JPH0618367Y2 - Developer discharge structure of developing device unit in copier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a developer discharging structure of a developing device unit in a copying machine, and more particularly to a developer discharging structure used in a magnetic brush type developing device.

[Conventional technology]

The developer used in the magnetic brush type developing device is composed of two components, a magnetic carrier and a toner whose main component is carbon black. Of these, the carrier is toner adhesion, abrasion, or deterioration. Since it deteriorates due to factors such as the above, it is necessary to replace the developer on a regular basis, and in order to once discharge the deteriorated developer from the developing device to the outside of the developing device, the developing device has a developer discharging structure. Need to be adopted.

On the other hand, as a structure for discharging the developer, conventionally, as described in JP-A-59-40678, the toner discharge port 2b is provided on the back surface of the box-shaped container 2 for collecting toner, and the toner is collected. A developer discharge structure has been proposed in which the toner is immediately discharged through the toner discharge port 2b and the box-shaped container 2 is swung about the shaft.

[Problems to be solved by the invention]

By the way, the developer discharging structure described in JP-A-59-40678 described above is applied to a cleaning device. In the case of this cleaning device, the developer scraped off by the blade is reused in the cleaning device. Since it is not used, it is sufficient to immediately discharge the scraped developer as in the developer discharge structure.However, in the case of the developing device, the developer is repeatedly reused for a certain period until deterioration, Unlike the conventional developer discharge structure described above, it is not possible to adopt a structure for immediately discharging the scraped developer.

In other words, when the above-described conventional developer discharging structure is applied to the developing device, there is a drawback that the original function of the developing device, that is, the developer scraped off is circulated for a certain period of time and reused, cannot be fulfilled. is there.

Further, in the developer discharge structure described in JP-A-59-40678, a configuration is adopted in which, when discharging the developer, the box-shaped container 2 supporting the blade is simply supported swingably about the shaft. However, in the cleaning device, the weight of the blade itself is small, so even if the length of the blade is increased according to the length of the photoconductor drum, the weight does not increase significantly, so it is easy to operate the operator. The cleaning device can be swung around the axis, but in the developing device, the weight of the transfer drum itself is heavy, and when the width of the copy paper becomes large, the length of the transfer drum also increases accordingly. Is extremely large, and it becomes difficult for the operator to easily swing the developing device around the shaft.

In view of the above-mentioned circumstances, the present invention allows the scraped developer to be circulated for a certain period of time and reused, and when the developer is replaced, the development work in a copying machine in which the replacement work by an operator is easy An object is to provide a developer discharge structure for an apparatus unit.

[Means for solving problems]

In the developer discharging structure of the present invention, the developing device is disposed adjacent to the photosensitive drum and is supported by the shaft so as to rotate in a direction away from the photosensitive drum from a position adjacent to the photosensitive drum. A unit and a position adjacent to the photosensitive drum, a developer discharge hole formed above the developing device unit and the developing device unit are constantly urged to rotate in one direction around the shaft. Urging means, and the developing device unit is rotated about the shaft in a direction away from the photosensitive drum from a position adjacent to the photosensitive drum by the urging force of the urging means. The developer contained in the device unit is sequentially discharged from the developer discharge hole.

[Action]

According to the developer discharge structure of the present invention described above, since the developer discharge hole is formed above the developing device unit,
The scraped developer is not immediately discharged, and the scraped developer can be circulated and reused for a certain period, and the biasing force of the biasing means is used when the developer is replaced. As a result, the heavy developing unit can be easily rotated about the axis to change the position of the developer discharge hole, and the developer can be sequentially discharged from the developer discharge hole.

〔Example〕

Hereinafter, one embodiment of the developer discharging structure according to the present invention will be described in detail.

FIG. 1 is an enlarged perspective view of essential parts of a copying machine 10 showing a developer discharging structure of the present invention.

In this copying machine 10, a developing device unit 14 is arranged adjacent to the peripheral surface 12 of the photosensitive drum 12. This developing device is a magnetic brush type developing device, and the magnet 16 exposed at one end of the unit 14 is the photosensitive drum 12
Is close to the peripheral surface 12a. On the other hand, the end portions 20 of the side plates 20 and 22 that form the housing 18 of the developing device unit 14
A shaft 24 is inserted and fitted between a and 22a,
Bearings 26, 28 are provided at the respective ends 24a, 24b of the shaft 24.
Has been inserted. The bearings 26 and 28 are housed in support blocks 32 and 34 having a U-shaped cross section, which are fixed to a housing 30 of the copying machine 10. The support blocks 32 and 34 are fixed to the housing 30 with screws 36, and the bearings 26 and 28 are fixed to the support blocks 32 and 34 with screws 38 that are screwed into the support blocks 32 and 34. Has been done.

