Patent Application
20140072345
The present invention relates to a developer accommodating unit for accommodating a developer, a developing device and a process cartridge which include the developer accommodating unit, and an image forming apparatus including these members.
The image forming apparatus forms an image on a recording material (medium) by using, e.g., an electrophotographic image forming process and may include, e.g., an electrophotographic copying machine, an electrophotographic printer (such as an LED printer or a laser, beam printer), an electrophotographic facsimile machine, and the like.
Further, the process cartridge refers to a cartridge, prepared by integrally assembling at least a developing means and a developing device, detachably mountable to a main assembly of the image forming apparatus and refers to a cartridge, prepared by integrally assembling the developing device and a photosensitive member unit including at least a photosensitive member, detachably mountable to the main assembly of the image forming apparatus.
Further, the developer accommodating unit is accommodated in the image forming apparatus or the process cartridge. The developer accommodating unit at least includes a flexible container for accommodating the developer.
In a conventional electrophotographic image forming apparatus using the electrophotographic image forming process, a process cartridge type in which an electrophotographic photosensitive member and process means acting on the photosensitive member are integrally assembled into a cartridge and this cartridge is detachably mountable to a main assembly of the electrophotographic image forming apparatus is employed.
In such a process cartridge, as shown in
In JP-A Hei 1-66980, in order to solve a problem such that the developer is scattered in the process cartridge in a developer filling step during manufacturing of the process cartridge, a method in which a developer is accommodated in a deformable inside container (flexible container) is described.
In a conventional constitution using the flexible container as described in JP-A Hei 4-66980, when the developer is localized in the deformable inside container, there was the case where density non-uniformity was generated in an output image. Particularly, during transportation such that the process cartridge or the image forming apparatus is stored in various states* there was a tendency that the above-described localization is liable to occur.
In view of the above-described circumstances, a principal object of the present invention is to provide a developer accommodating unit capable of reducing a degree of density non-uniformity of an output image by suppressing localization of a developer and deformation of a flexible container which are generated by vibration and long-term standing during transportation.
Another object of the present invention is to provide a developing device including the developer accommodating unit, a process cartridge including the developer accommodating unit, and an image forming apparatus including the process cartridge.
According to an aspect of the present invention, there is provided a developer accommodating unit comprising: a flexible container, provided with an opening for permitting discharge of a developer, for accommodating the developer; and a frame for accommodating the flexible container and for accommodating the developer discharged from the flexible container, wherein the flexible container includes a projected portion projected from a part of a side forming the flexible container toward an outside of or toward an inside of the flexible container.
According to another aspect of the present invention, there are provided the developing device including the developer accommodating unit, the process cartridge including the developer accommodating unit and the image terming apparatus
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings,
Parts (a) and (b) of
Parts (a) to (c) of
Parts (a) and (b) of
Parts (a) to (c) of
Parts (a) to (c) of
Parts (a) to (b) of
Parts (a) to (c) or
Parts (a) and (b) of
Parts (a) to (c) of
Parts (a) to (e) of
Parts (a) and (b) of
Parts (a) to (d) of
Parts (a) to (d) of
Parts (a) and (b) of
Parts (a) and (b) of
Parts (a) and (b) of
Parts (a) and (b) of
Parts (a) and (b) of
Parts (a) and (b) of
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Parts (a) to (d) or
Parts (a) and (b) of
In synchronism with this operation, the surface of the photosensitive drum 11 is electrically charged uniformly by a charging roller 12 as a charging means and exposed to light by an exposure device 8, so that an electrostatic latent image is formed on the surface of the photosensitive drum 11. In the cartridge A, a developer is accommodated and a developing roller 13 as a developer carrying member is provided. The developer is fed to the developing roller 13 by a supplying roller 23 to be carried in a thin layer on the surface of the developing roller 13 by a developing blade 15. Then, a developing bias is applied to the developing roller 13, so that the above-described electrostatic latent image is developed with the developer and thus a developer image is formed on tha surface of the photosensitive drum 11.
The developer image is transferred onto the conveyed sheet S by a transfer roller 9 supplied with a bias voltage. Then, the sheet S is conveyed to a fixing device 10 to fix the developer image thereon, and then is discharged onto a discharge portion 3 by a discharging roller 1. Incidentally, the apparatus main assembly B includes a controller 50, and the controller 50 controls drive of inside devices of the apparatus main assembly B. Further, although described later, the controller 50 controls drive of an urging sheet 21 (
The developer accommodating unit 25 includes a frame 17 as a first frame and a frame 18 as a second frame. In an upper region of the frames 17 and 18, the developer accommodating member 34 and an urging member (urging body or urging means) are disposed. The urging member includes, although described later, the urging sheet 21, a scaling member 19 and a rotatable member 20. However, the present invention is characterized by the developer accommodating member 34. The developer accommodating member 34 is provided with opening(s) 35a for permitting discharge or a developer G (G1), and is a container for accommodating the developer G (G1). In a lower region or the frames 17 and 18, the developing roller 13 and the supplying roller 23 are disposed. By employing such a constitution, the developer accommodating unit 25 is configured to accommodate the developer accommodating member 34 containing the developer in the upper region of the frames 17 and 18 and to accommodate the developer G (G2) after being discharged from the developer accommodating membex 34 in the lower region of the frames 17 and 18.
The urging member 500 is disposed so as to oppose a lower surface (side) of the developer accommodating member 34. On a rotatable member 20, an urging sheet 21 and a scaling member 19 are fixed. The sealing member 19 is a member tor urging the developer accommodating number 34 after the sealing 19 seals the openings 35a and then unseals the openings 35a by rotation of the rotatable member 20. Further, the urging sheet 21 urges, during or after an operation in which the sealing member 19 unseals the openings 35a, the lower surface (side) of the developer accommodating member 34 to deform the developer accommodating member 34.
