JP2001042721A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hardly cause turn-up of a blade even in the case that the contact pressure and/or the contact angle of a cleaning blade is increased. SOLUTION: This image forming device is provided with the blade 21 to scrape off toner remaining on an image carrier 10 which is a rotary body to carry a toner image after the toner image on the image carrier 10 is transferred while coming into contact with the surface of the image carrier 10 and a scoop sheet 22 to scoop out the toner scraped off by the blade while coming into contact with the image carrier on a lower side than the contact part C of the image carrier and the blade, and a heaping member 23b by which the toner scraped off by the blade is always heaped at the contact part C of the image carrier and the blade and a part U right under the part C is integrally provided with the scoop sheet.

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.

Further, as a transfer means, in order to transfer the toner image on the photoconductor to a recording medium such as paper, the toner image formed on the photoconductor is transferred (primary transfer) and carried thereon. There is known an image forming apparatus provided with an intermediate transfer member (an example of an image carrier) that further transfers (secondarily transfers) the toner image to a recording medium. This intermediate transfer member is also provided with a cleaning blade for scraping off and removing toner (residual toner) remaining on the surface after the transfer of the toner image.

[0004]

In recent years, in an image forming apparatus using an electrophotographic technique, high image quality (small particle size of toner), high speed, and long life have been desired. In order to meet this demand, in particular, the demand for higher image quality (smaller particle size of toner), it is necessary to improve the cleaning property in order to satisfactorily remove the toner remaining on the image carrier after transferring the toner image. As one measure for this, it is conceivable to increase the contact pressure and / or contact angle of the cleaning blade with respect to the surface of the image carrier.

However, when the contact pressure of the cleaning blade against the surface of the image carrier is increased, the frictional force between the blade and the surface of the image carrier increases, and especially when the contact angle is increased, the blade is turned up. The problem that it becomes easy occurs. This turning of the blade is particularly likely to occur when an image pattern with a small amount of residual toner on the surface of the image carrier is formed, or in a high-temperature, high-humidity environment.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide an image forming apparatus in which even when the contact pressure and / or contact angle of the cleaning blade is increased, the blade is unlikely to be turned.

[0007]

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 sheet for scooping toner scraped off by the cleaning blade, wherein the toner scraped off by the cleaning blade is brought into contact with the image carrier and the cleaning blade, and directly below the contact portion. Is provided, and the stacking member is provided integrally with the rake sheet.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the stacking member is configured so that a distance from the surface of the image carrier gradually increases upward. Features. 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. The image forming apparatus according to claim 4,
The image forming apparatus according to claim 1, 2, 3, or 3,
The surface roughness Rz of the rake sheet is equal to 1 / ton of the toner particle size.
5 or less. 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 An image forming apparatus according to a sixth aspect is the image forming apparatus according to the first aspect.
6. The image forming apparatus according to 3, 4, or 5, wherein the rake sheet is made of a material that charges the toner to a predetermined charge polarity.

[0008]

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. According to the image forming apparatus of the present invention, there is provided a deposition member for constantly depositing the toner scraped off by the cleaning blade at a contact portion between the image carrier and the cleaning blade and immediately below the contact portion. Therefore, by the action of the lubricant deposited on the contact portion and immediately below the contact portion as a lubricant,
As described below, the blade is less likely to be turned.
That is, since the toner scraped off by the blade is constantly deposited on the contact portion between the image carrier and the cleaning blade and directly below the same, the image pattern is formed on the contact portion between the rotating image carrier and the cleaning blade. The toner is always supplied without being affected by the toner. Since the toner acts as a lubricant, the presence of the toner reduces the frictional force between the blade and the surface of the image carrier, and as a result, increases the contact pressure and / or contact angle of the blade. However, the blade is hardly turned up. Further, for the same reason, it is difficult for the blade to be turned up even in a high temperature and high humidity environment. As described above, according to the image forming apparatus of the first aspect, even when the contact pressure and / or contact angle of the cleaning blade is increased, the blade is less likely to be turned. Further, the cleaning blade removes the toner by a so-called stick-slip behavior. However, according to the image forming apparatus of the first aspect, the frictional force between the blade and the surface of the image carrier is reduced. The above behavior is stabilized, and as a result, the cleaning performance is further improved.

