JP2002108037A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device where electric wiring to a rotating device is made compact, and also, facilitated. SOLUTION: As for the image forming device which is provided with a center shaft part 55a joined to the rotary shaft part 44a of a revolver developing unit 40 through a joint 60 so as to be rotated, a ring electrode 55e rotating with the central shaft part 55a as a center in synchronism with the revolver developing unit 40, a needle electrode 55f fixed to a casing 55b so that it may come into contact with the ring electrode 55e in rotating irrespective of the rotating angle, and which is constituted so that the inside and the outside of the revolver developing unit 40 may be electrically connected by harnesses 56 and 57 through a contact between the ring electrode 55e and the fixed electrode 55f, the joint 60 is formed to a separation type hollow cylindrical shape, and the harness 56 passes through the hollow part of the joint 60. Then, a space as the passage of the harness 56 is only required with reference to the inside diameter of the joint 60, and it is easy to make the harness 56 pass through the hollow part of the joint 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer, and the like. More specifically, the present invention relates to a power supply and a signal transmission / reception between an inside and a outside of a rotating device. The present invention relates to an image forming apparatus in which the inside and the outside of a rotating device are electrically connected by electric wiring.

[0002]

2. Description of the Related Art Conventionally, there has been known an image forming apparatus for developing an electrostatic latent image formed on an electrostatic latent image carrier such as a photoreceptor by a rotary developing device as a rotating device. This type of image forming apparatus is provided with a rotary developing device that holds a plurality of developing devices that use developers of different colors. Then, power is supplied from the main body to the rotary developing device to drive a developing roller and the like of each developing device, and to apply a developing bias voltage. Each developing unit is provided with a density sensor, and signals from these sensors are transmitted to a control unit in the main body of the image forming apparatus.

In supplying power and transmitting / receiving signals between the main body of the image forming apparatus and the rotary developing device, the center of rotation which is joined to the shaft member of the rotary developing device via the joining member is used. By providing a conductive ring as a rotating electrode around the shaft member and rubbing a conductive brush or the like as a fixed electrode supported by the electrode case on this,
It is known to use a so-called slip ring for electrically connecting the main body and the rotary developing device. By electrically connecting the main body and the rotary developing device via the slip ring, the electric wiring connecting the main body and the rotary developing device is not twisted even when the rotary developing device rotates.

For example, in Japanese Patent Application Laid-Open No. Hei 6-267627, the slip ring mechanism and the optical coupling mechanism are combined to electrically connect the main body and the rotary developing device and to control signals converted into optical signals. An image forming apparatus capable of transmitting and receiving images has been proposed. Specifically, a central shaft member that is joined to and rotates with the shaft member of the rotary developing device is rotatably supported by the electrode case, and the fixed electrode supported by the electrode case is fixed around the central axis. Power is supplied to the rotary developing device by being rubbed by the ring-shaped rotary electrode. On the other hand, transmission and reception of signals are performed by a light emitting element and a light receiving element provided at the front end of the central axis and at a position opposed thereto. Thus, the transmission and reception of signals between the main body and the rotary developing device are performed in a non-contact manner, so that noise superimposition on signals due to an increase in contact resistance due to contamination or the like is eliminated. In addition, the central shaft to which the rotating electrode is fixed, the fixed electrode, and the electrode case can be handled as a single unit, and these can be detachably attached to the rotary developing device.

[0005]

By the way, the shaft member of the rotary developing device and the center shaft member provided with the rotating electrode are joined via a joining member formed in a hollow cylindrical shape. The electric wiring from inside the rotary developing device is connected from the hollow inside of the shaft member of the rotary developing device to the rotary electrode through the hollow inside of the joining member. In this way, by passing the electric wiring through the hollow interior of each of the shaft member and the joining member, the electric wiring connecting the inside and the outside of the rotary developing device can be made the shortest length.

