JPH0667542A - Developing device - Google Patents

Abstract

PURPOSE:To always carry a stable quantity of developer by providing a developer carrying member which is displaced in accordance with the quantity of developer on a stirring means arranged in a hopper room. CONSTITUTION:The stirring means 1 arranged in the hopper room is constituted of a rotary shaft 2, plural arms 3 and a carrying member 5 rotatably supported by the supporting parts 4 of the arms 3, and also, the carrying member 5 is always pressed by the tension of an elastic member 6 in the direction of the rotary shaft 2. By having such a constitution, in the case that there is plenty of developer in the hopper room, the resistance of the developer is given to the carrying member 5, so that the carrying member 5 is rotated and shifted against the tension of the elastic member 6. Then, the carrying member 5 is displaced following with a stirring means 1 rotating direction, so that the developer carrying force is reduced, On the other hand, in the case that there is a little developer in the hopper room, the resistance given by the developer is low, so that the tension of the elastic member 6 becomes higher than the resistance of the developer, and the carrying member 5 is not rotated and shifted, then, the developer carrying force is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as an electrophotographic system or an electrostatic recording system for developing an electrostatic latent image formed on an image carrier into a visible image. In particular, the present invention relates to a developing device in which a developing chamber containing a developer carrier and a hopper chamber containing a developer are integrally provided.

[0002]

2. Description of the Related Art Conventionally, in image forming apparatuses such as electrophotographic copying machines and printers, downsizing of the apparatus main body and
For the purpose of facilitating the developer replenishment operation, carry the developer,
2. Description of the Related Art A developing device has been put into practical use in which a developer carrying member to be conveyed, for example, a developing chamber including a developing sleeve and a hopper chamber for accommodating the developer are integrally provided. Each of the developing chamber and the hopper chamber is provided with a stirring means for transporting and stirring the developer to the developing sleeve side.

In recent years, along with the miniaturization and multifunctionalization of image forming apparatuses in which the developing device is used, the size of the developing device itself is also restricted, and the size is reduced. In particular, as in the electrophotographic image forming apparatus shown in FIG. 13, the downsizing in the height direction is progressing along with the reduction in the diameter of the photosensitive drum as the image carrier, and therefore the developing device is also increased in height. Directional miniaturization is required.

The overall structure of the electrophotographic image forming apparatus shown in FIG. 13 will be briefly described. The image forming apparatus has an image carrier which is rotatably driven in the direction of an arrow in the drawing at a substantially central portion of the apparatus main body 21. In the present example, a primary charger 23 that uniformly charges the photosensitive drum 22 and an electrostatic latent image formed on the photosensitive drum 22 are provided around the photosensitive drum 22. The developing device 24 for developing the image, the transfer charger 25 for transferring the developed visible image (toner image) onto the recording material P, and the cleaner 26 for removing the toner remaining on the photosensitive drum are the rotating direction of the photosensitive drum 22. Are sequentially arranged along the line.

Further, a paper feed cassette 31 for accommodating the recording material P is arranged in the lower part of the apparatus main body, and the recording material P is taken out from the paper feed cassette 31 one by one by a pickup roller 32 and is fed to a paper feed guide. The sheet is fed to a transfer area below the photosensitive drum 22 by (not shown) and the conveyance rollers 33 and 34.

On the other hand, the original O placed between the original plate 40 made of glass on the upper part of the main body 21 of the apparatus and the original pressing plate 41 is illuminated by the lamp 42 and is scanned in the direction of arrow a by a motor (not shown) to cause the original O. The optical image reflected from is reflected by the mirrors 43, 44, 45, enters the lens 46, is condensed, and is further mirrors 47, 48, 49.
Is reflected by the primary charger 23 and the developing device 24 to expose the surface of the photoconductor drum to form an electrostatic latent image on the photoconductor drum 22.

This electrostatic latent image is developed by the developing device 24, and a visible image (toner image) is formed on the photosensitive drum 22. The visible image on the photosensitive drum 22 is transferred onto the recording material P transported to the transfer area by the action of the transfer charger 25.

When the transfer of the visible image is completed, the recording material P
Is discharged by a discharging charger 27 to which an AC voltage is applied, is sent by a conveyor belt 28 to a fixing device 29 including, for example, a pair of heat rollers, and is heated and fixed there.
The recording material is discharged from the recording material discharge port onto the discharge tray 30, thus completing one copying cycle.

For such an image forming apparatus, a developing device that is downsized in the height direction is used for the above-mentioned reason. FIG. 14 shows an example of the developing device 24 which is used in the image forming apparatus of FIG. 13 and which is miniaturized in the height direction. The developing container 50 is formed in a horizontally long shape whose height is suppressed. The developing unit 51 and the hopper unit 52 are arranged side by side. In the developing section 51, a developing sleeve 53 as a developer carrying member, a regulating blade 54 that regulates the amount of the developer (toner) carried and conveyed by the developing sleeve 53, and the developing section 51 is developed. A stirring member (stirring bar) 55 is provided for stirring the agent and supplying it to the developing sleeve 53. On the other hand, a developer transport member (stirring bar) for stirring the stored developer in the hopper unit 52 and transporting it to the developing unit 51.
56 is arranged almost in the center of the hopper 52,
This transport member 56 has one end as the center of rotation.
It rotates in the circular locus shown by the chain double-dashed line. When the amount of the developer in the hopper portion 52 decreases, a predetermined amount of the developer is replenished from the developer replenishing port 57 into the hopper portion 52.