On the other hand, the side plate 20 located in front of the developing device unit 14
A support arm 40 is projectingly provided on the support arm 40. The support arm 40 is engaged with a fixing device 42 such as a thumbscrew attached at a predetermined position of the housing 30 and is always fixed thereto. In addition, above the developing device unit 14, that is, the unit 14
On the upper surface of the case 18, a developer discharge hole 44 (not shown) accommodated in the case 18 is formed. A wear preventing plate 46 made of stainless steel or the like is attached to the lower surface 18a of the housing 18 of the developing device unit 14, and the wear preventing plate 46 includes a pair of biasing means torsion bars 48, 50. The tips 48a and 50a are in close contact with each other. The housing 18 is provided with torsion bars 48, 50.
Is always urged in the clockwise direction about the shaft 24 by the elastic force. The torsion bars 48, 50
The other end of the frame is fixed to a frame 52 having an L-shaped cross section installed below the housing 18 via a bracket 54.

Next, the operation of the above-described developing device structure will be described, and the configuration will be described in more detail.

According to the developer discharge described above, since the developer discharge hole 44 is formed above the developing device unit 14, that is, on the upper surface of the housing 18 of the unit 14, the developer discharge hole 44 is formed in the housing 18 in the normal use position. The scraped off developer is not immediately discharged, but the scraped off developer can be circulated for a certain period of time and reused.

When replacing the developer, the fixing device 42 shown in FIG. 1 is used.
When released, the developing device unit 14 is rotated clockwise about the shaft 24 by the urging force of the torsion bars 48 and 50, and as shown in FIG. 2 shown in the side sectional view of FIG. It rotates close and stops at a position where the rotational moment due to the torsion bar and the moment required for the rotation of the unit are balanced. In this way, the developing device unit 1
When 4 rotates, the developer (arrow A) accommodated in the casing 18 gradually drops downward and is discharged to the outside of the casing 14 through the developer discharge hole 44. The developer (arrow A) discharged to the outside of the developing device unit 14 is stored in a storage container (not shown) arranged below the developing device unit 14 and removed outside the copying machine 10. In addition, the torsion bar 4
It is desirable that the biasing forces of the developing units 8 and 50 with respect to the developing device unit 14 have the characteristics shown in the graph of FIG.
In particular, the rotational moment (I) (shown by the solid line) by the torsion bar is slightly higher than the moment (II) (shown by the alternate long and short dash line) necessary to rotate the developing device unit when the rotation angle is 0 °. desirable.

[Effect of device]

As described above, in this invention, since the developer discharge hole is formed above the developing device unit, the scraped developer is not immediately discharged, but the scraped developer is circulated for a certain period. When the developer is replaced, the position of the developer discharge hole is changed by a simple operation of rotating the developing device unit with respect to the photosensitive drum, and the developer is discharged from the developer discharge hole. Can be sequentially discharged. Furthermore, since the developing device unit is rotated around the axis by using the urging force of the urging means, it is extremely easy to replace the developer even if a large and heavy developing device unit is used. Becomes Further, since it is possible to rotate the developing device unit and gradually discharge the developer, the scattering of the developer is extremely small, and therefore, the contamination of the developer can be prevented as much as possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a copying machine showing a developer discharging structure of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is a graph showing characteristics of a torsion bar. 10 ... Copier, 12 ... Photosensitive drum, 14 ... Developing device unit, 24 ... Shaft, 44 ... Developer discharge hole, 4
8, 50 ... Biasing means (torsion bar).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-40678 (JP, A) JP-A-56-142559 (JP, A) Jitsukoku Sho-50-29947 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. A developing device unit disposed adjacent to a photosensitive drum and supported by a shaft so as to rotate in a direction away from the photosensitive drum from a position adjacent to the photosensitive drum, A developer discharge hole formed above the developing device unit at a position adjacent to the photosensitive drum, and a biasing means for biasing the developing device unit so as to always rotate in one direction about the shaft. The developing device unit is rotated about the shaft in a direction away from the photosensitive drum from a position adjacent to the photosensitive drum by the urging force of the urging means. A developer discharging structure of a developing device unit in a copying machine, wherein the stored developer is sequentially discharged from the developer discharging hole.