JPH11231741A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy demand for a reduction in the thickness of the device itself, at the same time, to satisfactorily maintain cleaning performance all the time by effectively preventing clog of residual matter scraped by a blade and also securely recovering the residual matter. SOLUTION: In the cleaning device, a cleaning housing 2, which extends almost in a horizontal direction, and the cleaning blade 3, which is attached to the lower edge of the opening of the cleaning housing 2 and extends almost in a horizontal direction, are provided, at the enhance of the opening of the cleaning housing 2 is a narrow entrance passage 4 formed between the cleaning blade 3 and itself, and also at the rear of the cleaning housing 2 is a storage space 5 which extends from the entrance passage 4. Here, a forcible carrying belt 6, by which residual matter on an image carrier 1 scraped by the cleaning blade 3 is forcibly carried to the storage space 5, is disposed all the way in the higher parts of the entrance passage 4 and storage space 5 so as to be movable in a circle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device used in an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to an improvement in a cleaning device employing a blade cleaning system.

[0002]

2. Description of the Related Art Conventionally, for example, in an electrophotographic image forming apparatus, an electrostatic latent image formed on an image carrier such as a photoreceptor drum is developed by a developing device with a toner (visualization). And
A method in which the toner image is transferred to a transfer medium such as a sheet or an intermediate transfer member by a transfer device, and the residual toner on the image carrier is collected by a cleaning device is usually adopted.
Then, as the cleaning device, a plate-shaped blade is attached to an opening edge of the cleaning housing that opens to the image carrier, and the blade is brought into contact with the image carrier to remove residual toner on the image carrier with the blade. A so-called blade cleaning method of scraping and collecting the toner at a toner collecting portion formed at the back side of the cleaning housing is often used.

In this type of blade cleaning method, there is no particular problem in a mode in which the residual toner scraped off by the blade immediately falls downward. For example, the blade is disposed substantially horizontally and On the other hand, in a mode in which the rotation direction of the image carrier goes from top to bottom, the residual toner scraped off by the blade passes above the blade. At this time, in order to avoid a situation in which the residual toner scraped by the blade is accumulated on the blade tip, the toner scraped by the blade is transported by a paddle, and is also sent to a toner collecting unit by a flicking member. The proposed technique has already been proposed (for example, see Japanese Patent Application Laid-Open No. H08-115026).

[0004]

However, in this type of cleaning device, a space for arranging the paddle and the flicking member must be secured above the blade, so that the entrance passage of the cleaning housing corresponding to the blade is required. Must be ensured widely, so that the vertical dimension of the cleaning housing is inevitably increased, and the cleaning device is enlarged. Therefore, when making the cleaning device thinner, the vertical width of the inlet passage of the cleaning housing is set to be small.
If the vertical width of the entrance passage is set to be narrow, even if the paddle and the flicking member can be provided, it is difficult to reliably transport (jump) the toner toward the toner collecting section, and the narrow entrance passage is difficult. Is easy to clog the residual toner,
A technical problem has been found that contamination in the apparatus is caused by toner spill.

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problems, and effectively avoids clogging of residues scraped by a blade while satisfying a demand for a thinner device itself. However, it is an object of the present invention to provide a cleaning device that reliably collects the residue and keeps the cleaning performance always good.

[0006]

That is, as shown in FIG. 1, the present invention provides a cleaning housing 2 which is opened facing an image carrier 1 and extends substantially in a horizontal direction. A cleaning blade 3 attached to the lower edge of the opening, extending substantially in the horizontal direction, and having a leading end in contact with the image carrier 1. A cleaning device that is formed at the back of the cleaning housing 2 and has a storage space portion 5 that expands with respect to the entrance passage 4. The cleaning device 3 stores the residue on the image carrier 1 scraped off by the cleaning blade 3. A forcedly conveyed belt 6 forcibly conveyed toward the space portion 5 can be circulated and moved over the entrance passage 4 and the upper portion of the storage space portion 5. It is characterized in that it has set.

In such a technical means, the cleaning device according to the present invention uses a drum-shaped or belt-shaped image carrier (not only a photosensitive member or a dielectric material for visualizing a latent image,
(Including an intermediate transfer member that temporarily holds a visible image on a photoreceptor or a dielectric)). It is valid. Further, as the cleaning blade 3, a member made of only an elastic material such as rubber may be attached via a holder, as long as the cleaning blade 3 can scrape and remove the residue on the image carrier 1. An appropriate selection may be made, for example, by using an elastic body fixed to the tip of a metal elastic plate.

