Image forming apparatus

Abstract

To provide an image forming apparatus that allows stable contact between a circuit board and a connection terminal.SOLUTION: An image forming apparatus comprises image carriers, developing devices, and a housing. The developing device supplies non-magnetic one-component developer to a surface of the image carrier, and develops an electrostatic latent image to form a toner image. The developing device has a toner carrier, a developer container, a circuit board, and a board holding part. The developer container rotatably supports both ends of a rotation shaft of the toner carrier, and stores the developer and the toner carrier. The developer container has projecting support parts projecting from both ends in an axial direction and rotatably supported by a holding frame. The developer container rotates with the projecting support parts as the fulcrum, and the toner carrier can reciprocate in contact and separation directions with respect to the image carrier. The board holding part is rotatably supported with a holding support part coaxial with the projecting support parts as the fulcrum, and is independent from the reciprocating of the developer container.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] A conventional image forming apparatus is disclosed in Patent Document 1. This image forming apparatus includes an image carrier, a developing device, and a housing. An electrostatic latent image is formed on the surface of the image carrier. The developing device supplies a developer to the surface of the image carrier, and develops the electrostatic latent image to form a toner image. The housing accommodates the image carrier and the developing device.

[0003] The developing device has a toner carrier, a developing container, and a circuit board. The toner carrier is disposed opposite the image carrier and carries toner to be supplied to the surface of the image carrier. The developing container rotatably supports both ends of the rotation shaft of the toner carrier and contains toner and the toner carrier. The circuit board is disposed at one end of the developing container in the axial direction.

[0004] By mounting the developing device in the housing, the circuit board is connected to connection terminals on the housing side. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-163155 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the configuration of Patent Document 1, when the developer is composed of a non-magnetic single-component toner, the developing container rotates around the container support part as a fulcrum, and the toner carrier moves back and forth in the direction toward and away from the image carrier. At this time, the circuit board rotates in conjunction with the developing container, and there is a possibility that the circuit board and the connection terminal will not come into contact with each other.

[0007] SUMMARY OF THE PRESENT DISCLOSURE In view of the above problems, an object of the present invention is to provide an image forming apparatus in which a circuit board and a connection terminal can be stably contacted with each other. [Means for solving the problem]

[0008] In order to achieve the above object, a first configuration of the present invention is an image forming apparatus including an image carrier, a developing device, and a housing. An electrostatic latent image is formed on the surface of the image carrier. The developing device supplies a non-magnetic one-component developer to the surface of the image carrier, and develops the electrostatic latent image to form a toner image. The housing accommodates the image carrier and the developing device. The developing device has a toner carrier, a developing container, a circuit board, and a board holding portion. The toner carrier is disposed opposite the image carrier and carries the developer to be supplied to the surface of the image carrier. The developing container rotatably supports both ends of the rotation shaft of the toner carrier and contains the developer and the toner carrier. The circuit board is disposed adjacent to one side of the developing container in the axial direction. The board holding portion holds the circuit board. The housing has a pair of holding frames and a terminal holder. The holding frames hold the developing container and the image carrier from both sides in the axial direction. The terminal holder is disposed above the holding frame and faces the circuit board in the up-down direction at one end in the axial direction of the developing container. The terminal holder has a connection terminal and an elastic member. The connection terminal contacts the circuit board. The elastic member presses the connection terminal toward the circuit board. The developing container has protruding support parts that protrude from both ends in the axial direction and are rotatably supported by the holding frame. The developing container rotates about the protruding support parts, and the toner carrier can move back and forth in the direction toward and away from the image carrier. The board holding part is rotatably supported about a holding support part that is coaxial with the protruding support part, and is independent of the reciprocating movement of the developing container. Effect of the Invention

