JPH10293462A - Developer stirring and carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely mix, stir and triboelectrify supplied toner with developer by providing a partition plate for regulating the movement in the axial direction of toner which exists on an upper side than spiral blades constituting a stirring and carrying means out of toner dropped and supplied to a developer carrying path. SOLUTION: The partition plate 130 is located at the same position as the upper end position of the spiral blades 118 and 120 of an upstream stirring and carrying means 114 whose lower end is disposed in an upstream carrying path. When the toner dropped to the center part of the upstream carrying path through a toner supply port 23 is accumulated on the upper side than the lower end of the plate 130, the movement of the toner on the upper side than the lower end of the plate 130 to both sides is regulated by the plate 130. The toner accumulated on the upper side than the lower end of the plate 130 is fed to both sides when it reaches to the lower side than the lower end of the plate 130 after the toner on the lower side is moved to both sides. Therefore, the toner is not carried in a state where it suspends while riding on the flow of the developer carried by the blades 118 and 120. Therefore, the supplied toner is mixed with the developer in an early stage and completely stirred and triboelectrified by the means 114.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer provided in an electrostatic latent image developing apparatus 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 stirring and conveying device.

[0002]

2. Description of the Related Art As is well known, an electrostatic latent image developing apparatus in which a developer including toner and carrier particles is used for developing an electrostatic latent image in an image forming machine 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 means for conveying the toner in a required direction, and a toner supplying means 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 agitating / conveying means agitates the developer in the developing housing and the toner supplied from the toner supplying means 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 being held by the developer applying means and transported to the developing area, and the ratio of toner to carrier particles is required. It is important that the developer which is within the range and is uniformly mixed is applied to the electrostatic latent image. Further, on the downstream side of the developing area, the developer in which the toner is attached to the electrostatic latent image and the ratio of the toner is reduced is effectively separated from the developer applying means, and is stirred again in the developing housing. It is important that they be transported.
For example, Japanese Patent Application Laid-Open No. Hei 7-175306 discloses a developer stirring and conveying device that conveys a developer while stirring it well. Japanese Patent Application Laid-Open No. Hei 7-175306 discloses that a downstream conveying path, a middle conveying path, and an upstream conveying path are provided in a developing housing in parallel with a developer applying unit, and a downstream conveying path, a middle conveying path, a middle conveying path, and an upstream conveying path are provided. A downstream partition and an upstream partition each having a developer transfer port at the center thereof are provided between the first and second passages, and a spiral winding direction of the spiral for conveying the developer from the center to both ends in the downstream transfer path is provided. The downstream agitating and conveying means provided with the first spiral blade and the second spiral blade formed opposite to each other, the winding directions of the spirals for transporting the developer in the middle flow path from both ends toward the center are mutually opposite. The middle agitating and conveying means provided with the first spiral blade and the second spiral blade formed in reverse, the winding directions of the spirals for transporting the developer from the center to both ends in the upstream transport path are opposite to each other. The first spiral blade formed and the second spiral blade Upstream stirring and conveying means provided with spiral blades are respectively provided, and the developer conveyed to the downstream conveying path by the upstream stirring and conveying means and the midstream stirring and conveying means and further conveyed by the downstream stirring and conveying means is applied to the developer. A developer agitating and conveying device configured to supply to the means is disclosed. In the developer stirring and conveying device configured as described above, 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 to the central portion of the upstream conveyance path from above. It is designed to be supplied by falling.

[0004]

When the toner dropped and supplied from above to the central portion of the upstream conveying path is deposited above the upstream stirring and conveying means, the toner is conveyed in the axial direction by the stirring and conveying means. There is a case where the toner is supplied to the developer applying unit in a state where the toner is sufficiently stirred and is not triboelectrically charged because the developer is merely suspended and carried on the flow of the developer. . As a result, the toner is not sufficiently adhered to the carrier magnetically attracted to the developer applying unit, which causes a development failure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a main technical problem thereof is that a developer capable of reliably mixing a supplied toner with a developer and sufficiently stirring to triboelectrically charge the developer. An object of the present invention is to provide a stirring and conveying device.

[0006]

According to the present invention, there is provided, in accordance with the present invention, at least two developer conveying paths provided in parallel in a housing;
And two stirring / transporting means arranged in each of the two developer conveying paths to convey the developer in the axial direction. One of the stirring / transporting means disposed in the one developer conveying path has a rotating shaft. And a spiral blade provided on the rotating shaft, wherein the one developer conveying path is configured to drop and supply toner from above the one developer conveying path. A developer agitating / conveying device provided with a partition plate for restricting the axial movement of the toner above the spiral blade constituting the one agitating / conveying means for the toner dropped into the developer agitating / conveying device.

