JPH0633476Y2 - Developing device in image forming apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention has a plurality of developing devices integrally incorporated and is rotatably supported around a central axis of a developing and forming apparatus main body, and the rotation thereof is supported. The predetermined developing device is brought to a developing position facing the latent image carrier, and the developing device is provided with a developing unit which visualizes the electrostatic latent image formed on the latent image carrier. And a developing device in the image forming apparatus.

2. Description of the Related Art A developing device of the above type used in various image forming apparatuses such as copying machines and printers is well known in the prior art, and its developing unit is provided on the image forming apparatus main body so that maintenance and inspection work can be performed easily. It is detachably supported.

Conventionally, for example, as disclosed in Japanese Patent Application No. 61-223211, a developing unit is carried on a unit carrier slidably supported on the main body of the image forming apparatus, and the developing unit is supported at the time of maintenance and inspection of the developing unit. At the same time, the unit carrier is pulled out from the image forming apparatus main body to the front side, whereby the developing unit is exposed to the outside and a predetermined work is performed. As described above, the simple maintenance work for the developing unit can be performed only by pulling out the unit carrier, but the complicated work is difficult.

Therefore, in such a case, the developing unit on the unit carrying body that has been pulled out is removed from the unit carrying body, and this is carried to a supporting surface such as a floor surface or a desk top, and the developing unit is individually placed on the supporting surface, and the predetermined size is set. Work.

However, since the developer transporting member including, for example, a developing roller is exposed on the outer surface of the developing unit, when the developing unit is removed from the unit carrier that is pulled out,
The developer adhering to the developing roller may come into contact with the worker's hand or clothes, and this may drop downward to stain the surrounding area or stain the worker's hands or clothes.

Further, since a developing unit having a plurality of developing devices is provided with a plurality of developer conveying members around it, it is difficult to place the developing unit independently on a floor surface in a stable state, If it is forcibly placed, the developer may spill from the developing unit.

Therefore, it is conceivable to mount the developing unit on the bottom surface or the like via a support base, but preparing such a support base outside the image forming apparatus main body increases the number of parts and the cost. In addition to inviting, the disadvantage that a large space for storing the support is required when the support is not used is inevitable.

Further, when the developing unit set at a predetermined position in the image forming apparatus main body is pulled out to the front side with respect to the image forming apparatus main body, the developing unit hits the latent image carrier and scratches its surface. However, there is a possibility that the developer on the developing unit side may drop and stain the inside of the image forming apparatus main body or its periphery with the developer.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and when the developing unit is attached to or detached from the main body of the image forming apparatus, the developing unit can be largely separated from the latent image carrier with a simple structure. To provide.

In order to achieve the above-mentioned object, the present invention has a plurality of developing devices that are integrally incorporated, and
It is rotatably supported around its central axis, and its rotation brings a predetermined developing device to a developing position facing the latent image carrier, and the electrostatic latent image formed on the latent image carrier is developed by the developing device. A developing unit for converting the latent image into a visible image, and a supporting unit supported by the main body so as to be detachable from the main body of the image forming apparatus while carrying the developing unit.
And a unit carrier that is supported on a supporting surface outside the main body while holding the developing unit when it is detached from the main body of the image forming apparatus; A unit carrying a developing unit and a positioning pin rotatably supported by a bearing on the back side plate of the image forming apparatus main body when the developing unit is set on a line and is set at a predetermined position in the image forming apparatus main body. When the carrier is started to be pulled toward the front side of the image forming apparatus main body and the positioning pin comes off the bearing of the rear side plate, the rear side portion of the developing unit is moved in a direction away from the latent image carrier. When the unit carrier for holding the developing unit whose back side is separated from the latent image carrier is pulled further to the front side, the unit carrier will An image forming device that guides the unit carrier in a direction to move to the side, and includes a guide unit that guides the unit carrier and the developing unit carried by the unit carrier in a direction further away from the latent image carrier. The developing device in the apparatus is proposed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which the developing unit 1 of the developing device in the image forming apparatus is set in the image forming apparatus main body (copier main body in this example). First, the basic configuration will be clarified. .

The developing unit 1 has a plurality of, three in the example shown, three developing units 3, 3R, 3B that are integrally incorporated, and a developer chamber of each developing unit.
4, 4R, 4B are partitioned by partition walls 6, 6R, 6B of the casing member 5 and two end walls 7, 8 at both ends thereof (see FIG. 2). It goes without saying that the end walls 7, 8 and the casing member 5 may be previously formed as an integral casing.

Developers having different colors or developers 9, 9R, 9B having the same color are stored in the respective developer chambers. These developers may be either a one-component system or a two-component system, and may be a magnetic developer or a non-magnetic developer, but in the example of the figure, a two-component system magnetic developer. Is used.

The first to third developing units 3, 3R, 3B are arranged radially around the central axis O of the developing unit 1, and all have the same structure. Therefore, in the following description, mainly the first
Only the configuration of the developing device 3 will be clarified. In FIG. 1, the first
The elements R and B are attached to the respective elements of the second or third developing device corresponding to the respective elements of the developing device 3, and the respective elements are made to correspond to each other.

In the developer chamber 4 of the first developing device 3, a developing roller 10 which is an example of a developer conveying member is rotatably arranged, and a part of the developing roller 10 is opened from an opening formed by two partition walls 6 and 6R. Is exposed to the outside (see also Fig. 2).

