JP3687328B2 - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning device, a process cartridge, and an image forming apparatus, and more particularly, to a cleaning device, a process cartridge, and an image forming apparatus that can maintain cleaning performance for a long period of time.
[0002]
[Prior art]
Conventional image forming apparatuses using an electrophotographic system can output high-quality images at high speed, and are widely used in various image forming apparatuses such as electrophotographic copying machines and printers.
[0003]
In such an image forming apparatus, the surface of an image carrier represented by a photosensitive drum or a photosensitive belt (hereinafter simply referred to as a photosensitive member) is charged first, and the charged photosensitive member is irradiated with light such as a laser beam. An electrostatic latent image is formed on the photoreceptor by exposing the surface of the body.
[0004]
Then, the electrostatic latent image is developed by selectively attracting toner to form a toner image.
[0005]
Further, the toner image is transferred from the photoreceptor to a recording medium such as plain paper (hereinafter referred to as paper unless otherwise specified), and then fixed by heat or pressure to form an image on the paper.
[0006]
This image forming apparatus is provided with a cleaning device for removing unnecessary toner adhering to the surface of the photosensitive drum.
[0007]
Conventional cleaning devices often use an elastic cleaning blade made of polyurethane rubber.
[0008]
This cleaning blade is deteriorated in cleaning performance and needs to be replaced with a new one as the number of times of use (number of printed sheets, number of copied sheets) advances to some extent in the image forming apparatus.
[0009]
There are various types of deterioration of the cleaning blade, but mainly, wear and damage of the blade edge, reduction of the urging force on the surface of the photosensitive drum due to the sag of the blade, and the like.
[0010]
Also, with process cartridges in which the image forming apparatus including the cleaning blade can be detached from the main body, recently used process cartridges are collected and used as recycled products by replacing deteriorated parts, cleaning, replenishing toner, etc. Thus, so-called recycling activities have been actively carried out.
[0011]
In this recycling, it is desirable that the parts can be used many times without changing as much as possible.
[0012]
For example, in Japanese Patent Application Laid-Open No. 7-77897, the setting position of two or more kinds of process cartridge cleaning blades can be changed, and at the time of reproduction, the blade tip is cut to form a new edge surface. The position is set where the edge surface and the image carrier are at a predetermined position.
[0013]
[Problems to be solved by the invention]
In the present invention, the tip of the cleaning blade is cut, but a special equipment for exclusive use is required to obtain an edge surface that requires precision.
[0014]
Further, when the blade tip is cut, the dimensions are shortened, and there is a concern that the urging force on the image carrier changes.
[0015]
Therefore, in many cases, the cleaning blade is usually replaced for each part.
[0016]
SUMMARY OF THE INVENTION In view of the above, has been made to solve the above problems, cleaning cleaning blade similar cleaning performance and when new regenerated multiple times, can maintain the cleaning performance for a long time An object is to provide an apparatus, a process cartridge, and an image forming apparatus .
[0017]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a cleaning device comprising a cleaning blade that contacts the surface of the image carrier of the image forming apparatus and cleans the surface of the image carrier, and a holder that holds the cleaning blade. The cleaning blade has a cutting portion for separating the cleaning blade into at least a first cleaning blade piece and a second cleaning blade piece, and the holder is provided on the image carrier side of the cleaning blade. A base member and a fixing member that perform the holding so as not to contact a part of the region, the fixing member holding a cleaning blade before separation between the base member and the base member; A second holding portion for holding the first cleaning blade piece or the second cleaning blade piece between the base member and the base member; That, it is characterized in that.
[0018]
The operation of the cleaning device according to claim 1 will be described .
[0019]
The cleaning device according to claim 1 , wherein the first cleaning blade piece or the second cleaning member is interposed between the first holding portion that holds the cleaning blade before separation between the fixing member and the base member, and the base member. And a second holding part for holding the blade piece, the cleaning blade before separation is held between the base member and the first holding part of the fixing member, and the first after the cleaning blade is separated. The cleaning blade piece or the second cleaning blade piece can be held between the base member and the second holding portion of the fixing member.