Further, as shown in FIG. 15, there is also proposed a developing device 24 in which the volume of the hopper portion 52 is increased in the lateral direction while suppressing the height. In the case of this developing device 24,
Two developer transport members 56a and 56b for transporting the developer to the developing unit 51 while stirring the developer in the hopper unit 52.
Are arranged side by side to compensate for the decrease in the developer scraping performance due to the increase in the developer storage amount in the lateral direction. Since the other configurations are the same as those of the developing device in FIG. 14, members, parts and the like corresponding to those in FIG. 14 are designated by the same reference numerals and the description thereof will be omitted.

Further, a developing device as shown in FIG. 16 is also used in the above-mentioned image forming apparatus. This developing device has a structure in which a developing section 100 and a hopper section 101 are arranged side by side, and a developer T is supplied from the hopper section 101 to the developing section 100, and the developer T is formed on the photosensitive drum 130. It develops an electrostatic latent image.

Usually, a one-component magnetic developer is used as the developer T in such a developing device. Development unit 100
A developing sleeve 105 as a developer carrying member is rotatably supported by both ends of the developing sleeve 105, and is rotatable in the direction of the arrow in the figure. This developing sleeve 1
Reference numeral 05 is made of a non-magnetic material such as aluminum or stainless steel, and a magnet roller 106 having a plurality of magnetic poles is fixedly arranged in the internal space as a magnetic field generating member.

The developing sleeve 105 is rotatable while being concentric with the non-rotating magnet roller 106. In the illustrated example, the magnet roller 106 has four magnetic poles 106a, 106b, 106c, and 106d, but the magnetic pole 106a is a developing pole arranged at a position facing the photoconductor drum 130, and is composed of the developing sleeve 105 and the photosensitive drum. Development is performed by applying a predetermined bias voltage from the bias power source E between the body drums 130. Magnetic pole 1
Reference numeral 06b denotes a blade member 107 that regulates the layer thickness of the developer T applied on the developing sleeve 105 so as to have a uniform predetermined thickness.
Is a developer coating electrode (cutting electrode) opposed to. Magnetic pole 10
Reference numerals 6c and 106d denote developer transporting electrodes, and the developing unit 100
The position of the developer T is determined depending on the transport state of the developer T therein. The blade member 107 is attached to the blade support base 108, and the suspended end portion maintains a predetermined gap with the developing sleeve 105. The blade member 107 may be a magnetic material or a non-magnetic material.

Further, at a predetermined position of the developing section 100, the developer T supplied from the hopper section 101 is applied to the developing sleeve 1.
05 Stirring member (stirring rod) for stirring and conveying to the vicinity
104 are provided. The stirring member 104 rotates clockwise in a direction opposite to the developing sleeve 105 that rotates counterclockwise by a drive source (not shown) in the developing unit 100, and stirs the developer T. Further, the magnetic field formed behind the blade member 107 by the fixed magnet 106 in the developing sleeve 105 causes the developer T
Produce a cyclic countercurrent, which also causes stirring. The amount of charge required to obtain a desired density is imparted to the developer T by such stirring and rubbing.

On the other hand, at a predetermined position in the hopper portion 101, a crank-shaped conveying member (conveying rod) 109 is arranged for sequentially conveying and moving the contained developer T toward the developing portion 100. The transport member 109 is rotationally driven in the direction of the arrow (clockwise) in the figure by a drive system (not shown).

Further, a residual amount detecting means (not shown) for detecting the residual amount of the developer T is arranged at a predetermined position in the hopper portion 101, and the developer T in the hopper portion 101 is for developing. If the developer T is consumed and needs to be replenished, the replenishment display means is turned on so that the developer T is replenished.

A supply port for replenishing the developer T is provided in the upper part of the hopper portion 101, and a soft cover such as a lid 111 and a sponge for preventing the developer T from scattering is provided at the supply port. A seal member 110 made of an elastic member is provided.

A regulating member 102 for regulating the movement amount of the developer T is provided between the developing section 100 and the hopper section 101. The regulation member 102 is formed in a shape that is substantially crank-shaped and overhangs in the opening C through which the developer passes. This is an effect that the developer T scraped up by the blade sheet 112 made of a soft elastic material attached to the tip of the conveying member 109 of the hopper 101 is forcibly pushed into the developing unit 100 through the curved opening C. The present invention aims to always move a fixed amount regardless of the remaining amount of the developer T stored in the hopper unit 101. Therefore, since the blade sheet 112 needs to follow the steps on the surfaces of the developing container 121 and the regulating member 102, it is made of a soft elastic material such as urethane. Further, if a shielding member made of a mylar sheet or the like is attached to the opening C, the backflow of the pushed developer T can be prevented, so that a further effect can be obtained.

The developer T supplied from the hopper portion 101 into the developing portion 100 is indicated by an arrow P in FIG.
After being conveyed to the vicinity of the developing sleeve 105 as shown by, it is adsorbed to the developing sleeve 105 by the attraction force of the conveying pole 106c of the magnet roller 106 in the developing sleeve 105. Since the developing sleeve 105 rotates counterclockwise, the adsorbed developer T is conveyed in the same direction and swallowed by the developer pool D ₁ formed behind the blade member 107. The developer pool D ₁ is formed by being regulated by the cut pole 106b of the non-rotating magnet roller 106 and the blade member 107, and the developer is charged by rubbing to obtain an optimum image.