The developing unit 1 is rotatably supported by the main body of the copying machine around the central axis O of the unit, and the developing roller 10, 10R, or 10B of each developing device is rotatably supported by the main body of the copying machine. The latent image carrier, which is the photosensitive drum 11 in this example, occupies a predetermined developing position, and the developing operation is performed in this state. That is, the rotation of the developing unit 1 brings a predetermined developing device to a developing position facing the photoconductor drum 11, and the electrostatic latent image formed on the photoconductor drum 11 is visualized by the developing device. It becomes an image. FIG. 1 shows a state in which the developing roller 10 of the first developing device 3 occupies the developing position. At this time, the developing roller 10 is positioned with a predetermined minute gap with respect to the photosensitive drum 11. However, when a one-component developer is used, the developing roller may be brought into pressure contact with the photosensitive drum.

The impeller 16 arranged in the developer chamber 4 is rotationally driven in the counterclockwise direction in FIG. 1, and supplies the developer in the developer chamber, that is, toner and carrier to the developing roller 10 while stirring.

Inside the developing roller 10, a magnet magnetized as shown
21 is fixedly arranged with respect to the casing member 5. By rotating the developing roller 10 counterclockwise,
The developer is carried on the surface of the roller 10 and conveyed in the same direction, and the layer thickness of the developer is regulated by the doctor blade 22 fixed to the casing member 5, and the developer is sent toward the photosensitive drum 11.

The photoconductor drum 11 is driven to rotate clockwise in FIG. 1, and an electrostatic latent image is formed on the surface of the photoconductor drum 11 by charging / exposure means (not shown). The latent image is formed on the photoconductor drum 11 and the developing roller 10. When the counter developing area D is reached, the toner in the developer is electrostatically transferred to the electrostatic latent image, and the latent image is visualized. This visible image is transferred to a transfer paper (not shown), and the developer that has passed through the developing area D is again in the developer chamber 4
Is returned to inside.

The developer chambers of the developing unit may contain different color developers, and the developing units may be sequentially and selectively used while rotating the developing unit to obtain a full-color image. The developing device can also be configured to obtain a monochromatic image.

Since the toner in the developer chamber is sequentially consumed when the above-described developing operation is performed, it is necessary from the toner replenishing devices 44, 44R, 44B connected and fixed to the front side of the developing unit 1 as shown in FIG. The toner is replenished accordingly. In FIG. 1, in order to clarify the positional relationship between the developing unit 1 and each toner replenishing device, the positions of these devices are shown by chain lines.

The developing unit 1 is generally configured as described above, but it is necessary to take it out of the main body of the copying machine when this unit is to be repaired or inspected. The configuration related to this will be clarified below.

The developing unit 1 is carried on a unit carrier 200 whose outline is shown in FIG.
Is supported by the main body 201 so as to be detachable from the main body 201 of the copying machine (see FIG. 2).

FIG. 2 shows that the unit carrier 200 is removed from the copying machine main body 201,
Moreover, FIG. 3 is a perspective view showing a state where the developing unit 1 is detached from the carrier 200, and FIG. 3 is a front view when the unit carrier 200 supporting the developing unit 1 is set in the copying machine main body. FIG. 3 is a diagram showing the unit 1 in a simplified manner and omitting a toner replenishing device.

2 and 3, the unit carrier 200 has a carrier body 202 having a substantially J-shaped cross section, and a front plate 203 fixed to the front end face thereof. A guide member 220 as shown in FIG. 5 is fixed to the bottom wall of the space inside the copying machine main body 201 which receives the developing unit 1 and its carrier 200, and a guide groove 222 is formed in this guide member 220. In addition, the guide pin 221 is projected.

On the other hand, as can be seen from FIG. 4, which is a front view similar to FIG. 3, showing the front plate 203 removed, the carrier body
A guide groove 224 and a guide pin 223 that are formed symmetrically with the guide groove 222 and the guide pin 221 are provided on the bottom surface of the 202, and the guide pin 223 on the unit carrier 200 side is a guide member.
A guide groove 222 of 220 and a guide pin 221 of the guide member 220 are slidably fitted in a guide groove 224 of the carrier 200 (in FIG. 5, the guide pin 223 of the unit carrier is shown). , And the guide groove 224 is shown by adding a chain line). As a result, the unit carrier 200 is slidably supported by the copying machine main body 201, and the unit carrying body 200 carrying the developing unit 1 is shown in front of the copying machine main body 201 (shown by an arrow A in FIGS. 2 and 5). Direction) or, conversely, push it toward the back (also in the direction indicated by arrow B) to place it in the main body 20.
Can be set within 1.

The front plate 203 of the unit carrier 200 has two support rollers.
76, 77 and the auxiliary roller 206 are rotatably supported, and a grip 213 is fixed to the front side of the side plate 203. In addition, three auxiliary rollers 207, 2 are provided on the end surface on the back side of the carrier body 202.
08,209 are rotatably supported. Furthermore, the front side plate 20
A pressure arm 211 is rotatably supported on the upper part of 3 via a pivot pin 211a, and a pressure roller 210 is attached to the tip of the arm 211.
Is rotatably supported.

