JP2001042738A - Image forming device - Google Patents

Abstract

(57) [Problem] To improve the assemblability by preventing the surface of an image carrier and the leading edge of a blade in contact with the image carrier from being scraped by paper dust or the like. SOLUTION: A blade 21 for scraping toner remaining on the image carrier after the toner image on the image carrier is transferred by contacting the surface of the image carrier 10 which is a rotating body carrying the toner image. And a scooping sheet 22 for scooping toner scraped by the blade in contact with the image carrier below the contact portion C between the image carrier and the blade. The stacking member 23b to be slidably deposited on the front surface 11 is formed of a thin plate member integrally provided with the rake sheet, and the linear expansion coefficient of the stacking member is smaller than the linear expansion coefficient of the rake sheet. It is characterized by being small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a facsimile, a copying machine, etc., for forming an image by using an electrophotographic technique. In particular, the present invention relates to a cleaning device using a cleaning blade (hereinafter, simply referred to as a blade) for removing residual toner on an image carrier that carries the toner image.

[0002]

2. Description of the Related Art Generally, an image forming apparatus using an electrophotographic technique has a photosensitive member (an example of an image carrier) having a photosensitive layer on an outer peripheral surface, and a charging means for uniformly charging the outer peripheral surface of the photosensitive member. Exposure means for selectively exposing the outer peripheral surface uniformly charged by the charging means to form an electrostatic latent image; and toner as a developer on the electrostatic latent image formed by the exposure means Developing means for giving a visible image (toner image) by applying
Transfer means for transferring the toner image developed by the developing means onto a transfer medium such as paper; and contacting the surface of the photoreceptor to scrape off toner (residual toner) remaining on the outer peripheral surface of the photoreceptor after transfer. A cleaning device using a cleaning blade for removing and removing the cleaning blade. In order to transfer the toner image on the photoreceptor to a recording medium such as paper, the transfer unit transfers (primarily transfers) the toner image formed on the photoreceptor and carries the toner image. Is further provided with an intermediate transfer member (an example of an image carrier) for transferring (secondary transfer) the toner image onto a recording medium, and the intermediate transfer member also remains on the surface of the intermediate transfer member after the toner image is transferred. A cleaning blade that scrapes and removes toner (residual toner) is provided.

As a conventional cleaning device, FIG.
As shown in (a) or (b), a contact portion C between the image carrier 1 and the cleaning blade 3 which rotates in the direction of arrow A.
There is known a method in which toner is deposited in a space S below the toner image, and is slid in contact with the surface of the deposited toner image carrier 1 to remove various foreign substances precipitated from paper (Japanese Patent Application Laid-Open No. Hei. 161288). According to this conventional cleaning device, various foreign matters are removed by the accumulated toner slidingly contacting the surface of the image carrier 1, so that the paper dust adhering to the surface of the image carrier and slipping through the rake sheet 4 is removed. Are also removed by being captured by the accumulated toner. The conventional rake sheet (for example, the rake sheet 4 shown in FIG. 5) is made of a relatively soft material (for example, thermoplastic polyurethane) so as not to damage the surface of the image carrier 1. Since the rake sheet has a relatively large coefficient of linear expansion, if no measures are taken, the rake sheet will be twisted under high temperature and high humidity, and a gap will be generated between the rake sheet and the image carrier. Therefore, conventionally, when a rake sheet is directly attached to a case (see reference numeral 2 in FIG. 5) in order to prevent the above-described skew, the rake sheet is relatively stretched or stretched at a high temperature in a relatively linear state. It was attached to a case made of a material having a small expansion coefficient. When the rake sheet is not directly adhered to the case, the rake sheet is also stretched at a high temperature or in a state of being stretched at a high temperature along a relatively hard plate-like member (supporting member having a relatively linear expansion coefficient). (A member made of a small material), and the joining member of the rake sheet and the support member is attached to the case.

[0004]