[0009] According to the first configuration of the present invention, it is possible to provide an image forming apparatus in which the circuit board and the connection terminals can be in stable contact with each other. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an image forming apparatus 100 according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a side cross-sectional view showing an internal configuration of an image forming apparatus 100 according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a perspective view showing a part of an image forming apparatus 100. [Figure 4] FIG. 1 is a side cross-sectional view showing a portion of an image forming apparatus 100. [Diagram 5] FIG. 1 is a perspective view showing a drum unit 200 mounted in an image forming apparatus 100. [Figure 6] FIG. 1 is a perspective view showing a drum unit 200 mounted in an image forming apparatus 100. [Figure 7] FIG. 1 is an enlarged perspective view showing a part of a holding frame 64a mounted on an image forming apparatus 100. [Figure 8] FIG. 1 is an enlarged perspective view showing a part of a holding frame 64b mounted on an image forming apparatus 100. [Figure 9] FIG. 2 is an enlarged perspective view showing a portion of a terminal holder 70 mounted in the image forming apparatus 100. [Figure 10] FIG. 1 is an enlarged perspective view showing an end portion of a developing device 3a mounted in an image forming apparatus 100. [Figure 11] FIG. 1 is an enlarged perspective view showing an end portion of a developing device 3a mounted in an image forming apparatus 100. [Figure 12] FIG. 1 is a side cross-sectional view showing a part of a developing device 3a mounted in an image forming apparatus 100. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (1. Overall Configuration of Image Forming Apparatus) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of an image forming apparatus 100 according to an embodiment of the present invention, and Fig. 2 is a side cross-sectional view showing the internal structure of the image forming apparatus 100. Note that the positions of the internal components of the image forming apparatus 100 in Fig. 2 do not limit the positional relationship of the present invention.

[0012] Image forming apparatus 100 includes photoconductor drums (image carriers) 1a to 1d, developing devices 3a to 3d, and a housing 300. Housing 300 constitutes the outer shell of image forming apparatus 100, and accommodates therein photoconductor drums (image carriers) 1a to 1d and developing devices 3a to 3d.

[0013] Four image forming units Pa, Pb, Pc, and Pd are arranged in sequence from the upstream side in the transport direction (the left side in FIG. 1) inside the main body of image forming apparatus 100 (here, a color printer). These image forming units Pa to Pd are provided corresponding to images of four different colors (yellow, cyan, magenta, and black), and sequentially form images of yellow, cyan, magenta, and black through the processes of charging, exposing, developing, and transferring, respectively.

[0014] The image forming units Pa to Pd include photoconductor drums (image carriers) 1a to 1d, charging devices 2a to 2d, an exposure device 5, developing devices 3a to 3d, and cleaning devices 7a to 7d. The image forming units Pa to Pd are provided with the photoconductor drums (image carriers) 1a to 1d that carry visible images (toner images) of each color, and an intermediate transfer belt (transfer recipient) 8 is provided adjacent to each of the image forming units Pa to Pd.

[0015] Primary transfer rollers (transfer members) 6a to 6d are disposed opposite photoconductor drums (image carriers) 1a to 1d, and transfer the visible images (toner images) of each color formed on the photoconductor drums (image carriers) 1a to 1d by applying a predetermined transfer voltage to the intermediate transfer belt (transferee) 8. As a result, the toner images formed on the photoconductor drums 1a to 1d are sequentially primarily transferred and superimposed on the intermediate transfer belt 8, which moves while contacting the photoconductor drums 1a to 1d.

[0016] Thereafter, the toner image primarily transferred onto the intermediate transfer belt 8 is secondarily transferred onto a transfer paper P, which is an example of a recording medium, by a secondary transfer roller 9. Furthermore, the transfer paper P onto which the toner image has been secondarily transferred is discharged from the main body of the image forming apparatus 100 after the toner image has been fixed in a fixing unit 13. In performing the image forming process for each of the photoconductor drums 1a to 1d, the photoconductor drums 1a to 1d rotate in the counterclockwise direction in FIG.

[0017] The transfer paper P onto which the toner image is secondarily transferred is stored in a paper cassette 16 arranged at the bottom of the main body of the image forming apparatus 100, and is transported to the nip between the secondary transfer roller 9 and the drive roller 11 of the intermediate transfer belt 8 via a paper feed roller 12a and a pair of registration rollers 12b. A sheet made of dielectric resin is used for the intermediate transfer belt 8, and a seamless belt is mainly used. In addition, a blade-shaped belt cleaner 19 is arranged downstream of the secondary transfer roller 9 to remove toner and the like remaining on the surface of the intermediate transfer belt 8.

