JP2005164637A - Developer container process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer container capable of easily changing a developer conveying force with a simple constitution. <P>SOLUTION: The developer container is provided with a plurality of developer housing parts 81, 83, 85 filled with the developer to be supplied to a developing mechanism 77, and is provided with a plurality of agitation members 93, 95, 97 which are arranged on the respective developer housing parts 81, 83, 85. The respective agitation members 93, 95, 97 are provided with rotation shafts 101, 105, 109 which are rotatively driven and elastic vane members 103, 107, 111 of which one end sides are attached to the rotation shafts 101, 105, 109 and the other end sides are brought into contact with the bottom parts of the developer housing parts 81, 83, 85. The developer container is designed so that slack quantities of the vane members 103, 107, 111 caused by differences between free lengths L1, L2, L3 from centers of the rotation shafts 101, 105, 109 to the other ends of the vane members 103, 107, 111 and heights H of the rotation shafts 101, 105, 109 from the bottom part come to maximum in the agitation member 93 of the developing mechanism 77 side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a developer container that supplies developer to a developing mechanism, a process cartridge that uses the developer container, and an image forming apparatus that uses the developer container.

  Conventionally, in a copying machine, a printer, or the like, an electrostatic latent image is formed on an image carrier, and the electrostatic latent image is developed using a developer by a developing mechanism. At that time, the developer is supplied from the developer container to the developing mechanism.

  As such a developer storage container, as disclosed in Patent Document 1, a plurality of storage portions filled with a developer are provided, and each storage portion is formed in a circular bottom and is partitioned by a partition member. Each storage portion is communicated with an opening formed by a partition member, and each storage portion is provided with a stirring member. The rotation of the stirring member stirs the developer and conveys the developer to the developing mechanism side. .

  Further, among the plurality of stirring members, the number of rotations of the stirring member closest to the developing mechanism is made the fastest, and the individual number of rotations of the plurality of stirring members is changed. By making the rotational speed of the stirring member closest to the developing mechanism the fastest, the developer can be sufficiently supplied to the developing mechanism until the end, and the stirring ability of the other stirring members is lowered.

Furthermore, the stirring ability is changed by using a sheet material having a different thickness and Young's modulus.
JP2002-182462

  However, in such a conventional apparatus, since the plurality of stirring members have different rotation speeds, the mechanism for rotating the plurality of stirring members becomes complicated, and the developer conveying force is relatively simple and relatively simple. There was a problem to change easily. That is, when the plurality of stirring members are rotated by one drive source, gears 205 to 207 are attached to the stirring members 201 to 203, respectively, and two gears 205 to 207 are interposed between the gears 205 to 207 as shown in FIG. It is necessary to provide step gears 209 and 211, and the mechanism is complicated. Or when it replaced with the two-stage gears 209 and 211 and provided the one-stage gear, it was necessary to change the number of teeth of the gears 205-207, and the mechanism was complicated. Further, when the developer conveying force is changed slightly, a large mechanism change is required.

  Further, each of the stirring members 201 to 203 has a structure in which a sheet material is attached to the rotating shaft, and the stirring force is made different by using each of the stirring members 201 to 203 having a different thickness or Young's modulus. However, various kinds of sheet materials have to be prepared, and there is a problem that the manufacturing becomes complicated.

  An object of the present invention is to provide a developer storage container, a process cartridge and an image forming apparatus using the same, which can easily change the developer conveying force with a simple configuration.

  In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is, a developer storage container including a plurality of developer storage portions filled with a developer supplied to the developing mechanism includes a plurality of stirring members respectively disposed in the developer storage portions. The member includes a rotation shaft that is rotationally driven, and a blade member that has one end attached to the rotation shaft and an elastic member that contacts the bottom of the developer storage portion at the other end. The blade extends from the center of the rotation shaft. The developer, wherein the amount of sag of the blade member, which is the difference between the free length to the other end of the member and the height of the rotating shaft from the bottom, is the largest in the stirring member on the developing mechanism side. That is the storage container.

  The blade member may be changed in length so that the amount of sag of the stirring member on the developing mechanism side is maximized. Further, the position of the blade member attached to the rotating shaft may be changed so that the amount of sag of the stirring member on the developing mechanism side is maximized. Furthermore, it is good also as a structure which changed the height position from the said bottom part of the said rotating shaft, and maximized the said slack amount of the said stirring member by the side of the said development mechanism. Alternatively, the amount of sag may be configured such that the amount of sag of the stirring member on the developing mechanism side is the largest, and the amount of the stirring member that is farther from the developing mechanism side is smaller.