In the conventional cleaning device described above, as is apparent from FIGS. 5A and 5B, the retaining wall 5 for depositing toner is relatively thick, or In addition, since it is provided in a state separated from the rake sheet 4, it is difficult to vibrate. Therefore, the accumulated toner is less likely to move in the accumulation area, so that the paper dust and the like captured by the accumulated toner are also less likely to move, and are likely to remain at the captured position, that is, the position in contact with the surface of the image carrier 1. . For this reason, the surface of the image carrier 1 may be shaved by the paper dust or the like. Further, since the deposited toner does not easily vibrate in the deposition area, it is difficult for the toner to enter between the captured paper dust and the like and the surface of the image carrier. Therefore, the paper dust once captured by the accumulated toner gradually moves along the surface of the image carrier (as if it were attached to the surface of the image carrier) while being hard to move as described above. And finally reaches the contact portion between the cleaning blade and the image carrier, and the surface of the image carrier and the leading edge of the blade in contact with the image carrier may be shaved by paper dust or the like. was there. Furthermore, directly attaching the rake sheet to the case in a state where the rake sheet is sufficiently pulled or stretched at a high temperature has a problem that the assemblability is poor. On the other hand, if the rake sheet is once adhered to the support member and this coupling member is adhered to the case, the assemblability is improved, but in this case,
There is a problem that a support member that is originally unnecessary is required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to reduce the possibility that the surface of the image carrier and the leading edge of the blade in contact with the image carrier are shaved by paper dust or the like. An object of the present invention is to provide an image forming apparatus capable of improving assemblability without using unnecessary members.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: an image carrier which is a rotating body for carrying a toner image; A cleaning blade that scrapes off toner remaining on the image carrier after the toner image on the image carrier is transferred, and contacts the image carrier below a contact portion between the image carrier and the cleaning blade. An image forming apparatus comprising: a scooping sheet for toner scraped off by the cleaning blade, wherein the toner scraped off by the cleaning blade is slidably deposited on the surface of the image carrier. The stacking member is a thin plate member integrally provided with the rake sheet, and the linear expansion coefficient of the stacking member is And wherein the smaller than the linear expansion coefficient of the bets. An image forming apparatus according to a second aspect is the first aspect.
In the above-described image forming apparatus, the deposition member is configured so that the distance from the surface of the image carrier gradually increases upward. According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the surface roughness Rz of the deposition member is equal to or less than ５ of the toner particle diameter. The “toner particle size” means the number average particle size of the toner used in the image forming apparatus. An image forming apparatus according to a fourth aspect is the image forming apparatus according to the first, second, or third aspect, wherein a surface roughness Rz of the rake sheet is 1/5 or less of a toner particle size. . According to a fifth aspect of the present invention, in the image forming apparatus of the first, second, third, or fourth aspect, the deposition member is made of a material that charges the toner to a predetermined charge polarity. And According to a sixth aspect of the present invention, in the image forming apparatus of the first, second, third, fourth, or fifth aspect, the rake sheet is made of a material for charging the toner to a predetermined charging polarity. Features.

[0007]

