Toner supply device and image forming apparatus

Abstract

To provide a toner supply device that can prevent, with a simple configuration, adhesion and aggregation of toner onto an inner wall surface of a single supply tube connected with two conveyance tubes.SOLUTION: A toner supply device comprises a supply tube 63, a first conveyance tube, a second conveyance tube, a first conveying member 68, a second conveying member 69, and a loosening member 79A. The loosening member 79A is arranged inside the supply tube 63 reciprocatably in an extension direction of the supply tube 63. The first conveyance tube and the second conveyance tube are arranged side by side in a direction intersecting the extension directions of the conveyance tubes to be joined to each other at a junction 60a with which the supply tube 63 is connected. The loosening member 79A is connected with the first conveying member 68 and the second conveying member 69 at the junction 60a and extends toward the inside of the supply tube 63.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a toner supply device and an image forming apparatus.

Background Art

[0002] In electrophotographic image forming apparatuses such as copiers and printers, an apparatus that develops an electrostatic latent image formed on the surface of a photoreceptor drum, which is an image carrier, with toner and then forms a toner image transferred onto paper is widely used. Regarding the supply of toner to the developing device, a technique for suppressing the adhesion and aggregation of toner to the inner wall surface of the toner conveyance tube has been proposed. An example of such a conventional technique is disclosed in Patent Document 1.

[0003] The conventional toner conveyance device disclosed in Patent Document 1 includes a horizontal conveyance tube for toner, a toner dropping conveyance tube for freely dropping toner downward from the horizontal conveyance tube, and a coil spring disposed vertically within the toner dropping conveyance tube. The upper end portion of the coil spring is rotatably locked to a protruding portion extending in the radial direction of a toner conveyance member that rotates within the horizontal conveyance tube. Thereby, when the toner conveyance member rotates, the coil spring reciprocates in the vertical direction, and it is possible to prevent the toner dropping conveyance tube from being blocked by toner.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described conventional toner conveyance device, although one horizontal conveyance tube is connected to the toner dropping conveyance tube, when two horizontal conveyance tubes are connected to the toner dropping conveyance tube, the configuration for suppressing the adhesion and aggregation of toner to the inner wall surface of the toner dropping conveyance tube becomes complicated, which has been a problem.

[0006] The present invention has been made in view of the above points, and aims to provide a toner supply device and an image forming apparatus that can suppress the adhesion and aggregation of toner on the inner wall surface of a single supply pipe connected to two transport pipes with a simple configuration. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a toner supply device for supplying toner from a first container and a second container to a developing device, comprising a supply pipe, a first transport pipe, a second transport pipe, a first transport member, a second transport member, and a loosening member. The supply pipe is single and connected to the developing device, through which the toner flows into the developing device. The first transport pipe is connected between the first container and the supply pipe, and the toner is transported from the first container side toward the supply pipe side. The second transport pipe is connected between the second container and the supply pipe, and the toner is transported from the second container side toward the supply pipe side. The first transport member is rotatably arranged within the first transport pipe and transports the toner from the first container side toward the supply pipe side. The second transport member is rotatably arranged within the second transport pipe and transports the toner from the second container side toward the supply pipe side. The loosening member is arranged within the supply pipe so as to be reciprocal in the extension direction of the supply pipe. The first and second conveying pipes are arranged in directions that intersect each other's extending directions so that they merge at the junction where the supply pipe is connected. The loosening member is connected to the first and second conveying members at the junction and extends toward the supply pipe. [Effects of the Invention]

[0008] According to the configuration of the present invention, the loosening member can be moved within the supply pipe along with the rotation of the first and second transport members. This makes it possible to suppress the adhesion and aggregation of toner on the inner wall surface of a single supply pipe connected to the first and second transport pipes with a simple configuration. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view of an image forming apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a block diagram showing the schematic configuration of an image forming apparatus. [Figure 3] Figure 1 is a cross-sectional view of the area around the image forming section of the image forming apparatus. [Figure 4] Figure 1 is a perspective view of the area around the toner supply device of the image forming apparatus. [Figure 5] Figure 4 is a front view of the area around the toner supply device. [Figure 6] Figure 4 is a side view of the area around the toner supply device. [Figure 7] Figure 4 is a perspective view of the toner supply device. [Figure 8] Figure 4 is a plan view of the toner supply device. [Figure 9] Figure 7 is a perspective view of the first and second transport pipes of the toner supply device. [Figure 10] Figure 7 is a side view of the first and second transport pipes of the toner supply device. [Figure 11] Figure 9 is a plan view of the first and second transport members of the toner supply device. [Figure 12] Figure 9 is a perspective view of the first and second transport members of the toner supply device. [Figure 13] Figure 10 is a cross-sectional rear view of the area around the transport drive unit of the toner supply device. [Figure 14] Figure 12 is a magnified perspective view of the area around the loosening member of the toner supply device. [Figure 15] Figure 14 is a perspective view of the loosening member of the first embodiment. [Figure 16] Figure 10 is a cross-sectional rear view of the rotation detection unit of the toner supply device. [Figure 17] This is an explanatory diagram showing the rotational state of the first and second detection axes in Figure 16. [Figure 18] This is an explanatory diagram showing the rotational state of the first and second detection axes in Figure 16. [Figure 19] It is an explanatory diagram showing the rotation states of the first detection axis and the second detection axis in FIG. 16. [Figure 20] It is a partial front view of the loosening member in FIG. 14. [Figure 21] It is a partial front view of the loosening member of the second embodiment. [Figure 22] It is a partial front view showing the displacement state of the loosening member in FIG. 21. [Figure 23] It is a partial front view of the loosening member of the third embodiment. [Figure 24] It is a front view of the loosening member of the fourth embodiment.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described based on the drawings. Note that the present invention is not limited to the following content.

[0011] FIG. 1 is a schematic cross-sectional view of an image forming apparatus 1 according to an embodiment. FIG. 2 is a block diagram showing the schematic configuration of the image forming apparatus 1 in FIG. 1. FIG. 3 is a cross-sectional view around an image forming unit 20 of the image forming apparatus 1 in FIG. 1. As an example of the image forming apparatus 1 of the present embodiment, it is a tandem type color printer that transfers a toner image to a sheet S using an intermediate transfer belt 31. The image forming apparatus 1 may be a so-called multifunction machine having functions such as printing, scanning (image reading), facsimile transmission, etc.

[0012] As shown in FIGS. 1, 2, and 3, the image forming apparatus 1 includes a paper feeding unit 3, a paper conveyance unit 4, an exposure unit 5, an image forming unit 20, a transfer unit 30, a fixing unit 6, a paper discharge unit 7, and a control unit 8 provided in its main body 2.

[0013] The paper feed unit 3 is located at the bottom of the main body 2. The paper feed unit 3 holds multiple sheets of paper S before printing and separates and feeds out the paper S one sheet at a time during printing. The paper transport unit 4 extends vertically along the side wall of the main body 2. The paper transport unit 4 transports the paper S fed from the paper feed unit 3 to the secondary transfer unit 33 and the fixing unit 6, and then discharges the fixed paper S from the paper discharge port 4a to the paper discharge unit 7. The exposure unit 5 is located above the paper feed unit 3. The exposure unit 5 irradiates the image forming unit 20 with laser light controlled based on image data.

[0014] The image forming unit 20 is positioned above the exposure unit 5 and below the intermediate transfer belt 31. The image forming unit 20 includes an image forming unit 20Y for yellow, an image forming unit 20C for cyan, an image forming unit 20M for magenta, and an image forming unit 20B for black. These four image forming units 20 have the same basic configuration. Therefore, in the following description, the identification symbols "Y," "C," "M," and "B" representing each color may be omitted unless specifically required.