[0018] Next, the image forming units Pa to Pd will be described. Around and above the rotatably arranged photoconductor drums (image carriers) 1a to 1d, there are provided charging devices 2a to 2d that charge the photoconductor drums 1a to 1d, an exposure device 5 that exposes image information onto each of the photoconductor drums 1a to 1d, developing devices 3a to 3d that form toner images on the photoconductor drums 1a to 1d, and cleaning devices 7a to 7d that remove developer (toner) and the like remaining on the photoconductor drums 1a to 1d.

[0019] The exposure device 5 exposes the photosensitive drums (image carriers) 1a to 1d charged by the charging devices 2a to 2d, thereby forming electrostatic latent images.

[0020] The developing devices 3a to 3d are disposed opposite the photosensitive drums (image carriers) 1a to 1d, and each include a developing roller (toner carrier) 21a to 21d, a supply roller 22a to 22d, and a developing container 4a to 4d. The developing devices 3a to 3d apply a predetermined developing voltage to the developing rollers 21a to 21d to cause non-magnetic one-component toner (developer) to adhere to the electrostatic latent image formed on the photosensitive drums 1a to 1d, thereby forming a toner image. The developing rollers 21a to 21d are disposed opposite the photosensitive drums (image carriers) 1a to 1d.

[0021] The developing containers 4a to 4d contain non-magnetic single-component toners of the respective colors of yellow, cyan, magenta, and black. Inside the developing containers 4a to 4d, developing rollers (toner carriers) 21a to 21d, supply rollers 22a to 22d, and stirring paddles (not shown) are arranged. The stirring paddles stir the toner in the developing containers 4a to 4d.

[0022] The supply rollers 22a to 22d are disposed opposite the developing rollers 21a to 21d. The supply rollers 22a to 22d hold the toner contained in the developing containers 4a to 4d on their outer circumferential surfaces. The supply rollers 22a to 22d also supply the developer held on their outer circumferential surfaces to the developing rollers 21a to 21d. A predetermined supply voltage (DC voltage) is applied to the supply rollers 22a to 22d to move the toner from the supply rollers 22a to 22d to the developing rollers 21a to 21d.

[0023] When image data is input from a host device such as a personal computer, first, the surfaces of the photoconductor drums 1a-1d are uniformly charged by the charging devices 2a-2d. Next, the exposure device 5 irradiates light according to the image data, and electrostatic latent images corresponding to the image data are formed on the photoconductor drums 1a-1d. The developing devices 3a-3d are filled with a predetermined amount of developer containing toner of each color of yellow, cyan, magenta, and black. The toner in the developer is supplied onto the photoconductor drums 1a-1d by the developing devices 3a-3d, and electrostatically adheres to the photoconductor drums 1a-1d, forming a toner image corresponding to the electrostatic latent image formed by exposure from the exposure device 5. In this embodiment, the developer is a non-magnetic single component.

[0024] Then, an electric field is applied between the primary transfer rollers 6a-6d and the photoconductor drums 1a-1d by the primary transfer rollers 6a-6d at a predetermined transfer voltage, and the yellow, cyan, magenta, and black toner images on the photoconductor drums 1a-1d are primarily transferred onto the intermediate transfer belt 8. These four color images are formed with a predetermined positional relationship for forming a predetermined full-color image. After that, in preparation for the subsequent formation of a new electrostatic latent image, the toner and the like remaining on the surfaces of the photoconductor drums 1a-1d after the primary transfer are removed by the cleaning devices 7a-7d.

[0025] The intermediate transfer belt 8 is stretched over a driven roller 10 on the upstream side and a driving roller 11 on the downstream side, and when the intermediate transfer belt 8 starts to rotate clockwise with the rotation of the driving roller 11 by a driving motor (not shown), the transfer paper P is transported at a predetermined timing from the registration roller pair 12b to a nip portion (secondary transfer nip portion) between the driving roller 11 and a secondary transfer roller 9 provided adjacent thereto, and the full-color image on the intermediate transfer belt 8 is secondarily transferred onto the transfer paper P. The transfer paper P to which the toner image has been secondarily transferred is transported to a fixing unit 13.

