The present invention relates to a cartridge, such as a photosensitive member unit, a developing unit, or the like, which is attachable to or detachable from an image forming apparatus that uses an electrophotographic system.
In a laser beam printer, a photocopier, or the like serving as an electrophotographic-type image forming apparatus, a toner image is formed on a photosensitive drum, and this toner image is then transferred to a sheet serving as a recording material to form an image on the recording material.
In laser beam printers, in order to achieve easier maintenance, a system is widely used in which, with some components of an image forming apparatus being provided in a cartridge, the cartridge is removed to the exterior of the apparatus main body to implement maintenance or replacement.
Japanese Patent Application Publication No. 2016-224221 discloses a process cartridge which enables a developing unit that contain toner to be attached to and detached from a photosensitive member unit that has a photosensitive drum.
In process cartridges having a structure which enables a developing unit that contains toner to be attached to and removed from a photosensitive member unit that has a photosensitive drum, there is room for further improvement in a variety of areas, e.g., size, cost, precision, usability, and service life.
An object of the present invention is to provide a technique which makes it possible to increase the volume of a space containing toner in a process cartridge.
In order to achieve the object described above, a process cartridge according to an embodiment of the present invention includes:
a photosensitive member unit; and
a developing unit that is attachable to and detachable from the photosensitive member unit,
wherein the photosensitive member unit includes:
a photosensitive drum on which an electrostatic latent image is formed;
a frame that supports the photosensitive drum; and
a pressing member that presses the developing unit toward the photosensitive member unit,
the developing unit includes:
a developing roller that supplies toner to the photosensitive drum and collects the toner remaining on a surface of the photosensitive drum;
a housing in which a holding space that holds the toner is formed; and
a pressing receiving portion that receives pressing force from the pressing member,
the housing includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space and
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space, in a state in use, and
when viewed in a direction of a rotation axis of the developing roller, at least part of the pressing receiving portion is located in a space surrounded by the first bottom portion, the second bottom portion, and a tangent line tangent to both an outer wall of the first bottom portion and an outer wall of the second bottom portion.
According to the present invention, the volume of a space containing toner in a process cartridge can be increased.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments for carrying out the invention will be described in detail hereinafter, on the basis of exemplary embodiments, with reference to the drawings. It should be noted, however, that the dimensions, materials, shapes, and relative dispositions of the constituent elements described in the embodiments are to be changed as appropriate depending on the configurations, conditions, and so on of the apparatus to which the invention is applied. In other words, the scope of the invention is not intended to be limited to the embodiments described hereinafter.
First, an image forming apparatus and a process cartridge according to an embodiment of the present invention will be described in detail with reference to the drawings where appropriate.
In the following descriptions, directions are defined on the basis of a user who uses the image forming apparatus 1. In other words, a front surface side of the image forming apparatus 1 is referred to as the “front”; a rear surface side, as the “rear”; an upper surface (top surface) side, as “up”; and a lower surface (bottom surface) side, as “down”. Additionally, viewing the image forming apparatus 1 from the front surface side, a left side of the image forming apparatus 1 is referred to as “left”, and a right side, as “right”.
The orientation (state) of the image forming apparatus 1 in each drawing is assumed to be the orientation (state) in use, and thus the same directions as the image forming apparatus 1 are defined for the process cartridge 5, under the assumption that the process cartridge 5 is in the same orientation as that used when the process cartridge 5 is mounted in the image forming apparatus 1. Each direction in the drawings is defined by the arrows denoted in the drawings. A front-rear direction, an up-down direction, and a left-right direction indicated by these arrows are directions which are orthogonal to each other. These directions are assumed to be the same throughout all the drawings. The up-down direction is parallel to a vertical direction, and the left-right direction and the front-rear direction are parallel to a horizontal direction. The left-right direction is also parallel to the direction of a rotation axis line of a photosensitive drum 61 and the direction of a rotation axis line of a developing roller 71.
The process cartridge 5 is an integrated entity constituted by a developing unit 7 being mounted to a photosensitive member unit 6. When being mounted in an apparatus main body 2, the process cartridge 5 is inserted in the direction indicated by an arrow S1 in the drawings (a mounting direction), and is removed in the direction indicated by an arrow S2.
As illustrated in
The process cartridge 5 is disposed below the exposure apparatus 4. The configuration is such that the process cartridge 5 is mounted in the apparatus main body 2 by being inserted, in an insertion direction S1, into a holding portion 23 of the apparatus main body 2 from an opening exposed when a door (an opening/closing member) 21 provided in the apparatus main body 2 is open (indicated by a dot-dash line in
An image formation process performed using this process cartridge 5 will be described next. The photosensitive drum 61 is rotationally driven while the image formation process is underway. First, the surface of the photosensitive drum 61 is uniformly charged by the charging apparatus 62, and is then exposed by laser light which is emitted from the exposure apparatus 4 and which corresponds to image data, forming an electrostatic latent image corresponding to the image data on the photosensitive drum 61.
Meanwhile, the toner within the toner holding portion 74 is agitated by the second agitator 75B and the first agitator 75A, and is supplied to the developing roller 71 by the supply roller 72. The toner supplied to the developing roller 71 advances between the developing roller 71 and the layer thickness regulating blade 73, and is held on the developing roller 71 as a thin layer having a constant thickness. The toner held on the developing roller 71 is supplied to the electrostatic latent image formed on the photosensitive drum 61. The toner adheres to the electrostatic latent image and becomes a visible image, and a toner image is formed on the photosensitive drum 61 as a result. The sheet S is then conveyed to the area between the photosensitive drum 61 and the transfer roller 63, and the toner image on the photosensitive drum 61 is transferred onto the sheet S. Untransferred toner remaining on the photosensitive drum 61 at this time is collected by the developing roller 71 and returned to the developing unit 7.
The fixing apparatus 8 is disposed to the rear of the process cartridge 5, and mainly includes a heat roller 92 and a pressure roller 91. The sheet S to which the toner image has been transferred traverses the fixing apparatus 8, at which time the sheet S is heated and compressed by the heat roller 92 and the pressure roller 91, which fixes the toner image onto the sheet S. The sheet S which has traversed the fixing apparatus 8 is discharged onto a paper discharge tray 22.
The various units of the process cartridge 5 will be described next. As described above, the process cartridge 5 includes the photosensitive member unit 6, and the developing unit 7 which is attachable to and detachable from the photosensitive member unit 6.
The configuration of the developing unit 7 will be described first.
As illustrated in
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As illustrated in
In tandem with an action of closing the door 21 provided in the apparatus main body 2, a developing drive transmission member (not shown) provided in the apparatus main body 2 moves to a position for engaging with the developing coupling 710. Conversely, in tandem with an action of opening the door 21, the developing drive transmission member moves to a position of disengaging from the developing coupling 710.
When the apparatus main body 2 operates after the door 21 has been closed, drive force is transmitted (input) from the developing drive transmission member to the developing coupling 710, which serves as a drive force receiving member. This drive force enables the developing roller 71 to be rotated via the developing roller gear 711, and the supply roller 72 to be rotated via the supply roller gear 712, from a gear provided on an outer circumferential surface of the developing coupling 710. The developing drive transmission member is configured to be capable of transmitting the drive force to the developing coupling 710 with an allowance provided for positional skew within a predetermined range of the developing coupling 710. Movement of the developing coupling 710, the developing roller gear 711, and the supply roller gear 712 in the axial direction is regulated by the side holder 719, which is attached to the housing 700.