The driving system of the forced conveying belt 6 may have its own driving source. However, a mode in which a driving force from an existing driving source (such as the image carrier 1 and the developing device) is used is used. preferable. For example, in order to use the driving force of the image carrier 1, the forced conveyance belt 6 may be brought into contact with the image carrier 1 and driven to rotate.

Further, from the viewpoint of reliably dropping the residue conveyed by the forced conveyance belt 6 into the storage space 5, a scraping member is provided at a portion of the forced conveyance belt 6 facing the storage space 5. 7 are preferably arranged in contact.

The forcible transport belt 6 is a member for transporting the residue. For example, in a situation where the storage space 5 is full of the collected residue, the collected residue remains adhered to the surface of the forcible transport belt 6. become. In such a case, the forced conveyance belt 6 is kept dirty with the collected residue.
For example, a belt surface detecting means 8 for detecting the state of the forcible conveying belt 6 is provided, and it is possible to perform a full residue detection process in the storage space 5 based on the detection information from the belt surface detecting means 8. Become.

Next, the operation of the above technical means will be described. As shown in FIG. 1, the forced conveying belt 6 is disposed so as to be able to circulate over the entrance passage 4 and the upper portion of the storage space 5, and is disposed on the image carrier 1 scraped off by the cleaning blade 3. The material is forcibly transported to the storage space 5 side. Therefore, the residue does not accumulate in the narrow entrance passage 4 and clogging does not occur.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings. Embodiment 1 FIG. 2 shows an embodiment of a color image forming apparatus to which the present invention is applied. In the figure, the color image forming apparatus vertically arranges image forming units 22 (specifically, 22a to 22d) of four colors (black, yellow, magenta, and cyan in the present embodiment) in a main body housing 21. A paper feed cassette 23 for accommodating paper to be supplied is arranged below the paper feed cassette, and paper (not shown) from the paper feed cassette 23 is transported to a position corresponding to each image forming unit 22. The paper transport path 24 which is a path is arranged in a vertical direction.

In the present embodiment, the image forming units 22 (22a to 22d) form toner images for black, yellow, magenta, and cyan in order from the upstream side of the paper transport path 24. , A photoreceptor cartridge 30 and an exposure unit 40. Here, the photoconductor cartridge 30 includes, for example, a photoconductor drum 31 and
A charging roll 32 for charging the photosensitive drum 31 in advance
And a developing unit 3 that develops the electrostatic latent image formed by exposure on the charged photosensitive drum 31 by the exposure unit 40 with a corresponding color toner (for example, negative polarity in this embodiment).
3 and a cleaning device 34 for removing residual toner on the photosensitive drum 31 are integrally formed as a cartridge. On the other hand, the exposure unit 40 stores a semiconductor laser (not shown), a polygon mirror 42, an imaging lens 43, and a mirror 44 in a case 41, deflects and scans light from the semiconductor laser (not shown) with the polygon mirror 42, The optical image is guided to an exposure point on the photosensitive drum 31 via the image lens 43 and the mirror 44.

Further, in the present embodiment, as shown in FIG. 2, a transport belt 80 circulating along the paper transport path 24 is disposed at a position corresponding to each photosensitive drum 31 of each image forming unit 22. Has been established. The transport belt 80 is made of a belt material (rubber or resin) capable of electrostatically adsorbing a sheet, and is stretched over a pair of stretching rolls 81 and 82. In this embodiment, the upper stretching belt is used. The roll 82 is a driving roll, and the lower stretching roll 81 is a driven roll.

Further, a transfer roll 50 is provided on the back side of the transport belt 80 corresponding to the photosensitive drum 31 of each image forming unit 22. The transfer roll 50 causes the photosensitive drum 31 and the transport belt 80 to move. The upper paper is brought into close contact. A transfer bias power supply (not shown) is connected to the transfer roll 50, and a predetermined transfer bias is applied at an appropriate timing.

In this embodiment, the paper feed cassette 2
Reference numeral 3 denotes a paper feed roll 6 for sending out paper at a predetermined timing.
1 is provided, and a delivery roll 62 for delivering a paper is provided in the paper transport path 24 located between the paper supply roll 61 and the transfer portion of the uppermost stream image forming unit 22a. Further, a fixing device 64 is provided in the sheet transport path 24 located on the downstream side of the most downstream image forming unit 22d, and a discharge roll 66 for discharging the sheet is provided on the downstream side of the fixing device 64. The discharge paper is stored in a storage tray 67 formed on the upper part of the storage 21. In FIG. 2, reference numeral 65 denotes a paper guide for guiding the paper sent from the paper conveyance belt 80 to the fixing device 64.

