JP2002196558A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of preventing foreign matter from entering a part using a rotary type electric connection system without causing the increase of a cost and with a simple constitution while giving consideration to the problem of a device equipped with the rotary type electric connection system. SOLUTION: As for the developing device 5 for developing different-colored visible images by making several developing units to successively face a photoreceptor 2 by a rotary body 5A equipped with the several developing units along a circumferential direction, the developing device is provided with a rotary connection means 22 capable of connecting an electrical component 5C4 arranged in the developing unit and an electrical component 27 arranged outside the developing device with rotation, and as for the rotary connection means 22, the rotary supporting part of the means 22 has a constitution 28 of suppressing the foreign matter from entering the electrical component 5C4 arranged in the developing unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and an image forming apparatus, and more particularly, to a lubricating structure of a rotating electrode portion for a plurality of developing units arranged in a circumferential direction.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile, a printer, and a printing machine, a developer such as a toner is applied to an electrostatic latent image carried on a photoconductor as a latent image carrier. To perform visible image processing. As a type of the developing device, in addition to one having a developing unit capable of supplying a single-color developer for forming a single-color image, one having a plurality of developing units for forming a multi-color image There is. The latter development format corresponds to the case where a multicolor image such as a full-color image is formed.

As one of the developing devices used for forming a multicolor image, there is a revolver developing device. The revolver developing device is provided with a plurality of developing units along a circumferential direction on a rotatable rotating support, and develops an electrostatic latent image corresponding to a color separation color formed on the photoreceptor to face the photoreceptor. A configuration for performing visible image processing by a unit is provided.

[0004]

In a developing device such as a revolver developing device, the concentration of the developer contained therein is controlled. In the revolver developing device as well, the concentration of the developer contained in each developing unit is controlled. A process for detecting the density of the developer and maintaining the density at a predetermined density or changing the image forming conditions in accordance with the density is performed.
As a configuration for managing the developer concentration, a configuration in which a toner sensor capable of detecting a toner amount is arranged in a developing unit is general. A toner sensor arranged in each developing unit is electrically connected to a main control unit provided in an image forming apparatus such as a color copying machine,
Specifically, they are connected using a harness.

However, since connection using a harness tends to cause an increase in assembly cost, it has been proposed to perform an integrated wiring using a connector (for example, JP-A-5-216305, JP-A-5-216305). 8-248717
JP, JP-A-11-7193).

[0006] Even when a connector is used, it is difficult to completely eliminate the harness, and at present, the electrical components are partially connected using the harness. In a revolver developing device provided with a rotating support, the harness extended from each developing unit is twisted with the rotation of the rotating support, and in the worst case, permanent distortion may occur and disconnection may occur. Therefore, a configuration is known in which a plurality of conductive portions that are insulated from each other are provided on the rotating side, and a contact made of a conductive brush is provided to make contact with each conductive portion, thereby maintaining a conductive state regardless of rotation.

In the rotary electric connection system, frictional resistance exists between the rotating portion and its shaft supporting portion, which hinders smooth rotation. For this reason, the shaft support uses a bearing to support the rotation shaft so that rotation is not hindered. However, the provision of the bearing increases the component cost accordingly.

[0008] In a configuration including an electric component such as a rotary electric connection system, foreign matter is prevented from entering a place where the electric component is installed from the periphery thereof, thereby preventing deterioration of a conduction state. I have. However, in the case of the rotary electric connection method, a structure for preventing foreign matter intrusion is required in addition to the support structure of the rotating body. There is a risk that the cost will increase.

SUMMARY OF THE INVENTION An object of the present invention is to increase the cost by preventing foreign matter from entering a portion using the above-mentioned conventional developing device, particularly, a device having a configuration using a rotary electric connection system. An object of the present invention is to provide a developing device and an image forming apparatus that can be implemented with a simple configuration without using a developing device.

