JP4351803B2 - Developing device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device and an image forming apparatus, and more particularly to a lubrication structure of a rotating electrode portion for a plurality of developing units arranged in the circumferential direction.
[0002]
[Prior art]
In an image forming apparatus such as a copying machine, a facsimile, a printer, or a printing machine, a visible image using a developer such as toner is applied to an electrostatic latent image carried on a photosensitive member that is a latent image carrier. Processing is performed.
As a type of developing device, in addition to a developing unit capable of supplying a single color developer for forming a single color image, a developing device having a plurality of developing units for forming a multi-color image. There is. The latter development format corresponds to the case of forming a multicolor image such as a full color image.
[0003]
One of the developing devices used for forming a multicolor image is a revolver developing device.
The revolver developing device includes a plurality of developing units along a circumferential direction of a rotatable rotating support, and each development that faces an electrostatic latent image corresponding to a color separation color formed on the photoreceptor. The unit is configured to perform visible image processing.
[0004]
[Problems to be solved by the invention]
Development devices such as revolver development devices control the concentration of the developer contained in them, and the revolver development device also detects the concentration of the developer contained in each development unit. Then, a process for maintaining the predetermined density or changing the image forming condition corresponding to the density is performed.
As a configuration for managing the developer concentration, a configuration in which a toner sensor capable of detecting the toner amount is arranged in the developing unit is general.
The toner sensor arranged in each developing unit is electrically connected to a main control unit equipped in an image forming apparatus such as a color copying machine, and specifically connected using a harness. .
[0005]
However, since connection using a harness tends to increase the assembly cost, it has been proposed to perform collective wiring using a connector (for example, JP-A-5-216305 and JP-A-8-248717). No. 1, JP-A-11-7193).
[0006]
Even in the case of using a connector, it is difficult to completely eliminate the harness, and the electrical parts are currently connected to each other partially using the harness.
In the revolver developing device provided with the rotating support, the harness extended from each developing unit is kinked with the rotation of the rotating support, and in the worst case, there is a possibility that permanent distortion occurs and the wire breaks. In view of this, a configuration is known in which a plurality of conductive portions insulated from each other are provided on the rotation side, and a contact made of a conductive brush that is in contact with each conductive portion is provided to maintain a conductive state regardless of rotation.
[0007]
In the rotary electrical connection method, a frictional resistance exists between the rotating part and the shaft support part, and smooth rotation is hindered. For this reason, the shaft support portion supports the rotating shaft using a bearing so that rotation is not hindered. However, the cost of parts increases to provide a bearing.
[0008]
In the configuration including the electrical component such as the rotary electrical connection method, it is possible to prevent the foreign matter from entering from the periphery to the installation location of the electrical component to prevent deterioration of the conduction state. However, in the case of the rotary electrical connection method, in addition to the support structure of the rotating body, a structure for preventing foreign matter intrusion is required, so the structure becomes complicated compared to the case where rotation support is not required, There is a risk of increasing costs.
[0009]
An object of the present invention is to easily prevent foreign matter from entering a portion using the connection method without causing an increase in cost in view of the problems in the above-described conventional developing device, in particular, a device having a configuration using the rotary electrical connection method. Another object of the present invention is to provide a developing device and an image forming apparatus that can be configured with various configurations.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 is a developing device that performs visible image processing of different colors by sequentially facing the developing unit with respect to the photosensitive member using a rotating body including a plurality of developing units along the circumferential direction. Rotating connection means that can connect while rotating the electrical parts arranged in the developing unit and the electrical parts arranged outside the developing apparatus, and the rotational connecting means corresponds to the number of the developing units. A rotating member in which conductive portions to be alternately provided across an insulator along the axial direction, a housing having a space surrounding the conductive portion while the rotation shaft of the rotating member is inserted and supported, A rotation support unit configured to include a harness for connecting the electrical components in the development unit and the electrical components outside the development unit via the conductive portion, and supporting the rotation shaft of the rotation member. is, 該筐The rotational support portion, in a position to shield and the conductive portion and the housing outside is constituted by the recess which opens toward the outer circumferential surface of the inner surface or the rotating shaft of the housing, the axial direction of the rotary shaft in the recess A liquid or solid lubricant is filled between the outer end surface and the surface of the casing opposite to the outer end surface to adsorb foreign substances from the outside in addition to the lubrication of the rotating shaft .
