JP2002229313A - Developer stirring device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer stirring device whose stirring property is excellent without causing a defective image such as density unevenness in the longitudinal direction of the hopper container of the developer stirring device. SOLUTION: The developer stirring device is provided with a storing part to store developer and a stirring/mixing part to stir and mix the developer. The storing part and the stirring/mixing part mutually communicate so as to make the flow-out/in of the developer feasible, and a developer capturing means to control the flow-out/in quantities of the developer is provided between the storing part and the stirring/mixing part. A cylindrical body, an outside spiral part formed on the outside surface of the cylindrical body, an inside spiral member attached at the inside of the cylindrical body, a developer sucking aperture part formed on the surface of the cylindrical body and a developer jetting aperture part formed on the surface of the cylindrical body are provided at the inside of the stirring/mixing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer stirring device used in an image forming apparatus such as a copying machine and a facsimile, and an image forming apparatus using the same.

[0002]

2. Description of the Related Art An image forming apparatus is provided with a developer stirring device.

FIG. 5 shows a conventional developer stirring device.
FIG. 5A is a cross-sectional view of the developer stirring device, and FIG. 5B shows a stirring means of the developer stirring device.

The developer stirring device includes a hopper container 100 for storing the developer and a stirring member 102 which rotates about a stirring shaft 101 in the hopper container 100 and stirs the developer 103 in the hopper container 100. Prepare. The developer 103 stirred in the hopper container 100 has a surface charged by frictional charging. Then, the image is collected by the collection magnet roller 104 and sent to a developing unit (not shown).

Further, the developer 1 is placed in the hopper container 100.
In addition to 03, the developer removed from the image bearing member after image formation is sent into the hopper container 100 via a conveying screw 105 provided above the stirring member 102 for reuse. At this time, since the developer collected by the cleaner or the like contains paper dust and dust of the transfer material, these must be removed from the developer. For this purpose, the developer is sent to a paper dust separating device for removing these paper dusts from the developer, as disclosed in JP-A-7-64443, and the developer removes paper dust, dust and the like. The recycled developer 106 from which the paper dust, dust, and the like have been removed in this manner is transported by the transport screw 105 from the back side to the front side in the direction perpendicular to the transfer material surface in FIG. It overflows and is sent into the hopper container 100. Then, the developer 103 and the reused developer 106 are mixed in the hopper container 100, and the mixed developer is sent to the developing device.

However, in the above-described conventional example, the reusable developer 106 is not uniformly replenished in the longitudinal direction of the hopper container 100, and the replenishment amount becomes uneven. Stirring member 102
In some cases, since the developer 193 and the reused developer 106 hardly move in the longitudinal direction of the hopper container 100, the unevenness in the replenishment amount is not solved. Therefore, the developer 103 and the reused developer 106 are mixed with unevenness in the longitudinal direction.
It is sent to the developing device.

In the above-described conventional example, the developer 1
03 and the recycled developer 106 could not be sufficiently mixed in the hopper container 100. Therefore, the developer is sent to the developing device while the mixing unevenness and the mixing defect are generated, and the image is formed. As a result, the image defect such as the density unevenness in the longitudinal direction occurs.

[0008] Even when the reused developer is not mixed with the developer in the hopper container 100, if the stirring is not sufficiently performed in the longitudinal direction of the hopper container, uneven charging in the longitudinal direction occurs, resulting in image defects. I was

In order to solve the above problems, it has been invented to use a stirring roller shown in FIG. 3 instead of the stirring member 102 of the conventional example. 3A is a perspective view, FIG. 3B is a longitudinal sectional view, and FIG. 3C is a transverse sectional view.

The stirring roller 2 has an outer screw 4a and an inner screw 5 on the inner and outer sides, respectively, with the inner screw 5 as the center. A driving force is transmitted to the inner screw 5 via a gear 6, and a driving force is transmitted to the outer screw 4 a via a gear 7. The developer around the stirring roller 2 slides in the direction of the arrow along the screw 4a with the rotation of the outer screw 4a.

At this time, since the fin 4b is formed at an angle θ with respect to the circumferential direction of the outer screw 4a, the developer sliding in the direction of the arrow is conveyed in the direction of the arrow while being stirred. Then, the transported developer moves from the developer suction port 4c to the inside of the stirring roller 2 and is transported by the inner screw 5 in the direction of the arrow. Then, the developer is ejected from the developer outlet 4d to the outside of the stirring roller 2, and is again conveyed to the outer screw 4a.