As shown in
At an opposing position to the opening-containing side X of the developer accommodating member 34, the rotatable member 20 is disposed. The rotatable member 20 is a member rotatable about its shaft (axis) as a rotation center. On the rotatable member 20, a base end portion of the sealing member 19 is fixed. Specifically, the sealing member 19 includes an engaging portion 19b, a connecting portion 19c and the sealing portion 19a. The engaging portion 19b is fixed on the rotatable member 20, and the sealing portion 19a is fixed on the discharging portion 35. When the rotatable member 20 is rotated in an arrow C direction, the sealing portion 19a opens the openings 35a. The sealing member 19 is fixed on the rotatable member 20 at the engaging portion 19b by a retaining member. (
As shown in
As shown in
Parts (a) to (c) of
As shown in (b) of
As shown in (c) of
By forming the developer accommodating member 34, in which the developer is accommodated, in a bag shape, the developer can be treated as a unit. For that reason, a developer filling step can be separated from a main assembling seep (manufacturing line) of the cartridge A. As a result, the developer is prevented from being scattered in the main assembling step (manufacturing line) of the cartridge A, so that maintenance such as cleaning of the manufacturing line can be reduced. By the prevention of the scattering of the developer during the assembling step, it is possible to omit a cleaning step of the cartridge A to be performed after the developer filling.
Also in the filling step of the developer in the developer accommodating member 34, the developer accommodating member 34 has flexibility, and thus the filling opening 39 for permitting the developer filling is also soft and therefore can be easily sealed with less scattering of the developer.
Further, the developer accommodating member 34 in which the developer is accommodated has flexibility and therefore can be assembled while following a shape of the frame.
Further, in the filling step, the developer accommodating member 34 has flexibility and therefore deforms its cross section to increase its volume in which the developer can be filled, so chat a filling amount can be increased during the filling.
Further, the flexible container 16 before the developer filling has flexibility and thus can be made small (thin), so that a scoring space during storage before the filling can be decreased compared with the frame which is a resinous structure.
In this embodiment, as the flexible container, the developer accommodating member 34 is used. Here, referring again to
As shown in
The molded portion 34a is formed in a shape close to a hat-like shape (trapezoidal configuration) and includes an upper bottom side 34g, a perpendicular side 34e and the opening-containing side X (tapered portion). From the perpendicular side 34g, an outer peripheral side 34c1 is extended upward vertically, and from the opening-containing side X, an outer peripheral side 34c2 is extended downward vertically. The outer peripheral sides 34c1 and 34c2 are bonded to the air permeable portion 34b. Further, at the outer peripheral side 34c2, fixing portions 16d to be fixed to the frame 18 are formed. The shape of the molded portion 34a follows the inside shape of the frames 17 and 18 (
On the developer accommodating member 34, the sealing member 19 for closing and unsealing the openings 34a of the discharging portion 35 is mounted. The sealing member 19 is mounted on one side of the rotatable member 20. Further, as shown in
Even when the developer accommodating unit 25 stored in the upstand attitude is mounted in the image forming apparatus 100 and then is returned to the horizontal attitude, the developer G is in a state in which the developer G is agglomerated and hard to move, and therefore the above-described localization state with respect to the longitudinal direction is maintained for some time. This is because when the localization of the developer in the developer accommodating member 34 with respect to the longitudinal direction is generated, at an expanded portion of the developer accommodating member 34, tension for returning the developer accommodating member 34 to the original state and power pressure by the self-weight of the accommodated developer G are likely to be kept in balance.
Incidentally, the above-described upstand attitude is an attitude which is assumed during transportation and which would be considered that the localization of the developer G accommodated in the flexible container 16 is largest. Therefore, in the case where the above-described developer accommodating unit 25 is stored in the upstand attitude, when compared with the normal state, the output image is liable to cause the density non-uniformity.
The reason why the output image causes the density non-uniformity will be described below.
In a comparison example In which the projected portion 34t is not provided on the perpendicular side 34e of the developer accommodating member 34, during an initial stage of image output in which the developer discharged from the developer accommodating member 34 is not accumulated in the developer accommodating unit 25, the above-described density non-uniformity is liable co generate. The reason is as follows. First, the developer accommodating member 34 is urged by the urging sheet 21 Lo discharge the accommodated developer G through the openings 35a, and the developer G is carried on the supplying roller 23 and then is supplied to the developing roller 13, so that a latent image is developed with the developer G to be outputted as the output image. Accordingly, when an amount of discharge of the developer from the developer accommodating member 34 varies with respect to the longitudinal direction, as a result, the density non-uniformity is generated on the output image.
Part (a) of
In this embodiment, as shown in (a) of
In this embodiment, as shown in (a) or
Parts (a) and (b) of
In the comparison example in which the projected portion 34t is not provided on the perpendicular side 34e, in the case where the developer accommodating unit 25 is stored in the upstand attitude, the developer accommodating unit 25 is placed in the state of (b) of
For that reason, as shown in (a) of
As in this embodiment, the reason why the strength of the perpendicular side 34e is increased when the projected portion 34t is provided on the perpendicular side 34e will be described below.
Part (c) of
In (c) and (d) of
In this embodiment, as shown in (a) and (b) of
Incidentally, by forming the molded portion 34a through the vacuum molding, the following effects are obtained.
As a first effect, the developer accommodating member 34 can be shaped so as to follow the inside shape of the frame. For that reason, it is possible to dispose the bag until corner portions of the frame, so that a space (spacing) is prevented from being formed between the developer accommodating member 34 and the frame 17 and thus the space does not constitute o dead space.
As a second effect, the developer accommodating member 34 can be shaped so as to follow the shape of the frame and therefore can be easily assembled with the frame. This is because there is no need to push the developer accommodating member into the frame during the assembling so that, its shape follows the shape of the frame.
As a third effect, control of the thickness and shape or each of the molded sides depending on molding shape and condition becomes easy, As a result, it becomes possible to control the stiffness of the side containing the openings 35a by providing the uneven shape to the side containing the openings 35a as in this embodiment.
Part (a) of
Here, a degree of the air permeability of the sheet-like air permeable portion 34b which is the air permeable portion may appropriately be selected so that the developer is prevented from leaking out of the developer accommodating member 34 based on a balance with a size of the developer (particle size of powder) to be accommodated.
As the material for the molded portion 34a, materials such as ABS, PMMA, PC, PP, PE, HIPS, PET, PVC and composite multi-layer materials of these materials may preferably be used. The thickness of the molded portion 34a in the sheet shape before the molding may preferably be about 0.1- 1 mm. The material and thickness of the molded portion 34a may appropriately be selected depending on cost, product specification, manufacturing condition, and the like.
