JPH0638175B2 - Rotary developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary developing device in which a plurality of developing devices are mounted on a rotating body and a selected developing device is moved to a developing position to perform a developing operation. In particular, the present invention is characterized by a rotating body driving device for a rotating body that mounts a developing device and rotationally moves the developing device.

2. Description of the Related Art In recent years, various developing devices have been proposed with the development of color electrophotographic image forming apparatuses. For example, in recent color printers, the size of the developed object is reduced, and the size of the entire apparatus is reduced. In order to realize the development, a rotary developing device has been proposed, in which a plurality of developing devices (developing units) are mounted on a rotating body, and the selected developing device is moved to a predetermined developing operation position to develop the developed object. Has been converted.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a developing device, a rotational direction for restricting the movement of the developer in each developing device to a predetermined movement state at the time of rotational movement is specified and rotational movement is performed only in that direction. Is customary.
However, at the time of maintenance and inspection, the operator may manually rotate in the direction opposite to the specified direction, which causes the developer in each developing device to move in an inconvenient state, resulting in the developer from each developing device being moved. Inconveniences such as scattering and changes in the developing characteristics of each developing device occur.

In order to prevent this, the present inventor has a shaft and a ring body fitted to the shaft in the rotation driving force transmission path, and provides a tapered recess on the inner surface of the ring body, Put a sphere in this recess and allow rotation of the annulus in one direction, but prevent rotation in the opposite direction by placing a one-way clutch that prevents the sphere from biting into the shaft and annulus. , Tried to prevent the reverse rotation of the rotating body equipped with a plurality of developing devices.

However, in the above one-way clutch,
Since the amount of play in the lock direction of the annulus is small with respect to the fixed shaft arranged in the rotating body drive transmission path, it has a large inertial force of the rotating body generated when the rotating body equipped with a plurality of developing devices is stopped. The rotational vibration may cause an impulsive locking phenomenon in the clutch portion, which may cause problems such as damage to the gear portion and tilting of the shaft. Also, the impact may cause loosening of screws in the device, which may adversely affect the interlocking of the mechanical parts. Such a problem is not preferable in that maintenance service is frequently required and a good image is obtained.

Therefore, an object of the present invention is to prevent reverse rotation of a rotating body equipped with a plurality of developing devices, prevent the occurrence of the inconvenience in the blocking mechanism, eliminate mechanical failure, and reduce the frequency of maintenance service. It is an object of the present invention to provide a rotary developing device which can reduce the number of images and can obtain good images.

Means for Solving the Problems The above object is achieved by the rotary developing apparatus according to the present invention. In summary, the present invention relates to a rotary developing device in which a plurality of developing devices are mounted on a rotating body, and the developing devices selected by rotating the rotating bodies are moved to a developing position to perform a developing operation. A first transmission gear that transmits the rotational drive force of the drive motor, and a second transmission gear that meshes with the first transmission gear and rotates by receiving the rotational drive force to rotate the rotating body. A fixed shaft arranged on the same axis as the shaft portion of the second transmission gear, and a coil spring, a part of which is fitted to the fixed shaft and one end of which is fixed to the fixed shaft, and A portion is fitted to the shaft portion of the second transmission gear to allow the second transmission gear to rotate in the coil loosening direction, but to fix the second transmission gear in the coil tightening direction. As the shaft is fixed, it cannot rotate. That includes a coil spring, a rotary developing apparatus wherein a rotating only the rotating body to a method for loosening the coil spring.

Next, the rotary developing device according to the present invention will be described in more detail with reference to the drawings.

FIG. 3 is a sectional view of the essential parts of a color electrophotographic copying machine for forming a full-color copied image to which the present invention can be applied.
In this embodiment, the photosensitive drum 1, which is a latent image carrier, rotates in the direction of the arrow. A charger 2, an exposure optical system 3, a developing device 4, a transfer system 5, and a cleaning device 6 are arranged around the photosensitive drum 1. The optical system 3 includes a document scanning unit 3
a and a color separation filter section 3b.

Further, in the developing device 4 according to the present invention, the central shaft 4 is used in this embodiment.
A yellow developing device 4Y that uses yellow toner, a magenta developing device 4M that uses magenta toner, and a magenta developing device 4 that uses cyan toner for a rotating body 4a that rotates around b.
C and a black developing device 4B using black toner are integrally mounted. As disclosed in Japanese Patent Publication No. 55-20579 by the applicant of the present invention, each developing device prevents the toner from scattering by the action of a magnetic field, is detachably held by the rotating body 4a, and rotates about the central axis 4b. The selected developing device is moved to the developing position. In addition, the rotary developing device is configured to be rotatable only in the direction of the arrow shown in FIG. 1 in order to regulate the movement of the developer in each developing device and from the operational safety.