[0020]
According to a second aspect of the present invention, there is provided a cleaning device comprising: a cleaning blade that contacts the surface of the image carrier of the image forming apparatus and cleans the surface of the image carrier; and a holder that holds the cleaning blade. The cleaning blade has a cutting portion for separating at least a first cleaning blade piece and a second cleaning blade piece, and the holder has an image of the cleaning blade before separation. Avoid contact with the edge opposite to the carrier side and the edge formed on the first cleaning blade piece and the edge formed on the second cleaning blade piece when separated by the cutting portion. A concave portion is formed.
[0021]
The operation of the cleaning device according to claim 2 will be described .
[0022]
In the cleaning device according to the second aspect, since the concave portion is formed in the holder, the edge opposite to the image carrier side when the cleaning blade before separation is held and the first edge when separated by the cutting portion are used. Three edges of the edge formed on the one cleaning blade piece and the edge formed on the second cleaning blade piece do not directly hit the holder. Therefore, these three edges can be kept in the best state.
[0023]
According to a third aspect of the present invention, in the cleaning device according to the first or second aspect, the cutting portion is a cut or a groove extending linearly from one end to the other end. .
[0024]
The operation of the cleaning device according to claim 3 will be described .
[0025]
In the cleaning blade of the cleaning device according to claim 3, since the cut or groove is formed linearly from one end to the other end, the first cleaning blade piece and the second cleaning blade are more easily formed than the cut or groove. It can be separated into cleaning blade pieces. Further, by separating from the cuts or grooves, the first cleaning blade piece and the second cleaning blade piece are each formed with an edge capable of efficiently removing unnecessary developer adhering to the surface of the image carrier. Is done.
[0026]
According to a fourth aspect of the present invention, there is provided a rotatable image carrier that forms an electrostatic latent image on an outer peripheral surface, and a developing unit that visualizes the developer by attaching a developer to the electrostatic latent image. The cleaning device according to any one of claims 1 to 3, wherein the cleaning device is detachable from the image forming apparatus main body, and is downstream of the developing unit in the rotation direction of the image carrier. It is characterized by having.
[0027]
The operation of the process cartridge according to claim 4 will be described .
[0028]
In the process cartridge according to the fourth aspect, when an electrostatic latent image is formed on the outer peripheral surface of the image carrier, the electrostatic latent image can be visualized by attaching a developer to the developing unit. The visualized image is then transferred to a sheet of the image forming apparatus.
[0029]
The image carrier after the image transfer is rotated by the driving device of the image forming apparatus, and the outer peripheral surface can be cleaned by the cleaning device.
[0030]
Since this process cartridge has the cleaning device according to any one of claims 1 to 3 , one cleaning blade can be used over a long period of time.
[0031]
According to a fifth aspect of the present invention, there is provided an image having a rotatable image carrier that forms an electrostatic latent image on an outer peripheral surface, and a developing unit that visualizes the developer by attaching a developer to the electrostatic latent image. A forming apparatus, comprising the cleaning device according to any one of claims 1 to 3 on a downstream side of the developing unit in a rotation direction of the image carrier.
[0032]
The operation of the image forming apparatus according to claim 5 will be described .
[0033]
In the image forming apparatus according to claim 5, when the electrostatic latent image is formed on the outer peripheral surface of the image carrier, the electrostatic latent image can be visualized by attaching a developer at the developing unit. . The visualized image is then transferred to a sheet of the image forming apparatus.
[0034]
The image carrier after the image transfer is rotated by the driving device of the image forming apparatus, and the outer peripheral surface can be cleaned by the cleaning device.
[0035]
Since this image forming apparatus has the cleaning device according to any one of claims 1 to 3 , one cleaning blade can be used for a long period of time.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
[0037]
[Entire configuration of image forming apparatus]
FIG. 1 shows a schematic configuration of a laser beam printer 1 as an example of an image forming apparatus of the present invention.
[0038]
As shown in FIG. 1, the laser beam printer 1 is provided with a laser scanning device 5 for irradiating a photosensitive drum 9 as an image carrier to be described later with a laser beam. Is provided with a semiconductor laser (not shown).
[0039]
The semiconductor laser is modulated based on print data sent from an information processing device (not shown) directly connected to the laser beam printer 1 or an information processing device connected via a network such as a LAN (local area network). The laser beam is output.