[0020]

However, in the first developing device in which the developing chamber and the hopper chamber are integrally formed, the developer provided in the hopper chamber depends on the amount of the developer stored in the hopper chamber. The amount of the developer conveyed to the developing chamber side is changed by the stirring / conveying means.
For this reason, when the developer amount in the developing chamber becomes excessive, the developer is filled in the developing chamber and the developer cannot be circulated.
The so-called blocking phenomenon occurs. Further, when the amount of the developer in the developing chamber decreases, the supply of the developer for developing becomes insufficient, which causes a defect that the density of the image becomes uneven.

Further, in the second developing device shown in FIG. 14 or 15 in which the developing section and the hopper section are arranged side by side to reduce the size in the height direction, they are housed in the hopper section and used effectively. The capacity of the developer that can be formed is limited by the scraping ability of the developer transport member, and in the developing devices that have been proposed so far, as described above, the developer transport member has a rotational circular motion, so that the developer has a radius of rotation that causes the developer to move. The effective storage capacity of is limited. For this reason, (1) by reducing the height of the developing device, the storage amount of the developer is reduced, and the developer must be replenished frequently from the outside. (2)
In order to increase the storage amount of the developer, it is necessary to add a conveying member and the like, and there are drawbacks such as an increase in the cost of the developing device and an unavoidable increase in mechanical parts.

Further, in the third developing device shown in FIG. 16, when the supply amount of the developer conveyed from the hopper portion to the developing portion accompanying the image formation is larger than the consumption amount,
When the developer pool gradually grows and causes poor circulation, poor image quality such as low density due to insufficient charge amount of the developer occurs. Of course,
It goes without saying that the image quality becomes poor even when the consumption amount is large, which is not preferable. In order to solve this problem, the amount of developer supplied from the hopper must be adjusted according to the amount of consumption, and the sensor that detects the remaining amount of developer in the developing unit and the movement of other drive parts There is a method of providing a drive mechanism that drives the stirring / conveying member of the hopper independently of
Increasing the complexity of the structure and increasing the cost are inevitable, and it is difficult to say that this is the preferred method.

Therefore, one object of the present invention is to provide a stirring means provided in the hopper chamber with a developer transport member which is displaced in accordance with the amount of the developer stored in the hopper chamber, so that it is always stable. It is an object of the present invention to provide a developing device capable of conveying a specified amount of developer from a hopper chamber to a developing chamber.

Another object of the present invention is to provide a rotary developer conveying member for agitating the stored developer provided in the hopper portion and conveying it to the developing portion so as to change the radius of gyration depending on the rotation angle. The present invention provides a developing device in which the developer agitating and conveying area of the developer by the developer conveying member is enlarged.

Still another object of the present invention is to provide a stirring / conveying means in the developer reservoir behind the developer regulating member, and to feed the developer backward from the developer reservoir to the hopper. It is an object of the present invention to provide a developing device having a simple structure and capable of keeping the amount of the developer in the developing unit constant by providing the feeding means without increasing the cost.

[0026]

The above object can be achieved by the developing device according to the present invention. In summary, the present invention is
In the first aspect, a developing chamber including a developer carrier,
A hopper chamber for accommodating the developer is juxtaposed together, and the developer is agitated in each of the developing chamber and the hopper chamber,
In a developing device having a stirring means for transporting, the stirring means disposed in the hopper chamber is provided with a developer transporting member that is displaced according to the amount of the developer stored in the hopper chamber. Is a developing device.

Further, in the second aspect, the present invention provides:
In a developing device in which a developing section including a developer carrying member and a hopper section for accommodating the developer are integrally arranged side by side, the developer contained in the hopper section is stirred and conveyed to the developing section. The developing device is characterized in that the rotation radius length of the rotary type developer transport member is varied according to the rotation angle so as to increase the stirring and transport region.

Further, in a third aspect, the present invention provides a developing section including a developer carrier for carrying and carrying a developer for developing an electrostatic latent image formed on the image carrier, and a developing unit. And a developing unit,
A developer regulating unit that is located substantially above the developer carrier and regulates and equalizes the amount of the developer carried and conveyed by the developer carrier, and agitates the developer supplied from the hopper section. In a developing device further including a conveying stirring unit, the hopper unit stirs the developer accommodated in the hopper unit, and the conveying unit conveys the developer to the developing unit, substantially above the developer carrier, and An agitating / conveying means for agitating the developer is disposed behind the developer regulating means, one end is located in the vicinity of the agitating / conveying means, and the other end is lower in height than the one end. And a developer back-feeding means projecting to the hopper portion is provided, and a certain amount or more of the developer accumulated behind the developer regulating means is agitated / conveyed by the developer back-feeding means. Characterized by sending back to the department A developing device for.

[0029]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following examples, the case where the present invention is applied to a developing device used in an electrophotographic image forming apparatus will be described. However, the present invention is applicable to electrophotographic systems, electrostatic recording systems, etc. other than the examples. It is equally applicable to developing devices used in image forming apparatuses of various configurations.

