JP5023922B2 - Developer transport device and image forming apparatus - Google Patents

Description

  The present invention relates to a developer conveying device and an image forming apparatus that convey a developer using a traveling wave electric field.

  In general, a developer transport device that transports a developer using a traveling wave electric field has a transport body in which a large number of linear transport electrodes are arranged in a line, and each transport electrode of the transport body is provided with each transport electrode. On the other hand, a traveling wave electric field is formed by sequentially applying a multiphase AC voltage, and the charged developer is conveyed. Specifically, for example, the negatively charged developer is held in a lump on the transport electrode that is a positive pole among the plurality of transport electrodes, and the positive and negative of the plurality of transport electrodes are alternately switched, A plurality of developer lumps are transported on the transport body at predetermined intervals.

  As such a developer transport device, a device that transports liquid toner (a developer in which fine particles of a developer are dispersed in a liquid) is conventionally known (see Patent Document 1). In this developer conveyance device, one conveyance body is arranged for the photosensitive drum rotating at a predetermined speed, and the lump of liquid toner conveyed by the conveyance body is closest to the photosensitive drum on the conveyance body. At the supplied position, it is attracted to the photosensitive drum and supplied to the photosensitive drum.

JP 2005-31427 A

  However, in the above-described prior art, since the viscosity of the liquid constituting the liquid toner is high, the transport speed may be much slower than the rotational speed of the photosensitive drum. In this case, if the predetermined position of the photosensitive drum passes the supply position when the lump of liquid toner has not reached the supply position, a portion where the liquid toner is not supplied is formed on the photosensitive drum. There was a problem that occurred. Such a problem may occur in the same way even when the developer is in the form of powder, if the rotational speed of the photosensitive drum is increased.

  SUMMARY An advantage of some aspects of the invention is that it provides a developer transport device and an image forming apparatus that can sufficiently supply a developer to a supply target such as a photosensitive drum.

The present invention that solves the above-described problems is a developer conveying device that supplies a charged developer to a moving supply target, and has a supply port that accommodates the developer and opens toward the supply target. A developer transport body that includes a case and a plurality of transport electrodes, and transports the developer contained in the developer case toward the supply target by forming a traveling-wave electric field with the transport electrodes; , And a plurality of the developer transport bodies are arranged at positions where the developer can be supplied to the supply target so as to be different from each other in the moving direction of the supply target, and the surface of the supply target When any part in the moving direction of each of the developer transport bodies reaches the respective supply positions in the plurality of developer transport bodies, the position of the developer with respect to the part is different in each developer transport body, Serial transport electrodes of the developer carrier is characterized in that it is displaced in the transport direction.

  According to the present invention, the plurality of developer transport bodies are arranged so as to be different from each other in the movement direction of the supply target. For example, the first developer transport body supplies the developer to the supply target. Even if it cannot be supplied, the developer can be supplied to the supply target by the second and subsequent developer carriers.

  According to the present invention, the developer is supplied to the supply target by at least one of the plurality of developer transport bodies by disposing a plurality of developer transport bodies so as to be at different positions in the moving direction of the supply target. Therefore, the developer can be sufficiently supplied to the supply target.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a side view showing a schematic configuration of a laser printer according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a structure of a toner supply device. FIG. 3 is a plan view (a) and a cross-sectional view (b) showing the toner carrier, and FIG. 4 is a diagram showing a waveform of a voltage output from each power feeding unit. Further, FIG. 5 is a cross-sectional view showing a toner conveyance state, a cross-sectional view (a) showing a state at time t1, a cross-sectional view (b) showing a state at time t2, and a time t3. It is sectional drawing (c) which shows the state of time.

<Laser printer>
As shown in FIG. 1, a laser printer 1 as an example of an image forming apparatus includes a paper transport mechanism 2, a photosensitive drum 3 as an example of a supply target, a charger 4, a scanner unit 5, and a developer transport. As an example of the apparatus, a toner supply device 7 and a control device 8 are provided. Although not shown, the laser printer 1 is appropriately provided with known configurations such as a paper feed tray and a fixing device.

  The paper transport mechanism 2 is a known mechanism that transports the paper P from the paper feed tray, and transports the paper P to the transfer position of the photosensitive drum 3 via a plurality of rollers (for example, registration rollers 21).

