TONER CASE AND IMAGE FORMING APPARATUS INCLUDING THE SAME

INCORPORATION BY REFERENCE

This application is based on and claims the benefit of priority from Japanese patent application No. 2015-240483 filed on Dec. 9, 2015, which is incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to a toner case which contains a toner (developer), and an image forming apparatus which includes the toner case.

An electrographic image forming apparatus includes a developing device which develops a toner image on a surface of a photosensitive drum (image carrier) by using a toner supplied from a toner case. Further, the image forming apparatus includes a cleaning device which removes the toner remained on the surface of the photosensitive drum. The toner removed by the cleaning device is collected as a waste toner in a waste toner case.

There is a case where the image forming apparatus uses a toner case (empty case) which has supplied the toner to the developing device and has become empty as a waste toner case. In this regard, a supply toner case is attached to a toner case attachment part by orienting a toner supplying port downward. By contrast with this, the empty case (waste toner case) is attached to a waste toner case attachment part by orienting the toner supplying port upward.

Further, there is a case where a toner supplying cylindrical member includes a spiral toner feeding protrusion part protruding on an inner face of a surrounding wall. A plurality of toner supplying ports of small slit shapes are bored in the toner feeding protrusion part. A plurality of the toner supplying ports are formed in a range corresponding to a toner conveying roller. A plurality of toner supplying ports are arranged at equal intervals and with a phase shifted in a circumferential direction. One toner supplying port rotates (discharges a toner) while the toner supplying cylindrical member rotates once. The toner feeding protrusion part is formed to smoothly convey the toner.

SUMMARY

In accordance with the first aspect of the present disclosure, a toner case includes a case main body, a housing frame, a communicating port, a conveying rib, and a conveying screw. The case main body is capable of containing a waste toner discharged from an image forming part arranged inside an apparatus main body. The housing frame is configured to communicate with an inside of the case main body and to rotatably support the case main body. The communicating port is opened on a circumferential face of the housing frame and connected with the image forming part. The conveying rib is configured to spirally protrude on an inner circumferential face of the case main body. The conveying screw is arranged inside the housing frame. The conveying rib rotates integrally with the case main body in a first direction so as to convey the waste toner along a direction of introducing the waste toner into the case main body. The conveying screw rotates integrally with the case main body in the first direction so as to convey the waste toner introduced into the housing frame via the communicating port toward the inside of the case main body.

In accordance with the first aspect of the present disclosure, an image forming apparatus includes the toner case in accordance with the first aspect and the image forming part arranged inside the apparatus main body.

In accordance with the second aspect of the present disclosure, a toner case includes a case main body, a housing frame, a collecting port, a supplying port, a conveying rib, and a conveying screw. The case main body is capable of containing a supply toner supplied to an image forming part arranged inside an apparatus main body or a waste toner discharged from the image forming part. The housing frame is configured to communicate with an inside of the case main body and to rotatably support the case main body. The collecting port is opened on a circumferential face of the housing frame so as to introduce the waste toner from the image forming part to the housing frame. The supplying port is opened on the circumferential face of the housing frame so as to discharge the supply toner from the housing frame to the image forming part. The conveying rib is configured to spirally protrude on an inner circumferential face of the case main body. The conveying screw is arranged inside the housing frame. The conveying rib rotates integrally with the case main body in a first direction so as to convey the waste toner along a direction of introducing the waste toner into the case main body and rotates integrally with the case main body in a second direction so as to convey the supply toner along a direction of discharging the supply toner from the case main body to the housing frame. The conveying screw rotates integrally with the case main body in the first direction so as to convey the waste toner introduced into the housing frame via the collecting port toward the inside of the case main body and rotates integrally with the case main body in the second direction so as to discharge the supply toner in the housing frame via the supplying port.

In accordance with the second aspect of the present disclosure, an image forming apparatus includes the toner case in accordance with the second aspect and the image forming part arranged inside the apparatus main body.

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present disclosure is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view schematically showing an internal structure of a color printer according to a first embodiment of the present disclosure.

FIG. 2 is a perspective view showing a part of a toner supplying device, in the color printer according to the first embodiment of the present disclosure.

FIG. 3 is a sectional view schematically showing the toner supplying device, in the color printer according to the first embodiment of the present disclosure.

FIG. 4 is a perspective view showing a toner case according to the first embodiment of the present disclosure.

FIG. 5 is a sectional view showing the toner case according to the first embodiment of the present disclosure.

FIG. 6 is a sectional view showing a state that a supplying port of the toner case is opened, according to the first embodiment of the present disclosure.

FIG. 7 is a perspective view showing a conveying screw or the like of the toner case, according to the first embodiment of the present disclosure.

FIG. 8 is a sectional view showing a state that a collecting port of the toner case is opened, according to the first embodiment of the present disclosure.

FIG. 9 is a sectional view schematically showing a cleaning structure and a waste toner case, in the color printer according to the first embodiment of the present disclosure.

FIG. 10 is a sectional view showing a section along an X-X line of FIG. 9.

FIG. 11 is a rear view schematically showing a toner case according to another embodiment of the present disclosure.

FIG. 12 is a sectional view showing a state that a toner case is attached to a supplying attachment part, according to a second embodiment of the present disclosure.

FIG. 13 is a sectional view showing a state that the toner case is attached to a collecting attachment part, according to the second embodiment of the present disclosure.

DETAILED DESCRIPTION

A preferred embodiment of the present disclosure will be described below with reference to the accompanying drawings. Incidentally, in the following description, a near side in FIGS. 1, 3 and 10 is a front side, and a direction shown in each drawing serves as a reference.

An entire configuration of a color printer 1 as an image forming apparatus according to a first embodiment of the present disclosure will be described with reference to FIG. 1. FIG. 1 is a sectional view schematically showing an internal structure of the color printer 1.