Further, according to the present invention, the first, second, and third developer conveying paths provided in parallel in the housing, and the first developer conveying path is disposed in the first developer conveying path. A first stirring / transporting unit including a pair of spiral blades in which the spiral direction of the spiral transported from the center to the both ends is formed in opposite directions, and disposed in the second developer transporting path; A second stirring / conveying means including a pair of spiral blades formed so that winding directions of spirals for conveying the developer from both ends toward the center are opposite to each other; A third stirring / transporting means provided with a pair of spiral blades in which a spiral for transporting the developer from the central portion toward both ends is formed in opposite directions. Of the developer agitating and transporting device configured to supply the toner from above the central portion of the developer transporting path. A partition plate that regulates axial movement of the toner above the pair of spiral blades constituting the third stirring and conveying means in the toner dropped to the central portion of the third developer conveying path. A developer stirring and conveying device is provided. For other features of the invention,
It will be clarified by the following description.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a developer stirring / conveying apparatus according to a preferred embodiment of the present invention.

FIG. 1 shows a preferred embodiment of an electrostatic latent image developing apparatus including a part of a rotary drum 2 constituting an image carrier and a developer stirring / conveying apparatus constructed according to the present invention. I have. The rotating drum 2 is provided with an appropriate electrostatic photoreceptor on its peripheral surface, and is rotated in a direction indicated by an arrow 4 in the figure by an appropriate driving means (not shown) so as to pass through the developing area 6. Have been. The developing zone 6 extends in the vertical direction in the direction of movement of the peripheral surface of the rotary drum 2 (therefore, the direction of movement of the image carrier), and is therefore rotated in the direction indicated by arrow 4 in the figure. The peripheral surface of No. 2 moves the developing zone 6 downward from above. 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 a suitable electrostatic latent image forming means known per se. In the developing area 6, the electrostatic latent image formed on the peripheral surface of the rotating drum 2 is developed into a toner image by an electrostatic latent image developing device generally denoted by reference numeral 8. The toner image thus developed is transferred to a transfer member such as plain paper by a transfer unit on the downstream side of the development area 6. Then, the toner image transferred to the transfer member is heat-fixed by a fixing unit to obtain a copy or printed matter.

Referring to FIGS. 1 and 2, the electrostatic latent image developing device 8 includes a developing housing 10. The developing housing 10, which can be formed 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. A cover member 22 made of a synthetic resin that covers the upper surface of the developing housing 10 configured as described above is provided.

At the forefront of the developing housing 10 (the leftmost part in FIG. 1, the uppermost part in FIG. 2), a first developer applying means 24 and a lower part of the first developer applying means 24 are arranged. Second developer applying means 26 is provided.
The first developer application means 24 extends substantially horizontally in the developing area 6 in the width direction (the direction perpendicular to the paper surface in FIG. 1 and the left-right direction in FIG. 2) and is disposed in parallel with the rotating drum 2. And a first magnet means 30 disposed in the first sleeve member 28. The first sleeve member 28 is formed of a non-magnetic material such as aluminum and the like.
It is rotatably mounted on. The first magnet means 30
Is constituted by a stationary permanent magnet, and is fixed at a predetermined position in the first sleeve member 28. The cross-sectional shape of the stationary permanent magnet constituting the first magnet means 30 is not circular, and there is a fan-shaped missing portion 32 on the right side in FIG. As shown in FIG. 1, S poles and N poles are alternately formed on the outer peripheral surface of the stationary permanent magnet as the first magnet means 30 configured as described above. Due to the presence of the missing portion 32 of the stationary permanent magnet, a magnetic attraction force for attracting the developer to the surface of the first sleeve member 28 is provided on the right side of the first sleeve member 28 in FIG. Developer stripping area 3 which is substantially absent, or at least slightly present
4 are formed. As shown in FIG. 2, the rotation shaft 36 to which the first sleeve member 28 is fixed extends through the rear end wall 20 of the developing housing 10 and protrudes rearward. An input gear (not shown) is fixed to the protruding end of the rotating shaft 36, and the input gear can be an electric motor via a suitable transmission gear (not shown). Drive). The first sleeve member 28 of the first developer applying unit 24 thus configured is moved in the direction indicated by the arrow 38 in FIG. 1, that is, in the developing area 6 in the direction opposite to the movement of the rotary drum 2. It is rotationally driven to move.