In addition, since the stacking member is provided integrally with the rake sheet, the following operation and effect can be further 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, and the stacking member also vibrates minutely. The toner deposited by the action of the stacking member circulates in accordance with the rotation direction of the image carrier. At this time, the toner having a relatively small particle diameter is brought into contact with the image carrier by the action of the fine vibration. It is easy to be supplied to the contact part with the blade,
The friction force between the blade and the surface of the image bearing member is more favorably reduced by the toner having the small particle diameter. Therefore, the above-described curling suppressing action of the blade and improvement of the cleaning performance can be more favorably obtained.

As a conventional cleaning device, as shown in FIG. 4A or 4B, a contact portion is provided below a contact portion C between the image carrier 1 and the cleaning blade 3 rotating in the direction of arrow A. Space S provided at an interval from C
It is known that toner is deposited on the paper and various foreign substances deposited on the paper are removed by the deposited toner (Japanese Patent Laid-Open No. 1-161288). The toner is deposited in a space S provided below the contact portion C of the cleaning blade 3 with the contact portion C at a distance from the contact portion C, and the contact between the image carrier and the cleaning blade is made as in the above-mentioned invention. 2. The above-described operation and effect according to the invention of claim 1, since the toner is not deposited on the portion and the portion immediately below the portion, and the depositing member 5 is not provided integrally with the rake sheet 4. Cannot be obtained.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the stacking member is configured so that the distance from the surface of the image carrier gradually increases upward. Therefore, the above-described toner circulation is efficiently performed. Therefore, the supply of the toner having a relatively small particle diameter to the contact portion is also efficiently performed, so that the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the above-described curling of the blade is achieved. The suppression effect and the improvement of the cleaning performance can be more reliably obtained. In addition, as a result of the deposition member being configured such that the distance from the surface of the image carrier gradually increases upward, the distance from the surface of the image carrier decreases below the lower portion. Thus, 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, in the image forming apparatus of the first or second aspect, the surface roughness Rz of the stacking member is equal to or less than 1/5 of the toner particle size. The toner easily moves on the surface of the application member, and the circulation efficiency of the deposited toner is further improved. Accordingly, the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the above-described blade turning-up suppressing action and the improvement of the cleaning performance are more reliably obtained. 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. In addition, the toner easily moves on the surface of the rake sheet, and the circulation efficiency of the deposited toner is further improved. Accordingly, the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the above-described blade turning-up suppressing action and the improvement of the cleaning performance are more reliably obtained. 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 (residual toner) remaining on the image carrier after the transfer of the toner image on the image carrier is a mixture of a toner charged to a certain polarity and a toner having the opposite polarity. It is in a state where it has been done. 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, the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the above-described blade turning-up suppressing action and the cleaning performance are further improved. It will be surely obtained. According to the image forming apparatus of the sixth aspect, in the image forming apparatus of the first, second, third, fourth, or fifth aspect, the rake sheet is made of a material that charges the toner to a predetermined charging polarity. Therefore, when the residual toner adhering to the surface of the image carrier slips between the rake sheet and the rake sheet after being deposited, the rake sheet and the rake sheet are combined with the rake sheet. ) By contact or sliding contact, they are made to have the same polarity. Therefore, the circulation efficiency of the deposited toner is further improved, the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the above-described blade turning-up suppressing action and the cleaning performance are further improved. It will be surely obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> 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 thereof, and FIG. It is an enlarged view of a rake sheet and a member for accumulation.