According to the image forming apparatus of the first aspect, the toner remaining on the image carrier after the transfer of the toner image on the image carrier, which is a rotating body for carrying the toner image, is performed by the image forming apparatus. The cleaning blade in contact with the surface of the carrier scrapes off and removes the toner, and the scraped toner is scooped with a scoop sheet. Further, since a depositing member for depositing the toner scraped off by the cleaning blade on the surface of the image carrier so as to be slidable is provided, the toner deposited by the depositing member causes the toner of the image carrier to be accumulated. The paper dust or the like adhering to the surface is trapped and removed before reaching the contact portion with the blade. According to the image forming apparatus of the first aspect, since the stacking member is constituted by the thin plate member provided integrally with the rake sheet, the following operation and effect can be obtained. That is, since the rake sheet is in contact with the image carrier, it slightly vibrates according to the rotation of the image carrier. This minute vibration is also transmitted to the stacking member provided integrally with the rake sheet. Since the stacking member is formed of a thin plate-shaped member, the stacking member also slightly vibrates. The toner deposited by the action of the depositing member is slidable on the surface of the image carrier, so that the toner can be circulated and moved in accordance with the rotation direction of the image carrier. Due to the action of the fine vibration of the stacking member, the deposited toner also vibrates finely, and the action of the fine vibration promotes the circulating movement of the toner, and also causes a gap between the captured paper dust and the surface of the image carrier. The toner easily enters. Therefore, paper dust and the like captured by the accumulated toner are also easily moved by the toner entering the surface of the image carrier, and are easily separated from the captured position, that is, the position in contact with the surface of the image carrier. . Therefore, the possibility that the surface of the image carrier is shaved by the paper dust or the like is reduced. Further, the toner easily enters between the captured paper dust and the like and the surface of the image carrier, so that the paper dust and the like once captured by the accumulated toner are moved along the surface of the image carrier (of the image carrier). It is less likely to move (in a state where it is attached to the surface). Therefore, it is less likely that the paper dust or the like once captured reaches the contact portion between the cleaning blade and the image carrier, and as a result, the surface of the image carrier and the leading edge of the blade in contact with the image carrier are shaved. The risk of being caught is reduced. Furthermore, of the accumulated toner, surplus toner (toner that cannot be accumulated by the accumulation member) overflows so as to get over the accumulation member, but the accumulated toner is slightly vibrated. By the circulating movement, paper dust having a larger particle diameter than the toner generally tends to collect on the upper portion of the deposited toner, so that the paper dust overflows preferentially. Therefore, the frequency at which the paper powder or the like comes into contact with the surface of the image carrier and the possibility that the paper blade or the like reaches the contact portion between the cleaning blade and the image carrier is further reduced, and as a result,
The possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier will be shaved is further reduced. Moreover, since the coefficient of linear expansion of the stacking member is smaller than the coefficient of linear expansion of the rake sheet,
It can function as a support member for preventing the rake sheet from being distorted. That is, by using this deposition member as a support member, it is possible to improve the assemblability. As described above, according to the image forming apparatus of the first aspect, the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier are less likely to be shaved by paper dust or the like. As a result, the assemblability can be improved without using a member that is originally unnecessary.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the stacking member is configured such that the distance from the surface of the image carrier gradually increases upward. Therefore, the circulation movement of the toner described above is efficiently performed. Therefore, the frequency at which paper dust or the like comes into contact with the surface of the image carrier and the risk of reaching the contact portion between the cleaning blade and the image carrier is further reduced, and as a result, the surface of the image carrier and the contact therewith are reduced. The possibility that the leading edge of the blade is cut off is further reduced. Moreover, the material for deposition is
As a result of the configuration in which the distance from the image carrier surface gradually increases toward the upper side, the distance from the image carrier surface decreases in the lower area, and accordingly the initial use of the image forming apparatus is correspondingly reduced. , The toner is quickly deposited. According to the image forming apparatus of the third aspect,
3. The image forming apparatus according to claim 1, wherein the surface roughness Rz of the deposition member is equal to or less than ト ナ ー of a toner particle size, so that the toner easily moves on the surface of the deposition member. The circulation efficiency of the deposited toner is further improved. Therefore, the frequency at which paper dust or the like comes into contact with the surface of the image carrier and the risk of reaching the contact portion between the cleaning blade and the image carrier is further reduced, and as a result, the surface of the image carrier and the contact therewith are reduced. The possibility that the leading edge of the blade is cut off is further reduced. According to the image forming apparatus of the fourth aspect, in the image forming apparatus of the first, second, or third aspect, the surface roughness Rz of the rake sheet is 1/5 or less of the toner particle size. , The toner easily moves on the surface of the rake sheet,
The circulation efficiency of the deposited toner is further improved. Therefore, the frequency at which the paper powder or the like contacts the surface of the image carrier, and
The possibility of reaching the contact portion between the cleaning blade and the image carrier is further reduced, and as a result, the possibility that the surface of the image carrier and the leading edge of the blade in contact with the image carrier are scraped is further reduced. According to the image forming apparatus of the fifth aspect, in the image forming apparatus of the first, second, third, or fourth aspect, the deposition member is made of a material that charges the toner to a predetermined charging polarity. Further, the following operation and effect can be obtained. That is,
The toner remaining on the image carrier after the toner image on the image carrier is transferred (residual toner) is a state in which a toner charged to a certain polarity and a toner having the opposite polarity are mixed. It has become. Therefore, when the toner is left unattended, the circulating efficiency of the toner deposited as described above may decrease due to the attraction force between the toners.
On the other hand, according to the image forming apparatus of the fifth aspect, since the deposition member is made of a material that charges the toner to a predetermined charging polarity, the deposited toner contacts the deposition member. Or, by sliding contact, they are made to have the same polarity. Therefore, the circulation efficiency of the deposited toner is further improved, and the frequency of paper dust and the like contacting the surface of the image carrier and the possibility of reaching the contact portion between the cleaning blade and the image carrier are further reduced, and as a result, This further reduces the risk that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier will be shaved. According to the image forming apparatus of the sixth aspect,
6. The image forming apparatus according to claim 1, wherein the rake sheet is made of a material that charges the toner to a predetermined charge polarity, so that the rake sheet adheres to the surface of the image carrier. When the toner passes between the rake sheet and the rake sheet after being deposited, the rake sheet comes into contact with the rake sheet (or the deposition member when combined with the configuration of claim 5) or slides into contact with the rake sheet to have the same polarity. It will be aligned. Therefore, the circulation efficiency of the deposited toner is further improved, and the frequency of paper dust and the like contacting the surface of the image carrier and the possibility of reaching the contact portion between the cleaning blade and the image carrier are further reduced, and as a result, This further reduces the risk that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier will be shaved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG.
2 is a schematic front sectional view showing a first embodiment of the image forming apparatus according to the present invention, FIG. 2A is an enlarged view of a main part thereof, FIG.
(B) is an enlarged view of a rake sheet and a stacking member.

This image forming apparatus is an apparatus capable of forming a full-color image using a developing device using four color toners of yellow (Y), cyan (C), magenta (M), and black (K). .

In FIG. 1, reference numeral 10 denotes a photoreceptor as an image carrier, which is rotated in a direction indicated by an arrow in FIG. Around the photoreceptor 10, along a rotation direction thereof, a charging roller 12 as a charging unit,
Developing roller 13 (Y, C, M, K) as developing means,
An intermediate transfer device 30 and a cleaning device 20 are provided.

The charging roller 12 contacts the outer peripheral surface of the photoreceptor 10 to uniformly charge the outer peripheral surface. An outer peripheral surface of the uniformly charged photoconductor 10 is subjected to selective exposure L according to desired image information by an exposure unit (not shown), and an electrostatic latent image is formed on the photoconductor 10 by the exposure L. You. This electrostatic latent image is developed with toner applied by a developing roller 13. In this embodiment, a developing roller 13Y for yellow, a developing roller 13C for cyan, a developing roller 13M for magenta, and a developing roller 13K for black are provided as developing rollers. These developing rollers 13Y, 13C, 13M, and 13K can selectively contact the photoconductor 10, and when they come into contact with each other, apply any one of yellow, cyan, magenta, and black toner to the photoconductor 10. The electrostatic latent image on the photoconductor 10 is developed by being applied to the surface of the photoconductor 10. The developed toner image is
The image is transferred onto an intermediate transfer belt 36 as an intermediate transfer body described later (see the primary transfer unit Tr1).

