JPH0363754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device of an image forming apparatus such as an electronic copying machine.

Conventionally, in electronic copying machines, the developing device has often been installed and removed from the main body of the copying machine by specialized service personnel in order to replace the developer, clean, maintain, and inspect the device. However, as the types of copying machines become more diverse,
There is an increasing need for general users to attach and detach developing devices. For example, in order to make multicolor copies using a copying machine equipped with one developing device, there is a method in which a plurality of developing devices containing different color developers are prepared and the developing devices are replaced as necessary. According to this method, it is possible to easily obtain multicolor copies. In this case, the user must necessarily replace the developing device, and a plurality of developing devices are placed outside the copying machine.

The developing device includes a rotating body such as a non-magnetic sleeve, a magnetic roller, a charging roller, etc. for holding and transporting the developer. In particular, in a developing device using a one-component magnetic developer, the rotating body must be a non-magnetic sleeve with a uniform surface roughness, and if the sleeve is left exposed outside the copying machine, it is susceptible to damage from the outside.

In addition, developer adheres to the surface of the rotating body, and when the developing device is attached or detached, the developer may come into contact with the surface and become dirty.

The present invention aims to solve the above-mentioned inconveniences when storing and attaching/detaching the developing device.

A developing device of the present invention that achieves the above object is provided in an opening of a housing housing a developer so that a portion thereof faces outside the housing, and holds the developer on the surface to carry an electrostatic latent image. In a developing device which is provided with a developing rotary body composed of a non-magnetic sleeve or a magnetic roll having a magnetic material arranged inside and is removably attached to the main body of an image forming apparatus, the developing rotary body is supplied to a body. A movable shutter protects the portion facing outside of the housing opening, and the shutter opens when the developing device is attached to the image forming apparatus main body, and the shutter opens when the developing device is removed from the image forming apparatus main body. It is characterized by having a shutter opening/closing means for closing the shutter, and a spring member for holding the shutter in the open position when the shutter is opened by the shutter opening/closing means and in the closed position when the shutter is closed. It is something.

The present invention will be explained in detail below.

FIG. 1 is a sectional view of a developing device to which the present invention is applied, which is installed in the main body of an electronic copying machine, which is an image forming device. This developing device is exemplified as having a non-magnetic sleeve 1 as a rotating body for holding developer.

The shutter 2 is shown in an open state in the figure, and the sleeve 1 opposes a photosensitive drum D (shown by chain lines), which is an image bearing member of the copying machine, at an opening 3 of the developing device.

When the developing device is removed from the copying machine main body, the shutter 2 is in a closed state, covering the opening 3 and protecting the sleeve 1, as shown in FIG. In order to prevent magnetization, the shutter 2 is preferably made of non-magnetic material such as plastic or aluminum.

In addition, in FIG. 1, reference numeral 4 denotes a magnetic body, and 5 indicates a hopper portion of the developing device in which developer is accommodated, and an agitator 6 for stirring the developer and the like are arranged.

FIG. 3 shows the opening/closing mechanism of the shutter 2, and as in FIG. 1, it shows a state in which the developing device is attached to the main body of the copying machine and the geodetic shutter 2 is in an open state.

The developing device is structured to be pulled out in the direction of arrow A. A roller 7 is attached to the developing device, and the roller 7 is provided with a helical grooved cam 7a, which engages with a guide 8 attached to the main body. Therefore, when the developing device is pulled out in the direction A, the roller 7 rotates in the direction indicated by the arrow. The rotation of roller 7 is caused by pulley 9, wire 10, pulley 11,
The rotation shaft 1 of the shutter 2 is controlled by the gears 12 and 14.
6 can be conveyed. Although the shaft 16 loosely fits the rotation shaft of the sleeve 1, the shaft 16 is not limited thereto. 1
0a is a spring provided on a part of the wire 10 to absorb shocks applied to the wire 10. 15
A disc 2 rotates coaxially with the pulley 11 using a separate spring.
0 and a part of the developing device, and the shutter 2
When the shutter 2 is opened, pull the disk 20 above the axis of the disk 20 to fix the shutter 2 in the open state, and when the shutter 2 is closed, pull the disk 20 below the axis of the disk 20. Fix the tension shutter 2 in the closed state.