However, a component such as a connector for connecting to a component in the rotary developing device is attached to the tip of the electric wire. Therefore, when trying to pass electric wiring through the hollow interior of the joining member, if the joining member is formed, for example, indivisible, the inside diameter of the joining member requires a space through which the above-mentioned connector and other components can pass. The diameter of the member increases. Further, when the joining member is formed so as not to be divided, there is a problem that it takes time and effort to pass electric wiring through the hollow interior of the joining member.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of compactly and easily implementing electric wiring to a rotating device. is there.

[0008]

In order to achieve the above object, an object of the present invention is to provide a center shaft member which is joined to a shaft member of a rotating device via a joining member and rotates, and the center shaft member is rotated. A rotating electrode that rotates at the same cycle as the rotating device at the center,
A fixed electrode fixed to a fixed portion so as to contact the rotating rotating electrode regardless of its rotation angle,
In an image forming apparatus in which the inside and the outside of the rotating device are electrically connected to each other by electrical wiring via a contact point between the rotating electrode and the fixed electrode, the joining member is formed into a divisible hollow cylindrical shape, and the joining member is Characterized in that electric wiring passes through the hollow interior.

In this image forming apparatus, since the joining member is formed so as to be dividable, even when the electric wire is passed through the hollow inside of the joining member, it is sufficient that the inner space of the joining member is large enough for the electric wire to pass through. Further, since the joining member is formed so as to be dividable, even if a component such as a connector to be connected to another component is attached to the end of the electric wire, it is easy to pass the electric wire through the hollow inside of the joining member. Therefore, electric wiring to the rotating device can be implemented compactly and easily.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the outer diameter of the joining member is substantially equal to the inner diameter of the shaft member of the rotating device, and the inner diameter of the joining member is the center shaft. It is characterized by being formed substantially equal to the outer diameter of the member.

In this image forming apparatus, since the joining member can be inserted into the space where the shaft member of the rotating device and the central shaft member overlap, there is no need to provide a space for the joining member in the axial direction, and less space is required. It is possible to carry out the electric wiring.

Further, the invention of claim 3 provides the invention according to claim 1 or 2
Wherein the movement of the joining member in the axial direction is regulated by a notch provided on a shaft member of the rotating device and a step provided on the center shaft member. It is.

In this image forming apparatus, the axial movement of the joining member is restricted by the notch provided in the shaft member of the rotating device and the step provided in the central shaft member. A special stopper is not required for restricting the axial movement of the member, and the operation can be performed at low cost.

According to a fourth aspect of the present invention, in the image forming apparatus of the first, second, or third aspect, the dividable joining member is formed of an integral part.

In this image forming apparatus, since the joining member is formed of an integral part, the handling and assembling of the joining member becomes easier as compared with the case where the joining member is constituted of two parts, and the electric power to the rotating device is reduced. Wiring can be performed more easily. Further, since the joining member is formed of an integral part, the cost and the like required for molding can be reduced as compared with the case where the joining member is constituted of a two-point part.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a color electrophotographic printer (hereinafter, referred to as a printer) as an image forming apparatus will be described below. First, the configuration and operation of the entire printer according to the present embodiment will be described. FIG. 1 is an overall schematic configuration diagram. In FIG. 1, the surface of a photosensitive drum 1 as a latent image carrier is indicated by an arrow A in the figure.
After being uniformly charged by the charging charger 2 while being driven to rotate in the direction, a scanning exposure process based on image information is performed by the laser optical device 3 to form an electrostatic latent image. This image information is single-color image information obtained by decomposing the image information of the full-color image for each of yellow, magenta, cyan, and black. The electrostatic latent image formed on the photosensitive drum 1 is transferred to a rotary developing device 4 as a rotating body.
To produce a yellow, magenta, cyan or black toner image.

On the photosensitive drum 1, these yellow,
Magenta, cyan, and black toner images are sequentially formed, and these toner images are formed on the intermediate transfer belt 5 rotating in the direction of arrow B in FIG. The primary transfer charger 6 sequentially superimposes and transfers the images. By such superposition transfer, a full-color toner image is formed on the intermediate transfer belt 5.