[0026] The transfer paper P transported to the fixing section 13 is heated and pressurized by the fixing roller pair 13a, so that the toner image is fixed to the surface of the transfer paper P, and a predetermined full-color image is formed. The transfer paper P on which the full-color image has been formed is then transported in a different direction by the branching section 14, which branches into multiple directions, and is discharged directly (or after being sent to the double-sided transport path 18 and having images formed on both sides) onto the discharge tray 17 by the discharge roller pair 15.

[0027] (2. Structure of the drum unit) Fig. 3 is a perspective view showing a part of image forming apparatus 100, and Fig. 4 is a side cross-sectional view showing a part of image forming apparatus 100. Figs. 3 and 4 show a state in which a part of housing 300 has been removed from image forming apparatus 100 to expose drum unit 200. Figs. 5 and 6 are perspective views of drum unit 200, and Fig. 5 shows a state in which developing devices 3a to 3d are attached. Also, Fig. 6 shows a state in which developing devices 3a to 3d have been removed.

[0028] In image forming apparatus 100, drum unit 200 is exposed by pulling forward front cover 301 disposed on the front surface of housing 300. In this state, a user can remove developing devices 3a to 3d supported by drum unit 200.

[0029] The drum unit 200 includes photosensitive drums (image carriers) 1a to 1d, developing devices 3a to 3d, charging devices 2a to 2d, an exposure device 5, holding frames 64a and 64b, cleaning devices 7a to 7d, and a terminal holder .

[0030] When the developer stored in each of the developing devices 3a to 3d becomes empty, the developing devices 3a to 3d can be replaced with other developing devices 3a to 3d filled with developer. The developing devices 3a to 3d are also removed as necessary when performing maintenance on the inside of the image forming apparatus 100. In this embodiment, the developing devices 3a to 3d are supported by the housing 300 so as to be detachable therefrom.

[0031] The holding frames 64a and 64b are parts of a housing 300, and the drum unit 200 is fixed to the housing 300 via the holding frames 64a and 64b. That is, the housing 300 has the holding frames 64a and 64b.

[0032] The holding frames 64a, 64b are metallic plate-shaped members extending in the front-rear direction, and are provided as a pair to sandwich the photosensitive drums (image carriers) 1a-1d and the developing devices 3a-3d in the left-right direction. At this time, the photosensitive drums 1a-1d and the developing devices 3a-3d are arranged alternately in the front-rear direction.

[0033] The terminal holder 70 is movable in the vertical direction via a drive device (not shown), and when the front cover 301 is pulled forward, the terminal holder 70 moves upward and moves away from the drum unit 200. On the other hand, when the front cover 301 is pushed backward to attach it to the housing 300, the terminal holder 70 moves downward and approaches the drum unit 200.

[0034] 7 is an enlarged perspective view of a portion of the holding frame 64a, and FIG. 8 is an enlarged perspective view of a portion of the holding frame 64b. The pair of holding frames 64a, 64b each have a guide portion 65, a board recess 66, and a restriction recess 67.

[0035] The guide portions 65 are disposed on the inner surfaces of the holding frames 64a and 64b facing each other in the left-right direction. Four guide portions 65 are provided on each of the holding frames 64a and 64b, and are arranged at predetermined intervals in the front-rear direction. The guide portions 65 guide each of the developing devices 3a to 3d to a predetermined mounting position when the developing devices 3a to 3d are mounted on the drum unit 60. In this embodiment, the guide portions 65 are grooves formed on the inner surfaces of the holding frames 64a and 64b, and the upper end faces are open. The upper end of the guide portion 65 extends linearly downward, and the lower end bends in a direction away from the photosensitive drum 1a. In this embodiment, the lower end of the guide portion 65 extends at an angle backward as it goes downward.

[0036] The board recess 66 is formed by being recessed downward from the upper surface of the holding frame 64a, and a part of a circuit board 330 described later is disposed inside the board recess 66. The board recess 66 is disposed in four positions aligned in the front-rear direction. In this embodiment, each board recess 66 is disposed adjacent to the rear side of each guide portion 65.

[0037] The restricting recess 67 is formed by recessing a part of the bottom surface of the substrate recess 66 downward. Each restricting recess 67 has a restricting protrusion 324 described later arranged therein, and has a different shape corresponding to the arranged restricting protrusion 324. This prevents the development devices 3a to 3d that do not correspond to the restricting recess 67 from being attached, thereby functioning as a color incompatible device.