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 photosensitive member as an image carrier, which is rotated in a direction indicated by an arrow by an appropriate driving means (not shown). 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 shown in FIG. 2, the stacking section 23 in this embodiment includes a photosensitive member surface, the rake sheet 22, and a plate-shaped stack provided integrally with the rake sheet 22. The toner T scraped off by the blade 21 is always deposited on the contact portion C between the photoreceptor 10 and the cleaning blade 21 and directly below U by the deposition portion 23. It has become. The rake sheet 22 and the stacking member 23b extend in a direction perpendicular to the paper surface, and the stacking portion 23 is provided over the entire length below the contact portion C. A gap 23 is provided between the upper end 23c of the deposition member 23b and the blade 21.
d is formed, and excess toner among the toner T accumulated in the accumulation section 23 overflows to the receiving section 24 through the interval 23d.

The deposition member 23b in this embodiment
As shown in FIG. 2B, the lower portion 23b1 is
An adhesive layer (for example, an adhesive) 29a is provided integrally with a lower portion 22a of the rake sheet 22. The rake sheet 22 and the stacking member 23b are attached to the adhesive layer 2a.
An adhesive layer 29b (shorter in the vertical direction (the rotation direction of the image carrier 10) in FIG. 2) than the adhesive layer 29b is fixed to the mounting surface 26b of the case 26. Since the adhesive layer 29b for the case 26 is configured to be shorter than the adhesive layer 29a for fixing the rake sheet 22 and the stacking member 23b, the adhesive layer 29b of the rake sheet 22 and the stacking member 23b is fixed. Some parts are not backed up depending on the case 26. That is, assuming that the length of the adhesive layer 29a is H1 and the length of the adhesive layer 29b is H2, the H3 (= H1-H2) portion, which is a part of the fixing portion between the rake sheet 22 and the deposition member 23b, Depending on the case 26, it is a part that is not backed up. 2A, the rake sheet 22 and the stacking member 23b are fixed to the case 26, and the rake sheet 22 comes into contact with the photoreceptor 10 and vibrates slightly according to the rotation of the photoreceptor 10. As shown in FIG. At this time, a vibration transmitting portion for transmitting the vibration to the deposition member 23b is formed. That is, the micro 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 microvibrates. The toner T deposited by the action of the depositing member 23b is
As shown by an arrow a in FIG. 2A, the photosensitive body 10 circulates clockwise according to the rotation direction (counterclockwise in FIG. 2A). By the action, the toner having a relatively small particle diameter is easily supplied to the contact portion C between the photoconductor 10 and the blade 21. More specifically, in the course of circulation of the accumulated toner T, excess toner that cannot be accommodated in the accumulation unit 23 overflows to the receiving unit 24 as indicated by an arrow a1, but the photosensitive member 10 , Rake sheet 22, and stacking member 23b
Is slightly vibrated as described above, so that toner having a relatively large particle diameter tends to collect on the upper portion of the deposition unit 23. Therefore, as shown by the arrow a1, the receiving portion 24
Most of the toner spilling over becomes large-diameter toner (large-diameter toner is preferentially spilled out). As a result, relatively small-diameter particle toner remains in the accumulation unit 23. . For this reason, the toner having a relatively small particle diameter is easily supplied to the contact portion C between the photoconductor 10 and the blade 21.
Even if foreign matter such as paper dust is mixed in the toner T, the foreign matter preferentially overflows due to the action of the fine vibration, so that the foreign matter may be supplied to the contact portion C. Less likely to occur.

