JPS6021070A - Developing device - Google Patents

Abstract

PURPOSE:To remove a stain due to a toner particle and to open a cover automatically at time of mounting requiring no specific work by covering the exposed part of a developing roll automatically with a cover when the developing device is removed from an electrophotographic copying machine body. CONSTITUTION:When the developing device body 21 is removed from the copying machine body, the cover 31 is energized in a clockwise direction by the force of a coil spring 38 and a retain piece 35 for the cover 31 is abutted on the retain piece 26 of the device body 21. Namely, the blocks 31 closes the opening 25 of the device body 21 completely and the developing roll 23 is completely covered. When the device body 21 is mounted on a prescribed position in the copying machine body, the opening 25 of the developing device 21 is completely opened and the developing roll 23 is exposed as designated. Since the cover can be automatically opened/closed at the mount/dismount of the developing device, it is unnecessary to execute specific work.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a developing device in an electronic copying machine.

[Prior art]

In an electronic copying machine, a photosensitive drum is used to create a copy image through charging, exposure, development, transfer, and fixing steps.

FIG. 1 shows an example of such a conventional electronic copying machine.

In this electronic copying machine, when the photosensitive drum 1 rotates in the six directions of arrows, the surface of the photosensitive drum 1 is first charged by the charger 2. When the charged surface of the photosensitive drum 1 passes a predetermined position,
An exposure device (not shown) exposes an image as indicated by an arrow B, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. The electrostatic latent image is developed by magnetic brush development at a location facing the developing roll 4 of the developing device 3, and a toner image is formed.

On the other hand, the paper 5 sent out from a paper cassette (not shown) is transported as indicated by arrow C by a transport device (also not shown), and is superimposed on the toner image formed on the photosensitive drum l. The toner image on the photosensitive drum 1 is transferred onto the stacked sheets 5 by the action of the transfer device 6. The paper 5 after the transfer is peeled off from the photosensitive drum 1 by the action of the static eliminator 7, sent to a fixing device (not shown) by the first general feeding device 8 and fixed thereon, and then discharged to a discharge tray (also not shown). Toner particles remaining on the surface of the photosensitive drum 1 are cleaned by a cleaning device 9.

Incidentally, in such an electronic copying machine, the developing device 3 is detachably attached to the main body of the electronic copying machine (not shown), so that its maintenance can be easily performed.

The method for attaching and detaching the developing device 3 is to guide pins (not shown) provided on the front and rear surfaces of the main body 10 to guide rails (not shown) provided in the main body of the electronic copying machine. There is a method of moving it in a horizontal radial direction, that is, in the arrow E direction. However, in such a developing device 3, since the portion of the developing roll 4 facing the photosensitive drum 1 is exposed, when the developing device 3 is removed, hands or clothes may touch the developing roll 4 and get dirty. Furthermore, when the developing device 3 is removed, toner particles may spill out and stain the floor or the like. In particular, if the removed developing device 3 is tilted by mistake, a large amount of toner particles may spill out.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a developing device that can automatically cover the exposed portion of the developing roll when removed from the main body of an electronic copying machine.

[Structure of the invention]

The present invention includes a developing device main body that is detachable from the electronic copying machine main body in the horizontal radial direction of the photosensitive drum provided therein, and a portion provided within the developing device main body that faces the photosensitive drum. An exposed developing roll, a cover provided on the developing device body so as to open and close the exposed portion of the developing roll, a biasing member biasing the cover in a closing direction, and a biasing member provided on the electronic copying machine body and the cover. and opening means for opening the cover against the force of the biasing member when the developing device main body is mounted on the electronic copying machine main body,
When the developing device main body is removed from the electronic copying machine main body, the exposed portion of the developing roll is covered with a cover.

〔Example〕

The present invention will be described in detail below with reference to Examples. .

2 to 4 show the main parts of a developing device in an embodiment of the present invention.

The main body 21 of this developing device is arranged in the horizontal radial direction of the photosensitive drum 22 with respect to the main body of the electronic copying machine (not shown), that is, in the direction indicated by the arrow F.
It is designed to be detachably attached in the G direction. A developing roll 23 is attached to the shaft 2 at a predetermined location within the developing device main body 21.
4 and is rotatably provided. Developing roll 23
The portion facing the photosensitive drum 22 is the developing device main body 21.
It is exposed through an opening 25 provided in the. A locking piece 26 is provided on the outer surface of the lower end of the opening 25 of the developing device body 21 over the entire length. The portion of the developing device main body 21 where the developing roll 23 is disposed has a shape that is a part of a cylindrical body.