[0015] The image forming unit 20 includes a photosensitive drum (image carrier) 21 that is rotatably supported in a predetermined direction (clockwise in Figures 1 and 3). The image forming unit 20 further includes a charging unit 22 arranged around the photosensitive drum 21 along its rotational direction, a developing device 40, and a drum cleaning unit 23. A primary transfer unit 32 is positioned between the developing device 40 and the drum cleaning unit 23.

[0016] The photoreceptor drum 21 has a photosensitive layer on its outer surface. The charging unit 22 charges the outer surface of the photoreceptor drum 21 to a predetermined potential. The exposure unit 5 exposes the outer surface of the photoreceptor drum 21, which has been charged by the charging unit 22, and forms an electrostatic latent image of the original image on the outer surface of the photoreceptor drum 21. The developing device 40 supplies toner to this electrostatic latent image and develops it to form a toner image. Each of the four image forming units 20 forms a toner image of a different color. The drum cleaning unit 23 cleans the outer surface of the photoreceptor drum 21 by removing any remaining toner, etc., after the toner image has been primary transferred to the outer surface of the intermediate transfer belt 31. In this way, the image forming units 20 form the image (toner image) that will later be transferred to the paper S.

[0017] The transfer unit 30 comprises an intermediate transfer belt 31, primary transfer units 32Y, 32C, 32M, and 32B, a secondary transfer unit 33, and a belt cleaning unit 34. The intermediate transfer belt 31 is positioned above the four image forming units 20. The intermediate transfer belt 31 is supported so as to be rotatable in a predetermined direction (counterclockwise in Figure 1) and is an endless intermediate transfer body on which toner images formed in each of the four image forming units 20 are sequentially superimposed and primary transferred. The four image forming units 20 are arranged in a so-called tandem configuration, lined up in a row from the upstream side to the downstream side in the rotational direction of the intermediate transfer belt 31.

[0018] The primary transfer units 32Y, 32C, 32M, and 32B are positioned above the respective color image forming units 20Y, 20C, 20M, and 20B, with the intermediate transfer belt 31 in between. The secondary transfer unit 33 is positioned upstream of the fixing unit 6 with respect to the paper transport direction of the paper transport unit 4, and downstream of the four image forming units 20Y, 20C, 20M, and 20B with respect to the rotation direction of the intermediate transfer belt 31. The belt cleaning unit 34 is positioned downstream of the secondary transfer unit 33 with respect to the rotation direction of the intermediate transfer belt 31.

[0019] The primary transfer unit 32 transfers the toner image formed on the outer surface of the photoreceptor drum 21 to the intermediate transfer belt 31. In other words, the toner image is first transferred to the outer surface of the intermediate transfer belt 31 by the primary transfer units 32Y, 32C, 32M, and 32B of each color. Then, as the intermediate transfer belt 31 rotates, the toner images from the four image forming units 20 are successively superimposed and transferred to the intermediate transfer belt 31 at predetermined timings, thereby forming a color toner image on the outer surface of the intermediate transfer belt 31 in which the toner images of the four colors—yellow, cyan, magenta, and black—are superimposed.

[0020] The color toner image on the outer surface of the intermediate transfer belt 31 is transferred to the paper S, which is fed synchronously by the paper transport unit 4, by the secondary transfer nip formed in the secondary transfer unit 33. The belt cleaning unit 34 cleans the intermediate transfer belt 31 by removing any toner or other deposits remaining on its outer surface after the secondary transfer. In this way, the transfer unit 30 transfers (records) the toner image formed on the outer surface of the photoreceptor drum 21 onto the paper S.

[0021] The fixing unit 6 is positioned above the secondary transfer unit 33. The fixing unit 6 heats and pressurizes the paper S onto which the toner image has been transferred, fixing the toner image to the paper S.

[0022] The paper output unit 7 is located above the transfer unit 30. Paper S, on which the toner image has been fixed and printing is complete, is transported to the paper output unit 7. The paper output unit 7 ejects the printed paper (printed material) from the top.

[0023] The control unit 8 includes a CPU, an image processing unit, a memory unit, and other electronic circuits and electronic components (none of which are shown). The CPU controls the operation of each component provided in the image forming apparatus 1 based on control programs and data stored in the memory unit, and performs processing related to the functions of the image forming apparatus 1. The paper feeding unit 3, paper transport unit 4, exposure unit 5, image forming unit 20, transfer unit 30, and fixing unit 6 each receive individual commands from the control unit 8 and perform printing on the paper S in conjunction with each other. The memory unit consists of a combination of non-volatile memory devices such as program ROM (Read Only Memory) and data ROM, and volatile memory devices such as RAM (Random Access Memory).

[0024] Next, the development unit 40 and its surrounding components will be explained using Figure 3. Since the development unit 40 for each color has the same basic configuration, the identification symbols representing each color and their descriptions for the components will be omitted.

[0025] The developing device 40 supplies toner to the outer surface of the photoreceptor drum 21. The developing device 40 comprises a developing container 41, a first agitation and conveying member 42, a second agitation and conveying member 43, a developing roller 44, and a regulating member 45.

[0026] The developing container 41 has an elongated shape that extends along the axial direction of the photoreceptor drum 21 (the depth direction of the paper in Figure 3), and is positioned with its longitudinal direction horizontal. The developing container 41 contains, for example, a magnetic one-component developer containing magnetic toner as the developer. The developer may also be, for example, a non-magnetic one-component developer or a two-component developer containing toner and a magnetic carrier. The developing container 41 has a partition 411, a first transport chamber 412, and a second transport chamber 413.

[0027] The partition 411 is provided in the lower part of the interior of the developing container 41. The partition 411 is located approximately in the center of the lower part of the developing container 41 in a direction intersecting the axial direction (left-right direction in Figure 3), and extends in the axial direction and the vertical direction. The partition 411 divides the interior of the developing container 41 in a direction intersecting the axial direction (left-right direction in Figure 3). The developing container 41 is provided with communication sections (not shown) between the first transport chamber 412 and the second transport chamber 413 at both ends of the partition 411 in the axial direction (depth direction of the paper in Figure 3).

[0028] The first transport chamber 412 and the second transport chamber 413 are located inside the developing container 41. The first transport chamber 412 and the second transport chamber 413 are formed by dividing the inside of the developing container 41 with a partition 411 and are arranged side by side. The second transport chamber 413 is located inside the developing container 41, adjacent to the area below where the developing roller 44 is located. The first transport chamber 412 is located inside the developing container 41, in an area further away from the developing roller 44 than the second transport chamber 413. The first transport chamber 412 receives toner replenishment via the replenishment pipe connection part 412a shown in Figure 3.

[0029] The first agitation and conveying member 42 is positioned inside the first conveying chamber 412. The second agitation and conveying member 43 is positioned inside the second conveying chamber 413. The second agitation and conveying member 43 extends parallel to and close to the developing roller 44. The first agitation and conveying member 42 and the second agitation and conveying member 43 are supported by the developing container 41 so as to be rotatable around an axis that extends parallel to the photoreceptor drum 21. By rotating around their respective axes, the first agitation and conveying member 42 and the second agitation and conveying member 43 convey the developer while agitating it in opposite directions along the axial direction of the rotation.

[0030] As the first agitation and conveying member 42 and the second agitation and conveying member 43 rotate, the developer circulates between the first conveying chamber 412 and the second conveying chamber 413 through the connecting parts located at both ends of the partition 411 in the axial direction. In the first conveying chamber 412 and the second conveying chamber 413, the toner supplied from the outside is agitated and charged.

