Developing device

Abstract

To reduce the likelihood of the occurrence of deformation of a developing device body 14 even if a developing device 10 and an image forming apparatus body 101 are connected at electrical connection parts.SOLUTION: A developing device 10 comprises a fixation part 13, a developing device body 14, and a developing-side electrical contact part 120. The fixation part 13 is fixed to an image forming apparatus body 101 when the developing device 10 is mounted in the image forming apparatus body 101, with a first positioning hole 131 being positioned by a first positioning shaft 901 of the image forming apparatus body 101. The developing device body 14 has a developing roller 12 for developing an electrostatic latent image on a photoconductor drum with developer, and is movably connected to the fixation part 13 with an engagement part 15. The developing-side electrical contact part 120 is provided on the fixation part 13, and when the developing device 10 is mounted in the image forming apparatus body 101, brought into contact with a body-side electrical contact part 911 provided on the image forming apparatus body 101.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a developing device that develops an electrostatic latent image formed on an image carrier with a developer, and to an image forming apparatus such as a copier, printer, facsimile, or a multifunction machine having a plurality of these functions. [Background technology]

[0002] In an image forming apparatus, a configuration is known in which a developing device is detachable from the image forming apparatus body for easy maintenance and replacement. The developing device is movable to a position separated from a developer carrier such as a developing roller with respect to a photosensitive drum so as not to come into contact with an image carrier such as a photosensitive drum in the image forming apparatus body when the developing device is attached to or detached from the image forming apparatus body.

[0003] For example, the developing device in Patent Document 1 is capable of swinging about an axis to approach and separate from the photosensitive unit when mounted in the normal mounting position of the device body. Furthermore, the developing device is provided with a bridging member that bridges the opening of the front frame of the device body from top to bottom, attached to the front frame of the developing device, and the front end of the axis is rotatably supported by a bearing provided on the bridging member. Patent Document 1 also describes that a configuration may be adopted in which the developing device combined with the bridging member is inserted into the device body, and the bridging member is attached to the front frame of the device body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-58627 A Summary of the Invention [Problem to be solved by the invention]

[0005] Here, the developing device is generally provided with electrical components such as a toner concentration sensor. In order to communicate between these electrical components and the image forming device main body, the developing device and the image forming device main body are provided with electrical connection configurations such as connectors. However, electrical connection configurations using connectors have chronic issues such as the possibility of bending pins in the connector when connecting, and poor connection due to half-insertion. For this reason, replacement of the developing device by a user who is not familiar with image forming devices may make these issues more apparent.

[0006] In response to this, it is possible to adopt an electrical contact method for the electrical connection configuration. The electrical contact method is a configuration in which electrical connection is guaranteed by the contact pressure between the contact parts. This contact pressure acts as a reaction force on the parts having the contact parts or on the device itself. Therefore, if this reaction force is not properly handled, there is a risk that the device itself will be deformed, such as flexed or twisted. In particular, the developing device is required to have an appropriate positional relationship between the photosensitive drum and the developing roller when mounted on the image forming device main body. However, for example, if the developing device main body, including the developing container that holds the developing roller, is deformed, this positional relationship cannot be made appropriate.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a configuration in which the developing device main body is less likely to deform even when the developing device and the image forming apparatus main body are connected by an electrical contact portion. [Means for solving the problem]

[0008] The developing device of the present invention is a developing device that is detachable from an image forming device main body, and is characterized in that it comprises: a positioned portion that is positioned to a positioning portion of the image forming device main body when the developing device is attached to the image forming device main body, a fixed portion that is fixed to the image forming device main body with the positioned portion positioned to the positioning portion; a developing device main body that has a developer carrier for developing an electrostatic latent image on an image carrier provided in the image forming device main body with a developer, and is movably connected to the fixed portion by an engagement portion; and a developing side electrical contact portion that is provided on the fixed portion and comes into contact with a main body side electrical contact portion provided on the image forming device main body when the developing device is attached to the image forming device main body. Effect of the Invention

[0009] According to the present invention, even if the developing device and the image forming apparatus main body are connected by an electrical contact portion, the developing device main body is unlikely to deform. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a photoconductor unit according to the embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of a photoconductor unit according to the embodiment. [Figure 4] FIG. 4A is a perspective view of a developing device according to an embodiment, and FIG. 4B is a perspective view of the developing device as viewed from the opposite side to FIG. [Diagram 5] FIG. 2 is a cross-sectional view of a developing device according to the embodiment. [Figure 6] 5A is a perspective view showing a state in which the pressure of the developing device according to the embodiment is released, and FIG. 5B is an enlarged cross-sectional view of an engagement portion. [Figure 7] FIG. 4 is a cross-sectional view showing a pressure-released state of the developing device according to the embodiment. [Figure 8] FIG. 4 is a perspective view showing a pressurized state of the developing device according to the embodiment. [Figure 9] FIG. 4 is a cross-sectional view showing a pressurized state of the developing device according to the embodiment. [Figure 10]1 is a perspective view of a front portion and a frame of a developing device according to an embodiment, illustrating a state in which the developing device is being inserted into an image forming apparatus main body. [Figure 11] 4 is a cross-sectional view of a front portion and a frame of the developing device, illustrating a state immediately before the developing device according to the embodiment is positioned in the image forming apparatus main body. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiment will be described with reference to Figures 1 to 11. First, the schematic configuration of an image forming apparatus according to the present embodiment will be described with reference to Figure 1.

