The present invention relates an image forming apparatus and a movable member used in the image forming apparatus. Particularly, the present invention relates to an electrophotographic image forming apparatus employing an electrophotographic type and a movable member used in the electrophotographic image forming apparatus.
Conventionally, an image forming apparatus in which a developing cartridge with a particular specification is mountable and in which a developing cartridge with a specification different from the particular specification is not mountable has been proposed.
In Japanese laid-Open Patent Application (JP-A) 2017-116852, a cleaning member movable by being operated by a user is provided, along an axial direction (rotational axis direction) of a photosensitive drum, in a pulling-out member movable between an (inside) mounting position and an (outside) pulling-out position relative to the image forming apparatus. The cleaning member is capable of cleaning a charging member for electrically charging the photosensitive drum.
Incidentally, the cleaning member in JP-A 2017-116852 further includes a projected portion, and when the cartridge with the different specification is being mounted, the projected portion and the developing cartridge are in contact with each other, so that the developing cartridge is not mounted in the pulling-out member. On the other hand, when the developing cartridge with the particular specification corresponding to the pulling-out member is being mounted, the projected portion enters a predetermined recessed portion of the developing cartridge, so that the developing cartridge is mounted in the pulling-out member.
However, the cleaning member in JP-A 2017-116852 is provided close to a charging member, and when the user performs a moving operation of the charging member, the user erroneously contacts also the charging member in some cases, so that there was a possibility that the contact of the user with the charging member has the influence on a charging performance of the charging member.
In view of the aforementioned problem, a principal object of the present invention is to provide a movable member and an image forming apparatus which are capable of alleviating a risk of contact with a charging member when a user operates a cleaning member.
According to an aspect of the present invention, there is provided a movable member movable between a first position inside an image forming apparatus and a second position where the movable member is pulled out to an outside of the image forming apparatus, while mounting a cartridge provided with a predetermined recessed portion, the movable member comprising: a frame; a mounting portion provided in the frame and permitting mounting and dismounting of the cartridge; a rotatable image bearing member provided in the frame; a charging member provided in the frame and configured to electrically charge a surface of the image bearing member, the charging member extending along an axial direction of a rotation shaft of the image bearing member; and a cleaning member provided in the frame and configured to clean the charging member by being disposed close to the charging member, the cleaning member being movable between an end portion of the frame on one side with respect to the axial direction and an end portion of the frame on the other side with respect to the axial direction, wherein the cleaning member comprises: a base portion including a first surface positioned on the one side and crossing the axial direction, a second surface positioned on the can alleviate other side and crossing the axial direction, and a third surface positioned between the first surface and the second surface; and a projected portion projected from the third surface toward an outside and capable of entering the predetermined recessed portion when the cartridge is mounted in the mounting portion in a state in which the cleaning member is positioned at the end portion on the one side of the frame, wherein the projected portion includes a first side surface crossing the axial direction and positioned on the can alleviate other side and a second side surface crossing the axial direction and positioned on the one side, wherein the first side surface is positioned between the first surface and the second surface, and wherein the first side surface constitutes an end surface of the projected portion on the other side with respect to the axial direction, and the second side surface constitutes an end surface of the projected portion on the one side with respect to the axial direction. Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Part (a) of
Parts (a) and (b) of
Part (a) of
In the following, with reference to the drawings, embodiments for carrying out the present invention will be specifically described. However, as regards functions, materials, shapes, relative arrangement, and the like of constituent elements described below, a scope of the present invention is not intended to be limited thereto unless otherwise specified. Further, in the following description, the functions, the materials, the shapes, and the like which have been once described are similar to those in the first description unless otherwise specified again.
Further, in the following description, with respect to an image forming apparatus, a side where a front door is provided is referred to as a front side, and a side opposite from the front side is referred to as a rear side in some cases. Further, when the image forming apparatus is viewed from the front side, a left-hand side is referred to as a left side, and a right-hand side is referred to as a right side in some cases.
Further, a direction in which a member extends in a drum axis of a photosensitive drum included in a cartridge tray is defined as a first direction and is referred to as a “D1 direction”. Further, a direction (in this embodiment, an inserting direction of a developing cartridge into the cartridge tray) crossing the D1 direction is defined as a second direction and is referred to as a “D2 direction”. In addition, a direction in which the cartridge tray is inserted into the image forming apparatus is defined as a third direction and is referred to as a “D3 direction”.