[0031] The developing roller 44 is positioned inside the developing container 41, above the second agitation and conveying member 43. The developing roller 44 is supported by the developing container 41 so as to be rotatable around an axis that extends parallel to the axis of the photoreceptor drum 21. The developing roller 44 has, for example, a cylindrical developing sleeve that rotates counterclockwise in Figure 3, and a developing roller-side magnetic pole fixed inside the developing sleeve (neither of which are shown).

[0032] The developing roller 44 has a portion of its outer surface exposed from the developing container 41, facing and in close proximity to the photoreceptor drum 21. In the region facing the photoreceptor drum 21, the developing roller 44 carries toner on its outer surface to be supplied to the outer surface of the photoreceptor drum 21. The developing roller 44 causes the toner in the second transport chamber 413 to adhere to the electrostatic latent image on the outer surface of the photoreceptor drum 21, forming a toner image.

[0033] The regulating member 45 is positioned in the region where the developing roller 44 and the photoreceptor drum 21 face each other, on the upstream side in the rotational direction of the developing roller 44. The regulating member 45 is positioned in close proximity to the developing roller 44, with a predetermined gap between its tip and the outer circumferential surface of the developing roller 44. The regulating member 45 extends over the entire axial direction of the developing roller 44 (the depth direction of the paper in Figure 3). The regulating member 45 regulates the thickness of the developer (toner) layer carried on the outer circumferential surface of the developing roller 44.

[0034] The toner in the developing container 41 is agitated, circulated, and charged by the first agitation and conveying member 42 and the second agitation and conveying member 43, and then passed to the outer surface of the developing roller 44 by the second agitation and conveying member 43. After the layer thickness of the toner is restricted by the regulating member 45, the toner is conveyed to the area facing the developing roller 44 and the photoreceptor drum 21 by the rotation of the developing roller 44. When a predetermined developing voltage is applied to the developing roller 44, the potential difference between the potential of the outer surface of the photoreceptor drum 21 and the developing roller 44 causes the toner carried on the outer surface of the developing roller 44 to fly to the outer surface of the photoreceptor drum 21 in the developing space, and the electrostatic latent image on the outer surface of the photoreceptor drum 21 is developed.

[0035] Regarding the replenishment of toner to the developing unit 40, the image forming apparatus 1 includes a first container 51, a second container 52, and a toner replenishment device 60 (see Figure 4). The first container 51, the second container 52, and the toner replenishment device 60 are positioned above the developing unit 40. One of each of the four colors, yellow, cyan, magenta, and black, is provided.

[0036] Next, the configuration of the toner supply device 60 of the first embodiment will be described using Figures 4 to 12. Figure 4 is a perspective view of the area around the toner supply device 60 of the image forming apparatus 1 in Figure 1. Figures 5 and 6 are a front view and a side view of the area around the toner supply device 60 in Figure 4. Figures 7 and 8 are a perspective view and a plan view of the toner supply device 60 in Figure 4. Figures 9 and 10 are a perspective view and a side view of the first transport pipe 66 and the second transport pipe 67 of the toner supply device 60 in Figure 7. Figures 11 and 12 are a plan view and a perspective view of the first transport member 68 and the second transport member 69 of the toner supply device 60 in Figure 9. Figure 13 is a cross-sectional rear view of the area around the transport drive unit 70 of the toner supply device 60 in Figure 10.

[0037] The first container 51, the second container 52, and the toner replenisher 60 include the first container 51Y, the second container 52Y, and the toner replenisher 60Y for yellow, the first container 51C, the second container 52C, and the toner replenisher 60C for cyan, the first container 51M, the second container 52M, and the toner replenisher 60M for magenta, and the first container 51B, the second container 52B, and the toner replenisher 60B for black. These first containers 51, the second containers 52, and the toner replenisher 60 for each color have the same basic configuration. Therefore, in the following description, the identification symbols "Y", "C", "M", and "B" representing each color may be omitted unless specifically required.

[0038] The first container 51 is positioned above the second container 52. The second container 52 is positioned below the first container 51. When viewed from the front, the first container 51 and the second container 52 are positioned offset in the direction of the arrangement of the image forming unit 20 and the toner supply device 60. The first container 51 and the second container 52 are detachable from the main body 2 and contain toner supplied to the developing device 40.

[0039] The first container 51 and the second container 52 are elongated cylindrical shapes extending along the axial direction Dx of the photoreceptor drum 21, and are arranged with their longitudinal direction horizontal. The peripheral walls of the first container 51 and the second container 52 have helical projections 51s and 52s that project radially inward and extend in the longitudinal direction.

[0040] The first container 51 and the second container 52 are closed at one end (front) in the axial direction Dx and have an opening (not shown) at the other end (rear). The first container 51 and the second container 52 are connected to the first container connection part 61 and the second container connection part 62 of the toner supply device 60 at the rear side, which is the opening side. The first container 51 and the second container 52 are supported by the toner supply device 60 so as to be rotatable about an axis that extends parallel to the axial direction Dx of the photoreceptor drum 21.

[0041] The first container 51 and the second container 52 are rotated by a drive unit (not shown) around an axis that extends parallel to the axial direction Dx of the photoreceptor drum 21. As the first container 51 and the second container 52 rotate, the toner inside is sent toward the rear side, which is the opening side, by the spiral projections 51s and 52s. As a result, the toner inside each of the first container 51 and the second container 52 flows into the toner supply device 60 through the opening.

[0042] The toner supply devices 60 are located behind the first container 51 and the second container 52. The four toner supply devices 60 are arranged in a line in the same order as the four image forming units 20. The toner supply devices 60 replenish the toner in the first container 51 and the second container 52 to the developing unit 40.

[0043] The toner replenishment device 60 includes a first container connection part 61, a second container connection part 62, a replenishment pipe 63, a first vertical pipe 64, a second vertical pipe 65, a first transport pipe 66, a second transport pipe 67, a first transport member 68, a second transport member 69, a transport drive unit 70, a loosening member 79A, and a rotation detection unit 80.

[0044] The first container connection section 61 is located at the top of the toner supply device 60 and is positioned above the second container connection section 62. The first container connection section 61 has a toner flow passage (not shown) inside. The opening side of the first container 51 is connected to the first container connection section 61, and the first container 51 is rotatably supported. The downstream end of the first container connection section 61 in the toner flow direction is connected to the first vertical pipe 64. When toner in the first container 51 is supplied to the developer device 40, the toner flows from the first container 51 into the first container connection section 61, passes through the first container connection section 61, and flows out toward the first vertical pipe 64.

[0045] The second container connection section 62 is located above the toner supply device 60 and below the first container connection section 61. The second container connection section 62 has a toner flow passage (not shown) inside. The opening side of the second container 52 is connected to the second container connection section 62, and the second container 52 is rotatably supported. The downstream end of the second container connection section 62 in the toner flow direction is connected to the second vertical pipe 65. When toner in the second container 52 is supplied to the developer device 40, the toner flows from the second container 52 into the second container connection section 62, passes through the second container connection section 62, and flows out toward the second vertical pipe 65.

[0046] The replenishment pipe 63 is located at the bottom of the toner replenishment device 60. The toner replenishment device 60 comprises a single replenishment pipe 63. The replenishment pipe 63 is formed in a cylindrical shape that extends vertically. The upper end of the replenishment pipe 63 is connected to the junction 60a where the first transport pipe 66 and the second transport pipe 67 merge. The lower end of the replenishment pipe 63 is connected to the replenishment pipe connection part 412a of the developing device 40. When toner in the first container 51 and the second container 52 is replenished to the developing device 40, the toner flows from the junction 60a into the replenishment pipe 63, passes through the replenishment pipe 63, and flows into the developing device 40.