  This is a process cartridge comprising a developing mechanism for developing a latent image formed on an image carrier and any one of the developer storage containers described above for supplying the developer to the developing mechanism. The process cartridge may further include an image carrier. Further, an image carrier on which a latent image is formed, a developing mechanism for developing the latent image formed on the image carrier, and any of the developer storage containers described above that supply the developer to the developing mechanism. This is an image forming apparatus including the image forming apparatus.

  As described above, the developer container of the present invention has an effect that the developer can be appropriately stirred and transported with a simple configuration. When this container is used in a process cartridge or an image forming apparatus, the developer is properly stirred and transported by a simple mechanism.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, a color laser printer 1 as an image forming apparatus has a main body casing 3 in which a sheet feeding unit 7 for feeding a sheet 5 as a recording medium and a sheet 5 that has been fed are predetermined. The image forming unit 9 for forming the image is provided. The paper feed unit 7 includes a paper feed tray 11 in which the papers 5 are stacked and stored, a paper feed roller 13 that contacts the paper 5 at the top of the paper feed tray 11 and picks up the paper 5 one by one by rotation, A conveyance roller 15 and a registration roller 17 are provided for conveying the paper 5 to the image forming position.

  This image forming position is a transfer position for transferring a toner image on a transfer belt 51, which will be described later, onto the paper 5. In the present embodiment, this is a contact position between the transfer belt 51 and a transfer roller 27, which will be described later. The image forming unit 9 includes a scanner unit 21, a process unit 23, a transfer belt mechanism unit 25, a transfer roller 27, a fixing unit 29, and the like.

  The scanner unit 21 includes a laser light emitting unit (not shown), a polygon mirror, a plurality of lenses, and a reflecting mirror at the center in the main body casing 3. In the scanner unit 21, a laser beam based on image data emitted from the laser light emitting unit is allowed to pass or reflect through a polygon mirror, a reflecting mirror, and a lens, so that the photosensitive belt 33 of the photoconductor belt mechanism unit 31 described later. Irradiate the surface with high speed scanning.

  The process unit 23 includes a plurality (four) of cartridges 35 that constitute a developing mechanism, a photosensitive belt mechanism unit 31, and the like. The four cartridges 35 are filled with a developer (hereinafter referred to as toner) for each color. A yellow cartridge 35Y filled with yellow toner, a magenta cartridge 35M filled with magenta toner, and cyan toner are filled. The filled cyan cartridge 35C and the black cartridge 35K filled with black toner are sequentially arranged in parallel in the main body casing 3 from the bottom to the top at a predetermined interval in the vertical direction. Yes.

  Each cartridge 35 includes a developing roller 37 (yellow developing roller 37Y, magenta developing roller 37M, cyan developing roller 37C, black developing roller 37K), a layer thickness regulating blade 75, a supply roller 73, and a plurality of developer containing portions 81, 83, 85, etc., and a separation solenoid 38 (a yellow separation solenoid 38Y, a magenta separation solenoid 38M, a cyan separation) in order to bring the developing rollers 37 into contact with or separate from the surface of the photoreceptor belt 33 described later. The solenoid 38C for black and the solenoid 38K for black separation) are configured to be movable in the horizontal direction.

  The developing roller 37 includes a metal support shaft, and the support shaft is formed by covering with a conductive rubber. Specifically, the developing roller 37 includes an elastic layer made of conductive urethane rubber, silicone rubber, EPDM rubber or the like containing carbon particles, and urethane rubber or urethane resin coated on the surface of the elastic layer. Further, it is covered with a two-layer structure with a coat layer, which is mainly composed of polyimide resin or the like.

  The photosensitive belt mechanism 31 includes a first photosensitive roller 39, a second photosensitive roller 41, a third photosensitive roller 43, and photosensitive members wound around the first to third photosensitive rollers 39, 41, and 43. A body belt 33, a photoreceptor belt charger 45, a potential adder 47, and a potential gradient controller 49 are provided. The configuration of the photoreceptor belt mechanism 31 will be described in detail later.

  The transfer belt mechanism unit 25 is disposed on the rear side of the photosensitive belt mechanism unit 31, and is a first transfer disposed substantially opposite to the second photosensitive roller 41 via the photosensitive belt 33 and a transfer belt 51 described later. Roller 53, a second transfer roller 55 disposed obliquely below and below the first transfer roller 53, and a rear side of the second transfer roller 55 via a transfer roller 27 and a transfer belt 51, which will be described later. And a transfer belt 51 wound around the outer periphery of the first transfer roller 53 through the third transfer roller 57. The transfer belt 51 is formed of an endless belt made of a resin such as conductive polycarbonate or polyimide in which conductive particles such as carbon are dispersed.

