JPH08137178A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of stably controlling the rotation of a developing unit without causing the faulty rotation of a positioning roller. CONSTITUTION: This image forming device is provided with an endless moving body attached to a device main body so that endless movement such as rotation can be possible, a roller 66 attached to the device main body, a supporting means for rotatably supporting the roller 66 so that it may rotate by following the endless moving body, and an energizing means for energizing the roller 66 to the endless moving body side. By forming a recessed part at the specified spot of the endless moving body and fitting the roller 66 in the recessed part, the endless moving body is positioned. Then, the supporting means is constituted by arranging a ball bearing 110.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically, a rotary positioning means capable of accurately performing rotary positioning of a rotary developing unit having a plurality of developing devices. The present invention relates to an image forming apparatus having.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus of this type, a rotary developing device unit provided with a plurality of developing devices and rotatably provided in the vicinity of a photosensitive member as a latent image carrier is provided for each developing device. Is known to have a rotary developing device in which the latent image on the photoconductor is developed with toner of each color by sequentially rotating to a developing position opposite to the photoconductor (for example, Japanese Patent Laid-Open No. 62- No. 251772, JP-A-63-78170, and JP-A-63-41164).

In such an image forming apparatus, it is necessary to sequentially move each developing device to the developing position and position it accurately. Therefore, for example, a concave portion corresponding to each developing device is formed on the peripheral wall portion of the rear end wall of the rotary developing device unit, and a roller fitted into the concave portion is rotatably provided at a fixed position on the apparatus main body side,
Rotate the rotary developer unit by the amount of rotation necessary to make the recess corresponding to the developing device to be used face the roller provided at the fixed position on the main body side, and fit the roller into the recess. Therefore, it has been proposed to accurately position each developing device.

Further, in such an image forming apparatus, the positioning roller 66 is, for example, as shown in FIG.
It has a cylindrical shape made of a material such as resin, and has a shaft 100
The shaft 100 is fitted around the shaft 100 and is rotatable about the shaft 100. Then, when the rotary developing device unit is positioned using such a positioning roller 66, in order to securely fit the positioning roller 66 in the recess, the positioning roller 66 is biased by a biasing means such as a spring 67. Is preferably biased to the rotary developer unit.

[0005]

However, in the case where the structure of the positioning roller 66 is simply fitted into the shaft 100 as described above, the positioning roller 66 has a spring 67.
Since it is urged to the side of the rotary developing device unit by an urging means such as, the friction with the shaft 100 increases, causing a rotation failure, and in some cases, a fixed state with respect to the shaft 100. There is. Further, the scattering of the image forming substance such as toner into the gap between the shaft 100 and the shaft 100 also increases the friction with the shaft 100 and causes a rotation failure. When the rotation failure occurs as described above, particularly when the positioning roller 66 is in a fixed state, the positioning roller 66 causes a rubbing phenomenon on the contact surface with the peripheral wall portion of the rear end wall 51 of the rotary developing device unit, and the rubbing phenomenon occurs. As a result, the rotation of the rotary developing device unit is hindered, and an excessive load is applied to the rotary driving motor that applies rotary drive to the rotary unit, for example. Then, the rotation driving motor may be adversely affected by this excessive load, and normal rotation control of the rotary developing device unit may not be performed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of stably controlling the rotation of the developing unit without causing the positioning roller to be defective in rotation. That is.

[0007]

In order to achieve the above-mentioned object, the invention of claim 1 is an endless moving body attached to an apparatus main body so as to be capable of endless movement such as rotation, and attached to the apparatus main body. And a support means for rotatably supporting the roller so as to be driven to rotate with respect to the endless moving body,
Urging means for urging the roller toward the endless moving body, a recess is provided at a predetermined position of the endless moving body, and the roller is fitted into the recess to position the endless moving body. In the image forming apparatus for performing the above, the supporting means is configured by providing a ball bearing.

[0008]

In the first aspect of the invention, the roller supported by the ball bearing is driven to rotate with respect to the endless moving body while smoothly rotating.