After the transfer, the cleaning device 20
A photoreceptor blade (cleaning blade) 21 for scraping off toner (residual toner) remaining on and adhering to the outer peripheral surface of the photoreceptor 10, and a sheet for scooping toner (T) scraped off by the blade 21 and falling 22
A stacking section 23 for stacking the falling toner, a receiving section 24 for receiving the toner overflowing from the stacking section 23,
A screw 25 for conveying the toner in the receiving portion 24 to a waste toner bottle (not shown) and a case 26 are provided.

The upper portion of the blade 21 is fixed to a blade holder 27. The blade holder 27 has both ends (both ends in a direction orthogonal to the paper surface) at the shafts 27a,
27a (only one shown) allows the side 26 of the case 26
a, 26a (only one is shown) so as to be swingable. A blade urging spring (compression coil spring) 28 is provided between the case 26 and the blade holder 27, and the tip of the blade 21 (the tip of the blade 21) is generated by the urging force of the blade urging spring 28 and the elastic force of the blade 21 itself. The edge 21 a comes into contact with the surface of the photoconductor 10. The rake sheet 22 comes into contact with the photoconductor 10 below the contact portion C between the blade 21 and the photoconductor 10, and scoops the toner scraped off by the blade 21.

As clearly shown in FIG. 2, the deposition section 23 in this embodiment includes a surface 11 of the photoreceptor 10, the rake sheet 22, and a thin plate provided integrally with the rake sheet 22. The toner T scraped off by the cleaning blade 21 is deposited on the surface 11 of the photoreceptor 10 by the deposition portion 23.
Are deposited so as to be slidable. The rake sheet 22 and the stacking member 23b extend in a direction orthogonal to the paper surface, and the stacking portion 23 is provided over the entire length below the contact portion C between the photoconductor 10 and the blade 21. An interval 23d is formed between the upper end 23c of the stacking member 23b and the blade 21. Through this interval 23d, excess toner out of the toner T accumulated in the accumulation section 23 is transferred to the receiving section 24. It is overflowing.

The deposition member 23b according to this embodiment
As shown in FIG. 2B, the lower portion 23b1 is
An adhesive layer (for example, an adhesive) 29a is provided integrally with the lower portion 22a of the rake sheet 22. The rake sheet 22 is made of a relatively soft material (for example, a thermoplastic polyurethane material having a relatively large linear expansion coefficient) so as not to damage the surface 11 of the photoreceptor 10. 23b is made of a relatively hard material (for example, polyethylene terephthalate) having a relatively small coefficient of linear expansion. The rake sheet 22 is integrally adhered to the deposition member 23b with an adhesive layer 29a in a state where the rake sheet 22 is sufficiently pulled or stretched at a high temperature. The rake sheet 22 and the stacking member 23
The bonding member b (FIG. 2B) is shorter than the adhesive layer 29a (shorter in the vertical direction (the rotation direction of the image carrier 10) in FIG. 2) by the adhesive layer 29b and the mounting surface 26b of the case 26.
It is stuck to. Adhesive layer 29b for case 26
However, since it is configured to be shorter than the adhesive layer 29a that fixes the rake sheet 22 and the stacking member 23b, part of the fixing portion between the rake sheet 22 and the stacking member 23b Some parts are not backed up. That is, the length of the adhesive layer 29a is H1,
Assuming that the length of the adhesive layer 29b is H2, the rake sheet 22
H3 which is a part of the fixing portion between the substrate and the deposition member 23b
The (= H1-H2) portion is a portion that is not backed up depending on the case 26. This H3 part is shown in FIG.
As shown in (a), when the rake sheet 22 and the stacking member 23b are fixed to the case 26, and when the rake sheet 22 comes into contact with the photoconductor 10 and vibrates slightly according to the rotation of the photoconductor 10, the vibration is accumulated. A vibration transmitting portion for transmitting the vibration to the member 23b is formed. That is, the fine vibration of the rake sheet 22 is also transmitted to the deposition member 23b through the vibration transmission unit H3, and the deposition member 23b also vibrates finely. As a result, the deposited toner T also vibrates finely. The toner T deposited by the action of the depositing member 23b is
2A, the photosensitive member 10 circulates clockwise according to the rotation direction (counterclockwise in FIG. 2A) as indicated by an arrow a. This makes it easier for the toner to circulate. In the course of circulation of the accumulated toner T, excess toner that cannot be accommodated in the accumulation section 23 overflows to the receiving section 24 as indicated by an arrow a1, but the photosensitive element 1
0, the rake sheet 22, the depositing member 23b, and the deposited toner vibrate finely as described above, so that foreign matters such as paper dust having a diameter larger than that of the toner are generally formed on the upper portion of the depositing portion 23. Gather more easily. Therefore,
As shown by the arrow a1, the foreign matter such as paper dust preferentially overflows together with the toner overflowing to the receiving portion 24.