In addition, gears 17, 18, and 19 are for transmitting rotation from a drive source (not shown) to the sleeve 1, and when the developing device is pulled out, the gear 17 is separated from the idle gear 18 and integrated with the developing device. The structure is such that it can be drawn out.

When pulling out the developing device configured as described above from the main body of the copying machine, the developing device is removed from the photosensitive drum D slightly so as not to interfere with the rotation of the shutter 2. When the developing device is pulled out, the shutter 2 rotates in the direction of arrow B and automatically closes. When inserting the developing device, the end of the grooved cam 7a is engaged with the guide 8 of the main body, and then the shutter 2 rotates in the opposite direction and opens automatically. Next, the developing device is returned to the position in which it is in use and is opposed to the photosensitive drum D.

Note that if the guide 8 is movable upward from the position of the grooved cam 7a and disengaged from the grooved cam 7a, the shutter can be closed while the developing device is inserted into the copying machine main body, and the shutter can be closed while the developing device is inserted into the copying machine main body. It is convenient for cleaning etc.

In the above embodiment, a non-magnetic sleeve is used as the rotating body for holding the developer, but it is also possible to use a magnetic roller.

As explained above, when the present invention is applied, the shutter automatically closes when the developing unit is removed from the main body of the apparatus, so there is no risk of damaging the surface of the rotating body, and there is no risk of getting your hands dirty during attachment/detachment work. The shutter opens automatically when you put it on, so you won't forget to open it.

Therefore, it is extremely easy for general users to attach and detach the developing device, and it is also extremely convenient to store the developing device outside the main body of the apparatus.

In addition, with a developing device that is detachable from the image forming device, the operator can decide where to place the developing device after it has been taken out from the image forming device, and generally it is placed near the location where the image forming device is installed. It is often placed on the floor, desk, shelf, etc. However, magnetic metal pieces such as paper clips, staples, and machine screws are often found in such places, and if the developing device is placed near such items, the non-magnetic sleeves The above magnetic metal piece is attracted to the surface of the non-magnetic sleeve or magnetic roll by the magnetic force of the magnetic body or magnetic roll, and then when the developing device is attached to the image forming apparatus and operated, this metal piece is Accidents that damage the image carrier, non-magnetic sleeve, or magnetic roll are likely to occur, but the present invention prevents such metal pieces from adhering to the non-magnetic sleeve or magnetic roll using the shutter. prevent various accidents.

In addition, since the shutter is held in the open position and the closed position by spring members, the shutter is prevented from being opened inadvertently when the developing device is taken out of the image forming apparatus. This will prevent the shutter from closing when the shutter is closed.

[Brief explanation of drawings]

1 and 2 are sectional views of a developing device to which the present invention is applied, and FIG. 3 is a perspective view showing an embodiment of the present invention. 1 is a non-magnetic sleeve, 2 is a shutter, 7a is a grooved cam, and 8 is a guide.

Claims (1)

[Claims] 1. A magnetic body is provided inside the opening of the housing that houses the developer so that a part of it faces outside the housing, and holds the developer on the surface and supplies it to the electrostatic latent image carrier. In a developing device which is equipped with a developing rotary body composed of a non-magnetic sleeve or a magnetic roll and is detachable from the main body of the image forming apparatus, the portion of the developing rotary body facing outside the housing opening is protected. a shutter opening/closing means for opening the shutter in conjunction with attachment of the developing device to the image forming apparatus body and closing the shutter in conjunction with taking out the developing device from the image forming device body; a spring member that holds the shutter in the open position when the shutter is opened by the opening/closing means and in the closed position when the shutter is closed;
A developing device comprising: