JP3025988B2 - Developer stirring and conveying device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing apparatus used for developing an electrostatic latent image into a toner image in an image forming machine such as an electrostatic copying machine and an electrostatic printing machine. The present invention relates to a developer stirring and conveying device to be provided.

[0002]

2. Description of the Related Art As is well known, an electrostatic latent image developing apparatus in which a developer comprising toner and carrier particles is used for developing an electrostatic latent image in an image generator is widely used. . The electrostatic latent image developing device includes a developing housing for containing a developer, a developer applying unit for applying the developer in the developing housing to the electrostatic latent image, and agitating the developer in the developing housing. And a developer stirring / conveying device for conveying the toner in a required direction, and a toner supply unit for supplying toner into the developing housing. The developer applying means usually includes a rotating sleeve member, holds the developer on the peripheral surface of the sleeve member, conveys the developer to a developing area, and selects a toner in the developer into an electrostatic latent image in the developing area. The electrostatic latent image is developed into a toner image. When the toner in the developer is consumed according to the development of the electrostatic latent image, the toner is supplied from the toner supply unit into the development housing. The developer stirring and conveying device stirs the developer in the developing housing to mix and frictionally charge the toner and the carrier particles, and convey the toner and the carrier particles in a required direction.

In the above-described electrostatic latent image developing apparatus, the developer is sufficiently agitated before it is held by the developer applying means and conveyed to the developing area, so that the ratio between the toner and the carrier particles is reduced. It is important that a developer which is within the required range and which is sufficiently uniformly mixed is applied to the electrostatic latent image. Further, on the downstream side of the developing area, the toner is attached to the electrostatic latent image, so that the developer in which the ratio of the toner is reduced is effectively separated from the developer applying means, and is again in the developing housing. It is important that the material be stirred and transported. In order to satisfy such requirements for stirring and transporting the developer, Japanese Utility Model Publication No. 50-33333
JP-A-3-260678 and JP-A-3-260678 disclose a developing device comprising a first stirring / conveying member extending adjacent to a developer applying unit and a second stirring / conveying member disposed upstream of the first stirring / conveying member. An agent stirring and conveying device is disclosed. The first stirring and conveying member is formed with a rotating shaft extending in the width direction (that is, the axial direction of the rotating sleeve member in the developer applying unit) and an axially spaced space between the rotating shaft and the winding direction. The second stirring / conveying member is also formed of a pair of spiral blades which are opposite to each other, and is similarly formed with a rotating shaft extending in the axial direction and spaced apart from the rotating shaft in the width direction, and the winding directions are opposite to each other. Consists of a pair of spiral blades. The first stirring and conveying member is rotated in a predetermined direction, and conveys the developer from both axial end portions toward the central portion in the axial direction while stirring the developer. The developer is transferred to the central portion in the axial direction of the first stirring and conveying member. Let me transport you. Similarly, the second stirring and conveying member rotated in a predetermined direction conveys the developer from the axial center to both ends in the axial direction while stirring the developer, and performs the first stirring and conveying at both ends in the axial direction. The developer is transferred to the member. The developer being conveyed from the center in the axial direction to both ends in the axial direction by the second stirring / conveying member is held by the developer applying unit and conveyed to the developing area. A partition wall having a passage at the center of the width is disposed between the first stirring and conveying member and the second stirring and conveying member. The developer conveyed toward the section is transferred to a second stirring / conveying member through a passage provided in the center of the width of the partition wall.

[0004]

SUMMARY OF THE INVENTION However, the developer agitating and conveying device described above requires the developer carrier to deteriorate when the fluidity of the developer decreases due to environmental changes such as deterioration of the developer carrier and increase in humidity.
The developer stays near the center of the first stirring and conveying member that conveys the developer from both ends in the axial direction toward the center in the axial direction,
The amount of the developer on the side of the second stirring and conveying member becomes insufficient, and the circulation balance is broken, which causes problems in toner density control and stirring and charging performance of the developer.

The present invention has been made in view of the above-mentioned circumstances, and a technical problem thereof is that a developer stays near the center of a stirring and conveying member that conveys from both ends in the axial direction toward the center in the axial direction. An object of the present invention is to provide a developer stirring and conveying device that can constantly stir and convey a developer without any problem.

[0006]

According to the present invention, at least one partition provided in a housing and provided with a developer transfer port in a central portion, and the partition is provided. A first stirring and conveying member provided with a first spiral blade and a second spiral blade that are arranged along the partition on one side thereof and that transports the developer from both ends toward the center, and the other side of the partition A first stirring blade and a second stirring blade, which are provided along the partition wall and transport the developer from the central portion toward both ends, and a second stirring and conveying member having a second spiral blade. The opening edge of the developer transfer port is substantially parallel to each other in the vertical direction at a predetermined interval, and the upper end position reaches a position substantially corresponding to the initial developer height, from the upper end position of the parallel portion Formed by a notch cut out toward the outer end Developer stirring and conveying apparatus is provided, wherein.