The yellow, magenta, cyan, and black images superimposed on the intermediate transfer belt 5 are supplied from the automatic paper feed cassette 7 for both-sided copying and the manual paper feed tray 7a.
The secondary transfer charger 11 collectively transfers the transfer paper 10 onto the transfer paper 10 that has been conveyed to the transfer unit via the paper feed rollers 8 and 8a and the registration roller 9. The transfer paper 10 onto which the full-color toner image has been transferred in this way is sent out from the transfer section to the fixing device 12, where the full-color toner image is fixed, and then discharged out of the apparatus as a full-color print.

The residual toner on the photosensitive drum 1 that has not been transferred onto the intermediate transfer belt 5 is removed from the photosensitive drum 1 by the photosensitive cleaner 13. Further, the residual toner on the intermediate transfer belt 5 that has not been transferred onto the transfer paper 10 is removed from the intermediate transfer belt 5 by the intermediate transfer belt cleaner 14.

FIG. 2 is a sectional view showing a schematic configuration of the rotary developing device 4. FIG. 3 is a cross-sectional view showing a state where the rotary developing device 4 is pulled out of the printer main body. FIG.
3 and FIG. 3, the support frame 2 of the rotary developing device 4 is shown.
0, a developing drawer unit 30 movably supported in a direction away from or approaching the photosensitive drum 1 during a pull-out or insertion operation with respect to the printer body;
A revolver developing unit 40 having four cylindrical black, cyan, yellow, magenta, and cyan color developing units and having a substantially cylindrical outer periphery, which is rotatably mounted around a rotation axis, is mounted.

The developing drawer unit 30 includes a drawer rear side plate 31, a drawer front side plate 32,
And a pair of first stays 33 connecting the first and second stays 32.
The developing drawer unit 30 includes a bearing housing 34 attached to the drawer rear side plate 31 as described later.
Bearing 35 and the bearing 3 press-fitted into the drawer front side plate 32
6, the revolver developing unit 40 is rotatably supported. Then, as shown in FIG. 3, the developing drawer unit 30 is supported by a slide rail 21 formed on the support frame 20 so as to be movable left and right in the drawing at the time of pulling or inserting operation with respect to the printer main body.

The revolver developing unit 40 is a hollow cylindrical member made of aluminum which connects the after-developing side plate 41, the before-developing side plate 42, and both side plates 41 and 42, and rotates around a rotation axis to position each developing device. Second stay 43
And a rear flange 44 protruding from the central portion of the post-developing side plate 41 and formed integrally with the gear, and a front flange 45 protruding from the central portion of the pre-developing side plate 42. The rotating shaft portion 44 a protruding on the rotating axis of the rear flange 44 is set on the inner ring of the bearing 35 of the bearing housing 34 attached to the drawn back side plate 31. The rotary shaft portion 45 a protruding from the rotary axis of the front flange 45 is set on the inner ring of the bearing 36 press-fitted into the drawer front side plate 32. A part of the gear 44b of the rear flange 44 is connected to the output gear 22a of the drive motor 22 attached to the support frame 20.
The engagement causes the revolver developing unit 40 to rotate around the rotation axis. The revolver developing unit 40 configured as described above sequentially connects each developing device to the photosensitive drum 1.
The electrostatic latent image on the photosensitive drum 1 is visualized by moving to a developing position facing the photosensitive drum 1.

Next, the internal structure of the revolver developing unit 40 will be described. FIG. 4 is a schematic sectional view showing the internal configuration of the revolver developing unit 40. As shown in FIG. 4, in a cylindrical revolver developing unit 40, four developing devices 46K having substantially the same shape in the circumferential direction are provided.
46Y, 46M and 46C are arranged. In the illustrated example, the black developing device 46K containing the black toner and the carrier is located at the developing position facing the photoreceptor drum 1, and the yellow developing device containing the yellow toner and the carrier in the counterclockwise direction in the drawing. 46Y, a magenta developing device 46M containing magenta toner and carrier, and a cyan developing device 46C containing cyan toner and carrier. Here, since the internal configurations of the four developing units 46K, 46Y, 46M, and 46C are exactly the same, the internal configuration will be described below using the black developing unit 46K at the developing position as an example.

