third abutting portion that abuts against an end portion of the folded portion of the support portion folded from the fixed portion.   The cleaning member according to claim 1, wherein the fulcrum portion is a fourth contact portion that contacts an end portion of a spacer provided between the fixed portion and the fixed portion.   The cleaning member according to claim 1, wherein the blade portion is supported only by the one end portion.   The cleaning member according to claim 1, wherein the support portion is a metal leaf spring. In a cleaning device used in an image forming apparatus,
The fixing portion provided on the frame;
A cleaning member according to any one of claims 1 to 7,
An accommodating portion for accommodating the developer removed from the object to be cleaned;
Having a cleaning device.   The cleaning apparatus according to claim 8, wherein the fixed portion is provided on the downstream side in the moving direction of the cleaning target body with respect to the contact portion.   The cleaning apparatus according to claim 8, wherein the object to be cleaned is an image carrier on which an electrostatic latent image is formed.   The cleaning apparatus according to claim 8, wherein the member to be cleaned is a transfer member to which a developed image is transferred. A process cartridge that can be attached to and detached from the main body of the image forming apparatus,
A cleaning device according to claim 10;
A photosensitive drum as the image carrier;
A process cartridge.

Images