First, referring to FIGS. 1 to 3, the first embodiment of the present invention will be described.
An example will be described.

FIG. 3 is a schematic sectional view showing the overall construction of the developing device according to the first embodiment of the present invention. The developing device 7 includes a developing chamber 9 including a developing sleeve 10 as a developer carrying member.
And the hopper chamber 8 for accommodating the developer T are juxtaposed and integrated with each other. The developing chamber 9 and the hopper chamber 8 are partitioned by a partition plate 11 except for the developer carrying path, and the amount of the developer carried and carried by the developing sleeve 10 is regulated above the developing sleeve 10. A developer regulating plate 12 is provided. Further, a cover plate 13 is attached to the upper part of the device. The developer carried on the developing sleeve 10 adheres to the electrostatic latent image formed on the photosensitive drum 14 in the developing area to form a visible image.

In the developing device thus constructed,
The developer T contained in the hopper chamber 8 is agitated by the rotation of the agitating means 1 provided in the hopper chamber 8 and is conveyed to the developing chamber 9. On the other hand, the developer T transported to the developing chamber 9 is further stirred by the stirring member 15 provided in the developing chamber 9 and simultaneously transported to the developing sleeve 10.

Next, the stirring means 1 of the present embodiment will be described in detail with reference to FIG.

The agitating means 1 conveys a rotary shaft 2, a plurality of arms 3 attached to the rotary shaft 2 at a predetermined interval, and a developer rotatably supported by the arms 3. And a conveying member 5 for supporting the rotary shaft 2 rotatably supported on both side surfaces of an inner wall of the developing device (not shown), so that the stirring means 1 as a whole is rotated.
It will rotate around. In this embodiment, the arm 3 is formed integrally with the rotary shaft 2, and U-shaped bearing portions 4 are formed at the free ends of these arms 3, and the carrier members are attached to these bearing portions 4. The transport member 5 is rotatably supported by the arm 3 by rotatably engaging the shaft-shaped portion 5a of the carrier 5.

The transport member 5 has a structure in which a plate-shaped main body portion 5b having a thickness is integrally formed on the shaft-shaped portion 5a, and the plate-shaped main body portion 5b is provided with an arm 3 so as to be rotatable. The intersection is cut off. In other words, the transport member 5 has a configuration in which a plurality of plate-shaped main body portions 5b are fixed to the shaft-shaped portion 5a between the adjacent arms 3. Further, each main body portion 5b of the transport member 5 is
It is constantly urged in the direction of the rotary shaft 2 by the tensile force of an elastic member 6 such as a tension spring attached between the b and the rotary shaft 2.

FIG. 2 is for explaining the operation of the stirring means 1 of this embodiment. FIG. 2A shows the case where the developer T in the hopper chamber 8 is large, and FIG. Hopper room 8
The case where the developer T in the inside has decreased is shown.

As shown in FIG. 2A, when the developer T in the hopper chamber 8 is large, the conveying member 5 receives the resistance of the developer T and resists the tensile force of the elastic member 6 so that the shaft is prevented. The plate-shaped main body portion 5b is rotationally displaced about the plate-shaped portion 5a. Here, as the elastic member 6, when the amount of the developer T is large, it is possible to use one in which the biasing force (tensile force in this embodiment) of the elastic member 6 is slightly weaker than the resistance force received from the developer. Of course. Therefore, the transport member 5 is displaced in accordance with the rotation direction of the stirring means 1, and the transport force of the developer T is weakened.

On the other hand, when the developer T in the hopper chamber 8 is small, as shown in FIG.
Since the resistance force received from the developer T is small, the elastic member 6
Is greater than the resistance of the developer T, and therefore the plate-shaped main body portion 5b of the transport member 5 is not rotationally displaced. Therefore, the carrying force of the developer T becomes strong.

As described above, in this embodiment, when the predetermined amount of the developer T is stored in the hopper chamber 8, the resistance force of the developer received by the conveying member 5 is substantially equal to the resistance force of the developer. Since the elastic member 6 having a force is used to urge the conveying member 5 of the stirring means 1 toward the rotation shaft 2, the conveying member 5 of the stirring means 1 corresponds to the amount of the developer in the hopper chamber. Then, it is rotationally displaced, and the carrying force of the developer is adjusted according to the amount of the developer. Therefore, it is possible to eliminate the blocking phenomenon due to the excessive conveyance of the developer into the developing chamber 9 and the shortage of the developer in the developing chamber 9, and it is possible to reduce the rotational load of the stirring unit 1. . Further, there is an advantage that the amount of developer conveyed to the developing chamber 9 is stable.

Next, referring to FIGS. 4 to 6, the second embodiment of the present invention will be described.
An example will be described.

FIG. 4 is a schematic sectional view showing the overall construction of a developing device according to the second embodiment of the present invention. In the developing device 60, a developing container 61 is formed in a horizontally long shape with its height suppressed. The developing unit 62 and the hopper unit 63 are arranged side by side. In the developing section 62, a developing sleeve 64 as a developer carrying member, a regulating blade 65 for regulating the amount of the developer (toner) carried and conveyed by the developing sleeve 64,
A stirring member 66 is provided for stirring the developer conveyed in the developing unit 62 and supplying the developer to the developing sleeve 64. On the other hand, the hopper portion 63 is formed horizontally longer than usual in order to increase the storage amount of the developer, and the developer stored in the hopper portion 63 is agitated and conveyed to the developing portion 62. Developer conveying member 6
7 is disposed substantially in the center of the hopper portion 63, and as will be described later, the conveying member 67 rotates about a rotation axis 68 in an elliptical locus shown by a two-dot chain line in FIG.

