JP3458868B2 - Rotary developing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary developing device applied to an image forming apparatus such as a copying machine, a facsimile machine, a printer, and more specifically, a plurality of developing devices arranged around a rotation center line. The present invention relates to a rotary developing device that rotates a developing device unit that it has around the rotation center line to move an arbitrary developing device to a developing position facing a latent image carrier to perform development.

[0002]

2. Description of the Related Art Conventionally, as a rotary developing device of this type, for example, in Japanese Patent Laid-Open No. 63-78170, at least one of both ends of a developing unit in the direction of the rotation center line is abutted against the peripheral surface of the end wall. There is disclosed a structure in which a rotatable supporting roller in contact is rotatably supported and an arbitrary developing device is moved to a developing position facing a latent image carrier to perform development. With such a supporting structure of the developing device unit using the supporting rollers, since the developing unit can be lifted from the supporting rollers, the inspection and cleaning work of the developing device unit can be easily performed.

[0003]

By the way, in the developing device unit in this type of rotary developing device, since a plurality of developing devices are arranged, the inside of each developing device is cleaned and the parts of each developing device are replaced. There is a risk that the burden of disassembling the developing device unit will become heavy for replacement. For example, the developing device unit rotatably supports a developing roller as a developer carrying member and other rotating members by its both end walls, and an opening for partially exposing each developer carrying member. If both end portions of the side wall of the hollow cylindrical developing device unit in which is formed are also supported by the both end walls, the following disassembly work is required to clean the inside of each developing device and replace the developing roller etc. Is. That is, first, the thrust-direction positioning members (for example, E-rings) of all the developing rollers and the like supported by the one developing unit end wall are removed, and the one developing unit end wall is removed. Next, with respect to, for example, the developing roller which may be obstructive or need to be replaced for cleaning the inside of the developing chamber, the thrust direction positioning member on the side wall of the other developing unit is removed.
Then, the current roller is first pulled out from the end portion side where the side wall of the developing unit has been removed, the inside of the developing chamber is cleaned, and then a new developing roller is inserted into the developing unit from the end portion side, and the leading end side is set to the developing unit. The side wall is supported and a thrust direction positioning member is attached. Here, when the developing roller is replaced, a new developing roller is inserted into the developing unit from the end side, and similarly, the leading end side is supported on the side wall of the developing unit and a positioning member in the thrust direction is attached. And finally, remove the developing unit end wall that was removed
After mounting so as to support the end portions of all the developing rollers and the like, the positioning members in the thrust direction are attached to the end portions of all the developing rollers and the like. As described above, since the entire one end wall of the developing unit is removed, it is necessary to remove the positioning member in the thrust direction once for the parts other than the parts that interfere with the cleaning or become the replacement target. It will be a laborious task.
Further, since the entire side wall of the developing unit is removed, if there is a risk of developer leakage in the developing device, even when cleaning the inside of a specific developing device or replacing parts, a plurality of parts may be removed prior to the disassembling work described above. It is necessary to once collect the developer from the developing device.

Therefore, in the present application, a rotary developing device has been developed in which the burden of disassembling the developing device unit is small in order to clean the inside of each developing device or replace the parts of each developing device. In this rotary developing device, both end walls of a developing device unit that supports both ends of an accommodating member such as a developer carrier in each developing device are provided with one outer peripheral surface of each end device for each part corresponding to each developing device. The part including the part and forming the part of the peripheral wall of the developing device unit to which both ends are attached is separable.

In this rotary developing device, when the inside of each developing device is cleaned or the parts are replaced, both end wall portions of the separable developing device unit corresponding to the developing device for cleaning or parts replacement Is separated from the other end wall portions. A part of the peripheral wall of the developing device unit, both ends of which are attached to this separable end wall part, is also separated from the developing device unit, and the inside of the developing device is exposed to the outside. Cleaning or the like is performed through this exposure port. Further, when the component itself having both ends attached to the separable end wall portions is a replacement component, the replacement component is detachably attached to the separable end wall portions. According to this, in a state in which the separable both end wall portions are separated from the developing device unit, the replacement part is removed from the both end wall parts and new parts are attached, and then the both end wall parts are attached to the developing device unit. By installing
The parts can be replaced.