The black developing device 46K is provided with a developing roller 47K for partially exposing the peripheral surface from an opening toward the photosensitive drum 1. A doctor blade 48 for regulating the amount of developer carried on the developing roller 47K and conveyed to a portion facing the photosensitive drum 1 is provided therein.
K, an upper transport screw 49K for transporting a two-component developer (hereinafter simply referred to as a developer) regulated by the doctor blade 48K from the back side to the front side in the figure, and a guide 49a thereof.
K, stirring paddle 5 for stirring the developer in black developing unit 46K
0K, a magnetic permeability sensor (hereinafter referred to as a T sensor) 52K for detecting the toner concentration of the developer in the black developing device 46K based on the magnetic permeability of the developer in the black developing device 46K is provided. This stirring paddle 50K includes a plurality of paddle members on the outer peripheral surface of the hollow cylindrical portion. A plurality of discharge holes (not shown) are formed in the hollow cylindrical portion, and a lower transfer screw 51K for transporting the developer from the near side to the far side in the drawing is accommodated in the hollow cylindrical portion. . A part of the developer transported by the lower transport screw 51K is discharged from the discharge hole to the outside of the hollow cylindrical portion. In this manner, in the transport process, a part of the developer circulated and transported in the black developing device 46K is pumped up and transported by the developing roller 47K. The developer carried and conveyed by the developing roller 47K is thinned by a doctor blade 48K and then conveyed to a developing area, where the electrostatic latent image on the photosensitive drum 1 is converted into a toner image in the developing area.

As shown in FIGS. 2 and 3, the above-mentioned revolver developing unit 40 has one-to-one correspondence with each developing unit 46, and corresponds to black, cyan, yellow, magenta, and magenta, respectively.
The toner hoppers 53 containing the four color toners of cyan are attached to the hopper side plate 54 so as to be substantially coaxial with the revolver developing unit 40, and rotate integrally with the revolver developing unit. Of the developer in each of the developing devices 46 of the revolver developing unit 40, the toner is consumed every time development is performed. For example, the black developer 46
When the toner is detected by the K toner concentration sensor 52K, the toner is supplied from the toner hopper 53 containing the toner for replenishment to the black developing device 46K into the black developing device 46K by a toner replenishing device (not shown). This allows
The toner density is kept at a predetermined density, and the image density is kept constant. The toner hopper 53 is detachable from the revolver developing unit 40. When the toner in the toner hopper 53 is consumed, the toner hopper 53 can be replaced.

Further, a slip ring 55 is attached to the bearing housing 34 provided on the drawer rear side plate 31 of the developing drawer unit 30 at a position facing the rotating shaft 44a of the rear flange 44. A harness 56 composed of a plurality of electric wires individually connected to the T sensor 52 from each developing device passes through the hollow inside of the second stay 43 and the rotating shaft portion 44a of the rear flange 44 to the slip ring 55. Connected. The harness 57 composed of a plurality of electric wires connected to the slip ring 55 is connected to a rack connector 58a provided on the rear side plate 31 and a panel connector 58b attached to the support frame 20 via a panel connector 58b. Connected to control board 59. The control board 59 calculates the optimum image processing based on the toner density in each developing unit 46 in the revolver developing unit 40. Note that the rack connector 58a and the panel connector 58b can be automatically separated and connected in conjunction with the attaching / detaching operation of the developing drawer unit 30.

FIG. 5 is a schematic sectional view showing the internal structure of the slip ring. In FIG. 5, the slip ring 55
Includes a central shaft portion 55a that is joined to the rotating shaft portion 44a of the rear flange 44 and rotates, and a casing 55b into which the central shaft portion 55a is inserted. This central shaft portion 55a
Are two bearings 55 disposed opposite to each other on the casing 55b.
Crosslinked and supported rotatably by c and 55d. Inside the casing 55b, the central shaft portion 55a
A plurality of ring electrodes 55e as rotating electrodes are formed on the peripheral surface of the wire harness 56, and the ends of the electric wires of the harness 56 are individually connected to the ring electrodes 55e. On the other hand, the casing 55b is
and a plurality of needle electrodes 55f as fixed electrodes arranged so as to individually contact with each other. Electric wires are individually connected to the needle electrodes 55f, respectively, and the harness 57 is formed by the plurality of electric wires.