[0011]
According to a second aspect of the present invention, in the developing device according to the first aspect, the washer holds a lubricant capable of adsorbing and collecting foreign matter on the insertion surface of the rotating shaft .
[0012]
A third aspect of the invention is characterized in that the developing device according to the first or second aspect is used in an image forming apparatus .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the illustrated examples.
FIG. 1 is a schematic diagram showing 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 shown in FIG. 1 is a full-color image using a developer having a color corresponding to color separation. This is a color copier capable of forming multicolor images. In the present invention, as described above, the image forming apparatus is not limited to a copying machine, but of course includes a printer and a facsimile machine.
[0018]
In FIG. 1, a color copying machine 1 includes a rotatable drum-shaped photoconductor 2, and a charging device for performing image forming processing along the rotation direction (arrow direction in the drawing) around the photoconductor 2. 3. A writing device (only the optical path is shown for convenience) 4, a developing device 5, a transfer device 6 and a cleaning device 7 are arranged.
[0019]
In this embodiment, as the transfer device 6, an intermediate transfer device 6A capable of superimposing and transferring an image formed with a developer having a color corresponding to color separation, and an image superimposed and transferred to the intermediate transfer device 6A on a recording sheet. A batch transfer device 6B for batch transfer is provided, and a transfer belt 6A1 that can electrostatically transfer an image from the photoreceptor 2 is used as the intermediate transfer device 6A.
[0020]
At a position where the recording sheet moves after the transfer at the batch transfer position facing the photoreceptor 2 and the batch transfer device 6B, a transport device 8 having a belt 8A capable of placing and transporting the record sheet after the batch transfer is completed. Is arranged so that the recording sheet after transfer can be conveyed toward a fixing device (not shown). A registration roller 9 for setting the transfer timing of a recording sheet fed from a paper feeding device (not shown) is disposed at a position facing the conveying device 8 across the batch transfer position. The batch transfer device 6B is configured to switch the contact state by the cam 6B1 so as to face and contact the transfer belt 6A1 in the intermediate transfer device 6A only at the time of batch 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 pre-cleaning static elimination device for the photoreceptor 2.
[0021]
In the case of the present embodiment, the developing device 5 is a developing unit that can supply developers of cyan, magenta, yellow, and black, which are colors corresponding to the color separation, along the circumferential direction of the rotating body 5A (for convenience, reference numeral 5C, 5M, 5Y, and 5B), and a developing unit capable of supplying a developer corresponding to the color of the electrostatic latent image formed on the photosensitive member 2 faces the photosensitive member 2. In the case of a full-color image, each developing unit sequentially performs a visible image process every time an electrostatic latent image is formed on the photoreceptor 2.
[0022]
The developing units 5C, 5M, 5Y, and 5B all have the same configuration, and have a configuration capable of supplying one cyan developer, and a developing unit capable of supplying one cyan developer. The configuration will be described as follows.
The developing unit 5C includes a developing sleeve 5C1 that can supply a developer facing the photoreceptor 2, a supply sleeve 5C2 that can supply the developer to the developing sleeve 5C1, and a toner in the developer container 5C3. A supply sleeve 5C5 for supplying 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 5 </ b> C <b> 2 has a screw structure in which a lead direction is set in a relative direction, and the developer is uniformly distributed along the axial direction of the photoreceptor 2. The replenishment sleeve 5C5 is configured by a screw member capable of transferring replenishment toner from a replenishment tank 19 (see FIG. 2) attached to the developing unit 5C toward an opening part of the developing container.