[0009]

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 not 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 4 according to this embodiment will be described. 2 is an exploded perspective view of the developing device 4, FIG. 3 is a plan view of the developing device 4, and FIG. 4 is a partially enlarged perspective view of the developing device 4. In FIG. 2, the rotary developing device 4 is
For example, developing units for four colors of black, cyan, yellow, and magenta are formed inside, and a developing unit 40 having a substantially cylindrical outer periphery mounted rotatably around the central axis in the printer main body, and each developing unit. The four toner containers 41, 42, 43, and 44, which respectively correspond to the containers in one-to-one correspondence with the toners of black, yellow, magenta, and cyan, respectively, are held, and on the front side of the developing unit 40 in the central axis direction. A toner container unit 45 mounted so as to be substantially coaxial and rotating integrally with the developing device unit 40 around the central axis, and the developing device unit 40 and the toner container unit 45 (hereinafter referred to as a revolver developing unit). ), The storage stand 46 slidable on the printer body substantially parallel to the central axis and the rotation supply unit are covered. And a cover 47 provided non-rotatable.

The revolver developing unit includes a receiving table 46.
The disk-shaped front end wall 5 of the developing device unit 40 includes, for example, two supporting rollers 49 rotatably attached to the front supporting plate 48 of the developing device unit 40.
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.

The housing base 46 has a front support plate 48, a rear support plate 55, and a side cover 59 having front and rear end portions fixed to both support plates and reinforced by connecting rods 56, 57 and 58.
Have and. 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.
Further, as shown in FIG.
An intermediate plate 63 supported by the connecting rods 56 and 57 is attached in the vicinity of 5, and a positioning pin 63b that fits into a positioning hole 63a formed in the rear plate of the main body is provided in the intermediate plate 63 so as to project. A base end portion of a bracket 64 is swingably attached to a positioning pin portion between the intermediate plate 63 and the rear support plate 55, and a predetermined portion of the peripheral surface portion of the rear end wall of the developing device unit is attached to the front end portion of the bracket 64. A positioning roller 66 that falls into any of a plurality of (four in this example) recesses 65 formed at a location is rotatably supported. This bracket 64 is urged in the direction of the arrow by a spring 67, and when the recess 65 faces the roller due to the rotation of the revolver developing unit, for example, as shown by the broken line in FIG. 7, the roller is surely dropped into the recess 65. It is designed to fit. Positioning of the rotational position of the revolver developing unit using the recess 65 and the positioning roller 66 will be described later in detail.

On the other hand, a front plate 68 of the main body of the printer is formed with an insertion hole 69 or the like into which the above-mentioned storage stand 46 carrying the revolver developing unit can be inserted.
Upper and lower guides 70, 71 for slidably supporting the storage stand 46 are hung between the main body rear side plate 53 and the main body. 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. The pin groove 7 into which the guide pin 74 planted upward in the guide 71 is inserted.
5 is formed. The pin groove is provided in the accommodating table 46 when the accommodating table 46 is inserted into or pulled out from the printer body.
The revolver developing unit so that the revolver developing unit can be guided to a predetermined position relatively close to the photosensitive drum 1 when the insertion is completed and the revolver developing unit can be guided away from the photosensitive drum 1. Then, the shape is bent so that it becomes closer to the photosensitive drum 1.

Further, the tip of the positioning pin 63b projectingly provided on the intermediate plate 63 has a tapered shape, and the tip of the rear plate 53 of the main body immediately before the completion of insertion of the storage base into the printer main body. The rear support plate 55 of the accommodating base 46 can be accurately positioned in the main body when it is inserted into the positioning hole 63a and the insertion is completed. On the other hand, 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. Instead of this, a tape-shaped positioning pin may be used similarly to the rear support plate 55. The rear end portion of the revolver developing unit is supported by the rear side plate 53 of the storage table 46 when the storage table 46 is pulled out. Gradually, it gets in and is lifted up, and at the time of completion of the insertion, it completely floats up from the rear support plate 55. As a result, the revolver developing unit includes the support table 48 on the front of the accommodating base accurately positioned on the main body.
The front end portion is supported by the support roller 49, and the rear end portion is rotatably positioned by the main body rear side plate 53 through the central shaft 52 so that the rear end portion is rotatable.