In such a configuration, even if the revolver developing unit 40 rotates, the harness 56 extending from the side of the unit does not twist or twist. In addition, regardless of the rotation angle of the central shaft portion 55a, and thus regardless of the rotation angle of the revolver developing unit 40 that indirectly applies a rotational driving force thereto, the electrical connection between the plurality of ring electrodes 55e and the needle electrodes 55f is made. Contacts can be maintained. Thus, regardless of the rotation angle of the revolver developing unit 40, the respective sensors (T sensors 52K, 52Y, 52M, 52C) disposed in the respective developing units 46K, 46Y, 46M, 46C, A plurality of electrical conduction paths are individually formed to individually connect the control board 59 and the control board 59.

FIG. 6 shows the rotating shaft 4 of the rear flange 44.
FIG. 4 is an exploded perspective view for explaining a state of joining of the slip ring 4a and a central shaft portion 55a of a slip ring 55. FIG. 7 is a cross-sectional view illustrating a state where the rotary shaft portion 44a of the rear flange 44 and the central shaft portion 55a of the slip ring 55 are joined.
It is sectional drawing which looked at FIG. 6 from C direction. 6 and 7, the rotating shaft portion 44a of the rear flange 44 as the shaft member of the revolver developing unit 40 and the center shaft portion 55a as the center shaft member are joined via a joint 60 as a joining member. I have. Through this joint 60,
The rotational drive of the rotating shaft 44a of the revolver developing unit 49 is transmitted to the central shaft 55a.

The printer according to the present embodiment is characterized in that a joint 60 formed in a hollow cylindrical shape so as to be dividable is used as the joining member, and the harness 56 is passed through the hollow inside of the joint 60. is there. FIG.
As shown in the figure, the joint 60 is divided into a joint 60a and a joint 60b vertically in the figure on a plane parallel to the rotation axis of the rotation shaft portion 44a. The joint 60a has an end on the slip ring 55 side of a peripheral surface that abuts on the joint 60b, and a rotation shaft 44 that extends in a direction orthogonal to the axial direction.
Rectangular projections 60c having substantially the same thickness as a are formed. The joint 60b has a joint 60
A rectangular projection 60d substantially equal in thickness to the rotating shaft portion 44a is formed in a direction orthogonal to the axial direction at an end portion of the peripheral surface that contacts the slip ring 55 on the side of the slip ring 55, and is divided into contact with the joint 60a. At the end of the surface on the side of the rotating shaft 44a,
Rising portions 60e are formed to regulate movement of the joint 60a toward the rotation shaft portion 44a.
As shown in FIG. 7, at the time of assembly, the joint 60 has an inner diameter substantially equal to the outer diameter of the central shaft portion 55 a of the slip ring 55, and the outer diameter of the rotation shaft portion 44.
It is formed substantially equal to the inner diameter of a, and is held in the space between the rotating shaft portion 44a and the central shaft portion 55a. The harness 56 connected to the T sensor 52 provided in each developing device 46 of the revolver developing unit 40 passes through the hollow interior of the rotating shaft portion 44a, then passes through the hollow interior of the joint 60, and the center of the slip ring 55 The shaft 55a is reached.

On the other hand, a notch 44c of the same shape as the projections 60c, 60d is provided at a position corresponding to the projections 60c, 60d on the end face of the rotary shaft 44a on the joint 60 side.
Are formed. A D-shaped milling surface 55g is formed on the joint 60 side of the central shaft portion 55a of the slip ring 55 from the end thereof, and a rising side surface 55h as a step of the central shaft portion 55a is formed. As a result, the projections 60c and 60d of the joint 60 are sandwiched between the notches 44c of the rotary shaft 44a, and the joint 6
The end surface on the slip ring side of No. 0 comes into contact with the rising side surface 55h, and the axial thrust of the joint 60 is stopped.