  The photosensitive drum 3, the charger 4 and the scanner unit 5 have a known configuration. Briefly, the surface 3A of the photosensitive drum 3 is uniformly negatively charged by the charger 4, and then exposed by high-speed scanning of the laser beam LB from the scanner unit 5. As a result, the potential of the exposed portion changes and an electrostatic latent image based on the image data is formed. Next, toner T (see FIG. 2) as an example of a developer is supplied from the toner supply device 7 to the electrostatic latent image on the photosensitive drum 3, and this toner T is selected on the surface 3 </ b> A of the photosensitive drum 3. Thus, a toner image is formed. Thereafter, the photosensitive drum 3 and the transfer roller 22 are rotationally driven so as to sandwich and convey the paper P between them, and at this time, the toner image carried on the surface 3A of the photosensitive drum 3 is transferred to the transfer roller. By being attracted to 22, the image is transferred onto the paper P.

<Toner supply device>
As shown in FIG. 2, the toner supply device 7 includes a cartridge case 71 as an example of a developer case, an agitator 72, and a toner transport body 73 as an example of a developer transport body.

  The cartridge case 71 includes a single upper wall 71A, four side walls 71B, and a single bottom wall 71C. The cartridge case 71 has a negatively chargeable, non-chargeable material mainly composed of polyester. A black liquid toner T having a single magnetic component is contained. Here, as the liquid toner T, a known toner can be used, for example, a dispersion medium such as an isoparaffin solvent, a higher fatty acid ester, a silicone oil and the like added with a colorant, a resin, and a charge control agent. Can be used. The upper wall 71A is a rectangular plate-like member in plan view, and is disposed horizontally. A supply port 71 </ b> D disposed at a position facing the photosensitive drum 3 is formed at a proper position on the upper wall 71 </ b> A. The bottom wall 71 </ b> C is formed so that a part thereof is inclined upward toward the downstream side in the transport direction of the toner T by the toner transport body 73, so that the toner T in the cartridge case 71 is transferred to the toner transport body. 73 at the upstream end.

  The agitator 72 is rotatably provided at the deepest part in the cartridge case 71 and agitates the toner T accumulated in the cartridge case 71. The toner T moves to the positive polarity side by electrophoresis when an electric field is formed in the liquid.

  The toner transport body 73 is disposed in the cartridge case 71, and is disposed on the support plate 731 which is a plate member made of synthetic resin and the support plate 731 as shown in FIG. A plurality of transport electrodes 732 and a coating film 733 covering the side of the support plate 731 on which the transport electrodes 732 are disposed are provided. Here, as the coating film 733, for example, a nylon coating film which is a synthetic resin can be employed. The surface of the coating film 733 serves as a transport surface TS for transporting the toner T.

  As shown in FIG. 3A, the transport electrodes 732 are linear wiring patterns made of a metal thin film, and are arranged at equal intervals in the toner T transport direction and orthogonal to the toner T transport direction. They extend along the direction (the axial direction of the photosensitive drum 3) and are arranged in parallel to each other. As shown in FIG. 3B, the first feeding unit VA, the second feeding unit VB, the third feeding unit VC, and the fourth feeding unit VD that output voltages having different phases to the transport electrodes 732, respectively. Are appropriately connected. Specifically, the first power feeding unit VA, the second power feeding unit VB, the third power feeding unit VC, and the fourth power feeding unit VD are repeatedly connected to the respective transport electrodes 732 in this order from the upstream side in the transport direction. . In other words, every three transport electrodes 732 are connected to the same power supply unit (for example, the first power supply unit VA) every third. In the following description, for the sake of convenience, the transport electrode 732 connected to the first power supply unit VA is referred to as “transport electrode EA”, the transport electrode 732 connected to the second power supply unit VB is referred to as “transport electrode EB”, and third. The transport electrode 732 connected to the power supply unit VC is also referred to as “transport electrode EC”, and the transport electrode 732 connected to the fourth power supply unit VD is also referred to as “transport electrode ED”.

  Each of the power supply units VA to VD outputs a voltage having a waveform as shown in FIG. 4 by being appropriately controlled by the control device 8 disposed in the laser printer 1. In other words, the voltages output from the power supply units VA to VD have the same waveform, but are out of phase by 90 °. Specifically, the phase of the voltage waveform is delayed by 90 ° in the order of the first power supply unit VA, the second power supply unit VB, the third power supply unit VC, and the fourth power supply unit VD. Then, a traveling-wave voltage is applied to each transport electrode 732 by each of the power supply units VA to VD controlled by the control device 8 in this manner, thereby forming a traveling-wave electric field on the transport surface TS. .