[0010]

According to the first aspect of the present invention,
In a developing device that performs visible image processing of different colors by sequentially facing the developing unit to the photoconductor using a rotating body having a plurality of developing units along a circumferential direction, the developing device is disposed in the developing unit. A rotating connection means for rotatingly connecting an electrical component and an electrical component disposed outside the developing device. The rotary connecting means is disposed in the developing unit on a rotation support portion thereof. It is characterized in that a configuration is provided for preventing foreign substances from entering the electrical components.

According to a second aspect of the present invention, the rotary connecting means includes a rotary member in which conductive portions corresponding to the number of the developing units are alternately provided along an axial direction with an insulator interposed therebetween;
A housing having a space through which the rotating shaft of the rotating member is inserted and supported, and having a space surrounding the conductive portion; and a harness for connecting electrical components inside the developing unit and electrical components outside the developing unit via the conductive portion. And a rotation support portion that supports a rotation axis of the rotation member is configured by a part of the housing, and the rotation support portion is provided between the conductive portion and the outside of the housing in a part of the housing. It is characterized in that a lubricating part is provided which is in contact with the shaft peripheral surface and shields the conductive part and the outside of the housing.

According to a third aspect of the present invention, the connection means includes:
A rotating member in which conductive portions corresponding to the number of the developing units are alternately provided along an axial direction with an insulator interposed therebetween, and a space in which the rotating shaft of the rotating member is inserted and supported and surrounds the conductive portion. And a harness that connects the electrical components inside the developing unit and the electrical components outside the developing unit via the conductive part, and a part of the rotating shaft of the rotating member includes the rotating member. And a member for reducing the sliding friction between the conductive portion and the inner wall surface of the housing is inserted, and a lubricating portion is provided on the outer sliding resistance reducing member.

According to a fourth aspect of the present invention, the lubricating portion is positioned in a recess formed in one of the rotating shaft and the portion through which the rotating shaft is inserted in the housing and opened to face the other. It is characterized by having.

The invention according to claim 5 is characterized in that the lubricating portion uses a liquid or solid lubricant.

According to a sixth aspect of the present invention, the lubricating portion is held by a washer inserted between an end surface of the rotating shaft on the conductive portion side where the outer diameter changes and an inner surface of the housing facing the end portion. It is characterized by being used.

According to a seventh aspect of the present invention, there is provided the developing device according to the first aspect.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus to which a developing device according to an embodiment of the present invention is applied. The image forming apparatus illustrated in FIG. 1 uses a developer of a color corresponding to color separation to form a full-color image. And a color copying machine capable of forming a multicolor image. In the present invention, the above-described image forming apparatus is not limited to a copying machine, but includes a printer and a facsimile machine.

In FIG. 1, a color copying machine 1 includes a rotatable drum-shaped photosensitive member 2,
A charging device 3, a writing device (only an optical path is shown for convenience) 4, a developing device 5, a transfer device 6, and a cleaning device 7 for performing image forming processing along the rotation direction (the direction of the arrow in the drawing) are arranged. Have been.

In this embodiment, as the transfer device 6, an intermediate transfer device 6A capable of superimposing and transferring an image formed by a developer of a color corresponding to color separation, and an image superimposedly transferred to the intermediate transfer device 6A on a recording sheet And a batch transfer device 6B that transfers the image from the photoreceptor 2 electrostatically to the intermediate transfer device 6A.

At a position where the recording sheet moves after the transfer with the batch transfer position facing the photosensitive member 2 and the batch transfer device 6B, a belt 8A capable of placing and transporting the recording sheet after the batch transfer is provided. A transport device 8 is provided so that the transferred recording sheet can be transported to a fixing device (not shown). A registration roller 9 for setting a transfer timing of a recording sheet fed from a sheet feeding device (not shown) is disposed at a position opposite to the conveyance device 8 across the batch transfer position. The contact state of the collective transfer device 6B is switched by the cam 6B1 so as to oppose and contact the transfer belt 6A1 in the intermediate transfer device 6A only during collective transfer. In FIG. 1, reference numeral 10 denotes a cleaning device for the transfer belt 6A1 in the intermediate transfer device 6A, reference numeral 11 denotes an image density detection sensor, and reference numeral 12 denotes a static elimination device for the photoconductor 2 before cleaning.