On the other hand, the front side portion and the back side portion of the developing unit 1, that is, the outer peripheral surfaces of the end walls 7 and 8 in the example of the drawing are formed in a cylindrical shape,
When the developing unit 1 is supported by the carrier 200, the front end wall 7 is rotatably supported by the two support rollers 76 and 77 provided on the front plate 203, as clearly shown in FIG.
Moreover, the pressure roller 210 is urged by a spring (not shown) to come into pressure contact with the outer peripheral surface of the end wall 7. Also a unit carrier
When 200 is pulled out to the front side, the rear end wall 8 of the developing unit 1 is supported by the two auxiliary rollers 207 and 208 on the rear side of the carrier, which will be described in detail later.

The support shaft that rotatably supports the support roller 76 on the front plate 203 also serves as the positioning reference pin 204 for the unit carrier 200. That is, when the unit carrier 200 supporting the developing unit 1 is set in the copying machine main body 201, the carrier 20
As shown in FIG. 6 (a), the reference pin 204 of 0 is the photosensitive member side plate.
It fits into a positioning hole 226a formed in 226. Further, another reference pin 205 protruding from the front side plate 203 of the unit carrier 200 is fitted into a positioning hole 83a formed in the main body front side plate 83 of the copying machine main body 201. The photoconductor side plate 226 is a member that rotatably supports the photoconductor drum 11 and is fixed to the main body front side plate 83 to correctly position the photoconductor drum 11 with respect to the main body 201. By fitting the reference pins 204 and 205 of the unit carrier 200 to the main body front side plate 83, the front side of the unit carrier 200 is correctly positioned with respect to the copying machine main body 201 and the photoconductor drum 11. At this time, the front end wall 7 of the developing unit 1 is 3
Since the rollers 76, 77, 210 are positioned from three sides, the front side of the developing unit 1 is positioned at a predetermined position with respect to the copying machine main body 201 and the photosensitive drum 11.

On the other hand, the back side portion of the developing unit 1, that is, the back side end wall 8 thereof
6A and 7A, a positioning pin 78 is projectingly provided on the central axis O of the unit carrier 200 and the developing unit 1 at predetermined positions in the copying machine main body 201. Locating pin 78 above when set to
8 is also rotatably fitted and supported by a bearing 227 attached to the back side plate 2 of the copying machine main body 201, as shown in FIG.
As a result, the back side of the developing unit 1 is the main body 201 of the copying machine,
Therefore, the developing unit 1 is positioned with respect to the photosensitive drum 11, and the developing unit 1 is properly positioned with respect to the photosensitive drum 11 on both the front side and the rear side thereof. At this time, the developing unit 1 has a predetermined distance a (FIG. 4) from the photosensitive drum 11.
Are placed opposite each other.

(When the developing roller in the developing position is pressed against the photosensitive drum 11, a = 0).

When the positioning pin 78 is fitted into the bearing 227, the outer peripheral surface of the rear end wall 8 of the developing unit 1 is slightly separated from the auxiliary rollers 207 and 208 as shown in FIG.
The rear side of the main body is supported by the body rear side plate 2 only by the positioning pin 78. Further, the pressure arm 211 is provided with a lock device (not shown), and by releasing the lock, the pressure arm 221 and the pressure roller 210 are rotated as shown by a chain line in FIG. Can be separated from the outer peripheral surface of the end wall 7.

When removing the developing unit 1 from the main body of the copying machine, first, as described above, the lock device is released to separate the pressure roller 210 from the end wall 7, and then the grip 213 is gripped to the front side (direction of arrow A). Pull to. When the unit carrier 200 is pulled in this way, the reference pins 204, 205 on the front side of the unit carrier 200 are disengaged from the positioning holes 226a, 83a as shown in FIG. 6 (b).

Further, the developing unit 1 supported by the unit carrier 200 is also pulled out together with the carrier 200, so that the positioning pin 78 on the back side is disengaged from the bearing 227 as shown in FIGS. 6 and 7B. At this time, since the front side of the developing unit 1 is still supported by the front side plate 203 via the two supporting rollers 76 and 77, the rear side of the developing unit 1 is set to the rear side as shown in FIG. 6 (b). The unit 1 descends in the direction of arrow E around the front side of the unit 1 by its own weight, and the end wall 8 on the back side is rotatably supported on the two auxiliary rollers 207, 208 on the back side as shown in FIG. During this operation, the back side of the developing unit 1 rotates about the front side thereof in the direction indicated by the arrow H in FIG. 9, that is, in the direction away from the photoconductor drum 11, so that the photoconductor drum 11 on the back side is rotated. The spacing a1 of the developing unit 1 is set when the developing unit 1 is set at a predetermined position (fourth
(A1> a).

The reason why such an effect is obtained is as follows. That is, as can be seen from FIG. 4, when the developing unit 1 is set,
The peripheral surface of the rear end wall 8 of the unit 1 and the auxiliary rollers 207,
The interval with 208 is smaller in the former than in the latter. For this reason, the unit carrier 200 is started to be pulled toward the front side, and the positioning pin 78 thereof comes out of the bearing 227 and the developing unit 1
When the rear side of the unit 1 is lowered by its own weight, the peripheral surface of the rear side end wall 8 of the unit 1 first comes into contact with one auxiliary roller 207 during the lowering, whereby the developing unit 1 moves to H Then, the peripheral surface of the end wall 8 finally comes into contact with the other auxiliary roller 208 to complete the rotation.