As described above, in the printer according to the present embodiment, the joint 60 is formed so as to be separable, is held in the hollow interior of the rotating shaft portion 44a at the time of assembly, and the harness 56 is wired inside the hollow interior. So
It is sufficient that the inner diameter of the joint 60 has a space through which the harness 56 can pass. Even if a component such as a connector is attached to the tip of the harness 56, it is easy to pass the harness through the joint 60.

Further, in the printer according to the present embodiment, the thrust stop in the axial direction of the joint 60 is provided in the notch portion 44c provided in the rotary shaft portion 44a and the central shaft portion 55a of the slip ring 55. The use of the rising side surface 55h can be performed at low cost without requiring a dedicated stopper.

Next, another embodiment will be described. In the above embodiment, the joint is composed of two parts, so that the joint can be completely divided. However, here, the joint is composed of an integral part. FIG. 8A is a perspective view illustrating a state of assembling a joint formed of an integral part, and FIG. 8B is a perspective view illustrating a state of a deployed state of a joint formed of an integral part. FIG. FIG.
In (a) and (b), the joint 61 is connected to the rotating shaft 4.
A joint 61 is provided on the left and right sides in the figure on a plane parallel to the rotation axis of 4a.
a and the joint 61b and the slip ring 5
The joint 61a and the joint 61b are connected by a thin bent portion 61c formed on a part of the end face on the fifth side. The joint 61a has a rectangular convex portion 61d formed at a position facing the bent portion 61c.
A protrusion 61e is formed on the peripheral surface between c and the protrusion 61d. A hook-shaped latch portion 61f is formed on the joint 61b at a position facing the bent portion 61c.
A projection 61g is formed on the peripheral surface between the and the latch 61f. Then, as shown in FIG. 8A, at the time of assembling, the joint 61 is closed in the direction of arrow D in the figure so that the convex portion 61d and the latch portion 61f engage with each other. The outer diameter of the portion 55a is substantially equal to the outer diameter of the rotary shaft portion 44a, and is held in a space between the rotary shaft portion 44a and the central shaft portion 55a. Each developing device 4 of the revolver developing unit 40
Harness 56 connected to a T sensor 52 provided in
Passes through the hollow interior of the rotary shaft portion 44a and then through the hollow interior of the joint 61 to reach the central shaft portion 55a of the slip ring 55.

As described above, in the printer according to the present embodiment, since the joint 61 is formed as an integral part, the cost and the like required for molding are reduced as compared with the case where the joint 60 is formed as a two-point part. can do. In addition, the joint 61 is easier to handle and assemble than the case where the joint 61 is composed of two parts like the joint 60, and the harness 56 is hooked on the joint 61 in the closed state. Wiring becomes easier. As described above, the protrusions 61e and 61g are sandwiched between the notches 44c provided on the rotary shaft 44a, and the joint 61
The end on the side of the slip ring 51 abuts on a rising side surface 55 h provided on the central shaft portion 55 a of the slip ring 55. Thereby, thrust stop in the axial direction of the joint 61 can be performed.

As described above, in the present embodiment, the one shown in FIG. 5 is used as the internal configuration of the slip ring 55, but the present invention is not limited to this. For example,
A rotating electrode substrate in which a plurality of ring electrodes having different diameters are arranged concentrically, and a plurality of needle-like electrodes arranged so as to individually contact these ring electrodes, respectively, form a slip ring. The interior may be configured. Further, FIG. 5 shows an example in which each ring electrode becomes a rotating electrode and each needle electrode becomes a fixed electrode. However, the opposite, that is, each ring electrode becomes a fixed electrode, and each needle electrode becomes a rotating electrode. May be. Specifically, the needle electrode is provided upright on the inner peripheral surface of the central axis in a direction perpendicular to the axial direction, and the ring electrodes are provided inside the ring so as to penetrate the central axis. Then, it is preferable that each needle electrode is made to protrude from a notch provided on the central axis to come into contact with each ring electrode.

