JP4549147B2 - Image forming apparatus - Google Patents

Description

  The present invention belongs to the technical field of image forming apparatuses such as electrostatic copying machines and printers, and in particular, includes a large-capacity toner replenishing device outside the developing device and replenishes toner regardless of the position of the developing device. The present invention belongs to the technical field of image forming apparatuses.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrostatic copying machine or a printer, an electrostatic latent image carried on a latent image carrier such as a photoconductor is developed into a toner image by a developing device, and the toner image is then transferred to paper or the like. An image is obtained by fixing the toner image transferred to the recording medium and further transferred to the recording medium.

  In order to perform development, it is necessary to supply toner to the developing device. Therefore, various toner replenishing devices for replenishing toner to the developing device have been conventionally proposed. As one of conventional toner replenishing devices, for example, a rotary developing device that replenishes toner from a toner container provided outside the rotary is proposed in Patent Document 1.

  As shown in FIG. 8, the conventional rotary developing device 101 includes a rotary 102 that is rotatably provided, and yellow, magenta, cyan, and black developing devices (not shown) supported by the rotary 102. And. Each developing device is arranged in the circumferential direction of the rotary 102 in the clockwise direction at equal intervals. A cylindrical toner receiving portion 103 that protrudes in the axial direction coaxially with the rotary 101 is provided from one end of the rotary 102, and the toner receiving portion 103 is rotated integrally with the rotary 102.

  As shown in FIG. 9, four fan-shaped toner moving paths 104, 105, 106, and 107 are defined in the internal space of the toner receiving portion 103. Each toner moving path 104, 105, 106, 107 is connected to each developing device. In the outer periphery of the toner receiving portion 103, the toner moving paths 104, 105, 106, and 107 are communicated with the outside to introduce the toner into the toner moving paths 104, 105, 106, and 107 from the outer periphery of the toner receiving section 103. Four toner inlets (only the toner inlet 108 corresponding to yellow toner is shown in FIG. 9) are formed. The toner receiving ports are adjacent to each other with an interval in the axial direction, and are provided with a phase shift of 90 ° in the circumferential direction. Then, four toner temporary storage portions 109, 110, 111, and 112 are formed so as to cover the outer periphery of the toner receiving portion 103 including each toner receiving port. Each toner temporary storage unit 109, 110, 111, 112 is connected to each of four toner containers 113, 114, 115, 116 of yellow, magenta, cyan, and black, and each toner container 113, 114, 115, 116. The toner of each color supplied from is temporarily stored.

When the rotary 102 rotates with this configuration, the toner of each color stored in each toner temporary storage unit 109, 110, 111, 112 is introduced into each toner moving path 104, 105, 106, 107 from each toner receiving port. The developer is replenished through the toner moving paths 104, 105, 106, and 107. Therefore, the toner can be supplied regardless of the position of the developing device.
JP 2001-318520 A

  However, in the rotary developing device proposed in Patent Document 1, toner temporary storage portions 109, 110, 111, and 112 arranged on the outer periphery of the toner receiving portion 103 are arranged for each toner color in the axial direction of the rotary 102. Therefore, there is a problem that the space occupied by the toner receiving portion is large and the main body of the image forming apparatus is enlarged.

  An object of the present invention is to reduce the size of a toner receiving portion in the rotary developing device as described above.

  To achieve the above object, the present invention provides a rotating body, a plurality of developing units attached to the rotating body, a toner container that is provided outside the developing unit and stores toner to be supplied to the developing unit, A toner receiving portion provided so as to protrude from one end of the rotating body in the axial direction coaxially with the rotating body, a toner moving path provided inside the toner receiving portion and for moving the toner to the corresponding developing device, An image forming apparatus comprising: a toner replenishing port provided at one end of the developing device and connected to a downstream end of the toner moving path; and a toner receiving port connected to an upstream end of the toner moving path. Are arranged in the same rotation plane inside the toner receiving portion.

  In addition, the toner replenishing port is arranged at the same distance from the rotation center (on the circumference of the same radius) regardless of the toner color.

  Further, the toner receiving port is arranged at a different distance from the rotation center for each toner color, and the toner replenishing operation to the developing device is performed on the developing device of the color being developed. It is characterized by being performed only on the other hand.

  Further, a normally closed shutter is provided at each toner receiving port, and an opening / closing mechanism that opens only the shutter of the toner receiving port of the color being developed is provided.

  Each toner supply port is provided with a check valve for preventing the backflow of toner.