[0023]
In the color copying machine having the above configuration, an electrostatic latent image for each color separation is formed by the writing device 4 after being uniformly charged in the rotation process of the photosensitive member 2, and the image subjected to the visible image processing by the developing device 5. Is transferred to the intermediate transfer device 6A. When such an operation is repeated a number of times according to the color separation, when an 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 paper feeding device. The images on the intermediate transfer belt 6A1 are collectively transferred, and the image held on the recording sheet is fixed.
[0024]
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, FIG. 2 shows cyan and yellow developing units based on the arrangement of the developing units shown in FIG. 1). A rotating body 5A is configured by including flanged shaft cylinders 5A2 and 5A2 ′ provided at both ends and a unit rotating shaft 5A3 in which both ends are integrated between the shaft cylinders.
[0025]
The developing device 5 includes a housing including a side plate 13 provided with bearings 14 that are respectively disposed at both longitudinal ends of the developing units 5C and 5Y in the axial direction of the shaft cylinder 5A2 and into which the shaft cylinder 5A can be inserted. As shown in FIG. 3, this housing can be pulled out from the inside of the copying machine. For this reason, as shown in FIG. 3, the developing device 5 is arranged in a unit housing 15 that can slide on the guide rail indicated by R in FIG. 3, and the unit housing 15 is pulled out or pushed in. It can be inserted into and removed from a color copier.
[0026]
A gear 16 is provided on the outer peripheral surface of one of the shaft cylinders 5A2 indicated by reference numeral 5A2 'in FIG. 2, and this gear 16 is connected to an output shaft of a drive motor 18 attached to a frame 17 of a color copying machine. By meshing with the drive gear 18 </ b> A, the development unit of the development device 5 is rotationally driven so as to face the photoreceptor 2.
[0027]
On one side 13 of the side plate, a hopper 19 containing replenishment toner in each developing unit is provided so as to be able to rotate together with each developing unit.
The toner replenishment start timing from the hopper 19 is determined by the density determination by the toner sensor 5C4 disposed in the developing unit, that is, the result of toner amount detection.
[0028]
A harness 20 is extended from the toner sensor 5C4, and the harness 20 is connected by a bearing 14 to a rotary electrical connection means 22 arranged in a bearing unit 21 provided in a stationary state regardless of the rotation of the shaft cylinder 5A2. Yes. The rotary electrical connection means 22 is a means for maintaining an electrical conduction state without causing the harness 20 to be cut off while rotating, and the configuration thereof will be described in detail later.
[0029]
One more harness 23 is extended from the rotary electrical connecting means 22, and the harness 23 is connected to a terminal 21 </ b> A fixed to the bearing unit 21.
The terminal 21A includes a connector 25 that can be connected to a connector 24 provided on the frame 17 side, and can be electrically connected by engaging with a connector 24 that forms 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.
[0030]
The rotary electrical connecting means 22 has the configuration shown in FIG.
In FIG. 4, the rotary electrical connection means 22 partitions the plurality of conductive portions 22A to which the respective ends of the harness 20 extended from the toner sensor 5C4 disposed in each developing unit are connected, and the respective conductive portions 22A. A casing having a space surrounding a conductive portion 22A by inserting and supporting a rotating member 22C in which a plurality of insulators 22B are arranged in the axial direction and a rotating shaft 22C1 integrated at both ends of the rotating member 22C. And a main body housing 22D.
[0031]
The main body housing 22D is attached to the bearing unit 21 (see FIG. 2) in the developing device 5 through an attachment hole 22D1 formed in the flange portion, and there is only one opening 22D2 formed in a part of the wall portion. A terminal plate 22E to which the terminal portion of the harness 23 is connected is attached. Conductive terminals 22E1 connected to the respective harnesses 21 are provided on the terminal plate 22E, and the distal ends of the conductive portions 22A are pressed against each other.
[0032]
The rotating shaft 22C1 of the rotating member 22C is provided with a lubricating portion 28 as a configuration that prevents foreign matter from entering from the outside of the main body housing.
