WO2019088467A1

WO2019088467A1 - Toner cartridge

Info

Publication number: WO2019088467A1
Application number: PCT/KR2018/011718
Authority: WO
Inventors: Kenji Tanaka
Original assignee: Hp Printing Korea Co., Ltd.
Priority date: 2017-10-31
Filing date: 2018-10-04
Publication date: 2019-05-09
Also published as: JP2019082583A

Abstract

A toner cartridge includes a toner container, a rotary coupler, and a transport coil having a first coil and a second coil. The toner container has a first end and a second end. The first coil of the transport coil has a spiral large-diameter coil portion having a first end connected to a rotary coupler and a second end extending toward a second end of a toner container. The second coil has a small-diameter coil portion located inside the large-diameter coil portion. The second coil has a first end connected to the rotary coupler and a second end extending toward the second end of the toner container. The second end of the first coil is continuously integrated with the second end of the second coil.

Description

TONER CARTRIDGE

An image forming apparatus is equipped with a toner cartridge. Some toner cartridges include a large coil and a small coil within a toner container. The large coil and the small coil are each formed spirally, but have opposite winding directions. The large coil and the small coil are each fixed to a coupling at an end of the toner container. When the coupling is rotated, the large coil and the small coil are rotated. Accordingly the large coil and the small coil transport the toner in mutually opposite directions. As a result, the toner is circulated and stirred within the toner container.

FIG. 1 is a schematic structural diagram showing the overall structure of an example image forming apparatus.

FIG. 2 is a perspective view showing the overall structure of an example toner cartridge.

FIG. 3 is side view of an example toner container viewed from an end.

FIG. 4 is a top view of the example toner container, with an upper cover being removed.

FIG. 5 is a lateral view of an example transport coil.

FIG. 6 is a perspective view enlarging the vicinity of an example coupling.

FIG. 7 shows a result of a study on the driving torque of a single-coil toner cartridge.

FIG. 8 is a graph comparing the driving torque of a single-coil toner cartridge and with a driving torque in an example toner cartridge.

FIG. 9 is a lateral view of an example transport coil.

FIG. 10 is a lateral view of another example transport coil.

In the following description, with reference to the drawings, the same reference numbers are assigned to the same components or to similar components having the same function, and overlapping description is omitted. .

Overall structure of image forming apparatus

A schematic construction of an example image forming apparatus 1 will be described. As shown in FIG. 1, the image forming apparatus 1 is an apparatus to form color images using magenta, yellow, cyan and block color toner cartridges 60. The image forming apparatus 1 forms an image on a paper sheet (recording medium) P.

The image forming apparatus 1 is provided with a recording medium conveyance unit 10 for conveying a paper sheet P, developer devices 20 for developing an electrostatic latent image, a transfer unit 30 for secondarily transferring the toner image to the paper sheet P, photosensitive drums 40 that are electrostatic latent image carriers, on circumferential surfaces of which the image is formed, and a fixation unit 50 for fixing the toner image onto the paper sheet P.

The recording medium conveyance unit 10 conveys a paper sheet P to be formed with an image along a conveyance path R1. The paper sheet P is stacked and contained in a cassette K, picked up by a paper feed roller and conveyed. The recording medium conveyance unit 10 conveys the paper sheet P in such a timing that the paper sheet P arrives at a secondary transfer region R2 through the conveyance path R1 when a toner image to be transferred to the paper sheet P arrives at the secondary transfer region R2.

Four developer devices 20 are provided for the respective colors. Each of the developer devices 20 is provided with a developer roller 21 for carrying toner to the photosensitive drum 40. In the developer device 20, toner and carrier are adjusted to have a desired mixing ratio. In the developer device 20, the toner is uniformly dispersed to prepare a developer agent imparted with a suitable amount of charge. The developer agent is carried by the developer roller 21. As the developer roller 21 rotates to carry the developer agent to a region facing the photosensitive drum 40, toner is moved out of the developer agent carried on the developer roller 21 and onto an electrostatic latent image formed on a circumferential surface of the photosensitive drum 40 to develop the electrostatic latent image.

The transfer unit 30 carries the toner image formed with the developer device 20 to the secondary transfer region R2 where the toner image is secondarily transferred to the paper sheet P. The transfer unit 30 is provided with a transfer belt 31,

support rollers

31a, 31b, 31c and 31d for supporting the transfer belt 31, primary transfer rollers 32 for holding the transfer belt 31 with the photosensitive drums 40, and a secondary transfer roller 33 for holding the transfer belt with the support roller 31d.

The transfer belt 31 is an endless belt circularly moved by the

support rollers

31a, 31b, 31c and 31d. The primary transfer rollers 32 are disposed to press the photosensitive drums 40 from the inside of the transfer belt 31. The secondary transfer roller 33 is disposed to press the support roller 31d from the outside of the transfer belt 31.

Four photosensitive drums 40 are provided for the respective colors. Each of the photosensitive drums 40 is provided along the direction of movement of the transfer belt 31. Around the circumference of the photosensitive drum 40, the developer device 20, a charge roller 41, an exposure unit 42 and a cleaning unit 43 are arranged.