The developing unit 7 stirs the toner within the toner holding portion 74 using the first agitator 75A and the second agitator 75B. The first agitator 75A includes the stirring rod 78A and a stirring sheet 79A. The first agitator 75A is configured to be capable of rotating by receiving drive force from the developing coupling 710 via the idle gear 715A, using the first agitator gear 713. The second agitator 75B includes the stirring rod 78B and a stirring sheet 79B. The second agitator 75B is configured to be capable of rotating by receiving drive force from the first agitator gear 713 via the idle gears 715B and 715C, using the second agitator gear 714.
The second agitator 75B supplies toner from within the toner holding portion 74 to the first agitator 75A. Toner in the toner holding portion 74 which is near the first agitator 75A is stirred by the first agitator 75A, supplied to the supply roller 72, and is furthermore supplied to the developing roller 71 by the supply roller 72.
Additionally, as illustrated in
Actions of the detection member 81 will be described with reference to
The configuration of the photosensitive member unit 6 will be described in detail next.
As illustrated in
A first positioning projection 660 which projects coaxially with the photosensitive drum from the left side wall 611, and a first guide rib 662, are provided toward the rear of the frame 610. Likewise, a second positioning projection 661 which projects coaxially with the photosensitive drum from the right side wall 612, and a second guide rib 663, are provided as well (see
The service life of the developing unit 7, which is determined by the amount of toner held in the developing unit 7, is set to be shorter than the service life of the photosensitive member unit 6, which is determined by the thickness of a photosensitive layer on the photosensitive drum 61. As such, it is necessary for a developing unit 7 which has reached the end of its service life to be replaced separately from the photosensitive member unit 6. In this case, the door 21 is opened and the process cartridge 5 is removed from the apparatus main body 2, the developing unit 7 which has reached the end of its service life is removed from the photosensitive member unit 6, and another developing unit 7 is then attached to the photosensitive member unit 6 as indicated by a mounting direction AD in
As illustrated in
Additionally, as illustrated in
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When a user presses an operation portion 642A of the lift member 642 against the force of the compression spring 650 and rotates the lift member 642 in the direction R2, the lift member 642 presses a projecting portion 751 and causes the developing unit 7 to move in a separation direction LD, separating from the photosensitive member unit 6. This creates a state in which the developing unit 7 can be removed from the photosensitive member unit 6. The operation portion 642A is disposed on the right end part side (one end part side) of the photosensitive member unit 6.
As illustrated in
As illustrated in
Embodiment 1 according to the present invention will be described next with reference to
As illustrated in
The photosensitive member unit 260 is provided with a paper dust removal roller 64A, a paper dust collection roller 64B, and a paper dust collection chamber 64C. The paper dust removal roller 64A makes contact with the photosensitive drum 61, and is disposed downstream, in the rotation direction of the photosensitive drum 61, from the transfer roller 63, and upstream, in the rotation direction of the photosensitive drum 61, from the charging apparatus 62. The paper dust collection roller 64B makes contact with the paper dust removal roller 64A, and is disposed further toward the rear than the paper dust removal roller 64A. The paper dust collection chamber 64C is an enclosed space formed by the paper dust collection roller 64B and the frame 610. The paper dust removal roller 64A removes paper dust remaining on the photosensitive drum 61 from the photosensitive drum 61 after the toner image on the photosensitive drum 61 has been transferred onto the sheet S (not shown). The paper dust removed by the paper dust removal roller 64A is collected in the paper dust collection chamber 64C by the paper dust collection roller 64B.
A first agitator 211 and a second agitator 221 are provided within the developing unit 270. The first agitator 211 is disposed within a first stirring chamber 210 provided further to the front than the developing roller 71 and the supply roller 72. The second agitator 221 is disposed within a second stirring chamber 220 provided further to the front than the first stirring chamber 210.
The first stirring chamber 210 is a space which holds toner, formed by a top surface 240 of the stirring chambers, which is provided higher than the first agitator 211 in the gravitational direction, and the first wall surface 212, which is provided lower than the first agitator 211 in the gravitational direction. The second stirring chamber 220 is a space which holds toner, formed by the top surface 240 of the stirring chambers, and the second wall surface 222, which is provided lower than the second agitator 221 in the gravitational direction. At least part of the first wall surface 212 is a convex (arc-shaped) wall surface (bottom part) projecting downward in the gravitational direction with respect to the first agitator 211. Likewise, at least part of the second wall surface 222 is a convex (arc-shaped) wall surface (bottom part) projecting downward in the gravitational direction with respect to the second agitator 221.
As illustrated in
The first depressed portion 231 is formed at the boundary between the first wall surface 212 and the second wall surface 222 in the front-rear direction, and the first wall surface 212 and the second wall surface 222 are connected by the first depressed portion 231. The first depressed portion 231 is disposed between centers of rotation of the first agitator 211 and the second agitator 221 in the front-rear direction. A pressing receiving portion 231A which receives the pressing from the pressing member 200 is provided in the first depressed portion 231. When the pressing receiving portion 231A receives pressing force from the pressing member 200 in the direction of a first line T201, the developing roller 71 makes contact with the photosensitive drum 61 at a predetermined contact pressure. Here, the first line T201 is a straight line which is perpendicular to the direction of the rotation axis of the developing roller 71 (the left-right direction) and which passes through the first wall surface 212 and the second wall surface 222.
The center of rotation of the second agitator 221 is located near a second line T202 in the up-down direction. Here, the second line T202 is a straight line which is perpendicular to the direction of the rotation axis of the developing roller 71 (the left-right direction) and which connects the centers of rotation of the developing roller 71 and the first agitator 211. The second line T202 passes through the second stirring chamber 220.
The pressing receiving portion 231A and the pressing member 200 are preferably provided at both end parts of the frame 610 in the left-right direction, from the standpoint of stabilizing the left-right distribution of the contact pressure from the developing roller 71 on the photosensitive drum 61. On the other hand, from the standpoint of costs, the number of components can be reduced by providing the pressing receiving portion 231A and the pressing member 200 near the center of the frame 610 in the left-right direction.
Furthermore, from the standpoint of further stabilizing the contact pressure, the pressing receiving portion 231A and the pressing member 200 may be provided at both ends and near the center of the frame 610, in the left-right direction. Additionally, from the standpoint of making the developing unit 270 smaller in the left-right direction, the pressing receiving portion 231A and the pressing member 200 may be disposed further toward the center of the frame 610 in the left-right direction than the lift member 642, and may be disposed overlapping in the left-right direction within a range that does not protrude beyond the outer part of the lift member 642.
In this manner, the process cartridge 5 according to Embodiment 1 illustrated in
The housing 250 includes: the arc-shaped (downwardly-convex) first wall surface 212 (first bottom portion outer wall), which projects outward with respect to the first stirring chamber 210; and the arc-shaped (downwardly-convex) second wall surface 222 (second bottom portion outer wall), which projects outward with respect to the second stirring chamber 220. The configuration is such that when viewed in a direction of the rotation axis of the developing roller 71 (facing the drawing head-on), the pressing receiving portion 231A is at least partially disposed within the first depressed portion 231, which is surrounded by the common tangent T203 tangent to both the first wall surface 212 and the second wall surface 222, and the first wall surface 212, and moreover the second wall surface 222.