  Specifically, at time t1 in FIG. 4, when “−550V” is negative and “−450V” is positive with respect to the intermediate potential “−500V”, the first power supply unit VA and the fourth power supply unit VD A negative voltage is output, and positive voltages are output from the second power supply unit VB and the third power supply unit VC. As a result, as shown in FIG. 5A, an electric field EF1 that is opposite to the transport direction is formed between the negative transport electrode EA and the positive transport electrode EB, and the positive transport electrode EC and the negative transport electrode EC are negative. An electric field EF2 is formed in the transport direction between the transport electrode ED. Therefore, a large amount of negative toner T is collected around the positive transport electrodes EB and EC.

  As shown in FIG. 4, at time t2, a negative voltage is output from the first power supply unit VA and the second power supply unit VB, and a positive voltage is output from the third power supply unit VC and the fourth power supply unit VD. . As a result, as shown in FIG. 5B, an electric field EF1 is formed between the negative transport electrode EB and the positive transport electrode EC, so that the toner around the transport electrodes EB and EC at time t1. T moves around the transport electrodes EC and ED that have become positive this time. Similarly, at time t3 (see FIG. 4), as shown in FIG. 5C, an electric field EF1 is formed between the negative transport electrode EC and the positive transport electrode ED, so that time t2 The toner T around the transport electrodes EC and ED moves around the transport electrodes ED and EA that have become positive this time. By repeating the above operation, the toner T is transported on the transport surface TS. That is, the toner T is transported mainly by the movement of the toner T held in a large amount around the positive transport electrode, whereby a large amount of toner T is transported at a predetermined interval. (See FIGS. 5A and 5C).

  As shown in FIG. 2, the toner transport body 73 configured as described above includes a plurality of transport bodies, that is, a first toner transport body 73A and a second toner transport body 73B. The bodies 73 </ b> A and 73 </ b> B are arranged at positions where the toner T can be supplied to the photosensitive drum 3 so as to be different positions in the rotation direction of the photosensitive drum 3. Each of the toner transport bodies 73A and 73B is connected to the power supply device VM including the four power supply units VA to VD described above, and the voltage applied to each of the toner transport bodies 73A and 73B is controlled by the control device. 8 is controlled.

  The first toner transport body 73A is bent in a substantially L shape, and has an inclined portion A1 that inclines toward the supply port 71D as it goes upward from the deepest side of the cartridge case 71, and a downstream of the inclined portion A1 in the transport direction. And a horizontal portion A2 extending in the lateral direction from the end portion on the side. Specifically, the horizontal portion A <b> 2 is disposed so as to be orthogonal to the radial direction of the photosensitive drum 3, and the supply position where the substantially central portion in the toner T transport direction is closest to the surface 3 </ b> A of the photosensitive drum 3. PP.

  Here, the “supply position” refers to a position on the transport surface of the developer transport body where the developer can be drawn (jumped) to the surface to be supplied. Therefore, for example, when the supply target is a flat plate and moves along the surface direction, an arbitrary portion of the transport surface parallel to the surface of the flat plate supply target among the transport surfaces of the developer Can be set as the supply position.

  The second toner transport body 73B is formed in substantially the same manner as the first toner transport body 73A, and is disposed downstream of the first toner transport body 73A in the moving direction of the photosensitive drum 3. That is, the inclined portion B1 and the horizontal portion B2 that are substantially the same as the first toner conveyance body 73A are provided, and the horizontal portion B2 is disposed so as to be orthogonal to the radial direction of the photosensitive drum 3. The substantially central portion closest to the surface 3A of the photosensitive drum 3 in the horizontal portion B2 is the supply position PP.

  In the first toner transport body 73A and the second toner transport body 73B configured as described above, the positional relationship of the transport electrodes 732 with respect to the respective supply positions PP is the same as shown in FIG. It has become. That is, in the horizontal portion A2 of the first toner transport body 73A, the two transport electrodes 732 are arranged symmetrically with respect to the supply position PP, whereas in the horizontal portion B2 of the second toner transport body 73B. Also, the two transport electrodes 732 are arranged symmetrically with respect to the supply position PP.