In this embodiment, the T sensor 5
The example in which the harness 56 connected to the joint 2 is passed through the hollow interior of the joints 60 and 61 has been described. However, a developing bias voltage is applied to the developing roller provided in each developing device to the harness passed through the joint. Needless to say, a harness may be included. Further, an embodiment in which a harness is connected to another component such as a non-optical sensor that detects the presence or absence of toner in a toner container that supplies toner to each developing device, and the harness is passed through a joint is also conceivable.

In this embodiment, the rotary developing device 4 serving as a rotating device is connected via a slip ring 55.
Although the printer in which the inside and the outside of the (revolver developing unit 40) are electrically connected has been described,
The present invention is not limited to this. For example, an embodiment in which the inside and the outside of another rotating device such as the inside and the outside of the photosensitive drum are electrically connected via a slip ring is also conceivable.

[0039]

According to the first to fourth aspects of the present invention, there is an excellent effect that electric wiring to the rotating device can be implemented compactly and easily.

In particular, according to the invention of claim 2, there is an excellent effect that electric wiring can be implemented in a smaller space.

Further, according to the third aspect of the present invention, there is an excellent effect that it is not necessary to use a special stopper for restricting the movement of the joining member in the axial direction, and it can be implemented at low cost.

According to the fourth aspect of the present invention, it is easy to handle and assemble the joining member, so that the electric wiring to the rotating device can be more easily performed and the cost can be reduced. Has an effect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating the overall configuration of a printer according to an embodiment.

FIG. 2 is a schematic sectional view showing a configuration of a rotary developing device of the printer.

FIG. 3 is a schematic sectional view illustrating a state in which the rotary developing device is pulled out of a printer main body.

FIG. 4 is a schematic sectional view showing an internal configuration of a revolver developing unit of the rotary developing device.

FIG. 5 is a schematic sectional view showing the internal configuration of the slip ring.

FIG. 6 is an exploded perspective view illustrating a joint state between a rotation shaft of the revolver developing unit and a center shaft of the slip ring.

FIG. 7 is a cross-sectional view illustrating a joint state between a rotation shaft of the revolver developing unit and a center shaft of the slip ring.

FIG. 8A is a perspective view for explaining a state of assembling a joint constituted by integral parts. (B) is a perspective view explaining the state at the time of deployment of the joint comprised by an integral part.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 4 rotary developing device 20 support frame 30 developing drawer unit 40 revolver developing unit 44 rear flange 44a rotating shaft portion 44b gear 44c cutout portion 46 developing device 52 T sensor 55 slip ring 55a central shaft portions 56, 57 harness 60, 61 joint

Claims (4)

[Claims] 1. A central shaft member that is joined to a shaft member of a rotating device via a joining member and rotates, a rotating electrode that rotates about the central shaft member at the same cycle as the rotating device, and the rotating shaft that rotates. A fixed electrode fixed to a fixed portion so as to be in contact with the electrode irrespective of its rotation angle, and the inside and the outside of the rotating device are connected by electric wiring via a contact point between the rotating electrode and the fixed electrode. In the image forming apparatus to be conducted, the joining member is formed in a hollow cylindrical shape which can be divided, and an electric wiring passes through the hollow inside of the joining member. 2. An image forming apparatus according to claim 1, wherein an outer diameter of said joining member is substantially equal to an inner diameter of a shaft member of said rotating device, and an inner diameter of said joining member is substantially equal to an outer diameter of said central shaft member. An image forming apparatus, comprising: 3. The image forming apparatus according to claim 1, wherein the joint member is moved in an axial direction by a notch provided in a shaft member of the rotating device and a step provided in the central shaft member. An image forming apparatus characterized by being regulated by: 4. The image forming apparatus according to claim 1, wherein the dividable joining member is formed as an integral part.