JP4192815B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In an electrophotographic color image forming apparatus, yellow, magenta, cyan, and black toner images are sequentially formed, and finally, the color toner images are superimposed on a sheet to obtain a color image. For this reason, a developing device that visualizes the electrostatic latent image formed on the image carrier with each color toner is required for the four colors. In order to arrange the plurality of developing devices as efficiently as possible, the plurality of developing devices are integrated.

The developing device generally forms an electric field with the image carrier in order to increase development efficiency, and the power required to form the electric field is supplied from the power source of the image forming apparatus. It is supplied to the plurality of developing devices via a cord. Further, a toner concentration sensor is provided to detect the toner concentration stored in the developing device, and exchanges electric signals with the control board.
JP-A-8-146687

  In an image forming apparatus having a plurality of developing units, power supply for electric field formation and transmission / reception of electric signals are performed for each developing unit. Therefore, codes for signal transmission / reception and power supply are provided in the image forming apparatus. It may be complicatedly routed in the interior, causing contact with other parts, damage due to friction, and electric leakage. In addition, since the handling is prioritized, a plurality of codes are bundled, causing a bad influence on image formation such as a control failure caused by a decrease in signal transmission efficiency due to mutual interference between signals transmitted in adjacent codes. It was. In particular, the electrical signal exchanged between the toner density sensor and the control board is easily affected by the high-voltage current supplied to the developing device for forming an electric field between the developing sleeve and the image carrier, and is accurate. In some cases, the toner density cannot be detected, and an appropriate image output cannot be obtained.

  SUMMARY An advantage of some aspects of the invention is that it provides a developing device and an image forming apparatus that can obtain image forming conditions with high accuracy.

According to a first aspect of the present invention, there is provided an image carrier, a latent image forming means for forming a latent image on the image carrier, a plurality of developers containing a developer having a developer base plate provided with a developing sleeve, and a plurality of developers. A side plate for fixing the developer unit lid on the stacked developer unit lid and a plurality of the developer units from both sides to fix the relative positions of the developer unit lid and the developer unit; In the image forming apparatus comprising a control board that transmits and receives electrical signals and a bias power source that supplies power to the developing sleeve, the developing unit includes a sensor that detects the state of the developer, and the side plate Has a conductive member that connects the sensor and the control board, and is formed through the overlapped adjacent two developing units and the stacked developing units. Through the open space And a power supply path for connecting the bias power supply and over blanking, said conductive member and said electric power supply path is an image forming apparatus characterized by being separated by the developing unit bottom plate.

According to a second aspect of the present invention, the power supply path includes an electrode plate, and the electrode plate supplies power to the developing sleeve and has a spring force for urging the developing sleeve toward the image carrier. The image forming apparatus according to claim 1.

  According to the image forming apparatus of the first aspect, it is possible to reduce the number of exposed portions of the codes, and it is possible to reduce the influences such as breakage of the codes and mutual interference with signals of other codes. In addition, the length of the power supply path connecting the power supply unit and the developing device can be made as short as possible, and the possibility that other electric components are subject to the interference of electrical noise can be further reduced.

  Further, no complicated jigs are required when assembling the developing device, and the number of steps and parts can be reduced. Further, when the image forming apparatus is disassembled, the power supply paths can be easily separated, and the power supply paths can be easily recycled.

  Further, even when a thin plate-like power supply path is used, it is possible to avoid damage to the power supply path. In addition, since a power supply path for supplying power is accommodated inside the plurality of integrated developing devices, it is necessary to worry about handling of codes when replacing the plurality of integrated developing devices. In addition, the possibility that the power feeding path is damaged at the time of replacement can be made extremely low.

Further , by separating the power feeding path and the conductive member, the mutual interference between the electric power supplied to each developing unit and the electric signal exchanged between each developing unit and the control board is extremely reduced. It becomes possible. In addition, it is possible to avoid a connection error when attaching each developing means.

According to the image forming apparatus of claim 2 , the electrode plate urges the developing sleeve toward the image carrier by a spring force , so that the pressing force is applied between the image carrier and the roller. This helps to determine the position of the cartridge displacement portion.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional configuration diagram illustrating a configuration of a color printer which is an example of an image forming apparatus. In this color printer, the respective color toner images sequentially formed on the image carrier are superimposed, and then transferred onto the transfer material at a transfer portion at a time to form a color image, and then the transfer material is separated by a separating means. Is a color image forming apparatus of a type that peels from the surface of the image carrier.