[0012] [Image forming equipment] The image forming apparatus 100 of this embodiment is an electrophotographic tandem-type full-color printer equipped with four image forming units PY, PM, PC, and PK, each of which has a photosensitive drum 201 as an image carrier. The image forming apparatus 100 forms a toner image on a recording material in response to an image signal from a document reading device 102 connected to the image forming apparatus main body 101 or a host device such as a personal computer connected to the image forming apparatus main body 101 so as to be able to communicate with the image forming apparatus main body 101. Examples of the recording material include sheet materials such as paper, plastic film, and cloth. The image forming units PY, PM, PC, and PK form yellow, magenta, cyan, and black toner images, respectively.

[0013] The four image forming units PY, PM, PC, and PK included in the image forming apparatus 100 have substantially the same configuration, except for the different developing colors. Therefore, the image forming unit PY will be described as a representative, and descriptions of the other image forming units will be omitted.

[0014] In the image forming unit PY, a cylindrical photosensitive member, i.e., a photosensitive drum 201, is disposed as an image carrier. The photosensitive drum 201 is rotated by a driving force transmitted from a driving unit (not shown) provided in the image forming apparatus main body 101. In the image forming unit PY, a charging roller 204 as a charging unit, a developing device 10, a primary transfer roller 31 as a transfer member, and a cleaning blade 206 as a cleaning member are disposed around the photosensitive drum 201. An exposure device (a laser scanner in this embodiment) 22 as an exposure unit is disposed below the photosensitive drum 201 in the figure.

[0015] In the image forming section PY, a cylindrical photosensitive member, i.e., a photosensitive drum 201, is disposed as an image carrier. The photosensitive drum 201 is rotated by a driving force transmitted from a driving section, such as a motor (not shown), provided in the image forming apparatus main body 101. Around the photosensitive drum 201, a charging roller 204 as a charging section, a developing device 10, a primary transfer roller 31 as a transfer member, and a cleaning blade 206 as a cleaning member are disposed. An exposure device (a laser scanner in this embodiment) 22 as an exposure section is disposed below the photosensitive drum 201 in the figure.

[0016] Toner is supplied to the developing device 10 from a toner bottle 21 serving as a toner storage container through a toner transport path (not shown). In addition, in the image forming section PY, a cleaning roller 205 serving as a charge cleaning member for cleaning the charge member is arranged in contact with the charge roller 204 (see FIG. 3). In this embodiment, the charge roller 204 is brought into contact with the surface of the photosensitive drum 201 with a predetermined pressing force by a biasing member such as a spring, and rotates in accordance with the rotation of the photosensitive drum 201. In addition, the cleaning roller 205 is brought into contact with the surface of the charge roller 204 with a predetermined pressing force by a biasing member such as a spring, and rotates in accordance with the rotation of the charge roller 204.

[0017] An intermediate transfer device 300 is disposed above each image forming unit in FIG. 1. The intermediate transfer device 300 is configured such that an endless intermediate transfer belt 30 serving as an intermediate transfer body is stretched around a plurality of rollers and moves (rotates). A primary transfer roller 31 is disposed at a position facing each photosensitive drum 201 on the inner peripheral surface side (back surface side) of the intermediate transfer belt 30. The primary transfer roller 31 is pressed against the photosensitive drum 201 via the intermediate transfer belt 30, forming a primary transfer portion where the intermediate transfer belt 30 and the photosensitive drum 201 are in contact with each other. The primary transfer roller 31 rotates in accordance with the rotation of the intermediate transfer belt 30.

[0018] Further, a secondary transfer roller 32, which is a roller-shaped secondary transfer member, is disposed at a position facing the secondary transfer opposing roller 33 on the outer circumferential surface side (front surface side) of the intermediate transfer belt 30. The secondary transfer roller 32 is pressed against the secondary transfer opposing roller 33 via the intermediate transfer belt 30, forming a secondary transfer section where the intermediate transfer belt 30 and the secondary transfer roller 32 are in contact with each other. Further, a belt cleaning device 35, which serves as an intermediate transfer body cleaning section, is disposed at a position facing the tension roller 34 on the outer circumferential surface side of the intermediate transfer belt 30. The intermediate transfer belt 30 is formed endlessly from a dielectric resin such as polyimide.

[0019] A fixing device 60 that fixes the toner image to the recording material P is disposed downstream of the secondary transfer portion in the recording material transport direction. The fixing device 60 has, for example, a fixing roller as a fixing rotator heated by a heat source such as a heater, and a pressure roller as a pressure rotator that forms a fixing nip portion between the fixing roller and the fixing roller. The toner image on the recording material transported to the fixing nip portion is heated and pressurized, thereby fixing the toner image to the recording material.

[0020] A cassette 40 containing recording material P is disposed at the bottom of the image forming apparatus 100. The recording material P fed from the cassette 40 is conveyed by conveying rollers 41 toward the registration rollers 50. Then, the leading edge of the recording material P hits the registration rollers 50, which are in a stopped state, and a loop is formed, thereby correcting the skew of the recording material P. Thereafter, the registration rollers 50 start to rotate in synchronization with the toner image on the intermediate transfer belt 30, and the recording material P is conveyed to the secondary transfer section.

[0021] A process of forming, for example, a four-color full-color image by the image forming apparatus 100 configured as described above will be described. First, when an image forming operation starts, the surface of the rotating photosensitive drum 201 is uniformly charged to a predetermined potential of a predetermined polarity by the charging roller 204. In this embodiment, a voltage is applied to the charging roller 204 from a high-voltage power source (not shown), causing discharge on the surface of the photosensitive drum 201, thereby charging the surface of the photosensitive drum 201.

