The present invention relates to an image forming apparatus that forms an image on a recording material by using an electrophotographic system.
Conventionally, an electrophotographic image forming apparatus has a configuration in which a developer replenishing container that stores toner is detachably provided in the image forming apparatus in order to replenish toner (developer) consumed in image formation. Japanese Patent Application Publication No. 2014-066967 describes a technique of sealing the toner supply opening of a cartridge with a sealing member and peeling off the sealing member when the cartridge is used. Furthermore, Japanese Patent Application Publication No. 2022-139159 proposes a configuration that uses a pump as a unit for discharging toner from a toner cartridge in order to replenish the cartridge with toner.
During an initial operation that drives respective parts of a cartridge before an image forming operation, an action of peeling off the sealing member is additionally performed when the cartridge is new. This may significantly increase the load on the motor depending on the combination of operation timings of respective members and the toner storage condition. The increase in the motor load may lead to damage to the components forming the drive portion and the motor itself.
An object of the present invention is to provide a technique capable of reducing the operational load in a toner cartridge that is used by peeling off a sealing member that seals a toner discharge port.
In order to solve the above problems, an image forming apparatus according to the present invention includes:
In order to solve the above problems, an image forming apparatus according to the present invention includes:
According to the present invention, it is possible to reduce the operational load in a toner cartridge that is used by peeling off a sealing member that seals a toner discharge port.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Referring to the drawings, exemplary modes for carrying out the present invention will be described in detail using embodiments. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments may be modified as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions. That is, the description is not intended to limit the scope of the present invention to the following embodiments.
Referring to
As shown in
In addition to the photosensitive drum 11, the cleaning unit 10 includes a cleaning blade 17 as a cleaning member for the photosensitive drum 11, a charging roller 12 as a charging member, and a charging roller cleaner 14 as a cleaning member for the charging roller 12. Furthermore, the cleaning unit 10 includes a primary waste toner storage portion 10a and a second waste toner conveyance passage 10b.
The charging roller 12 is disposed in contact with the outer circumference surface of the photosensitive drum 11 and charges the photosensitive drum 11 by application of a voltage from a high-voltage power supply (high-voltage power supply 204 in
The cleaning blade 17 is an elastic member that is disposed in contact with the outer circumference surface of the photosensitive drum 11. The distal end of the cleaning blade 17 is elastically in contact with the photosensitive drum 11. Thus, the toner remaining on the photosensitive drum 11 after a sheet S, which is a recording material described below, passes between the photosensitive drum 11 and a transfer roller 104 (
As shown in
The developing roller 16 bears toner as a developer bearing member and also supplies toner to the developing zone of the photosensitive drum 11. The developing roller 16 then develops an electrostatic latent image formed on the photosensitive drum 11 using the toner.
A developing blade 18 is in contact with the circumference surface of the developing roller 16 and regulates the amount of toner adhering to the circumference surface of the developing roller 16 as a regulating member. The developing blade 18 also applies a frictional charge to the toner borne on the developing roller 16.
The toner stored in the developer storage chamber 152 is sent to the developing chamber 151 by the rotation of a stirring member 154, and is supplied to the developing roller 16.
The laser printer 1 of this embodiment includes a unit for detecting the amount of toner remaining in the developer storage chamber 152 (a remaining amount sensor 208 in
The process cartridge B and the toner cartridge C are attachable to and detachable from the printer main body A, as will be described in detail below.
Referring to
The photosensitive drum 11 is driven and rotated by a driving force provided by a motor 215 (
Meanwhile, in parallel with the toner image forming operation, a sheet S is conveyed along the sheet feeding portion 103. Specifically, a feeding roller 103b rotates and starts feeding the sheet S. Then, the sheet S is conveyed to a nip portion between the photosensitive drum 11 and the transfer roller 104 in time with the formation of a toner image on the photosensitive drum 11. When the sheet S passes through the nip portion, the toner image is transferred from the photosensitive drum 11 to the sheet S as an unfixed image by applying a bias to the transfer roller 104 with a high-voltage power supply 204 (
The sheet S to which the toner image has been transferred is then conveyed to the fixing portion 105. When the sheet S conveyed to the fixing portion 105 passes through the fixing portion 105, the unfixed image is heated and pressed to be fixed to the surface of the sheet S. The sheet S on which the image has been fixed is further conveyed by the sheet feeding portion 103 and discharged to and stacked on a discharge tray 106.