The color printer 1 includes an apparatus main body 2, a sheet feeding cassette 3 and a sheet ejection tray 4. The sheet feeding cassette 3 is attachable to and detachable from a lower part of the apparatus main body 2 of a roughly cuboid shape. In the sheet feeding cassette 3, (a bundle of) sheets S are contained. The sheet ejection tray 4 is arranged at an upper part of the apparatus main body 2. Incidentally, the sheets S are not limited to pieces of paper and may be resin films or OHP sheets.

Further, the color printer 1 includes a sheet feeding part 10, an image forming part 11, a fixing device 12, a toner supplying device 13, a waste toner collecting device 14 and a control device 15, which are housed in the apparatus main body 2. The sheet feeding part 10 is arranged at an upstream side of a conveying path 16 extending from the sheet feeding cassette 3 to the sheet ejection tray 4. The image forming part 11 is arranged at an intermediate part of the apparatus main body 2. The fixing device 12 is arranged at a downstream side of the conveying path 16. The toner supplying device 13 includes four toner cases 41 which contain supply toners (developers) of four colors (yellow, magenta, cyanogen and black). The waste toner collecting device 14 collects a waste toner which has not been used for image formation. The control device 15 integrally controls each component of the color printer 1. Incidentally, the toner may be a two-component developer including the toner and a carrier, or may be a one-component developer including a magnetic toner.

The image forming part 11 includes an intermediate transfer unit 21, four drum units 22 and an optical scanning device 23. The intermediate transfer unit 21 is arranged below the sheet ejection tray 4. The four drum units 22 are arranged at a lower side of the intermediate transfer unit 21 and aligned in a left and right direction. The optical scanning device 23 is arranged at a lower side of each drum unit 22.

The intermediate transfer unit 21 includes a driving roller 25, a driven roller 26, an intermediate transfer belt 27 and a belt cleaning device 28. The driving roller 25 is arranged at a right side in the apparatus main body 2, and the driven roller 26 is arranged at a left side in the apparatus main body 2. The driving roller 25 is driven by a motor (not shown) to rotate. The intermediate transfer belt 27 as a transferring body is wound around the driving roller 25 and the driven roller 26. The intermediate transfer belt 27 runs circularly and counterclockwise (see an arrow in FIG. 1) when a predetermined tension is applied to the intermediate transfer belt 27 and the driving roller 25 is driven to rotate. The belt cleaning device 28 is arranged at a left side of the driven roller 26.

The four drum units 22 are arranged in association with respective colors of toners. Each drum unit 22 includes a photosensitive drum 30, a charging device 31, a developing device 32, a primary transfer roller 33, a drum cleaning device 34 and a static eliminator 35. Incidentally, the four drum units 22 employ the same configuration, and therefore one drum unit 22 will be described below.

The photosensitive drum 30 as an image carrier is driven by the motor (not shown) to rotate in a state that the photosensitive drum 30 is in contact with a surface at a lower side of the intermediate transfer belt 27. The charging device 31, the developing device 32, the primary transfer roller 33, the drum cleaning device 34 and the static eliminator 35 are arranged around the photosensitive drum 30 in order of a transfer process. The primary transfer roller 33 faces the photosensitive drum 30 from above and across the intermediate transfer belt 27. A secondary transfer roller 36 comes into pressure contact with a right side of the intermediate transfer belt 27 (driving roller 25) so as to form a secondary transfer nip part N.

Hereinafter, an operation of the color printer 1 will be described. The control device 15 executes image formation processing based on inputted image data as follows.

Each charging device 31 charges a surface of each photosensitive drum 30. The optical scanning device 23 performs exposure, which corresponds to the image data, to each photosensitive drum 30 (see a broken line arrow in FIG. 1) so as to form an electrostatic latent image on the surface of each photosensitive drum 30. Each developing device 32 develops the electrostatic latent image, which is formed on the surface of each photosensitive drum 30 by using a supply toner supplied from each toner case 41, to a toner image. Toner images of four colors carried by the four photosensitive drums 30 are primarily transferred to the intermediate transfer belt 27 in order by the primary transfer rollers 33 to which primary transfer biases have been applied. Thus, a full-color toner image is formed on the surface of the intermediate transfer belt 27.

Each sheet S supplied from the sheet feeding cassette 3 is conveyed on the conveying path 16 and passes through the secondary transfer nip part N. The full-color toner image is secondarily transferred to each sheet S by the secondary transfer roller 36 to which a secondary transfer bias has been applied. The fixing device 12 fixes the full-color toner image to each sheet S. Each sheet S after fixing processing is ejected to the sheet ejection tray 4. Each drum cleaning device 34 removes the waste toner (remained toner) remained on the surface of each photosensitive drum 30 after the primary transfer process. Each static eliminator 35 irradiates static eliminating light to remove a charge of each photosensitive drum 30. Further, the belt cleaning device 28 removes the waste toner remained on the surface of the intermediate transfer belt 27 after the secondary transfer process.

Next, the toner supplying device 13, a cleaning structure 17 and the waste toner collecting device 14 will be described with reference to FIGS. 2 to 10. FIG. 2 is a perspective view showing a part of the toner supplying device 13. FIG. 3 is a sectional view schematically showing the toner supplying device 13. FIG. 4 is a perspective view showing the toner case 41. FIG. 5 is a sectional view showing the toner case 41. FIG. 6 is a sectional view showing a state that a supplying port 51 of the toner case 41 is opened. FIG. 7 is a perspective view showing a conveying screw 45 or the like. FIG. 8 is a sectional view showing a state that a collecting port 52 of the toner case 41 is opened. FIG. 9 is a sectional view schematically showing the cleaning structure 17 and a waste toner case 91. FIG. 10 is a sectional view showing a section along an X-X line of FIG. 9.

As shown in FIGS. 2 and 3, the toner supplying device 13 includes a supplying attachment part 40, the four toner cases 41 and an intermediate conveying part 42.