However, when a structure using the above-mentioned conventionally known supporting rollers is adopted as a supporting structure on one end side of the developing device unit to be applied to the rotary developing device according to this development, the supporting rollers come into contact with each other. The outer circumference of the end wall of the developing device unit is separably divided as described above, and has a step at the dividing boundary portion, so that the developing device unit vibrates while the developing device unit is rotating. Due to this vibration, the revolver
The stepping motor used to drive the developing unit may lose step, or the pitch unevenness on the image may occur.
There was a problem such as toner falling off at the cleaning part.

The present invention has been made in view of the above problems, and an object of the present invention is to facilitate cleaning and replacement of parts in each developing device, and to develop while adopting a roller-shaped support structure. A rotary developing device capable of smoothly rotating a container unit.

[0008]

In order to achieve the above object, a rotary developing device according to a first aspect of the present invention comprises a developing device unit having a plurality of developing devices arranged around a rotation center line. In a rotary developing device that rotates around a center line to move an arbitrary developing device to a developing position facing a latent image carrier to perform development, in the developing device, each end of a containing member such as a developer carrier is Support both end walls of the developing unit,
For each part corresponding to each developing device, a part including an outer peripheral surface of the both end walls, and a part to which both ends of a part of the peripheral wall of the developing device unit are attached are configured to be separable, A tubular portion whose centerline is the rotation center line is provided outside one end of the developing unit that is in the direction of the rotation center line and outside the separable side wall portion, and the outer peripheral surface of the tubular portion is formed by a roller-shaped member. It is characterized by being rotatably supported.

A rotary developing device according to a second aspect of the present invention is the rotary developing device according to the first aspect, wherein an identifying portion corresponding to each developing device is formed on the tubular portion, and the identifying portion is detected on the apparatus main body side. It is characterized in that a detector is provided.

A rotary developing device according to a third aspect is the rotary developing device according to the first aspect, wherein the one end of the developing device unit is maintained so that the outer peripheral surface of the developing device unit is kept in contact with the roller-shaped member. It is characterized in that a roller-shaped member made of an elastic body is provided at a position where the vibration of the portion can be regulated so as to be in contact with the outer peripheral surface and rotatable.

[0011]

In the rotary developing device according to the first aspect of the present invention, when the inside of each developing device is cleaned or the parts are replaced, a separable developing device unit corresponding to the developing device for cleaning or parts replacement is provided. The end wall portions are separated from the other end wall portions. A part of the peripheral wall of the developing device unit, both ends of which are attached to this separable end wall part, is also separated from the developing device unit, and the inside of the developing device is exposed to the outside. Cleaning or the like is performed through this exposure port. Further, when the component itself having both ends attached to the separable end wall portions is a replacement component, the replacement component is detachably attached to the separable end wall portions. According to this, in a state in which the separable both end wall portions are separated from the developing device unit, the replacement part is removed from the both end wall parts and new parts are attached, and then the both end wall parts are attached to the developing device unit. By installing
The parts can be replaced.

In the developing device unit, one end in the direction of the rotation center line is rotatably supported by a roller-shaped member, and by rotating about the rotation center line, any developing device faces the latent image carrier at a developing position. Can be moved to. Here, since the outer peripheral portion of the developing device unit with which the roller-shaped member abuts is the outer peripheral surface of the tubular portion having the rotation center line as the center line, which is provided outside the separable side wall portion, it is separable. Unlike the case where the roller-shaped member is in contact with the side wall portion, there is no stepped portion on the outer peripheral surface, and the developing unit can smoothly rotate while being supported by the roller-shaped member.

In the rotary developing device according to the second aspect of the invention, the identification portion corresponding to each developing device formed in the tubular portion is detected by the detector provided on the apparatus main body side. Then, this detection result is used for rotation control of the developing device unit that moves an arbitrary developing device to a developing position facing the latent image carrier.

In the rotary developing device of the third aspect, a roller-shaped member made of a rotatable elastic member is brought into contact with the outer peripheral surface of the developing device unit at a position where vibration of one end of the developing device unit can be regulated. The outer peripheral surface is kept in contact with the roller-shaped member that rotatably supports the developing unit.