[0022] Next, the photosensitive drum 201 is scanned and exposed by a laser beam corresponding to an image signal generated by the exposure device 22. As a result, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 201. The electrostatic latent image on the photosensitive drum 201 (on the image carrier) is visualized by toner contained in the developing device 10 as a developer, and becomes a visible image. In this embodiment, the normal charging polarity of the toner is negative. The developing device 10 has a developing roller 12 as a developer carrier that carries the toner and transports it to a portion (developing position) facing the photosensitive drum 201. The developing roller 12 is driven to rotate. During development, a predetermined developing voltage is applied to the developing roller 12 from a high-voltage power source as a developing power source (not shown).

[0023] The toner image formed on the photosensitive drum 201 is primarily transferred to the intermediate transfer belt 30 at a primary transfer section formed between the photosensitive drum 201 and a primary transfer roller 31 arranged with the intermediate transfer belt 30 sandwiched therebetween. At this time, a primary transfer bias, which is a voltage of the opposite polarity (positive polarity in this embodiment) to the charge polarity of the toner during development, is applied to the primary transfer roller 31 from a high-voltage power source (not shown). Toner remaining on the surface of the photosensitive drum 1 after the primary transfer (transfer residual toner) is removed by a cleaning blade 206, collected in a collected toner transport path, and discharged outside the photosensitive unit 20 by a toner transport screw 207 (see FIG. 3).

[0024] Such an operation is performed in sequence in each image forming section for yellow, magenta, cyan, and black, and the four color toner images are superimposed on the intermediate transfer belt 30. After that, the recording material P stored in the cassette 40 is conveyed to the secondary transfer section in accordance with the timing of the formation of the toner images. Then, in the secondary transfer section, the four color toner images on the intermediate transfer belt 30 are secondarily transferred all at once onto the recording material P by the action of the secondary transfer opposing roller 33. When the recording material P passes through the secondary transfer section, a secondary transfer voltage, which is a voltage of the opposite polarity to the charge polarity of the toner at the time of development, is applied to the secondary transfer roller 32 from a high-voltage power source (not shown). Toner that was not transferred in the secondary transfer section and remains on the intermediate transfer belt 30 is removed by a belt cleaning device 35.

[0025] Next, the recording material P is conveyed to the fixing device 6, where it is heated and pressurized as it passes through the fixing nip. The toner on the recording material P is then melted and mixed, and fixed as a full-color image onto the recording material P. Thereafter, the recording material P is discharged onto the discharge tray 80 by the discharge rollers 70. This completes a series of image forming processes.

[0026] In addition, the image forming apparatus 100 of this embodiment is also capable of forming a monochrome or multi-color image, such as a monochrome black image, by using image forming units for a desired monochrome color or for some of the four colors.

[0027] [Photoconductor unit] 2 and 3, the configuration of the photoconductor unit 20 will be described. The photoconductor unit 20 of this embodiment is configured such that a photoconductor drum 201 as a photoconductor, a charging roller 204 as a charging member, a cleaning roller 205 as a charging cleaning member, and a cleaning blade 206 as a cleaning member are integrally held by a drum frame 202 as a frame. The photoconductor unit 20 is detachable from the image forming apparatus main body 101 by sliding it from the image forming apparatus main body 101 along the longitudinal direction (the direction of the rotation axis of the photoconductor drum 201), and can be replaced for maintenance or the like.

[0028] A photosensitive drum 201 is supported on the drum frame 202 so as to be rotatable about a rotation axis via a bearing (not shown). The photosensitive drum 201 is provided with a coupling 203 for receiving a driving force from a motor (not shown) provided in the image forming apparatus main body 101 as a driving source and rotating the photosensitive drum 201 when the photosensitive drum 201 is attached to the image forming apparatus main body 101.

[0029] The charging roller 204 is rotatably supported by a charging roller bearing (not shown), and is pressed against the photosensitive drum 201 by a pressure spring (not shown). The cleaning roller 205 is rotatably supported by a cleaning roller bearing (not shown), and is pressed against the charging roller 204 by a pressure spring (not shown). In addition, a cleaning blade 206 is fixed to the drum frame 202 as a cleaning member for cleaning the surface of the photosensitive drum 201, and is provided so as to come into contact with the surface of the photosensitive drum 201 in a counter direction to the rotation direction of the photosensitive drum 201 during image formation.

[0030] A toner transport path is provided near the cleaning blade 206 to collect and transport the transfer residual toner removed from the surface of the photosensitive drum 201 by the cleaning blade 206. The toner transport path is provided with a toner transport screw 207 as a transport member for transporting the collected toner to the outside of the photosensitive unit 20. The toner transported to the outside of the photosensitive unit 20 by the toner transport screw 207 is collected in a collected toner container (not shown) provided in the image forming apparatus main body 101.

[0031] [Developing device] Next, the configuration of the developing device 10 will be described with reference to Figures 4(a), (b) and 5. Figure 4(a) is a perspective view of the developing device 10 as seen from the front side, which will be described later, and Figure 4(b) is a perspective view of the developing device 10 as seen from the back side, which will be described later. The developing device 10 is a developing device that uses a two-component developer containing non-magnetic toner and magnetic carrier. The developing device 10 of this embodiment is configured to be detachable from the image forming device main body 101 by sliding it from the image forming device main body 101 along the longitudinal direction (the direction of the rotation axis of the developing roller 12), and can be replaced for maintenance or the like.

[0032] In this embodiment, the developing device 10 and the above-mentioned photoconductor unit 20 can be inserted and pulled out along the longitudinal direction relative to the image forming apparatus main body 101. The insertion direction (X direction) of the developing device 10 and the photoconductor unit 20 is the direction from the front side to the rear side of the image forming apparatus 100 (from the front side to the rear side of the paper in FIG. 1). The front side of the image forming apparatus 100 is the side where an operator operates the image forming apparatus 100, and is, for example, the side where an operation unit for operating the image forming apparatus 100, such as an operation panel, is located. Hereinafter, when the terms "front side" and "rear side" are simply used, they refer to the front side and the rear side of the image forming apparatus 100.