FIG. 3 shows details of the cleaning device 34 used in the present embodiment. In the figure, a cleaning device 34 has a cleaning housing 100 which is opened facing the photosensitive drum 31 (rotated clockwise in this example) and extends in the horizontal direction. For example, a cleaning blade 110 made of an elastic material such as rubber is attached via a metal blade holder 111 (a rigid body in this example), the cleaning blade 110 is arranged in a horizontal direction, and the tip of the cleaning blade 110 is This is an elastic contact with the drum 31. FIG. 3 shows a natural state of the cleaning blade 110.

A narrow entrance passage 101 is formed between the cleaning blade 110 and the blade holder 111 at the opening entrance side of the cleaning housing 100, and extends toward the back side of the cleaning housing 100 with respect to the entrance passage 101. A toner collecting unit (storage space) 102 is formed. In the present embodiment, the minimum vertical width h of the entrance passage 101 is equal to the cleaning point P.
Distance L from C (the contact point of the cleaning blade 110 with the photosensitive drum 31) to the toner collecting unit 102
(H: 4 mm, L: 30 m in this example)
m).

Further, a forced conveying belt 120 is provided between the entrance passage 101 and the upper portion of the toner collecting section 102. The forced conveying belt 120 is formed of, for example, a resin such as a polyester resin or rubber, and is stretched over a pair of stretching rolls 121 and 122. In the present embodiment, a pair of tension rolls 121, 12
2 are different from each other, and one of the tension rolls 1
Numeral 21 is configured to function as a rotational force transmitting roll for transmitting the rotational force from the photosensitive drum 31 to the forced conveying belt 120 by bringing the forced conveying belt 120 into contact with the vicinity of the uppermost point of the photosensitive drum 31.

Further, a small-diameter holding roll 123 is provided near the tension roll 121 so as to bring the forced transport belt 120 into contact with a 3/4 portion of the peripheral surface of the tension transport roll 121. The vertical width of the forced conveying belt 120 other than 121 is set to m (about 2 mm in this example) shorter than the vertical width h of the entrance passage 101.

Next, the operation of the color image forming apparatus according to this embodiment will be described. A sheet (not shown) is conveyed by a conveying belt 80, and each image forming unit 22 (2
2a to 22d), the color component toner images on the photosensitive drum 31 are sequentially transferred onto the sheet by the transfer electric field generated by the transfer roll 50. Then, when the leading end of the sheet enters the fixing device 64 and finishes passing,
The sheet on which the unfixed toner image is fixed is discharged to a storage tray 67 through a discharge roll 66.

In such an image forming process, in each image forming unit 22, a cleaning process is performed by the cleaning device 34 after the transfer process. Specifically, as shown in FIG. 4, the residual toner on the photosensitive drum 31 is scraped off by the cleaning blade 110, and the residual toner is sequentially deposited on the cleaning blade 110.
On the cleaning blade 110, a toner pool 130
Occurs. However, when the photoconductor drum 31 is rotating, the rotational force from the photoconductor drum 31 is transmitted to the forced conveyance belt 120. Therefore,
When the toner accumulation 130 accumulates until the toner accumulation 130 comes into contact with the forced conveyance belt 120, the collected toner 131 that has come into contact
Is forcibly conveyed along the forcible conveying belt 120 as shown by the arrow in the figure, and falls naturally into the toner collecting section 102 when it reaches the toner collecting section 102. For this reason,
Even when the entrance passage 101 is narrow, the collected toner 131 does not clog the entrance passage 101.

Further, in the color image forming apparatus according to the present embodiment, since the cleaning device 34 can be configured to be thin, even in a vertical tandem type device as shown in FIG. The vertical dimension can be set to a short dimension.

Second Embodiment FIG. 5 shows a second embodiment of a cleaning apparatus to which the present invention is applied. In the figure, the basic configuration of the cleaning device 34 is substantially the same as that of the first embodiment, however, in addition to the configuration of the first embodiment, a tension roll 122 on the toner collection unit 102 side of the forced conveyance belt 120 is attached. The scraping member 140 is arranged in contact with a corresponding portion. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here.