[0015]

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) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a printer according to this embodiment. First, an outline of the entire printer will be described. In FIG. 1, a photosensitive drum 1 serving as a latent image carrier is uniformly driven by a charging charger 2 serving as uniform charging means while being rotationally driven in the direction of arrow A, and then image information is generated by a laser optical device 3. Scanning exposure is performed on the basis of the above to form an electrostatic latent image on the surface. Here, the image information to be exposed is image information of a single color obtained by separating a desired full-color image into color information of yellow, magenta, cyan, and black. The electrostatic latent image formed on the photoconductor drum 1 is developed by the rotary developing device 4 described later with yellow, magenta, cyan, and black toners as predetermined developers, respectively. An image of each color is formed on.

Each color image formed on the photoconductor drum 1 is formed on the intermediate transfer belt 5 which rotates in the direction of arrow B in the figure in synchronization with the photoconductor drum 1 for each color of yellow, magenta, cyan and black. The primary transfer charger 6 sequentially performs the superimposed transfer. The yellow, magenta, cyan, and black images that are superposed on the intermediate transfer belt 5 are transferred from the automatic paper feed cassette 7 for double-sided copying or the manual paper feed tray 7a through the paper feed rollers 8 and 8a and the registration rollers 9. The secondary transfer charger 11 collectively transfers the transferred sheet 10 onto the transfer sheet 10. After the transfer is completed, the toner image is fixed on the transfer paper 10 by the fixing device 12, and the transfer paper 10 is discharged outside the machine as a full color print.

The toner on the photoconductor drum 1 that has not been transferred onto the intermediate transfer belt 5 is removed by the photoconductor cleaner 13.
Is removed from the photosensitive drum 1 by the
The toner on the intermediate transfer belt 5 that has not been transferred onto the
It is removed from the intermediate transfer belt 5 by the intermediate transfer belt cleaner 14.

Next, the rotary developing device according to this embodiment will be described. 2 is an exploded perspective view of the developing device, FIG. 3 is a cross-sectional view showing the internal structure of the developing device unit 40 of the developing device, and FIG. 4 is the above-described upper and lower conveying screws 86, 9 of the black developing device.
2 is a vertical cross-sectional view of a plane including the central axis 52 of FIG. In FIG. 2, the rotary developing device is internally provided with developing devices for four colors of black, cyan, yellow and magenta, respectively.
In addition, the developing unit 40 is attached to the printer body so as to be rotatable about the central axis and has a substantially cylindrical outer periphery.
And four toner containers 41, 42, 43 and 44 respectively corresponding to the developing devices and containing black, yellow, magenta and cyan toners, respectively, and the central axis of the developing device unit 40. And a toner container unit 45 which is attached so as to be substantially coaxial with the front side in the direction and rotates integrally with the developing device unit 40 around the central axis, and the developing device unit 40 and the toner container unit 45.
In the state of carrying (hereinafter referred to as a revolver developing unit), a storage stand 46 slidable in the printer main body substantially in parallel with the central axis line, and a non-rotatably provided cover 47 for covering the rotation supply unit. .

The revolver developing unit is provided with a receiving table 46.
The disk-shaped front end wall 5 of the developing device unit 40 includes, for example, two support rollers 49 rotatably attached to the front support plate 48 of
0, and a central axis 52 of the tip end taper protruding from the center of the disk-shaped rear end wall 51 of the developing device unit 40.
Is rotatably supported by a central shaft insertion hole 54 formed in the rear plate 53 of the main body, so that the rotation axis of the main body is substantially the same as the rotation axis of the photosensitive drum 1 in the printer main body as shown in FIG. They are positioned so as to be parallel to each other in the same horizontal plane and are rotatable.

First, the mechanism for rotatably supporting the revolver developing unit will be described with reference to FIG. The housing base 46 has front and rear end portions fixed to the front support plate 48, the rear support plate 55, and both support plates, and has connecting rods 56, 5
And a side cover 59 reinforced with 7, 58. An insertion hole 60 into which the revolver developing unit can be inserted is formed in the front support plate 48, and in addition to the support roller 49, a motor 61 for driving a toner replenishing roller provided in the toner container unit 45 and the motor 61. A gear train 62 driven by a motor 61 is attached. An intermediate plate 63 is attached to the connecting rods 56 and 57 in the vicinity of the rear support plate 55, and a positioning pin 63b is fitted into the positioning hole 63a formed in the rear plate of the main body of the intermediate plate 63 (see FIG. 3). three
) Is projected. A base end portion of a bracket 64 holding a rotary positioning roller 66 is swingably attached to a positioning pin portion between the middle plate 63 and the rear support plate 55. The bracket 64 is provided with a spring 67 in a direction in which the rollers 66 are fitted at predetermined positions on the peripheral surface of the developing device unit rear end wall 51 into four recesses 65 formed in order to position each developing device at the developing position. Being energized.

