The present invention relates to a powder feed device and an image forming apparatus.
According to an aspect of the invention, there is provided a powder feed device including a casing having an opening, a powder sent from a powder housing portion being received through the opening, the powder housing portion housing the powder, the casing extending to a fed body, the fed body being fed with the powder, at least an inner side of the casing having a substantially cylindrical shape; a transport member that rotates and transports the powder received in the casing through the opening to the fed body, the transport member being arranged in the casing and extending in a transport direction, the powder being transported in the transport direction; and a shutter member that is arranged at a closed position at which the opening is closed, receives a force from the transport member by the rotation of the transport member, and moves to an open position at which the opening is open. The transport member includes a transport portion that contributes to the transport of the powder, and a non-transport portion that does not contribute to the transport, and handles the movement of the shutter member to the open position. The shutter member moves to the open position when the shutter member receives an effect of the non-transport portion.
An exemplary embodiment of the present invention will be described in detail based on the following figure, wherein:
An exemplary embodiment of the present invention is described below.
The printer 1 shown in
The toner cartridge 3 houses a toner for supply. This toner corresponds to an example of a powder according to the exemplary embodiment of the present invention. The toner in the toner cartridge 3 is stirred by rotation of a stirring member 31 and hence the toner is prevented from being aggregated. A drive force is transmitted to the stirring member 31 from a motor 111 provided in the printer body 11 through gears (described later). The toner in the toner cartridge 3 is fed to a developing unit 21 provided in the process cartridge 2.
The process cartridge 2 includes, in addition to the developing unit 21, a photoconductor 22, a charging unit 23, and a cleaner 24. A waste-toner housing chamber 25 is provided between the toner cartridge 3, and the developing unit 21 and the photoconductor 22. The waste-toner housing chamber 25 houses a waste toner that is scraped from the photoconductor 22 by the cleaner 24.
Further, the printer body 11 includes an exposure unit 112 that radiates the photoconductor 22 with exposure light 112a, and a transfer unit 113 that is arranged at a position to face the photoconductor 22.
The photoconductor 22 receives various effects (described later) while the photoconductor 22 is rotated in a direction indicated by arrow A.
The charging unit 23 causes the surface of the photoconductor 22 to be electrically charged with a predetermined potential.
The exposure unit 112 radiates the electrically charged surface of the photoconductor 22 with the exposure light 112a corresponding to an image signal, and forms an electrostatic latent image on the surface of the photoconductor 22.
The developing unit 21 houses a developer containing a carrier and a toner. The developer moves in a circulating manner in a direction perpendicular to a paper face of
A paper cartridge 115 is mounted in a lower portion of the printer body 11 so that the paper cartridge 115 may be pulled out to the right side in
For printing on both sides of paper P, paper P with an image printed on one side in the above-described manner is sent by the paper output roller 119 to an intermediate position, then the paper output roller 119 is reversely rotated, the paper P is transported through a transport path d3, and the paper P reaches the registration roller 118 again. Then, the above-described printing operation is repeated again, the paper P with images printed on both sides is output onto the paper output tray 120 by the paper output roller 119.
A cover 121 that is a part of covers of the printer body 11 is openable and closable in a direction indicated by arrows C and D around a hinge portion 121a, i.e., to the front surface side of the apparatus. When the cover 121 is opened, a grip 261 of a semi-cylindrical fixing member 26 provided at the process cartridge 2 is gripped with a hand, and the fixing member 26 is rotated in a direction indicated by arrow E, an attachment/detachment opening is opened for attachment and detachment of the toner cartridge 3, and the toner cartridge 3 may be removed by pulling a grip 32 of the toner cartridge 3. When the toner cartridge 3 is mounted on the process cartridge 2, an operation reverse to the above-described operation is performed. In particular, the grip 32 of the toner cartridge 3 is gripped with a hand, the toner cartridge 3 is mounted on the process cartridge 2, then the grip 261 of the fixing member 26 of the process cartridge 2 is gripped with the hand, and the fixing member 26 is rotated in a direction indicated by arrow F. When the fixing member 26 is rotated in the direction indicated by arrow F, the toner cartridge 3 is fixed at a predetermined position in the process cartridge 2. Then, the cover 121 is closed in the direction indicated by arrow D.
Also, when the process cartridge 2 itself is replaced, for example, because the photoconductor 22 is deteriorated, the cover 121 is opened, then a grip 27 of the process cartridge 2 is gripped, the process cartridge 2 is pulled and removed regardless of the presence of the toner cartridge 3, and a new process cartridge 2 may be mounted by an operation reverse to the above-described operation.
The toner cartridge 3 has an opening 310a at a lower portion when the toner cartridge 3 is mounted. The toner in the toner cartridge 3 is fed to the developing unit 21 through the opening 310a. The opening 310a is closed with a shutter when the toner cartridge 3 is separated from the process cartridge 2. When the toner cartridge 3 is mounted on the process cartridge 2 and the fixing member 26 of the process cartridge 2 is rotated in the direction indicated by arrow F, the shutter is opened.
The toner housed in the toner cartridge 3 is sent in a direction indicated by arrow G through the opening 310a, is received in a casing 41 of the toner feed device 4 through an opening 41a provided at the casing 41, is transported in a transport direction indicated by arrow H by rotation of a transport member 42 arranged in the casing 41, falls in a direction indicated by arrow J, and is fed to the developing unit 21.
The toner feed device 4 corresponds to an example of a powder feed device according to the exemplary embodiment of the present invention, and also corresponds to an example of a powder feed unit in the image forming apparatus according to the exemplary embodiment of the present invention. Also, the developing unit 21 corresponds to a fed body in the powder feed device according to the exemplary embodiment of the present invention.
The detail of the toner feed device 4 is described later.