[0047] The first vertical tube 64 is positioned between the first container connection 61 and the first transport tube 66. The first vertical tube 64 is formed in a cylindrical shape that extends vertically. The upper end of the first vertical tube 64 is connected to the first container connection 61. The lower end of the first vertical tube 64 is connected to the first transport tube 66. When toner in the first container 51 is supplied to the developing device 40, the toner flows from the first container connection 61 into the first vertical tube 64, passes through the first vertical tube 64, and flows out toward the first transport tube 66.

[0048] The second vertical tube 65 is positioned between the second container connection 62 and the second transport tube 67. The second vertical tube 65 is formed in a cylindrical shape that extends vertically. The upper end of the second vertical tube 65 is connected to the second container connection 62. The lower end of the second vertical tube 65 is connected to the second transport tube 67. When toner in the second container 52 is supplied to the developing device 40, the toner flows from the second container connection 62 into the second vertical tube 65, passes through the second vertical tube 65, and flows out toward the second transport tube 67.

[0049] Because the first container 51 and the first container connector 61 are positioned above the second container 52 and the second container connector 62, the first vertical tube 64 is longer vertically than the second vertical tube 65. Because the second container 52 and the second container connector 62 are positioned below the first container 51 and the first container connector 61, the second vertical tube 65 is shorter vertically than the first vertical tube 64. The first vertical tube 64 and the second vertical tube 65 are positioned at the same location in the axial direction Dx of the photoreceptor drum 21. In other words, the first vertical tube 64 and the second vertical tube 65 are juxtaposed on a straight line perpendicular to the axial direction Dx.

[0050] The first transport pipe 66 is positioned between the first vertical pipe 64 and the supply pipe 63 in the vertical direction. The first transport pipe 66 is formed in a cylindrical shape that extends horizontally. The first vertical pipe 64 is connected to one end of the first transport pipe 66 in the direction of extension. The other end of the first transport pipe 66 in the direction of extension is connected to the confluence section 60a. When toner in the first container 51 is supplied to the developing device 40, the toner flows from the first vertical pipe 64 into the first transport pipe 66 and flows out through the first transport pipe 66 towards the confluence section 60a. In other words, the first transport pipe 66 is connected between the first container 51 and the supply pipe 63, and toner is transported from the first container 51 side to the supply pipe 63 side.

[0051] The second transport pipe 67 is positioned between the second vertical pipe 65 and the supply pipe 63 in the vertical direction. The second transport pipe 67 is formed in a cylindrical shape that extends horizontally. The second vertical pipe 65 is connected to one end of the second transport pipe 67 in the direction of extension. The other end of the second transport pipe 67 in the direction of extension is connected to the confluence section 60a. When toner in the second container 52 is supplied to the developing device 40, the toner flows from the second vertical pipe 65 into the second transport pipe 67 and flows out through the second transport pipe 67 towards the confluence section 60a. In other words, the second transport pipe 67 is connected between the second container 52 and the supply pipe 63, and toner is transported from the second container 52 side to the supply pipe 63 side.

[0052] The first conveyor pipe 66 and the second conveyor pipe 67 are arranged in a direction intersecting their respective extension directions (horizontal direction) so that they merge at the junction 60a where the supply pipe 63 is connected. In other words, the first conveyor pipe 66 and the second conveyor pipe 67 are arranged so that their extension lines intersect at the junction 60a side in their respective extension directions. The angle between the extension directions of the first conveyor pipe 66 and the second conveyor pipe 67 is acute in the horizontal direction, and they are arranged in a V-shape when viewed from above or below.

[0053] The first conveying member 68 is positioned inside the first conveying pipe 66. The first conveying member 68 has a rotating shaft 681 provided between the axial ends of the cylindrical first conveying pipe 66, and a first conveying blade 682 formed on the outer surface of the rotating shaft 681 and extending spirally along the axial direction. The first conveying member 68 is supported inside the first conveying pipe 66 so as to be rotatable about an axis extending in the horizontal direction. One axial end of the first conveying member 68 is located inside the confluence section 60a.

[0054] The first conveying member 68 rotates around its axis, agitating and conveying the toner in the first conveying pipe 66 along a toner conveying direction f1 (see Figures 8, 9, 11, and 12) parallel to the axis of rotation. The first conveying member 68 conveys the toner in the first conveying pipe 66 from the first vertical pipe 64 side toward the confluence section 60a side. In other words, the first conveying member 68 conveys the toner from the first container 51 side toward the replenishment pipe 63 side.

[0055] The second conveying member 69 is positioned inside the second conveying pipe 67. The second conveying member 69 has a rotating shaft 691 provided between the axial ends of the cylindrical second conveying pipe 67, and a second conveying blade 692 formed on the outer surface of the rotating shaft 691 that extends spirally along the axial direction. The second conveying member 69 is supported inside the second conveying pipe 67 so as to be rotatable around an axis extending in the horizontal direction. One axial end of the second conveying member 69 is located inside the confluence section 60a.

[0056] The second transport member 69 rotates around its axis, agitating and transporting the toner in the second transport pipe 67 along a toner transport direction f2 parallel to the axis of rotation (see Figures 8, 9, 11, and 12). The second transport member 69 transports the toner in the second transport pipe 67 from the second vertical pipe 65 side toward the confluence section 60a side. In other words, the second transport member 69 transports the toner from the second container 52 side toward the replenishment pipe 63 side.

[0057] As described above, the first conveying pipe 66 and the second conveying pipe 67 are arranged in a V-shape when viewed from above. That is, the rotation axis 681 of the first conveying member 68 and the rotation axis 691 of the second conveying member 69 are arranged with a predetermined axial angle α.

[0058] The transport drive unit 70 is located at the rear of the toner supply device 60 and is positioned upstream of the first transport pipe 66 and the second transport pipe 67 in the toner transport direction. The transport drive unit 70 comprises a motor 71, a first gear 72, a second gear 73, a third gear 74, an oscillating gear 75, an idler gear 76, and a fourth gear 77.

[0059] The motor 71 generates the driving force to rotate the first conveying member 68 and the second conveying member 69. The motor 71 is controlled by the control unit 8. An output shaft 711 is connected to the motor 71. The output shaft 711 is located below the second conveying member 69 and extends parallel to the rotation axis 691 of the second conveying member 69.

[0060] The first gear 72 is fixed to the output shaft 711 of the motor 71. The first gear 72 is located below the second gear 73, the third gear 74, and the oscillating gear 75. The first gear 72 is rotated by the motor 71. The first gear 72 meshes with the oscillating gear 75 and transmits the driving force of the motor 71 to the oscillating gear 75.

[0061] The second gear 73 is located above the oscillating gear 75. The second gear 73 is fixed coaxially with the rotation axis 691 of the second conveying member 69. The second gear 73 receives driving force from the motor 71 via the oscillating gear 75 and rotates together with the second conveying member 69.

[0062] The third gear 74 is located above the oscillating gear 75. The third gear 74 is spaced apart from and parallel to the second gear 73. The third gear 74 is located closer to the first conveying member 68 than the second gear 73. The third gear 74 rotates by obtaining driving force from the motor 71 via the oscillating gear 75.

[0063] The oscillating gear 75 is located above the first gear 72 and below the second gear 73 and the third gear 74. The oscillating gear 75 is always meshed with the first gear 72. The rotation axis 751 of the oscillating gear 75 is rotatably supported within an arc-shaped guide 78. The arc-shaped guide 78 is formed in an arc shape that extends along the circumferential direction of the first gear 72. As a result, the oscillating gear 75 meshes with the first gear 72 and oscillates along the arc-shaped guide 78 on the outer circumference of the first gear 72. Through its oscillation, the oscillating gear 75 selectively meshes with either the second gear 73 or the third gear 74. The oscillating gear 75 transmits the driving force of the motor 71, obtained via the first gear 72, to either the second gear 73 or the third gear 74.