On the other hand, the transfer system 5 has a gripper 5a and has a transfer drum 5b.
And a transfer discharger 5c is provided inside the drum 5b.

In the above structure, a copy of a full-color image is produced by sequentially transferring color toners onto a transfer material supported on the transfer drum 5b, as in a conventional copying machine. This transfer material is supplied from the cassette 7, and the transfer material that has completed the transfer process is separated by the separating means 8 and reaches the tray 10 via the fixing device 9c.

1 and 2 show the drive mechanism of the rotary developing device according to the present invention described above. In the present embodiment, the rotary body gear 40 is integrally attached to the rotary body 4a of the rotary developing device on the back side of the rotary body. A driving force is transmitted from the driving means 50 to the rotary body gear 40.

The driving means 50, as shown in FIG.
1, 52, and the drive motor M is attached to the side plate 51. The driving force of the drive motor M is applied from the output gear 53 to a one-way clutch 6 via a reduction gear 55 rotatably attached to a shaft 54 fixed to the side plates 51 and 52.
Transmitted to 0.

The one-way clutch 60 includes a shaft 61 attached to the side plates 51 and 52, a drum 63 fixed to the shaft 61 with a screw 62, and a transmission gear 65 rotatably attached to the shaft 61 via a bearing 64. And. Also, the transmission gear 65
Has a shaft portion 65a arranged on the same axis as the shaft portion 63a of the drum 63, and a coil spring 66 is fitted to the shaft portion 63a of the drum 63 and the shaft portion 65a of the transmission gear 65. More specifically, a part of the coil spring 66 is fitted to the shaft 63a of the drum 63 and one end of the coil is fixed to the shaft 63a of the drum 63, and the remaining part of the coil spring is the same as that of the transmission gear. The shaft portion 65a is fitted while giving an appropriate tightening force, so that the transmission gear 65 can be rotated in the loosening direction of the coil 66 and cannot be rotated in the opposite direction by the tightening force of the coil spring 66. It is said that

The transmission gear 65 meshes with the rotating body gear 40, which allows the rotating body to rotate only in one direction, but does not allow the rotating body to rotate in the opposite direction. Can be prevented. Further, even when the operator manually rotates the rotating body, the rotating direction is not mistaken.

As described above, since the one-way restricting means including the transmission gear 65, the drum 63, and the coil spring 66 uses a spring, the spring deformation amount in the rotatable direction and the spring deformation in the non-rotatable direction. There is a region (play portion) where the transmission gear 65 can freely rotate in both directions depending on the amount. This range is based on the specifications of the spring (spring constant) and the idler gear 65.
It can be arbitrarily set by appropriately selecting the fitting state of the spring and the spring. Therefore, the damping vibration of the rotating body 4a becomes possible within the range in which the coil spring 66 can rotate in both directions, and the shock when the rotating body is stopped is absorbed.

Therefore, collisions between the gears at the time of stopping are prevented, and problems such as gear damage and shaft tilt can be solved.

EFFECTS OF THE INVENTION Since the rotary developing device according to the present invention is configured as described above, the rotary member can be suitably driven in one direction and rotation in the reverse direction is prevented, so that the development in each developing device is prevented. The agent can be prevented from constantly flowing and scattering and changing the development characteristics, and can absorb the shock when the rotating body is driven within the allowable displacement (play) of the spring built in the one-way clutch. It is possible to eliminate mechanical failure, reduce the frequency of maintenance service, and obtain good quality images.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a driving end portion of a rotary developing device according to the present invention. FIG. 2 is a sectional view of the driving means. FIG. 3 is a sectional view of a color electrophotographic copying machine to which the apparatus shown in FIG. 1 is applied. 40: Rotating body gear 50: Driving means 60: One-way clutch 63: Drum 63a: Drum shaft portion 65: Transmission gear 65a: Transmission gear shaft portion 66: Spring

Claims (1)

[Claims] 1. A rotary developing device in which a plurality of developing devices are mounted on a rotating body, and by rotating the rotating bodies, the selected developing device is moved to a developing position to perform a developing operation, a drive motor and a driving motor. A first transmission gear that transmits the rotational driving force of the drive motor, a second transmission gear that meshes with the first transmission gear and that rotates by receiving the rotational driving force to rotate the rotating body; A drum, which is arranged on the same axis as the shaft of the second transmission gear and is fixed in rotation, and a coil spring, a part of which is fitted to the shaft of the drum and one end of which is fixed to the drum. The remaining portion is fitted to the shaft portion of the second transmission gear so that the second transmission gear can rotate in the loosening direction of the coil.
And a coil spring for fixing the second transmission gear to the drum so that it cannot rotate in the coil tightening direction, and rotating the rotating body only in a direction for loosening the coil spring. Developing device.