[0033] The developing device 10 is provided with a toner supply port 133 as a supply port, and when the developing device 10 is attached to the image forming apparatus main body 101, the toner supply port 133 is connected to a supply port of a toner transport path provided in the image forming apparatus main body 101. The toner transport path is connected to a toner bottle 21 that contains replenishment toner as a developer storage container. Therefore, replenishment toner is supplied to the toner supply port 133 from the toner bottle 21 via the toner transport path.

[0034] The developing device 10 also includes a developing container 11 that contains a developer, and a developing roller 12 as a developer carrier. The developing roller 12 is held rotatably relative to the developing container 11 about a rotation axis α, and is configured to develop an electrostatic latent image formed on the photosensitive drum 201 at a development position where the photosensitive drum 201 and the developing roller 12 face each other. Driving force is transmitted to the developing roller 12 from the rear side of the image forming apparatus main body 101 via a coupling 17.

[0035] In addition, in the developing device 10, there are disposed a developing blade 112 for regulating the toner coat amount on the surface of the developing roller 12 to a constant amount, and screw members 113 and 114 for stirring and conveying the toner in the toner storage section 111 in the developing container 11. In the developing device 10, the developer in the toner storage section 111 is stirred and conveyed by the screw members 113 and 114 to be carried on the surface of the developing roller 12, and the layer thickness (coat amount) of the developer carried on the developing roller 12 is regulated by the developing blade 112. Then, the developer whose layer thickness has been regulated is conveyed to a development position by the rotation of the developing roller 12, and is used to develop an electrostatic latent image on the photosensitive drum 201. The developer remaining on the developing roller 12 after development is collected in the toner storage section 111, and is stirred and conveyed again by the screw members 113 and 114.

[0036] The developing device 10 also has a toner concentration sensor 117 that detects the concentration of toner in the developer stirred in the developing container 11. The toner concentration sensor 117 is an inductance sensor, and a detection portion that detects the developer is located inside the developing container 11, and a portion of the sensor is exposed to the outside. A cable 118 that is an electrical signal path from the toner concentration sensor 117 to the image forming apparatus main body 101 is disposed along the side of the developing container 11. The cable 118 is connected to a contact board 119. The contact board 119 has a developing side electrical contact portion 120. The developing side electrical contact portion 120 is formed with surface plating (generally gold plating) to prevent oxidation, and electrical continuity is ensured.

[0037] 4(b), a high-voltage contact portion 121 for receiving a supply of a development voltage from the image forming apparatus main body 101 is provided on the rear end surface of the developing device 10. The high-voltage contact portion 121 is provided on the rear end surface of the developing device main body 14, which will be described later. Since the developing device main body 14 rotates as will be described later, the high-voltage contact portion 121 has a large area so that contact with the contact portion on the image forming apparatus main body 101 side can be maintained even when the developing device main body 14 rotates.

[0038] After being inserted into the image forming apparatus main body 101, the developing device 10 is pressed by a developing pressure mechanism 23 (described later) provided in the image forming apparatus main body 101, whereby the developing device 10 is positioned relative to the photosensitive unit 20, and the developing roller 12 and the photosensitive drum 201 are disposed close to each other with a predetermined gap between them. In addition, the developing side electrical contact portion 120 comes into contact with a main body side electrical contact portion 911 (see FIG. 10, etc.) provided in the image forming apparatus main body 101 when the developing device 10 is attached to the image forming apparatus main body 101, as described later.

[0039] [Development pressure mechanism] As described above, the developing device 10 can be replaced for maintenance or the like, but in the image forming state, the developing roller 12 and the photosensitive drum 201 are disposed in close proximity to each other. Therefore, if the developing device 10 is inserted or removed from the image forming apparatus main body 101 in this state, there is a possibility that the developing roller 12 or the photosensitive drum 201 may be scratched by friction. Therefore, when installing or removing the developing device 10 or the photosensitive unit 20, it is necessary to first separate the developing roller 12 and the photosensitive drum 201 by a sufficient distance so that they do not rub against each other.

[0040] For this reason, the developing device 10 of this embodiment has a fixed part 13 fixed to the image forming device main body 101, and a developing device main body 14 which is a movable part movable relative to the fixed part 13. The fixed part 13 is located upstream of the developing roller 12 in terms of the insertion direction of the developing device 10 into the image forming device main body 101. In other words, the fixed part 13 is a part which positions and fixes the front part of the developing device 10 with respect to the image forming device main body 101.

[0041] In this embodiment, as described later, after the fixing part 13 is positioned on a frame 90 (see FIG. 10, etc.) of the image forming apparatus main body 101, the fixing part 13 is fixed to the frame 90 by a fastening member such as a screw. As a result, the developing device 10 is fixed to the image forming apparatus main body 101 and prevented from coming off from the image forming apparatus main body 101. The prevention of the developing device 10 from coming off is not limited to this configuration. For example, after the developing device 10 is mounted on the image forming apparatus main body 101, as described later, when the pressure lever 233 is rotated to position the developing device main body 14 at the pressure position, a part of the pressure lever 233 or a member provided on the pressure shaft 231 may be engaged with the end face on the front side of the fixing part 13. In any case, it is sufficient that after the fixing part 13 is positioned on the frame 90, the fixing part 13 is fastened or engaged with a member on the image forming apparatus main body 101 side, so that the developing device 10 is fixed so as not to come off on the front side in the insertion direction.