  In FIG. 1, a photosensitive drum 10 which is an image carrier according to the present invention is formed by coating an organic photosensitive member on a drum base, and is driven to rotate in the clockwise direction shown in the drawing. The scorotron charger 12 applies uniform charging to the peripheral surface of the photosensitive drum 10 by corona discharge.

  After the photosensitive drum 10 is uniformly charged, the image exposure unit 13 performs image exposure based on the image signal. The image exposure means 13 uses a laser diode (not shown) as a light source, and passes through a polygon mirror 131, an fθ lens 132, and a cylindrical lens 133 that rotate at high speed, and the optical path is bent by a reflection mirror 134 to perform main scanning on the photosensitive drum 10. In addition to that, an electrostatic latent image is formed by the rotation (sub-scanning) of the photosensitive drum 10.

  Around the photosensitive drum 10, developing units 14Y and 14M each containing a two-component developer composed of toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier are incorporated. , 14C, 14K are provided. The developing cartridge C according to the developing device of the present invention includes developing devices 14Y, 14M, and 14C according to the developing means of the present invention. The developing cartridge K has a developing device 14K. The developing cartridge C and the developing cartridge K are placed on a support frame (not shown) and are fixed at a predetermined position on the support frame by a lock mechanism (not shown).

  In the color printer of FIG. 1, development is first performed by the yellow developing device 14Y. The developing sleeve 141 contains a magnet and rotates while holding the two-component developer. The two-component developer comprises a carrier having ferrite as a core and coated with an insulating resin around the toner, and a toner containing polyester as a main material and a pigment according to color, a charge control agent, silica, titanium oxide and the like. Thus, the developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 141 and conveyed to the developing area where the developing sleeve 141 and the photosensitive drum 10 are opposed to each other. The gap between the developing sleeve 141 and the photosensitive drum 10 in the developing area is 0.2 to 1.0 mm, which is larger than the developer layer thickness, and an AC bias and a DC bias are applied in an overlapping manner, and a developing electric field is generated. It is formed. The yellow toner, which has been triggered to leave the carrier by the AC bias, does not adhere to a portion having a higher potential than the DC bias, but adheres to a portion having a lower potential than the DC bias and is visualized.

  After the first color visualization is completed, the second magenta image forming process is started, and uniform charging is performed again by the scorotron charger 12, and an electrostatic latent image based on the second color image data is formed by the image exposure means 13. The electrostatic latent image is formed with magenta toner by the magenta developing device 14M. For the third color cyan and the fourth color black, an image forming process similar to that of the second color magenta is performed, and a four-color visible image is formed on the circumferential surface of the photosensitive drum 10.

  On the other hand, one transfer material (plain paper, OHP sheet, etc.) P carried out from the paper feed cassette 15 via the half-moon roller 16 temporarily stops, and when the transfer timing is ready, the registration roller pair 17 of the paper feed unit. Is fed to a transfer area where the photosensitive drum 10 and the transfer roller 18 face each other. In the transfer area, the transfer roller 18 is pressed against the peripheral surface of the photosensitive drum 10 in synchronism with the transfer timing, and the multi-color image is transferred collectively with the fed transfer material P interposed therebetween.

  Next, the transfer material P is neutralized by the separating means 19 brought into the pressure contact state almost simultaneously, separated from the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 21, and heated and pressed by the heat roller 211 and the pressure roller 212. After the toner is welded, the toner is discharged to the outside of the apparatus via the paper discharge roller 22. The transfer roller 18 and the separating means 19 are separated from the peripheral surface of the photosensitive drum 10 after the transfer material P has passed, and prepare for the next toner image formation.

  On the other hand, the photosensitive drum 10 from which the transfer material P has been separated removes and cleans residual toner by the pressure contact of the blade 231 of the cleaning device 23 and enters the next image forming process. The blade 231 moves immediately after cleaning the photoreceptor surface and retracts from the circumferential surface of the photoreceptor drum 10.

  FIG. 2 is a sectional view of the developing device according to the present invention.

  The developing cartridge C has developing units 14Y, 14M, and 14C. Each developing device has developer accommodating portions 147Y, 147M, 147C, stirring screws 142Y, 142M, 142C, supply paddles 143Y, 143M, 143C, developing sleeves 141Y, 141M, 141C, and layer thickness regulating members 144Y, 144M, 144C. Therefore, it is disposed at a specified position with respect to the photosensitive drum 10.