  The transfer roller 27 is disposed so as to face the third transfer roller 57 of the transfer belt mechanism unit 25 with the transfer belt 51 interposed therebetween, and a metal roller shaft is covered with a roller made of a conductive rubber material. It is supported rotatably. The transfer roller 27 is configured to be movable between a standby position that is separated from the transfer belt 51 and a transferable position that is close to the transfer belt 51 by a transfer roller contact / separation mechanism (not shown). Note that the standby position and the transferable position are opposed to each other across the conveyance path 59 of the paper 5, and at the transferable position, the paper 5 passing through the conveyance path 59 is pressed between the transfer belt 51 and the transfer position. Is configured to do.

  As will be described later, the transfer roller 27 is positioned at the standby position while the visible image for each color is sequentially transferred to the transfer belt 51, and all the visible images are transferred to the photosensitive belt 33 during printing. When the color image is formed on the transfer belt 51 by being transferred from the transfer belt 51 to the transfer belt 51, the transfer belt 51 is located at a transferable position. The transfer roller 27 is applied with a predetermined transfer bias to the transfer belt 51 at a transferable position by a transfer bias application circuit (not shown).

  The fixing unit 29 is disposed behind the transfer belt mechanism unit 25 and includes a heating roller 61 and a pressing roller 63 that presses the heating roller 61. The heating roller 61 is heated with an outer layer made of silicon rubber and an inner layer made of metal. Has a halogen lamp for.

  Next, the photosensitive belt mechanism 31 of the image forming unit 9 will be described in more detail. The first photosensitive roller 39 is disposed opposite to the rear of the four cartridges 35, and is disposed below the lowest yellow cartridge 35Y. The first photosensitive roller 39 is a roller that is driven to rotate.

  The second photosensitive roller 41 is disposed above the first photosensitive roller 39 in the vertical direction and above the uppermost black cartridge 35K. The second photosensitive roller 41 is rotationally driven by a drive motor (not shown). The third photosensitive roller 43 is disposed obliquely above and rearward of the first photosensitive roller 39. The third photosensitive roller 43 is a roller that is driven to rotate. The first photosensitive roller 39, the second photosensitive roller 41, and the third photosensitive roller 43 are arranged in a triangular shape.

  The second photosensitive roller 41 is given a potential of +800 volts by the potential adder 47 arranged in the vicinity thereof using the power supply of the photosensitive belt charger 45. The first photosensitive roller 39 and the third photosensitive roller 43 are made of a conductive member such as aluminum, and are in contact with a later-described base material layer of the photosensitive belt 33 and connected to a GND terminal (not shown). . That is, the first photosensitive roller 39 and the third photosensitive roller 43 keep the potential of the photosensitive belt 33 at the place where they are in contact with GND.

  The photosensitive belt 33 is wound around a first photosensitive roller 39, a second photosensitive roller 41, and a third photosensitive roller 43. Then, the second photosensitive roller 41 is driven to rotate, and the first photosensitive roller 39 and the third photosensitive roller 43 are driven, so that the photosensitive belt 33 moves around (counterclockwise). To do.

  The photoreceptor belt 33 is an endless belt provided with a base layer (conductive base layer) having a thickness of 0.08 mm and a photosensitive layer having a thickness of 25 μm on one side. The base material layer is made of a nickel conductor formed by a nickel electroforming method, and the photosensitive layer is made of a polycarbonate resin photoconductor.

  As shown in FIG. 1, the photosensitive belt charger 45 is below the photosensitive belt mechanism 31, and on the upstream side of the exposed portion of the photosensitive belt 33 by the scanner unit 21, the first photosensitive roller 39. Near the photosensitive belt 33 so as not to contact the photosensitive belt 33 with a predetermined interval. The photoreceptor belt charger 45 is a positively-charged scorotron charger that generates corona discharge from a charging wire such as tungsten, so that the surface of the photoreceptor belt 33 is uniformly charged positively. It is configured.

  The potential gradient controller 49 is positioned between the second photosensitive roller 41 and the first photosensitive roller 39, and is in contact with the base material layer of the photosensitive belt 33 above the black cartridge 35K. This potential gradient controller 49 drops the potential of the base material layer to GND at the place where it contacts.

  Next, the cartridge 35 will be described in detail. The cartridge 35 for each color has the same configuration, and only the color of the toner as the developer that is filled is different. As shown in FIG. 2, the cartridge 35 includes a cartridge case 71. The cartridge case 71 is formed in a flat hollow shape having a substantially rectangular parallelepiped shape, and one end in the longitudinal direction is opened. A developing roller 37 is partly exposed to the outside in this opening.