The supplying attachment part 40 is arranged at the upper part of the apparatus main body 2 (see FIG. 1). In more detail, the supplying attachment part 40 is arranged closer to an upper side than the intermediate transfer unit 21 (each developing device 32). The supplying attachment part 40 includes four supplying space parts 40a in which the four toner cases 41 are inserted. The four supplying space parts 40a are aligned in the left and right direction. Each supplying space part 40a is formed as a space of a roughly columnar shape with an opened front end face. Incidentally, a supplying cover (not shown) which covers a front face of the supplying attachment part 40 (supplying space parts 40a) is openable and closable on the apparatus main body 2.

As shown in FIGS. 4 and 5, each toner case 41 includes a case main body 43, a cover member 44, and a conveying screw 45. Each toner case 41 (case main body 43) is attachable to and detachable from the supplying attachment part 40 (supplying space parts 40a) in the apparatus main body 2 (see FIG. 3). The toner case 41 for the black toner is attached to the supplying space part 40a at a right end, and this toner case 41 is formed to be thicker (with a larger diameter) than the other toner cases 41. However, the four toner cases 41 employ the same configuration except the diameters, and therefore the black toner case 41 will be described below. Incidentally, the toner cases 41 will be described based on a posture in which the toner case 41 is attached to the supplying attachment part 40.

The case main body 43 is formed in a roughly cylindrical shape elongated in a front and rear direction. The case main body 43 is formed by using a synthetic resin material, such as a PET resin (polyethylene terephthalate). A containing space SP is formed inside the case main body 43. The case main body 43 contains a supply toner supplied to the developing device 32 (image forming part 11).

The case main body 43 is integrally formed by a large diameter cylinder part 43a, a small diameter cylinder part 43b and a cover attachment part 43c. The large diameter cylinder part 43a is formed in a roughly cylindrical shape with a closed front end face. A grip part G is protruded on the front end face of the large diameter cylinder part 43a. The small diameter cylinder part 43b is formed in a roughly cylindrical shape thinner than the large diameter cylinder part 43a. The small diameter cylinder part 43b is extended backward from a rear end face of the large diameter cylinder part 43a. A stepped part D1 is formed between the small diameter cylinder part 43b and the large diameter cylinder part 43a. The cover attachment part 43c is formed in a roughly cylindrical shape thinner than the small diameter cylinder part 43b. The cover attachment part 43c extends backward from a rear end face of the small diameter cylinder part 43b. A stepped part D2 is formed between the cover attachment part 43c and the small diameter cylinder part 43b. An opening part 43d is opened on a rear end face of the cover attachment part 43c (see FIG. 6).

A conveying rib 46 is formed integrally with a surrounding wall of the case main body 43 along the front and rear direction. The conveying rib 46 is spirally protruded on an inner circumferential face of the case main body 43 toward an axial center (inside).

Incidentally, the case main body 43 and the conveying rib 46 are formed with a substantially identical thickness. Although described in detail below, the conveying rib 46 has a function of conveying a supply toner toward the opening part 43d (backward) by rotating the case main body 43. Incidentally, although the conveying rib 46 is formed integrally with the case main body 43, the present disclosure is not limited to this and the conveying rib and the case main body may be composed of different members.

As shown in FIGS. 6 and 7, a transmission gear 47 (transmission member) of a roughly annular shape is fixed to a rear part (at a side of the opening part 43d) of an outer circumferential face of the cover attachment part 43c. The transmission gear 47 is connected with a driving motor M (driving source) via a power transmitting mechanism (not shown), such as a shaft and a gear.

As shown in FIGS. 4 to 6, the cover member 44 includes a housing frame 50, a supplying port 51, a collecting port 52, a supplying shutter 53 and a collecting shutter 54. The supplying port 51 is formed to discharge the supply toner from an inside of the housing frame 50 to the image forming part 11 (developing device 32). The collecting port 52 is formed to introduce the waste toner, which is remained without being used for image formation, from the image forming part 11 (each cleaning device 28 and 34) to the inside of the housing frame 50. The supplying shutter 53 is arranged to open and close the supplying port 51. The collecting shutter 54 is arranged to open and close the collecting port 52.

The housing frame 50 is formed in a roughly cylindrical shape with a closed rear end face. The housing frame 50 is arranged to cover the opening part 43d at a position closer to a rear side than the transmission gear 47. The housing frame 50 engages with a rear end part of the cover attachment part 43c from an outside in a radial direction. The housing frame 50 communicates with an inside (containing space SP) of the case main body 43. The housing frame 50 supports the cover attachment part 43c (case main body 43) rotatably in a circumferential direction.

As shown in FIG. 6, the supplying port 51 and the collecting port 52 are openings of roughly rectangular shapes which penetrate the surrounding wall (circumferential face) of the housing frame 50. The supplying port 51 and the collecting port 52 are formed in an identical shape. The supplying port 51 and the collecting port 52 communicate an inside and an outside of the case main body 43. The supplying port 51 is opened on a circumferential face of a lower side of the housing frame 50. The collecting port 52 is opened on a circumferential face at an upper side of the housing frame 50. The supplying port 51 and the collecting port 52 are formed so as to face each other in the circumferential direction of the case main body 43 (housing frame 50). That is, the collecting port 52 is formed so as to be shifted 180 degrees from the supplying port 51 in the circumferential direction.

The supplying shutter 53 and the collecting shutter 54 are slidable in the front and rear direction with respect to the housing frame 50. More specifically, the supplying shutter 53 is slidable between an opening position O1 to open the supplying port 51 and a closing position C1 (see FIG. 8) to close the supplying port 51. Similarly, the collecting shutter 54 is slidable between an opening position O2 (see FIG. 8) to open the collecting port 52 and a closing position C2 to close the collecting port 52. The supplying shutter 53 and the collecting shutter 54 are formed so as to face each other in the circumferential direction of the case main body 43 (housing frame 50).