The revolver developing unit is shown in FIG.
As shown in FIG. 7, a revolver rotation motor 7 which is attached to the main body rear side plate 53 and includes, for example, a stepping motor.
A revolver output gear 78, which is also mounted on the rear plate 53 of the main body, driven by 7, has a revolver input of approximately the same diameter as the rear end plate 51 fixed to the rear surface of the rear end plate of the developing device unit 40 by screws or the like. It is adapted to be meshed with the gear 79 to be rotationally driven. On the rear plate 53 of the main body, a developing drive motor 80 for driving a developing roller in the developing device unit 40 described later, a developing output gear 81 driven by the developing drive motor 80, each motor and each output gear. A gear box 82 and the like that accommodates a gear train 62 that connects the and are also attached. (Hereinafter, margin)

FIG. 5 is a sectional view taken along line XX in FIG. 3 for showing the internal structure of the developing device unit 40. The developing device unit 40 includes the above-mentioned substantially disk-shaped front and rear end plates (see FIG. 3), and partition walls provided between the front and rear end plates as shown in FIG. This partition wall is a hollow cylindrical portion 8 into which a cylindrical black toner bottle containing black toner can be inserted.
2 and developing device casing portions 83, 83C that radially extend from the hollow cylindrical portion 82 and divide the space around the hollow cylindrical portion 82 into four developing chambers of substantially the same type in the circumferential direction,
It consists of 83M and 83Y. Each of these developing chambers contains a carrier as a developer and a two-component developer including toner of each color. In the example shown in the drawing, the developing chamber of the black developing device containing the black toner and the carrier is located at the developing position opposed to the photosensitive drum, and the developing device of the yellow developing device containing the yellow toner and the carrier is arranged in the counterclockwise direction in the figure. A developing chamber is a developing chamber of a magenta developing device containing magenta toner and a carrier, and a developing chamber of a cyan developing device containing cyan toner and a carrier.

Since the internal structure of each of the four developing chambers is exactly the same, the internal structure of the other developing chambers will be described below by taking the black developing chamber at the developing position in FIG. 5 as an example. 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 in the developing position in the figure, 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 serves as a deteriorated developer discharge port and, if necessary, an unused developer (toner-mixed) inlet when the developer is replaced due to the deterioration of development in the developing chamber. An agent discharge port 92 extending in the rotation axis direction for use is formed, and a cap 93 that covers the discharge port 92 from the outside is fixed by a screw 94 or the like.

Incidentally, in order to efficiently discharge the deteriorated developer from the discharge port 92, the revolver developing unit is placed in the receiving table 4.
6, the development input gear 95 (see FIG. 6), which will be described later, is rotated using a jig, and the developing roller 84, the vertical transport screws 86 and 91, and the paddle 88 are rotated to deteriorate the development. It is desirable to expel the agent. Further, even when the unused developer is introduced from the discharge port 92, the developer can be uniformly dispersed in the developer by rotating the developing roller 84, the upper and lower conveying screws 86 and 91, and the stirring paddle 88 in the same manner. .

FIG. 6 is a vertical sectional view of a plane including the central axis 52 of the upper and lower conveying screws 86 and 91 of the black developing device. As shown in the figure, the front end portions of the vertical transport screws 86 and 91 extend outside the effective width region of the developing roller 84 (in the example shown, outside the front end wall 50 of the developing device unit), and this extension. A drop portion 96 for dropping the developer, which has been transported by the upper transport screw 86, onto the lower transport screw 91 by its own weight is provided at a position. The front end portion of the lower transport screw 91 extends further to the front side than the drop portion 96, and the toner container unit 45 described later in detail.
Toner supply roller 9 provided corresponding to each developing chamber
7 It extends to the communication room below. As a result, of the developer drawn up by the developing roller 84, the developer regulated by the doctor blade 85 and conveyed to the front side by the guide 87 and the upper conveying screw 86 is dropped onto the lower conveying screw 91 by the dropping portion 96. Then, it is conveyed by the lower conveying screw 91 within the effective width of the developing roller 84, and is discharged into the developing chamber from the developer discharge port of the stirring paddle hollow cylindrical portion within the width so that it can be carried by the developing roller 84 again. Become. 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 at the lower portion of the developing chamber is so-called vertical stirring performed by the stirring plate portion by the rotation of the stirring paddle 88. 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.