As described above, the developer circulates through the inside and outside of the stirring roller 2, and the stirring is performed in the process.
The number of teeth of the gears 6 and 7 is determined so that the amount of developer transported by the inner screw 5 and the outer screw 4a is substantially the same, and the number of rotations of the screws is different.

The stirring roller 2 described above is disposed in the hopper container 100 shown in FIG. 5 instead of the stirring member 102, and the developer suction port 4c and the developer ejection port 4d are arranged so as to be adjacent to each other.

If the developer 103 and the reusable developer 106 are mixed by the stirring roller 2 in the hopper container 100, the unevenness in the longitudinal direction is reduced, and the unevenness in density in the longitudinal direction is reduced.

[0015]

However, this is when the developer 103 is located below the apex of the stirring roller 2 and when the developer 103 is located above the apex of the stirring roller 2, The agitation of the developer 103 and the reused developer 106 is reduced. The reason is that when the developer 103 is located below the top of the stirring roller 2, the developer around the stirring roller 2 flows, but the developer 103 is located above the top of the stirring roller 2. This is because the developer 103 above the apex of the stirring roller 2 does not flow and is not agitated. As a result, the developer 103 and the reused developer 1
06 was not sufficiently stirred in the hopper container 100, and image defects such as uneven image density in the longitudinal direction of the hopper container occurred.

An object of the present invention is to provide a developer stirring device having excellent stirring performance without causing image defects such as uneven density in the longitudinal direction of a hopper container of the developer stirring device.

[0017]

Means for Solving the Problems The first aspect of the present invention achieves the object of the present invention, which comprises a storage section for storing a developer, and a stirring and mixing section for stirring and mixing the developer. ,
The storage section and the stirring and mixing section are connected to each other so that the developer can flow in and out, and a developer collecting means is provided between the storage section and the stirring and mixing section so as to control the amount of the developer flowing in and out. A cylindrical body, an outer spiral part formed on the outer surface of the cylindrical body, an inner spiral member attached inside the cylindrical body, and a cylindrical body formed on the surface of the cylindrical body. Drive means for driving the outer spiral member and the inner spiral member in the axial direction of the cylindrical body, comprising: a developer agitating roller having an opened developer suction opening and a developer ejection opening. A developer stirring device comprising:
The stirring / mixing unit includes a detection unit that detects that the amount of the developer inside the cylindrical body reaches an apex of the upper surface of the developer to reach the vertex of the outer circumferential circle of the developer stirring roller, and is emitted from the detection unit. A developer stirring device, wherein the operation of the developer collection means is controlled in accordance with a detection signal. ”.

The developer stirring device of the present invention includes at least two storage units for storing different types of developers, for example, a new developer and a reused developer. It is provided between the agent stirring and mixing sections.

In the developer stirring device of the present invention, the storage unit includes a hopper container including an upper container and a lower container, the upper container and the lower container are connected to each other, and a collection magnet roll is provided between the two containers. Developer collecting means is provided,
The upper container has an opening for developer, a stirring member is provided in the upper container, the lower container is divided into a storage unit and a stirring and mixing unit, and between the storage unit and the stirring and mixing unit in the lower container. Is provided with collection means consisting of a collection magnet roll,
A transport roll for reused developer is provided in the storage section in the lower container, a gutter is provided below the transport roll, and a plurality of rotating plates for stirring and transport are provided below the gutter. It can be. In addition, a collection means including a collection magnet roll can be provided below the stirring and mixing member.

In the developer stirring device of the present invention, the storage unit includes a hopper container having an upper container and a lower container, the upper container and the lower container are connected to each other, and a collection magnet is provided between the two containers. A developer collecting means comprising a roll is provided, the upper container has a developer opening, a stirring member is provided in the upper container, and the lower container is connected to a transfer chamber having a reused developer transfer roll. Configuration can be adopted. Further, a collecting means comprising a collecting magnet roll can be provided below the stirring and mixing member.

In the developer stirring device of the present invention, a predetermined amount of fresh developer and reused developer are put into the stirring and mixing section by the developer collecting means from the storage section respectively storing them. The amount of the developer to be mixed is controlled by the detecting means to the amount at which the stirring effect of the stirring roller can be obtained by the developer collecting means. By this action, the new developer and the reused developer are sufficiently stirred.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described with reference to embodiments of the present invention. FIG. 4 shows hopper containers 51 and 62 to be described later in which the developer stirring device of the present embodiment is incorporated.
1 is a cross-sectional view of an image forming apparatus equipped with the image forming apparatus.