The supplying shutter 53 and the collecting shutter 54 are formed in a substantially identical shape. More specifically, the supplying shutter 53 and the collecting shutter 54 are formed in roughly plate shapes. A pair of left and right protrusion parts 53a are protruded on a lower face of the supplying shutter 53 (an opposite face of the supplying port 51). Similarly, a pair of left and right protrusion parts 54a are protruded on an upper face of the collecting shutter 54 (an opposite face of the collecting port 52).

As shown in FIGS. 4 and 5, the above-mentioned case main body 43 (except the cover attachment part 43c) is formed in a cylindrical shape with a larger diameter than the diameter of the housing frame 50. The case main body 43 is arranged coaxially with the housing frame 50. Hence, the supplying port 51 is arranged closer to an upper side than a lowermost end part of the small diameter cylinder part 43b when seen from a side face (back face) (see a broken line L in FIG. 5). The collecting port 52 is arranged closer to a lower side than an uppermost end part of the small diameter cylinder part 43b when seen from the side face (back face) (see a broken line U in FIG. 5). That is, the supplying port 51 and the collecting port 52 are arranged at an inside in the radial direction of the small diameter cylinder part 43b when seen from the side face (back face).

As shown in FIG. 6, the conveying screw 45 is arranged inside the housing frame 50. The conveying screw 45 includes a rotation axis 45a and a spiral fin 45b fixed on a circumferential face of the rotation axis 45a. A value (P/D) calculated by dividing a pitch (P) of the fin 45b by an outer diameter (D) of the fin 45b is set to equal to or less than 1. In the first embodiment, the above-mentioned value (P/D) is set to 0.5. Incidentally, the value (P/D) calculated by dividing the pitch (P) of the fin 45b by the outer diameter (D) of the fin 45b is preferably set to a value between 0.2 and 0.8.

As shown in FIGS. 6 and 7, a fitting part 45c of a roughly annular shape is formed at a front end part (first end part) of the rotation axis 45a. The fitting part 45c fits into the opening part 43d of the cover attachment part 43c. A rear end part (second end part) of the rotation axis 45a rotatably fits into a bearing hole 50a formed on a rear part of the housing frame 50. The conveying screw 45 (rotation axis 45a) is arranged coaxially with the case main body 43, and is fixed to the case main body 43 via the fitting part 45c. Hence, the conveying screw 45 integrally rotates with the case main body 43 around a rotation axis A (see FIG. 3).

As shown in FIG. 3, the intermediate conveying part 42 is arranged between each toner case 41 and each developing device 32. The intermediate conveying part 42 includes an intermediate housing 55, four intermediate supplying pipes 56, four intermediate discharging pipes 57, four intermediate conveying paths 58 and an intermediate conveying screw 59.

The intermediate housing 55 is formed in a roughly cuboid shape, and is arranged inside the intermediate transfer belt 27. The four intermediate supplying pipes 56 are aligned in the left and right direction on an upper face at a rear side of the intermediate housing 55. Each intermediate supplying pipe 56 is formed so as to correspond to each supplying port 51 of each toner case 41 attached to the supplying attachment part 40. The four intermediate discharging pipes 57 are aligned in the left and right direction on a lower face at the rear side of the intermediate housing 55. Each intermediate discharging pipe 57 is connected with an introducing port 32a opened upward on the developing device 32. The four intermediate conveying paths 58 are formed in roughly crank shapes inside the intermediate housing 55. Each intermediate conveying path 58 communicates each intermediate supplying pipe 56 and each intermediate discharging pipe 57. The intermediate conveying screw 59 is supported so as to penetrate horizontal parts of all intermediate conveying paths 58. The intermediate conveying screw 59 includes spiral fins on a circumferential face of a rotation axis extending in the left and right direction. The intermediate conveying screw 59 is driven by the motor (not shown) to rotate.

Hereinafter, a process of attaching the toner case 41 to the supplying attachment part 40 will be described. Incidentally, in a state that the toner case 41 is detached from the supplying attachment part 40, the supplying shutter 53 is displaced to the closing position C1, and the collecting shutter 54 is displaced to the closing position C2 (see FIG. 4).

A user opens the supplying cover of the apparatus main body 2, and pushes the toner case 41 (case main body 43) backward from a front face of the supplying space part 40a with the grip part G placed at the near side and in a posture in which the supplying port 51 is oriented downward (see FIG. 2). In the process of pushing the toner case 41 in the supplying space part 40a, each protrusion part 53a of the supplying shutter 53 comes into contact with (interferes with) each engagement part (not shown) arranged at the supplying attachment part 40. When the toner case 41 is further pushed, the supplying shutter 53 slides relatively forward. According to this, the supplying shutter 53 moves from the closing position C1 to the opening position O1 (see FIG. 6). That is, the supplying port 51 is opened. Further, when the supplying cover is closed, an operation of attaching each toner case 41 is finished.

The case main body 43 is rotatably supported inside the supplying space part 40a in the state that the case main body 43 (toner case 41) is attached to the supplying attachment part 40. Meanwhile, in this state, the cover member 44 is supported inside the supplying space part 40a so that the cover member 44 is not rotatable. Further, in this state, the supplying port 51 is opened downward and is connected with the intermediate supplying pipe 56 (see FIG. 3). That is, the supplying port 51 of the toner case 41 is connected with the introducing port 32a of the developing device 32 (image forming part 11) via the intermediate conveying part 42. Incidentally, the collecting shutter 54 closes each collecting port 52 (the collecting shutter 54 is displaced to the closing position C2) in the state that the case main body 43 is attached to the supplying attachment part 40 (see FIG. 6).

