JP2009086224A - Developer conveying member and developer conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a decrease in an amount of developer conveyance, which is caused by elastic deformation of a developer conveying member. <P>SOLUTION: The developer conveying member is a toner conveying screw 722 that conveys toner in one direction, and has a shaft portion 722a and a conveying portion 722b. The shaft portion 722a extends in one direction. One end of the shaft portion 722a is fixed and supported, and the other end is free to move. The shaft portion 722a is elastically deformable. The conveying portion 722b is disposed on the periphery of the shaft 722a and conveys toner. The shaft portion 722a is formed such that one end is thicker than the other end. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developer conveying member and a developer conveying device, and more particularly to a developer conveying member that conveys a developer in one direction and a developer conveying device having the developer conveying member.

  An electrophotographic image forming apparatus such as a copying machine or a printer includes a developing device, forms an image on a sheet, a fixing unit that fixes the formed image on the sheet, and conveys the sheet to the image forming unit. In some cases, the printer includes a paper transport unit that discharges, a discharge unit that discharges the paper on which the image is fixed, and a developer transport device that transports the developer to the developing device. In such an image forming apparatus, an image is formed on a sheet by an image forming unit, and the image is fixed on the sheet by a fixing unit. The sheet on which the image is fixed is discharged from the discharge unit. When the developer in the developing device decreases, the developer is transported to the developing device by the developer transport device (see Patent Document 1).

Here, the developer transport device includes a developer storage container that is disposed outside the development device and stores the developer therein, a developer supply member that supplies the developer in the developer storage container to the development device, and development A cylindrical member disposed between the developer storage container and the developing device, and a developer transport member disposed inside the cylindrical member for transporting the developer from the developer storage container to the developer supply device. There is. The developer conveying member is a screw-like member having a spiral blade provided on the shaft. When transporting the developer, the developer transport member rotates about the axis so that the developer is transported from the developer storage container to the developer supply member. When the developer is conveyed to the developer supply member, the developer is supplied to the developing device by the developer supply member.
JP 2002-23472 A

  In such a developer transport device, an opening for supplying the developer to the developer transport member is provided in the developer storage container, and an opening overlapping the opening of the developer storage container is also disposed in the cylindrical member. ing. A space is formed in a portion where the opening of the developer container and the opening of the cylindrical member overlap. Here, since the developer conveying member is generally a resin molded product and is a member that is easily elastically deformed, when the developer conveying member rotates, the developer conveying member is twisted and deformed, There is a case to get caught in the space. When the developer conveying member is sandwiched in the space of the opening portion as described above, the developer conveying efficiency is lowered, and the amount of the developer conveyed to the developing device is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to prevent a decrease in developer conveyance amount due to elastic deformation of a developer conveyance member.

  A developer conveying member according to a first aspect is a developer conveying member that conveys the developer in one direction, and includes a shaft portion and a conveying portion. The shaft portion extends in one direction, is fixedly supported at one end side and is movable at the other end side, and is a portion that can be elastically deformed. A conveyance part is a part which is provided in the outer peripheral side of a shaft part, and conveys a developing agent. One end side of the shaft portion is formed thicker than the other end side.

  In this developer conveying member, since one end side is formed thicker than the other end side, the one end side is hardly elastically deformed. For this reason, it can suppress that a developer conveyance member greatly elastically deforms and the conveyance amount of a developer reduces.

  A developer conveying member according to a second aspect is the developer conveying member according to the first aspect, wherein the shaft portion and the conveying portion are integrally molded products made of resin.

  Here, the developer conveying member can be easily manufactured.

  A developer conveying member according to a third aspect is the developer conveying member according to the first or second aspect, wherein the conveying portion is a spiral blade.

  Here, the developer can be transported by rotating the shaft portion.

  A developer conveying device according to a fourth aspect is a developer conveying device that conveys a developer from a developer container to a developing device, and includes a developer conveying member, a cylindrical member, and a developer supply member. I have. The developer conveying member is a member according to any one of claims 1 to 3. The cylindrical member is a cylindrical member having a developer conveying member provided therein and one end connected to the developer storage container. The developer supply member is a member that is connected to the other end of the cylindrical member and can supply the developer conveyed through the cylindrical member to the developing device.

  In this developer transport device, the developer is supplied from the developer storage container to the cylindrical member, and the developer is transported to the developer supply member by the developer transport member in the cylindrical member. Then, the developer is supplied to the developing device by the developer supply member.

