JP2004004224A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely remove a toner remaining on an intermediate transfer belt after a toner image is transferred to a recording medium and to securely collect the toner. <P>SOLUTION: An image forming apparatus is equipped with the intermediate transfer body 21 which transfers the toner image to the recording medium and a cleaning device 38 having first and second cleaning members 39a and 39b which clean the toner remaining on the intermediate transfer body and are arranged closely to each other, a toner collecting box 40 which has an opening facing both the cleaning members 39 to collect the cleaned toner, and a couple of carrier members 41 which are disposed side by side in the toner collection box and recover the collected toner; and one carrier member 39a between the couple of carrying members sends the toner toward the other carrier member 39b, which sends the toner in a direction crossing the moving direction of the intermediate transfer body 21. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic image forming apparatus used for a copying machine, a printer, and the like, and more particularly, to an image forming apparatus having a cleaning member for cleaning toner remaining on an intermediate transfer belt.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus for forming a color image, toner images of mutually different colors are formed on a plurality of photoconductors, and the toner images are sequentially superimposed on an intermediate transfer body to perform primary transfer. To form a color image on paper by secondary-transferring the multi-color toner image to paper, and to form a color image on paper after the primary transfer of the toner image onto the intermediate transfer member. The toner remaining on the photoconductor and the toner remaining on the intermediate transfer body after the secondary transfer of the multicolor toner on the paper are cleaned by a cleaning device provided for each of the photoconductors and the intermediate transfer body. A method of configuring an image forming cycle is widely used.
[0003]
As a cleaning device, a plate-shaped blade is brought into contact with the surface of the photosensitive member or the intermediate transfer member, which carries the toner image, to scrape residual toner, or a brush or a roll is contacted to electrostatically attract the toner. In general, the remaining toner is scraped off with a blade, and the removed residual toner is generally collected in a housing and collected in a toner collecting unit using a paddle or an auger.
[0004]
For example, in Japanese Patent Laid-Open Publication No. Hei 10-301460, a residual toner on a photoreceptor is removed by a cleaning blade, and the gravity of the toner cannot be used. A technique for conveying the waste toner to a waste toner storage unit is disclosed.
[0005]
According to this technique, since no brush is used, there is an advantage that the blowing of the toner is prevented, and the toner can be reliably transported regardless of the installation position of the cleaning device.
[0006]
In Japanese Patent Application Laid-Open No. 10-301460, the housing of the cleaning device is made thinner, and the inside of the thinner housing is directed to the toner collecting section by providing a forced conveying belt for conveying the accumulated toner removed by a cleaning blade. There is disclosed a technique for reliably transporting.
[0007]
According to this technique, there is an advantage that the cleaning device can be downsized.
On the other hand, Japanese Patent Application Laid-Open No. H11-38776 has two cleaning means, one of which mechanically removes toner remaining on the belt by rubbing the belt, and the other of which removes toner remaining on the belt. There is disclosed a technique for removing electrostatically by contact with a bias voltage.
[0008]
However, in recent years, there is a tendency that the diameter of toner used in an image forming apparatus is reduced due to a demand for higher definition of an image. Therefore, even if a cleaning device having a single blade, for example, is attached to the photoreceptor or the intermediate transfer member to scrape off the residual toner, the small-diameter toner slips through the blade and completely removes the residual toner. There is a problem that can not be.
[0009]
Therefore, a method of reliably removing the residual toner having a reduced diameter by providing a plurality of cleaning members provided in the cleaning device can be considered. However, a toner recovery unit such as a housing, a paddle, and an auger of a conventionally used cleaning device is directly used. Even if the cleaning member such as a blade is simply provided with a plurality of blades, when the cleaning device is attached to the intermediate transfer belt, for example, when the cleaning device is attached to the intermediate transfer belt, the blades and the like overlap with each other, and the scraped toner is removed. Since the residual toner accumulates in the overlapping portion, it is difficult to reliably collect the residual toner in the housing and to collect the residual toner in the toner collecting unit. Further, for example, if toner is clogged between a plurality of blades abutting on the intermediate transfer belt, there is a problem that cleaning performance deteriorates.