[0040]
The output laser beam is deflected by the polygon mirror 15 that rotates in a predetermined direction and enters the fθ lens 16.
[0041]
The laser beam emitted from the fθ lens 16 is sequentially reflected by the first mirror 17 and the second mirror 18 to irradiate the exposure position 19 on the surface of the photosensitive drum 9 (hereinafter referred to as the drum surface) described later. Is done. The optical path of the laser beam is indicated by a dotted line 20.
[0042]
The laser beam printer 1 is detachably provided with a process cartridge 4 including a photosensitive drum 9, a developing device 13, a cleaning device, and the like.
[0043]
The cylindrical photosensitive drum 9 is rotated at a constant angular velocity in a predetermined rotation direction indicated by an arrow Q by a main motor (not shown), and the laser beam is deflected by the rotating polygon mirror 15, so that the surface of the drum is exposed to the photosensitive drum. The scanning is repeated in the axial direction 9 (main scanning direction). The laser beam scans the drum surface at a constant speed by the action of the fθ lens 16. A charging roll 11 is in contact with the drum surface slightly upstream of the exposure position 19 along the drum rotation direction indicated by the arrow Q, so that the drum surface is uniformly charged. The photoconductive drum 9 of the present embodiment uses an organic photoconductor and has a characteristic that should be negatively charged in order to form an electrostatic latent image. A negative voltage with a bias voltage superimposed is applied.
[0044]
An electrostatic latent image corresponding to print data is formed at the exposure position 19 on the drum surface that has been uniformly negatively charged.
[0045]
This electrostatic latent image is developed by the developing device 13 disposed on the downstream side of the exposure position 19 along the drum rotation direction indicated by the arrow Q.
[0046]
A developing roll 10 and a toner supply mechanism 12 are disposed in the developing device 13.
[0047]
The toner supply mechanism 12 is a mechanism for sequentially supplying the toner in the developing device 13 to the developing roll 10, and the developing roll 10 magnetically raises the toner to form the electrostatic latent image on the drum surface. It is a roll for forming a toner image corresponding to the electrostatic latent image by approaching or contacting the area.
[0048]
A negative development bias voltage obtained by superimposing a negative DC bias voltage on an AC voltage is applied to the developing device 13.
[0049]
In this embodiment, an electrostatic latent image is formed on the negatively charged drum surface, and the potential of the formation area of the electrostatic latent image is close to 0 volts.
[0050]
On the other hand, since a negative developing bias voltage is applied to the developing device 13, the potential difference between the negatively charged toner of the developing device 13 and the drum surface is small in the area where the electrostatic latent image is not formed. It becomes large in the formation area of the electrostatic latent image. For this reason, the toner is adsorbed only in the formation area of the electrostatic latent image.
[0051]
The toner image formed on the drum surface by the developing device 13 moves to a position where the transfer bias roll 29 is in contact with the drum surface by the rotation of the photosensitive drum 9.
[0052]
Here, the toner image is transferred to the paper 35 sent through the registration roll 24. In FIG. 1, the conveyance path of the paper 35 is indicated by a dotted line 32.
[0053]
The laser beam printer 1 includes a high voltage power supply 7 that supplies power to each device in the laser beam printer 1 and a CPU (not shown), and controls the operation of each device in the laser beam printer 1. A device 8 is provided.
[0054]
Next, the paper conveyance path of the laser beam printer 1 will be described. A cassette tray 6 is detachably disposed at the bottom of the apparatus body 2. On the cassette tray 6, sheets 35 cut into a predetermined size are stacked. The stacked sheets 35 are fed rightward in FIG. 1 one by one by the intermittent rotation of the half moon roll 21. In addition to the half-moon roll 21, another roll such as a retard roll or a mechanism for sucking and feeding the paper 35 may be used.
[0055]
The sheet 35 fed from the cassette tray 6 is conveyed to the registration roll 24 through the conveyance rolls 22 and 23 in order, and is stopped here, and then leftward in FIG. 1 in synchronization with the rotation of the photosensitive drum 9. It is conveyed to. A predetermined positive DC bias voltage is applied to the transfer bias roll 29 only when the paper 35 passes between the photosensitive drum 9 and the transfer bias roll 29. As a result, a toner image composed of negatively charged toner particles on the photosensitive drum 9 is electrostatically attracted to the transfer bias roll 29, and the toner image is transferred to the paper 35.
