JP5114165B2 - Development device - Google Patents

Description

  The present invention includes a plurality of toner cartridges that store replenishment toners, and a plurality of developing devices that perform image forming processing using the replenishment toners supplied from the plurality of toner cartridges. The present invention relates to a developing device in which a replenishing toner is conveyed by a screw in a horizontal direction in a toner replenishing path to the developing unit.

  Conventionally, developing devices used in image forming apparatuses such as copiers, printers, facsimiles, or multifunction devices that are functionally combined with these include yellow (Y), magenta (M), cyan (C), and the like. A plurality of developing units are arranged in parallel and one endless shape is opposed to each developing unit, such as a tandem type color printer that performs image formation using four color toners of black (K). A transfer belt (or a transport belt) is arranged, and toner is transferred to the surface of transfer paper in the transport process by the rotational movement of the transfer belt (see, for example, Patent Document 1).

  At this time, each developing device is provided with a toner sensor for detecting the toner amount in the developing device, and the replenishing toner is supplied from the toner container containing the replenishing toner to the developing device according to the detection result of the toner sensor. It is replenished.

  Further, when replenishing toner from the toner container to the developing device, the toner discharge port of the toner container and the toner receiving port of the developing device are taken into consideration due to the layout of various components in the image forming apparatus main body. The entrance may be displaced in the horizontal direction for each color.

Therefore, such a horizontal shift is caused by arranging a screw for supplying the replenishing toner in the horizontal direction in the toner replenishing path from the toner container to the developing device for each color, and independently driving the screw for each color. The toner supply timing is synchronized by being driven by the power source.
JP 09-160338 A

  However, in the developing device configured as described above, since the screw is arranged for each color and the screw for each color is driven by an independent drive source, the toner replenishment timing is achieved. There has been a problem that the timing control is complicated.

  In view of the above circumstances, an object of the present invention is to provide a developing device that can simplify the toner replenishment timing control.

  The developing device according to the present invention includes a plurality of toner cartridges that store replenishment toner, a plurality of developing devices that perform image forming processing using the replenishment toner supplied from the plurality of toner cartridges, and the plurality of toner cartridges. A developing device comprising: a screw disposed in a toner replenishing path extending from the plurality of developing devices to convey the replenishing toner in a substantially horizontal direction; and a driving source for rotating the screw. The screw pitch is made different according to the distance between each toner discharge port of the plurality of toner cartridges and each toner receiving port of the plurality of developing devices.

  At this time, the screw has a horizontal separation distance L1, L2,... Ln (n is the number of installed toner cartridges) from each toner discharge port to each toner reception port and at least each toner reception port from each toner discharge port. The screw pitches P1, P2,... Pn are preferably L1 / P1 = L2 / P2 = ... = Ln / Pn, and L1 / P1 = L2 / P2 = ... = Ln / Pn = natural number.

  The developing device of the present invention can realize simplification of toner replenishment timing control.

  Next, a developing device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram of a tandem type full-color printer as an image forming apparatus provided with a developing device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the developing device according to an embodiment of the present invention, and FIG. It is explanatory drawing of the principal part of the developing device which concerns on one Embodiment of this invention.

(Overall configuration of the color printer 11)
In FIG. 1, a color printer 11 according to an embodiment of the present invention includes a paper cassette 13 that stores transfer paper (not shown) inside a printer main body 12, and a paper supply that takes out the transfer paper from the paper cassette 13. An image forming unit 15 that performs image forming processing on a transfer unit supplied from a paper unit 14, a paper feed cassette 13 or a manual feed tray (not shown), and a transfer paper supplied from the paper feed cassette 13 or a manual feed tray The image forming unit 15 includes a secondary transfer unit 17 that transfers the toner image subjected to the image forming process while being guided along the transfer paper conveyance path 16, and a fixing unit 18 that fixes the transferred toner image onto the transfer paper.

  The transfer paper onto which the toner image has been transferred by the secondary transfer unit 17 is fixed by the fixing unit 18 through the transfer paper transport path 16 and then guided to the end of the transfer paper transport path 16 to be transferred to the printer main body 12. The paper is discharged toward a paper discharge tray 12a that also serves as an upper surface.

(Configuration of the image forming unit 15)
For example, the image forming unit 15 employs a tandem method in which toners (developers) of four colors of magenta (M), cyan (C), yellow (Y), and black (K) are arranged to perform image forming processing. And a plurality of toner containers 19 that store toner for replenishing each color, and a drum that forms a toner image based on image data included in print data transmitted from a personal computer (not shown). -Shaped photoconductor 20, a developing device 21 for supplying toner to the photoconductor 20, and an endless belt-shaped intermediate transfer belt (primary transfer body) as a primary transfer body onto which a toner image formed on the photoconductor 20 is transferred 22, a primary transfer roller 23 disposed opposite to the photosensitive member 20 for each color and the intermediate transfer belt 22, and a developing device 21 on the most downstream side in the rotational movement direction of the intermediate transfer belt 22. A toner concentration detection sensor 24 disposed between the secondary transfer unit 17 and a cleaning device disposed substantially on the opposite side of the toner concentration detection sensor 24 to remove residual toner attached to the surface of the intermediate transfer belt 22. 25.

  Each photoconductor 20 has a drum shape and is disposed below the intermediate transfer belt 22 together with the developing device 21. Further, on each photoconductor 20, a charger 26, an exposure device 27, a developing device 21, a primary transfer roller 23, and a static eliminator 28 are arranged around the photoconductor 20 in this order (development process order). The image forming unit 15 is substantially constituted. In addition, a cleaning device 29 is provided between the primary transfer roller 23 and the static eliminator 28 to remove residual toner and the like attached to the surface of the photoreceptor 20. Thus, the toner images of the respective colors can be carried on the surface of each photoconductor 20 based on the laser beam emitted from the exposure device 27 and the toner image can be transferred to the intermediate transfer belt 22.