In the case of the present embodiment, the developing device 5
A developing unit (for convenience, reference numerals 5C, 5M, 5Y, and 5C) capable of supplying developers of cyan, magenta, yellow, and black, which are colors according to color separation, along the circumferential direction of A
5B), and a developing unit capable of supplying a developer corresponding to the color of the electrostatic latent image formed on the photoconductor 2 faces the photoconductor 2. For full color images,
Each developing unit sequentially performs a visible image process by facing each time an electrostatic latent image is formed on the photoconductor 2.

Each of the developing units 5C, 5M, 5Y, and 5B has the same configuration, and has a configuration capable of supplying a cyan developer as one of them, and can supply a cyan developer as one of them. The configuration of the developing unit will be described below. The developing unit 5C includes a developing sleeve 5C1 capable of supplying a developer facing the photoconductor 2, a supply sleeve 5C2 capable of supplying the developer to the developing sleeve 5C1, and a toner in the developer accommodating portion 5C3. A replenishing sleeve 5C5 for replenishing new toner according to the detection result of the toner sensor 5C4 for detecting the density is provided as a main part. The supply sleeve 5C2 has a screw structure in which the lead direction is set in a relative direction, and distributes the developer uniformly along the axial direction of the photoconductor 2. The replenishing sleeve 5C5 is constituted by a screw member capable of transferring replenished toner from a replenishing tank 19 (see FIG. 2) attached to the developing unit 5C to an opening provided in a part of the developing accommodating layer.

In the color copying machine having the above configuration, the writing device 4 is charged uniformly after the photosensitive member 2 rotates.
As a result, an electrostatic latent image is formed for each color separation, and the image subjected to visible image processing by the developing device 5 is transferred to the intermediate transfer device 6A. Such an operation is repeated a number of times according to the color separation, and when the image for each color separation is superimposed on the intermediate transfer device 6A, the batch transfer device 6B is used for the recording sheet fed from the sheet feeding device. The images on the intermediate transfer belt 6A1 are collectively transferred, and the images held on the recording sheet are fixed.

The developing device 5 has the configuration shown in FIG. In FIG. 2, the developing device 5 includes a longitudinal direction of each casing 5 </ b> A <b> 1 of each developing unit (for convenience, in FIG. 2, cyan and yellow developing units are shown based on the arrangement of each developing unit shown in FIG. 1). A rotating body 5A is provided with flanged barrels 5A2, 5A2 'provided at both ends and a unit rotating shaft 5A3 having both ends integrated between the barrels.

The developing device 5 is provided with a side plate 13 provided with bearings 14 which are respectively disposed at both longitudinal ends of the developing units 5C and 5Y in the axial direction of the barrel 5A2 and are provided with the bearings 14 into which the barrel 5A can be inserted. This housing can be pulled out from the inside of the copying machine as shown in FIG. For this reason, as shown in FIG. 3, the developing device 5 is disposed in a unit housing 15 slidable on a guide rail indicated by a reference symbol R in FIG. Can be inserted into and removed from the color copier.

A shaft cylinder 5A indicated by reference numeral 5A2 'in FIG.
A gear 16 is provided on one of the outer peripheral surfaces of one of the two.
The gear 16 meshes with a drive gear 18A provided on an output shaft of a drive motor 18 attached to a frame 17 of a color copying machine, so that each developing unit of the developing device 5 is rotated so as to face the photosensitive member 2. Is done.

On one side 13 of the side plate, a hopper 19 containing replenishing toner in each developing unit is provided so as to be able to rotate together with each developing unit. The timing at which toner supply from the hopper 19 is started is determined based on the result of toner density detection by the toner sensor 5C4 disposed in the developing unit, that is, the result of toner amount detection.