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 an end thereof 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 process 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 operational effects 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.
According to this image forming apparatus, there is provided a deposition member 23b for constantly depositing the toner scraped off by the cleaning blade 21 on the contact portion C between the image carrier 10 and the cleaning blade 21 and on the immediately lower portion U thereof. Therefore, the action of the toner deposited on the contact portion C and the immediately lower portion U thereof as a lubricant makes it difficult for the blade 21 to be turned up as described below. That is, the toner scraped off by the blade 21 is applied to the contact portion C between the image carrier 10 and the cleaning blade 21 and the 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, for the same reason, it is difficult for the blade to be turned up even in a high temperature and high humidity environment. As described above, according to the image forming apparatus of this embodiment, even when the contact pressure and / or the contact angle of the cleaning blade 21 is increased, the blade 21 is less likely to be turned. Further, the cleaning blade 21 removes the toner by a so-called stick-slip behavior.
By reducing the frictional force between the image bearing member 1 and the surface of the image carrier 10, the above behavior is stabilized, and as a result, the cleaning performance is further improved.

Moreover, since the stacking member 23b is provided integrally with the rake sheet 22, the following operation and effect can be further 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 23b provided integrally with the rake sheet 22, and the stacking member 23b also minutely vibrates. The toner deposited by the action of the deposition member 23b is
Circulates in accordance with the rotation direction of the toner. At this time, due to the action of the fine vibration, the toner having a relatively small particle diameter is easily supplied to the contact portion C between the image carrier 10 and the blade 21. With the small particle size toner, the frictional force between the blade 21 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.

In the early stage of use of the image forming apparatus (for example, when the image forming apparatus is provided to a user and started to be used),
It takes a short time, though a short time, for the toner to accumulate.However, in this type of image forming apparatus, usually, in order to prevent the blade from being turned up in the early stage of use, the surface of the blade is Since the lubricant such as polyvinylidene fluoride is applied, the blade is not turned up even in the early stage of use until the toner is deposited.

(B) Since the deposition member 23b is configured so that the distance from the surface of the image carrier 10 gradually increases upward, the above-described toner circulation is efficiently performed. . Accordingly, the toner having a relatively small particle diameter can be efficiently supplied to the contact portion C, so that the frictional force between the blade 21 and the surface of the image carrier 10 is more reliably reduced. The curling suppressing action of the blade 21 and the improvement of the cleaning performance can be more reliably obtained. Moreover, as a result of the deposition member 23b being configured so that the distance from the surface of the image carrier gradually increases upward, the distance from the surface of the image carrier toward the bottom decreases. 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 frictional force between the blade 21 and the surface of the image carrier 10 is more reliably reduced, and the above-described action of suppressing the turning of the blade 21 and improving the cleaning performance are more reliably obtained. (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 frictional force between the blade 21 and the surface of the image carrier 10 is more reliably reduced, and the above-described action of suppressing the turning of the blade 21 and improving the cleaning performance are more reliably obtained. (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, the frictional force between the blade 21 and the surface of the image carrier 10 is more reliably reduced, and the above-described curling suppressing action and cleaning performance of the blade 21 are improved. Can be obtained more reliably. (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, the frictional force between the blade 21 and the surface of the image carrier 10 is more reliably reduced, and the above-described curling suppressing action and cleaning performance of the blade 21 are improved. Can be obtained more reliably. (G) According to the image forming apparatus of this embodiment, since the intermediate transfer body 36 and the cleaning means 38 for removing the secondary residual toner thereof are provided, the following operation and effect can be obtained. Assuming that the toner image formed on the photoreceptor 10 is not provided on the recording medium P such as paper without providing the intermediate transfer body 36.
If it is configured to transfer directly to the transfer portion (Tr1
In this case, foreign matter such as paper dust attached to the surface of the photoconductor 10 from paper or the like is scraped off by the blade 21 together with the residual toner. Therefore, the blade 21
If the configuration is such that the toner scraped off by the above is always deposited on the contact portion C between the photoreceptor 10 and the blade 21 and directly below U, foreign matter such as paper dust is deposited together with the toner. There is a possibility that the surface of the photoconductor 10 or the blade 21 may be shaved by powder or the like. On the other hand, according to the image forming apparatus of this embodiment, since the intermediate transfer body 36 and the cleaning means 38 for removing the secondary residual toner thereof are provided, the intermediate transfer body Paper dust and the like adhering to the toner 36 are removed by the cleaning means 38 together with the secondary residual toner. That is, in the image forming apparatus of this embodiment, the primary transfer portion Tr
1 is in contact with the intermediate transfer body 36 in a state in which paper dust and the like have been removed, and thus the blade 21
The toner (primary residual toner) scraped off by the
In this configuration, foreign matters such as paper dust and the like remain together with the primary residual toner, even though the configuration is such that foreign matters are always deposited on the contact portion C between the blade and the blade 21 (the provisional foreign matter is temporarily accumulated). The amount will be very small, if at all.) Moreover, as described above, even if foreign matter such as paper dust is mixed in the deposited toner T, the foreign matter preferentially overflows due to the action of the fine vibration. Is very unlikely to occur. Therefore,
Toner scraped off by blade 21 (primary residual toner)
Although T is always deposited on the contact portion C between the photoreceptor 10 and the blade 21 and immediately below the contact portion C,
The possibility that the surface of the photoconductor 10 or the blade 21 is shaved by paper dust or the like is eliminated.