  A supply roller 73 that contacts the rear of the developing roller 37 is rotatably supported in the cartridge case 71. A layer thickness regulating blade 75 that contacts the outer periphery of the developing roller 37 is also provided. A developing mechanism 77 is formed by the developing roller 37, the supply roller 73, and the layer thickness regulating blade 75, and the developing mechanism 77 is disposed in a mechanism housing portion 79 formed in the cartridge case 71.

  A predetermined developing bias is applied to the developing roller 37 when developing the photosensitive belt 33, and a predetermined collecting bias is applied when collecting toner. For example, the predetermined development bias is + 300V, and the predetermined recovery bias is −200V.

  Each developing cartridge 35 is filled with a positively charged non-magnetic one-component spherical polymer toner as a developer of each color of yellow, magenta, cyan, and black. At the time of development, the toner is supplied to the developing roller 37 by the rotation of the supply roller 73, is positively frictionally charged between the supply roller 73 and the developing roller 37, and is further supplied onto the developing roller 37. As the developing roller 37 rotates, it enters between the layer thickness regulating blade 75 and the developing roller 37, where it is further sufficiently frictionally charged and carried on the developing roller 37 as a thin layer of a certain thickness. Is done. At the time of recovery, a reverse bias is applied to the developing roller 37 to recover the toner from the photosensitive belt 33 and the toner is accommodated in the cartridge 35.

  In the cartridge case 71, a plurality of first to third developer accommodating portions 81, 83, and 85 in the present embodiment are formed. The first developer accommodating portion 81 is connected to the mechanism accommodating portion 79 and is formed close to the developing mechanism 77. The bottom portion of the mechanism storage portion 79 is formed in an arc shape along the outer shape of the supply roller 73, and the bottom portion of the first developer storage portion 81 is also formed in an arc shape that swells downward.

  A second developer accommodating portion 83 is formed so as to be connected to the first developer accommodating portion 81, and the bottom of the second developer accommodating portion 83 is formed in an arc shape that swells downward. A third developer accommodating portion 85 is formed so as to be connected to the second developer accommodating portion 83, and the bottom of the third developer accommodating portion 85 is formed in an arc shape that swells downward. In the present embodiment, the bottom surfaces of the mechanism storage portion 79 and the first to third developer storage portions 81, 83, and 85 are formed so that the lowest inner surface of each bottom portion has the same height. However, the height of the lowest inner surface may be different for each storage unit due to the difference in the thickness of the bottom.

  The first agitating member 93 is disposed in the first developer accommodating portion 81, the second agitating member 95 is disposed in the second developer accommodating portion 83, and the third agitating member 97 is disposed in the third developer accommodating portion. The portion 85 is disposed. As shown in FIG. 3, the first stirring member 93 includes a rotating shaft 101 and a blade member 103, and the rotating shaft 101 is rotatably supported by the cartridge case 71. The rotating shaft 101 is made of resin, and a flat portion 104 is formed along the longitudinal direction of the rotating shaft 101.

  The elastic blade member 103 is made of PET having a thickness of 0.05 to 0.25 mm, and is formed to have a Young's modulus of 4 GPa. Further, the blade member 103 is formed in a rectangular shape, and one end side of the blade member 103 is attached to the flat portion 104 of the rotating shaft 101 with an adhesive material 106. The blade member 103 has a width that can be stored in the first developer storage portion 81. As shown by a broken line in FIG. 2, the blade member 103 has a free length from the center of the rotating shaft 101 to the other end of the blade member 103 in a state where the blade member 103 is drooped straight without bending the blade member 103. It is formed to be L1.

  Similarly to the first stirring member 93, the second stirring member 95 includes a rotation shaft 105 and a blade member 107. The blade member 107 extends from the center of the rotation shaft 105 to the other end of the blade member 107. Without being bent, the free length in a state where it hangs down straight is formed to be L2.

  Similarly to the first stirring member 93, the third stirring member 97 includes a rotation shaft 109 and a blade member 111. The blade member 111 extends from the center of the rotation shaft 109 to the other end of the blade member 111. Is formed so that the free length in a state where it hangs down straight becomes L3 without bending.

  In the free length L1 of the first stirring member 93, the free length L2 of the second stirring member 95, and the free length L3 of the third stirring member 97, the free length L1 of the first stirring member 93 is the longest, and the third The stirring member 97 is formed so that the free length L3 is the shortest (L1> L2> L3). In the present embodiment, the blade members 103, 107, and 111 are formed with the same material, the same thickness, and the same width, differ only in length, and can be formed by cutting from the same sheet-like material. And easy to manufacture.