Further, according to the present invention, an upstream partition and a downstream partition which are arranged in parallel in a housing at an interval and each have a developer transfer port at a central portion, an upstream partition and a downstream partition. A first stirring / transporting member provided with a first spiral blade and a second spiral blade for transporting the developer from both ends toward the central portion, and a downstream side of the downstream partition wall. A second stirring / transporting member provided along the downstream partition and having a first spiral blade and a second spiral blade for transporting the developer from the center toward both ends, and an upstream side of the upstream partition. A third stirring / transporting member provided with a first spiral blade and a second spiral blade for transporting the developer from a central portion toward both ends from the central portion. The opening edges of the developer transfer ports provided on the upstream partition and the downstream partition are respectively provided at predetermined intervals. A parallel portion extending substantially parallel to each other in the up-down direction and reaching an upper end position substantially corresponding to the initial developer height, and a notch portion cut out from the upper end position of the parallel portion toward the outer end. And a developer stirring / conveying device is provided.

[0008]

In the developer stirring and conveying device of the present invention, the first
When the developer conveyed to the central portion in the axial direction by the first spiral blade of the stirring and conveying member is conveyed to a developer transfer port formed in the partition, the developer is transferred to the second stirring and conveying member side through the developer transfer port. Be transported. In this transporting process, the developer which has been reduced in fluidity due to environmental changes such as deterioration of the developer carrier and an increase in humidity, and which has tended to stay near the center of the first stirring and transporting member, The developer is transported to the second stirring / transporting member side through a notch that forms an opening edge of the developer transport port.

Further, in the developer stirring and conveying device of the present invention, the developer conveyed to the central portion in the axial direction by the first spiral blade of the first stirring and conveying member is formed on the upstream partition and the downstream partition. When the developer is conveyed to the transferred developer transfer port, the developer is transferred to the second stirring and conveying member side and the second stirring and conveying member side through the developer transfer port. In this transporting process, the developer that has been reduced in fluidity due to environmental changes such as deterioration of the developer carrier and an increase in humidity, and that has tended to stay near the center of the first stirring and transporting member is Then, the developer is transferred to the second stirring and conveying member side and the third stirring and conveying member side through the notch portions respectively forming the opening edges of the developer transfer ports.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a developer agitating / conveying apparatus constructed in accordance with the present invention.

FIG. 1 shows an electrostatic latent image developing apparatus provided with a developer stirring / conveying device constructed in accordance with the present invention, together with a part of a rotating drum constituting an electrostatic copying machine.
The rotating drum 2 on which an appropriate electrostatic photoreceptor is disposed on the peripheral surface is rotated in a direction indicated by an arrow 4 to form a developing area 6.
It is configured to pass through. On the upstream side of the developing area 6, an electrostatic latent image is formed on the peripheral surface of the rotating drum 2 by an appropriate method known per se. In the developing area 6, the electrostatic latent image on the peripheral surface of the rotating drum 2 is converted into a toner image by an electrostatic latent image developing apparatus generally designated by reference numeral 8 provided with a developer stirring / conveying apparatus 7 configured according to the present invention. Is developed. Such a toner image is transferred to a transfer member such as plain paper and fixed there on the downstream side of the development area 6, and thus a copy or printed matter is obtained.

Continuing the description with reference to FIGS. 1 and 2,
The electrostatic latent image developing device 8 includes a developing housing 10. The developing housing 10, which can be molded from any suitable synthetic resin, includes a front end wall 18 and a rear end wall 20, along with a bottom wall 12 and a rear wall 16 extending substantially vertically upward from the rear edge of the bottom wall 12. I have. The rear wall 16 is connected to an upper wall 22 that projects substantially horizontally forward from the upper end thereof, and a cover wall 24 is further connected to the upper wall 22.

Continuing the description with reference to FIGS. 1 and 2,
The electrostatic latent image developing device 8 includes a developing housing 10. The developing housing 10, which can be molded from any suitable synthetic resin, includes a front end wall 18 and a rear end wall 20, along with a bottom wall 12 and a rear wall 16 extending substantially vertically upward from the rear edge of the bottom wall 12. I have. The rear wall 16 is connected to an upper wall 22 that projects substantially horizontally forward from the upper end thereof, and a cover wall 24 is further connected to the upper wall 22.

A developer applying means 26 is provided at the forefront of the developing housing 10 (the leftmost part in FIG. 1, and the uppermost part in FIG. 2). The developer applying means 26 includes a sleeve member 28 extending substantially horizontally in the width direction, and a permanent magnet member 30 disposed in the sleeve member 28. The sleeve member 28 is made of a non-magnetic material such as aluminum and is rotatably mounted.
The permanent magnet member 30 is fixed at a predetermined position. As shown in FIG. 2, the rotating shaft 31 to which the sleeve member 28 is fixed projects through the rear end wall 20 of the developing housing 10 and projects rearward.
2 is fixed. The input gear 32 is drivingly connected to a rotary drive source (not shown), which may be an electric motor, via an input gear (not shown) of the rotary drum 2, and is driven to rotate in a direction shown by an arrow 34. Can be Free edge 35 of the cover wall 24 of the developing housing 10
Is located close to the peripheral surface of the sleeve member 28 of the developer applying means 26, and as will be described in more detail later, the developer is held on the peripheral surface of the sleeve member 28 and transported to the development area 6. It functions as a so-called ear cutting means for regulating the amount of the agent.