A harness 20 is extended from the toner sensor 5C4.
2 is connected to a rotary electric connection means 22 disposed on a bearing unit 21 provided in a stationary state irrespective of rotation. The rotary electric connection unit 22 is a unit for maintaining an electrical conduction state without causing the harness 20 to twist while rotating, and the configuration thereof will be described later in detail.

A further harness 23 is extended from the rotary electric connection means 22, and the harness 23 is connected to a terminal 21 A fixed to the bearing unit 21. The terminal 21A includes a connector 25 connectable to a connector 24 provided on the frame 17 side, and is capable of electrical connection by engaging with the connector 24 forming a relationship between a plug and a receptacle. . A harness 26 serving as a signal line from the connector 24 is connected to an input terminal of a main control board 27 provided in the color copying machine.

The rotary electric connection means 22 has the structure shown in FIG. In FIG. 4, the rotary electrical connection means 22
Is a toner sensor 5C disposed in each developing unit.
A rotating member 22C in which a plurality of conductive portions 22A to which respective ends of the harness 20 extended from the connecting member 4 are connected and insulators 22B that partition the conductive portions 22A are arranged in the axial direction; A main body housing 22D that forms a housing having a space surrounding the conductive portion 22A through which the rotating shaft 22C1 integrated with both ends of the 22C is inserted and supported.
And

The main housing 22D is attached to a bearing unit 21 (see FIG. 2) of the developing device 5 through a mounting hole 22D1 formed in a flange, and an opening 22D2 formed in a part of a wall. Is a terminal plate 22E to which the terminal of another harness 23 is connected.
Is attached. Conductive terminals 22E1 connected to the respective harnesses 21 are provided on the terminal plate 22E, and the tips of the conductive portions 22A are pressed against each other.

A lubricating portion 28 is provided on the rotating shaft 22C1 of the rotating member 22C so as to prevent foreign matter from entering from outside the main body housing. The lubricating portion 28 is formed of a recess having an opening formed on one of the rotating shaft 22C1 and the insertion position of the rotating shaft 22C1 in the main body housing 22D and facing the other. In the configuration shown in FIG.
Reference numeral 8 denotes a concave portion which opens toward the inner surface of the main body housing which is an insertion support portion of the rotary shaft 22C1 on the outer peripheral surface of the rotary shaft 22C1, and in the configuration shown in FIG.
A concave portion (shown by reference numeral 28 'for convenience) that opens toward the outer peripheral surface of the rotary shaft 22C1 is shown in the rotary shaft insertion portion on the 2D side. In the configuration shown in FIG. 5, since the cross-sectional area forming the concave portion is used larger than that of the rotating shaft 22C1,
The volume of the lubricating part 28 can be increased.

The lubricating portion 28 is positioned at a position where the conductive member 22A side of the rotating member 22 and the outside of the main body housing 22D are shielded in the insertion support portion of the rotary shaft 22C in the main body housing 22D, and the liquid is contained therein. Alternatively, it is filled with a solid lubricant. The lubricant used in the present embodiment has a characteristic of being able to adsorb foreign substances when foreign substances enter from outside, in addition to lubrication of the rotating shaft 22C1, and in the case of a solid, it is shown in FIG. As described above, a ring-shaped felt impregnated with a liquid lubricant or an oil-impregnated sintered member is used.

Since the present embodiment has the above configuration,
In the developing device 5, the amount of toner contained is detected by the toner sensor 5C4, and toner supply control is performed according to the result. As a configuration used for toner supply control, as described in FIG.
And 23, 26, rotary electric connection means 22, terminal plate 2
5, the main control plate 27;

In the rotary electric connection means 22, the harness 2
0 is connected to each conductive part 22A.
A conductive line from the toner sensor 5C4 to the main control plate 27 is formed by pressing the conductive terminal 22E1 of the terminal plate 22E against the terminal.

