GB2148152A - Developer powder transporting device - Google Patents

Abstract

A transporting device for developer powder has magnetic roll (20) positioned within a sleeve (4). Vibrating plate (6) has a magnetic portion (9) disposed facing the sleeve (4). The vibrating plate starts to vibrate due to the alternation of the magnetic field produced by the rotation of the magnetic roll, whereby developer powder (7) in a container flows along the surface of the vibrating plate and is then transported to the rotating sleeve (4). The developer powder attracted on the surface of the sleeve is applied to the image-bearing surface, thereby developing an electrostatic latent image into a visible image. <IMAGE>

Description

SPECIFICATION Powder transporting device The present invention relates to a powder transporting device and more particularly to a magnetic powder transporting device to be used to develop an electrostatic latent image formed on the image carrier member in an electrostatic copier, a facsimile apparatus, a non-impact printer or the like.

In conventional powder transporting devices, especially for use in the development apparatus of copying machines, a screw or auger means is used as a developer transporting device and this is rotatably mounted to the housing and positioned adjacent to the developing sleeve to transfer the developer thereto. The developer in the developer container moves toward the developing sleeve as the transporting device rotates.

However, such a conventional device has disadvantages in that it occupies a large space because of the necessity of a driving means and in that the developer gets stuffed in the journal section of the device or is scattered out of the device.

Furthermore, in order to eliminate such disadvantages, an additionai means must be mounted to the device and it therefore becomes more complex.

The present invention provides a powder transporting device comprising a container for storing a finely divided powder therein, vibrating guide means having at least one magnetic portion connected to the container, feeding means for feeding powder from the vibrating means, and magnetic means rotatably disposed within the feeding means, whereby said vibrating means vibrates upon the rotation of the magnetic means to transport the powder from the container to the feeding means via the vibrating guide means.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawing which shows a cross section through a transporting device in accordance with the invention.

A photoconductive member 10 is rotatably mounted to a stationary portion (not shown) of a copying machine. The photoconductive member 1 carries on its surface a latent electrostatic image corresponding to an original image to be copied.

A developing device 2 is positioned facing the photoconductive member 1. A housing 3 of the developing device is fixed to a stationary portion of the machine.

A non-magnetic sleeve 4 is used as a developer feed means and is rotatably disposed between side plates (not shown) of the housing 3. The sleeve 4 applies a developer to the photoconductive member and thereby functions to convert the electrostatic latent image into a visible image.

A single component magnetically attractive developer 7 is preferred, but it is possible to use any single-component developer.

A container for storing therein the developer 7 is defined by members 5 and 6. The member 5 is fixed to the housing 3 at its one end and forms a Ushaped exit 8 in association with the member 6. The member 6 is fixed to the housing 3 at its one end and extends to a position facing the bottom portion of the sleeve 4 at its other end. In this embodiment, the member 6 also functions as a vibrating means and, as such, is made of a thin resilient plate.

The portion of the member 6 which faces the sleeve 4 includes a magnetic material 9. Also, in order to prevent dissipation of the developer 7 out of the developing device, there is provided a stopper member 10 projecting from the surface of the member 6 at a forward portion thereof. A magnetic member 20 having different magnetic poles is disposed within the sleeve 4 and is rotatably mounted between side plates of the housing.

Further, the magnetic member 20 is connected to a driving means M, which is operable, for example, during the operation of the copying machine or the developing device, or at the time of developing the latent image or when the quantity of developer deposited on the sleeve 4 is reduced. Since the magnetic member 20 functions to agitate the developer on the sleeve in this embodiment, it is arranged such that the driving means M may operate in response to the operation of the developing device. Since the magnetic material 9 of the vibrating means 6 is positioned in the area subjected to the magnetic field of the magnetic member 20, it is also subjected to the alternating magnetic field generated by the rotation of the magnetic member 20. Accordingly, the vibrating means 6 begins to vibrate at the initiation of the rotation of the magnetic member 20.