This allows the pressing member 200 to be disposed within the first depressed portion 231, which normally would be dead space, and the developing unit 270 can therefore be made smaller. In other words, the volume of the space for holding the toner can be increased without increasing the size of the developing unit.
Additionally, the developing unit 270 according to Embodiment 1 includes, as members which convey the toner within the holding space of the housing 250: the first agitator 211 (a first conveyance member), which conveys the toner by rotating in a state of contacting with an inner wall of the first wall surface 212; and the second agitator 221 (a second conveyance member), which conveys the toner by rotating in a state of contacting with an inner wall of the second wall surface 222. The pressing receiving portion 231A is disposed between the center of rotation of the first agitator 211 and the center of rotation of the second agitator 221, in the horizontal direction.
Additionally, in the process cartridge 5 according to Embodiment 1, when an extension line that passes through a point where the pressing member 200 makes contact with the pressing receiving portion 231A and that is parallel to the pressing direction of the pressing member 200 is taken as the first line T201, the first line T201 passes through (crosses) the first wall surface 212 and the second wall surface 222. Additionally, in the process cartridge 5 according to Embodiment 1, when viewed in a direction of the rotation axis of the developing roller 71, the second line T202, which passes through the center of rotation of the developing roller 71 and the center of rotation of the first agitator 211, also passes through the second stirring chamber 220, which serves as a conveyance chamber housing the second agitator 221.
In the process cartridge 5 according to this embodiment, the pressing member 200 is provided in the first depressed portion 231, and as a result, the pressing receiving portion 231A receives pressing force from the pressing member 200 in the direction of the first line T201. The pressing receiving portion 231A is provided closer to the developing roller 71 than the second wall surface 222 in the front-rear direction (i.e., further to the rear). Accordingly, deformation of the housing 250 caused by the pressing force can be suppressed in a configuration in which the second wall surface 222, which is provided further from the developing roller 71 (further to the front) than the first wall surface 212 in the front-rear direction, is pressed. As a result, loss of contact pressure from the developing roller 71 on the photosensitive drum 61 caused by deformation in the housing 250 can be suppressed.
Additionally, in this embodiment, the pressing member 200 is provided in the first depressed portion 231, and thus more space can be conserved in the horizontal direction (the front-rear direction) than when the pressing member 200 is provided to the front of the second wall surface 222. Additionally, the process cartridge 5 according to Embodiment 1 can conserve more space in the up-down direction than in a configuration where the pressing member 200 is biased by a part, of either the first wall surface 212 or the second wall surface 222, located lower than the first depressed portion 231 in the gravitational direction.
Additionally, in this embodiment, the center of rotation of the second agitator 221 is located near the second line T202 in the up-down direction. The second line T202 is inclined more toward a horizontal line (the front-rear direction) than a vertical line (the up-down direction), and thus an elevation difference between the first stirring chamber 210 and the second stirring chamber 220 in the up-down direction can be kept small. The up-down direction size (the height) of the developing unit 270 can therefore be made small, which in turn makes it possible to reduce the up-down direction sizes (the heights) of the process cartridge 5 and the image forming apparatus 1. Additionally, because the height from which the toner falls when the toner is conveyed from the second stirring chamber 220 to the first stirring chamber 210 by the second agitator 221 is kept low, an increase in powder pressure produced when the toner accumulates in the up-down direction can be prevented. This suppresses degradation caused by an increase in the powder pressure of the toner, which in turn makes it possible to further extend the service life of the developing unit 270.
Additionally, in this embodiment, by disposing the pressing receiving portion 231A and the pressing member 200 closer to the center of the frame 610 than the lift member 642 in the left-right direction, the left-right direction size (the width) of the developing unit 270 can be made small. This makes it possible to reduce the left-right direction sizes (widths) of the process cartridge 5 and the image forming apparatus 1.
Additionally, in this embodiment, the pressing member 200 is provided in the first depressed portion 231, and thus the first depressed portion 231 and the pressing member 200 can be used as uneven shapes for engagement, for the purpose of preventing erroneous mounting of multiple process cartridges having different specifications, such as service life and speed. Specifically, if the first depressed portion 231 of the developing unit 270 is provided in a different location of the photosensitive member unit from the pressing member 200, one of the first wall surface 212 and the second wall surface 222 will contact the pressing member 200 when the developing unit 270 is mounted in the photosensitive member unit 260. In such a case, the developing unit 270 cannot be inserted to a fully-mounted position such as that illustrated in
Embodiment 2 according to the present invention will be described next with reference to
As illustrated in
A rotation stopping portion 202, serving as a substitute for the projecting portions 643 illustrated in
At this time, the pressing receiving portion 231A receives a counterforce from the rotation stopping roller portion 202A in the direction of an arrow 202F. In other words, the arrow 202F represents a vector of a rotation stopping contact force which restricts the freedom with which the developing unit 271 rotates about the developing roller 71. An arrow 202H and an arrow 202V represent a horizontal component (front-rear direction partial force component) and a vertical component (up-down direction partial force component), respectively, of the rotation stopping contact force 202F. The horizontal component 202H is oriented in a direction facing from the front side toward the rear side, and the vertical component 202V is oriented in a direction facing from the bottom side toward the top side.
The pressing receiving portion 231A and the rotation stopping portion 202 are preferably provided at both end parts of the frame 610 in the left-right direction, from the standpoint of stabilizing the left-right distribution of the contact pressure from the developing roller 71 on the photosensitive drum 61. On the other hand, from the standpoint of costs, the number of components can be reduced by providing the pressing receiving portion 231A and the rotation stopping portion 202 near the center of the frame 610 in the left-right direction.
Furthermore, from the standpoint of further stabilizing the contact pressure, the pressing receiving portion 231A and the rotation stopping portion 202 may be provided at both ends and near the center of the frame 610, in the left-right direction. Additionally, from the standpoint of making the developing unit 271 smaller in the left-right direction, the pressing receiving portion 231A and the rotation stopping portion 202 may be disposed further toward the center of the frame 610 in the left-right direction than the lift member 642, and may be disposed overlapping in the left-right direction within a range that does not protrude beyond the outer part of the lift member 642.
The first stirring chamber 210 and the second stirring chamber 220 of the developing unit 271 are respectively constituted by the first wall surface 212 and the second wall surface 222, which form a bottom surface on the lower side in the gravitational direction, and a first top surface 241 and a second top surface 242, which form a top surface on the upper side in the gravitational direction. The first top surface 241 and the second top surface 242 are connected by an intersecting portion 242A, which is a leading end part of the second top surface 242 on the rear side thereof. The intersecting portion 242A has a shape which extends from the front side toward the rear side in the second top surface 242, and is therefore disposed so as to overlap with the first top surface 241 in the front-rear direction. In other words, the intersecting portion 242A and the first top surface 241 are provided intersecting in the front-rear direction.