Referring to
As described above, the cleaning unit 10 includes the photosensitive drum 11, the charging roller 12, and the cleaning blade 17. Similarly, the developing unit 15 includes the developing roller 16, the developing blade 18, the developing chamber 151, the developer storage chamber 152, and the receiving chamber 153.
As shown in
As shown in
As shown in
Also, as shown in
As described above, the developing unit 15 is supported rotatably about the swing axis 8 relative to the cleaning unit 10. The developing unit 15 is urged toward the photosensitive drum 11 of the cleaning unit 10 by pressure springs 19a and 19b, which are elastic members, so that the developing roller 16 is in contact with the photosensitive drum 11.
Referring to
As shown in
As shown in
When the spacing mechanism 100 returns from the position in
Referring to
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As shown in
The toner storage portion 30a includes a toner storage portion screw member (hereinafter, screw member) 35 and a toner storage portion stirring and conveying member (hereinafter, stirring member) 36.
The screw member 35 is a conveying member for conveying toner in the longitudinal direction of the toner storage portion 30a toward the toner discharge port 31a. The screw member 35 includes a rotation shaft and a blade portion, which extends helically on the outer circumference surface of the rotation shaft. The blade portion of the screw member 35 is configured such that the rotation of the screw member 35 can cause the toner around the blade portion to form a toner flow that moves in the longitudinal direction of the toner storage portion 30a.
The stirring member 36 is a conveying member for conveying toner toward the screw member 35. The stirring member 36 includes a rotation shaft 36a and a stirring portion 36b, which is a flexible sheet-shaped member. The rotation shaft 36a is configured to be rotatable about a rotation axis extending in the longitudinal direction (Y direction) of the toner storage portion 30a. One end side of the stirring portion 36b is attached to the surface of the rotation shaft 36a along the rotation axis, and extends over substantially the entire area in the longitudinal direction of the toner storage portion 30a. The other end side (free end side) of the stirring member 36 opposite to the one end side (fixed end side) is in contact with the inner wall surfaces of the supply portion frame 31 and the supply portion lid 32, which form the toner storage portion 30a. As the rotation shaft 36a rotates, the stirring portion 36b moves around the rotation axis of the rotation shaft 36a while its end portion side (free end side), which is away from the fixed portion fixed to the rotation shaft 36a, slides in contact with the inner wall surfaces of the supply portion frame 31 and the supply portion lid 32, which form the toner storage portion 30a. As a result, the toner in the toner storage portion 30a is pushed toward the region of the toner storage portion 30a in which the screw member 35 is disposed. The toner conveyed to the toner discharge port 31a by the stirring and conveying action of the screw member 35 and the stirring member 36 is discharged from the toner discharge port 31a by the volumetric fluctuation of a pump 37a. The pump 37a is provided integrally with the toner storage portion 30a so as to form a toner storage space (more specifically, a discharge chamber 81) in the toner cartridge C together with the toner storage portion 30a.