As shown in FIG. 6, in this state, the transmission gear 47 of the toner case 41 is connected with the driving motor M via the power transmitting mechanism. The transmission gear 47 transmits a driving force (rotation force) from the driving motor M to the case main body 43. The case main body 43 rotates clockwise (in a second direction) around the rotation axis A extending in the front and rear direction (see an arrow F in FIG. 3). The conveying rib 46 also rotates clockwise integrally with the case main body 43. Further, the conveying rib 46 conveys the supply toner along a direction (backward) of discharging the supply toner from the case main body 43 to the housing frame 50 (see a broken line arrow in FIG. 6). Furthermore, the conveying screw 45 also rotates clockwise integrally with the case main body 43. Still further, the conveying screw 45 discharges the supply toner in the housing frame 50 via the supplying port 51 and conveys the supply toner to the developing device 32 (image forming part 11) (see the broken line arrow in FIG. 6).

The supply toner is discharged from the supplying port 51, passes through the intermediate supplying pipe 56 and enters the intermediate conveying path 58 (see a broken line arrow in FIG. 3). The intermediate conveying screw 59 is driven by the motor to rotate, and conveys the supply toner in the intermediate conveying path 58 toward the intermediate discharging pipe 57. The supply toner passes through the intermediate discharging pipe 57 and is supplied (refilled) from the introducing port 32a to the developing device 32 (see the broken line arrow in FIG. 3). Incidentally, even when the case main body 43 rotates as mentioned above, the cover member 44 does not rotate and maintains a rotation stop state.

By the configuration as described above, the conveying rib 46, which rotates, introduces the supply toner from the inside of the case main body 43 to the inside of the housing frame 50, and the conveying screw 45, which rotates, discharges the supply toner via the supplying port 51. According to this, it is possible to smoothly supply the supply toner to the developing device 32 (image forming part 11).

Next, a process of detaching the toner case 41 from the supplying attachment part 40 will be described. The user opens the supplying cover of the apparatus main body 2, grips the grip part G and draws each toner case 41 toward the near side (see FIG. 2). In accordance with drawing (detaching operation) of each toner case 41, the transmission gear 47 and the driving motor M are disconnected. Further, in accordance with the detaching operation of each toner case 41, a biasing member (not shown) arranged in the supplying space part 40a biases the supplying shutter 53 backward. According to this, the supplying shutter 53 moves from the opening position O1 to the closing position C1 (see FIG. 8). That is, the supplying port 51 is closed. Further, when the toner case is completely drawn, the detaching operation is finished. As mentioned above, the supplying shutter 53 opens the supplying port 51 in accordance with attachment of the case main body 43 to the supplying attachment part 40, and closes the supplying port 51 in accordance with detachment of the case main body 43 from the supplying attachment part 40.

Next, as shown in FIGS. 9 and 10, the cleaning structure 17 includes the above-mentioned four drum cleaning devices 34, the above-mentioned belt cleaning device 28 and a discharging conveying device 37.

The four drum cleaning devices 34 are arranged in association with the four photosensitive drums 30 (see FIG. 1). Incidentally, the four drum cleaning devices 34 employ the same configuration, and therefore one drum cleaning device 34 will be described below.

As shown in FIG. 10, the drum cleaning device 34 includes a drum-side housing 60, a polishing roller 61, a restricting roller 62, a cleaning blade 63 and a drum-side screw 64.

The drum-side housing 60 is formed in a roughly box shape elongated in the front and rear direction (see FIG. 9). An opening is formed on a left face (a face facing the photosensitive drum 30) of the drum-side housing 60.

The polishing roller 61 and the restricting roller 62 are formed in roughly cylindrical shapes elongated in the front and rear directions. The polishing roller 61 and the restricting roller 62 are supported rotatably around axes in the drum-side housing 60. A part of the polishing roller 61 is exposed through the opening of the drum-side housing 60, and is in contact with the photosensitive drum 30. The restricting roller 62 is in contact with a lower right side of the polishing roller 61. The cleaning blade 63 is formed in a plate shape by using a synthetic resin, for example, and is fixed to the drum-side housing 60. A distal end part of the cleaning blade 63 is in contact with the photosensitive drum 30.

The drum-side screw 64 has a spiral fin on a circumferential face of a rotation axis extending in the front and rear direction (see FIG. 9). The drum-side screw 64 is supported rotatably around an axis in the drum-side housing 60. The drum-side screw 64 is disposed at a lower left part of the drum-side housing 60. A drum-side discharging port 65 connected with the discharging conveying device 37 is opened on a rear bottom face of the drum-side housing 60 (see FIG. 9). Incidentally, the polishing roller 61 rotates with the photosensitive drum 30, and the restricting roller 62 rotates with the polishing roller 61. The drum-side screw 64 is driven by a motor (not shown) to rotate. Incidentally, the present disclosure is not limited to the above, and the polishing roller 61 and the restricting roller 62 may be driven by the motor to rotate.

Next, as shown in FIG. 10, the belt cleaning device 28 includes a belt-side housing 70, a bias brush 71, a collecting roller 72, a collecting blade 73 and a belt-side screw 74.

The belt-side housing 70 is formed in a roughly box shape elongated in the front and rear direction (see FIG. 9). An opening is formed on a right face (a face facing the intermediate transfer belt 27) of the belt-side housing 70.

The bias brush 71 and the collecting roller 72 are formed in roughly cylindrical shapes elongated in the front and rear direction. The bias brush 71 and the collecting roller 72 are supported rotatably around axes in the belt-side housing 70. A part of the bias brush 71 is exposed through the opening of the belt-side housing 70, and is in contact with the intermediate transfer belt 27. The collecting roller 72 is in contact with an upper left side of the bias brush 71. The collecting blade 73 is formed in a plate shape by using a synthetic resin, for example, and is fixed to the belt-side housing 70. A distal end part of the collecting blade 73 is in contact with the collecting roller 72.

The belt-side screw 74 includes a spiral fin on a circumferential face of a rotation axis extending in the front and rear direction (see FIG. 9). The belt-side screw 74 is supported rotatably around an axis in the belt-side housing 70. The belt-side screw 74 is arranged at a lower left part of the belt-side housing 70. A belt-side discharging port 75 connected with the discharging conveying device 37 is opened on a bottom face at a rear side of the belt-side housing 70 (see FIG. 9). Incidentally, the bias brush 71, the collecting roller 72 and the belt-side screw 74 are rotated by a motor (not shown) to rotate.

