Patent Grant
7623820
1. Field of the Invention
The present invention relates to an image forming apparatus having a collecting container which contains the toner collected from an image bearing member.
2. Description of the Related Art
There is a cleaning unit as a conventional technique for cleaning the toner on an image bearing member of an image forming apparatus. The image forming apparatus disclosed in the Japanese Patent Application Laid-Open No. H05-173457 has a brush roller for collecting the toner on a photosensitive drum, and the toner collected by the brush roller is pushed into a cleaning unit. The photosensitive drum and the cleaning unit are arranged side by side. If there is a biased amount of toner on the photosensitive drum in the longitudinal direction, the toner is pushed into the cleaning unit with the bias. If a large biased amount of toner is collected at a position apart from a toner detection unit in the cleaning unit, then the problem that the toner flows from the position where the large biased amount of toner has been collected before the full toner is detected is recognized. To solve this problem, Japanese Patent Application Laid-Open No. H05-173457 describes that the toner in the cleaning container is collected by moving the toner immediately below the toner detection unit.
However, there can be a result of detecting a large amount of collected toner although there is a small amount of toner in the cleaning unit when the toner is automatically conveyed to the detection unit of, for example, the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. H05-173457.
The present invention has been developed to solve the foregoing problem.
There is also Japanese Patent Application Laid-Open No. 2002-148884 having the configuration of conveying toner in a cleaning unit, but the application does not originally have the problem from biased toner in the longitudinal direction of an image bearing member.
A purpose of the present invention is to correctly grasp the amount of toner in a collecting container or to improve the toner containing efficiency of a toner collecting container.
Another purpose of the present invention is to provide an image forming apparatus including: a toner bearing member which bears toner, the toner bearing member being movable in a moving direction; a toner container which contains toner collected from the toner bearing member; a conveyance member for conveying the toner in the toner container; and a toner sensor for detecting the toner at a deteet detection position in the toner container. In a direction orthogonal to the moving direction of the toner bearing member, the conveyance member conveys the toner in a direction of leaving the detection position.
A further purpose of the present invention is to provide an image forming apparatus including: a toner bearing member which bears toner, the toner bearing member being movable in a moving direction; a toner container which contains toner collected from the toner bearing member; a conveyance member for conveying the toner in the toner container; a toner sensor for detecting the toner at a detection position in the toner container; a first area in the toner container; and a second area in the toner container closer to the detection position than the first area in a direction orthogonal to the moving direction of the toner bearing member. In the first area, the conveyance member conveys the toner toward the detection position, and the movement of the toner toward the detection position is suppressed in the second area.
A further purpose of the present invention is to provide an image forming apparatus including: a toner bearing member which bears toner, the toner bearing member being movable in a moving direction; a toner container which contains toner collected from the toner bearing member; a toner sensor for detecting the toner at a detection position in the toner container; a first area in the toner container; and a second area in the toner container closer to the detection position than the first area. In the first area, the toner is conveyed toward the detection position. In the second area, the movement of the toner toward the detection position is suppressed. The detection position is in an area in which the toner bearing member bears the toner in the direction orthogonal to the moving direction of the toner bearing member.
A further purpose of the present invention is to provide an image forming apparatus including: an image bearing member for bearing a toner image; a transfer member for transferring the toner image on the image bearing member; a toner container which contains toner collected from the toner bearing member; a toner sensor for detecting the toner at a detection position in the toner container; a first area in the toner container; and a second area in the toner container closer to the detection position than the first area. The transfer member transfers only an area of a part of a toner image on the image bearing member to a record member. In the first area, the toner is conveyed toward the detection position. In the second area, the conveyance of the toner toward the detection position is suppressed.
A further purpose of the present invention is to provide an image forming apparatus including: a toner bearing member which bears toner in a moving direction; a transfer member for transferring a toner image on the image bearing member; a collecting member for collecting remaining toner on the image bearing member; a toner container which contains toner collected by the collecting member; and a conveyance member for conveying the toner in the toner container. In the direction orthogonal to the moving direction of the image bearing member, the transfer member transfers a toner image to a record member except an end portion area of the toner image, and the conveyance member conveys the toner toward the center of the toner container.
A further purpose of the present invention is to provide an image forming apparatus including: a toner bearing member which bears toner in a moving direction; a toner container which contains toner collected from the toner bearing member; a toner sensor for detecting the toner at a detection position in the toner container; a first area in the toner container; and a second area in the toner container closer to the detection position than the first area in a direction orthogonal to the moving direction of the toner bearing member. In the first area, the toner is conveyed toward the detection position. In the second area, the toner is conveyed in a direction of leaving the detection position.