[0064] The idler gear 76 is positioned between the third gear 74 and the fourth gear 77. The idler gear 76 meshes with both the third gear 74 and the fourth gear 77. The idler gear 76 transmits the driving force of the motor 71, obtained via the third gear 74, to the fourth gear 77.

[0065] The fourth gear 77 is fixed coaxially with the rotation axis 681 of the first conveying member 68. The fourth gear 77 meshes with the idler gear 76. The rotation axis 761 of the idler gear 76 is parallel to the rotation axis of the second gear 73 (the rotation axis 691 of the second conveying member 69). In other words, the fourth gear 77 is a gear that has an axial angle α between its input axis (the rotation axis 761 of the idler gear 76) and its output axis (the rotation axis 681 of the first conveying member 68).

[0066] When the motor 71 is driven and the first gear 72 is rotated clockwise in Figure 13, the oscillating gear 75 rotates by obtaining driving force from the first gear 72 and moves clockwise along the outer circumference of the first gear 72 in Figure 13 along the arc-shaped guide 78. As a result, the oscillating gear 75 meshes with the third gear 74 and transmits the driving force of the motor 71 to the third gear 74. The driving force of the motor 71 transmitted to the third gear 74 is then transmitted to the fourth gear 77 via the idler gear 76. The first transport member 68 is then rotated by the transport drive unit 70 via the fourth gear 77 and transports toner along the toner transport direction f1. Meanwhile, the second transport member 69 stops rotating.

[0067] When the motor 71 is driven and the first gear 72 is rotated counterclockwise in Figure 13, the oscillating gear 75 rotates by obtaining driving force from the first gear 72 and moves counterclockwise along the outer circumference of the first gear 72 in Figure 13 along the arc-shaped guide 78. As a result, the oscillating gear 75 meshes with the second gear 73 and transmits the driving force of the motor 71 to the second gear 73. The second transport member 69 is then rotated by the transport drive unit 70 via the second gear 73 and transports toner along the toner transport direction f2. Meanwhile, the first transport member 68 stops rotating.

[0068] In this way, the transport drive unit 70 selectively rotates one of the first transport member 68 and the second transport member 69.

[0069] The loosening member 79A is positioned inside the supply pipe 63. The loosening member 79A is made of a metal wire, such as stainless steel. The loosening member 79A is connected to the first conveying member 68 and the second conveying member 69, respectively, and extends toward the inside of the supply pipe 63. The loosening member 79A extends, for example, along the entire length of the supply pipe 63 in the vertical direction. The loosening member 79A is positioned to reciprocate in the extension direction (vertical direction) of the supply pipe 63.

[0070] With the above configuration, the loosening member 79A can be moved within the supply pipe 63 along with the rotation of the first transport member 68 and the second transport member 69, respectively. This makes it possible to suppress the adhesion and aggregation of toner on the inner wall surface of a single supply pipe 63 connected to the first transport pipe 66 and the second transport pipe 67 with a simple configuration.

[0071] <First Embodiment> Next, the configuration of the loosening member 79A of the first embodiment will be described. Figure 14 is a partially enlarged perspective view of the area around the loosening member 79A of the toner supply device 60 shown in Figure 12. Figure 15 is a perspective view of the loosening member 79A of the first embodiment shown in Figure 14.

[0072] The first conveying member 68 has a first crank section 68a, and the second conveying member 69 has a second crank section 69a. The first crank section 68a and the second crank section 69a are arranged at the merging section 60a. A loosening member 79A is connected to the first crank section 68a and the second crank section 69a.

[0073] The first crank portion 68a protrudes in a direction intersecting the axial direction of the first conveying member 68. In other words, the first crank portion 68a protrudes radially outward from the axis of the rotation axis 681 of the first conveying member 68 and is bent in a substantially U-shape when viewed from a direction intersecting the axial direction. The central part of the first crank portion 68a in the axial direction is formed in a cylindrical shape extending in that axial direction.

[0074] The second crank portion 69a protrudes in a direction intersecting the axial direction of the second conveying member 69. In other words, the second crank portion 69a protrudes radially outward from the axis of the rotation axis 691 of the second conveying member 69 and is bent in a substantially U-shape when viewed from a direction intersecting the axial direction. The central part of the second crank portion 69a in the axial direction is formed in a cylindrical shape extending in that axial direction.

[0075] The loosening member 79A is connected to the first conveying member 68 and the second conveying member 69 at the merging section 60a. The loosening member 79A has a connecting section 791A and a loosening section 792.

[0076] The connecting portion 791A is positioned above the loosening member 79A. The connecting portion 791A is located above the upper end of the supply pipe 63 and is positioned within the confluence portion 60a. The connecting portion 791A is annular when viewed from the axial direction of the first conveying member 68 and the second conveying member 69. More specifically, the connecting portion 791A is curved, for example, in a roughly C shape and has an opening 7911A with a portion missing in the circumferential direction. The opening 7911A is located above the connecting portion 791A. Both ends of the wire of the connecting portion 791A are further bent upwards.

[0077] The connecting portion 791A is connected across the first crank portion 68a and the second crank portion 69a. In other words, the connecting portion 791A encloses the first crank portion 68a and the second crank portion 69a. The first crank portion 68a and the second crank portion 69a are connected to the inside of the connecting portion 791A via the opening 7911A. With this configuration, the loosening member 79A can be easily connected to the first crank portion 68a and the second crank portion 69a.

[0078] The loosening section 792 is located below the loosening member 79A. The loosening section 792 has a connecting section 7921, an extending section 7922, and a bending section 7923.

[0079] The connecting portion 7921 is located at the upper end of the loosening portion 792. The connecting portion 7921 is bent into an annular shape when viewed from a direction intersecting the axial direction of the first conveying member 68 and the second conveying member 69. The lower part of the connecting portion 791A passes through the connecting portion 7921. As a result, the loosening portion 792 is connected to the connecting portion 791A.

[0080] The extended portion 7922 and the bent portion 7923 extend downward from the connecting portion 7921. That is, the loosening portion 792 extends toward the inside of the supply pipe 63. The extended portion 7922 extends linearly downward from the connecting portion 7921, along the extension direction of the supply pipe 63.

[0081] The bent portion 7923 extends further downward following the extended portion 7922. The bent portion 7923 is formed by bending the extended portion 7922 in the radial direction of the supply pipe 63. When viewed from a direction intersecting the extension direction of the supply pipe 63, the bent portion 7923 is bent into, for example, a roughly V-shape.

[0082] An annular portion 7924 is formed at the lower end of the bent portion 7923. The annular portion 7924 is bent into an annular shape, for example, when viewed from a direction intersecting the extension direction of the supply pipe 63. In this embodiment, the annular portion 7924 is formed into an annular shape with two turns, for example.

[0083] With the above configuration, the loosening member 79A can be moved back and forth vertically within the supply pipe 63 along with the rotation of the first crank section 68a and the second crank section 69a. This makes it possible to suppress the adhesion and aggregation of toner on the inner wall surface of a single supply pipe 63 connected to the first transport pipe 66 and the second transport pipe 67 with a simple configuration.

[0084] Furthermore, the loosening member 79A has a weight (annular portion 7924) at its lower end located inside the supply pipe 63, and by utilizing its inertia, the effect of suppressing the adhesion and aggregation of toner to the inner wall surface of the supply pipe 63 can be enhanced.