  The operation in the developing device 14Y will be described. Toner supplied from a toner replenishment box (not shown) to the developer accommodating portion 147Y is agitated and mixed with the carrier by a pair of agitating screws 142Y rotating in opposite directions, and predetermined charging is performed by frictional charging. Charged to the amount. The agitated two-component developer is conveyed to the developing sleeve 141Y via the supply paddle 143Y, and the layer thickness is regulated by the layer thickness regulating member 144Y and conveyed to the developing area of the photosensitive drum 10. Develop the electrostatic latent image. In this development method, development is performed in a non-contact state between the developer head and the photosensitive drum 10, and non-contact two-component development is performed by a development electric field in which an AC bias and a DC bias are superimposed. Similarly to the developing unit 14Y, the developing units 14M and 14C develop the electrostatic latent image.

  FIG. 3 is an exploded sectional view of the developing device according to the present invention. The developing cartridge C includes a yellow developing device lid 146 according to the first forming member of the present invention, a yellow developing device bottom plate 145Y and a magenta developing device bottom plate 145M according to the developer containing partition wall member of the present invention, and a second forming of the present invention. It has a cyan developer base plate 145C as a member. The developing device bottom plates 145Y, 145M, and 145C and the yellow developing device lid 146 form the outer wall of the developing device of the present invention, such as injection molding, blow molding, cut-out ABS resin, polyester resin, polycarbonate resin, etc. Is used.

  The developing device bottom plates 145Y, 145M, and 145C each have one developing device mounted thereon. For example, the developing device bottom plate 145C positioned at the lowermost portion includes a rotating side plate 148 that includes a pair of stirring screws 142C and a supply paddle 143C supported by an unillustrated integrated bearing, a developing sleeve 141C, and a layer thickness regulating member 144C. The parts supported by the are placed. The stirring screw 142C and the supply paddle 143C supported by the integrated bearing are fitted into the upper surface of the developing device bottom plate 145C, thereby ensuring rotational accuracy and simplifying the assembling work and the disassembling work after use. It is said.

  In the developing cartridge C, a yellow developing device lid 146 is further placed on the uppermost yellow developing device bottom plate 145Y among the developing device bottom plates 145Y, 145M and 145C, and a developing device side plate 51 which will be described later. Further, both ends of the developing device bottom plates 145Y, 145M, and 145C and the yellow developing device lid 146 are fixed by the developing device side plate 52. The developing device bottom plates 145Y, 145M, 145C and the yellow developing device lid 146 are fixed by fitting with the developing device side plate 51 and the developing device side plate 52, and the invention is provided between the developing device bottom plates and the developing device cover. The molds 61Y, 61M, and 61C related to the elastic member are installed. Here, at least one portion of the developing device bottom plates 145Y, 145M, and 145C and the yellow developing device lid 146 is directly or indirectly in contact with the other bottom plate or the developing device lid, and is preferably adjacent to overlap with the projection direction. That is, adjacent to each other. Preferably, the installation area and the volume can be reduced by adjoining substantially parallel to the rotation direction of the photosensitive drum 10. Further, the developer bottom plates 145Y, 145M, and 145C and the yellow developer unit lid 146 are fitted to each other, so that leakage of the developer can be prevented.

  The molds 61Y, 61M, and 61C fill the gaps between the components constituting each developing device and prevent the developer from leaking, and fixing by the developing device side plate 51 and the developing device side plate 52 is performed by the developing device bottom plate 145Y. 145M, 145C and the yellow developing device lid 146 are installed for the purpose of maintaining a certain distance so that the assembly accuracy of the developing cartridge C is not affected. FIG. 4 is a view of the developing device bottom plate 145C as viewed from directly above, and the mold 61C is installed so as to surround the developer accommodating portion 147C. The interval is preferably 2 mm to 5 mm. A material that elastically deforms is used for the molds 61Y, 61M, and 61C, preferably a rubber material such as latex rubber or silicon rubber, or a synthetic resin such as polyurethane or polyethylene. The material has elasticity and self-foams after application. The self-foaming polyurethane is applied to the contact surfaces of the developing device bottom plates 145Y, 145M and 145C and the yellow developing device lid 146 when the developing cartridge C of the present invention is assembled until the self-foaming polyurethane starts to foam. It is preferable to join other parts to the airtightness of the developing cartridge C and the assembling work of the developing cartridge C.