Behind the developer applying means 26, a developer stirring and conveying device 7 constructed in accordance with the present invention is provided. In the illustrated embodiment, the developer stirring and conveying device 7 includes an upstream partition 38 that is disposed parallel to the developing housing 10 at predetermined intervals in the front-rear direction (the left-right direction in FIG. 1 and the up-down direction in FIG. 2). And a downstream partition 40. The upstream partition wall 38 is provided on the bottom wall 1 of the developing housing 8.
2 are defined by upright walls 42 and 44 projecting substantially vertically upward. Similarly, the downstream partition means 40 also includes the upright walls 46 and 4 projecting substantially vertically upward from the bottom wall 12 of the developing housing 8.
8. As can be clearly understood from FIG. 1, the lower end side surfaces of each of the upright walls 42, 44, 46 and 48 are formed in a concave arc shape. As can be clearly understood by referring to FIG. 2, the width direction (the direction perpendicular to the paper surface in FIG. 1, the left-right direction in FIG. 2)
Upright walls 42 and 4 at the center and both ends in the width direction
4 are not present, and the developer transfer ports 50, 52, and 5 are provided at the center in the width direction and both ends in the width direction of the upstream partition wall 38, respectively.
4 are provided. Similarly, the upright walls 46 and 48 are not present at the widthwise center portion and the widthwise both end portions, and the developer transfer ports 56, 58 and 60 are also provided at the widthwise center portion and the widthwise both end portions of the downstream partition wall 40, respectively. Are arranged.

A developer transfer port 50 provided at the center in the width direction of the upstream partition 38 is defined between the inner ends of the upright walls 42 and 44 constituting the upstream partition 38 as shown in FIG. The opening edges are parallel portions 422 and 442 extending in a vertical direction at predetermined intervals, and are cut out from the upper ends of the parallel portions 422 and 442 to the respective outer ends. It is formed by notches 424 and 444. The upper ends of the parallel portions 422 and 442, that is, the notch portions 4
The starting points 426 and 446 of 24 and 444 are set at positions corresponding to the initial developer height (H) or slightly higher than the initial developer height (H). In the present embodiment, the positions substantially correspond to the initial developer height (H). It is set at a position about 5 mm higher than that. Here, the initial developer height (H) means that the carrier and the toner are first mixed, the developer which has not yet been developed is put into the electrostatic latent image developing device, and the developer stirring and conveying device is operated. Means the height of the developer from the bottom surface of the developing housing when the flow of the developer is stabilized. This initial developer height (H) is
Even if the developer is conveyed and circulated by the stirring and conveying member described later, there is no large change. The notch portions 424 and 444 constituting the opening edge of the developer transfer port 50 have an inclination angle α of 4
It is desirably 5 ° or less, and is set to about 30 ° in this embodiment. The height of the upright walls 42 and 44 constituting the upstream partition 38 depends on the fluidity of the developer to be used. However, the height is 5 from the starting points 426 and 446 of the notches 424 and 444.
It is necessary to set it at a position higher than about mm.

The developer transfer port 56 provided at the center in the width direction of the downstream partition 40 is also defined between the inner ends of the upright walls 46 and 48 constituting the downstream partition 40 as shown in FIG. The opening edges are parallel portions 462, 482 extending in the vertical direction at predetermined intervals and are substantially notched so as to be inclined from the upper ends of the parallel portions 462, 482 toward the outer ends. It is formed by notches 464 and 484. The upper ends of the parallel portions 462 and 482, that is, the notch 4
In the present embodiment, the starting points 466 and 486 of 64 and 484 are set at positions higher than the position corresponding to the initial developer height (H) by about 5 mm, and the upright walls 42 and 44 constituting the upstream partition wall 38. Is set at a position higher than the starting points 466 and 486 of the notches 464 and 484 by about 5 mm or more. Further, the inclination angle α of the notches 464 and 484 is set to about 30 ° similarly to the notches 424 and 444 forming the opening edge of the developer transfer port 50 formed in the upstream partition wall 38. The interval W2 between the parallel portions 462 and 482 forming the opening edge of the developer transfer port 56 provided at the center of the downstream partition 40 in the width direction is provided at the center of the upstream partition 38 in the width direction. Developer transfer port 5
The distance W1 between the parallel portions 422 and 442 constituting the opening edge of 0
It is set larger. That is, if the interval W2 and the interval W1 are configured to be substantially the same, the developer accumulates in the central portion, and if the interval W2 is too large relative to the interval W1, the developer in the central portion runs short. The above interval W
The relationship between 2 and W1 is set by various factors such as the size of the apparatus and the copying speed. According to experiments performed by the present inventors, the interval W2 is 1.3 to 4.0 of the interval W1.
The ratio is preferably 1.5 times, preferably 1.5 to 2.5 times.

Next, another embodiment relating to the shape of the opening edge constituting the developer transfer ports 50 and 56 will be described with reference to FIG.
This will be described with reference to FIG. The same members as those in the embodiment shown in FIG. 3 are denoted by the same reference numerals, detailed description thereof will be omitted, and the developer transfer ports 50 and 56 will have the same shape. The description of the reference numerals indicating the parts is given in parentheses. In the embodiment shown in FIG. 5, the notch constituting the developer transfer port 50 (56) has a parallel portion 422 (46).
2), the upper end of 442 (482), ie, the starting point 4 of the notch
Horizontal portions 423 (463) and 443 (483) extending from 26 (466) and 446 (486) to the outer ends, respectively.
And the inclined portions 425 (465), 4 inclined from the horizontal portions 423 (463), 443 (483) toward the outer ends, respectively.
45 (485). FIG.
In the embodiment shown in FIG. 5, the notch constituting the developer transfer port 50 (56) is the upper end of the parallel portions 422 (462) and 442 (482), that is, the notches 424 (466) and 444 (486).
Arc portions 427 each extending toward the outer end from the starting point of
(467) and 447 (487).