In the rotary electric connection means 2, the rotating member 2
2 is provided between the rotating shaft 22C1 and the main body housing 22D through which the rotating shaft 22C1 is inserted, so that foreign matters such as dust floating outside the main body housing 22D can be inserted through the rotating shaft 22C1 and the main body housing 22D. When it enters between the supporting portion and the support portion, it is captured by the lubricating portion 28 and the conductive portion 22
Intrusion into the A side is prevented. As a result, it is possible to prevent poor contact between the conductive portion 22A and the conductive terminal 22E1, which may occur when foreign matter enters the conductive portion 22A side. Since the lubricating portion 28A is located between the rotating shaft 22C1 and the insertion support portion thereof, it is a matter of course that the rotation of the rotating shaft 22C1 is smoothed.

According to the present embodiment, it is only necessary to form a lubricating portion between the existing rotary shaft and the rotary support portion thereof, so that the rotary lubricating action of the shaft and the prevention of foreign matter infiltration can be achieved with simple processing. It becomes possible.

Next, another example according to the embodiment of the present invention will be described. In FIG. 6, another embodiment is characterized in that a lubricating portion is provided on a sliding friction reducing member disposed between a rotating member and a main body housing. In FIG. 6, the rotation shaft 22C1
Is smaller in diameter than the portion where the conductive portion 22A is formed. The lubricating portion 29 is provided at a position where the lubricating portion 29 is rubbed when the amount member comes into contact between the axially outer end surface of the rotating member 22 having the conductive portion 22A and the inner wall surface of the main body housing 22D facing the end surface. Have been. Lubrication part 2 in this case
As shown in FIG. 7 (B), 9 is a washer used to reduce the rubbing resistance generated between the two members, a so-called washer (hereinafter referred to as washer 29), and a rotating shaft 22C1 of the washer 29 is used. The lubricant 29A is held on the insertion surface of the lubrication device.

Since the present embodiment has the above configuration,
A washer 29 used to reduce sliding resistance on the surface of the rotating member 22 that opposes the conductive portion 22A and the main body housing 22D that supports the conductive portion 22A is used to prevent foreign matter from entering. That is, since the lubricant is held on the insertion surface of the rotating shaft 22C1 in the washer 29, the conductive portion 22 is inserted through the insertion surface.
Foreign matter that is going to enter A is adsorbed. This embodiment also corresponds to the arrangement of the washer 29 at a position that shields the conductive portion 22A and the outside of the main body housing 22D.

According to the present embodiment, the foreign matter which is a function completely different from the function of reducing the frictional resistance generated between the existing member and the inner wall surface of the main body housing when the shingle breaking member rotates. It is possible to have a function of preventing intrusion.

[0041]

According to the first aspect of the present invention, since the rotation supporting portion of the rotary connection means is provided with a structure for preventing foreign matter from entering the electrical components arranged in the developing unit, A plurality of functions such as rotation support and foreign matter intrusion prevention are provided in a single part, thereby making it possible to suppress an increase in cost.

According to the second and fourth aspects of the present invention, the rotating shaft of the rotary connection means is supported by a part of the housing, the rotary support is supported by a part of the housing, and the conductive part of the supporting part is provided. A lubricating portion is formed between the housing and the outside of the housing. Foreign matter can be prevented from entering. In particular, according to the second aspect of the present invention, it is possible to prevent foreign matter from entering in a part of the housing forming the support portion of the rotary shaft, so that foreign matter can be prevented from entering by a simple configuration without a bearing member or the like. According to the fourth aspect of the present invention, since the lubricating portion provided in the concave portion opened toward the outer peripheral surface of the rotary shaft is used, a single configuration achieves a function different from that of preventing the rotary shaft from invading lubricating objects. Becomes possible.

According to the third and sixth aspects of the present invention, the frictional resistance between the conductive portion of the rotating member and the housing wall surface facing the conductive portion is reduced by being provided on a part of the rotating shaft of the rotating member. Since the lubricating portion is provided on the member to be cleaned, that is, the washer, it is possible to prevent foreign matter from entering without using a special structure only by using the washer as an existing member.