  In the present embodiment, the lowest portions of the bottom of the first developer accommodating portion 81, the bottom of the second developer accommodating portion 83, and the bottom of the third developer accommodating portion 85 are the same. The first to third stirring members 93, 95, and 97 are arranged so that the rotational shafts 101, 105, and 109 have the same height H. The distance a between the rotation centers of the first stirring member 93 and the second stirring member 95 is arranged to be the same as the distance a between the rotation centers of the second stirring member 95 and the third stirring member 97. .

  When the first stirring member 93 is disposed in the first developer accommodating portion 81, the other end of the blade member 103 is in contact with the bottom of the first developer accommodating portion 81. Then, a sag of a difference between a free length L1 from the center of the rotating shaft 101 to the other end of the blade member 103 and a height H from the bottom to the center of the rotating shaft 101 occurs, and the blade member 103 has a sag amount Δ1. According to (= L1 -H), it is arranged in an elastically deformed state along the arc at the bottom.

  The same applies to the second stirring member 95 disposed in the second developer accommodating portion 83, and the other end of the blade member 107 is in contact with the bottom of the second developer accommodating portion 83. Then, a sag of a difference between a free length L2 from the center of the rotating shaft 105 to the other end of the blade member 107 and a height H from the bottom to the center of the rotating shaft 105 is generated, and the blade member 107 has a sag amount Δ2. According to (= L2 -H), it is arranged in an elastically deformed state along the arc at the bottom.

  The same applies to the third stirring member 97 disposed in the third developer accommodating portion 85, and the other end of the blade member 111 is in contact with the bottom of the third developer accommodating portion 85. Then, a sag of a difference between a free length L3 from the center of the rotating shaft 109 to the other end of the blade member 111 and a height H from the bottom to the center of the rotating shaft 109 is generated, and the blade member 111 has a sag amount Δ3. According to (= L3 -H), it is arranged in an elastically deformed state along the arc at the bottom. The deflection amount Δ1 of the first stirring member 93 is the largest, the deflection amount Δ3 of the third stirring member 97 is the smallest, and in this embodiment, the ratio of the deflection amounts is Δ1: Δ2: Δ3 = 3: 2: 1.

  On the other hand, as shown in FIG. 4, the blade members 103, 107, 111 of the first to third stirring members 93, 95, 97 are formed to have the same width and the same length, Flat portions 104a, 104b, and 104c whose positions are shifted in the vertical direction may be formed at 105 and 109, respectively.

  The flat portions 104a, 104b, and 104c are formed in a staircase pattern with their positions shifted in the vertical direction. As shown in FIG. 4 (a), the blade member 103 is attached to the lower flat portion 104c. The free length from the center of the rotating shaft 101 to the other end of the blade member 103 is L1. Further, as shown in FIG. 4B, by attaching the blade member 107 to the middle flat portion 104b, the free length from the center of the rotating shaft 105 to the other end of the blade member 107 is set to L2. Further, as shown in FIG. 4C, by attaching the blade member 111 to the upper flat portion 104a, the free length from the center of the rotating shaft 109 to the other end of the blade member 111 is set to L3. Even in this case, the present invention can be implemented in the same manner, and the rotating shafts 101, 105, and 109 and the blade members 103, 107, and 111 can be manufactured in the same shape, and the manufacturing becomes easier.

  Further, as shown in FIG. 5, gears 113, 115, and 117 are fixed to one ends of the rotation shafts 101, 105, and 109 of the first to third stirring members 93, 95, and 97, respectively. The gears 113, 115, 117 have the same shape. Idle gears 119 and 121 arranged between these gears 113, 115 and 117 are rotatably supported by the cartridge case 71. Both idle gears 119, 121 have the same shape.

  Since the gears 113, 115, 117 and the idle gears 119, 121 are arranged in a line, the cartridge 35 can be formed compactly. Further, since the first to third stirring members 93, 95, 97 are rotated at the same rotational speed by a drive source (not shown), the gears 113, 115, 117 and the idle gears 119, 121 can be formed in the same shape. Easy to manufacture.

Next, the operation of the color laser printer 1 will be described.
When printing is started, the paper feed roller 13 is pressed against the uppermost one of the papers 5 stored in the paper feed tray 11 of the paper feed unit 7. The sheets 5 are taken out one by one. The taken paper 5 is fed to the image forming position by the conveying roller 15 and the registration roller 17. A predetermined registration is performed on the fed paper 5 by the registration roller 17.