The stacking member 23b of this embodiment is configured such that the distance from the photosensitive member surface gradually increases upward, and the rake sheet 22 and the stacking member 2
The integral part with 3b has a substantially Y-shape. Further, the surface roughness Rz of the rake sheet 22 and the stacking member 23b in this embodiment is configured to be 1/5 or less of the toner particle size. Further, the material of the friction charging series of the rake sheet 22 and the stacking member 23b is selected so that the toner is charged in a predetermined charging polarity. That is, the rake sheet 22 and the stacking member 23b are made of a material that charges the toner to a predetermined charge polarity. The case 26 is made of a hard material, for example, a hard synthetic resin.

The above-described cleaning device is configured as a unit by a case 26, and is detachably attached to a frame (not shown) of the image forming apparatus main body.

The intermediate transfer device 30 includes a driving roller 31,
It has four driven rollers 32, 33, 34, 35, an endless intermediate transfer belt 36 as an intermediate transfer member stretched over these rollers, a secondary transfer roller 37, and a cleaning unit 38. ing.

The driving roller 31 is driven to rotate at substantially the same peripheral speed as the photosensitive member 10 by engaging a gear (not shown) fixed to the end with a driving gear (not shown) of the photosensitive member 10. Therefore, the intermediate transfer belt 36 is circulated in the direction indicated by the arrow at substantially the same peripheral speed as the photoconductor 10. The driven roller 35 is a primary transfer roller, and is pressed against the photoconductor 10 via the intermediate transfer belt 36, and forms a primary transfer portion Tr1 between the photoconductor 10 and the intermediate transfer belt 36 at the pressed portion. ing. Drive roller 31
Is provided with an electrode roller (not shown) via an intermediate transfer belt 36, and a primary transfer voltage is applied to the intermediate transfer belt 36 via the electrode roller.
The driven roller 32 is a tension roller, and urges the intermediate transfer belt 36 in the tension direction by an urging means (not shown). The driven roller 33 is a backup roller that forms the secondary transfer unit Tr2. A secondary transfer roller 37 is opposed to the backup roller 33 via an intermediate transfer belt 36. The secondary transfer roller 37 is
It can be moved toward and away from the intermediate transfer belt 36 by a contacting / separating mechanism (not shown). A secondary transfer voltage is applied to the secondary transfer roller 37. The driven roller 34 is a backup roller for the cleaning unit 38. The cleaning unit 38 is configured by an intermediate transfer member blade that comes into contact with the intermediate transfer belt 36 and scrapes off the remaining toner (secondary transfer residual toner) on the outer peripheral surface thereof. The intermediate transfer member blade can be moved toward and away from the intermediate transfer belt 36 by a contact / separation mechanism (not shown). The toner scraped off by the intermediate transfer member blade 38 is received by a receiving portion (not shown), and is conveyed to a waste toner bottle by a screw (not shown).

In the course of circulating the intermediate transfer belt 36, the toner image on the photosensitive member 10 is transferred onto the intermediate transfer belt 36 in the primary transfer section Tr1, and the toner image transferred onto the intermediate transfer belt 36 is In the secondary transfer section Tr2, the image is transferred onto a recording medium P such as a sheet to be transferred, which is supplied to the secondary transfer roller 37. Recording medium P
Is supplied from a sheet feeding device (not shown) and supplied to the secondary transfer unit Tr2 at a predetermined timing.

The operation of the entire image forming apparatus as described above is as follows. (I) When a print command signal (image forming signal) from a not-shown host computer or the like (a personal computer or the like) is input to the control unit of the image forming apparatus, the tension roller 32 operates to put the intermediate transfer belt 36 in a stretched state. Becomes
The photosensitive member 10 and the developing roller 1 are driven by driving means (not shown).
3, and the intermediate transfer belt 36 is driven to rotate. (Ii) The outer peripheral surface of the photoconductor 10 is uniformly charged by the charging roller 12. (Iii) Selectively exposing the outer peripheral surface of the uniformly charged photoconductor 10 according to image information of the first color (for example, magenta (M)) by an exposing unit (not shown),
An electrostatic latent image for magenta is formed. (Iv) The first color (for example, magenta) is applied to the photoconductor 10.
Only the developing roller 13 </ b> M comes into contact, whereby the electrostatic latent image is developed, and a toner image of the first color (for example, magenta) is formed on the photoconductor 10. (V) A primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied to the intermediate transfer belt 36, and the toner image formed on the photoconductor 10 is transferred to the primary transfer unit Tr1, that is, the photoconductor 10 and the intermediate transfer belt. The toner image is transferred onto the intermediate transfer belt 36 at a pressure contact portion Tr1 with the intermediate transfer belt 36. At this time, the secondary transfer roller 37 and the cleaning unit 38 are separated from the intermediate transfer belt 36. (Vi) After the toner (primary residual toner) remaining on the photoreceptor 10 is removed by the photoreceptor blade 21, the photoreceptor 1 is discharged by discharging light from a discharging unit (not shown).
0 is eliminated. (Vii) The above operations (ii) to (vi) are repeated as necessary. That is, the second color, the third color, and the fourth color are repeated in accordance with the content of the print command signal, and the toner images corresponding to the content of the print command signal are superimposed on the intermediate transfer belt 36 to form an intermediate image. It is formed on the transfer belt 36. (Viii) The recording medium P is supplied at a predetermined timing, and immediately before or after the leading end of the recording medium P reaches the secondary transfer portion Tr2 (in short, at a desired position on the recording medium P, on the intermediate transfer belt 36). (At the timing when the toner image of the intermediate transfer belt is transferred).
6, the secondary transfer voltage is applied, and the toner image (basically a full-color image) on the intermediate transfer belt 36 is transferred onto the recording medium P. Further, the intermediate transfer member blade 38 comes into contact with the intermediate transfer belt 36, and the toner (secondary residual toner) remaining on the intermediate transfer belt 36 after the secondary transfer is removed. (Ix) The toner image is fixed on the recording medium P by passing the recording medium P through a fixing device (not shown).
The recording medium P is discharged out of the apparatus. (X) If the image forming signal is not input for a predetermined time or the power of the apparatus is turned off after the operations (i) to (ix) are performed, the tension transfer roller 36 is operated to operate the intermediate transfer belt 36 in a stretched state. Is released.