Specifically, as shown in
The interior of the toner storage portion 30a is partitioned into a storage chamber 30b, in which the stirring member 36 is disposed, and a discharge chamber 81, which includes the toner discharge port 31a, in a manner that enables communication between them. The partition separating the storage chamber 30b and the discharge chamber 81 includes a partition 313 shown in
The screw member 35 is configured to be capable of forming a toner flow in which the toner moves from the storage chamber 30b to the discharge chamber 81 by rotating in the forward rotation direction during the image forming operation. The toner in the storage chamber 30b is conveyed toward the screw member 35 by the rotation of the stirring member 36, and is conveyed from the storage chamber 30b toward the discharge chamber 81 by the rotation of the screw member 35. At the same time, the volume of the discharge chamber 81 changes due to the expansion and contraction of the pump 37a, thereby discharging the toner inside the discharge chamber 81 from the toner discharge port 31a. The toner discharged from the toner discharge port 31a is supplied to the receiving chamber 153 of the process cartridge B. Waste Toner Storage Unit
As shown in
The waste toner storage container 41 is formed by a waste toner storage portion frame 41a, which includes the waste toner storage portion 40, and a waste toner storage lid 41b. The waste toner storage lid 41b has the waste toner receiving port 42 for receiving the waste toner collected from the process cartridge. The waste toner storage lid 41b includes a waste toner shutter member 43, which opens and closes the waste toner receiving port 42. The waste toner shutter member 43 opens and closes in the directions of arrow R3 in
As shown in
As shown in
With the above-described configuration, the stirring driving input gear 38 can be driven even when a pump/screw driving input gear 39 is not driven. In other words, even when the toner supply portion 30 is not replenishing toner to the process cartridge B, the first and second waste toner storage screws 44 and 45 in the waste toner storage portion 40 can be driven to maintain a state in which waste toner can be collected.
Furthermore, since the driving force from the printer main body A can be input to one end of the toner cartridge C, the gear train of the printer main body A can be simplified. Moreover, by using the stirring member 36 to transmit drive from one end of the supply portion frame 32a to the other end, the drive can be transmitted to the waste toner storage portion 40 without increasing the number of parts for drive transmission. This allows waste toner to be stored in the toner cartridge C while limiting an increase in size of the toner cartridge C and the printer main body A in the direction of the rotation axis of the photosensitive drum 11 due to the drive unit of the toner cartridge C.
Referring to
As shown in
A stirring gear 38b for transmitting a rotational driving force to the stirring member 36 is provided next to the stirring driving input gear 38 and coaxially with the stirring member 36. The stirring gear 38b receives a driving force from the stirring driving input gear 38 and rotates the stirring member 36 in the R1 direction in
A cam drive gear 39a, which rotates by receiving a driving force from the pump/screw driving input gear 39, is provided next to the pump/screw driving input gear 39. A cam gear 39b, which rotates by receiving a driving force from the cam drive gear 39a, is provided next to the cam drive gear 39a. The cam gear 39b is formed integrally with the cam 37b and therefore guides the link arm 37c linearly in the longitudinal direction as the pump/screw driving input gear 39 rotates. With this configuration, the pump can be expanded and contracted by driving and rotating the cam gear 39b. A toner storage portion screw drive gear 39c, which transmits a rotational driving force to the screw member 35, is provided next to the cam gear 39b and coaxially with the screw member 35.
The printer main body A includes a stirring drive portion 206 (first drive portion) for driving the stirring driving input gear 38 and a pump drive portion 207 (second drive portion) for driving the pump/screw driving input gear 39 (
As shown in
Similarly, when the toner cartridge C is attached to the printer main body A, the cartridge-side coupling 391 of the toner cartridge C engages with the main-body-side coupling 191, allowing the motor driving force of the printer main body A to be input to the pump/screw driving input gear 39. That is, the main-body-side coupling 191 forms a part of the second drive portion that provides the toner cartridge C with a driving force (second driving force) that drives the screw member 35 and the pump unit 37.
In
The toner storage portion screw drive gear 39c receives a driving force from the cam gear 39b and rotates the screw member 35, thereby conveying the toner in the toner storage portion 30a in the longitudinal direction (the direction of arrow L2 in
Referring to
As shown in
The other end of the sealing member 80 serves as a fixed portion and is fixed to the shaft 36a of the stirring member 36, which is driven and rotated, by a means such as heat welding. Here, the sealing member 80 is folded back near the toner discharge port 31a, and is peeled off from the side farthest from the other end. This allows the sealing member 80 to be peeled off with a small force. The sealing member 80 is made of a laminate of polyester, low density polyethylene, and a polyethylene sealant. The sealing member 80 may also be made of other materials having similar properties.