The charge roller 41 is a charge means for charging, in a uniform manner, the surface of the photosensitive drum 40 at a predetermined potential. The charge roller 41 is moved to follow the rotation of the photosensitive drum 40. The exposure unit 42 exposes the surface of the photosensitive drum 40 charged by the charge roller 41 in accordance with an image to be formed on the paper sheet P. The potential of portions of the surface of the photosensitive drum 40 exposed by the exposure unit 42 is thereby changed to form an electrostatic latent image. The four developer devices 20 each uses the toner supplied from the toner cartridge 60 provided opposite to the developer device 20 to develop the electrostatic latent image formed on the photosensitive drum 40 and creates a toner image. The toner cartridges 60 are respectively filled with magenta, yellow, cyan and black toners. The cleaning unit 43 recovers the toner remaining on the photosensitive drum 40 after the toner image formed on the photosensitive drum 40 has been initially (primarily) transferred onto the transfer belt 31.

The fixation unit 50 adheres and fixates onto the paper sheet P, the toner image that has been secondarily transferred from the transfer belt 31 to the paper sheet P. The fixation unit 50 is provided with a heater roller 51 for heating the paper sheet P and a pressure roller 52 for pressing the heater roller 51. The heater roller 51 and the pressure roller 52 are formed in cylindrical shapes, and the heater roller 51 is internally provided with a heat source such as a halogen lamp. A contact area called a fixation nip is formed between the heater roller 51 and the pressure roller 52, and the toner image is fused and fixated onto the paper sheet P while passing the paper sheet P through the fixation nip. After the toner image has been secondarily transferred onto the paper sheet P, the toner remaining on the transfer belt 31 is recovered by a belt cleaning device.

Further, the image forming apparatus 1 is provided with

discharge rollers

53 and 54 for discharging the paper sheet P with the fixated toner image to the outside of the apparatus.

Printing operation

Next, the printing operation of the image forming apparatus 1 will be described. When an image signal of a recording image is input to the image forming apparatus 1, the image forming apparatus 1 rotates the paper feed roller to pick up and convey a paper sheet P stacked in the cassette K. Then, the surface of the photosensitive drum 40 is uniformly charged at a predetermined potential by the charge roller 41 (charging). After that, an electrostatic latent image is formed by irradiating laser light onto the surface of the photosensitive drum 40 with the exposure unit 42 based on the received image signal (exposing).

In the developer device 20, the electrostatic latent image is developed to form a toner image (developing). Thus, the toner image formed, is initially (primarily) transferred from the photosensitive drum 40 to the transfer belt 31 at a region where the photosensitive drum 40 faces the transfer belt 31 (transferring). The toner images formed on the four photosensitive drums 40 are successively overlaid to form a single overlaid toner image on the transfer belt 31. Then, the overlaid toner image is secondarily transferred onto the paper sheet P conveyed from the recording medium conveyance unit 10 in the secondary transfer region R2 at which the support roller 31d faces the secondary transfer roller 33.

The paper sheet P, with the secondarily transferred overlaid toner image, is conveyed to the fixation unit 50. The overlaid toner image is fused and fixated onto the paper sheet P while the paper sheet P is made to pass under heat and pressure between the heater roller 51 and the pressure roller 52 (fixating). After that, the paper sheet P is discharged to the outside of the image forming apparatus 1 by the

discharge rollers

53 and 54.

Structure of toner cartridge

Toner cartridges having a large coil and a small coil have fixed ends connected to a coupling, and free ends opposite the fixed ends. Because of this, the large coil and the small coil may have offset axes, and this may lower the transportation capacity. On the other hand, the free ends of the large coil and the small coil can be fitted over a periphery of a protruding member for maintaining the axial positions of the large coil and the small coil. In this case, however, the large coil and the small coil may slidably contact the protruding member to generate frictional heat, leading to increase in temperature of the toner. This can form toner aggregates, and deficiencies can be caused to printed images. Further, the provision of such member increases the number of parts of the toner cartridge.

In some examples, a toner cartridge comprises: a toner container to be filled with toner; a rotary coupler provided at one end (a first end) of the toner container and to be driven to rotate; and a transport coil extending in a longitudinal direction of the toner container and connected to the rotary coupler, characterized in that the transport coil includes a first coil having a spiral large-diameter coil portion, one end (a first end) of the first coil being connected to the rotary coupler and the other end (a second end of the first coil) extending toward the other end (a second end) of the toner container; and a second coil having a small-diameter coil portion disposed inside the large-diameter coil portion, one end (a first end) of the second coil being connected to the rotary coupler and the other end (a second end of the second coil) extending toward the other end (the second end) of the toner container, and the first coil and the second coil are continuously integrated at the other ends (i.e. the second end of the second coil extends integrally from the second end of the first coil).

In some examples, the first coil having the large-diameter coil portion and the second coil having the small-diameter coil portion are each connected at a first end to the rotary coupler. Accordingly, when the rotary coupler is driven and rotated, the first coil and the second coil are rotated to stir and transport the toner in the toner container.

The second ends of the first coil and the second coil are joined to each other. The first coil and the second coil are thereby integrated into a single component. In this construction, as compared to a case where the first coil and the second coil are in a free state at the second ends, the transport coil has a higher rigidity at the second end, and offset between axial positions of the first coil and the second coil can be suppressed. Accordingly, the axial positions of the first coil and the second coil can be maintained without requiring a component to restrict the first coil and the second coil.