[0042] In this embodiment, the direction of movement of the developing device main body 14 relative to the fixed portion 13 is the direction of rotation about an engagement portion 15, which will be described later. The developing device main body 14 has a developing roller 12. A developing and pressurizing mechanism 23 can move the developing device main body 14 between a first position (contact position) where the developing roller 12 is close to the photosensitive drum 201 and a second position (separated position) where the developing roller 12 is further away from the photosensitive drum 201 than the first position. At the contact position, a part of the developing device main body 14 contacts a part of the photosensitive unit 20, thereby determining the positional relationship between the developing roller 12 and the photosensitive drum 201.

[0043] The configuration and operation of such a developing and pressurizing mechanism 23 will be described with reference to Figs. 6(a) to 9. Figs. 6(a) and 7 are perspective and sectional views showing a developing and pressurizing release state, i.e., a state in which the developing device 10 is not pressed against the photosensitive unit 20 and the developing device main body 14 is located at a second position where the developing roller 12 is separated from the photosensitive drum 201. Figs. 8 and 9 are perspective and sectional views showing a developing and pressurizing state, i.e., a state in which the developing device 10 is pressed against the photosensitive unit 20 and the developing device main body 14 is located at a first position where the developing roller 12 is close to the photosensitive drum 201. Fig. 6(b) is an enlarged sectional view of a fixing portion 13 and an engagement portion 15 of the developing device main body 14, which will be described later.

[0044] The developing and pressurizing mechanism 23 includes a rod-shaped pressurizing shaft 231 arranged parallel to the longitudinal direction of the developing device 10, and a pressing portion 232 is arranged on the pressurizing shaft 231. In this embodiment, the pressing portions 232 are provided at two positions, one on the front side and one on the rear side of the pressurizing shaft 231, and each of them rotates together with the pressurizing shaft 231. A pressing lever 233 is engaged with the pressurizing shaft 231 on the front side of the image forming apparatus main body 101, and the pressurizing shaft 231 can be rotated by operating the pressing lever 233. In addition, the pressing portion 232 is biased by a biasing member such as a spring (not shown) so as to protrude in a direction away from the pressurizing shaft 231.

[0045] As shown in FIGS. 7 and 9, when the developing device 10 is attached to the image forming device main body 101, the developing device main body 14 is connected to the fixed part 13 by the engagement part 15 on the front side, and is connected to the image forming device main body 101 by the engagement part 115 on the rear side. The developing device main body 14 is rotatable about the rotation axis β (see FIG. 4) of the rotation shafts 15a, 115a of the engagement parts 15, 115. The rotation shafts 15a and 115a are arranged coaxially. In this embodiment, the developing device main body 14 is directly positioned with respect to the image forming device main body 101 at the rear side of the developing device 10. On the other hand, the developing device main body 14 is positioned with respect to the image forming device main body 101 via the fixing part 13 at the front side of the developing device 10.

[0046] The rear engagement portion 115 is an engagement portion between a rotation shaft 115a provided on the rear side of the image forming apparatus main body 101 and a hole 115b formed in an attachment portion 150 provided on the rear side of the developing device main body 14. That is, when the developing device 10 is inserted, the hole 115b provided on the rear side of the developing device main body 14 engages (specifically, fits) with the rotation shaft 115a provided on the rear side of the image forming apparatus main body 101 so as to protrude toward the front side. As a result, the rear side of the developing device main body 14 is positioned so as to be rotatable about the engagement portion 115 between the hole 115b and the rotation shaft 115a.

[0047] As shown in FIG. 6(b), the front engaging portion 15 is composed of a first hole 15b provided in the fixed portion 13, a second hole 15c provided in the developing device main body 14, and a rotating shaft 15a as a shaft portion that engages with the first hole 15b and the second hole 15c. The rotating shaft 15a is a bolt having a head 15a1 at its base end and a threaded portion 15a2 at its tip outer circumferential surface. An insert nut 15d is provided in the fixed portion 13, and the inner circumferential surface of the insert nut 15d constitutes the first hole 15b. That is, the inner circumferential surface of the first hole 15b is a female threaded portion. The inner circumferential surface of the second hole 15c is a cylindrical surface with no threaded portion formed thereon. Also, a female threaded portion may be formed directly on the inner circumferential surface of the first hole 15b.

[0048] When connecting the fixed part 13 and the developing device main body 14, the first hole part 15b of the fixed part 13 and the second hole part 15c formed in the mounting part 151 provided on the front side of the developing device main body 14 are arranged coaxially, and the rotating shaft 15a is inserted through the second hole part 15c. Then, the screw part 15a2 of the rotating shaft 15a is screwed and fixed into the first hole part 15b, so that the mounting part 151 is sandwiched between the fixed part 13 and the head part 15a1. As a result, the developing device main body 14 is connected to the fixed part 13 by the engagement part 15 so as to be rotatable about the rotating shaft 15a.

[0049] The rear engaging portion 115 may have a rotation shaft on the developing device main body 14 side and a hole on the image forming device main body 101 side. The front engaging portion 15 may have an inner peripheral surface of the second hole portion 15c as a female screw portion and a first hole portion 15b as a cylindrical surface without a screw portion, and the rotation shaft 15a may be inserted through the first hole portion 15b. In this case, the fixing portion 13 is sandwiched between the head portion 15a1 of the rotation shaft 15a and the mounting portion 151 of the developing device main body 14, so that the developing device main body 14 is connected to the fixing portion 13 so as to be rotatable about the rotation shaft 15a.