The second developer applying means 26 is located downstream of the rotating area 2 with respect to the first developer applying means 24 in the developing zone 6 (in FIG. 1, the first developer applying means). 24). This second
Of the first developer applying means 24
Similarly, the second sleeve member 40 extends substantially horizontally in the width direction (the direction perpendicular to the paper surface in FIG. 1 and the left-right direction in FIG. 2) and is disposed in parallel with the rotating drum 2. And second magnet means 42 disposed in the second sleeve member 40. The second sleeve member 40 is formed of a non-magnetic material such as aluminum, and is rotatably mounted on the developing housing 10. The second magnet means 42 is constituted by a stationary permanent magnet having a circular cross-sectional shape, and is fixed at a predetermined position in the first sleeve member 28. As shown in FIG. 1, sequentially located south poles, north poles, south poles, north poles, and south poles are formed on the peripheral surface of the stationary permanent magnet constituting the second magnet means 42. Therefore, in the embodiment shown in FIG. 1, the S pole and the S pole are adjacent to each other at the lower right side, and a portion between the adjacent S poles is used to suck the developer onto the surface of the second sleeve member 28. The developer peeling area 44 in which the magnetic attraction force substantially does not exist or is slight is defined. As shown in FIG. 2, the rotation shaft 46 to which the second sleeve member 40 is fixed extends through the rear end wall 20 of the developing housing 10 and protrudes rearward. An input gear (not shown) is fixed to the protruding end of the rotating shaft 46, and the input gear is fixed to the rotating shaft 36 of the first developer applying means 24 (not shown). Transmission connection.
The second developer applying unit 26 having the above-described configuration
The sleeve member 40 is driven to rotate so as to move in a direction indicated by an arrow 48 in FIG. 1, that is, in a forward direction with respect to the movement of the rotary drum 2 in the developing area 6.

Continuing the description with reference to FIG. 1, the electrostatic latent image developing device 8 is further provided with a head cutting means 50. In the illustrated embodiment, the ear cutting means 50 includes a second
1 is formed in a width direction (a direction perpendicular to the paper surface in FIG. 1) along the developer application means 26. In the illustrated embodiment, the ear-cutting plate 51 is made of non-magnetic stainless steel, and rotates in the direction of rotation of the second sleeve member 40 that constitutes the second developer applying unit 26 (the direction indicated by the arrow 48). As seen in the figure, on the upstream side of the developing area 6 and on the upstream side of the closest part 53 between the first sleeve member 28 and the second sleeve member 40, the peripheral surface of the second sleeve member 40 is approached. It has a leading edge. The gap G1 between the leading edge of the ear cutting board 51 and the peripheral surface of the second sleeve member 40 is 0.5 in the illustrated embodiment.
It is set to about 2 mm.

Behind the second developer applying means 26, a developer stirring and conveying device 60 constructed according to the present invention is provided. In the illustrated embodiment, a downstream transport path 6 as a first developer transport path is provided in the developing housing 10.
2 and an intermediate conveyance path 64 as a second developer conveyance path and an upstream conveyance path 66 as a third developer conveyance path are parallel to each other in the front-rear direction (the left-right direction in FIG. 1 and the up-down direction in FIG. 2). Is provided. An upstream partition means 68 is disposed between the middle flow path 64 and the upstream path 66. The upstream bulkhead means 68 is defined by upright walls 70 and 72 which project substantially vertically upward from the bottom wall 12 of the developer housing 10. Upright wall 7
As shown in FIG. 1, 0 and 72 have a concave arc shape on both side surfaces at the lower end. As shown in FIG. 2, the upright walls 70 and 72 have opposed inner ends spaced apart from each other. Therefore, a developer transfer port 74 is formed in the center of the upstream partition means 68. Also, a predetermined distance is provided between the outer end of each of the upright walls 70 and 72 and the front end wall 18 and the rear end wall 20 of the developing housing 8 as shown in FIG. 68 are provided at both ends in the width direction, respectively.
8 are formed.

A downstream partition means 80 is also provided between the downstream transport path 62 and the midstream transport path 64. The downstream bulkhead means 80 is defined by upright walls 72 and 84 which project substantially vertically upward from the bottom wall 12 of the developer housing 10. Upright walls 82 and 84
As shown in FIG. 1, both side surfaces of each lower end are formed in a concave arc shape. As shown in FIG. 2, the upright walls 82 and 84 have opposing inner ends spaced from each other, and therefore, a developer transfer port 86 is formed in the center of the downstream partition wall means 80. 2, a predetermined distance is provided between the outer end of each of the upright walls 82 and 84 and the front end wall 18 and the rear end wall 20 of the developing housing 8 as shown in FIG. At both ends in the width direction of 80, developer transfer ports 88 and 90 are formed, respectively.