According to the above-described image forming apparatus, the following operation and effect can be obtained. (A) The cleaning blade 21 in which the toner remaining on the image carrier 10 after the toner image on the image carrier 10 which is a rotating body carrying the toner image is transferred contacts the surface of the image carrier 10. The scraped toner is scraped off by the scooping sheet 22.
Further, since a deposition member 23 for slidably depositing the toner scraped off by the cleaning blade 21 on the surface 11 of the image carrier 10 is provided, the deposition member 23 is provided.
As a result, the paper dust and the like adhering to the surface 11 of the image carrier 10 are removed by the toner T deposited so as to be captured before reaching the contact portion C with the blade 21. According to this image forming apparatus, since the stacking member 23 is constituted by the thin plate member provided integrally with the rake sheet 22, the following operation and effect can be obtained. That is, since the rake sheet 22 is in contact with the image carrier 10, the rake sheet 22 slightly vibrates according to the rotation of the image carrier 10. This minute vibration is also transmitted to the stacking member 23 provided integrally with the rake sheet 22. Since the deposition member 23 is formed of a thin plate member, the deposition member 23 also vibrates slightly. Since the toner T deposited by the action of the deposition member 23 can slide on the surface 11 of the image carrier 10, it can be circulated in accordance with the rotation direction of the image carrier. Rake sheet 2 above
The deposited toner also vibrates finely due to the action of the micro vibration of the stacking member 2 and the stacking member 23, and the circulation of the toner T is promoted by the action of the fine vibration, and the captured paper dust and the like and the surface of the image carrier are 11 easily enters the toner. Therefore, the paper dust and the like captured by the accumulated toner T are also easily moved by the toner T entering between the image carrier surface 11 and the captured position, that is, the position in contact with the image carrier surface 11. Easier to get away from. Therefore,
The possibility that the surface 11 of the image carrier is shaved by the paper dust or the like is reduced. Further, the toner T easily enters between the captured paper dust and the like and the image carrier surface 11, so that the paper dust and the like once captured by the accumulated toner T move along the image carrier surface 11 ( It is unlikely that the image carrier moves (in a state where it is attached to the surface 11 of the image carrier). Therefore, it is unlikely that the paper dust or the like once captured reaches the contact portion C between the cleaning blade 21 and the image carrier 10, and as a result, the surface 11 of the image carrier and the blade 21 in contact therewith Is less likely to be scraped off. Furthermore, of the accumulated toner, surplus toner (toner that can no longer be accumulated by the accumulation member 23) is accumulated in the accumulation member 2.
3, but overflows as the deposited toner T circulates with slight vibration.
Generally, paper dust and the like having a larger particle diameter than the toner tend to collect on the upper portion of the deposited toner T, so that the paper dust and the like overflow preferentially. Therefore, the frequency with which paper dust or the like comes into contact with the surface 11 of the image carrier and the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 are further reduced.
1 and the leading edge 21 of the blade 21 in contact therewith
a is less likely to be removed. Moreover,
Since the linear expansion coefficient of the stacking member 23b is smaller than the linear expansion coefficient of the rake sheet 22, the stacking member 23b can serve as a support member for preventing the rake sheet 22 from being twisted. It is. That is,
By using the deposition member 23b as a support member, it is possible to improve the assemblability. As described above, according to this image forming apparatus, the surface 1 of the image carrier 10
1 and the leading edge 21 of the blade 21 in contact therewith
a is less likely to be scraped off by paper dust or the like, and the assemblability can be improved without using any members that are originally unnecessary.