[0050] Also, the engagement portion 15 on the front side may be composed of a shaft portion provided on one of the fixed portion 13 and the developing device main body 14, and a hole portion provided on the other and engageable with the shaft portion. For example, a shaft portion is provided on the fixed portion 13, and a hole portion is provided on the developing device main body 14. Also, the tip of the shaft portion is made a threaded portion, and after the shaft portion is inserted into the hole portion, a nut is screwed onto this threaded portion, thereby connecting the fixed portion 13 and the developing device main body 14. Of course, the relationship between the shaft portion and the hole portion may be reversed. That is, the shaft portion may be provided on the developing device main body 14 side, and the hole portion may be provided on the fixed portion 13 side.

[0051] In this embodiment, the pivot shaft 115a and hole 115b that constitute the rear engagement portion 115, and the pivot shaft 15a and second hole 15c that constitute the front engagement portion 15 are engaged (specifically, fitted) so that the developing device main body 14 can rotate around the engagement portions 15 and 115, respectively.

[0052] In this way, the developing device main body 14 of the developing device 10 can rotate around the rotation shafts 15a, 115a to be movable between the abutment position and the separated position relative to the photosensitive unit 20. When the developing device main body 14 is simply mounted in the mounting position relative to the image forming device main body 101, it is in a state in which it is tilted counterclockwise CCW in the figure around the rotation axis β of the rotation shafts 15a, 115a due to its own weight as shown in Fig. 7, and the developing roller 12 is separated from the photosensitive drum 201. In other words, the developing device main body 14 is in the separated position. When the developing roller 12 and the photosensitive drum 201 are in this separated state, the developing device 10 can be attached to and detached from the image forming device main body 101 without colliding with or coming into contact with each other.

[0053] When the pressure lever 233 is rotated clockwise (CW) with the developing device 10 attached to the image forming apparatus main body 101, the pressing portion 232 on the pressure shaft 231 comes into contact with the pressure force receiving portions 143, 116 as contact portions provided on the developing device main body 14, as shown in Figures 8 and 9. The pressure force receiving portions 143, 116 are formed on mounting portions 151, 150 on the rear and front sides of the developing device main body 14, respectively.

[0054] Then, the developing device main body 14 rotates clockwise CW around the rotation axis β of the rotation shafts 15a and 115a, and the developing roller 12 moves to a contact position (first position) close to the photosensitive drum 201. At this time, the pressing portion 232 is biased by a biasing member (not shown), so that the developing device main body 14 is biased in the clockwise CW direction. The position of the pressing portion 232 in this case is referred to as a third position.

[0055] When the developing device main body 14 is in contact with the photosensitive unit 20, the pressing lever 233 is rotated counterclockwise CCW to release the pressing portion 232 on the pressing shaft 231 from contacting the pressure receiving portions 143 and 116 as shown in FIGS. 6 and 7. Then, the developing device main body 14 tilts counterclockwise CCW, the contact between the developing roller 12 and the photosensitive drum 201 is released, and the developing roller 12 moves to the separated position (second position). The position of the pressing portion 232 in this case is called the fourth position. In this way, the pressing portion 232 is movable between the third position where the pressing portion 232 contacts the pressure receiving portions 143 and 116 and presses the developing device main body 14 at the contact position as shown in FIGS. 8 and 9, and the fourth position where the pressing portion 232 is separated from the pressure receiving portions 143 and 116 and can move the developing device main body 14 to the separated position as shown in FIGS. 6 and 7.

[0056] As described above, the developing device 10 is divided into the developing device main body 14 as a movable part that rotates around the rotation shafts 15a, 115a by the pressure force of the developing pressure mechanism 23, and the fixed part 13 that is fixed to the image forming device main body 101. Specifically, the position of the fixed part 13 is restricted by the image forming device main body 101, and is connected to the developing device main body 14 by an engagement part (first connecting part) 15 via the rotation shaft 15a.

[0057] Further, the toner supply port 133, through which the developer is supplied from the image forming apparatus main body 101 side, is provided in the fixed part 13. The toner supply port 133 and a connection port 142 (FIGS. 4 and 8) provided in the developing device main body 14 are connected by a developer transport path 16 formed of a bellows-shaped elastic member. The connection port 142 is connected to the toner storage section 111 inside the developing device main body 14. That is, the developer transport path 16 is disposed between the fixed part 13 and the developing device main body 14, and connects the toner supply port 133 and the connection port 142 to supply the developer supplied from the toner supply port 133 to the toner storage section 111 inside the developing device main body 14 through the connection port 142. The developer transport path 16 is elastically deformable, and is configured to be capable of communicating the toner supply port 133 with the connection port 142 when the developing device main body 14 is in either the abutting position (pressurized position) or the separating position (pressurized release position).

[0058] [Positioning structure of the front side of the developing unit] Next, a positioning configuration of the front side of the developing device 10 in this embodiment relative to the image forming device main body 101 will be described with reference to Figures 10 and 11. Figure 10 is a diagram showing a state in which the developing device 10 is in the middle of being inserted into the image forming device main body 101. Figure 11 is a diagram showing a state immediately before the front side of the developing device 10 is positioned relative to the image forming device main body 101.

[0059] The developing device 10 can be inserted into and removed from the image forming apparatus main body 101 in the X direction shown in FIG. 10. The X direction is parallel to the longitudinal direction of the developing device 10, i.e., the direction of the rotation axis α of the developing roller 12. The image forming apparatus main body 101 is provided with a first positioning shaft 901 and a second positioning shaft 902 for positioning the developing device 10 with respect to the image forming apparatus main body 101. The first positioning shaft 901 and the second positioning shaft 902 are formed on the frame 90 on the front side of the image forming apparatus main body 101 so as to protrude toward the front side along the first direction. The first direction is parallel to the central axis 901A of the first positioning shaft 901 and is also parallel to the X direction, which is the insertion / removal direction of the developing device 10.