The D1 direction and the D2 direction cross each other, preferably are perpendicular to each other. The D2 direction and the D3 direction cross each other, preferably are perpendicular to each other. The D3 direction and the D1 direction cross each other, preferably are perpendicular to each other.
[General Structure]
First, the image forming apparatus of an embodiment of the present invention will be described using
In this embodiment, an image forming apparatus 1 is a full-color laser beam printer which uses an electrophotographic image forming process and which is based on four colors (Y, M, C, K), and forms a color image on a sheet S.
As shown in
The cartridge tray 3 and the developing cartridges 8 are mounted so as to be mountable in and dismountable from the apparatus main assembly 2. The cartridge tray 3 is a tray capable of holding the four developing cartridges 8. The cartridge tray 3 and the developing cartridges 8 constitute a pulling-out unit 38.
Incidentally, in the following, the cartridge tray 3 in a state in which the four developing cartridges 8 are mounted is also simply referred to as the cartridge tray 3 in some cases. That is, the cartridge tray (movable member) 3 of the present invention constitutes at least a part of the pulling-out unit 38.
The cartridge tray 3 (the pulling-out unit 38) is movable between an image forming position as a first position PI where a photosensitive drum is capable of forming an image and a pulling-out position as a second position PO where the developing cartridge 8 is exposed to an outside of the apparatus main assembly 2.
The image forming apparatus 1 forms the image on the sheet S (for example, print sheet) by a developer (for example, toner) supplied from the developing cartridge 8.
In this embodiment, the four developing cartridges 8 are mounted in a single cartridge tray 3. The four developing cartridges 8 accommodates developers (hereinafter, also referred to as toner) of colors (for example, respective colors of yellow Y, magenta M, cyan C, black K) which are different from each other. However, the number of the developing cartridges 8 mounted on the cartridge tray 3 may also be 1 to 3 and may also be 5 or more.
Incidentally, the developing cartridges 8 have a substantially similar constitution except for the colors of toner images. For this reason, a constitution of the developing cartridge 8Y (yellow) will be principally described as a representative example. Incidentally, a difference from other developing cartridges 8 (8M, 8C, 8K) will be described timely.
As shown in
The charging unit 5Y is a corona charger of a scorotron type, and includes a charging wire 5aY (5a) and a grid electrode 51bY. The developing cartridge 8Y includes a developing roller 6Y for developing an electrostatic latent image on the photosensitive drum 4Y.
In
Under the developing cartridges 8 and the cartridge tray 3, an electrostatic attraction belt unit 11 is provided. This electrostatic attraction belt unit 11 includes a driving roller 13 and a tension roller 14, and an electrostatic attraction belt 12 having plasticity is extended around the driving roller 13 and the tension roller 14. The photosensitive drums 4 (4Y, 4M, 4C, 4K) provided in the cartridge tray 3 contact an upper surface of the electrostatic attraction belt 12.
Inside the electrostatic attraction belt 12, transfer rollers 16 (16Y, 16M, 16C, 16K) are provided at positions opposing the photosensitive drums 4. The toner images carried on the photosensitive drums 4 are transferred onto the sheet S by applying a transfer bias to the transfer rollers 16.
Below the electrostatic attraction belt unit 11, a feeding unit 18 is provided. This feeding unit 18 includes a feeding tray 19 in which sheets S are stacked and accommodated, and a feeding roller 20, and feeds the sheet S. On a rear side (right side of
Part (a) of
As shown in part (a) of
The apparatus main assembly 2 is provided with an opening 25 through which a pulling out unit 38 passes. The front door 40 is supported by the apparatus main assembly 2 so as to be movable between a closed position where the front door 40 covers the opening 25 and an open position where the opening is open.
[Image Forming Operation]
Next, an image forming operation will be described using
Incidentally, in the image forming apparatus 1 of the present invention, an operation for forming a full-color image is performed as follows. As regards the cartridge tray 3 and the developing cartridges 8, mounting thereof into the image forming apparatus 1 is completed in a state in which the front door 40 is closed.
When the front door 40 is closed, unshown drum driving couplings provided in the image forming apparatus 1 engage with drum coupling 54 (54Y, 54M, 54C, 54L) (see
Each of the drum couplings 54 is rotationally driven via an unshown drive output motor and an unshown gear of the image forming apparatus 1. The associated photosensitive drum 4 is rotationally driven in an arrow direction of
The electrostatic attraction belt 12 is also rotationally driven at a speed corresponding to the speed of the photosensitive drum 4.