In this embodiment, the other end of the sealing member 80 and the shaft 36a of the stirring member 36 are fixed to each other by thermal welding. However, there is no limitation to this, and other means such as adhesion, double-sided tape, or engagement between a hole and a projection may also be used.
Referring to
A control portion 200 includes a central processing unit (CPU) 201, which is a central element for performing calculation processing, a memory 202, which is a storage unit such as a ROM or RAM, and an input/output I/F 203, which inputs and outputs information to and from peripheral devices. The RAM stores the results of sensor detection and calculations, while the ROM stores the control program, pre-calculated data tables, and the like.
The control portion 200 is a control unit that comprehensively controls the operation of the laser printer 1, and each control target in the laser printer 1 is connected to the control portion 200 via the input/output I/F 203. The control portion 200 controls the transmission and reception of various electrical information signals, drive timings, and the like, and controls the flowchart processing described below.
A motor drive portion 205 refers to a drive configuration including a motor as a drive source, a drive train that transmits the driving force of the motor to each part of an image forming portion 210, and the like. The motor is a drive source for rotating and driving each member included in the image forming portion 210, such as the laser scanner 101, the photosensitive drum 11, and the developing roller 16, and operates on the basis of a control signal from the control portion 200.
The motor drive portion 205 includes the stirring drive portion 206 and the pump drive portion 207. The stirring drive portion 206 is a drive portion that drives the stirring member 36. The stirring drive portion 206 includes, as a drive portion configuration (first drive portion) on the side corresponding to the printer main body A, the main-body-side coupling 181 that engages with the cartridge-side coupling 381 of the toner cartridge C (
The high-voltage power supply 204 is a power supply that applies a high voltage to the photosensitive drum 11, the charging roller 12, the developing roller 16, the transfer roller 104, the fixing portion 105, and the like.
Furthermore, data communication is performed between the control portion 200 and the memory 90 via a memory communication portion 209. The control portion 200, the memory 90, the memory communication portion 209, and the like form a new-product detection unit that detects whether the toner cartridge C is new (unused).
Here, new refers to an initial state before use. Alternatively, it refers to a state in which the toner stored in the toner cartridge C has not been used yet. Furthermore, when the control portion 200 determines whether the toner cartridge C attached to the printer main body A is in an initial state, the determination is not limited to a mode in which the control portion 200 reads the usage history in the memory (storage element) 90 and determines on the basis of the read information. For example, a mechanical flag protruding from the toner cartridge C may be provided. The mechanical flag may be configured to be retracted by coming into contact with a predetermined section of the main body when the toner cartridge C is attached to the printer main body A for the first time, and configured so as not to protrude thereafter. This allows the control portion 200 to determine the initial state by detecting whether the mechanical flag is in the retracted state. In this case, since the mechanical flag will not move across the photosensor once retracted within the cartridge, the control portion 200 can determine that the attached toner cartridge C is not in the initial state.
Additionally, the control portion 200 is connected with a remaining amount sensor 208 for detecting whether the remaining amount of toner stored in the developer storage chamber 152 of the process cartridge B is less than or equal to a predetermined amount.
Referring to
As shown in
At this time, if it is detected from the information stored in the memory 90 that the toner cartridge C is new, an initial sequence is performed (Yes at S1002 in
In the initial sequence, first, the stirring member 154 (
In a new toner cartridge C, the toner may be locally consolidated in the toner storage portion 30a due to vibrations during distribution, and the load for rotating the stirring member 36 may be higher than usual. For this reason, the rotational speed of the stirring drive portion 206 during the initial sequence is set to be slower than that during the replenishing operation, thereby reducing the load on the motor. The driving force provided from the printer main body A to the toner cartridge C when the sealing member 80 is peeled off is a driving force that causes the rotational speed of the stirring member 36 to be slower than the rotational speed caused the driving force provided from the printer main body A to the toner cartridge C in the toner supply operation during the image forming operation.