FIG. 7A is a perspective view of the rear end wall 51 of the developing device unit 40 as seen from the front side. The revolver input gear 7 fixed to the rear end wall portion, specifically, the rear end wall 51.
The illustrated gears are provided on the rear side of the gear 9. That is, the developing roller gear 98 is fixed to the shaft end portion of the developing roller 84 that penetrates through the rear end wall 51 and the like and protrudes to the rear side of the revolver input gear 79. Vertical transport screw gears 99 and 100 are fixedly mounted on the respective shaft ends of the vertical transport screws 86 and 91 protruding to the rear side. In the illustrated example, the developing roller 84 gear and the lower carrying screw gear 10 are used.
Idle gear 101 meshing with 0 and the rear plate 53 of the main body
Development input gear 95 for meshing with a development output gear 81 which is attached to the
Is attached to the rear side of the rear end wall 51 of the developing device unit. As described above, the revolver developing unit in which these gears are provided on the rear end wall side is carried by the storage stand 46 and inserted into the printer main body, as shown in FIG.
As shown in (a), the development output gear 81 on the main body side meshes with the development input gear 95 on the revolver development unit side. At the same time, as shown in FIG. 7A, the revolver input gear 79 on the revolver developing unit side meshes with the revolver output gear 78 on the main body side.

Incidentally, FIG. 8A is a plan view of the drive motor section of the rotary type developing device, and FIG. 8B is a front view of the drive motor section. As can be seen from these figures, the gears 78, 81 on the main body side are retractable in the slide direction of the storage base so that the gears on the main body side and the revolver developing unit side are meshed well with the insertion of the storage base. Installed,
In addition, the springs 102 and 103 as biasing means push and bias it toward the front side of the main body. As a result, the gears 78 and 81 on the main body side and the gear 7 on the revolver developing unit side
Even when 9 and 95 interfere with each other when the storage table is inserted, the gears 78 and 81 on the main body side retract and the storage table 46 can be completely inserted. And the main body side gear 78 after that,
The interference of the gears can be eliminated with the driving of 81, and the main body gears 78, 8 are closest to the revolver developing unit side by the biasing force.
1 is pushed out, and the gear 79 on the revolver developing unit side,
Complete engagement with 95 can be realized.

In FIG. 7 (a) in the state where the above complete meshing is realized, the developing output gear 81 is driven in the direction shown by the arrow A in the drawing, and the vertical conveying screw gear is engaged via the developing input gear 95 meshing with this. 99 and 100 rotate to rotate the upper and lower transport screws. Further, the developing roller gear 98 is rotated via the developing input gear 95, the lower carrying screw gear 100 and the idle gear 101, and the developing roller 84 is rotationally driven.

In the example shown in FIG. 5, the front and rear end wall portions that support the developing roller 84Y and the doctor blade 85Y are separated from other front and rear end wall portions as shown in the yellow developing device, for example. It is configured on the end wall portion 104. As a result, when cleaning the interior of the developing chamber or replacing parts,
The developing roller 84Y and the doctor blade 85Y are removed together with the small end wall portion 104 so that the developing chamber can be easily accessed.

Further, as shown in FIG. 7C, at the fixed position of the main body rear side plate 53 facing the end of the developing roller shaft 98a of the developing device positioned at the developing position, a developing bias for connecting to the bias circuit 105 is applied. The rod-shaped terminal 106 is attached by a bracket 107 so as to be retractable in the sliding direction of the storage table, and is pushed and urged toward the front side of the main body by a spring 107a as urging means. The tip portion of the rod-shaped terminal 106 is formed in a hemispherical shape, and the shaft end portion of the developing roller 84 is formed with an indentation having an arcuate cross section having a slightly larger radius of curvature than the hemisphere. It is possible to reduce the amount of additional contact when the shaft end portion of the developing roller 84, which reaches the portion facing the rod-shaped terminal 106 with the rotation, and the tip end of the rod-shaped terminal, and to reduce the contact and stabilize the contact during the engagement.

FIG. 9 is a sectional view taken along line YY in FIG. 3 showing the internal structure of the toner container unit 45.
11 corresponds to a sectional view of the toner container unit 45 when the black developing device is in the developing position. The toner container unit 45 includes a disk-shaped unit face plate 108.
(See also FIG. 2), and a total of four toner receiving cases 109Y, M, C, 110 mounted on the front surface of the face plate in a one-to-one correspondence with each developing device, and inside each toner receiving case. Toner replenishing rollers 97 provided in the respective
It has Y, M, C, 97 and the like. The toner replenishing roller is located almost directly above the extending portion of the lower conveying screw 91 into the case when the corresponding developing chamber is located at the developing position. Is supported by.