  According to the present invention, since the toner moving paths for the respective colors in the toner receiving portion are arranged in the same rotation surface, the protrusion of the toner receiving portion in the rotary axis direction can be suppressed as compared with the conventional case, and image formation is accordingly performed. The apparatus body can be downsized.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a rotary developing device according to the present invention. The rotary developing device 2 includes a rotary 3 that is rotatably provided, and cyan (C), magenta (M), yellow (Y), and black (K) supported on a rotary shaft 3 a of the rotary 3. Development units 4, 5, 6, and 7 are provided. These developing devices 4, 5, 6 and 7 are arranged in the circumferential direction of the rotary 3 in the clockwise direction and at equal intervals in this order. The developing rollers 4a, 5a, 6a and 7a and the supply roller 4b, respectively. , 5b, 6b, 7b, regulating members 4c, 5c, 6c, 7c for regulating the toner layer thickness of the developing rollers 4a, 5a, 6a, 7a, and stirring blades 4d, 5d, 6d, 7d. As the rotary 3 rotates in the clockwise direction indicated by the arrow α, the developing rollers 4a, 5a, 6a, and 7a sequentially contact the photoconductor 8 in the developing units 4, 5, 6, and 7, respectively. The developing position is set.

  Cyan, magenta, yellow, and black toners sent from toner moving paths 17, 18, 19, and 20, which will be described later, are provided on one end face in the axial direction of each developing device 4, 5, 6, and 7 as developing devices 4. Toner replenishing ports 4e, 5e, 6e, 7e for replenishing in 5, 6 and 7 are provided. The toner supply ports 4e, 5e, 6e, and 7e are disposed at the same distance from the rotation center (on the circumference of the same radius) regardless of the toner color. Each toner supply port 4e, 5e, 6e, 7e is provided with a check valve (only the check valve 61 of the black toner container 7 is shown in FIG. 3) for preventing the back flow of toner.

  As shown in FIGS. 2 and 3, the rotary developing device 2 includes a toner receiving portion 9 that protrudes from one end of the rotary 3 in the axial direction coaxially with the rotary 3. The toner receiving unit 9 extends coaxially with the rotary 3 in the axial direction, and rotates to rotate integrally with the rotary 3. The toner receiving unit 9 is separated from the rotary disk 10 by a predetermined distance on the main body side of the image forming apparatus. It consists of a fixed stationary disk portion 11 that is fixed.

  As shown in FIG. 4, the inside of the rotating disk portion 10 is a cavity, and the sector is divided into four fan-shaped spaces 13, 14, 15, and 16 by a cross-shaped partition wall 12. In each of the fan-shaped spaces 13, 14, 15, and 16, toner moving paths 17, 18, 19, and 20 each including a square tube are provided. The toner moving paths 17, 18, 19, and 20 have different tube lengths so that they become longer in this order, and cyan, magenta, yellow, and black toners are respectively introduced.

  Each of the toner moving paths 17, 18, 19, and 20 has one of its side walls in close contact with the partition wall 12 in each of the fan-shaped spaces 13, 14, 15, and 16, and one of its edge portions as the peripheral wall of the rotating disk portion 10. It is provided at a position that contacts the inner surface. Accordingly, the toner moving paths 17, 18, 19, and 20 have their tube length directions orthogonal to the axial direction of the rotating disk portion 10, and are phased by 90 ° in the clockwise direction in the order of cyan, magenta, yellow, and black toners. Are provided in an offset arrangement. That is, since the toner moving paths 17, 18, 19, and 20 are arranged on the same rotation surface in the rotary disk portion 10, the protrusion of the toner receiving portion 9 in the rotary axis direction can be suppressed. Therefore, the image forming apparatus main body can be downsized.

  Each of the toner moving paths 17, 18, 19, and 20 has a circular toner inlet 17a, 18a, 19a, and 20a on one of a pair of side walls that face each other in the rotary axial direction and contact the inner surface of the rotating disk portion 10. Each is formed with a circular toner outlet 17b, 18b, 19b, 20b. The respective toner inlets 17a, 18a, 19a, and 20a are provided at the end portions of the respective toner moving paths 17, 18, 19, and 20 that are closer to the rotation center of the rotary disk portion 10, and the respective toner outlets 17b, 18b, Reference numerals 19 b and 20 b are provided at end portions of the toner moving paths 17, 18, 19, and 20 far from the rotation center of the rotating disk unit 10. Conveying screws 21, 22, 23, and 24 that are rotationally driven by driving means 25, 26, 27, and 28 are provided in the toner moving paths 17, 18, 19, and 20, respectively. By individually driving 22, 23, and 24, the toner of each color in each of the toner moving paths 17, 18, 19, and 20 is conveyed in the radial direction.