After the sealing member 80 is peeled off and the stirring drive portion 206 of the printer main body A stops providing the stirring member 36 with a driving force, the pump drive portion 207 (
Here, as compared with a state in which the toner discharge port 31a is closed by the sealing member 80, peeling off the sealing member 80 in advance limits fluctuations in the internal pressure of the toner storage portion 30a, thereby reducing the driving load of the pump 37a.
Simultaneously with the pump operation, the screw member 35 rotates in the direction of arrow M (
For example, if the pump drive portion 207 of the printer main body A is driven in forward rotation rather than reverse rotation in the initial sequence, the following concerns may arise depending on the configuration of the toner storage portion of the toner cartridge. That is, if toner is present in the discharge chamber 81 at the start of performing the initial sequence, the screw member 35 would add more toner into the discharge chamber 81. This would increase the toner density inside the discharge chamber 81, so that the pump 37a may fail to discharge the toner to the outside.
Also, the pump 37a is set in an expanded state (expanded state that increases the volume of the toner storage portion 30a or the discharge chamber 81) during assembly, and the toner cartridge C is shipped in this state. At the start of performing the initial sequence, the pump 37a is compressed from the expanded state. This operation allows the toner in the discharge chamber 81 to be discharged through the toner discharge port 31a, thereby limiting entry of toner into the pump 37a when the pump 37a expands from the compressed state next time.
Then, the driving of the pump drive portion 207 of the printer main body A is stopped (S1006 in
As described above, according to this embodiment, it is possible to provide an image forming apparatus that prevents damage to parts and a motor due to an increase in the motor load during pump operation for a new toner cartridge, and allows the motor to be smaller.
In the above embodiment, the pump unit 37 and the like are driven in reverse rotation after the seal peeling operation. This configuration is most preferable from the viewpoint of minimizing an increase in the motor load. However, when the toner storage portion of the toner cartridge has a configuration that is unlikely to locally increase the toner density, the pump unit 37 and the like may be driven in forward rotation. That is, by controlling the timing of the operation of stirring and conveying the toner in the toner storage portion so as not to overlap with the seal peeling operation, it is possible to limit an increase in the motor load.
Also, the above embodiment has a configuration in which the driving of the pump unit 37 and the like after the seal peeling operation is started after stopping providing the stirring driving input gear 38 with a driving force. This configuration is most preferable from the viewpoint of minimizing an increase in the motor load. However, for example, if the limitation of the increase in torque during the seal peeling operation is sufficient, the driving of the pump unit 37 and the like may be started after the sealing member 80 is peeled off, without stopping providing the stirring driving input gear 38 with a driving force.
Also, the above embodiment is configured to start driving the pump unit 37 and the like after the sealing member 80 is completely peeled off, but the present invention is not limited to this configuration. For example, when at least a part of the toner discharge port 31a is opened, the sealing state of the toner storage portion 30a by the sealing member 80 is released (a state is achieved that allows communication between the toner storage portion 30a and the outside of the toner cartridge C). This limits an increase in the motor load considerably. As such, it may be configured to start the driving of the pump unit 37 and the like after the seal peeling operation has been started and the complete sealing state of the sealing member 80 has been released (at least a part of the toner discharge port 31a has been opened), but before the seal peeling operation is completed. In other words, the driving of the pump unit 37 and the like may be started after the weld portion 82 of the sealing member 80 is at least partially peeled off from the inner wall surface of the supply portion frame 31, thereby bringing the toner discharge port 31a into a state that provides communication between the inside and the outside of the toner storage portion 30a.
Furthermore, the above embodiment is configured to drive the pump unit 37 and the like during the initial sequence when the toner cartridge C is new. However, the pump unit 37 and the like may be driven for the first time during a toner replenishing operation after the initial sequence is performed.
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. 2023-197549, filed on Nov. 21, 2023, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2023-197549 | Nov 2023 | JP | national |