[0056]
The sheet 35 onto which the toner image has been transferred is discharged from the back (from the side opposite to the side on which the toner image has been transferred) from behind by a charge removal needle 37 disposed adjacent to the exit side of the transfer bias roll 29. The discharged paper 35 is peeled off from the drum surface, proceeds to the left in FIG. 1 along the conveyance path 32, and proceeds to the rolling contact position between the heat roll 25 and the pressure roll 26 that constitute the fixing device 59. The heat roll 25 is kept at a constant high temperature, and the pressure roll 26 presses the paper 35 against the heat roll 25, and efficient heat transfer is performed in the nip region between the two, so that the toner image is on the paper 35. To be established. After the fixing, the paper 35 passes through the transport roll 27 and is transported upward on the transport path 32 in a state where the switching piece 28 faces left upper in FIG. 1 (the state of the switching piece 28 in FIG. 1). Then, the paper is discharged to a discharge tray 3 provided on the upper portion of the apparatus main body 2 through a transport roll 30 and a discharge roll 31 in order. This is a conveyance path when printing on one side of the paper 35. When printing is performed on both sides of the paper 35, the switching piece 28 is switched to the state facing upward in FIG. 1 (the state of the switching piece 28A in FIG. 1), and the paper 35 is fed by the transport rolls 30, 33, 34. It is conveyed downward along the conveyance path 38. Thereafter, the paper 35 is transported by the half-moon roll 21, the transport rolls 22, 23, etc. along the same transport path as that for single-sided printing.
[0057]
In addition, while the sheet 35 is not present between the photosensitive drum 9 and the transfer bias roll 29, the photosensitive drum 9 and the transfer bias roll 29 are rotating (at least the transfer bias roll 29 makes one turn). In the meantime, a cleaning bias voltage having the same polarity as that at the time of transfer is applied to the transfer bias roll 29, and the contaminated toner charged on the transfer bias polarity side and attached to the surface of the transfer bias roll 29 is shifted to the photosensitive drum 9 side.
[0058]
Further, a cleaning bias voltage having a polarity opposite to that of the transfer is applied to the transfer bias roller 29 at least during the rotation of the transfer bias roller 29 once again, and the positive polarity attached to the surface of the transfer bias roller 29 (on the side opposite to the transfer bias). The toner is transferred to the photosensitive drum 9 side. In this way, the surface of the transfer bias roll 29 is cleaned.
[0059]
The toner transferred to the photosensitive drum 9 by the cleaning process is removed from the drum surface by a cleaning device 14 (described later) disposed between the transfer bias roll 29 and the charging roll 11. The cleaned photosensitive drum 9 is uniformly charged again by the charging roll 11 to prepare for the next image forming process.
[0060]
[Description of cleaning device]
As shown in FIGS. 1 and 2, the cleaning device 14 includes a thick plate-like cleaning device body 40 attached to the process cartridge 4.
[0061]
As shown in FIGS. 2 and 3, the cleaning device main body 40 has an end 40 </ b> A on the side of the photoconductor drum 9 parallel to the photoconductor drum 9, and a distance in a direction away from the photoconductor drum 9 from the end 40 </ b> A. Two screw holes 42 and two positioning bosses 44 are formed on a line L apart.
[0062]
A cleaning blade 48 is fixed to the cleaning device main body 40 by a holding metal fitting 46.
[0063]
The holding metal fitting 46 is formed of a rectangular metal plate, and a step 50 bent by a press or the like is formed in a part thereof. A wide portion 52 having a constant width is formed on one side of the step 50 and a width having a constant width on the other. A narrow portion 54 is provided.
[0064]
The wide portion 52 is formed with a round hole 56A and a long hole 58A into which the boss 44 is inserted, and a round hole 59A through which the screw 60 to be screwed into the screw hole 42 is inserted.