In some examples, a supply port for supplying the toner to a developer device is provided at the second end of the toner container, the large-diameter coil portion is wound in a first winding direction to transport the toner from the first end of the toner container to the second end, and the small-diameter coil portion is wound in a second winding direction opposite to that of the large-diameter coil portion.

When the large-diameter coil is rotated, the toner at the first end of the toner container is transported toward the supply port at the second end of the toner container. This enables to continuously transport the toner to the supply port.

On the other hand, when the small-diameter coil is rotated, the toner at the second end of the toner container can be transported to the first end of the toner container. The rotation of the small-diameter coil enables to loosen the toner in a compacted state, in particular at the second end (supply port side) of the toner container, thereby compensating for the operation of the rotary coupler and the transport coil.

In more detail, during shipping or the like of a new toner cartridge, when vibrations generated during the shipping are applied to the toner container with the second end of the toner container oriented downward, the toner may be compacted at the second end of the toner container. If the toner cartridge of this state is equipped to an image forming apparatus or the like and the rotary coupler is rotationally driven by a motor or the like, a driving torque of the motor or the like may increase significantly. Such effects may be amplified in a structure which is provided with a first coil having a large-diameter part but not provided with a second coil having a small-diameter part.

When the first coil is rotationally driven with the toner being compacted at the supply port of the toner container, the large-diameter coil tends to act in a direction to further compact the toner at the supply port of the toner container. In this case, the large-diameter coil is compressed due to a counteraction, and the compacted toner cannot be loosened. As a result, the driving torque of the motor or the like increases.

In order to avoid an unintentional increase in driving torque, the toner at the second end of the toner container is transported to the first end of the toner container by the small-diameter coil portion. Because of this, even if the toner is compacted at the second end of the toner container, that toner can be loosened while being transported to the first end of the toner container. Further, the toner transported by the large-diameter coil portion is transported to a low density portion of the toner loosened by the small-diameter coil.

In addition, as the first coil and the second coil are integrated, the transport coil has a higher rigidity at the second end and compacted toner can be loosened more easily. As a result, the driving torque of the motor or the like can be reduced, and the operation of the transport coil of the toner cartridge can be compensated for.

In some examples, the second coil has a straight linear portion between the first end of the second coil and the small-diameter coil.

The structure of the second coil can be simplified by the provision of the linear portion between the first end of the second coil and the small-diameter coil, leading to a lower cost for the second coil. On the other hand, even if the toner is compacted at the second end of the toner container as described above, that toner is unlikely to build up to the vicinity of the linear portion. Therefore, even if the linear portion is provided in this position, the compacted toner can be sufficiently loosened by the small-diameter coil at the second end of the toner container.

In some examples, the first coil has a spiral intermediate coil portion with a smaller winding pitch than that of the large-diameter coil portion, located between the first end of the first coil and the large-diameter coil portion.

As the intermediate coil portion with a smaller winding pitch than that of the large-diameter coil portion is formed closer to the first end of the first coil, the first coil can flex more easily at a portion closer to the rotary coupler. With this structure, when the transport coil is rotated by a motor or the like, the small-diameter coil portion may rotate in advance of the large-diameter coil portion. Accordingly, even if the toner is compacted at the second end of the toner container, that toner can be loosened in priority by the small-diameter coil portion, and increase in the driving torque of the motor or the like can be suppressed.

In some examples, the supply port is provided in a peripheral wall of the toner container, an opposing portion (or facing portion, or bridge portion) of the second coil opposing the supply port (e.g. facing the supply port, or located adjacent the supply port, or aligned with the supply port) is formed in a spiral shape with a diameter smaller than that of the small-diameter coil or in a linear shape, and the small-diameter coil is continuous with the first coil through the opposing portion (e.g. the bridge portion integrally links the small-diameter coil portion with the first coil).

In the opposing portion facing the supply port, the second coil is formed to have a spiral shape with a diameter smaller than that of the small-diameter coil or a linear shape. This can suppress disturbance, which may be caused by the rotation of the second coil, to a flow of toner that tends to carry the toner by the first coil toward the supply port. As a result, in a usual operation of the toner cartridge, the toner can be supplied by the transport coil to the supply port in a stable manner.

In some examples, a toner fill port is provided in a side wall of the toner container at the second end, and the small-diameter coil portion is adapted to surround the entire toner fill port, when the small-diameter coil portion is viewed in the axial direction.

The toner fill port at the second end of the toner container is disposed inside the small-diameter coil portion. Because of this, when a toner filling nozzle is inserted inwardly from the toner fill port during operation to fill the toner container with toner, interference to the small-diameter coil portion by the nozzle can be suppressed.

The rigidity of the transport coil as a whole can be increased, as the second ends of the first coil and the second coil are made continuous with each other. As a result, the axes of the first coil and the second coil can be maintained without providing a component to restrict the positions of the first coil and the second coil. Accordingly, the transporting performance is increased, while reducing the number of components of the toner cartridge.

In addition, a sliding contact (or friction) of the first coil and the second coil with other components (since no restriction component is necessary) or with each other can also be suppressed. Accordingly, increase in temperature of the toner caused by frictional heat of the transport coil can be suppressed, and aggregation of the toner, or the like can also be suppressed.