  FIG. 5 is an exploded perspective view of the developing device according to the present invention. Protrusions 1451 are provided on the side surfaces of the developing device bottom plates 145Y, 145M, and 145C, three on each side on the front side of the paper, and two on the side on the back side of the paper, and on the side of the yellow developer lid 146. 1461 is installed at three places on the front side of the paper and two places on the side of the back side of the paper, and is fitted to support holes 511 and 521 provided in the developer side plate 51 and the developer side plate 52 described later. It is installed to do. The relative positions of the developing device bottom plates 145Y, 145M, and 145C and the yellow developing device lid 146 are fixed so as to be sandwiched by the developing device side plate 51 and the developing device side plate 52 from both ends. At this time, the developing device side plate 51 and the developing device side plate 52 are installed so as to be substantially perpendicular to the longitudinal direction of the developing device bottom plates 145Y, 145M, 145C and the yellow developing device lid 146. In other words, the developing sleeve 141 and the photosensitive drum 10 are installed so as to be perpendicular to the developing area facing each other.

  FIG. 6 is a front view and a side view of the developing device side plate 51 according to the coupling member of the present invention. The developing device side plate 51 is made of ABS resin, polyester resin, polycarbonate resin, or the like molded by injection molding, blow molding, or cutting. The developing device side plate 51 is provided with 3 support holes 511 in a row, 4 rows in total, 12 in total. The protrusions 1451 provided on the side portions of the developing device bottom plates 145Y, 145M, and 145C, and the yellow developing device lid The projections 1461 provided on the side portion of 146 and the respective forming members are fitted at three positions. The tips of the projections 1451 and 1461 are formed to have a slightly smaller diameter than the base, and the initial insertion into the support hole 511 can permit the displacement of the insertion position. As the protrusions 1451 and 1461 are inserted deeply into the support hole 511, the gap formed between the roots of the protrusions 1451 and 1461 and the support hole 511 decreases, and the developing device bottom plates 145Y, 145M, and 145C and the yellow developing device lid 146 and the development are developed. The fixation with the container side plate 51 is made strong. Since each of the developing device side plate and the developing device lid is fixed by fitting two or more protrusions and support holes, the relative positions of the developing devices 14Y, 14M, and 14C are displaced in the direction facing the photosensitive drum 10. do not do.

  FIG. 7 is a front view and a side view of the developing device side plate 52 according to the coupling member of the present invention. The developing device side plate 52 is also made of the same material as the developing device side plate 51, and a total of eight support holes 521 are provided. Further, like the developing device side plate 51, the projections 1451 and 1461 are fitted.

  The developing device side plate 52 further includes a conductive member 522. The conductive member 522 transmits an electrical signal generated by a toner concentration detection unit (not shown) built in the developing unit to a control board (not shown). In the toner concentration detecting means, the toner concentration is detected by a magnetic permeability detecting method, and an electric signal of this output frequency is transmitted to the control means of the present invention, and the control means is not shown in order to maintain an appropriate toner concentration. The amount of toner supplied from the toner replenishment box to the developer accommodating portions 147Y, 147M, and 147C is controlled. As the conductive member 522, a lead wire, a metal jumper wire, a wire, a metal plate, a conductive resin, or the like is used. Preferably, a metal plate material or a flexible printed circuit board in which a metal is thinly coated on a flexible resin film. Is used. The electrical signal transmitted by the conductive member 522 may be an AC bias and a DC bias applied to the developing sleeve 141 in addition to the electrical signal generated by the toner density detecting unit.

  FIG. 8 is a sectional view of the developing device side plate 52 according to the coupling member of the present invention. The developing device side plate 52 is composed of two plate-like members, and a shaft-supported gear group, which is a drive transmission member of the present invention, is installed therebetween. A part of the gear 543 is exposed to the outside of the developing device, and meshes with a drive gear (not shown). The gear 544 that meshes with the gear 543 meshes with the gear 42 that is coaxial with the rotation shaft 36 of the developing sleeve 141, and transmits rotational driving from the driving source to the developing sleeve 141. A gear 525 (not shown) coaxial with the gear 523 meshes with a gear 526 (not shown), and a gear 527 (not shown) coaxial with the gear 526 and the gear 45 shown in FIG. Furthermore, if necessary, an elastic connecting member can be provided in the middle of the rotation shaft of these gears, or the gear surface can be coated with a vibration absorbing material to make it difficult for vibration from the drive source to be transmitted to the developing sleeve. The rotation of the developing sleeve can be stabilized, and the toner supply to the developing area can be stabilized.

  FIG. 9 is a cross-sectional view of a main portion around the developing sleeve 141Y related to the developer carrying surface of the present invention. Although FIG. 9 shows the developing sleeve 141Y of the developing cartridge C, the same configuration is provided around the developing sleeve 141M and the developing sleeve 141C.