[0065]
The narrow portion 54 is formed with a round hole 56B and a long hole 58B into which the boss 44 is inserted, and a round hole 59B through which the screw 60 screwed into the screw hole 42 is inserted.
[0066]
As shown in FIGS. 3 and 4, the cleaning blade 48 is a rectangular elastic sheet (for example, a polyurethane rubber sheet) having a constant thickness t.
[0067]
On one side of the cleaning blade 48, a cut 62 having a depth D (<t) extending in a straight line from one end side to the other side in the longitudinal direction is formed in the central portion in the width direction.
[0068]
By forming the cut 62 in this way, four edges 64A, 64B, 64C, and 64D are formed on the cleaning blade 48 as shown in FIG. 4C.
[0069]
As shown in FIGS. 2 and 3, the new cleaning blade 48 is threaded through a round hole 59 </ b> B formed in the narrow portion 54 of the holding metal fitting 46, and the screw 60 is screwed into the screw hole 42 to hold the holding metal fitting. It is sandwiched and fixed between the wide portion 52 of 46 and the cleaning device main body 40.
[0070]
At this time, if one end in the width direction of the cleaning blade 48 is abutted and fixed to the step 50, the other end in the width direction of the cleaning blade 48 protrudes from the end 40A of the cleaning device main body 40 to the photosensitive drum 9 side by a predetermined dimension. The edge 64 </ b> A of the blade 48 contacts the outer peripheral surface of the photosensitive drum 9.
[0071]
In addition, grooves 66 and 68 are formed in the cleaning device main body 40 so that the cut line 62 and the edge 64B of the cleaning blade 48 do not contact each other.
[Action]
Unnecessary toner adhering to the outer peripheral surface of the photosensitive drum 9 (toner transferred from the transfer bias roll 29) is scraped from the outer peripheral surface by the edge 64A of the cleaning blade 48 as the photosensitive drum 9 rotates. To be removed.
[0072]
When the processing progresses and the cleaning performance deteriorates due to sag, edge wear, damage, etc., the cleaning blade 48 is attached in the opposite direction, and the opposite edge 64B is applied to the outer peripheral surface of the photosensitive drum 9 for cleaning. Do.
[0073]
When the cleaning performance of the opposite edge 64B deteriorates, the cleaning blade 48 is removed, and the cleaning blade 48 is separated into two parts from the cut 62 portion. Then, as shown in FIG. 5, one of the cleaning blades 48 </ b> A 48 </ b> A is fixed by the narrow portion 54 of the holding metal 46, and a new edge 64 </ b> C is abutted against the outer peripheral surface of the photosensitive drum 9.
[0074]
Further, when the cleaning performance by the edge 64C is deteriorated, the other 48B of the cleaning blade 48 separated into the other 48B is fixed by the holding metal 46 similarly to the case of FIG. Butt against the outer surface of the.
[0075]
As described above, in this embodiment, the four cleaning edges 48 can use the four edges 64A, 64B, 64C, and 64D, and the cleaning performance can be maintained for a longer period than in the past.
[0076]
Further, since the unused edge is not directly in contact with the cleaning device main body 40 by the groove 66, the optimum state can be maintained until it is used.
[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description.
[0077]
As shown in FIGS. 6 and 7, in the holding metal fitting 46 of this embodiment, a hole 59 </ b> C through which the screw 60 is inserted is formed in the vicinity of the step 50, and the screw 60 through which the hole 59 </ b> C is inserted into the cleaning device main body 40. A screw hole 42 for screwing is formed.
[0078]
Therefore, the screw 60 can be tightened near one side 48A (or the other side 48B) of the separated cleaning blade 48, and the fixing becomes stronger.
[0079]
Note that the cut 62 formed in the cleaning blade 48 of the above embodiment has a constant cut depth. However, as shown in FIGS. 8A and 8B, the cut depth changes alternately in magnitude. , A part may penetrate to the opposite side.
[0080]
Further, the cut 62 may be formed by cutting with a cutter knife, or may be a groove 70 instead of the cut as shown in FIG. 9 if an edge is formed.
[0081]
Further, when the cleaning blade 48 does not sag due to use, it is possible to form the groove 70 (or the cut 62) from both sides and use the eight edges 64A to H as shown in FIG. It is.