  As shown in FIG. 5, four seal members 29, 30, 31, and 32 having different radii concentrically from the outside are attached to one end surface 10 a of the rotary disk portion 10 in the rotary axis direction. The seal members 29, 30, 31, and 32 are circular elastic members having a certain thickness and height, and are opposed to the front end surface thereof and the inner disk surface of the fixed disk portion 11 (one end surface 10 a of the rotating disk portion 10). The space 33, 34, 35, 36 sealed off inside the respective seal members 29, 30, 31, 32 is partitioned by sliding contact with the surface). In a partition area between the two seal members 29 and 30, a toner receiving port 37 through which the toner moving path 17 communicates with the outside to introduce cyan toner into the toner moving path 17 from one end surface 10 a of the rotating disk portion 10. Further, in the partition region between the two seal members 30 and 31, the toner moving path 18 and the outside communicate with each other, and magenta toner is fed into the toner moving path 18 from one end surface 10a of the rotating disk portion 10. A toner receiving port 38 to be introduced is perforated, and further, in a partition region between the two seal members 31 and 32, the toner moving path 19 and the outside are communicated with each other, and yellow toner is fed from one end surface 10a of the rotating disk portion 10. A toner receiving port 39 to be introduced into the toner moving path 19 is formed. Further, in the inner region of the seal member 32, the toner moving path 20 and the outside are communicated with each other, and black toner is supplied to one end surface of the rotating disk portion 10. Toner receiving port 40 for introducing the toner movement path 20 from 0a is drilled. That is, the toner receiving ports 37, 38, 39, and 40 are disposed at positions corresponding to the toner outlets 17b, 18b, 19b, and 20b of the respective toner moving paths at different distances from the rotation center for each toner color. The toner receiving ports 37, 38, 39, and 40 are provided with phases shifted by 90 ° in the clockwise direction in the order of cyan, magenta, yellow, and black toners. In other words, the toner receiving ports 37, 38, 39, and 40 are provided at positions corresponding to the toner inlets 17 a, 18 a, 19 a, and 20 a of each toner moving path on the one end surface 10 a of the rotating disk portion 10. . Similarly, the other end surface 10b (see FIG. 3) of the rotating disk portion 10 is provided with a toner discharge port (not shown) at a position corresponding to the toner outlets 17b, 18b, 19b, and 20b of each toner moving path. .

  As shown in FIG. 6, the fixed disk portion 11 has a partition region between the two seal members 29, 30 that communicates the space 33 and the outside to allow cyan toner to flow from one end surface 11 a of the fixed disk portion 11. A toner introduction port 41 for introducing the toner into the space 33 is formed. Further, in a partition area between the two seal members 30 and 31, one end surface of the fixed disk portion 11 is connected to the space 34 and the outside to send magenta toner. A toner introduction port 42 for introducing the toner into the space 34 from 11 a is formed, and further, in the partition region between the two seal members 31, 32, the yellow toner is supplied to the fixed disk portion 11 by communicating the space 35 with the outside. A toner introduction port 43 for introducing the toner into the space 35 from the one end surface 11 a is formed. Further, in the inner region of the seal member 32, the black toner is communicated with the outside through the space 36 and the one end surface 11 a of the fixed disk portion 11. From space 36 They are bored toner introduction port 44 for introducing the. The toner introduction ports 41, 42, 43, and 44 are arranged in a line without any phase shift for cyan, magenta, yellow, and black toners. The toner introduction ports 41, 42, 43, and 44 are connected to downstream ends of toner transport pipes 45, 46, 47, and 48, respectively. The upstream ends of the toner transport pipes 45, 46, 47, and 48 are connected to toner containers 49, 50, 51, and 52 that store cyan, magenta, yellow, and black toners. In the toner transport pipes 45, 46, 47, and 48, a conveying screw (not shown) that is rotationally driven by a driving means (not shown) is disposed. Further, in the toner containers 49, 50, 51, and 52, a delivery screw (not shown) that is rotationally driven by a driving means (not shown) is disposed.