[0038] 9 is an enlarged perspective view of a portion of the terminal holder 70. The terminal holder 70 is a part of the housing 300, and is fixed to the housing 300 so as to be movable in the up-down direction. In other words, the housing 300 has the terminal holder 70. Specifically, the terminal holder 70 extends in the front-rear direction, and is movable in the up-down direction above the holding frame 64a disposed on the left side (one axial side).

[0039] The terminal holder 70 has a plurality of connection terminals 651a, 651b, a terminal holding portion 652, and a coil spring (elastic member) 653. Four sets of the connection terminals 651a, 651b, the terminal holding portion 652, and the coil spring (elastic member) 653 are arranged in the front-rear direction corresponding to the respective developing devices 3a to 3d.

[0040] The terminal holding portion 652 holds the connection terminals 651a, 651b at its lower end, and has a pair of board pressing pieces 652a that protrude downward from the lower surface of the terminal holding portion 652. The connection terminals 651a, 651b are disposed between the pair of board pressing pieces 652a. The lower ends of the pair of board pressing pieces 652a are located above the lower ends of the connection terminals 651a, 651b.

[0041] When the terminal holder 70 moves downward and approaches the drum unit 200, the connection terminals 651a, 651b come into contact with and are connected to the upper surface of a circuit board 330, which will be described later. The connection terminals 651a, 651b are biased downward via a coil spring 653 that presses the upper surface of the terminal holding portion 652 downward. That is, the coil spring (elastic member) 653 presses the connection terminals 651a, 651b toward the circuit board 330.

[0042] The connection terminals 651a, 651b biased downward come into contact with the circuit board 330 and deform. This allows the circuit board 330 and the connection terminals 651a, 651b to come into stable contact with each other. At this time, the board pressing piece 652a comes into contact with the circuit board 330, and the vertical distance between the upper surface of the circuit board 330 and the lower surface of the terminal holding portion 652 is kept constant. This allows the circuit board 330 and the connection terminals 651a, 651b to come into more stable contact with each other.

[0043] The connection terminals 651a and 651b are elastically deformable, and the positions of the lower ends of the connection terminals 651a and 651b are different in the vertical direction. In this embodiment, the lower end of the connection terminal 651a is located lower than the lower end of the connection terminal 651b. The connection terminal 651a is a terminal for grounding, and the connection terminal 651b is a terminal for current and signals. As a result, when the terminal holder 70 moves downward and approaches the drum unit 200, the connection terminal 651a contacts the circuit board 330 before the connection terminal 651b. Therefore, when replacing the circuit board 33, a hot-plug state is prevented, and damage to the circuit board 33 can be prevented.

[0044] By connecting the connection terminals 651a and 651b to the circuit board 330, the developing device 3a is electrically connected to a main control unit (not shown) including a CPU or the like that controls each unit of the image forming apparatus 100.

[0045] (3. Configuration of Developing Device Detachable Mechanism) 10 and 11 are enlarged perspective views showing the left end (one side) of the developing device 3a. Both axial side surfaces of the developing container 31 are covered with sidewall portions 318, and each sidewall portion 318 has bearing portions 340 and 350 and a protruding support portion 319. The bearing portion 340 rotatably supports the developing roller 32. The bearing portion 350 rotatably supports the supply roller 33. As a result, the developing roller 37 and the supply roller 33 are rotatably supported within the developing container 31.

[0046] The protruding support portions 319 protrude outward in the axial direction from the side surfaces of the both side wall portions 318, and are inserted into the above-mentioned guide portions 65. The developing container 31 is supported by the protruding support portions 319 so as to be rotatable.

[0047] Further, a circuit board 330 and a board holding portion 320 that holds the circuit board 330 are disposed axially outward of a side wall portion 318 on the left side (one axial side) of the developing container 31. That is, the circuit board 330 is disposed adjacent to the left side (one axial side) of the developing container 31. The board holding portion 320 has an arm portion 321, claw portions 322a and 322b, a holding protrusion portion 323, and a restricting protrusion portion 324.