At this time, the laser scanner unit LB is driven and emits light. In synchronism with the light emission of the laser scanner unit LB, surfaces of the photosensitive drums 4 are electrically charged uniformly to a predetermined polarity and a predetermined potential by the charging units (charging members) 5 (5Y, 5M, 5C, 5K). The laser scanner unit LB subjects the surfaces of the photosensitive drums 4 to scanning exposure to the laser light Z depending on image signals for the respective colors. By this, electrostatic latent images depending on the image signals for the corresponding colors are formed on the surfaces of the photosensitive drums 4.
The electrostatic latent image formed on the photosensitive drum 4Y is developed by the developing roller 6Y rotationally driven in an arrow E direction of
By such an electrophotographic image forming process, on the photosensitive drum 4Y, a yellow toner image corresponding to a yellow component of the full-color image is formed. On the other hand, the sheets S are separated and fed one by one at a predetermined control timing by the feeding unit 18. Then, the sheet S is conveyed along the photosensitive drums 4 by the electrostatic attraction belt 12.
The sheet S reaches the photosensitive drum 4Y at a predetermined control timing, and the toner image on the photosensitive drum 4Y is transferred onto the sheet S. Similarly, on other photosensitive drums 4 (4M, 4C, 4K), toner images corresponding to the colors of magenta, cyan and black are formed. Then, these toner images are superposed transferred onto the yellow toner image on the sheet S in the order of the toner images of magenta, cyan and black. Thus, the full-color (unfixed) toner image based on the four colors of yellow, magenta, cyan and black is formed on the sheet S.
The toner image transferred on the sheet S is fixed by the fixing unit 21. Then, the sheet S passed through the fixing unit 21 is discharged onto a discharge tray 23 by the discharging unit 22.
Residual toner and paper powder which remain on the photosensitive drum 4Y are physical and electrically removed from the photosensitive drum 4Y by the first cleaning roller 7Y. A part of the residual toner is held on the first cleaning roller 7Y, and another part of the residual toner is charged by the first cleaning roller 7Y and then is returned onto the photosensitive drum 4Y. The residual toner returned to the photosensitive drum 4Y is returned to the developing roller 6Y. The paper dust is physically and electrically removed from the first cleaning roller 7Y by the second cleaning roller 9Y.
[Constitution of Cartridge Tray]
Next, a constitution of the cartridge tray 3 will be described using
Part (a) of
The cartridge tray 3 includes a tray frame 30 (frame), slots 31 (mounting portion), penetrating shafts 55, the photosensitive drums 4 (image bearing members), the charging units 5, and cleaning frames 27 (27Y, 27M, 27C, 27K) (see
As shown in part (a) of
the left side surface 301, and end portions thereof project from the right side surface 30r and the left side surface 301 toward the outsides with respect to the D1 direction. Further, on the rear side of the right side surface 30r and the left side surface 301, positioning grooves 56 are formed (the positioning groove 56 on the left side surface 301 side is not shown). Here, the penetrating shafts 55 are supported by shaft engaging portions 57 of the apparatus main assembly 2 shown in part (b) of
As shown in part (a) of
As shown in
The tray developing contacts 610, the first tray charging contacts 611, and the second tray charging contacts 612 contact unshown contacts of the apparatus main assembly 2, so that voltages are supplied thereto. Similarly, the first tray cleaner contacts 613 and the second tray cleaner contact 614 also contact unshown contacts of the apparatus main assembly 2, so that voltages are supplied thereto.
Next, electrical connection will be specifically described with reference to
The tray charging contacts 610 are electrically connected to the developing rollers 6 (6Y, 6M, 6C, 6K), respectively.
The first tray charging contacts 611 are electrically connected to the charging wires 5a (5aY, 5aM, 5aC, 5aK), respectively. The second tray charging contacts 612 are electrically connected to the grid electrodes 5b (5bY, 5bM, 5bC, respectively.
The first tray cleaner contacts 613 is electrically connected to the first cleaning rollers 7 (7Y, 7M, 7C, 7K) which extend in the D1 direction and which are each rotatable about rotation shaft, respectively.
The second tray cleaner contact 614 is electrically connected to the second charging roller 9Y.
In this embodiment, the cleaning rollers 7 and 9 are used, but a constitution in which removal of the residual toner and the paper dust is carried out by a rubber blade or a sheet may also be employed.