The downstream transport path 62 is provided with a downstream stirring transport unit 92 as a first stirring transport unit.
As shown in FIG. 2, the downstream stirring and conveying means 92 has a rotating shaft 94 rotatably mounted between both end walls 18 and 20 of the developing housing 10. The rotating shaft 94 has a pair of spiral blades 96 spaced apart in the axial direction, that is, the width direction.
And 98 are formed. The spiral blade 96 and the spiral blade 98 are formed so that the winding directions are opposite to each other. The outer diameter of the spiral blade 96 and the outer diameter of the spiral blade 98 are the same. The inner ends in the width direction of the spiral blades 96 and 98 are connected to the developer transfer port 8 provided at the center in the width direction of the conveying path forming means 80.
Preferably, it is located substantially corresponding to the center of 6. The outer ends of the spiral blades 96 and 98 in the width direction are connected to the downstream partition means 8.
The developer transfer ports 88 and 90 provided at both ends in the width direction of 0 are positioned substantially corresponding to the middle in the width direction. Rotating shaft 9
Auxiliary spiral blades 100 and 102 are formed at both ends of 4 so as to face spiral blades 96 and 98, respectively. The auxiliary spiral blades 100 and 102 have the same outer diameter as the outer diameters of the spiral blades 96 and 98, and are formed over an angle range of approximately 360 degrees.
The winding directions of the auxiliary spiral blades 100 and 102 are as follows.
The direction is opposite to the winding direction of the opposing spiral blades 96 and 98, respectively.

In the middle conveying path 64, a middle stirring and conveying means 104 as a second stirring and conveying means is provided. The midstream stirring and conveying means 104 is provided in the developing housing 1.
0 has a rotating shaft 106 rotatably mounted between both end walls 18 and 20. A pair of spiral blades 108 and 110 are formed on the rotating shaft 106 at intervals in the axial direction, that is, in the width direction. The spiral blades 108 and 110 are formed so that the winding directions are opposite to each other. The outer diameter of the spiral blade 108 is the same as the outer diameter of the spiral blade 110, and is larger than the outer diameter of the spiral blades 96 and 98 of the downstream stirring and conveying means 92 described above. The inner ends in the width direction of the spiral blades 108 and 110 are located slightly outside the developer transfer port 86 provided at the center in the width direction of the conveying path forming means 80, and the spiral blades 108 Each of the outer ends of the width direction of each of the developer transfer ports 88 is provided at both ends in the width direction of the downstream partition wall means 80.
And 90 are located substantially at the center in the width direction or somewhat outside. The rotating shaft 106 is further provided with an inclined elliptical plate 112 at the center in the width direction. The widthwise dimension of the inclined elliptical plate 112 is substantially the same as the widthwise dimension of the developer transfer port 86 provided at the center in the widthwise direction of the conveyance path forming means 80. The inclined elliptical plate 112 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 spiral blades 108 and 110.

The upstream conveying path 66 is provided with an upstream stirring and conveying means 114 as a third stirring and conveying means. The upstream agitating and conveying means 114 is provided with the developing housing 1.
0 has a rotating shaft 116 rotatably mounted between both end walls 18 and 20. A pair of spiral blades 118 and 120 are formed on the rotating shaft 116 at intervals in the axial direction, that is, in the width direction. The spiral blades 118 and the spiral blades 120 are formed with winding directions opposite to each other. The outer diameter of the spiral blade 118 and the outer diameter of the spiral blade 120 are the same, and are also configured to be the same as the outer diameters of the spiral blades 108 and 110 of the above-described medium-flow agitating and conveying means 104. The inner ends of the spiral blades 118 and 120 in the width direction are located slightly outside the developer transfer port 74 disposed at the center in the width direction of the upstream partition wall means 68, and are spirally arranged. The widthwise outer ends of 118 and 120 are located substantially corresponding to the widthwise middle of developer transfer ports 76 and 78 provided at both widthwise ends of upstream partition means 68. The spiral blade 11 is provided at both ends of the rotating shaft 116.
Auxiliary spiral blade 1 located opposite to each of 8 and 120
22 and 124 are formed. Auxiliary spiral blade 12
The outer diameters of 2 and 124 are the same as the outer diameters of the spiral blades 118 and 120. This auxiliary spiral blade 122
And 124 are formed over an angular range of approximately 360 degrees, and the winding directions thereof are respectively opposite spiral blades 118.
And 120 are opposite to the winding direction.