As a material for the sheet-like air permeable portion 34b, a nonwoven fabric or the like formed of polyethylene telephthalate (PET), polyethylene (PE), polypropylene (PP) or the like in a thickness of 0.03-0.15 mm may preferably be used. Further, even when the material for the sheet-like air permeable portion 34b is not the nonwoven fabric, a material having minute holes which is smaller in diameter than the powder such as the developer accommodated in the developer accommodating member 34 may also be used.
Further, in this embodiment, as shown in
As a material for the developer accommodating member 34 other than the sheet-like air permeable portion 34b, a material having flexibility so as to improve efficiency during the discharge of the developer described later may preferably be used. Further, the material for the air sheet-like air permeable portion 34b may also have flexibility.
(Effect of Developer Accommodating Member having Air Permeability)
The reason why the air permeability is imparted to the developer accommodating member 34 as described above is that the developer accommodating member 34 can meet states during manufacturing, during transportation until a user uses the cartridge A, and during storage. First, the reason for the state during the manufacturing is chat the developer accommodating member 34 is made deformable and reducible in order to facilitate assembling the developer accommodating member 34 with the frames 17 and 18. In the case where the developer accommodating member 34 is not provided with the sheet-like air permeable portion 34b, the size thereof cannot be changed from that in a state in which the developer accommodating member 34 is filled with the developer (the bag is closed; and therefore the developer accommodating member 34 is not readily deformed. For that reason, it takes takes to assembly the developer accommodating member 34 and the seep is complicated. Therefore, when the air permeability is imparted to at least a part of the developer accommodating member 34, the size oil the developer accommodating member 34 can be changed from that in the state in which the developer accommodating member 34 is filled with the developer and then is closed, thus facilitating the assembling of the developer accommodating member 34.
Next, the reason for the stages during the transportation and during the storage is that the developer accommodating member 34 can meet a change (difference) in air pressure between the inside and outside of the developer accommodating member 34 during the transportation and during the storage of the cartridge A. The difference in air pressure between the inside and outside of the developer accommodating member 34 is generated in the case where the developer accommodating member 34 is in a lower air-pressure environment during the transportation or the like than during the manufacturing or in the case where the developer accommodating member 34 is stored at a higher temperature than during the manufacturing. For that reason, by expansion of the developer accommodating member 34, there is a possibility Chat parts contacting the developer accommodating member 34 are deformed or broken. Therefore, there is a need to control the air pressure end the temperature during the transportation and during the storage, so that facilitates for that purpose are required and a cost is increased. However, problems caused due to the difference in air pressure between the inside and outside of the developer accommodating member 34 can be solved by partly imparting the air permeability to the developer accommodating member 34.
Further, in the case where the nonwoven fabric is provided with the discharging portion 35 and bonding portions 22 (22a, 22b in
As shown in
Further, the discharging portion 35 is continuously surrounded by the bonding portion 22 to be unsealably bonded, so that the developer accommodated in the developer accommodating member 34 is sealed with the scaling member 19.
The bonding portion 22 has a rectangular shape consisting of two lines extending in a long direction (arrow F direction) and two lines extending in a short direction (arrow E direction) so as to surround the discharging portion 35 and therefore the bonding portion 22 enables the sealing of the discharge portion 35.
Here, of the two lines of the welded bonding portion 22 extending in the long direction (arrow F direction), a bonding portion which is first unsealed is referred to as a first bonding portion 22a and a bonding portion which is unsealed later is referred to as a second bonding portion 22b. In this embodiment, in the case where the bonding portion 22 is viewed along the surface of the sealing member 19, a bonding portion closer to a fold-back portion 19d (
In this embodiment, an unsealing direction is the arrow E direction. The unsealing direction is defined as follows. In the case where the unsealing is effected by moving the sealing member 19, of the first bonding portion 22a and the second bonding portion 22b opposing to each other via the openings 35a, the first bonding portion 22a is first unsealed (peeled). Thus, a direction directed from the first bonding portion 22a to be first unsealed toward the second bonding portion 22b is the unsealing direction (arrow E direction).
When the sealing member 19 is unsealed (peeled) from the developer accommodating member 34 in the arrow E direction, in some cases, the peeling microscopically progresses also in the arrow F direction due to the deformation of the developer accommodating member 34 by an unsealing force also in the first bonding portion 22a and in the second bonding portion 22b. However, the unsealing direction in this embodiment does not refer to such a microscopic unsealing direction.
Next, disposition of the openings 35a will be described with reference to
The reason why the rotational axis direction of the developing roller 13 and the arrow F direction in which the plurality of openings 35a are arranged are and made equal is that the developer is easily supplied, during the discharge thereof, to the developing roller 13 over the entire longitudinal direction without being localized.
The plurality of openings 35a are shifted and disposed along the arrow F direction and therefore the discharging portion 35 is long in the arrow F direction and is short in the arrow E direction. That is, with respect to the arrow F direction, a distance from an end to another end of the plurality of openings 35a is longer than that with respect, to the arrow E direction.
Thus, the discharging portion 35 where the plurality of openings 35a are shifted and disposed in the rotational axis direction (arrow F direction) perpendicular to the unsealing direction (arrow E direction) is long in the arrow F direction and is short in the arrow E direction. For that, reason, the distance required for the unsealing can be made shorter than that required for the unsealing in the long direction (arrow F direction) and therefore a time required for the unsealing can also be made short.
Further, a constitution in which the sealing member 19 for covering the discharging portion 35 is wound up by the rotatable member 20 is employed, the rotational axis direction of the rotatable member 20 and the arrow F direction substantially perpendicular to the unsealing direction (arrow E direction) are made equal, so that winding distance and time of the sealing member 19 can be shortened.
Each of the plurality of openings 35a in this embodiment has a circular shape. When a discharging property is taken into consideration, an area of the openings 35a may preferably be large. Further, the connecting portions 35b defining the openings 35a may preferably be large (thick) in order to enhance the stiffness of the developer accommodating member 34. Therefore, the area of the openings 35a and the area of the connecting portions 35b are required to achieve a balance in view of a material and a thickness of the discharging portion 35 and a force relationship with peeling strength during the unsealing described later and may be appropriately selected. The shape of each opening 35a may also be, in addition to the circular shape, a polygonal shape such as a rectangular shape, an elongated circular shape, and the like shape.