  The rotating shaft 36 of the developing sleeve 141Y is rotatably held on the rotating side plate 148 by a bearing 30. One end of the rotation pin 149 is fixed to the developing device bottom plate 145Y. The rotation side plate 148 has a rotation pin 149 inserted through the insertion hole. Accordingly, the rotation side plate 148 and the rotation pin 149 can hold the developing sleeve 141Y so that the developing sleeve 141Y can turn and can be displaced relative to the photosensitive drum 10. The bearing 31 is fixed to the developing device bottom plate 145Y, and rotatably holds the supply paddle 143Y. The bearing 32 is fixed to the developing device bottom plate 145 and rotatably holds the stirring screw 142Y.

The abutting rollers 35 are rollers that maintain a distance between the developing sleeve 141Y and the photosensitive drum 10, and are disposed at both ends of the developing sleeve 141Y. When the developing cartridge C is positioned at a predetermined position with respect to the photosensitive drum 10, the roller 35 comes into contact with the surface of the photosensitive drum 10, and the roller 35 receives the pressing force generated between the photosensitive drums 10. The cartridge displacement portion including the rotation side plate 148 , the developing sleeve 141 Y , and the rotation shaft 36 of the developing sleeve is rotationally displaced about the rotation pin 149, and the position of the cartridge displacement portion is determined. That is, the difference in diameter between the developing sleeve 141 Y and the roller 35 is the distance between the developing sleeve 141 Y and the photosensitive drum 10. In addition, even if the image carrier has a rotational center that is eccentric due to improper mounting of the rotating shaft of the image carrier or a bearing, or even if the processing of the curved surface of the photosensitive drum 10 is uneven, the cartridge displacement portion follows, so the photosensitive drum. 10 and the developing sleeve 141Y can be properly maintained.

  The gear 41 was fixed coaxially with the rotation shaft 36 of the developing sleeve 141Y. The gear 42 and the gear 43 are a pair of gears that drive and transmit to the supply paddle 143Y. The gear 42 is fixed coaxially with the rotation shaft 36, and the gear 43 is fixed coaxially with the rotation shaft of the supply paddle 143Y. The gear 41 is driven and transmitted from the gear 524 of FIG. The gear 44 and the gear 45 are a pair of gears that drive and transmit to the stirring screw 142, and are respectively fixed coaxially to the stirring screw 142, so that the pair of stirring screws rotate in the opposite directions. The gear 45 is driven by a gear 527 (not shown) to rotate a coaxial stirring screw. Since the developer is conveyed to the developing region by the developing sleeve 141 during image formation, the supply paddle 143 for supplying the developer to the developing sleeve 141Y and the developing sleeve 141Y are configured to rotate simultaneously.

FIG. 10 is a schematic perspective view of a conductive member and a power feeding path according to the present invention. The electrode plate 33 and the electrode plate 34 according to the conductive member of the present invention are disposed so as to contact each other, and the developing sleeve 141, the electrode plate 33, and the electrode plate 34 are electrically connected to each other and are electrically connected to the electrode plate 34. A developing bias voltage is applied to the developing sleeve 141 by a power source (not shown). The electrode plate 33 and the electrode plate 34 have contact surfaces for maintaining a contact state even when the rotary side plate 148 is displaced. The electrode plate 33 has spring elasticity, and a pressing force is generated between the roller 35 by abutting against the photosensitive drum 10 by the contact pressure with the power feeding path and the spring elasticity, and the position of the cartridge displacement portion. Help decision. The electrode is a conductive brush, and the brush may always be in contact with the rotating shaft 36 of the developing sleeve to supply power. However, in order to generate a sufficient pressing force, the rotating shaft 36 of the developing sleeve is supported on the shaft. Further, a plate-like metal having spring elasticity is preferable.

  The electrode plate 34Y of the yellow developing device 14Y is a metal plate routed along the shape of the side surface of the developing device bottom plate 145Y. The electrode plate 34Y contacts the power supply path 35Y on the rear surface of the developing device, that is, on the wall surface facing the developing sleeve. Yes. The surface of the electrode plate 34Y that is in contact with the power supply path 35Y is folded back to form a rib shape, which is in good contact with the power supply path 35Y. The power supply path 35Y is a metal plate that extends to the central portion of the developing device along the back surface facing the developing sleeve of the developing device, bends at the central portion, and extends to connect to a bias power source vertically below. The power feeding path 35Y passes through a space formed by the groove 351Y of the developing device bottom plate 145Y and the groove 352Y of the developing device bottom plate 145M, and further passes through a space 353Y that penetrates the developing device bottom plate 145M and a space 354Y that penetrates the developing device bottom plate 145C. It is exposed to the lower surface of the developing cartridge C. The exposed power feeding path 35Y is in contact with the electrode 37Y by a bias power source.

