JPH0196668A - Multicolor developing device - Google Patents

Abstract

PURPOSE:To simplify a positioning means and to replace a developing device smoothly by setting an engagement part in the opposite energizing direction of an energizing force to a lock part from the rotating direction of a rotary body. CONSTITUTION:Hollows 1Y, 1M, and 1C which become engagement parts for positioning are formed in the outer peripheral surface of the rotary body 1 outside a gear 1 corresponding to three developing devices 9Y, 9M, and 9C. A device main body, on the other hand, is provided with a positioning claw 5 as the lock part which is provided in a free rotating and displacing state around a fulcrum 5a and engages and disengages selectively from one of the hollows 1Y, 1M, and 1C. This positioning claw 5 is energized by a spring 6 as an energizing means as shown by an arrow A. Namely, the tip of the positioning claw 5 is so energized as to engage one of the hollows 1Y, 1M, and 1C on the rotary body 1. Consequently, the positioning means is simplified and developing device replaced is performed smoothly in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a so-called revolver type multicolor developing device for a color copying machine or a laser printer, etc., which is equipped with a plurality of developing devices.

PRIOR ART Conventionally, in this type of revolver type multicolor developing device, the rotating body has yellow Y, magenta M, cyan C, and black B.
The developing devices are sequentially arranged in the rotational direction, and these developing devices are sequentially positioned and stopped at developing positions facing the photoreceptor, and development with toner of each color is repeated. In other words, in this type of developing device, it is necessary to rotate the rotating body to reliably position and stop the desired developing device at the developing position. In this regard, in the past, it was necessary to stop the rotating body at a precise position and to smoothly latching the rotating body to rotate the rotating body again after the electrostatic latent image on the photoreceptor was developed by each developing device. There is. For this reason, in the conventional rotary body, a cam plate is disposed on the rotary body, and clutching is performed by engaging or disengaging a locking body on the apparatus main body side with an engaging portion provided on the cam plate. However, when using such a method, the engagement between the engaging part and the locking body may deteriorate due to the action of rotational moment when transmitting drive from the outside to the rotating body, or due to deformation of the engaging part due to long-term use of the rotating body. During this time, a force is generated that prevents the locking body from disengaging, and the copying sequence is often interrupted without the locking body being released from the engagement portion.

In this regard, there is an improved method as disclosed in, for example, Japanese Unexamined Patent Publication No. 61-77873. First, a developing device drive motor is installed in the apparatus main body, and a gear is provided on the output shaft of this drive motor via a one-way clutch. On the other hand, Y
, M, C, and B are each provided with a developing device driving gear, and these driving gears mesh with the gear on the drive motor side at the developing position of each developing device based on the rotation of the rotating body. Configure it as follows. Furthermore, the drive motor rotates and stops, and is controlled by a forward/reverse rotation command signal from the control unit, so that it rotates in the normal direction during development by each developing unit, and further rotates the rotating body by the rotating body drive motor after development. Reverse it before. Furthermore, along with or in place of the reverse rotation of the drive motor, the rotating body drive motor is temporarily reversed, and then the rotating body is rotated in the normal direction.

With this configuration, the rotating body rotates and each developing device is stopped at the developing position by engagement between the engaging portion and the locking body, and at the same time, the developing device drive gear disposed in each developing device is rotated. and a gear attached to the output shaft of a developing device drive motor installed in the main body of the apparatus are engaged by the free action of the one-way clutch, and each developing device is driven to perform development. After the development is completed and before the rotating body rotates, the developing unit drive motor is driven in the reverse direction by a reverse rotation command signal from the control unit, and when the driving force is transmitted from the developing unit driving motor to the rotating body, the developing unit driving motor is driven in the reverse direction. The force that prevents the engagement part and the locking body from disengaging due to the action of rotational moment is removed, and by temporarily reversing the rotor drive motor, the engagement part is prevented from deforming due to long-term use. The joining part and the locking body can be easily separated.

However, in the case of such a conventional method, the control for frequently rotating the developing device drive motor in forward and reverse directions is complicated, and if the rotating body drive motor is also temporarily reversed, a means for doing so is required, and the control is difficult. It becomes increasingly complex. Also, as a result of this configuration, unnecessary operations will increase,
The time required to replace the developing device also becomes longer.

Purpose The present invention has been made in view of the above points, and it is possible to easily position each developing device to stop it at a predetermined position and to release the release thereof, thereby making it possible to replace the developing device smoothly and in a short time. The purpose is to obtain a multicolor developing device.

Structure In order to achieve the above object, the present invention has a method in which a plurality of developing devices are sequentially mounted in the rotational direction of a rotating body, and a locking portion provided on the apparatus main body side is engaged with an engaging portion provided for each developing device. In the multi-color developing device, in which each developing device is stopped at a developing position, the biasing direction of a driving force that applies a biasing force to the locking portion on the engaging portion is set to the rotation direction of the rotating body. It is characterized by being set in the opposite direction.