The arrangement of the openings 35a may only be required to be such that the openings 35a are shifted (spaced) with respect to the arrow F direction perpendicular to the unsealing direction (arrow E direction). Constitutions shown in (a) and (b) of
Further, the direction of the openings 35a may preferably be such that the developer accommodated in the developer bag 34 is easily discharged in an attitude during image formation. For that reason, in the attitude during image formation, the openings 35a are disposed so as to be open downward with respect to the gravitational direction. The state in which the openings 35a open downward with respect to the gravitational direction refers to that the direction of the openings 35a has a downward component with respect to the gravitational direction,
Fixing between Developer Accommodating Member and Frame)
With reference to
First, as a first fixing portion, the first fixing portion 16d of the developer accommodating member 34 where a force is received when the sealing member 19 is unsealed (removed) from the developer accommodating member 34 as described later is provided. The first fixing portion 16d is provided at a plurality of positions in parallel to the arrow F direction along which the plurality of openings 35a are arranged. Different from the arrangement at the plurality of positions, the first fixing portion 16d may also be a single fixing portion elongated in parallel to the arrow F direction (not shown).
The first fixing portion 16d is positioned in the neighborhood of the openings 35a of the developer accommodating member 34.
The first fixing portion 16d of the developer accommodating member 34 is fixed to a first fixing portion 18a of the frame 18.
The first fixing portion 16d is a fixing portion necessary for the time of unsealing the developer accommodating member 34, and its action and arrangement will be described later in the description of the unsealing.
Further, as a second fixing portion, the second fixing portion 16e for preventing movement of the developer accommodating member 34 downward or toward the developing roller 13 and the developer supplying roller 23 is provided.
The second fixing portion 16e is provided for the following two reasons. A first reason Ls that the second fixing portion 16e of the developer accommodating member 34 is prevented from moving the developer accommodating member 34 downward in the attitude during the image formation. For that reason, the second fixing portion 16e may preferably be disposed at an upper position in the attitude during the image formation.
Further, a second reason is that the developer accommodating member 34 is prevented from disturbing the image in contact with the developing roller 13 and the developer supplying roller 23 during the image formation. For that reason, the second fixing portion 16e of the developer accommodating member 34 may preferably be provided at a position remote from the developing roller 13 and the developer supplying roller 23. In this embodiment, the second fixing portion 16e of che developer accommodating member 34 is disposed at an upper position remote from the developing roller 13 as shown in
The second fixing portion 16e of the developer accommodating member 34 is fixed to a second fixing portion 18b of the frame 18.
<Fixing Method between Developer Accommodating Member and Frame)
Parts (a) to (d) of
First, as shown in (b) of
Then, as shown in (c) of
Then, as shown in (d) of
As shown in
An assembling step is as follows. Projections of the second fixing portions 18b of the frame 18 are passed through the second fixing portions 16e or the developer accommodating member 34, and then the developer accommodating member 34 is clamped by the frame 17 so that the second fixing portions 16e (holes) of the developer accommodating member 34 are not disengaged (dropped) from the projections to be fixed.
Incidentally/ the developer accommodating member 34 is formed by the vacuum molding, and therefore the developer accommodating member 34 itself will keep its shape and the developer accommodating member 34 has a shape along the frames, so that the developer accommodating member 34 is supported by the frames as a whole. Therefore, it is possible to omit the second fixing portion for preventing (limiting) the movement of the developer accommodating member 34 toward the supplying roller 23 and the developing roller 13 as described in this embodiment.
As other fixing means, different from the above-described ultrasonic clamping, it is also possible to use fixing means using ultrasonic wave. For example, heat clamping using heat, (heat) welding or ultrasonic welding for directly welding the developer accommodating member 34 to the frame 17 or the frame 18, bonding using a solvent or an adhesive, insertion of the developer accommodating member 34 between the frames, hooking using the heat clamping, the ultrasonic clamping, a screw, or a combination of holes and projections (such as bosses), and the like means may also be used. Further, the developer accommodating membex 34 may also be fixed via a separate member provided between the frames 17 and 18 depending on appropriate design based on relationships in space, arrangement or the like between the developer; accommodating member 34 and the frames 17 and 18 (not shown).
As shown in
(Sealing portion of Sealing member)
A sealing portion 19a refers to a region where the sealing member 19 seals the plurality of openings 35a and connecting portions 35b of the developer accommodating member 34. By the sealing portion 19a, the developer is prevented from being leaked from the inside of the developer accommodating member 34 until before use of the cartridge A.
The sealing member 19 has a free end portion in one end side thereof with respect to the unsealing direction (arrow E direction), and at the free end portion, the engaging portion 19b to be engaged with the rotatable member 20 for moving the sealing member 19 is provided. The engaging portion 19b as an end portion of the sealing member 19 for exposing the openings 35a is engaged with the rotatable member 20. The sealing member 19 may also be configured to be automatically subjected to the unsealing (pealing) by receiving a driving force from the image forming apparatus main assembly B. Or, the sealing member 19 may also be configured to be subjected to the unsealing (peeling) by being held and moved by the user. In this embodiment, the rotatable member 20 is a rotation shaft provided in the frame, and the sealing member 19 engaged with the rotatable member 20 is pulled, so that the developer accommodating member 34 accommodating the developer is unsealed.
A portion connecting the bonding portion 22 and the engaging portion 19b is the connecting portion 19c (
Referring to
The rotatable member 20 is disposed closer to the second bonding portion 22b than the plane N2 passing through the first bonding portion 22a. In other words, the sealing member 19 includes when it is seen along the surface of the sheet-like sealing member 19, a fold-back portion 19d where the sealing member 19 is folded back at the portion (connecting portion 19c) between the connecting portion 22 and the engaging portion 19b engaged with the rotatable member 20. The fold-back portion 19d may be provided with or not provided with a fold (crease). A folding angle Q of the sealing member 19 may preferably be 90 degrees or less. The folding angle Q is an angle Q between a plane of the bonding portion 22 of the developer accommodating member 34 and a plane along the arrow D direction in which the sealing member 19 is pulled.