The unit face plate 108 is shown in FIG.
A circular through hole 111 through which a cylindrical black toner container as shown in (a) and (b) can pass is formed in the center thereof, and the toner receiving cases 109Y, M, and
C and 110 are attached by escaping the through hole 111. Further, the unit face plate 108 is also formed with through holes corresponding to the lower transport screw 91 extending from the developing chamber of each developing device and a trough-shaped screw cover 112 (see FIG. 10) provided as necessary. The lower conveying screw is provided with the toner receiving cases 109Y, M, C, 11 on the front surface of the unit face plate 108 through the through holes.
It extends within 0.

FIG. 10 shows a cyan toner receiving case 10.
9C and cyan toner container 44 attached thereto
Fig. 11 is a perspective view of Fig. 11, and Fig. 11 is a side view of these. The four toner receiving cases 109Y, M, C, 109
Among them, the three color toner receiving cases 109Y, M, C corresponding to the respective color developing devices have the same shape. That is, taking the case for receiving cyan toner as an example, as shown in FIG. 10, the toner is enclosed when the inwardly extending portion of the lower carrying screw 91 and the toner replenishing roller 97C are surrounded and the corresponding developing chamber is located at the developing position. A peripheral wall portion having a toner receiving port is formed at a position above the replenishing roller 97C, and a color toner container 44 having the same shape for each color containing color toner is provided around the toner receiving port. A color toner container mounting portion 113 is formed so as to face downwards and to be aligned with the toner receiving port. Further, a seal member 114C that seals between the toner supply roller 97C and the peripheral surface of the toner supply roller 97C is attached to the inner wall surface of the case facing the toner supply roller 97C. The seal and the toner replenishing roller 97C partition the inside of the toner container mounting portion 113 into the toner container side and the developing chamber side, and the seal and the toner replenishing roller 97C and the lower conveying screw 91C.
With the peripheral wall of the case that surrounds the
A communication chamber that communicates with the developing chamber of the corresponding developing device via the above-mentioned dropping portion is defined.

The color toner container mounting portion 113 is
As shown in FIG. 10 and FIG. 11, the toner container is made detachable by sliding in the rotation axis direction of the revolver developing unit, and the color toner container once attached is simply slid in the opposite direction, that is, toward the front. A pull-out prevention member 115 (see FIG. 11) that enters into the already mounted color toner container through the toner discharge port is provided so as not to be removed only by itself. When removing the mounted color toner container, the shutter member 117 for shielding the discharge port is inserted into the slit 116 formed at the discharge port of the color toner container and the pull-out prevention member 115 is pushed down to push down the color toner container. Evacuate from inside. Such a color toner container mounting portion 113
When setting a new color toner container in the printer, slide the color toner container with the sealing member attached to the toner outlet into the sealed state, and then remove the seal member to remove the toner. It is desirable to open the outlet.

Here, the color toner containers 42, 43,
Reference numeral 44 has a shape capable of fitting with a peripheral wall portion around the lower transporting screw 91 of the toner receiving case upstream of the corresponding toner receiving case in the rotation direction of the revolver developing unit, and of the rear end wall 51. Attached to the outer surface portion on the revolver developing unit side, for example, as shown in FIGS.
The protrusions 119Y, M, and C to be detected which are detected by the set detection device 118 as shown in FIG. The set detection device 118 shown in the figure has a through hole 12 formed in the unit face plate when the color toner container is set in the mounting portion.
A transmissive or reflective optical sensor 118Y attached to the rear surface of the face plate so that the tips of the protrusions 119Y, M, and C for detection that penetrate through 0 and project to the rear surface of the face plate can be detected. It is composed of M and C.