A cover 31 for opening and closing the opening 25 is provided at a predetermined location on the outside of the developing device main body 21 . cover 3
1 includes a cover main body 32 having an arcuate cross section, and support plates 33 and 34 provided at both ends of the cover main body 32, respectively;
It consists of a locking piece 35 provided on the inner surface of the rear end portion of the cover main body 32 over the entire length. The base end portions of the support plates 33 and 34 are rotatably attached to the shaft 24 of the developing roll 23. Pins 36 and 37 are provided at predetermined locations on the developing device main body 21 and one support plate 33, respectively. A coil spring 38 is provided between these pins 36,37. The cover 31 is always urged clockwise by the force of the coil spring 38. A gear 39 having a substantially 1/4 arc shape is provided at a predetermined location on one of the support plates 33 .

A rack 40 is provided at a predetermined location within the main body of the electronic copying machine in correspondence with the gear 39.

Now, assume that the main body 21 of this developing device is removed from the main body of the electronic copying machine. In this state, as shown in FIG. 4, the cover 31 is biased clockwise by the force of the coil spring 38, and its locking piece 35 comes into contact with the locking piece 26 of the developing device main body 21. . That is, the cover 31 completely closes the opening 25 of the developing device main body 21 and completely covers the developing roll 23.

When installing the developing device main body 21 into the electronic copying machine main body, first insert the developing device main body 21 into the electronic copying machine main body with its opening 25 first, and then connect one end of the gear 39 to the rack 40. Engage one end. After this, the developing device main body 2
1 is further inserted in the direction of arrow F, the gear 39 is rotated counterclockwise by engagement with the rack 40, and the cover 31 is accordingly rotated in the same direction against the force of the coil spring 38. That is, as the developing device main body 21 is inserted into the electronic copying machine main body, the cover 31 is automatically and gradually opened. When the developing device main body 21 is installed in the desired position in the electronic copying machine main body, the developing device main body 21 is attached as shown in FIG.
The opening 25 is completely opened, and the developing roll 23 is exposed as expected. In this state, the gear 39 is engaged with the rack 40, so the cover 31 is held in the open position. When the developing device body 21 is installed at a desired position within the electronic copying machine body, the shaft 24 of the developing roll 23 is connected to a morph (also not shown) via a transmission system (not shown). This transmission system is usually located at the back of the main body of the electronic copying machine.

For this reason, it is preferable to provide the rack 40 on the front side of the main body of the electronic copying machine.

On the other hand, in order to remove the developing device main body 21 from the electronic copying machine main body, the developing device main body 21 can be pulled out in the direction of arrow G. At this time, due to the meshing with the rack 40, the gear 3
9 is rotated clockwise, and the cover 31 is accordingly rotated in the same direction. That is, as the developing device main body 21 is pulled out from the electronic copying machine main body, the cover 31 is automatically gradually closed. When the developing device main body 21 is removed from the electronic copying machine main body, the cover 31 completely closes the opening 25 of the developing device main body 21 and completely covers the developing roll 23, as described above.

〔Effect of the invention〕

As explained above, according to the present invention, when the developing roll is removed from the main body of the electronic copying machine, the exposed part of the developing roll is covered with a cover, so it is possible to eliminate dirt caused by toner particles. It is possible to prevent foreign substances such as Further, since the cup can be automatically opened and closed as the developing device main body is attached and detached, there is no need to perform any special work.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an example of a conventional electronic copying machine, FIG. 2 is a perspective view showing main parts of a developing device in an embodiment of the present invention, and FIG. 3 is a front view of the same developing device. FIG. 4 is a longitudinal sectional front view showing the main body of the developing device removed from the main body of the electronic copying machine. 21... Development device main body, 22... Photosensitive drum, 23... Development roll, 25... Opening, 26... Locking piece. , 31... Cover, 35... Locking piece, 38... Coil nook, 39... Gear, 40... U... Tsuku. Applicant Fuji Zero Z-X Co., Ltd. Representative Patent Attorney Umeo Yamauchi Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A developing device main body that can be freely attached to and removed from the electronic copying machine main body in the horizontal radial direction of a photosensitive drum provided inside the main body, and a developing device that is provided inside the developing device main body and has a portion facing the photosensitive drum exposed. a roll, a cover provided on the developing device main body so as to open and close the exposed portion of the developing roll, a biasing member that urges the cover in the closing direction, and a developing device main body provided on the electronic copying machine main body and the cover. 1. A developing device comprising: opening means for opening a cover against the force of an urging member when the developing device is mounted on an electronic copying machine main body.