[0085] Figure 16 is a cross-sectional rear view of the rotation detection unit 80 of the toner supply device 60 shown in Figure 10. Figures 17, 18, and 19 are explanatory diagrams showing the rotation state of the first detection shaft 81 and the second detection shaft 82 of Figure 16. The rotation detection unit 80 is located at the rear of the toner supply device 60 and is positioned upstream of the transport drive unit 70 in the toner transport direction of the second transport pipe 67. The rotation detection unit 80 comprises a first detection shaft 81, a second detection shaft 82, and an optical sensor 83.

[0086] The first detection shaft 81 is connected to the third gear 74 by extending it coaxially with the rotation shaft 741 of the third gear 74 (see Figures 12 and 13). The first detection shaft 81 is connected to the first conveying member 68 via the third gear 74, idler gear 76, and fourth gear 77, and rotates together with the first conveying member 68. The first detection shaft 81 rotates in the same direction and at the same rotational speed as the first conveying member 68. In this embodiment, the first detection shaft 81 is adjacent to the second detection shaft 82 and extends parallel to the second detection shaft 82.

[0087] The first detection axis 81 has, for example, two first light-shielding plates 811. The two first light-shielding plates 811 extend radially outward from the first detection axis 81 and are arranged at 180-degree angular intervals in the circumferential direction. As the first detection axis 81 rotates, the first light-shielding plates 811 move in and out of the optical path of the optical sensor 83.

[0088] The second detection shaft 82 is extended and connected coaxially with the rotation axis of the second gear 73 (see Figures 12 and 13). The second gear 73 is fixed coaxially with the rotation axis 691 of the second conveying member 69. In other words, the second detection shaft 82 is connected to the second conveying member 69 and rotates together with the second conveying member 69. The second detection shaft 82 rotates in the same direction and at the same rotational speed as the second conveying member 69.

[0089] The second detection axis 82 has, for example, two second light-shielding plates 821. The two second light-shielding plates 821 extend radially outward from the second detection axis 82 and are arranged at 180-degree angular intervals in the circumferential direction. As the second detection axis 82 rotates, the second light-shielding plates 821 move in and out of the optical path of the optical sensor 83.

[0090] The optical sensor 83 is positioned above the first detection axis 81 and the second detection axis 82. The rotation detection unit 80 includes a single optical sensor 83. The optical sensor 83 is, for example, a light-transmitting sensor and comprises a light-emitting unit and a light-receiving unit (both not shown), and has an optical path 83a extending from the light-emitting unit to the light-receiving unit. The optical path 83a extends parallel to the axial direction of the first detection axis 81 and the second detection axis 82, along the depth direction of the paper in Figure 16. The optical sensor 83 detects the shielding (blocking) and unshielding (transmission) of the optical path 83a.

[0091] The first light-shielding plate 811 of the first detection axis 81 and the second light-shielding plate 821 of the second detection axis 82 enter and retract into the optical path 83a of the optical sensor 83. As a result, the optical sensor 83 detects the rotation of the first detection axis 81 and the second detection axis 82. In other words, the optical sensor 83 detects the rotation of the second gear 73 and the third gear 74. The optical sensor 83 outputs signals related to the detection of the rotation of the second gear 73 and the third gear 74 to the control unit 8.

[0092] The control unit 8 receives the output signal from the optical sensor 83. The control unit 8 has a remaining charge detection unit 8a as shown in Figure 2. The remaining charge detection unit 8a's function is implemented in software by a CPU calculation process according to a program stored in the memory unit. Alternatively, the remaining charge detection unit 8a may be formed by an electrical hardware circuit.

[0093] The remaining toner detection unit 8a detects the remaining amount of toner in the first container 51 and the second container 52 based on the output signal from the optical sensor 83. More specifically, the remaining toner detection unit 8a counts the rotational speeds of the second gear 73 and the third gear 74 based on the output signal from the optical sensor 83, and detects the remaining amount of toner in the first container 51 and the second container 52 based on these rotational speeds.

[0094] The remaining amount detection unit 8a counts the rotation speed of the third gear 74 (first transport member 68) based on the output signal from the optical sensor 83, and detects that the toner in the first container 51 is empty based on the rotation speed. The control unit 8 controls the motor 71 to stop the rotation of the first transport member 68 and stops the supply of toner from the first container 51 to the developing unit 40. Subsequently, the control unit 8 reverses the rotation of the motor 71 to rotate the second gear 73 (second transport member 69) and starts supplying toner from the second container 52 to the developing unit 40.

[0095] Similarly, the remaining amount detection unit 8a detects that the toner in the second container 52 is empty based on the rotation speed of the second gear 73 (second transport member 69). Subsequently, the control unit 8 controls the motor 71 to rotate the third gear 74 (first transport member 68) and starts supplying toner from the first container 51 to the developing device 40.

[0096] With the above configuration, a single optical sensor 83 can individually detect the rotation of the second gear 73 (second transport member 69) and the third gear 74 (first transport member 68). This makes it possible to accurately detect the remaining amount of toner in each of the two containers (first container 51 and second container 52) that supply toner to a single developing device 40, while maintaining a low cost and compact size.

[0097] For example, when the toner in the first container 51 becomes empty, the first detection shaft 81 may stop rotating, as shown in Figure 17. According to Figure 17, the first light-shielding plate 811 of the first detection shaft 81 is located on the optical path 83a of the optical sensor 83 and is blocking the optical path.

[0098] Next, the control unit 8 controls the motor 71 to start the rotation of the second transport member 69 and begin supplying toner from the second container 52. As a result, the second detection shaft 82 rotates together with the second transport member 69. Then, as shown in Figure 18, the second light-shielding plate 821 of the second detection shaft 82 comes into contact with the first light-shielding plate 811 on the optical path 83a of the optical sensor 83.

[0099] Furthermore, as the second detection axis 82 rotates, the second light-shielding plate 821 pushes the first light-shielding plate 811 aside, as shown in Figure 19, causing the first light-shielding plate 811 to move out of the optical path 83a of the optical sensor 83. The first light-shielding plate 811 moves out of the rotation area of ​​the second light-shielding plate 821 (inside the dashed circle in Figure 19) and is not detected by the optical sensor 83.

[0100] Furthermore, the image forming apparatus 1 can replenish toner from the first container 51 to the developing apparatus 40, for example, when the toner in the second container 52 becomes empty. Similarly, when the second light-shielding plate 821 is located on the optical path 83a of the optical sensor 83, the first light-shielding plate 811 contacts and pushes away the second light-shielding plate 821, thereby moving the second light-shielding plate 821 away from the optical path 83a of the optical sensor 83.

[0101] In this way, one of the first light-shielding plate 811 and the second light-shielding plate 821 rotates and comes into contact with the other, thereby moving the other out of the optical path 83a of the optical sensor 83. That is, one of the first light-shielding plate 811 and the second light-shielding plate 821 forcibly rotates the other, and further rotates one of the first transport member 68 and the second transport member 69 connected to the other.

[0102] Figure 20 is a partial front view of the loosening member 79A in Figure 14. The connecting portion 791A of the loosening member 79A is connected to the first crank portion 68a and the second crank portion 69a.

[0103] The first crank section 68a has its central axis circling along the trajectory CC1 shown in Figure 20. The dashed line on the trajectory CC1 in Figure 20 represents the circling first crank section 68a. The first crank section 68a is furthest from the second crank section 69a at position P11 on the trajectory CC1, and closest to the second crank section 69a at position P12 on the trajectory CC1.

[0104] The second crank section 69a has its central axis circling along the trajectory CC2 shown in Figure 20. The dashed line on the trajectory CC2 in Figure 20 represents the circling second crank section 69a. The second crank section 69a is furthest from the first crank section 68a at position P21 on the trajectory CC2, and closest to the first crank section 68a at position P22 on the trajectory CC2.