  Here, since one end side of the developer conveying member is thicker than the other end side, the one end side is not easily elastically deformed with respect to the other end side, and one end of the developer conveying member is placed on the developer storage container side. By disposing the side, it is possible to suppress the developer conveying member from being greatly elastically deformed and reducing the developer conveying amount.

  The developer transport device according to claim 5 is the developer transport device according to claim 4, wherein the cylindrical member includes a first cylindrical portion connected to the developer supply member, and a first cylindrical portion. And a second cylindrical part disposed between the developer container and the developer container. The developer conveying member is formed so that the portion located in the second cylindrical portion is thicker than the other portions.

  Here, since the part located in the 2nd cylindrical part connected to a developing agent storage container is thick compared with another part, it is hard to elastically deform in a 2nd cylindrical part. Further, since the portion other than the portion located in the second cylindrical portion is thin, it is easily bent, and in particular, in the case of a configuration in which the developer supply member moves, the portion is easily deformed along with the movement.

  A developer conveying device according to a sixth aspect is the developer conveying device according to the fifth aspect, wherein the developer conveying member gradually becomes thicker from an end portion of the second cylindrical portion on the first cylindrical portion side. ing.

  Here, since the thickness is gradually increased, the conveyance of the developer is hardly hindered.

  In the present invention, it is possible to prevent a decrease in the developer conveyance amount due to the elastic deformation of the developer conveyance member.

1. Configuration FIG. 1 shows a color printer 1 as an image forming apparatus according to an embodiment of the present invention. FIG. 1 is a schematic diagram for illustrating the arrangement of each component, and details of each part are omitted.

  The color printer 1 is connected to a computer (not shown) or the like, and is a device that can print a color image on paper based on image information sent from an external computer or the like. The color printer 1 includes an image forming unit 2, a paper transport unit 3, a fixing unit 4, a paper storage unit 5, a discharge unit 6, and a toner supply device 7. Here, the toner replenishing device 7 will be described in detail later.

  The image forming unit 2 includes a photosensitive drum 21, a rotary developing device 22, a charging device 23, a laser unit 24, and a cleaning device 25.

  The photosensitive drum 21 is a member on which an electrostatic latent image is formed, and is disposed at the approximate center of the color printer 1. The photosensitive drum 21 is a drum-shaped member, and a rotation shaft is provided in a direction orthogonal to the paper surface of FIG. An intermediate transfer belt 211 for transferring a toner image on the photosensitive drum 21 to a sheet is disposed below the photosensitive drum 21 in the vicinity of the photosensitive drum 21.

  The rotary developing device 22 is a member disposed adjacent to the photosensitive drum 21 and is a cylindrical device as a whole. The rotary developing device 22 includes four developing devices 221 (developing devices) and a frame 222 that supports the four developing devices 221. The developing device 221 includes a container body 223 and a developing roller 224 as shown in FIG. The container body 223 has a shape in which a cylinder is divided into four in the circumferential direction, and has an opening extending in the longitudinal direction. A toner supply port 223a through which a toner supply pipe 723, which will be described later, can pass, is formed on the surface of the container body 223. The toner supply port 223a includes a seal member 223b. The seal member 223b is a substantially square sheet-like elastic member, and has a single slit 223c formed in the approximate center. The four container main bodies 223 store yellow, cyan, magenta, and black toners, respectively. Here, FIG. 3 shows one of the developing devices 221. The developing roller 224 extends in the rotation axis direction of the rotary developing device 22 and is disposed in the opening of the container main body 223. The developing roller 224 is a member for supplying toner to the surface of the photosensitive drum 21. At both ends of the developing roller 224, distance regulating rollers 225 for maintaining a distance between the photosensitive drum 21 and the developing roller 224 are disposed. The distance regulating roller 225 is a disk-like member having a larger radius than the developing roller 224, and keeps the distance between the photosensitive drum 21 and the developing roller 224 constant.

  The charging device 23 is a device for charging the surface of the photosensitive drum 21, and is disposed on the upper side of the photosensitive drum 21.

  The laser unit 24 is a member arranged on the upper side of the rotary developing device 22 and is a portion for irradiating a laser beam to form an electrostatic latent image based on image data on the photosensitive drum 21. It is.

  The cleaning device 25 is a device for removing deposits such as residual toner remaining on the photosensitive drum 21. In the color printer 1, the cleaning is performed on the entire axial direction of the photosensitive drum 21 above the photosensitive drum 21. A blade is provided.

  The paper transport unit 3 has a transport path that continues from the paper storage unit 5 through the image forming unit 2 and the fixing unit 4 to the discharge unit 6.