Further, fixing between the sealing member 19 and the rotatable member 20 is, in this embodiment, made by the ultrasonic clamping similarly as in the case of the first fixing portion 16d. other than the ultrasonic clamping, the fixing may also be made by the (heat) welding, the ultrasonic welding, the bonding, the insertion between the frames, the hooking by a hole and a projection, or the like similarly as the means for fixing the first fixing portion 16d and the second fixing portion 16e.
(Portion having Easy-Unsealing Property of Sealing Member)
A method of providing a peeling force of the bonding portion 22 with a desired value will be described. In this embodiment, in order to provide the peeling force with the desired value (a minimum force within a range in which the toner sealing property can be maintained), two methods are principally employed.
In a first method, a laminate material having a sealant layer for enabling easy unsealing of the sealing member is applied. Further, the first method is a method in which the easy unsealing is enabled at the bonding portion by using, as the material for the developer accommodating member 34, a sheet material (of, e.g., polyethylene or polypropylene) which is weldable with the sealant layer and which has flexibility. By changing a combination of formulation of the sealant layer with the material to be bonded, the peeling force can be adjusted correspondingly to a desired condition. In this embodiment, a material having a peeling strength of about 3N/15 mm measured by testing methods for heat sealed flexible packages (JIS-Z0238) is used.
A second method is a method in which as shown in
The rotatable (unsealing) member 20 is used for the purpose of peeling the sealing member 19 from the developer accommodating member 34 by applying a force to the sealing member 19 to move the sealing member 19. The rotatable member 20 includes a supporting portion (not shown) which has a shaft shape and which is rotatably supported by the second frame 18 at its ends, and includes an engaging portion 20b to which the engaging portion 19b of the sealing member 19. In this embodiment, the rotatable member 20 has a rectangular shaft shape, and the engaging portion 19b of the scaling member 19 is engaged with the engaging portion 20b at one of four sides of the rectangular shaft.
The urging sheet 21 for externally acting on the developer accommodating member 34 to discharge the developer accommodated in the developer accommodating member 34, and the rotatable member 20 may be separate members but in this embodiment, the same part performs functions of the rotatable member 20 and the urging sheet 21.
Further, a function of stirring the developer discharged from the developer accommodating member 34 and a function of the rotatable member 20 may be performed by separate members but in this embodiment, the rotatable member 20 also perform the stirring function of the stirring member.
Thus, by using the same part (member) as the rotatable member 20, the urging sheet 21 and the stirring member, the number of parts is reduced, so that it becomes possible to realize cost reduction and space saving.
The unsealing of the developer accommodating member (developer accommodating bag) 34 will be described with reference to
For unsealing the developer accommodating member 34, the developer accommodating unit 25 includes a power application point portion 20a where the rotatable member 20 applies the force for pulling the sealing member 19, and includes the fixing portion 18a of the frame for fixing the developer accommodating member 34 to be pulled.
The power application point portion 20a is a portion, closest to the bonding portion 22, of a portion where the sealing member 19 and the rotatable member 20 contact at the moment of the unsealing. In (b) of
As shown in
A state immediately before the sealing member 19 is pulled by further rotation of the rotatable member 20 to start the unsealing is shown in
When the sealing member 19 is pulled, the developer accommodating member 34 is pulled via the bonding portion 22. Then, a force is applied to the first fixing portion 16d of the developer accommodating member 34, so that the developer accommodating member 34 is pulled from the fixing portion 18c toward the power application point portion 20b by the fixing portion 18c. Then, in a cross section perpendicular to the rotation shaft of the rotatable member 20, the first bonding portion 22a is moved to approach a line connecting the power application point portion 20a and the fixing portion 18c. At this time, with respect to the arrow D direction, from a side close to the rotation shaft of the rotatable member 20, the portions are disposed in the order of the openings 35a, the first bonding portion 22a, the fold-back portion 19d and the fixing portion 18c ((b) of
Together with the corner portion 20c, also the power application point portion 20a is moved in the arrow C direction, and when the sealing member contacts a corner portion 20d, the power application point portion 20a is moved from the corner portion 20c to the corner portion 20d. Part (b) of
As shown in
Thus, the sealing member 19 is wound up around the rotatable member 20 by the rotation of the rotatable member 20, so that the bonding portion 22 is unsealed. The sealing member 19 is wound up by the rotation of the rotatable member 20, and therefore a space required to move the rotatable member 20 may only be required to be a rotation space of the rotatable member 20, and compared with the case where the sealing member 19 is moved by movement other than the rotation, it is possible to realize space saving.
By providing the sealing member 19 with the fold-back portion 19d, so that the bonding portion 22 can be inclination-peeled without using shearing peeling and thus can be unsealed with reliability.
Further, the engaging portion 19b, to be engaged with the rotatable member 20, for unsealing the sealing member 19 in an end side of the sealing member 19 with respect to a direction substantially perpendicular to the arrow F direction in which the plurality of openings 35a are arranged is provided, so that the sealing member 19 can be engaged and unsealed with reliability.
Further, by providing the frame with the fixing portion 18c, the developer accommodating member 34 is supported by the frame during the unsealing, so that even a soft and deferrable developer accommodating member 34 becomes unsealable with reliability.
With respect to the discharge of the developer during the unsealing, as described above, the bonding portion 22 is moved along the line connecting the power application point portion 20a and the fixing portion 18c (in the order of (a) of
(Positional Relation of Fixing Portion Associated with Unsealing)
As shown in
In this way, the fixing portion 18c is provided upstream with respect co the movement direction (arrow D direction) of the sealing member 19, so that reliable unsealing becomes possible.
(Distance Relation of Fixing Portion Associated with Unsealing)
As shown in
In this case, a relationship of M1<M2 is satisfied to permit the peeling-off of the first bonding portion 22a. The relationship of M1<M2 will be described specifically.
First, in the case where M1<M2 is satisfied, as shown in
On the ether hand, in the case of M1>M2, as shown in
Part (a) of
Definition of a manner of measuring the above-described distances M1 and M2 will be described. The distances M1 and M2 are important when the sealing member 19 is pulled during the unsealing. In the case where there is no projection (projected connecting portion) 16t at an intermediate position of paths of M1 and M2, the distances developed as shown in
As described above, based on the relationship of M1<M2, the first bonding portion 22a is unsealed earlier than the second bonding portion 22b. As a result, the fold-back portion 19d of the sealing member 19 is provided closer to the first bonding portion 22a. By this fold-back portion 19d, the peeling is not the shearing peeling but is the inclination peeling. As a result, with reliability, the dealing member 19 can be peeled off from the developer accommodating member 34, so that it is possible to provide an unsealable developer accommodating unit 25.