  The toner introduction ports 41, 42, 43, and 44 are normally closed by shutters 53, 54, 55, and 56 biased by biasing means such as a spring. FIG. 7 is a cross-sectional view showing an opening / closing mechanism of a shutter 56 provided in the toner introduction port 44 for black toner. On the inner disk surface of the fixed disk portion 11 (the surface facing the one end surface 10a of the rotating disk portion 10), the shutter 56 is positioned above and below the disk-shaped shutter 56 and the arc trajectory on the surface (see FIG. 6). And a pair of arcuate guide rails 57 that restrict the rotation of the shutter 56 at the position where the shutter 56 fully closes or fully opens the toner inlet 44 (both ends of the arc locus). . The shutter 56 is urged in the fully closed direction by a spring 58 (see FIG. 7A). A projection 56 a having an inclined surface is provided on the back surface of the shutter 56. An opening 60 is formed in the rotating disk portion 10 at a predetermined position on the rotation direction side of the rotating disk portion 10 with respect to the toner receiving port 40, and an elastic hook 59 is elastically supported in the opening 60. A protrusion 59a having an inclined surface is provided at the tip of the elastic hook 59, and the protrusion 59a protrudes from the opening 60 toward the fixed disk portion 11 so as to be able to project and retract. When black development is performed, the rotating disk portion 10 rotates so that the toner receiving port 40 coincides with the toner introduction port 44 of the fixed disk portion 11. At this time, the elastic hook 59 moves in the circumferential direction along with the rotation of the rotary disk portion 10. When the toner receiving port 40 approaches a predetermined distance from the toner introduction port 44, the inclined surfaces of the protrusions 59a of the elastic hook 59 and the protrusions 56a of the shutter 56 come into contact with each other with a certain amount of friction, and the elastic hook 59 By moving in the circumferential direction, the shutter 56 moves on the guide rail 57 against the bias by the spring 58, and the shutter 56 can be held in the fully open position (see FIG. 7B). A similar shutter opening / closing mechanism is also provided at the toner inlet and the toner inlet for cyan, magenta and yellow toners.

  When the black development process is completed, the rotating disk portion 10 starts to rotate again to perform yellow development. At this time, since the movement of the shutter 56 is regulated by the guide rail 57, the elastic hook 59 has a shape in which the movement in the circumferential direction is locked, but the elastic hook 59 is as shown by the arrow in FIG. Thus, the protrusion 59a of the elastic hook 59 can move over the protrusion 56a of the shutter 56.

  Next, the operation of supplying toner to the developing device in the image forming apparatus configured as described above will be described. When a toner replenishment signal is received from the main body of the image forming apparatus, a driving unit (not shown) is operated, and a feeding screw (not shown) and a conveying screw (not shown) are rotationally driven, whereby each of the toner containers 49 and 50. , 51, 52 are conveyed toward the toner inlets 41, 42, 43, 44 of the fixed disk portion 11 via the toner transport pipes 45, 46, 47, 48.

  At this time, the rotary 3 is driven to rotate, and the developing unit corresponding to the toner color to be developed is arranged at the position for developing. The toner receiving port of the rotating disk unit 10 corresponding to the toner color to be developed coincides with the toner introduction port of the fixed disk unit 11. FIG. 1 shows an example in which the developing device 7 for black toner is arranged at the developing position. At this time, as shown in FIG. Only the toner receiving port 40 for black toner is connected to the corresponding toner transport pipe 48. Then, when the rotary 3 rotates 90 ° and the yellow developing device 6 is disposed at the developing position, the toner introduction port 43 of the yellow toner and the toner receiving port 39 coincide with each other, and only the shutter 55 is opened and the yellow developing unit 6 is opened. Only the toner receiving port 39 of the toner is connected to the corresponding toner transport pipe 47. Further, when the rotary 3 is rotated by 90 ° and the magenta developing device 5 is arranged at the developing position, the toner introduction port 42 and the toner receiving port 38 of the magenta toner coincide with each other, and only the shutter 54 opens and the magenta Only the toner receiving port 38 of the toner is connected to the corresponding toner transport pipe 46. Further, when the rotary 3 is rotated by 90 ° and the cyan developing device 4 is arranged at the developing position, the toner introduction port 41 of the cyan toner and the toner receiving port 37 coincide with each other, and only the shutter 53 is opened to open the cyan. Only the toner receiving port 37 of the toner is connected to the corresponding toner transport pipe 45.

  When the black toner developing device 7 is disposed at the developing position, the toner introduction port 44 and the toner receiving port 40 coincide with each other as described above, and as a result, the black toner is introduced into the toner moving path 20. Will be able to. At this time, the toner spilled into the gap between the rotating disk portion 10 and the fixed disk portion 11 from the toner introduction port 44 and the toner receiving port is sealed by the seal member 32 and stays in the space 36, so that one end face 10 a of the rotating disk portion 10. It is possible to prevent the black toner from being mixed with other color toners or the toner from dropping and soiling the main body of the image forming apparatus.