A still further purpose of the present invention will be more clearly described with reference to the following descriptions and the attached drawings.
The exemplary embodiments of the present invention are described below in detail with reference to the attached drawings. The dimensions, materials, shapes, the relative arrangements, etc. of the components described in the following embodiments of the present invention are to be appropriately changed depending on the configurations of the devices to which the present invention is applied and various conditions. Therefore, the scope of the present invention is not limited to the modes described below.
In the descriptions below, a rough configuration of the image forming apparatus is first described by referring to
[General Description of the Image Forming Apparatus]
In the present embodiment, the device includes four electronic photosensitive drums 1a, 1b, 1c and 1d (hereinafter referred to simply as “photosensitive drums 1”) for yellow, magenta, cyan and black as the image bearing members mounted at an angle as shown in
A toner image formed on each photosensitive drum 1 is transferred to the intermediate transferring belt 12e by the effect of primary transfer units 12a, 12b, 12c and 12d. Around the photosensitive drum 1, primary charge devices 2a, 2b, 2c and 2d (hereinafter referred to simply as “primary charge devices 2”), developing units 40a, 40b, 40c and 40d (hereinafter referred to simply as “developing units 40”, and cleaning units 8a, 8b, 8c and 8d (hereinafter referred to simply as “cleaning units 8”) are arranged in order from the upstream in the rotation direction.
The primary charge device 2 is a charge unit for evenly charging the surface of the photosensitive drum 1. A electrostatic latent image is formed on the surface of the photosensitive drum 1, which is evenly charged by the primary charge device 2 after an exposing unit 3 irradiates the surface with a laser beam according to image information. The developing unit 40 develops a toner image by attaching the toner (developing agent) of each color on the surface of the photosensitive drum 1 on which the electrostatic latent image is formed. The cleaning unit 8 removes the remaining toner on the surface of the photosensitive drum 1 after the transfer.
On the other hand, a record member 500 supplied from a pickup roller 9 out of a feed cassette is separately fed piece by piece from a separating unit not shown in the attached drawings. Then, the member is transmitted by a convey roller pair 13 to a registration roller pair 17, and is conveyed by the registration roller pair 17 to the space between the intermediate transferring belt 12e and a secondary transfer unit 101 with predetermined timing. The secondary transfer unit 101 performs a secondary transfer to a record member 500 on the toner image primarily transferred to the intermediate transferring belt 12e.
The record member 500, to which the toner image has been transferred, has the toner image fixed by a fixing unit 14, is conveyed by an eject roller pair 20, and is ejected on an eject tray 21 mounted on the upper portion of the body of the device.
[Description of the Arrangement of the Residual Toner Conveyance Unit]
The configurations of the secondary transfer unit and the cleaning device according to the present embodiment are described by referring to
In these figures, the secondary transfer roller 101 as a rotation member as a secondary transfer unit is illustrated. A cleaning device 100 for removing and storing the toner (developing agent) attached to the surface of the secondary transfer roller 101 is mounted. The cleaning device 100 has a cleaning blade 111 as a cleaning member which contacts the surface of the secondary transfer roller 101 and removes the toner attached to the surface of the secondary transfer roller 101. The cleaning device 100 also has a residual toner container 150 as a collecting container for containing the toner removed from the secondary transfer roller 101. Furthermore, the cleaning device 100 has a residual toner detection device 350 as a toner detection unit for detecting the toner in the residual toner container 150. The residual toner detection device 350 is located at the center in the axis direction of the secondary transfer roller 101. The cleaning device 100 has a residual toner conveyance unit 200 as a toner conveyance unit for conveying toner in the residual toner container 150.
As shown in
The residual toner container 150 is provided with the cleaning blade 111, and is configured to correctly contact the secondary transfer roller 101 at a predetermined position. A first seal member 112 is mounted at both ends of the cleaning blade 111 so that residual toner cannot leak from the end portions. A sweeper strip 113 (refer to
The residual toner conveyance unit 200 is arranged such that an axis S1 of the secondary transfer roller 101 can be substantially parallel with the axis S2 of the residual toner conveyance unit 200. The residual toner conveyance unit 200 is arranged below the position where the cleaning blade 111 contacts the secondary transfer roller 101 at the upper portion of the residual toner container 150 (refer to
As shown in
A second seal member 162 is arranged between the residual toner container 150 and the residual toner conveyance unit drive gear 160. With the configuration, the residual toner can be prevented from leaking out from the engagement portion between the residual toner conveyance unit 200 and the residual toner container 150.