  In addition, between the adjacent first toner conveyance body 73A and second toner conveyance body 73B, the first toner conveyance body 73A located on the upstream side in the rotation direction of the photosensitive drum 3 and the first toner conveyance body 73A located on the downstream side in the rotation direction. A guard member 9 that suppresses the drop of the toner T onto the two-toner transport body 73B is provided. Specifically, the guard member 9 is a flat plate-like member and is disposed between the inclined portions A1 and B1 so as to be parallel to the inclined portions A1 and B1. Further, the upper end of the guard member 9 is disposed so as to be positioned closer to the second toner transport body 73B than the end of the horizontal portion A2 of the first toner transport body 73A on the downstream side in the transport direction. Further, the lower end of the guard member 9 is disposed so as to be positioned closer to the first toner transport body 73A than the lower end of the second toner transport body 73B.

<Control device>
As shown in FIG. 2, the control device 8 appropriately controls the power supply devices VM (power supply units VA to VD) connected to the toner transport bodies 73A and 73B, thereby supplying the toner T to the respective supply positions PP. The timing at which the sheet is conveyed is appropriately controlled. Specifically, as shown in FIGS. 6A and 6B, the control device 8 is configured so that an arbitrary portion 31 in the moving direction of the surface 3A of the photosensitive drum 3 is in each of the two toner conveying bodies 73A and 73B. Each of the power feeding units VA to VD in each power feeding device VM is controlled so that the position of the toner T with respect to the portion 31 is different in each of the toner transport bodies 73A and 73B. More specifically, the control device 8 determines that the toner T (the toner T closest to the supply position PP; hereinafter, also referred to as “neighbor toner T”) when the portion 31 reaches the supply position PP of the first toner transport body 73A. ) Is arranged farthest from the part 31, the vicinity toner T is closest to the part 31 when the part 31 reaches the supply position PP of the second toner conveyance body 73 </ b> B. Each power supply device VM is controlled so that it becomes. That is, the control device 8 causes the toner T periodically supplied to each supply position PP to be shifted from each other by a half cycle when the portion 31 reaches the supply position PP on each toner transport body 73A, 73B ( Each power supply device VM is controlled so that the phase of each toner T is shifted by 180 °.

  As described above, the position of the adjacent toner T with respect to the portion 31 when the arbitrary portion 31 of the photosensitive drum 3 reaches each supply position PP is the rotational speed of the photosensitive drum 3, the transport speed of the toner T, It is greatly affected by the distance between the supply positions PP. Therefore, the method for shifting the phase of the voltage may be set as appropriate based on the difference in parameters.

  Next, the operation of the toner supply device 7 according to this embodiment will be described. In the drawings to be referred to, FIG. 6 is a cross-sectional view (a) and (b) showing a state where the first part of the photosensitive drum has reached each supply position, and FIG. 7 shows the second part of the photosensitive drum. It is sectional drawing (a) and (b) which show the state which reached | attained each supply position. FIG. 8 is a cross-sectional view (a) and (b) showing a state in which the third portion of the photosensitive drum has reached each supply position.

  As shown in FIG. 6A, when an arbitrary portion 31 (hereinafter, also referred to as “first portion 31”) on the surface 3A of the photosensitive drum 3 reaches the supply position PP of the first toner conveyance body 73A. The neighboring toner T on the first toner conveyance body 73A is arranged farthest from the first portion 31. As a result, almost no toner T is supplied from the first toner transport body 73A to the first part 31, and the first part 31 passes through the supply position PP as it is.

  Thereafter, as shown in FIG. 6B, when the first part 31 reaches the supply position PP of the second toner transport body 73B, the neighboring toner T on the second toner transport body 73B is transferred to the first part 31. It is located at the closest position, that is, the supply position PP. As a result, a large amount of toner T is supplied to the first portion 31. Therefore, if the amount of toner T to be supplied to the first part 31 is “10”, the amount of toner supplied from the first toner transport body 73A to the first part 31 and the second toner transport body 73B The ratio with respect to the toner amount supplied to the first part 31 is, for example, “0:10”.