A doctor blade 21 regulates the quantity of the developer that is deposited on the sleeve. The doctor blade 21 is fixed to the housing 3 at its one end and is opposed to the sleeve 4 in spaced relationship at its other end.

A cartridge 22 is provided for replenishing the developer, and is set on the upper portion of the container by a suitable means.

The operation of the described developing device will now be explained.

Upon setting the cartridge 22 on the container, the developer 7 packed therein flows out and is stored in the container defined by the members 5 and 6. At this point while the developer 7 falls down by gravity, a large quantity of the developer 7, due to its limited flowage, is caught at the U-shaped exit 8 and the rest of the developer reaches a position near the sleeve 4. Therefore, the developer 7 is held at the Ushaped exit 8 in a bridging state.

When the photoconductive member 1 bearing an electrostatic latent image enters the developing zone of the copying machine, both the sleeve 4 and the magnetic member 20 are rotated. By the rotation of the sleeve 4, the developer 7 retained in the lower portion of the container is applied to the surface of the photoconductive member 1 after being subject to the action of the doctor blade 2. Thus the latent image is converted into a visible image corresponding to the original.

As the magnetic member 20 rotates, an alternating magnetic field is generated in an adjacent region. As is described before, the magnetic material 9 of the vibrating member 6 is disposed under the influence of the abovementioned magnetic field so that the vibrating member 6 vibrates in synchronism with the rotation of the magnetic member 20. Then, the bridging state of the developer 7 held at the vicinity of the Ushaped exit 8 is destroyed due to the vibration of the vibrating member 6. Further, the developer 7 is guided and fed toward the sleeve 4while vibrating on slanting surface 61 of the large vibrating member 6. At this time, a relatively large block of the bridging developer 7 is also destroyed on the slanting surface 61, and only the fine particle developer powder is transported to the sleeve 4.In this embodiment, the slanting surface 61 is adjusted at an angle of about 35". The detailed parameters, such as magnetic force or number of poles of the magnetic member 20, thickness or quality of the magnetic material 9 and size of the opening of the U-shaped exit 8, are determined mainly by the flowage characteristics of the developer used.

Non-magnetic phosphor bronze material or nonmagnetic stainless steel may be used as the vibrating member 6. The thickness and length of the slanting surface of the member 6 may be determined during the design of the device.

As is explained before, the present transporting device does not require a rotary member for transporting the developer powder to the sleeve 4, and so the number of parts may be reduced and a low manufacturing cost and compactness may be accomplished.

Also the described device prevents an abnormal developed image due to the bridging state of the developer. Furthermore, since the process of transporting the powder is more static in comparison with the conventional device using a rotary member, the hysteresis of the developer powder may be reduced.

Claims (7)

1. A powder transporting device comprising a container for storing a finely divided powder therein, vibrating guide means having at least one magnetic portion connected to the container, feeding means for feeding powder from the vibrating means, and magnetic means rotatably disposed within the feeding means, whereby said vibrating means vibrates upon the rotation of the magnetic means to transport the powder from the container to the feeding means via the vibrating guide means.

2. A device for developing a latent image on an image-bearing member for use in an electrostatic reproducing machine, comprising a container for storing single component developer powder, vibrating guide means having at least one magnetic portion connected to the container, feeding means for feeding the developer to the image-bearing member, and magnetic means rotatably disposed within the feeding means, said feeding means being positioned facing the vibrating means, said magnetic portion being positioned within the magnetic field produced by said magnetic means, whereby said vibrating means vibrates upon the rotation of the magnetic means to transport the powder from the container to the feeding means via the vibrating guide means.

3. A device as claimed in claim 1 or 2, wherein said feeding means comprises a rotary cylinder sleeve.

4. A device as claimed in claim 3, wherein a doctor blade is provided in spaced relationship to the sleeve.

5. A device as claimed in any one of the preceding claims, wherein a stopper member is provided on the surface of the vibrating means.

6. A powder transporting device substantially as herein described with reference to the accompanying drawing.

7. A device for developing a latent image substantially as herein described with reference to the accompanying drawing.