The rotation shaft 94 of the downstream stirring and conveying means 92,
Each of the rotating shaft 106 of the middle-flow stirring and conveying means 104 and the rotating shaft 116 of the upstream stirring and conveying means 114 is protruded rearward through the rear end wall 20 of the developing housing 10. Input gears (not shown) are fixed to the rear ends of 106 and 116, respectively.
This input gear is operatively connected to an input gear (not shown) fixed to the rotating shaft 36 of the first developer applying unit 24. The downstream stirring / transporting means 92, the midstream stirring / transporting means 104, and the upstream stirring / transporting means 114 configured as described above are driven to rotate in directions indicated by arrows 126, 127 and 128 in FIG. 1, respectively.

The developer carrying capacity of each of the downstream stirring / conveying means 92, the midstream stirring / conveying means 104, and the upstream stirring / conveying means 114 constructed as described above will be described. The transfer capacity of the middle stream stirring and conveying means 104 is the same as that of the downstream stirring and conveying means 9.
The transfer capacity is set to be larger than each transfer capacity of the second and upstream stirring transfer means 114. The transport of the developer from both ends in the axial direction to the central portion in the axial direction and the transport of the developer from the central portion in the axial direction to both ends in the axial direction are substantially balanced, so that the developer is uniformly present throughout the entire axial direction. In order to achieve this, it is desirable that the transfer capacity of the middle-flow stirring transfer means 104 is configured to substantially match the sum of the transfer capacity of the downstream stirring transfer means 92 and the transfer capacity of the upstream stirring transfer means 114. Further, it is desirable that the transfer capacity of the downstream stirring and conveying means 92 is set to be larger than the transfer capacity of the upstream stirring and conveying means 114. It is desirable to be about 2 to 2.5 times. The developer carrying capacity of each of the downstream stirring / conveying means 92, the middle flow stirring / conveying means 104, and the upstream stirring / conveying means 114 is set as required by appropriately setting the rotation speed, pitch and outer diameter of each spiral blade. can do. In the illustrated embodiment, the rotational speed per unit time of the downstream stirring and conveying means 92 and the upstream stirring and conveying means 11
Although the number of rotations per unit time of 4 is the same, the number of rotations per unit time of the middle flow stirring and conveying means 104 is set to be larger than these numbers of rotations. Downstream stirring and conveying means 92
The pitch of the spiral blades 96 and 98 is larger than the pitch of the spiral blades 118 and 120 of the upstream stirring and conveying means 114, and the spiral blades 108 and 1 of the midstream stirring and conveying means 104
The pitch of 10 is even larger than the spiral blades 96 and 98 of the downstream stirring and conveying means 92.

Referring to FIGS. 1 and 2, a circular opening 12a is formed in a predetermined portion of the bottom wall 12 of the developing housing 10 which faces the middle flow path 64. A detector 13 for detecting a toner concentration in a developer 134 including carrier particles and toner contained in the developing housing 10 is provided in the opening 12a.
6 are provided. This detector 136 has an aperture 12a
Detecting the toner concentration in the developer 134 by detecting the magnetic permeability of the developer 134 present on the upper surface exposed in the developing housing 10 through the through hole may be of a known form.

The cover member 22 that covers the upper surface of the developing housing 10 is provided with a toner supply port 23 at a position facing the center of the upstream conveyance path 66 in the width direction. The toner supply port 23 is connected to a supply pipe of toner supply means (not shown). When the toner concentration in the developer 134 detected by the detector 136 becomes equal to or lower than a predetermined value, a toner supply unit (not shown) is operated, and the toner supply unit is disposed from the toner supply port 23 to the upstream conveyance path 66 in the development housing 10. Spiral blades 118 and 12 of the upstream stirring and conveying means 114
It falls between 0. When the toner concentration detected by the detector 136 becomes equal to or higher than a predetermined value, the operation of the toner conveying means in the feed pipe is stopped, and the developing housing 1 is stopped.
The supply of the toner into 0 is stopped.

Referring to FIG. 3 together with FIGS. 1 and 2, the inner surface of the cover member 22 that covers the upper surface of the developing housing 10 has partition plates 130, 130 on both sides in the width direction of the toner supply port 23. Are integrally formed. The partition plates 130, 130 are formed to have a width corresponding to the width of the upstream transport path 66, and the lower ends thereof are spiral blades 118 and 120 of the upstream stirring transport means 114 disposed in the upstream transport path 66. Is configured to be substantially the same as or slightly below the upper end position of the. In the illustrated embodiment, the partition plate 130 is integrally formed with the cover member 22 made of a synthetic resin. Can be easier.