  Each developing device 21 basically has the same configuration and is arranged adjacent to the lower side of the intermediate transfer belt 22 along the rotational movement direction.

  The intermediate transfer belt 22 is an endless belt disposed in the printer body 12 so as to extend in the horizontal direction, and is circulated and driven (rotated) in accordance with an image forming operation.

  The toner image transferred onto the intermediate transfer belt 22 at each primary transfer portion constituted by the cooperation of the photoconductor 20 and the primary transfer roller 23 passes through the transfer paper transport path 16 from the paper feed cassette 13 or the manual feed tray. Then, the image is transferred by the secondary transfer unit 17 to the transfer paper that has been conveyed.

  The toner density detection sensor 24 measures the reflection density of the toner image on the intermediate transfer belt 22 and, based on the detected value, development conditions such as toner replenishment of each developing device 21 and bias voltage applied to the developing device 21, charging device This is used to execute calibration of the charging conditions of 26, the exposure conditions such as the laser power of the exposure unit 27, the erase light quantity of the static eliminator 28, and the like.

  A plurality of toner density detection sensors 24 can be provided in the rotational direction of the intermediate transfer belt 22 and in the width direction orthogonal to the rotational direction. At this time, the toner density detection sensor 24 is preferably arranged in the vicinity of both widths because the toner density on only one side in the width direction of the intermediate transfer belt 22 cannot be dealt with in the case of one side burn.

  Further, since each toner container 19 and each developing device 21 are spaced apart from each other above and below the intermediate transfer belt 22, replenishment of replenishment toner from the toner container 19 to the developing device 21 as shown in FIG. In order to avoid the intermediate transfer belt 22, the first toner replenishment path 30 that conveys the replenishment toner in a substantially horizontal direction, and at least a distance corresponding to at least the vertical separation distance between the toner container 19 and the developing device 21. A toner replenishment path is constituted by the second toner replenishment path 31 that transports the replenishment toner.

  At this time, in the first toner supply path 30, the supply toner is conveyed by one screw 32. The screw 32 is provided corresponding to each toner container 19, and rotates on the same axis and is simultaneously rotated by being shared by one drive motor 33. The drive motor 33 can be shared by a drive motor 34 that drives a drive system for stirring and transporting the toner for replenishment in the toner container 19 in the toner container 19.

  Further, the toner discharge port of the toner container 19 (substituting by the pipe 35) and the toner receiving port of the developing unit 21 (substituting by the second toner supply path 31) are the layout and size (for example, use) of each toner container 19 The separation distances L <b> 1 to L <b> 4 are different from each other due to the relationship such as for high-frequency black).

  Therefore, when one screw 32 is shared by one drive motor 33 and simultaneously rotated, toner of each color is replenished by the same amount at the same timing.

For example, as shown in FIG. 3, horizontal separation distances L1, L2, L3, L4 from each toner discharge port (pipe 35) to each toner receiving port (second toner supply path 31), and at least each toner discharge port ( Screw pitches P1, P2, P3, P4 from the pipe 35) to each toner receiving port (second toner supply path 31)
L1 / P1 = L2 / P2 = L3 / P3 = L4 / P4
And

  As a result, the toner feed distance during one rotation of the screw 32 can be adjusted, the supply time (supply timing) from the replenishment of each toner container 19 to each developing device 21 can be made constant, and each color can be centrally controlled. In addition, an inexpensive and simple developing device with a small number of equipment can be obtained.

On this occasion,
L1 / P1 = L2 / P2 = L3 / P3 = L4 / P4 = 1 (natural number)
Then, the rotation speed control of the screw 32 becomes easier.

  In the above-described embodiment, the developing device of the present invention is applied to the tandem color printer 11. However, the developing device can be applied to all image forming apparatuses such as a copying machine and a multifunction machine. Of course.

1 is an explanatory diagram of a tandem full-color printer as an image forming apparatus including a developing device according to an embodiment of the present disclosure. FIG. It is explanatory drawing of the developing device which concerns on one Embodiment of this invention. It is explanatory drawing of the principal part of the developing device which concerns on one Embodiment of this invention. It is explanatory drawing of the other developing apparatus which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 19 ... Toner cartridge 21 ... Developing device 31 ... 2nd toner supply path (toner receiving port)
32 ... Screw 33 ... Drive motor (drive source)
35 ... Piping (toner outlet)

Claims (2)

A plurality of toner cartridges containing replenishing toner, a plurality of developing units for performing image forming processing using the replenishing toner supplied from the plurality of toner cartridges, and the plurality of toner cartridges to the plurality of developing units in the developing device provided with a screw for conveying a substantially horizontal direction replenishment toner is disposed in the toner supply path extending, and a single drive source for rotating the one screw, and
The screws have different screw pitches according to the distances between the respective toner outlets of the plurality of toner cartridges and the respective toner inlets of the plurality of developing units, and the respective toner inlets from the respective toner outlets. Ln (n is the number of installed toner cartridges) and at least the screw pitches P1, P2,... Pn from each of the toner discharge ports to each of the toner receiving ports,
L1 / P1 = L2 / P2 = ... = Ln / Pn
A developing device characterized by that. The developing device according to claim 1 , wherein L1 / P1 = L2 / P2 = ... = Ln / Pn = natural number .

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