  Then, the developing roller 7a and the like in the developing device 7 are rotationally driven, and black development is started. The operation of the developing device 2 is interlocked with the conveying screw 24 in the toner moving path 20 and toner replenishment is started. That is, the conveying screw 24 in the toner moving path 20 is driven, and the toner ascends in the toner moving path 20 from the toner inlet 20a toward the toner outlet 20b, and is conveyed to the toner replenishing port 7e of the developing unit 7 to be developed. 7 is replenished. At this time, the check valve 61 provided in the toner replenishing port 7e prevents the backflow of toner from the developing device 7 to the toner moving path 20.

  Even when the output of the toner replenishment signal from the image forming apparatus is stopped, the driving of the conveying screw 24 is interlocked with the operation of the developing device 2, so that the toner replenishment is continued for a while during the development. Since the drive of the feed screw (not shown) in 52 and the transport screw (not shown) in the toner transport pipe 48 are stopped, the toner is replenished into the developing device 7 as soon as the toner in the toner moving path 20 runs out. Is configured to stop.

  The present invention can be used in an image forming apparatus such as an electrostatic copying machine or a printer.

These are typical sectional views of the rotary developing device according to the present invention. FIG. 3 is a schematic perspective view of a rotary developing device and a toner container according to the present invention. These are sectional drawings of the axial direction of the rotary developing device according to the present invention. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. These are sectional views taken along the line BB in FIG. These are CC sectional views taken on the line CC in FIG. These are sectional views showing the shutter opening / closing mechanism provided at the toner inlet of black toner when the shutter is fully closed (a) and when fully opened (b). These are typical side views of an example of a conventional rotary developing device. [Fig. 9] is a sectional view taken along line XX in Fig. 8.

Explanation of symbols

2 Rotary developing device 3 Rotary 3a Rotating shaft 4, 5, 6, 7 Developer 4a, 5a, 6a, 7a Developing roller 4b, 5b, 6b, 7b Supply roller 4d, 5d, 6d, 7d Stirring blade 4e, 5e, 6e, 7e Toner supply port 8 Photoreceptor 9 Toner receiving part 10 Rotating disk part 10b Other end face 11 Fixed disk part 12 Partition wall 13, 14, 15, 16 Fan-shaped space 17, 18, 19, 20 Toner moving path 17b, 18b, 19b, 20b Toner outlet 17a, 18a, 19a, 20a Toner inlet 17, 18, 19, 20 Toner moving path 21, 22, 23, 24 Conveying screw 25, 26, 27, 28 Driving means 29, 30, 31, 32 Seal Member 33, 34, 35, 36 Space 37, 38, 39, 40 Toner receiving port 41, 42, 43, 44 Toner introducing port 45 46, 47, 48 toner transport pipe 49, 50, 51, 52 a toner container 53, 54, 55, 56 shutter 56a projections 57 guide rail 58 spring 59 elastically hook 59a projecting 60 opening 61 check valve

Claims (6)

A rotating body, a plurality of developing units attached to the rotating body, a plurality of toner containers that are provided outside the developing unit and store respective toners supplied to the corresponding developing units, and one end of the rotating body A toner receiving portion provided coaxially with the rotating body and projecting in the axial direction; and a plurality of toner moving paths provided inside the toner receiving portion and each of the toners moving to the corresponding developing device. a plurality of toner supply port that is connected to the downstream end of the toner moving path corresponding provided at one end of each of the developing devices, a plurality of toner receiving opening which is connected to the upstream end of the toner moving path, wherein In the image forming apparatus provided with a plurality of toner transport pipes that are provided between a toner container and the toner receiving portion and supply each toner to the corresponding toner moving path, the rotating body has a predetermined The toner transport pipe and the corresponding toner receiving port are connected to each other, so that the toner receiving port, the toner moving path corresponding to the toner receiving port, and the toner moving path correspond to each other. The toner replenishing port communicates, and a predetermined toner can be replenished,
2. The image forming apparatus according to claim 1, wherein the toner moving path is disposed in the same rotation surface inside the toner receiving portion.   The image forming apparatus according to claim 1, wherein the toner supply port is disposed at the same distance from the rotation center regardless of the toner color.   The image forming apparatus according to claim 2, wherein the toner receiving port is disposed at a different distance from the rotation center for each toner color.   The image forming apparatus according to claim 1, wherein the toner replenishment operation to the developing device is performed only for the developing device of the color being developed.   5. An image forming apparatus according to claim 1, further comprising an opening / closing mechanism provided with a normally closed shutter at each toner receiving port and opening only the shutter of the toner receiving port of the color being developed. apparatus.   The image forming apparatus according to claim 1, wherein each toner supply port is provided with a check valve for preventing a back flow of toner.

Images