In FIG. 4, an image formed by an image forming unit 10 that performs a known image forming process is transferred to a transfer material P stored in a cassette 9 that can be pulled out to the near side in the figure. The sheet is sent to the fixing device 12 and is fixed by the heat and pressure of the fixing device 12.
When 0, the copier body 22 is discharged from the discharge port to the outside of the machine. The transfer material P discharged to the outside of the copying machine main body 22 enters the entrance 14 of the sheet separation device 13 and
Sheet separation device 1 by a discharge roller 15 provided in
3 and is stacked on a discharge tray 16.

When the document is set on the pressure plate 17, the document is read by the exposure device 18, a toner image is formed in the image forming section 10, and the formed toner image is transferred to the transfer material P. When copying two or more copies of multiple originals,
The path of the transfer material P is changed in the direction of the roller 20 by the flapper 19 which is a sheet conveying path changing means in the sheet separating device 13, and is discharged onto the discharge tray 16 by the discharge roller 21. The discharge tray 16 has a configuration in which a plurality of bins are stacked in multiple stages. The discharge tray 16 is indexed and moved in the direction of arrow F by a discharge tray driving means (not shown), and each bin is made to coincide with the exit side of the discharge roller 21 and is classified into a plurality of copies. In the above-described copying machine main body, the front loading cassette 9, the transport unit 11, and the fixing device 12 can be pulled out to the near side in a direction perpendicular to the surface of the transfer material in the drawing to maintain the apparatus and supply the transfer material P. It is configured as follows.

When it is detected by a developer sensor (not shown) that the mixed developer stored and agitated by the developer agitating device 62 has decreased in the developing unit 25, the collection magnet roller 104c is rotated. ,
The developer is supplied into the developing device 25. Further, a similar developer sensor is provided in the developer stirring device 62. When the amount of the developer in the developer agitator 62 becomes low, a message is output to an operation unit (not shown) of the copying machine 22, and the operator is notified. You are told to replenish the developer.

(First Embodiment) FIG. 1 shows a first embodiment of the developer stirring device of the present invention, FIG. 1 (a) is a sectional view, and FIG. 1 (b) is FIG. 1 (a). FIG. 2 is a sectional view taken along line AA in FIG. Components having the same role as the components of the conventional developer stirring device shown in FIGS. 3 and 5 are denoted by the same reference numerals, and description thereof is omitted.

In the developer stirring device according to the first embodiment of the present invention, the hopper container 51 for storing and storing the developer 103 comprises an upper container 52 and a lower container 53.
Both containers 52 and 53 are fastened and fixed to each other by screws (not shown) or the like. A stirring member 102 that rotates about a stirring shaft 101 is attached inside the upper container 52. The upper container 52 has an opening 52a in the upper part.
The developer 103 is put into the upper container 52 from 2a.
A pressure sensor (not shown) for detecting that the amount of the developer in the upper container 52 has become smaller than a predetermined amount is provided on a side surface of the upper container 52. In response to the detection of the amount of the developer, a pressure sensor (not shown) is provided. The collection magnet roll is rotated to prompt the user to replenish the hopper container 51 with the developer. At the same time, the stirring shaft 101 is rotated at a rotation speed of, for example, 10 rpm for 5 minutes to mix and stir the developer 103.

In the lower container 53, a recycled developer 106 is fed from a paper dust separating device (not shown) to the conveying screw 1.
1 is transported from the back side to the trouble side in the direction perpendicular to the transfer material surface in FIG.
Fall into. The reused developer 106 that has fallen is collected in the lower container 53, and is conveyed in the lower left direction by rotating the non-conductive rotating plate 55 fixed to the shaft 54 in the direction of the arrow.

At the lower part of the upper container 52 and the lower part of the lower container 53, collecting magnet rolls 104a and 104b each composed of a sleeve made of a magnetic magnet are arranged as shown in FIG. The developer 103 and the reusable developer 106 are put into a stirring chamber 53b formed in the lower container 53 by rotating the collection magnet rolls 104a and 104b. The rotation speed of the collection magnet rolls 104a and 104b is, for example, the developer 103:
The recycled developer 106 is set to be 9: 1. The stirring roller 2 is disposed in the stirring chamber 53b,
The driving force of a driving means (not shown) such as a motor is transmitted to the inner screw 5 and the outer screw 4a via gears 57 and 58 connected to a shaft 56 shown in FIG. 1B. . Stirring roller 2 (FIG. 3) and lower container 5
The gap t between the three walls is preferably, for example, about 1 mm.