According to the fourth aspect of the present invention, since the lubricating portion uses a liquid or fixed lubricant, the lubricant of the rotating shaft can be used as a foreign matter infiltrating member without requiring a special structure. Becomes

According to the present invention, it is possible to prevent foreign matter from penetrating into the conductive portion at a connection portion between the electric component provided inside the developing / developing unit and the electric component provided outside the developing device. Accordingly, it is possible to prevent electrical damage to the electrical components due to foreign matter intrusion, and to maintain normal operations such as density control in the developing unit.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a color copying machine as an example of an image forming apparatus using a developing device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a configuration of a developing device used in the color copying machine shown in FIG.

FIG. 3 is a schematic view showing one embodiment of the developing device shown in FIG.

FIG. 4 is a schematic diagram for explaining a configuration of a rotary electric connection unit used in the developing device shown in FIG. 2;

FIG. 5 is a schematic view showing a partially modified example of the configuration of the rotary electric connection means shown in FIG.

FIG. 6 is a schematic diagram for explaining another embodiment of the rotary electric connection means shown in FIG.

7A and 7B are diagrams illustrating a configuration of a lubrication unit used in the rotary electric connection unit illustrated in FIGS. 4 to 6; FIG. 7A illustrates an example in which the configuration illustrated in FIGS. (B) is FIG.
Are shown for each of the configurations shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Color copying machine which is an example of an image forming apparatus 2 Photoconductor 5 Developing device 5A Rotating body 5C, 5M, 5Y, 5B Developing unit 20, 23, 26 Harness which connects between electrical components 22 Rotary electrical connection means 22A Conductive part 22B Insulator 22C Rotating member 22C1 Rotating shaft 22D Main body housing 28, 28 ', 29 Lubricating part

Claims (7)

[Claims] 1. A developing device for performing visible image processing of different colors by successively opposing said developing units to a photoreceptor using a rotating body having a plurality of developing units along a circumferential direction. Rotating connection means for connecting an electrical component disposed inside the developing device and an electrical component disposed outside the developing device while rotating the rotating component. A structure for preventing foreign matter from entering the electrical components disposed in the developing device. 2. The developing device according to claim 1, wherein said rotating connection means comprises a rotating member in which conductive portions corresponding to the number of said developing units are alternately provided along an axial direction with an insulator interposed therebetween. A housing having a space in which the rotating shaft of the rotating member is inserted and supported and having a space surrounding the conductive portion; and an electrical component inside the developing unit and an electrical component outside the developing unit connected to each other via the conductive portion. A rotation support portion that supports a rotation shaft of the rotation member, is configured by a part of the housing, and a portion of the housing is provided between the conductive portion and the outside of the housing. A developing device, comprising: a lubricating portion that is in contact with a peripheral surface of a rotating shaft and shields the conductive portion and the outside of the housing. 3. The developing device according to claim 1, wherein said connecting means comprises: a rotating member in which conductive portions corresponding to the number of said developing units are alternately provided along an axial direction with an insulator interposed therebetween; A housing having a space through which the rotating shaft of the rotating member is inserted and supported and which surrounds the conductive portion; and a harness for connecting electrical components inside the developing unit and electrical components outside the developing unit via the conductive portion. A member for reducing the sliding friction between the conductive portion of the rotating member and the inner wall surface of the housing is inserted into a part of the rotating shaft of the rotating member, and a lubricating portion is attached to the outer sliding resistance reducing member. Is provided. 4. The developing device according to claim 2, wherein the lubricating portion is formed on one of a rotating shaft and a portion through which the rotating shaft is inserted in the housing, and the recess is opened to face the other. A developing device, wherein the developing device is positioned. 5. The developing device according to claim 2, wherein the lubricating portion uses a liquid or solid lubricant. 6. The developing device according to claim 3, wherein the lubricating portion is inserted between an end surface of the rotating shaft on the side of the conductive portion on which the outer diameter changes and an inner surface of the housing facing the end surface. A developing device, wherein the developing device is used while being held. 7. An image forming apparatus using the developing device according to claim 1.