An intermediate gear 170 is arranged so as to engage with an intermediate gear axis 154, and transmits the drive force from the secondary transfer roller drive gear 120 to the residual toner conveyance unit drive gear 160 as shown in
The residual toner conveyance unit 200 has first screws 210a and 210b as first convey units for conveying toner in the direction of the axis of the secondary transfer roller 101 from both ends toward the center in the residual toner container 150. Additionally, the residual toner conveyance unit has second screws 220a and 220b as second convey units for conveying toner in the direction of the axis of the secondary transfer roller 101 from the center toward both ends of the secondary transfer roller 101.
In the residual toner conveyance unit 200, the first screws 210a and 210b are formed with the inverse spiral directions from the both ends toward the center in the axis direction of the secondary transfer roller 101. The second screws 220a and 220b are formed with the inverse spiral directions from the center toward both ends in the axis direction of the secondary transfer roller 101. By the residual toner conveyance unit 200 rotating and driving clockwise as shown in
The residual toner conveyance unit 200 is not provided with a screw (convey unit) formed in the spiral direction between the first screw 210a and the second screw 210a and between the first screw 210b and the second screw 220b.
The first screws 210a and 210b are arranged from outside to inside of the maximum print area of the image forming apparatus. To be more specific, the first screws 210a and 210b are mounted from outside to inside of the contact area of the cleaning blade 111 in contact with the secondary transfer roller 101 in the axis direction of the secondary transfer roller 101. Thus, the residual toner T that can be accumulated on both end portions of the residual toner container 150 can be correctly conveyed toward the center.
To detect the accumulation level of the residual toner T to the residual toner container 150, the residual toner detection device 350 is provided at the central portion of the residual toner container 150. The residual toner detection device 350 is a light guide of a transparent member, and is fixed to the residual toner container 150.
As shown in
That is, if the residual toner T contained in the residual toner container 150 has not been accumulated to reach the residual toner detection device 350 as shown in
The two detection planes 352 and 353 of the residual toner detection device 350 are formed to perpendicularly cross the optical axis of the infrared light 370. The two detection planes 352 and 353 in the residual toner detection device 350 are inserted as entering the upper wall in the residual toner container 150. Thus, the residual toner can be removed from the two detection planes 352 and 353 by a cleaning member 300 without leaving the residual toner in the concave portion of the residual toner detection device 350.
Furthermore, the residual toner T removed from the secondary transfer roller 101 is constantly scattered in the residual toner container 150. By the attachment of the scattered residual toner T to the residual toner detection device 350, there is the possibility of a decreasing amount or cutoff of received light in the photosensor 361. To prevent this, the cleaning member 300 (refer to
As shown in
If there is sufficient residual toner T accumulated in the residual toner container 150, the toner exceeds the cleaning capability of the cleaning member 300, and the detected light from the first plane of irradiation 352 to the second plane of incidence 353 is cut off by the residual toner T. If there is sufficient residual toner T accumulated in the residual toner container 150, then the cleaning member 300 rotates in the residual toner T, and slides on the surfaces of the first plane of irradiation 352 and the second plane of incidence 353. However, the toner is filled immediately after the cleaning member 300 passes. That is, as shown in
[Description of Frameless Print]
The frameless print obtained by forming an image over the entire record member 500 is described below by referring to
The image forming apparatus according to the present embodiment can be operated in a normal print mode (first mode) and a frameless print mode (second mode). The normal print mode (also referred to as a “normal mode”) refers to a mode in which a margin is formed on the entire perimeter of a record member. A frameless print mode refers to a mode in which no margin is formed on any perimeter of a record member. The frameless print also refers to a print on which no margin is formed on any perimeter of a record member.
In the frameless print mode, a toner image is formed in a broader range than the record member 500 on the intermediate transferring belt 12e. By transferring the toner image to the record member 500 by the secondary transfer roller 101, a frameless record can be made on the record member 500. If a large image formed on the intermediate transferring belt 12e is superposed on the record member, a toner image larger than the record member is generated. Since the toner image larger than the record member is not transferred to the record member, the image is directly transferred to the secondary transfer roller 101. That is, in the frameless print mode, a toner image excluding a part of the toner image on the intermediate transferring belt 12e is transferred to a record member. Thus, the toner image can be transferred to the end of the record member.