Collection magnet rolls 104a, 104b
Developer 10 placed in the stirring chamber 53b by the rotation of
3 and the mixed developer 69 composed of the reused developer 106 are:
The mixed developer 69 in the stirring chamber 53b is provided on the side surface of the lower container 53.
Is detected by the pressure center 59, which detects that the upper surface is near the top of the stirring roller 2, and the rotation of the collection magnet rolls 104a, 104b is stopped according to the detection signal. After the pressure sensor 59 detects that the upper surface of the mixed developer 69 has reached the vicinity of the top of the stirring roller 2, the stirring roller 2 is rotated for a predetermined time, and the mixed developer 69 is moved in the direction indicated by the arrow in FIG. It is conveyed and stirred in the direction. At this time, the mixed developer 69 enters the inside of the stirring roller 2 and the upper surface of the mixed developer 69 is lowered. The lowering of the upper surface is also detected by the pressure sensor 59, and the rotation of the collection magnet rolls 104a and 104b is controlled.
The upper surface of the mixed developer 69 is located near the top of the stirring roller 2.

When the mixing and stirring in the stirring chamber 53b is completed in this manner, a drive connection signal is input to the electrode clutch 60 shown in FIG. 1B, and the driving force is applied to the collection magnet roll 104c via the gear 61. Is transmitted. Then, a connection signal is input to the electromagnetic clutch 60 for a predetermined time until the mixed developer 69 in the stirring chamber 53b runs out for a predetermined time. Thereafter, the connection of the electromagnetic clutch 60 is disconnected, and the rotation of the stirring roller 2 is also stopped. The above operation is repeated, and the replenishment / stirring / discharging operation of the developer is performed in the hopper container 51.

In the first embodiment, the hopper container 51 is constructed so that only the upper container 52 and its internal components can be used as a developer stirring device.

(Second Embodiment) Next, a second embodiment of the developer stirring container of the present invention will be described.

FIG. 2 shows a second embodiment of the developer stirring container of the present invention. FIG. 2 (a) is a sectional view, and FIG.
FIG. 2A is a sectional view taken along line BB of FIG. 2A, and FIG.
(B) is a sectional view taken along line CC. Components having the same role as those of the conventional developer stirring device and the components of the first embodiment shown in FIGS. 3 and 5 are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 2, in the developer stirring device according to the second embodiment of the present invention, the hopper container 62 for storing and storing the developer 103 comprises an upper container 52 and a lower container 53. Both containers 52 and 53 are fastened and fixed to each other by screws (not shown) or the like.

A stirring roller 65 is provided inside the lower container 64 as in the first embodiment. Stirring roller 65
Is substantially the same as that shown in FIG. 3 except that the end 66f of the inner cylinder 66e inside the outer screw 66a is open. The driving force is transmitted to the inner screw 5 of the stirring roller 65 from the power source via the gear 6, while the opposite side of the inner screw 5 is supported by a bearing 66 g.

The reused developer is a paper powder separating device (not shown)
2 is conveyed by a screw 67 arranged in a supply pipe (not shown) in the direction of the right arrow shown in FIG. One end of the screw 67 is pivotally supported by the bearing portion 64b, and the other end is provided with driving means and driving transmission means for the screw 67. Inside the lower container 64, a pressure sensor 59 is provided at the same position as in the first embodiment. The developer 103 and the reused developer 1 are placed in the stirring chamber 64a.
06, the stirring roller 65 is rotated, and the collection magnet roll 104a and the screw 67 are rotated.
Is rotated.

The reused developer 106 merges with the developer 103 near the developer suction port 66c of the stirring roller 65, and thereafter, is circulated inside and outside the stirring roller 65 to be stirred and mixed.

Further, the stirring chamber 64a for the reused developer 106
The rotation speeds of the screw 67 and the collection magnet roll 104a are set so that the transport amount to the developer and the replenishment amount of the developer 103 are such that the transport amount: the replenishment amount = 1: 9. When the pressure sensor 59 detects that the upper surface of the mixed developer 68 has risen to the vicinity of the apex of the stirring roller 65 in the stirring chamber 64a, the collection magnet roll 10
4a and the screw 67 are stopped. After the stirring roller 65 is rotated for a predetermined time, the stirring roller 65 is stopped, and the mixed developer 68 is discharged to the outside of the hopper container 62 in the same manner as in the first embodiment.