[0048] The arm portion 321 extends in the radial direction from the rotation axis H, and the tip portion is bent in the circumferential direction to approach the developing roller 37. The tip portion of the arm portion 321 has a flat upper surface, on which the circuit board 330 is disposed.

[0049] A through hole 321a is formed at the end of the arm 321 on the rotation axis H side, penetrating along the rotation axis H. The protruding support portion 319 is inserted into the through hole 321a. This allows the arm 321 to be supported rotatably with the through hole (holding support portion) 321a as a fulcrum.

[0050] Claws 322a and 322b protrude upward from the upper surface of the tip of arm 321 and are bent in a direction approaching each other. Circuit board 330 arranged on the upper surface of the tip of arm 321 is sandwiched and fixed between claws 322a and 322b and the upper surface of the tip of arm 321.

[0051] The holding protrusion 323 is formed to protrude from the tip of the arm 321 radially outward of the rotation axis H. The holding protrusion 323 is disposed in a slit 325a formed in a protrusion guide 325 that protrudes axially from the outer circumferential edge of the side wall 318. The slit 325a penetrates the protrusion guide 325 in the radial direction of the rotation axis H and extends in the circumferential direction. The holding protrusion 323 moves along the slit 325a, thereby allowing the substrate holding part 320 to rotate stably without shifting in the axial direction of the rotation axis H.

[0052] The restricting protrusion 324 is inserted into the restricting recess 67. The restricting protrusion 324 has a different shape for each of the developing devices 3a to 3d. This makes it possible to prevent the developing devices 3a to 3d from being erroneously attached to the photoconductor drums 1a to 1d corresponding to different colors.

[0053] 12 is a side cross-sectional view showing a part of the developing device 3a mounted on the image forming apparatus 100. Each of the developing devices 3a to 3d is guided along each of the guide portions 65 from the open upper end of each of the guide portions 65. When each of the developing devices 3a to 3d is guided to the mounting position at the end of each of the guide portions 65, the developing rollers 37 come into contact with the photoconductor drums 1a to 1d.

[0054] At this time, the tip of arm 321 , the upper end of arm 321 on which circuit board 330 is arranged on the upper surface, is placed in board recess 66 , and part of circuit board 330 is arranged within board recess 66 .

[0055] When the terminal holder 70 moves downward and approaches the drum unit 200, the upper surface of the circuit board 330 is pressed downward by the connection terminals 651a, 651b. As a result, the board holding part 320 is sandwiched between the terminal holder 70 and the holding frame and held at a predetermined rotational position. At this time, the circuit board 330 and the connection terminals 651a, 651b come into contact with each other.

[0056] On the other hand, the developing container 31 is pressed by the pressing mechanism 36 (see FIG. 3) in a direction approaching the photosensitive drum 1a, and the developing container 31 rotates in a direction in which the developing roller 32 approaches the photosensitive drum 1a (direction A in FIG. 10). At this time, the board holding part 320 is supported rotatably with the through hole (holding support part) 321a coaxial with the protruding support part 319 as a fulcrum, and is independent of the reciprocating movement of the developing container 31. This prevents the board holding part 320 from rotating in conjunction with the rotation of the developing container 31, and the circuit board 330 and the connection terminals 651a and 651b are stably held in a state of contact with each other. Therefore, it is possible to provide an image forming apparatus 100 in which the circuit board 330 and the connection terminals 651a and 651b can be stably contacted with each other.

[0057] In addition, when the image forming apparatus 100 further includes a rotation mechanism (not shown) capable of rotatably driving the developing container 31, the developing container 31 can be rotated at the end of printing to separate the developing roller 32 from the photosensitive drum 1a. At this time, the developing container 31 rotates in a direction in which the developing roller 32 moves away from the photosensitive drum 1a (direction B in FIG. 10). That is, the developing container 31 rotates about the protruding support portion 319 as a fulcrum, and the developing roller 32 can move back and forth in the approaching and separating direction relative to the photosensitive drum 1a. At this time, the board holding portion 320 is supported to be rotatable about a through hole (holding support portion) coaxial with the protruding support portion 319 as a fulcrum, and is independent of the reciprocating movement of the developing container 31. This prevents the board holding portion 320 from rotating in conjunction with the rotation of the developing container 31, and the circuit board 330 and the connection terminals 651a and 651b are stably held in a state of contact with each other.