[0105] With respect to the first detection axis 81, as shown in Figure 17, when one of the first light-shielding plates 811 is located on the optical path 83a, the first crank portion 68a is positioned, for example, at position P11 on the trajectory CC1. Conversely, when the other of the first light-shielding plates 811 is located on the optical path 83a, the first crank portion 68a is positioned, for example, at position P12 on the trajectory CC1.

[0106] With respect to the second detection axis 82, when one of the second light-shielding plates 821 is located on the optical path 83a, the second crank portion 69a is positioned, for example, at position P21 on the trajectory CC2. Conversely, when the other of the second light-shielding plates 821 is located on the optical path 83a, the second crank portion 69a is positioned, for example, at position P22 on the trajectory CC2.

[0107] When the first crank section 68a is at position P11 and the second crank section 69a is at position P21, the first crank section 68a and the second crank section 69a are at their furthest distance apart. Conversely, when the first crank section 68a is at position P12 and the second crank section 69a is at position P22, the first crank section 68a and the second crank section 69a are at their closest proximity.

[0108] As described above, one of the first light-shielding plate 811 and the second light-shielding plate 821 retracts the other from the optical path 83a, causing one of the first transport member 68 and the second transport member 69 connected to the other to rotate. That is, when the toner in the first container 51 is empty and the first transport member 68 stops rotating and the second transport member 69 starts rotating, the second light-shielding plate 821 retracts the first light-shielding plate 811 from the optical path 83a, thereby moving the first crank unit 68a from position P11 or position P12. Also, when the toner in the second container 52 is empty and the second transport member 69 stops rotating and the first transport member 68 starts rotating, the first light-shielding plate 811 retracts the second light-shielding plate 821 from the optical path 83a, thereby moving the second crank unit 69a from position P21 or position P22.

[0109] Here, when the first crank section 68a and the second crank section 69a are at their furthest distance apart, they are restrained by the connecting section 791A of the loosening member 79A, making it difficult for the first conveying member 68 and the second conveying member 69 to rotate. Also, when the first crank section 68a and the second crank section 69a are at their closest distance apart, the looseness of the connecting section 791A increases, making it easier for the connecting section 791A to detach from the first crank section 68a and the second crank section 69a. Furthermore, when these conditions are met, there is a risk of malfunctions such as the generation of abnormal noises.

[0110] In contrast, according to the above configuration of this embodiment, one of the first light-shielding plate 811 and the second light-shielding plate 821 is moved out of the optical path 83a, thereby shortening the distance between the first crank portion 68a and the second crank portion 69a from the farthest distance state, or lengthening it from the closest distance state. With this configuration, the farthest distance state and the closest distance state between the first crank portion 68a and the second crank portion 69a can be eliminated. As a result, the first transport member 68 and the second transport member 69 can be rotated smoothly, the connection of the loosening member 79A to the first crank portion 68a and the second crank portion 69a can be maintained, and the generation of abnormal noise can be suppressed.

[0111] <Second Embodiment> Next, the configuration of the loosening member 79B of the second embodiment will be described. Figure 21 is a partial front view of the loosening member 79B of the second embodiment. Figure 22 is a partial front view showing the displacement state of the loosening member 79B of Figure 21. Note that the basic configuration of the second embodiment is the same as that of the first embodiment described earlier, so common components may be given the same reference numerals or names as before, and their descriptions may be omitted.

[0112] The loosening member 79B of the second embodiment has a connecting portion 791B and a loosening portion 792. The connecting portion 791B is formed in a shape that is, for example, substantially oblong or elliptical when viewed from the axial direction of the first conveying member 68 and the second conveying member 69. The connecting portion 791B encloses the first crank portion 68a and the second crank portion 69a. That is, the connecting portion 791B is connected across the first crank portion 68a and the second crank portion 69a.

[0113] The connecting portion 791B has a first external contact portion 7911B and a second external contact portion 7912B. The first external contact portion 7911B and the second external contact portion 7912B are positioned at both ends of the connecting portion 791B with respect to the juxtaposition direction (left-right lateral direction in Figure 21) Db in which the first conveying member 68 and the second conveying member 69 are aligned. The first external contact portion 7911B and the second external contact portion 7912B contact the circumferential surfaces of the first crank portion 68a and the second crank portion 69a from the outside with respect to the juxtaposition direction Db.

[0114] In Figure 21, "L1" is the length Db in the parallel direction between the first outer contact portion 7911B and the second outer contact portion 7912B. "C1" is the distance between the furthest outer circumferences of the first crank portion 68a and the second crank portion 69a in the parallel direction Db when the first crank portion 68a and the second crank portion 69a are at position P11 on trajectory CC1 and position P21 on trajectory CC2. That is, the length L1 in the parallel direction Db between the first outer contact portion 7911B and the second outer contact portion 7912B is shorter than the distance C1 between the furthest outer circumferences of the first crank portion 68a and the second crank portion 69a in the parallel direction Db when the first crank portion 68a and the second crank portion 69a are furthest apart.

[0115] According to the above configuration, when the first crank section 68a and the second crank section 69a are stopped in their furthest apart position, the elastic force of the connecting section 791B moves one of them inward in the parallel direction Db from position P11 on the trajectory CC1 or position P21 on the trajectory CC2, as shown in Figure 22. In other words, the state in which the first crank section 68a and the second crank section 69a are furthest apart can be eliminated. As a result, constraints and rattles are eliminated in the connection between the connecting section 791B and the first conveying member 68 and the second conveying member 69, making it possible to rotate the first conveying member 68 and the second conveying member 69 smoothly.

[0116] <Third Embodiment> Next, the configuration of the loosening member 79C of the third embodiment will be described. Figure 21 is a partial front view of the loosening member 79C of the third embodiment. Note that the basic configuration of the third embodiment is the same as that of the previously described embodiment, so common components may be given the same reference numerals or names as before, and their descriptions may be omitted.

[0117] The loosening member 79C of the third embodiment has a connecting portion 791C and a loosening portion 792. The connecting portion 791C is formed in a shape that is, for example, approximately oblong or elliptical when viewed from the axial direction of the first conveying member 68 and the second conveying member 69. Furthermore, the connecting portion 791C has a recess 7913C in which the central part in the juxtaposition direction Db where the first conveying member 68 and the second conveying member 69 are aligned is recessed downwards. Outside the recess 7913C, the connecting portion 791C encloses the first crank portion 68a and the second crank portion 69a. That is, the connecting portion 791C is connected across the first crank portion 68a and the second crank portion 69a.

[0118] The connecting portion 791C has a first inner contact portion 7911C and a second inner contact portion 7912C. The first inner contact portion 7911C and the second inner contact portion 7912C are positioned at both ends of the recess 7913C with respect to the juxtaposition direction Db. The first inner contact portion 7911C and the second inner contact portion 7912C contact the circumferential surfaces of the first crank portion 68a and the second crank portion 69a from the inside with respect to the juxtaposition direction Db.

[0119] In Figure 21, "L2" is the length Db in the parallel direction between the first inner contact portion 7911C and the second inner contact portion 7912C. "C2" is the distance between the closest outer circumferences of the first crank portion 68a and the second crank portion 69a in the parallel direction Db when the first crank portion 68a and the second crank portion 69a are at position P12 on trajectory CC1 and position P22 on trajectory CC2. That is, the length L2 in the parallel direction Db between the first inner contact portion 7911C and the second inner contact portion 7912C is longer than the distance C2 between the closest outer circumferences of the first crank portion 68a and the second crank portion 69a in the parallel direction Db when the first crank portion 68a and the second crank portion 69a are in their closest state.