When the process is described by referring to
[Description of the Effect of the Residual Toner Conveyance Unit]
When the frameless print process is performed, the residual toner T concentrates and piles on both ends in the residual toner container 150 much more than it piles on the central portion. As described above, the both end toner image 503 of a record member is transferred on the secondary transfer roller 101, and enters the residual toner container 150. When the frameless print mode is continued, the residual toner T piling on both end portions reaches the residual toner conveyance unit 200 arranged at the upper portion of the residual toner container 150 as indicated by the status A shown in
When the frameless print is continued, the residual toner T reaches the second screws 220a and 220b at the center in the longitudinal direction. After the residual toner T reaches them, the second screws 220a and 220b convey the toner from the center to both ends in the longitudinal direction. The first screw 210 and the second screw 220 are opposite in the convey direction, and since there is no screw between the first screw 210 and the second screw 220, the residual toner T is piled between the first screw 210 and the second screw 220. That is, the residual toner T piling around the residual toner detection device 350 can be suppressed, and the residual toner T piles as indicated by the status C shown in
With the above-mentioned configuration, the residual toner detection device 350 can be prevented from getting dirty by the piled residual toner T until the residual toner container 150 becomes full of the residual toner T, and can be prevented from getting dirtier than the cleaning capability of the cleaning member 300. Therefore, the volume of the residual toner container 150 can be efficiently filled with the residual toner T, thereby improving the toner containing efficiency of the residual toner container 150, and correctly detecting the accumulation level of the toner in the residual toner container 150.
The cleaning device according to the embodiment 2 of the present invention is described below by referring to
A cleaning device 400 according to the present mode has a residual toner container 156 whose bottom is tapered downward from the center to both ends in the axis direction of the secondary transfer roller 101. In
As in the above-mentioned embodiment 1 of the present invention, when the frameless print process is performed, the pile of the residual toner T concentrates on both end portions as compared with the pile of the residual toner T at the central portion. When the frameless print process is continued, the residual toner T piled on both end portions reaches the residual toner conveyance unit 200 arranged at the upper portion of the residual toner container 156. Since the residual toner conveyance unit 200 is rotation-driven, the residual toner T piled on the drive side is conveyed toward the center by the first screw 210a. Similarly, the residual toner T piled on the non-driven side is conveyed toward the center by the first screw 210b.
At this time, the effect of the slope portion 155 generates large convey resistance against the conveyance of the residual toner T from both end sides of the residual toner container 156 to the center. Therefore, the amount of residual toner T conveyed toward the central portion of the residual toner container 150 decreases. As a result, the residual toner T piled around the residual toner detection device 350 is suppressed. Thus, the erroneous detection by the residual toner detection device 350 can be furthermore suppressed, thereby more correctly detecting the accumulation level of the toner in the residual toner container 156, and improving the toner containing efficiency in the residual toner container 156.
The cleaning device according to the embodiment 3 of the present invention is described below by referring to
A cleaning device 401 has a cleaning member 301 which is provided for the residual toner conveyance unit 200 whose rotation enables the member to contact the residual toner detection device 350 and intermittently clean the residual toner detection device 350.
The cleaning member 301 is made of an elastic member such as urethane and the like. As shown in
The cleaning member 301 has a notch 310 inside at a free end portion 301a opposite the center of the rotation. The notch 310 is triangular, has a bottom side of 4.5 mm and a height of 3.8 mm, and has the bottom side at the free end portion 301a.
The cleaning member 301 is attached to the residual toner conveyance unit 200 with a cohesive agent such that the end portion opposite the free end portion 301a can be parallel with the central axis of the rotation of the residual toner conveyance unit 200. The cleaning member 301 is designed to have its free end portion 301a contacting and passing the two detection planes 352 and 353 in the concave portion of the residual toner detection device 350 when the cleaning member rotates around the rotation center axis. At this time, as shown in
The cleaning device 401 has guide members 230a and 230b that are provided for the residual toner conveyance unit 200, and touch the residual toner detection device 350 to determine the position of the cleaning member 301 relative to the residual toner detection device 350.
Practically, as shown in
The guide members 230a and 230b have the form of a disk as shown in
As shown in
The central axis of the rotation of the residual toner conveyance unit 200 is parallel with the optical axis of the detected light (infrared light 370 shown in
Thus, the guide members 230a and 230b constantly contact the residual toner detection device 350, and determine the position of the cleaning member 301 relative to the residual toner detection device 350. Therefore, when the residual toner conveyance unit 200 rotates, the cleaning member 301 attached to the residual toner conveyance unit 200 contacts and passes, in a curved state, the two detection planes 352 and 353 between the first plane of irradiation 352 and the second plane of incidence 353. In
As described above, according to the present embodiment, as in the above-mentioned embodiments of the present invention, the toner containing efficiency of the residual toner container 150 can be improved, and the accumulation level of the toner in the residual toner container 150 can be correctly detected. Furthermore, since the position of the cleaning member 301 can be determined relative to the residual toner detection device 350 by the guide members 230a and 230b, the toner attached to the detection planes 352 and 353 in the container can be correctly removed by the cleaning member 301. Therefore, there is no erroneous detection, and the detection can be performed correctly and stably. Other embodiments are almost the same as those according to the above-mentioned embodiments of the present invention.