(B) Since the space between the deposition member 23b and the image carrier surface 11 is gradually increased upward, the circulation movement of the toner T is efficiently performed. Becomes Therefore, the frequency of contact of the paper dust or the like with the surface 11 of the image carrier and the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 are further reduced, and as a result, the surface 1 of the image carrier is reduced.
1 and the leading edge 21 of the blade 21 in contact therewith
The possibility that a is scraped is further reduced. Moreover, as a result of the deposition member 23b being configured so that the distance from the image carrier surface 11 gradually increases upward, the distance from the image carrier surface 11 decreases downward. Accordingly, the toner is quickly deposited in the early stage of use of the image forming apparatus. (C) Since the surface roughness Rz of the deposition member 23b is 1/5 or less of the toner particle diameter, the toner easily moves on the surface of the deposition member 23b, and the circulation efficiency of the deposited toner is reduced. Further improve. Therefore, the frequency at which paper dust or the like comes into contact with the surface 11 of the image carrier and the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 are further reduced. The possibility that the leading edge 21a of the blade 21 in contact with the blade 21 is scraped is further reduced. (D) Since the surface roughness Rz of the rake sheet 22 is 1/5 or less of the toner particle size, the toner can easily move on the surface of the rake sheet 22 and the circulation efficiency of the deposited toner is further improved. I do. Therefore, the frequency at which paper dust or the like comes into contact with the surface 11 of the image carrier and the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 are further reduced. The possibility that the leading edge 21a of the blade 21 in contact with the blade 21 is scraped is further reduced. (E) Since the deposition member 23b is made of a material that charges the toner to a predetermined charge polarity, the following operation and effect can be further obtained. That is, the toner (residual toner) remaining on the image carrier 10 after the transfer of the toner image on the image carrier 10 is a toner charged to a certain polarity.
A state in which the polarity is reversed is mixed. Therefore, when the toner is left unattended, the circulating efficiency of the toner deposited as described above may decrease due to the attraction force between the toners. On the other hand, according to the image forming apparatus of this embodiment, the deposition member 23
Since b is made of a material that charges the toner to a predetermined charge polarity, the deposited toner comes into contact with or slidably contacts the deposition member 23b, so that the same polarity is obtained. Therefore, the circulation efficiency of the deposited toner is further improved, and paper dust and the like are removed from the surface 11 of the image carrier.
And the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 is further reduced, and as a result, the surface 11 of the image carrier 10 and the leading edge 21a of the blade 21 in contact with the surface 11 The possibility that the steel is scraped is further reduced. (F) Since the rake sheet 22 is made of a material that charges the toner to a predetermined charge polarity, the residual toner adhering to the surface of the image carrier 10 and the rake sheet 22 (see FIG. 2A) (See reference numeral C1), and by contacting or slidingly contacting the rake sheet 22 after being deposited, they are made to have the same polarity. Therefore, the circulation efficiency of the deposited toner is further improved, and the frequency of contact of the paper dust or the like with the surface 11 of the image carrier and the possibility of reaching the contact portion C between the cleaning blade 21 and the image carrier 10 are further reduced. As a result, the possibility that the surface 11 of the image carrier and the leading edge 21a of the blade 21 in contact with the image carrier are shaved is further reduced.

<Second Embodiment> FIG. 3A is an enlarged view showing a rake sheet 22 and a stacking member 23b in an image forming apparatus according to a second embodiment of the present invention. In the figure, the same or corresponding parts as in the first embodiment are denoted by the same reference numerals. This embodiment is different from the first embodiment in that a lower portion 22a of a rake sheet 22 and a lower portion 23 of a stacking member 23b are provided.
b1 means that the adhesive layer (for example, double-sided adhesive tape) 29a is fixed below the lower portion 23b1 of the deposition member 23b in a state where the adhesive layer 29a is exposed, and there is no other difference. In this embodiment, the rake sheet 22 and the deposition member 23 are formed at the exposed portion (H4 portion) of the adhesive layer 29a.
b is fixed to the case 26. According to this embodiment, the same operation and effect as those of the first embodiment can be obtained.

<Third Embodiment> FIG. 3B is an enlarged view showing a rake sheet 22 and a stacking member 23b in an image forming apparatus according to a third embodiment of the present invention. In the figure, the same or corresponding parts as in the first embodiment are denoted by the same reference numerals. This embodiment differs from the first embodiment in that the stacking member 23b is configured to be substantially parallel to the rake sheet 22, and there is no other difference. Also in this embodiment, except for the operation and effect of the above (b),
The same operation and effect as the operation and effect according to the first embodiment can be obtained.