  Next, the supply of the toner T to the second portion 32 that is separated from the first portion 31 by a predetermined distance rearward in the moving direction of the surface 3A of the photosensitive drum 3 will be described with reference to FIG. As shown in FIG. 7A, when the second portion 32 reaches the supply position PP of the first toner transport body 73A, the adjacent toner T on the first toner transport body 73A is the most from the supply position PP. It is located at a position closer to the supply position PP than a distant position (see FIG. 6A). Accordingly, a small amount of toner T is supplied from the first toner transport body 73A to the second portion 32.

  Thereafter, as shown in FIG. 7B, when the second portion 32 reaches the supply position PP of the second toner transport body 73B, the neighboring toner T on the second toner transport body 73B is slightly smaller than the supply position PP. Located on the downstream side in the toner conveyance direction. As a result, a larger amount of toner T is supplied to the second portion 32 than the amount supplied by the first toner transport body 73A. Therefore, the ratio between the amount of toner supplied from the first toner transport body 73A to the second portion 32 and the amount of toner supplied from the second toner transport body 73B to the second portion 32 is, for example, “2: 8. "

  Next, the supply of the toner T to the third portion 33 that is separated from the second portion 32 by a predetermined distance rearward in the moving direction of the surface 3A of the photosensitive drum 3 will be described with reference to FIG. As shown in FIG. 8A, when the third portion 33 reaches the supply position PP of the first toner transport body 73A, the neighboring toner T on the first toner transport body 73A is changed to that shown in FIG. The position is closer to the supply position PP than the position of. Thus, a larger amount of toner T than the amount of toner T supplied to the second portion 32 in the state of FIG. 7A is supplied from the first toner transport body 73A to the third portion 33. The

  Thereafter, as shown in FIG. 8B, when the third portion 33 reaches the supply position PP of the second toner transport body 73B, the neighboring toner T on the second toner transport body 73B is changed to that shown in FIG. It is located slightly downstream of the position in the toner conveyance direction. As a result, the third portion 33 is supplied with a smaller amount of toner T than the amount of toner T supplied to the second portion 32 in the state of FIG. Therefore, the ratio of the toner amount supplied from the first toner transport body 73A to the third portion 33 and the toner amount supplied from the second toner transport body 73B to the third portion 33 is, for example, “5: 5. "

  Thereafter, by repeating the above-described operation, the ratio of the amount of toner supplied from the toner conveying bodies 73A and 73B to the surface 3A of the photosensitive drum 3 is, for example, “8: 2” → “10: 0” → “8: 2” → “5: 5” → “2: 8” → “0:10” →... As a result, the toner T is uniformly supplied to the surface 3 </ b> A of the photosensitive drum 3.

According to the above, the following effects can be obtained in the present embodiment.
By arranging the two toner conveying bodies 73 at different positions in the moving direction of the surface 3A of the photosensitive drum 3, the toner T is transferred to the photosensitive drum 3 by one of the two toner conveying bodies 73. Since the toner T can be supplied, the toner T can be sufficiently supplied to the photosensitive drum 3.

  When arbitrary portions 31 to 33 on the surface 3A of the photosensitive drum 3 reach the respective supply positions PP in the toner transport bodies 73A and 73B, the position of the toner T with respect to the portions 31 to 33 is the respective toner transport. Since the control device 8 controls each power supply device VM as differently in the bodies 73A and 73B, the toner T can be uniformly supplied to the surface 3A of the photosensitive drum 3.

  Since the guard member 9 is provided between the toner transport bodies 73A and 73B, the toner T that has fallen from the downstream edge of the first toner transport body 73A in the transport direction is prevented from falling on the second toner transport body 73B. Is done. Therefore, the conveyance of the toner T by the second toner conveyance body 73B can be maintained satisfactorily.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above-described embodiment, the position of the portion 31 of the photosensitive drum 3 and the toner T at each supply position PP is shifted by shifting the phase of the voltage output from each power supply device VM. It is not limited. For example, as shown in FIG. 9, the position of each transport electrode 732 relative to the supply position PP of the first toner transport body 73A and the position of each transport electrode 732 relative to the supply position PP of the second toner transport body 73B are defined in the transport direction. By shifting, the position of the portion 31 of the photosensitive drum 3 and the toner T at each supply position PP may be shifted.