As shown in FIGS. 9 and 10, the discharging conveying device 37 includes a conveying housing 80 and a conveying screw 81. The discharging conveying device 37 conveys a toner removed by each drum cleaning device 34 and the belt cleaning device 28 toward the waste toner collecting device 14.

The conveying housing 80 is formed in a cuboid shape elongated in the left and right direction. Four drum-side introducing pipes 82 and a belt-side introducing pipe 83 are aligned in the left and right direction on an upper face of the conveying housing 80. The four drum-side introducing pipes 82 are connected with the drum-side discharging ports 65 of the drum cleaning devices 34. The belt-side introducing pipe 83 is connected with the belt-side discharging port 75 of the belt cleaning device 28. A conveying discharging pipe 84 connected with the waste toner collecting device 14 is formed on a bottom face at a left side of the conveying housing 80.

The conveying screw 81 includes a spiral fin on a circumferential face of a rotation axis extending in the left and right direction. The conveying screw 81 is supported rotatably around an axis in the conveying housing 80. The conveying screw 81 is driven by a motor (not shown) to rotate. Incidentally, the bias brush 71, each drum-side screw 64, the belt-side screw 74 and the conveying screw 81 are connected with a bias power supply which applies a bias of an inverse polarity from a charging polarity (positive charge) of the toner.

Next, a function (toner removing operation) of the cleaning structure 17 will be described. Incidentally, in the following description, the bias power supply is controlled by the control device 15, and applies a bias of a negative polarity to the bias brush 71 and each of the screws 64, 74 and 81.

First, a function of the drum cleaning device 34 will be described. When the above-mentioned image formation processing is executed, the polishing roller 61 and the restricting roller 62 rotate with the photosensitive drum 30. The drum-side screw 64 is driven by the motor to rotate.

A waste toner (remained toner) remained on the surface of the photosensitive drum 30 adheres to a surface of the polishing roller 61 so as to form a toner layer. The polishing roller 61 polishes the surface of the photosensitive drum 30 via the toner layer. The restricting roller 62 makes a layer thickness of the toner layer uniform. The cleaning blade 63 scrapes the remained toner adhered to the surface of the photosensitive drum 30. The waste toner removed from the photosensitive drum 30 is introduced into the drum-side housing 60. The drum-side screw 64 conveys the waste toner in the drum-side housing 60 toward the drum-side discharging port 65 (see an arrow in FIG. 9). The waste toner is discharged via the drum-side discharging port 65 opened downward, passes through the drum-side introducing pipe 82 and enters the conveying housing 80 (see an arrow in FIG. 10).

Next, a function of the belt cleaning device 28 will be described. When the image formation processing is executed, the bias brush 71, the collecting roller 72 and the belt-side screw 74 are driven by the motor to rotate.

The bias brush 71 adsorbs the waste toner (remained toner) adhered to the surface of the intermediate transfer belt 27 by an electrostatic adsorbing force. The collecting roller 72 receives the waste toner having moved to the bias brush 71. The collecting blade 73 scrapes the waste toner having moved to the collecting roller 72. The waste toner removed from the collecting roller 72 is introduced into the belt-side housing 70. The belt-side screw 74 conveys the waste toner in the belt-side housing 70 toward the belt-side discharging port 75 (see an arrow in FIG. 9). The waste toner is discharged via the belt-side discharging port 75 opened downward, passes through the belt-side introducing pipe 83 and enters the conveying housing 80 (see an arrow in FIG. 10).

The waste toner having entered the conveying housing 80 is conveyed toward the conveying discharging pipe 84 by driving the conveying screw 81 to rotate (see arrows in FIG. 10).

Next, as shown in FIGS. 9 and 10, the waste toner collecting device 14 includes a collecting attachment part 90 and a waste toner case 91.

The collecting attachment part 90 is arranged at a left side of an intermediate part of the apparatus main body 2 (see FIG. 1). In more detail, the collecting attachment part 90 is arranged closer to a lower side than each of the cleaning devices 28 and 34. The collecting attachment part 90 includes a collecting space part 90a in which the waste toner case 91 is inserted. The collecting space part 90a is formed as a space of a roughly columnar shape with an opened front end face. The collecting space part 90a is formed so as to correspond to the conveying discharging pipe 84 of the discharging conveying device 37. Incidentally, a collecting cover (not shown) which covers a front face of the collecting space part 90a is openable and closable on the apparatus main body 2.

The waste toner case 91 is one of the four toner cases 41 (which is also referred to as an “empty case 41E” below) which has consumed a supply toner and becomes empty. That is, the one empty case 41E is used (reused) for the waste toner case 91, too, for collecting the waste toner. Incidentally, the waste toner case 91 has a shape identical to the shape of each toner case 41 mentioned above, and therefore the waste toner case 91 will not be described in detail. Further, the same components as those of each toner case 41 will be assigned the same reference numerals.

The waste toner case 91 (case main body 43) is attachable to and detachable from the collecting attachment part 90 (collecting space part 90a) in the apparatus main body 2. The case main body 43 of the waste toner case 91 contains the waste toner discharged from each of the cleaning devices 28 and 34 (image forming part 11).

Hereinafter, a process of attaching the waste toner case 91 to the collecting attachment part 90 will be described. The user opens the supplying cover of the apparatus main body 2, and detaches the toner case 41 (empty case 41E), which has consumed the supply toner and becomes empty, from the supplying attachment part 40. The supplying shutter 53 of the empty case 41E having been detached from the supplying attachment part 40 is displaced to the closing position C1, and the collecting shutter 54 is displaced to the closing position C2 (see FIG. 4).