In
The toner feed device 4 includes the casing 41 and the transport member 42. The casing 41 has the opening 41a through which the casing 41 receives the toner from the toner cartridge 3. The casing 41 is a hollow cylindrical casing extending to the developing unit 21 that is a feed target of the received toner.
It is to be noted that the cylindrical shape may be satisfied as long as at least an inner side of the casing 41 has a substantially cylindrical shape. An outer periphery shape of the casing 41 is not limited to a circular shape. Also, the casing 41 may be unitized with or formed separately from the process cartridge 2.
Also, the transport member 42 is arranged in the casing 41, extends in the transport direction in which the toner is transported, is rotated when the transport member 42 receives a drive force from the motor 111 (see
Further, the toner feed device 4 includes a shutter member 43. The shutter member 43 is arranged at a closed position at which the shutter member 43 closes an opening 42a before the transport member 42 is rotated for the first time (initial rotation) or when the process cartridge 2 is new. The shutter member 43 receives the force from the transport member 42 by the initial rotation of the transport member 42 and moves to an open position at which the shutter member 43 opens the opening 42a. Hence, the toner is not present in the casing 41 of the toner feed device 4 before the printer 1 is operated. A phenomenon, in which the toner is aggregated in the toner feed device 4, the transport member 42 does not effectively work, and defective feed of the toner occurs, is avoided.
The transport member 42 includes a transport portion 42A that contributes to the transport of the toner, and a non-transport portion 42B that does not contribute to the transport of the toner and handles the movement of the shutter member 43 to the open position. In this exemplary embodiment, the non-transport portion 42B is provided upstream of the transport portion 42A in the transport direction of the toner (in the direction indicated by arrow H in
If a portion of the transport member 42 that transports the toner handles the movement of the shutter member 43, the portion that transports the toner has to have a structure that retains the shutter member 43 after the shutter member 43 moves to the open position. The structure may disturb the flow of the toner. In this exemplary embodiment, the non-transport portion 42B that handles the movement of the shutter member 43 is provided in addition to the transport portion 42A used for the transport of the toner. Thus, a phenomenon, in which the structure that causes the shutter member 43 to move and retains the shutter member 43 at the open position disturbs the flow of the transport of the toner, is prevented.
The shutter member 43 has an arc-shaped shutter surface 431. The shutter surface 431 closes the opening 41a before the initial rotation of the transport member 42.
Also, the shutter member 43 has a protrusion 432 at an inner surface of the shutter member 43. The protrusion 432 protrudes to the transport member 42.
The entire transport member 42 extends in a rod shape, receives the drive force from the motor 111 (see
The transport portion 42A has a blade 421 having a spiral form around a rotation center line of the transport member 42. When the transport member 42 is rotated in the direction indicated by arrow I, the blade 421 transports the toner around the transport portion 42A in the direction indicated by arrow H. Also, a shaft 426 that is a portion of the transport portion 42A excluding the blade 421 has a large-diameter part 426a and a small-diameter part 426b. This is a countermeasure for increasing transportability of the toner by pressing the toner to the inner wall of the casing 41 and loosening the pressure.
The non-transport portion 42B is a portion that does not contribute to the transport of the toner and contributes to the transport of the shutter to the open position as described above. The non-transport portion 42B has a spiral groove 422 having a spiral or substantially spiral shape around the rotation center line of the transport member 42. The spiral groove 422 is rotated in a direction reverse to the direction of the blade 421 provided at the transport portion 42A. The protrusion 432 of the shutter member 43 (see
As shown in
As described above, since the transport member 42 is arranged at the obliquely downward posture to the developing unit 21, the transport portion 42A further smoothly transports the toner, and the toner in the transport portion 42A is prevented from entering the non-transport portion 42B.
The spiral groove 422 extends in a spiral or substantially spiral shape from a start position to an end position, which are described later. The start position is a position at which the protrusion 432 of the shutter member 43 enters the spiral groove 422 when the shutter member 43 is located at the closed position at which the opening 41a (see
When the shutter member 43 moves to the open position, the protrusion 432 of the shutter member 43 enters the end-side circumferential groove 424, the transport member 42 is freely rotated with respect to the protrusion 432, and the shutter member 43 remains at the open position without moving from the open position.
The start-side circumferential groove 423 has a step 423a (see
Also, the transport member 42 has a flange 425 at a boundary portion between the transport portion 42A and the non-transport portion 42B. The flange 425 extends along the circumferential direction by one turn, and has a large diameter to be close to an inner wall of the casing 41. The flange 425 blocks entry of the toner from the transport portion 42A to the non-transport portion 42B, and prevents the toner from entering the non-transport portion 42B.
The motor 111 (also refer to
The rotational drive force transmitted to the gear 53 is also transmitted to a gear 55 shown in
The process cartridge 2 is removably mounted on the printer body 11. When the process cartridge 2 is not mounted on the printer body 11, the gear 53 does not mesh with the gear 52 of the printer body 11. Also, the toner cartridge 3 may be removed from the process cartridge 2. When the toner cartridge 3 is not present, the gear 53 does not mesh with the gear 54, and the gear 53 may be manually rotated.
When the shutter member 43 unintentionally moves from the closed position to the open position, the gear 53 is manually reversely rotated. Then, a drive force of reverse rotation is transmitted to the gears 55 and 56, the transport member 42 is reversely rotated, and the shutter member 43 moves to the closed position.
In the above-described exemplary embodiment, the toner feed device 4 is applied to the printer 1 that performs printing with a single color. However, the toner feed device 4 may be applied to, for example, a tandem printer that forms a color image.
The foregoing description of the exemplary embodiment of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiment was chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
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2012-069516 | Mar 2012 | JP | national |
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2012-069516 filed Mar. 26, 2012.