The illustrated developer stirring and conveying device 7 includes a first stirring and conveying member 62 disposed between the upstream partition 38 and the downstream partition 40, and a downstream side of the downstream partition 40. That is, the second side disposed along the downstream partition 40 on the front side)
A third conveying member 64 disposed along the upstream partition wall 38 on the upstream side (that is, the rear side) of the upstream partition wall 38.
Is provided. The first stirring and conveying member 62, the second stirring and conveying member 64, and the third stirring and conveying member 66 are disposed on the same plane in the illustrated embodiment.

The first stirring and conveying member 62 has a rotating shaft 68 rotatably mounted between both end walls 18 and 20 of the developing housing 10. A pair of first spiral blades 7 are provided on the rotating shaft 68 at intervals in the width direction (ie, axial direction).
Zero and second spiral blades 72 are formed. This first
Neither of the inner ends of the spiral blade 70 and the second spiral blade 72 reach the axial center of the first stirring and conveying member 62, and the inner ends of the first stirring and conveying member 62 1
Of the spiral blade 70 and the second spiral blade 72 are not provided. The first spiral blade 70 and the second spiral blade 72
The spirals are wound in opposite directions. The outer diameter of the first spiral blade 70 and the outer diameter of the second spiral blade 72 are the same. The first developer stirring and conveying member 62 thus configured is rotated in a direction indicated by an arrow 108 in FIG. 1, and conveys the developer from both ends toward the center while stirring. An inclined elliptical plate 73 is provided at the axial center of the rotating shaft 68. The axial dimension of the inclined elliptical plate 73 is determined by the parallel portions 462 and 482 constituting the developer transfer port 56 provided at the center in the width direction of the downstream partition wall 40.
Are formed substantially the same as the interval W2. Inclined elliptical plate 73
Has a circular shape in a side view, and the diameter of the circular shape is substantially the same as the outer diameter of the first spiral blade 70 and the second spiral blade 72.

The second stirring and conveying member 64 also has a rotating shaft 74 rotatably mounted between both end walls 18 and 20 of the developing housing 10. A pair of first spiral blades 7 are spaced apart from each other on the rotating shaft 74 in the width direction (ie, axial direction).
Sixth and second spiral blades 78 are formed. This first
Neither of the inner ends of the spiral blades 76 and the second spiral blades 78 reach the axial center of the second stirring and conveying member 64, and the inner ends of the second stirring and conveying member 64 1
Of the spiral blade 76 and the second spiral blade 78 are not provided. Note that the first stirring and conveying member 64
The inner ends of the spiral blade 76 and the second spiral blade 78 are connected to the first spiral blade 7 provided on the first stirring and conveying member 62.
It is located inside, that is, on the axial center 200 side from the inner ends of the zero and second spiral blades 72. The first spiral blade 76 and the second spiral blade 78 are formed such that the spiral winding directions are opposite to each other. The outer diameter of the first spiral blade 76 and the outer diameter of the second spiral blade 78 are the same. The outer ends of the first spiral blade 76 and the second spiral blade 78 in the axial direction are connected to the developer transfer ports 5 disposed at both widthwise ends of the downstream partition 40.
Conveniently, it is located substantially corresponding to the middle in the width direction of 8 and 60. A first spiral blade 76 is provided at both ends of the rotating shaft 74.
A first auxiliary spiral blade 80 and a second auxiliary spiral blade 82 are formed so as to face the second spiral blade 78, respectively. The outer diameters of the first auxiliary spiral blade 80 and the second auxiliary spiral blade 82 may be the same as the outer diameters of the first spiral blade 76 and the second spiral blade 78. The winding direction of the first auxiliary spiral blade 80 and the second auxiliary spiral blade 82 extending over an angle range of approximately 360 degrees is relative to the winding direction of the opposing first spiral blade 76 and second spiral blade 78. In the opposite direction. The second developer stirring and conveying member 6 configured as described above
Reference numeral 4 is rotated in a direction indicated by an arrow 110 in FIG. 1, and conveys the developer from the center to both ends while stirring.

Continuing the description with reference to FIG.
The agitating and conveying member 66 also has a rotating shaft 84 rotatably mounted between both end walls 18 and 20 of the developing housing 10. A pair of first spiral blades 86 and second spiral blades 88 are formed on the rotating shaft 84 at intervals in the width direction (ie, axial direction). The inner ends of the first spiral blade 86 and the second spiral blade 88 do not reach the axial center of the third stirring / conveying member 66, and the axial center of the third stirring / conveying member 66. The portion is not provided with the first spiral blade 86 and the second spiral blade 88. The first spiral blade 86 and the second spiral blade 88 are formed such that the spiral winding directions are opposite to each other. The outer diameter of the first spiral blade 86 and the outer diameter of the second spiral blade 88 are the same. The widthwise outer ends of each of the first spiral blade 86 and the second spiral blade 88 are located substantially at the center in the width direction of the developer transfer ports 52 and 54 provided at both widthwise ends of the upstream partition means 38. Conveniently located correspondingly. The first ends of the rotating shaft 84
A first auxiliary spiral blade 90 and a second auxiliary spiral blade 92 located opposite to the spiral blade 86 and the second spiral blade 88, respectively. The outer diameters of the first auxiliary spiral blade 90 and the second auxiliary spiral blade 92 may be the same as the outer diameters of the first spiral blade 86 and the second spiral blade 88. The winding direction of the first auxiliary spiral blade 90 and the second auxiliary spiral blade 92 extending over an angle range of about 360 degrees is the same as the winding direction of the opposing first spiral blade 86 and second spiral blade 88. In the opposite direction. The third developer stirring and conveying member 66 configured as described above is rotated in the direction indicated by the arrow 106 in FIG. 1, and conveys the developer from the center to both ends while stirring. An inclined elliptical plate 93 is provided at the axial center of the rotating shaft 84. This inclined elliptical plate 9
The axial dimension of 3 is the parallel portion 422 that forms the developer transfer port 50 provided at the center in the width direction of the upstream partition wall 38.
And 442 are substantially the same as the interval W1. The inclined elliptical plate 93 has a circular shape in the side view similarly to the inclined elliptical plate 73, and the diameter of the circular shape is the first spiral blade 86.
And the outer diameter of the second spiral blade 88 is substantially the same.