  The fixing unit 4 is disposed below the rotary developing device 22 and has a heating roller 41 and a pressure roller 42. The heating roller 41 is a member for melting toner that forms an image formed on a sheet by heat, and is disposed on the upper side of the pressure roller 42.

  The paper storage unit 5 is a part disposed at the lower part of the color printer 1 and has a paper feed cassette 51.

  The discharge unit 6 is disposed on the upper surface of the color printer 1 and discharges a sheet on which an image is formed.

2. As shown in FIG. 1 or 2, the toner replenishing device 7 is for replenishing toner to the developing device 221, and includes a toner container (developer storage container) 71 and a toner transport device 72. ing.

  The toner container 71 is disposed at substantially the same height as the laser unit 24 above the photosensitive drum 21. The toner container 71 is a box-shaped member that stores toner therein, and a lower opening is provided with a first opening 711 for supplying toner to the toner transport pipe 721 when toner is supplied.

  The toner conveying device 72 is a device for conveying the toner in the toner container 71 to the developing device 221, and includes a toner conveying pipe 721 (cylindrical member), a toner conveying screw 722 (developer conveying member), and a toner supply. A pipe 723 (developer supply member) and a toner supply pipe moving mechanism 74 are provided.

  The toner transport pipe 721 is disposed between the toner container 71 and the toner supply pipe 723, and one end thereof is connected to the toner container 71. Further, as shown in FIGS. 2 and 4, the toner transport pipe 721 includes a first cylindrical portion 721a and a second cylindrical portion 721b. One end of the first cylindrical portion 721a is connected to the toner supply pipe 723, and is formed of an elastic member. The second cylindrical portion 721b is connected to the other end side of the first cylindrical portion 721a and the toner container 71, and is disposed below the toner container 71 in FIG. Further, the second cylindrical portion 721b has a second opening 721c that overlaps the first opening 711 of the toner container 71, and has a space through which toner can pass in the vicinity of the second opening 721c. Further, the second cylindrical portion 721b is an input gear in which driving force is input from a driving source (not shown) to the opposite end portion (the right end portion in FIG. 2) of the side end portion where the first cylindrical portion 721a is disposed. 721d is arranged. The toner transport pipe 721 is a flexible pipe so that it can move following the vertical movement of the toner supply pipe 723.

  The toner conveying screw 722 is a member that conveys toner from the toner container 71 side to the toner supply pipe 723, and includes a shaft portion 722a and a blade portion 722b (conveying portion). The toner conveying screw 722 is formed of an elastically deformable elastomer and is disposed inside the toner conveying pipe 721. One end of the shaft portion 722a is rotatably supported at the opposite end of the side end to which the first tubular portion 721a of the second tubular portion 721b is connected, and rotates integrally with the input gear 721d. Are arranged as follows. Further, the shaft portion 722a is formed so that the portion disposed in the space near the second opening 721c is thicker than the other portions. Specifically, the second cylindrical portion 721b gradually becomes thicker from the side end portion where the first cylindrical portion 721a is disposed toward the side end portion where the input gear 721d is disposed, In the space below the opening 721c in FIG. 4, the thickness is uniform. Further, the end portion of the shaft portion 722a on the toner supply pipe 723 side is a free end and is movable. The wing | blade part 722b is provided in the outer peripheral side of the axial part 722a, and is arrange | positioned helically in the substantially whole shaft part 722a. The comparison of the thickness of the shaft portion described in this embodiment is a comparison with respect to a portion for conveying toner (portion where the blade portion is disposed), and a portion where the shaft portion is supported or a gear. The part where is placed is not included. Here, FIG. 4 is a sectional view of the toner transport pipe 721.

  The toner supply pipe 723 is long in the vertical direction, and the upper end is inclined to the right side in FIG. 1 and the lower end is inclined to the left side in FIG. In addition, an opening for supplying toner is provided at the tip of the toner supply pipe 723. The toner supply pipe 723 has a tapered tip, and when the toner supply pipe 723 moves toward the developing unit 221, the leading end passes through a slit 223c formed in a seal member 223b disposed on the surface of the developing unit 221. Can enter inside. A toner conveying screw member 723a is rotatably provided inside the toner supply pipe 723.

  As shown in FIG. 2, the toner supply pipe moving mechanism 74 includes a rack 741 provided along the axial direction on the outer periphery of the toner supply pipe 723 and a pinion gear 742 that meshes with the rack 741. . The pinion gear 742 is rotatably supported by the frame of the apparatus, and is driven by a motor, a worm, a worm wheel, and a reduction gear train. Then, the toner supply pipe moving mechanism 74 allows the four toner supply pipes 723 to take the upper retracted position and the lower supply position where the tip portion enters the inside of the developing device 221. Here, FIG. 2 is a diagram showing the toner transport pipe 721, the toner supply pipe 723, and the like.