Incidentally, the hopper container 62 of this embodiment has a structure which can be used as a developer stirring device with the upper container 63 and its internal components similarly to the first embodiment.

[0041]

As described above, according to the present invention, the following effects can be obtained.

(1) stirring the developer in a hopper container,
Since mixing becomes possible, it is not necessary to provide a stirring and mixing means in the developing device. As a result, it is possible to reduce image defects that the stirring and mixing means in the developing device exerts during the developing operation.

(2) Since the hopper container is divided into a developer storage section and a stirring section, only the storage section can be used as a hopper container for supplying the developer to the developing device. Therefore, according to the user's acceptance, use conditions, use environment, it is possible to choose between using a hopper container containing only ordinary new developer or using a hopper container that mixes reused developer with new developer Become.

(3) Even when the developer stirring device of the present invention is used for storing and stirring only a new developer, the developer can be uniformly friction-charged by sufficiently stirring in the stirring section. . As a result, a uniform amount of the developer can be attached to the developing sleeve during development, and the image density can be made uniform.

[Brief description of the drawings]

FIG. 1 is a sectional view of a developer stirring device according to a first embodiment.

FIG. 2 is a sectional view of a developer stirring device according to a second embodiment.

FIG. 3 is a diagram showing a stirring roller used in the first embodiment and the second embodiment.

FIG. 4 is a schematic view of an image forming apparatus provided with the developer stirring device of the present invention.

FIG. 5 is a view showing a conventional developer stirring device.

[Explanation of symbols]

52 Storage section 53b Stirring / mixing section 104a, 104b Developer collecting means (collecting magnet roll) 2, 65 Stirring roller 4a Inner screw 5 Outer screw 4a, 66c Developer suction port 4b Developer jet port 66e Inner cylinder 51 Developer Stirrer 59 Detection means 103 New developer 106 Reused developer

Claims (5)

[Claims] 1. A storage unit for storing a developer, and a stirring and mixing unit for stirring and mixing the developer, wherein the storage unit and the stirring and mixing unit are connected to each other so that the developer can flow in and out. A developer collecting means is provided between the storage section and the stirring and mixing section so as to control the amount of developer flowing in and out, and a cylindrical body and an outer surface of the cylindrical body are provided inside the stirring and mixing section. A developer stirring roller including an outer spiral portion formed, an inner spiral member attached inside the cylindrical body, a developer suction opening formed on the surface of the cylindrical body, and a developer ejection opening. A developer stirring device comprising: a driving unit for driving the outer spiral member and the inner spiral member in the axial direction of the cylindrical body; and a driving force transmitting unit, wherein the stirring and mixing unit is provided inside the cylindrical body. The amount of developer is equal to the outer circumference of the developer stirring roller. A developer detecting means for detecting that the amount reaches the peak of the developer, and wherein the operation of the developer collecting means is controlled in accordance with a detection signal emitted from the detecting means. apparatus. 2. The apparatus according to claim 1, further comprising at least two storage sections for storing different types of developer, respectively, wherein the developer collection means is provided between each storage section and the developer stirring and mixing section. 2. The developer stirring device according to 1. 3. The storage section includes a hopper container including an upper container and a lower container, the upper container and the lower container being in communication with each other, and a developer collecting means including a collecting magnet roll between the two containers. Is provided, the upper container has a developer opening, a stirring member is provided in the upper container, the lower container is divided into a storage unit and a stirring and mixing unit, and the stirring unit is mixed with the storage unit in the lower container. Collection means consisting of collection magnet rolls is provided between the sections, a storage roll in the lower container is provided with a transport roll for reused developer, and a gutter is provided below the transport roll. 2. The developer stirring device according to claim 1, wherein a plurality of stirring / transporting rotary plates are provided below the gutter. 4. The storage section includes a hopper container comprising an upper container and a lower container, the upper container and the lower container being in communication with each other, and a developer collecting means comprising a collecting magnet roll between the two containers. Is provided, the upper container has a developer opening, a stirring member is provided in the upper container, and the lower container is connected to a transfer chamber provided with a reused developer transfer roll. The developer stirring device according to claim 1. 5. An image forming apparatus having a developer stirring means for stirring a developer and forming an image of the developer on a transfer material, wherein the developer stirring means is provided. An image forming apparatus, which is the developer stirring device according to any one of the preceding claims.