In this manner, the process cartridge 5 according to Embodiment 2 illustrated in
The housing 251 includes: the arc-shaped first wall surface 212, which projects outward with respect to the first stirring chamber 210; the arc-shaped second wall surface 222, which projects outward with respect to the second stirring chamber 220; the first top surface 241, which is provided on the upper side in the gravitational direction; the second top surface 242, which is provided higher in the gravitational direction than the first top surface 241 and which is disposed so as to partially overlap with the first top surface 241 when viewed from above; and the intersecting portion 242A (a connecting portion), which connects the first top surface 241 and the second top surface 242. The intersecting portion 242A has an opposing surface 242B which opposes the first top surface 241 below the second top surface 242. Thus as illustrated in
Additionally, the rotation stopping portion 202 according to Embodiment 2 includes the rotation stopping roller portion 202A, which supports the developing unit 271 when the developing unit 271 is mounted in the photosensitive member unit 261. When viewed if a direction of the rotation axis of the developing roller 71, the rotation stopping roller portion 202A is disposed in the first depressed portion 231, as in Embodiment 1. This allows the rotation stopping portion 202 to be disposed within the first depressed portion 231, which normally would be dead space, and the developing unit 271 can therefore be made smaller. In other words, the volume of the space for holding the toner can be increased without increasing the size of the developing unit 271.
According to this embodiment, by providing the rotation stopping portion 202 in the first depressed portion 231, the pressing receiving portion 231A receives pressing force of the rotation stopping contact force 202F from the rotation stopping portion 202. The process cartridge 5 according to Embodiment 2 can conserve more space in the up-down direction than in a configuration where the rotation stopping portion 202 supports a part, of either the first wall surface 212 or the second wall surface 222, located lower than the first depressed portion 231 in the gravitational direction.
Furthermore, in this embodiment, the horizontal component 202H acting on the developing unit 271 from the rotation stopping portion 202 is oriented in the same direction as the horizontal pressing force component 201H, i.e., in the direction from the front toward the rear. Accordingly, a biasing force of the developing roller 71 acting on the photosensitive drum 61 is added by the horizontal component 202H, which makes it possible to further stabilize the state of contact between the developing roller 71 and the photosensitive drum 61.
Additionally, the means with which the developing roller 71 contacts the photosensitive drum 61 is distributed between the pressing member 201 and the rotation stopping portion 202, which keeps the compression spring force of the pressing member 201 low. Keeping the compression spring force of the pressing member 201 low makes it possible to suppress creep deformation in the frame 610 occurring when the process cartridge 5 is left standing for a long time, which in turn makes it possible to reduce the strength required of the frame 610. Costs can therefore be reduced by making the frame 610 thinner and so on.
Additionally, in this embodiment, the intersecting portion 242A intersects with the first top surface 241 of the stirring chambers in the front-rear direction. Accordingly, when the developing unit 271 is mounted to and removed from the photosensitive member unit 261, the intersecting portion 242A can be used as a handle of the developing unit 271, which a user can hook their finger on and grip. This makes it possible to conserve more space in the horizontal direction (the front-rear direction) than with a configuration in which a handle of the developing unit 271 is provided further to the front than the second wall surface 222. Furthermore, a location closer to a center of gravity 251G of the developing unit 271 in the horizontal direction (the front-rear direction) can be gripped than with a configuration in which a handle of the developing unit 271 is provided further to the front than the second wall surface 222. Accordingly, a burden placed on the wrist when mounting and removing the developing unit 271 to and from the photosensitive member unit 261, i.e., a load of moment about the wrist produced when gripping the developing unit 271, can be reduced.
Additionally, in this embodiment, the rotation stopping portion 202 is provided in the first depressed portion 231, and thus the first depressed portion 231 and the rotation stopping portion 202 can be used as uneven shapes for engagement, for the purpose of preventing erroneous mounting of multiple process cartridges having different specifications, such as service life and speed. Specifically, if the first depressed portion 231 of the developing unit 271 is provided in a different location from the rotation stopping portion 202, one of the first wall surface 212 and the second wall surface 222 will contact the rotation stopping portion 202 when the developing unit 271 is mounted in the photosensitive member unit 261. In such a case, the developing unit 271 cannot be inserted to a fully-mounted position such as that illustrated in
Embodiment 3 according to the present invention will be described next with reference to
As illustrated in
At least part of the pressing member 200 or the lift member 642 overlaps with a space between the first stirring chamber side wall 213 and the second stirring chamber side wall 223 in the left-right direction. In other words, the pressing member 200 and the lift member 642 are disposed, in the left-right direction, further from the center of the developing unit 272 in the left-right direction than the first stirring chamber side wall 213. Additionally, at least part of the pressing member 200 or the lift member 642 is located closer, in the left-right direction, to the center of the developing unit 272 in the left-right direction than the second stirring chamber side wall 223.
The pressing member 200 or the lift member 642 is disposed further to the rear than the second stirring chamber 220 and further to the front than the developing roller 71, in the front-rear direction.
Although the pressing member 200 is provided on the left side of the lift member 642 in this embodiment, from the standpoint of usability when removing the developing unit, the positional relationship in the left-right direction can be reversed, i.e., the pressing member 200 can be provided on the right side of the lift member 642. Additionally, although the pressing member 200 and the lift member 642 are, in this embodiment, disposed so as to at least partially overlap in the area between the first stirring chamber side wall 213 and the second stirring chamber side wall 223 in the left-right direction, the pressing member 200 may be disposed in the first depressed portion 231 described in Embodiment 2.
Thus like the above-described embodiments, the developing unit 272 according to Embodiment 3 and illustrated in
The lift member 642 is provided further from the left-right direction center of the developing unit 272 than the first stirring chamber side wall 213 in the left-right direction, and is provided between the second stirring chamber 220 and the developing roller 71 in the front-rear direction. The lift member 642 can therefore be seen from the same perspective as that illustrated in the top view in
The second stirring chamber longitudinal width 223H is made longer than the first stirring chamber longitudinal width 213H, and thus the volume of the toner held in the second stirring chamber 220 can be increased by an amount equivalent to the difference between the second stirring chamber longitudinal width 223H and the first stirring chamber longitudinal width 213H. This makes it possible to further increase the service life of the developing unit 272.
Embodiment 4 according to the present invention will be described next with reference to
As illustrated in
The first stirring rod 311S is provided with the stirring blades 313 to convey the toner in the first stirring chamber 210 to a central part. Toner which has accumulated on the supply roller 72 is again expelled into the first stirring chamber 210 by rubbing against the developing roller 71. Some of this expelled toner is conveyed to both end sides of the supply roller 72 in the axial direction thereof. The first stirring rod 311S is provided with the stirring blades 313 to return this toner, which has been conveyed to both end sides, back to the central part of the first stirring chamber 210 in the left-right direction.
A plurality of the stirring blades 313 are provided on the first stirring rod 311S, at intervals along the left-right direction of the first stirring rod 311S. In this embodiment, six of the stirring blades 313 are provided. The stirring blades 313 according to this embodiment are plate-shaped members having semi-oval shapes, and are configured so that a normal line at an intersection point 311P where the stirring blades 313 intersect with the first rotation shaft 311A intersects with the first rotation shaft 311A at an angle 313θ. The three stirring blades 313 on the right side are provided so that the angle 313θ is in the counterclockwise direction relative to the first rotation shaft 311A, and the three stirring blades 313 on the left side are provided so that the angle 313θ is in the clockwise direction relative to the first rotation shaft 311A. In other words, the six stirring blades 313 are provided with bilateral symmetry. Accordingly, when the first stirring rod 311S rotates, the toner at the end parts of the first stirring chamber 210 in the left-right direction is subject to a conveyance force, moving toward the center in the left-right direction, from the stirring blades 313.