The lubrication part 28 is comprised by the recessed part which is formed in one of rotating shaft 22C1 in main body housing 22D, and this insertion position, and has the opening which faces the other. In the configuration shown in FIG. 4, a recess that opens toward the inner surface of the main body housing that is the insertion support portion of the lubrication portion 28 on the outer peripheral surface of the rotating shaft 22C1 is shown. In the configuration shown in FIG. In the rotating shaft insertion portion on the housing 22D side, there is shown a concave portion (denoted by reference numeral 28 'for convenience) that opens toward the outer peripheral surface of the rotating shaft 22C1. In the configuration shown in FIG. 5, the volume of the lubrication portion 28 can be increased because the cross-sectional area that forms the recess is larger than that of the rotation shaft 22 </ b> C <b> 1.
[0033]
The lubrication portion 28 is positioned at a position where the conductive portion 22A side of the rotating member 22 and the outside of the main body housing 22D are shielded at the insertion support portion of the rotation shaft 22C in the main body housing 22D. Filled with lubricant. The lubricant used in the present embodiment has a characteristic of adsorbing foreign matter when the foreign matter enters from the outside in addition to lubrication of the rotary shaft 22C1, and in the case of a solid, the lubricant is shown in FIG. Thus, a ring-shaped felt impregnated with a liquid lubricant or an oil-containing sintered member is used.
[0034]
Since the present embodiment is configured as described above, the developing device 5 detects the amount of toner accommodated by the toner sensor 5C4 and performs toner replenishment control according to the result. As described with reference to FIG. 2, the harnesses 20 and 23, 26, the rotary electrical connection means 22, the terminal plate 25, and the main control plate 27 are used for toner replenishment control.
[0035]
In the rotary electrical connection means 22, the harness 20 is connected to each conductive portion 22A, and the conductive terminal 22E1 included in the terminal plate 22E is pressed against each conductive portion 22A, so that the toner sensor 5C4 is connected to the main control plate 27. A conductive line is formed.
[0036]
In the rotary electrical connection means 2, since the lubrication part 28 is provided between the rotating shaft 22C1 in the rotating member 22 and the main body housing 22D through which the rotating shaft 22 is inserted, dust or the like floating outside the main body housing 22D is provided. When foreign matter enters between the rotating shaft 22C1 and its insertion support portion, it is captured by the lubricating portion 28, and entry into the conductive portion 22A side is prevented. As a result, it is possible to prevent a contact failure between the conductive portion 22A and the conductive terminal 22E1, which may occur when a foreign substance 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 goes without saying that the rotation of the rotating shaft 22C1 is made smooth.
[0037]
According to this embodiment, it is only necessary to configure a lubrication part between the existing rotating shaft and its rotation support part, so that it is possible to prevent the intrusion of foreign matter and rotational lubrication of the shaft with simple processing. It becomes.
[0038]
Next, another example according to the embodiment of the present invention will be described.
In FIG. 6, the feature of another embodiment is that a rubbing resistance reducing member disposed between the rotating member and the main body housing is provided with a lubricating portion.
In FIG. 6, in the axial direction of the rotating member 22, the rotating shaft 22C1 has a smaller diameter than the portion where the conductive portion 22A is formed.
Lubricating part 29 is provided at a location where the quantity member is slid when it comes into contact between the axially outer end face of rotating member 22 provided with conductive part 22A and the inner wall face on the main body housing 22D side facing this end face. It has been. In this case, as shown in FIG. 7B, the lubricating portion 29 is a washer used to reduce the frictional resistance that occurs between the two members, a so-called washer (hereinafter referred to as a washer 29). The lubricant 29A is held on the insertion surface of the rotary shaft 22C1 at 29.