  The surface of the photosensitive belt 33 is uniformly positively charged by the photosensitive belt charger 45 and then exposed by high-speed scanning of a laser beam from the scanner unit 21 based on the image data. Since the charge is eliminated in the exposed portion, an electrostatic latent image in which a positively charged portion and an uncharged portion are arranged according to the image data is formed on the surface of the photosensitive belt 33. The

  At this time, the first photosensitive roller 39 and the third photosensitive roller 43 supply power to the base material layer of the photosensitive belt 33 with which they abut, and maintain the potential of the abutting portion at GND. The yellow cartridge 35Y of the cartridge 35 is moved rearward in the horizontal direction by the yellow separation solenoid 38Y to the photosensitive belt 33 on which the electrostatic latent image is formed, and the developing roller 37 of the yellow cartridge 35Y is moved to the electrostatic latent image. It is brought into contact with the photosensitive belt 33 on which an image is formed.

  The yellow toner filled in the yellow cartridge 35Y is positively charged and adheres only to an uncharged portion on the photosensitive belt 33. As a result, a yellow visible image is formed on the photosensitive belt 33. At this time, the magenta cartridge 35M, the cyan cartridge 35C, and the black cartridge 35K are moved forward in the horizontal direction by the separation solenoids 38M, 38C, and 38K and separated from the photosensitive belt 33.

  The yellow visible image formed on the photoconductor belt 33 is transferred to the surface of the transfer belt 51 when the photoconductor belt 33 moves and faces the transfer belt 51. At this time, a forward bias (+300 V) is applied to the second photosensitive roller 41 by the power supply of the photosensitive belt charger 45. Then, the photosensitive layer near the second photosensitive roller 41 also has a potential of +300 V through the conductive base material layer. Therefore, a repulsive force is generated between the positively charged yellow toner and the photosensitive layer, and the toner is easily transferred to the transfer belt 51.

  Similarly to the above, for magenta, an electrostatic latent image is formed on the photosensitive belt 33, and then a magenta visible image is formed. Further, the magenta visible image is transferred to the transfer belt 51. . That is, an electrostatic latent image is formed again on the photosensitive belt 33, and then the magenta cartridge 35M is moved rearward in the horizontal direction by the magenta separation solenoid 38M, and the developing roller 37 of the magenta cartridge 35M is moved to the photosensitive body. The yellow cartridge 35Y, the cyan cartridge 35C, and the black cartridge 35K are moved in the horizontal direction by the separation solenoids 38Y, 38C, and 38K to be separated from the photosensitive belt 33 while being brought into contact with the belt 33. When a visible image of magenta is formed on the photoreceptor belt 33 only with the magenta toner filled in the magenta cartridge 35M, the visible image of magenta is moved by the movement of the photoreceptor belt 33 in the same manner as described above. The visible image of the magenta is against the transfer belt 51. When you already yellow visible image is transferred, it is transferred superimposed on the photoreceptor belt 33.

  Such a similar operation is repeated by cyan toner filled in the cyan cartridge 35C and black toner filled in the black cartridge 35K, whereby a color image is formed on the transfer belt 51. The color image formed on the transfer belt 51 is batch-transferred onto the paper 5 by the transfer roller 27 positioned at a transferable position while the paper 5 passes between the transfer belt 51 and the transfer roller 27. The heating roller 61 of the image forming unit 9 fixes the color image transferred onto the paper 5 while the paper 5 passes between the heating roller 61 and the pressing roller 63. Thus, the sheet 5 on which the color image is thermally fixed in the fixing unit 29 is conveyed by the conveying roller 65 to the pair of discharge rollers. The paper 5 sent to the paper discharge roller is discharged onto a paper discharge tray formed on the upper portion of the main body casing 3 by the paper discharge roller.

  On the other hand, at the time of printing, toner is agitated and conveyed in each cartridge 35. As shown in FIG. 2, the first to third stirring members 93, 95, and 97 are rotated at the same rotational speed. In the first developer accommodating portion 81, the blade member 103 comes into contact with the bottom portion by the rotation of the first stirring member 93, and rotates along the bottom portion while being curved according to the shape of the bottom portion. Accordingly, the toner moves together with the blade member 103 and is conveyed from the first developer storage unit 81 to the mechanism storage unit 79.

  The first agitating member 93 has the largest amount of deflection Δ1, the blade member 103 is in contact with the bottom of the first developer storage portion 81 with the largest contact force, and the blade member 103 is in the most curved state. Since it rotates, the stirring force / conveyance force of the toner by the blade member 103 is large, and a lot of toner is strongly agitated, and a lot of toner is conveyed to the mechanism housing portion 79.

  In the second developer accommodating portion 83, the blade member 107 comes into contact with the bottom portion by the rotation of the second stirring member 95, and rotates along the bottom portion while being curved according to the shape of the bottom portion. As a result, the toner moves together with the blade member 107 and is conveyed from the second developer accommodating portion 83 to the first developer accommodating portion 81.