FIG. 5 shows an enlarged detail of the vicinity of the developer transport member 67. A gourd-shaped guide groove 69 is formed on the side wall surface 61 a of the developing container 61. The developer transport member 67 includes a plate-shaped developer transport body 70 made of an elastic member such as rubber, and a crank-shaped rod-shaped body 71 that rotatably supports the developer transport body 70.
The end portion of the arm portion 71a is bent outward at a right angle to form a guide arm 72, and the guide arm 72 is engaged with the guide groove 69. The arm 71a of the rod 71 is slidably inserted into the through hole of the rotary shaft 68 rotatably attached to the side wall surface 61a of the developing container 61 at the substantially center position of the guide groove 69. When the rotary shaft 68 is rotationally driven, the rod-shaped body 71 rotates around the rotary shaft 68. However, since the guide arm 72 of the rod-shaped body 71 is engaged with the guide groove 69, the guide arm 72 Depending on the position in the guide groove 69, the arm portion 71a of the rod-shaped body 71 rotates,
As shown by an arrow B in the drawing, the rotary shaft 68 slides in the through hole. Therefore, the radius of gyration of the rod-shaped body 71 (the arm portion 71
The radius of gyration a) changes according to the angle of rotation, so that an elliptical locus as shown in the drawing is drawn.
Needless to say, the above-described structure is similarly applied to the side wall surfaces of the developing container 61 which face each other.

FIG. 6 is a detailed view of the drive mechanism for the rotary shaft 68 for rotating the rod-shaped body 71 of the developer carrying member 67 as viewed in the direction of arrow A in FIG. The rotating shaft 68 is a drive gear 80.
Is coaxially connected to the drum gear 8 on the apparatus main body side.
The rotational driving force of No. 1 is transmitted to the drive gear 80 in a decelerated state via the relay gears 82, 83, 84, so that the drive gear 80 is rotationally driven in the direction of the arrow in the figure.
As a result, the rotary shaft 68 is also driven to rotate.

When the rotating shaft 68 is rotated in the direction shown by the arrow in FIG. 4 by the drive mechanism, the rod-shaped body 71 is rotated. At this time, as described above, the guide arm 72 of the rod-shaped body 71
Is moved along the guide groove 69, the radius of rotation of the developer transport body 70 fixed to the main body of the rod-shaped body 71 changes according to the rotation angle, and an elliptical locus shown by a two-dot chain line in the figure. Will be drawn and rotated. This makes it possible to scrape out and stir the developer in a wide range within this elliptical area, so that the scraping ability is enhanced, the heightwise dimension of the hopper is reduced, and the volume is increased laterally. Even in such a case, it is possible to eliminate the drawbacks such as the effective capacity of the developer being limited and the need for an additional developer conveying member.

Although the guide groove 69 has a gourd shape in the second embodiment, it is not limited to this.
Depending on the shape of the internal space of the hopper portion 63, the guide groove 69
If the shape of the developer carrying member 67 is changed, the scraping ability of the developer carrying member 67 can be correspondingly increased. For example, as shown in FIG. 7, in the case where the internal space of the hopper portion 63 bulges outward in the lower right region 63a compared to the case of FIG. The shape of the guide groove 69 is slightly deformed so that the agent transport member 67 draws an elliptical locus shown by a two-dot chain line in FIG. 7. As a result, the developer contained in the bulged area 63a can also be conveyed to the developing section side.

In the second embodiment, the developing container 61 is also used.
The trajectory drawn by the developer transport member 67 is restricted by engaging the guide arm 72 of the rod-shaped body 71 of the developer transport member 67 with the guide groove 69 formed on the side wall surface 61a of the above. However, the present invention is not limited to this. It is not something that will be done.

FIG. 8 is a schematic perspective view showing an essential part of the third embodiment of the present invention. Instead of the guide groove 69 in the second embodiment, a guide wall 73 is provided on the side wall surface 61a of the developing container 61. On the other hand, on the other hand, the rod-shaped body 71 of the developer transport member 67 is provided.
The main body portion to which the developer transport body 70 is fixed is projected outward from the arm portion 71a, and a rotatable roller 74 is attached to the projected portion, and this roller 74 is constantly applied to the guide wall 73 with a light pressure. The spring 75 makes contact.

Also in this embodiment, the developer carrying member 67 is used.
It is obvious that the radius of gyration can be changed in accordance with the shape of the guide wall 73, so a detailed description thereof will be omitted. However, when the guide wall 73 is provided as in the present embodiment, the guide groove is As in the case of the second embodiment in which 69 is provided, the developer enters the guide groove 69, and the rod-shaped body 71
It has the advantage that it does not suffer from the drawback that it will not move or will not move in some cases. Of course, the rotation radius length of the developer carrying member 67 may be changed by a method other than these embodiments.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 9 and 10.