[0058] For example, during monochrome printing, the developing roller 32 of the developing device 3d filled with black developer is brought close to the photoconductor drum 1d, and the developing rollers 32 of the developing devices 3a to 3c filled with yellow, cyan, and magenta developers are moved away from the photoconductor drums 1a to 1c, respectively. This makes it possible to stop driving the developing devices 3a to 3c during monochrome printing and reduce the driving time of the developing devices 3a to 3c. In addition, by moving the developing roller 32 away from the photoconductor drums 1a to 1c, respectively, the cleaning performance of the photoconductor drums 1a to 1d can be improved.

[0059] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. [Industrial Applicability]

[0060] The present invention can be applied to an image forming apparatus that uses a non-magnetic one-component developer containing a toner. [Explanation of symbols]

[0061] 1a~1d Photoconductor drum 2a~2d Charging device 3a~3d developing device 5 Exposure equipment 6a~6d Primary transfer roller 7a~7d Cleaning device 8 Intermediate transfer belt 9 Secondary transfer roller 10 Driven roller 11 Drive roller 12a Paper feed roller 12b Registration roller pair 13 Fixing section 13a Fixing roller pair 14 Branch 15 Discharge Roller Pair 16 Paper Cassette 17 Output Tray 18-sided conveyor 21a to 21d Developing roller (toner carrier) 22a~22d Supply rollers 60 Drum unit 64a, 64b Retaining frame 65 Guide part 66 Board recess 67 Regulating recess 70 Terminal holder 100 Image forming device 200 Drum Unit 300 Housing 301 Front cover 318 Side wall 319 Protruding support part 320 Board holding part 321 Arm 321a Through hole 322a, 322b claw part 323 Holding protrusion 324 Regulatory protrusion 325 Protrusion guide part 325a Slit 330 Circuit Board 340, 350 bearing part 361 Pressing member 362 Compression spring 651a Connection terminal 651a, 651b connection terminal 652 Terminal holding part 652a Board pressing piece 653 Coil Spring H Rotational axis P Transfer paper Pa~Pd Image forming section

Claims

1. an image carrier on whose surface an electrostatic latent image is formed; a developing device that supplies a non-magnetic one-component developer to the surface of the image carrier and develops the electrostatic latent image to form a toner image; a housing that accommodates the image carrier and the developing device; In an image forming apparatus comprising: The developing device is a toner carrier disposed opposite the image carrier and carrying the developer to be supplied to a surface of the image carrier; a developing container that rotatably supports both ends of a rotation shaft of the toner carrier and contains the developer and the toner carrier; a circuit board disposed adjacent to one side of the developing container in an axial direction; a board holder for holding the circuit board; having The housing includes: a pair of holding frames that hold the developing container and the image carrier from both sides in an axial direction; a terminal holder disposed above the holding frame and facing the circuit board in a vertical direction at one end of the developing container in an axial direction; having The terminal holder includes: a connection terminal that contacts the circuit board; an elastic member that presses the connection terminal toward the circuit board; having The developing container is The support member has protruding support portions protruding from both ends in the axial direction and rotatably supported by the holding frame, the developing container rotates about the protruding support portion as a fulcrum, and the toner carrier is reciprocally movable in a direction toward and away from the image carrier; the substrate holding portion is supported rotatably about a holding support portion coaxial with the protruding support portion as a fulcrum, and is independent of the reciprocating movement of the developing container.

2. 2. The image forming apparatus according to claim 1, wherein the board holding portion has at one end a through hole through which the protrusion is inserted, and at the other end a arm portion on an upper surface of which the circuit board is placed.

3. The holding frame includes: a board recess having an upper surface recessed downward in which a portion of the circuit board is disposed; a restriction recess formed by recessing a portion of a bottom surface of the substrate recess downward; having The developing device is arranged in a plurality of rows, 3. The image forming apparatus according to claim 1, wherein the restricting recess has a restricting protrusion protruding from the board holding portion and has a different shape corresponding to the restricting protrusion.

4. The connection terminal is elastically deformable and is arranged in plurality.

3. The image forming apparatus according to claim 1, wherein the connection terminals have lower ends at different positions in the up-down direction.

Images