3. Operation An image forming operation will be described.

  When image information is transmitted from a computer connected to the outside, the surface of the photosensitive drum 21 is charged by the charging device 23 and irradiated from the irradiation device based on the image information. When an electrostatic latent image is formed on the photosensitive drum 21, the frame 222 rotates and toner is supplied from each developing device 221 to the photosensitive drum 21. When an image is formed on the photosensitive drum 21 in this way, the image is transferred onto a sheet via the intermediate transfer belt 211. The sheet onto which the image has been transferred is conveyed to the fixing unit 4 where the image is fixed. Thereafter, the paper is discharged from the discharge unit 6 to the outside of the color printer 1.

  Next, an operation of supplying toner when the toner in the developing device 221 is reduced will be described.

  When the toner in the developing device 221 decreases, the pinion gear 742 is rotated by the power of the motor, and the toner supply pipe 723 moves downward in FIG. 6 as the pinion gear 742 rotates. At this time, the toner conveyance screw 722 in the toner conveyance pipe 721 is driven, and the toner is conveyed from the toner container 71 to the toner supply pipe 723 side. Then, the toner conveying screw member 723a inside the toner supply pipe 723 rotates to convey the toner to the front end side of the toner supply pipe 723. In this way, the toner in the toner container 71 is supplied to the developing device 221.

  Here, the toner conveying screw 722 is bent because the thickness of the portion of the shaft portion 722 a of the toner conveying screw 722 located in the space below the second opening 721 c is thicker than the vicinity of the toner supply pipe 723. It becomes difficult. Therefore, when the toner in the toner container 71 is transported to the toner supply pipe 723 by the toner transport pipe 721, the toner transport screw 722 is sandwiched in a space near the second opening 721c to close the second opening 721c. It is possible to prevent the conveyance amount from decreasing. Further, the vicinity of the toner supply pipe 723 of the toner conveyance screw 722 is easily bent because the shaft portion 722a is not thick, and the toner conveyance pipe 721 is easily deformed as the toner supply pipe 723 moves up and down.

4). Other Embodiments (a) Although the color printer 1 has been described in the above embodiment, the present invention is not limited to this, and may be a copying machine, a multifunction machine, or the like.

  (B) In the above embodiment, the toner replenishing device has been described. However, the toner replenishing device can also be used as a conveying member of a developer collecting device that conveys the developer from the cleaning device to the waste developer collecting container.

1 is an overall schematic diagram of a color printer including a toner conveying screw according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a toner supply device. The figure which shows a developing device. Sectional drawing of a toner conveyance pipe.

Explanation of symbols

1 Color Printer 7 Toner Supply Device 71 Toner Container (Developer Storage Container)
72 Toner Conveying Device 74 Toner Supply Pipe Moving Mechanism 221 Developing Device (Developing Device)
711 First opening 721 Toner transport pipe (cylindrical member)
721a First cylindrical portion 721b Second cylindrical portion 721c Second opening 722 Toner conveying screw (developer conveying member)
722a Shaft 722b Blade 723 Toner supply pipe (developer supply member)

Claims (6)

A developer conveying member for conveying the developer,
A shaft portion that extends in one direction, one end side is fixedly supported and the other end side is movable, and is elastically deformable,
A transport section that is provided on the outer peripheral side of the shaft section and transports the developer;
With
The shaft portion is formed such that the one end side is thicker than the other end side,
Developer conveying member.   The developer conveying member according to claim 1, wherein the shaft portion and the conveying portion are integrally molded products made of resin.   The developer transport member according to claim 1, wherein the transport unit is a spiral blade. A developer conveying device for conveying the developer from the developer container to the developing device,
The developer conveying member according to any one of claims 1 to 3,
A cylindrical member provided inside the developer transport member, one end of which is connected to the developer container;
A developer supply member connected to the other end of the cylindrical member and capable of supplying the developer conveyed through the cylindrical member to the developing device;
A developer transport device. The cylindrical member includes a first cylindrical part connected to the developer supply member, and a second cylindrical part disposed between the first cylindrical part and the developer container. ,
The developer conveying member is formed such that a portion located in the second cylindrical portion is thicker than other portions.
The developer conveying device according to claim 4. The developer conveying device according to claim 5, wherein the developer conveying member is gradually thickened from an end portion of the second cylindrical portion on the first cylindrical portion side.

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