FIG. 9 is a schematic sectional view showing the overall construction of the developing device of the fourth embodiment of the present invention. The developing device of this embodiment is similar to the conventional developing device shown in FIG. The developing unit 100 and the hopper unit 101 are arranged side by side. In addition, since other parts of the configuration are similar to those of the developing device shown in FIG. 16, corresponding parts and members are denoted by the same reference numerals, and the description thereof will be omitted unless necessary.

In the developing device having the structure shown in FIG. 9, the supply amount of the developer T from the hopper portion 101 to the developing portion 100 is determined by the opening area of the opening portion 103 of the regulating member 102 and the rotation of the conveying member 109 in the hopper portion 101. Depends on the number. That is,
The supply amount is increased by increasing the opening area of the opening 103 and increasing the rotation speed of the conveying member 109. Conversely, the supply amount is decreased by decreasing the opening area and decreasing the rotation speed.

As described above, the developer T supplied from the hopper unit 101 into the developing unit 100 by the rotation of the conveying member 109 is disposed at a predetermined position in the developing unit 100 and rotates clockwise. After being stirred by 104 and conveyed to the vicinity of the developing sleeve 105 as shown by an arrow P in the figure, it is attracted to the developing sleeve 105 by the attraction force of the conveying pole 106c of the magnet roller 106 in the developing sleeve 105. Since the developing sleeve 105 rotates counterclockwise, the adsorbed developer T is conveyed in the same direction, and the developer pool D ₁ formed in the region (developer pool portion) D on the back surface of the blade member 107. Will be swallowed by. The developer pool D ₁ is generated by the magnetic force of the cut pole 106b of the non-rotating magnet roller 106 and the blade member 107.
The toner is formed by regulating the developer T in FIG. 6, and the addition of electric charge to the developer is most given by the sliding friction with the developing sleeve 105. Further, in the developer pool D ₁ , a counterflow in a direction indicated by an arrow q in the drawing occurs as the developing sleeve 105 rotates.

In this embodiment, the blade member 107
Screw-shaped agitator in the developer pool D behind the
When the transport means 141 is provided and the developer pool D ₁ grows to a certain amount or more, the stirring / transport means 141 feeds back the developer of a certain amount or more to the hopper section 101, and the developer pool D 1 the more than a certain amount _{of 1} is one in which the construction so as not to grow.

Therefore, one end is located in the vicinity of the stirring / conveying means 141, the other end is slightly projected into the hopper portion 101, and a reverse feeding member 151 inclined downward toward the hopper portion 101 is provided for developing. When the developer pool D ₁ grows to a certain amount or more, the developer is moved onto the backward feeding member 151 and is rotated in the direction of the arrow (clockwise direction) shown in the drawing, and the excess developer is fed backward by the stirring / conveying means 141. It is moved onto the member 151, and as shown by the arrow r in the drawing, the hopper portion 101
I try to send it back.

That is, as the amount of the developer T supplied from the hopper section 101 increases, the developer pool D ₁ grows. When the developer pool D ₁ increases by a certain amount or more, the developer scraped out from the developer pool D ₁ by the agitating / conveying means 141 is fed onto the reverse feeding member 151. The developer D ₂ on the reverse feeding member 151 is forcibly moved by the developer fed one after another by the stirring / conveying means 141 as indicated by an arrow r, and the reverse feeding member 151 is moved toward the hopper portion 101. Since the developer D ₂ inclines downward and assists the flow movement of the developer D ₂ , the developer D ₂ on the reverse feeding member 151 sequentially drops into the hopper portion 101 and is used again. .

Since the stirring / conveying means 141 is arranged in the vicinity of the blade member 107, it does not affect the magnetic pole of the cut pole 106b of the magnet roller 106. It is made of material. Further, since a continuous screw may send the developer in one direction and cause aggregation, as shown in FIG. 10, in the stirring / conveying means 141, it is better to arrange a plurality of screws having different winding directions in groups. It is more preferable in combination with the circulation of the agent pool D ₁ .

In the structure of the present embodiment, in order to form a stable high-quality image without density unevenness, density decrease, etc., it is necessary to always keep the amount of electrostatic charge of the developer constant. Therefore, for that purpose, it is necessary to keep the amount of the developer pool D ₁ constant and to actively perform the circulating flow.

Since the agitating / conveying means 141 is a one-way rotating body capable of keeping the amount of the developer pool D _{1 at} a constant value depending on its position, it also has an effect of assisting the circulating flow of the developer pool D ₁ . However, since it is not preferable that the amount of the developer pool D ₁ changes depending on the amount of the developer consumed for image formation, it is necessary to control the supply amount of the developer moving from the hopper section 101 to the developing section 100. I have to.

The present embodiment can achieve this object by a simple means. That is, in the configuration of the present embodiment, if the developer is set to be supplied from the hopper unit 101 to the developing unit 100 in a larger amount than in the case of solid black or the like in which the amount of image information is the largest and the amount of developer consumption is large. Good. Setting of the supply amount of the developer, stirring / conveying means 141, and reverse feeding member 1
By combining with the forced circulation conveyance system consisting of 51, the developer pool D ₁ always grows to a certain amount or more. Therefore, the excess developer in the developer pool D ₁ is collected by the forced circulation conveyance system of this embodiment. By feeding the developer back to the hopper unit 101, a constant amount of developer pool D ₁ can be maintained with a simple structure regardless of the amount of developer consumed for image formation.