A relation between a plurality of fixing portions and the unsealing will be described with reference to (a) and (b) of
With reference to
This is because in the case where L1 is larger than L2, the second bonding portion 22b reaches the power application point portion 22a before the peeling of the second bonding portion 22b is ended, and thus the second bonding portion 22b is wound about the rotatable member 20. Therefore, the force cannot be applied so as to peel off the sealing member 19 from the second bonding portion 22b. For that reason, it becomes difficult to unseal the sealing member 19 from the developer accommodating member 34.
As described above, the relationship between the distance L1 and L2 is made to satisfy: L1<L2, so chat the sealing member 19 is satisfactorily unsellable without being wound about the rotatable member 20.
A summary of the connecting portions 35b, defining the openings 35a, which perform a large function in the unsealing operation of the developer accommodating member 34 will be described.
A similar effect can be obtained also in cases other than the case where the openings 35a are arranged in the direction (arrow F direction) perpendicular to the unsealing direction (arrow E direction) as shown in (b) of
Further, as shown in (b) of
As for a relationship between the rotation shaft of the rotatable member 20 and the openings 35a, it can be said that the openings 35a are shifted and disposed in the direction (arrow F direction) of the rotation shaft of the rotatable member 20. As a result, the connecting portions 35b for connecting the first and second bonding portions 22a and 22b with respect to the direction (the arrow E direction) perpendicular to the rotation shaft of the urging member 20 is provided. The openings 35a may only be required to be shifted and disposed in the rotational axis direction (indicated by the arrow F) of the unsealing member. Even when the openings 35a overlap with each other with respect to the rotational axis direction (indicated by the arrow F) as shown in (b) of
Thus, by the presence of the connecting portions 35b for connecting the first, and Second bonding portions 22a and 22b at the discharging portion 35, the developer accommodating member 34 accommodating the developer can transmit the unsealing force of the rotatable member 20 until the second bonding portion 22b is unhealed, so that the discharging portion 35 can be unsealed with reliability.
A relationship between the openings 35a and the engaging portion 19b of the sealing member 19 will be described (
A relationship between the openings 35a and the rotatable member 20 will be described (
Also in such a constitution, it is possible to obtain the effect of transmitting the unsealing force of the rotatable member 20 by the connecting portions 35b until the second bonding portion 22b is unsealed.
The connecting portions 35b defining the openings 35a may also be provided as a separate member (connecting members 16f) as shown in
Also in the case where the developer accommodating member 34 is provided with the connecting members 16f, the sealing member 19 is folded back between the bonding portion 22 and the engaging portion 18b as described above and is wound around the rotatable member 20, so that the flexible container 16 is unsellable. By employing such a constitution, the connecting portions 35b defining the openings 35a in the case where the plurality of openings 35a are provided, and the connecting members 16f perform the same function. That is, the single long opening 116a is the same as the plurality of openings 35a by providing the connecting members 16f.
Therefore, when the sealing member 19 is peeled at the second bonding portion 22b after the unsealing of the first bonding portion 22a is ended, the force (arrow D direction) during the unsealing of the second bonding portion 22b by the rotatable member 20 can be received by the first fixing portion 16d via the connecting members 16f with respect to the arrow H direction. Thus, the force for peeling the sealing member 19 from the developer accommodating member 34 can be transmitted. That is, the forces are applied to the second bonding portion 22b in the arrow D direction and the arrow H direction, so that also the second bending portion 22b is unsellable.
In this way, the single long opening 116a is combined with the connecting members 16f to form the plurality of openings 35a, so that it also becomes possible to increase the stiffness of only the connecting members 16f.
An example in which the present invention is not applied and thus it is difficult to unseal the developer accommodating member 34 will be described. This is the case where there are no connecting portions 35b and thus it becomes difficult to unseal the developer accommodating member 34 as shown in
In this case, a state in which the unsealing is advanced to the second bonding portion 22b is shown in (a) of
In this case, a force acting on the second bonding portion 22b fails to provide the inclination peeling positional relationship as shown in
Incidentally, when a developer accommodating member is a rigid structure, there is no such a deformation* so that the sealing member is unsealable as in the conventional example. However, in the case of a constitution in which the developer is accommodated in a soft deformation bag-like member and an opening which 13 deformed during unsealing is unsealed, as described above, when chore are no connecting portions 35b, it is difficult to effect the unsealing.
As described above, the sealing member 19 (toner seal) is made unsealable transmitting the driving force to the rotatable member 20 of the image forming apparatus 100 and thus there is no need for the user to peel off the toner seal, so that the developer accommodating unit 25 and the cartridge A can be simply and easily replaced and used. Further, the sealing member 19 after the unsealing is fixed to the rotatable member 20, so that the unsealing can be effected without demounting a waste material from the cartridge A.
As shown in
The developer accommodating member 34 is disposed at a part of the inner wall surface (in the upper region of the frames 17 and 18) . When the urging sheet 21 of the urging member 500 or the sealing member 19 urges the developer accommodating member 34 to increase the urging force acting on the developer accommodating member 34 against the frames 17 and 18, the developer accommodating member 34 is pressed against the frames 17 and 18 to be contracted. When the urging force of the urging member toward the developer accommodating member 34 is weakened, the developer accommodating member 34 is rebounded by the frames 17 and 18 to be expanded. Thus, the developer accommodating member 34 becomes small by being pressed against the frames 17 and 18 and becomes large by being rebounded by the frames 17 and 18, so that the developer accommodating member 34 is efficiently contracted and expanded to facilitate the discharge of the developer G from the openings 35a.
The urging member, changes the position of the opening-containing side X by urging the developer accommodating member 34. This is because the developer G is discharged from a portion thereof at a periphery of the openings 35a and thus the change is position of the opening-containing side X most facilitates the discharge of the developer G.
The developer accommodating member 34 is formed so that a position between the plurality of surface portions is curved, and the urging member urges the opening-containing side X. The developer G is discharged from the portion thereof at the periphery of the openings 35a and thus when the position of the opening-containing side X is changed, the urging of the opening-containing side X most facilitates the discharge of the developer G.