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 shows a schematic configuration of a part of a revolver type multicolor developing device that uses three colors, Y, M, and C. First, a rotating body 1 is provided, which is rotatably supported by the main body of the apparatus about a fulcrum 1a provided at the center of the end. A gear 1b is formed on the circumferential surface of one end of the rotating body 1, and this gear 1b is connected to a gear 2.
Drive gear 4a of developing unit drive motor 4 via 3a and 3b.
is connected to. Thereby, the rotating body 1 is configured to be rotationally driven by the developing section drive motor 4 in a clockwise direction (in the direction of the arrow in FIG. 2).

On the other hand, within the rotating body 1, three developing devices for Y, M, and C are arranged in three parts in order in the rotational direction.

Each of the developing units has a rotatable developing sleeve that protrudes a predetermined amount from an opening on the outer circumferential surface of the rotating body 1 and faces the photoreceptor when positioned at the developing position.

Recesses "V'+ IMt lc, which serve as engagement portions for positioning each of the three developing devices, are formed at predetermined positions on the outer circumferential surface of the rotating body 1 outside the gear 1.

On the other hand, a positioning pawl 5 is provided as a locking portion which is rotatably displaceable about a fulcrum 5 with respect to the main body of the device and selectively engages and disengages from any one of the recesses IY+IMt tc. ing. This positioning pawl 5 is biased in the direction of arrow A by a spring 6 as biasing means.

That is, considering the tip of the positioning claw 5, the tip of the positioning claw 5 can be placed in any of the recesses lY, IM,
It is biased in the direction of engagement with tc. Here, the shape of these recesses 'VT IMI lc is such that, in relation to the positioning pawl 5, the rotational direction of the rotary body 1 is in the direction in which the rotation direction of the rotary body 1 is disengaged, that is, as the rotary body 1 rotates, the positioning pawl 5 gradually moves. The shape is such that it has a detaching inclined surface and an engaging vertical surface so as to be in a detachable state. A fish 7 is also integrally attached to the positioning claw 5. That is, the second fissure 7 protrudes from the fulcrum 5a on the opposite side of the positioning claw 5, but rotates by the same amount in conjunction with the positioning claw 5, for example, inside the photo-interrupter type sensor 8. The positioning claw 5 moves in and out to detect the state of the positioning claw 5. As a result, the depression I
By sequentially engaging the tips 5b of the positioning claws 5 with Y, LM, and IC, the three developing units 9Y, -9M,
9c can be positioned and stopped at a predetermined developing position.

Further, sleeve drive gears IOY and IOM for each developing sleeve are provided at the end of each developing device.

10c is provided on each shaft with a one-way clutch 11 built therein. These sleeve drive gears 10y, Low, and 10c are arranged on the same circumference, and when any of the developing units 9Y, 9M, and 9c is positioned and stopped at the developing position, the corresponding sleeve drive gear IO
A gear 12 that meshes with Y, IOM, and 10c is provided at a predetermined position on the device main body side. This gear 12 is driven by a sleeve drive motor 13.

In such a configuration, FIGS. 2 to 5 show the situation when, for example, the developing device 9c is replaced with the developing device 9Y.

First, FIG. 2 shows the same state as FIG. 1, in which the positioning pawl 5 is engaged with the cyan recess 1c, and the gear 12 is in mesh with the sleeve drive gear lOc. Therefore, when developing with cyan C, the sleeve drive motor 1
3 rotates the gear 12 and rotates the sleeve drive gear 10c in the direction of arrow B in FIG. Here, gear 10c
The rotation in the direction of arrow B is the drive transmission direction for the one-way clutch 11, rotates the developing sleeve on the curved shaft, and executes the cyan developing operation.

On the other hand, when the sleeve drive gear 10c rotates in the direction opposite to the direction of arrow B, the one-way clutch 11 is in a free state, and no power is transmitted to the developing sleeve. In other words,
The developing sleeve is prevented from rotating in the reverse direction when the sleeve drive motor 13 rotates in reverse or when the revolver-type rotating body 1 rotates (in the direction of the arrow).

Incidentally, the developing sleeve is driven in the direction of arrow B by the sleeve drive motor 13, but at this time, a force is generated that attempts to rotate the entire rotating body l in the direction of arrow C.

As a result, a force F is applied to the positioning claw 5 through the depression lc.
is added in the direction of the arrow.

This acts in a locking direction to prevent the positioning claw 5 from leaving the recess 1c. In this embodiment, since the rotational movement direction of the rotating body 1 is in the direction indicated by the arrow, and the force is in a direction that opposes the force F, no consideration is required for the force F. Further, as the rotational movement of the rotating body l progresses in the direction of the arrow, the positioning pawl 5 becomes depressed 1c as shown in FIG.
According to the shape, it will naturally separate and ride on the outer peripheral surface. Therefore, unlike conventional solenoids, there is no need for a driving source for disengagement.