[0039]
Since the present embodiment is configured as described above, the washer 29 used for reducing the frictional resistance on the surface of the rotating member 22 facing the conductive portion 22A and the main body housing 22D that supports the conductive portion 22A is used to prevent foreign matter from entering. Used. That is, since the lubricant is held on the insertion surface of the rotating shaft 22C1 in the washer 29, the foreign matter that is about to enter the conductive portion 22A is adsorbed through the insertion surface. This embodiment also corresponds to the fact that the washer 29 is disposed at a position that shields the conductive portion 22A and the outside of the main body housing 22D.
[0040]
According to the present embodiment, the frictional resistance reducing member, which is an existing member, prevents foreign material intrusion, which is a function completely different from the function of reducing the frictional resistance generated between the inner wall surface of the main body housing when the defrosting point member is rotated. It becomes possible to combine functions.
[0041]
【The invention's effect】
According to the first aspect of the present invention, the concave portion provided at a position shielded from the outside by a part of the casing used as the supporting portion of the rotating member in the rotating connecting means is used as the rotating support portion. Since it is filled with lubricant and has a function different from the lubrication of the rotating shaft, it can have foreign matter adsorption and collection. It is possible to prevent the occurrence of electrical damage to the electrical component due to the entry of the hand and foreign matter.
[0045]
According to the third aspect of the present invention, it is possible to prevent foreign matter from entering the conductive portion at the connection portion between the electrical component disposed in the development / development unit and the electrical component provided outside the development apparatus. In addition, it is possible to prevent electrical damage to the electrical components due to the entry of foreign matter and to maintain normal operations such as density control in the developing unit.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a color copying machine as an example of an image forming apparatus in which a developing device according to an embodiment of the present invention is used.
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 diagram showing an embodiment of the developing device shown in FIG.
4 is a schematic diagram for explaining a configuration of a rotary electric connecting means used in the developing device shown in FIG. 2. FIG.
FIG. 5 is a schematic diagram showing a partial modification of the configuration of the rotary electrical connecting means shown in FIG. 4;
6 is a schematic view for explaining another embodiment of the rotary electrical connecting means shown in FIG. 4. FIG.
7 is a diagram showing a configuration of a lubrication unit used in the rotary electrical connection means shown in FIGS. 4 to 6, and FIG. 7A is an example for the configuration shown in FIGS. (B) shows an example for the configuration shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Color copier which is an example of image forming apparatus 2 Photosensitive body 5 Developing apparatus 5A Rotating body 5C, 5M, 5Y, 5B Developing unit 20, 23, 26 Harness 22 for connecting electrical components 22 Rotating electrical connection means 22A Conducting portion 22B Insulator 22C Rotating member 22C1 Rotating shaft 22D Main body housings 28, 28 ', 29 constituting the casing Lubrication part

Claims (3)

In a developing device that performs visible image processing of different colors by sequentially facing the developing unit with respect to a photosensitive member using a rotating body including a plurality of developing units along a circumferential direction,
Rotating connection means capable of connecting while rotating the electrical component disposed in the developing unit and the electrical component disposed outside the developing device,
The rotation connecting means includes a rotating member in which conductive portions corresponding to the number of the developing units are alternately provided across an insulator along the axial direction;
A housing having a space surrounding the conductive portion while the rotation shaft of the rotating member is inserted and supported;
A harness for connecting the electrical components in the development unit and the electrical components outside the development unit via the conductive part,
The rotation support portion that supports the rotation shaft of the rotation member is configured by a part of the housing, and the rotation support portion of the housing is located at a position that shields the conductive portion and the outside of the housing. A concave portion that opens toward the inner surface or the outer peripheral surface of the rotary shaft, and a liquid or solid lubrication is provided between the axially outer end surface of the rotary shaft and the surface of the casing facing the rotary shaft in the concave portion. A developing device which is filled with an agent and adsorbs foreign matter in addition to the lubrication of the rotating shaft . The developing device according to claim 1,
The developing device, wherein the washer holds a lubricant capable of adsorbing and collecting foreign matter on an insertion surface of the rotating shaft.   An image forming apparatus using the developing device according to claim 1.

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