A detailed structure of the toner cartridge 60 will now be described with reference to FIG. 2 to FIG. 6.

The toner cartridge 60 is attachably and detachably mounted to the image forming apparatus 1. The toner cartridge 60 includes a toner container 61 and a dial 100 as an accessory.

Toner container

The toner container 61 is a sealed container of a substantially cylindrical shape. The interior of the toner container 61 is filled with toner. The toner container 61 has a container body 62 with an open top, and an upper cover 63 to close the top of the container body 62. The container 62 and the upper cover 63 are fixed together. The container body 62 includes a bottom wall 64 formed at the bottom, a first side wall 65 formed at one longitudinal end (first longitudinal end), and a second side wall 66 formed at the other longitudinal end (second longitudinal end).

The bottom wall 64 is formed to have a substantially arcuate cross section, and extends in the depth direction of the image forming apparatus 1. A circular supply port 67 (discharge port) is formed in the vicinity of the second longitudinal end of the bottom wall 64 (vicinal to the second side wall 66). The supply port 67 is an opening for supplying the toner from within the toner container 61 to the developer device 20 of the image forming apparatus 1.

The first side wall 65 is formed at a rear end of the container body 62 (far side of the example image forming apparatus 1). As shown in FIG. 2 and FIG. 4, a coupling 70, which is an example rotary coupler, is rotatably mounted at the center of the first side wall 65.

The second side wall 66 is formed at a front end of the container body 62 (near side of the example image forming apparatus 1). As shown in FIG. 3 and FIG. 4, a circular toner fill port 68 is formed at the center of the second side wall 66. The toner fill port 68 is an opening for filling the toner container 61 with toner during manufacture or the like of the toner cartridge 60. A cap 68a is attached to the toner fill port 68 for closing the toner fill port 68.

Coupling

In the example shown in FIG. 6 and others, the coupling 70 is formed in a substantially columnar shape. The coupling 70 has a base 71 positioned externally of the container body 62, and a support 72 extending from the base 71 inwardly of the container body 62. An engaging groove 73 is formed in the base 71 of the coupling 70. The engaging groove 73 is formed to have a toothed inner circumferential surface. A tip end (with toothed external circumferential surface) of the accessory dial 100 can fit into the engaging groove 73. Prior to loading a new toner cartridge 60 into the image forming apparatus 1, the user performs operations to rotate the dial 100 and then remove the dial 100. The toner in the toner cartridge 61 is thereby stirred/transported (detailed later).

The support 72 of the coupling 70 is formed with a bore 74 radially extending through a base portion of the support 72, and an elongated groove 75 formed in a top end of the support 72. The support 72 is formed with a lateral hole (not shown) extending from a tip end of the elongated groove 75 toward the base 71. One end of a first coil 81 penetrates through and is supported by the bore 74. One of a second coil 91 fits into and is supported by the elongated groove 75 and the lateral hole.

When the toner cartridge 60 is loaded into the image forming apparatus 1, a driving mechanism (not shown) of the image forming apparatus 1 is coupled to the coupling 70. The driving mechanism includes a motor and a driving shaft rotationally driven by the motor. When the toner cartridge is loaded into the image forming apparatus 1, a tip end of the driving shaft (with a toothed outer circumferential surface) engages the engaging groove 73. Because of this, when the toner cartridge 60 is loaded, the toner in the toner container 61 can be stirred/transported by the driving mechanism.

Transport coil

In the example shown in FIG. 4 and FIG. 5, the toner cartridge 60 is provided with one transport coil 80 connected to the coupling 70. The transport coil 80 extends along the longitudinal direction of the container body 62 and is housed within the container body 62. The transport coil 80 is rotationally driven as the coupling 70 is rotated, and stirs and transports the toner in the toner container 61.

The transport coil 80 includes a first coil 81 and a second coil 91. The first end of the first coil 81 and first end of the second coil 91 are connected to the support 72 of the coupling 70. The second end of the first coil 81 and the second end of the second coil 91 are mutually continuously integrated (e.g. the second end of the first coil 81 is integrally connected with the second end of the second coil 91).

First coil

The first coil 81 is configured with a first connector 82, a large-diameter coil portion 83 and a coil connector 84, which are successively continuous from a first end to the second end.

The first connector 82 is positioned at a first end of the first coil 81 and linearly extends in the radial direction of the toner container 61. The first connector 82 is fixed in the coupling 70 by fitting into the bore 74 of the support 72 of the coupling 70.

The large-diameter coil portion 83 extends from the vicinity of the first side wall 65 to the vicinity of the second side wall 66 of the toner container 61, in the longitudinal direction (axial direction) of the toner container 61. The large-diameter coil portion 83 is formed in a spiral shape, with the center coinciding with the axis of the coupling 70. The second end of the large-diameter coil portion 83 faces (or aligns with) the supply port 67.

As the large-diameter coil portion 83 rotates, the toner in the toner container 61 is stirred and transported. The winding direction of the large-diameter coil portion 83 is determined in accordance with the direction of rotation of the coupling 70. The winding direction of the large-diameter coil portion 83 may be set such that, when the coupling 70 rotates, the toner is transported from a first end toward a second end (from the side of the coupling 70 to the side of the supply port 67) of the toner container 61.