In this way, the auxiliary rollers 207, 208 supported by the unit carrier 200 start pulling the unit carrier 200 carrying the developing unit 1 toward the front side of the copying machine main body 201, and the positioning pin 78 causes the back side plate. When it is disengaged from the second bearing 227, the back side portion of the developing unit 1 is moved in a direction away from the photoconductor drum 11 to receive it.

The above operation is performed in a state in which the guide pin 223 of the unit carrier 200 is fitted in the first portion 222a (FIG. 5) located closest to the photosensitive drum 11 in the guide groove 222.
At this time, the guide pin 221 of the guide member 220 is fitted into the first portion 224a in the guide groove 224 on the unit carrier side. As can be seen from FIG. 5, the first portions 222a and 224a of the guide grooves 222 and 224 are formed into the inclined second portions 2a and 2b, respectively.
22b, 224b, the third part 222c, 2 farthest from each other
Although it has moved to 24c, the developing unit 1 is supported by the supporting roller 76,
When the unit carrier 200 supported by the 77 and the auxiliary rollers 207, 208 is further pulled in the direction of arrow A, the guide pins 223, 2
21 moves to the third portion 222c, 2224c through the second portion 222b, 224b of each guide groove 222, 224, and is guided there.
Therefore, the unit carrier 200 is sequentially separated from the photoconductor drum 11 while carrying the developing unit 1, and the pins 22
When 3,221 reaches the third portion 222c, 224c, the developing unit 1
The photosensitive drum 11 and the photosensitive drum 11 are largely separated from each other as indicated by an interval a2 in FIG. 7 (c), and in this state, the unit 1 and its carrier 200 are pulled in the direction of arrow A (to be exact, the interval). a2
Is the distance between the back side of the developing unit 1 and the photoconductor drum 11).

As described above, the guide member 220 having the guide groove 222 and the guide pin 221, and the guide groove 224 and the guide pin 223 provided in the unit carrier 200 have the developing unit 1 whose back portion is separated from the photosensitive drum 11. Unit carrier to carry 20
When 0 is pulled further to the front side, the unit carrier 200
Guides the unit 200 in such a direction that it moves toward the front side, and constitutes guide means for guiding the unit carrier 200 and the developing unit 1 carried by the unit carrier in a direction further away from the photosensitive drum 11. .

As described above, the developing unit 1 is so arranged that the rear side thereof is separated from the photosensitive drum 11 by the distance a1.
As shown by a2, the developing unit 1 and the carrier 200 for the developing unit 1 are largely separated from each other so that the entire developing unit 1 is pulled out from the photosensitive drum 11 as a whole.
There is no fear of interfering with the peripheral surface of the and scratching it. In particular, in this example, a gear 240 to be described later is provided on the rear side of the developing unit 1.
(See Fig. 2 and Fig. 13)
If 240 interferes with the photoconductor drum 11, it will be seriously damaged. However, since the photoconductor drum 11 and the development unit 1 are separated as described above when the development unit 1 is pulled out, there is a risk of such interference. There is no. Also the developing roller 10
Since the developer is carried on the surface of the developing unit 1, the developer on the developing roller is scraped off by the photosensitive drum 11 if the unit 1 is pulled out while keeping the developing unit 1 and the photosensitive drum 11 at a minute gap a. There is a possibility that it will fall downwards or scatter and pollute the surroundings, but if the developing unit 1 is separated from the photoconductor drum 11 and pulled out as in the configuration shown in the figure, stains due to the developer also occur. do not do. Further, a drive gear (not shown) is provided on the inner side of the photosensitive drum 11.
Is provided, and gears (not shown) fixed to the shafts of the developing rollers 10, 10R, 10B are located on the rear side of the rear end wall 8 of the developing unit 1, as shown in FIG. Development unit 1
When is set, the gear of the developing roller at the developing position is engaged with the drive gear on the photoconductor side to drive the developing roller at the developing position. When the developing unit 1
Since it rotates in the direction and separates from the photosensitive drum 11, both gears that have been engaged until then are disengaged, and in this state the carrier
200 and development unit 1 can be pulled out smoothly.

When the unit carrier 200 carrying the developing unit 1 is further pulled out in the direction of arrow A, the guide pins 221 and 223 are disengaged from the guide grooves 224 and 222, and the carrier 200 is disengaged from the copying machine main body 201 while supporting the developing unit 1. Therefore, an operator can hold the developing unit 1 on the carrier 200 and grip the carrier 200 to mount it on a supporting surface such as a floor (see FIG. 10). That is, the operator can place the developing unit 1 in a predetermined place without directly touching it. Therefore, the developing roller 10, 3R, 3B developing roller 10,
Even if 10R and 10B carry the developer and are exposed on the outer peripheral surface of the unit 1, the work can be efficiently performed without soiling hands or clothes or dropping the developer. Since the developing unit 1 including a plurality of developing devices requires a large number of maintenance and inspection operations, it is very advantageous to perform this operation efficiently. Development unit 1
Do not place the unit directly on the floor or on a desk, etc.
Since the carrier 200 can be mounted via the carrier, the carrier 200 serves as a support for stabilizing and supporting the developing unit 1, and it is not necessary to prepare a special support.

Thus, when the unit carrier 200 is detached from the copying machine main body 201, it is supported on the supporting surface outside the main body 201 while carrying the developing unit 1.