  The second agitating member 95 has a medium amount of deflection Δ2, a medium abutting force with the bottom of the blade member 107, and a medium agitating force and conveying force of the curved blade member 107. The toner is stirred and conveyed by the rotation of the second stirring member 95. Since the amount of deflection Δ2 is medium, toner conveyance to the first developer storage unit 81 is moderately regulated.

  Further, in the third developer accommodating portion 85, the blade member 111 comes into contact with the bottom portion by the rotation of the third stirring member 97, and rotates along the bottom portion while being curved according to the shape of the bottom portion. Accordingly, the toner moves together with the blade member 111 and is conveyed from the third developer accommodating portion 85 to the second developer accommodating portion 83. The third stirring member 97 has the smallest amount of deflection Δ3, the smallest contact force with the bottom of the blade member 111, and the smallest degree of bending of the blade member 111, so that the toner stirring force and conveying force are also small. The toner is stirred and conveyed by the rotation of the third stirring member 97.

  As described above, in the cartridge 35, the toner is transported from the third developer accommodating portion 85 to the second developer accommodating portion 83, and the first developer accommodating portion is transferred from the second developer accommodating portion 83. The toner is conveyed to the portion 81, and further, the toner is conveyed one after another from the first developer accommodating portion 81 to the mechanism accommodating portion 79.

  At this time, the toner transport amount from the third developer storage portion 85 is the smallest, the toner transport amount from the first developer storage portion 81 is the largest, and the toner transport amount from the second developer storage portion 83 is increased. The amount of toner transport is medium. Therefore, the conveyance amount to the mechanism storage unit 79 that consumes toner is the largest, and the toner is reliably supplied. Further, since the conveyance amount from the third developer storage portion 85 is the smallest, unnecessary toner conveyance can be suppressed, and even when the cartridge 35 is flat and thin, development by the developing roller 37 is ensured. Done.

  Next, a cartridge according to a second embodiment different from the above-described embodiment will be described with reference to FIG. The same members as those in the embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, the rotation center heights H1 of the first to third stirring members 93, 95, and 97 from the lowest inner surfaces of the bottoms of the first to third developer accommodating portions 81, 83, and 85, respectively. H3 is different, and the rotation center height H1 of the first stirring member 93 from the lowest inner surface of the bottom of the first developer accommodating portion 81 is the lowest, and the lowest inner surface of the bottom of the third developer accommodating portion 85 is. The rotation center height H3 of the third agitating member 97 is the highest (H1 <H2 <H3). The rotation center distance a1 between the first stirring member 93 and the second stirring member 95 is arranged to be smaller than the rotation center distance a2 between the second stirring member 95 and the third stirring member 97.

  Moreover, each shape of the 1st-3rd stirring members 93,95,97 is the same, and the blade member 103,107,111 of the same shape is attached to the rotating shaft 101,105,109 of the same shape. As indicated by broken lines in FIG. 6, the blade members 103, 107, and 111 are formed by connecting the blade members 103, 107, and 111 from the center of the rotation shafts 101, 105, and 109 to the other ends of the blade members 103, 107, and 111. The free length L in a state where it hangs down straight without being bent is all formed to be the same.

  When the first stirring member 93 is disposed in the first developer accommodating portion 81, the other end of the blade member 103 is in contact with the bottom of the first developer accommodating portion 81. Then, a sag of a difference between a free length L from the center of the rotating shaft 101 to the other end of the blade member 103 and a height H1 from the bottom to the center of the rotating shaft 101 occurs, and the blade member 103 has a sag amount Δ1. In accordance with (= L−H1), they are arranged in an elastically deformed state along the bottom arc.

  The same applies to the second agitating member 95 disposed in the second developer accommodating portion 83, and the free length L from the center of the rotating shaft 105 to the other end of the blade member 107 and the bottom to the center of the rotating shaft 105. The blade member 107 is arranged in an elastically deformed state along the bottom arc according to the amount of sag Δ2 (= L−H2).

  The same applies to the third stirring member 97 disposed in the third developer accommodating portion 85, and the free length L from the center of the rotating shaft 109 to the other end of the blade member 111 and the bottom of the rotating shaft 109. The sag of the difference from the height H3 to the center is generated, and the blade member 111 is arranged in an elastically deformed state along the arc at the bottom according to the sag amount Δ3 (= L−H3).

  Even in the case of the second embodiment, the deflection amount Δ1 of the first stirring member 93 is the largest and the deflection amount Δ3 of the third stirring member 97 is the smallest. Accordingly, as in the above-described embodiment, the toner transport amount from the third developer storage portion 85 is the smallest, the toner transport amount from the first developer storage portion 81 is the largest, and the second development is performed. The amount of toner transported from the agent storage unit 83 is medium.