The front plate 68 of the main body is formed with an insertion hole 69 or the like into which the storage stand 46 carrying the revolver developing unit can be inserted. The front plate 68 of the main body and the rear plate 53 of the main body are provided with the above-mentioned insertion holes 69. Upper and lower guides 70, 71 for slidably supporting the storage base 46 are hung. Guided portions 72 and 73 are provided at the upper end and side portions of the storage table side cover 59 as the receiving table portion guided by these guides 70 and 71, and the lower surface portion of the guided portion 73 on the side of these is provided. A guide pin groove 75 into which the guide pin 74 that is planted upward in the guide 71 is inserted is formed in the.

In the support mechanism of the revolver developing unit described above, when the storage stand 46 is inserted into the main body, the tapered tip end of the positioning pin 63b protruding from the intermediate plate 63 is provided just before the completion of insertion of the storage stand into the printer main body. , Body rear side plate 53
When the insertion is completed, the rear support plate 55 of the accommodating base 46 and the bracket 63 are inserted.
Positioning roller 6 held by the intermediate plate 64 via
Position 6 correctly in the body. Meanwhile, storage 46
In the pulled-out state, the rear end portion of the revolver developing unit supported by the rear side plate 53 of the accommodating base 46 has the tapered central axis 52 in the central axis insertion hole 54 immediately before the main body of the accommodating stand 46 is completely inserted. When the insertion is completed, the rear support plate 55 is completely lifted.
Emerge from. Then, the front support plate 48 of the storage table 46 is fixed to the front plate 68 of the main body with screws 76 or the like after the insertion of the storage table 46 into the main body is completed. As a result, the revolver developing unit has its front end supported by the support roller 49 of the housing stand front support plate 48 accurately positioned on the main body, and the central shaft 5
The rear end portion is rotatably positioned on the rear plate 53 of the main body via 2 and is rotatable.

Next, the developing unit 40 will be described with reference to FIGS. In FIG. 2, since the revolver developing unit is driven to rotate, the main body rear side plate 53 has
Revolver for motor consisting of a stepping motor
In revolver output gear 78 to be driven is mounted, which meshes with the revolver input gear 79 approximately the same diameter as the rear end plate 51 fixed by screws or the like on the back of the rear end plate of the developing unit 40, a revolver The developing unit is rotationally driven. It mounted well as developing output gear 81 which is driven by the developing drive motor for driving and developing roller of the developing device unit 40 described later in this body rear plate 53.

In FIG. 3, the developing device unit 40 includes the above-mentioned substantially disc-shaped front and rear end plates and a partition wall provided between the front and rear end plates. This partition wall has a hollow cylindrical portion 82 into which a cylindrical black toner bottle containing black toner can be inserted, and a partition wall extending radially from the hollow cylindrical portion 82 so that the space around the hollow cylindrical portion 82 is substantially in the circumferential direction. Developing device casing parts 83, 8 which are divided into four developing chambers of the same type
3C, 83M, 83Y. Each of these developing chambers contains a carrier as a developer and a two-component developer including toner of each color. In the illustrated example, the developing position facing the photoconductor drum is the developing chamber of the black developing device containing the black toner and the carrier, and in the counterclockwise order in the figure, the yellow developing device containing the yellow toner and the carrier is arranged. A developing chamber, a developing chamber of a magenta developing unit containing magenta toner and a carrier, and a developing chamber of a cyan developing unit containing cyan toner and a carrier.

Since the internal structures of the four developing chambers are exactly the same, the internal structure of the black developing chamber in the developing position will be described below as an example in FIG. 3, and the internal structures of the other developing chambers will be described. Are the same reference numerals as the corresponding reference numerals in the black developing chambers, but with the suffixes Y, M, and C added to distinguish the yellow, magenta, and cyan developing chambers from each other. To do.