Further, when the developing unit 1 is set in the main body of the copying machine (FIG. 4), the developing unit 1 is rotationally driven around its central axis O as necessary, so that in order to prevent interference with other elements, It is not appropriate to attach a handle to the developing unit 1. Therefore, if the developing unit itself is configured to be carried as a single unit as in the conventional case, the developing unit without a handle has to be gripped, resulting in very poor workability. However, in the configuration shown in the figure, since the carrier is carried while the developing unit 1 is supported by the unit carrier, the carrying operation can be performed easily.

Even after the developing unit 1 is detached from the copying machine main body 201 as described above and the unit carrier 200 is placed on the floor or the like, the unit 1 is rotatably supported on the unit carrier 200. It is possible to rotate the unit 1 and efficiently perform a predetermined work by directing the portion requiring repair or maintenance to the front of the worker. When the unit carrier 200 is placed in the posture shown in FIG. 10, the back side of the developing unit 1 is through the two auxiliary rollers 208 and 209, and the front side is the support roller 77.
And, it is rotatably supported by the carrier 200 via the auxiliary roller 206. Also, when the developing unit 1 is taken out of the main unit,
If the pressure roller 210 is brought into pressure contact with the developing unit and the developing unit 1 is supported by locking the roller, the developing unit 1 can be freely rotated on the unit carrier, but can be held in a state of being prevented from being detached. 1 is its carrier 20
You can easily carry it without worrying about going off. Since there are many types of developer colors (three or more) to be used, when it is not possible to store all of them in one developing unit, a spare developing unit should be prepared. If the developing unit 1 is held against the spare unit carrier 200 so as not to come off as described above and is stored, the management thereof is very easy. Moreover, the developing unit can be easily replaced.

Of course, it is also possible to release the pressure roller 210 if necessary, remove the developing unit 1 from the carrier 200, and carry this alone.

When the developing unit 1 is set in the main body of the copying machine after completing the predetermined work, the carrier 200 is lifted while the unit 1 is supported by the carrier 200, and the guide pins 221 and 223 are fitted into the guide grooves 224 and 222. It suffices to push the carrier 200 inward. At this time, the reverse operation is performed as described above, and the unit carrier 200 and the developing unit 1 supported by the unit carrier 200 can be smoothly set to the predetermined positions.

At that time, the guide pins 221, 223 are first fitted into the third portions 222c, 224C of the respective guide grooves 222, 224, and then the second portions 222b, 222b.
The first portions 222a and 224a are reached through 224b. During this operation, the entire developing unit 1 and the unit carrier 200 approach the photoconductor drum 11, and the back side of the developing unit 1 approaches the photoconductor drum 11 at a distance a2 to a1. Finally, the positioning pin 78 is fitted into the bearing 227, and the distance between the developing unit 1 and the photosensitive drum 11 becomes a minimum, and at this time, any one gear fixed to the shaft of each developing roller is on the photosensitive drum side. , And the reference pins 204, 205 are fitted in the mating holes 226a, 83a. In this way, first, the back side of the developing unit 1 is brought close to the photosensitive drum 11 to the position a1, and then the gears are engaged with each other as described above. The gears can be smoothly engaged with each other, as compared with the case where the engagement operation is performed. That is, first, the developing unit and its supporting member are brought closer to the photoconductor 11 to a relatively small distance, and then the positioning pin 78 is fitted into the bearing 227 and the back side of the developing unit 1 is gradually exposed. The gears are brought close to the body drum, and the gears are smoothly meshed with each other. As shown in FIG. 8, the bearing 227 has an inclined guide surface 228. Therefore, when the unit carrier 200 is pushed in, a positioning pin projecting on the rear side of the developing unit 1 is provided. The tapered portion of the tip of 78 is smoothly fitted to the bearing 227 while being guided by the guide surface 228. Since the guide member 220 having a simple shape is used instead of the expensive slide device for the purpose of sliding the unit carrier, the cost can be reduced.

Since the developing unit 1 can be attached / detached together with the unit carrier 200 as described above, the attaching / detaching work is not only easy, but also the supplementary inspection work and the like for the developing unit can be efficiently performed regardless of the work place. . Further, when the inside of the copying machine body is contaminated due to the scattering of the toner, the unit carrier 200 and the developing unit 1 can be easily removed and the cleaning operation can be easily performed when cleaning the body.

By the way, when the developing unit 1 and its carrier 200 are taken out of the main body of the copying machine and placed on the floor or the like, the unit carrier 200 may be directly placed on the floor or the like as described above. Particularly, as in the illustrated example, the developing unit 1 is integrally connected with elements such as toner replenishing devices 44, 44R, 44B,
If the entire outer diameter is larger than the outer diameter of the developing unit 1, if the unit carrier 200 is placed directly on a supporting surface such as a floor surface or a desk top, the stability is poor. Further, in particular, when the developing unit alone is directly placed on the supporting surface as in the conventional case, the stability is significantly impaired, the workability of the maintenance work is deteriorated, and if the developing unit is forcedly placed, the developing unit 1 The developer spills from the device, or a large bending stress is generated in the toner replenishing device and the connecting portion between this and the developing unit 1,
In some cases, these parts may be deformed or damaged. When the developing unit 1 is set in the copying machine main body 201, in order to make the storage space of the developing unit 1 as compact as possible and to increase the toner storage amount of the toner replenishing device, the outer diameter of the developing unit should be as small as possible, and conversely. Although it is advantageous to increase the outer diameter of the toner replenishing device, this causes the outer diameter of the toner replenishing device to be larger than the outer diameter of the developing unit 1, thus causing the above-mentioned problem. Therefore, in the illustrated embodiment, when the stand device 218 schematically shown in FIGS. 4 and 10 is attached to the unit carrier 200 in advance and the developing unit 1 and the carrier 200 are taken out of the copying machine main body. As clearly shown in FIG. 11, the developing unit 1 is supported by the unit carrier 200, and the carrier 200 can be supported by the supporting surface via the stand device 218.