  Similar to the yellow developing device 14Y, the electrode plate 34M of the magenta developing device 14M is a metal plate routed along the shape of the side surface of the developing device bottom plate 145M, and is on the back surface of the developing device, that is, on the wall surface facing the developing sleeve. It is in contact with the power supply path 35M. The power supply path 35M is a metal plate that extends to the central portion of the developing device along the back surface facing the developing sleeve of the developing device, bends at the central portion, and extends to connect to a bias power source vertically below. The power supply path 35M passes through a space formed by the groove 351M of the developing device bottom plate 145M and the groove 352M of the developing device bottom plate 145C, and further passes through the space 353M penetrating the developing device bottom plate 145C and is exposed to the lower surface of the developing cartridge C. is doing. The exposed power supply path 35M is in contact with the electrode 37M by a bias power source.

  The electrode plate 34C of the cyan developing device 14C is a metal plate that is routed along the shape of the side surface of the developing device bottom plate 145C, and is in contact with the power supply path 35C on the rear surface of the developing device, that is, on the wall surface facing the developing sleeve. Yes. The power supply path 35C extends to the central portion of the developing device along the back surface facing the developing sleeve of the developing device, and is exposed on the lower surface of the developing cartridge C by a metal plate bent at the central portion and extending vertically downward. The exposed portion of the power supply path 35C is in contact with the bias power supply electrode 37C.

  At this time, it is preferable to use an insulating material for the inner walls of the groove 351, the groove 352, the space 353, and the space 354 for the purpose of avoiding electric leakage, but if the power supply path 35Y is covered with an insulating material, it is conductive. It may be a material. In addition, an electromagnetic wave absorbing material is used for the inner walls of the groove 351, the groove 352, the space 353, and the space 354, or other electric components due to signal disturbance or noise leakage due to external noise by covering the power supply path 35Y with the electromagnetic wave absorbing material, It is possible to prevent electromagnetic interference to other electronic devices installed around.

  At this time, the power supply path for supplying power to the developing sleeve and the electrode plate are isolated from the conductive member 522 of FIG. 8 by the bottom plate, and no electrical signal or current leakage or electromagnetic wave interference occurs.

1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus. Sectional drawing which shows the Example of a developing cartridge. Sectional drawing which shows the Example of a developing cartridge. FIG. 3 is a perspective view illustrating an example of a developing cartridge. FIG. 3 is a perspective view illustrating an example of a developing cartridge. Sectional drawing which shows the Example of a side plate. Sectional drawing which shows the Example of a side plate. Sectional drawing which shows the Example of a side plate. The conceptual diagram which shows arrangement | positioning of a drive transmission means. The perspective view which shows the Example of an electric power feeding path | route.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photosensitive drum 14 Developing device C Developing cartridge 40 Driving gear 41 Driven gear 140 Support frame 141 Developing sleeve 145 Developing device bottom plate 1451, 1461 Protrusion 146 Yellow developing device lid 148 Rotating side plate 149 Rotating pin 33, 34 Electrode plate 35 Abutting Roller 35Y, 35M, 35C Power supply path 51, 52 Side plate 522 Conductive member 61 Mold

Claims (2)

An image carrier;
Latent image forming means for forming a latent image on the image carrier;
A plurality of developers containing a developer having a developer base plate with a developing sleeve; and
A side plate that fixes a plurality of the developing devices on top of each other, places a developing device lid thereon, sandwiches the superimposed developing device lids and the plurality of developing devices from both sides, and fixes their relative positions;
A control board for exchanging electrical signals with the developing unit;
In an image forming apparatus comprising a bias power source for supplying power to the developing sleeve ,
The developer has a sensor for detecting the state of the developer,
The side plate has a conductive member that connects the sensor and the control board,
A power supply path that connects the developing sleeve and the bias power source through a space formed between two adjacent stacked developing devices and a space formed through the stacked developing devices; Have
The image forming apparatus, wherein the conductive member and the power supply path are separated by the developing device bottom plate . The power supply path has an electrode plate,
The image forming apparatus according to claim 1, wherein the electrode plate has a spring force for supplying power to the developing sleeve and biasing the developing sleeve toward the image carrier .

Images