The coil connector 84 is formed at the second end of the first coil 81. The coil connector 84 extends in the radial direction of the toner container 61 for connecting the large-diameter coil portion 83 and a small-diameter coil portion 93.

Second coil

The second coil 91 is configured with a second connector 92, the small-diameter coil portion 93 and a linear portion 94, which are successively continuous from a first end to a second end.

The second connector 92 is formed at the first end of the second coil 91. The second connector 92 is formed to have an L-shape (hook-shape) for fitting into the elongated groove 75 and the lateral hole (not shown) of the coupling 70. The second connector 92 is fixed in the coupling 70 by fitting into the elongated groove 75 and the lateral hole.

The small-diameter coil portion 93 extends from the vicinity of the first side wall 65 to the vicinity of the second side wall 66 of the toner container 61, in the longitudinal direction (axial direction) of the toner container 61. The small-diameter coil portion 93 is formed in a spiral shape, with the center coinciding with the axes of the coupling 70 and the large-diameter coil portion 83. The second end of the small-diameter coil portion 93 is positioned closer to the coupling 70 than the supply port 67, such that the small-diameter coil portion 93 does not face (or extend to align with) the supply port 67.

As the small-diameter coil portion 93 rotates, the toner in the toner container 61 is stirred and transported. The winding direction of the small-diameter coil portion 93 is opposite to the winding direction of the large-diameter coil portion 83, and is determined in accordance with the direction of rotation of the coupling 70. The winding direction of the small-diameter coil portion 93 may be set such that, as the coupling 70 rotates, the toner is transported from the second end toward the first end (from the side of the supply port 67 to the side of the coupling 70) of the toner container 61.

The linear portion 94 is positioned at the second end of the first coil 81 (in the vicinity of the second side wall 66) and faces (or aligns with) the supply port 67. Namely, the linear portion 94 forms a bridge portion (or a facing portion, or an opposing portion) facing (or aligned with) the supply port 67. The linear portion 94 extends linearly along the axial direction of the large-diameter coil portion 83. Because of this, the linear portion 94 contributes relatively little to the transportation of the toner.

Relation of sizes

In the example shown in FIG. 5, a coil diameter D1 of the large-diameter coil portion 83 is larger than a coil diameter D2 of the small-diameter coil portion 93. A number of turns n1 of the large-diameter coil portion 83 is smaller than a number of turns n2 of the small-diameter coil portion 93. In some examples, a winding pitch P2 of the small-diameter coil portion 93 is smaller than a winding pitch P1 of the large-diameter coil portion 83. A pitch angle α2 of the small-diameter coil portion 93 may be approximately equal to a pitch angle α1 of the large-diameter coil portion 83.

In the example shown in FIG. 3, the inner diameter of the large-diameter coil portion 83 and the inner diameter of the small-diameter coil portion 93 are larger than the opening diameter of the toner fill port 68. The large-diameter coil portion 83 and the small-diameter coil portion 93 are disposed to surround the toner fill port 68 entirely, when viewed in the axial direction of the toner container 61. For example, when viewed in the axial direction of the toner container 61, the toner fill port 68 appears inside the large-diameter coil portion 83 and the small-diameter coil portion 93.

Operation of toner cartridge

The basic operation of the toner cartridge 60 will now be described for a case where the toner cartridge 60 is loaded into the example image forming apparatus 1.

When the toner cartridge 60 is loaded into the example image forming apparatus 1, the driving shaft engages the engaging groove 73 of the coupling 70. As the driving shaft is rotationally driven by the motor, the coupling 70 is rotated and, in turn, the transport coil 80 is rotated.

As the transport coil 80 is rotated, the first coil 81 and the second coil 91 are integrally rotated. As the large-diameter coil portion 83 of the first coil 81 is rotated, the toner in a radially outer region of the toner container 61 is transported in the direction indicated by solid arrows in FIG. 4. The toner on the side of the coupling 70 is thereby moved toward the side of the supply port 67. The toner flown into the the supply port 67 is supplied to the developer device 20 external to the toner container 61.

As the small-diameter coil portion 93 of the second coil 91 is rotated, the toner in an axial region of the toner container 61 is transported in the direction indicated by dotted arrows in FIG. 4. The toner on the side of the supply port 67 is thereby moved toward the coupling 70. In this manner, the toner in the toner container 61 alternately circulates along the radially outer region and the axial region of the toner container 61.

In the transport coil 80, the second end of the first coil 81 and the second end of the second coil 91 are mutually connected to integrate (e.g. integrally connect) the first coil 81 and the second coil 91. This enables to suppress offset in position between the axes of the first coil 81 and the second coil 91, as compared with a structure where the second ends of the first coil 81 and the second coil 91 are separated from each other. Accordingly, the toner can be transported in a stable manner, without having to provide a component for restricting the axial positions of the first coil 81 and the second coil 91.

A part of the large-diameter coil portion 83 in the vicinity of the second end is in a position facing the supply port 67 (e.g. a portion of the large-diameter coil portion 83 faces or is aligned with the supply port 67). Therefore, the toner in the vicinity of the supply port 67 can be reliably transported to the supply port 67. In the second coil 91, the small-diameter coil portion 93 is not facing (or aligned with) the supply port 67 but the linear portion 94 faces (or is aligned with) the supply port 67. Therefore, in the vicinity of the supply port 67, disturbance caused by the rotation of the small-diameter coil portion 93 to a flow of toner generated by the large-diameter coil portion 83 can be suppressed.