Referring to FIG. 2 and FIG. 7, the first
The rotating shaft 68 of the stirring and conveying member 62, the rotating shaft 74 of the second stirring and conveying member 64, and the rotating shaft 84 of the third stirring and conveying member 66 pass through the rear end wall 20 of the developing housing 10 and move rearward. These rotating shafts 68,
At the rear ends of 74 and 84, input gears 98, 100,
102 is fixed. The input gear 102 is the input gear 9
8 and the input gear 98 is the input gear 1
00, and the input gear 100 is engaged with the input gear 32 of the developer applying means 26 via a transmission gear 104 rotatably mounted on the rear end wall 20. Accordingly, when the sleeve member 28 of the developer applying unit 26 is rotated in the direction indicated by the arrow 34 by the above-mentioned rotation drive source (not shown), the first stirring / conveying member 62 is moved to the arrow 108 as shown in FIG. , The second stirring and conveying member 64 is rotated in the direction indicated by the arrow 110, and the third stirring and conveying member 66 is rotated in the direction indicated by the arrow 106.

As shown in FIG. 1, the developing housing 10
A developer 112 composed of toner and carrier particles is accommodated therein. The developer 112 flows upstream of the upstream partition 38 (right side in FIG. 1 and lower in FIG. 2), between the upstream partition 38 and the downstream partition 40, and in the downstream partition 40.
Are appropriately dispersed and accommodated on the downstream side (left side in FIG. 1, upper side in FIG. 2). The third stirring and conveying member 66 rotated in the direction indicated by the arrow 106 conveys the developer from the central portion in the axial direction to both ends in the axial direction while stirring the developer on the upstream side of the upstream partition wall 38. That is, the first spiral blade 86 of the third stirring / conveying member 66 conveys the developer from the central portion in the axial direction to one end in the axial direction (the left end portion in FIG. 2) while stirring the developer. The second spiral blade 88 of the member 66 conveys the developer from the center in the axial direction to the other end in the width direction (the right end in FIG. 2) while stirring the developer. Third
The first auxiliary spiral blade 90 of the agitating and conveying member 66 forcibly pushes the developer in the axial direction at one end in the width direction, and the first auxiliary spiral blade 92 pushes the developer in the axial direction at the other end in the axial direction. To force. The first stirring and conveying member 62 rotated in the direction indicated by the arrow 108 conveys the developer from the both ends in the axial direction toward the center in the axial direction while stirring the developer between the upstream partition 38 and the downstream partition 40. I do. That is, the first spiral blade 70 of the first stirring and conveying member 62 conveys the developer from one end in the axial direction (left end in FIG. 2) toward the center in the axial direction while stirring the developer. The second spiral blade 72 of the member 62 conveys the developer while stirring it. Arrow 1
Second stirring and conveying member 64 rotated in the direction indicated by 10
Transports the developer from the central portion in the axial direction to both ends in the axial direction while stirring the developer on the downstream side of the downstream partition wall 40.
That is, the first spiral blade 76 of the second stirring and conveying member 64 conveys the developer from the central portion in the axial direction to one end in the axial direction (the left end portion in FIG. 2) while stirring the developer. The second spiral blade 78 of the member 64 conveys the developer from the center in the axial direction to the other end in the axial direction (the right end in FIG. 2) while stirring the developer. The first of the second stirring and conveying members 64
The auxiliary spiral blade 80 forcibly pushes the developer axially inward at one end in the axial direction, and the second auxiliary spiral blade 82 pushes the developer axially inward at the other end in the axial direction.