<Fourth Embodiment> FIG. 4A is an enlarged view of a main part of an image forming apparatus according to a fourth embodiment of the present invention, and FIG. 4B is a rake sheet and a stacking member. FIG. In the figure, the same or corresponding parts as in the first embodiment are denoted by the same reference numerals.
The difference between this embodiment and the first embodiment is that
The stacking member 23b is configured to be longer than that of the first embodiment, and the toner T scraped off by the blade 21 is formed.
Is always deposited on the contact portion C between the image carrier 10 and the blade 21 and the portion U immediately below the contact portion C, and the other points remain unchanged. As the structures of the rake sheet 22 and the stacking member 23b, those shown in FIGS. 3A and 3B can be used. According to this embodiment, the following operation and effect can be obtained in addition to the operation and effect of the first embodiment. That is, the blade 21
The toner scraped off at the time is always deposited on the contact portion C between the image carrier 10 and the blade 21 and directly below U,
The action of the toner as a lubricant makes it difficult for the blade 21 to be turned up as described below. More specifically, the toner scraped off by the blade 21 is applied to a contact portion C between the image carrier 10 and the blade 21 and a portion U immediately below the contact portion C.
Therefore, the toner is always supplied to the contact portion C between the rotating image carrier 10 and the cleaning blade 21 without being affected by the image pattern. Since the toner acts as a lubricant, the presence of the toner reduces the frictional force between the blade 21 and the surface of the image carrier 10, and as a result, increases the contact pressure and / or contact angle of the blade 21. In this case, the blade 21 is unlikely to be turned. Further, the cleaning blade 21 removes the toner by a so-called stick-slip behavior. However, according to this embodiment, the frictional force between the blade 21 and the surface of the image carrier 10 is reduced, whereby The behavior is stabilized, and as a result, the cleaning performance is further improved. In addition, as described above, when the toner deposited by the action of the depositing member 23b circulates in accordance with the rotation direction of the image carrier 10, the toner having a relatively small particle diameter is formed by the action of the fine vibration. The toner is easily supplied to the contact portion C between the carrier 10 and the blade 21.
The frictional force between 1 and the surface of the image carrier 10 is further reduced. Therefore, the above-described curling suppressing action of the blade and improvement of the cleaning performance can be more favorably obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the present invention. For example, in the above embodiment, the case where the image carrier is a photoconductor has been described, but the present invention is also applicable when the image carrier is an intermediate transfer member. Further, in the above embodiment, the case where the image carrier (photoconductor) is cylindrical has been described, but the present invention is also applicable to the case where the image carrier is belt-shaped. In the above embodiment, the rake sheet 22 and the deposition member 23b are integrally formed by the adhesive layer 29a, but may be integrally formed by welding. The same applies to the adhesive layer 29b.

[0029]

According to any of the image forming apparatuses of the first to sixth aspects, the possibility that the surface of the image carrier and the leading edge of the blade in contact with the image carrier are shaved by paper dust is reduced. In addition, assemblability can be improved without using members that are originally unnecessary. further,
According to the image forming apparatus of the second aspect, the possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier is shaved is further reduced. In addition, the toner is quickly deposited in the early stage of use of the image forming apparatus. According to the image forming apparatus of the third aspect, the possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier is shaved is further reduced. According to the image forming apparatus of the fourth aspect, the possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier is shaved is further reduced. According to the image forming apparatus of the fifth aspect, the possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier is shaved is further reduced. According to the image forming apparatus of the sixth aspect, the possibility that the surface of the image carrier and the leading edge of the blade that is in contact with the image carrier is shaved is further reduced.

[0030]

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing a first embodiment of an image forming apparatus according to the present invention.

FIG. 2A is an enlarged view of a main part of the first embodiment,
(B) is an enlarged view of a rake sheet and a stacking member.

FIG. 3A illustrates a rake sheet 22 and a stacking member 2 in an image forming apparatus according to a second embodiment of the present invention.
FIG. 3B is an enlarged view showing the rake sheet 22 and the stacking member 23b in the third embodiment of the image forming apparatus according to the present invention.

4A is an enlarged view of a main part of an image forming apparatus according to a fourth embodiment of the present invention, and FIG. 4B is an enlarged view of a rake sheet and a stacking member.

FIGS. 5A and 5B are explanatory diagrams of a conventional technique.

[Explanation of symbols]

 T toner 10 photoreceptor (image carrier) 11 surface 21 cleaning blade 22 rake sheet 23b deposition member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Maeda 3-3-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Corporation F-term (reference) 2H034 AA01 BA00 BF00

Claims (6)

[Claims] An image bearing member, which is a rotating member for carrying a toner image, is in contact with the surface of the image bearing member, and after the toner image on the image bearing member has been transferred, remains on the image bearing member. Image forming apparatus, comprising: a cleaning blade for scraping off toner, and a rake sheet for contacting the image carrier below a contact portion between the image carrier and the cleaning blade and scooping the toner scraped off by the cleaning blade. A stacking member for stacking the toner scraped by the cleaning blade on the surface of the image carrier so as to be slidable, and the stacking member is provided integrally with the rake sheet. An image forming apparatus comprising: a thin plate-shaped member; and a linear expansion coefficient of the stacking member is smaller than a linear expansion coefficient of the rake sheet. 2. The image forming apparatus according to claim 1, wherein the deposition member is configured so that the distance from the surface of the image carrier gradually increases upward. 3. The image forming apparatus according to claim 1, wherein a surface roughness Rz of the deposition member is 1/5 or less of a toner particle diameter. 4. The image forming apparatus according to claim 1, wherein the rake sheet has a surface roughness Rz of 1/5 or less of a toner particle size. 5. The image forming apparatus according to claim 1, wherein the deposition member is made of a material that charges the toner to a predetermined charge polarity. 6. The image forming apparatus according to claim 1, wherein the rake sheet is made of a material that charges the toner to a predetermined charge polarity.