The electrostatic latent image developing device 8 provided with the developer stirring and conveying device 60 constructed according to the present invention is configured as described above, and its operation and effect will be described below.
The toner dropped from the toner supply device (not shown) to the center of the upstream transport path 66 through the toner supply port 23 is supplied to the developer existing in the upstream transport path 66 by the upstream stirring and transporting means 114 as shown by an arrow in FIG. At the same time, it is sent to both sides from the central portion in the axial direction, and is mixed with the developer 134 in the developing housing 10. The developer 134 present in the upstream conveyance path 66 is conveyed from the axial center toward both sides in the axial direction while being stirred by the action of the pair of spiral blades 118 and 120 of the upstream stirring and conveying means 114. Since the conveying capacity of the upstream stirring and conveying means 114 is set relatively small, the developer 134 is conveyed by the upstream stirring and conveying means 114 at a relatively low speed from the center in the axial direction to both sides in the axial direction. Let me stir. The developer 134 conveyed to both sides in the axial direction by the upstream stirring and conveying means 114 is transferred forward through developer transfer ports 76 and 78 provided on both sides in the width direction of the upstream partition means 68, and is transported in the middle direction. Introduced into road 64. In addition,
When the toner dropped to the center of the upstream conveyance path 66 through the toner supply port 23 accumulates above the lower ends of the partition plates 130, 130, the toner located above the lower ends of the partition plates 130, 130 is not separated. The movement to both sides is regulated by the plates 130, 130. Partition plates 130, 130
The toner deposited on the upper side of the lower end of the partition plate 130 is moved to both sides, and is sent to both sides when it reaches below the lower end of the partition plates 130, 130. Therefore, the supplied toner is not carried on the flow of the developer carried by the pair of spiral blades 118 and 120 of the upstream stirring / conveying means 114 while being floated. Therefore, the supplied toner is mixed with the developer at an early stage, and is sufficiently stirred and charged by friction by the upstream stirring and conveying means 114.

The developer 134 introduced into the middle flow path 64 by the upstream stirring and conveying means 114 is stirred from the both sides in the axial direction toward the center in the axial direction while being stirred by the action of the spiral blades 108 and 110 of the medium stirring and conveying means 104. Transported. The developer 134 conveyed from both axial sides to the center in the axial direction by the midstream stirring / conveying means 104 is transferred to the downstream conveyance path 62 through a developer transfer port 86 provided at the center in the width direction of the downstream partition means 80. In addition, a part of the developer 134 passes through a developer transfer port 74 provided at the center in the width direction of the upstream partition means 68, that is, the rear, that is, the upstream transport path 6.
Transferred to 6. In this case, the medium-flow stirring and conveying means 104
, The developer 134 conveyed from one side in the axial direction is appropriately distributed to both sides in the axial direction, and the developer 134 conveyed from the other side in the axial direction.
Are appropriately distributed on both sides in the axial direction.

The developer 134 transported to the downstream transport path 62 by the midstream agitating and transporting means 104 is directed from the axial center to both axial sides while being agitated by the action of the spiral blades 96 and 98 of the downstream agitating and transporting means 92. Transported. Then, the developer 134 conveyed to both sides in the axial direction
Is transported backward through developer transport ports 88 and 90 provided at both ends in the width direction of the downstream partition wall means 80 and returned to the middle flow path 64, and then the middle flow stirring and transport means 1
While being stirred by the action of 04, it is conveyed from both axial sides toward the axial center.

Continuing the description with reference to FIG. 1, on the downstream side (left side in FIG. 1) of the downstream transport path 62, the second
The second sleeve member 40 of the developer applying means 26 is rotated in the direction indicated by the arrow 48. The number 140 in FIG.
In the developer pumping area shown by, the downstream stirring and conveying means 9
A part of the developer 134 which is being conveyed toward both sides in the width direction while being stirred by the action of the second sleeve part 40 is caused by the magnetic field formed by the second magnet means 42.
Pumped to the surrounding surface. The developer 134 pumped to the peripheral surface of the second sleeve member 40 is
It is moved in the direction indicated by the arrow 48 accompanying the rotation of 0. The hot-cutting plate 51 constituting the hot-cutting means 50 acts on the developer 134 which is magnetically held on the peripheral surface of the second sleeve member 40 and is moved, so that the excess developer 134
Is removed from the second sleeve member 40, and the layer thickness of the developer 134 held on the peripheral surface of the second sleeve member 40 is appropriately regulated. The second sleeve member 40 passes through the closest part 53 between the second sleeve member 40 constituting the second developer applying unit 26 and the first sleeve member 28 constituting the first developer applying unit 24. Is moved, a part of the developer 134 held on the peripheral surface of the second sleeve member 40 is subjected to the magnetic field formed by the first magnet means 30 of the first developer applying means 24. As a result, it is transferred to the peripheral surface of the first sleeve member 28. The developer 134 transferred to the peripheral surface of the first sleeve member 28 and magnetically held therein is moved accompanying the rotation of the first sleeve member 28 in the direction indicated by the arrow 38, and thus the developing zone 6 through the upstream half (the upper half in FIG. 1). Therefore, the developer 134 held on the surface of the first sleeve member 28 in the upstream half of the developing zone 6
Rubs the peripheral surface of the rotating drum 2 to apply a developing action to the electrostatic latent image formed on the peripheral surface of the rotating drum 2. On the other hand, the developer 134 that has been magnetically held on the surface of the second sleeve member 40 without being transferred to the peripheral surface of the first sleeve member 28 is moved in the direction indicated by the arrow 48 of the second sleeve member 40. , So that it is moved through the downstream half (the lower half in FIG. 1) of the developing zone 6. For this reason, in the downstream half of the developing zone 6, the developer 134 held on the peripheral surface of the second sleeve member 40 rubs the peripheral surface of the rotary drum 2 and is formed on the peripheral surface of the rotary drum 2. The developing action is applied to the electrostatic latent image. The electrostatic latent image formed on the peripheral surface of the rotary drum 2 is subjected to the developing action of the first developer applying unit 24 in the upstream half of the developing zone 6, and then is subjected to the second developing half in the downstream half of the developing zone 6. The toner is developed into a toner image by receiving the developing action of the developer applying unit 26.