[Cleaning Member]
Next, a constitution of a cleaning member 50Y will be described using
Parts (a) and (b) of
As described above, the cartridge tray 3 in this embodiment is movable between the first position PI where the cartridge tray 3 is positioned inside the image forming apparatus 1 and the second position PO where the cartridge tray 3 is pulled out to the outside of the image forming apparatus 1. Further, the cartridge tray 3 is capable of moving while mounting the developing cartridges 8 each provided with a recessed portion 801 (predetermined recessed portion) in the neighborhood of an end portion with respect to a longitudinal direction (axial direction D1).
Further, the cartridge tray 3 includes the tray frame 30, the slot 31 provided in the frame and to which the cartridge is detachably mountable, the rotatable photosensitive drum 4 provided in the frame, and the charging unit 5 for electrically charging a peripheral surface of the photosensitive drum 4. Incidentally, the charging unit 5 is disposed so as to extend along the axial direction D1 of a rotation shaft (rotational axis) L1 of the photosensitive drum 4.
In this embodiment, the cartridge tray 3 is movable between an end portion 501 provided in the frame on one side (D11) of the frame with respect to the axial direction D1 and an end portion 502 provided in the frame on the other side (D12) of the frame with respect to the axial direction D1, and includes the cleaning member 50 disposed close to the charging member and for cleaning the charging member.
In this embodiment, the cleaning member 50 is constituted by a base portion 51 and a projected portion 514.
Incidentally, the base portion 51 includes a first surface 511 positioned on the one side (D11) and crossing the axial direction D1, a second surface 512 positioned on the two other side (D12) and crossing the axial direction D1, and a third surface 513 positioned between the first surface 511 and the second surface 512 with respect to the axial direction D1.
Specifically, in this embodiment, the first surface 511 and the second surface 512 are two side surfaces crossing (perpendicular to) the axial direction D1 in an attitude of the cleaning member 50 during use, and the third surface 513 is a top surface positioned between the first surface 511 and the second surface 512 and connecting the first surface 511 and the second surface 512. When the developing cartridge is mounted in the cartridge tray, the third embodiment 513 opposes the cartridge.
Incidentally, the first to third surfaces 511 to 513 may be flat surfaces or curved surfaces such that the flat surfaces are deformed so as to be provided with grooves (or ribs). Further, in this embodiment, the third surface 513 is positioned between the first surface 511 and the second surface 512 and may only be required to be disposed so as to cross the first surface 511 and the second surface 512.
The projected portion 514 is formed so as to project from the third surface 513 toward an outside (a side where the developing cartridge to be mounted is provided). In a state in which the cleaning member 50 is positioned at the end portion of the frame on one side, when the cartridge is mounted in the mounting portion, the projected portion 514 is capable of entering the recessed portion 801.
In this embodiment, the projected portion 514 includes a first side surface 516 crossing the axial direction D1 and positioned on the other side, and the first side surface 516 is positioned between the first surface 511 and the second surface 512 with respect to the axial direction D1. That is, the first side surface 516 positioned on the same side as the second surface 512 is disposed at a position retracted from a position of the second surface 512 (toward the one side (D11)) in the axial direction D1.
By this, as described later, when a user operates the projected portion 514, a risk such that the user touches the charging unit 5 (charging wire 5a) is remarkably reduced. That is, when the user grips the first side surface 516 and a second side surface 515 of the projected portion 514, a fingertip (tip of figure) of the user on the other side (D12) facing the opening 801 is capable of touching a part of the third surface 513 (top surface) of the base portion 51. For this reason, by feeling or the like of the fingertip positioned on the other side (D12), an opportunity that the user touches the second surface 512 (side surface) of the base portion 51 becomes small, and consequently, a risk that the user touches the charging wire 5a positioned on a further rear side (the opening 801 side) is also alleviated.
Particularly, with respect to the axial direction D1, when the first side surface 516 is retracted from the second surface 512 in a further distant direction, the risk that the user touches the charging wire 5a can be further alleviated. For example, the first side surface 516 of the projected portion 514 may also be disposed so as to be positioned between the first surface 511 and a center position 51cp of the base portion 51.
In this embodiment, the projected portion 514 further includes the second side surface 515 crossing the axial direction D1 and positioned on one side (D11). With respect to the axial direction D1, the second side surface 515 is disposed so as to be positioned between the first surface 511 and the second surface 512.
Further, the charging unit 5 includes the charging wire 5a. The frame 30 is provided with an opening 301 where the charging wire 5a is exposed, so that the cleaning member 50 can be disposed in the neighborhood of the charging wire 5a through the opening 301. In the following, the cleaning member 50Y will be specifically described.