Next, the user opens the collecting cover of the apparatus main body 2, and moves the empty case 41E, which has been detached from the supplying attachment part 40, to a position in front of the collecting attachment part 90. The user pushes the empty case 41E (case main body 43) backward from the front face of the collecting space part 90a in a posture in which the collecting port 52 is oriented upward (the supplying port 51 is oriented downward). That is, the case main body 43 is attached to the collecting attachment part 90 in a posture identical to a posture in which the case main body 43 is attached to the supplying attachment part 40. Consequently, for example, even the user who is not used to performing an exchanging operation can easily perform the exchanging operation and prevents an erroneous operation, too.

In the process of pushing the empty case 41E (waste toner case 91) in the collecting space part 90a, each protrusion part 54a of the collecting shutter 54 contacts (interferes with) the engagement part (not shown) arranged at the collecting attachment part 90. When the waste toner case 91 is further pushed, the collecting shutter 54 slides from the closing position C2 to the opening position O2 (see FIG. 8). That is, the collecting port 52 is opened. Further, when the collecting cover is closed, the operation of attaching the waste toner case 91 is finished.

Incidentally, although not shown and described in detail, the toner case 41 (waste toner case 91), the supplying attachment part 40 and the collecting attachment part 90 are provided with an erroneous attachment preventing mechanism (not shown). This erroneous attachment preventing mechanism prevents the waste toner case 91 from being attached again to the supplying attachment part 40.

The case main body 43 is supported rotatably inside the collecting space part 90a in a state that the case main body 43 (waste toner case 91) is attached to the collecting attachment part 90. Meanwhile, in this state, the cover member 44 is supported inside the collecting space part 90a so that the cover member 44 is not rotatable. Further, in this state, the collecting port 52 is opened upward and is connected with the conveying discharging pipe 84 (see FIGS. 8 and 10). That is, the collecting port 52 of the waste toner case 91 is connected with each of the discharging ports 65 and 75 of each of the cleaning devices 28 and 34 (image forming part 11) via the discharging conveying device 37. Incidentally, the supplying shutter 53, which is displaced to the closing position C1, closes the supplying port 51 in the state that the case main body 43 is attached to the collecting attachment part 90 (see FIG. 8).

Further, in this state, the transmission gear 47 of the waste toner case 91 is connected with the driving motor M via the shaft and the gear. The case main body 43 is driven by the driving motor M to rotate counterclockwise (in a first direction) around the rotation axis A (see an arrow R in FIG. 10). The conveying rib 46 and the conveying screw 45 rotate counterclockwise integrally with the case main body 43. That is, the case main body 43 or the like rotates in a reverse direction to a direction in which the case main body 43 rotates when the case main body 43 is attached to the supplying attachment part 40.

A waste toner in the conveying housing 80 passes through the conveying discharging pipe 84, and enters the housing frame 50 via the collecting port 52 (see the arrow in FIG. 10). The conveying screw 45 conveys the waste toner, which is introduced into the housing frame 50 via the collecting port 52, toward an inside of the case main body 43 (forward). Further, the conveying rib 46 conveys the waste toner along a direction (forward) of introducing the waste toner into the case main body 43 (see a broken line arrow in FIG. 8). The conveying rib 46 makes a surface of the waste toner stored in the containing space SP even while conveying the waste toner in a direction (forward) remote from the opening part 43d. As mentioned above, the waste toner is collected in the waste toner case 91 (case main body 43).

Incidentally, the collecting attachment part 90 is provided with a sensor (not shown) which detects the waste toner case 91 is full of the waste toner. When the sensor detects that the waste toner case 91 is full, the control device 15 controls a liquid crystal display or a speaker (not shown) to notify the user of an exchange of the waste toner case 91.

To detach the waste toner case 91 from the collecting attachment part 90, the user needs to open the collecting cover of the apparatus main body 2, and to grip the grip part G and draw the waste toner case 91 toward the near side. In accordance with drawing of the toner case 41, the transmission gear 47 and the driving motor M are disconnected, and the collecting shutter 54 moves from the opening position O2 to the closing position C2 (see FIG. 6). As mentioned above, the collecting shutter 54 opens the collecting port 52 in accordance with attachment of the case main body 43 to the collecting attachment part 90, and closes the collecting port 52 in accordance with detachment of the case main body 43 from the collecting attachment part 90.

In this regard, as shown in FIG. 5, the case main body 43 (except cover attachment part 43c) is formed with a larger diameter than a diameter of the housing frame 50, and is arranged coaxially with the housing frame 50. If the conveying screw 45 is omitted, it is difficult to fill the entire containing space SP of the case main body 43 with the waste toner. An upper limit of a storage amount of the waste toner in the case main body 43 is limited by a position (height) of the collecting port 52, the diameter of the opening part 43d or the like (see the broken line U in FIG. 5). Hence, the waste toner is supposed to be stored closer to a lower side than the collecting port 52 (the broken line U in FIG. 5) in the containing space SP of the case main body 43. That is, when the conveying screw 45 is omitted, the containing space SP closer to the upper side than the upper limit (the broken line U in FIG. 5) becomes a dead space which cannot be effectively used.

By contrast with this, in the toner case 41 (waste toner case 91) according to the first embodiment, the waste toner enters the housing frame 50 via the collecting port 52, and is given a conveying force from the rotating conveying screw 45. The waste toner is pushed into the case main body 43 by a function of the conveying screw 45, and is spread inside the case main body 43 (containing space SP) by a function of the conveying rib 46. The conveying screw 45 forcibly conveys the waste toner, so that the case main body 43 (containing space SP) is filled with the waste toner. That is, the waste toner is stored in the containing space SP beyond the broken line U in FIG. 5. Consequently, it is possible to efficiently collect the waste toner in the case main body 43 without making the dead space in the containing space SP in the case main body 43.

Further, by setting the value (P/D), which is calculated by dividing the pitch (P) of the fin 45b by the outer diameter (D) of the fin 45b, equal to or less than 1, it is possible to apply an appropriate conveying force to the waste toner or the supply toner.