On the other hand, as shown in FIG. 9, the black toner receiving case 110 corresponding to the black developing device has the color toner receiving cases 109Y, M, and C with the color toner accommodating containers 42, 43, and 44 attached thereto. Both have a peripheral wall shape that is substantially the same as the overall peripheral wall shape. A peripheral wall portion having a shape similar to that of the color toner receiving case is also provided with a seal member 114 for sealing between the toner replenishing roller 97 and the inner wall surface of the case. A communication chamber with the developing chamber accommodating the extended portion of the screw 91 is formed. In addition, in the portion facing the center line of the revolver developing unit in the peripheral wall portion having the same shape as the color toner container, FIG.
A toner receiving opening 122 having a shape corresponding to the toner discharging opening 121 of the black toner container 41 as shown in FIGS.
Are formed. The toner received from the black toner container via the toner receiving port 122 has a peripheral wall portion having the same shape as the color toner container and the toner replenishing roller 9.
The toner is stored in a region corresponding to a hopper in a normal toner replenishing device surrounded by 7 and the like, and is discharged into the communication chamber by rotation of the toner replenishing roller 97. The toner receiving port 122 can be closed from the inside by a shutter 124 whose one end is rotatably supported by a support shaft 123 parallel to the rotation shaft of the revolver developing unit. The shutter 124 swings around the support shaft 123 by its own weight as the revolver developing unit rotates, and automatically opens and closes the toner receiving port 122. Further, the toner receiving port 12 is provided at the edge of the shutter 124.
A seal member 125 for enhancing the shielding property of No. 2 is attached.

Further, the toner replenishing rollers 97Y, M,
C and 97 have a roller portion in which a plurality of grooves extending in the axial direction are formed on the peripheral surface portion as shown in FIG. 10, and are provided to the developing unit 40 side via the bearing portion of the unit face plate 108 as shown in FIG. A gear 135 is fixed to the shaft end portion that penetrates through, and a supplementary input gear 13 for driving input that meshes with the gear 135.
6 is fixed. Of the replenishment input gear 136 provided for each toner replenishment roller, the replenishment input gear 136 of the toner replenishment roller 97 in the case corresponding to the developing device in the developing position as shown in FIG. A gear 62 driven by a replenishment motor 61 attached to the front support plate 48 meshes with the gear 62 so that it can be rotationally driven by the motor 61. (Hereinafter, margin)

Here, the black toner container 41 is shown in FIG.
As shown in (a) and (b), a toner discharge port 121 is formed on the peripheral wall portion at one end in the longitudinal direction, and a toner feed protrusion 126 is formed on the inner peripheral surface of the toner discharge port 121 from the other end. 1
It is formed in a spiral shape toward the 21 side. The spiral projecting portion 126 sends the stored toner from the rear end portion to the front end portion where the toner discharge port 121 is formed by the rotation integrally with the revolver developing unit when attached to the revolver developing unit. It is spiraled. Further, a protrusion 128 for detection is formed on the outer surface of the peripheral wall on the rear end side in the longitudinal direction from the toner discharge port 121, and the knob 12 is provided on the front end.
9 are provided. The detection projection 128 is shown in FIG.
By the set detection device 127 attached to the revolver developing unit side as indicated by the broken line, specifically, to the rear surface of the front support plate 48 of the accommodating base, the support shaft 123 is also attached to the rear surface of the front support plate 48. Link 1 swingably attached
Detected via 34.

That is, in the black toner container 41, the sealing member that seals the toner discharge port 121 in the posture in which the toner discharge port 121 faces upward is removed, and the protrusion 1 for detection 1 is removed.
28 passes through the passage notch 130 formed in the cover 47 shown in FIG. 2, and is inserted through the toner container insertion notch 47a of the cover 47 as shown by the broken line in FIG. The rear end portion is the hollow cylindrical portion 82 of the developing device unit 40.
It is inserted into the inside of the toner container unit 45 until it reaches the inside and is substantially flush with the front surface of the front end wall of each case of the toner container unit 45. Then, holding the knob 129, it is rotated clockwise in the drawing so that the toner discharge port coincides with the toner receiving port 122 of the black toner receiving case. At this time, the detected protrusion 128 engages with the link 134 on the revolver developing unit side to push it up and rotate it, and this rotation is detected by the set detection device, whereby the black toner container 41 is set. Is detected.