The stand device 218 includes a mounting plate 241 fixed to the main body 202 of the unit carrier 200 as shown in FIGS. 12 (a) and 12 (b).
A support plate 246 pivotally attached to the attachment plate 241 via a shaft 247, and a support plate 244 pivotally attached to the tip of the support plate 246 via a pivot pin 245. A guide shaft 243 fixed to the other end of the plate 244 is provided with a long hole 24 formed in the mounting plate 241.
2 is slidably fitted.

When the developing unit 1 and the carrier 200 are accommodated in the main body 201 of the copying machine, the stand device 218 is folded as shown in FIG. 12 (a), and therefore, in the main body 201 as shown in FIG. The storage space of the stand device 218 can be kept small.

When the unit carrier 200 is taken out of the main body 201, if the support plate 246 is rotated around the shaft 247 as shown in FIG. 12 (b), the guide shaft 243 moves in the elongated hole 242 to the right in the drawing. To engage with the lock groove 242a formed at the end of the elongated hole 244, and the support plate 244 rises as shown. In this state, the support piece 244a at the tip of the support plate 244 is placed on the floor or the like as shown in FIG. At this time, the handle 213 attached to the unit carrier 200 is also placed on the floor, so that the carrier 200 supporting the developing unit 1 has the stand device 218 and the handle 21.
It is supported on the floor by 3, etc. The unit carrier can be configured to be supported on the support surface only by the stand device. However, if the stand device 218 and the handle 213 cooperate to support the unit carrier 200, the handle 213 is supported. The supporting member for supporting the body 200 is also used, so that it is possible to reduce the total number of parts, simplify the structure, and reduce the cost.

When the unit carrier 200 is placed as described above,
As shown in the figure, the carrier 200 is rotated by 90 ° from the state shown in FIG. 4, and the developing unit 1 has the auxiliary roller 20.
It is rotatably supported by the carrier 200 through 6,208,209 and the supporting roller 77. At this time, the carrier 200 is the stand device 2
Since it is supported by two supporting means of 18 and handle 213, it is supported in a stable state without being disturbed by the toner replenishing devices 44, 44R, 44B having a large outer diameter, and further, the developing unit, the toner replenishing device, and It is possible to securely hold the unit 1 and to easily perform the work without applying extra force to the connecting portion and preventing the developer from spilling. Therefore, the working time can be shortened and the maintenance cost of the copying machine can be reduced.
Further, the place where the developing unit is placed is not particularly limited, and the developing unit can be placed in virtually any place without polluting the surrounding area. Even when the preliminary developing unit is stored as described above, if the unit holder is supported by the stand device, it can be stored in a stable state.

By the way, if a two-component developer is used as the developer,
Since the carrier deteriorates with time, it is necessary to replace the developers 9, 9R, 9B in the developer chambers 4, 4R, 4B as needed. Further, in order to change the color of the developer in the developer chamber, the developer may be discharged. In such a case, it is necessary to replace the developer even when using the one-component developer. For this purpose, in the illustrated example, as shown in FIG.
In the part of the 202 where the stand device 218 is attached,
Agent case 217 for receiving the developer discharged from the developer chamber
Is set so that it can be attached and removed freely while being inserted from the back side of the carrier body. An agent recovery port 249 (see FIGS. 2 and 10) is formed through the portion of the carrier body 202 between the agent case 217 and the developing unit 1.

When the developer is to be replaced, the developing unit 1 and its carrier 200 are removed from the copying machine main body 201 as described above, and they are erected on the floor or the like as shown in FIG. At this time, the agent case 217 is located below the developing unit 1 with its upper opening facing upward. Therefore, the developing unit 1 is rotated to turn down the developing device 3, 3R or 3B in which the developer should be exchanged. For example, when the developer of the first developing device 3 is replaced, the developing roller 10 of the developing device 3 is brought to the bottom as shown in FIG. In this state, if the developing roller 10 is rotated, for example, manually or by connecting a driving device (not shown), the developer in the developer chamber 4 drops downward, and the developer case 217 passes through the recovery port 249. Will be recovered in. In this way, the developer chamber of the developing device, in which the developer should be replaced, is brought to the bottom to collect the developer, so that the developer in the developer chamber is hardly exhausted and is easily discharged in a short time. Can be made. In addition, the developer can be collected in any working place without polluting the surroundings, and the replacement work can be performed at any time when the replacement occurs randomly, thus reducing the maintenance cost of the copying machine. Is possible. When discharging the developer for the purpose of changing the color of the developer stored in the developing chamber, discharge the developer so that the remaining amount of the previously used developer is as small as possible, preferably completely. However, the configuration shown in the figure can substantially satisfy such a requirement. Further, particularly in the rotary developing device, there are a plurality of developing devices, and the replacement timing of the developer therein occurs randomly depending on the usage frequency of each developer, so that the total number of replacement of the developer increases. Therefore, it is very advantageous in actual use of the developing device that the developer replacement work can be performed easily and efficiently as described above.