Operation to stir toner

During shipping of the toner cartridge 60, the toner in the toner container 61 may be compacted due to vibrations or the like. If the toner cartridge 60 is loaded into the image forming apparatus 1 and the transport coil 80 is rotationally driven by the motor, with the toner in the compacted state, the driving torque of the motor increases excessively and this may be a cause of malfunction.

Accordingly, prior to loading a new toner cartridge 60 into the image forming apparatus 1, the coupling 70 may be manually rotated by way of a dial 100 attached thereto as a packaging material as shown in FIG. 2. The dial 100 is configured not to be removed from the toner container 61 unless being rotated by one turn. The transport coil 80 is thereby rotated, and the toner compacted in the toner container 61 can be loosened.

When the toner is compacted in the vicinity of the supply port 67 of the toner container 61, the toner can be moved from the vicinity of the supply port 67 toward the coupling 70 as the small-diameter coil portion 93 is rotated (detailed later). This enables to loosen the toner compacted in the vicinity of the supply port 67 in a reliable manner. Accordingly, after loading the toner cartridge 60, the driving torque of the motor can be decreased and the reliability of the toner cartridge 60 can be improved.

It should be noted that the effect of loosening the compacted toner by the transport coil 80 may also be obtained in an initial operation after loading the toner cartridge 60 into the image forming apparatus 1.

Result of study

With reference to FIG. 7 and FIG. 8, results of a study on the effect of reducing a driving torque with the toner cartridge are described in detail.

FIG. 7 shows a result of measuring a driving torque of a single-coil toner cartridge that includes only one coil . During the test, vibrations were imparted to the single-coil toner cartridge under three different conditions A to C. Under the condition A, vibrations were imparted to the single-coil toner cartridge in a horizontally oriented state. Under the condition B, vibrations were imparted with the side of the supply port of the toner container of the single-coil cartridge, oriented upward. Under the condition C, vibrations were imparted with the side of the supply port of the toner container of the single-coil cartridge, oriented downward. After imparting vibrations under the conditions A to C, a dial of the single-coil toner cartridge was rotated by one turn and then the driving torque was measured.

The result shows that the driving torque of the condition C was significantly large, as compared with the conditions A and B. This is speculated to have been due to the following reasons. When vibrations are imparted to the toner container of the single-coil cartridge, with the side of the supply port oriented downward, the toner is compacted in the vicinity of the supply port of the toner container of the single-coil cartridge. Furthermore, when the dial is rotated by one turn, the toner is urged to the vicinity of the supply port as the coil is rotated. Accordingly, the toner is urged into a portion compacted by the vibrations; the toner cannot be loosened and may be further compacted. As such, with the transport coil of the single-coil cartridge, the toner solidified on the side of the supply port cannot be loosened sufficiently and it can be speculated this has led to the increase in the driving torque.

FIG. 8 compares driving torques of the single-coil cartridge and the toner cartridge 60, measured after imparting vibrations under the condition C and rotating the dial 100 by one turn. While the driving torque was around 10 kgf·cm for the single-coil cartridge, the driving torque was reduced to about 8 kgf·cm. This result corroborates that the toner cartridge 60 is effective in loosening the toner compacted in the vicinity of the supply port 67.

It is speculated that the driving torque was reduced for the following reasons.

As the small-diameter coil portion 93 of the second coil 91 rotates, the toner in the vicinity of the supply port 67 is moved away from the toner supply port 67. The small-diameter coil portion 93 transports the compacted toner to a direction where the toner density is lower, and the toner in the vicinity of the supply port 67 can be loosened thereby.

The toner urged by the large-diameter coil portion 83 toward the side of the supply port 67 may be moved to the low density toner part loosened by the small-diameter coil portion 93. This enables to suppress further compaction of the toner on the side of the supply port 67 by the rotation of the large-diameter coil portion 83.

The second end of the first coil 81 and the second end of the second coil 91 are mutually connected and integrated. Accordingly, a higher rigidity at the second end of the transport coil 80 is achieved, as compared with the afore-mentioned single-coil cartridge in which the coil is free toward the toner supply port. Therefore, as the transport coil 80 is rotated, the toner compacted on the side of the supply port 67 can be loosened more reliably.

As the second end of the first coil 81 extends integrally from the second end of the second coil 91 (i.e. mutually continuous), the axial positions of the first coil 81 and the second coil 91 are less likely to become offset from each other without requiring a restriction component or the like. Accordingly, the axial positions of the large-diameter coil portion 83 and the small-diameter coil portion 93 can be maintained, while simplifying the toner cartridge 60. Further, as frictional heat due to the provision of a restriction component or the like is not generated, temperature increase in the toner can be suppressed and, in turn, coagulation of the toner can be suppressed.

The small-diameter coil portion 93 of the second coil 91 transports toner from the side of the supply port 67 toward the side of the coupling 70. Therefore, the toner compacted on the side of the supply port 67 can be reliably loosened and the driving torque of the motor can be reduced. As a result, the reliability of the toner cartridge 60 can be improved.