The transporting ability of the first stirring and transporting member 62 for transporting the developer from both ends in the axial direction toward the center in the axial direction is as follows.
A second stirring and conveying member 64 and a third stirring and conveying member 66 that convey the developer from the axial center toward both ends in the axial direction.
It is important that the transfer capacity is set to be larger than each transfer capacity. The transport of the developer from the axial ends to the axial center and the transport of the developer from the axial center to the axial ends are substantially balanced, and the developer is sufficiently uniform over the entire axial direction. In order to make it exist, the conveying capacity of the first stirring and conveying member 62 is made to substantially match the sum of the conveying ability of the second stirring and conveying member 64 and the conveying ability of the third stirring and conveying member 66. Is preferred. Further, it is preferable that the transfer capacity of the second stirring and conveying member 64 is set to be larger than that of the third stirring and conveying member 66, and the conveying capacity of the second stirring and conveying member 64 is set to be the third. It is convenient that the transfer capacity is about 1.2 to 2.5 times the transfer capacity of the stirring transfer member 66 (the reason will be further described later). The transfer capacity of the first stirring and conveying member 62, the second stirring and conveying member 64, and the third stirring and conveying member 66 are the first and second stirring and conveying members.
The rotation speed, pitch and outer diameter of the spiral blades 70 and 72, 76 and 78 and 86 and 88 can be set as required. In the illustrated embodiment, the rotation speed per unit time of the second stirring and conveying member 64 and the rotation speed per unit time of the third stirring and conveying member 66 are the same. The rotation speed of the stirring and conveying member 62 per unit time is set to be large. The pitch of the first and second spiral blades 76 and 78 of the second stirring and conveying member 64 is the third stirring and conveying member 66.
Is larger than the pitch of the first and second spiral blades 86 and 88, and the pitch of the first and second spiral blades 70 and 72 of the first stirring and conveying member 62 is the first and second of the second stirring and conveying member 64. It is even larger than the second spiral blades 76 and 78.
The first and second spiral blades 86 of the third stirring and conveying member 66
And 88 and the outer diameters of the first and second spiral blades 76 and 78 of the second stirring and conveying member 64 are the same, but are larger than these outer diameters. The outer diameter of the second spiral blades 70 and 72 is large.

Continuing the description with reference to FIGS. 1 and 2,
A circular opening 114 is formed in the bottom wall 12 of the developing housing 10 between the upstream partition 38 and the downstream partition 40 and at the center in the width direction. The opening 114 has a detector 1 for detecting the toner concentration in the developer 112.
16 are provided. This detector 116 has an aperture 11
The detection of the toner density in the developer 112 by detecting the magnetic permeability of the developer 112 present on the upper surface exposed in the development housing 10 through the sensor 4 may be of a known form. The electrostatic latent image developing device 8 further includes a developer 11 detected by a detector 116.
2 is provided with a toner supply unit that is operated in accordance with the toner concentration in the toner supply unit 2. The toner supply means includes a supply pipe 118 provided on the upper wall 22 of the developing housing 10. One end of the feed pipe 118 is
The third agitating / conveying member 66 is positioned above a central portion in the axial direction, and a lower surface thereof has an outlet 120 communicating with the inside of the developing housing 10. The other end of the feed pipe 118 extending from the one end to the front end in the width direction is communicated with a toner container (not shown).
A toner conveying means (not shown), which can be constituted by spiral blades, is provided in the inside 18. When the toner concentration in the developer 112 detected by the detector 116 becomes equal to or lower than a predetermined value, the toner conveying means in the supply pipe 118 is operated, and the toner is conveyed from the toner container through the supply pipe 118, and the toner is conveyed. From the outlet 120 to the developing housing 1
It is dropped on the inclined elliptical plate 93 of the third stirring / conveying member 66 in the area 0. When the toner concentration detected by the detector 116 becomes equal to or more than a predetermined value, the operation of the toner conveying means in the supply pipe 118 is stopped, and the supply of the toner into the developing housing 10 is stopped.

Next, the operation and effect of the electrostatic latent image developing device 8 having the developer stirring and conveying device 7 as described above will be summarized and described as follows. As shown by the arrows in FIG. 2, the toner dropped from the delivery port 120 formed in the delivery pipe 118 of the toner supply means is moved from the central portion in the axial direction by the action of the inclined elliptical plate 93 of the third stirring / conveying member 66. The toner is evenly distributed on both sides and mixed with the developer 112 in the developing housing 10. The developer 1 existing on the upstream side (the right side in FIG. 1) of the third upstream partition 38.
12 is conveyed from the axial center to both sides in the axial direction while being stirred by the action of the first and second spiral blades 86 and 88 of the third stirring and conveying member 66. Since the conveying capacity of the third stirring and conveying member 66 is set relatively small, the developer 112 is conveyed by the third stirring and conveying member 66 from the central portion in the axial direction to both sides in the axial direction at a relatively low speed.
At this time, it is sufficiently stirred. Developer 112 conveyed to both axial sides by third stirring / conveying member 66
Is transferred forward through developer transfer ports 52 and 54 provided on both sides in the width direction of the upstream partition 38 and is introduced between the upstream partition 38 and the downstream partition 40.