In the black developing device at the developing position in the drawing, an opening portion facing the photosensitive drum 1 is formed in the developing device casing portion 83, and a part is exposed through the opening portion in the developing chamber. A developing roller 84 is provided. Further, in the developing chamber, a doctor blade 85 which is carried by the developing roller 84 and regulates the amount of the developer conveyed to the portion facing the photoconductor drum 1, and the development which is regulated by the doctor blade 85 and pressed into the developing chamber An upper conveying screw 86 for conveying a part of the developer along the central axis direction from the front to the front and a guide 87 therefor, and a stirring paddle 88 for stirring the developer in the developing chamber are provided. The stirring paddle 88 has a plurality of developer discharge holes 89a across the width of the developing roller 84.
And a plurality of stirring plate portions 90 radially extending from the peripheral surface of the hollow cylindrical portion 89. The hollow cylindrical portion 89 is provided with the above-mentioned upper transfer along the central axis direction. A lower carrying screw 91 for carrying the developer in the opposite direction to the screw 86 is housed. The developer casing below the lower transport screw 91 is provided with a developer discharge port used as a discharge port for a deteriorated developer or an input port for unused developer (toner mixed) when a developer is replaced due to deterioration of development in the developing chamber. An outlet 92 is formed. The discharge port 92 is covered from the outside by a cap 93 attached with a screw 94. (Hereafter, margin)

In FIG. 4, the upper and lower conveying screws 86,
The front end of 91 is outside the effective width region of the developing roller 84 (in the example shown, outside the front end wall 50 of the developing unit).
A drop portion 96 for extending the developer conveyed by the upper conveying screw 86 to the lower conveying screw 91 by its own weight is provided at this extending portion. The front end of the lower conveying screw 91 extends further to the front side than the drop portion 96, and extends to the communication chamber below the toner supply roller 97 provided corresponding to each developing chamber of the toner container unit 45. ing. As a result, of the developer drawn up by the developing roller 84, the doctor blade 8
5, the guide 87 and the upper conveying screw 8
The developer conveyed to the front side in 6 falls on the lower conveying screw 91 at the dropping portion 96, and the lower conveying screw 91
Is conveyed within the effective width of the developing roller 84, is discharged into the developing chamber from the developer discharge port of the stirring paddle hollow cylindrical portion within the width, and is again carried by the developing roller 84. That is, so-called lateral stirring of the developer is performed in the developing chamber. Then, the developer discharged from the developer discharge port of the hollow cylindrical portion 82 of the stirring paddle 88 to the developer pool under the developing chamber is stirred by the stirring paddle 88.
The so-called vertical stirring is performed by the rotation of the stirring plate. Further, the toner dropped on the lower conveying screw 91 in the communication chamber by the rotation of the replenishing roller 97 is conveyed by the lower conveying screw 91 to the dropping portion 96, where it is taken into the developer dropped from the upper conveying screw 86. Are mixed with each other, and the mixed developer enters the developing chamber through the developer discharge port, thereby increasing the toner concentration of the developer in the developing chamber.

Incidentally, the rear end wall 51 of the developing device unit 40.
Part, specifically, the development output gear 8 on the main body side, behind the revolver input gear 79 fixedly mounted on the rear end wall 51.
A developing input gear on the revolver developing unit side (not shown) that meshes with 1 is rotatably provided, and the developing roller 84 and the shafts of the upper and lower conveying screws 86 and 91 protruding through the rear end wall 51 and the like. Gears are fixed at the ends. With these, each rotating body (developing roller, etc.) is driven via the developing input gear and the like.

[0029] The toner container unit 45, a disk-shaped unit faceplate 107 (see FIG. 2), a total of four toner receiving attached to the front surface of said surface plate as a one-to-one correspondence with each of the developing devices Case 91 Y, M, C, 110
And toner replenishing rollers 97Y, M, C, 97, etc. respectively provided in the respective toner receiving cases. The toner replenishing roller is located substantially directly above the portion of the lower conveying screw 91 extending into the case when the corresponding developing chamber is located at the developing position. 7 is pivotally supported.