The urging member is rotatably provided in the frames 17 and 18, and a distance from its rotation center to an outer edge thereof is different with respect to the circumferential direction when viewed from its cross section perpendicular to the rotation center thereof. Particularly, the cross-sectional shape of the rotatable member 20 is not a circle but may also be a polygon and this is also a point in that the distance from the rotation center Lo the outer edge is different with respect to the circumferential direction. Therefore, when the urging sheet 21 is rotated, the urging member repeats such an operation that it pushes and pulls the developer accommodating member 34.
The urging member 500 (particularly the urging sheet 21 or the sealing member 19) is capable of stirring the developer G, inside the frames 17 and 16, discharged from the developer accommodating member 34 and then is capable of feeding the developer G toward the supplying roller 23 and the developing roller 13.
<Summary of Developer Discharge from Developer Accommodating Member (Bag)>
(Summary of Discharge from before Unsealing to during Unseal)
First, the discharge of the developer from before the unsealing to the time of start of the unsealing will be described. As described above with reference to
(Summary of Discharge after Unsealing/During Urging)
The openings 35a formed to open downward with respect to the vertical direction. Before image formation, a part of the sealing member 19 of the urging member 500 closes the openings 35a, and during the image formation, the part of the sealing member 19 opens the openings 35a. The openings 35a are formed to open downward, and therefore only by opening the openings 35a by the sealing member 19, the developer G is discharged from the developer accommodating member 34 by the gravitation. Thus, when the openings 35a of the developer accommodating member 34 are unsealed, the developer in the neighborhood of the openings 35a is readily discharged by the action of the gravitation of the developer itself and vibration of the developer accommodating member 34, and the like.
After the unsealing, when the rotatable member 20 is further rotated, also the urging sheet 21b for urging the developer accommodating member 34 fixed to the rotatable member 20 is rotated, so that the urging sheet 21 is wound about the rotatable member 20 by the developer accommodating member 34 as shown in
Thus, by the decrease in inside volume of and the change in entire shape of the developer accommodating member 34, the developer inside the developer accommodating member 34 is stirred and as a result, the developer is readily discharged from the openings 35a. At this time, the developer accommodating member 34 is closed except for the openings 35a and thus there is no escape route except for the openings 35a, and therefore the discharging property from the openings 35a is high. By the discharging action as described above, the developer is readily discharged in the arrow I direction.
In the case, when the developer accommodating member 34 is contacted co and pressed against the second frame 10 at least at a part thereof, the developer accommodating member 34 is deformable.
By aligning the rotational axis direction of the developing roller 13 and the arrangement direction (arrow F direction) of the plurality of openings 35a, the developer can be easily supplied over the entire longitudinal direction of the developing roller 13 during the discharge without being localized.
When the developer accommodating unit 25 is mounted in the image forming apparatus 100, by providing the openings 35a so as to open toward the direction of gravitation, the developer discharging property can be improved.
Further, the urging sheet 21 provided in the frames 17 and 18 urges the developer accommodating member 34 so as to be pressed against the frame 18, so that the developer discharging property can be improved.
As shown in
In the case where the developer immediately after the unsealing is accommodated in the developer accommodating member 34 in a large amount, a penetration depth (entering amount) of the urging sheet 21, the sealing member 19 and the rotatable member 20 with respect to the developer accommodating member 34 is repetitively changed, so that the developer accommodating member 34 is deformed so as to be pressed against the frame 18. Contraction of the developer accommodating member 34 by the urging with the urging member 21 and restoration of the shape of the developer accommodating member 34 by the weight of the developer inside the developer accommodating member 34 and by the flexibility of the developer accommodating member 34 are repeated. Further, by the above-described action, the developer accommodating member 34 itself is moved and therefore the developer accommodating member 34 is vibrated, so that the developer inside the developer accommodating member 34 is discharged from the openings 35a also by the vibration of the developer accommodating member 34. The urging sheet 21 is rotated and therefore is capable of repetitively urging the developer accommodating member 34.
(Example in Which Developer Accommodating Member is applied to Frame)
A portion 21 where the developer accommodating member 34 is urged against the frame 18 is as shown in
The case where the amount of the developer inside the developer accommodating member 34 is decreased by image formation will be described with reference to (a) and (b) of
A single part may be used as the urging sheet 21 and the sealing member 19 to have functions of those members. After the unsealing, the bonding portion 22 is separated from the developer accommodating member 34 and therefore an end of the sealing member 19 in the bonding portion 22 side is a free end. For this reason, the sealing member 19 can have the function of the urging sheet 21. Thus, the rotatable member 20 can have the function of the rotatable member 20 for the urging sheet 21, and the sealing member 19 can have the function of the urging sheet 21. As a result, it is possible to reduce the number or parts and thus cost reduction can be realized,
As described above, the developer inside the developer accommodating member 34 can be satisfactorily discharged without providing another discharging part such as a developer discharging roller at the openings 35a as a developer discharging port, so that agglomeration and bridge of the developer in the neighborhood of the openings 35a can be prevented. As a result, even in the case where the developer in the developer accommodating member 34 is agglomerated by tapping during transportation, storage or the like, the agglomerated developer if broken by the movement of the entire developer accommodating member 34 and the periphery of the openings 35a as described above, so that it is possible to prevent a state In which it is difficult to discharge the developer.
Further, even when the rotatable member 20 is disposed in the immediate neighborhood of the developer accommodating member 34, the stiffness of the opening-containing side X is increased, and therefore not all the loads due to the flexure of the opening-containing side X by the weight of the developer filled in the developer accommodating member 34 are exerted on the rotatable member 20. As a result, the rotatable member 20 and the developer accommodating member 34 can be disposed close to each other, and therefore the developer accommodating unit 25 can be lowered with respect to the vertical direction and thus the process cartridge can be downsized.