As shown in
As shown in
As shown in
As shown in
That is, the projected portion 514Y is disposed such that the first side surface 516Y positioned on the other side is closer to the first surface 511Y (the right-side end portion in
When the developing cartridge 8Y is exchanged, the cleaning member is positioned at the cartridge mountable position in many cases. Further, the upper portion of the charging wire 5aY is open, so that there is a liability that the user erroneously touches the charging wire 5aY when the user moves and operates the cleaning member 50Y from the cartridge mountable position. In the present invention, the projected portion 514Y which is easily gripped by the user when the user operates the cleaning member 50 is disposed at the aforementioned position, so that it is possible to reduce a possibility that the user erroneously touches the charging wire 5aY.
[Mounting of Developing Cartridge]
Next, mounting of the developing cartridge 8 into the cartridge tray 3 will be described using
The constitution for the yellow (Y) will be described as a representative example. For convenience of explanation, description will be made by omitting the symbol “Y” in some cases.
In this embodiment, the cartridge tray 3 is capable of restricting mounting of a developing cartridge with a “difference specification” from the developing cartridge with a particular specification suitable for the image forming operation. That is, in a state in which the cleaning member 50 is positioned at the end portion 501 of the frame 30 on one side, when the developing cartridge with the “different specification” is mounted in the slot 31, the projected portion 514 cannot enter the recessed portion 801 and contacts the developing cartridge. By this, it is possible to prevent the mounting of the developing cartridge with the “different specification”.
Specifically, as shown in
The cover member 8aY is provided with the recessed portion 801Y at an overlapping position with the projected portion 514Y of the cleaning member 50 with respect to the DI direction when the developing cartridge 8Y is mounted in the cartridge tray 3.
As shown in
In the case where the developing cartridge with the different specification is mounted in the cartridge tray 3, the projected portion 514Y of the cleaning member 50 and the developing cartridge are in contact with each other, so that mounting of the developing cartridge with the different specification can be prevented.
The present invention can be summarized as follows.
Further, the movable member 3 includes the frame 30, the mounting portion 31 provided in the frame and to which the cartridge is detachably mountable, the rotatable image bearing member 4 provided in the frame, the charging member 5 provided in the frame and not only extending along the axial direction D1 of the rotation shaft (rotational axis) L1 of the image bearing member but also for electrically charging the surface of the image bearing member, and the cleaning member 50 provided in the frame and movable between the end portion 501 of the frame on one side with respect to the axial direction and the end portion 502 of the frame on the other side with respect to the axial direction, the cleaning member 50 being disposed close to the charging member and being used for cleaning the charging member.
The cleaning member 50 includes the base portion 51 and the projected portion 514.
The base portion 51 includes the first surface 511 positioned on one side and crossing the axial direction D1, the second surface 512 positioned on the other side and crossing the axial direction D1, and the third surface 513 positioned between the first surface 511 and the second surface 512 with respect to the axial direction D1.
The projected portion 514 is the projected portion projecting from the third surface 513 toward the outside and is capable of entering the recessed portion when the cartridge is mounted in the mounting portion in the state in which the cleaning member is positioned at the end portion of the frame on one side.
The projected portion 514 includes the first side surface 516 crossing the axial direction and positioned on the other side and the second side surface 515 crossing the axial direction and positioned on one side, and the first side surface 516 is positioned between the first surface 511 and the second surface 512 with respect to the axial direction.
The first side surface 516 constitutes the end surface of the projected portion 514 on the other side with respect to the axial direction, and the second side surface 515 constitutes the end surface of the projected portion 514 on one side with respect to the axial direction.
By this, when the user operates the projected portion 514, the risk that the user touches the charging member can be alleviated.
By this, when the user operates the projected portion, the risk that the user touches the charging member can be further alleviated.
By this, when the user once releases his (her) fingers from the projected portion and then grips the projected portion again with his (her) fingers during movement of the projected portion by the user, it is also possible to alleviate the risk that the user touches the charging member.
According to the present invention, it is possible to alleviate the risk that the user contacts the charging member when the user operates the cleaning member.
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. 2020-173317 filed on Oct. 14, 2020, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2020-173317 | Oct 2020 | JP | national |
This is a divisional of U.S. patent application Ser. No. 17/475,672, filed Sep. 15, 2021.
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Number | Date | Country | |
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20230297000 A1 | Sep 2023 | US |
Number | Date | Country | |
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Parent | 17475672 | Sep 2021 | US |
Child | 18321168 | US |