Further, in the housing frame 50, the supplying port 51 which supplies a supply toner to the developing device 32 (image forming part 11), and the collecting port which receives the waste toner from each of the cleaning devices 28 and 34 (image forming part 11) are separately formed. Consequently, the supplying port 51 and the collecting port 52 can be formed so as to correspond to connecting portions with the image forming part 11. Hence, the empty case 41E is attached to the collecting attachment part 90 in a posture identical to a posture in which the toner case 41 is detached from the supplying attachment part 40. Consequently, it is not necessary to change the posture of the empty case 41E, so that it is possible to simplify the exchange operation for reusing the empty case 41E as the waste toner case 91. Further, the supplying port 51 and the collecting port 52 are closed by each of the shutters 53 and 54 in a state that the case main body 43 is detached from the supplying attachment part 40 or the collecting attachment part 90. In addition, it is not necessary to change the posture of the empty case 41E during the above-mentioned exchanging operation, so that it is possible to prevent the toner from dropping from the supplying port 51 or the collecting port 52.

Incidentally, the collecting port 52 of the toner case 41 according to the first embodiment is formed so as to be shifted 180 degrees in the circumferential direction from the supplying port 51. However, the present disclosure is not limited to this. As shown in FIG. 11, for example, in a range of 90 degrees to 270 degrees of an angle (center angle) formed between a perpendicular line drawn from the supplying port 51 to the rotation axis A and a perpendicular line drawn from the collecting port 52 to the rotation axis A, the supplying port 51 (supplying shutter 53) and the collecting port 52 (collecting shutter 54) may be formed. That is, the supplying port 51 may be formed in a range of ±90 degrees around the position facing the collecting port 52 in a circumferential direction of the case main body 43 (housing frame 50).

Next, a toner case 100 according to a second embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is a sectional view showing a state that the toner case 100 is attached to the supplying attachment part 40. FIG. 13 is a sectional view showing a state that the toner case 100 is attached to the collecting attachment part 90. Incidentally, in the following description, the same components as those of the toner case 41 according to the first embodiment will be assigned the same reference numerals and will not be described. Further, one toner case 100 will be described.

As shown in FIG. 12, the toner case 100 includes the case main body 43, a cover member 101 and the conveying screw 45. The cover member 101 rotatably supports the case main body 43. The cover member 101 includes the housing frame 50, a communicating port 102 and a shutter 103.

The communicating port 102 is an opening which is the substantially same as the supplying port 51 and the collecting port 52. As shown in FIG. 12, in the state that the toner case 100 (case main body 43) is attached to the supplying attachment part 40, the communicating port 102 is opened downward and is connected with the introducing port 32a (see FIG. 3) of the developing device 32 via the intermediate conveying part 42. Further, as shown in FIG. 13, in the state that the toner case 100 (case main body 43) is attached to the collecting attachment part 90, the communicating port 102 is opened upward and is connected with each of the discharging ports 65 and 75 (see FIG. 10) of each of the cleaning devices 28 and 34 via the discharging conveying device 37.

As shown in FIG. 12, the shutter 103 employs the substantially same configuration as those of the supplying shutter 53 and the collecting shutter 54. The shutter 103 is slidable in the front and rear direction between an opening position O3 to open the communicating port 102 and a closing position C3 to close the communicating port 102. The shutter 103 opens the communicating port 102 in accordance with attachment of the case main body 43 to the supplying attachment part 40 or collecting attachment part 90, and closes the communicating port 102 in accordance with detachment of the case main body 43 from the supplying attachment part 40 or the collecting attachment part 90.

Hereinafter, a process (function) of attaching the toner case 100 to the supplying attachment part 40 or the collecting attachment part 90 will be described. In a state that the toner case 100 is detached from the supplying attachment part 40 or the collecting attachment part 90, the shutter 103 is displaced to the closing position C3 (see a two-dot chain line in FIG. 12). Incidentally, the same function as the function of the toner case 41 according to the first embodiment will not be described below.

As shown in FIG. 12, the toner case 100 is pushed backward from the front face of the supplying space part 40a with the grip part G placed at the near side and in a posture in which the communicating port 102 is oriented downward. When the toner case 100 is pushed, each protrusion part 103a of the shutter 103 interferes with an engagement part, and the shutter 103 moves from the closing position C3 to the opening position O3 (the communicating port 102 is opened). When the toner case 100 (case main body 43) is attached to the supplying attachment part 40, the communicating port 102 is connected with the intermediate supplying pipe 56 of the intermediate conveying part 42. Further, the case main body 43 (conveying rib 46) and the conveying screw 45 rotate clockwise, and supply a supply toner to the developing device 32 (see a broken line arrow in FIG. 12).

The toner case 100 (empty case 100E) which has become empty is detached from the supplying attachment part 40, and is used as a waste toner case 106. The empty case 100E having been detached from the supplying attachment part 40 is rotated upside down. Further, as shown in FIG. 13, the empty case 100E is attached to the collecting attachment part 90 (collecting space part 90a) in a posture in which the communicating port 102 is oriented upward. When the toner case 100 is pushed, the shutter 103 moves, so that the communicating port 102 is opened. When the case main body 43 is attached to the collecting attachment part 90, the communicating port 102 is connected with the conveying discharging pipe 84 of the discharging conveying device 37. Further, the case main body 43 (conveying rib 46) and the conveying screw 45 rotate counterclockwise, and collect a waste toner in the case main body 43 (containing space SP).

The toner case 100 (waste toner case 106) according to the second embodiment described above can efficiently collect the waste toner in the case main body 43, and smoothly supply the supply toner to the developing device 32 (image forming part 11).

Incidentally, a case where the present disclosure is applied to the color printer 1 has been described as an example in the embodiment. However, the present disclosure is not limited to this, and may be applied to a monochrome printer, a copying machine, a facsimile or an MFP (multi-function peripheral).

While the present disclosure has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present disclosure.

TONER CASE AND IMAGE FORMING APPARATUS INCLUDING THE SAME

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CPC

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