The linear portion 94 is provided in a part of the second coil 91 facing (or aligned with) the supply port 67. This can suppress disturbance by an opposite toner flow caused by the rotation of the small-diameter coil portion 93, to a flow of toner caused by the rotation of the large-diameter coil portion 83 toward the side of the supply port 67.

In the example shown in FIG. 3, the large-diameter coil portion 83 and the small-diameter coil portion 93 are disposed to surround the toner fill port 68 entirely, when viewed in the axial direction of the toner container 61. This enables to insert a toner filling nozzle easily into the toner container 61 during the production or the like of the toner cartridge 60. For example, at the time of performing an operation to fill the toner container 61 with toner, the toner filling nozzle may be inserted into the toner container 61 through the toner fill port 68 and the toner may be injected in this state. In this case, the nozzle can be inserted inside the large-diameter coil portion 83 and the small-diameter coil portion 93. Accordingly, the toner filling operation can be performed without the large-diameter coil portion 83 and the small-diameter coil portion 93 interfering the nozzle.

Additional examples

The transport coil 80 may have the following constructions. In an example of the transport coil 80 is shown in FIG. 9, the second coil 91 has a straight second linear portion 95. For example, the second coil 91 has the second connector 92, the second linear portion 95, the small-diameter coil portion 93 and the linear portion 94 (first linear portion), successively from a first end to a second end. A first end of the second linear portion 95 is continuous with the second connector 92, and the second end of the second linear portion 95 is continuous with a first end of the small-diameter coil portion 93. The second linear portion 95 extends linearly in the longitudinal direction, along the axis of the toner container 61. The first end of the second linear portion 95 is positioned in the vicinity of the first side wall 65, and the second end of the small-diameter coil portion 93 is positioned in the vicinity of the second side wall 66 of the toner container 61.

L represents the whole length of the toner container 61, L1 represents the distance from the second side wall 66 of the toner container 61 to the first end of the small-diameter coil portion 93, and L2 represents the distance from the first side wall 65 of the toner container 61 to the second end of the second linear portion 95. In this case, L1 may be within a range of from 1/2L to 2/3L. Accordingly, L2 may be within a range of from 1/3L to 1/2L.

The toner on the side of the supply port 67 of the toner container 61 may tend to be compacted in a range of 1/2L to 2/3L from the second side wall 66. As such, even if the small-diameter coil portion 93 is formed only in this range, the toner compacted on the side of the supply port 67 can be loosened sufficiently. On the other hand, even if the rest of the second coil 91 is formed as the straight second linear portion 95, it may not have a substantial impact on the efficiency of loosening the toner. Thus formed second linear portion 95 enables to simplify the structure of the second coil 91 and to lower the cost.

In another example of the transport coil 80 shown in FIG. 10, the first coil 81 has an intermediate coil portion 85 of a spiral shape. The first coil 81 has the first connector 82, the intermediate coil portion 85, the large-diameter coil portion 83 and the coil connector 84, successively from a first end to the second end. A first end of the intermediate coil portion 85 is continuous with the first connector 82, and the second end of the intermediate coil portion 85 is continuous with a first end of the large-diameter coil portion 83. The intermediate coil portion 85 is formed in a spiral shape, with a center coinciding with the axis of the toner container 61. The first end of the intermediate coil portion 85 is positioned in the vicinity of the first side wall 65, and the second end of the large-diameter coil portion 83 is positioned in the vicinity of the second side wall 66 of the toner container 61.

The winding pitch P3 of the intermediate coil portion 85 may be smaller than the winding pitch P1 of the large-diameter coil portion 83. Further, the winding pitch P3 of the intermediate coil portion 85 may be larger than the winding pitch P2 of the small-diameter coil portion 93.

In this example, L represents the whole length of the toner container 61, L3 represents the distance from the second side wall 66 of the toner container 61 to the first end of the large-diameter coil portion 83, and L4 represents the distance from the first side wall 65 of the toner container 61 to the second end of the intermediate coil portion 85. In this case, L3 may be in a range of from 1/2L to 2/3L. Accordingly , L4 may be in a range of from 1/3L to 1/2L.

If the intermediate coil portion 85 is formed only in this range, the first coil 81 can flex easily at a portion closer to the coupling 70. With this structure, the toner compacted on the side of the supply port 67 can be loosened more efficiently.

When the dial 100 is rotated in this structure, because of the flexure of the intermediate coil portion 85, the small-diameter coil portion 93 rotates in advance of the large-diameter coil portion 83. As a result, the toner on the side of the supply port 67 can be quickly loosened and moved toward the side of the coupling 70. Then, the toner transported by the large-diameter coil portion 83 may be moved to a low density part where the toner is loosened by the small-diameter coil portion 93.

As described above, the toner on the side of the supply port 67 of the toner container 61 tends to be compacted in a range of 1/2L to 2/3L from the second side wall 66. As such, if the length L4 of the intermediate coil portion 85 is made to have a length of 1/3L to 1/2L, the region of the intermediate coil portion 85 may be exposed from the compacted toner. The intermediate coil portion 85 can thereby be flexed more reliably to facilitate the rotation of the small-diameter coil portion 93. As a result, the toner can be loosened more efficiently with the small-diameter coil portion 93.