  The cartridge 35 is filled with toner before use, but the rotation center of the third stirring member 97 having the highest rotation center height H3 is higher than the original filling height filled with toner before use. To be there. The third stirring member 97 is also disposed in the third developer accommodating portion 85 that is farthest from the developing mechanism 77. Since the rotation center height H3 of the third stirring member 97 is higher than the initial filling height, it is possible to prevent the third stirring member 97 from conveying excess toner at the beginning of use of the cartridge 35.

  The distance a2 between the rotation centers of the second stirring member 95 and the third stirring member 97 is larger than the distance a1 between the rotation centers of the first stirring member 93 and the second stirring member 95. The stirring force / conveying force of the stirring member 97 is weakened. Therefore, the stirring / conveying of the toner by the rotation of the third stirring member 97 is the weakest.

  In the above-described embodiment, the photosensitive belt 33 functions as an image carrier. However, the image carrier may be a photosensitive drum, or a so-called process cartridge in which a photosensitive drum as an image carrier is integrated. Even if it exists, it can implement similarly. As described in JP-A-9-304994, process cartridges are well known.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention. For example, the first to third stirring members 93, 95, and 97 in the first embodiment are driven at different rotational speeds, the first stirring member 93 is rotated the fastest, and the third stirring member 97 is the slowest. You may make it rotate.

1 is a schematic configuration diagram of a color laser printer as one embodiment of the present invention. It is an expanded sectional view of the cartridge of this embodiment. It is an expansion disassembled perspective view of the stirring member of this embodiment. It is an enlarged side view as other embodiment of a stirring member. It is explanatory drawing which shows the arrangement | sequence of the gearwheel which transmits rotation to each stirring member as this embodiment. It is an expanded sectional view of the cartridge as a 2nd embodiment. It is explanatory drawing which shows the arrangement | sequence of the gearwheel which transmits rotation to each conventional stirring member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Color laser printer 3 ... Main body casing 5 ... Paper 7 ... Paper feed part 9 ... Image forming part 21 ... Scanner unit 23 ... Process part 25 ... Transfer belt mechanism part 27 ... Transfer roller 29 ... Fixing part 31 ... Photoconductor belt mechanism Numeral 33 ... Photosensitive belt 35 ... Cartridge 37 ... Developing roller 38 ... Separating solenoid 45 ... Photosensitive belt charger 47 ... Potential adder 49 ... Potential gradient controller 51 ... Transfer belt 59 ... Conveyance path 71 ... Cartridge case 73 ... Supply roller 75 ... Layer thickness regulating blade 77 ... Development mechanism 79 ... Mechanism storage part 81 ... First developer storage part 83 ... Second developer storage part 85 ... Third developer storage part 93 ... First stirring member 95 ... Second stirring member 97 ... Third stirring member 101, 105, 109 ... Rotating shaft 103, 107, 111 ... Blade member 104, 104a, 104 , 104c ... flat portion 113, 115, 117 ... gear 119, 121 ... Idle gear

Claims (8)

In a developer container having a plurality of developer containers filled with a developer supplied to the developing mechanism,
Each of the developer accommodating portions includes a plurality of agitating members, and the agitating member includes a rotation shaft that is driven to rotate, one end side attached to the rotation shaft, and the other end side at the bottom of the developer accommodating portion. A blade member having elasticity that comes into contact with the blade, and a slack of the blade member formed by a difference between a free length from the center of the rotating shaft to the other end of the blade member and a height of the rotating shaft from the bottom portion The developer storage container characterized in that the amount of the stirring member on the developing mechanism side is the largest. 2. The developer container according to claim 1, wherein the length of the blade member is changed to maximize the amount of sag of the stirring member on the developing mechanism side. 2. The developer container according to claim 1, wherein the amount of sag of the stirring member on the developing mechanism side is maximized by changing the mounting position of the blade member on the rotating shaft. 2. The developer container according to claim 1, wherein the amount of sag of the stirring member on the developing mechanism side is maximized by changing a height position of the rotating shaft from the bottom. 5. The sag amount is the largest in the amount of sag of the agitating member on the developing mechanism side, and is smaller as the agitating member is farther from the developing mechanism side. 6. The developer container as described. A developing mechanism for developing a latent image formed on the image carrier;
6. A process cartridge comprising the developer container according to claim 1, wherein the developer is supplied to the developing mechanism. The process cartridge according to claim 6, further comprising an image carrier. An image carrier on which a latent image is formed;
A developing mechanism for developing the latent image formed on the image carrier;
An image forming apparatus comprising the developer container according to claim 1, wherein the developer is supplied to the developing mechanism.

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