[0120] According to the above configuration, when the first crank section 68a and the second crank section 69a stop in their closest position, the elastic force of the connecting section 791C moves one of them outward in the parallel direction Db from position P12 on the trajectory CC1 or position P22 on the trajectory CC2. In other words, the closest position between the first crank section 68a and the second crank section 69a can be eliminated. As a result, constraints and looseness are eliminated in the connection between the connecting section 791C and the first conveying member 68 and the second conveying member 69, making it possible to rotate the first conveying member 68 and the second conveying member 69 smoothly.

[0121] <Fourth Embodiment> Next, the configuration of the loosening member 79D of the fourth embodiment will be described. Figure 24 is a front view of the loosening member 79D of the fourth embodiment. Note that the basic configuration of the fourth embodiment is the same as that of the previously described embodiments, so common components may be given the same reference numerals or names as before, and their descriptions may be omitted.

[0122] The loosening member 79D of the fourth embodiment has a connecting portion 791D and a loosening portion 792D. The connecting portion 791D has two circular portions 7911D and two straight portions 7912D.

[0123] The two circular sections 7911D are formed in a substantially circular shape when viewed from the axial direction of the first conveying member 68 and the second conveying member 69. Each of the two circular sections 7911D encloses the first crank section 68a and the second crank section 69a, respectively, and is adjacent to their outer circumference over the entire circumferential area.

[0124] The two straight sections 7912D are connected to the inside of each of the two circular sections 7911D in the juxtaposition direction Db where the first transport member 68 and the second transport member 69 are aligned. The two straight sections 7912D extend inward in the juxtaposition direction Db from the connection points with each of the two circular sections 7911D. The two straight sections 7912D are arranged on the same straight line as each other.

[0125] The loosening section 792D is positioned in the center of the loosening member 79D with respect to the juxtaposition direction Db. The loosening section 792D is connected to the central end of each of the two straight sections 7912D in the juxtaposition direction Db. The loosening section 792D protrudes downward relative to the two straight sections 7912D and is bent in a roughly U-shape when viewed from the axial direction of the first conveying member 68 and the second conveying member 69. The loosening section 792D extends toward the inside of the supply pipe 63.

[0126] With the above configuration, the elastic force of the roughly U-shaped loosening section 792D makes it possible to eliminate the state in which the first crank section 68a and the second crank section 69a are furthest apart and the state in which they are furthest apart. As a result, the first conveying member 68 and the second conveying member 69 can be rotated smoothly, the connection of the loosening section 79D to the first crank section 68a and the second crank section 69a can be maintained, and the generation of abnormal noise can be suppressed.

[0127] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications can be made to implement the invention without departing from the spirit of the invention.

[0128] For example, in the above embodiment, the image forming apparatus 1 is a so-called tandem-type color printing image forming apparatus that sequentially superimposes images of multiple colors, but it is not limited to such a model. The image forming apparatus may be a color printing image forming apparatus that is not of the tandem type, or a monochrome printing image forming apparatus. [Industrial applicability]

[0129] The present invention can be used in toner supply devices and image forming apparatuses. [Explanation of Symbols]

[0130] 1. Image forming apparatus 8 Control Unit 8a Remaining amount detection unit 20 Image forming unit 21. Photosensitive drum (image carrier) 40 Developing equipment 41 Developing container 51 Container No. 1 52 Container No. 2 60 Toner Refilling Device 60a Junction 63 Supply pipe 66. First conveyor pipe 67. Second conveyor pipe 68 First conveying member 68a First crank section 69 Second conveying member 69a Second crank section 79A, 79B, 79C, 79D Loosening Members 80 Rotation detection unit 81 First detection axis 82 Second detection axis 83 Optical Sensors 83a light path 791A, 791B, 791C, 791D connection part 792, 792D Relaxation Section 811 1st light shielding plate 821 2nd light shielding plate 7911A opening 7911B 1st external contact part 7911C 1st inner contact part 7912B 2nd external contact part 7912C 2nd inner contact part Db juxtaposition direction S paper

Claims

1. In a toner supply device that supplies toner from the first container and the second container to the developing device, A single supply pipe connected to the developing device through which the toner flows into the developing device, A first transport pipe is connected between the first container and the supply pipe, and the toner is transported from the first container side toward the supply pipe side, A second transport pipe is connected between the second container and the supply pipe, and the toner is transported from the second container side toward the supply pipe side, A first transport member is rotatably positioned within the first transport pipe and transports the toner from the first container side toward the supply pipe side, A second transport member is rotatably positioned within the second transport pipe and transports the toner from the second container side toward the supply pipe side, Within the supply pipe, a loosening member is arranged to reciprocate in the extension direction of the supply pipe, Equipped with, The first and second transport pipes are arranged in directions that intersect each other's extension directions so that they merge at the junction where the supply pipe is connected. The loosening member is connected to the first conveying member and the second conveying member at the confluence and extends toward the supply pipe. The first conveying member has a first crank portion that protrudes in a direction intersecting the axial direction of the first conveying member and to which the loosening member is connected, The second conveying member has a second crank portion that protrudes in a direction intersecting the axial direction of the second conveying member and to which the loosening member is connected. The loosening member is, An annular connecting portion that connects the first crank portion and the second crank portion, A loosening section connected to the aforementioned connecting section and extending toward the inside of the supply pipe, A toner supply device characterized by having the following features.

2. The connecting portion has an opening in which a part in the circumferential direction is missing, The toner supply device according to claim 1, characterized in that the first crank portion and the second crank portion are connected to the inside of the connecting portion via the opening.

3. The connecting portion has a first external contact portion and a second external contact portion that contact the circumferential surfaces of the first crank portion and the second crank portion from the outside, in the direction in which the first conveying member and the second conveying member are aligned side by side. The toner supply device according to claim 1, characterized in that the length in the juxtaposition direction between the first outer contact portion and the second outer contact portion is shorter than the distance between the furthest outer peripheral portions of the first crank portion and the second crank portion in the juxtaposition direction when the first crank portion and the second crank portion are in their furthest apart state.

4. The connecting portion has a first inner contact portion and a second inner contact portion that contact the circumferential surfaces of the first crank portion and the second crank portion from the inside, in the direction in which the first conveying member and the second conveying member are aligned side by side. The toner supply device according to claim 1, characterized in that the length in the juxtaposition direction between the first internal contact portion and the second internal contact portion is longer than the distance between the closest outer peripheral portions of the first crank portion and the second crank portion in the juxtaposition direction when the first crank portion and the second crank portion are in their closest position.

5. A first detection shaft connected to the first transport member and rotating together with the first transport member, A second detection shaft is connected to the second transport member and rotates together with the second transport member, A single optical sensor for detecting the rotation of the first detection axis and the second detection axis, A remaining amount detection unit that counts the rotations of the first detection axis and the second detection axis based on the output signal from the optical sensor, and detects the remaining amount of toner in the first container and the second container based on the rotations, Equipped with, The first detection axis has a first light-shielding plate that enters and retracts from the optical path of the optical sensor, The second detection axis has a second light-shielding plate that enters and retracts from the optical path of the optical sensor. The toner supply device according to claim 1, characterized in that one of the first light-shielding plate and the second light-shielding plate rotates and contacts the other, thereby moving the other out of the optical path of the optical sensor, and rotating one of the first transport member and the second transport member connected to the other, thereby shortening the distance between the first crank portion and the second crank portion relative to the farthest distance, or lengthening it relative to the closest distance.

6. The developing apparatus that supplies toner to an image carrier, The first container and the second container contain the toner supplied to the developing device, A toner supply device according to claim 1, which supplies the toner in the first container and the second container to the developing device, An image forming apparatus equipped with [a specific feature].

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