In the above-mentioned embodiments of the present invention, the secondary transfer roller is exemplified as a rotation member for removing toner. However, the present embodiment exemplifies a cleaning device 402 with almost the same configuration as the cleaning device 401 according to the embodiment 3 of the present invention as a cleaning device for removing the toner on the intermediate transferring belt 12e. The components having the same functions as the cleaning device 401 are assigned the identical reference numerals. The cleaning device 402 faces a driven roller 12j through the intermediate transferring belt 12e. In the present embodiment, a tension roller 12i applies tension to the intermediate transferring belt 12e.
As described above, when the frameless print process is performed, a toner image larger than a record member is formed on the intermediate transferring belt 12e. The toner for the portion larger than the record member is attached to the secondary transfer roller 101. However, all corresponding toner is not attached to the surface of the secondary transfer roller 101, but the toner not attached to the secondary transfer roller 101 remains on the intermediate transferring belt 12e as what is called residual toner after transfer. There is a larger amount of residual toner after transfer for the portion not corresponding to the record member than the amount corresponding to the record member because, with reference to the surface properties and the like, the record member and the secondary transfer roller 101 are different from each other, and the transfer condition is set such that the transfer efficiency on the record member can be higher. Thus, the amount of toner remaining on the intermediate transferring belt 12e after the second transfer tends to be larger on both sides in the longitudinal direction. Then, as the distribution of the collected toner of the cleaning device 402 for collecting the residual toner on the intermediate transferring belt 12e, a larger amount is detected on both sides in the longitudinal direction as in the cases of other cleaning devices 401 according to the other embodiments of the present invention. Therefore, as in the other embodiments of the present invention, the toner is moved in the longitudinal direction in the cleaning device 402, and the correctness of the detection of the amount of toner in the cleaning device 402 can be guaranteed.
In the above-mentioned embodiments 1 to 3, the cleaning device is exemplified for cleaning the secondary transfer roller 101. However, a record member bearing belt can be cleaned to obtain a similar effect. That is, using a record member bearing member, an image forming apparatus can transfer a toner image by sequentially superposing each color of toner image on the record member borne by the record member.
The embodiment 4 of the present invention exemplifies the cleaning device 402 having the intermediate transferring belt 12e, but the same effect can be obtained by using a cleaning device having what is called a photosensitive drum as a cleaning device for a toner image bearing member. When a toner image is transferred from the photosensitive drum directly to the record member, it is especially effective.
In the above-mentioned embodiments of the present invention, a printer is exemplified as an image forming apparatus, but the influence is not limited to this application. For example, it can be an image forming apparatus of a copying machine, a facsimile device, etc., or other image forming apparatus for composite devices as combinations of plural functions. In addition, a record member bearing member can be used in an image forming apparatus to transfer a toner image by sequentially superposing a toner image of each color on the record member borne by the record member bearing member. By applying the present invention to the cleaning devices in these image forming apparatus, identical effects can be obtained.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-044699, filed Feb. 22, 2006, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-044699 | Feb 2006 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5890034 | Hiroshi et al. | Mar 1999 | A |
| 6298217 | Murayama et al. | Oct 2001 | B1 |
| 20060039710 | Tawada | Feb 2006 | A1 |
| Number | Date | Country |
|---|---|---|
| 0 833 225 | Apr 1998 | EP |
| 1 065 575 | Jan 2001 | EP |
| 01-97980 | Apr 1989 | JP |
| 5-165331 | Jul 1993 | JP |
| 5-173457 | Jul 1993 | JP |
| 2000-132033 | May 2000 | JP |
| 2000-330440 | Nov 2000 | JP |
| 2001-222168 | Aug 2001 | JP |
| 2001-356619 | Dec 2001 | JP |
| 2002-148884 | May 2002 | JP |
| 2003-015493 | Jan 2003 | JP |
| 2004-045451 | Feb 2004 | JP |
| 2004-341051 | Dec 2004 | JP |
| 2004-354524 | Dec 2004 | JP |
| 2005-352402 | Dec 2005 | JP |
| 1998-025160 | Jul 1998 | KR |
| Number | Date | Country | |
|---|---|---|---|
| 20070196147 A1 | Aug 2007 | US |