Next, the developer replacement operation will be explained. First, when the development with cyan C is completed in the state shown in FIG. 2, the rotating body 1 is rotated in the direction indicated by the arrow by the developing unit drive motor 4 in order to replace it with the next developing unit 10Y. At this time, the fish 7 attached to the first positioning claw 5 is positioned above the sensor 8 as shown in FIG. 2, so the sensor 8 is in an OFF state. In other words, it is detected that the positioning claw 5 is engaged with any of the recesses. Also, during the rotational movement of the rotating body l, the gear 12 is moved to the third position by the sleeve drive motor 13.
If the rotating body 1 is rotated in the direction of arrow E in the figure, the rotational movement of the rotating body 1 will proceed smoothly. To prevent the developing sleeve from reversing at this time, the one-way clutch 1 on the shaft of the sleeve drive gear 10c
Do this according to step 1.

FIG. 3 shows the state immediately after the rotational movement of the rotating body 1 has started, and the positioning pawl 5 is gradually coming off in accordance with the shape of the depression lc.

FIG. 4 shows a state immediately before the rotation of the rotating body 1 further advances and the next depression IY reaches the positioning claw 5. The positioning claw 5 has its tip 5b pressed against the outer circumferential surface of the rotating body 1 by the biasing force of a spring 6.

At this time, the fish 7 moves downward and cuts off the sensor 8, so the output of the sensor 8 is in an on state.

Further, in the state shown in FIG. 4, the gear 12 and the sleeve drive gear IOY begin to contact each other, but the gear 12 is rotated in the direction of arrow E by the sleeve drive motor 13, and the sleeve drive gear IOY is rotated by the one-way clutch 11. Due to the free action of gear 12. IOY meshes smoothly.

In the state shown in FIG. 5, the recess IY reaches the positioning pawl 5, and the biasing force of the spring 6 causes the tip 5b to fall into engagement with the recess IY from the outer peripheral surface. At this time, the fish 7 is displaced upward from the sensor 8 in conjunction with the operation of the positioning claw 5, and the output of the sensor 8 is switched to the OFF state. The control section uses such a change in the output of the sensor 8 as a completion signal for replacing the developer, and stops the rotation of the developer drive motor 4 and the sleeve drive motor 13.

At this time, generally, due to the inertia of the rotating body 1, the overhead of the CPU, etc., the rotating body 1 rotates beyond the predetermined stop position as shown in FIG. 5, and it is difficult to return the rotating body 1 to the predetermined position. Is required. As a means for this, after stopping the rotation of the developing unit drive motor 4 and the sleeve drive motor 13 at the end of the developer exchange, one or both motors are temporarily rotated in the opposite direction. , rotate the rotating body l in the direction of arrow C in FIG.
There is a way to make it work. At this time, the sleeve drive motor 1
3 in the direction of arrow G in FIG. 5, it may also be used to rotate the sleeve drive motor 13 to drive the sleeve during the next development. As can be seen from the flowchart of the control system shown, $tlJ control becomes extremely simple.

As described above, in this embodiment, when the rotational movement direction of the rotating body 1 is the direction indicated by the arrow, any one of the depressions 'V*'
A sleeve drive motor 13, a gear 12,
Any one sleeve drive gear toy, to,,,to
The transmission route e is used, and the biasing direction of the driving force is set in the direction of arrow C, that is, in the opposite direction to the direction of arrow C. As for the specific movement, the depression 'Y+
When rotating the rotating body 1 in the opposite direction to the direction of the driving force that applies the urging force to the IMI 10, the driving force that applies the urging force to the depression "Y+ 'M+ lc" is actually reversed. be.

Effects Since the present invention is constructed as described above, it is possible to position and stop the rotating body without the need for a means for removing the biasing force acting on the engaging portion, simplifying the positioning means and simplifying the control system. As a result, the developer can be replaced smoothly.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a schematic perspective view, FIGS. 2 to 5 are side views showing the developer exchange operation, and FIG. 6 is a schematic flow chart of the control system. 1... Rotating body, 'Vr lxt lc... Recess (engaging part), 5... Positioning claw (locking body), 9Y,
9M, 9c...Developer, 13...Sleeve drive motor 3''

Claims (1)

[Claims] A plurality of developing devices are installed in order in the rotational direction of the rotating body, and a locking portion provided on the main body of the apparatus is engaged with an engaging portion provided for each developing device to stop each developing device at the developing position. In the multicolor developing device according to the present invention, the biasing direction of the driving force that applies the biasing force to the locking portion on the engaging portion is set in the opposite direction to the rotating direction of the rotating body. A multicolor developing device.