[0060] Meanwhile, the developing device 10 is provided with a first positioning hole 131 and a second positioning hole 132 that engage with a first positioning shaft 901 and a second positioning shaft 902 of the image forming apparatus main body 101. The first positioning hole 131 and the second positioning hole 132 are formed in the fixed portion 13 so as to penetrate along the second direction and the predetermined direction. The second direction and the predetermined direction are parallel to a central axis 131A of the first positioning hole 131.

[0061] Here, the first positioning hole 131 is a hole for positioning the developing device 10, and the second positioning hole 132 is an elongated hole that functions as a hole for preventing rotation of the developing device 10. The second positioning hole 132 is formed so that its length in the up-down direction is longer than that of the first positioning hole 131 when the developing device 10 is attached to the image forming apparatus main body 101.

[0062] Therefore, when the developing device 10 is attached, first, the first positioning shaft 901 enters the first positioning hole 131 to position the developing device 10. At this time, the second positioning shaft 902 also enters the second positioning hole 132. However, since the second positioning hole 132 is an elongated hole, positioning in the vertical direction is not performed, but rotation about the engagement portion between the first positioning hole 131 and the first positioning shaft 901 is restricted.

[0063] In this embodiment, the first positioning hole 131 corresponds to the positioned portion, and the first positioning shaft 901 that engages with the first positioning hole corresponds to the positioning portion. The relationship between the shaft and the hole may be reversed. That is, one of the positioning portion and the positioned portion may be a hole portion formed along the first direction, and the other may be a protrusion formed along the second direction that can engage with the hole portion. In short, the positioning portion and the positioned portion may have a shape that allows them to be positioned when the developing device 10 is inserted into the image forming apparatus main body 101. The relationship between the shaft and the hole may also be reversed for the second positioning shaft 902 and the second positioning hole 132.

[0064] [Electrical connection configuration] Next, referring to Figs. 4(a) and 4(b), the electrical connection configuration between the developing device 10 and the image forming device main body 101 of the present embodiment will be described using Figs. 10 and 11. As described above, the developing device 10 is provided with the developing side electrical contact portion 120. The developing side electrical contact portion 120 is a contact portion for communicating with the image forming device main body side, and in this embodiment, is a contact portion for communicating between the toner concentration sensor 117 and the image forming device main body 101 side. In this embodiment, the developing side electrical contact portion 120 is provided on the fixed portion 13. The developing side electrical contact portion 120 has a contact surface 120a that contacts with the main body side electrical contact portion 911 described later. The contact surface 120a is a surface that is approximately parallel to the direction of gravity.

[0065] The developer-side electrical contact portion 120 is disposed on the surface at the rear side of the fixed portion 13. For this reason, in this embodiment, the fixed portion 13 is provided with a through hole 118a through which the cable 118 can be inserted, and the cable 118 can be connected to the contact board 119 from the side opposite to the surface on which the developer-side electrical contact portion 120 is provided. Note that if the cable 118 can be connected to the contact board 119 on the rear side of the fixed portion 13, the through hole 118a may be omitted.

[0066] The developing side electrical contact 120 may be a contact for communicating between the image forming apparatus main body 101 and another sensor other than the toner concentration sensor 117, such as a sensor for detecting the amount of developer in the developing container 11, or may be a contact for communicating between a plurality of sensors and the image forming apparatus main body 101. In this embodiment, the high-voltage contact 121 for receiving the supply of the developing voltage is provided on the rear side of the developing device 10, but the developing side electrical contact 120 may be a high-voltage contact.

[0067] On the other hand, on the image forming apparatus main body 101 side, a main body side electrical contact portion 911 is provided as a contact portion that receives an electrical signal such as a signal from the toner concentration sensor 117 from the developing device 10. In this embodiment, a contact board 910 connected to a control portion inside the image forming apparatus main body 101 is provided on the frame 90, and the contact board 910 has a main body side electrical contact portion 911. The main body side electrical contact portion 911 is disposed on the front surface of the frame 90. When the developing device 10 is inserted, the developing side electrical contact portion 120 provided on the rear surface of the fixed portion 13 and the main body side electrical contact portion 911 provided on the front surface of the frame 90 can come into contact with each other.

[0068] That is, the developing device 10 is inserted into the image forming device main body 101 along the longitudinal direction, the first positioning hole 131 and the second positioning hole 132 on the developing device 10 side engage with the first positioning shaft 901 and the second shaft positioning 902, and after the fixing portion 13 is roughly positioned with respect to the image forming device main body 101, the developing side electrical contact portion 120 comes into contact with the main body side electrical contact portion 911. Then, the developing device 10 is further pressed in the insertion direction to be mounted to a predetermined position, and then the fixing portion 13 is fixed to the image forming device main body 101.

[0069] Here, the reason why the developer-side electrical contact portion 120 is arranged so that the developer-side electrical contact portion 120 and the main body-side electrical contact portion 911 come into contact with each other after the first positioning hole 131 and the second positioning hole 132 are positioned on the first positioning shaft 901 and the second shaft positioning 902 is as follows. That is, if the developer-side electrical contact portion 120 comes into contact with the main body-side electrical contact portion 911 before the fixing portion 13 holding the developer-side electrical contact portion 120 is positioned on the image forming apparatus main body 101, the conductive elastic body included in the main body-side electrical contact portion 911 may come into contact with a place other than a predetermined place (i.e., the developer-side electrical contact portion 120), and the main body-side electrical contact portion 911 may be deformed or damaged. In addition, by making the developer-side electrical contact portion 120 come into contact with the main body-side electrical contact portion 911 after the fixing portion 13 is roughly positioned on the image forming apparatus main body 101, it is possible to reduce the risk of deformation or damage even for a user who is not familiar with handling an image forming apparatus.