Additionally, a second agitator 321, which is capable of rotating, is provided in the second stirring chamber 220. The second agitator 321 includes a second rotation shaft 321A extending in the left-right direction and a second stirring sheet 322 constituted by a flexible sheet member, and conveys toner from the second stirring chamber 220 toward the first stirring chamber 210 by rotating about the second rotation shaft 321A. The second stirring sheet 322 has linear cutouts 322C extending in a direction having a set angle 3220 relative to the second rotation shaft 321A.
In this embodiment, six of the cutouts 322C are provided, and the cutouts 322C are positioned between the intersection points 311P between the stirring blades 313 and the first rotation shaft 311A, in the left-right direction. The amount of toner conveyed by the second agitator 321 is smaller than the amount of toner conveyed by the first agitator 311. The three cutouts 322C on the right side are provided so that the angle 322θ is in the counterclockwise direction relative to the second rotation shaft 321A, and the three cutouts 322C on the left side are provided so that the angle 322θ is in the clockwise direction relative to the second rotation shaft 321A. In other words, the six cutouts 322C are provided with bilateral symmetry.
The stirring blades 313 described in this embodiment are examples, and the shape and number of the stirring blades 313 can be set freely from the standpoint of adjusting the stirring performance. For example, although the stirring blades 313 have semi-oval plate shapes in this embodiment, the stirring blades 313 may have screw shapes with an angle of torsion relative to the first rotation shaft 311A, shapes with unevenness in the sides or on the surfaces, and so on. Furthermore, the shapes, sizes, thicknesses, and angles in which the surfaces are oriented can also be varied among the plurality of stirring blades 313 from the standpoint of changing the circulation performance at each of positions in the left-right direction. It is furthermore not absolutely necessary for the plurality of stirring blades 313 to be located at equal intervals, nor is it absolutely necessary for the directions of the normal lines of the surface to be the same at each of the intersection points 311P.
Additionally, although this embodiment describes the shape of the cutouts 322C as being lines having the set angle 3220 relative to the second rotation shaft 321A, this set angle 322θ may be any angle aside from 0 and 180 degrees, and the width of the line may be set freely from the standpoint of processability. Furthermore, the shape, number, and interval of the cutouts 322C described in this embodiment are examples, and can be set freely from the standpoint of adjusting the conveyance performance. Further still, the shapes, sizes, and intervals can be varied among the plurality of cutouts 322C from the standpoint of varying the conveyance performance depending on the location in the left-right direction.
In this manner, the developing unit 372 according to Embodiment 4 and illustrated in
Additionally, the first agitator 311 includes a plurality of the stirring blades 313. At least part of each of the cutouts 322C is positioned between two adjacent stirring blades 313 with respect to the axis line of the first rotation shaft 311A, as seen from a direction orthogonal to the first rotation shaft 311A. Each of the cutouts 322C has a first end 322A located on a free end side of the second stirring sheet 322, and a second end 322B located on the side opposite from the first end 322A. Each of the cutouts 322C extends from the second end 322B to the first end 322A, from the center toward the outer side of the second stirring sheet 322 in a direction of the second rotation shaft 321A. Accordingly, the toner in the first stirring chamber 210 and the second stirring chamber 220 can be conveyed in a circulating manner.
A developing unit 500 according to Embodiment 4 and illustrated in
The first agitator 211 is disposed above the first wall surface 212, the second agitator 221 is disposed above the second wall surface 222, and the third agitator 501 is disposed above the third wall surface 505. As illustrated in
Note that the third agitator 501 is capable of rotating, and a center of rotation of the third agitator 501 may be located higher, in the gravitational direction, than a straight line L1 connecting the center of rotation of the first agitator 211 with the center of rotation of the second agitator 221.
In this embodiment, the cutouts 322C in the second stirring sheet 322 are provided, in the left-right direction, between the plurality of intersection points 311P where the stirring blades 313 intersect with the first rotation shaft 311A. Furthermore, the amount of toner conveyed by the second agitator 321 is smaller than the amount of toner conveyed by the first agitator 311. This makes it possible to prevent the supply of an amount of toner excessive for the stirring blades 313 provided in the first agitator 311, which in turn makes it possible to suppress degradation in the toner within the developing chamber.
Embodiment 5 according to the present invention will be described next with reference to
The first agitator 311 includes the first stirring rod 311S, the first rotation shaft 311A extending in the left-right direction, the first stirring sheet 312 constituted by a flexible sheet member, and the plurality of stirring blades 313, and supplies toner to the supply roller 72 by rotating about the first rotation shaft 311A. The first stirring rod 311S is provided with the stirring blades 313 to convey the toner in the first stirring chamber 210 (a first toner holding chamber) to a central part. Toner which has accumulated on the supply roller 72 is again expelled into the first stirring chamber 210 by rubbing against the developing roller 71. Some of this expelled toner is conveyed to both end sides of the supply roller 72 in the axial direction thereof.
The first stirring rod 311S is provided with the stirring blades 313 to return this toner, which has been conveyed to both end sides, back to the central part of the first stirring chamber 210 in the left-right direction. Additionally, the stirring blades 313 at both end parts in the longitudinal direction reduce the toner pressure at both end parts, and thus by filling a gap between both end parts of the developing roller 71 in the longitudinal direction and the housing 700, toner leakage from a toner seal portion (not shown), which prevents such toner leakage, can be reduced.
A plurality of the stirring blades 313 are provided at intervals along the left-right direction of the first stirring rod 311S. In this embodiment, six of the stirring blades 313 are provided. The stirring blades 313 have semi-oval plate shapes, and a normal line at the intersection point 311P, where the stirring blades 313 intersect with the first rotation shaft 311A, intersects with the first rotation shaft 311A at the angle 313θ. Additionally, a second agitator 321, which is capable of rotating, is provided in the second stirring chamber 220 (a second toner holding chamber).
The second agitator 321 includes a second stirring rod 321S, the second rotation shaft 321A extending in the left-right direction, and the second stirring sheet 322 constituted by a flexible sheet member, and conveys toner from the second stirring chamber 220 toward the first stirring chamber 210 by rotating about the second rotation shaft 321A. The amount of toner conveyed by the second agitator 321 is smaller than the amount of toner conveyed by the first agitator 311.
Additionally, a third agitator 401, which is capable of rotating, is provided in a third stirring chamber 403 (a third toner holding chamber). The third agitator 401 includes a third stirring rod 401S, a third rotation shaft 401A extending in the left-right direction, and a third stirring sheet 402 constituted by a flexible sheet member, and conveys toner from the third stirring chamber 403 toward the second stirring chamber 220 by rotating about the third rotation shaft 401A. The amount of toner conveyed by the third agitator 401 is smaller than the amount of toner conveyed by the second agitator 321. This makes it possible to prevent an excessive amount of toner from backing up in the rearward direction in the second stirring chamber 220 and the first stirring chamber 210.
A center of rotation of the third agitator 401 is located near a second line T302 in the up-down direction, as indicated in
The center of rotation of the third agitator 401 is located near the second line T302 in the up-down direction. The second line T302 is inclined more toward a horizontal line (the front-rear direction) than a vertical line (the up-down direction), and thus an elevation difference between the first stirring chamber 210, the second stirring chamber 220, and the third stirring chamber 403 in the up-down direction can be kept small. The up-down direction size (the height) of the developing unit 470 can therefore be made small, which in turn makes it possible to reduce the up-down direction sizes (the heights) of the process cartridge 5 and the image forming apparatus 1.