The urging sheet 21 is not constituted by separate parts consisting of the rotatable member 20 and the urging sheet 21 but may also be constituted by a single part, as shown in (a) of
This is because when the urging sheet 21 is disposed so as to contact at least the developer accommodating member 34, a distance from the rotation center of the urging sheet 21 to the outer end of the urging member is changed and therefore the penetration depth of the urging sheet 21 with respect to the developer accommodating member 34 is also changed. That is, so long as the shaft portion (urging member) is not a shaft portion having a circular cross section including the rotation shaft as its center, the developer accommodating member 34 can be deformed by the rotation of the urging sheet 21. As shown in
Part (b) of
Thus, the developer accommodating member 34 is urged by the urging sheet 21 (in the arrow J direction) to be pressed against the frame 29, thus being deformed to decrease its inside volume, so that the inside developer is pushed out to be discharged from the openings 35a (arrow I direction).
In an attitude during the image formation, the rotatable member 20 of the urging sheet 21 is positioned under the developer accommodating member 34 in contact with the developer accommodating member 34 with respect to the direction of gravitation. The cross-sectional shape of the rotatable member 20 of the urging sheet 21 is rectangular not is not circular and therefore by the rotation of the rotatable member 20, the penetration depth of the rotatable member 20 with respect to the developer accommodating member 34 is periodically changed as described above. Also by the change in penetration depth of the rotatable member 20 with respect to the developer accommodating member 34, the developer accommodating member 24 can be changed in volume and can be vibrated, so that the developer discharging property can be improved.
Next, another structural example with respect to the above-described projected portion provided on the side forming the developer accommodating member 34 will be described. In Embodiment 1, as shown in (a) and (b) of
Part (a) of
Also in this embodiment, the perpendicular side 34e is provided with the projected portions 34t, whereby compared with the case where there is no projected portion 34t, the strength of the perpendicular side 34e of the developer accommodating member 34 is increased and thus the developer accommodating member 34 is not readily deformed. Further, the strength of the perpendicular side 34e of the developer accommodating member 34 is made larger than that, in Embodiment 1, so that the developer accommodating member 34 is not readily deformed further. This is because similarly as the mechanism described in <Effect of projected portion> in Embodiment 1, the plurality of projected portions 34t are separately provided to increase the number of the supporting points and thus the beam strength is increased.
That is, in Embodiment 1, as shown in (a) of
On the other hand, in this embodiment, as shown in (a) of
As described above, on the perpendicular side 34e of the developer accommodating member 34, by the plurality of projected portions 34t separately provided along the widthwise direction, the strength of the developer accommodating member 34 is further increased, so that the developer accommodating member 34 is not readily deformed further. As a result, the powder pressure change of the developer with respect co the openings 35a is suppressed, and thus advance of the packing state can be suppressed, so that the discharging property of the developer G from the developer accommodating member 34 is maintained. Therefore, it is possible to suppress the occurrence of the density non-uniformity on the output image.
In this embodiment, with respect to the above-described projected portion provided on the side forming the developer accommodating member 34, an example in which a plurality of projected portions are provided separately with respect to the longitudinal direction will be described.
Part (a) of
Also in this embodiment, the perpendicular side 34e is provided with the projected portions 34t, whereby similarly as the mechanism described in <Effect of projected portion> in Embodiment 1, the number of the supporting points is increased and thus the beam strength is increased with the result that the developer accommodating member 34 is not readily deformed.
That is, in Embodiment 3, as shown in (c) of
As described above, on the perpendicular side 34e of the developer accommodating member 34, by the plurality of projected portions 34t separately provided along the longitudinal direction, the strength of the developer accommodating member 34 is increased, so that the developer accommodating member 34 is not readily deformed further. As a result, the powder pressure change of the developer with respect to the openings 35a is suppressed, and thus advance of the packing state can be suppressed, so that the discharging property of the developer G from the developer accommodating member 34 is maintained. Therefore, it is possible to suppress the occurrence of the density non-uniformity on the output image.
In Embodiments 1 to 3, examples in which each of the projected portions formed on the side of the developer accommodating member 34 has a bilaterally-symmetrical shape are described, but an asymmetrical shape as shown in
Also with respect to the arrangement of the plurality or projected portions formed on the side of the developer accommodating member 34, even when the projected portions are arranged in any manner as shown in (a) and (b) of
Further, in the case where the plurality of projected portions 34t formed on the side of the developer accommodating member 34 are arranged in a manner as shown in (c) of
<Arrangement of Projected Portion with Respect to Longitudinal Direction>
In a state in which the developer accommodating unit 25 is erected in an attitude (upright, attitude) in which the rotation shaft of the dew loping roller 13 is parallel to the direction of gravitation, the developer accommodating member is expanded and deformed at its end portion in the lower side with respect to the vertical direction. Here, in order to suppress the deformation of the developer accommodating member 34, rather than a constitution in which the projected portions 34t are disposed only in a side with respect to a longitudinal central portion, a constitution in which the projected portions 34t are disposed in both sides with respect to the longitudinal central portion is preferred. That is, it is desirable that the projected portions 34t are provided in a side and another side with respect to the longitudinal direction of the developer accommodating member 34. It is further desirable that the projected portions 34t are provided In symmetrical positions with respect to the longitudinal central portion of the developer accommodating member 34.
Parts (a) and (b) of
In this embodiment, a constitution in which the urging sheet 21 is not provided, and the sealing member 19 is unsealed by peeling off in a direction in which the openings are arranged, i.e., in a direction parallel to che rotation shaft of the developing roller by the user or a winding-up mechanism is employed. In Embodiments 1 to 6, the urging sheet 21 conveys the developer G, and thus the developer G is diffused also in the longitudinal direction, and therefore when compared with a constitution in which there is no conveying member for conveying the developer G, the above-described density non-uniformity tends to be further suppressed. Therefore, in the constitution in which there is no urging sheet 21, the projected portion 34t is provided, similarly as in Embodiments 1 to 6, on the side forming the developer accommodating member 31, whereby the deformation of the developer accommodating member 34 is prevented and thus the density non-uniformity on the output image is effectively suppressed.
According to the present invention, it is possible to suppress the localization of the developer in the flexible container and the deformation of the flexible container which are generated by vibration and long-term standing during transportation, thus suppressing the density non-uniformity of the output image.
While the invention has been described with reference to the structures disclosed herein, it Ls not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 201763/2012 filed Sep. 13, 2012 and 175536/2013 filed Aug. 27, 2013, which is hereby incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-201763 | Sep 2012 | JP | national |
| 2013-175536 | Aug 2013 | JP | national |