As described above, according to the present embodiment, the developer that agglomerates in the developer reservoir D is forcibly sent to the reverse feeding member 151 by the stirring / conveying means 141, and the circulation to the hopper 101 is activated. By this, since the amount of the developer in the developing unit 100 is kept constant, it is possible to always obtain a stable high-quality image.

Further, since the agitating / conveying means 141 also has an effect of positively circulating the developer in the developer reservoir D, the image density is lowered due to the insufficient charge amount of the developer which is observed after being left for a long time. Can be prevented.

As described above, the supply amount of the developer can be determined by the size of the area of the opening 103 of the regulating member 102 and the rotation speed of the conveying member 109.

The winding pitch interval of the screw of the stirring / conveying means 141 and the total pitch number may be determined in consideration of the optimum shape of the developer pool D ₁ , the form of the developing device, and the drive transmission system. It goes without saying that the present invention is not limited to the embodiment.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
1 and FIG. 12 will be described.

FIG. 11 is a schematic sectional view showing the overall construction of the developing device of the fifth embodiment of the present invention. This embodiment shows the construction of the stirring / conveying means 141 disposed in the developer reservoir D. Since it is different from the fourth embodiment in that it is changed,
Corresponding parts and members are designated by the same reference numerals and the description thereof is omitted unless necessary.

The stirring / conveying means 141 of this embodiment is not of a screw type, but its rotating shaft 142 has a detent 143 at its end as shown in an enlarged view in FIG.
In addition, a large number of stirring blocks 144 are attached to the rotary shaft 142.
Has a configuration that is inserted without a gap. These stirring blocks 144 have almost the same structure, and as shown in an enlarged view in FIG. 12B, one blade 144a having an arbitrary shape is provided on the outer peripheral portion of the cylindrical block body, and The rotary shaft 142 is inserted through the through hole 144b.
Further, a pair of projections 144c projecting in the axial direction is formed on one end surface of the block body, and these projections 144c (actually, the rotation stopper 143 of the rotating shaft 142 are formed on the other end surface.
Alternatively, a pair of groove portions 144d that engage with the protrusions of adjacent stirring blocks) are formed in the axial direction. In this case, the protrusion 1
44c and the groove portion 144d have a predetermined angle,
At different positions (ie different positions on the circumference)
Each is formed. Then, as shown in FIG. 12A, the stirring block 144 thus configured is inserted into the rotating shaft 142, and the groove portion 144 d of the stirring block 144 inserted into the rotating shaft 142 is inserted into the rotating shaft 142 first. The stirring block 144 that is engaged with the rotation stopper 143 and is inserted thereafter has a protrusion 144c and a groove portion 144d.
And the blade 144a
The agitation / conveyance means 141 is arranged in various positions.

Agitating / conveying means 14 configured as described above
It can be said that 1 is a configuration capable of effectively performing forced circulation of the developer onto the reverse feeding member 151. The shape of the blade 144a of the agitation block 144 is not limited to this embodiment, and for example, as shown in FIG. 12 (C), the blade 144a is bent in a V shape.
But it's okay. That is, it may be determined in consideration of the optimum shape of the developer pool D _1, the form of the developing device, and the drive transmission system.

In the above embodiment, the case where the present invention is applied to the electrophotographic image forming apparatus has been described.
The present invention is not limited to this, and is equally applicable to electrophotographic color or monochromatic (black and white) image forming apparatuses of various configurations and electrostatic recording type image forming apparatuses. Needless to say.

[0069]

As described above, according to the developing device of the present invention, the stirring means arranged in the hopper chamber of the developing device is provided with the conveying member which is displaced in accordance with the amount of the developer in the hopper chamber. Therefore, the carrying force of the developer from the hopper chamber by the carrying member can be adjusted according to the amount of the developer. Therefore, it is possible to solve the blocking phenomenon due to excessive conveyance of the developer into the developing chamber and the shortage of the developer in the developing chamber, and it is possible to reduce the rotational load of the stirring means. Further, there is an effect that the amount of the developer conveyed to the developing chamber becomes stable.

Further, according to the developing device of the present invention, the radius of rotation of the developer conveying member provided in the hopper portion of the developing device changes according to the rotation angle, so that the stirring member can be agitated and conveyed by the conveying member. Is not limited to a circle, but can be changed to a range of any other shape. As a result, there is an effect that the developer can be efficiently stirred and conveyed without creating a dead space in the hopper portion that stores the developer. Further, since the rotation range of the developer conveying member can be set according to the shape of the developing container, it is possible to use a developing container having a shape that can efficiently store the developer, and thus increase the storage amount of the developer. This makes it possible to reduce the frequency of replenishment of the developer. Further, since it is easy to change the shape of the developing container without reducing the amount of developer stored, there is more flexibility in considering the overall configuration of the image forming apparatus, cost reduction, downsizing of the apparatus, etc. Has the effect that it becomes easier.