[0082]
【The invention's effect】
As described above , the cleaning device according to claim 1, the process cartridge according to claim 4, and the image forming apparatus according to claim 5 are configured as described above. The cleaning performance is regenerated a plurality of times, and the cleaning performance can be maintained over a long period of time.
[0083]
Further, the cleaning blade has an excellent effect that it can be easily separated into two parts from the cutting part without using a special cutter or the like, and a new edge can be used.
[0084]
In addition, the cleaning performance similar to that of a new product can be regenerated a plurality of times with a single cleaning blade, and the cleaning performance can be maintained for a long period of time, so that there is an excellent effect that the disposal of parts can be minimized.
[0085]
In the process cartridge according to the fourth aspect and the image forming apparatus according to the fifth aspect, the cleaning performance similar to that at the time of a new product can be reproduced a plurality of times. It has an excellent effect that a recycled product can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment.
FIG. 2 is a side view of the cleaning device.
FIG. 3 is an exploded perspective view of the cleaning device.
4A is a perspective view of a blade, FIG. 4B is a cross-sectional view of the blade shown in FIG. 4A, taken along line 4 (B) -4 (B), and FIG. 4C is an enlarged view of the blade. It is a side view.
FIG. 5 is a side view of the cleaning device.
FIG. 6 is a perspective view of a cleaning device according to a second embodiment.
FIG. 7 is a side view of a cleaning device according to a second embodiment.
8A is a perspective view of a cleaning blade according to another embodiment, and FIG. 8B is a cross-sectional view taken along line 8 (B) -8 (B) of the blade shown in FIG. 8A.
FIG. 9 is a side view of a cleaning blade according to still another embodiment.
FIG. 10 is a side view of a cleaning blade according to still another embodiment.
[Explanation of symbols]
1 Laser beam printer (image forming device)
4 Process cartridge
9 Photosensitive drum (image carrier)
13 Developing device 40 Cleaning device body (base member, holder)
46 Retaining bracket (fixing member, retainer)
48 cleaning blade 48A first cleaning blade piece 48B second cleaning blade piece 52 wide part (first holding part)
54 Narrow part (second holding part)
62 Cut (cut)
66 Groove (concave)
68 Groove (concave)
70 groove (cutting part)

Claims (5)

A cleaning blade that contacts the surface of the image carrier of the image forming apparatus and cleans the surface of the image carrier;
  A holder for holding the cleaning blade;
  A cleaning device comprising:
  The cleaning blade has a cutting part for separating at least a first cleaning blade piece and a second cleaning blade piece,
  The holder has a base member and a fixing member that perform the holding so as not to contact a part of the cleaning blade on the image carrier side.
  The fixing member holds the first cleaning blade piece or the second cleaning blade piece between the first holding portion for holding the cleaning blade before separation with the base member, and the base member. A second holding portion to
  A cleaning device. A cleaning blade that contacts the surface of the image carrier of the image forming apparatus and cleans the surface of the image carrier;
  A holder for holding the cleaning blade;
  A cleaning device comprising:
  The cleaning blade has a cutting part for separating at least a first cleaning blade piece and a second cleaning blade piece,
  The holder includes an edge opposite to the image carrier side of the cleaning blade before separation, an edge formed on the first cleaning blade piece when separated by the cutting portion, and the second cleaning blade A recess is formed so as not to contact the edge formed on the piece,
  A cleaning device. The cleaning device according to claim 1, wherein the cutting portion is a cut or a groove extending linearly from one end to the other end. A rotatable image carrier that forms an electrostatic latent image on the outer peripheral surface, and a developing unit that visualizes the electrostatic latent image by attaching a developer to the image forming apparatus main body. A possible process cartridge,
  4. A process cartridge comprising the cleaning device according to claim 1, further downstream in the rotation direction of the image carrier than the developing unit. 5. An image forming apparatus comprising: a rotatable image carrier that forms an electrostatic latent image on an outer peripheral surface; and a developing unit that visualizes the developer by attaching a developer to the electrostatic latent image,
  An image forming apparatus comprising the cleaning device according to claim 1, further on the downstream side in the rotation direction of the image carrier than the developing unit.

Images