After the developer is collected in the agent case 217, the case 217
As shown in the drawing, since it can be pulled out in the direction of arrow C, the used recovered developer can be easily discarded without polluting the surroundings. In addition, the service person does not need to carry a special case for collecting the agent, but only carry a new empty agent case to the user, or prepare an empty agent case for the user, and as described above. After collecting the developer, put a new developer case on the unit carrier 20.
Just plug it into 0.

The supply of new developer to the developer chamber can be performed using, for example, the toner replenishing devices 44, 44R, 44B described above.

By the way, while the developing unit 1 is set in the copying machine main body 201, the unit 1 can be rotated about its axis O to bring a desired developing device to the developing position and use it. The driving structure will be described below for understanding the present invention.

In FIGS. 13 and 14, the drive motor 230 is fixed to the back side plate 2 of the copying machine body, and the output gear 231 fixed to the output shaft thereof is the gear 233 of the clutch 232 supported by the back side plate 2.
Meshes with. The gear 233 is brought into contact with or separated from (on / off) the clutch shaft 234 of the clutch 232 via the clutch means.
To be done. A gear 237 fixed to the clutch shaft 234 meshes with an idle gear 238, and the idle gear is engaged with the above-described gear 240 fixed to the rear end surface of the developing unit 1. An arm 235 is swingably supported by the clutch shaft 234, and the idle gear 238 described above is rotatably supported by a shaft 239 provided on the arm 235. The arm 235 is biased in the clockwise direction in FIG. 14 around the clutch shaft 234 by a spring (not shown),
Therefore, normally, the idle gear 238 is the gear 2 of the developing unit 1.
Mesh with 40. The rotation center of the gear 240 is the developing unit 1
Coincides with the axis O of. With this configuration, the clutch
Turn the drive motor 230 to output gear 23
It can be transmitted to the gear 240 of the developing unit 1 via the first gear 233, 237 and the idle gear 238. Therefore, when replacing the developing devices 3, 3R, 3B to be used, the motor 230 is operated to turn on the clutch 232, the rotation of the motor 230 is transmitted to the developing unit 1, and this is rotated about its axis O. When the developing device to be used reaches the developing position, its rotation is stopped.

The developing unit 1 is rotated to bring the developing units 3, 3R and 3B to the developing position, and the developing units can be positioned as shown in FIG.
As shown in FIGS. 4 and 13, a cam 214 is fixed to the back side of the developing unit 1. The cam 214 has cam grooves 214a, 214b, and 214c (three in this example) in the same number as the number of developing devices on the outer circumference thereof. Further, as clearly shown in FIG. 4, a click arm 216 is rotatably supported by a click shaft 250 on the rear end surface of the main body 202 of the unit carrier 200, and the click roller 215 is attached to the tip of the arm 216. Is rotatably supported. The click arm 216 is given a turning tendency in the clockwise direction in FIG. 4 by a spring (not shown), whereby the click roller 215 presses against the outer peripheral surface of the cam 214 and engages with each cam groove 214a, 214b, 214c. can do.

As described above, the developing unit 1 is rotated to bring a desired developing device to the developing position, and when the developing roller reaches a predetermined position with respect to the photosensitive drum 1, the three cam grooves 21 are provided.
The click roller 215 engages with any one of 4a, 214b, and 214c to position the developing unit 1 at that position.

In FIGS. 13 and 14, the main body 2 of the unit carrier 200 is shown.
The 02 is integrally provided with a projection 219, while the arm 235 has an engaging piece 236 fixed thereto. Development unit 1
When it is set in the main body of the copying machine, the engaging piece 236 is positioned so as to cover the periphery of the protrusion 219 as is apparent from FIG. 13, but there is a slight gap between the two. , No interference.

As described above, when the unit carrier 200 starts to be pulled out to the front side (direction of arrow A), the protrusion 219 engages with the engagement piece 236 and pushes it in the direction of arrow J. Therefore, arm 23
As shown in FIG. 15, 5 rotates in the direction of arrow K about the clutch shaft 234, and the mesh between the idle gear 238 and the gear 240 of the developing unit is released. Therefore, the developing unit 1 can be rotated in the arrow H direction (see FIG. 9) and can be continuously moved in the arrow A direction without being disturbed by the idle gear 238.

The shaft 239 attached to the arm 235 is an arc-shaped long hole of the back side plate 2.
The shaft 239 is slidably fitted in the 239a, and when the arm 235 swings, the shaft 239 moves in the arc-shaped long hole 239a and restricts the motions of the shaft 239 and the arm 235. That is, when the developing unit 1 and its carrier 200 are pulled in the direction of arrow A, and the projection 219 passes through the engagement piece 236 and the engagement between them is released, the arm 235.
The shaft 239 and the shaft 239 rotate in the direction opposite to the arrow K by the above-mentioned spring, but when these are returned to the positions substantially shown in FIGS. 13 and 14, the shaft 239 has an end of the arc-shaped elongated hole 239a. The arm 235 and the shaft 239 stop there.