Additionally, because the height from which the toner falls when the toner is conveyed from the third stirring chamber 403 to the second stirring chamber 220 by the third agitator 401 is kept low, an increase in powder pressure produced when the toner accumulates in the up-down direction can be prevented. This suppresses degradation caused by an increase in the powder pressure of the toner, which in turn makes it possible to further extend the service life of the developing unit 270.
As described above, the third agitator 401 is constituted by the third rotation shaft 401A and the third stirring sheet 402, but the configuration is not limited thereto. For example, as illustrated in
The third stirring rod 451S is provided with the stirring blades 452 to convey the toner in the third stirring chamber 403 outward in the axial direction of the third stirring rod 451S. A plurality of the stirring blades 452 are provided on the third stirring rod 451S, at intervals along the left-right direction of the third stirring rod 451S. In this embodiment, six of the stirring blades 452 are provided. The stirring blades 452 according to this embodiment have semi-oval plate shapes, and are configured so that a normal line at an intersection point 451P where the stirring blades 452 intersect with the third rotation shaft 451A intersects with the third rotation shaft 451A at an angle 453θ.
When the first to third agitators rotate, the toner within the third stirring chamber 403 is conveyed outward in the axial direction of the third stirring rod 451S, and is also conveyed from the third stirring chamber 403 toward the second stirring chamber 220 by the third stirring sheet 455. Furthermore, when the second agitator 321 rotates, the toner within the second stirring chamber 220 is conveyed from the second stirring chamber 220 toward the first stirring chamber 210. The first stirring rod 311S of the first agitator 311 is provided with the stirring blades 313 for conveying the toner within the first stirring chamber 210 toward the central part thereof, and thus the first, second, and third agitators produce toner circulation, indicated by arrows 480 and 481 in
The amount of toner conveyed by the third agitator 450 is set to be the same or smaller than the amount of toner conveyed by the first agitator 311. This makes it possible to prevent an excessive amount of toner from backing up in the rearward direction in the second stirring chamber 220 and the first stirring chamber 210. Although this embodiment describes a configuration in which the third agitator is provided with a plurality of stirring blades, the configuration may be such that the second agitator is provided with a plurality of stirring blades and conveys toner outward in the axial direction of the stirring rod, and only the stirring sheet is fixed to the rotation shaft of the third agitator.
Additionally, in this embodiment, the above-described lift member 642 and the like are not present in the periphery of the third stirring chamber 403, which is in a position distant from the developing roller, as illustrated in
In this manner, the developing unit 470 according to Embodiment 5 and illustrated in
The housing 700 includes: the arc-shaped first wall surface 212, which projects outward with respect to the first stirring chamber 210; the arc-shaped second wall surface 222, which projects outward with respect to the second stirring chamber 220; and an arc-shaped third wall surface 505, which projects outward with respect to the third stirring chamber 403. The first agitator 311 is disposed above the first wall surface 212, the second agitator 321 is disposed above the second wall surface 222, and the third agitator 401 is disposed above the third wall surface 505.
Additionally, as illustrated in
Additionally, as illustrated in
As illustrated in
Providing the third agitator 401 within the third stirring chamber 403 makes it possible to increase the volume of the toner holding chamber. Additionally, because the center of rotation of the third agitator 401 is located near the second line T302 in the up-down direction, i.e., within the rotational radius of the leading end of the third stirring sheet 402, the up-down direction size (height) of the developing unit 270 can be reduced. Additionally, the toner pressure at both end parts is reduced by the stirring blades 313 of the first agitator 311, and thus toner leakage from toner seal portions at the end parts of the developing roller 71 can be prevented. Furthermore, because the third stirring rod 451S includes the stirring blades 452 for conveying the toner outward in the axial direction, degradation of the toner can be suppressed, which makes it possible to further extend the service life of the developing unit 270. Further still, the side wall surfaces of the third stirring chamber 403 can be located further outward in the left-right direction, which makes it possible to increase the volume of the toner receptacle.
Embodiment 6 according to the present invention will be described next with reference to
As illustrated in
In this embodiment, the process cartridge is configured so that when the developing unit 500 is mounted in the photosensitive member unit 260, the third stirring chamber 503 of the developing unit 500 projects further to the front than the frame 610 of the photosensitive member unit 260.
Additionally, the center of rotation of the third agitator 501 is located higher than the straight line L1 connecting the center of rotation of the first agitator 211 with the center of rotation of the second agitator 221.
As illustrated in
As illustrated in
Next, as illustrated in
As illustrated in
As illustrated in
A new component detection mechanism using the above-described detection member 81 and detection projection 83 (see
As illustrated in
In this manner, the apparatus main body 2 of the image forming apparatus according to Embodiment 6 and illustrated in
Additionally, the photosensitive member unit 260 according to Embodiment 6 includes the pressing member 509. The developing unit 500 has the roller receiving portion 514 (pressing receiving portion) which is pressed by the pressing member 509. The configuration is such that when viewed in a direction of the rotation axis of the developing roller 71, the roller receiving portion 514 (pressing receiving portion) is at least partially disposed within the third depressed portion 506, which is surrounded by a tangent line tangent to both the second wall surface 222 and the third wall surface 505, and the second wall surface 222, and moreover the third wall surface 505. Additionally, as illustrated in
In this embodiment, the configuration is such that when the developing unit 500 is mounted in the photosensitive member unit 260, the third stirring chamber 503 of the developing unit 500 projects further to the front than the frame 610 of the photosensitive member unit 260. In this configuration, a configuration for supporting the developing unit 500 with respect to the photosensitive member unit 260 is the same as in the developing unit 270. Accordingly, a plurality of developing units having different service lives (toner capacities) can be mounted without changing the photosensitive member unit 260. This suppresses the number of types of photosensitive member units which are incorporated when manufacturing the process cartridge. The number of molding molds required for the different types of photosensitive member units can therefore be reduced. This also makes it sufficient for an assembly apparatus to handle a comparatively low number of types of photosensitive member units, which simplifies the assembly apparatus and by extension suppresses manufacturing costs.
Additionally, in this embodiment, the center of rotation of the third agitator 501 is located higher than the straight line L1 connecting the center of rotation of the first agitator 211 with the center of rotation of the second agitator 221. Toner can therefore be conveyed from the third agitator 501 to the second agitator 221 using the force of gravity. Accordingly, the third depressed portion 506 may be eliminated, the third wall surface 505 and the second wall surface 222 may be connected by a sloped surface that slopes downward, in the gravitational direction, from the third wall surface 505 toward the second wall surface 222, and the toner may be conveyed by sliding along the sloped surface. Additionally, eliminating the third depressed portion 506 makes it possible to increase the filling amount of the toner.
Additionally, as illustrated in
To prevent such a situation, the first engagement portion 507 and the second engagement portion 508 are made to interfere with each other when the developing unit is mounted in the apparatus main body 2, which prevents the developing unit 500 from being mounted in the apparatus main body 2. Additionally, in this embodiment, the first engagement portion 507 is provided in the developing unit 500 instead of the photosensitive member unit 260, and thus when providing a plurality of developing units having different specifications as products, the photosensitive member unit 260 can be used in common with those units. Although the compatibility is achieved using the unevenness in the relationship between the first engagement portion 507 and the second engagement portion 508 in this embodiment, the means for implementing compatibility is not limited thereto, and a variety of means can be used, including positional relationships, size relationships, and so on.