Further, according to the developing device of the present invention, the amount of the developer supplied from the hopper portion of the developing device to the developing portion is set to be larger than the maximum consumption amount of the developer consumed during image formation. Agitate the excess developer in the developing unit.
Since it is configured to forcibly circulate from the developing section to the hopper section by the conveying means and the reverse feeding means, the amount of the developer in the developing section can be kept constant regardless of the consumption amount of the developer, and the developer is charged. Since the amount is made uniform, there is an effect that a stable and high-quality image can be always formed by an inexpensive apparatus without image deterioration such as image dropout or density reduction.

[Brief description of drawings]

FIG. 1 is an enlarged schematic perspective view of a stirring unit used in a developing device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining an operation mode of a stirring unit in FIG.

FIG. 3 is a schematic sectional view showing the overall configuration of the developing device according to the first embodiment of the present invention.

FIG. 4 is a schematic sectional view showing the overall configuration of a developing device according to a second embodiment of the present invention.

FIG. 5 is a schematic perspective view showing an enlarged vicinity of one end portion of a developer carrying member used in the developing device of the second embodiment of the present invention.

FIG. 6 is a schematic view showing an example of a drive system for rotationally driving a developer carrying member used in the developing device according to the second embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a modified example of the developing device according to the second embodiment of the present invention.

FIG. 8 is an enlarged schematic perspective view showing the vicinity of one end of a developer carrying member used in the developing device of the third embodiment of the present invention.

FIG. 9 is a schematic sectional view showing the overall structure of a developing device according to a fourth embodiment of the present invention.

FIG. 10 is an enlarged schematic view of a stirring / conveying unit used in the developing device according to the fourth embodiment of the present invention.

FIG. 11 is a schematic sectional view showing the overall structure of a developing device according to a fifth embodiment of the present invention.

FIG. 12 is an enlarged schematic perspective view showing an agitating / conveying means used in a developing device of a fifth embodiment of the present invention.

FIG. 13 is a schematic cross-sectional view showing the overall configuration of an example of a conventional electrophotographic image forming apparatus.

FIG. 14 is a schematic sectional view showing an example of a developing device used in a conventional electrophotographic image forming apparatus.

FIG. 15 is a schematic cross-sectional view showing another example of a developing device used in a conventional electrophotographic image forming apparatus.

FIG. 16 is a schematic sectional view showing still another example of a developing device used in a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stirring means 2 Rotating shaft 3 Arm 4 Support part 5 Conveying member 6 Elastic member 7 Developing device 8 Hopper chamber 9 Developing chamber 10 Developing sleeve 12 Developer regulating plate 14 Photosensitive drum 15 Stirring member 60 Developing device 61 Developing container 62 Developing part 63 Hopper part 64 Developing sleeve 65 Regulation blade 66 Stirring member 67 Developer conveying member 68 Rotating shaft 69 Guide groove 70 Developer conveying body 71 Rod-like body 72 Guide arm 73 Guide wall 74 Roller 80 Driving gear 81 Drum gear 100 Developing part 101 Hopper part 102 regulating member 103 opening 104 stirring member 105 developing sleeve 106 magnet roller 107 blade member 108 blade supporting base 109 conveying member 112 blade sheet 121 developing container 130 photosensitive drum 141 stirring / conveying means 142 rotation 143 detent 144 stirred block 151 reverse feed member T developer D ₁ developer pool

Claims (7)

[Claims] 1. A developing chamber containing a developer carrier and a hopper chamber for accommodating the developer are integrally juxtaposed to each other, and stirring means for stirring and transporting the developer into each of the developing chamber and the hopper chamber. In the developing device having the above-mentioned, the agitating means arranged in the hopper chamber is provided with a developer conveying member that is displaced in accordance with the amount of the developer stored in the hopper chamber. . 2. A developing device in which a developing section including a developer carrying member and a hopper section for accommodating the developer are integrally juxtaposed with each other, while stirring the developer contained in the hopper section and developing the developer. 1. A developing device, wherein a rotation radius length of a rotary-type developer transporting member that is transported to a section is changed according to a rotation angle so that a stirring and transporting area becomes large. 3. A developing section including a developer carrying body carrying and carrying a developer for developing an electrostatic latent image formed on the image carrying body, and a hopper section containing the developer, The developing section is located substantially above the developer carrying body, and is supplied from the hopper section with a developer regulating means that regulates and equalizes the amount of the developer carried and conveyed by the developer carrying body. Further comprising a stirring means for stirring and transporting the developer,
In a developing device including a transporting unit that stirs the developer accommodated in the hopper unit and transports the developer to the developing unit, the developer is provided substantially above the developer carrier and behind the developer regulating unit. An agitating / conveying means for agitating is provided, one end of which is located in the vicinity of the agitating / conveying means, and the other end of which is lower in height than the one end and protrudes into the hopper. A feeding means is provided, and a certain amount or more of the developer accumulated behind the developer regulating means is fed back to the hopper section by the stirring / conveying means and the developer feeding means. Characteristic developing device. 4. The agitating / conveying means rotates in a direction in which the developer can be smoothly moved from the back surface of the developer regulating means toward the developer back-feeding means. Developing device. 5. The developing device according to claim 3, wherein the agitating / conveying means has a shape of a plurality of continuous spiral screws having different winding directions. 6. The agitating / conveying means has a structure in which a plurality of blade-shaped members are arranged in the rotational axis direction at a predetermined relative angle in the rotational direction. Development device. 7. The developing device according to claim 3, wherein the developer is a one-component magnetic developer.