Next, the upstream partition 38 and the downstream partition 40
Between the first stirring and conveying member 6
While being stirred by the action of the second first and second spiral blades 70 and 72, it is conveyed from both sides in the axial direction to the center in the axial direction. At the central portion in the axial direction of the first stirring / conveying member 62, a part of the developer 112 is transferred forward through the developer transfer port 56 provided at the central portion in the width direction of the downstream partition means 38, and the development is performed. Part of the agent 112 is used as the upstream partition means 4
The developer is transported rearward through a developer transport port 50 disposed at the center in the width direction of the “0”. At this time, the developer 112 conveyed from one side in the axial direction is appropriately distributed to both sides in the axial direction and is conveyed from the other side in the axial direction by the action of the inclined elliptical plate 73 in the first stirring and conveying member 62. The developer 112 is appropriately distributed on both axial sides. The interval W2 between the parallel portions 462 and 482 forming the developer transfer port 56 disposed at the center in the width direction of the downstream partition means 40
Is relatively large, a relatively large amount of the developer 112 is caused to enter the downstream side of the downstream partition means 40 through the developer transfer port 56. Upstream partition means 30
Since the distance W1 between the parallel portions 422 and 442 constituting the developer transfer port 50 disposed at the center in the width direction is set relatively small, the upstream side of the upstream partition means 38 passes through the developer transfer port 50. The amount of the developer 112 returned to the toner supply port is relatively small, and the toner dropped from the toner outlet 120 described above is transferred to the third stirring / conveying member 66.
Thus, it is possible to sufficiently and reliably avoid being introduced between the upstream partition means 38 and the downstream partition means 40 through the developer transfer port 50 without being transported while being stirred. In the transporting process, when the fluidity of the developer decreases due to environmental changes such as deterioration of the developer carrier and increase in humidity, the developer is transported from both axial ends to the axial center. The developer stays in the vicinity of the center of the first stirring and conveying member 62, and the amount of the developer on the second stirring and conveying member 64 and the third stirring and conveying member 66 is in an insufficient state. Problems occur in density control. In the illustrated embodiment, the opening edges of the developer transfer ports 50 and 56 formed in the upstream partition wall 38 and the downstream partition wall 40 provided on both sides of the first stirring and conveying member 62 have a predetermined interval. Parallel portions 42 extending substantially in the vertical direction
2, 442 and 462, 482 and the parallel portions 422, 4
Cutouts 424, 444, and 46, which are cut out from the upper ends of 42, 462, and 482, respectively, toward the outer ends.
4 and 484, the developer that has sought to stay near the center of the first stirring / conveying member 62 has the cutouts 424, 444 and 46.
4 and 484 through the third stirring and conveying member 66 side and the second
Is transferred to the stirring and conveying member 64 side. Therefore, the developer is smoothly circulated without staying near the center of the first stirring and conveying member 62.

The developer transferred to the front from the developer transfer port 56 including the lower opening 564 and the upper opening 562 disposed at the center in the width direction of the downstream partition 40 is supplied to the second stirring and transporting member 64. While being stirred by the action of the first spiral blade 76 and the second spiral blade 78, it is conveyed from the axial center to both axial sides. Then, the developer 112 conveyed to both sides in the axial direction is transferred rearward through the developer transfer ports 58 and 60 provided on both sides in the width direction of the downstream partition 40, and is connected to the upstream partition 38 and the downstream. After being returned to the space between the side partition walls 40 and then being stirred by the action of the first spiral blade 70 and the second spiral blade 72 of the first stirring and transporting member 62, the transport is carried from the axially opposite side portions to the axially central portion. Is done.

Continuing the description with reference to FIGS.
The downstream side of the third stirring and conveying member 64 (the left side in FIG. 1,
2 (upper side in FIG. 2), the sleeve member 28 of the developer applying unit 26 is rotated in the direction indicated by the arrow 34. In the developer pumping area indicated by reference numeral 122 in FIG. 1, while being stirred by the action of the first spiral blade 76 and the second spiral blade 78 of the second stirring and conveying member 64, both sides in the axial direction from the axial center portion. A part of the developer 112 conveyed to the portion is pumped to the peripheral surface of the sleeve member 28 due to the magnetic field formed by the stationary permanent magnet member 30. The developer 112 pumped to the peripheral surface of the sleeve member 28 is rotated by the arrow
Are transported in the direction shown by the arrow and transported to the developing zone 6. At this time, the free edge 3 of the cover wall 24 of the developing housing 10 is
By the operation of 5, excess developer 112 is removed from the peripheral surface of the sleeve member 28. In the developing area 6, as described above, the toner in the developer 112 is selectively adhered to the electrostatic latent image formed on the peripheral surface of the rotating drum 4, and the electrostatic latent image is formed on the toner image. Developed. In the developer stripping region 124 located downstream of the developing region 6, the developer 1 is removed from the peripheral surface of the sleeve member 28 due to the magnetic field formed by the permanent magnet member 30 being reduced.
12 is removed. The toner density of the developer 112 is reduced due to consumption of the toner in the developing area 6. The developer 112 released from the peripheral surface of the sleeve member 28 is mixed into the developer 112 in the developing housing 10 and is acted on by the first spiral blade 76 and the second spiral blade 78 of the second stirring and conveying member 64. It is conveyed to both sides in the axial direction while being stirred. Since the carrying capacity of the second stirring / conveying member 64 is set to be larger than the carrying capacity of the third stirring / conveying member 66, the developer peeling area 1
At 24, the developer 112 is sufficiently satisfactorily removed from the peripheral surface of the sleeve member 28, and the developer 112 is mixed with the developer 112 into the developing housing 10 quickly enough to be stirred.

Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to only the embodiment, and various modifications are possible within the technical idea of the present invention. In the above-described embodiment, an example in which three stirring and conveying members are used has been described. However, two or more stirring and conveying members may be used.

[0032]

As described above, the developer stirring and conveying device according to the present invention is arranged between the first stirring and conveying member and the second stirring and conveying member (and the third stirring and conveying member). The opening edge of the developer transfer port provided in the partition wall is substantially parallel to each other in the vertical direction at a predetermined interval, and the parallel portion reaches an upper end position substantially corresponding to the initial developer height; And the notch portion cut out from the upper end position toward the outer end, the fluidity of the developer decreases due to environmental changes such as deterioration of the developer carrier and increase in humidity, and the first The developer that has sought to stay near the central portion of the stirring and conveying member is transferred to the second stirring and conveying member through a cutout portion of the opening edge constituting the developer transfer port. Therefore, the developer is smoothly circulated without staying near the center of the first stirring and conveying member, and the proper toner density can be always maintained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of an electrostatic latent image developing device provided with a developer stirring and conveying device configured according to the present invention.