Additionally, in this embodiment, the pressing member 509 can be disposed, without wasting space, in the space formed by the frame 610 of the photosensitive member unit 260 and the first depressed portion 231 or the third depressed portion 506 of the developing unit 500, which makes it possible to press the developing roller 71 toward the photosensitive drum 61 without affecting the size of the apparatus main body 2. In the same technical spirit, the attitude of the developing unit 500 can be stabilized by disposing the rotation stopping roller portion 202A in a space formed by the frame 610 and a second depressed portion 232 or the first depressed portion 231 of the stirring chambers. Additionally, in this embodiment, the developing roller 71 can press against the photosensitive drum 61 in a stable manner. Note that the numbers of the pressing member 509 and the rotation stopping roller portion 202A are not limited to one.
Additionally, by disposing the handle 510 above, in the gravitational direction, the second stirring chamber 220, which is close to a center of gravity 500G of the developing unit 500, the load arising when the user grips the developing unit 500 can be reduced.
Additionally, in this embodiment, the pressing member 509 is provided in the third depressed portion 506, and thus the third depressed portion 506 and the pressing member 509 can be used as uneven shapes for engagement, for the purpose of preventing erroneous mounting of multiple process cartridges having different specifications, such as service life and speed. Specifically, if the third depressed portion 506 of the developing unit 500 is provided in a different location from the pressing member 509, one of the second wall surface 222 and the third wall surface 505 will contact the pressing member 509 when the developing unit 500 is mounted in the photosensitive member unit 260. This ensures that the unit cannot be inserted to the fully-mounted position illustrated in
Note that the configurations described in the foregoing embodiments can be combined as appropriate within a scope that does not produce any conflicts.
The present invention can be summarized as follows.
(1) A process cartridge (5) according to a first aspect of the present invention including:
a photosensitive member unit (6, 260); and
a developing unit (7, 270) that is attachable to and detachable from the photosensitive member unit (6, 260),
wherein the photosensitive member unit (6, 260) includes:
a photosensitive drum (61) on which an electrostatic latent image is formed;
a frame (610) that supports the photosensitive drum (61); and
a pressing member (200) that presses the developing unit (7, 270) toward the photosensitive member unit (6, 260),
the developing unit (7, 270) includes:
a developing roller (71) that supplies toner to the photosensitive drum (61) and collects the toner remaining on a surface of the photosensitive drum (61);
a housing (250) in which a holding space that holds the toner is formed; and
a pressing receiving portion (231A) that receives pressing force from the pressing member (200),
the housing (250) includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space; and
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space, in a state in use, and
when viewed in a direction of a rotation axis of the developing roller (71), at least part of the pressing receiving portion (231A) is located in a space surrounded by the first bottom portion, the second bottom portion, and a tangent line tangent to both an outer wall of the first bottom portion and an outer wall of the second bottom portion.
(2) The process cartridge (5) according to a first aspect of the present invention,
wherein the developing unit (7, 270) preferably further includes:
a first conveyance member for conveying the toner, that rotates in a state of contacting with an inner wall of the first bottom portion; and
a second conveyance member for conveying the toner, that rotates in a state of contacting with an inner wall of the second bottom portion, and
preferably when viewed in the direction of the rotation axis of the developing roller (71), the pressing receiving portion (231A) is located between a rotation center of the first conveyance member and a rotation center of the second conveyance member in a horizontal direction.
(3) The process cartridge (5) according to the first aspect of the present invention,
wherein preferably when viewed in the direction of the rotation axis of the developing roller (71), a first straight line extending along a pressing direction, in which the pressing member (200) presses the pressing receiving portion (231A), passes through the first bottom portion and the second bottom portion.
(4) The process cartridge (5) according to the first aspect of the present invention,
wherein preferably when viewed in the direction of the rotation axis of the developing roller (71), a second straight line passing through a rotation center of the developing roller (71) and the rotation center of the first conveyance member passes through a conveyance chamber that houses the second conveyance member.
(5) The process cartridge (5) according to the first aspect of the present invention,
wherein preferably the photosensitive member unit (6, 260) includes a lift member (642) that presses and moves the developing unit (7, 270), and
preferably the pressing member (200) is disposed at a position on further toward a center side of the frame (610) than the lift member (642) in a rotation axial direction of the photosensitive drum (61).
(6) A process cartridge (5) according to a second aspect of the present invention including:
a photosensitive member unit (6, 261); and
a developing unit (7, 271) that is attachable to and detachable from the photosensitive member unit (6, 261),
wherein the photosensitive member unit (6, 261) includes:
a photosensitive drum (61) on which an electrostatic latent image is formed;
a frame (610) that supports the photosensitive drum (61); and
a pressing member (201) that presses the developing unit (7, 271) toward the photosensitive member unit (6, 261),
the developing unit (7, 271) includes:
a developing roller (71) that supplies toner to the photosensitive drum (61) and collects the toner remaining on a surface of the photosensitive drum (61);
a housing (251) in which a holding space that holds the toner is formed; and
a pressing receiving portion (231A) that receives pressing force from the pressing member (201),
the housing (251) includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space;
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space;
a first top surface (241);
a second top surface (242) provided upward of the first top surface (241) in a gravitational direction, in a state in use; and
a connecting portion that connects the first top surface (241) and the second top surface (242), and
the connecting portion has an opposing surface opposite the first top surface (241).
(7) The process cartridge (5) according to the second aspect of the present invention,
wherein preferably the photosensitive member unit (6, 261) includes a rotation stopping roller portion (202A) that supports the developing unit (7, 271) when the developing unit (7, 271) is attached to the photosensitive member unit (6, 261), and
preferably when viewed in a direction of a rotation axis of the developing roller (71), at least part of the rotation stopping roller portion (202A) is located in a space surrounded by the first bottom portion, the second bottom portion, and a tangent line tangent to both an outer wall of the first bottom portion and an outer wall of the second bottom portion.
(8) The process cartridge (5) according to the second aspect of the present invention,
wherein preferably the developing unit (7, 271) further includes:
a first conveyance member for conveying the toner, that rotates in a state of contacting with an inner wall of the first bottom portion;
a second conveyance member for conveying the toner, that rotates in a state of contacting with an inner wall of the second bottom portion;
a first conveyance chamber that houses the first conveyance member; and
a second conveyance chamber that houses the second conveyance member, and
preferably a width of the second conveyance chamber, in the direction of the rotation axis of the developing roller (71), is greater than a width of the first conveyance chamber.
(9) A process cartridge (5) according to a third aspect of the present invention including:
a photosensitive member unit (6, 362); and
a developing unit (7, 372) that is attachable to and detachable from the photosensitive member unit (6, 362),
wherein the photosensitive member unit (6, 362) includes:
a photosensitive drum (61) on which an electrostatic latent image is formed; and
a frame (610) that supports the photosensitive drum (61),
wherein, the developing unit (7, 372) includes:
a developing roller (71) that supplies toner to the photosensitive drum (61) and collects the toner remaining on a surface of the photosensitive drum (61);
a housing (700) in which a holding space that holds the toner is formed;
a first conveyance member that conveys the toner toward the developing roller (71); and
a second conveyance member that conveys the toner toward the first conveyance member,
wherein, the housing (700) includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space; and
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space, in a state in use,
wherein, the first conveyance member is disposed above the first bottom portion in a state in use,
wherein, the first conveyance member includes:
a rotation shaft; and
a stirring blade (313) that is inclined relative to an axis line of the rotation shaft,
wherein, the second conveyance member is disposed above the second bottom portion in state in use, and
wherein, the second conveyance member includes:
a rotation shaft; and
a stirring sheet that is provided with a slit.