Therefore, according to the present embodiment, the residual toner on the photosensitive drum 31 is
And is deposited on the cleaning blade 110. When the toner reservoir 130 comes into contact with the forced conveying belt 120, the contacted collected toner 131 is forcibly conveyed along the forced conveying belt 120 as shown by an arrow in FIG. , Falls naturally into the toner collecting unit 102. Further, the collected toner 131 adhered to the forced conveyance belt 120 is scraped off by the scraping member 140 and collected by the toner collecting unit 102. Therefore, in the present embodiment, the forced conveyance belt 120 always performs the operation of conveying the collected toner 131 on a clean surface.

Third Embodiment FIG. 6 shows a cleaning device according to a third embodiment of the present invention. In the figure, the basic configuration of the cleaning device 34 is substantially the same as that of the first embodiment, but in addition to the configuration of the first embodiment, a scraping member is provided near the entrance of the toner collection unit 102 of the forced conveyance belt 120. A belt surface detection sensor 150 for detecting a state of the surface of the forced conveyance belt 120 is provided on the upper wall of the cleaning housing 100 facing the upper bridging portion of the forced conveyance belt 120 while the contact 141 is arranged. This belt surface detection sensor 15
Reference numeral 0 denotes an optical sensor that detects the transmittance or the reflectance of the surface of the forced conveyance belt 120.

On the other hand, the detection signal from the belt surface detection sensor 150 is taken into the control device 160, and the control device 1
Reference numeral 60 denotes, for example, a display 170 that warns that the toner collection unit 102 is full when a detection signal from the belt surface detection sensor 150 exceeds an allowable level (a state in which the forced conveyance belt 120 is on a clean surface). A message for replacing the photoreceptor cartridge 30 is displayed. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here.

Therefore, according to the present embodiment, in addition to the same operation as that of the second embodiment, for example,
In a situation where the amount of the collected toner of No. 02 is full, the collected toner in the toner collecting unit 102 adheres again to the surface of the forced conveyance belt 120 that has passed through the scraping member 141, so that the forced The conveyor belt 120 passes the belt surface detection sensor 150. At this time, the control device 160 determines the full state of the toner collecting unit 102 based on the detection signal from the belt surface detection sensor 150, and a warning is displayed on the display 170. Therefore, in the present embodiment, the life of the cleaning device 34, in other words, the life of the photoreceptor cartridge 30 can be managed by monitoring the state of the belt surface of the forced conveyance belt 120.

[0029]

As described above, according to the present invention,
Even if the cleaning housing is made thinner, the residual material scraped from the image carrier by the blade with the forced conveyance belt is surely conveyed to the storage space from the narrow entrance passage. While effectively avoiding clogging of the residue scraped off by the blade, the residue can be reliably collected and the cleaning performance can be always kept good.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a cleaning device according to the present invention.

FIG. 2 is an explanatory diagram showing an example of an image forming apparatus incorporating the first embodiment of the cleaning device to which the present invention is applied.

FIG. 3 is an explanatory diagram illustrating details of a cleaning device according to the first embodiment;

FIG. 4 is an explanatory diagram illustrating an operation state of the cleaning device according to the first embodiment.

FIG. 5 is an explanatory diagram showing details of a cleaning device according to a second embodiment.

FIG. 6 is an explanatory diagram illustrating details of a cleaning device according to a third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image carrier, 2 ... Cleaning housing, 3 ... Cleaning blade, 4 ... Inlet passage, 5 ... Storage space part, 6
... Forced conveyor belt, 7 ... Scraping member, 8 ... Belt surface detecting means

Claims (5)

[Claims] A cleaning housing which is opened facing the image carrier and extends substantially in the horizontal direction; a cleaning housing attached to a lower edge of the opening of the cleaning housing which extends substantially in the horizontal direction, and a tip of which contacts the image carrier. A cleaning blade having a narrow entrance passage formed between the cleaning blade and the cleaning housing at an opening entrance side of the cleaning housing, and a storage space extending toward the entrance passage at the back side of the cleaning housing. A forced transport belt for forcibly transporting the residue on the image carrier scraped by the cleaning blade to the storage space side so as to be circulated and movable over the entrance passage and the upper portion of the storage space portion. A cleaning device characterized by being provided. 2. The cleaning device according to claim 1, wherein the forcible conveying belt is driven to rotate following contact with the image carrier. 3. The cleaning device according to claim 1, wherein a scraping member is disposed in contact with a portion of the forced conveyance belt facing the storage space. 4. The cleaning device according to claim 1, further comprising a belt surface detecting means for detecting a state of a forced conveying belt surface. 5. The cleaning device according to claim 4, wherein a full-residue detection process in the storage space is performed based on detection information from the belt surface detection unit.