When the developing unit 1 and its carrier 200 are set, the reverse operation is performed, the protrusion 219 swings the arm 235 and the shaft 239 again in the direction of arrow K, and finally the idle gear 238 and the gear 2
40 can be smoothly meshed with each other.

In the configuration shown in FIG. 13, since the motor 230, the clutch 232, the arm 235, the idle gear 238, etc. are provided on the copying machine main body side, the weight of the unit carrier can be reduced, and therefore the attachment / detachment work can be performed. It can be performed with a small operating force.

The present invention can be widely applied to developing devices in image forming apparatuses such as printers other than copying machines.

Effects According to the present invention, since the unit carrier can be detached from or attached to the main body of the image forming apparatus while the developing unit is carried, the developer scatters when the developing unit is attached or detached, and the surrounding area is soiled. It is possible to suppress the inconvenience of contaminating a worker's hand or clothes with a developer. Also, when the developing unit is taken out of the main body of the image forming apparatus, this unit can be supported on the supporting surface of the main body of the image forming apparatus by the unit carrier, so a dedicated support base for supporting the developing unit is prepared in advance outside the main body. It is also possible to avoid the trouble of keeping. Further, when the developing unit is detached from the main body of the image forming apparatus, if the unit carrier starts to be pulled toward the front side, the back side portion of the developing unit separates from the latent image carrier,
When the unit support is further pulled toward the front side, the carrier and the developing unit carried on the unit support are further separated from the latent image carrier, so that the latent image carrier is not damaged and the developer is It is possible to pull out the developing unit and the unit carrier toward the front side while preventing the falling of the sheet.

[Brief description of drawings]

FIG. 1 is a vertical sectional view when the developing unit is set at a predetermined position in the copying machine main body, in which the copying machine main body is omitted and only the outline of the unit carrier is shown. FIG. 3 is a schematic perspective view showing the unit carrier detached from the main body of the copying machine and the developing unit separated from the unit carrier. FIG. 3 shows the developing unit and the unit carrier at a predetermined position in the main body of the copying machine. FIG. 4 is a front view of the apparatus when set, in which the main body of the copying machine and the toner replenishing device are omitted and the developing unit is simplified for the sake of clarity. FIG. 4 shows the front side plate of the unit carrier. FIG. 5 is a front view similar to FIG. 3 and FIG. 5 is a plan view of a guide member fixed to the main body of the copying machine, in which a guide groove and a guide pin provided on the unit carrier side are added by chain lines. Figure 6 and Figure 6 FIGS. 7 (a) and 7 (b) are schematic explanatory views of the state in which the developing unit and the unit carrier are set and the action when pulling them out, as seen from the left side of FIG. 1, FIG. ), (B), and (c) are schematic diagrams of the state seen from above in FIG. 1, showing a state in which the developing unit and the unit carrier are pulled out similarly to FIG. 6. Explanatory drawing, FIG. 8 is a cross-sectional view showing the relationship between the positioning pin and the bearing, and FIG. 9 is a view showing a state where the developing unit is rotated and separated from the photosensitive drum, and some elements are omitted. FIG. 10 is a sectional view showing a state in which a unit carrier carrying a developing unit is supported on the floor or the like via a stand device outside the copying machine main body, Similar to FIG. 9, some of the elements are omitted and shown in a simplified manner. Figure 11 is number 10
It is a side view showing the same state as the figure, omitting a part,
FIG. 12 (a) and FIG. 12 (b) are a simplified view, and FIG. 12 (a) and FIG. 12 (b) are views showing the folded state of the stand device and the situation when the stand device is in use, and FIG. 13 is a plan view showing the drive system of the developing unit. FIG. 14 is an explanatory view illustrating a state in which the idle gear is engaged with the gear of the developing unit, and FIG. 15 is a diagram in which the idle gear is disengaged from the gear of the developing unit. It is explanatory drawing which shows the state which was opened. 1 ... Developing unit, 2 ... Back side plate 3,3R, 3B ... Developing device, 78 ... Positioning pin 200 ... Unit carrier, 201 ... Main body 227 ... Bearing, O ... Central axis

Claims (1)

[Scope of utility model registration request] 1. A plurality of developing devices integrally incorporated,
In addition, the image forming apparatus main body is rotatably supported about its central axis, and its rotation brings a predetermined developing device to a developing position facing the latent image carrier, and the developing device causes the latent image carrier to rotate. A developing unit that visualizes the electrostatic latent image formed on the image carrier, and a unit that supports the unit and is detachably supported by the main body of the image forming apparatus while the developing unit is supported.
And a unit carrier that is supported on a supporting surface outside the main body while holding the developing unit when it is detached from the main body of the image forming apparatus; A unit carrying a developing unit and a positioning pin rotatably supported by a bearing on the back side plate of the image forming apparatus main body when the developing unit is set on a line and is set at a predetermined position in the image forming apparatus main body. When the carrier is started to be pulled toward the front side of the image forming apparatus main body and the positioning pin comes off the bearing of the rear side plate, the rear side portion of the developing unit is moved in a direction away from the latent image carrier. When the unit carrier for holding the developing unit whose back side is separated from the latent image carrier is pulled further to the front side, the unit carrier will An image forming device that guides the unit carrier in a direction to move to the side, and includes a guide unit that guides the unit carrier and the developing unit carried by the unit carrier in a direction further away from the latent image carrier. Development device in the device.