The developer 134 held on the peripheral surface of the first sleeve member 28 of the first developer applying means 24 and passed through the developing zone 6 is viewed in the rotation direction of the first rotary sleeve member 28. As a result, the magnetic attraction force is substantially absent or small in the developer stripping zone 34 located downstream of the developing zone 6, so that it is separated from the surface of the first sleeve member 28 and is moved downward downstream. The sheet is dropped toward the transport path 62. Then, the developer 134 is mixed with the developer 134 which is being agitated and transported by the action of the downstream agitating and transporting means 92 which is constituted by the rotary spiral blade means disposed in the downstream transport path 62, and is transported to both sides in the axial direction to be fed in the middle direction. Returned to road 64.

The developer 134 held on the peripheral surface of the second sleeve member 40 of the second developer applying means 26 and passed through the developing area 6 has substantially a magnetic attraction force in the developer peeling area 44. The developer 13 which is agitated and transported by the downstream agitating and transporting means 92 in the developer stripping area 44 due to the absence or slight presence of the developer 13
Due to the fact that 4 acts on the peripheral surface of the second sleeve member 40, the developer 134 is detached from the peripheral surface of the second sleeve member 40 and is agitated and transported by the downstream agitating and transporting means 92. It is mixed and effectively stirred before being pumped again to the peripheral surface of the second sleeve member 40 of the second developer applying means 26 in the developer pumping area 140.

Next, another embodiment of the developer stirring and conveying device according to the present invention will be described with reference to FIG. In this embodiment, a pair of the spiral blades 118 and the spiral blades 120 of the upstream stirring and conveying means 114 disposed in the upstream conveying path 66 are provided.
And a pair of sub-spiral blades 218 and 220 are disposed between them. The outer diameters of the sub-spiral blades 218 and 220 are the same, are smaller than the outer diameters of the spiral blades 118 and 120, and are configured so as not to interfere with the partition plates 130 and 130. In addition, the secondary spiral blade 2
The winding directions of the spiral blades 18 and 220 are opposite to each other. The winding direction of the sub-spiral blade 218 is the same as that of the spiral blade 118, and the winding direction of the sub-spiral blade 220 is the same as that of the spiral blade 120. Is configured. Thus, the pair of spiral blades 118 of the upstream stirring and conveying means 114
And the spiral blade 120, a pair of sub-spiral blades 218 and 220 are provided.
The toner dropped between the fourteen spiral blades 118 and the spiral blades 120 can be quickly and reliably sent to both sides.

Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the embodiment only, and various modifications are possible within the scope of the technical idea of the present invention. In the illustrated embodiment, an example in which three stirring / transporting means are used has been described. However, the present invention may be applied to a developer stirring / transporting apparatus having two or more stirring / transporting means. Also, in the illustrated embodiment, an example in which the present invention is applied to an electrostatic latent image developing device provided with two developer applying units has been described, but an electrostatic latent image developing device provided with one developer applying unit has been described. Needless to say, it may be applied to

[0032]

The developer stirring and conveying device according to the present invention is configured as described above, and has the following effects.