[0010]
Furthermore, if a plurality of cleaning devices are provided, installation space and cost become problems.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and provides an image forming apparatus capable of reliably removing toner remaining on an intermediate transfer belt after a toner image is transferred to a recording medium and reliably collecting the toner. With the goal.
[0012]
[Means for Solving the Problems]
An image forming apparatus of the present invention that achieves the above object forms an image by forming a toner image and finally transferring and fixing the toner image on a recording medium,
An intermediate transfer body that carries and moves the toner image and transfers the toner image to a recording medium;
First and second cleaning members disposed in close proximity to each other for cleaning toner remaining on the intermediate transfer body after transferring a toner image from the intermediate transfer body to a recording medium; and the first and second cleaning members. A toner collection box for collecting toner cleaned by the first and second cleaning members, the toner collection box having an opening facing both of the cleaning members, the toner collection box being juxtaposed in the toner collection box, and being collected in the toner collection box. A cleaning device having a pair of conveying members for collecting the toner,
One conveying member of the pair of conveying members sends the toner toward the other conveying member, and the other conveying member sends the toner in a direction intersecting with the moving direction of the intermediate transfer body. Characterized in that:
[0013]
As described above, the cleaning device provided for the intermediate transfer member includes the two cleaning members that are close to each other, and can reliably clean the residual toner on the intermediate transfer member, and furthermore, the cleaned toner is collected in the common toner collection box. And the two conveying members arranged in parallel in the toner collection box share roles, so that the toner can be surely collected.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0015]
FIG. 1 is a schematic configuration diagram showing an embodiment of a color copying machine to which the image forming apparatus of the present invention is applied.
[0016]
The image forming apparatus shown in FIG. 1 includes photoconductor drums 11Y, 11M, which rotate in the A direction on which yellow (Y), magenta (M), cyan (C), and black (K) toner images are formed, respectively. Four 11C and 11K are juxtaposed. Further, the intermediate transfer belt 21, which is stretched over the drive roll 22, the driven roll 23, the tension roll 24, and the opposing roll 25, circulates in the B direction while contacting each of the four photosensitive drums 11Y, 11M, 11C, and 11K. Have. Around each photoconductor drum 11, each of chargers 12Y, 12M, 12C, and 12K for charging the photoconductor drum 11 exposes the photoconductor drum 11 charged based on image data decomposed for each color. Exposure devices 13Y, 13M, 13C, and 13K that form electrostatic latent images by irradiating the electrostatic latent images, and develops the electrostatic latent images with toners of the respective colors of Y, M, C, and K from close positions to form toner images. Developing devices 14Y, 14M, 14C, and 14K, which face each photosensitive drum 11 with the intermediate transfer belt 21 interposed therebetween, and primary transfer of the toner image formed on the photosensitive drum 11 to the intermediate transfer belt 21 Cleaning devices 16Y and 16 for cleaning the primary transfer rolls 27Y, 27M, 27C and 27K, and the toner remaining on the photosensitive drum 11 after the transfer with a conductive brush and a blade. , 16C, 16K is provided. Further, a secondary transfer roll 28 for secondary-transferring the toner image onto the paper P, which is opposed to the opposing roll 25 with the intermediate transfer belt 21 interposed therebetween and is superimposed on the toner image on the intermediate transfer belt 21, is provided from a paper tray (not shown). A registration roll 35 for sending the transported paper P to a secondary transfer roll 28 via a chute 34, a transport belt 36 for transporting the paper P on which the toner image has been secondary-transferred, and on the paper P transported by the transport belt 36. A fixing device 30 including a heating roll 31 and a pressure roll 32 for fixing the toner image on the paper P is provided. The secondary transfer roll 28 is provided with a cleaning device 28a, and the intermediate transfer belt is provided with a belt cleaning device 38. The belt cleaning device 38 includes a first cleaning member 39a and a second cleaning member 39b that are close to each other, and are provided opposite to the driving roll 22 and the driven roll 23 that stretch the intermediate transfer belt 21, respectively. Is provided immediately below the cleaning member 39a and the second cleaning member 39b, a toner collection box 40 for collecting the residual toner that has been cleaned, and the toner collection box 40 is provided with a pair of toner conveying members 41. One transport member 41a sends the collected toner by rotation to the other transport member 41b, and the other transport member 41b rotates the collected toner by moving the intermediate transfer belt 21. By sending the toner in a direction intersecting with the direction B, the collected toner is transferred to a toner (not shown). It is recovered by the recovery unit.