In the above-described embodiment, the phase of the voltage output from each power supply device VM is shifted, but the present invention is not limited to this, and the position of the portion 31 of the photosensitive drum 3 and the toner T at each supply position PP. If there is a shift, the phase of the voltage need not be shifted.
In the above embodiment, the present invention is applied to the liquid toner T, but the present invention is not limited to this, and the present invention may be applied to powdered toner.

  In the embodiment, the two toner transport bodies 73 are provided. However, the present invention is not limited to this, and three or more toner transport bodies may be provided. In addition, it is desirable that the phase shift of each toner in each toner transport body is the same. That is, for example, when three toner transport bodies are provided, the phase of each toner on each toner transport body is shifted by 120 °. For example, when four toner transport bodies are provided, the phase of each toner on each toner transport body. Is preferably shifted by 90 °.

In the above embodiment, the present invention is applied to the laser printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.
In the above-described embodiment, the photosensitive drum 3 is employed as a supply target. However, the present invention is not limited to this, and a flat or belt-shaped photoreceptor may be employed, for example.
In the above-described embodiment, the toner T that is negatively charged is used. However, the present invention is not limited to this, and a toner that is charged positively may be used. In this case, the charged state of the photosensitive drum or the like may be reversed from that in the above embodiment.

  In the embodiment, the moving direction of the surface 3A of the photosensitive drum 3 and the transport direction of the toner T (specifically, the transport direction on the horizontal portions A2 and B2) are set to the same direction, but the present invention is not limited to this. It may not be the reverse direction. In this case, the guard member is disposed so as to suppress the fall of the toner from the developer transport body located on the downstream side in the movement direction of the surface of the photosensitive drum to the developer transport body located on the upstream side in the movement direction. do it.

1 is a side view showing a schematic configuration of a laser printer according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a structure of a toner supply device. FIG. 4 is a plan view (a) and a cross-sectional view (b) showing a toner transport body. It is a figure which shows the waveform of the voltage output from each electric power feeding part. FIG. 4 is a cross-sectional view showing a toner conveyance state, a cross-sectional view (a) showing a state at time t1, a cross-sectional view (b) showing a state at time t2, and a cross-section showing a state at time t3. It is a figure (c). FIG. 4 is a cross-sectional view (a) and (b) illustrating a state where a first portion of the photosensitive drum has reached each supply position. FIG. 6 is a cross-sectional view (a) and (b) showing a state in which a second portion of the photosensitive drum has reached each supply position. FIGS. 6A and 6B are cross-sectional views illustrating a state where a third portion of the photosensitive drum has reached each supply position. FIGS. FIG. 6 is a cross-sectional view illustrating a modified example of a toner transport body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser printer 3 Photosensitive drum 3A Surface 7 Toner supply apparatus 8 Control apparatus 9 Guard member 31 1st site | part 32 2nd site | part 33 3rd site | part 71 Cartridge case 71D Supply port 73 Toner conveyance body 73A 1st toner conveyance body 73B Second toner transport body 731 Support plate 732 Transport electrode 733 Coating film A1 Inclination part A2 Horizontal part B1 Inclination part B2 Horizontal part PP Supply position T Toner VA First power supply part VB Second power supply part VC Third power supply part VD Fourth Power supply unit VM Power supply device

Claims (3)

In a developer transport device for supplying a charged developer to a moving supply target,
A developer case that contains the developer and has a supply port that opens toward the supply target;
A plurality of transport electrodes, and a developer transport body that transports the developer contained in the developer case toward the supply target by forming a traveling-wave electric field with the transport electrodes. ,
A plurality of the developer transport bodies are arranged at positions where the developer can be supplied to the supply target so as to be different from each other in the movement direction of the supply target .
When any part in the movement direction of the surface of the supply target reaches each supply position in the plurality of developer transport bodies, the position of the developer with respect to the part is different in each developer transport body, 2. A developer conveying device according to claim 1, wherein a conveying electrode of each developer conveying member is shifted in a conveying direction . A guard member that suppresses the falling of the developer from the developer transport body to the adjacent developer transport body is provided between the developer transport bodies adjacent in the moving direction of the supply target. The developer conveying device according to claim 1 . A developer conveying device according to claim 1;
A power supply unit for supplying power to the developer transport body;
When any part in the movement direction of the surface of the supply target reaches each supply position in the plurality of developer transport bodies, the position of the developer with respect to the part is different in each developer transport body, An image forming apparatus comprising: a control device that controls the power feeding unit.

Images