(10) The process cartridge (5) according to the third aspect of the present invention,
wherein preferably the first conveyance member has a plurality of the stirring blades (313), and
preferably when viewed in a direction orthogonal to an axis line direction of the rotation shaft, at least part of the slit is located between two adjacent ones of the stirring blades (313) in the axis line direction.
(11) The process cartridge (5) according to the third aspect of the present invention,
wherein preferably the slit includes:
a first end located on a free end side of the stirring sheet; and
a second end located on an opposite side to the first end, and
preferably the slit is arranged to be inclined relative to the axis line of the rotation shaft so as to be extended from the second end toward the first end from the center of the rotation shaft toward an outer side in the axis line direction.
(12) A process cartridge (5) according to a fourth aspect of the present invention including:
a photosensitive member unit (6); and
a developing unit (7, 470) that is attachable to and detachable from the photosensitive member unit (6),
wherein the photosensitive member unit (6) includes:
a photosensitive drum (61) on which an electrostatic latent image is formed; and
a frame (610) that supports the photosensitive drum (61),
wherein, the developing unit (7, 470) includes:
a developing roller (71) that supplies toner to the photosensitive drum (61) and collects the toner remaining on a surface of the photosensitive drum (61);
a housing (700) in which a holding space that holds the toner is formed;
a first conveyance member that conveys the toner within the holding space toward the developing roller (71);
a second conveyance member that conveys the toner within the holding space toward the first conveyance member; and
a third conveyance member that conveys the toner within the holding space toward the second conveyance member,
wherein, the housing (700) includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space;
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space; and
a third bottom portion that has an arc shape and that projects toward the outer side of the holding space, in a state in use,
wherein, the first conveyance member is disposed above the first bottom portion,
the second conveyance member is disposed above the second bottom portion, and
the third conveyance member is disposed above the third bottom portion, in a state in use.
(13) The process cartridge (5) according to the fourth aspect of the present invention,
wherein preferably the first conveyance member includes:
a first rotation shaft; and
a first stirring blade that is fixed to the first rotation shaft, and
preferably the first stirring blade is disposed so as to be inclined at an angle relative to an axis line of the first rotation shaft to produce a force, by which the toner is conveyed inward from two end sides in an axis line direction of the first rotation shaft, when the first rotation shaft rotates.
(14) The process cartridge (5) according to the fourth aspect of the present invention,
wherein preferably at least one of the second conveyance member and the third conveyance member includes:
a second rotation shaft; and
a second stirring blade that is fixed to the second rotation shaft, and
preferably the second stirring blade is disposed so as to be inclined at an angle relative to an axis line of the second rotation shaft to produce a force, by which the toner is conveyed outward from a center in an axis line direction of the second rotation shaft, when the second rotation shaft rotates.
(15) The process cartridge (5) according to the fourth aspect of the present invention, wherein preferably the first stirring blade has a plate shape.
(16) The process cartridge (5) according to the fourth aspect of the present invention preferably further including:
a first conveyance chamber that houses the first conveyance member;
a second conveyance chamber that houses the second conveyance member; and
a third conveyance chamber that houses the third conveyance member, and
preferably a width of the third conveyance chamber, in a direction of a rotation axis of the second conveyance member, is greater than a width of the second conveyance chamber.
(17) A process cartridge (5) according to a fifth aspect of the present invention including:
a photosensitive member unit (6, 260, 362); and
a developing unit (7, 270, 372, 500) that is attachable to and detachable from the photosensitive member unit (6, 260, 362),
wherein the photosensitive member unit (6, 260, 362) includes:
a photosensitive drum (61) on which an electrostatic latent image is formed; and
a frame (610) that supports the photosensitive drum (61),
wherein, the developing unit (7, 270, 372, 500) includes:
a developing roller (71) that supplies toner to the photosensitive drum (61) and collects the toner remaining on a surface of the photosensitive drum (61);
a housing (700) in which a holding space that holds the toner is formed;
a first conveyance member that is capable of rotating and that conveys the toner within the holding space toward the developing roller (71);
a second conveyance member that is capable of rotating and that conveys the toner within the holding space toward the first conveyance member; and
a third conveyance member that conveys the toner within the holding space toward the second conveyance member,
wherein, the housing (700) includes:
a first bottom portion that has an arc shape and that projects toward an outer side of the holding space;
a second bottom portion that has an arc shape and that projects toward the outer side of the holding space; and
a third bottom portion that has an arc shape and that projects toward the outer side of the holding space, in a state in use,
wherein, the first conveyance member is disposed above the first bottom portion,
the second conveyance member is disposed above the second bottom portion, and
the third conveyance member is disposed above the third bottom portion, in a state in use, and
when viewed in a direction of a rotation axis of the first conveyance member, at least part of the third bottom portion extends from an end part of the photosensitive member unit (6, 260, 362) at one side opposite to the other side where the photosensitive drum (61) is located, so as to be further away from the photosensitive drum (61), in a direction in which a straight line passing through a rotation center of the first conveyance member and a rotation center of the second conveyance member extends.
(18) The process cartridge (5) according to the fifth aspect of the present invention,
wherein preferably the third conveyance member is capable of rotating, and
preferably when viewed in a direction of a rotation axis of the first conveyance member, a rotation center of the third conveyance member is located above a straight line connecting the rotation center of the first conveyance member with the rotation center of the second conveyance member, in a state in use.
(19) The process cartridge (5) according to the fifth aspect of the present invention,
wherein preferably the process cartridge (5) is attachable to and detachable from an apparatus main body of an image forming apparatus, and
preferably the third bottom portion includes an engagement portion that can engage with a main body engagement portion included in the apparatus main body.
(20) The process cartridge (5) according to the fifth aspect of the present invention,
wherein preferably the photosensitive member unit (6, 260) includes a pressing member (509),
preferably the developing unit (7, 500) includes a pressing receiving portion (514) that is pressed by the pressing member (509), and
preferably when viewed in a direction of a rotation axis of the developing roller (71), at least part of the pressing receiving portion (514) is located in a space surrounded by the second bottom portion, the third bottom portion, and a tangent line tangent to both an outer wall of the second bottom portion and an outer wall of the third bottom portion.
(21) The process cartridge (5) according to the fifth aspect of the present invention,
wherein preferably the photosensitive member unit (6, 260) includes a pressing member (509),
preferably the developing unit (7, 500) includes a pressing receiving portion (514) that is pressed by the pressing member (509), and
preferably when viewed in a direction of a rotation axis line of the developing roller (71), at least part of the pressing receiving portion (514) is located in a space surrounded by the first bottom portion, the second bottom portion, and a tangent line tangent to both the first bottom portion and the second bottom portion.
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. 2019-235594, filed on Dec. 26, 2019, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2019-235594 | Dec 2019 | JP | national |