[0030] The unit faceplate 10 7, circular through-hole cylindrical black toner container can penetrate is formed in the center portion, each of the toner receiving case for 91 Y,
M, C and 110 are attached by escaping the through holes . Also the unit faceplate 10 7 through hole is also formed for the lower conveying screw 91 that extends from the developing chamber of the developing device, the front of the unit face plate 107 each lower conveying screw via the through-holes Part of the toner receiving case 91Y , M, C, 110.

Further the unit faceplate 10 7, the toner supply roller 97Y, M, C, 97 axis of has a bearing, shaft end projecting into the developing unit 40 side through the said surface plate 107 A gear 97a is fixed to the portion. And the surface of the developing unit side of the unit face plate 107, supply input gear for driving the input, not shown, which meshes with the gear 97a is rotatably provided. Of the replenishment input gears provided for each toner replenishment roller, the replenishment input gear of the toner replenishment roller 97 in the case corresponding to the developing device at the developing position is the front support plate 48 of the accommodating base.
It is adapted to be meshed with a gear driven by a replenishment motor 61 attached to the motor and to be rotationally driven by the motor 61. The toner replenishment control is performed by the drive control of the replenishment motor 61.

The above four toner receiving cases 91 Y,
M, of C, 1 10, three corresponding to the respective color developing units color toner receiving case for 91 Y, M, C are all the same shape. That is, a toner receiving port is formed at a portion that surrounds the inner extending portion of the lower conveying screw 91 and the toner replenishing roller 97 and that is located above the toner replenishing roller 97 when the corresponding developing chamber is located at the developing position. Has a peripheral wall portion. Around the toner receiving port, a color toner storing device 44 having the same shape for each color and storing color toner is attached by sliding in the direction of the rotation center line of the revolver developing unit with the toner discharge port facing downward. A vessel mounting portion is formed.

On the other hand, as shown in FIG. 2, the black toner receiving case 110 corresponding to the black developing device is arranged in the color toner receiving case 91Y , M, C as shown in FIG.
It has a peripheral wall shape that is substantially the same as the overall peripheral wall shape of both with 2, 43 and 44 attached. Further, a toner receiving opening having a shape corresponding to the toner discharging opening of the black toner container 41 is formed at a portion of the peripheral wall portion having a shape similar to that of the color toner receiving case and facing the center line of the revolver developing unit. .

The black toner container 41 is the black toner container 4
Reference numeral 1 denotes a cylindrical shape, and a toner discharge port is formed on a peripheral wall portion at one end in the longitudinal direction, and a ridge portion for toner feeding is spirally formed on the inner peripheral surface portion from the other end portion to the toner discharge port side. Is formed in. With this spiral protrusion, the stored toner is sent from the rear end portion to the front end portion where the toner discharge port is formed by the rotation integrally with the revolver developing unit attached to the unit. Has become. Such a black toner container 41 is used for the cover 4 shown in FIG.
7, the rear end of the toner container insertion notch 47a is inserted into the hollow cylindrical portion 82 of the developing device unit 40, and the front end of the toner container inserting notch 47a is formed. Each case is set in a state in which it is inserted until it is substantially flush with the front surface of the front end wall portion.

Here, in the present embodiment, for example, the developing roller 8 as shown in FIG. 3 for the yellow developing device.
State the front and rear end wall portion is configured to separable small end wall portion 104 Y from the other of the front and rear end wall portions, is fitted against said other of the front and rear end wall portions for supporting the 4Y and the doctor blade 85Y It is fixed with screws. Thus, when cleaning or parts replacement of the developing chamber, the small wall portion 104 Y
The developing roller 84Y and the doctor blade 85Y are removed together to facilitate access to the developing chamber.
Further, the front side of the revolver developing unit is different from the rear side of the revolver developing unit in which the central shaft 52 (see FIG. 2) is inserted into the insertion hole 54 formed in the rear plate 53 of the main body to rotatably support the revolver developing unit. Since the outer peripheral surface of the front end portion is rotatably supported by being received by the support rollers 49 of the front support plate 48 of the accommodating base, a hole is formed in the center of the front end wall to accommodate the black toner in the hollow inside of the revolver developing unit. It can be used as a storage space at the rear end of the container. Also small front and rear walls
Unit, developing roller, and doctor blade can be handled as one integrated unit, and therefore, in a copying machine production process in a factory, a device for automatically adjusting the distance (doctor gap) between the developing roller surface and the doctor blade tip is used as the integrated unit. Only one can be set to automatically adjust the spacing.