FIG. 2 is a plan view showing the electrostatic latent image developing device provided with the developer agitating and conveying device shown in FIG. 1 and omitting an upper wall and a cover member of a developing housing;

FIG. 3 is an enlarged explanatory view showing a developer transfer port formed in an upstream partition wall in the developer stirring and transporting device configured according to the present invention shown in FIG. 1;

FIG. 4 is an explanatory diagram showing an enlarged view of a developer transfer port formed in a downstream partition in the developer stirring and transporting device configured according to the present invention shown in FIG. 1;

FIG. 5 is an explanatory diagram showing, in an enlarged manner, another embodiment of the developer transfer port formed in the upstream partition and the downstream partition in the developer stirring and transporting device configured according to the present invention shown in FIG. 1;

FIG. 6 is an enlarged explanatory view showing still another embodiment of a developer transfer port formed in an upstream partition and a downstream partition in the developer stirring and transporting device shown in FIG. 1 according to the present invention.

FIG. 7 is a simplified diagram showing a driving connection gear in the electrostatic latent image developing device shown in FIG. 1;

[Explanation of symbols]

 2: rotating drum 6: developing area 7: developer stirring and conveying device 8: electrostatic latent image developing device 10: developing housing 26: developer applying means 28: sleeve member 30: permanent magnet member 38: upstream partition wall 40: downstream Side partition 42: Upright wall 44: Upright wall 46: Upright wall 48: Upright wall 50: Developer transfer port 52: Developer transfer port 56: Developer transfer port 56: Developer transfer port 58: Developer transfer port 60: Developer transfer port 62: first stirring and conveying member 64: second stirring and conveying means 66: third stirring and conveying means 68: rotating shaft 70: first spiral blade 72: second spiral blade 74: rotating shaft 76: 1st spiral blade 78: 2nd spiral blade 80: 1st auxiliary spiral blade 82: 2nd auxiliary spiral blade 84: rotating shaft 86: 1st spiral blade 88: 2nd spiral blade 90: First auxiliary spiral blade 92: Second Auxiliary spiral blade 112: developer 116: detector (toner density detector) 118: delivery pipe of toner supply means 120: delivery port 422: parallel section 424: notch section 442: parallel section 444: notch section 462: parallel section 464 : Notch 482: Parallel part 484: Notch

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinji Kikuta 1-2-2, Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Inventor Akihiko 1-2-28 Tamazo, Chuo-ku, Osaka-shi Mita Kogyo (56) References JP-A-5-72891 (JP, A) JP-A-7-121017 (JP, A) JP-A 8-220890 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03G 15/08-15/095

Claims (6)

(57) [Claims] At least one partition provided in a housing and having a developer transfer port at a center portion, and disposed along the partition on one side of the partition, and the developer is supplied from both ends to the central portion. A first stirring / transporting member having a first spiral blade and a second spiral blade for transporting the developer, and the developer is disposed along the partition on the other side of the partition, and the developer is directed from the center toward both ends. A second stirring and conveying member having a first spiral blade and a second spiral blade for conveying, and an opening edge of a developer transfer port provided in the partition wall is vertically spaced at a predetermined interval. A parallel portion extending substantially parallel to each other and having an upper end position substantially corresponding to the initial developer height, and a notch portion cut out from the upper end position of the parallel portion toward an outer end thereof. A developer stirring and conveying device. 2. An upstream partition and a downstream partition which are arranged in parallel in a housing at intervals and each have a developer transfer port at a central portion, and are disposed between the upstream partition and the downstream partition. And a first spiral blade and a second spiral blade for transporting the developer from both ends toward the center.
A first stirring / transporting member provided with a spiral blade, a first spiral blade disposed downstream of the downstream partition along the downstream partition and transporting the developer from a central portion toward both ends; A second stirring / conveying member having a second spiral blade; a first spiral disposed on the upstream side of the upstream partition along the upstream partition, and transporting the developer from the center toward both ends. A third stirring / transporting member having a blade and a second spiral blade; and an opening edge of a developer transfer port provided in the upstream partition and the downstream partition is vertically spaced at predetermined intervals, respectively. A parallel portion extending substantially parallel to each other in the direction and reaching an upper end position substantially corresponding to the initial developer height, and a notch portion cut out from the upper end position of the parallel portion toward the outer end, A developer stirring and conveying device, comprising: 3. The conveying capacity of the first stirring and conveying member is as follows:
The developer stirring and conveying device according to claim 2, wherein the conveying capacity of the second stirring and conveying member and the conveying capability of the third stirring and conveying member are set to be larger. 4. The transport capacity of the first stirring transport member is as follows:
3. The developer stirring and conveying apparatus according to claim 2, wherein the conveying ability of the second stirring and conveying member and the conveying ability of the third stirring and conveying member substantially match. 5. The conveyance capacity of the second stirring and conveying member is as follows:
3. The developer stirring and conveying apparatus according to claim 2, wherein the conveying capacity of the third stirring and conveying member is set to be larger than that of the third stirring and conveying member. 6. An interval between parallel portions forming an opening edge of the developer transfer port provided in the downstream partition wall is equal to that of a parallel portion forming an opening edge of the developer transfer port provided in the upstream partition wall. 3. The developer stirring and conveying device according to claim 2, wherein the distance is set to be larger than the interval.