FIG. 14 is a block diagram of the electrical components of the printer body. The control device 160 of this electrical component includes a CPU, a RAM, a ROM, an I / O interface,
It is composed of a timer and the like. This controller 160
To the CPU of the home position sensor 151, the front cover detection device 152, through the I / O interface,
An optical sensor P (see FIG. 1) used for toner concentration control, and a set detection device 118 that is a replacement detection device for the toner container.
Y, M, C, 127, drive circuits 77a, 61a, 80a of various motors 77, 61, 80, and operation panel 161.
Etc. are connected. On the operation panel 161, toner near-end lamps 162Y, M, C, BK for displaying the toner near-end of each color developing device, and for the user instructing replacement of the toner accommodating containers 41, 42, 43, 44 of each color. Replacement instruction buttons 163Y, M, C, BK, a cover opening lamp 164 indicating that the front cover is opened, a ten-key 165, a print start button 166, and the like are provided. The home position sensor 151 shown in FIG.
As shown in FIG. 3, the revolver developing unit is attached to, for example, the front support plate 48 of the accommodating base so that the detected member 150 for home position detection can be detected. At the time of standby after the printing operation or after the printing operation, the home position position where the sensor 151 detects the detected member 150, that is, FIG.
The signal from the sensor 151 is used for the initial operation to keep the black developing device at a rotational position where the black developing device is located at the developing position as shown in FIG. To be

Next, the recess 65 of the revolver developing unit,
Positioning of the rotational position of the revolver developing unit using the positioning roller 66, the revolver driving motor 77, the developing drive motor 80, etc. will be described. In this embodiment, a revolver drive motor 77 including a stepping motor or the like.
7A, the revolver output gear 79 is driven to rotate in the direction of arrow B in the drawing to rotate the revolver developing unit in the direction of arrow C, thereby moving the revolver output gear 79 to the developing position. The revolver developing unit is positioned by inserting the positioning roller 66 into the recessed portion 65 formed at a predetermined position on the peripheral surface portion of the rear end wall 51 of the revolver developing unit for switching. Then, due to variations in the revolver drive motor and variations in the load on the revolver developing unit side, when the rotation angle of the revolver developing unit is a desired rotation angle (for example, when one upstream developing device in the rotation direction is moved to the developing position). However, the positioning roller 66 does not fit into the corresponding recessed portion 65 and accurate positioning cannot be performed, and the distance between the developing roller 84 and the photosensitive drum 1 is different from the desired distance. The following improvements have been added to prevent this.

In other words, the rotation control of the revolver drive motor 77 is controlled to correspond to an angle slightly larger than the desired angle (for example, an angle about 3 degrees larger) in consideration of the above variation so that the rotation of the revolver drive motor can be surely performed at the desired angle. I am trying to use the value. As a result of controlling the rotation with such a control value, the rotation moment given to the revolver developing unit by starting the driving of the developing drive motor so that the revolver developing unit can be accurately positioned even if the revolver developing unit actually rotates beyond the desired angle. Accurate positioning can be performed by using. Specifically, as shown in FIG. 7A, the rotation of the developing output gear 81 meshing with the developing input gear 95 of the developing device at the developing position is rotated in the direction of arrow A in the figure (the direction during normal developing drive). Rotation) gives a rotational moment to the unit in a direction opposite to the direction of rotation of the normal revolver developing unit indicated by an outlined arrow D in the figure so that the unit can be returned, and the return of the unit is performed. , The bracket 64 to which the positioning roller 66 is attached serves as a counter for the rotation in the returning direction so that the rotation of the revolver unit can be locked by stopping when the positioning roller 66 is fitted into the corresponding concave portion 65. Further, the position of the positioning pin 63, which is the bracket support shaft, and the contact position with respect to the revolver developing unit are determined.

In the above-described structure, when the cyan developing device is located at the developing position from the home position where the black developing device is located at the developing position shown in FIGS. 5 and 9, it is necessary to rotate 90 degrees counterclockwise. is there.
At this time, in consideration of variations in the revolver drive motor 77, etc., the motor 77 is rotationally controlled by a control value that can reliably rotate the revolver developing unit by 90 degrees or more, and the concave portion 65 corresponding to the cyan developing device is slightly positioned. Rotate to the rotation position that passes through. Then, the developing drive motor 8
When the positioning roller 66 is fitted in the recess 65 by reversing the revolver developing unit by starting the driving of 0 and the rotation moment by this driving, the bracket 6 in the counter posture.
A strong stopping force is exerted by the positioning roller 66 attached to the front end of 6 to position the revolver developing unit.

