JPH02287577A - electrophotographic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic apparatus, such as a laser printer, a copying machine, or a facsimile machine, which performs recording on paper using an electrophotographic process.

Conventionally, in this type of apparatus, for example, the developing device is operated by a pressure spring 3 disposed between the image forming case 1 and the developing device 1!2 in the device main body, as shown in FIG. The entire developing device 2 is urged toward the photoreceptor 4, and the developing roller 5 is pressed against the surface of the photoreceptor 4. Then, the rotation of a drive motor (not shown) inside the device body is transmitted to the input shaft via a gear to create a developing bag! ! ! 2 is driven, toner is applied to the photoreceptor 4, and the electrostatic latent image on the surface of the photoreceptor is visualized.

Problems to be Solved by the Invention However, in the past, the rotation of the drive motor was transmitted to the input shaft of the developing device through gears, so the vibrations generated by the meshing of the gears caused the entire developing device to vibrate, and the developing roller was uniformly rotated. It is difficult to bring the photoreceptor into contact with the photoreceptor, which causes the problem of image defects.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent vibrations transmitted to the developing device and to uniformly contact the photoreceptor and the developing roller to prevent image chipping.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention transmits the rotation of a drive motor to an input shaft to drive a developing device, and
In an electrophotographic device that records on paper using an electrophotographic process of charging, writing, exposing, developing, transferring, and cleaning, the drive shaft of the drive motor and the input shaft of the developing device are connected via an Oldham joint. It is characterized by

Therefore, the rotation of the drive motor is caused by the Oldham joint.
It is transmitted as is to the input shaft of the developing device.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 schematically shows the entire internal structure of a laser printer to which the present invention is applied. In the figure, reference numeral 10 is a printer main body, and 11 and 11 are paper feed cassettes provided in the printer main body 10. The paper 50 fed from one of the paper feed cassettes 11 in the direction of arrow A is transported to a pair of registration rollers 12.
The photoreceptor is transported to the drum-shaped photoreceptor 13 at the appropriate timing. The photoconductor 13 is driven to rotate in a clockwise direction, the surface of which is uniformly charged by the charging charger 14, and the photoconductor 1 is irradiated with laser light from a laser optical system 15.
An electrostatic latent image is formed on 3. This latent image is visualized by toner when passing through the developing device 16, this visible image is transferred to the paper 50 conveyed to the photoreceptor 13 by the transfer charger 17, and the visible image on the transferred paper 5o is visualized by the fixing device. Fixed by 18. Then, the paper 50 exiting the fixing device 18
For example, the paper is discharged to the paper discharge portions 19, 19 in the direction of the arrow. On the other hand, the cleaning device 20 removes residual toner from the photoreceptor 13 after the visible image has been transferred.

In the present invention, the drive motor 22 and the developing device 16 are connected via an Oldham joint 23, as shown in FIG.

The drive motor 22 is installed inside the printer body 10, and a motor gear 24a is fixed to a motor shaft 24.

The developing device 116 is provided with an input shaft 25 that protrudes outside the device.

The Oldham joint 23 is connected to the drive side disk 2 as shown in FIG.
7, an intermediate disk 28, and a driven side disk 29.

A gear portion 27a is provided on the outer periphery of one side of the drive-side disc 27, and a linear protrusion 27b passing through the rotation center 0 is provided on the other side.
A linear groove 28a is formed on one surface of the intermediate disc 28 to slidably engage with the linear protrusion 27b. The other surface of the intermediate disk 28 is provided with a straight groove 28b orthogonal to the straight groove 28a. A linear protrusion 29a that slidably engages with the linear groove 28b is provided on one surface of the driven disk 29. The linear protrusion 29 passes through the rotation center 0' of the driven disk 29.

The above-described Oldham joint 23 fixes the driven disk 29 to the input shaft 25 of the developing device M16, as shown in FIG. Outside the driven side disk 29, an intermediate disk 28 and a driving side disk 27 are arranged in that order, and the linear groove 28a and the linear protrusion 27b are engaged with each other so that the joint shaft 3
Attach to 0. The joint shaft 30 is attached to the frame 31 inside the printer body 10 as a developing device! It is provided so as to protrude toward the 16 side.

One end of the spring 32 is pressed against the frame 31, and the other end is pressed against the drive side disc 27. The spring 32 biases the drive side disk 27 and the intermediate disk 28 toward the developing device M16, and the gear portion 27a of the drive side disk 27
meshes with the motor gear 24a.

Then, the developing device [116 is installed in the printer main body 10, and the linear protrusion 29a of the driven-side disk 29 is engaged with the linear groove 28b of the intermediate disk 28, thereby forming the developing device!
16 is connected to the drive motor 22 via an Oldham joint 23.

Therefore, when the drive motor 22 is rotationally driven, the motor gear 24a and the gear portion 27a are engaged with each other, and the drive motor 22 is rotated.
2 to the drive-side disk 27, and also
7b and the linear groove 28a mesh to transmit the rotation of the drive side disk 27 to the intermediate disk 28, and further, the linear groove 28b and the linear protrusion 29a mesh to sequentially transmit the rotation of the intermediate disk 27 to the driven side disk 29. Then, the developing device 16 is rotationally driven.

In the above embodiment, the Oldham joint 23 has the straight groove 28a.
28b and the linear protrusions 27b and 29a are configured to be directly slidably engaged, but they may be configured to be slidably engaged via a bearing as shown in FIG.

In that case, recesses 34 are provided on the side surfaces of the straight grooves 28a and 28b of the intermediate disk 28 to face each other, and a bearing 35 is accommodated in the recess 34 and supported by a shaft 36. The bearings 35 are arranged in pairs on the left and right with the straight grooves 28a and 28b sandwiched between them, and the outer periphery of the bearings slightly protrudes into the straight grooves 28a and 28b.

As a result, the straight grooves 28a and 28b have the straight protrusions 27b and 28b.
When 29a engages, it contacts the bearing 35, so
The function of the Oldham joint 23 becomes smooth.

From the above, according to the present invention, the drive shaft of the drive motor and the input shaft of the developing device are connected via the Oldham joint, so that the rotation of the drive motor is directly transmitted to the developing device. The developing device can be rotated without vibration, the developing roller can be stably pressed against the photoreceptor, and image chipping can be prevented.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention, in which Figure 1 is a schematic configuration diagram of connecting a drive motor and a developing device with an Oldham joint, Figure 2 is a perspective view of the Oldham joint, and Figure 3 is a 1 is a schematic diagram of the entire internal mechanism of a laser printer to which the present invention is applied; FIG. FIG. 4 shows another embodiment of the Oldham joint used in the present invention, and FIG. 4 (1) is a side view of its intermediate disk. FIG. 4(2) is a side view of the straight groove side. FIG. 5 shows a conventional example, and is a schematic diagram of a photoreceptor and a developing device. 10...Printer body 14...Photoreceptor 16...Developing device 22...Drive motor 23. ...... Oldham joint 25 ...... Input shaft of developing device 27 ...
... Drive side disk 28 ...... Intermediate disk 29 ... Driven side disk Figure 1 Figure 3 Old 20 +3 17 Figure 4

Claims (1)

[Claims] In an electrophotographic apparatus that transmits the rotation of a drive motor to an input shaft to drive a developing device and records on paper using electrophotographic processes such as charging, writing, development, transfer, and cleaning, the drive shaft of the drive motor and An electrophotographic apparatus, wherein the input shaft of the developing device is connected via an Oldham joint.