However, a step occurs at the fitting boundary on the outer peripheral surface of the front end wall of the revolver developing unit thus divided. For this reason, the above-mentioned housing stand front support plate 4 for rotatably supporting the front end portion of the revolver developing unit.
When the support roller 49 of No. 8 is brought into contact with and supported by the outer peripheral surface of the front end wall portion, the revolver developing unit vibrates during rotation, and the stepping motor used to drive the revolver developing unit loses synchronization. Or uneven pitch on the image may occur, or toner may drop at the cleaning portion.

Therefore, in the present embodiment, FIG.
As schematically shown in FIG. 3, the tubular portion 200 is provided on the front side of the front end wall 50 of the revolver developing unit 40. The tubular portion 200 may be formed integrally with the front end wall 50, or may be formed by separately attaching a tubular member to the front portion of the front end wall. The outer peripheral surface of the tubular portion 200 is received by the support roller 49. As a result, it is possible to prevent uneven pitch due to vibration, toner drop in the cleaning portion, and revolver-developing device rotation torque UP due to a step. In this way, by supporting the tubular portion 200 provided on the front side of the front end wall 50 of the revolver developing unit 40 by the support roller 49,
It is possible to make the length of the shaft 49a (see FIG. 5B) that supports the support roller 49 on the front support plate 48 of the accommodation table relatively short. Therefore, as compared with the case where the shaft 49a is relatively long, the tilting of the shaft is less likely to occur, the positional accuracy of the support roller can be improved by improving the squareness accuracy of the shaft, and as a result, the front of the revolver developing unit can be improved. The positioning accuracy on the side is also improved.

The tubular portion 200 is shown in FIG.
As shown in (c), the slit portions 200a corresponding to the positions of the developing devices of the revolver developing unit and different from each other (for example, one black slit, two cyan slits, three magenta slits, and a yellow slit). -While forming different numbers of slits such as four slits),
As shown in FIG. 5B, the slit portion 20 is provided on the device body side.
0a is detected, for example, a detector 201 including an optical sensor
May be provided, and the position of the developing device may be detected when switching the developing device to be used. Further, instead of the slit portion 200a, a bar code seal or the like may be attached and read by a sensor. According to these, since the tubular member 200 has high positional accuracy with respect to each developing device, the tubular member 200 does not collide with the detector 201, and the cost is lower than the case where a sensor is provided for each developing device. It is possible to detect the position of each developing device with a simple structure having merit. Further, since the position of each developing device is detected, it is possible to detect the position of the developing device as compared with the case where only one home position is detected and the rotation of the revolver developing device unit is controlled based on this. There is little time loss.

Further, as shown in, for example, FIGS. 6A and 6B, the outer peripheral surface of the tubular portion 200 is brought into contact with the tubular portion 200, and the position thereof is set in contact with the support roller 49. The elastic roller 202 that is regulated so as to be kept may be rotatably provided. According to such an elastic roller 202, in order to maintain the contact state between the end portion of the revolver developing unit and the support roller, the pressing force is larger than that in the conventional method in which the roller is pressed by the leaf spring. Is low (the pressing force is almost 0 when the roller A350 and the tubular member 200 are in contact with each other). Therefore, it is possible to avoid an increase in the rotation torque of the revolver developing unit. Note that, as shown in FIG. 6B, if the position of the shaft 202a supporting the elastic roller 202 on the front support plate 48 of the accommodating base can be adjusted, the pressing force can be adjusted.
Further, the position may be automatically adjusted so as to automatically maintain the contact state with the outer circumference of the tubular portion.

[0040]

According to the rotary type developing device of the first aspect, since predetermined portions of both end walls of the developing device unit are separable, it is possible to clean the inside of each developing device or replace parts. By separating the separable portion from the other end wall portions, the inside of the developing device can be exposed to the outside and cleaning can be easily performed. In addition, if replacement parts are detachably attached to the separable end wall portions, the replacement parts can be easily replaced with new parts in a state where the separable end wall portions are separated from the developing device unit. Unlike this, the separable end wall portions can be replaced together. Then, a roller-shaped member is brought into contact with an outer peripheral surface of a tubular portion having a centerline of the rotation center line provided outside the separable side wall portion to rotatably support the developing device unit and the separation is possible. Unlike the case where the roller-shaped member is brought into contact with a large side wall portion, the developing unit is supported so that it can rotate smoothly, so that the vibration during rotation of the developing unit is small and the stepping motor used for driving the revolver developing unit. It is possible to prevent uneven pitch on the image due to out-of-step, vibration, and toner drop at the cleaning portion.