Incidentally, in order to reduce the load on the drive system when the revolver developing unit rotates beyond the desired angle and exits the recess 65 that has once entered by the rotation control based on the above control value, FIG. As shown in the drawing, it is desirable that the inclination of the recessed portion 65a when the positioning portion comes out during the normal rotation is gentler than that of the locking recessed portion 65a to facilitate the removal.

Further, in the above-mentioned embodiment, the positioning roller 66 is, as shown in FIGS. 7 (a) and 7 (b),
Since the shaft 100 is fitted into the shaft 100 and rotatable about the shaft 100, when the positioning is performed as described above, the rotation failure may occur as described above. Therefore, when performing positioning as described above, the positioning roller 66
However, even if the spring 67 is biased toward the revolver developing unit, the following structure is adopted as the structure of the supporting means for rotatably supporting the positioning roller 66 so as to prevent the rotation failure. are doing.

That is, the positioning roller 66 in the present embodiment.
As shown in FIG. 14, the shaft 100 is rotatably supported by a shaft 100 fixedly mounted on a bracket 64 via a ball bearing 110, and the frictional force generated between the shaft 100 and the shaft 100 is reduced to prevent rotation failure. It is less likely to occur.

The positioning roller 66 is used to position the revolver developing unit as described above.
While smoothly rotating around the shaft 100, the revolver developing unit is driven to rotate on the peripheral surface of the rear end wall 51 and fitted into the recess 65. Therefore, the positioning roller 66 does not cause a rubbing phenomenon on the contact surface of the rear end wall 51 with the peripheral wall portion as described above, and does not apply an excessive load to the revolver driving motor. Can stably control the rotation of the revolver developing unit. Even if the scattered toner enters the gap between the shaft 100 and the shaft 100, the frictional force does not increase enough to cause a fixed state, and the positioning roller 66 smoothly rotates about the shaft 100. The drive motor can stably control the rotation of the revolver developing unit.

[0045]

According to the first aspect of the present invention, since the rollers supported by the ball bearings rotate smoothly about the shaft without causing rotation failure, the endless moving body drive means is provided in the endless moving body. The rotation control can be stably performed.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of an electrophotographic printer according to an embodiment.

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

FIG. 3 is a plan view of the rotary developing device.

FIG. 4 is a partially enlarged perspective view of the rotary developing device.

5 is a sectional view taken along line XX in FIG.

FIG. 6 is an explanatory view of a connection structure between a developing device and a toner container in the rotary developing device.

FIG. 7A is a perspective view from the front showing a drive system of the rotary developing device. FIG. 3B is an explanatory diagram of a developing bias supply device for the developing device. (C) is explanatory drawing of the modification of the same rotary type developing device.

FIG. 8A is a plan view of a drive motor unit of the rotary developing device. (B) is a front view of the drive motor section.

9 is a sectional view taken along line YY in FIG.

FIG. 10 is a perspective view of a color toner container and a container mounting portion in the rotary developing device.

FIG. 11A is an explanatory view of a method of attaching the container to the container attachment portion. (B) is explanatory drawing of the same container set detector in the same attachment part.

FIG. 12A is a side view of a black toner container of the rotary developing device. (B) is a front view of the same container.

FIG. 13 is a block diagram of an electric component section of the printer.

FIG. 14 is a cross-sectional view showing a cross section of a positioning roller used in this embodiment.

15 is a cross-sectional view showing a cross section of the positioning roller in FIG.

[Explanation of symbols]

 1 Photoreceptor Drum 63 Positioning Pin 64 Bracket 66 Positioning Roller 69 Concave Formed on Rear End Wall of Developer Unit 77 Revolver Drive Motor 78 Revolver Output Gear 79 Gear at Rear End of Developer Unit 80 Development Drive Motor 81 Development Output Gear 95 Development input gear 98 Development gear 100 Shaft 110 Ball bearing

Claims (1)

[Claims] Claim: What is claimed is: 1. An endless moving body attached to an apparatus main body so as to be capable of endless movement such as rotation, a roller attached to the apparatus main body, and the roller so as to be driven to rotate with respect to the endless moving body. A support means for rotatably supporting and an urging means for urging the roller toward the endless moving body are provided, a recess is provided at a predetermined position of the endless moving body, and the roller is fitted into the recess. Thus, in the image forming apparatus for positioning the endless moving body, the supporting means is constituted by providing a ball bearing.