[0070] Generally, the conductive elastic body included in the main body side electrical contact portion 911 is configured to contact the development side electrical contact portion 120 with a force F of about 100 g to 800 g, thereby ensuring electrical continuity. Therefore, the developing device 10 having the development side electrical contact portion 120 and the image forming device main body 101 having the elastic main body side electrical contact portion 911 each receive the force F by action and reaction. If this force F is received at any location of the developing device main body 14 via the development side electrical contact portion 120 on the developing device 10 side, for example, the developing container 11 of the developing device main body 14 may be deformed, and the contact pressure that contacts the developing device main body 14 with the photosensitive unit 20 to ensure the gap between the developing roller 12 and the photosensitive drum 201 may become unstable. If the contact pressure is increased to ensure the gap between the developing roller 12 and the photosensitive drum 201 as a countermeasure, an additional operating force of the pressure lever 233 is required, which reduces user operability.

[0071] For this reason, in this embodiment, as described above, the developer-side electrical contact portion 120 is provided on the fixed portion 13 of the developing device 10. As described above, the fixed portion 13 is fixed to the image forming device main body 101 by a fastening member such as a screw or an engagement member, so that the force F is received by the fastening member or engagement member via the fixed portion 13. In addition, the developing device main body 14 is rotatably supported on the fixed portion 13 via the engagement portion 15. The engagement portion 15 is engaged slightly loosely to allow the developing device main body 14 to rotate relative to the fixed portion 13. Therefore, the force F is not transmitted from the fixed portion 13 to the developing device main body 14. For this reason, in this embodiment, even if the developing device 10 and the image forming device main body 101 are connected by the electrical contact portion, the developing device main body 14 is unlikely to deform. Therefore, it is possible to reduce the deformation of the developing container 11 due to the above-mentioned force F and the unstable contact pressure between the developing device main body 14 and the photoconductor unit 20.

[0072] In addition, in this embodiment, the contact surface 120a of the developing side electrical contact portion 120 is a surface that is approximately parallel to the direction of gravity. Since the developing device 10 stores and stirs toner, there is a possibility that toner may scatter from the vicinity of the developing roller 12 or the vicinity of the toner supply port 133 when the image forming apparatus 100 is in operation or when the developing device 10 is inserted or removed. If the scattered toner adheres to the developing side electrical contact portion 120, the toner may get between the main body side electrical contact portion 911 of the elastic body and the developing side electrical contact portion 120, causing a conduction failure, since the toner is a non-conductive material. For this reason, in this embodiment, the contact surface 120a of the developing side electrical contact portion 120 is disposed approximately parallel to the direction of gravity, thereby suppressing the accumulation of the scattered toner on the developing side electrical contact portion 120. [Explanation of symbols]

[0073] 10. Developing device 12 Developing roller (developer carrier) 13... Fixed part 14. Developing device body 15 Engagement part 100 Image forming apparatus 101... Image forming apparatus main body 117 Toner concentration sensor 120...Development side electrical contact 120a...Contact surface 131: First positioning hole (positioned portion) 201: Photosensitive drum (image carrier) 901: First positioning axis (positioning portion) 911 Electrical contact part on the main body

Claims

1. A developing device that can be attached to an image forming apparatus, a main body portion having a developer container that contains a developer containing toner and a carrier, and a developer carrier that carries and transports the developer to a development position where an electrostatic image formed on an image carrier is developed; a fixing portion that is fixed to the image forming apparatus in a state in which the main body portion is positioned on the image forming apparatus and the fixing portion is positioned on the image forming apparatus in order to mount the developing device on the image forming apparatus; a connecting portion that connects the main body portion and the fixing portion; a developer-side electrical contact portion provided on the fixed portion and contacting a main body-side electrical contact portion of the image forming apparatus when the main body portion is positioned on the image forming apparatus and the fixed portion is positioned on the image forming apparatus; Equipped with When the developing device is pressed by a pressure unit of the image forming apparatus with the fixed unit fixed to the image forming apparatus, the main body unit rotates about the connecting unit as a rotation center so that the developer carrier moves from a separated position separated from the developing position to the developing position. A developing device characterized by:

2. the developing-side electrical contact portion has a contact surface that comes into contact with the main-body-side electrical contact portion, The contact surface is a surface that is approximately parallel to the direction of gravity.

2. The developing device according to claim 1.

3. the developer carrier is rotatable, When the fixed portion is fixed to the image forming apparatus, the developing-side electrical contact portion is located below the rotation axis of the developer carrier in the direction of gravity.

2. The developing device according to claim 1.

4. The developing-side electrical contact portion is a contact portion for communicating with the image forming apparatus.

2. The developing device according to claim 1.

5. the main body further includes a toner concentration sensor that detects the toner concentration of the developer contained in the developer container, The developing-side electrical contact portion is a contact portion for communicating between the toner concentration sensor and the image forming apparatus.

2. The developing device according to claim 1.

6. In a mounting direction in which the developing device is mounted to the image forming apparatus, the fixed portion is located upstream of the developer carrier in the mounting direction.

2. The developing device according to claim 1.

7. In a mounting direction in which the developing device is mounted to the image forming apparatus, a position at which the fixing portion is positioned in the image forming apparatus is upstream of a position at which the main body portion is positioned in the image forming apparatus.

2. The developing device according to claim 1.

8. The fixing portion is fixed to the image forming apparatus by a fastening member in a state in which the main body portion is positioned on the image forming apparatus and the fixing portion is positioned on the image forming apparatus.

2. The developing device according to claim 1.

Images