According to the rotary type developing device of the second aspect, each position detecting device for controlling the rotation of the developing device unit for moving an arbitrary developing device to a developing position facing the latent image carrier. Since the identification portion corresponding to the developing device is provided at the one end of the developing device unit and is formed in the tubular portion integral with the developing device unit, the relative positional accuracy between the identification portion and the developing device is high, and the accuracy is high. The position of the developing device can be detected. Further, since the identification section corresponding to each developing device is detected by the common detector provided on the apparatus main body side, the cost can be reduced as compared with the case of using a plurality of detectors corresponding to each developing device.

According to the rotating type developing device of the third aspect, the roller-shaped member made of a rotatable elastic body is used to regulate the vibration of one end of the developing unit rotatably supported by the roller-shaped member. Therefore, the pressing force can be lower than that of the conventional method in which the roller is pressed by the leaf spring. For this reason, it is possible to avoid an increase in the developing unit rotation torque as compared with the related art, and it is possible to reduce the size and cost of the developing unit rotation drive motor.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a copying machine according to an embodiment.

FIG. 2 is an exploded perspective view of a rotary developing device of the copying machine.

FIG. 3 is a sectional view of a developing unit of the rotary developing device.

FIG. 4 is an explanatory view of a connection structure between a developing device and a toner container in the rotary developing device.

FIG. 5A is an explanatory diagram of a front end portion of the revolver developing unit. (B) And (c) is explanatory drawing of the revolver development unit which concerns on a modification.

6A and 6B are explanatory views of a revolver developing unit according to another modification.

[Explanation of symbols]

1 photoconductor drum 4 Rotating developing device 40 developer unit 41 Black toner container 42 Yellow toner container 43 Magenta Toner Container 44 Cyan toner container 45 Toner container unit 49 Supporting roller 50 Front end wall 200 tubular section 200a slit 201 sensor 202 Elastic roller

─────────────────────────────────────────────────── ─── Continued Front Page (72) Shinji Kato 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Kazuyuki Sugihara 1-3-6 Nakamagome, Ota-ku, Tokyo No. in Ricoh Co., Ltd. (72) Inventor Katsuhiro Kosuge 1-3-6 Nakamagome, Ota-ku, Tokyo In Ricoh Co., Ltd. (56) Reference JP-A-63-278073 (JP, A) JP-A-63 -78170 (JP, A) JP 7-152239 (JP, A) JP 5-341616 (JP, A) JP 3-264967 (JP, A) JP 1-235967 (JP, A) ) Actual Kaihei 4-67657 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08-15/095 G03G 21/16 G03G 15/01 113

Claims (3)

(57) [Claims] 1. A developing unit in which a developing device unit having a plurality of developing devices arranged around a rotation center line is rotated about the rotation center line so that an arbitrary developing device faces a latent image carrier. In a rotary type developing device for performing development by moving to both sides, the both end walls of the developing device unit that supports both ends of the accommodating member such as the developer carrying member in each developing device are A part that includes a part of the outer peripheral surface of the wall and that is attached to both ends of a part that constitutes a part of the peripheral wall of the developing device unit is separable, and at one end of the developing device unit in the direction of the rotation center line. There is provided a tubular portion having the rotation center line as a center line on the outer side of the separable side wall portion, and the outer peripheral surface of the tubular portion is rotatably supported by a roller member. Development device. 2. The rotary developing device according to claim 1, wherein the tubular portion is provided with an identifying portion corresponding to each developing device, and a detector for detecting the identifying portion is provided on the apparatus main body side. . 3. The outer peripheral surface of the developing unit is rotated to a position where vibration of the one end of the developing unit can be regulated so that the outer peripheral surface of the developing unit is kept in contact with the roller-shaped member. The rotary developing device according to claim 1, wherein a roller-shaped member made of an elastic material is provided.