Example

In the second coil 91, the opposing portion (or facing portion) to face the supply port 67 is the straight linear portion 94. However, this opposing portion may have a spiral shape with a spiral diameter smaller than the small-diameter coil portion 93. This structure can also suppress disturbance by an opposite toner flow caused by the rotation of the small-diameter coil portion 93, to a flow of toner caused by the rotation of the large-diameter coil portion 83 toward the side of the supply port 67.

Although the winding pitch P2 of the small-diameter coil portion 93 is smaller than the winding pitch P1 of the large-diameter coil portion 83 according to the examples, the winding pitch P2 may be made to be equal to or larger than the winding pitch P1.

It is to be understood that not all aspects, advantages and features described herein may necessarily be achieved by, or included in, any one particular example. Indeed, having described and illustrated various examples herein, it should be apparent that other examples may be modified in arrangement and detail.

List of Reference Numbers

60 toner cartridge; 61 toner container; 67 supply port; 68 toner fill port; 70 coupling (rotary coupler); 80 transfer coil; 81 first coil; 83 large-diameter coil portion;93 small-diameter coil portion; 94 linear portion (opposing portion, or facing portion, or bridge portion.

Claims

A toner cartridge comprising:

a toner container to be filled with toner, the toner container having a first end and a second end opposite the first end;

a rotary coupler located at the first end of the toner container, the rotary coupler to be driven to rotate; and

a transport coil extending in a longitudinal direction of the toner container and connected to the rotary coupler, the transport coil comprising:

a first coil having a spiral large-diameter coil portion, the first coil having a first end connected to the rotary coupler and a second end extending toward the second end of the toner container; and

a second coil having a small-diameter coil portion located inside the large-diameter coil portion, the second coil having a first end connected to the rotary coupler and a second end extending toward the second end of the toner container,

wherein the second end of the first coil is continuously integrated with the second end of the second coil.
The toner cartridge according to claim 1, further comprising a supply port located at the second end of the toner container, to supply the toner to a developer device,

the large-diameter coil portion to transport the toner from the first end of the toner container toward the second end,

wherein the small-diameter coil portion is wound in a winding direction opposite to a winding direction of the large-diameter coil portion.
The toner cartridge according to claim 2, wherein the second coil has a straight linear portion between the first end of the second coil and the small-diameter coil portion.
The toner cartridge according to claim 2, wherein the first coil has a spiral intermediate coil portion having a winding pitch smaller than a winding pitch of the large-diameter coil portion, and the spiral intermediate coil portion is located between the first end of the first coil and the large-diameter coil portion.
The toner cartridge according to claim 2, wherein the supply port is located in a peripheral wall of the toner container,

a facing portion of the second coil facing the supply port has a spiral shape, the facing portion having a diameter smaller than a diameter of the small-diameter coil portion or the facing portion having a linear shape, and

the small-diameter coil portion is integrally connected with the first coil through the facing portion.
The toner cartridge according to claim 1, wherein a toner fill port is located in a side wall of the toner container at the second end, and the small-diameter coil portion extends along an axial direction, the small-diameter coil portion to entirely surround the toner fill port, when the small-diameter coil portion is viewed in the axial direction.
A toner cartridge comprising:

a toner container having a first end and a second end opposite the first end;

a rotary coupler located at the first end of the toner container; and

a transport coil extending in a longitudinal direction of the toner container and connected to the rotary coupler, the transport coil comprising:

a first coil having a large-diameter coil portion, the first coil having a first end connected to the rotary coupler and a second end extending toward the second end of the toner container; and

a second coil having a small-diameter coil portion located inside the large-diameter coil portion, the second coil having a first end connected to the rotary coupler and a second end extending toward the second end of the toner container,

wherein the second end of the second coil extends integrally from the second end of the first coil.
The toner cartridge according to claim 7, further comprising a supply port located at the second end of the toner container, wherein

the small-diameter coil portion is wound in a first direction to transport toner from the second end of the toner container toward the first end of the toner container, and

the large-diameter coil portion is wound in a second direction opposite to the first direction of the small-diameter coil portion, to transport the toner from the first end toward the second end of the toner container.
The toner cartridge according to claim 7, wherein the second coil has a linear portion extending between the first end of the second coil and the small-diameter coil portion of the second coil.
The toner cartridge according to claim 7, wherein the first coil has an intermediate coil portion located between the first end of the first coil and the large-diameter coil portion of the first coil, and the intermediate coil portion has a winding pitch smaller than a winding pitch of the large-diameter coil portion.
The toner cartridge according to claim 8, wherein

the supply port is located in a peripheral wall of the toner container,

the second coil comprises a bridge portion located adjacent the supply port, and

the bridge portion integrally links the small-diameter coil portion with the first coil.
The toner cartridge according to claim 11, wherein the bridge portion has a spiral shape having a diameter smaller than a diameter of the small-diameter coil portion.
The toner cartridge according to claim 11, wherein the bridge portion has a linear shape.
The toner cartridge according to claim 11, further comprising a toner fill port located at the second end of the toner container, wherein

the small-diameter coil portion has an axis extending along an axial direction, the small-diameter coil portion to entirely surround the toner fill port, when the small-diameter coil portion is viewed in the axial direction.