That is, the developer stirring and conveying device according to the present invention includes a partition plate for regulating the axial movement of the toner above the spiral blade constituting the stirring and conveying means for the toner dropped and supplied to the developer conveying path. Therefore, when the toner dropped and supplied to the developer transport path accumulates above the lower end of the partition plate, the movement of the toner located above the lower end of the partition plate in the axial direction is restricted by the partition plate. . Then, the toner accumulated above the lower end of the partition plate is moved in the axial direction by the stirring and conveying means when the lower toner is moved and reaches below the lower end of the partition plate. Therefore, the supplied toner is not carried on the flow of the developer conveyed by the spiral blade of the stirring and conveying means while being floated. Therefore, the supplied toner is mixed with the developer at an early stage, and is sufficiently stirred and charged by friction by the upstream stirring and conveying means 114.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrostatic latent image developing device provided with an embodiment of 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 stirring and conveying device configured according to the present invention shown in FIG. 1 without a cover member covering an upper surface of a developing housing;

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a cross-sectional view of a main part showing another embodiment of a developer stirring and conveying device configured according to the present invention.

[Explanation of symbols]

 2: rotating drum 6: developing area 8: electrostatic latent image developing device 10: developing housing 22: cover member 24: first developer applying unit 26: second developer applying unit 28: first sleeve member 30 Reference numeral: first magnet means 34: developer peeling area 40: second sleeve member 42: second magnet means 44: developer peeling area 50: ear cutting means 51: ear cutting plate 60: developer stirring and conveying means 62 : Downstream transport path (first developer transport path) 64: Midstream transport path (second developer transport path) 66: Upstream transport path (third developer transport path) 68: Partition means 80: Transport path formation Means 92: Downstream stirring and conveying means (first stirring and conveying means) 104: Midstream stirring and conveying means (second stirring and conveying means) 114: Upstream stirring and conveying means (third stirring and conveying means) 130: Partition plate 134: Development Agent 136: Toner concentration detector

Claims (9)

[Claims] At least two developer conveying paths provided in parallel in a housing, and two agitating and conveying means respectively provided in the two developer conveying paths for conveying the developer in an axial direction. And one stirring / transporting means provided in the one developer transport path includes a rotary shaft and a spiral blade provided on the rotary shaft, and is provided above the one developer transport path. A developer agitating and conveying device configured to drop and supply toner from the developer, wherein the axial movement of toner above the spiral blades constituting the one agitating and conveying means in the toner dropped into the one developer conveying path A developer stirring and conveying device, comprising: a partition plate for regulating the pressure. 2. The electrostatic latent image developing device according to claim 1, wherein a cover member that covers an upper surface of the housing is provided, and the partition plate is provided on the cover member. 3. One of the stirring and conveying means disposed in the one of the developer conveying paths includes a pair of spirals for conveying the developer from a central portion toward both ends, the winding directions of the spirals being opposite to each other. The other stirring / conveying means provided with the spiral blades and disposed on the two developer conveying paths is a pair of spirals for conveying the developer from both ends toward the center, the winding directions of which are formed opposite to each other. The spiral blade is provided, and the toner is configured to be supplied by being dropped from above the central portion of the one developer transport path.
The electrostatic latent image developing device according to claim 1. 4. The device according to claim 3, wherein a partition means having a developer transfer port at a central portion is provided between the one developer transport path and the other developer transport path. An electrostatic latent image developing device. 5. A pair of sub-spiral blades having a diameter smaller than the outer diameter of the pair of spiral blades is provided between the pair of spiral blades constituting the one stirring and conveying means. Electrostatic latent image developing device. 6. A first, a second, and a third developer conveying path provided in parallel in the housing, and the developer is disposed in the first developer conveying path. A first stirring / conveying means provided with a pair of spiral blades in which spiral directions of the spirals conveyed toward each other are formed in opposite directions; and a second developer conveying path is provided in the second developer conveying path. A second stirring / conveying means including a pair of spiral blades in which spiral directions of the spirals conveyed toward the central portion are formed to be opposite to each other; and A third stirring / conveying means including a pair of spiral blades in which spiral directions of the spirals conveyed from the center to the both ends are formed to be opposite to each other; A developer stirring and conveying device configured to drop and supply toner from above the central portion; A developer that is provided with a partition plate that regulates axial movement of toner above the pair of spiral blades that constitutes the third stirring / conveying means for the toner dropped to the center of the feeding path. Stirring transport device. 7. The electrostatic latent image developing device according to claim 6, wherein a cover member for covering an upper surface of the developing housing is provided, and the partition plate is provided on the cover member. 8. A partition means having a developer transfer port at a central portion is provided between the second developer transport path and the third developer transport path. The electrostatic latent image developing device as described in the above. 9. A pair of sub-spiral blades having a diameter smaller than the outer diameter of the pair of spiral blades is provided between the pair of spiral blades constituting the third stirring and conveying means. The electrostatic latent image developing device as described in the above.