[0017]
Here, in the present embodiment, a blade is used for each of the two cleaning members 39a and 39b, but the cleaning member is not necessarily a blade, and one or both may be a brush or a roll. Good.
[0018]
An electrostatic latent image is formed by irradiating the surface of the photosensitive drum 11 uniformly charged by the charger 12 with exposure light having a pulse width modulated based on image data decomposed for each color from the exposure device 13. Then, the electrostatic latent image is developed with each color toner of the developing device 14 to form a toner image of each color on the surface of the photosensitive drum 11. The respective color toner images on the photosensitive drum 11 are sequentially multiplex-transferred onto the intermediate transfer belt 21 by the primary transfer roll 27, and the multiplex-transferred color toner images are transferred onto the paper P by the secondary transfer roll 28. The toner image on the sheet P is further fixed on the sheet by the fixing device 30 to form an image including the fixed toner image.
[0019]
Here, the image forming apparatus of the present embodiment includes four photosensitive drums 11Y, 11M, 11C, and 11K and an intermediate transfer belt 21 as a transfer object. It may be a transfer drum. Further, a corotron is used for the charger 12, but a contact-type charger may be used. Further, the cleaning device 16 does not necessarily need to be configured by a conductive brush and a blade, but may be configured by a conductive roll and a blade having a large number of holes, for example.
[0020]
FIG. 2 is a schematic enlarged view showing a side cross section of the belt cleaning device of the present embodiment.
[0021]
As shown in an enlarged manner in FIG. 2, there is an intermediate transfer belt 21 which is stretched between a driving roll 22 and a driven roll and moves in the direction of arrow B. The intermediate transfer belt has a cleaning device 38 for cleaning residual toner. Is provided.
[0022]
The cleaning device 38 includes a second cleaning member 39b at a position facing the drive roll 22 with the intermediate transfer belt 21 interposed therebetween, a first cleaning member 39a at a position facing the driven roll 23, and a first and a second cleaning member 39b. And a toner collecting box 40 for collecting residual toner immediately below the drive roll 22 and the driven roll 23, and for collecting the toner collected in the toner collection box 40. A pair of conveying members 41 a and 41 b are provided in the toner collecting box 40 side by side.
[0023]
In the present embodiment, a rubber cleaning blade is used for the first cleaning member 39a, and a metal cleaning blade is used for the second cleaning member 39b, and the transport member installed on the upstream side in the direction of arrow B is used. A paddle is used for 41a, and a screw auger is used for the transport member 41b installed on the downstream side in the arrow B direction.
[0024]
The driven roll 23 facing the rubber cleaning blade is provided with a position adjusting means capable of adjusting the position facing the rubber cleaning blade.
[0025]
Since the first cleaning member 39a and the second cleaning member 39b are close to each other when projected from above and are set so as not to overlap in the direction of arrow B, the first and second cleaning members 39b The toner cleaned by the second cleaning members 39a and 39b surely falls without being caught in the middle. The first cleaning member 39a comes into contact with the intermediate transfer belt 21 at a position facing the driven roller 23 to scrape off the toner remaining on the intermediate transfer belt 21, and the second cleaning member 39b faces the drive roll 22. The remaining toner abuts on the intermediate transfer belt 21 at the position where the first cleaning member 39a passes.
[0026]
The scraped toner falls downward due to the gravity of the toner, and is collected in the toner collection box 40. The residual toner collected in the toner collecting box 40 is sent by the conveying member 41a on the upstream side in the direction of the arrow B toward the conveying member 41b on the downstream side in the direction of the arrow B, and on the downstream side in the direction of the arrow B. The toner is sent in a direction crossing the arrow B direction by the installed conveying member 41b, and is collected by a toner collecting unit (not shown).
[0027]
As described above, the toner collection box 40 collects the toner cleaned by the two cleaning members in common, and the pair of conveying members 41a and 41b share the collected toner to collect the collected toner. Can be reduced in size, and the occupied space can be saved.