<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.

The difference between this embodiment and the first embodiment is that the lower portion 22a of the rake sheet 22 and the lower portion 23b1 of the stacking member 23b are bonded under the lower portion 23b1 of the stacking member 23b. (For example, double-sided adhesive tape) 29a is fixed in an exposed state,
Other points remain the same. In this embodiment, the rake sheet 22 is formed at the exposed portion (H4 portion) of the adhesive layer 29a.
The stacking member 23b 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 formed substantially parallel to the rake sheet 22, and there is no other difference. According to this embodiment, the same operation and effect as those of the first embodiment can be obtained except for the operation and effect of (b).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be appropriately modified and implemented 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. However, the rake sheet 22 and the deposition member 23b may be integrally formed by welding, or may be integrally formed by integral molding from the beginning. The same applies to the adhesive layer 29b.

[0035]

According to the image forming apparatus of any one of claims 1 to 6, the contact pressure of the cleaning blade and / or
Alternatively, even when the contact angle is increased, the blade is less likely to be turned. Further, the so-called stick-slip behavior of the cleaning blade is stabilized, and as a result, the cleaning performance is further improved. Moreover, since the stacking member is provided integrally with the rake sheet,
The toner having a relatively small particle diameter can be easily supplied to the contact portion between the image carrier and the blade, and the effect of suppressing the curling of the blade and improving the cleaning performance can be further improved. Furthermore, according to the image forming apparatus of the second aspect, the frictional force between the blade and the surface of the image carrier is more reliably reduced, and the curling suppressing action and the cleaning performance of the blade are more reliably obtained. It will be. 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 curling suppressing action of the blade and the improvement of the cleaning performance can be more reliably obtained. According to the image forming apparatus of the fourth aspect, the curling suppressing action of the blade and the improvement of the cleaning performance can be more reliably obtained. According to the image forming apparatus of the fifth aspect, the curling suppressing action of the blade and the improvement of the cleaning performance can be more reliably obtained. According to the image forming apparatus of the sixth aspect, it is possible to more reliably obtain the curling suppressing action of the blade and the improvement of the cleaning performance.

[0036]

[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.

FIGS. 4A and 4B are explanatory diagrams of a conventional technique.

[Explanation of symbols]

 T toner 10 photoreceptor (image carrier) 21 cleaning blade 22 rake sheet 23b deposition member 26 case C contact portion U immediately below

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Maeda 3-3-5 Yamato, Suwa-shi, Nagano F-term in Seiko Epson Corporation (Reference) 2H034 BA02 BA03 BA03 BF01 BF06

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 deposition member for constantly depositing the toner scraped off by the cleaning blade at a contact portion between the image carrier and the cleaning blade and immediately below the contact portion,
An image forming apparatus, wherein the stacking member is provided integrally with 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.