[0028]
FIG. 3 is a schematic diagram showing the position adjusting means provided on the driven roll.
[0029]
3, a first cleaning member 39a made of a rubber cleaning blade is in contact with the intermediate transfer belt 21. A driven roller 23 is opposed to a position where the first cleaning member 39 a made of a rubber cleaning blade is in contact with the intermediate transfer belt 21. The driven roll 23 is fixed by a roll holding member 43, and is fixed to the roll holding member 43 by a boss screw 43a for fixing one end of the roll holding member 43 and a screw inserted into the oblong hole 43b. The position where the roll holding member 43 is fixed by the screw inserted into the oval hole 43b can be adjusted within the range of the hole size of the oval hole 43b. The driven roll 23 plays a role as a position adjusting means for adjusting a position facing the first cleaning blade 39a.
[0030]
Therefore, after the first cleaning member 39a is fixed, the screwing position of the elongated hole 43b of the roll holding member 43 is adjusted while looking at the position where the first cleaning member 39a contacts the intermediate transfer belt 21. Accordingly, the driven roll 23 can be opposed to the first cleaning member 39a at a position where the first cleaning member 39a contacts the intermediate transfer belt 21.
[0031]
If such a position adjusting means is provided, the adjustment of the contact position between the intermediate transfer belt 21 and the cleaning member can be easily performed, so that the belt cleaning device 38 can be easily attached.
[0032]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention, the intermediate transfer member is provided with the single cleaning device having the two cleaning members, the common toner collection box, and the transport member arranged side by side. In addition, the residual toner on the intermediate transfer member can be reliably removed, and the removed toner can be reliably recovered.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a color copying machine to which an image forming apparatus of the present invention is applied.
FIG. 2 is a schematic enlarged view showing a side cross section of the belt cleaning device of the present embodiment.
FIG. 3 is a schematic view showing a position adjusting means provided on a driven roll.
[Explanation of symbols]
11, 11Y, 11M, 11C, 11K Photoconductor drums 12, 12Y, 12M, 12C, 12K Chargers 13, 13Y, 13M, 13c, 13K Exposure devices 14, 14Y, 14M, 14C, 14K Developing devices 16, 16Y, 16M , 16C, 16K Cleaning device 21 Intermediate transfer belt 22 Drive roll 23 Follower roll 24 Tension roll 25 Opposing rolls 27, 27Y, 27M, 27C, 27K Primary transfer roll 28 Secondary transfer roll 28a Cleaning device 30 Fixing device 31 Heating roll 32 Pressure roll 34 Chute 35 Registration roll 36 Conveyor belt 38 Belt cleaning device 39a First cleaning member 39b Second cleaning member 40 Toner collection box 41a Upstream transport member 41b Downstream transport Member 42 opening 43 roll holder 43a boss screw 43b oblong hole

Claims (4)

In an image forming apparatus for forming an image by forming a toner image and finally transferring and fixing the toner image on a recording medium,
An intermediate transfer member that carries and moves the toner image and transfers the toner image to a recording medium;
First and second cleaning members disposed in close proximity to each other for cleaning toner remaining on the intermediate transfer body after transferring a toner image from the intermediate transfer body to a recording medium; and the first and second cleaning members. A toner collection box for collecting toner cleaned by the first and second cleaning members, the toner collection box having an opening facing both of the cleaning members, the toner collection box being juxtaposed in the toner collection box, and being collected in the toner collection box. A cleaning device having a pair of conveying members for collecting the toner,
One conveying member of the pair of conveying members sends the toner toward the other conveying member, and the other conveying member sends the toner in a direction intersecting with the moving direction of the intermediate transfer body. An image forming apparatus, comprising: 2. The image forming apparatus according to claim 1, wherein the first and second cleaning members are close to each other when projected from above. The intermediate transfer member is an intermediate transfer belt that is stretched and moved by a plurality of rolls, and each of the first and second cleaning members faces one of the plurality of rolls. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus contacts the intermediate transfer belt at a position. 4. The image forming apparatus according to claim 3, wherein the roll facing the cleaning member has a position adjusting unit that adjusts a position facing the cleaning member.

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